merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

724 files changed, 106405 insertions, 0 deletions

diff --git a/third_party/git/Documentation/.gitattributes b/third_party/git/Documentation/.gitattributes
new file mode 100644
index 0000000000..ddb030137d
--- /dev/null
+++ b/third_party/git/Documentation/.gitattributes
@@ -0,0 +1 @@
+*.txt whitespace
diff --git a/third_party/git/Documentation/.gitignore b/third_party/git/Documentation/.gitignore
new file mode 100644
index 0000000000..9022d48355
--- /dev/null
+++ b/third_party/git/Documentation/.gitignore
@@ -0,0 +1,17 @@
+*.xml
+*.html
+*.[1-8]
+*.made
+*.texi
+*.pdf
+git.info
+gitman.info
+howto-index.txt
+doc.dep
+cmds-*.txt
+mergetools-*.txt
+manpage-base-url.xsl
+SubmittingPatches.txt
+tmp-doc-diff/
+GIT-ASCIIDOCFLAGS
+/GIT-EXCLUDED-PROGRAMS
diff --git a/third_party/git/Documentation/CodingGuidelines b/third_party/git/Documentation/CodingGuidelines
new file mode 100644
index 0000000000..f45db5b727
--- /dev/null
+++ b/third_party/git/Documentation/CodingGuidelines
@@ -0,0 +1,639 @@
+Like other projects, we also have some guidelines to keep to the
+code.  For Git in general, a few rough rules are:
+
+ - Most importantly, we never say "It's in POSIX; we'll happily
+   ignore your needs should your system not conform to it."
+   We live in the real world.
+
+ - However, we often say "Let's stay away from that construct,
+   it's not even in POSIX".
+
+ - In spite of the above two rules, we sometimes say "Although
+   this is not in POSIX, it (is so convenient | makes the code
+   much more readable | has other good characteristics) and
+   practically all the platforms we care about support it, so
+   let's use it".
+
+   Again, we live in the real world, and it is sometimes a
+   judgement call, the decision based more on real world
+   constraints people face than what the paper standard says.
+
+ - Fixing style violations while working on a real change as a
+   preparatory clean-up step is good, but otherwise avoid useless code
+   churn for the sake of conforming to the style.
+
+   "Once it _is_ in the tree, it's not really worth the patch noise to
+   go and fix it up."
+   Cf. http://lkml.iu.edu/hypermail/linux/kernel/1001.3/01069.html
+
+Make your code readable and sensible, and don't try to be clever.
+
+As for more concrete guidelines, just imitate the existing code
+(this is a good guideline, no matter which project you are
+contributing to). It is always preferable to match the _local_
+convention. New code added to Git suite is expected to match
+the overall style of existing code. Modifications to existing
+code is expected to match the style the surrounding code already
+uses (even if it doesn't match the overall style of existing code).
+
+But if you must have a list of rules, here they are.
+
+For shell scripts specifically (not exhaustive):
+
+ - We use tabs for indentation.
+
+ - Case arms are indented at the same depth as case and esac lines,
+   like this:
+
+	case "$variable" in
+	pattern1)
+		do this
+		;;
+	pattern2)
+		do that
+		;;
+	esac
+
+ - Redirection operators should be written with space before, but no
+   space after them.  In other words, write 'echo test >"$file"'
+   instead of 'echo test> $file' or 'echo test > $file'.  Note that
+   even though it is not required by POSIX to double-quote the
+   redirection target in a variable (as shown above), our code does so
+   because some versions of bash issue a warning without the quotes.
+
+	(incorrect)
+	cat hello > world < universe
+	echo hello >$world
+
+	(correct)
+	cat hello >world <universe
+	echo hello >"$world"
+
+ - We prefer $( ... ) for command substitution; unlike ``, it
+   properly nests.  It should have been the way Bourne spelled
+   it from day one, but unfortunately isn't.
+
+ - If you want to find out if a command is available on the user's
+   $PATH, you should use 'type <command>', instead of 'which <command>'.
+   The output of 'which' is not machine parseable and its exit code
+   is not reliable across platforms.
+
+ - We use POSIX compliant parameter substitutions and avoid bashisms;
+   namely:
+
+   - We use ${parameter-word} and its [-=?+] siblings, and their
+     colon'ed "unset or null" form.
+
+   - We use ${parameter#word} and its [#%] siblings, and their
+     doubled "longest matching" form.
+
+   - No "Substring Expansion" ${parameter:offset:length}.
+
+   - No shell arrays.
+
+   - No strlen ${#parameter}.
+
+   - No pattern replacement ${parameter/pattern/string}.
+
+ - We use Arithmetic Expansion $(( ... )).
+
+ - Inside Arithmetic Expansion, spell shell variables with $ in front
+   of them, as some shells do not grok $((x)) while accepting $(($x))
+   just fine (e.g. dash older than 0.5.4).
+
+ - We do not use Process Substitution <(list) or >(list).
+
+ - Do not write control structures on a single line with semicolon.
+   "then" should be on the next line for if statements, and "do"
+   should be on the next line for "while" and "for".
+
+	(incorrect)
+	if test -f hello; then
+		do this
+	fi
+
+	(correct)
+	if test -f hello
+	then
+		do this
+	fi
+
+ - If a command sequence joined with && or || or | spans multiple
+   lines, put each command on a separate line and put && and || and |
+   operators at the end of each line, rather than the start. This
+   means you don't need to use \ to join lines, since the above
+   operators imply the sequence isn't finished.
+
+	(incorrect)
+	grep blob verify_pack_result \
+	| awk -f print_1.awk \
+	| sort >actual &&
+	...
+
+	(correct)
+	grep blob verify_pack_result |
+	awk -f print_1.awk |
+	sort >actual &&
+	...
+
+ - We prefer "test" over "[ ... ]".
+
+ - We do not write the noiseword "function" in front of shell
+   functions.
+
+ - We prefer a space between the function name and the parentheses,
+   and no space inside the parentheses. The opening "{" should also
+   be on the same line.
+
+	(incorrect)
+	my_function(){
+		...
+
+	(correct)
+	my_function () {
+		...
+
+ - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
+   [::], [==], or [..]) for portability.
+
+   - We do not use \{m,n\};
+
+   - We do not use -E;
+
+   - We do not use ? or + (which are \{0,1\} and \{1,\}
+     respectively in BRE) but that goes without saying as these
+     are ERE elements not BRE (note that \? and \+ are not even part
+     of BRE -- making them accessible from BRE is a GNU extension).
+
+ - Use Git's gettext wrappers in git-sh-i18n to make the user
+   interface translatable. See "Marking strings for translation" in
+   po/README.
+
+ - We do not write our "test" command with "-a" and "-o" and use "&&"
+   or "||" to concatenate multiple "test" commands instead, because
+   the use of "-a/-o" is often error-prone.  E.g.
+
+     test -n "$x" -a "$a" = "$b"
+
+   is buggy and breaks when $x is "=", but
+
+     test -n "$x" && test "$a" = "$b"
+
+   does not have such a problem.
+
+
+For C programs:
+
+ - We use tabs to indent, and interpret tabs as taking up to
+   8 spaces.
+
+ - We try to keep to at most 80 characters per line.
+
+ - As a Git developer we assume you have a reasonably modern compiler
+   and we recommend you to enable the DEVELOPER makefile knob to
+   ensure your patch is clear of all compiler warnings we care about,
+   by e.g. "echo DEVELOPER=1 >>config.mak".
+
+ - We try to support a wide range of C compilers to compile Git with,
+   including old ones.  You should not use features from newer C
+   standard, even if your compiler groks them.
+
+   There are a few exceptions to this guideline:
+
+   . since early 2012 with e1327023ea, we have been using an enum
+     definition whose last element is followed by a comma.  This, like
+     an array initializer that ends with a trailing comma, can be used
+     to reduce the patch noise when adding a new identifer at the end.
+
+   . since mid 2017 with cbc0f81d, we have been using designated
+     initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+   . since mid 2017 with 512f41cf, we have been using designated
+     initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+   These used to be forbidden, but we have not heard any breakage
+   report, and they are assumed to be safe.
+
+ - Variables have to be declared at the beginning of the block, before
+   the first statement (i.e. -Wdeclaration-after-statement).
+
+ - Declaring a variable in the for loop "for (int i = 0; i < 10; i++)"
+   is still not allowed in this codebase.
+
+ - NULL pointers shall be written as NULL, not as 0.
+
+ - When declaring pointers, the star sides with the variable
+   name, i.e. "char *string", not "char* string" or
+   "char * string".  This makes it easier to understand code
+   like "char *string, c;".
+
+ - Use whitespace around operators and keywords, but not inside
+   parentheses and not around functions. So:
+
+        while (condition)
+		func(bar + 1);
+
+   and not:
+
+        while( condition )
+		func (bar+1);
+
+ - We avoid using braces unnecessarily.  I.e.
+
+	if (bla) {
+		x = 1;
+	}
+
+   is frowned upon. But there are a few exceptions:
+
+	- When the statement extends over a few lines (e.g., a while loop
+	  with an embedded conditional, or a comment). E.g.:
+
+		while (foo) {
+			if (x)
+				one();
+			else
+				two();
+		}
+
+		if (foo) {
+			/*
+			 * This one requires some explanation,
+			 * so we're better off with braces to make
+			 * it obvious that the indentation is correct.
+			 */
+			doit();
+		}
+
+	- When there are multiple arms to a conditional and some of them
+	  require braces, enclose even a single line block in braces for
+	  consistency. E.g.:
+
+		if (foo) {
+			doit();
+		} else {
+			one();
+			two();
+			three();
+		}
+
+ - We try to avoid assignments in the condition of an "if" statement.
+
+ - Try to make your code understandable.  You may put comments
+   in, but comments invariably tend to stale out when the code
+   they were describing changes.  Often splitting a function
+   into two makes the intention of the code much clearer.
+
+ - Multi-line comments include their delimiters on separate lines from
+   the text.  E.g.
+
+	/*
+	 * A very long
+	 * multi-line comment.
+	 */
+
+   Note however that a comment that explains a translatable string to
+   translators uses a convention of starting with a magic token
+   "TRANSLATORS: ", e.g.
+
+	/*
+	 * TRANSLATORS: here is a comment that explains the string to
+	 * be translated, that follows immediately after it.
+	 */
+	_("Here is a translatable string explained by the above.");
+
+ - Double negation is often harder to understand than no negation
+   at all.
+
+ - There are two schools of thought when it comes to comparison,
+   especially inside a loop. Some people prefer to have the less stable
+   value on the left hand side and the more stable value on the right hand
+   side, e.g. if you have a loop that counts variable i down to the
+   lower bound,
+
+	while (i > lower_bound) {
+		do something;
+		i--;
+	}
+
+   Other people prefer to have the textual order of values match the
+   actual order of values in their comparison, so that they can
+   mentally draw a number line from left to right and place these
+   values in order, i.e.
+
+	while (lower_bound < i) {
+		do something;
+		i--;
+	}
+
+   Both are valid, and we use both.  However, the more "stable" the
+   stable side becomes, the more we tend to prefer the former
+   (comparison with a constant, "i > 0", is an extreme example).
+   Just do not mix styles in the same part of the code and mimic
+   existing styles in the neighbourhood.
+
+ - There are two schools of thought when it comes to splitting a long
+   logical line into multiple lines.  Some people push the second and
+   subsequent lines far enough to the right with tabs and align them:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+		span_more_than_a_single_line_of ||
+		the_source_text) {
+                ...
+
+   while other people prefer to align the second and the subsequent
+   lines with the column immediately inside the opening parenthesis,
+   with tabs and spaces, following our "tabstop is always a multiple
+   of 8" convention:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+	    span_more_than_a_single_line_of ||
+	    the_source_text) {
+                ...
+
+   Both are valid, and we use both.  Again, just do not mix styles in
+   the same part of the code and mimic existing styles in the
+   neighbourhood.
+
+ - When splitting a long logical line, some people change line before
+   a binary operator, so that the result looks like a parse tree when
+   you turn your head 90-degrees counterclockwise:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to
+	    || span_more_than_a_single_line_of_the_source_text) {
+
+   while other people prefer to leave the operator at the end of the
+   line:
+
+        if (the_beginning_of_a_very_long_expression_that_has_to ||
+	    span_more_than_a_single_line_of_the_source_text) {
+
+   Both are valid, but we tend to use the latter more, unless the
+   expression gets fairly complex, in which case the former tends to
+   be easier to read.  Again, just do not mix styles in the same part
+   of the code and mimic existing styles in the neighbourhood.
+
+ - When splitting a long logical line, with everything else being
+   equal, it is preferable to split after the operator at higher
+   level in the parse tree.  That is, this is more preferable:
+
+	if (a_very_long_variable * that_is_used_in +
+	    a_very_long_expression) {
+		...
+
+   than
+
+	if (a_very_long_variable *
+	    that_is_used_in + a_very_long_expression) {
+		...
+
+ - Some clever tricks, like using the !! operator with arithmetic
+   constructs, can be extremely confusing to others.  Avoid them,
+   unless there is a compelling reason to use them.
+
+ - Use the API.  No, really.  We have a strbuf (variable length
+   string), several arrays with the ALLOC_GROW() macro, a
+   string_list for sorted string lists, a hash map (mapping struct
+   objects) named "struct decorate", amongst other things.
+
+ - When you come up with an API, document its functions and structures
+   in the header file that exposes the API to its callers. Use what is
+   in "strbuf.h" as a model for the appropriate tone and level of
+   detail.
+
+ - The first #include in C files, except in platform specific compat/
+   implementations, must be either "git-compat-util.h", "cache.h" or
+   "builtin.h".  You do not have to include more than one of these.
+
+ - A C file must directly include the header files that declare the
+   functions and the types it uses, except for the functions and types
+   that are made available to it by including one of the header files
+   it must include by the previous rule.
+
+ - If you are planning a new command, consider writing it in shell
+   or perl first, so that changes in semantics can be easily
+   changed and discussed.  Many Git commands started out like
+   that, and a few are still scripts.
+
+ - Avoid introducing a new dependency into Git. This means you
+   usually should stay away from scripting languages not already
+   used in the Git core command set (unless your command is clearly
+   separate from it, such as an importer to convert random-scm-X
+   repositories to Git).
+
+ - When we pass <string, length> pair to functions, we should try to
+   pass them in that order.
+
+ - Use Git's gettext wrappers to make the user interface
+   translatable. See "Marking strings for translation" in po/README.
+
+ - Variables and functions local to a given source file should be marked
+   with "static". Variables that are visible to other source files
+   must be declared with "extern" in header files. However, function
+   declarations should not use "extern", as that is already the default.
+
+ - You can launch gdb around your program using the shorthand GIT_DEBUGGER.
+   Run `GIT_DEBUGGER=1 ./bin-wrappers/git foo` to simply use gdb as is, or
+   run `GIT_DEBUGGER="<debugger> <debugger-args>" ./bin-wrappers/git foo` to
+   use your own debugger and arguments. Example: `GIT_DEBUGGER="ddd --gdb"
+   ./bin-wrappers/git log` (See `wrap-for-bin.sh`.)
+
+For Perl programs:
+
+ - Most of the C guidelines above apply.
+
+ - We try to support Perl 5.8 and later ("use Perl 5.008").
+
+ - use strict and use warnings are strongly preferred.
+
+ - Don't overuse statement modifiers unless using them makes the
+   result easier to follow.
+
+	... do something ...
+	do_this() unless (condition);
+        ... do something else ...
+
+   is more readable than:
+
+	... do something ...
+	unless (condition) {
+		do_this();
+	}
+        ... do something else ...
+
+   *only* when the condition is so rare that do_this() will be almost
+   always called.
+
+ - We try to avoid assignments inside "if ()" conditions.
+
+ - Learn and use Git.pm if you need that functionality.
+
+ - For Emacs, it's useful to put the following in
+   GIT_CHECKOUT/.dir-locals.el, assuming you use cperl-mode:
+
+    ;; note the first part is useful for C editing, too
+    ((nil . ((indent-tabs-mode . t)
+                  (tab-width . 8)
+                  (fill-column . 80)))
+     (cperl-mode . ((cperl-indent-level . 8)
+                    (cperl-extra-newline-before-brace . nil)
+                    (cperl-merge-trailing-else . t))))
+
+For Python scripts:
+
+ - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/).
+
+ - As a minimum, we aim to be compatible with Python 2.6 and 2.7.
+
+ - Where required libraries do not restrict us to Python 2, we try to
+   also be compatible with Python 3.1 and later.
+
+ - When you must differentiate between Unicode literals and byte string
+   literals, it is OK to use the 'b' prefix.  Even though the Python
+   documentation for version 2.6 does not mention this prefix, it has
+   been supported since version 2.6.0.
+
+Error Messages
+
+ - Do not end error messages with a full stop.
+
+ - Do not capitalize ("unable to open %s", not "Unable to open %s")
+
+ - Say what the error is first ("cannot open %s", not "%s: cannot open")
+
+
+Externally Visible Names
+
+ - For configuration variable names, follow the existing convention:
+
+   . The section name indicates the affected subsystem.
+
+   . The subsection name, if any, indicates which of an unbounded set
+     of things to set the value for.
+
+   . The variable name describes the effect of tweaking this knob.
+
+   The section and variable names that consist of multiple words are
+   formed by concatenating the words without punctuations (e.g. `-`),
+   and are broken using bumpyCaps in documentation as a hint to the
+   reader.
+
+   When choosing the variable namespace, do not use variable name for
+   specifying possibly unbounded set of things, most notably anything
+   an end user can freely come up with (e.g. branch names).  Instead,
+   use subsection names or variable values, like the existing variable
+   branch.<name>.description does.
+
+
+Writing Documentation:
+
+ Most (if not all) of the documentation pages are written in the
+ AsciiDoc format in *.txt files (e.g. Documentation/git.txt), and
+ processed into HTML and manpages (e.g. git.html and git.1 in the
+ same directory).
+
+ The documentation liberally mixes US and UK English (en_US/UK)
+ norms for spelling and grammar, which is somewhat unfortunate.
+ In an ideal world, it would have been better if it consistently
+ used only one and not the other, and we would have picked en_US
+ (if you wish to correct the English of some of the existing
+ documentation, please see the documentation-related advice in the
+ Documentation/SubmittingPatches file).
+
+ Every user-visible change should be reflected in the documentation.
+ The same general rule as for code applies -- imitate the existing
+ conventions.
+
+ A few commented examples follow to provide reference when writing or
+ modifying command usage strings and synopsis sections in the manual
+ pages:
+
+ Placeholders are spelled in lowercase and enclosed in angle brackets:
+   <file>
+   --sort=<key>
+   --abbrev[=<n>]
+
+ If a placeholder has multiple words, they are separated by dashes:
+   <new-branch-name>
+   --template=<template-directory>
+
+ Possibility of multiple occurrences is indicated by three dots:
+   <file>...
+   (One or more of <file>.)
+
+ Optional parts are enclosed in square brackets:
+   [<extra>]
+   (Zero or one <extra>.)
+
+   --exec-path[=<path>]
+   (Option with an optional argument.  Note that the "=" is inside the
+   brackets.)
+
+   [<patch>...]
+   (Zero or more of <patch>.  Note that the dots are inside, not
+   outside the brackets.)
+
+ Multiple alternatives are indicated with vertical bars:
+   [-q | --quiet]
+   [--utf8 | --no-utf8]
+
+ Parentheses are used for grouping:
+   [(<rev> | <range>)...]
+   (Any number of either <rev> or <range>.  Parens are needed to make
+   it clear that "..." pertains to both <rev> and <range>.)
+
+   [(-p <parent>)...]
+   (Any number of option -p, each with one <parent> argument.)
+
+   git remote set-head <name> (-a | -d | <branch>)
+   (One and only one of "-a", "-d" or "<branch>" _must_ (no square
+   brackets) be provided.)
+
+ And a somewhat more contrived example:
+   --diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
+   Here "=" is outside the brackets, because "--diff-filter=" is a
+   valid usage.  "*" has its own pair of brackets, because it can
+   (optionally) be specified only when one or more of the letters is
+   also provided.
+
+  A note on notation:
+   Use 'git' (all lowercase) when talking about commands i.e. something
+   the user would type into a shell and use 'Git' (uppercase first letter)
+   when talking about the version control system and its properties.
+
+ A few commented examples follow to provide reference when writing or
+ modifying paragraphs or option/command explanations that contain options
+ or commands:
+
+ Literal examples (e.g. use of command-line options, command names,
+ branch names, URLs, pathnames (files and directories), configuration and
+ environment variables) must be typeset in monospace (i.e. wrapped with
+ backticks):
+   `--pretty=oneline`
+   `git rev-list`
+   `remote.pushDefault`
+   `http://git.example.com`
+   `.git/config`
+   `GIT_DIR`
+   `HEAD`
+
+ An environment variable must be prefixed with "$" only when referring to its
+ value and not when referring to the variable itself, in this case there is
+ nothing to add except the backticks:
+   `GIT_DIR` is specified
+   `$GIT_DIR/hooks/pre-receive`
+
+ Word phrases enclosed in `backtick characters` are rendered literally
+ and will not be further expanded. The use of `backticks` to achieve the
+ previous rule means that literal examples should not use AsciiDoc
+ escapes.
+   Correct:
+      `--pretty=oneline`
+   Incorrect:
+      `\--pretty=oneline`
+
+ If some place in the documentation needs to typeset a command usage
+ example with inline substitutions, it is fine to use +monospaced and
+ inline substituted text+ instead of `monospaced literal text`, and with
+ the former, the part that should not get substituted must be
+ quoted/escaped.
diff --git a/third_party/git/Documentation/Makefile b/third_party/git/Documentation/Makefile
new file mode 100644
index 0000000000..76f2ecfc1b
--- /dev/null
+++ b/third_party/git/Documentation/Makefile
@@ -0,0 +1,487 @@
+# Guard against environment variables
+MAN1_TXT =
+MAN5_TXT =
+MAN7_TXT =
+TECH_DOCS =
+ARTICLES =
+SP_ARTICLES =
+OBSOLETE_HTML =
+
+-include GIT-EXCLUDED-PROGRAMS
+
+MAN1_TXT += $(filter-out \
+		$(patsubst %,%.txt,$(EXCLUDED_PROGRAMS)) \
+		$(addsuffix .txt, $(ARTICLES) $(SP_ARTICLES)), \
+		$(wildcard git-*.txt))
+MAN1_TXT += git.txt
+MAN1_TXT += gitk.txt
+MAN1_TXT += gitweb.txt
+
+MAN5_TXT += gitattributes.txt
+MAN5_TXT += githooks.txt
+MAN5_TXT += gitignore.txt
+MAN5_TXT += gitmodules.txt
+MAN5_TXT += gitrepository-layout.txt
+MAN5_TXT += gitweb.conf.txt
+
+MAN7_TXT += gitcli.txt
+MAN7_TXT += gitcore-tutorial.txt
+MAN7_TXT += gitcredentials.txt
+MAN7_TXT += gitcvs-migration.txt
+MAN7_TXT += gitdiffcore.txt
+MAN7_TXT += giteveryday.txt
+MAN7_TXT += gitglossary.txt
+MAN7_TXT += gitnamespaces.txt
+MAN7_TXT += gitremote-helpers.txt
+MAN7_TXT += gitrevisions.txt
+MAN7_TXT += gitsubmodules.txt
+MAN7_TXT += gittutorial-2.txt
+MAN7_TXT += gittutorial.txt
+MAN7_TXT += gitworkflows.txt
+
+ifdef MAN_FILTER
+MAN_TXT = $(filter $(MAN_FILTER),$(MAN1_TXT) $(MAN5_TXT) $(MAN7_TXT))
+else
+MAN_TXT = $(MAN1_TXT) $(MAN5_TXT) $(MAN7_TXT)
+MAN_FILTER = $(MAN_TXT)
+endif
+
+MAN_XML = $(patsubst %.txt,%.xml,$(MAN_TXT))
+MAN_HTML = $(patsubst %.txt,%.html,$(MAN_TXT))
+GIT_MAN_REF = master
+
+OBSOLETE_HTML += everyday.html
+OBSOLETE_HTML += git-remote-helpers.html
+
+ARTICLES += howto-index
+ARTICLES += git-tools
+ARTICLES += git-bisect-lk2009
+# with their own formatting rules.
+SP_ARTICLES += user-manual
+SP_ARTICLES += howto/new-command
+SP_ARTICLES += howto/revert-branch-rebase
+SP_ARTICLES += howto/using-merge-subtree
+SP_ARTICLES += howto/using-signed-tag-in-pull-request
+SP_ARTICLES += howto/use-git-daemon
+SP_ARTICLES += howto/update-hook-example
+SP_ARTICLES += howto/setup-git-server-over-http
+SP_ARTICLES += howto/separating-topic-branches
+SP_ARTICLES += howto/revert-a-faulty-merge
+SP_ARTICLES += howto/recover-corrupted-blob-object
+SP_ARTICLES += howto/recover-corrupted-object-harder
+SP_ARTICLES += howto/rebuild-from-update-hook
+SP_ARTICLES += howto/rebase-from-internal-branch
+SP_ARTICLES += howto/keep-canonical-history-correct
+SP_ARTICLES += howto/maintain-git
+API_DOCS = $(patsubst %.txt,%,$(filter-out technical/api-index-skel.txt technical/api-index.txt, $(wildcard technical/api-*.txt)))
+SP_ARTICLES += $(API_DOCS)
+
+TECH_DOCS += MyFirstContribution
+TECH_DOCS += SubmittingPatches
+TECH_DOCS += technical/hash-function-transition
+TECH_DOCS += technical/http-protocol
+TECH_DOCS += technical/index-format
+TECH_DOCS += technical/long-running-process-protocol
+TECH_DOCS += technical/multi-pack-index
+TECH_DOCS += technical/pack-format
+TECH_DOCS += technical/pack-heuristics
+TECH_DOCS += technical/pack-protocol
+TECH_DOCS += technical/partial-clone
+TECH_DOCS += technical/protocol-capabilities
+TECH_DOCS += technical/protocol-common
+TECH_DOCS += technical/protocol-v2
+TECH_DOCS += technical/racy-git
+TECH_DOCS += technical/send-pack-pipeline
+TECH_DOCS += technical/shallow
+TECH_DOCS += technical/signature-format
+TECH_DOCS += technical/trivial-merge
+SP_ARTICLES += $(TECH_DOCS)
+SP_ARTICLES += technical/api-index
+
+ARTICLES_HTML += $(patsubst %,%.html,$(ARTICLES) $(SP_ARTICLES))
+HTML_FILTER ?= $(ARTICLES_HTML) $(OBSOLETE_HTML)
+DOC_HTML = $(MAN_HTML) $(filter $(HTML_FILTER),$(ARTICLES_HTML) $(OBSOLETE_HTML))
+
+DOC_MAN1 = $(patsubst %.txt,%.1,$(filter $(MAN_FILTER),$(MAN1_TXT)))
+DOC_MAN5 = $(patsubst %.txt,%.5,$(filter $(MAN_FILTER),$(MAN5_TXT)))
+DOC_MAN7 = $(patsubst %.txt,%.7,$(filter $(MAN_FILTER),$(MAN7_TXT)))
+
+prefix ?= $(HOME)
+bindir ?= $(prefix)/bin
+htmldir ?= $(prefix)/share/doc/git-doc
+infodir ?= $(prefix)/share/info
+pdfdir ?= $(prefix)/share/doc/git-doc
+mandir ?= $(prefix)/share/man
+man1dir = $(mandir)/man1
+man5dir = $(mandir)/man5
+man7dir = $(mandir)/man7
+# DESTDIR =
+
+ASCIIDOC = asciidoc
+ASCIIDOC_EXTRA =
+ASCIIDOC_HTML = xhtml11
+ASCIIDOC_DOCBOOK = docbook
+ASCIIDOC_CONF = -f asciidoc.conf
+ASCIIDOC_COMMON = $(ASCIIDOC) $(ASCIIDOC_EXTRA) $(ASCIIDOC_CONF) \
+		-agit_version=$(GIT_VERSION)
+TXT_TO_HTML = $(ASCIIDOC_COMMON) -b $(ASCIIDOC_HTML)
+TXT_TO_XML = $(ASCIIDOC_COMMON) -b $(ASCIIDOC_DOCBOOK)
+MANPAGE_XSL = manpage-normal.xsl
+XMLTO = xmlto
+XMLTO_EXTRA =
+INSTALL ?= install
+RM ?= rm -f
+MAN_REPO = ../../git-manpages
+HTML_REPO = ../../git-htmldocs
+
+MAKEINFO = makeinfo
+INSTALL_INFO = install-info
+DOCBOOK2X_TEXI = docbook2x-texi
+DBLATEX = dblatex
+ASCIIDOC_DBLATEX_DIR = /etc/asciidoc/dblatex
+DBLATEX_COMMON = -p $(ASCIIDOC_DBLATEX_DIR)/asciidoc-dblatex.xsl -s $(ASCIIDOC_DBLATEX_DIR)/asciidoc-dblatex.sty
+ifndef PERL_PATH
+	PERL_PATH = /usr/bin/perl
+endif
+
+-include ../config.mak.autogen
+-include ../config.mak
+
+#
+# For docbook-xsl ...
+#	-1.68.1,	no extra settings are needed?
+#	1.69.0,		set ASCIIDOC_ROFF?
+#	1.69.1-1.71.0,	set DOCBOOK_SUPPRESS_SP?
+#	1.71.1,		set ASCIIDOC_ROFF?
+#	1.72.0,		set DOCBOOK_XSL_172.
+#	1.73.0-,	no extra settings are needed
+#
+
+ifdef DOCBOOK_XSL_172
+ASCIIDOC_EXTRA += -a git-asciidoc-no-roff
+MANPAGE_XSL = manpage-1.72.xsl
+else
+	ifndef ASCIIDOC_ROFF
+	# docbook-xsl after 1.72 needs the regular XSL, but will not
+	# pass-thru raw roff codes from asciidoc.conf, so turn them off.
+	ASCIIDOC_EXTRA += -a git-asciidoc-no-roff
+	endif
+endif
+ifndef NO_MAN_BOLD_LITERAL
+XMLTO_EXTRA += -m manpage-bold-literal.xsl
+endif
+ifdef DOCBOOK_SUPPRESS_SP
+XMLTO_EXTRA += -m manpage-suppress-sp.xsl
+endif
+
+# Newer DocBook stylesheet emits warning cruft in the output when
+# this is not set, and if set it shows an absolute link.  Older
+# stylesheets simply ignore this parameter.
+#
+# Distros may want to use MAN_BASE_URL=file:///path/to/git/docs/
+# or similar.
+ifndef MAN_BASE_URL
+MAN_BASE_URL = file://$(htmldir)/
+endif
+XMLTO_EXTRA += -m manpage-base-url.xsl
+
+# If your target system uses GNU groff, it may try to render
+# apostrophes as a "pretty" apostrophe using unicode.  This breaks
+# cut&paste, so you should set GNU_ROFF to force them to be ASCII
+# apostrophes.  Unfortunately does not work with non-GNU roff.
+ifdef GNU_ROFF
+XMLTO_EXTRA += -m manpage-quote-apos.xsl
+endif
+
+ifdef USE_ASCIIDOCTOR
+ASCIIDOC = asciidoctor
+ASCIIDOC_CONF =
+ASCIIDOC_HTML = xhtml5
+ASCIIDOC_DOCBOOK = docbook45
+ASCIIDOC_EXTRA += -acompat-mode -atabsize=8
+ASCIIDOC_EXTRA += -I. -rasciidoctor-extensions
+ASCIIDOC_EXTRA += -alitdd='&\#x2d;&\#x2d;'
+DBLATEX_COMMON =
+endif
+
+SHELL_PATH ?= $(SHELL)
+# Shell quote;
+SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
+
+ifdef DEFAULT_PAGER
+DEFAULT_PAGER_SQ = $(subst ','\'',$(DEFAULT_PAGER))
+ASCIIDOC_EXTRA += -a 'git-default-pager=$(DEFAULT_PAGER_SQ)'
+endif
+
+ifdef DEFAULT_EDITOR
+DEFAULT_EDITOR_SQ = $(subst ','\'',$(DEFAULT_EDITOR))
+ASCIIDOC_EXTRA += -a 'git-default-editor=$(DEFAULT_EDITOR_SQ)'
+endif
+
+QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
+QUIET_SUBDIR1  =
+
+ifneq ($(findstring $(MAKEFLAGS),w),w)
+PRINT_DIR = --no-print-directory
+else # "make -w"
+NO_SUBDIR = :
+endif
+
+ifneq ($(findstring $(MAKEFLAGS),s),s)
+ifndef V
+	QUIET_ASCIIDOC	= @echo '   ' ASCIIDOC $@;
+	QUIET_XMLTO	= @echo '   ' XMLTO $@;
+	QUIET_DB2TEXI	= @echo '   ' DB2TEXI $@;
+	QUIET_MAKEINFO	= @echo '   ' MAKEINFO $@;
+	QUIET_DBLATEX	= @echo '   ' DBLATEX $@;
+	QUIET_XSLTPROC	= @echo '   ' XSLTPROC $@;
+	QUIET_GEN	= @echo '   ' GEN $@;
+	QUIET_LINT	= @echo '   ' LINT $@;
+	QUIET_STDERR	= 2> /dev/null
+	QUIET_SUBDIR0	= +@subdir=
+	QUIET_SUBDIR1	= ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
+			  $(MAKE) $(PRINT_DIR) -C $$subdir
+	export V
+endif
+endif
+
+all: html man
+
+html: $(DOC_HTML)
+
+man: man1 man5 man7
+man1: $(DOC_MAN1)
+man5: $(DOC_MAN5)
+man7: $(DOC_MAN7)
+
+info: git.info gitman.info
+
+pdf: user-manual.pdf
+
+install: install-man
+
+install-man: man
+	$(INSTALL) -d -m 755 $(DESTDIR)$(man1dir)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(man5dir)
+	$(INSTALL) -d -m 755 $(DESTDIR)$(man7dir)
+	$(INSTALL) -m 644 $(DOC_MAN1) $(DESTDIR)$(man1dir)
+	$(INSTALL) -m 644 $(DOC_MAN5) $(DESTDIR)$(man5dir)
+	$(INSTALL) -m 644 $(DOC_MAN7) $(DESTDIR)$(man7dir)
+
+install-info: info
+	$(INSTALL) -d -m 755 $(DESTDIR)$(infodir)
+	$(INSTALL) -m 644 git.info gitman.info $(DESTDIR)$(infodir)
+	if test -r $(DESTDIR)$(infodir)/dir; then \
+	  $(INSTALL_INFO) --info-dir=$(DESTDIR)$(infodir) git.info ;\
+	  $(INSTALL_INFO) --info-dir=$(DESTDIR)$(infodir) gitman.info ;\
+	else \
+	  echo "No directory found in $(DESTDIR)$(infodir)" >&2 ; \
+	fi
+
+install-pdf: pdf
+	$(INSTALL) -d -m 755 $(DESTDIR)$(pdfdir)
+	$(INSTALL) -m 644 user-manual.pdf $(DESTDIR)$(pdfdir)
+
+install-html: html
+	'$(SHELL_PATH_SQ)' ./install-webdoc.sh $(DESTDIR)$(htmldir)
+
+../GIT-VERSION-FILE: FORCE
+	$(QUIET_SUBDIR0)../ $(QUIET_SUBDIR1) GIT-VERSION-FILE
+
+-include ../GIT-VERSION-FILE
+
+#
+# Determine "include::" file references in asciidoc files.
+#
+docdep_prereqs = \
+	mergetools-list.made $(mergetools_txt) \
+	cmd-list.made $(cmds_txt)
+
+doc.dep : $(docdep_prereqs) $(wildcard *.txt) $(wildcard config/*.txt) build-docdep.perl
+	$(QUIET_GEN)$(RM) $@+ $@ && \
+	$(PERL_PATH) ./build-docdep.perl >$@+ $(QUIET_STDERR) && \
+	mv $@+ $@
+
+-include doc.dep
+
+cmds_txt = cmds-ancillaryinterrogators.txt \
+	cmds-ancillarymanipulators.txt \
+	cmds-mainporcelain.txt \
+	cmds-plumbinginterrogators.txt \
+	cmds-plumbingmanipulators.txt \
+	cmds-synchingrepositories.txt \
+	cmds-synchelpers.txt \
+	cmds-purehelpers.txt \
+	cmds-foreignscminterface.txt
+
+$(cmds_txt): cmd-list.made
+
+cmd-list.made: cmd-list.perl ../command-list.txt $(MAN1_TXT)
+	$(QUIET_GEN)$(RM) $@ && \
+	$(PERL_PATH) ./cmd-list.perl ../command-list.txt $(QUIET_STDERR) && \
+	date >$@
+
+mergetools_txt = mergetools-diff.txt mergetools-merge.txt
+
+$(mergetools_txt): mergetools-list.made
+
+mergetools-list.made: ../git-mergetool--lib.sh $(wildcard ../mergetools/*)
+	$(QUIET_GEN)$(RM) $@ && \
+	$(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && \
+		. ../git-mergetool--lib.sh && \
+		show_tool_names can_diff "* " || :' >mergetools-diff.txt && \
+	$(SHELL_PATH) -c 'MERGE_TOOLS_DIR=../mergetools && \
+		. ../git-mergetool--lib.sh && \
+		show_tool_names can_merge "* " || :' >mergetools-merge.txt && \
+	date >$@
+
+TRACK_ASCIIDOCFLAGS = $(subst ','\'',$(ASCIIDOC_COMMON):$(ASCIIDOC_HTML):$(ASCIIDOC_DOCBOOK))
+
+GIT-ASCIIDOCFLAGS: FORCE
+	@FLAGS='$(TRACK_ASCIIDOCFLAGS)'; \
+	    if test x"$$FLAGS" != x"`cat GIT-ASCIIDOCFLAGS 2>/dev/null`" ; then \
+		echo >&2 "    * new asciidoc flags"; \
+		echo "$$FLAGS" >GIT-ASCIIDOCFLAGS; \
+            fi
+
+clean:
+	$(RM) *.xml *.xml+ *.html *.html+ *.1 *.5 *.7
+	$(RM) *.texi *.texi+ *.texi++ git.info gitman.info
+	$(RM) *.pdf
+	$(RM) howto-index.txt howto/*.html doc.dep
+	$(RM) technical/*.html technical/api-index.txt
+	$(RM) SubmittingPatches.txt
+	$(RM) $(cmds_txt) $(mergetools_txt) *.made
+	$(RM) manpage-base-url.xsl
+	$(RM) GIT-ASCIIDOCFLAGS
+
+$(MAN_HTML): %.html : %.txt asciidoc.conf asciidoctor-extensions.rb GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
+	$(TXT_TO_HTML) -d manpage -o $@+ $< && \
+	mv $@+ $@
+
+$(OBSOLETE_HTML): %.html : %.txto asciidoc.conf asciidoctor-extensions.rb GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
+	$(TXT_TO_HTML) -o $@+ $< && \
+	mv $@+ $@
+
+manpage-base-url.xsl: manpage-base-url.xsl.in
+	$(QUIET_GEN)sed "s|@@MAN_BASE_URL@@|$(MAN_BASE_URL)|" $< > $@
+
+%.1 %.5 %.7 : %.xml manpage-base-url.xsl $(wildcard manpage*.xsl)
+	$(QUIET_XMLTO)$(RM) $@ && \
+	$(XMLTO) -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $<
+
+%.xml : %.txt asciidoc.conf asciidoctor-extensions.rb GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
+	$(TXT_TO_XML) -d manpage -o $@+ $< && \
+	mv $@+ $@
+
+user-manual.xml: user-manual.txt user-manual.conf asciidoctor-extensions.rb GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
+	$(TXT_TO_XML) -d book -o $@+ $< && \
+	mv $@+ $@
+
+technical/api-index.txt: technical/api-index-skel.txt \
+	technical/api-index.sh $(patsubst %,%.txt,$(API_DOCS))
+	$(QUIET_GEN)cd technical && '$(SHELL_PATH_SQ)' ./api-index.sh
+
+technical/%.html: ASCIIDOC_EXTRA += -a git-relative-html-prefix=../
+$(patsubst %,%.html,$(API_DOCS) technical/api-index $(TECH_DOCS)): %.html : %.txt \
+	asciidoc.conf GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(TXT_TO_HTML) $*.txt
+
+SubmittingPatches.txt: SubmittingPatches
+	$(QUIET_GEN) cp $< $@
+
+XSLT = docbook.xsl
+XSLTOPTS = --xinclude --stringparam html.stylesheet docbook-xsl.css
+
+user-manual.html: user-manual.xml $(XSLT)
+	$(QUIET_XSLTPROC)$(RM) $@+ $@ && \
+	xsltproc $(XSLTOPTS) -o $@+ $(XSLT) $< && \
+	mv $@+ $@
+
+git.info: user-manual.texi
+	$(QUIET_MAKEINFO)$(MAKEINFO) --no-split -o $@ user-manual.texi
+
+user-manual.texi: user-manual.xml
+	$(QUIET_DB2TEXI)$(RM) $@+ $@ && \
+	$(DOCBOOK2X_TEXI) user-manual.xml --encoding=UTF-8 --to-stdout >$@++ && \
+	$(PERL_PATH) fix-texi.perl <$@++ >$@+ && \
+	rm $@++ && \
+	mv $@+ $@
+
+user-manual.pdf: user-manual.xml
+	$(QUIET_DBLATEX)$(RM) $@+ $@ && \
+	$(DBLATEX) -o $@+ $(DBLATEX_COMMON) $< && \
+	mv $@+ $@
+
+gitman.texi: $(MAN_XML) cat-texi.perl texi.xsl
+	$(QUIET_DB2TEXI)$(RM) $@+ $@ && \
+	($(foreach xml,$(sort $(MAN_XML)),xsltproc -o $(xml)+ texi.xsl $(xml) && \
+		$(DOCBOOK2X_TEXI) --encoding=UTF-8 --to-stdout $(xml)+ && \
+		rm $(xml)+ &&) true) > $@++ && \
+	$(PERL_PATH) cat-texi.perl $@ <$@++ >$@+ && \
+	rm $@++ && \
+	mv $@+ $@
+
+gitman.info: gitman.texi
+	$(QUIET_MAKEINFO)$(MAKEINFO) --no-split --no-validate $*.texi
+
+$(patsubst %.txt,%.texi,$(MAN_TXT)): %.texi : %.xml
+	$(QUIET_DB2TEXI)$(RM) $@+ $@ && \
+	$(DOCBOOK2X_TEXI) --to-stdout $*.xml >$@+ && \
+	mv $@+ $@
+
+howto-index.txt: howto-index.sh $(wildcard howto/*.txt)
+	$(QUIET_GEN)$(RM) $@+ $@ && \
+	'$(SHELL_PATH_SQ)' ./howto-index.sh $(sort $(wildcard howto/*.txt)) >$@+ && \
+	mv $@+ $@
+
+$(patsubst %,%.html,$(ARTICLES)) : %.html : %.txt
+	$(QUIET_ASCIIDOC)$(TXT_TO_HTML) $*.txt
+
+WEBDOC_DEST = /pub/software/scm/git/docs
+
+howto/%.html: ASCIIDOC_EXTRA += -a git-relative-html-prefix=../
+$(patsubst %.txt,%.html,$(wildcard howto/*.txt)): %.html : %.txt GIT-ASCIIDOCFLAGS
+	$(QUIET_ASCIIDOC)$(RM) $@+ $@ && \
+	sed -e '1,/^$$/d' $< | \
+	$(TXT_TO_HTML) - >$@+ && \
+	mv $@+ $@
+
+install-webdoc : html
+	'$(SHELL_PATH_SQ)' ./install-webdoc.sh $(WEBDOC_DEST)
+
+# You must have a clone of 'git-htmldocs' and 'git-manpages' repositories
+# next to the 'git' repository itself for the following to work.
+
+quick-install: quick-install-man
+
+require-manrepo::
+	@if test ! -d $(MAN_REPO); \
+	then echo "git-manpages repository must exist at $(MAN_REPO)"; exit 1; fi
+
+quick-install-man: require-manrepo
+	'$(SHELL_PATH_SQ)' ./install-doc-quick.sh $(MAN_REPO) $(DESTDIR)$(mandir) $(GIT_MAN_REF)
+
+require-htmlrepo::
+	@if test ! -d $(HTML_REPO); \
+	then echo "git-htmldocs repository must exist at $(HTML_REPO)"; exit 1; fi
+
+quick-install-html: require-htmlrepo
+	'$(SHELL_PATH_SQ)' ./install-doc-quick.sh $(HTML_REPO) $(DESTDIR)$(htmldir) $(GIT_MAN_REF)
+
+print-man1:
+	@for i in $(MAN1_TXT); do echo $$i; done
+
+lint-docs::
+	$(QUIET_LINT)$(PERL_PATH) lint-gitlink.perl
+
+ifeq ($(wildcard po/Makefile),po/Makefile)
+doc-l10n install-l10n::
+	$(MAKE) -C po $@
+endif
+
+.PHONY: FORCE
diff --git a/third_party/git/Documentation/MyFirstContribution.txt b/third_party/git/Documentation/MyFirstContribution.txt
new file mode 100644
index 0000000000..f8670379c0
--- /dev/null
+++ b/third_party/git/Documentation/MyFirstContribution.txt
@@ -0,0 +1,1134 @@
+My First Contribution to the Git Project
+========================================
+:sectanchors:
+
+[[summary]]
+== Summary
+
+This is a tutorial demonstrating the end-to-end workflow of creating a change to
+the Git tree, sending it for review, and making changes based on comments.
+
+[[prerequisites]]
+=== Prerequisites
+
+This tutorial assumes you're already fairly familiar with using Git to manage
+source code.  The Git workflow steps will largely remain unexplained.
+
+[[related-reading]]
+=== Related Reading
+
+This tutorial aims to summarize the following documents, but the reader may find
+useful additional context:
+
+- `Documentation/SubmittingPatches`
+- `Documentation/howto/new-command.txt`
+
+[[getting-started]]
+== Getting Started
+
+[[cloning]]
+=== Clone the Git Repository
+
+Git is mirrored in a number of locations. Clone the repository from one of them;
+https://git-scm.com/downloads suggests one of the best places to clone from is
+the mirror on GitHub.
+
+----
+$ git clone https://github.com/git/git git
+$ cd git
+----
+
+[[identify-problem]]
+=== Identify Problem to Solve
+
+////
+Use + to indicate fixed-width here; couldn't get ` to work nicely with the
+quotes around "Pony Saying 'Um, Hello'".
+////
+In this tutorial, we will add a new command, +git psuh+, short for ``Pony Saying
+`Um, Hello''' - a feature which has gone unimplemented despite a high frequency
+of invocation during users' typical daily workflow.
+
+(We've seen some other effort in this space with the implementation of popular
+commands such as `sl`.)
+
+[[setup-workspace]]
+=== Set Up Your Workspace
+
+Let's start by making a development branch to work on our changes. Per
+`Documentation/SubmittingPatches`, since a brand new command is a new feature,
+it's fine to base your work on `master`. However, in the future for bugfixes,
+etc., you should check that document and base it on the appropriate branch.
+
+For the purposes of this document, we will base all our work on the `master`
+branch of the upstream project. Create the `psuh` branch you will use for
+development like so:
+
+----
+$ git checkout -b psuh origin/master
+----
+
+We'll make a number of commits here in order to demonstrate how to send a topic
+with multiple patches up for review simultaneously.
+
+[[code-it-up]]
+== Code It Up!
+
+NOTE: A reference implementation can be found at
+https://github.com/nasamuffin/git/tree/psuh.
+
+[[add-new-command]]
+=== Adding a New Command
+
+Lots of the subcommands are written as builtins, which means they are
+implemented in C and compiled into the main `git` executable. Implementing the
+very simple `psuh` command as a built-in will demonstrate the structure of the
+codebase, the internal API, and the process of working together as a contributor
+with the reviewers and maintainer to integrate this change into the system.
+
+Built-in subcommands are typically implemented in a function named "cmd_"
+followed by the name of the subcommand, in a source file named after the
+subcommand and contained within `builtin/`. So it makes sense to implement your
+command in `builtin/psuh.c`. Create that file, and within it, write the entry
+point for your command in a function matching the style and signature:
+
+----
+int cmd_psuh(int argc, const char **argv, const char *prefix)
+----
+
+We'll also need to add the declaration of psuh; open up `builtin.h`, find the
+declaration for `cmd_push`, and add a new line for `psuh` immediately before it,
+in order to keep the declarations sorted:
+
+----
+int cmd_psuh(int argc, const char **argv, const char *prefix);
+----
+
+Be sure to `#include "builtin.h"` in your `psuh.c`.
+
+Go ahead and add some throwaway printf to that function. This is a decent
+starting point as we can now add build rules and register the command.
+
+NOTE: Your throwaway text, as well as much of the text you will be adding over
+the course of this tutorial, is user-facing. That means it needs to be
+localizable. Take a look at `po/README` under "Marking strings for translation".
+Throughout the tutorial, we will mark strings for translation as necessary; you
+should also do so when writing your user-facing commands in the future.
+
+----
+int cmd_psuh(int argc, const char **argv, const char *prefix)
+{
+	printf(_("Pony saying hello goes here.\n"));
+	return 0;
+}
+----
+
+Let's try to build it.  Open `Makefile`, find where `builtin/push.o` is added
+to `BUILTIN_OBJS`, and add `builtin/psuh.o` in the same way next to it in
+alphabetical order. Once you've done so, move to the top-level directory and
+build simply with `make`. Also add the `DEVELOPER=1` variable to turn on
+some additional warnings:
+
+----
+$ echo DEVELOPER=1 >config.mak
+$ make
+----
+
+NOTE: When you are developing the Git project, it's preferred that you use the
+`DEVELOPER` flag; if there's some reason it doesn't work for you, you can turn
+it off, but it's a good idea to mention the problem to the mailing list.
+
+NOTE: The Git build is parallelizable. `-j#` is not included above but you can
+use it as you prefer, here and elsewhere.
+
+Great, now your new command builds happily on its own. But nobody invokes it.
+Let's change that.
+
+The list of commands lives in `git.c`. We can register a new command by adding
+a `cmd_struct` to the `commands[]` array. `struct cmd_struct` takes a string
+with the command name, a function pointer to the command implementation, and a
+setup option flag. For now, let's keep mimicking `push`. Find the line where
+`cmd_push` is registered, copy it, and modify it for `cmd_psuh`, placing the new
+line in alphabetical order.
+
+The options are documented in `builtin.h` under "Adding a new built-in." Since
+we hope to print some data about the user's current workspace context later,
+we need a Git directory, so choose `RUN_SETUP` as your only option.
+
+Go ahead and build again. You should see a clean build, so let's kick the tires
+and see if it works. There's a binary you can use to test with in the
+`bin-wrappers` directory.
+
+----
+$ ./bin-wrappers/git psuh
+----
+
+Check it out! You've got a command! Nice work! Let's commit this.
+
+`git status` reveals modified `Makefile`, `builtin.h`, and `git.c` as well as
+untracked `builtin/psuh.c` and `git-psuh`. First, let's take care of the binary,
+which should be ignored. Open `.gitignore` in your editor, find `/git-push`, and
+add an entry for your new command in alphabetical order:
+
+----
+...
+/git-prune-packed
+/git-psuh
+/git-pull
+/git-push
+/git-quiltimport
+/git-range-diff
+...
+----
+
+Checking `git status` again should show that `git-psuh` has been removed from
+the untracked list and `.gitignore` has been added to the modified list. Now we
+can stage and commit:
+
+----
+$ git add Makefile builtin.h builtin/psuh.c git.c .gitignore
+$ git commit -s
+----
+
+You will be presented with your editor in order to write a commit message. Start
+the commit with a 50-column or less subject line, including the name of the
+component you're working on, followed by a blank line (always required) and then
+the body of your commit message, which should provide the bulk of the context.
+Remember to be explicit and provide the "Why" of your change, especially if it
+couldn't easily be understood from your diff. When editing your commit message,
+don't remove the Signed-off-by line which was added by `-s` above.
+
+----
+psuh: add a built-in by popular demand
+
+Internal metrics indicate this is a command many users expect to be
+present. So here's an implementation to help drive customer
+satisfaction and engagement: a pony which doubtfully greets the user,
+or, a Pony Saying "Um, Hello" (PSUH).
+
+This commit message is intentionally formatted to 72 columns per line,
+starts with a single line as "commit message subject" that is written as
+if to command the codebase to do something (add this, teach a command
+that). The body of the message is designed to add information about the
+commit that is not readily deduced from reading the associated diff,
+such as answering the question "why?".
+
+Signed-off-by: A U Thor <author@example.com>
+----
+
+Go ahead and inspect your new commit with `git show`. "psuh:" indicates you
+have modified mainly the `psuh` command. The subject line gives readers an idea
+of what you've changed. The sign-off line (`-s`) indicates that you agree to
+the Developer's Certificate of Origin 1.1 (see the
+`Documentation/SubmittingPatches` +++[[dco]]+++ header).
+
+For the remainder of the tutorial, the subject line only will be listed for the
+sake of brevity. However, fully-fleshed example commit messages are available
+on the reference implementation linked at the top of this document.
+
+[[implementation]]
+=== Implementation
+
+It's probably useful to do at least something besides printing out a string.
+Let's start by having a look at everything we get.
+
+Modify your `cmd_psuh` implementation to dump the args you're passed, keeping
+existing `printf()` calls in place:
+
+----
+	int i;
+
+	...
+
+	printf(Q_("Your args (there is %d):\n",
+		  "Your args (there are %d):\n",
+		  argc),
+	       argc);
+	for (i = 0; i < argc; i++)
+		printf("%d: %s\n", i, argv[i]);
+
+	printf(_("Your current working directory:\n<top-level>%s%s\n"),
+	       prefix ? "/" : "", prefix ? prefix : "");
+
+----
+
+Build and try it. As you may expect, there's pretty much just whatever we give
+on the command line, including the name of our command. (If `prefix` is empty
+for you, try `cd Documentation/ && ../bin-wrappers/git psuh`). That's not so
+helpful. So what other context can we get?
+
+Add a line to `#include "config.h"`. Then, add the following bits to the
+function body:
+
+----
+	const char *cfg_name;
+
+...
+
+	git_config(git_default_config, NULL);
+	if (git_config_get_string_const("user.name", &cfg_name) > 0)
+		printf(_("No name is found in config\n"));
+	else
+		printf(_("Your name: %s\n"), cfg_name);
+----
+
+`git_config()` will grab the configuration from config files known to Git and
+apply standard precedence rules. `git_config_get_string_const()` will look up
+a specific key ("user.name") and give you the value. There are a number of
+single-key lookup functions like this one; you can see them all (and more info
+about how to use `git_config()`) in `Documentation/technical/api-config.txt`.
+
+You should see that the name printed matches the one you see when you run:
+
+----
+$ git config --get user.name
+----
+
+Great! Now we know how to check for values in the Git config. Let's commit this
+too, so we don't lose our progress.
+
+----
+$ git add builtin/psuh.c
+$ git commit -sm "psuh: show parameters & config opts"
+----
+
+NOTE: Again, the above is for sake of brevity in this tutorial. In a real change
+you should not use `-m` but instead use the editor to write a meaningful
+message.
+
+Still, it'd be nice to know what the user's working context is like. Let's see
+if we can print the name of the user's current branch. We can mimic the
+`git status` implementation; the printer is located in `wt-status.c` and we can
+see that the branch is held in a `struct wt_status`.
+
+`wt_status_print()` gets invoked by `cmd_status()` in `builtin/commit.c`.
+Looking at that implementation we see the status config being populated like so:
+
+----
+status_init_config(&s, git_status_config);
+----
+
+But as we drill down, we can find that `status_init_config()` wraps a call
+to `git_config()`. Let's modify the code we wrote in the previous commit.
+
+Be sure to include the header to allow you to use `struct wt_status`:
+----
+#include "wt-status.h"
+----
+
+Then modify your `cmd_psuh` implementation to declare your `struct wt_status`,
+prepare it, and print its contents:
+
+----
+	struct wt_status status;
+
+...
+
+	wt_status_prepare(the_repository, &status);
+	git_config(git_default_config, &status);
+
+...
+
+	printf(_("Your current branch: %s\n"), status.branch);
+----
+
+Run it again. Check it out - here's the (verbose) name of your current branch!
+
+Let's commit this as well.
+
+----
+$ git add builtin/psuh.c
+$ git commit -sm "psuh: print the current branch"
+----
+
+Now let's see if we can get some info about a specific commit.
+
+Luckily, there are some helpers for us here. `commit.h` has a function called
+`lookup_commit_reference_by_name` to which we can simply provide a hardcoded
+string; `pretty.h` has an extremely handy `pp_commit_easy()` call which doesn't
+require a full format object to be passed.
+
+Add the following includes:
+
+----
+#include "commit.h"
+#include "pretty.h"
+----
+
+Then, add the following lines within your implementation of `cmd_psuh()` near
+the declarations and the logic, respectively.
+
+----
+	struct commit *c = NULL;
+	struct strbuf commitline = STRBUF_INIT;
+
+...
+
+	c = lookup_commit_reference_by_name("origin/master");
+
+	if (c != NULL) {
+		pp_commit_easy(CMIT_FMT_ONELINE, c, &commitline);
+		printf(_("Current commit: %s\n"), commitline.buf);
+	}
+----
+
+The `struct strbuf` provides some safety belts to your basic `char*`, one of
+which is a length member to prevent buffer overruns. It needs to be initialized
+nicely with `STRBUF_INIT`. Keep it in mind when you need to pass around `char*`.
+
+`lookup_commit_reference_by_name` resolves the name you pass it, so you can play
+with the value there and see what kind of things you can come up with.
+
+`pp_commit_easy` is a convenience wrapper in `pretty.h` that takes a single
+format enum shorthand, rather than an entire format struct. It then
+pretty-prints the commit according to that shorthand. These are similar to the
+formats available with `--pretty=FOO` in many Git commands.
+
+Build it and run, and if you're using the same name in the example, you should
+see the subject line of the most recent commit in `origin/master` that you know
+about. Neat! Let's commit that as well.
+
+----
+$ git add builtin/psuh.c
+$ git commit -sm "psuh: display the top of origin/master"
+----
+
+[[add-documentation]]
+=== Adding Documentation
+
+Awesome! You've got a fantastic new command that you're ready to share with the
+community. But hang on just a minute - this isn't very user-friendly. Run the
+following:
+
+----
+$ ./bin-wrappers/git help psuh
+----
+
+Your new command is undocumented! Let's fix that.
+
+Take a look at `Documentation/git-*.txt`. These are the manpages for the
+subcommands that Git knows about. You can open these up and take a look to get
+acquainted with the format, but then go ahead and make a new file
+`Documentation/git-psuh.txt`. Like with most of the documentation in the Git
+project, help pages are written with AsciiDoc (see CodingGuidelines, "Writing
+Documentation" section). Use the following template to fill out your own
+manpage:
+
+// Surprisingly difficult to embed AsciiDoc source within AsciiDoc.
+[listing]
+....
+git-psuh(1)
+===========
+
+NAME
+----
+git-psuh - Delight users' typo with a shy horse
+
+
+SYNOPSIS
+--------
+[verse]
+'git-psuh [<arg>...]'
+
+DESCRIPTION
+-----------
+...
+
+OPTIONS[[OPTIONS]]
+------------------
+...
+
+OUTPUT
+------
+...
+
+GIT
+---
+Part of the linkgit:git[1] suite
+....
+
+The most important pieces of this to note are the file header, underlined by =,
+the NAME section, and the SYNOPSIS, which would normally contain the grammar if
+your command took arguments. Try to use well-established manpage headers so your
+documentation is consistent with other Git and UNIX manpages; this makes life
+easier for your user, who can skip to the section they know contains the
+information they need.
+
+Now that you've written your manpage, you'll need to build it explicitly. We
+convert your AsciiDoc to troff which is man-readable like so:
+
+----
+$ make all doc
+$ man Documentation/git-psuh.1
+----
+
+or
+
+----
+$ make -C Documentation/ git-psuh.1
+$ man Documentation/git-psuh.1
+----
+
+NOTE: You may need to install the package `asciidoc` to get this to work.
+
+While this isn't as satisfying as running through `git help`, you can at least
+check that your help page looks right.
+
+You can also check that the documentation coverage is good (that is, the project
+sees that your command has been implemented as well as documented) by running
+`make check-docs` from the top-level.
+
+Go ahead and commit your new documentation change.
+
+[[add-usage]]
+=== Adding Usage Text
+
+Try and run `./bin-wrappers/git psuh -h`. Your command should crash at the end.
+That's because `-h` is a special case which your command should handle by
+printing usage.
+
+Take a look at `Documentation/technical/api-parse-options.txt`. This is a handy
+tool for pulling out options you need to be able to handle, and it takes a
+usage string.
+
+In order to use it, we'll need to prepare a NULL-terminated array of usage
+strings and a `builtin_psuh_options` array.
+
+Add a line to `#include "parse-options.h"`.
+
+At global scope, add your array of usage strings:
+
+----
+static const char * const psuh_usage[] = {
+	N_("git psuh [<arg>...]"),
+	NULL,
+};
+----
+
+Then, within your `cmd_psuh()` implementation, we can declare and populate our
+`option` struct. Ours is pretty boring but you can add more to it if you want to
+explore `parse_options()` in more detail:
+
+----
+	struct option options[] = {
+		OPT_END()
+	};
+----
+
+Finally, before you print your args and prefix, add the call to
+`parse-options()`:
+
+----
+	argc = parse_options(argc, argv, prefix, options, psuh_usage, 0);
+----
+
+This call will modify your `argv` parameter. It will strip the options you
+specified in `options` from `argv` and the locations pointed to from `options`
+entries will be updated. Be sure to replace your `argc` with the result from
+`parse_options()`, or you will be confused if you try to parse `argv` later.
+
+It's worth noting the special argument `--`. As you may be aware, many Unix
+commands use `--` to indicate "end of named parameters" - all parameters after
+the `--` are interpreted merely as positional arguments. (This can be handy if
+you want to pass as a parameter something which would usually be interpreted as
+a flag.) `parse_options()` will terminate parsing when it reaches `--` and give
+you the rest of the options afterwards, untouched.
+
+Build again. Now, when you run with `-h`, you should see your usage printed and
+your command terminated before anything else interesting happens. Great!
+
+Go ahead and commit this one, too.
+
+[[testing]]
+== Testing
+
+It's important to test your code - even for a little toy command like this one.
+Moreover, your patch won't be accepted into the Git tree without tests. Your
+tests should:
+
+* Illustrate the current behavior of the feature
+* Prove the current behavior matches the expected behavior
+* Ensure the externally-visible behavior isn't broken in later changes
+
+So let's write some tests.
+
+Related reading: `t/README`
+
+[[overview-test-structure]]
+=== Overview of Testing Structure
+
+The tests in Git live in `t/` and are named with a 4-digit decimal number using
+the schema shown in the Naming Tests section of `t/README`.
+
+[[write-new-test]]
+=== Writing Your Test
+
+Since this a toy command, let's go ahead and name the test with t9999. However,
+as many of the family/subcmd combinations are full, best practice seems to be
+to find a command close enough to the one you've added and share its naming
+space.
+
+Create a new file `t/t9999-psuh-tutorial.sh`. Begin with the header as so (see
+"Writing Tests" and "Source 'test-lib.sh'" in `t/README`):
+
+----
+#!/bin/sh
+
+test_description='git-psuh test
+
+This test runs git-psuh and makes sure it does not crash.'
+
+. ./test-lib.sh
+----
+
+Tests are framed inside of a `test_expect_success` in order to output TAP
+formatted results. Let's make sure that `git psuh` doesn't exit poorly and does
+mention the right animal somewhere:
+
+----
+test_expect_success 'runs correctly with no args and good output' '
+	git psuh >actual &&
+	test_i18ngrep Pony actual
+'
+----
+
+Indicate that you've run everything you wanted by adding the following at the
+bottom of your script:
+
+----
+test_done
+----
+
+Make sure you mark your test script executable:
+
+----
+$ chmod +x t/t9999-psuh-tutorial.sh
+----
+
+You can get an idea of whether you created your new test script successfully
+by running `make -C t test-lint`, which will check for things like test number
+uniqueness, executable bit, and so on.
+
+[[local-test]]
+=== Running Locally
+
+Let's try and run locally:
+
+----
+$ make
+$ cd t/ && prove t9999-psuh-tutorial.sh
+----
+
+You can run the full test suite and ensure `git-psuh` didn't break anything:
+
+----
+$ cd t/
+$ prove -j$(nproc) --shuffle t[0-9]*.sh
+----
+
+NOTE: You can also do this with `make test` or use any testing harness which can
+speak TAP. `prove` can run concurrently. `shuffle` randomizes the order the
+tests are run in, which makes them resilient against unwanted inter-test
+dependencies. `prove` also makes the output nicer.
+
+Go ahead and commit this change, as well.
+
+[[ready-to-share]]
+== Getting Ready to Share
+
+You may have noticed already that the Git project performs its code reviews via
+emailed patches, which are then applied by the maintainer when they are ready
+and approved by the community. The Git project does not accept patches from
+pull requests, and the patches emailed for review need to be formatted a
+specific way. At this point the tutorial diverges, in order to demonstrate two
+different methods of formatting your patchset and getting it reviewed.
+
+The first method to be covered is GitGitGadget, which is useful for those
+already familiar with GitHub's common pull request workflow. This method
+requires a GitHub account.
+
+The second method to be covered is `git send-email`, which can give slightly
+more fine-grained control over the emails to be sent. This method requires some
+setup which can change depending on your system and will not be covered in this
+tutorial.
+
+Regardless of which method you choose, your engagement with reviewers will be
+the same; the review process will be covered after the sections on GitGitGadget
+and `git send-email`.
+
+[[howto-ggg]]
+== Sending Patches via GitGitGadget
+
+One option for sending patches is to follow a typical pull request workflow and
+send your patches out via GitGitGadget. GitGitGadget is a tool created by
+Johannes Schindelin to make life as a Git contributor easier for those used to
+the GitHub PR workflow. It allows contributors to open pull requests against its
+mirror of the Git project, and does some magic to turn the PR into a set of
+emails and send them out for you. It also runs the Git continuous integration
+suite for you. It's documented at http://gitgitgadget.github.io.
+
+[[create-fork]]
+=== Forking `git/git` on GitHub
+
+Before you can send your patch off to be reviewed using GitGitGadget, you will
+need to fork the Git project and upload your changes. First thing - make sure
+you have a GitHub account.
+
+Head to the https://github.com/git/git[GitHub mirror] and look for the Fork
+button. Place your fork wherever you deem appropriate and create it.
+
+[[upload-to-fork]]
+=== Uploading to Your Own Fork
+
+To upload your branch to your own fork, you'll need to add the new fork as a
+remote. You can use `git remote -v` to show the remotes you have added already.
+From your new fork's page on GitHub, you can press "Clone or download" to get
+the URL; then you need to run the following to add, replacing your own URL and
+remote name for the examples provided:
+
+----
+$ git remote add remotename git@github.com:remotename/git.git
+----
+
+or to use the HTTPS URL:
+
+----
+$ git remote add remotename https://github.com/remotename/git/.git
+----
+
+Run `git remote -v` again and you should see the new remote showing up.
+`git fetch remotename` (with the real name of your remote replaced) in order to
+get ready to push.
+
+Next, double-check that you've been doing all your development in a new branch
+by running `git branch`. If you didn't, now is a good time to move your new
+commits to their own branch.
+
+As mentioned briefly at the beginning of this document, we are basing our work
+on `master`, so go ahead and update as shown below, or using your preferred
+workflow.
+
+----
+$ git checkout master
+$ git pull -r
+$ git rebase master psuh
+----
+
+Finally, you're ready to push your new topic branch! (Due to our branch and
+command name choices, be careful when you type the command below.)
+
+----
+$ git push remotename psuh
+----
+
+Now you should be able to go and check out your newly created branch on GitHub.
+
+[[send-pr-ggg]]
+=== Sending a PR to GitGitGadget
+
+In order to have your code tested and formatted for review, you need to start by
+opening a Pull Request against `gitgitgadget/git`. Head to
+https://github.com/gitgitgadget/git and open a PR either with the "New pull
+request" button or the convenient "Compare & pull request" button that may
+appear with the name of your newly pushed branch.
+
+Review the PR's title and description, as it's used by GitGitGadget as the cover
+letter for your change. When you're happy, submit your pull request.
+
+[[run-ci-ggg]]
+=== Running CI and Getting Ready to Send
+
+If it's your first time using GitGitGadget (which is likely, as you're using
+this tutorial) then someone will need to give you permission to use the tool.
+As mentioned in the GitGitGadget documentation, you just need someone who
+already uses it to comment on your PR with `/allow <username>`. GitGitGadget
+will automatically run your PRs through the CI even without the permission given
+but you will not be able to `/submit` your changes until someone allows you to
+use the tool.
+
+If the CI fails, you can update your changes with `git rebase -i` and push your
+branch again:
+
+----
+$ git push -f remotename psuh
+----
+
+In fact, you should continue to make changes this way up until the point when
+your patch is accepted into `next`.
+
+////
+TODO https://github.com/gitgitgadget/gitgitgadget/issues/83
+It'd be nice to be able to verify that the patch looks good before sending it
+to everyone on Git mailing list.
+[[check-work-ggg]]
+=== Check Your Work
+////
+
+[[send-mail-ggg]]
+=== Sending Your Patches
+
+Now that your CI is passing and someone has granted you permission to use
+GitGitGadget with the `/allow` command, sending out for review is as simple as
+commenting on your PR with `/submit`.
+
+[[responding-ggg]]
+=== Updating With Comments
+
+Skip ahead to <<reviewing,Responding to Reviews>> for information on how to
+reply to review comments you will receive on the mailing list.
+
+Once you have your branch again in the shape you want following all review
+comments, you can submit again:
+
+----
+$ git push -f remotename psuh
+----
+
+Next, go look at your pull request against GitGitGadget; you should see the CI
+has been kicked off again. Now while the CI is running is a good time for you
+to modify your description at the top of the pull request thread; it will be
+used again as the cover letter. You should use this space to describe what
+has changed since your previous version, so that your reviewers have some idea
+of what they're looking at. When the CI is done running, you can comment once
+more with `/submit` - GitGitGadget will automatically add a v2 mark to your
+changes.
+
+[[howto-git-send-email]]
+== Sending Patches with `git send-email`
+
+If you don't want to use GitGitGadget, you can also use Git itself to mail your
+patches. Some benefits of using Git this way include finer grained control of
+subject line (for example, being able to use the tag [RFC PATCH] in the subject)
+and being able to send a ``dry run'' mail to yourself to ensure it all looks
+good before going out to the list.
+
+[[setup-git-send-email]]
+=== Prerequisite: Setting Up `git send-email`
+
+Configuration for `send-email` can vary based on your operating system and email
+provider, and so will not be covered in this tutorial, beyond stating that in
+many distributions of Linux, `git-send-email` is not packaged alongside the
+typical `git` install. You may need to install this additional package; there
+are a number of resources online to help you do so. You will also need to
+determine the right way to configure it to use your SMTP server; again, as this
+configuration can change significantly based on your system and email setup, it
+is out of scope for the context of this tutorial.
+
+[[format-patch]]
+=== Preparing Initial Patchset
+
+Sending emails with Git is a two-part process; before you can prepare the emails
+themselves, you'll need to prepare the patches. Luckily, this is pretty simple:
+
+----
+$ git format-patch --cover-letter -o psuh/ master..psuh
+----
+
+The `--cover-letter` parameter tells `format-patch` to create a cover letter
+template for you. You will need to fill in the template before you're ready
+to send - but for now, the template will be next to your other patches.
+
+The `-o psuh/` parameter tells `format-patch` to place the patch files into a
+directory. This is useful because `git send-email` can take a directory and
+send out all the patches from there.
+
+`master..psuh` tells `format-patch` to generate patches for the difference
+between `master` and `psuh`. It will make one patch file per commit. After you
+run, you can go have a look at each of the patches with your favorite text
+editor and make sure everything looks alright; however, it's not recommended to
+make code fixups via the patch file. It's a better idea to make the change the
+normal way using `git rebase -i` or by adding a new commit than by modifying a
+patch.
+
+NOTE: Optionally, you can also use the `--rfc` flag to prefix your patch subject
+with ``[RFC PATCH]'' instead of ``[PATCH]''. RFC stands for ``request for
+comments'' and indicates that while your code isn't quite ready for submission,
+you'd like to begin the code review process. This can also be used when your
+patch is a proposal, but you aren't sure whether the community wants to solve
+the problem with that approach or not - to conduct a sort of design review. You
+may also see on the list patches marked ``WIP'' - this means they are incomplete
+but want reviewers to look at what they have so far. You can add this flag with
+`--subject-prefix=WIP`.
+
+Check and make sure that your patches and cover letter template exist in the
+directory you specified - you're nearly ready to send out your review!
+
+[[cover-letter]]
+=== Preparing Email
+
+In addition to an email per patch, the Git community also expects your patches
+to come with a cover letter, typically with a subject line [PATCH 0/x] (where
+x is the number of patches you're sending). Since you invoked `format-patch`
+with `--cover-letter`, you've already got a template ready. Open it up in your
+favorite editor.
+
+You should see a number of headers present already. Check that your `From:`
+header is correct. Then modify your `Subject:` to something which succinctly
+covers the purpose of your entire topic branch, for example:
+
+----
+Subject: [PATCH 0/7] adding the 'psuh' command
+----
+
+Make sure you retain the ``[PATCH 0/X]'' part; that's what indicates to the Git
+community that this email is the beginning of a review, and many reviewers
+filter their email for this type of flag.
+
+You'll need to add some extra parameters when you invoke `git send-email` to add
+the cover letter.
+
+Next you'll have to fill out the body of your cover letter. This is an important
+component of change submission as it explains to the community from a high level
+what you're trying to do, and why, in a way that's more apparent than just
+looking at your diff. Be sure to explain anything your diff doesn't make clear
+on its own.
+
+Here's an example body for `psuh`:
+
+----
+Our internal metrics indicate widespread interest in the command
+git-psuh - that is, many users are trying to use it, but finding it is
+unavailable, using some unknown workaround instead.
+
+The following handful of patches add the psuh command and implement some
+handy features on top of it.
+
+This patchset is part of the MyFirstContribution tutorial and should not
+be merged.
+----
+
+The template created by `git format-patch --cover-letter` includes a diffstat.
+This gives reviewers a summary of what they're in for when reviewing your topic.
+The one generated for `psuh` from the sample implementation looks like this:
+
+----
+ Documentation/git-psuh.txt | 40 +++++++++++++++++++++
+ Makefile                   |  1 +
+ builtin.h                  |  1 +
+ builtin/psuh.c             | 73 ++++++++++++++++++++++++++++++++++++++
+ git.c                      |  1 +
+ t/t9999-psuh-tutorial.sh   | 12 +++++++
+ 6 files changed, 128 insertions(+)
+ create mode 100644 Documentation/git-psuh.txt
+ create mode 100644 builtin/psuh.c
+ create mode 100755 t/t9999-psuh-tutorial.sh
+----
+
+Finally, the letter will include the version of Git used to generate the
+patches. You can leave that string alone.
+
+[[sending-git-send-email]]
+=== Sending Email
+
+At this point you should have a directory `psuh/` which is filled with your
+patches and a cover letter. Time to mail it out! You can send it like this:
+
+----
+$ git send-email --to=target@example.com psuh/*.patch
+----
+
+NOTE: Check `git help send-email` for some other options which you may find
+valuable, such as changing the Reply-to address or adding more CC and BCC lines.
+
+NOTE: When you are sending a real patch, it will go to git@vger.kernel.org - but
+please don't send your patchset from the tutorial to the real mailing list! For
+now, you can send it to yourself, to make sure you understand how it will look.
+
+After you run the command above, you will be presented with an interactive
+prompt for each patch that's about to go out. This gives you one last chance to
+edit or quit sending something (but again, don't edit code this way). Once you
+press `y` or `a` at these prompts your emails will be sent! Congratulations!
+
+Awesome, now the community will drop everything and review your changes. (Just
+kidding - be patient!)
+
+[[v2-git-send-email]]
+=== Sending v2
+
+Skip ahead to <<reviewing,Responding to Reviews>> for information on how to
+handle comments from reviewers. Continue this section when your topic branch is
+shaped the way you want it to look for your patchset v2.
+
+When you're ready with the next iteration of your patch, the process is fairly
+similar.
+
+First, generate your v2 patches again:
+
+----
+$ git format-patch -v2 --cover-letter -o psuh/ master..psuh
+----
+
+This will add your v2 patches, all named like `v2-000n-my-commit-subject.patch`,
+to the `psuh/` directory. You may notice that they are sitting alongside the v1
+patches; that's fine, but be careful when you are ready to send them.
+
+Edit your cover letter again. Now is a good time to mention what's different
+between your last version and now, if it's something significant. You do not
+need the exact same body in your second cover letter; focus on explaining to
+reviewers the changes you've made that may not be as visible.
+
+You will also need to go and find the Message-Id of your previous cover letter.
+You can either note it when you send the first series, from the output of `git
+send-email`, or you can look it up on the
+https://public-inbox.org/git[mailing list]. Find your cover letter in the
+archives, click on it, then click "permalink" or "raw" to reveal the Message-Id
+header. It should match:
+
+----
+Message-Id: <foo.12345.author@example.com>
+----
+
+Your Message-Id is `<foo.12345.author@example.com>`. This example will be used
+below as well; make sure to replace it with the correct Message-Id for your
+**previous cover letter** - that is, if you're sending v2, use the Message-Id
+from v1; if you're sending v3, use the Message-Id from v2.
+
+While you're looking at the email, you should also note who is CC'd, as it's
+common practice in the mailing list to keep all CCs on a thread. You can add
+these CC lines directly to your cover letter with a line like so in the header
+(before the Subject line):
+
+----
+CC: author@example.com, Othe R <other@example.com>
+----
+
+Now send the emails again, paying close attention to which messages you pass in
+to the command:
+
+----
+$ git send-email --to=target@example.com
+		 --in-reply-to="<foo.12345.author@example.com>"
+		 psuh/v2*
+----
+
+[[single-patch]]
+=== Bonus Chapter: One-Patch Changes
+
+In some cases, your very small change may consist of only one patch. When that
+happens, you only need to send one email. Your commit message should already be
+meaningful and explain at a high level the purpose (what is happening and why)
+of your patch, but if you need to supply even more context, you can do so below
+the `---` in your patch. Take the example below, which was generated with `git
+format-patch` on a single commit, and then edited to add the content between
+the `---` and the diffstat.
+
+----
+From 1345bbb3f7ac74abde040c12e737204689a72723 Mon Sep 17 00:00:00 2001
+From: A U Thor <author@example.com>
+Date: Thu, 18 Apr 2019 15:11:02 -0700
+Subject: [PATCH] README: change the grammar
+
+I think it looks better this way. This part of the commit message will
+end up in the commit-log.
+
+Signed-off-by: A U Thor <author@example.com>
+---
+Let's have a wild discussion about grammar on the mailing list. This
+part of my email will never end up in the commit log. Here is where I
+can add additional context to the mailing list about my intent, outside
+of the context of the commit log. This section was added after `git
+format-patch` was run, by editing the patch file in a text editor.
+
+ README.md | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/README.md b/README.md
+index 88f126184c..38da593a60 100644
+--- a/README.md
++++ b/README.md
+@@ -3,7 +3,7 @@
+ Git - fast, scalable, distributed revision control system
+ =========================================================
+
+-Git is a fast, scalable, distributed revision control system with an
++Git is a fast, scalable, and distributed revision control system with an
+ unusually rich command set that provides both high-level operations
+ and full access to internals.
+
+--
+2.21.0.392.gf8f6787159e-goog
+----
+
+[[now-what]]
+== My Patch Got Emailed - Now What?
+
+[[reviewing]]
+=== Responding to Reviews
+
+After a few days, you will hopefully receive a reply to your patchset with some
+comments. Woohoo! Now you can get back to work.
+
+It's good manners to reply to each comment, notifying the reviewer that you have
+made the change requested, feel the original is better, or that the comment
+inspired you to do something a new way which is superior to both the original
+and the suggested change. This way reviewers don't need to inspect your v2 to
+figure out whether you implemented their comment or not.
+
+If you are going to push back on a comment, be polite and explain why you feel
+your original is better; be prepared that the reviewer may still disagree with
+you, and the rest of the community may weigh in on one side or the other. As
+with all code reviews, it's important to keep an open mind to doing something a
+different way than you originally planned; other reviewers have a different
+perspective on the project than you do, and may be thinking of a valid side
+effect which had not occurred to you. It is always okay to ask for clarification
+if you aren't sure why a change was suggested, or what the reviewer is asking
+you to do.
+
+Make sure your email client has a plaintext email mode and it is turned on; the
+Git list rejects HTML email. Please also follow the mailing list etiquette
+outlined in the
+https://kernel.googlesource.com/pub/scm/git/git/+/todo/MaintNotes[Maintainer's
+Note], which are similar to etiquette rules in most open source communities
+surrounding bottom-posting and inline replies.
+
+When you're making changes to your code, it is cleanest - that is, the resulting
+commits are easiest to look at - if you use `git rebase -i` (interactive
+rebase). Take a look at this
+https://www.oreilly.com/library/view/git-pocket-guide/9781449327507/ch10.html[overview]
+from O'Reilly. The general idea is to modify each commit which requires changes;
+this way, instead of having a patch A with a mistake, a patch B which was fine
+and required no upstream reviews in v1, and a patch C which fixes patch A for
+v2, you can just ship a v2 with a correct patch A and correct patch B. This is
+changing history, but since it's local history which you haven't shared with
+anyone, that is okay for now! (Later, it may not make sense to do this; take a
+look at the section below this one for some context.)
+
+[[after-approval]]
+=== After Review Approval
+
+The Git project has four integration branches: `pu`, `next`, `master`, and
+`maint`. Your change will be placed into `pu` fairly early on by the maintainer
+while it is still in the review process; from there, when it is ready for wider
+testing, it will be merged into `next`. Plenty of early testers use `next` and
+may report issues. Eventually, changes in `next` will make it to `master`,
+which is typically considered stable. Finally, when a new release is cut,
+`maint` is used to base bugfixes onto. As mentioned at the beginning of this
+document, you can read `Documents/SubmittingPatches` for some more info about
+the use of the various integration branches.
+
+Back to now: your code has been lauded by the upstream reviewers. It is perfect.
+It is ready to be accepted. You don't need to do anything else; the maintainer
+will merge your topic branch to `next` and life is good.
+
+However, if you discover it isn't so perfect after this point, you may need to
+take some special steps depending on where you are in the process.
+
+If the maintainer has announced in the "What's cooking in git.git" email that
+your topic is marked for `next` - that is, that they plan to merge it to `next`
+but have not yet done so - you should send an email asking the maintainer to
+wait a little longer: "I've sent v4 of my series and you marked it for `next`,
+but I need to change this and that - please wait for v5 before you merge it."
+
+If the topic has already been merged to `next`, rather than modifying your
+patches with `git rebase -i`, you should make further changes incrementally -
+that is, with another commit, based on top of the maintainer's topic branch as
+detailed in https://github.com/gitster/git. Your work is still in the same topic
+but is now incremental, rather than a wholesale rewrite of the topic branch.
+
+The topic branches in the maintainer's GitHub are mirrored in GitGitGadget, so
+if you're sending your reviews out that way, you should be sure to open your PR
+against the appropriate GitGitGadget/Git branch.
+
+If you're using `git send-email`, you can use it the same way as before, but you
+should generate your diffs from `<topic>..<mybranch>` and base your work on
+`<topic>` instead of `master`.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.1.txt b/third_party/git/Documentation/RelNotes/1.5.0.1.txt
new file mode 100644
index 0000000000..fea3f9935b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.1.txt
@@ -0,0 +1,42 @@
+GIT v1.5.0.1 Release Notes
+==========================
+
+Fixes since v1.5.0
+------------------
+
+* Documentation updates
+
+  - Clarifications and corrections to 1.5.0 release notes.
+
+  - The main documentation did not link to git-remote documentation.
+
+  - Clarified introductory text of git-rebase documentation.
+
+  - Converted remaining mentions of update-index on Porcelain
+    documents to git-add/git-rm.
+
+  - Some i18n.* configuration variables were incorrectly
+    described as core.*; fixed.
+
+* Bugfixes
+
+  - git-add and git-update-index on a filesystem on which
+    executable bits are unreliable incorrectly reused st_mode
+    bits even when the path changed between symlink and regular
+    file.
+
+  - git-daemon marks the listening sockets with FD_CLOEXEC so
+    that it won't be leaked into the children.
+
+  - segfault from git-blame when the mandatory pathname
+    parameter was missing was fixed; usage() message is given
+    instead.
+
+  - git-rev-list did not read $GIT_DIR/config file, which means
+    that did not honor i18n.logoutputencoding correctly.
+
+* Tweaks
+
+  - sliding mmap() inefficiently mmaped the same region of a
+    packfile with an access pattern that used objects in the
+    reverse order.  This has been made more efficient.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.2.txt b/third_party/git/Documentation/RelNotes/1.5.0.2.txt
new file mode 100644
index 0000000000..b061e50ff0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.2.txt
@@ -0,0 +1,65 @@
+GIT v1.5.0.2 Release Notes
+==========================
+
+Fixes since v1.5.0.1
+--------------------
+
+* Bugfixes
+
+  - Automated merge conflict handling when changes to symbolic
+    links conflicted were completely broken.  The merge-resolve
+    strategy created a regular file with conflict markers in it
+    in place of the symbolic link.  The default strategy,
+    merge-recursive was even more broken.  It removed the path
+    that was pointed at by the symbolic link.  Both of these
+    problems have been fixed.
+
+  - 'git diff maint master next' did not correctly give combined
+    diff across three trees.
+
+  - 'git fast-import' portability fix for Solaris.
+
+  - 'git show-ref --verify' without arguments did not error out
+    but segfaulted.
+
+  - 'git diff :tracked-file `pwd`/an-untracked-file' gave an extra
+    slashes after a/ and b/.
+
+  - 'git format-patch' produced too long filenames if the commit
+    message had too long line at the beginning.
+
+  - Running 'make all' and then without changing anything
+    running 'make install' still rebuilt some files.  This
+    was inconvenient when building as yourself and then
+    installing as root (especially problematic when the source
+    directory is on NFS and root is mapped to nobody).
+
+  - 'git-rerere' failed to deal with two unconflicted paths that
+    sorted next to each other.
+
+  - 'git-rerere' attempted to open(2) a symlink and failed if
+    there was a conflict.  Since a conflicting change to a
+    symlink would not benefit from rerere anyway, the command
+    now ignores conflicting changes to symlinks.
+
+  - 'git-repack' did not like to pass more than 64 arguments
+    internally to underlying 'rev-list' logic, which made it
+    impossible to repack after accumulating many (small) packs
+    in the repository.
+
+  - 'git-diff' to review the combined diff during a conflicted
+    merge were not reading the working tree version correctly
+    when changes to a symbolic link conflicted.  It should have
+    read the data using readlink(2) but read from the regular
+    file the symbolic link pointed at.
+
+  - 'git-remote' did not like period in a remote's name.
+
+* Documentation updates
+
+  - added and clarified core.bare, core.legacyheaders configurations.
+
+  - updated "git-clone --depth" documentation.
+
+
+* Assorted git-gui fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.3.txt b/third_party/git/Documentation/RelNotes/1.5.0.3.txt
new file mode 100644
index 0000000000..cd500f96bf
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.3.txt
@@ -0,0 +1,58 @@
+GIT v1.5.0.3 Release Notes
+==========================
+
+Fixes since v1.5.0.2
+--------------------
+
+* Bugfixes
+
+  - 'git.el' honors the commit coding system from the configuration.
+
+  - 'blameview' in contrib/ correctly digs deeper when a line is
+    clicked.
+
+  - 'http-push' correctly makes sure the remote side has leading
+    path.  Earlier it started in the middle of the path, and
+    incorrectly.
+
+  - 'git-merge' did not exit with non-zero status when the
+    working tree was dirty and cannot fast forward.  It does
+    now.
+
+  - 'cvsexportcommit' does not lose yet-to-be-used message file.
+
+  - int-vs-size_t typefix when running combined diff on files
+    over 2GB long.
+
+  - 'git apply --whitespace=strip' should not touch unmodified
+    lines.
+
+  - 'git-mailinfo' choke when a logical header line was too long.
+
+  - 'git show A..B' did not error out.  Negative ref ("not A" in
+    this example) does not make sense for the purpose of the
+    command, so now it errors out.
+
+  - 'git fmt-merge-msg --file' without file parameter did not
+    correctly error out.
+
+  - 'git archimport' barfed upon encountering a commit without
+    summary.
+
+  - 'git index-pack' did not protect itself from getting a short
+    read out of pread(2).
+
+  - 'git http-push' had a few buffer overruns.
+
+  - Build dependency fixes to rebuild fetch.o when other headers
+    change.
+
+* Documentation updates
+
+  - user-manual updates.
+
+  - Options to 'git remote add' were described insufficiently.
+
+  - Configuration format.suffix was not documented.
+
+  - Other formatting and spelling fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.4.txt b/third_party/git/Documentation/RelNotes/1.5.0.4.txt
new file mode 100644
index 0000000000..feefa5dfd4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.4.txt
@@ -0,0 +1,22 @@
+GIT v1.5.0.4 Release Notes
+==========================
+
+Fixes since v1.5.0.3
+--------------------
+
+* Bugfixes
+
+  - git.el does not add duplicate sign-off lines.
+
+  - git-commit shows the full stat of the resulting commit, not
+    just about the files in the current directory, when run from
+    a subdirectory.
+
+  - "git-checkout -m '@{8 hours ago}'" had a funny failure from
+    eval; fixed.
+
+  - git-gui updates.
+
+* Documentation updates
+
+* User manual updates
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.5.txt b/third_party/git/Documentation/RelNotes/1.5.0.5.txt
new file mode 100644
index 0000000000..eeec3d73d0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.5.txt
@@ -0,0 +1,26 @@
+GIT v1.5.0.5 Release Notes
+==========================
+
+Fixes since v1.5.0.3
+--------------------
+
+* Bugfixes
+
+  - git-merge (hence git-pull) did not refuse fast-forwarding
+    when the working tree had local changes that would have
+    conflicted with it.
+
+  - git.el does not add duplicate sign-off lines.
+
+  - git-commit shows the full stat of the resulting commit, not
+    just about the files in the current directory, when run from
+    a subdirectory.
+
+  - "git-checkout -m '@{8 hours ago}'" had a funny failure from
+    eval; fixed.
+
+  - git-gui updates.
+
+* Documentation updates
+
+* User manual updates
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.6.txt b/third_party/git/Documentation/RelNotes/1.5.0.6.txt
new file mode 100644
index 0000000000..c02015ad5f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.6.txt
@@ -0,0 +1,21 @@
+GIT v1.5.0.6 Release Notes
+==========================
+
+Fixes since v1.5.0.5
+--------------------
+
+* Bugfixes
+
+  - a handful small fixes to gitweb.
+
+  - build procedure for user-manual is fixed not to require locally
+    installed stylesheets.
+
+  - "git commit $paths" on paths whose earlier contents were
+    already updated in the index were failing out.
+
+* Documentation
+
+  - user-manual has better cross references.
+
+  - gitweb installation/deployment procedure is now documented.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.7.txt b/third_party/git/Documentation/RelNotes/1.5.0.7.txt
new file mode 100644
index 0000000000..670ad32b85
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.7.txt
@@ -0,0 +1,18 @@
+GIT v1.5.0.7 Release Notes
+==========================
+
+Fixes since v1.5.0.6
+--------------------
+
+* Bugfixes
+
+  - git-upload-pack failed to close unused pipe ends, resulting
+    in many zombies to hang around.
+
+  - git-rerere was recording the contents of earlier hunks
+    duplicated in later hunks.  This prevented resolving the same
+    conflict when performing the same merge the other way around.
+
+* Documentation
+
+  - a few documentation fixes from Debian package maintainer.
diff --git a/third_party/git/Documentation/RelNotes/1.5.0.txt b/third_party/git/Documentation/RelNotes/1.5.0.txt
new file mode 100644
index 0000000000..daf4bdb0d7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.0.txt
@@ -0,0 +1,469 @@
+GIT v1.5.0 Release Notes
+========================
+
+Old news
+--------
+
+This section is for people who are upgrading from ancient
+versions of git.  Although all of the changes in this section
+happened before the current v1.4.4 release, they are summarized
+here in the v1.5.0 release notes for people who skipped earlier
+versions.
+
+As of git v1.5.0 there are some optional features that changes
+the repository to allow data to be stored and transferred more
+efficiently.  These features are not enabled by default, as they
+will make the repository unusable with older versions of git.
+Specifically, the available options are:
+
+ - There is a configuration variable core.legacyheaders that
+   changes the format of loose objects so that they are more
+   efficient to pack and to send out of the repository over git
+   native protocol, since v1.4.2.  However, loose objects
+   written in the new format cannot be read by git older than
+   that version; people fetching from your repository using
+   older clients over dumb transports (e.g. http) using older
+   versions of git will also be affected.
+
+   To let git use the new loose object format, you have to
+   set core.legacyheaders to false.
+
+ - Since v1.4.3, configuration repack.usedeltabaseoffset allows
+   packfile to be created in more space efficient format, which
+   cannot be read by git older than that version.
+
+   To let git use the new format for packfiles, you have to
+   set repack.usedeltabaseoffset to true.
+
+The above two new features are not enabled by default and you
+have to explicitly ask for them, because they make repositories
+unreadable by older versions of git, and in v1.5.0 we still do
+not enable them by default for the same reason.  We will change
+this default probably 1 year after 1.4.2's release, when it is
+reasonable to expect everybody to have new enough version of
+git.
+
+ - 'git pack-refs' appeared in v1.4.4; this command allows tags
+   to be accessed much more efficiently than the traditional
+   'one-file-per-tag' format.  Older git-native clients can
+   still fetch from a repository that packed and pruned refs
+   (the server side needs to run the up-to-date version of git),
+   but older dumb transports cannot.  Packing of refs is done by
+   an explicit user action, either by use of "git pack-refs
+   --prune" command or by use of "git gc" command.
+
+ - 'git -p' to paginate anything -- many commands do pagination
+   by default on a tty.  Introduced between v1.4.1 and v1.4.2;
+   this may surprise old timers.
+
+ - 'git archive' superseded 'git tar-tree' in v1.4.3;
+
+ - 'git cvsserver' was new invention in v1.3.0;
+
+ - 'git repo-config', 'git grep', 'git rebase' and 'gitk' were
+   seriously enhanced during v1.4.0 timeperiod.
+
+ - 'gitweb' became part of git.git during v1.4.0 timeperiod and
+   seriously modified since then.
+
+ - reflog is an v1.4.0 invention.  This allows you to name a
+   revision that a branch used to be at (e.g. "git diff
+   master@{yesterday} master" allows you to see changes since
+   yesterday's tip of the branch).
+
+
+Updates in v1.5.0 since v1.4.4 series
+-------------------------------------
+
+* Index manipulation
+
+ - git-add is to add contents to the index (aka "staging area"
+   for the next commit), whether the file the contents happen to
+   be is an existing one or a newly created one.
+
+ - git-add without any argument does not add everything
+   anymore.  Use 'git-add .' instead.  Also you can add
+   otherwise ignored files with an -f option.
+
+ - git-add tries to be more friendly to users by offering an
+   interactive mode ("git-add -i").
+
+ - git-commit <path> used to refuse to commit if <path> was
+   different between HEAD and the index (i.e. update-index was
+   used on it earlier).  This check was removed.
+
+ - git-rm is much saner and safer.  It is used to remove paths
+   from both the index file and the working tree, and makes sure
+   you are not losing any local modification before doing so.
+
+ - git-reset <tree> <paths>... can be used to revert index
+   entries for selected paths.
+
+ - git-update-index is much less visible.  Many suggestions to
+   use the command in git output and documentation have now been
+   replaced by simpler commands such as "git add" or "git rm".
+
+
+* Repository layout and objects transfer
+
+ - The data for origin repository is stored in the configuration
+   file $GIT_DIR/config, not in $GIT_DIR/remotes/, for newly
+   created clones.  The latter is still supported and there is
+   no need to convert your existing repository if you are
+   already comfortable with your workflow with the layout.
+
+ - git-clone always uses what is known as "separate remote"
+   layout for a newly created repository with a working tree.
+
+   A repository with the separate remote layout starts with only
+   one default branch, 'master', to be used for your own
+   development.  Unlike the traditional layout that copied all
+   the upstream branches into your branch namespace (while
+   renaming their 'master' to your 'origin'), the new layout
+   puts upstream branches into local "remote-tracking branches"
+   with their own namespace. These can be referenced with names
+   such as "origin/$upstream_branch_name" and are stored in
+   .git/refs/remotes rather than .git/refs/heads where normal
+   branches are stored.
+
+   This layout keeps your own branch namespace less cluttered,
+   avoids name collision with your upstream, makes it possible
+   to automatically track new branches created at the remote
+   after you clone from it, and makes it easier to interact with
+   more than one remote repository (you can use "git remote" to
+   add other repositories to track).  There might be some
+   surprises:
+
+   * 'git branch' does not show the remote tracking branches.
+     It only lists your own branches.  Use '-r' option to view
+     the tracking branches.
+
+   * If you are forking off of a branch obtained from the
+     upstream, you would have done something like 'git branch
+     my-next next', because traditional layout dropped the
+     tracking branch 'next' into your own branch namespace.
+     With the separate remote layout, you say 'git branch next
+     origin/next', which allows you to use the matching name
+     'next' for your own branch.  It also allows you to track a
+     remote other than 'origin' (i.e. where you initially cloned
+     from) and fork off of a branch from there the same way
+     (e.g. "git branch mingw j6t/master").
+
+   Repositories initialized with the traditional layout continue
+   to work.
+
+ - New branches that appear on the origin side after a clone is
+   made are also tracked automatically.  This is done with an
+   wildcard refspec "refs/heads/*:refs/remotes/origin/*", which
+   older git does not understand, so if you clone with 1.5.0,
+   you would need to downgrade remote.*.fetch in the
+   configuration file to specify each branch you are interested
+   in individually if you plan to fetch into the repository with
+   older versions of git (but why would you?).
+
+ - Similarly, wildcard refspec "refs/heads/*:refs/remotes/me/*"
+   can be given to "git-push" command to update the tracking
+   branches that is used to track the repository you are pushing
+   from on the remote side.
+
+ - git-branch and git-show-branch know remote tracking branches
+   (use the command line switch "-r" to list only tracked branches).
+
+ - git-push can now be used to delete a remote branch or a tag.
+   This requires the updated git on the remote side (use "git
+   push <remote> :refs/heads/<branch>" to delete "branch").
+
+ - git-push more aggressively keeps the transferred objects
+   packed.  Earlier we recommended to monitor amount of loose
+   objects and repack regularly, but you should repack when you
+   accumulated too many small packs this way as well.  Updated
+   git-count-objects helps you with this.
+
+ - git-fetch also more aggressively keeps the transferred objects
+   packed.  This behavior of git-push and git-fetch can be
+   tweaked with a single configuration transfer.unpacklimit (but
+   usually there should not be any need for a user to tweak it).
+
+ - A new command, git-remote, can help you manage your remote
+   tracking branch definitions.
+
+ - You may need to specify explicit paths for upload-pack and/or
+   receive-pack due to your ssh daemon configuration on the
+   other end.  This can now be done via remote.*.uploadpack and
+   remote.*.receivepack configuration.
+
+
+* Bare repositories
+
+ - Certain commands change their behavior in a bare repository
+   (i.e. a repository without associated working tree).  We use
+   a fairly conservative heuristic (if $GIT_DIR is ".git", or
+   ends with "/.git", the repository is not bare) to decide if a
+   repository is bare, but "core.bare" configuration variable
+   can be used to override the heuristic when it misidentifies
+   your repository.
+
+ - git-fetch used to complain updating the current branch but
+   this is now allowed for a bare repository.  So is the use of
+   'git-branch -f' to update the current branch.
+
+ - Porcelain-ish commands that require a working tree refuses to
+   work in a bare repository.
+
+
+* Reflog
+
+ - Reflog records the history from the view point of the local
+   repository. In other words, regardless of the real history,
+   the reflog shows the history as seen by one particular
+   repository (this enables you to ask "what was the current
+   revision in _this_ repository, yesterday at 1pm?").  This
+   facility is enabled by default for repositories with working
+   trees, and can be accessed with the "branch@{time}" and
+   "branch@{Nth}" notation.
+
+ - "git show-branch" learned showing the reflog data with the
+   new -g option.  "git log" has -g option to view reflog
+   entries in a more verbose manner.
+
+ - git-branch knows how to rename branches and moves existing
+   reflog data from the old branch to the new one.
+
+ - In addition to the reflog support in v1.4.4 series, HEAD
+   reference maintains its own log.  "HEAD@{5.minutes.ago}"
+   means the commit you were at 5 minutes ago, which takes
+   branch switching into account.  If you want to know where the
+   tip of your current branch was at 5 minutes ago, you need to
+   explicitly say its name (e.g. "master@{5.minutes.ago}") or
+   omit the refname altogether i.e. "@{5.minutes.ago}".
+
+ - The commits referred to by reflog entries are now protected
+   against pruning.  The new command "git reflog expire" can be
+   used to truncate older reflog entries and entries that refer
+   to commits that have been pruned away previously with older
+   versions of git.
+
+   Existing repositories that have been using reflog may get
+   complaints from fsck-objects and may not be able to run
+   git-repack, if you had run git-prune from older git; please
+   run "git reflog expire --stale-fix --all" first to remove
+   reflog entries that refer to commits that are no longer in
+   the repository when that happens.
+
+
+* Crufts removal
+
+ - We used to say "old commits are retrievable using reflog and
+   'master@{yesterday}' syntax as long as you haven't run
+   git-prune".  We no longer have to say the latter half of the
+   above sentence, as git-prune does not remove things reachable
+   from reflog entries.
+
+ - There is a toplevel garbage collector script, 'git-gc', that
+   runs periodic cleanup functions, including 'git-repack -a -d',
+   'git-reflog expire', 'git-pack-refs --prune', and 'git-rerere
+   gc'.
+
+ - The output from fsck ("fsck-objects" is called just "fsck"
+   now, but the old name continues to work) was needlessly
+   alarming in that it warned missing objects that are reachable
+   only from dangling objects.  This has been corrected and the
+   output is much more useful.
+
+
+* Detached HEAD
+
+ - You can use 'git-checkout' to check out an arbitrary revision
+   or a tag as well, instead of named branches.  This will
+   dissociate your HEAD from the branch you are currently on.
+
+   A typical use of this feature is to "look around".  E.g.
+
+	$ git checkout v2.6.16
+	... compile, test, etc.
+	$ git checkout v2.6.17
+	... compile, test, etc.
+
+ - After detaching your HEAD, you can go back to an existing
+   branch with usual "git checkout $branch".  Also you can
+   start a new branch using "git checkout -b $newbranch" to
+   start a new branch at that commit.
+
+ - You can even pull from other repositories, make merges and
+   commits while your HEAD is detached.  Also you can use "git
+   reset" to jump to arbitrary commit, while still keeping your
+   HEAD detached.
+
+   Remember that a detached state is volatile, i.e. it will be forgotten
+   as soon as you move away from it with the checkout or reset command,
+   unless a branch is created from it as mentioned above.  It is also
+   possible to rescue a lost detached state from the HEAD reflog.
+
+
+* Packed refs
+
+ - Repositories with hundreds of tags have been paying large
+   overhead, both in storage and in runtime, due to the
+   traditional one-ref-per-file format.  A new command,
+   git-pack-refs, can be used to "pack" them in more efficient
+   representation (you can let git-gc do this for you).
+
+ - Clones and fetches over dumb transports are now aware of
+   packed refs and can download from repositories that use
+   them.
+
+
+* Configuration
+
+ - configuration related to color setting are consolidated under
+   color.* namespace (older diff.color.*, status.color.* are
+   still supported).
+
+ - 'git-repo-config' command is accessible as 'git-config' now.
+
+
+* Updated features
+
+ - git-describe uses better criteria to pick a base ref.  It
+   used to pick the one with the newest timestamp, but now it
+   picks the one that is topologically the closest (that is,
+   among ancestors of commit C, the ref T that has the shortest
+   output from "git-rev-list T..C" is chosen).
+
+ - git-describe gives the number of commits since the base ref
+   between the refname and the hash suffix.  E.g. the commit one
+   before v2.6.20-rc6 in the kernel repository is:
+
+	v2.6.20-rc5-306-ga21b069
+
+   which tells you that its object name begins with a21b069,
+   v2.6.20-rc5 is an ancestor of it (meaning, the commit
+   contains everything -rc5 has), and there are 306 commits
+   since v2.6.20-rc5.
+
+ - git-describe with --abbrev=0 can be used to show only the
+   name of the base ref.
+
+ - git-blame learned a new option, --incremental, that tells it
+   to output the blames as they are assigned.  A sample script
+   to use it is also included as contrib/blameview.
+
+ - git-blame starts annotating from the working tree by default.
+
+
+* Less external dependency
+
+ - We no longer require the "merge" program from the RCS suite.
+   All 3-way file-level merges are now done internally.
+
+ - The original implementation of git-merge-recursive which was
+   in Python has been removed; we have a C implementation of it
+   now.
+
+ - git-shortlog is no longer a Perl script.  It no longer
+   requires output piped from git-log; it can accept revision
+   parameters directly on the command line.
+
+
+* I18n
+
+ - We have always encouraged the commit message to be encoded in
+   UTF-8, but the users are allowed to use legacy encoding as
+   appropriate for their projects.  This will continue to be the
+   case.  However, a non UTF-8 commit encoding _must_ be
+   explicitly set with i18n.commitencoding in the repository
+   where a commit is made; otherwise git-commit-tree will
+   complain if the log message does not look like a valid UTF-8
+   string.
+
+ - The value of i18n.commitencoding in the originating
+   repository is recorded in the commit object on the "encoding"
+   header, if it is not UTF-8.  git-log and friends notice this,
+   and reencodes the message to the log output encoding when
+   displaying, if they are different.  The log output encoding
+   is determined by "git log --encoding=<encoding>",
+   i18n.logoutputencoding configuration, or i18n.commitencoding
+   configuration, in the decreasing order of preference, and
+   defaults to UTF-8.
+
+ - Tools for e-mailed patch application now default to -u
+   behavior; i.e. it always re-codes from the e-mailed encoding
+   to the encoding specified with i18n.commitencoding.  This
+   unfortunately forces projects that have happily been using a
+   legacy encoding without setting i18n.commitencoding to set
+   the configuration, but taken with other improvement, please
+   excuse us for this very minor one-time inconvenience.
+
+
+* e-mailed patches
+
+ - See the above I18n section.
+
+ - git-format-patch now enables --binary without being asked.
+   git-am does _not_ default to it, as sending binary patch via
+   e-mail is unusual and is harder to review than textual
+   patches and it is prudent to require the person who is
+   applying the patch to explicitly ask for it.
+
+ - The default suffix for git-format-patch output is now ".patch",
+   not ".txt".  This can be changed with --suffix=.txt option,
+   or setting the config variable "format.suffix" to ".txt".
+
+
+* Foreign SCM interfaces
+
+ - git-svn now requires the Perl SVN:: libraries, the
+   command-line backend was too slow and limited.
+
+ - the 'commit' subcommand of git-svn has been renamed to
+   'set-tree', and 'dcommit' is the recommended replacement for
+   day-to-day work.
+
+ - git fast-import backend.
+
+
+* User support
+
+ - Quite a lot of documentation updates.
+
+ - Bash completion scripts have been updated heavily.
+
+ - Better error messages for often used Porcelainish commands.
+
+ - Git GUI.  This is a simple Tk based graphical interface for
+   common Git operations.
+
+
+* Sliding mmap
+
+ - We used to assume that we can mmap the whole packfile while
+   in use, but with a large project this consumes huge virtual
+   memory space and truly huge ones would not fit in the
+   userland address space on 32-bit platforms.  We now mmap huge
+   packfile in pieces to avoid this problem.
+
+
+* Shallow clones
+
+ - There is a partial support for 'shallow' repositories that
+   keeps only recent history.  A 'shallow clone' is created by
+   specifying how deep that truncated history should be
+   (e.g. "git clone --depth 5 git://some.where/repo.git").
+
+   Currently a shallow repository has number of limitations:
+
+   - Cloning and fetching _from_ a shallow clone are not
+     supported (nor tested -- so they might work by accident but
+     they are not expected to).
+
+   - Pushing from nor into a shallow clone are not expected to
+     work.
+
+   - Merging inside a shallow repository would work as long as a
+     merge base is found in the recent history, but otherwise it
+     will be like merging unrelated histories and may result in
+     huge conflicts.
+
+   but this would be more than adequate for people who want to
+   look at near the tip of a big project with a deep history and
+   send patches in e-mail format.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.1.txt b/third_party/git/Documentation/RelNotes/1.5.1.1.txt
new file mode 100644
index 0000000000..91471213bd
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.1.txt
@@ -0,0 +1,65 @@
+GIT v1.5.1.1 Release Notes
+==========================
+
+Fixes since v1.5.1
+------------------
+
+* Documentation updates
+
+  - The --left-right option of rev-list and friends is documented.
+
+  - The documentation for cvsimport has been majorly improved.
+
+  - "git-show-ref --exclude-existing" was documented.
+
+* Bugfixes
+
+  - The implementation of -p option in "git cvsexportcommit" had
+    the meaning of -C (context reduction) option wrong, and
+    loosened the context requirements when it was told to be
+    strict.
+
+  - "git cvsserver" did not behave like the real cvsserver when
+    client side removed a file from the working tree without
+    doing anything else on the path.  In such a case, it should
+    restore it from the checked out revision.
+
+  - "git fsck" issued an alarming error message on detached
+    HEAD.  It is not an error since at least 1.5.0.
+
+  - "git send-email" produced of References header of unbounded length;
+    fixed this with line-folding.
+
+  - "git archive" to download from remote site should not
+    require you to be in a git repository, but it incorrectly
+    did.
+
+  - "git apply" ignored -p<n> for "diff --git" formatted
+    patches.
+
+  - "git rerere" recorded a conflict that had one side empty
+    (the other side adds) incorrectly; this made merging in the
+    other direction fail to use previously recorded resolution.
+
+  - t4200 test was broken where "wc -l" pads its output with
+    spaces.
+
+  - "git branch -m old new" to rename branch did not work
+    without a configuration file in ".git/config".
+
+  - The sample hook for notification e-mail was misnamed.
+
+  - gitweb did not show type-changing patch correctly in the
+    blobdiff view.
+
+  - git-svn did not error out with incorrect command line options.
+
+  - git-svn fell into an infinite loop when insanely long commit
+    message was found.
+
+  - git-svn dcommit and rebase was confused by patches that were
+    merged from another branch that is managed by git-svn.
+
+  - git-svn used to get confused when globbing remote branch/tag
+    spec (e.g. "branches = proj/branches/*:refs/remotes/origin/*")
+    is used and there was a plain file that matched the glob.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.2.txt b/third_party/git/Documentation/RelNotes/1.5.1.2.txt
new file mode 100644
index 0000000000..d88456306c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.2.txt
@@ -0,0 +1,50 @@
+GIT v1.5.1.2 Release Notes
+==========================
+
+Fixes since v1.5.1.1
+--------------------
+
+* Bugfixes
+
+  - "git clone" over http from a repository that has lost the
+    loose refs by running "git pack-refs" were broken (a code to
+    deal with this was added to "git fetch" in v1.5.0, but it
+    was missing from "git clone").
+
+  - "git diff a/ b/" incorrectly fell in "diff between two
+    filesystem objects" codepath, when the user most likely
+    wanted to limit the extent of output to two tracked
+    directories.
+
+  - git-quiltimport had the same bug as we fixed for
+    git-applymbox in v1.5.1.1 -- it gave an alarming "did not
+    have any patch" message (but did not actually fail and was
+    harmless).
+
+  - various git-svn fixes.
+
+  - Sample update hook incorrectly always refused requests to
+    delete branches through push.
+
+  - git-blame on a very long working tree path had buffer
+    overrun problem.
+
+  - git-apply did not like to be fed two patches in a row that created
+    and then modified the same file.
+
+  - git-svn was confused when a non-project was stored directly under
+    trunk/, branches/ and tags/.
+
+  - git-svn wants the Error.pm module that was at least as new
+    as what we ship as part of git; install ours in our private
+    installation location if the one on the system is older.
+
+  - An earlier update to command line integer parameter parser was
+    botched and made 'update-index --cacheinfo' completely useless.
+
+
+* Documentation updates
+
+  - Various documentation updates from J. Bruce Fields, Frank
+    Lichtenheld, Alex Riesen and others.  Andrew Ruder started a
+    war on undocumented options.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.3.txt b/third_party/git/Documentation/RelNotes/1.5.1.3.txt
new file mode 100644
index 0000000000..876408b65a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.3.txt
@@ -0,0 +1,45 @@
+GIT v1.5.1.3 Release Notes
+==========================
+
+Fixes since v1.5.1.2
+--------------------
+
+* Bugfixes
+
+  - git-add tried to optimize by finding common leading
+    directories across its arguments but botched, causing very
+    confused behaviour.
+
+  - unofficial rpm.spec file shipped with git was letting
+    ETC_GITCONFIG set to /usr/etc/gitconfig.  Tweak the official
+    Makefile to make it harder for distro people to make the
+    same mistake, by setting the variable to /etc/gitconfig if
+    prefix is set to /usr.
+
+  - git-svn inconsistently stripped away username from the URL
+    only when svnsync_props was in use.
+
+  - git-svn got confused when handling symlinks on Mac OS.
+
+  - git-send-email was not quoting recipient names that have
+    period '.' in them.  Also it did not allow overriding
+    envelope sender, which made it impossible to send patches to
+    certain subscriber-only lists.
+
+  - built-in write_tree() routine had a sequence that renamed a
+    file that is still open, which some systems did not like.
+
+  - when memory is very tight, sliding mmap code to read
+    packfiles incorrectly closed the fd that was still being
+    used to read the pack.
+
+  - import-tars contributed front-end for fastimport was passing
+    wrong directory modes without checking.
+
+  - git-fastimport trusted its input too much and allowed to
+    create corrupt tree objects with entries without a name.
+
+  - git-fetch needlessly barfed when too long reflog action
+    description was given by the caller.
+
+Also contains various documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.4.txt b/third_party/git/Documentation/RelNotes/1.5.1.4.txt
new file mode 100644
index 0000000000..df2f66ccb5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.4.txt
@@ -0,0 +1,30 @@
+GIT v1.5.1.4 Release Notes
+==========================
+
+Fixes since v1.5.1.3
+--------------------
+
+* Bugfixes
+
+  - "git-http-fetch" did not work around a bug in libcurl
+    earlier than 7.16 (curl_multi_remove_handle() was broken).
+
+  - "git cvsserver" handles a file that was once removed and
+    then added again correctly.
+
+  - import-tars script (in contrib/) handles GNU tar archives
+    that contain pathnames longer than 100 bytes (long-link
+    extension) correctly.
+
+  - xdelta test program did not build correctly.
+
+  - gitweb sometimes tried incorrectly to apply function to
+    decode utf8 twice, resulting in corrupt output.
+
+  - "git blame -C" mishandled text at the end of a group of
+    lines.
+
+  - "git log/rev-list --boundary" did not produce output
+    correctly without --left-right option.
+
+  - Many documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.5.txt b/third_party/git/Documentation/RelNotes/1.5.1.5.txt
new file mode 100644
index 0000000000..b0ab8eb371
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.5.txt
@@ -0,0 +1,42 @@
+GIT v1.5.1.5 Release Notes
+==========================
+
+Fixes since v1.5.1.4
+--------------------
+
+* Bugfixes
+
+  - git-send-email did not understand aliases file for mutt, which
+    allows leading whitespaces.
+
+  - git-format-patch emitted Content-Type and Content-Transfer-Encoding
+    headers for non ASCII contents, but failed to add MIME-Version.
+
+  - git-name-rev had a buffer overrun with a deep history.
+
+  - contributed script import-tars did not get the directory in
+    tar archives interpreted correctly.
+
+  - git-svn was reported to segfault for many people on list and
+    #git; hopefully this has been fixed.
+
+  - "git-svn clone" does not try to minimize the URL
+    (i.e. connect to higher level hierarchy) by default, as this
+    can prevent clone to fail if only part of the repository
+    (e.g. 'trunk') is open to public.
+
+  - "git checkout branch^0" did not detach the head when you are
+    already on 'branch'; backported the fix from the 'master'.
+
+  - "git-config section.var" did not correctly work when
+    existing configuration file had both [section] and [section "name"]
+    next to each other.
+
+  - "git clone ../other-directory" was fooled if the current
+    directory $PWD points at is a symbolic link.
+
+  - (build) tree_entry_extract() function was both static inline
+    and extern, which caused trouble compiling with Forte12
+    compilers on Sun.
+
+  - Many many documentation fixes and updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.6.txt b/third_party/git/Documentation/RelNotes/1.5.1.6.txt
new file mode 100644
index 0000000000..55f3ac13e3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.6.txt
@@ -0,0 +1,45 @@
+GIT v1.5.1.6 Release Notes
+==========================
+
+Fixes since v1.5.1.4
+--------------------
+
+* Bugfixes
+
+  - git-send-email did not understand aliases file for mutt, which
+    allows leading whitespaces.
+
+  - git-format-patch emitted Content-Type and Content-Transfer-Encoding
+    headers for non ASCII contents, but failed to add MIME-Version.
+
+  - git-name-rev had a buffer overrun with a deep history.
+
+  - contributed script import-tars did not get the directory in
+    tar archives interpreted correctly.
+
+  - git-svn was reported to segfault for many people on list and
+    #git; hopefully this has been fixed.
+
+  - git-svn also had a bug to crash svnserve by sending a bad
+    sequence of requests.
+
+  - "git-svn clone" does not try to minimize the URL
+    (i.e. connect to higher level hierarchy) by default, as this
+    can prevent clone to fail if only part of the repository
+    (e.g. 'trunk') is open to public.
+
+  - "git checkout branch^0" did not detach the head when you are
+    already on 'branch'; backported the fix from the 'master'.
+
+  - "git-config section.var" did not correctly work when
+    existing configuration file had both [section] and [section "name"]
+    next to each other.
+
+  - "git clone ../other-directory" was fooled if the current
+    directory $PWD points at is a symbolic link.
+
+  - (build) tree_entry_extract() function was both static inline
+    and extern, which caused trouble compiling with Forte12
+    compilers on Sun.
+
+  - Many many documentation fixes and updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.1.txt b/third_party/git/Documentation/RelNotes/1.5.1.txt
new file mode 100644
index 0000000000..daed367270
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.1.txt
@@ -0,0 +1,371 @@
+GIT v1.5.1 Release Notes
+========================
+
+Updates since v1.5.0
+--------------------
+
+* Deprecated commands and options.
+
+  - git-diff-stages and git-resolve have been removed.
+
+* New commands and options.
+
+  - "git log" and friends take --reverse, which instructs them
+    to give their output in the order opposite from their usual.
+    They typically output from new to old, but with this option
+    their output would read from old to new.  "git shortlog"
+    usually lists older commits first, but with this option,
+    they are shown from new to old.
+
+  - "git log --pretty=format:<string>" to allow more flexible
+    custom log output.
+
+  - "git diff" learned --ignore-space-at-eol.  This is a weaker
+    form of --ignore-space-change.
+
+  - "git diff --no-index pathA pathB" can be used as diff
+    replacement with git specific enhancements.
+
+  - "git diff --no-index" can read from '-' (standard input).
+
+  - "git diff" also learned --exit-code to exit with non-zero
+    status when it found differences.  In the future we might
+    want to make this the default but that would be a rather big
+    backward incompatible change; it will stay as an option for
+    now.
+
+  - "git diff --quiet" is --exit-code with output turned off,
+    meant for scripted use to quickly determine if there is any
+    tree-level difference.
+
+  - Textual patch generation with "git diff" without -w/-b
+    option has been significantly optimized.  "git blame" got
+    faster because of the same change.
+
+  - "git log" and "git rev-list" has been optimized
+    significantly when they are used with pathspecs.
+
+  - "git branch --track" can be used to set up configuration
+    variables to help it easier to base your work on branches
+    you track from a remote site.
+
+  - "git format-patch --attach" now emits attachments.  Use
+    --inline to get an inlined multipart/mixed.
+
+  - "git name-rev" learned --refs=<pattern>, to limit the tags
+    used for naming the given revisions only to the ones
+    matching the given pattern.
+
+  - "git remote update" is to run "git fetch" for defined remotes
+    to update tracking branches.
+
+  - "git cvsimport" can now take '-d' to talk with a CVS
+    repository different from what are recorded in CVS/Root
+    (overriding it with environment CVSROOT does not work).
+
+  - "git bundle" can help sneaker-netting your changes between
+    repositories.
+
+  - "git mergetool" can help 3-way file-level conflict
+    resolution with your favorite graphical merge tools.
+
+  - A new configuration "core.symlinks" can be used to disable
+    symlinks on filesystems that do not support them; they are
+    checked out as regular files instead.
+
+  - You can name a commit object with its first line of the
+    message.  The syntax to use is ':/message text'.  E.g.
+
+    $ git show ":/object name: introduce ':/<oneline prefix>' notation"
+
+    means the same thing as:
+
+    $ git show 28a4d940443806412effa246ecc7768a21553ec7
+
+  - "git bisect" learned a new command "run" that takes a script
+    to run after each revision is checked out to determine if it
+    is good or bad, to automate the bisection process.
+
+  - "git log" family learned a new traversal option --first-parent,
+    which does what the name suggests.
+
+
+* Updated behavior of existing commands.
+
+  - "git-merge-recursive" used to barf when there are more than
+    one common ancestors for the merge, and merging them had a
+    rename/rename conflict.  This has been fixed.
+
+  - "git fsck" does not barf on corrupt loose objects.
+
+  - "git rm" does not remove newly added files without -f.
+
+  - "git archimport" allows remapping when coming up with git
+    branch names from arch names.
+
+  - git-svn got almost a rewrite.
+
+  - core.autocrlf configuration, when set to 'true', makes git
+    to convert CRLF at the end of lines in text files to LF when
+    reading from the filesystem, and convert in reverse when
+    writing to the filesystem.  The variable can be set to
+    'input', in which case the conversion happens only while
+    reading from the filesystem but files are written out with
+    LF at the end of lines.  Currently, which paths to consider
+    'text' (i.e. be subjected to the autocrlf mechanism) is
+    decided purely based on the contents, but the plan is to
+    allow users to explicitly override this heuristic based on
+    paths.
+
+  - The behavior of 'git-apply', when run in a subdirectory,
+    without --index nor --cached were inconsistent with that of
+    the command with these options.  This was fixed to match the
+    behavior with --index.  A patch that is meant to be applied
+    with -p1 from the toplevel of the project tree can be
+    applied with any custom -p<n> option.  A patch that is not
+    relative to the toplevel needs to be applied with -p<n>
+    option with or without --index (or --cached).
+
+  - "git diff" outputs a trailing HT when pathnames have embedded
+    SP on +++/--- header lines, in order to help "GNU patch" to
+    parse its output.  "git apply" was already updated to accept
+    this modified output format since ce74618d (Sep 22, 2006).
+
+  - "git cvsserver" runs hooks/update and honors its exit status.
+
+  - "git cvsserver" can be told to send everything with -kb.
+
+  - "git diff --check" also honors the --color output option.
+
+  - "git name-rev" used to stress the fact that a ref is a tag too
+    much, by saying something like "v1.2.3^0~22".  It now says
+    "v1.2.3~22" in such a case (it still says "v1.2.3^0" if it does
+    not talk about an ancestor of the commit that is tagged, which
+    makes sense).
+
+  - "git rev-list --boundary" now shows boundary markers for the
+    commits omitted by --max-age and --max-count condition.
+
+  - The configuration mechanism now reads $(prefix)/etc/gitconfig.
+
+  - "git apply --verbose" shows what preimage lines were wanted
+    when it couldn't find them.
+
+  - "git status" in a read-only repository got a bit saner.
+
+  - "git fetch" (hence "git clone" and "git pull") are less
+    noisy when the output does not go to tty.
+
+  - "git fetch" between repositories with many refs were slow
+    even when there are not many changes that needed
+    transferring.  This has been sped up by partially rewriting
+    the heaviest parts in C.
+
+  - "git mailinfo" which splits an e-mail into a patch and the
+    meta-information was rewritten, thanks to Don Zickus.  It
+    handles nested multipart better.  The command was broken for
+    a brief period on 'master' branch since 1.5.0 but the
+    breakage is fixed now.
+
+  - send-email learned configurable bcc and chain-reply-to.
+
+  - "git remote show $remote" also talks about branches that
+    would be pushed if you run "git push remote".
+
+  - Using objects from packs is now seriously optimized by clever
+    use of a cache.  This should be most noticeable in git-log
+    family of commands that involve reading many tree objects.
+    In addition, traversing revisions while filtering changes
+    with pathspecs is made faster by terminating the comparison
+    between the trees as early as possible.
+
+
+* Hooks
+
+  - The part to send out notification e-mails was removed from
+    the sample update hook, as it was not an appropriate place
+    to do so.  The proper place to do this is the new post-receive
+    hook.  An example hook has been added to contrib/hooks/.
+
+
+* Others
+
+  - git-revert, git-gc and git-cherry-pick are now built-ins.
+
+Fixes since v1.5.0
+------------------
+
+These are all in v1.5.0.x series.
+
+* Documentation updates
+
+  - Clarifications and corrections to 1.5.0 release notes.
+
+  - The main documentation did not link to git-remote documentation.
+
+  - Clarified introductory text of git-rebase documentation.
+
+  - Converted remaining mentions of update-index on Porcelain
+    documents to git-add/git-rm.
+
+  - Some i18n.* configuration variables were incorrectly
+    described as core.*; fixed.
+
+  - added and clarified core.bare, core.legacyheaders configurations.
+
+  - updated "git-clone --depth" documentation.
+
+  - user-manual updates.
+
+  - Options to 'git remote add' were described insufficiently.
+
+  - Configuration format.suffix was not documented.
+
+  - Other formatting and spelling fixes.
+
+  - user-manual has better cross references.
+
+  - gitweb installation/deployment procedure is now documented.
+
+
+* Bugfixes
+
+  - git-upload-pack closes unused pipe ends; earlier this caused
+    many zombies to hang around.
+
+  - git-rerere was recording the contents of earlier hunks
+    duplicated in later hunks.  This prevented resolving the same
+    conflict when performing the same merge the other way around.
+
+  - git-add and git-update-index on a filesystem on which
+    executable bits are unreliable incorrectly reused st_mode
+    bits even when the path changed between symlink and regular
+    file.
+
+  - git-daemon marks the listening sockets with FD_CLOEXEC so
+    that it won't be leaked into the children.
+
+  - segfault from git-blame when the mandatory pathname
+    parameter was missing was fixed; usage() message is given
+    instead.
+
+  - git-rev-list did not read $GIT_DIR/config file, which means
+    that did not honor i18n.logoutputencoding correctly.
+
+  - Automated merge conflict handling when changes to symbolic
+    links conflicted were completely broken.  The merge-resolve
+    strategy created a regular file with conflict markers in it
+    in place of the symbolic link.  The default strategy,
+    merge-recursive was even more broken.  It removed the path
+    that was pointed at by the symbolic link.  Both of these
+    problems have been fixed.
+
+  - 'git diff maint master next' did not correctly give combined
+    diff across three trees.
+
+  - 'git fast-import' portability fix for Solaris.
+
+  - 'git show-ref --verify' without arguments did not error out
+    but segfaulted.
+
+  - 'git diff :tracked-file `pwd`/an-untracked-file' gave an extra
+    slashes after a/ and b/.
+
+  - 'git format-patch' produced too long filenames if the commit
+    message had too long line at the beginning.
+
+  - Running 'make all' and then without changing anything
+    running 'make install' still rebuilt some files.  This
+    was inconvenient when building as yourself and then
+    installing as root (especially problematic when the source
+    directory is on NFS and root is mapped to nobody).
+
+  - 'git-rerere' failed to deal with two unconflicted paths that
+    sorted next to each other.
+
+  - 'git-rerere' attempted to open(2) a symlink and failed if
+    there was a conflict.  Since a conflicting change to a
+    symlink would not benefit from rerere anyway, the command
+    now ignores conflicting changes to symlinks.
+
+  - 'git-repack' did not like to pass more than 64 arguments
+    internally to underlying 'rev-list' logic, which made it
+    impossible to repack after accumulating many (small) packs
+    in the repository.
+
+  - 'git-diff' to review the combined diff during a conflicted
+    merge were not reading the working tree version correctly
+    when changes to a symbolic link conflicted.  It should have
+    read the data using readlink(2) but read from the regular
+    file the symbolic link pointed at.
+
+  - 'git-remote' did not like period in a remote's name.
+
+  - 'git.el' honors the commit coding system from the configuration.
+
+  - 'blameview' in contrib/ correctly digs deeper when a line is
+    clicked.
+
+  - 'http-push' correctly makes sure the remote side has leading
+    path.  Earlier it started in the middle of the path, and
+    incorrectly.
+
+  - 'git-merge' did not exit with non-zero status when the
+    working tree was dirty and cannot fast forward.  It does
+    now.
+
+  - 'cvsexportcommit' does not lose yet-to-be-used message file.
+
+  - int-vs-size_t typefix when running combined diff on files
+    over 2GB long.
+
+  - 'git apply --whitespace=strip' should not touch unmodified
+    lines.
+
+  - 'git-mailinfo' choke when a logical header line was too long.
+
+  - 'git show A..B' did not error out.  Negative ref ("not A" in
+    this example) does not make sense for the purpose of the
+    command, so now it errors out.
+
+  - 'git fmt-merge-msg --file' without file parameter did not
+    correctly error out.
+
+  - 'git archimport' barfed upon encountering a commit without
+    summary.
+
+  - 'git index-pack' did not protect itself from getting a short
+    read out of pread(2).
+
+  - 'git http-push' had a few buffer overruns.
+
+  - Build dependency fixes to rebuild fetch.o when other headers
+    change.
+
+  - git.el does not add duplicate sign-off lines.
+
+  - git-commit shows the full stat of the resulting commit, not
+    just about the files in the current directory, when run from
+    a subdirectory.
+
+  - "git-checkout -m '@{8 hours ago}'" had a funny failure from
+    eval; fixed.
+
+  - git-merge (hence git-pull) did not refuse fast-forwarding
+    when the working tree had local changes that would have
+    conflicted with it.
+
+  - a handful small fixes to gitweb.
+
+  - build procedure for user-manual is fixed not to require locally
+    installed stylesheets.
+
+  - "git commit $paths" on paths whose earlier contents were
+    already updated in the index were failing out.
+
+
+* Tweaks
+
+  - sliding mmap() inefficiently mmaped the same region of a
+    packfile with an access pattern that used objects in the
+    reverse order.  This has been made more efficient.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.1.txt b/third_party/git/Documentation/RelNotes/1.5.2.1.txt
new file mode 100644
index 0000000000..d41984df0b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.1.txt
@@ -0,0 +1,47 @@
+GIT v1.5.2.1 Release Notes
+==========================
+
+Fixes since v1.5.2
+------------------
+
+* Bugfixes
+
+  - Temporary files that are used when invoking external diff
+    programs did not tolerate a long TMPDIR.
+
+  - git-daemon did not notice when it could not write into its
+    pid file.
+
+  - git-status did not honor core.excludesFile configuration like
+    git-add did.
+
+  - git-annotate did not work from a subdirectory while
+    git-blame did.
+
+  - git-cvsserver should have disabled access to a repository
+    with "gitcvs.pserver.enabled = false" set even when
+    "gitcvs.enabled = true" was set at the same time.  It
+    didn't.
+
+  - git-cvsimport did not work correctly in a repository with
+    its branch heads were packed with pack-refs.
+
+  - ident unexpansion to squash "$Id: xxx $" that is in the
+    repository copy removed incorrect number of bytes.
+
+  - git-svn misbehaved when the subversion repository did not
+    provide MD5 checksums for files.
+
+  - git rebase (and git am) misbehaved on commits that have '\n'
+    (literally backslash and en, not a linefeed) in the title.
+
+  - code to decode base85 used in binary patches had one error
+    return codepath wrong.
+
+  - RFC2047 Q encoding output by git-format-patch used '_' for a
+    space, which is not understood by some programs.  It uses =20
+    which is safer.
+
+  - git-fastimport --import-marks was broken; fixed.
+
+  - A lot of documentation updates, clarifications and fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.2.txt b/third_party/git/Documentation/RelNotes/1.5.2.2.txt
new file mode 100644
index 0000000000..7bfa341750
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.2.txt
@@ -0,0 +1,61 @@
+GIT v1.5.2.2 Release Notes
+==========================
+
+Fixes since v1.5.2.1
+--------------------
+
+* Usability fix
+
+  - git-gui is shipped with its updated blame interface.  It is
+    rumored that the older one was not just unusable but was
+    active health hazard, but this one is actually pretty.
+    Please see for yourself.
+
+* Bugfixes
+
+  - "git checkout fubar" was utterly confused when there is a
+    branch fubar and a tag fubar at the same time.  It correctly
+    checks out the branch fubar now.
+
+  - "git clone /path/foo" to clone a local /path/foo.git
+    repository left an incorrect configuration.
+
+  - "git send-email" correctly unquotes RFC 2047 quoted names in
+    the patch-email before using their values.
+
+  - We did not accept number of seconds since epoch older than
+    year 2000 as a valid timestamp.  We now interpret positive
+    integers more than 8 digits as such, which allows us to
+    express timestamps more recent than March 1973.
+
+  - git-cvsimport did not work when you have GIT_DIR to point
+    your repository at a nonstandard location.
+
+  - Some systems (notably, Solaris) lack hstrerror() to make
+    h_errno human readable; prepare a replacement
+    implementation.
+
+  - .gitignore file listed git-core.spec but what we generate is
+    git.spec, and nobody noticed for a long time.
+
+  - "git-merge-recursive" does not try to run file level merge
+    on binary files.
+
+  - "git-branch --track" did not create tracking configuration
+    correctly when the branch name had slash in it.
+
+  - The email address of the user specified with user.email
+    configuration was overridden by EMAIL environment variable.
+
+  - The tree parser did not warn about tree entries with
+    nonsense file modes, and assumed they must be blobs.
+
+  - "git log -z" without any other request to generate diff still
+    invoked the diff machinery, wasting cycles.
+
+* Documentation
+
+  - Many updates to fix stale or missing documentation.
+
+  - Although our documentation was primarily meant to be formatted
+    with AsciiDoc7, formatting with AsciiDoc8 is supported better.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.3.txt b/third_party/git/Documentation/RelNotes/1.5.2.3.txt
new file mode 100644
index 0000000000..addb22955b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.3.txt
@@ -0,0 +1,27 @@
+GIT v1.5.2.3 Release Notes
+==========================
+
+Fixes since v1.5.2.2
+--------------------
+
+ * Bugfixes
+
+   - Version 2 pack index format was introduced in version 1.5.2
+     to support pack files that has offset that cannot be
+     represented in 32-bit.  The runtime code to validate such
+     an index mishandled such an index for an empty pack.
+
+   - Commit walkers (most notably, fetch over http protocol)
+     tried to traverse commit objects contained in trees (aka
+     subproject); they shouldn't.
+
+   - A build option NO_R_TO_GCC_LINKER was not explained in Makefile
+     comment correctly.
+
+ * Documentation Fixes and Updates
+
+   - git-config --regexp was not documented properly.
+
+   - git-repack -a was not documented properly.
+
+   - git-remote -n was not documented properly.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.4.txt b/third_party/git/Documentation/RelNotes/1.5.2.4.txt
new file mode 100644
index 0000000000..75cff475f6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.4.txt
@@ -0,0 +1,28 @@
+GIT v1.5.2.4 Release Notes
+==========================
+
+Fixes since v1.5.2.3
+--------------------
+
+ * Bugfixes
+
+   - "git-gui" bugfixes, including a handful fixes to run it
+     better on Cygwin/MSYS.
+
+   - "git checkout" failed to switch back and forth between
+     branches, one of which has "frotz -> xyzzy" symlink and
+     file "xyzzy/filfre", while the other one has a file
+     "frotz/filfre".
+
+   - "git prune" used to segfault upon seeing a commit that is
+     referred to by a tree object (aka "subproject").
+
+   - "git diff --name-status --no-index" mishandled an added file.
+
+   - "git apply --reverse --whitespace=warn" still complained
+     about whitespaces that a forward application would have
+     introduced.
+
+ * Documentation Fixes and Updates
+
+   - A handful documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.5.txt b/third_party/git/Documentation/RelNotes/1.5.2.5.txt
new file mode 100644
index 0000000000..e8281c72a0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.5.txt
@@ -0,0 +1,30 @@
+GIT v1.5.2.5 Release Notes
+==========================
+
+Fixes since v1.5.2.4
+--------------------
+
+ * Bugfixes
+
+   - "git add -u" had a serious data corruption problem in one
+     special case (when the changes to a subdirectory's files
+     consist only deletion of files).
+
+   - "git add -u <path>" did not work from a subdirectory.
+
+   - "git apply" left an empty directory after all its files are
+     renamed away.
+
+   - "git $anycmd foo/bar", when there is a file 'foo' in the
+     working tree, complained that "git $anycmd foo/bar --" form
+     should be used to disambiguate between revs and files,
+     which was completely bogus.
+
+   - "git checkout-index" and other commands that checks out
+     files to the work tree tried unlink(2) on directories,
+     which is a sane thing to do on sane systems, but not on
+     Solaris when you are root.
+
+ * Documentation Fixes and Updates
+
+   - A handful documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.2.txt b/third_party/git/Documentation/RelNotes/1.5.2.txt
new file mode 100644
index 0000000000..e8328d090a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.2.txt
@@ -0,0 +1,197 @@
+GIT v1.5.2 Release Notes
+========================
+
+Updates since v1.5.1
+--------------------
+
+* Plumbing level superproject support.
+
+  You can include a subdirectory that has an independent git
+  repository in your index and tree objects of your project
+  ("superproject").  This plumbing (i.e. "core") level
+  superproject support explicitly excludes recursive behaviour.
+
+  The "subproject" entries in the index and trees of a superproject
+  are incompatible with older versions of git.  Experimenting with
+  the plumbing level support is encouraged, but be warned that
+  unless everybody in your project updates to this release or
+  later, using this feature would make your project
+  inaccessible by people with older versions of git.
+
+* Plumbing level gitattributes support.
+
+  The gitattributes mechanism allows you to add 'attributes' to
+  paths in your project, and affect the way certain git
+  operations work.  Currently you can influence if a path is
+  considered a binary or text (the former would be treated by
+  'git diff' not to produce textual output; the latter can go
+  through the line endings conversion process in repositories
+  with core.autocrlf set), expand and unexpand '$Id$' keyword
+  with blob object name, specify a custom 3-way merge driver,
+  and specify a custom diff driver.  You can also apply
+  arbitrary filter to contents on check-in/check-out codepath
+  but this feature is an extremely sharp-edged razor and needs
+  to be handled with caution (do not use it unless you
+  understand the earlier mailing list discussion on keyword
+  expansion).  These conversions apply when checking files in
+  or out, and exporting via git-archive.
+
+* The packfile format now optionally supports 64-bit index.
+
+  This release supports the "version 2" format of the .idx
+  file.  This is automatically enabled when a huge packfile
+  needs more than 32-bit to express offsets of objects in the
+  pack.
+
+* Comes with an updated git-gui 0.7.1
+
+* Updated gitweb:
+
+  - can show combined diff for merges;
+  - uses font size of user's preference, not hardcoded in pixels;
+  - can now 'grep';
+
+* New commands and options.
+
+  - "git bisect start" can optionally take a single bad commit and
+    zero or more good commits on the command line.
+
+  - "git shortlog" can optionally be told to wrap its output.
+
+  - "subtree" merge strategy allows another project to be merged in as
+    your subdirectory.
+
+  - "git format-patch" learned a new --subject-prefix=<string>
+    option, to override the built-in "[PATCH]".
+
+  - "git add -u" is a quick way to do the first stage of "git
+    commit -a" (i.e. update the index to match the working
+    tree); it obviously does not make a commit.
+
+  - "git clean" honors a new configuration, "clean.requireforce".  When
+    set to true, this makes "git clean" a no-op, preventing you
+    from losing files by typing "git clean" when you meant to
+    say "make clean".  You can still say "git clean -f" to
+    override this.
+
+  - "git log" family of commands learned --date={local,relative,default}
+    option.  --date=relative is synonym to the --relative-date.
+    --date=local gives the timestamp in local timezone.
+
+* Updated behavior of existing commands.
+
+  - When $GIT_COMMITTER_EMAIL or $GIT_AUTHOR_EMAIL is not set
+    but $EMAIL is set, the latter is used as a substitute.
+
+  - "git diff --stat" shows size of preimage and postimage blobs
+    for binary contents.  Earlier it only said "Bin".
+
+  - "git lost-found" shows stuff that are unreachable except
+    from reflogs.
+
+  - "git checkout branch^0" now detaches HEAD at the tip commit
+    on the named branch, instead of just switching to the
+    branch (use "git checkout branch" to switch to the branch,
+    as before).
+
+  - "git bisect next" can be used after giving only a bad commit
+    without giving a good one (this starts bisection half-way to
+    the root commit).  We used to refuse to operate without a
+    good and a bad commit.
+
+  - "git push", when pushing into more than one repository, does
+    not stop at the first error.
+
+  - "git archive" does not insist you to give --format parameter
+    anymore; it defaults to "tar".
+
+  - "git cvsserver" can use backends other than sqlite.
+
+  - "gitview" (in contrib/ section) learned to better support
+    "git-annotate".
+
+  - "git diff $commit1:$path2 $commit2:$path2" can now report
+    mode changes between the two blobs.
+
+  - Local "git fetch" from a repository whose object store is
+    one of the alternates (e.g. fetching from the origin in a
+    repository created with "git clone -l -s") avoids
+    downloading objects unnecessarily.
+
+  - "git blame" uses .mailmap to canonicalize the author name
+    just like "git shortlog" does.
+
+  - "git pack-objects" pays attention to pack.depth
+    configuration variable.
+
+  - "git cherry-pick" and "git revert" does not use .msg file in
+    the working tree to prepare commit message; instead it uses
+    $GIT_DIR/MERGE_MSG as other commands do.
+
+* Builds
+
+  - git-p4import has never been installed; now there is an
+    installation option to do so.
+
+  - gitk and git-gui can be configured out.
+
+  - Generated documentation pages automatically get version
+    information from GIT_VERSION.
+
+  - Parallel build with "make -j" descending into subdirectory
+    was fixed.
+
+* Performance Tweaks
+
+  - Optimized "git-rev-list --bisect" (hence "git-bisect").
+
+  - Optimized "git-add $path" in a large directory, most of
+    whose contents are ignored.
+
+  - Optimized "git-diff-tree" for reduced memory footprint.
+
+  - The recursive merge strategy updated a worktree file that
+    was changed identically in two branches, when one of them
+    renamed it.  We do not do that when there is no rename, so
+    match that behaviour.  This avoids excessive rebuilds.
+
+  - The default pack depth has been increased to 50, as the
+    recent addition of delta_base_cache makes deeper delta chains
+    much less expensive to access.  Depending on the project, it was
+    reported that this reduces the resulting pack file by 10%
+    or so.
+
+
+Fixes since v1.5.1
+------------------
+
+All of the fixes in v1.5.1 maintenance series are included in
+this release, unless otherwise noted.
+
+* Bugfixes
+
+  - Switching branches with "git checkout" refused to work when
+    a path changes from a file to a directory between the
+    current branch and the new branch, in order not to lose
+    possible local changes in the directory that is being turned
+    into a file with the switch.  We now allow such a branch
+    switch after making sure that there is no locally modified
+    file nor un-ignored file in the directory.  This has not
+    been backported to 1.5.1.x series, as it is rather an
+    intrusive change.
+
+  - Merging branches that have a file in one and a directory in
+    another at the same path used to get quite confused.  We
+    handle such a case a bit more carefully, even though that is
+    still left as a conflict for the user to sort out.  This
+    will not be backported to 1.5.1.x series, as it is rather an
+    intrusive change.
+
+  - git-fetch had trouble with a remote with insanely large number
+    of refs.
+
+  - "git clean -d -X" now does not remove non-excluded directories.
+
+  - rebasing (without -m) a series that changes a symlink to a directory
+    in the middle of a path confused git-apply greatly and refused to
+    operate.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.1.txt b/third_party/git/Documentation/RelNotes/1.5.3.1.txt
new file mode 100644
index 0000000000..7ff546c743
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.1.txt
@@ -0,0 +1,10 @@
+GIT v1.5.3.1 Release Notes
+==========================
+
+Fixes since v1.5.3
+------------------
+
+This is solely to fix the generated RPM's dependencies.  We used
+to have git-p4 package but we do not anymore.  As suggested on
+the mailing list, this release makes git-core "Obsolete" git-p4,
+so that yum update would not complain.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.2.txt b/third_party/git/Documentation/RelNotes/1.5.3.2.txt
new file mode 100644
index 0000000000..4bbde3cab4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.2.txt
@@ -0,0 +1,58 @@
+GIT v1.5.3.2 Release Notes
+==========================
+
+Fixes since v1.5.3.1
+--------------------
+
+ * git-push sent thin packs by default, which was not good for
+   the public distribution server (no point in saving transfer
+   while pushing; no point in making the resulting pack less
+   optimum).
+
+ * git-svn sometimes terminated with "Malformed network data" when
+   talking over svn:// protocol.
+
+ * git-send-email re-issued the same message-id about 10% of the
+   time if you fired off 30 messages within a single second.
+
+ * git-stash was not terminating the log message of commits it
+   internally creates with LF.
+
+ * git-apply failed to check the size of the patch hunk when its
+   beginning part matched the remainder of the preimage exactly,
+   even though the preimage recorded in the hunk was much larger
+   (therefore the patch should not have applied), leading to a
+   segfault.
+
+ * "git rm foo && git commit foo" complained that 'foo' needs to
+   be added first, instead of committing the removal, which was a
+   nonsense.
+
+ * git grep -c said "/dev/null: 0".
+
+ * git-add -u failed to recognize a blob whose type changed
+   between the index and the work tree.
+
+ * The limit to rename detection has been tightened a lot to
+   reduce performance problems with a huge change.
+
+ * cvsimport and svnimport barfed when the input tried to move
+   a tag.
+
+ * "git apply -pN" did not chop the right number of directories.
+
+ * "git svnimport" did not like SVN tags with funny characters in them.
+
+ * git-gui 0.8.3, with assorted fixes, including:
+
+   - font-chooser on X11 was unusable with large number of fonts;
+   - a diff that contained a deleted symlink made it barf;
+   - an untracked symbolic link to a directory made it fart;
+   - a file with % in its name made it vomit;
+
+
+Documentation updates
+---------------------
+
+User manual has been somewhat restructured.  I think the new
+organization is much easier to read.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.3.txt b/third_party/git/Documentation/RelNotes/1.5.3.3.txt
new file mode 100644
index 0000000000..d213846951
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.3.txt
@@ -0,0 +1,31 @@
+GIT v1.5.3.3 Release Notes
+==========================
+
+Fixes since v1.5.3.2
+--------------------
+
+ * git-quiltimport did not like it when a patch described in the
+   series file does not exist.
+
+ * p4 importer missed executable bit in some cases.
+
+ * The default shell on some FreeBSD did not execute the
+   argument parsing code correctly and made git unusable.
+
+ * git-svn incorrectly spawned pager even when the user
+   explicitly asked not to.
+
+ * sample post-receive hook overquoted the envelope sender
+   value.
+
+ * git-am got confused when the patch contained a change that is
+   only about type and not contents.
+
+ * git-mergetool did not show our and their version of the
+   conflicted file when started from a subdirectory of the
+   project.
+
+ * git-mergetool did not pass correct options when invoking diff3.
+
+ * git-log sometimes invoked underlying "diff" machinery
+   unnecessarily.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.4.txt b/third_party/git/Documentation/RelNotes/1.5.3.4.txt
new file mode 100644
index 0000000000..b04b3a45a5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.4.txt
@@ -0,0 +1,35 @@
+GIT v1.5.3.4 Release Notes
+==========================
+
+Fixes since v1.5.3.3
+--------------------
+
+ * Change to "git-ls-files" in v1.5.3.3 that was introduced to support
+   partial commit of removal better had a segfaulting bug, which was
+   diagnosed and fixed by Keith and Carl.
+
+ * Performance improvements for rename detection has been backported
+   from the 'master' branch.
+
+ * "git-for-each-ref --format='%(numparent)'" was not working
+   correctly at all, and --format='%(parent)' was not working for
+   merge commits.
+
+ * Sample "post-receive-hook" incorrectly sent out push
+   notification e-mails marked as "From: " the committer of the
+   commit that happened to be at the tip of the branch that was
+   pushed, not from the person who pushed.
+
+ * "git-remote" did not exit non-zero status upon error.
+
+ * "git-add -i" did not respond very well to EOF from tty nor
+   bogus input.
+
+ * "git-rebase -i" squash subcommand incorrectly made the
+   author of later commit the author of resulting commit,
+   instead of taking from the first one in the squashed series.
+
+ * "git-stash apply --index" was not documented.
+
+ * autoconfiguration learned that "ar" command is found as "gas" on
+   some systems.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.5.txt b/third_party/git/Documentation/RelNotes/1.5.3.5.txt
new file mode 100644
index 0000000000..7ff1d5d0d1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.5.txt
@@ -0,0 +1,94 @@
+GIT v1.5.3.5 Release Notes
+==========================
+
+Fixes since v1.5.3.4
+--------------------
+
+ * Comes with git-gui 0.8.4.
+
+ * "git-config" silently ignored options after --list; now it will
+   error out with a usage message.
+
+ * "git-config --file" failed if the argument used a relative path
+   as it changed directories before opening the file.
+
+ * "git-config --file" now displays a proper error message if it
+   cannot read the file specified on the command line.
+
+ * "git-config", "git-diff", "git-apply" failed if run from a
+   subdirectory with relative GIT_DIR and GIT_WORK_TREE set.
+
+ * "git-blame" crashed if run during a merge conflict.
+
+ * "git-add -i" did not handle single line hunks correctly.
+
+ * "git-rebase -i" and "git-stash apply" failed if external diff
+   drivers were used for one or more files in a commit.  They now
+   avoid calling the external diff drivers.
+
+ * "git-log --follow" did not work unless diff generation (e.g. -p)
+   was also requested.
+
+ * "git-log --follow -B" did not work at all.  Fixed.
+
+ * "git-log -M -B" did not correctly handle cases of very large files
+   being renamed and replaced by very small files in the same commit.
+
+ * "git-log" printed extra newlines between commits when a diff
+   was generated internally (e.g. -S or --follow) but not displayed.
+
+ * "git-push" error message is more helpful when pushing to a
+   repository with no matching refs and none specified.
+
+ * "git-push" now respects + (force push) on wildcard refspecs,
+   matching the behavior of git-fetch.
+
+ * "git-filter-branch" now updates the working directory when it
+   has finished filtering the current branch.
+
+ * "git-instaweb" no longer fails on Mac OS X.
+
+ * "git-cvsexportcommit" didn't always create new parent directories
+   before trying to create new child directories.  Fixed.
+
+ * "git-fetch" printed a scary (but bogus) error message while
+   fetching a tag that pointed to a tree or blob.  The error did
+   not impact correctness, only user perception.  The bogus error
+   is no longer printed.
+
+ * "git-ls-files --ignored" did not properly descend into non-ignored
+   directories that themselves contained ignored files if d_type
+   was not supported by the filesystem.  This bug impacted systems
+   such as AFS.  Fixed.
+
+ * Git segfaulted when reading an invalid .gitattributes file.  Fixed.
+
+ * post-receive-email example hook was fixed for non-fast-forward
+   updates.
+
+ * Documentation updates for supported (but previously undocumented)
+   options of "git-archive" and "git-reflog".
+
+ * "make clean" no longer deletes the configure script that ships
+   with the git tarball, making multiple architecture builds easier.
+
+ * "git-remote show origin" spewed a warning message from Perl
+   when no remote is defined for the current branch via
+   branch.<name>.remote configuration settings.
+
+ * Building with NO_PERL_MAKEMAKER excessively rebuilt contents
+   of perl/ subdirectory by rewriting perl.mak.
+
+ * http.sslVerify configuration settings were not used in scripted
+   Porcelains.
+
+ * "git-add" leaked a bit of memory while scanning for files to add.
+
+ * A few workarounds to squelch false warnings from recent gcc have
+   been added.
+
+ * "git-send-pack $remote frotz" segfaulted when there is nothing
+   named 'frotz' on the local end.
+
+ * "git-rebase --interactive" did not handle its "--strategy" option
+   properly.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.6.txt b/third_party/git/Documentation/RelNotes/1.5.3.6.txt
new file mode 100644
index 0000000000..069a2b2cf9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.6.txt
@@ -0,0 +1,48 @@
+GIT v1.5.3.6 Release Notes
+==========================
+
+Fixes since v1.5.3.5
+--------------------
+
+ * git-cvsexportcommit handles root commits better.
+
+ * git-svn dcommit used to clobber when sending a series of
+   patches.
+
+ * git-svn dcommit failed after attempting to rebase when
+   started with a dirty index; now it stops upfront.
+
+ * git-grep sometimes refused to work when your index was
+   unmerged.
+
+ * "git-grep -A1 -B2" acted as if it was told to run "git -A1 -B21".
+
+ * git-hash-object did not honor configuration variables, such as
+   core.compression.
+
+ * git-index-pack choked on a huge pack on 32-bit machines, even when
+   large file offsets are supported.
+
+ * atom feeds from git-web said "10" for the month of November.
+
+ * a memory leak in commit walker was plugged.
+
+ * When git-send-email inserted the original author's From:
+   address in body, it did not mark the message with
+   Content-type: as needed.
+
+ * git-revert and git-cherry-pick incorrectly refused to start
+   when the work tree was dirty.
+
+ * git-clean did not honor core.excludesfile configuration.
+
+ * git-add mishandled ".gitignore" files when applying them to
+   subdirectories.
+
+ * While importing a too branchy history, git-fastimport did not
+   honor delta depth limit properly.
+
+ * Support for zlib implementations that lack ZLIB_VERNUM and definition
+   of deflateBound() has been added.
+
+ * Quite a lot of documentation clarifications.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.7.txt b/third_party/git/Documentation/RelNotes/1.5.3.7.txt
new file mode 100644
index 0000000000..2f690616c8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.7.txt
@@ -0,0 +1,45 @@
+GIT v1.5.3.7 Release Notes
+==========================
+
+Fixes since v1.5.3.6
+--------------------
+
+ * git-send-email added 8-bit contents to the payload without
+   marking it as 8-bit in a CTE header.
+
+ * "git-bundle create a.bndl HEAD" dereferenced the symref and
+   did not record the ref as 'HEAD'; this prevented a bundle
+   from being used as a normal source of git-clone.
+
+ * The code to reject nonsense command line of the form
+   "git-commit -a paths..." and "git-commit --interactive
+   paths..." were broken.
+
+ * Adding a signature that is not ASCII-only to an original
+   commit that is ASCII-only would make the result non-ASCII.
+   "git-format-patch -s" did not mark such a message correctly
+   with MIME encoding header.
+
+ * git-add sometimes did not mark the resulting index entry
+   stat-clean.  This affected only cases when adding the
+   contents with the same length as the previously staged
+   contents, and the previous staging made the index entry
+   "racily clean".
+
+ * git-commit did not honor GIT_INDEX_FILE the user had in the
+   environment.
+
+ * When checking out a revision, git-checkout did not report where the
+   updated HEAD is if you happened to have a file called HEAD in the
+   work tree.
+
+ * "git-rev-list --objects" mishandled a tree that points at a
+   submodule.
+
+ * "git cvsimport" was not ready for packed refs that "git gc" can
+   produce and gave incorrect results.
+
+ * Many scripted Porcelains were confused when you happened to have a
+   file called "HEAD" in your work tree.
+
+Also it contains updates to the user manual and documentation.
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.8.txt b/third_party/git/Documentation/RelNotes/1.5.3.8.txt
new file mode 100644
index 0000000000..0e3ff58a46
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.8.txt
@@ -0,0 +1,25 @@
+GIT v1.5.3.8 Release Notes
+==========================
+
+Fixes since v1.5.3.7
+--------------------
+
+ * Some documentation used "email.com" as an example domain.
+
+ * git-svn fix to handle funky branch and project names going over
+   http/https correctly.
+
+ * git-svn fix to tone down a needlessly alarming warning message.
+
+ * git-clone did not correctly report errors while fetching over http.
+
+ * git-send-email added redundant Message-Id: header to the outgoing
+   e-mail when the patch text already had one.
+
+ * a read-beyond-end-of-buffer bug in configuration file updater was fixed.
+
+ * git-grep used to show the same hit repeatedly for unmerged paths.
+
+ * After amending the patch title in "git-am -i", the command did not
+   report the patch it applied with the updated title.
+
diff --git a/third_party/git/Documentation/RelNotes/1.5.3.txt b/third_party/git/Documentation/RelNotes/1.5.3.txt
new file mode 100644
index 0000000000..0668d3c0ca
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.3.txt
@@ -0,0 +1,366 @@
+GIT v1.5.3 Release Notes
+========================
+
+Updates since v1.5.2
+--------------------
+
+* The commit walkers other than http are officially deprecated,
+  but still supported for now.
+
+* The submodule support has Porcelain layer.
+
+  Note that the current submodule support is minimal and this is
+  deliberately so.  A design decision we made is that operations
+  at the supermodule level do not recurse into submodules by
+  default.  The expectation is that later we would add a
+  mechanism to tell git which submodules the user is interested
+  in, and this information might be used to determine the
+  recursive behaviour of certain commands (e.g. "git checkout"
+  and "git diff"), but currently we haven't agreed on what that
+  mechanism should look like.  Therefore, if you use submodules,
+  you would probably need "git submodule update" on the
+  submodules you care about after running a "git checkout" at
+  the supermodule level.
+
+* There are a handful pack-objects changes to help you cope better
+  with repositories with pathologically large blobs in them.
+
+* For people who need to import from Perforce, a front-end for
+  fast-import is in contrib/fast-import/.
+
+* Comes with git-gui 0.8.2.
+
+* Comes with updated gitk.
+
+* New commands and options.
+
+  - "git log --date=<format>" can use more formats: iso8601, rfc2822.
+
+  - The hunk header output from "git diff" family can be customized
+    with the attributes mechanism.  See gitattributes(5) for details.
+
+  - "git stash" allows you to quickly save away your work in
+    progress and replay it later on an updated state.
+
+  - "git rebase" learned an "interactive" mode that let you
+    pick and reorder which commits to rebuild.
+
+  - "git fsck" can save its findings in $GIT_DIR/lost-found, without a
+    separate invocation of "git lost-found" command.  The blobs stored by
+    lost-found are stored in plain format to allow you to grep in them.
+
+  - $GIT_WORK_TREE environment variable can be used together with
+    $GIT_DIR to work in a subdirectory of a working tree that is
+    not located at "$GIT_DIR/..".
+
+  - Giving "--file=<file>" option to "git config" is the same as
+    running the command with GIT_CONFIG=<file> environment.
+
+  - "git log" learned a new option "--follow", to follow
+    renaming history of a single file.
+
+  - "git filter-branch" lets you rewrite the revision history of
+    specified branches. You can specify a number of filters to
+    modify the commits, files and trees.
+
+  - "git cvsserver" learned new options (--base-path, --export-all,
+    --strict-paths) inspired by "git daemon".
+
+  - "git daemon --base-path-relaxed" can help migrating a repository URL
+    that did not use to use --base-path to use --base-path.
+
+  - "git commit" can use "-t templatefile" option and commit.template
+    configuration variable to prime the commit message given to you in the
+    editor.
+
+  - "git submodule" command helps you manage the projects from
+    the superproject that contain them.
+
+  - In addition to core.compression configuration option,
+    core.loosecompression and pack.compression options can
+    independently tweak zlib compression levels used for loose
+    and packed objects.
+
+  - "git ls-tree -l" shows size of blobs pointed at by the
+    tree entries, similar to "/bin/ls -l".
+
+  - "git rev-list" learned --regexp-ignore-case and
+    --extended-regexp options to tweak its matching logic used
+    for --grep filtering.
+
+  - "git describe --contains" is a handier way to call more
+    obscure command "git name-rev --tags".
+
+  - "git gc --aggressive" tells the command to spend more cycles
+    to optimize the repository harder.
+
+  - "git repack" learned a "window-memory" limit which
+    dynamically reduces the window size to stay within the
+    specified memory usage.
+
+  - "git repack" can be told to split resulting packs to avoid
+    exceeding limit specified with "--max-pack-size".
+
+  - "git fsck" gained --verbose option.  This is really really
+    verbose but it might help you identify exact commit that is
+    corrupt in your repository.
+
+  - "git format-patch" learned --numbered-files option.  This
+    may be useful for MH users.
+
+  - "git format-patch" learned format.subjectprefix configuration
+    variable, which serves the same purpose as "--subject-prefix"
+    option.
+
+  - "git tag -n -l" shows tag annotations while listing tags.
+
+  - "git cvsimport" can optionally use the separate-remote layout.
+
+  - "git blame" can be told to see through commits that change
+    whitespaces and indentation levels with "-w" option.
+
+  - "git send-email" can be told not to thread the messages when
+    sending out more than one patches.
+
+  - "git send-email" can also be told how to find whom to cc the
+    message to for each message via --cc-cmd.
+
+  - "git config" learned NUL terminated output format via -z to
+    help scripts.
+
+  - "git add" learned "--refresh <paths>..." option to selectively refresh
+    the cached stat information.
+
+  - "git init -q" makes the command quieter.
+
+  - "git -p command" now has a cousin of opposite sex, "git --no-pager
+    command".
+
+* Updated behavior of existing commands.
+
+  - "gitweb" can offer multiple snapshot formats.
+
+    ***NOTE*** Unfortunately, this changes the format of the
+    $feature{snapshot}{default} entry in the per-site
+    configuration file 'gitweb_config.perl'.  It used to be a
+    three-element tuple that describe a single format; with the
+    new configuration item format, you only have to say the name
+    of the format ('tgz', 'tbz2' or 'zip').  Please update the
+    your configuration file accordingly.
+
+  - "git clone" uses -l (hardlink files under .git) by default when
+    cloning locally.
+
+  - URL used for "git clone" and friends can specify nonstandard SSH port
+    by using ssh://host:port/path/to/repo syntax.
+
+  - "git bundle create" can now create a bundle without negative refs,
+    i.e. "everything since the beginning up to certain points".
+
+  - "git diff" (but not the plumbing level "git diff-tree") now
+    recursively descends into trees by default.
+
+  - "git diff" does not show differences that come only from
+    stat-dirtiness in the form of "diff --git" header anymore.
+    It runs "update-index --refresh" silently as needed.
+
+  - "git tag -l" used to match tags by globbing its parameter as if it
+    has wildcard '*' on both ends, which made "git tag -l gui" to match
+    tag 'gitgui-0.7.0'; this was very annoying.  You now have to add
+    asterisk on the sides you want to wildcard yourself.
+
+  - The editor to use with many interactive commands can be
+    overridden with GIT_EDITOR environment variable, or if it
+    does not exist, with core.editor configuration variable.  As
+    before, if you have neither, environment variables VISUAL
+    and EDITOR are consulted in this order, and then finally we
+    fall back on "vi".
+
+  - "git rm --cached" does not complain when removing a newly
+    added file from the index anymore.
+
+  - Options to "git log" to affect how --grep/--author options look for
+    given strings now have shorter abbreviations.  -i is for ignore case,
+    and -E is for extended regexp.
+
+  - "git log" learned --log-size to show the number of bytes in
+    the log message part of the output to help qgit.
+
+  - "git log --name-status" does not require you to give "-r" anymore.
+    As a general rule, Porcelain commands should recurse when showing
+    diff.
+
+  - "git format-patch --root A" can be used to format everything
+    since the beginning up to A.  This was supported with
+    "git format-patch --root A A" for a long time, but was not
+    properly documented.
+
+  - "git svn dcommit" retains local merge information.
+
+  - "git svnimport" allows an empty string to be specified as the
+    trunk/ directory.  This is necessary to suck data from a SVN
+    repository that doe not have trunk/ branches/ and tags/ organization
+    at all.
+
+  - "git config" to set values also honors type flags like --bool
+    and --int.
+
+  - core.quotepath configuration can be used to make textual git
+    output to emit most of the characters in the path literally.
+
+  - "git mergetool" chooses its backend more wisely, taking
+    notice of its environment such as use of X, Gnome/KDE, etc.
+
+  - "gitweb" shows merge commits a lot nicer than before.  The
+    default view uses more compact --cc format, while the UI
+    allows to choose normal diff with any parent.
+
+  - snapshot files "gitweb" creates from a repository at
+    $path/$project/.git are more useful.  We use $project part
+    in the filename, which we used to discard.
+
+  - "git cvsimport" creates lightweight tags; there is no
+    interesting information we can record in an annotated tag,
+    and the handcrafted ones the old code created was not
+    properly formed anyway.
+
+  - "git push" pretends that you immediately fetched back from
+    the remote by updating corresponding remote tracking
+    branches if you have any.
+
+  - The diffstat given after a merge (or a pull) honors the
+    color.diff configuration.
+
+  - "git commit --amend" is now compatible with various message source
+    options such as -m/-C/-c/-F.
+
+  - "git apply --whitespace=strip" removes blank lines added at
+    the end of the file.
+
+  - "git fetch" over git native protocols with "-v" option shows
+    connection status, and the IP address of the other end, to
+    help diagnosing problems.
+
+  - We used to have core.legacyheaders configuration, when
+    set to false, allowed git to write loose objects in a format
+    that mimics the format used by objects stored in packs.  It
+    turns out that this was not so useful.  Although we will
+    continue to read objects written in that format, we do not
+    honor that configuration anymore and create loose objects in
+    the legacy/traditional format.
+
+  - "--find-copies-harder" option to diff family can now be
+    spelled as "-C -C" for brevity.
+
+  - "git mailsplit" (hence "git am") can read from Maildir
+    formatted mailboxes.
+
+  - "git cvsserver" does not barf upon seeing "cvs login"
+    request.
+
+  - "pack-objects" honors "delta" attribute set in
+    .gitattributes.  It does not attempt to deltify blobs that
+    come from paths with delta attribute set to false.
+
+  - "new-workdir" script (in contrib) can now be used with a
+    bare repository.
+
+  - "git mergetool" learned to use gvimdiff.
+
+  - "gitview" (in contrib) has a better blame interface.
+
+  - "git log" and friends did not handle a commit log message
+    that is larger than 16kB; they do now.
+
+  - "--pretty=oneline" output format for "git log" and friends
+    deals with "malformed" commit log messages that have more
+    than one lines in the first paragraph better.  We used to
+    show the first line, cutting the title at mid-sentence; we
+    concatenate them into a single line and treat the result as
+    "oneline".
+
+  - "git p4import" has been demoted to contrib status.  For
+    a superior option, checkout the "git p4" front end to
+    "git fast-import" (also in contrib).  The man page and p4
+    rpm have been removed as well.
+
+  - "git mailinfo" (hence "am") now tries to see if the message
+    is in utf-8 first, instead of assuming iso-8859-1, if
+    incoming e-mail does not say what encoding it is in.
+
+* Builds
+
+  - old-style function definitions (most notably, a function
+    without parameter defined with "func()", not "func(void)")
+    have been eradicated.
+
+  - "git tag" and "git verify-tag" have been rewritten in C.
+
+* Performance Tweaks
+
+  - "git pack-objects" avoids re-deltification cost by caching
+    small enough delta results it creates while looking for the
+    best delta candidates.
+
+  - "git pack-objects" learned a new heuristic to prefer delta
+    that is shallower in depth over the smallest delta
+    possible.  This improves both overall packfile access
+    performance and packfile density.
+
+  - diff-delta code that is used for packing has been improved
+    to work better on big files.
+
+  - when there are more than one pack files in the repository,
+    the runtime used to try finding an object always from the
+    newest packfile; it now tries the same packfile as we found
+    the object requested the last time, which exploits the
+    locality of references.
+
+  - verifying pack contents done by "git fsck --full" got boost
+    by carefully choosing the order to verify objects in them.
+
+  - "git read-tree -m" to read into an already populated index
+    has been optimized vastly.  The effect of this can be seen
+    when switching branches that have differences in only a
+    handful paths.
+
+  - "git add paths..." and "git commit paths..." has also been
+    heavily optimized.
+
+Fixes since v1.5.2
+------------------
+
+All of the fixes in v1.5.2 maintenance series are included in
+this release, unless otherwise noted.
+
+* Bugfixes
+
+  - "gitweb" had trouble handling non UTF-8 text with older
+    Encode.pm Perl module.
+
+  - "git svn" misparsed the data from the commits in the repository when
+    the user had "color.diff = true" in the configuration.  This has been
+    fixed.
+
+  - There was a case where "git svn dcommit" clobbered changes made on the
+    SVN side while committing multiple changes.
+
+  - "git-write-tree" had a bad interaction with racy-git avoidance and
+    gitattributes mechanisms.
+
+  - "git --bare command" overrode existing GIT_DIR setting and always
+    made it treat the current working directory as GIT_DIR.
+
+  - "git ls-files --error-unmatch" does not complain if you give the
+    same path pattern twice by mistake.
+
+  - "git init" autodetected core.filemode but not core.symlinks, which
+    made a new directory created automatically by "git clone" cumbersome
+    to use on filesystems that require these configurations to be set.
+
+  - "git log" family of commands behaved differently when run as "git
+    log" (no pathspec) and as "git log --" (again, no pathspec).  This
+    inconsistency was introduced somewhere in v1.3.0 series but now has
+    been corrected.
+
+  - "git rebase -m" incorrectly displayed commits that were skipped.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.1.txt b/third_party/git/Documentation/RelNotes/1.5.4.1.txt
new file mode 100644
index 0000000000..d4e44b8b09
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.1.txt
@@ -0,0 +1,17 @@
+GIT v1.5.4.1 Release Notes
+==========================
+
+Fixes since v1.5.4
+------------------
+
+ * "git-commit -C $tag" used to work but rewrite in C done in
+   1.5.4 broke it.
+
+ * An entry in the .gitattributes file that names a pattern in a
+   subdirectory of the directory it is in did not match
+   correctly (e.g. pattern "b/*.c" in "a/.gitattributes" should
+   match "a/b/foo.c" but it didn't).
+
+ * Customized color specification was parsed incorrectly when
+   numeric color values are used.  This was fixed in 1.5.4.1.
+
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.2.txt b/third_party/git/Documentation/RelNotes/1.5.4.2.txt
new file mode 100644
index 0000000000..21d0df59fb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.2.txt
@@ -0,0 +1,43 @@
+GIT v1.5.4.2 Release Notes
+==========================
+
+Fixes since v1.5.4
+------------------
+
+ * The configuration parser was not prepared to see string
+   valued variables misspelled as boolean and segfaulted.
+
+ * Temporary files left behind due to interrupted object
+   transfers were not cleaned up with "git prune".
+
+ * "git config --unset" was confused when the unset variables
+   were spelled with continuation lines in the config file.
+
+ * The merge message detection in "git cvsimport" did not catch
+   a message that began with "Merge...".
+
+ * "git status" suggests "git rm --cached" for unstaging the
+   earlier "git add" before the initial commit.
+
+ * "git status" output was incorrect during a partial commit.
+
+ * "git bisect" refused to start when the HEAD was detached.
+
+ * "git bisect" allowed a wildcard character in the commit
+   message expanded while writing its log file.
+
+ * Manual pages were not formatted correctly with docbook xsl
+   1.72; added a workaround.
+
+ * "git-commit -C $tag" used to work but rewrite in C done in
+   1.5.4 broke it.  This was fixed in 1.5.4.1.
+
+ * An entry in the .gitattributes file that names a pattern in a
+   subdirectory of the directory it is in did not match
+   correctly (e.g. pattern "b/*.c" in "a/.gitattributes" should
+   match "a/b/foo.c" but it didn't).  This was fixed in 1.5.4.1.
+
+ * Customized color specification was parsed incorrectly when
+   numeric color values are used.  This was fixed in 1.5.4.1.
+
+ * http transport misbehaved when linked with curl-gnutls.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.3.txt b/third_party/git/Documentation/RelNotes/1.5.4.3.txt
new file mode 100644
index 0000000000..b0fc67fb2a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.3.txt
@@ -0,0 +1,27 @@
+GIT v1.5.4.3 Release Notes
+==========================
+
+Fixes since v1.5.4.2
+--------------------
+
+ * RPM spec used to pull in everything with 'git'.  This has been
+   changed so that 'git' package contains just the core parts,
+   and we now supply 'git-all' metapackage to slurp in everything.
+   This should match end user's expectation better.
+
+ * When some refs failed to update, git-push reported "failure"
+   which was unclear if some other refs were updated or all of
+   them failed atomically (the answer is the former).  Reworded
+   the message to clarify this.
+
+ * "git clone" from a repository whose HEAD was misconfigured
+   did not set up the remote properly.  Now it tries to do
+   better.
+
+ * Updated git-push documentation to clarify what "matching"
+   means, in order to reduce user confusion.
+
+ * Updated git-add documentation to clarify "add -u" operates in
+   the current subdirectory you are in, just like other commands.
+
+ * git-gui updates to work on OSX and Windows better.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.4.txt b/third_party/git/Documentation/RelNotes/1.5.4.4.txt
new file mode 100644
index 0000000000..323c1a88c7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.4.txt
@@ -0,0 +1,66 @@
+GIT v1.5.4.4 Release Notes
+==========================
+
+Fixes since v1.5.4.3
+--------------------
+
+ * Building and installing with an overtight umask such as 077 made
+   installed templates unreadable by others, while the rest of the install
+   are done in a way that is friendly to umask 022.
+
+ * "git cvsexportcommit -w $cvsdir" misbehaved when GIT_DIR is set to a
+   relative directory.
+
+ * "git http-push" had an invalid memory access that could lead it to
+   segfault.
+
+ * When "git rebase -i" gave control back to the user for a commit that is
+   marked to be edited, it just said "modify it with commit --amend",
+   without saying what to do to continue after modifying it.  Give an
+   explicit instruction to run "rebase --continue" to be more helpful.
+
+ * "git send-email" in 1.5.4.3 issued a bogus empty In-Reply-To: header.
+
+ * "git bisect" showed mysterious "won't bisect on seeked tree" error message.
+   This was leftover from Cogito days to prevent "bisect" starting from a
+   cg-seeked state.  We still keep the Cogito safety, but running "git bisect
+   start" when another bisect was in effect will clean up and start over.
+
+ * "git push" with an explicit PATH to receive-pack did not quite work if
+   receive-pack was not on usual PATH.  We earlier fixed the same issue
+   with "git fetch" and upload-pack, but somehow forgot to do so in the
+   other direction.
+
+ * git-gui's info dialog was not displayed correctly when the user tries
+   to commit nothing (i.e. without staging anything).
+
+ * "git revert" did not properly fail when attempting to run with a
+   dirty index.
+
+ * "git merge --no-commit --no-ff <other>" incorrectly made commits.
+
+ * "git merge --squash --no-ff <other>", which is a nonsense combination
+   of options, was not rejected.
+
+ * "git ls-remote" and "git remote show" against an empty repository
+   failed, instead of just giving an empty result (regression).
+
+ * "git fast-import" did not handle a renamed path whose name needs to be
+   quoted, due to a bug in unquote_c_style() function.
+
+ * "git cvsexportcommit" was confused when multiple files with the same
+   basename needed to be pushed out in the same commit.
+
+ * "git daemon" did not send early errors to syslog.
+
+ * "git log --merge" did not work well with --left-right option.
+
+ * "git svn" prompted for client cert password every time it accessed the
+   server.
+
+ * The reset command in "git fast-import" data stream was documented to
+   end with an optional LF, but it actually required one.
+
+ * "git svn dcommit/rebase" did not honor --rewrite-root option.
+
+Also included are a handful documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.5.txt b/third_party/git/Documentation/RelNotes/1.5.4.5.txt
new file mode 100644
index 0000000000..bbd130e36d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.5.txt
@@ -0,0 +1,56 @@
+GIT v1.5.4.5 Release Notes
+==========================
+
+Fixes since v1.5.4.4
+--------------------
+
+ * "git fetch there" when the URL information came from the Cogito style
+   branches/there file did not update refs/heads/there (regression in
+   1.5.4).
+
+ * Bogus refspec configuration such as "remote.there.fetch = =" were not
+   detected as errors (regression in 1.5.4).
+
+ * You couldn't specify a custom editor whose path contains a whitespace
+   via GIT_EDITOR (and core.editor).
+
+ * The subdirectory filter to "git filter-branch" mishandled a history
+   where the subdirectory becomes empty and then later becomes non-empty.
+
+ * "git shortlog" gave an empty line if the original commit message was
+   malformed (e.g. a botched import from foreign SCM).  Now it finds the
+   first non-empty line and uses it for better information.
+
+ * When the user fails to give a revision parameter to "git svn", an error
+   from the Perl interpreter was issued because the script lacked proper
+   error checking.
+
+ * After "git rebase" stopped due to conflicts, if the user played with
+   "git reset" and friends, "git rebase --abort" failed to go back to the
+   correct commit.
+
+ * Additional work trees prepared with git-new-workdir (in contrib/) did
+   not share git-svn metadata directory .git/svn with the original.
+
+ * "git-merge-recursive" did not mark addition of the same path with
+   different filemodes correctly as a conflict.
+
+ * "gitweb" gave malformed URL when pathinfo stype paths are in use.
+
+ * "-n" stands for "--no-tags" again for "git fetch".
+
+ * "git format-patch" did not detect the need to add 8-bit MIME header
+   when the user used format.header configuration.
+
+ * "rev~" revision specifier used to mean "rev", which was inconsistent
+   with how "rev^" worked.  Now "rev~" is the same as "rev~1" (hence it
+   also is the same as "rev^1"), and "rev~0" is the same as "rev^0"
+   (i.e. it has to be a commit).
+
+ * "git quiltimport" did not grok empty lines, lines in "file -pNNN"
+   format to specify the prefix levels and lines with trailing comments.
+
+ * "git rebase -m" triggered pre-commit verification, which made
+   "rebase --continue" impossible.
+
+As usual, it also comes with many documentation fixes and clarifications.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.6.txt b/third_party/git/Documentation/RelNotes/1.5.4.6.txt
new file mode 100644
index 0000000000..3e3c3e55a3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.6.txt
@@ -0,0 +1,43 @@
+GIT v1.5.4.6 Release Notes
+==========================
+
+I personally do not think there is any reason anybody should want to
+run v1.5.4.X series these days, because 'master' version is always
+more stable than any tagged released version of git.
+
+This is primarily to futureproof "git-shell" to accept requests
+without a dash between "git" and subcommand name (e.g. "git
+upload-pack") which the newer client will start to make sometime in
+the future.
+
+Fixes since v1.5.4.5
+--------------------
+
+ * Command line option "-n" to "git-repack" was not correctly parsed.
+
+ * Error messages from "git-apply" when the patchfile cannot be opened
+   have been improved.
+
+ * Error messages from "git-bisect" when given nonsense revisions have
+   been improved.
+
+ * reflog syntax that uses time e.g. "HEAD@{10 seconds ago}:path" did not
+   stop parsing at the closing "}".
+
+ * "git rev-parse --symbolic-full-name ^master^2" printed solitary "^",
+   but it should print nothing.
+
+ * "git apply" did not enforce "match at the beginning" correctly.
+
+ * a path specification "a/b" in .gitattributes file should not match
+   "sub/a/b", but it did.
+
+ * "git log --date-order --topo-order" did not override the earlier
+   date-order with topo-order as expected.
+
+ * "git fast-export" did not export octopus merges correctly.
+
+ * "git archive --prefix=$path/" mishandled gitattributes.
+
+As usual, it also comes with many documentation fixes and clarifications.
+
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.7.txt b/third_party/git/Documentation/RelNotes/1.5.4.7.txt
new file mode 100644
index 0000000000..9065a0e273
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.7.txt
@@ -0,0 +1,10 @@
+GIT v1.5.4.7 Release Notes
+==========================
+
+Fixes since 1.5.4.7
+-------------------
+
+ * Removed support for an obsolete gitweb request URI, whose
+   implementation ran "git diff" Porcelain, instead of using plumbing,
+   which would have run an external diff command specified in the
+   repository configuration as the gitweb user.
diff --git a/third_party/git/Documentation/RelNotes/1.5.4.txt b/third_party/git/Documentation/RelNotes/1.5.4.txt
new file mode 100644
index 0000000000..f1323b6174
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.4.txt
@@ -0,0 +1,377 @@
+GIT v1.5.4 Release Notes
+========================
+
+Removal
+-------
+
+ * "git svnimport" was removed in favor of "git svn".  It is still there
+   in the source tree (contrib/examples) but unsupported.
+
+ * As git-commit and git-status have been rewritten, "git runstatus"
+   helper script lost all its users and has been removed.
+
+
+Temporarily disabled
+--------------------
+
+ * "git http-push" is known not to work well with cURL library older
+   than 7.16, and we had reports of repository corruption.  It is
+   disabled on such platforms for now.  Unfortunately, 1.5.3.8 shares
+   the same issue.  In other words, this does not mean you will be
+   fine if you stick to an older git release.  For now, please do not
+   use http-push from older git with cURL older than 7.16 if you
+   value your data. A proper fix will hopefully materialize in
+   later versions.
+
+
+Deprecation notices
+-------------------
+
+ * From v1.6.0, git will by default install dashed form of commands
+   (e.g. "git-commit") outside of users' normal $PATH, and will install
+   only selected commands ("git" itself, and "gitk") in $PATH.  This
+   implies:
+
+   - Using dashed forms of git commands (e.g. "git-commit") from the
+     command line has been informally deprecated since early 2006, but
+     now it officially is, and will be removed in the future.  Use
+     dash-less forms (e.g. "git commit") instead.
+
+   - Using dashed forms from your scripts, without first prepending the
+     return value from "git --exec-path" to the scripts' PATH, has been
+     informally deprecated since early 2006, but now it officially is.
+
+   - Use of dashed forms with "PATH=$(git --exec-path):$PATH; export
+     PATH" early in your script is not deprecated with this change.
+
+   Users are strongly encouraged to adjust their habits and scripts now
+   to prepare for this change.
+
+ * The post-receive hook was introduced in March 2007 to supersede
+   the post-update hook, primarily to overcome the command line length
+   limitation of the latter.  Use of post-update hook will be deprecated
+   in future versions of git, starting from v1.6.0.
+
+ * "git lost-found" was deprecated in favor of "git fsck"'s --lost-found
+   option, and will be removed in the future.
+
+ * "git peek-remote" is deprecated, as "git ls-remote" was written in C
+   and works for all transports; "git peek-remote" will be removed in
+   the future.
+
+ * "git repo-config" which was an old name for "git config" command
+   has been supported without being advertised for a long time.  The
+   next feature release will remove it.
+
+ * From v1.6.0, the repack.usedeltabaseoffset config option will default
+   to true, which will give denser packfiles (i.e. more efficient storage).
+   The downside is that git older than version 1.4.4 will not be able
+   to directly use a repository packed using this setting.
+
+ * From v1.6.0, the pack.indexversion config option will default to 2,
+   which is slightly more efficient, and makes repacking more immune to
+   data corruptions.  Git older than version 1.5.2 may revert to version 1
+   of the pack index with a manual "git index-pack" to be able to directly
+   access corresponding pack files.
+
+
+Updates since v1.5.3
+--------------------
+
+ * Comes with much improved gitk, with i18n.
+
+ * Comes with git-gui 0.9.2 with i18n.
+
+ * gitk is now merged as a subdirectory of git.git project, in
+   preparation for its i18n.
+
+ * progress displays from many commands are a lot nicer to the eye.
+   Transfer commands show throughput data.
+
+ * many commands that pay attention to per-directory .gitignore now do
+   so lazily, which makes the usual case go much faster.
+
+ * Output processing for '--pretty=format:<user format>' has been
+   optimized.
+
+ * Rename detection of diff family while detecting exact matches has
+   been greatly optimized.
+
+ * Rename detection of diff family tries to make more natural looking
+   pairing.  Earlier, if multiple identical rename sources were
+   found in the preimage, the source used was picked pretty much at random.
+
+ * Value "true" for color.diff and color.status configuration used to
+   mean "always" (even when the output is not going to a terminal).
+   This has been corrected to mean the same thing as "auto".
+
+ * "git diff" Porcelain now respects diff.external configuration, which
+   is another way to specify GIT_EXTERNAL_DIFF.
+
+ * "git diff" can be told to use different prefixes other than
+   "a/" and "b/" e.g. "git diff --src-prefix=l/ --dst-prefix=k/".
+
+ * "git diff" sometimes did not quote paths with funny
+   characters properly.
+
+ * "git log" (and any revision traversal commands) misbehaved
+   when --diff-filter is given but was not asked to actually
+   produce diff.
+
+ * HTTP proxy can be specified per remote repository using
+   remote.*.httpproxy configuration, or global http.proxy configuration
+   variable.
+
+ * Various Perforce importer updates.
+
+ * Example update and post-receive hooks have been improved.
+
+ * Any command that wants to take a commit object name can now use
+   ":/string" syntax to name a commit.
+
+ * "git reset" is now built-in and its output can be squelched with -q.
+
+ * "git reset --hard" does not make any sense in a bare
+   repository, but did not error out; fixed.
+
+ * "git send-email" can optionally talk over ssmtp and use SMTP-AUTH.
+
+ * "git rebase" learned --whitespace option.
+
+ * In "git rebase", when you decide not to replay a particular change
+   after the command stopped with a conflict, you can say "git rebase
+   --skip" without first running "git reset --hard", as the command now
+   runs it for you.
+
+ * "git rebase --interactive" mode can now work on detached HEAD.
+
+ * Other minor to serious bugs in "git rebase -i" have been fixed.
+
+ * "git rebase" now detaches head during its operation, so after a
+   successful "git rebase" operation, the reflog entry branch@{1} for
+   the current branch points at the commit before the rebase was
+   started.
+
+ * "git rebase -i" also triggers rerere to help your repeated merges.
+
+ * "git merge" can call the "post-merge" hook.
+
+ * "git pack-objects" can optionally run deltification with multiple
+   threads.
+
+ * "git archive" can optionally substitute keywords in files marked with
+   export-subst attribute.
+
+ * "git cherry-pick" made a misguided attempt to repeat the original
+   command line in the generated log message, when told to cherry-pick a
+   commit by naming a tag that points at it.  It does not anymore.
+
+ * "git for-each-ref" learned %(xxxdate:<date-format>) syntax to show the
+   various date fields in different formats.
+
+ * "git gc --auto" is a low-impact way to automatically run a variant of
+   "git repack" that does not lose unreferenced objects (read: safer
+   than the usual one) after the user accumulates too many loose
+   objects.
+
+ * "git clean" has been rewritten in C.
+
+ * You need to explicitly set clean.requireForce to "false" to allow
+   "git clean" without -f to do any damage (lack of the configuration
+   variable used to mean "do not require -f option to lose untracked
+   files", but we now use the safer default).
+
+ * The kinds of whitespace errors "git diff" and "git apply" notice (and
+   fix) can be controlled via 'core.whitespace' configuration variable
+   and 'whitespace' attribute in .gitattributes file.
+
+ * "git push" learned --dry-run option to show what would happen if a
+   push is run.
+
+ * "git push" does not update a tracking ref on the local side when the
+   remote refused to update the corresponding ref.
+
+ * "git push" learned --mirror option.  This is to push the local refs
+   one-to-one to the remote, and deletes refs from the remote that do
+   not exist anymore in the repository on the pushing side.
+
+ * "git push" can remove a corrupt ref at the remote site with the usual
+   ":ref" refspec.
+
+ * "git remote" knows --mirror mode.  This is to set up configuration to
+   push into a remote repository to store local branch heads to the same
+   branch on the remote side, and remove branch heads locally removed
+   from local repository at the same time.  Suitable for pushing into a
+   back-up repository.
+
+ * "git remote" learned "rm" subcommand.
+
+ * "git cvsserver" can be run via "git shell".  Also, "cvs" is
+   recognized as a synonym for "git cvsserver", so that CVS users
+   can be switched to git just by changing their login shell.
+
+ * "git cvsserver" acts more like receive-pack by running post-receive
+   and post-update hooks.
+
+ * "git am" and "git rebase" are far less verbose.
+
+ * "git pull" learned to pass --[no-]ff option to underlying "git
+   merge".
+
+ * "git pull --rebase" is a different way to integrate what you fetched
+   into your current branch.
+
+ * "git fast-export" produces data-stream that can be fed to fast-import
+   to reproduce the history recorded in a git repository.
+
+ * "git add -i" takes pathspecs to limit the set of files to work on.
+
+ * "git add -p" is a short-hand to go directly to the selective patch
+   subcommand in the interactive command loop and to exit when done.
+
+ * "git add -i" UI has been colorized.  The interactive prompt
+   and menu can be colored by setting color.interactive
+   configuration.  The diff output (including the hunk picker)
+   are colored with color.diff configuration.
+
+ * "git commit --allow-empty" allows you to create a single-parent
+   commit that records the same tree as its parent, overriding the usual
+   safety valve.
+
+ * "git commit --amend" can amend a merge that does not change the tree
+   from its first parent.
+
+ * "git commit" used to unconditionally strip comment lines that
+   began with '#' and removed excess blank lines.  This behavior has
+   been made configurable.
+
+ * "git commit" has been rewritten in C.
+
+ * "git stash random-text" does not create a new stash anymore.  It was
+   a UI mistake.  Use "git stash save random-text", or "git stash"
+   (without extra args) for that.
+
+ * "git stash clear extra-text" does not clear the whole stash
+   anymore.  It is tempting to expect "git stash clear stash@{2}"
+   to drop only a single named stash entry, and it is rude to
+   discard everything when that is asked (but not provided).
+
+ * "git prune --expire <time>" can exempt young loose objects from
+   getting pruned.
+
+ * "git branch --contains <commit>" can list branches that are
+   descendants of a given commit.
+
+ * "git log" learned --early-output option to help interactive GUI
+   implementations.
+
+ * "git bisect" learned "skip" action to mark untestable commits.
+
+ * "git bisect visualize" learned a shorter synonym "git bisect view".
+
+ * "git bisect visualize" runs "git log" in a non-windowed
+   environments.  It also can be told what command to run (e.g. "git
+   bisect visualize tig").
+
+ * "git format-patch" learned "format.numbered" configuration variable
+   to automatically turn --numbered option on when more than one commits
+   are formatted.
+
+ * "git ls-files" learned "--exclude-standard" to use the canned set of
+   exclude files.
+
+ * "git tag -a -f existing" begins the editor session using the existing
+   annotation message.
+
+ * "git tag -m one -m bar" (multiple -m options) behaves similarly to
+   "git commit"; the parameters to -m options are formatted as separate
+   paragraphs.
+
+ * The format "git show" outputs an annotated tag has been updated to
+   include "Tagger: " and "Date: " lines from the tag itself.  Strictly
+   speaking this is a backward incompatible change, but this is a
+   reasonable usability fix and people's scripts shouldn't have been
+   relying on the exact output from "git show" Porcelain anyway.
+
+ * "git cvsimport" did not notice errors from underlying "cvsps"
+   and produced a corrupt import silently.
+
+ * "git cvsexportcommit" learned -w option to specify and switch to the
+   CVS working directory.
+
+ * "git checkout" from a subdirectory learned to use "../path" to allow
+   checking out a path outside the current directory without cd'ing up.
+
+ * "git checkout" from and to detached HEAD leaves a bit more
+   information in the reflog.
+
+ * "git send-email --dry-run" shows full headers for easier diagnosis.
+
+ * "git merge-ours" is now built-in.
+
+ * "git svn" learned "info" and "show-externals" subcommands.
+
+ * "git svn" run from a subdirectory failed to read settings from the
+   .git/config.
+
+ * "git svn" learned --use-log-author option, which picks up more
+   descriptive name from From: and Signed-off-by: lines in the commit
+   message.
+
+ * "git svn" wasted way too much disk to record revision mappings
+   between svn and git; a new representation that is much more compact
+   for this information has been introduced to correct this.
+
+ * "git svn" left temporary index files it used without cleaning them
+   up; this was corrected.
+
+ * "git status" from a subdirectory now shows relative paths, which
+   makes copy-and-pasting for git-checkout/git-add/git-rm easier.  The
+   traditional behavior to show the full path relative to the top of
+   the work tree can be had by setting status.relativepaths
+   configuration variable to false.
+
+ * "git blame" kept text for each annotated revision in core needlessly;
+   this has been corrected.
+
+ * "git shortlog" learned to default to HEAD when the standard input is
+   a terminal and the user did not give any revision parameter.
+
+ * "git shortlog" learned "-e" option to show e-mail addresses as well as
+   authors' names.
+
+ * "git help" learned "-w" option to show documentation in browsers.
+
+ * In addition there are quite a few internal clean-ups. Notably:
+
+   - many fork/exec have been replaced with run-command API,
+     brought from the msysgit effort.
+
+   - introduction and more use of the option parser API.
+
+   - enhancement and more use of the strbuf API.
+
+ * Makefile tweaks to support HP-UX is in.
+
+Fixes since v1.5.3
+------------------
+
+All of the fixes in v1.5.3 maintenance series are included in
+this release, unless otherwise noted.
+
+These fixes are only in v1.5.4 and not backported to v1.5.3 maintenance
+series.
+
+ * The way "git diff --check" behaves is much more consistent with the way
+   "git apply --whitespace=warn" works.
+
+ * "git svn" talking with the SVN over HTTP will correctly quote branch
+   and project names.
+
+ * "git config" did not work correctly on platforms that define
+   REG_NOMATCH to an even number.
+
+ * Recent versions of AsciiDoc 8 has a change to break our
+   documentation; a workaround has been implemented.
+
+ * "git diff --color-words" colored context lines in a wrong color.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.1.txt b/third_party/git/Documentation/RelNotes/1.5.5.1.txt
new file mode 100644
index 0000000000..7de419708f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.1.txt
@@ -0,0 +1,44 @@
+GIT v1.5.5.1 Release Notes
+==========================
+
+Fixes since v1.5.5
+------------------
+
+ * "git archive --prefix=$path/" mishandled gitattributes.
+
+ * "git fetch -v" that fetches into FETCH_HEAD did not report the summary
+   the same way as done for updating the tracking refs.
+
+ * "git svn" misbehaved when the configuration file customized the "git
+   log" output format using format.pretty.
+
+ * "git submodule status" leaked an unnecessary error message.
+
+ * "git log --date-order --topo-order" did not override the earlier
+   date-order with topo-order as expected.
+
+ * "git bisect good $this" did not check the validity of the revision
+   given properly.
+
+ * "url.<there>.insteadOf" did not work correctly.
+
+ * "git clean" ran inside subdirectory behaved as if the directory was
+   explicitly specified for removal by the end user from the top level.
+
+ * "git bisect" from a detached head leaked an unnecessary error message.
+
+ * "git bisect good $a $b" when $a is Ok but $b is bogus should have
+   atomically failed before marking $a as good.
+
+ * "git fmt-merge-msg" did not clean up leading empty lines from commit
+   log messages like "git log" family does.
+
+ * "git am" recorded a commit with empty Subject: line without
+   complaining.
+
+ * when given a commit log message whose first paragraph consists of
+   multiple lines, "git rebase" squashed it into a single line.
+
+ * "git remote add $bogus_name $url" did not complain properly.
+
+Also comes with various documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.2.txt b/third_party/git/Documentation/RelNotes/1.5.5.2.txt
new file mode 100644
index 0000000000..391a7b02ea
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.2.txt
@@ -0,0 +1,27 @@
+GIT v1.5.5.2 Release Notes
+==========================
+
+Fixes since v1.5.5.1
+--------------------
+
+ * "git repack -n" was mistakenly made no-op earlier.
+
+ * "git imap-send" wanted to always have imap.host even when use of
+   imap.tunnel made it unnecessary.
+
+ * reflog syntax that uses time e.g. "HEAD@{10 seconds ago}:path" did not
+   stop parsing at the closing "}".
+
+ * "git rev-parse --symbolic-full-name ^master^2" printed solitary "^",
+   but it should print nothing.
+
+ * "git commit" did not detect when it failed to write tree objects.
+
+ * "git fetch" sometimes transferred too many objects unnecessarily.
+
+ * a path specification "a/b" in .gitattributes file should not match
+   "sub/a/b".
+
+ * various gitweb fixes.
+
+Also comes with various documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.3.txt b/third_party/git/Documentation/RelNotes/1.5.5.3.txt
new file mode 100644
index 0000000000..f22f98b734
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.3.txt
@@ -0,0 +1,12 @@
+GIT v1.5.5.3 Release Notes
+==========================
+
+Fixes since v1.5.5.2
+--------------------
+
+ * "git send-email --compose" did not notice that non-ascii contents
+   needed some MIME magic.
+
+ * "git fast-export" did not export octopus merges correctly.
+
+Also comes with various documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.4.txt b/third_party/git/Documentation/RelNotes/1.5.5.4.txt
new file mode 100644
index 0000000000..2d0279ecce
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.4.txt
@@ -0,0 +1,7 @@
+GIT v1.5.5.4 Release Notes
+==========================
+
+Fixes since v1.5.5.4
+--------------------
+
+ * "git name-rev --all" used to segfault.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.5.txt b/third_party/git/Documentation/RelNotes/1.5.5.5.txt
new file mode 100644
index 0000000000..30fa3615c7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.5.txt
@@ -0,0 +1,11 @@
+GIT v1.5.5.5 Release Notes
+==========================
+
+I personally do not think there is any reason anybody should want to
+run v1.5.5.X series these days, because 'master' version is always
+more stable than any tagged released version of git.
+
+This is primarily to futureproof "git-shell" to accept requests
+without a dash between "git" and subcommand name (e.g. "git
+upload-pack") which the newer client will start to make sometime in
+the future.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.6.txt b/third_party/git/Documentation/RelNotes/1.5.5.6.txt
new file mode 100644
index 0000000000..d5e85cb70e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.6.txt
@@ -0,0 +1,10 @@
+GIT v1.5.5.6 Release Notes
+==========================
+
+Fixes since 1.5.5.5
+-------------------
+
+ * Removed support for an obsolete gitweb request URI, whose
+   implementation ran "git diff" Porcelain, instead of using plumbing,
+   which would have run an external diff command specified in the
+   repository configuration as the gitweb user.
diff --git a/third_party/git/Documentation/RelNotes/1.5.5.txt b/third_party/git/Documentation/RelNotes/1.5.5.txt
new file mode 100644
index 0000000000..2932212488
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.5.txt
@@ -0,0 +1,207 @@
+GIT v1.5.5 Release Notes
+========================
+
+Updates since v1.5.4
+--------------------
+
+(subsystems)
+
+ * Comes with git-gui 0.10.1
+
+(portability)
+
+ * We shouldn't ask for BSD group ownership semantics by setting g+s bit
+   on directories on older BSD systems that refuses chmod() by non root
+   users.  BSD semantics is the default there anyway.
+
+ * Bunch of portability improvement patches coming from an effort to port
+   to Solaris has been applied.
+
+(performance)
+
+ * On platforms with suboptimal qsort(3) implementation, there
+   is an option to use more reasonable substitute we ship with
+   our software.
+
+ * New configuration variable "pack.packsizelimit" can be used
+   in place of command line option --max-pack-size.
+
+ * "git fetch" over the native git protocol used to make a
+   connection to find out the set of current remote refs and
+   another to actually download the pack data.  We now use only
+   one connection for these tasks.
+
+ * "git commit" does not run lstat(2) more than necessary
+   anymore.
+
+(usability, bells and whistles)
+
+ * Bash completion script (in contrib) are aware of more commands and
+   options.
+
+ * You can be warned when core.autocrlf conversion is applied in
+   such a way that results in an irreversible conversion.
+
+ * A catch-all "color.ui" configuration variable can be used to
+   enable coloring of all color-capable commands, instead of
+   individual ones such as "color.status" and "color.branch".
+
+ * The commands refused to take absolute pathnames where they
+   require pathnames relative to the work tree or the current
+   subdirectory.  They now can take absolute pathnames in such a
+   case as long as the pathnames do not refer outside of the
+   work tree.  E.g. "git add $(pwd)/foo" now works.
+
+ * Error messages used to be sent to stderr, only to get hidden,
+   when $PAGER was in use.  They now are sent to stdout along
+   with the command output to be shown in the $PAGER.
+
+ * A pattern "foo/" in .gitignore file now matches a directory
+   "foo".  Pattern "foo" also matches as before.
+
+ * bash completion's prompt helper function can talk about
+   operation in-progress (e.g. merge, rebase, etc.).
+
+ * Configuration variables "url.<usethis>.insteadof = <otherurl>" can be
+   used to tell "git-fetch" and "git-push" to use different URL than what
+   is given from the command line.
+
+ * "git add -i" behaves better even before you make an initial commit.
+
+ * "git am" refused to run from a subdirectory without a good reason.
+
+ * After "git apply --whitespace=fix" fixes whitespace errors in a patch,
+   a line before the fix can appear as a context or preimage line in a
+   later patch, causing the patch not to apply.  The command now knows to
+   see through whitespace fixes done to context lines to successfully
+   apply such a patch series.
+
+ * "git branch" (and "git checkout -b") to branch from a local branch can
+   optionally set "branch.<name>.merge" to mark the new branch to build on
+   the other local branch, when "branch.autosetupmerge" is set to
+   "always", or when passing the command line option "--track" (this option
+   was ignored when branching from local branches).  By default, this does
+   not happen when branching from a local branch.
+
+ * "git checkout" to switch to a branch that has "branch.<name>.merge" set
+   (i.e. marked to build on another branch) reports how much the branch
+   and the other branch diverged.
+
+ * When "git checkout" has to update a lot of paths, it used to be silent
+   for 4 seconds before it showed any progress report.  It is now a bit
+   more impatient and starts showing progress report early.
+
+ * "git commit" learned a new hook "prepare-commit-msg" that can
+   inspect what is going to be committed and prepare the commit
+   log message template to be edited.
+
+ * "git cvsimport" can now take more than one -M options.
+
+ * "git describe" learned to limit the tags to be used for
+   naming with --match option.
+
+ * "git describe --contains" now barfs when the named commit
+   cannot be described.
+
+ * "git describe --exact-match" describes only commits that are tagged.
+
+ * "git describe --long" describes a tagged commit as $tag-0-$sha1,
+   instead of just showing the exact tagname.
+
+ * "git describe" warns when using a tag whose name and path contradict
+   with each other.
+
+ * "git diff" learned "--relative" option to limit and output paths
+   relative to the current directory when working in a subdirectory.
+
+ * "git diff" learned "--dirstat" option to show birds-eye-summary of
+   changes more concisely than "--diffstat".
+
+ * "git format-patch" learned --cover-letter option to generate a cover
+   letter template.
+
+ * "git gc" learned --quiet option.
+
+ * "git gc" now automatically prunes unreachable objects that are two
+   weeks old or older.
+
+ * "git gc --auto" can be disabled more easily by just setting gc.auto
+   to zero.  It also tolerates more packfiles by default.
+
+ * "git grep" now knows "--name-only" is a synonym for the "-l" option.
+
+ * "git help <alias>" now reports "'git <alias>' is alias to <what>",
+   instead of saying "No manual entry for git-<alias>".
+
+ * "git help" can use different backends to show manual pages and this can
+   be configured using "man.viewer" configuration.
+
+ * "gitk" does not restore window position from $HOME/.gitk anymore (it
+   still restores the size).
+
+ * "git log --grep=<what>" learned "--fixed-strings" option to look for
+   <what> without treating it as a regular expression.
+
+ * "git gui" learned an auto-spell checking.
+
+ * "git push <somewhere> HEAD" and "git push <somewhere> +HEAD" works as
+   expected; they push the current branch (and only the current branch).
+   In addition, HEAD can be written as the value of "remote.<there>.push"
+   configuration variable.
+
+ * When the configuration variable "pack.threads" is set to 0, "git
+   repack" auto detects the number of CPUs and uses that many threads.
+
+ * "git send-email" learned to prompt for passwords
+   interactively.
+
+ * "git send-email" learned an easier way to suppress CC
+   recipients.
+
+ * "git stash" learned "pop" command, that applies the latest stash and
+   removes it from the stash, and "drop" command to discard the named
+   stash entry.
+
+ * "git submodule" learned a new subcommand "summary" to show the
+   symmetric difference between the HEAD version and the work tree version
+   of the submodule commits.
+
+ * Various "git cvsimport", "git cvsexportcommit", "git cvsserver",
+   "git svn" and "git p4" improvements.
+
+(internal)
+
+ * Duplicated code between git-help and git-instaweb that
+   launches user's preferred browser has been refactored.
+
+ * It is now easier to write test scripts that records known
+   breakages.
+
+ * "git checkout" is rewritten in C.
+
+ * "git remote" is rewritten in C.
+
+ * Two conflict hunks that are separated by a very short span of common
+   lines are now coalesced into one larger hunk, to make the result easier
+   to read.
+
+ * Run-command API's use of file descriptors is documented clearer and
+   is more consistent now.
+
+ * diff output can be sent to FILE * that is different from stdout.  This
+   will help reimplementing more things in C.
+
+Fixes since v1.5.4
+------------------
+
+All of the fixes in v1.5.4 maintenance series are included in
+this release, unless otherwise noted.
+
+ * "git-http-push" did not allow deletion of remote ref with the usual
+   "push <remote> :<branch>" syntax.
+
+ * "git-rebase --abort" did not go back to the right location if
+   "git-reset" was run during the "git-rebase" session.
+
+ * "git imap-send" without setting imap.host did not error out but
+   segfaulted.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.1.txt b/third_party/git/Documentation/RelNotes/1.5.6.1.txt
new file mode 100644
index 0000000000..4864b16445
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.1.txt
@@ -0,0 +1,28 @@
+GIT v1.5.6.1 Release Notes
+==========================
+
+Fixes since v1.5.6
+------------------
+
+* Last minute change broke loose object creation on AIX.
+
+* (performance fix) We used to make $GIT_DIR absolute path early in the
+  programs but keeping it relative to the current directory internally
+  gives 1-3 per-cent performance boost.
+
+* bash completion knows the new --graph option to git-log family.
+
+
+* git-diff -c/--cc showed unnecessary "deletion" lines at the context
+  boundary.
+
+* git-for-each-ref ignored %(object) and %(type) requests for tag
+  objects.
+
+* git-merge usage had a typo.
+
+* Rebuilding of git-svn metainfo database did not take rewriteRoot
+  option into account.
+
+* Running "git-rebase --continue/--skip/--abort" before starting a
+  rebase gave nonsense error messages.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.2.txt b/third_party/git/Documentation/RelNotes/1.5.6.2.txt
new file mode 100644
index 0000000000..5902a85a78
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.2.txt
@@ -0,0 +1,40 @@
+GIT v1.5.6.2 Release Notes
+==========================
+
+Futureproof
+-----------
+
+ * "git-shell" accepts requests without a dash between "git" and
+   subcommand name (e.g. "git upload-pack") which the newer client will
+   start to make sometime in the future.
+
+Fixes since v1.5.6.1
+--------------------
+
+* "git clone" from a remote that is named with url.insteadOf setting in
+  $HOME/.gitconfig did not work well.
+
+* "git describe --long --tags" segfaulted when the described revision was
+  tagged with a lightweight tag.
+
+* "git diff --check" did not report the result via its exit status
+  reliably.
+
+* When remote side used to have branch 'foo' and git-fetch finds that now
+  it has branch 'foo/bar', it refuses to lose the existing remote tracking
+  branch and its reflog.  The error message has been improved to suggest
+  pruning the remote if the user wants to proceed and get the latest set
+  of branches from the remote, including such 'foo/bar'.
+
+* "git reset file" should mean the same thing as "git reset HEAD file",
+  but we required disambiguating -- even when "file" is not ambiguous.
+
+* "git show" segfaulted when an annotated tag that points at another
+  annotated tag was given to it.
+
+* Optimization for a large import via "git-svn" introduced in v1.5.6 had a
+  serious memory and temporary file leak, which made it unusable for
+  moderately large import.
+
+* "git-svn" mangled remote nickname used in the configuration file
+  unnecessarily.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.3.txt b/third_party/git/Documentation/RelNotes/1.5.6.3.txt
new file mode 100644
index 0000000000..f61dd3504a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.3.txt
@@ -0,0 +1,52 @@
+GIT v1.5.6.3 Release Notes
+==========================
+
+Fixes since v1.5.6.2
+--------------------
+
+* Setting core.sharedrepository to traditional "true" value was supposed to make
+  the repository group writable but should not affect permission for others.
+  However, since 1.5.6, it was broken to drop permission for others when umask is
+  022, making the repository unreadable by others.
+
+* Setting GIT_TRACE will report spawning of external process via run_command().
+
+* Using an object with very deep delta chain pinned memory needed for extracting
+  intermediate base objects unnecessarily long, leading to excess memory usage.
+
+* Bash completion script did not notice '--' marker on the command
+  line and tried the relatively slow "ref completion" even when
+  completing arguments after one.
+
+* Registering a non-empty blob racily and then truncating the working
+  tree file for it confused "racy-git avoidance" logic into thinking
+  that the path is now unchanged.
+
+* The section that describes attributes related to git-archive were placed
+  in a wrong place in the gitattributes(5) manual page.
+
+* "git am" was not helpful to the users when it detected that the committer
+  information is not set up properly yet.
+
+* "git clone" had a leftover debugging fprintf().
+
+* "git clone -q" was not quiet enough as it used to and gave object count
+  and progress reports.
+
+* "git clone" marked downloaded packfile with .keep; this could be a
+  good thing if the remote side is well packed but otherwise not,
+  especially for a project that is not really big.
+
+* "git daemon" used to call syslog() from a signal handler, which
+  could raise signals of its own but generally is not reentrant.  This
+  was fixed by restructuring the code to report syslog() after the handler
+  returns.
+
+* When "git push" tries to remove a remote ref, and corresponding
+  tracking ref is missing, we used to report error (i.e. failure to
+  remove something that does not exist).
+
+* "git mailinfo" (hence "git am") did not handle commit log messages in a
+  MIME multipart mail correctly.
+
+Contains other various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.4.txt b/third_party/git/Documentation/RelNotes/1.5.6.4.txt
new file mode 100644
index 0000000000..d8968f1ecb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.4.txt
@@ -0,0 +1,47 @@
+GIT v1.5.6.4 Release Notes
+==========================
+
+Fixes since v1.5.6.3
+--------------------
+
+* Various commands could overflow its internal buffer on a platform
+  with small PATH_MAX value in a repository that has contents with
+  long pathnames.
+
+* There wasn't a way to make --pretty=format:%<> specifiers to honor
+  .mailmap name rewriting for authors and committers.  Now you can with
+  %aN and %cN.
+
+* Bash completion wasted too many cycles; this has been optimized to be
+  usable again.
+
+* Bash completion lost ref part when completing something like "git show
+  pu:Makefile".
+
+* "git-cvsserver" did not clean up its temporary working area after annotate
+  request.
+
+* "git-daemon" called syslog() from its signal handler, which was a
+  no-no.
+
+* "git-fetch" into an empty repository used to remind that the fetch will
+   be huge by saying "no common commits", but this was an unnecessary
+   noise; it is already known by the user anyway.
+
+* "git-http-fetch" would have segfaulted when pack idx file retrieved
+  from the other side was corrupt.
+
+* "git-index-pack" used too much memory when dealing with a deep delta chain.
+
+* "git-mailinfo" (hence "git-am") did not correctly handle in-body [PATCH]
+  line to override the commit title taken from the mail Subject header.
+
+* "git-rebase -i -p" lost parents that are not involved in the history
+  being rewritten.
+
+* "git-rm" lost track of where the index file was when GIT_DIR was
+  specified as a relative path.
+
+* "git-rev-list --quiet" was not quiet as advertised.
+
+Contains other various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.5.txt b/third_party/git/Documentation/RelNotes/1.5.6.5.txt
new file mode 100644
index 0000000000..47ca172462
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.5.txt
@@ -0,0 +1,29 @@
+GIT v1.5.6.5 Release Notes
+==========================
+
+Fixes since v1.5.6.4
+--------------------
+
+* "git cvsimport" used to spit out "UNKNOWN LINE..." diagnostics to stdout.
+
+* "git commit -F filename" and "git tag -F filename" run from subdirectories
+  did not read the right file.
+
+* "git init --template=" with blank "template" parameter linked files
+  under root directories to .git, which was a total nonsense.  Instead, it
+  means "I do not want to use anything from the template directory".
+
+* "git diff-tree" and other diff plumbing ignored diff.renamelimit configuration
+  variable when the user explicitly asked for rename detection.
+
+* "git name-rev --name-only" did not work when "--stdin" option was in effect.
+
+* "git show-branch" mishandled its 8th branch.
+
+* Addition of "git update-index --ignore-submodules" that happened during
+  1.5.6 cycle broke "git update-index --ignore-missing".
+
+* "git send-email" did not parse charset from an existing Content-type:
+  header properly.
+
+Contains other various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.6.txt b/third_party/git/Documentation/RelNotes/1.5.6.6.txt
new file mode 100644
index 0000000000..79da23db5a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.6.txt
@@ -0,0 +1,10 @@
+GIT v1.5.6.6 Release Notes
+==========================
+
+Fixes since 1.5.6.5
+-------------------
+
+ * Removed support for an obsolete gitweb request URI, whose
+   implementation ran "git diff" Porcelain, instead of using plumbing,
+   which would have run an external diff command specified in the
+   repository configuration as the gitweb user.
diff --git a/third_party/git/Documentation/RelNotes/1.5.6.txt b/third_party/git/Documentation/RelNotes/1.5.6.txt
new file mode 100644
index 0000000000..e143d8d61b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.5.6.txt
@@ -0,0 +1,115 @@
+GIT v1.5.6 Release Notes
+========================
+
+Updates since v1.5.5
+--------------------
+
+(subsystems)
+
+* Comes with updated gitk and git-gui.
+
+(portability)
+
+* git will build on AIX better than before now.
+
+* core.ignorecase configuration variable can be used to work better on
+  filesystems that are not case sensitive.
+
+* "git init" now autodetects the case sensitivity of the filesystem and
+  sets core.ignorecase accordingly.
+
+* cpio is no longer used; neither "curl" binary (libcurl is still used).
+
+(documentation)
+
+* Many freestanding documentation pages have been converted and made
+  available to "git help" (aka "man git<something>") as section 7 of
+  the manual pages. This means bookmarks to some HTML documentation
+  files may need to be updated (eg "tutorial.html" became
+  "gittutorial.html").
+
+(performance)
+
+* "git clone" was rewritten in C.  This will hopefully help cloning a
+  repository with insane number of refs.
+
+* "git rebase --onto $there $from $branch" used to switch to the tip of
+  $branch only to immediately reset back to $from, smudging work tree
+  files unnecessarily.  This has been optimized.
+
+* Object creation codepath in "git-svn" has been optimized by enhancing
+  plumbing commands git-cat-file and git-hash-object.
+
+(usability, bells and whistles)
+
+* "git add -p" (and the "patch" subcommand of "git add -i") can choose to
+  apply (or not apply) mode changes independently from contents changes.
+
+* "git bisect help" gives longer and more helpful usage information.
+
+* "git bisect" does not use a special branch "bisect" anymore; instead, it
+  does its work on a detached HEAD.
+
+* "git branch" (and "git checkout -b") can be told to set up
+  branch.<name>.rebase automatically, so that later you can say "git pull"
+  and magically cause "git pull --rebase" to happen.
+
+* "git branch --merged" and "git branch --no-merged" can be used to list
+  branches that have already been merged (or not yet merged) to the
+  current branch.
+
+* "git cherry-pick" and "git revert" can add a sign-off.
+
+* "git commit" mentions the author identity when you are committing
+  somebody else's changes.
+
+* "git diff/log --dirstat" output is consistent between binary and textual
+  changes.
+
+* "git filter-branch" rewrites signed tags by demoting them to annotated.
+
+* "git format-patch --no-binary" can produce a patch that lack binary
+  changes (i.e. cannot be used to propagate the whole changes) meant only
+  for reviewing.
+
+* "git init --bare" is a synonym for "git --bare init" now.
+
+* "git gc --auto" honors a new pre-auto-gc hook to temporarily disable it.
+
+* "git log --pretty=tformat:<custom format>" gives a LF after each entry,
+  instead of giving a LF between each pair of entries which is how
+  "git log --pretty=format:<custom format>" works.
+
+* "git log" and friends learned the "--graph" option to show the ancestry
+  graph at the left margin of the output.
+
+* "git log" and friends can be told to use date format that is different
+  from the default via 'log.date' configuration variable.
+
+* "git send-email" now can send out messages outside a git repository.
+
+* "git send-email --compose" was made aware of rfc2047 quoting.
+
+* "git status" can optionally include output from "git submodule
+  summary".
+
+* "git svn" learned --add-author-from option to propagate the authorship
+  by munging the commit log message.
+
+* new object creation and looking up in "git svn" has been optimized.
+
+* "gitweb" can read from a system-wide configuration file.
+
+(internal)
+
+* "git unpack-objects" and "git receive-pack" is now more strict about
+  detecting breakage in the objects they receive over the wire.
+
+
+Fixes since v1.5.5
+------------------
+
+All of the fixes in v1.5.5 maintenance series are included in
+this release, unless otherwise noted.
+
+And there are too numerous small fixes to otherwise note here ;-)
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.1.txt b/third_party/git/Documentation/RelNotes/1.6.0.1.txt
new file mode 100644
index 0000000000..49d7a1cafa
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.1.txt
@@ -0,0 +1,36 @@
+GIT v1.6.0.1 Release Notes
+==========================
+
+Fixes since v1.6.0
+------------------
+
+* "git diff --cc" did not honor content mangling specified by
+  gitattributes and core.autocrlf when reading from the work tree.
+
+* "git diff --check" incorrectly detected new trailing blank lines when
+  whitespace check was in effect.
+
+* "git for-each-ref" tried to dereference NULL when asked for '%(body)" on
+  a tag with a single incomplete line as its payload.
+
+* "git format-patch" peeked before the beginning of a string when
+  "format.headers" variable is empty (a misconfiguration).
+
+* "git help help" did not work correctly.
+
+* "git mailinfo" (hence "git am") was unhappy when MIME multipart message
+  contained garbage after the finishing boundary.
+
+* "git mailinfo" also was unhappy when the "From: " line only had a bare
+  e-mail address.
+
+* "git merge" did not refresh the index correctly when a merge resulted in
+  a fast-forward.
+
+* "git merge" did not resolve a truly trivial merges that can be done
+  without content level merges.
+
+* "git svn dcommit" to a repository with URL that has embedded usernames
+  did not work correctly.
+
+Contains other various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.2.txt b/third_party/git/Documentation/RelNotes/1.6.0.2.txt
new file mode 100644
index 0000000000..7d8fb85e1b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.2.txt
@@ -0,0 +1,81 @@
+GIT v1.6.0.2 Release Notes
+==========================
+
+Fixes since v1.6.0.1
+--------------------
+
+* Installation on platforms that needs .exe suffix to git-* programs were
+  broken in 1.6.0.1.
+
+* Installation on filesystems without symbolic links support did not
+  work well.
+
+* In-tree documentations and test scripts now use "git foo" form to set a
+  better example, instead of the "git-foo" form (which is an acceptable
+  form if you have "PATH=$(git --exec-path):$PATH" in your script)
+
+* Many commands did not use the correct working tree location when used
+  with GIT_WORK_TREE environment settings.
+
+* Some systems need to use compatibility fnmatch and regex libraries
+  independent from each other; the compat/ area has been reorganized to
+  allow this.
+
+
+* "git apply --unidiff-zero" incorrectly applied a -U0 patch that inserts
+  a new line before the second line.
+
+* "git blame -c" did not exactly work like "git annotate" when range
+  boundaries are involved.
+
+* "git checkout file" when file is still unmerged checked out contents from
+  a random high order stage, which was confusing.
+
+* "git clone $there $here/" with extra trailing slashes after explicit
+  local directory name $here did not work as expected.
+
+* "git diff" on tracked contents with CRLF line endings did not drive "less"
+  intelligently when showing added or removed lines.
+
+* "git diff --dirstat -M" did not add changes in subdirectories up
+  correctly for renamed paths.
+
+* "git diff --cumulative" did not imply "--dirstat".
+
+* "git for-each-ref refs/heads/" did not work as expected.
+
+* "git gui" allowed users to feed patch without any context to be applied.
+
+* "git gui" botched parsing "diff" output when a line that begins with two
+  dashes and a space gets removed or a line that begins with two pluses
+  and a space gets added.
+
+* "git gui" translation updates and i18n fixes.
+
+* "git index-pack" is more careful against disk corruption while completing
+  a thin pack.
+
+* "git log -i --grep=pattern" did not ignore case; neither "git log -E
+  --grep=pattern" triggered extended regexp.
+
+* "git log --pretty="%ad" --date=short" did not use short format when
+  showing the timestamp.
+
+* "git log --author=author" match incorrectly matched with the
+  timestamp part of "author " line in commit objects.
+
+* "git log -F --author=author" did not work at all.
+
+* Build procedure for "git shell" that used stub versions of some
+  functions and globals was not understood by linkers on some platforms.
+
+* "git stash" was fooled by a stat-dirty but otherwise unmodified paths
+  and refused to work until the user refreshed the index.
+
+* "git svn" was broken on Perl before 5.8 with recent fixes to reduce
+  use of temporary files.
+
+* "git verify-pack -v" did not work correctly when given more than one
+  packfile.
+
+Also contains many documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.3.txt b/third_party/git/Documentation/RelNotes/1.6.0.3.txt
new file mode 100644
index 0000000000..ae0577836a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.3.txt
@@ -0,0 +1,117 @@
+GIT v1.6.0.3 Release Notes
+==========================
+
+Fixes since v1.6.0.2
+--------------------
+
+* "git archive --format=zip" did not honor core.autocrlf while
+  --format=tar did.
+
+* Continuing "git rebase -i" was very confused when the user left modified
+  files in the working tree while resolving conflicts.
+
+* Continuing "git rebase -i" was also very confused when the user left
+  some staged changes in the index after "edit".
+
+* "git rebase -i" now honors the pre-rebase hook, just like the
+  other rebase implementations "git rebase" and "git rebase -m".
+
+* "git rebase -i" incorrectly aborted when there is no commit to replay.
+
+* Behaviour of "git diff --quiet" was inconsistent with "diff --exit-code"
+  with the output redirected to /dev/null.
+
+* "git diff --no-index" on binary files no longer outputs a bogus
+  "diff --git" header line.
+
+* "git diff" hunk header patterns with multiple elements separated by LF
+  were not used correctly.
+
+* Hunk headers in "git diff" default to using extended regular
+  expressions, fixing some of the internal patterns on non-GNU
+  platforms.
+
+* New config "diff.*.xfuncname" exposes extended regular expressions
+  for user specified hunk header patterns.
+
+* "git gc" when ejecting otherwise unreachable objects from packfiles into
+  loose form leaked memory.
+
+* "git index-pack" was recently broken and mishandled objects added by
+  thin-pack completion processing under memory pressure.
+
+* "git index-pack" was recently broken and misbehaved when run from inside
+  .git/objects/pack/ directory.
+
+* "git stash apply sash@{1}" was fixed to error out.  Prior versions
+  would have applied stash@{0} incorrectly.
+
+* "git stash apply" now offers a better suggestion on how to continue
+  if the working tree is currently dirty.
+
+* "git for-each-ref --format=%(subject)" fixed for commits with no
+  no newline in the message body.
+
+* "git remote" fixed to protect printf from user input.
+
+* "git remote show -v" now displays all URLs of a remote.
+
+* "git checkout -b branch" was confused when branch already existed.
+
+* "git checkout -q" once again suppresses the locally modified file list.
+
+* "git clone -q", "git fetch -q" asks remote side to not send
+  progress messages, actually making their output quiet.
+
+* Cross-directory renames are no longer used when creating packs.  This
+  allows more graceful behavior on filesystems like sshfs.
+
+* Stale temporary files under $GIT_DIR/objects/pack are now cleaned up
+  automatically by "git prune".
+
+* "git merge" once again removes directories after the last file has
+  been removed from it during the merge.
+
+* "git merge" did not allocate enough memory for the structure itself when
+  enumerating the parents of the resulting commit.
+
+* "git blame -C -C" no longer segfaults while trying to pass blame if
+   it encounters a submodule reference.
+
+* "git rm" incorrectly claimed that you have local modifications when a
+  path was merely stat-dirty.
+
+* "git svn" fixed to display an error message when 'set-tree' failed,
+   instead of a Perl compile error.
+
+* "git submodule" fixed to handle checking out a different commit
+  than HEAD after initializing the submodule.
+
+* The "git commit" error message when there are still unmerged
+  files present was clarified to match "git write-tree".
+
+* "git init" was confused when core.bare or core.sharedRepository are set
+  in system or user global configuration file by mistake.  When --bare or
+  --shared is given from the command line, these now override such
+  settings made outside the repositories.
+
+* Some segfaults due to uncaught NULL pointers were fixed in multiple
+  tools such as apply, reset, update-index.
+
+* Solaris builds now default to OLD_ICONV=1 to avoid compile warnings;
+  Solaris 8 does not define NEEDS_LIBICONV by default.
+
+* "Git.pm" tests relied on unnecessarily more recent version of Perl.
+
+* "gitweb" triggered undef warning on commits without log messages.
+
+* "gitweb" triggered undef warnings on missing trees.
+
+* "gitweb" now removes PATH_INFO from its URLs so users don't have
+  to manually set the URL in the gitweb configuration.
+
+* Bash completion removed support for legacy "git-fetch", "git-push"
+  and "git-pull" as these are no longer installed.  Dashless form
+  ("git fetch") is still however supported.
+
+Many other documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.4.txt b/third_party/git/Documentation/RelNotes/1.6.0.4.txt
new file mode 100644
index 0000000000..d522661d31
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.4.txt
@@ -0,0 +1,39 @@
+GIT v1.6.0.4 Release Notes
+==========================
+
+Fixes since v1.6.0.3
+--------------------
+
+* 'git add -p' said "No changes" when only binary files were changed.
+
+* 'git archive' did not work correctly in bare repositories.
+
+* 'git checkout -t -b newbranch' when you are on detached HEAD was broken.
+
+* when we refuse to detect renames because there are too many new or
+  deleted files, 'git diff' did not say how many there are.
+
+* 'git push --mirror' tried and failed to push the stash; there is no
+  point in sending it to begin with.
+
+* 'git push' did not update the remote tracking reference if the corresponding
+  ref on the remote end happened to be already up to date.
+
+* 'git pull $there $branch:$current_branch' did not work when you were on
+  a branch yet to be born.
+
+* when giving up resolving a conflicted merge, 'git reset --hard' failed
+  to remove new paths from the working tree.
+
+* 'git send-email' had a small fd leak while scanning directory.
+
+* 'git status' incorrectly reported a submodule directory as an untracked
+  directory.
+
+* 'git svn' used deprecated 'git-foo' form of subcommand invocation.
+
+* 'git update-ref -d' to remove a reference did not honor --no-deref option.
+
+* Plugged small memleaks here and there.
+
+* Also contains many documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.5.txt b/third_party/git/Documentation/RelNotes/1.6.0.5.txt
new file mode 100644
index 0000000000..a08bb96738
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.5.txt
@@ -0,0 +1,56 @@
+GIT v1.6.0.5 Release Notes
+==========================
+
+Fixes since v1.6.0.4
+--------------------
+
+* "git checkout" used to crash when your HEAD was pointing at a deleted
+  branch.
+
+* "git checkout" from an un-checked-out state did not allow switching out
+  of the current branch.
+
+* "git diff" always allowed GIT_EXTERNAL_DIFF and --no-ext-diff was no-op for
+  the command.
+
+* Giving 3 or more tree-ish to "git diff" is supposed to show the combined
+  diff from second and subsequent trees to the first one, but the order was
+  screwed up.
+
+* "git fast-export" did not export all tags.
+
+* "git ls-files --with-tree=<tree>" did not work with options other
+  than -c, most notably with -m.
+
+* "git pack-objects" did not make its best effort to honor --max-pack-size
+  option when a single first object already busted the given limit and
+  placed many objects in a single pack.
+
+* "git-p4" fast import frontend was too eager to trigger its keyword expansion
+  logic, even on a keyword-looking string that does not have closing '$' on the
+  same line.
+
+* "git push $there" when the remote $there is defined in $GIT_DIR/branches/$there
+  behaves more like what cg-push from Cogito used to work.
+
+* when giving up resolving a conflicted merge, "git reset --hard" failed
+  to remove new paths from the working tree.
+
+* "git tag" did not complain when given mutually incompatible set of options.
+
+* The message constructed in the internal editor was discarded when "git
+  tag -s" failed to sign the message, which was often caused by the user
+  not configuring GPG correctly.
+
+* "make check" cannot be run without sparse; people may have meant to say
+  "make test" instead, so suggest that.
+
+* Internal diff machinery had a corner case performance bug that choked on
+  a large file with many repeated contents.
+
+* "git repack" used to grab objects out of packs marked with .keep
+  into a new pack.
+
+* Many unsafe call to sprintf() style varargs functions are corrected.
+
+* Also contains quite a few documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.6.txt b/third_party/git/Documentation/RelNotes/1.6.0.6.txt
new file mode 100644
index 0000000000..64ece1ffd5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.6.txt
@@ -0,0 +1,33 @@
+GIT v1.6.0.6 Release Notes
+==========================
+
+Fixes since 1.6.0.5
+-------------------
+
+ * "git fsck" had a deep recursion that wasted stack space.
+
+ * "git fast-export" and "git fast-import" choked on an old style
+   annotated tag that lack the tagger information.
+
+ * "git mergetool -- file" did not correctly skip "--" marker that
+   signals the end of options list.
+
+ * "git show $tag" segfaulted when an annotated $tag pointed at a
+   nonexistent object.
+
+ * "git show 2>error" when the standard output is automatically redirected
+   to the pager redirected the standard error to the pager as well; there
+   was no need to.
+
+ * "git send-email" did not correctly handle list of addresses when
+   they had quoted comma (e.g. "Lastname, Givenname" <mail@addre.ss>).
+
+ * Logic to discover branch ancestry in "git svn" was unreliable when
+   the process to fetch history was interrupted.
+
+ * Removed support for an obsolete gitweb request URI, whose
+   implementation ran "git diff" Porcelain, instead of using plumbing,
+   which would have run an external diff command specified in the
+   repository configuration as the gitweb user.
+
+Also contains numerous documentation typofixes.
diff --git a/third_party/git/Documentation/RelNotes/1.6.0.txt b/third_party/git/Documentation/RelNotes/1.6.0.txt
new file mode 100644
index 0000000000..de7ef166b6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.0.txt
@@ -0,0 +1,258 @@
+GIT v1.6.0 Release Notes
+========================
+
+User visible changes
+--------------------
+
+With the default Makefile settings, most of the programs are now
+installed outside your $PATH, except for "git", "gitk" and
+some server side programs that need to be accessible for technical
+reasons.  Invoking a git subcommand as "git-xyzzy" from the command
+line has been deprecated since early 2006 (and officially announced in
+1.5.4 release notes); use of them from your scripts after adding
+output from "git --exec-path" to the $PATH is still supported in this
+release, but users are again strongly encouraged to adjust their
+scripts to use "git xyzzy" form, as we will stop installing
+"git-xyzzy" hardlinks for built-in commands in later releases.
+
+An earlier change to page "git status" output was overwhelmingly unpopular
+and has been reverted.
+
+Source changes needed for porting to MinGW environment are now all in the
+main git.git codebase.
+
+By default, packfiles created with this version uses delta-base-offset
+encoding introduced in v1.4.4.  Pack idx files are using version 2 that
+allows larger packs and added robustness thanks to its CRC checking,
+introduced in v1.5.2 and v1.4.4.5.  If you want to keep your repositories
+backwards compatible past these versions, set repack.useDeltaBaseOffset
+to false or pack.indexVersion to 1, respectively.
+
+We used to prevent sample hook scripts shipped in templates/ from
+triggering by default by relying on the fact that we install them as
+unexecutable, but on some filesystems, this approach does not work.
+They are now shipped with ".sample" suffix.  If you want to activate
+any of these samples as-is, rename them to drop the ".sample" suffix,
+instead of running "chmod +x" on them.  For example, you can rename
+hooks/post-update.sample to hooks/post-update to enable the sample
+hook that runs update-server-info, in order to make repositories
+friendly to dumb protocols (i.e. HTTP).
+
+GIT_CONFIG, which was only documented as affecting "git config", but
+actually affected all git commands, now only affects "git config".
+GIT_LOCAL_CONFIG, also only documented as affecting "git config" and
+not different from GIT_CONFIG in a useful way, is removed.
+
+The ".dotest" temporary area "git am" and "git rebase" use is now moved
+inside the $GIT_DIR, to avoid mistakes of adding it to the project by
+accident.
+
+An ancient merge strategy "stupid" has been removed.
+
+
+Updates since v1.5.6
+--------------------
+
+(subsystems)
+
+* git-p4 in contrib learned "allowSubmit" configuration to control on
+  which branch to allow "submit" subcommand.
+
+* git-gui learned to stage changes per-line.
+
+(portability)
+
+* Changes for MinGW port have been merged, thanks to Johannes Sixt and
+  gangs.
+
+* Sample hook scripts shipped in templates/ are now suffixed with
+  *.sample.
+
+* perl's in-place edit (-i) does not work well without backup files on Windows;
+  some tests are rewritten to cope with this.
+
+(documentation)
+
+* Updated howto/update-hook-example
+
+* Got rid of usage of "git-foo" from the tutorial and made typography
+  more consistent.
+
+* Disambiguating "--" between revs and paths is finally documented.
+
+(performance, robustness, sanity etc.)
+
+* index-pack used too much memory when dealing with a deep delta chain.
+  This has been optimized.
+
+* reduced excessive inlining to shrink size of the "git" binary.
+
+* verify-pack checks the object CRC when using version 2 idx files.
+
+* When an object is corrupt in a pack, the object became unusable even
+  when the same object is available in a loose form,  We now try harder to
+  fall back to these redundant objects when able.  In particular, "git
+  repack -a -f" can be used to fix such a corruption as long as necessary
+  objects are available.
+
+* Performance of "git-blame -C -C" operation is vastly improved.
+
+* git-clone does not create refs in loose form anymore (it behaves as
+  if you immediately ran git-pack-refs after cloning).  This will help
+  repositories with insanely large number of refs.
+
+* core.fsyncobjectfiles configuration can be used to ensure that the loose
+  objects created will be fsync'ed (this is only useful on filesystems
+  that does not order data writes properly).
+
+* "git commit-tree" plumbing can make Octopus with more than 16 parents.
+  "git commit" has been capable of this for quite some time.
+
+(usability, bells and whistles)
+
+* even more documentation pages are now accessible via "man" and "git help".
+
+* A new environment variable GIT_CEILING_DIRECTORIES can be used to stop
+  the discovery process of the toplevel of working tree; this may be useful
+  when you are working in a slow network disk and are outside any working tree,
+  as bash-completion and "git help" may still need to run in these places.
+
+* By default, stash entries never expire.  Set reflogexpire in [gc
+  "refs/stash"] to a reasonable value to get traditional auto-expiration
+  behaviour back
+
+* Longstanding latency issue with bash completion script has been
+  addressed.  This will need to be backmerged to 'maint' later.
+
+* pager.<cmd> configuration variable can be used to enable/disable the
+  default paging behaviour per command.
+
+* "git-add -i" has a new action 'e/dit' to allow you edit the patch hunk
+  manually.
+
+* git-am records the original tip of the branch in ORIG_HEAD before it
+  starts applying patches.
+
+* git-apply can handle a patch that touches the same path more than once
+  much better than before.
+
+* git-apply can be told not to trust the line counts recorded in the input
+  patch but recount, with the new --recount option.
+
+* git-apply can be told to apply a patch to a path deeper than what the
+  patch records with --directory option.
+
+* git-archive can be told to omit certain paths from its output using
+  export-ignore attributes.
+
+* git-archive uses the zlib default compression level when creating
+  zip archive.
+
+* git-archive's command line options --exec and --remote can take their
+  parameters as separate command line arguments, similar to other commands.
+  IOW, both "--exec=path" and "--exec path" are now supported.
+
+* With -v option, git-branch describes the remote tracking statistics
+  similar to the way git-checkout reports by how many commits your branch
+  is ahead/behind.
+
+* git-branch's --contains option used to always require a commit parameter
+  to limit the branches with; it now defaults to list branches that
+  contains HEAD if this parameter is omitted.
+
+* git-branch's --merged and --no-merged option used to always limit the
+  branches relative to the HEAD, but they can now take an optional commit
+  argument that is used in place of HEAD.
+
+* git-bundle can read the revision arguments from the standard input.
+
+* git-cherry-pick can replay a root commit now.
+
+* git-clone can clone from a remote whose URL would be rewritten by
+  configuration stored in $HOME/.gitconfig now.
+
+* "git-clone --mirror" is a handy way to set up a bare mirror repository.
+
+* git-cvsserver learned to respond to "cvs co -c".
+
+* git-diff --check now checks leftover merge conflict markers.
+
+* "git-diff -p" learned to grab a better hunk header lines in
+  BibTex, Pascal/Delphi, and Ruby files and also pays attention to
+  chapter and part boundary in TeX documents.
+
+* When remote side used to have branch 'foo' and git-fetch finds that now
+  it has branch 'foo/bar', it refuses to lose the existing remote tracking
+  branch and its reflog.  The error message has been improved to suggest
+  pruning the remote if the user wants to proceed and get the latest set
+  of branches from the remote, including such 'foo/bar'.
+
+* fast-export learned to export and import marks file; this can be used to
+  interface with fast-import incrementally.
+
+* fast-import and fast-export learned to export and import gitlinks.
+
+* "gitk" left background process behind after being asked to dig very deep
+  history and the user killed the UI; the process is killed when the UI goes
+  away now.
+
+* git-rebase records the original tip of branch in ORIG_HEAD before it is
+  rewound.
+
+* "git rerere" can be told to update the index with auto-reused resolution
+  with rerere.autoupdate configuration variable.
+
+* git-rev-parse learned $commit^! and $commit^@ notations used in "log"
+  family.  These notations are available in gitk as well, because the gitk
+  command internally uses rev-parse to interpret its arguments.
+
+* git-rev-list learned --children option to show child commits it
+  encountered during the traversal, instead of showing parent commits.
+
+* git-send-mail can talk not just over SSL but over TLS now.
+
+* git-shortlog honors custom output format specified with "--pretty=format:".
+
+* "git-stash save" learned --keep-index option.  This lets you stash away the
+  local changes and bring the changes staged in the index to your working
+  tree for examination and testing.
+
+* git-stash also learned branch subcommand to create a new branch out of
+  stashed changes.
+
+* git-status gives the remote tracking statistics similar to the way
+  git-checkout reports by how many commits your branch is ahead/behind.
+
+* "git-svn dcommit" is now aware of auto-props setting the subversion user
+  has.
+
+* You can tell "git status -u" to even more aggressively omit checking
+  untracked files with --untracked-files=no.
+
+* Original SHA-1 value for "update-ref -d" is optional now.
+
+* Error codes from gitweb are made more descriptive where possible, rather
+  than "403 forbidden" as we used to issue everywhere.
+
+(internal)
+
+* git-merge has been reimplemented in C.
+
+
+Fixes since v1.5.6
+------------------
+
+All of the fixes in v1.5.6 maintenance series are included in
+this release, unless otherwise noted.
+
+ * git-clone ignored its -u option; the fix needs to be backported to
+   'maint';
+
+ * git-mv used to lose the distinction between changes that are staged
+   and that are only in the working tree, by staging both in the index
+   after moving such a path.
+
+ * "git-rebase -i -p" rewrote the parents to wrong ones when amending
+   (either edit or squash) was involved, and did not work correctly
+   when fast forwarding.
+
diff --git a/third_party/git/Documentation/RelNotes/1.6.1.1.txt b/third_party/git/Documentation/RelNotes/1.6.1.1.txt
new file mode 100644
index 0000000000..8c594ba02f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.1.1.txt
@@ -0,0 +1,59 @@
+GIT v1.6.1.1 Release Notes
+==========================
+
+Fixes since v1.6.1
+------------------
+
+* "git add frotz/nitfol" when "frotz" is a submodule should have errored
+  out, but it didn't.
+
+* "git apply" took file modes from the patch text and updated the mode
+  bits of the target tree even when the patch was not about mode changes.
+
+* "git bisect view" on Cygwin did not launch gitk
+
+* "git checkout $tree" did not trigger an error.
+
+* "git commit" tried to remove COMMIT_EDITMSG from the work tree by mistake.
+
+* "git describe --all" complained when a commit is described with a tag,
+  which was nonsense.
+
+* "git diff --no-index --" did not trigger no-index (aka "use git-diff as
+  a replacement of diff on untracked files") behaviour.
+
+* "git format-patch -1 HEAD" on a root commit failed to produce patch
+  text.
+
+* "git fsck branch" did not work as advertised; instead it behaved the same
+  way as "git fsck".
+
+* "git log --pretty=format:%s" did not handle a multi-line subject the
+  same way as built-in log listers (i.e. shortlog, --pretty=oneline, etc.)
+
+* "git daemon", and "git merge-file" are more careful when freopen fails
+  and barf, instead of going on and writing to unopened filehandle.
+
+* "git http-push" did not like some RFC 4918 compliant DAV server
+  responses.
+
+* "git merge -s recursive" mistakenly overwritten an untracked file in the
+  work tree upon delete/modify conflict.
+
+* "git merge -s recursive" didn't leave the index unmerged for entries with
+  rename/delete conflicts.
+
+* "git merge -s recursive" clobbered untracked files in the work tree.
+
+* "git mv -k" with more than one erroneous paths misbehaved.
+
+* "git read-tree -m -u" hence branch switching incorrectly lost a
+  subdirectory in rare cases.
+
+* "git rebase -i" issued an unnecessary error message upon a user error of
+  marking the first commit to be "squash"ed.
+
+* "git shortlog" did not format a commit message with multi-line
+  subject correctly.
+
+Many documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.1.2.txt b/third_party/git/Documentation/RelNotes/1.6.1.2.txt
new file mode 100644
index 0000000000..be37cbb858
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.1.2.txt
@@ -0,0 +1,39 @@
+GIT v1.6.1.2 Release Notes
+==========================
+
+Fixes since v1.6.1.1
+--------------------
+
+* The logic for rename detection in internal diff used by commands like
+  "git diff" and "git blame" has been optimized to avoid loading the same
+  blob repeatedly.
+
+* We did not allow writing out a blob that is larger than 2GB for no good
+  reason.
+
+* "git format-patch -o $dir", when $dir is a relative directory, used it
+  as relative to the root of the work tree, not relative to the current
+  directory.
+
+* v1.6.1 introduced an optimization for "git push" into a repository (A)
+  that borrows its objects from another repository (B) to avoid sending
+  objects that are available in repository B, when they are not yet used
+  by repository A.  However the code on the "git push" sender side was
+  buggy and did not work when repository B had new objects that are not
+  known by the sender.  This caused pushing into a "forked" repository
+  served by v1.6.1 software using "git push" from v1.6.1 sometimes did not
+  work.  The bug was purely on the "git push" sender side, and has been
+  corrected.
+
+* "git status -v" did not paint its diff output in colour even when
+  color.ui configuration was set.
+
+* "git ls-tree" learned --full-tree option to help Porcelain scripts that
+  want to always see the full path regardless of the current working
+  directory.
+
+* "git grep" incorrectly searched in work tree paths even when they are
+  marked as assume-unchanged.  It now searches in the index entries.
+
+* "git gc" with no grace period needlessly ejected packed but unreachable
+  objects in their loose form, only to delete them right away.
diff --git a/third_party/git/Documentation/RelNotes/1.6.1.3.txt b/third_party/git/Documentation/RelNotes/1.6.1.3.txt
new file mode 100644
index 0000000000..cd08d8174e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.1.3.txt
@@ -0,0 +1,28 @@
+GIT v1.6.1.3 Release Notes
+==========================
+
+Fixes since v1.6.1.2
+--------------------
+
+* "git diff --binary | git apply" pipeline did not work well when
+  a binary blob is changed to a symbolic link.
+
+* Some combinations of -b/-w/--ignore-space-at-eol to "git diff" did
+  not work as expected.
+
+* "git grep" did not pass the -I (ignore binary) option when
+  calling out an external grep program.
+
+* "git log" and friends include HEAD to the set of starting points
+  when --all is given.  This makes a difference when you are not
+  on any branch.
+
+* "git mv" to move an untracked file to overwrite a tracked
+  contents misbehaved.
+
+* "git merge -s octopus" with many potential merge bases did not
+  work correctly.
+
+* RPM binary package installed the html manpages in a wrong place.
+
+Also includes minor documentation fixes and updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.1.4.txt b/third_party/git/Documentation/RelNotes/1.6.1.4.txt
new file mode 100644
index 0000000000..ccbad794c0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.1.4.txt
@@ -0,0 +1,41 @@
+GIT v1.6.1.4 Release Notes
+==========================
+
+Fixes since v1.6.1.3
+--------------------
+
+* .gitignore learned to handle backslash as a quoting mechanism for
+  comment introduction character "#".
+  This fix was first merged to 1.6.2.1.
+
+* "git fast-export" produced wrong output with some parents missing from
+  commits, when the history is clock-skewed.
+
+* "git fast-import" sometimes failed to read back objects it just wrote
+  out and aborted, because it failed to flush stale cached data.
+
+* "git-ls-tree" and "git-diff-tree" used a pathspec correctly when
+  deciding to descend into a subdirectory but they did not match the
+  individual paths correctly.  This caused pathspecs "abc/d ab" to match
+  "abc/0" ("abc/d" made them decide to descend into the directory "abc/",
+  and then "ab" incorrectly matched "abc/0" when it shouldn't).
+  This fix was first merged to 1.6.2.3.
+
+* import-zips script (in contrib) did not compute the common directory
+  prefix correctly.
+  This fix was first merged to 1.6.2.2.
+
+* "git init" segfaulted when given an overlong template location via
+  the --template= option.
+  This fix was first merged to 1.6.2.4.
+
+* "git repack" did not error out when necessary object was missing in the
+  repository.
+
+* git-repack (invoked from git-gc) did not work as nicely as it should in
+  a repository that borrows objects from neighbours via alternates
+  mechanism especially when some packs are marked with the ".keep" flag
+  to prevent them from being repacked.
+  This fix was first merged to 1.6.2.3.
+
+Also includes minor documentation fixes and updates.
diff --git a/third_party/git/Documentation/RelNotes/1.6.1.txt b/third_party/git/Documentation/RelNotes/1.6.1.txt
new file mode 100644
index 0000000000..7b152a6fdc
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.1.txt
@@ -0,0 +1,280 @@
+GIT v1.6.1 Release Notes
+========================
+
+Updates since v1.6.0
+--------------------
+
+When some commands (e.g. "git log", "git diff") spawn pager internally, we
+used to make the pager the parent process of the git command that produces
+output.  This meant that the exit status of the whole thing comes from the
+pager, not the underlying git command.  We swapped the order of the
+processes around and you will see the exit code from the command from now
+on.
+
+(subsystems)
+
+* gitk can call out to git-gui to view "git blame" output; git-gui in turn
+  can run gitk from its blame view.
+
+* Various git-gui updates including updated translations.
+
+* Various gitweb updates from repo.or.cz installation.
+
+* Updates to emacs bindings.
+
+(portability)
+
+* A few test scripts used nonportable "grep" that did not work well on
+  some platforms, e.g. Solaris.
+
+* Sample pre-auto-gc script has OS X support.
+
+* Makefile has support for (ancient) FreeBSD 4.9.
+
+(performance)
+
+* Many operations that are lstat(3) heavy can be told to pre-execute
+  necessary lstat(3) in parallel before their main operations, which
+  potentially gives much improved performance for cold-cache cases or in
+  environments with weak metadata caching (e.g. NFS).
+
+* The underlying diff machinery to produce textual output has been
+  optimized, which would result in faster "git blame" processing.
+
+* Most of the test scripts (but not the ones that try to run servers)
+  can be run in parallel.
+
+* Bash completion of refnames in a repository with massive number of
+  refs has been optimized.
+
+* Cygwin port uses native stat/lstat implementations when applicable,
+  which leads to improved performance.
+
+* "git push" pays attention to alternate repositories to avoid sending
+  unnecessary objects.
+
+* "git svn" can rebuild an out-of-date rev_map file.
+
+(usability, bells and whistles)
+
+* When you mistype a command name, git helpfully suggests what it guesses
+  you might have meant to say.  help.autocorrect configuration can be set
+  to a non-zero value to accept the suggestion when git can uniquely
+  guess.
+
+* The packfile machinery hopefully is more robust when dealing with
+  corrupt packs if redundant objects involved in the corruption are
+  available elsewhere.
+
+* "git add -N path..." adds the named paths as an empty blob, so that
+  subsequent "git diff" will show a diff as if they are creation events.
+
+* "git add" gained a built-in synonym for people who want to say "stage
+  changes" instead of "add contents to the staging area" which amounts
+  to the same thing.
+
+* "git apply" learned --include=paths option, similar to the existing
+  --exclude=paths option.
+
+* "git bisect" is careful about a user mistake and suggests testing of
+  merge base first when good is not a strict ancestor of bad.
+
+* "git bisect skip" can take a range of commits.
+
+* "git blame" re-encodes the commit metainfo to UTF-8 from i18n.commitEncoding
+  by default.
+
+* "git check-attr --stdin" can check attributes for multiple paths.
+
+* "git checkout --track origin/hack" used to be a syntax error.  It now
+  DWIMs to create a corresponding local branch "hack", i.e. acts as if you
+  said "git checkout --track -b hack origin/hack".
+
+* "git checkout --ours/--theirs" can be used to check out one side of a
+  conflicting merge during conflict resolution.
+
+* "git checkout -m" can be used to recreate the initial conflicted state
+  during conflict resolution.
+
+* "git cherry-pick" can also utilize rerere for conflict resolution.
+
+* "git clone" learned to be verbose with -v
+
+* "git commit --author=$name" can look up author name from existing
+  commits.
+
+* output from "git commit" has been reworded in a more concise and yet
+  more informative way.
+
+* "git count-objects" reports the on-disk footprint for packfiles and
+  their corresponding idx files.
+
+* "git daemon" learned --max-connections=<count> option.
+
+* "git daemon" exports REMOTE_ADDR to record client address, so that
+  spawned programs can act differently on it.
+
+* "git describe --tags" favours closer lightweight tags than farther
+  annotated tags now.
+
+* "git diff" learned to mimic --suppress-blank-empty from GNU diff via a
+  configuration option.
+
+* "git diff" learned to put more sensible hunk headers for Python,
+  HTML and ObjC contents.
+
+* "git diff" learned to vary the a/ vs b/ prefix depending on what are
+  being compared, controlled by diff.mnemonicprefix configuration.
+
+* "git diff" learned --dirstat-by-file to count changed files, not number
+  of lines, when summarizing the global picture.
+
+* "git diff" learned "textconv" filters --- a binary or hard-to-read
+  contents can be munged into human readable form and the difference
+  between the results of the conversion can be viewed (obviously this
+  cannot produce a patch that can be applied, so this is disabled in
+  format-patch among other things).
+
+* "--cached" option to "git diff has an easier to remember synonym "--staged",
+  to ask "what is the difference between the given commit and the
+  contents staged in the index?"
+
+* "git for-each-ref" learned "refname:short" token that gives an
+  unambiguously abbreviated refname.
+
+* Auto-numbering of the subject lines is the default for "git
+  format-patch" now.
+
+* "git grep" learned to accept -z similar to GNU grep.
+
+* "git help" learned to use GIT_MAN_VIEWER environment variable before
+  using "man" program.
+
+* "git imap-send" can optionally talk SSL.
+
+* "git index-pack" is more careful against disk corruption while
+  completing a thin pack.
+
+* "git log --check" and "git log --exit-code" passes their underlying diff
+  status with their exit status code.
+
+* "git log" learned --simplify-merges, a milder variant of --full-history;
+  "gitk --simplify-merges" is easier to view than with --full-history.
+
+* "git log" learned "--source" to show what ref each commit was reached
+  from.
+
+* "git log" also learned "--simplify-by-decoration" to show the
+  birds-eye-view of the topology of the history.
+
+* "git log --pretty=format:" learned "%d" format element that inserts
+  names of tags that point at the commit.
+
+* "git merge --squash" and "git merge --no-ff" into an unborn branch are
+  noticed as user errors.
+
+* "git merge -s $strategy" can use a custom built strategy if you have a
+  command "git-merge-$strategy" on your $PATH.
+
+* "git pull" (and "git fetch") can be told to operate "-v"erbosely or
+  "-q"uietly.
+
+* "git push" can be told to reject deletion of refs with receive.denyDeletes
+  configuration.
+
+* "git rebase" honours pre-rebase hook; use --no-verify to bypass it.
+
+* "git rebase -p" uses interactive rebase machinery now to preserve the merges.
+
+* "git reflog expire branch" can be used in place of "git reflog expire
+  refs/heads/branch".
+
+* "git remote show $remote" lists remote branches one-per-line now.
+
+* "git send-email" can be given revision range instead of files and
+  maildirs on the command line, and automatically runs format-patch to
+  generate patches for the given revision range.
+
+* "git submodule foreach" subcommand allows you to iterate over checked
+  out submodules.
+
+* "git submodule sync" subcommands allows you to update the origin URL
+  recorded in submodule directories from the toplevel .gitmodules file.
+
+* "git svn branch" can create new branches on the other end.
+
+* "gitweb" can use more saner PATH_INFO based URL.
+
+(internal)
+
+* "git hash-object" learned to lie about the path being hashed, so that
+  correct gitattributes processing can be done while hashing contents
+  stored in a temporary file.
+
+* various callers of git-merge-recursive avoid forking it as an external
+  process.
+
+* Git class defined in "Git.pm" can be subclasses a bit more easily.
+
+* We used to link GNU regex library as a compatibility layer for some
+  platforms, but it turns out it is not necessary on most of them.
+
+* Some path handling routines used fixed number of buffers used alternately
+  but depending on the call depth, this arrangement led to hard to track
+  bugs.  This issue is being addressed.
+
+
+Fixes since v1.6.0
+------------------
+
+All of the fixes in v1.6.0.X maintenance series are included in this
+release, unless otherwise noted.
+
+* Porcelains implemented as shell scripts were utterly confused when you
+  entered to a subdirectory of a work tree from sideways, following a
+  symbolic link (this may need to be backported to older releases later).
+
+* Tracking symbolic links would work better on filesystems whose lstat()
+  returns incorrect st_size value for them.
+
+* "git add" and "git update-index" incorrectly allowed adding S/F when S
+  is a tracked symlink that points at a directory D that has a path F in
+  it (we still need to fix a similar nonsense when S is a submodule and F
+  is a path in it).
+
+* "git am" after stopping at a broken patch lost --whitespace, -C, -p and
+  --3way options given from the command line initially.
+
+* "git diff --stdin" used to take two trees on a line and compared them,
+  but we dropped support for such a use case long time ago.  This has
+  been resurrected.
+
+* "git filter-branch" failed to rewrite a tag name with slashes in it.
+
+* "git http-push" did not understand URI scheme other than opaquelocktoken
+  when acquiring a lock from the server (this may need to be backported to
+  older releases later).
+
+* After "git rebase -p" stopped with conflicts while replaying a merge,
+ "git rebase --continue" did not work (may need to be backported to older
+  releases).
+
+* "git revert" records relative to which parent a revert was made when
+  reverting a merge.  Together with new documentation that explains issues
+  around reverting a merge and merging from the updated branch later, this
+  hopefully will reduce user confusion (this may need to be backported to
+  older releases later).
+
+* "git rm --cached" used to allow an empty blob that was added earlier to
+  be removed without --force, even when the file in the work tree has
+  since been modified.
+
+* "git push --tags --all $there" failed with generic usage message without
+  telling saying these two options are incompatible.
+
+* "git log --author/--committer" match used to potentially match the
+  timestamp part, exposing internal implementation detail.  Also these did
+  not work with --fixed-strings match at all.
+
+* "gitweb" did not mark non-ASCII characters imported from external HTML fragments
+  correctly.
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.1.txt b/third_party/git/Documentation/RelNotes/1.6.2.1.txt
new file mode 100644
index 0000000000..dfa36416af
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.1.txt
@@ -0,0 +1,19 @@
+GIT v1.6.2.1 Release Notes
+==========================
+
+Fixes since v1.6.2
+------------------
+
+* .gitignore learned to handle backslash as a quoting mechanism for
+  comment introduction character "#".
+
+* timestamp output in --date=relative mode used to display timestamps that
+  are long time ago in the default mode; it now uses "N years M months
+  ago", and "N years ago".
+
+* git-add -i/-p now works with non-ASCII pathnames.
+
+* "git hash-object -w" did not read from the configuration file from the
+  correct .git directory.
+
+* git-send-email learned to correctly handle multiple Cc: addresses.
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.2.txt b/third_party/git/Documentation/RelNotes/1.6.2.2.txt
new file mode 100644
index 0000000000..fafa9986b0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.2.txt
@@ -0,0 +1,45 @@
+GIT v1.6.2.2 Release Notes
+==========================
+
+Fixes since v1.6.2.1
+--------------------
+
+* A longstanding confusing description of what --pickaxe option of
+  git-diff does has been clarified in the documentation.
+
+* "git-blame -S" did not quite work near the commits that were given
+  on the command line correctly.
+
+* "git diff --pickaxe-regexp" did not count overlapping matches
+  correctly.
+
+* "git diff" did not feed files in work-tree representation to external
+  diff and textconv.
+
+* "git-fetch" in a repository that was not cloned from anywhere said
+  it cannot find 'origin', which was hard to understand for new people.
+
+* "git-format-patch --numbered-files --stdout" did not have to die of
+  incompatible options; it now simply ignores --numbered-files as no files
+  are produced anyway.
+
+* "git-ls-files --deleted" did not work well with GIT_DIR&GIT_WORK_TREE.
+
+* "git-read-tree A B C..." without -m option has been broken for a long
+  time.
+
+* git-send-email ignored --in-reply-to when --no-thread was given.
+
+* 'git-submodule add' did not tolerate extra slashes and ./ in the path it
+  accepted from the command line; it now is more lenient.
+
+* git-svn misbehaved when the project contained a path that began with
+  two dashes.
+
+* import-zips script (in contrib) did not compute the common directory
+  prefix correctly.
+
+* miscompilation of negated enum constants by old gcc (2.9) affected the
+  codepaths to spawn subprocesses.
+
+Many small documentation updates are included as well.
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.3.txt b/third_party/git/Documentation/RelNotes/1.6.2.3.txt
new file mode 100644
index 0000000000..4d3c1ac91c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.3.txt
@@ -0,0 +1,22 @@
+GIT v1.6.2.3 Release Notes
+==========================
+
+Fixes since v1.6.2.2
+--------------------
+
+* Setting an octal mode value to core.sharedrepository configuration to
+  restrict access to the repository to group members did not work as
+  advertised.
+
+* A fairly large and trivial memory leak while rev-list shows list of
+  reachable objects has been identified and plugged.
+
+* "git-commit --interactive" did not abort when underlying "git-add -i"
+  signaled a failure.
+
+* git-repack (invoked from git-gc) did not work as nicely as it should in
+  a repository that borrows objects from neighbours via alternates
+  mechanism especially when some packs are marked with the ".keep" flag
+  to prevent them from being repacked.
+
+Many small documentation updates are included as well.
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.4.txt b/third_party/git/Documentation/RelNotes/1.6.2.4.txt
new file mode 100644
index 0000000000..f4bf1d0986
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.4.txt
@@ -0,0 +1,39 @@
+GIT v1.6.2.4 Release Notes
+==========================
+
+Fixes since v1.6.2.3
+--------------------
+
+* The configuration parser had a buffer overflow while parsing an overlong
+  value.
+
+* pruning reflog entries that are unreachable from the tip of the ref
+  during "git reflog prune" (hence "git gc") was very inefficient.
+
+* "git-add -p" lacked a way to say "q"uit to refuse staging any hunks for
+  the remaining paths.  You had to say "d" and then ^C.
+
+* "git-checkout <tree-ish> <submodule>" did not update the index entry at
+  the named path; it now does.
+
+* "git-fast-export" choked when seeing a tag that does not point at commit.
+
+* "git init" segfaulted when given an overlong template location via
+  the --template= option.
+
+* "git-ls-tree" and "git-diff-tree" used a pathspec correctly when
+  deciding to descend into a subdirectory but they did not match the
+  individual paths correctly.  This caused pathspecs "abc/d ab" to match
+  "abc/0" ("abc/d" made them decide to descend into the directory "abc/",
+  and then "ab" incorrectly matched "abc/0" when it shouldn't).
+
+* "git-merge-recursive" was broken when a submodule entry was involved in
+  a criss-cross merge situation.
+
+Many small documentation updates are included as well.
+
+---
+exec >/var/tmp/1
+echo O=$(git describe maint)
+O=v1.6.2.3-38-g318b847
+git shortlog --no-merges $O..maint
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.5.txt b/third_party/git/Documentation/RelNotes/1.6.2.5.txt
new file mode 100644
index 0000000000..b23f9e95d1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.5.txt
@@ -0,0 +1,21 @@
+GIT v1.6.2.5 Release Notes
+==========================
+
+Fixes since v1.6.2.4
+--------------------
+
+* "git apply" mishandled if you fed a git generated patch that renames
+  file A to B and file B to A at the same time.
+
+* "git diff -c -p" (and "diff --cc") did not expect to see submodule
+  differences and instead refused to work.
+
+* "git grep -e '('" segfaulted, instead of diagnosing a mismatched
+  parentheses error.
+
+* "git fetch" generated packs with offset-delta encoding when both ends of
+  the connection are capable of producing one; this cannot be read by
+  ancient git and the user should be able to disable this by setting
+  repack.usedeltabaseoffset configuration to false.
+
+
diff --git a/third_party/git/Documentation/RelNotes/1.6.2.txt b/third_party/git/Documentation/RelNotes/1.6.2.txt
new file mode 100644
index 0000000000..ad060f4f89
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.2.txt
@@ -0,0 +1,164 @@
+GIT v1.6.2 Release Notes
+========================
+
+With the next major release, "git push" into a branch that is
+currently checked out will be refused by default.  You can choose
+what should happen upon such a push by setting the configuration
+variable receive.denyCurrentBranch in the receiving repository.
+
+To ease the transition plan, the receiving repository of such a
+push running this release will issue a big warning when the
+configuration variable is missing.  Please refer to:
+
+  http://git.or.cz/gitwiki/GitFaq#non-bare
+  http://thread.gmane.org/gmane.comp.version-control.git/107758/focus=108007
+
+for more details on the reason why this change is needed and the
+transition plan.
+
+For a similar reason, "git push $there :$killed" to delete the branch
+$killed in a remote repository $there, if $killed branch is the current
+branch pointed at by its HEAD, gets a large warning.  You can choose what
+should happen upon such a push by setting the configuration variable
+receive.denyDeleteCurrent in the receiving repository.
+
+
+Updates since v1.6.1
+--------------------
+
+(subsystems)
+
+* git-svn updates.
+
+* gitweb updates, including a new patch view and RSS/Atom feed
+  improvements.
+
+* (contrib/emacs) git.el now has commands for checking out a branch,
+  creating a branch, cherry-picking and reverting commits; vc-git.el
+  is not shipped with git anymore (it is part of official Emacs).
+
+(performance)
+
+* pack-objects autodetects the number of CPUs available and uses threaded
+  version.
+
+(usability, bells and whistles)
+
+* automatic typo correction works on aliases as well
+
+* @{-1} is a way to refer to the last branch you were on.  This is
+  accepted not only where an object name is expected, but anywhere
+  a branch name is expected and acts as if you typed the branch name.
+  E.g. "git branch --track mybranch @{-1}", "git merge @{-1}", and
+  "git rev-parse --symbolic-full-name @{-1}" would work as expected.
+
+* When refs/remotes/origin/HEAD points at a remote tracking branch that
+  has been pruned away, many git operations issued warning when they
+  internally enumerated the refs.  We now warn only when you say "origin"
+  to refer to that pruned branch.
+
+* The location of .mailmap file can be configured, and its file format was
+  enhanced to allow mapping an incorrect e-mail field as well.
+
+* "git add -p" learned 'g'oto action to jump directly to a hunk.
+
+* "git add -p" learned to find a hunk with given text with '/'.
+
+* "git add -p" optionally can be told to work with just the command letter
+  without Enter.
+
+* when "git am" stops upon a patch that does not apply, it shows the
+  title of the offending patch.
+
+* "git am --directory=<dir>" and "git am --reject" passes these options
+  to underlying "git apply".
+
+* "git am" learned --ignore-date option.
+
+* "git blame" aligns author names better when they are spelled in
+  non US-ASCII encoding.
+
+* "git clone" now makes its best effort when cloning from an empty
+  repository to set up configuration variables to refer to the remote
+  repository.
+
+* "git checkout -" is a shorthand for "git checkout @{-1}".
+
+* "git cherry" defaults to whatever the current branch is tracking (if
+  exists) when the <upstream> argument is not given.
+
+* "git cvsserver" can be told not to add extra "via git-CVS emulator" to
+  the commit log message it serves via gitcvs.commitmsgannotation
+  configuration.
+
+* "git cvsserver" learned to handle 'noop' command some CVS clients seem
+  to expect to work.
+
+* "git diff" learned a new option --inter-hunk-context to coalesce close
+  hunks together and show context between them.
+
+* The definition of what constitutes a word for "git diff --color-words"
+  can be customized via gitattributes, command line or a configuration.
+
+* "git diff" learned --patience to run "patience diff" algorithm.
+
+* "git filter-branch" learned --prune-empty option that discards commits
+  that do not change the contents.
+
+* "git fsck" now checks loose objects in alternate object stores, instead
+  of misreporting them as missing.
+
+* "git gc --prune" was resurrected to allow "git gc --no-prune" and
+  giving non-default expiration period e.g. "git gc --prune=now".
+
+* "git grep -w" and "git grep" for fixed strings have been optimized.
+
+* "git mergetool" learned -y(--no-prompt) option to disable prompting.
+
+* "git rebase -i" can transplant a history down to root to elsewhere
+  with --root option.
+
+* "git reset --merge" is a new mode that works similar to the way
+  "git checkout" switches branches, taking the local changes while
+  switching to another commit.
+
+* "git submodule update" learned --no-fetch option.
+
+* "git tag" learned --contains that works the same way as the same option
+  from "git branch".
+
+
+Fixes since v1.6.1
+------------------
+
+All of the fixes in v1.6.1.X maintenance series are included in this
+release, unless otherwise noted.
+
+Here are fixes that this release has, but have not been backported to
+v1.6.1.X series.
+
+* "git-add sub/file" when sub is a submodule incorrectly added the path to
+  the superproject.
+
+* "git bundle" did not exclude annotated tags even when a range given
+  from the command line wanted to.
+
+* "git filter-branch" unnecessarily refused to work when you had
+  checked out a different commit from what is recorded in the superproject
+  index in a submodule.
+
+* "git filter-branch" incorrectly tried to update a nonexistent work tree
+  at the end when it is run in a bare repository.
+
+* "git gc" did not work if your repository was created with an ancient git
+  and never had any pack files in it before.
+
+* "git mergetool" used to ignore autocrlf and other attributes
+  based content rewriting.
+
+* branch switching and merges had a silly bug that did not validate
+  the correct directory when making sure an existing subdirectory is
+  clean.
+
+* "git -p cmd" when cmd is not a built-in one left the display in funny state
+  when killed in the middle.
diff --git a/third_party/git/Documentation/RelNotes/1.6.3.1.txt b/third_party/git/Documentation/RelNotes/1.6.3.1.txt
new file mode 100644
index 0000000000..2400b72ef7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.3.1.txt
@@ -0,0 +1,10 @@
+GIT v1.6.3.1 Release Notes
+==========================
+
+Fixes since v1.6.3
+------------------
+
+* "git checkout -b new-branch" with a staged change in the index
+  incorrectly primed the in-index cache-tree, resulting a wrong tree
+  object to be written out of the index.  This is a grave regression
+  since the last 1.6.2.X maintenance release.
diff --git a/third_party/git/Documentation/RelNotes/1.6.3.2.txt b/third_party/git/Documentation/RelNotes/1.6.3.2.txt
new file mode 100644
index 0000000000..b2f3f0293c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.3.2.txt
@@ -0,0 +1,61 @@
+GIT v1.6.3.2 Release Notes
+==========================
+
+Fixes since v1.6.3.1
+--------------------
+
+ * A few codepaths picked up the first few bytes from an sha1[] by
+   casting the (char *) pointer to (int *); GCC 4.4 did not like this,
+   and aborted compilation.
+
+ * Some unlink(2) failures went undiagnosed.
+
+ * The "recursive" merge strategy misbehaved when faced rename/delete
+   conflicts while coming up with an intermediate merge base.
+
+ * The low-level merge algorithm did not handle a degenerate case of
+   merging a file with itself using itself as the common ancestor
+   gracefully.  It should produce the file itself, but instead
+   produced an empty result.
+
+ * GIT_TRACE mechanism segfaulted when tracing a shell-quoted aliases.
+
+ * OpenBSD also uses st_ctimspec in "struct stat", instead of "st_ctim".
+
+ * With NO_CROSS_DIRECTORY_HARDLINKS, "make install" can be told not to
+   create hardlinks between $(gitexecdir)/git-$builtin_commands and
+   $(bindir)/git.
+
+ * command completion code in bash did not reliably detect that we are
+   in a bare repository.
+
+ * "git add ." in an empty directory complained that pathspec "." did not
+   match anything, which may be technically correct, but not useful.  We
+   silently make it a no-op now.
+
+ * "git add -p" (and "patch" action in "git add -i") was broken when
+   the first hunk that adds a line at the top was split into two and
+   both halves are marked to be used.
+
+ * "git blame path" misbehaved at the commit where path became file
+   from a directory with some files in it.
+
+ * "git for-each-ref" had a segfaulting bug when dealing with a tag object
+   created by an ancient git.
+
+ * "git format-patch -k" still added patch numbers if format.numbered
+   configuration was set.
+
+ * "git grep --color ''" did not terminate.  The command also had
+   subtle bugs with its -w option.
+
+ * http-push had a small use-after-free bug.
+
+ * "git push" was converting OFS_DELTA pack representation into less
+   efficient REF_DELTA representation unconditionally upon transfer,
+   making the transferred data unnecessarily larger.
+
+ * "git remote show origin" segfaulted when origin was still empty.
+
+Many other general usability updates around help text, diagnostic messages
+and documentation are included as well.
diff --git a/third_party/git/Documentation/RelNotes/1.6.3.3.txt b/third_party/git/Documentation/RelNotes/1.6.3.3.txt
new file mode 100644
index 0000000000..1c28398bb6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.3.3.txt
@@ -0,0 +1,38 @@
+GIT v1.6.3.3 Release Notes
+==========================
+
+Fixes since v1.6.3.2
+--------------------
+
+ * "git archive" running on Cygwin can get stuck in an infinite loop.
+
+ * "git daemon" did not correctly parse the initial line that carries
+   virtual host request information.
+
+ * "git diff --textconv" leaked memory badly when the textconv filter
+   errored out.
+
+ * The built-in regular expressions to pick function names to put on
+   hunk header lines for java and objc were very inefficiently written.
+
+ * in certain error situations git-fetch (and git-clone) on Windows didn't
+   detect connection abort and ended up waiting indefinitely.
+
+ * import-tars script (in contrib) did not import symbolic links correctly.
+
+ * http.c used CURLOPT_SSLKEY even on libcURL version 7.9.2, even though
+   it was only available starting 7.9.3.
+
+ * low-level filelevel merge driver used return value from strdup()
+   without checking if we ran out of memory.
+
+ * "git rebase -i" left stray closing parenthesis in its reflog message.
+
+ * "git remote show" did not show all the URLs associated with the named
+   remote, even though "git remote -v" did.  Made them consistent by
+   making the former show all URLs.
+
+ * "whitespace" attribute that is set was meant to detect all errors known
+   to git, but it told git to ignore trailing carriage-returns.
+
+Includes other documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.6.3.4.txt b/third_party/git/Documentation/RelNotes/1.6.3.4.txt
new file mode 100644
index 0000000000..cad461bc76
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.3.4.txt
@@ -0,0 +1,36 @@
+GIT v1.6.3.4 Release Notes
+==========================
+
+Fixes since v1.6.3.3
+--------------------
+
+ * "git add --no-ignore-errors" did not override configured
+   add.ignore-errors configuration.
+
+ * "git apply --whitespace=fix" did not fix trailing whitespace on an
+   incomplete line.
+
+ * "git branch" opened too many commit objects unnecessarily.
+
+ * "git checkout -f $commit" with a path that is a file (or a symlink) in
+   the work tree to a commit that has a directory at the path issued an
+   unnecessary error message.
+
+ * "git diff -c/--cc" was very inefficient in coalescing the removed lines
+   shared between parents.
+
+ * "git diff -c/--cc" showed removed lines at the beginning of a file
+   incorrectly.
+
+ * "git remote show nickname" did not honor configured
+   remote.nickname.uploadpack when inspecting the branches at the remote.
+
+ * "git request-pull" when talking to the terminal for a preview
+   showed some of the output in the pager.
+
+ * "git request-pull start nickname [end]" did not honor configured
+   remote.nickname.uploadpack when it ran git-ls-remote against the remote
+   repository to learn the current tip of branches.
+
+Includes other documentation updates and minor fixes.
+
diff --git a/third_party/git/Documentation/RelNotes/1.6.3.txt b/third_party/git/Documentation/RelNotes/1.6.3.txt
new file mode 100644
index 0000000000..418c685cf8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.3.txt
@@ -0,0 +1,182 @@
+GIT v1.6.3 Release Notes
+========================
+
+With the next major release, "git push" into a branch that is
+currently checked out will be refused by default.  You can choose
+what should happen upon such a push by setting the configuration
+variable receive.denyCurrentBranch in the receiving repository.
+
+To ease the transition plan, the receiving repository of such a
+push running this release will issue a big warning when the
+configuration variable is missing.  Please refer to:
+
+  http://git.or.cz/gitwiki/GitFaq#non-bare
+  http://thread.gmane.org/gmane.comp.version-control.git/107758/focus=108007
+
+for more details on the reason why this change is needed and the
+transition plan.
+
+For a similar reason, "git push $there :$killed" to delete the branch
+$killed in a remote repository $there, if $killed branch is the current
+branch pointed at by its HEAD, gets a large warning.  You can choose what
+should happen upon such a push by setting the configuration variable
+receive.denyDeleteCurrent in the receiving repository.
+
+When the user does not tell "git push" what to push, it has always
+pushed matching refs.  For some people it is unexpected, and a new
+configuration variable push.default has been introduced to allow
+changing a different default behaviour.  To advertise the new feature,
+a big warning is issued if this is not configured and a git push without
+arguments is attempted.
+
+
+Updates since v1.6.2
+--------------------
+
+(subsystems)
+
+* various git-svn updates.
+
+* git-gui updates, including an update to Russian translation, and a
+  fix to an infinite loop when showing an empty diff.
+
+* gitk updates, including an update to Russian translation and improved Windows
+  support.
+
+(performance)
+
+* many uses of lstat(2) in the codepath for "git checkout" have been
+  optimized out.
+
+(usability, bells and whistles)
+
+* Boolean configuration variable yes/no can be written as on/off.
+
+* rsync:/path/to/repo can be used to run git over rsync for local
+  repositories.  It may not be useful in practice; meant primarily for
+  testing.
+
+* http transport learned to prompt and use password when fetching from or
+  pushing to http://user@host.xz/ URL.
+
+* (msysgit) progress output that is sent over the sideband protocol can
+  be handled appropriately in Windows console.
+
+* "--pretty=<style>" option to the log family of commands can now be
+  spelled as "--format=<style>".  In addition, --format=%formatstring
+  is a short-hand for --pretty=tformat:%formatstring.
+
+* "--oneline" is a synonym for "--pretty=oneline --abbrev-commit".
+
+* "--graph" to the "git log" family can draw the commit ancestry graph
+  in colors.
+
+* If you realize that you botched the patch when you are editing hunks
+  with the 'edit' action in git-add -i/-p, you can abort the editor to
+  tell git not to apply it.
+
+* @{-1} is a new way to refer to the last branch you were on introduced in
+  1.6.2, but the initial implementation did not teach this to a few
+  commands.  Now the syntax works with "branch -m @{-1} newname".
+
+* git-archive learned --output=<file> option.
+
+* git-archive takes attributes from the tree being archived; strictly
+  speaking, this is an incompatible behaviour change, but is a good one.
+  Use --worktree-attributes option to allow it to read attributes from
+  the work tree as before (deprecated git-tar tree command always reads
+  attributes from the work tree).
+
+* git-bisect shows not just the number of remaining commits whose goodness
+  is unknown, but also shows the estimated number of remaining rounds.
+
+* You can give --date=<format> option to git-blame.
+
+* "git-branch -r" shows HEAD symref that points at a remote branch in
+  interest of each tracked remote repository.
+
+* "git-branch -v -v" is a new way to get list of names for branches and the
+  "upstream" branch for them.
+
+* git-config learned -e option to open an editor to edit the config file
+  directly.
+
+* git-clone runs post-checkout hook when run without --no-checkout.
+
+* git-difftool is now part of the officially supported command, primarily
+  maintained by David Aguilar.
+
+* git-for-each-ref learned a new "upstream" token.
+
+* git-format-patch can be told to use attachment with a new configuration,
+  format.attach.
+
+* git-format-patch can be told to produce deep or shallow message threads.
+
+* git-format-patch can be told to always add sign-off with a configuration
+  variable.
+
+* git-format-patch learned format.headers configuration to add extra
+  header fields to the output.  This behaviour is similar to the existing
+  --add-header=<header> option of the command.
+
+* git-format-patch gives human readable names to the attached files, when
+  told to send patches as attachments.
+
+* git-grep learned to highlight the found substrings in color.
+
+* git-imap-send learned to work around Thunderbird's inability to easily
+  disable format=flowed with a new configuration, imap.preformattedHTML.
+
+* git-rebase can be told to rebase the series even if your branch is a
+  descendant of the commit you are rebasing onto with --force-rebase
+  option.
+
+* git-rebase can be told to report diffstat with the --stat option.
+
+* Output from git-remote command has been vastly improved.
+
+* "git remote update --prune $remote" updates from the named remote and
+  then prunes stale tracking branches.
+
+* git-send-email learned --confirm option to review the Cc: list before
+  sending the messages out.
+
+(developers)
+
+* Test scripts can be run under valgrind.
+
+* Test scripts can be run with installed git.
+
+* Makefile learned 'coverage' option to run the test suites with
+  coverage tracking enabled.
+
+* Building the manpages with docbook-xsl between 1.69.1 and 1.71.1 now
+  requires setting DOCBOOK_SUPPRESS_SP to work around a docbook-xsl bug.
+  This workaround used to be enabled by default, but causes problems
+  with newer versions of docbook-xsl.  In addition, there are a few more
+  knobs you can tweak to work around issues with various versions of the
+  docbook-xsl package.  See comments in Documentation/Makefile for details.
+
+* Support for building and testing a subset of git on a system without a
+  working perl has been improved.
+
+
+Fixes since v1.6.2
+------------------
+
+All of the fixes in v1.6.2.X maintenance series are included in this
+release, unless otherwise noted.
+
+Here are fixes that this release has, but have not been backported to
+v1.6.2.X series.
+
+* "git-apply" rejected a patch that swaps two files (i.e. renames A to B
+  and B to A at the same time).  May need to be backported by cherry
+  picking d8c81df and then 7fac0ee).
+
+* The initial checkout did not read the attributes from the .gitattribute
+  file that is being checked out.
+
+* git-gc spent excessive amount of time to decide if an object appears
+  in a locally existing pack (if needed, backport by merging 69e020a).
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.1.txt b/third_party/git/Documentation/RelNotes/1.6.4.1.txt
new file mode 100644
index 0000000000..e439e45b96
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.1.txt
@@ -0,0 +1,46 @@
+GIT v1.6.4.1 Release Notes
+==========================
+
+Fixes since v1.6.4
+------------------
+
+ * An unquoted value in the configuration file, when it contains more than
+   one whitespaces in a row, got them replaced with a single space.
+
+ * "git am" used to accept a single piece of e-mail per file (not a mbox)
+   as its input, but multiple input format support in v1.6.4 broke it.
+   Apparently many people have been depending on this feature.
+
+ * The short help text for "git filter-branch" command was a single long
+   line, wrapped by terminals, and was hard to read.
+
+ * The "recursive" strategy of "git merge" segfaulted when a merge has
+   more than one merge-bases, and merging of these merge-bases involves
+   a rename/rename or a rename/add conflict.
+
+ * "git pull --rebase" did not use the right fork point when the
+   repository has already fetched from the upstream that rewinds the
+   branch it is based on in an earlier fetch.
+
+ * Explain the concept of fast-forward more fully in "git push"
+   documentation, and hint to refer to it from an error message when the
+   command refuses an update to protect the user.
+
+ * The default value for pack.deltacachesize, used by "git repack", is now
+   256M, instead of unbounded.  Otherwise a repack of a moderately sized
+   repository would needlessly eat into swap.
+
+ * Document how "git repack" (hence "git gc") interacts with a repository
+   that borrows its objects from other repositories (e.g. ones created by
+   "git clone -s").
+
+ * "git show" on an annotated tag lacked a delimiting blank line between
+   the tag itself and the contents of the object it tags.
+
+ * "git verify-pack -v" erroneously reported number of objects with too
+   deep delta depths as "chain length 0" objects.
+
+ * Long names of authors and committers outside US-ASCII were sometimes
+   incorrectly shown in "gitweb".
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.2.txt b/third_party/git/Documentation/RelNotes/1.6.4.2.txt
new file mode 100644
index 0000000000..c11ec0115c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.2.txt
@@ -0,0 +1,32 @@
+GIT v1.6.4.2 Release Notes
+==========================
+
+Fixes since v1.6.4.1
+--------------------
+
+* --date=relative output between 1 and 5 years ago rounded the number of
+    years when saying X years Y months ago, instead of rounding it down.
+
+* "git add -p" did not handle changes in executable bits correctly
+  (a regression around 1.6.3).
+
+* "git apply" did not honor GNU diff's convention to mark the creation/deletion
+  event with UNIX epoch timestamp on missing side.
+
+* "git checkout" incorrectly removed files in a directory pointed by a
+  symbolic link during a branch switch that replaces a directory with
+  a symbolic link.
+
+* "git clean -d -f" happily descended into a subdirectory that is managed by a
+  separate git repository.  It now requires two -f options for safety.
+
+* "git fetch/push" over http transports had two rather grave bugs.
+
+* "git format-patch --cover-letter" did not prepare the cover letter file
+  for use with non-ASCII strings when there are the series contributors with
+  non-ASCII names.
+
+* "git pull origin branch" and "git fetch origin && git merge origin/branch"
+  left different merge messages in the resulting commit.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.3.txt b/third_party/git/Documentation/RelNotes/1.6.4.3.txt
new file mode 100644
index 0000000000..5643e6537d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.3.txt
@@ -0,0 +1,29 @@
+GIT v1.6.4.3 Release Notes
+==========================
+
+Fixes since v1.6.4.2
+--------------------
+
+* "git clone" from an empty repository gave unnecessary error message,
+  even though it did everything else correctly.
+
+* "git cvsserver" invoked git commands via "git-foo" style, which has long
+  been deprecated.
+
+* "git fetch" and "git clone" had an extra sanity check to verify the
+  presence of the corresponding *.pack file before downloading *.idx
+  file by issuing a HEAD request.  Github server however sometimes
+  gave 500 (Internal server error) response to HEAD even if a GET
+  request for *.pack file to the same URL would have succeeded, and broke
+  clone over HTTP from some of their repositories.  As a workaround, this
+  verification has been removed (as it is not absolutely necessary).
+
+* "git grep" did not like relative pathname to refer outside the current
+  directory when run from a subdirectory.
+
+* an error message from "git push" was formatted in a very ugly way.
+
+* "git svn" did not quote the subversion user name correctly when
+  running its author-prog helper program.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.4.txt b/third_party/git/Documentation/RelNotes/1.6.4.4.txt
new file mode 100644
index 0000000000..0ead45fc72
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.4.txt
@@ -0,0 +1,26 @@
+GIT v1.6.4.4 Release Notes
+==========================
+
+Fixes since v1.6.4.4
+--------------------
+
+* The workaround for Github server that sometimes gave 500 (Internal server
+  error) response to HEAD requests in 1.6.4.3 introduced a regression that
+  caused re-fetching projects over http to segfault in certain cases due
+  to uninitialized pointer being freed.
+
+* "git pull" on an unborn branch used to consider anything in the work
+  tree and the index discardable.
+
+* "git diff -b/w" did not work well on the incomplete line at the end of
+  the file, due to an incorrect hashing of lines in the low-level xdiff
+  routines.
+
+* "git checkout-index --prefix=$somewhere" used to work when $somewhere is
+  a symbolic link to a directory elsewhere, but v1.6.4.2 broke it.
+
+* "git unpack-objects --strict", invoked when receive.fsckobjects
+  configuration is set in the receiving repository of "git push", did not
+  properly check the objects, especially the submodule links, it received.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.5.txt b/third_party/git/Documentation/RelNotes/1.6.4.5.txt
new file mode 100644
index 0000000000..eb6307dcbb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.5.txt
@@ -0,0 +1,20 @@
+Git v1.6.4.5 Release Notes
+==========================
+
+Fixes since v1.6.4.4
+--------------------
+
+ * Simplified base85 implementation.
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git count-objects" did not handle packs larger than 4G.
+
+ * "git rev-parse --parseopt --stop-at-non-option" did not stop at non option
+   when --keep-dashdash was in effect.
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
+
+Other minor fixes and documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.4.txt b/third_party/git/Documentation/RelNotes/1.6.4.txt
new file mode 100644
index 0000000000..7a904419f7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.4.txt
@@ -0,0 +1,147 @@
+GIT v1.6.4 Release Notes
+========================
+
+With the next major release, "git push" into a branch that is
+currently checked out will be refused by default.  You can choose
+what should happen upon such a push by setting the configuration
+variable receive.denyCurrentBranch in the receiving repository.
+
+To ease the transition plan, the receiving repository of such a
+push running this release will issue a big warning when the
+configuration variable is missing.  Please refer to:
+
+  http://git.or.cz/gitwiki/GitFaq#non-bare
+  http://thread.gmane.org/gmane.comp.version-control.git/107758/focus=108007
+
+for more details on the reason why this change is needed and the
+transition plan.
+
+For a similar reason, "git push $there :$killed" to delete the branch
+$killed in a remote repository $there, if $killed branch is the current
+branch pointed at by its HEAD, gets a large warning.  You can choose what
+should happen upon such a push by setting the configuration variable
+receive.denyDeleteCurrent in the receiving repository.
+
+
+Updates since v1.6.3
+--------------------
+
+(subsystems)
+
+ * gitweb Perl style clean-up.
+
+ * git-svn updates, including a new --authors-prog option to map author
+   names by invoking an external program, 'git svn reset' to unwind
+   'git svn fetch', support for more than one branches, documenting
+   of the useful --minimize-url feature, new "git svn gc" command, etc.
+
+(portability)
+
+ * We feed iconv with "UTF-8" instead of "utf8"; the former is
+   understood more widely.  Similarly updated test scripts to use
+   encoding names more widely understood (e.g. use "ISO8859-1" instead
+   of "ISO-8859-1").
+
+ * Various portability fixes/workarounds for different vintages of
+   SunOS, IRIX, and Windows.
+
+ * Git-over-ssh transport on Windows supports PuTTY plink and TortoisePlink.
+
+(performance)
+
+ * Many repeated use of lstat() are optimized out in "checkout" codepath.
+
+ * git-status (and underlying git-diff-index --cached) are optimized
+   to take advantage of cache-tree information in the index.
+
+(usability, bells and whistles)
+
+ * "git add --edit" lets users edit the whole patch text to fine-tune what
+   is added to the index.
+
+ * "git am" accepts StGIT series file as its input.
+
+ * "git bisect skip" skips to a more randomly chosen place in the hope
+   to avoid testing a commit that is too close to a commit that is
+   already known to be untestable.
+
+ * "git cvsexportcommit" learned -k option to stop CVS keywords expansion
+
+ * "git fast-export" learned to handle history simplification more
+   gracefully.
+
+ * "git fast-export" learned an option --tag-of-filtered-object to handle
+   dangling tags resulting from history simplification more usefully.
+
+ * "git grep" learned -p option to show the location of the match using the
+   same context hunk marker "git diff" uses.
+
+ * https transport can optionally be told that the used client
+   certificate is password protected, in which case it asks the
+   password only once.
+
+ * "git imap-send" is IPv6 aware.
+
+ * "git log --graph" draws graphs more compactly by using horizontal lines
+   when able.
+
+ * "git log --decorate" shows shorter refnames by stripping well-known
+   refs/* prefix.
+
+ * "git push $name" honors remote.$name.pushurl if present before
+   using remote.$name.url.  In other words, the URL used for fetching
+   and pushing can be different.
+
+ * "git send-email" understands quoted aliases in .mailrc files (might
+   have to be backported to 1.6.3.X).
+
+ * "git send-email" can fetch the sender address from the configuration
+   variable "sendmail.from" (and "sendmail.<identity>.from").
+
+ * "git show-branch" can color its output.
+
+ * "add" and "update" subcommands to "git submodule" learned --reference
+   option to use local clone with references.
+
+ * "git submodule update" learned --rebase option to update checked
+   out submodules by rebasing the local changes.
+
+ * "gitweb" can optionally use gravatar to adorn author/committer names.
+
+(developers)
+
+ * A major part of the "git bisect" wrapper has moved to C.
+
+ * Formatting with the new version of AsciiDoc 8.4.1 is now supported.
+
+Fixes since v1.6.3
+------------------
+
+All of the fixes in v1.6.3.X maintenance series are included in this
+release, unless otherwise noted.
+
+Here are fixes that this release has, but have not been backported to
+v1.6.3.X series.
+
+ * "git diff-tree -r -t" used to omit new or removed directories from
+   the output.  df533f3 (diff-tree -r -t: include added/removed
+   directories in the output, 2009-06-13) may need to be cherry-picked
+   to backport this fix.
+
+ * The way Git.pm sets up a Repository object was not friendly to callers
+   that chdir around.  It now internally records the repository location
+   as an absolute path when autodetected.
+
+ * Removing a section with "git config --remove-section", when its
+   section header has a variable definition on the same line, lost
+   that variable definition.
+
+ * "git rebase -p --onto" used to always leave side branches of a merge
+   intact, even when both branches are subject to rewriting.
+
+ * "git repack" used to faithfully follow grafts and considered true
+   parents recorded in the commit object unreachable from the commit.
+   After such a repacking, you cannot remove grafts without corrupting
+   the repository.
+
+ * "git send-email" did not detect erroneous loops in alias expansion.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.1.txt b/third_party/git/Documentation/RelNotes/1.6.5.1.txt
new file mode 100644
index 0000000000..309ba181b2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.1.txt
@@ -0,0 +1,20 @@
+GIT v1.6.5.1 Release Notes
+==========================
+
+Fixes since v1.6.5
+------------------
+
+ * An corrupt pack could make codepath to read objects into an
+   infinite loop.
+
+ * Download throughput display was always shown in KiB/s but on fast links
+   it is more appropriate to show it in MiB/s.
+
+ * "git grep -f filename" used uninitialized variable and segfaulted.
+
+ * "git clone -b branch" gave a wrong commit object name to post-checkout
+   hook.
+
+ * "git pull" over http did not work on msys.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.2.txt b/third_party/git/Documentation/RelNotes/1.6.5.2.txt
new file mode 100644
index 0000000000..aa7ccce3a2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.2.txt
@@ -0,0 +1,19 @@
+GIT v1.6.5.2 Release Notes
+==========================
+
+Fixes since v1.6.5.1
+--------------------
+
+ * Installation of templates triggered a bug in busybox when using tar
+   implementation from it.
+
+ * "git add -i" incorrectly ignored paths that are already in the index
+   if they matched .gitignore patterns.
+
+ * "git describe --always" should have produced some output even there
+   were no tags in the repository, but it didn't.
+
+ * "git ls-files" when showing tracked files incorrectly paid attention
+   to the exclude patterns.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.3.txt b/third_party/git/Documentation/RelNotes/1.6.5.3.txt
new file mode 100644
index 0000000000..b2fad1b22e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.3.txt
@@ -0,0 +1,63 @@
+Git v1.6.5.3 Release Notes
+==========================
+
+Fixes since v1.6.5.2
+--------------------
+
+ * info/grafts file didn't ignore trailing CR at the end of lines.
+
+ * Packages generated on newer FC were unreadable by older versions of
+   RPM as the new default is to use stronger hash.
+
+ * output from "git blame" was unreadable when the file ended in an
+   incomplete line.
+
+ * "git add -i/-p" didn't handle deletion of empty files correctly.
+
+ * "git clone" takes up to two parameters, but did not complain when
+   given more arguments than necessary and silently ignored them.
+
+ * "git cvsimport" did not read files given as command line arguments
+   correctly when it is run from a subdirectory.
+
+ * "git diff --color-words -U0" didn't work correctly.
+
+ * The handling of blank lines at the end of file by "git diff/apply
+   --whitespace" was inconsistent with the other kinds of errors.
+   They are now colored, warned against, and fixed the same way as others.
+
+ * There was no way to allow blank lines at the end of file without
+   allowing extra blanks at the end of lines.  You can use blank-at-eof
+   and blank-at-eol whitespace error class to specify them separately.
+   The old trailing-space error class is now a short-hand to set both.
+
+ * "-p" option to "git format-patch" was supposed to suppress diffstat
+   generation, but it was broken since 1.6.1.
+
+ * "git imap-send" did not compile cleanly with newer OpenSSL.
+
+ * "git help -a" outside of a git repository was broken.
+
+ * "git ls-files -i" was supposed to be inverse of "git ls-files" without -i
+   with respect to exclude patterns, but it was broken since 1.6.5.2.
+
+ * "git ls-remote" outside of a git repository over http was broken.
+
+ * "git rebase -i" gave bogus error message when the command word was
+   misspelled.
+
+ * "git receive-pack" that is run in response to "git push" did not run
+   garbage collection nor update-server-info, but in larger hosting sites,
+   these almost always need to be run.  To help site administrators, the
+   command now runs "gc --auto" and "u-s-i" by setting receive.autogc
+   and receive.updateserverinfo configuration variables, respectively.
+
+ * Release notes spelled the package name with incorrect capitalization.
+
+ * "gitweb" did not escape non-ascii characters correctly in the URL.
+
+ * "gitweb" showed "patch" link even for merge commits.
+
+ * "gitweb" showed incorrect links for blob line numbers in pathinfo mode.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.4.txt b/third_party/git/Documentation/RelNotes/1.6.5.4.txt
new file mode 100644
index 0000000000..d3a2a3e712
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.4.txt
@@ -0,0 +1,32 @@
+Git v1.6.5.4 Release Notes
+==========================
+
+Fixes since v1.6.5.3
+--------------------
+
+ * "git help" (without argument) used to check if you are in a directory
+   under git control. There was no breakage in behaviour per-se, but this
+   was unnecessary.
+
+ * "git prune-packed" gave progress output even when its standard error is
+   not connected to a terminal; this caused cron jobs that run it to
+   produce crufts.
+
+ * "git pack-objects --all-progress" is an option to ask progress output
+   from write-object phase _if_ progress output were to be produced, and
+   shouldn't have forced the progress output.
+
+ * "git apply -p<n> --directory=<elsewhere>" did not work well for a
+   non-default value of n.
+
+ * "git merge foo HEAD" was misparsed as an old-style invocation of the
+   command and produced a confusing error message.  As it does not specify
+   any other branch to merge, it shouldn't be mistaken as such.  We will
+   remove the old style "git merge <message> HEAD <commit>..."  syntax in
+   future versions, but not in this release,
+
+ * "git merge -m <message> <branch>..." added the standard merge message
+   on its own after user-supplied message, which should have overridden the
+   standard one.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.5.txt b/third_party/git/Documentation/RelNotes/1.6.5.5.txt
new file mode 100644
index 0000000000..ecfc57d875
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.5.txt
@@ -0,0 +1,49 @@
+Git v1.6.5.5 Release Notes
+==========================
+
+Fixes since v1.6.5.4
+--------------------
+
+ * Manual pages can be formatted with older xmlto again.
+
+ * GREP_OPTIONS exported from user's environment could have broken
+   our scripted commands.
+
+ * In configuration files, a few variables that name paths can begin with
+   ~/ and ~username/ and they are expanded as expected.  This is not a
+   bugfix but 1.6.6 will have this and without backporting users cannot
+   easily use the same ~/.gitconfig across versions.
+
+ * "git diff -B -M" did the same computation to hash lines of contents
+   twice, and held onto memory after it has used the data in it
+   unnecessarily before it freed.
+
+ * "git diff -B" and "git diff --dirstat" was not counting newly added
+   contents correctly.
+
+ * "git format-patch revisions... -- path" issued an incorrect error
+   message that suggested to use "--" on the command line when path
+   does not exist in the current work tree (it is a separate matter if
+   it makes sense to limit format-patch with pathspecs like that
+   without using the --full-diff option).
+
+ * "git grep -F -i StRiNg" did not work as expected.
+
+ * Enumeration of available merge strategies iterated over the list of
+   commands in a wrong way, sometimes producing an incorrect result.
+
+ * "git shortlog" did not honor the "encoding" header embedded in the
+   commit object like "git log" did.
+
+ * Reading progress messages that come from the remote side while running
+   "git pull" is given precedence over reading the actual pack data to
+   prevent garbled progress message on the user's terminal.
+
+ * "git rebase" got confused when the log message began with certain
+   strings that looked like Subject:, Date: or From: header.
+
+ * "git reset" accidentally run in .git/ directory checked out the
+   work tree contents in there.
+
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.6.txt b/third_party/git/Documentation/RelNotes/1.6.5.6.txt
new file mode 100644
index 0000000000..a9eaf76f62
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.6.txt
@@ -0,0 +1,23 @@
+Git v1.6.5.6 Release Notes
+==========================
+
+Fixes since v1.6.5.5
+--------------------
+
+ * "git add -p" had a regression since v1.6.5.3 that broke deletion of
+   non-empty files.
+
+ * "git archive -o o.zip -- Makefile" produced an archive in o.zip
+   but in POSIX tar format.
+
+ * Error message given to "git pull --rebase" when the user didn't give
+   enough clue as to what branch to integrate with still talked about
+   "merging with" the branch.
+
+ * Error messages given by "git merge" when the merge resulted in a
+   fast-forward still were in plumbing lingo, even though in v1.6.5
+   we reworded messages in other cases.
+
+ * The post-upload-hook run by upload-pack in response to "git fetch" has
+   been removed, due to security concerns (the hook first appeared in
+   1.6.5).
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.7.txt b/third_party/git/Documentation/RelNotes/1.6.5.7.txt
new file mode 100644
index 0000000000..dc5302c21c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.7.txt
@@ -0,0 +1,19 @@
+Git v1.6.5.7 Release Notes
+==========================
+
+Fixes since v1.6.5.6
+--------------------
+
+* If a user specifies a color for a <slot> (i.e. a class of things to show
+  in a particular color) that is known only by newer versions of git
+  (e.g. "color.diff.func" was recently added for upcoming 1.6.6 release),
+  an older version of git should just ignore them.  Instead we diagnosed
+  it as an error.
+
+* With help.autocorrect set to non-zero value, the logic to guess typos
+  in the subcommand name misfired and ran a random nonsense command.
+
+* If a command is run with an absolute path as a pathspec inside a bare
+  repository, e.g. "rev-list HEAD -- /home", the code tried to run
+  strlen() on NULL, which is the result of get_git_work_tree(), and
+  segfaulted.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.8.txt b/third_party/git/Documentation/RelNotes/1.6.5.8.txt
new file mode 100644
index 0000000000..8b24bebb96
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.8.txt
@@ -0,0 +1,28 @@
+Git v1.6.5.8 Release Notes
+==========================
+
+Fixes since v1.6.5.7
+--------------------
+
+* "git count-objects" did not handle packfiles that are bigger than 4G on
+  platforms with 32-bit off_t.
+
+* "git rebase -i" did not abort cleanly if it failed to launch the editor.
+
+* "git blame" did not work well when commit lacked the author name.
+
+* "git fast-import" choked when handling a tag that points at an object
+  that is not a commit.
+
+* "git reset --hard" did not work correctly when GIT_WORK_TREE environment
+  variable is used to point at the root of the true work tree.
+
+* "git grep" fed a buffer that is not NUL-terminated to underlying
+  regexec().
+
+* "git checkout -m other" while on a branch that does not have any commit
+  segfaulted, instead of failing.
+
+* "git branch -a other" should have diagnosed the command as an error.
+
+Other minor documentation updates are also included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.9.txt b/third_party/git/Documentation/RelNotes/1.6.5.9.txt
new file mode 100644
index 0000000000..bb469dd71e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.9.txt
@@ -0,0 +1,18 @@
+Git v1.6.5.9 Release Notes
+==========================
+
+Fixes since v1.6.5.8
+--------------------
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git blame -L $start,$end" segfaulted when too large $start was given.
+
+ * "git rev-parse --parseopt --stop-at-non-option" did not stop at non option
+   when --keep-dashdash was in effect.
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
+
+Other minor fixes and documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.5.txt b/third_party/git/Documentation/RelNotes/1.6.5.txt
new file mode 100644
index 0000000000..ee141c19ad
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.5.txt
@@ -0,0 +1,169 @@
+GIT v1.6.5 Release Notes
+========================
+
+In git 1.7.0, which was planned to be the release after 1.6.5, "git
+push" into a branch that is currently checked out will be refused by
+default.
+
+You can choose what should happen upon such a push by setting the
+configuration variable receive.denyCurrentBranch in the receiving
+repository.
+
+Also, "git push $there :$killed" to delete the branch $killed in a remote
+repository $there, when $killed branch is the current branch pointed at by
+its HEAD, will be refused by default.
+
+You can choose what should happen upon such a push by setting the
+configuration variable receive.denyDeleteCurrent in the receiving
+repository.
+
+To ease the transition plan, the receiving repository of such a
+push running this release will issue a big warning when the
+configuration variable is missing.  Please refer to:
+
+  http://git.or.cz/gitwiki/GitFaq#non-bare
+  http://thread.gmane.org/gmane.comp.version-control.git/107758/focus=108007
+
+for more details on the reason why this change is needed and the
+transition plan.
+
+Updates since v1.6.4
+--------------------
+
+(subsystems)
+
+ * various updates to gitk, git-svn and gitweb.
+
+(portability)
+
+ * more improvements on mingw port.
+
+ * mingw will also give FRSX as the default value for the LESS
+   environment variable when the user does not have one.
+
+ * initial support to compile git on Windows with MSVC.
+
+(performance)
+
+ * On major platforms, the system can be compiled to use with Linus's
+   block-sha1 implementation of the SHA-1 hash algorithm, which
+   outperforms the default fallback implementation we borrowed from
+   Mozilla.
+
+ * Unnecessary inefficiency in deepening of a shallow repository has
+   been removed.
+
+ * "git clone" does not grab objects that it does not need (i.e.
+   referenced only from refs outside refs/heads and refs/tags
+   hierarchy) anymore.
+
+ * The "git" main binary used to link with libcurl, which then dragged
+   in a large number of external libraries.  When using basic plumbing
+   commands in scripts, this unnecessarily slowed things down.  We now
+   implement http/https/ftp transfer as a separate executable as we
+   used to.
+
+ * "git clone" run locally hardlinks or copies the files in .git/ to
+   newly created repository.  It used to give new mtime to copied files,
+   but this delayed garbage collection to trigger unnecessarily in the
+   cloned repository.  We now preserve mtime for these files to avoid
+   this issue.
+
+(usability, bells and whistles)
+
+ * Human writable date format to various options, e.g. --since=yesterday,
+   master@{2000.09.17}, are taught to infer some omitted input properly.
+
+ * A few programs gave verbose "advice" messages to help uninitiated
+   people when issuing error messages.  An infrastructure to allow
+   users to squelch them has been introduced, and a few such messages
+   can be silenced now.
+
+ * refs/replace/ hierarchy is designed to be usable as a replacement
+   of the "grafts" mechanism, with the added advantage that it can be
+   transferred across repositories.
+
+ * "git am" learned to optionally ignore whitespace differences.
+
+ * "git am" handles input e-mail files that has CRLF line endings sensibly.
+
+ * "git am" learned "--scissors" option to allow you to discard early part
+   of an incoming e-mail.
+
+ * "git archive -o output.zip" works without being told what format to
+   use with an explicit "--format=zip".option.
+
+ * "git checkout", "git reset" and "git stash" learned to pick and
+   choose to use selected changes you made, similar to "git add -p".
+
+ * "git clone" learned a "-b" option to pick a HEAD to check out
+   different from the remote's default branch.
+
+ * "git clone" learned --recursive option.
+
+ * "git clone" from a local repository on a different filesystem used to
+   copy individual object files without preserving the old timestamp, giving
+   them extra lifetime in the new repository until they gc'ed.
+
+ * "git commit --dry-run $args" is a new recommended way to ask "what would
+   happen if I try to commit with these arguments."
+
+ * "git commit --dry-run" and "git status" shows conflicted paths in a
+   separate section to make them easier to spot during a merge.
+
+ * "git cvsimport" now supports password-protected pserver access even
+   when the password is not taken from ~/.cvspass file.
+
+ * "git fast-export" learned --no-data option that can be useful when
+   reordering commits and trees without touching the contents of
+   blobs.
+
+ * "git fast-import" has a pair of new front-end in contrib/ area.
+
+ * "git init" learned to mkdir/chdir into a directory when given an
+   extra argument (i.e. "git init this").
+
+ * "git instaweb" optionally can use mongoose as the web server.
+
+ * "git log --decorate" can optionally be told with --decorate=full to
+   give the reference name in full.
+
+ * "git merge" issued an unnecessarily scary message when it detected
+   that the merge may have to touch the path that the user has local
+   uncommitted changes to. The message has been reworded to make it
+   clear that the command aborted, without doing any harm.
+
+ * "git push" can be told to be --quiet.
+
+ * "git push" pays attention to url.$base.pushInsteadOf and uses a URL
+   that is derived from the URL used for fetching.
+
+ * informational output from "git reset" that lists the locally modified
+   paths is made consistent with that of "git checkout $another_branch".
+
+ * "git submodule" learned to give submodule name to scripts run with
+   "foreach" subcommand.
+
+ * various subcommands to "git submodule" learned --recursive option.
+
+ * "git submodule summary" learned --files option to compare the work
+   tree vs the commit bound at submodule path, instead of comparing
+   the index.
+
+ * "git upload-pack", which is the server side support for "git clone" and
+   "git fetch", can call a new post-upload-pack hook for statistics purposes.
+
+(developers)
+
+ * With GIT_TEST_OPTS="--root=/p/a/t/h", tests can be run outside the
+   source directory; using tmpfs may give faster turnaround.
+
+ * With NO_PERL_MAKEMAKER set, DESTDIR= is now honoured, so you can
+   build for one location, and install into another location to tar it
+   up.
+
+Fixes since v1.6.4
+------------------
+
+All of the fixes in v1.6.4.X maintenance series are included in this
+release, unless otherwise noted.
diff --git a/third_party/git/Documentation/RelNotes/1.6.6.1.txt b/third_party/git/Documentation/RelNotes/1.6.6.1.txt
new file mode 100644
index 0000000000..f1d0a4ae2d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.6.1.txt
@@ -0,0 +1,37 @@
+Git v1.6.6.1 Release Notes
+==========================
+
+Fixes since v1.6.6
+------------------
+
+ * "git blame" did not work well when commit lacked the author name.
+
+ * "git branch -a name" wasn't diagnosed as an error.
+
+ * "git count-objects" did not handle packfiles that are bigger than 4G on
+   platforms with 32-bit off_t.
+
+ * "git checkout -m other" while on a branch that does not have any commit
+   segfaulted, instead of failing.
+
+ * "git fast-import" choked when fed a tag that do not point at a
+   commit.
+
+ * "git grep" finding from work tree files could have fed garbage to
+   the underlying regexec(3).
+
+ * "git grep -L" didn't show empty files (they should never match, and
+   they should always appear in -L output as unmatching).
+
+ * "git rebase -i" did not abort cleanly if it failed to launch the editor.
+
+ * "git reset --hard" did not work correctly when GIT_WORK_TREE environment
+   variable is used to point at the root of the true work tree.
+
+ * http-backend was not listed in the command list in the documentation.
+
+ * Building on FreeBSD (both 7 and 8) needs OLD_ICONV set in the Makefile
+
+ * "git checkout -m some-branch" while on an unborn branch crashed.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.6.2.txt b/third_party/git/Documentation/RelNotes/1.6.6.2.txt
new file mode 100644
index 0000000000..4eaddc0106
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.6.2.txt
@@ -0,0 +1,46 @@
+Git v1.6.6.2 Release Notes
+==========================
+
+Fixes since v1.6.6.1
+--------------------
+
+ * recursive merge didn't correctly diagnose its own programming errors,
+   and instead caused the caller to segfault.
+
+ * The new "smart http" aware clients probed the web servers to see if
+   they support smart http, but did not fall back to dumb http transport
+   correctly with some servers.
+
+ * Time based reflog syntax e.g. "@{yesterday}" didn't diagnose a misspelled
+   time specification and instead assumed "@{now}".
+
+ * "git archive HEAD -- no-such-directory" produced an empty archive
+   without complaining.
+
+ * "git blame -L start,end -- file" misbehaved when given a start that is
+   larger than the number of lines in the file.
+
+ * "git checkout -m" didn't correctly call custom merge backend supplied
+   by the end user.
+
+ * "git config -f <file>" misbehaved when run from a subdirectory.
+
+ * "git cvsserver" didn't like having regex metacharacters (e.g. '+') in
+   CVSROOT environment.
+
+ * "git fast-import" did not correctly handle large blobs that may
+   bust the pack size limit.
+
+ * "git gui" is supposed to work even when launched from inside a .git
+   directory.
+
+ * "git gui" misbehaved when applying a hunk that ends with deletion.
+
+ * "git imap-send" did not honor imap.preformattedHTML as documented.
+
+ * "git log" family incorrectly showed the commit notes unconditionally by
+   mistake, which was especially irritating when running "git log --oneline".
+
+ * "git status" shouldn't require an write access to the repository.
+
+Other minor documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.6.3.txt b/third_party/git/Documentation/RelNotes/1.6.6.3.txt
new file mode 100644
index 0000000000..11483acaec
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.6.3.txt
@@ -0,0 +1,23 @@
+Git v1.6.6.3 Release Notes
+==========================
+
+Fixes since v1.6.6.2
+--------------------
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git bisect $path" did not correctly diagnose an error when given a
+   non-existent path.
+
+ * "git blame -L $start,$end" segfaulted when too large $start was given.
+
+ * "git imap-send" did not write draft box with CRLF line endings per RFC.
+
+ * "git rev-parse --parseopt --stop-at-non-option" did not stop at non option
+   when --keep-dashdash was in effect.
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
+
+Other minor fixes and documentation updates are included.
diff --git a/third_party/git/Documentation/RelNotes/1.6.6.txt b/third_party/git/Documentation/RelNotes/1.6.6.txt
new file mode 100644
index 0000000000..c50b59c495
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.6.6.txt
@@ -0,0 +1,224 @@
+Git v1.6.6 Release Notes
+========================
+
+Notes on behaviour change
+-------------------------
+
+ * In this release, "git fsck" defaults to "git fsck --full" and
+   checks packfiles, and because of this it will take much longer to
+   complete than before.  If you prefer a quicker check only on loose
+   objects (the old default), you can say "git fsck --no-full".  This
+   has been supported by 1.5.4 and newer versions of git, so it is
+   safe to write it in your script even if you use slightly older git
+   on some of your machines.
+
+Preparing yourselves for compatibility issues in 1.7.0
+------------------------------------------------------
+
+In git 1.7.0, which is planned to be the release after 1.6.6, there will
+be a handful of behaviour changes that will break backward compatibility.
+
+These changes were discussed long time ago and existing behaviours have
+been identified as more problematic to the userbase than keeping them for
+the sake of backward compatibility.
+
+When necessary, a transition strategy for existing users has been designed
+not to force them running around setting configuration variables and
+updating their scripts in order to either keep the traditional behaviour
+or adjust to the new behaviour, on the day their sysadmin decides to install
+the new version of git.  When we switched from "git-foo" to "git foo" in
+1.6.0, even though the change had been advertised and the transition
+guide had been provided for a very long time, the users procrastinated
+during the entire transition period, and ended up panicking on the day
+their sysadmins updated their git installation.  We are trying to avoid
+repeating that unpleasantness in the 1.7.0 release.
+
+For changes decided to be in 1.7.0, commands that will be affected
+have been much louder to strongly discourage such procrastination, and
+they continue to be in this release.  If you have been using recent
+versions of git, you would have seen warnings issued when you used
+features whose behaviour will change, with a clear instruction on how
+to keep the existing behaviour if you want to.  You hopefully are
+already well prepared.
+
+Of course, we have also been giving "this and that will change in
+1.7.0; prepare yourselves" warnings in the release notes and
+announcement messages for the past few releases.  Let's see how well
+users will fare this time.
+
+ * "git push" into a branch that is currently checked out (i.e. pointed by
+   HEAD in a repository that is not bare) will be refused by default.
+
+   Similarly, "git push $there :$killed" to delete the branch $killed
+   in a remote repository $there, when $killed branch is the current
+   branch pointed at by its HEAD, will be refused by default.
+
+   Setting the configuration variables receive.denyCurrentBranch and
+   receive.denyDeleteCurrent to 'ignore' in the receiving repository
+   can be used to override these safety features.  Versions of git
+   since 1.6.2 have issued a loud warning when you tried to do these
+   operations without setting the configuration, so repositories of
+   people who still need to be able to perform such a push should
+   already have been future proofed.
+
+   Please refer to:
+
+   http://git.or.cz/gitwiki/GitFaq#non-bare
+   http://thread.gmane.org/gmane.comp.version-control.git/107758/focus=108007
+
+   for more details on the reason why this change is needed and the
+   transition process that already took place so far.
+
+ * "git send-email" will not make deep threads by default when sending a
+   patch series with more than two messages.  All messages will be sent
+   as a reply to the first message, i.e. cover letter.  Git 1.6.6 (this
+   release) will issue a warning about the upcoming default change, when
+   it uses the traditional "deep threading" behaviour as the built-in
+   default.  To squelch the warning but still use the "deep threading"
+   behaviour, give --chain-reply-to option or set sendemail.chainreplyto
+   to true.
+
+   It has been possible to configure send-email to send "shallow thread"
+   by setting sendemail.chainreplyto configuration variable to false.
+   The only thing 1.7.0 release will do is to change the default when
+   you haven't configured that variable.
+
+ * "git status" will not be "git commit --dry-run".  This change does not
+   affect you if you run the command without pathspec.
+
+   Nobody sane found the current behaviour of "git status Makefile" useful
+   nor meaningful, and it confused users.  "git commit --dry-run" has been
+   provided as a way to get the current behaviour of this command since
+   1.6.5.
+
+ * "git diff" traditionally treated various "ignore whitespace" options
+   only as a way to filter the patch output.  "git diff --exit-code -b"
+   exited with non-zero status even if all changes were about changing the
+   amount of whitespace and nothing else.  and "git diff -b" showed the
+   "diff --git" header line for such a change without patch text.
+
+   In 1.7.0, the "ignore whitespaces" will affect the semantics of the
+   diff operation itself.  A change that does not affect anything but
+   whitespaces will be reported with zero exit status when run with
+   --exit-code, and there will not be "diff --git" header for such a
+   change.
+
+
+Updates since v1.6.5
+--------------------
+
+(subsystems)
+
+ * various gitk updates including use of themed widgets under Tk 8.5,
+   Japanese translation, a fix to a bug when running "gui blame" from
+   a subdirectory, etc.
+
+ * various git-gui updates including new translations, wm states fixes,
+   Tk bug workaround after quitting, improved heuristics to trigger gc,
+   etc.
+
+ * various git-svn updates.
+
+ * "git fetch" over http learned a new mode that is different from the
+   traditional "dumb commit walker".
+
+(portability)
+
+ * imap-send can be built on mingw port.
+
+(performance)
+
+ * "git diff -B" has smaller memory footprint.
+
+(usability, bells and whistles)
+
+ * The object replace mechanism can be bypassed with --no-replace-objects
+   global option given to the "git" program.
+
+ * In configuration files, a few variables that name paths can begin with ~/
+   and ~username/ and they are expanded as expected.
+
+ * "git subcmd -h" now shows short usage help for many more subcommands.
+
+ * "git bisect reset" can reset to an arbitrary commit.
+
+ * "git checkout frotz" when there is no local branch "frotz" but there
+   is only one remote tracking branch "frotz" is taken as a request to
+   start the named branch at the corresponding remote tracking branch.
+
+ * "git commit -c/-C/--amend" can be told with a new "--reset-author" option
+   to ignore authorship information in the commit it is taking the message
+   from.
+
+ * "git describe" can be told to add "-dirty" suffix with "--dirty" option.
+
+ * "git diff" learned --submodule option to show a list of one-line logs
+   instead of differences between the commit object names.
+
+ * "git diff" learned to honor diff.color.func configuration to paint
+   function name hint printed on the hunk header "@@ -j,k +l,m @@" line
+   in the specified color.
+
+ * "git fetch" learned --all and --multiple options, to run fetch from
+   many repositories, and --prune option to remove remote tracking
+   branches that went stale.  These make "git remote update" and "git
+   remote prune" less necessary (there is no plan to remove "remote
+   update" nor "remote prune", though).
+
+ * "git fsck" by default checks the packfiles (i.e. "--full" is the
+   default); you can turn it off with "git fsck --no-full".
+
+ * "git grep" can use -F (fixed strings) and -i (ignore case) together.
+
+ * import-tars contributed fast-import frontend learned more types of
+   compressed tarballs.
+
+ * "git instaweb" knows how to talk with mod_cgid to apache2.
+
+ * "git log --decorate" shows the location of HEAD as well.
+
+ * "git log" and "git rev-list" learned to take revs and pathspecs from
+   the standard input with the new "--stdin" option.
+
+ * "--pretty=format" option to "log" family of commands learned:
+
+   . to wrap text with the "%w()" specifier.
+   . to show reflog information with "%g[sdD]" specifier.
+
+ * "git notes" command to annotate existing commits.
+
+ * "git merge" (and "git pull") learned --ff-only option to make it fail
+   if the merge does not result in a fast-forward.
+
+ * "git mergetool" learned to use p4merge.
+
+ * "git rebase -i" learned "reword" that acts like "edit" but immediately
+   starts an editor to tweak the log message without returning control to
+   the shell, which is done by "edit" to give an opportunity to tweak the
+   contents.
+
+ * "git send-email" can be told with "--envelope-sender=auto" to use the
+   same address as "From:" address as the envelope sender address.
+
+ * "git send-email" will issue a warning when it defaults to the
+   --chain-reply-to behaviour without being told by the user and
+   instructs to prepare for the change of the default in 1.7.0 release.
+
+ * In "git submodule add <repository> <path>", <path> is now optional and
+   inferred from <repository> the same way "git clone <repository>" does.
+
+ * "git svn" learned to read SVN 1.5+ and SVK merge tickets.
+
+ * "git svn" learned to recreate empty directories tracked only by SVN.
+
+ * "gitweb" can optionally render its "blame" output incrementally (this
+   requires JavaScript on the client side).
+
+ * Author names shown in gitweb output are links to search commits by the
+   author.
+
+Fixes since v1.6.5
+------------------
+
+All of the fixes in v1.6.5.X maintenance series are included in this
+release, unless otherwise noted.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.1.txt b/third_party/git/Documentation/RelNotes/1.7.0.1.txt
new file mode 100644
index 0000000000..8ff5bcada8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.1.txt
@@ -0,0 +1,35 @@
+Git v1.7.0.1 Release Notes
+==========================
+
+Fixes since v1.7.0
+------------------
+
+ * In a freshly created repository "rev-parse HEAD^0" complained that
+   it is dangling symref, even though "rev-parse HEAD" didn't.
+
+ * "git show :no-such-name" tried to access the index without bounds
+   check, leading to a potential segfault.
+
+ * Message from "git cherry-pick" was harder to read and use than necessary
+   when it stopped due to conflicting changes.
+
+ * We referred to ".git/refs/" throughout the documentation when we
+   meant to talk about abstract notion of "ref namespace".  Because
+   people's repositories often have packed refs these days, this was
+   confusing.
+
+ * "git diff --output=/path/that/cannot/be/written" did not correctly
+   error out.
+
+ * "git grep -e -pattern-that-begin-with-dash paths..." could not be
+   spelled as "git grep -- -pattern-that-begin-with-dash paths..." which
+   would be a GNU way to use "--" as "end of options".
+
+ * "git grep" compiled with threading support tried to access an
+   uninitialized mutex on boxes with a single CPU.
+
+ * "git stash pop -q --index" failed because the unnecessary --index
+   option was propagated to "git stash drop" that is internally run at the
+   end.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.2.txt b/third_party/git/Documentation/RelNotes/1.7.0.2.txt
new file mode 100644
index 0000000000..fcb46ca6a4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.2.txt
@@ -0,0 +1,40 @@
+Git v1.7.0.2 Release Notes
+==========================
+
+Fixes since v1.7.0.1
+--------------------
+
+ * GIT_PAGER was not honored consistently by some scripted Porcelains, most
+   notably "git am".
+
+ * updating working tree files after telling git to add them to the
+   index and while it is still working created garbage object files in
+   the repository without diagnosing it as an error.
+
+ * "git bisect -- pathspec..." did not diagnose an error condition properly when
+   the simplification with given pathspec made the history empty.
+
+ * "git rev-list --cherry-pick A...B" now has an obvious optimization when the
+   histories haven't diverged (i.e. when one end is an ancestor of the other).
+
+ * "git diff --quiet -w" did not work as expected.
+
+ * "git fast-import" didn't work with a large input, as it lacked support
+   for producing the pack index in v2 format.
+
+ * "git imap-send" didn't use CRLF line endings over the imap protocol
+   when storing its payload to the draft box, violating RFC 3501.
+
+ * "git log --format='%w(x,y,z)%b'" and friends that rewrap message
+   has been optimized for utf-8 payload.
+
+ * Error messages generated on the receiving end did not come back to "git
+   push".
+
+ * "git status" in 1.7.0 lacked the optimization we used to have in 1.6.X series
+   to speed up scanning of large working tree.
+
+ * "gitweb" did not diagnose parsing errors properly while reading tis configuration
+   file.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.3.txt b/third_party/git/Documentation/RelNotes/1.7.0.3.txt
new file mode 100644
index 0000000000..3b355737c0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.3.txt
@@ -0,0 +1,34 @@
+Git v1.7.0.3 Release Notes
+==========================
+
+Fixes since v1.7.0.2
+--------------------
+
+ * Object files are created in a more ACL friendly way in repositories
+   where group permission is ACL controlled.
+
+ * "git add -i" didn't handle a deleted path very well.
+
+ * "git blame" padded line numbers with one extra SP when the total number
+   of lines was one less than multiple of ten due to an off-by-one error.
+
+ * "git fetch --all/--multi" used to discard information for remotes that
+   are fetched earlier.
+
+ * "git log --author=me --grep=it" tried to find commits that have "it"
+   or are written by "me", instead of the ones that have "it" _and_ are
+   written by "me".
+
+ * "git log -g branch" misbehaved when there was no entries in the reflog
+   for the named branch.
+
+ * "git mailinfo" (hence "git am") incorrectly removed initial indent from
+   paragraphs.
+
+ * "git prune" and "git reflog" (hence "git gc" as well) didn't honor
+   an instruction never to expire by setting gc.reflogexpire to never.
+
+ * "git push" misbehaved when branch.<name>.merge was configured without
+   matching branch.<name>.remote.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.4.txt b/third_party/git/Documentation/RelNotes/1.7.0.4.txt
new file mode 100644
index 0000000000..cf7f60e60d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.4.txt
@@ -0,0 +1,27 @@
+Git v1.7.0.4 Release Notes
+==========================
+
+Fixes since v1.7.0.3
+--------------------
+
+ * Optimized ntohl/htonl on big-endian machines were broken.
+
+ * Color values given to "color.<cmd>.<slot>" configuration can now have
+   more than one attributes (e.g. "bold ul").
+
+ * "git add -u nonexistent-path" did not complain.
+
+ * "git apply --whitespace=fix" didn't work well when an early patch in
+   a patch series adds trailing blank lines and a later one depended on
+   such a block of blank lines at the end.
+
+ * "git fast-export" didn't check error status and stop when marks file
+   cannot be opened.
+
+ * "git format-patch --ignore-if-in-upstream" gave unwarranted errors
+   when the range was empty, instead of silently finishing.
+
+ * "git remote prune" did not detect remote tracking refs that became
+   dangling correctly.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.5.txt b/third_party/git/Documentation/RelNotes/1.7.0.5.txt
new file mode 100644
index 0000000000..3149c91b7b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.5.txt
@@ -0,0 +1,26 @@
+Git v1.7.0.5 Release Notes
+==========================
+
+Fixes since v1.7.0.4
+--------------------
+
+ * "git daemon" failed to compile on platforms without sockaddr_storage type.
+
+ * Output from "git rev-list --pretty=oneline" was unparsable when a
+   commit did not have any message, which is abnormal but possible in a
+   repository converted from foreign scm.
+
+ * "git stash show <commit-that-is-not-a-stash>" gave an error message
+   that was not so useful.  Reworded the message to "<it> is not a
+   stash".
+
+ * Python scripts in contrib/ area now start with "#!/usr/bin/env python"
+   to honor user's PATH.
+
+ * "git imap-send" used to mistake any line that begins with "From " as a
+   message separator in format-patch output.
+
+ * Smart http server backend failed to report an internal server error and
+   infinitely looped instead after output pipe was closed.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.6.txt b/third_party/git/Documentation/RelNotes/1.7.0.6.txt
new file mode 100644
index 0000000000..b2852b67d0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.6.txt
@@ -0,0 +1,13 @@
+Git v1.7.0.6 Release Notes
+==========================
+
+Fixes since v1.7.0.5
+--------------------
+
+ * "git diff --stat" used "int" to count the size of differences,
+   which could result in overflowing.
+
+ * "git rev-list --abbrev-commit" defaulted to 40-byte abbreviations, unlike
+   newer tools in the git toolset.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.7.txt b/third_party/git/Documentation/RelNotes/1.7.0.7.txt
new file mode 100644
index 0000000000..d0cb7ca7e2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.7.txt
@@ -0,0 +1,16 @@
+Git v1.7.0.7 Release Notes
+==========================
+
+Fixes since v1.7.0.6
+--------------------
+
+ * "make NO_CURL=NoThanks install" was broken.
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git config --path conf.var" to attempt to expand a variable conf.var
+   that uses "~/" short-hand segfaulted when $HOME environment variable
+   was not set.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.8.txt b/third_party/git/Documentation/RelNotes/1.7.0.8.txt
new file mode 100644
index 0000000000..7f05b48e17
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.8.txt
@@ -0,0 +1,10 @@
+Git v1.7.0.8 Release Notes
+==========================
+
+This is primarily to backport support for the new "add.ignoreErrors"
+name given to the existing "add.ignore-errors" configuration variable.
+
+The next version, Git 1.7.4, and future versions, will support both
+old and incorrect name and the new corrected name, but without this
+backport, users who want to use the new name "add.ignoreErrors" in
+their repositories cannot use older versions of Git.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.9.txt b/third_party/git/Documentation/RelNotes/1.7.0.9.txt
new file mode 100644
index 0000000000..bfb3166387
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.9.txt
@@ -0,0 +1,8 @@
+Git v1.7.0.9 Release Notes
+==========================
+
+Fixes since v1.7.0.8
+--------------------
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
diff --git a/third_party/git/Documentation/RelNotes/1.7.0.txt b/third_party/git/Documentation/RelNotes/1.7.0.txt
new file mode 100644
index 0000000000..0bb8c0b2a2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.0.txt
@@ -0,0 +1,214 @@
+Git v1.7.0 Release Notes
+========================
+
+Notes on behaviour change
+-------------------------
+
+ * "git push" into a branch that is currently checked out (i.e. pointed at by
+   HEAD in a repository that is not bare) is refused by default.
+
+   Similarly, "git push $there :$killed" to delete the branch $killed
+   in a remote repository $there, when $killed branch is the current
+   branch pointed at by its HEAD, will be refused by default.
+
+   Setting the configuration variables receive.denyCurrentBranch and
+   receive.denyDeleteCurrent to 'ignore' in the receiving repository
+   can be used to override these safety features.
+
+ * "git send-email" does not make deep threads by default when sending a
+   patch series with more than two messages.  All messages will be sent
+   as a reply to the first message, i.e. cover letter.
+
+   It has been possible already to configure send-email to send "shallow thread"
+   by setting sendemail.chainreplyto configuration variable to false.  The
+   only thing this release does is to change the default when you haven't
+   configured that variable.
+
+ * "git status" is not "git commit --dry-run" anymore.  This change does
+   not affect you if you run the command without argument.
+
+ * "git diff" traditionally treated various "ignore whitespace" options
+   only as a way to filter the patch output.  "git diff --exit-code -b"
+   exited with non-zero status even if all changes were about changing the
+   amount of whitespace and nothing else;  and "git diff -b" showed the
+   "diff --git" header line for such a change without patch text.
+
+   In this release, the "ignore whitespaces" options affect the semantics
+   of the diff operation.  A change that does not affect anything but
+   whitespaces is reported with zero exit status when run with
+   --exit-code, and there is no "diff --git" header for such a change.
+
+ * External diff and textconv helpers are now executed using the shell.
+   This makes them consistent with other programs executed by git, and
+   allows you to pass command-line parameters to the helpers. Any helper
+   paths containing spaces or other metacharacters now need to be
+   shell-quoted.  The affected helpers are GIT_EXTERNAL_DIFF in the
+   environment, and diff.*.command and diff.*.textconv in the config
+   file.
+
+ * The --max-pack-size argument to 'git repack', 'git pack-objects', and
+   'git fast-import' was assuming the provided size to be expressed in MiB,
+   unlike the corresponding config variable and other similar options accepting
+   a size value.  It is now expecting a size expressed in bytes, with a possible
+   unit suffix of 'k', 'm', or 'g'.
+
+Updates since v1.6.6
+--------------------
+
+(subsystems)
+
+ * "git fast-import" updates; adds "option" and "feature" to detect the
+   mismatch between fast-import and the frontends that produce the input
+   stream.
+
+ * "git svn" support of subversion "merge tickets" and miscellaneous fixes.
+
+ * "gitk" and "git gui" translation updates.
+
+ * "gitweb" updates (code clean-up, load checking etc.)
+
+(portability)
+
+ * Some more MSVC portability patches for msysgit port.
+
+ * Minimum Pthreads emulation for msysgit port.
+
+(performance)
+
+ * More performance improvement patches for msysgit port.
+
+(usability, bells and whistles)
+
+ * More commands learned "--quiet" and "--[no-]progress" options.
+
+ * Various commands given by the end user (e.g. diff.type.textconv,
+   and GIT_EDITOR) can be specified with command line arguments.  E.g. it
+   is now possible to say "[diff "utf8doc"] textconv = nkf -w".
+
+ * "sparse checkout" feature allows only part of the work tree to be
+   checked out.
+
+ * HTTP transfer can use authentication scheme other than basic
+   (i.e./e.g. digest).
+
+ * Switching from a version of superproject that used to have a submodule
+   to another version of superproject that no longer has it did not remove
+   the submodule directory when it should (namely, when you are not
+   interested in the submodule at all and didn't clone/checkout).
+
+ * A new attribute conflict-marker-size can be used to change the size of
+   the conflict markers from the default 7; this is useful when tracked
+   contents (e.g. git-merge documentation) have strings that resemble the
+   conflict markers.
+
+ * A new syntax "<branch>@{upstream}" can be used on the command line to
+   substitute the name of the "upstream" of the branch.  Missing branch
+   defaults to the current branch, so "git fetch && git merge @{upstream}"
+   will be equivalent to "git pull".
+
+ * "git am --resolved" has a synonym "git am --continue".
+
+ * "git branch --set-upstream" can be used to update the (surprise!) upstream,
+   i.e. where the branch is supposed to pull and merge from (or rebase onto).
+
+ * "git checkout A...B" is a way to detach HEAD at the merge base between
+   A and B.
+
+ * "git checkout -m path" to reset the work tree file back into the
+   conflicted state works even when you already ran "git add path" and
+   resolved the conflicts.
+
+ * "git commit --date='<date>'" can be used to override the author date
+   just like "git commit --author='<name> <email>'" can be used to
+   override the author identity.
+
+ * "git commit --no-status" can be used to omit the listing of the index
+   and the work tree status in the editor used to prepare the log message.
+
+ * "git commit" warns a bit more aggressively until you configure user.email,
+   whose default value almost always is not (and fundamentally cannot be)
+   what you want.
+
+ * "git difftool" has been extended to make it easier to integrate it
+   with gitk.
+
+ * "git fetch --all" can now be used in place of "git remote update".
+
+ * "git grep" does not rely on external grep anymore.  It can use more than
+   one thread to accelerate the operation.
+
+ * "git grep" learned "--quiet" option.
+
+ * "git log" and friends learned "--glob=heads/*" syntax that is a more
+   flexible way to complement "--branches/--tags/--remotes".
+
+ * "git merge" learned to pass options specific to strategy-backends.  E.g.
+
+    - "git merge -Xsubtree=path/to/directory" can be used to tell the subtree
+      strategy how much to shift the trees explicitly.
+
+    - "git merge -Xtheirs" can be used to auto-merge as much as possible,
+      while discarding your own changes and taking merged version in
+      conflicted regions.
+
+ * "git push" learned "git push origin --delete branch", a syntactic sugar
+   for "git push origin :branch".
+
+ * "git push" learned "git push --set-upstream origin forker:forkee" that
+   lets you configure your "forker" branch to later pull from "forkee"
+   branch at "origin".
+
+ * "git rebase --onto A...B" means the history is replayed on top of the
+   merge base between A and B.
+
+ * "git rebase -i" learned new action "fixup" that squashes the change
+   but does not affect existing log message.
+
+ * "git rebase -i" also learned --autosquash option that is useful
+   together with the new "fixup" action.
+
+ * "git remote" learned set-url subcommand that updates (surprise!) url
+   for an existing remote nickname.
+
+ * "git rerere" learned "forget path" subcommand.  Together with "git
+   checkout -m path" it will be useful when you recorded a wrong
+   resolution.
+
+ * Use of "git reset --merge" has become easier when resetting away a
+   conflicted mess left in the work tree.
+
+ * "git rerere" had rerere.autoupdate configuration but there was no way
+   to countermand it from the command line; --no-rerere-autoupdate option
+   given to "merge", "revert", etc. fixes this.
+
+ * "git status" learned "-s(hort)" output format.
+
+(developers)
+
+ * The infrastructure to build foreign SCM interface has been updated.
+
+ * Many more commands are now built-in.
+
+ * THREADED_DELTA_SEARCH is no more.  If you build with threads, delta
+   compression will always take advantage of it.
+
+Fixes since v1.6.6
+------------------
+
+All of the fixes in v1.6.6.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * "git branch -d branch" used to refuse deleting the branch even when
+   the branch is fully merged to its upstream branch if it is not merged
+   to the current branch.  It now deletes it in such a case.
+
+ * "filter-branch" command incorrectly said --prune-empty and --filter-commit
+   were incompatible; the latter should be read as --commit-filter.
+
+ * When using "git status" or asking "git diff" to compare the work tree
+   with something, they used to consider that a checked-out submodule with
+   uncommitted changes is not modified; this could cause people to forget
+   committing these changes in the submodule before committing in the
+   superproject. They now consider such a change as a modification and
+   "git diff" will append a "-dirty" to the work tree side when generating
+   patch output or when used with the --submodule option.
diff --git a/third_party/git/Documentation/RelNotes/1.7.1.1.txt b/third_party/git/Documentation/RelNotes/1.7.1.1.txt
new file mode 100644
index 0000000000..3f6b3148a3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.1.1.txt
@@ -0,0 +1,96 @@
+Git v1.7.1.1 Release Notes
+==========================
+
+Fixes since v1.7.1
+------------------
+
+ * Authentication over http transport can now be made lazily, in that the
+   request can first go to a URL without username, get a 401 response and
+   then the client will ask for the username to use.
+
+ * We used to mistakenly think "../work" is a subdirectory of the current
+   directory when we are in "../work-xyz".
+
+ * The attribute mechanism now allows an entry that uses an attribute
+   macro that set/unset one attribute, immediately followed by an
+   overriding setting; this makes attribute macros much easier to use.
+
+ * We didn't recognize timezone "Z" as a synonym for "UTC" (75b37e70).
+
+ * In 1.7.0, read-tree and user commands that use the mechanism such as
+   checkout and merge were fixed to handle switching between branches one
+   of which has a file while the other has a directory at the same path
+   correctly even when there are some "confusing" pathnames in them.  But
+   the algorithm used for this fix was suboptimal and had a terrible
+   performance degradation especially in larger trees.
+
+ * "git am -3" did not show diagnosis when the patch in the message was corrupt.
+
+ * After "git apply --whitespace=fix" removed trailing blank lines in an
+   patch in a patch series, it failed to apply later patches that depend
+   on the presence of such blank lines.
+
+ * "git bundle --stdin" segfaulted.
+
+ * "git checkout" and "git rebase" overwrote paths that are marked "assume
+   unchanged".
+
+ * "git commit --amend" on a commit with an invalid author-name line that
+   lacks the display name didn't work.
+
+ * "git describe" did not tie-break tags that point at the same commit
+   correctly; newer ones are preferred by paying attention to the
+   tagger date now.
+
+ * "git diff" used to tell underlying xdiff machinery to work very hard to
+   minimize the output, but this often was spending too many extra cycles
+   for very little gain.
+
+ * "git diff --color" did not paint extended diff headers per line
+   (i.e. the coloring escape sequence didn't end at the end of line),
+   which confused "less -R".
+
+ * "git fetch" over HTTP verifies the downloaded packfiles more robustly.
+
+ * The memory usage by "git index-pack" (run during "git fetch" and "git
+   push") got leaner.
+
+ * "GIT_DIR=foo.git git init --bare bar.git" created foo.git instead of bar.git.
+
+ * "git log --abbrev=$num --format='%h' ignored --abbrev=$num.
+
+ * "git ls-files ../out/side/cwd" refused to work.
+
+ * "git merge --log" used to replace the custom message given by "-m" with
+   the shortlog, instead of appending to it.
+
+ * "git notes copy" without any other argument segfaulted.
+
+ * "git pull" accepted "--dry-run", gave it to underlying "git fetch" but
+   ignored the option itself, resulting in a bogus attempt to merge
+   unrelated commit.
+
+ * "git rebase" did not faithfully reproduce a malformed author ident, that
+   is often seen in a repository converted from foreign SCMs.
+
+ * "git reset --hard" started from a wrong directory and a working tree in
+   a nonstandard location is in use got confused.
+
+ * "git send-email" lacked a way to specify the domainname used in the
+   EHLO/HELO exchange, causing rejected connection from picky servers.
+   It learned --smtp-domain option to solve this issue.
+
+ * "git send-email" did not declare a content-transfer-encoding and
+   content-type even when its payload needs to be sent in 8-bit.
+
+ * "git show -C -C" and other corner cases lost diff metainfo output
+   in 1.7.0.
+
+ * "git stash" incorrectly lost paths in the working tree that were
+   previously removed from the index.
+
+ * "git status" stopped refreshing the index by mistake in 1.7.1.
+
+ * "git status" showed excess "hints" even when advice.statusHints is set to false.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.1.2.txt b/third_party/git/Documentation/RelNotes/1.7.1.2.txt
new file mode 100644
index 0000000000..61ba14e262
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.1.2.txt
@@ -0,0 +1,28 @@
+Git v1.7.1.2 Release Notes
+==========================
+
+Fixes since v1.7.1.1
+--------------------
+
+ * "git commit" did not honor GIT_REFLOG_ACTION environment variable, resulting
+   reflog messages for cherry-pick and revert actions to be recorded as "commit".
+
+ * "git clone/fetch/pull" issued an incorrect error message when a ref and
+   a symref that points to the ref were updated at the same time.  This
+   obviously would update them to the same value, and should not result in
+   an error condition.
+
+ * "git diff" inside a tree with many pathnames that have certain
+   characters has become very slow in 1.7.0 by mistake.
+
+ * "git rev-parse --parseopt --stop-at-non-option" did not stop at non option
+   when --keep-dashdash was in effect.
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git config --path conf.var" to attempt to expand a variable conf.var
+   that uses "~/" short-hand segfaulted when $HOME environment variable
+   was not set.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.1.3.txt b/third_party/git/Documentation/RelNotes/1.7.1.3.txt
new file mode 100644
index 0000000000..5b18518449
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.1.3.txt
@@ -0,0 +1,10 @@
+Git v1.7.1.3 Release Notes
+==========================
+
+This is primarily to backport support for the new "add.ignoreErrors"
+name given to the existing "add.ignore-errors" configuration variable.
+
+The next version, Git 1.7.4, and future versions, will support both
+old and incorrect name and the new corrected name, but without this
+backport, users who want to use the new name "add.ignoreErrors" in
+their repositories cannot use older versions of Git.
diff --git a/third_party/git/Documentation/RelNotes/1.7.1.4.txt b/third_party/git/Documentation/RelNotes/1.7.1.4.txt
new file mode 100644
index 0000000000..7c734b4f7b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.1.4.txt
@@ -0,0 +1,8 @@
+Git v1.7.1.4 Release Notes
+==========================
+
+Fixes since v1.7.1.3
+--------------------
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
diff --git a/third_party/git/Documentation/RelNotes/1.7.1.txt b/third_party/git/Documentation/RelNotes/1.7.1.txt
new file mode 100644
index 0000000000..9d89fedb36
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.1.txt
@@ -0,0 +1,89 @@
+Git v1.7.1 Release Notes
+========================
+
+Updates since v1.7.0
+--------------------
+
+ * Eric Raymond is the maintainer of updated CIAbot scripts, in contrib/.
+
+ * gitk updates.
+
+ * Some commands (e.g. svn and http interfaces) that interactively ask
+   for a password can be told to use an external program given via
+   GIT_ASKPASS.
+
+ * Conflict markers that lead the common ancestor in diff3-style output
+   now have a label, which hopefully would help third-party tools that
+   expect one.
+
+ * Comes with an updated bash-completion script.
+
+ * "git am" learned "--keep-cr" option to handle inputs that are
+   a mixture of changes to files with and without CRLF line endings.
+
+ * "git cvsimport" learned -R option to leave revision mapping between
+   CVS revisions and resulting git commits.
+
+ * "git diff --submodule" notices and describes dirty submodules.
+
+ * "git for-each-ref" learned %(symref), %(symref:short) and %(flag)
+   tokens.
+
+ * "git hash-object --stdin-paths" can take "--no-filters" option now.
+
+ * "git init" can be told to look at init.templatedir configuration
+   variable (obviously that has to come from either /etc/gitconfig or
+   $HOME/.gitconfig).
+
+ * "git grep" learned "--no-index" option, to search inside contents that
+   are not managed by git.
+
+ * "git grep" learned --color=auto/always/never.
+
+ * "git grep" learned to paint filename and line-number in colors.
+
+ * "git log -p --first-parent -m" shows one-parent diff for merge
+   commits, instead of showing combined diff.
+
+ * "git merge-file" learned to use custom conflict marker size and also
+   to use the "union merge" behaviour.
+
+ * "git notes" command has been rewritten in C and learned many commands
+   and features to help you carry notes forward across rebases and amends.
+
+ * "git request-pull" identifies the commit the request is relative to in
+   a more readable way.
+
+ * "git reset" learned "--keep" option that lets you discard commits
+   near the tip while preserving your local changes in a way similar
+   to how "git checkout branch" does.
+
+ * "git status" notices and describes dirty submodules.
+
+ * "git svn" should work better when interacting with repositories
+   with CRLF line endings.
+
+ * "git imap-send" learned to support CRAM-MD5 authentication.
+
+ * "gitweb" installation procedure can use "minified" js/css files
+   better.
+
+ * Various documentation updates.
+
+Fixes since v1.7.0
+------------------
+
+All of the fixes in v1.7.0.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * "git add frotz/nitfol" did not complain when the entire frotz/ directory
+   was ignored.
+
+ * "git diff --stat" used "int" to count the size of differences,
+   which could result in overflowing.
+
+ * "git rev-list --pretty=oneline" didn't terminate a record with LF for
+   commits without any message.
+
+ * "git rev-list --abbrev-commit" defaulted to 40-byte abbreviations, unlike
+   newer tools in the git toolset.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.1.txt b/third_party/git/Documentation/RelNotes/1.7.10.1.txt
new file mode 100644
index 0000000000..71a86cb7c6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.1.txt
@@ -0,0 +1,78 @@
+Git v1.7.10.1 Release Notes
+===========================
+
+Additions since v1.7.10
+-----------------------
+
+Localization message files for Danish and German have been added.
+
+
+Fixes since v1.7.10
+-------------------
+
+ * "git add -p" is not designed to deal with unmerged paths but did
+   not exclude them and tried to apply funny patches only to fail.
+
+ * "git blame" started missing quite a few changes from the origin
+   since we stopped using the diff minimization by default in v1.7.2
+   era.
+
+ * When PATH contains an unreadable directory, alias expansion code
+   did not kick in, and failed with an error that said "git-subcmd"
+   was not found.
+
+ * "git clean -d -f" (not "-d -f -f") is supposed to protect nested
+   working trees of independent git repositories that exist in the
+   current project working tree from getting removed, but the
+   protection applied only to such working trees that are at the
+   top-level of the current project by mistake.
+
+ * "git commit --author=$name" did not tell the name that was being
+   recorded in the resulting commit to hooks, even though it does do
+   so when the end user overrode the authorship via the
+   "GIT_AUTHOR_NAME" environment variable.
+
+ * When "git commit --template F" errors out because the user did not
+   touch the message, it claimed that it aborts due to "empty
+   message", which was utterly wrong.
+
+ * The regexp configured with diff.wordregex was incorrectly reused
+   across files.
+
+ * An age-old corner case bug in combine diff (only triggered with -U0
+   and the hunk at the beginning of the file needs to be shown) has
+   been fixed.
+
+ * Rename detection logic used to match two empty files as renames
+   during merge-recursive, leading to unnatural mismerges.
+
+ * The parser in "fast-import" did not diagnose ":9" style references
+   that is not followed by required SP/LF as an error.
+
+ * When "git fetch" encounters repositories with too many references,
+   the command line of "fetch-pack" that is run by a helper
+   e.g. remote-curl, may fail to hold all of them. Now such an
+   internal invocation can feed the references through the standard
+   input of "fetch-pack".
+
+ * "git fetch" that recurses into submodules on demand did not check
+   if it needs to go into submodules when non branches (most notably,
+   tags) are fetched.
+
+ * "log -p --graph" used with "--stat" had a few formatting error.
+
+ * Running "notes merge --commit" failed to perform correctly when run
+   from any directory inside $GIT_DIR/.  When "notes merge" stops with
+   conflicts, $GIT_DIR/NOTES_MERGE_WORKTREE is the place a user edits
+   to resolve it.
+
+ * The 'push to upstream' implementation was broken in some corner
+   cases. "git push $there" without refspec, when the current branch
+   is set to push to a remote different from $there, used to push to
+   $there using the upstream information to a remote unrelated to
+   $there.
+
+ * Giving "--continue" to a conflicted "rebase -i" session skipped a
+   commit that only results in changes to submodules.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.2.txt b/third_party/git/Documentation/RelNotes/1.7.10.2.txt
new file mode 100644
index 0000000000..7a7e9d6fd1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.2.txt
@@ -0,0 +1,85 @@
+Git v1.7.10.2 Release Notes
+===========================
+
+Fixes since v1.7.10.1
+---------------------
+
+ * The test scaffolding for git-daemon was flaky.
+
+ * The test scaffolding for fast-import was flaky.
+
+ * The filesystem boundary was not correctly reported when .git directory
+   discovery stopped at a mount point.
+
+ * HTTP transport that requires authentication did not work correctly when
+   multiple connections are used simultaneously.
+
+ * Minor memory leak during unpack_trees (hence "merge" and "checkout"
+   to check out another branch) has been plugged.
+
+ * In the older days, the header "Conflicts:" in "cherry-pick" and "merge"
+   was separated by a blank line from the list of paths that follow for
+   readability, but when "merge" was rewritten in C, we lost it by
+   mistake. Remove the newline from "cherry-pick" to make them match
+   again.
+
+ * The command line parser choked "git cherry-pick $name" when $name can
+   be both revision name and a pathname, even though $name can never be a
+   path in the context of the command.
+
+ * The "include.path" facility in the configuration mechanism added in
+   1.7.10 forgot to interpret "~/path" and "~user/path" as it should.
+
+ * "git config --rename-section" to rename an existing section into a
+   bogus one did not check the new name.
+
+ * The "diff --no-index" codepath used limited-length buffers, risking
+   pathnames getting truncated.  Update it to use the strbuf API.
+
+ * The report from "git fetch" said "new branch" even for a non branch
+   ref.
+
+ * The http-backend (the server side of the smart http transfer) used
+   to overwrite GIT_COMMITTER_NAME and GIT_COMMITTER_EMAIL with the
+   value obtained from REMOTE_USER unconditionally, making it
+   impossible for the server side site-specific customization to use
+   different identity sources to affect the names logged. It now uses
+   REMOTE_USER only as a fallback value.
+
+ * "log --graph" was not very friendly with "--stat" option and its
+   output had line breaks at wrong places.
+
+ * Octopus merge strategy did not reduce heads that are recorded in the
+   final commit correctly.
+
+ * "git push" over smart-http lost progress output a few releases ago;
+   this release resurrects it.
+
+ * The error and advice messages given by "git push" when it fails due
+   to non-ff were not very helpful to new users; it has been broken
+   into three cases, and each is given a separate advice message.
+
+ * The insn sheet given by "rebase -i" did not make it clear that the
+   insn lines can be re-ordered to affect the order of the commits in
+   the resulting history.
+
+ * "git repack" used to write out unreachable objects as loose objects
+   when repacking, even if such loose objects will immediately pruned
+   due to its age.
+
+ * A contrib script "rerere-train" did not work out of the box unless
+   user futzed with her $PATH.
+
+ * "git rev-parse --show-prefix" used to emit nothing when run at the
+   top-level of the working tree, but now it gives a blank line.
+
+ * The i18n of error message "git stash save" was not properly done.
+
+ * "git submodule" used a sed script that some platforms mishandled.
+
+ * When using a Perl script on a system where "perl" found on user's
+   $PATH could be ancient or otherwise broken, we allow builders to
+   specify the path to a good copy of Perl with $PERL_PATH.  The
+   gitweb test forgot to use that Perl when running its test.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.3.txt b/third_party/git/Documentation/RelNotes/1.7.10.3.txt
new file mode 100644
index 0000000000..703fbf1d60
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.3.txt
@@ -0,0 +1,43 @@
+Git v1.7.10.3 Release Notes
+===========================
+
+Fixes since v1.7.10.2
+---------------------
+
+ * The message file for German translation has been updated a bit.
+
+ * Running "git checkout" on an unborn branch used to corrupt HEAD.
+
+ * When checking out another commit from an already detached state, we
+   used to report all commits that are not reachable from any of the
+   refs as lossage, but some of them might be reachable from the new
+   HEAD, and there is no need to warn about them.
+
+ * Some time ago, "git clone" lost the progress output for its
+   "checkout" phase; when run without any "--quiet" option, it should
+   give progress to the lengthy operation.
+
+ * The directory path used in "git diff --no-index", when it recurses
+   down, was broken with a recent update after v1.7.10.1 release.
+
+ * "log -z --pretty=tformat:..." did not terminate each record with
+   NUL.  The fix is not entirely correct when the output also asks for
+   --patch and/or --stat, though.
+
+ * The DWIM behaviour for "log --pretty=format:%gd -g" was somewhat
+   broken and gave undue precedence to configured log.date, causing
+   "git stash list" to show "stash@{time stamp string}".
+
+ * "git status --porcelain" ignored "--branch" option by mistake.  The
+   output for "git status --branch -z" was also incorrect and did not
+   terminate the record for the current branch name with NUL as asked.
+
+ * When a submodule repository uses alternate object store mechanism,
+   some commands that were started from the superproject did not
+   notice it and failed with "No such object" errors.  The subcommands
+   of "git submodule" command that recursed into the submodule in a
+   separate process were OK; only the ones that cheated and peeked
+   directly into the submodule's repository from the primary process
+   were affected.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.4.txt b/third_party/git/Documentation/RelNotes/1.7.10.4.txt
new file mode 100644
index 0000000000..326670df6e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.4.txt
@@ -0,0 +1,29 @@
+Git v1.7.10.4 Release Notes
+===========================
+
+Fixes since v1.7.10.3
+---------------------
+
+ * The message file for Swedish translation has been updated a bit.
+
+ * A name taken from mailmap was copied into an internal buffer
+   incorrectly and could overun the buffer if it is too long.
+
+ * A malformed commit object that has a header line chomped in the
+   middle could kill git with a NULL pointer dereference.
+
+ * An author/committer name that is a single character was mishandled
+   as an invalid name by mistake.
+
+ * The progress indicator for a large "git checkout" was sent to
+   stderr even if it is not a terminal.
+
+ * "git grep -e '$pattern'", unlike the case where the patterns are
+   read from a file, did not treat individual lines in the given
+   pattern argument as separate regular expressions as it should.
+
+ * When "git rebase" was given a bad commit to replay the history on,
+   its error message did not correctly give the command line argument
+   it had trouble parsing.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.5.txt b/third_party/git/Documentation/RelNotes/1.7.10.5.txt
new file mode 100644
index 0000000000..4db1770e38
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.5.txt
@@ -0,0 +1,12 @@
+Git v1.7.10.5 Release Notes
+===========================
+
+Fixes since v1.7.10.4
+---------------------
+
+ * "git fast-export" did not give a readable error message when the
+   same mark erroneously appeared twice in the --import-marks input.
+
+ * "git rebase -p" used to pay attention to rebase.autosquash which
+    was wrong.  "git rebase -p -i" should, but "git rebase -p" by
+    itself should not.
diff --git a/third_party/git/Documentation/RelNotes/1.7.10.txt b/third_party/git/Documentation/RelNotes/1.7.10.txt
new file mode 100644
index 0000000000..58100bf04e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.10.txt
@@ -0,0 +1,219 @@
+Git v1.7.10 Release Notes
+=========================
+
+Compatibility Notes
+-------------------
+
+ * From this release on, the "git merge" command in an interactive
+   session will start an editor when it automatically resolves the
+   merge for the user to explain the resulting commit, just like the
+   "git commit" command does when it wasn't given a commit message.
+
+   If you have a script that runs "git merge" and keeps its standard
+   input and output attached to the user's terminal, and if you do not
+   want the user to explain the resulting merge commits, you can
+   export GIT_MERGE_AUTOEDIT environment variable set to "no", like
+   this:
+
+	#!/bin/sh
+	GIT_MERGE_AUTOEDIT=no
+	export GIT_MERGE_AUTOEDIT
+
+   to disable this behavior (if you want your users to explain their
+   merge commits, you do not have to do anything).  Alternatively, you
+   can give the "--no-edit" option to individual invocations of the
+   "git merge" command if you know everybody who uses your script has
+   Git v1.7.8 or newer.
+
+ * The "--binary/-b" options to "git am" have been a no-op for quite a
+   while and were deprecated in mid 2008 (v1.6.0).  When you give these
+   options to "git am", it will now warn and ask you not to use them.
+
+ * When you do not tell which branches and tags to push to the "git
+   push" command in any way, the command used "matching refs" rule to
+   update remote branches and tags with branches and tags with the
+   same name you locally have.  In future versions of Git, this will
+   change to push out only your current branch according to either the
+   "upstream" or the "current" rule.  Although "upstream" may be more
+   powerful once the user understands Git better, the semantics
+   "current" gives is simpler and easier to understand for beginners
+   and may be a safer and better default option.  We haven't decided
+   yet which one to switch to.
+
+
+Updates since v1.7.9
+--------------------
+
+UI, Workflows & Features
+
+ * various "gitk" updates.
+   - show the path to the top level directory in the window title
+   - update preference edit dialog
+   - display file list correctly when directories are given on command line
+   - make "git-describe" output in the log message into a clickable link
+   - avoid matching the UNIX timestamp part when searching all fields
+   - give preference to symbolic font names like sans & monospace
+   - allow comparing two commits using a mark
+   - "gitk" honors log.showroot configuration.
+
+ * Teams for localizing the messages from the Porcelain layer of
+   commands are starting to form, thanks to Jiang Xin who volunteered
+   to be the localization coordinator.  Translated messages for
+   simplified Chinese, Swedish and Portuguese are available.
+
+ * The configuration mechanism learned an "include" facility; an
+   assignment to the include.path pseudo-variable causes the named
+   file to be included in-place when Git looks up configuration
+   variables.
+
+ * A content filter (clean/smudge) used to be just a way to make the
+   recorded contents "more useful", and allowed to fail; a filter can
+   now optionally be marked as "required".
+
+ * Options whose names begin with "--no-" (e.g. the "--no-verify"
+   option of the "git commit" command) can be negated by omitting
+   "no-" from its name, e.g. "git commit --verify".
+
+ * "git am" learned to pass "-b" option to underlying "git mailinfo", so
+   that a bracketed string other than "PATCH" at the beginning can be kept.
+
+ * "git clone" learned "--single-branch" option to limit cloning to a
+   single branch (surprise!); tags that do not point into the history
+   of the branch are not fetched.
+
+ * "git clone" learned to detach the HEAD in the resulting repository
+   when the user specifies a tag with "--branch" (e.g., "--branch=v1.0").
+   Clone also learned to print the usual "detached HEAD" advice in such
+   a case, similar to "git checkout v1.0".
+
+ * When showing a patch while ignoring whitespace changes, the context
+   lines are taken from the postimage, in order to make it easier to
+   view the output.
+
+ * "git diff --stat" learned to adjust the width of the output on
+   wider terminals, and give more columns to pathnames as needed.
+
+ * "diff-highlight" filter (in contrib/) was updated to produce more
+   aesthetically pleasing output.
+
+ * "fsck" learned "--no-dangling" option to omit dangling object
+   information.
+
+ * "git log -G" and "git log -S" learned to pay attention to the "-i"
+   option.  With "-i", "log -G" ignores the case when finding patch
+   hunks that introduce or remove a string that matches the given
+   pattern.  Similarly with "-i", "log -S" ignores the case when
+   finding the commit the given block of text appears or disappears
+   from the file.
+
+ * "git merge" in an interactive session learned to spawn the editor
+   by default to let the user edit the auto-generated merge message,
+   to encourage people to explain their merges better. Legacy scripts
+   can export GIT_MERGE_AUTOEDIT=no to retain the historical behavior.
+   Both "git merge" and "git pull" can be given --no-edit from the
+   command line to accept the auto-generated merge message.
+
+ * The advice message given when the user didn't give enough clue on
+   what to merge to "git pull" and "git merge" has been updated to
+   be more concise and easier to understand.
+
+ * "git push" learned the "--prune" option, similar to "git fetch".
+
+ * The whole directory that houses a top-level superproject managed by
+   "git submodule" can be moved to another place.
+
+ * "git symbolic-ref" learned the "--short" option to abbreviate the
+   refname it shows unambiguously.
+
+ * "git tag --list" can be given "--points-at <object>" to limit its
+   output to those that point at the given object.
+
+ * "gitweb" allows intermediate entries in the directory hierarchy
+   that leads to a project to be clicked, which in turn shows the
+   list of projects inside that directory.
+
+ * "gitweb" learned to read various pieces of information for the
+   repositories lazily, instead of reading everything that could be
+   needed (including the ones that are not necessary for a specific
+   task).
+
+ * Project search in "gitweb" shows the substring that matched in the
+   project name and description highlighted.
+
+ * HTTP transport learned to authenticate with a proxy if needed.
+
+ * A new script "diffall" is added to contrib/; it drives an
+   external tool to perform a directory diff of two Git revisions
+   in one go, unlike "difftool" that compares one file at a time.
+
+Foreign Interface
+
+ * Improved handling of views, labels and branches in "git-p4" (in contrib).
+
+ * "git-p4" (in contrib) suffered from unnecessary merge conflicts when
+   p4 expanded the embedded $RCS$-like keywords; it can be now told to
+   unexpand them.
+
+ * Some "git-svn" updates.
+
+ * "vcs-svn"/"svn-fe" learned to read dumps with svn-deltas and
+   support incremental imports.
+
+ * "git difftool/mergetool" learned to drive DeltaWalker.
+
+Performance
+
+ * Unnecessary calls to parse_object() "git upload-pack" makes in
+   response to "git fetch", have been eliminated, to help performance
+   in repositories with excessive number of refs.
+
+Internal Implementation (please report possible regressions)
+
+ * Recursive call chains in "git index-pack" to deal with long delta
+   chains have been flattened, to reduce the stack footprint.
+
+ * Use of add_extra_ref() API is now gone, to make it possible to
+   cleanly restructure the overall refs API.
+
+ * The command line parser of "git pack-objects" now uses parse-options
+   API.
+
+ * The test suite supports the new "test_pause" helper function.
+
+ * Parallel to the test suite, there is a beginning of performance
+   benchmarking framework.
+
+ * t/Makefile is adjusted to prevent newer versions of GNU make from
+   running tests in seemingly random order.
+
+ * The code to check if a path points at a file beyond a symbolic link
+   has been restructured to be thread-safe.
+
+ * When pruning directories that has become empty during "git prune"
+   and "git prune-packed", call closedir() that iterates over a
+   directory before rmdir() it.
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.7.9
+------------------
+
+Unless otherwise noted, all the fixes since v1.7.9 in the maintenance
+releases are contained in this release (see release notes to them for
+details).
+
+ * Build with NO_PERL_MAKEMAKER was broken and Git::I18N did not work
+   with versions of Perl older than 5.8.3.
+   (merge 5eb660e ab/perl-i18n later to maint).
+
+ * "git tag -s" honored "gpg.program" configuration variable since
+   1.7.9, but "git tag -v" and "git verify-tag" didn't.
+   (merge a2c2506 az/verify-tag-use-gpg-config later to maint).
+
+ * "configure" script learned to take "--with-sane-tool-path" from the
+   command line to record SANE_TOOL_PATH (used to avoid broken platform
+   tools in /usr/bin) in config.mak.autogen.  This may be useful for
+   people on Solaris who have saner tools outside /usr/xpg[46]/bin.
+
+ * zsh port of bash completion script needed another workaround.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.1.txt b/third_party/git/Documentation/RelNotes/1.7.11.1.txt
new file mode 100644
index 0000000000..577eccaacd
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.1.txt
@@ -0,0 +1,9 @@
+Git v1.7.11.1 Release Notes
+===========================
+
+Fixes since v1.7.11
+-------------------
+
+ * The cross links in the HTML version of manual pages were broken.
+
+Also contains minor typofixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.2.txt b/third_party/git/Documentation/RelNotes/1.7.11.2.txt
new file mode 100644
index 0000000000..f0cfd02d6f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.2.txt
@@ -0,0 +1,53 @@
+Git v1.7.11.2 Release Notes
+===========================
+
+Fixes since v1.7.11.1
+---------------------
+
+ * On Cygwin, the platform pread(2) is not thread safe, just like our
+   own compat/ emulation, and cannot be used in the index-pack
+   program.  Makefile variable NO_THREAD_SAFE_PREAD can be defined to
+   avoid use of this function in a threaded program.
+
+ * "git add" allows adding a regular file to the path where a
+   submodule used to exist, but "git update-index" does not allow an
+   equivalent operation to Porcelain writers.
+
+ * "git archive" incorrectly computed the header checksum; the symptom
+   was observed only when using pathnames with hi-bit set.
+
+ * "git blame" did not try to make sure that the abbreviated commit
+   object names in its output are unique.
+
+ * Running "git bundle verify" on a bundle that records a complete
+   history said "it requires these 0 commits".
+
+ * "git clone --single-branch" to clone a single branch did not limit
+   the cloning to the specified branch.
+
+ * "git diff --no-index" did not correctly handle relative paths and
+   did not correctly give exit codes when run under "--quiet" option.
+
+ * "git diff --no-index" did not work with pagers correctly.
+
+ * "git diff COPYING HEAD:COPYING" gave a nonsense error message that
+   claimed that the tree-ish HEAD did not have COPYING in it.
+
+ * When "git log" gets "--simplify-merges/by-decoration" together with
+   "--first-parent", the combination of these options makes the
+   simplification logic to use in-core commit objects that haven't
+   been examined for relevance, either producing incorrect result or
+   taking too long to produce any output.  Teach the simplification
+   logic to ignore commits that the first-parent traversal logic
+   ignored when both are in effect to work around the issue.
+
+ * "git ls-files --exclude=t -i" did not consider anything under t/ as
+   excluded, as it did not pay attention to exclusion of leading paths
+   while walking the index.  Other two users of excluded() are also
+   updated.
+
+ * "git request-pull $url dev" when the tip of "dev" branch was tagged
+   with "ext4-for-linus" used the contents from the tag in the output
+   but still asked the "dev" branch to be pulled, not the tag.
+
+Also contains minor typofixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.3.txt b/third_party/git/Documentation/RelNotes/1.7.11.3.txt
new file mode 100644
index 0000000000..64494f89d9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.3.txt
@@ -0,0 +1,53 @@
+Git v1.7.11.3 Release Notes
+===========================
+
+Fixes since v1.7.11.3
+---------------------
+
+ * The error message from "git push $there :bogo" (and its equivalent
+   "git push $there --delete bogo") mentioned that we tried and failed
+   to guess what ref is being deleted based on the LHS of the refspec,
+   which we don't.
+
+ * A handful of files and directories we create had tighter than
+   necessary permission bits when the user wanted to have group
+   writability (e.g. by setting "umask 002").
+
+ * "commit --amend" used to refuse amending a commit with an empty log
+   message, with or without "--allow-empty-message".
+
+ * "git commit --amend --only --" was meant to allow "Clever" people to
+   rewrite the commit message without making any change even when they
+   have already changes for the next commit added to their index, but
+   it never worked as advertised since it was introduced in 1.3.0 era.
+
+ * Even though the index can record pathnames longer than 1<<12 bytes,
+   in some places we were not comparing them in full, potentially
+   replacing index entries instead of adding.
+
+ * "git show"'s auto-walking behaviour was an unreliable and
+   unpredictable hack; it now behaves just like "git log" does when it
+   walks.
+
+ * "git diff", "git status" and anything that internally uses the
+   comparison machinery was utterly broken when the difference
+   involved a file with "-" as its name.  This was due to the way "git
+   diff --no-index" was incorrectly bolted on to the system, making
+   any comparison that involves a file "-" at the root level
+   incorrectly read from the standard input.
+
+ * We did not have test to make sure "git rebase" without extra options
+   filters out an empty commit in the original history.
+
+ * "git fast-export" produced an input stream for fast-import without
+   properly quoting pathnames when they contain SPs in them.
+
+ * "git checkout --detach", when you are still on an unborn branch,
+   should be forbidden, but it wasn't.
+
+ * Some implementations of Perl terminates "lines" with CRLF even when
+   the script is operating on just a sequence of bytes.  Make sure to
+   use "$PERL_PATH", the version of Perl the user told Git to use, in
+   our tests to avoid unnecessary breakages in tests.
+
+Also contains minor typofixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.4.txt b/third_party/git/Documentation/RelNotes/1.7.11.4.txt
new file mode 100644
index 0000000000..3a640c2d4d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.4.txt
@@ -0,0 +1,31 @@
+Git v1.7.11.4 Release Notes
+===========================
+
+Fixes since v1.7.11.3
+---------------------
+
+ * "$GIT_DIR/COMMIT_EDITMSG" file that is used to hold the commit log
+   message user edits was not documented.
+
+ * The advise() function did not use varargs correctly to format
+   its message.
+
+ * When "git am" failed, old timers knew to check .git/rebase-apply/patch
+   to see what went wrong, but we never told the users about it.
+
+ * "git commit-tree" learned a more natural "-p <parent> <tree>" order
+   of arguments long time ago, but recently forgot it by mistake.
+
+ * "git diff --no-ext-diff" did not output anything for a typechange
+   filepair when GIT_EXTERNAL_DIFF is in effect.
+
+ * In 1.7.9 era, we taught "git rebase" about the raw timestamp format
+   but we did not teach the same trick to "filter-branch", which rolled
+   a similar logic on its own.
+
+ * When "git submodule add" clones a submodule repository, it can get
+   confused where to store the resulting submodule repository in the
+   superproject's .git/ directory when there is a symbolic link in the
+   path to the current directory.
+
+Also contains minor typofixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.5.txt b/third_party/git/Documentation/RelNotes/1.7.11.5.txt
new file mode 100644
index 0000000000..0a2ed855c5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.5.txt
@@ -0,0 +1,36 @@
+Git v1.7.11.5 Release Notes
+===========================
+
+Fixes since v1.7.11.4
+---------------------
+
+ * The Makefile rule to create assembly output (primarily for
+   debugging purposes) did not create it next to the source.
+
+ * The code to avoid mistaken attempt to add the object directory
+   itself as its own alternate could read beyond end of a string while
+   comparison.
+
+ * On some architectures, "block-sha1" did not compile correctly
+   when compilers inferred alignment guarantees from our source we
+   did not intend to make.
+
+ * When talking to a remote running ssh on IPv6 enabled host, whose
+   address is spelled as "[HOST]:PORT", we did not parse the address
+   correctly and failed to connect.
+
+ * git-blame.el (in compat/) have been updated to use Elisp more
+   correctly.
+
+ * "git checkout <branchname>" to come back from a detached HEAD state
+   incorrectly computed reachability of the detached HEAD, resulting
+   in unnecessary warnings.
+
+ * "git mergetool" did not support --tool-help option to give the list
+   of supported backends, like "git difftool" does.
+
+ * "git grep" stopped spawning an external "grep" long time ago, but a
+   duplicated test to check internal and external "grep" was left
+   behind.
+
+Also contains minor typofixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.6.txt b/third_party/git/Documentation/RelNotes/1.7.11.6.txt
new file mode 100644
index 0000000000..ba7d3c3966
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.6.txt
@@ -0,0 +1,84 @@
+Git v1.7.11.6 Release Notes
+===========================
+
+Fixes since v1.7.11.5
+---------------------
+
+ * "ciabot" script (in contrib/) has been updated with extensive
+   documentation.
+
+ * "git foo" errored out with "Not a directory" when the user had a
+   non-directory on $PATH, and worse yet it masked an alias "foo" from
+   running.
+
+ * When the user exports a non-default IFS without HT, scripts that
+   rely on being able to parse "ls-files -s | while read a b c..."
+   started to fail.  Protect them from such a misconfiguration.
+
+ * When the user gives an argument that can be taken as both a
+   revision name and a pathname without disambiguating with "--", we
+   used to give a help message "Use '--' to separate".  The message
+   has been clarified to show where that '--' goes on the command
+   line.
+
+ * Documentation for the configuration file format had a confusing
+   example.
+
+ * Older parts of the documentation described as if having a regular
+   file in .git/refs/ hierarchy were the only way to have branches and
+   tags, which is not true for quite some time.
+
+ * It was generally understood that "--long-option"s to many of our
+   subcommands can be abbreviated to the unique prefix, but it was not
+   easy to find it described for new readers of the documentation set.
+
+ * The "--topo-order", "--date-order" (and the lack of either means
+   the default order) options to "rev-list" and "log" family of
+   commands were poorly described in the documentation.
+
+ * "git commit --amend" let the user edit the log message and then
+   died when the human-readable committer name was given
+   insufficiently by getpwent(3).
+
+ * The exit status code from "git config" was way overspecified while
+   being incorrect.  The implementation has been updated to give the
+   documented status for a case that was documented, and introduce a
+   new code for "all other errors".
+
+ * The output from "git diff -B" for a file that ends with an
+   incomplete line did not put "\ No newline..." on a line of its own.
+
+ * "git diff" had a confusion between taking data from a path in the
+   working tree and taking data from an object that happens to have
+   name 0{40} recorded in a tree.
+
+ * The "--rebase" option to "git pull" can be abbreviated to "-r",
+   but we didn't document it.
+
+ * When "git push" triggered the automatic gc on the receiving end, a
+   message from "git prune" that said it was removing cruft leaked to
+   the standard output, breaking the communication protocol.
+
+ * The reflog entries left by "git rebase" and "git rebase -i" were
+   inconsistent (the interactive one gave an abbreviated object name).
+
+ * "git send-email" did not unquote encoded words that appear on the
+   header correctly, and lost "_" from strings.
+
+ * "git stash apply/pop" did not trigger "rerere" upon conflicts
+   unlike other mergy operations.
+
+ * "git submodule <cmd> path" did not error out when the path to the
+   submodule was misspelt.
+
+ * "git submodule update -f" did not update paths in the working tree
+   that has local changes.
+   (merge 01d4721 sz/submodule-force-update later to maint).
+
+ * "gitweb" when used with PATH_INFO failed to notice directories with
+   SP (and other characters that need URL-style quoting) in them.
+
+ * Fallback 'getpass' implementation made unportable use of stdio API.
+
+ * A utility shell function test_seq has been added as a replacement
+   for the 'seq' utility found on some platforms.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.7.txt b/third_party/git/Documentation/RelNotes/1.7.11.7.txt
new file mode 100644
index 0000000000..e743a2a8e4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.7.txt
@@ -0,0 +1,46 @@
+Git v1.7.11.7 Release Notes
+===========================
+
+Fixes since v1.7.11.6
+---------------------
+
+ * The synopsis said "checkout [-B branch]" to make it clear the
+   branch name is a parameter to the option, but the heading for the
+   option description was "-B::", not "-B branch::", making the
+   documentation misleading.
+
+ * Git ships with a fall-back regexp implementation for platforms with
+   buggy regexp library, but it was easy for people to keep using their
+   platform regexp.  A new test has been added to check this.
+
+ * "git apply -p0" did not parse pathnames on "diff --git" line
+   correctly.  This caused patches that had pathnames in no other
+   places to be mistakenly rejected (most notably, binary patch that
+   does not rename nor change mode).  Textual patches, renames or mode
+   changes have preimage and postimage pathnames in different places
+   in a form that can be parsed unambiguously and did not suffer from
+   this problem.
+
+ * After "gitk" showed the contents of a tag, neither "Reread
+   references" nor "Reload" did not update what is shown as the
+   contents of it, when the user overwrote the tag with "git tag -f".
+
+ * "git for-each-ref" did not correctly support more than one --sort
+   option.
+
+ * "git log .." errored out saying it is both rev range and a path
+   when there is no disambiguating "--" is on the command line.
+   Update the command line parser to interpret ".." as a path in such
+   a case.
+
+ * Pushing to smart HTTP server with recent Git fails without having
+   the username in the URL to force authentication, if the server is
+   configured to allow GET anonymously, while requiring authentication
+   for POST.
+
+ * "git show --format='%ci'" did not give timestamp correctly for
+   commits created without human readable name on "committer" line.
+   (merge e27ddb6 jc/maint-ident-missing-human-name later to maint).
+
+ * "git show --quiet" ought to be a synonym for "git show -s", but
+   wasn't.
diff --git a/third_party/git/Documentation/RelNotes/1.7.11.txt b/third_party/git/Documentation/RelNotes/1.7.11.txt
new file mode 100644
index 0000000000..15b954ca4b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.11.txt
@@ -0,0 +1,139 @@
+Git v1.7.11 Release Notes
+=========================
+
+Updates since v1.7.10
+---------------------
+
+UI, Workflows & Features
+
+ * A new mode for push, "simple", which is a cross between "current"
+   and "upstream", has been introduced. "git push" without any refspec
+   will push the current branch out to the same name at the remote
+   repository only when it is set to track the branch with the same
+   name over there.  The plan is to make this mode the new default
+   value when push.default is not configured.
+
+ * A couple of commands learned the "--column" option to produce
+   columnar output.
+
+ * A third-party tool "git subtree" is distributed in contrib/
+
+ * A remote helper that acts as a proxy and caches ssl session for the
+   https:// transport is added to the contrib/ area.
+
+ * Error messages given when @{u} is used for a branch without its
+   upstream configured have been clarified.
+
+ * Even with the "-q"uiet option, "checkout" used to report setting up
+   tracking.  Also "branch" learned the "-q"uiet option to squelch
+   informational message.
+
+ * Your build platform may support hardlinks but you may prefer not to
+   use them, e.g. when installing to DESTDIR to make a tarball and
+   untarring on a filesystem that has poor support for hardlinks.
+   There is a Makefile option NO_INSTALL_HARDLINKS for you.
+
+ * The smart-http backend used to always override GIT_COMMITTER_*
+   variables with REMOTE_USER and REMOTE_ADDR, but these variables are
+   now preserved when set.
+
+ * "git am" learned the "--include" option, which is an opposite of
+   existing the "--exclude" option.
+
+ * When "git am -3" needs to fall back to an application of the patch
+   to a synthesized preimage followed by a 3-way merge, the paths that
+   needed such treatment are now reported to the end user, so that the
+   result in them can be eyeballed with extra care.
+
+ * The output from "diff/log --stat" used to always allocate 4 columns
+   to show the number of modified lines, but not anymore.
+
+ * "git difftool" learned the "--dir-diff" option to spawn external
+   diff tools that can compare two directory hierarchies at a time
+   after populating two temporary directories, instead of running an
+   instance of the external tool once per a file pair.
+
+ * The "fmt-merge-msg" command learned to list the primary contributors
+   involved in the side topic you are merging in a comment in the merge
+   commit template.
+
+ * "git rebase" learned to optionally keep commits that do not
+   introduce any change in the original history.
+
+ * "git push --recurse-submodules" learned to optionally look into the
+   histories of submodules bound to the superproject and push them
+   out.
+
+ * A 'snapshot' request to "gitweb" honors If-Modified-Since: header,
+   based on the commit date.
+
+ * "gitweb" learned to highlight the patch it outputs even more.
+
+Foreign Interface
+
+ * "git svn" used to die with unwanted SIGPIPE when talking with an HTTP
+   server that uses keep-alive.
+
+ * "git svn" learned to use platform specific authentication
+   providers, e.g. gnome-keyring, kwallet, etc.
+
+ * "git p4" has been moved out of the contrib/ area and has seen more
+   work on importing labels as tags from (and exporting tags as labels
+   to) p4.
+
+Performance and Internal Implementation (please report possible regressions)
+
+ * Bash completion script (in contrib/) have been cleaned up to make
+   future work on it simpler.
+
+ * An experimental "version 4" format of the index file has been
+   introduced to reduce on-disk footprint and I/O overhead.
+
+ * "git archive" learned to produce its output without reading the
+   blob object it writes out in memory in its entirety.
+
+ * "git index-pack" that runs when fetching or pushing objects to
+   complete the packfile on the receiving end learned to use multiple
+   threads to do its job when available.
+
+ * The code to compute hash values for lines used by the internal diff
+   engine was optimized on little-endian machines, using the same
+   trick the kernel folks came up with.
+
+ * "git apply" had some memory leaks plugged.
+
+ * Setting up a revision traversal with many starting points was
+   inefficient as these were placed in a date-order priority queue
+   one-by-one.  Now they are collected in the queue unordered first,
+   and sorted immediately before getting used.
+
+ * More lower-level commands learned to use the streaming API to read
+   from the object store without keeping everything in core.
+
+ * The weighting parameters to suggestion command name typo have been
+   tweaked, so that "git tags" will suggest "tag?" and not "stage?".
+
+ * Because "sh" on the user's PATH may be utterly broken on some
+   systems, run-command API now uses SHELL_PATH, not /bin/sh, when
+   spawning an external command (not applicable to Windows port).
+
+ * The API to iterate over the refs/ hierarchy has been tweaked to
+   allow walking only a subset of it more efficiently.
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.7.10
+-------------------
+
+Unless otherwise noted, all the fixes since v1.7.10 in the maintenance
+releases are contained in this release (see release notes to them for
+details).
+
+ * "git submodule init" used to report "registered for path ..."
+   even for submodules that were registered earlier.
+   (cherry-pick c1c259e jl/submodule-report-new-path-once later to maint).
+
+ * "git diff --stat" used to fully count a binary file with modified
+   execution bits whose contents is unmodified, which was not quite
+   right.
diff --git a/third_party/git/Documentation/RelNotes/1.7.12.1.txt b/third_party/git/Documentation/RelNotes/1.7.12.1.txt
new file mode 100644
index 0000000000..b8f04af19f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.12.1.txt
@@ -0,0 +1,134 @@
+Git 1.7.12.1 Release Notes
+==========================
+
+Fixes since v1.7.12
+-------------------
+
+ * "git apply -p0" did not parse pathnames on "diff --git" line
+   correctly.  This caused patches that had pathnames in no other
+   places to be mistakenly rejected (most notably, binary patch that
+   does not rename nor change mode).  Textual patches, renames or mode
+   changes have preimage and postimage pathnames in different places
+   in a form that can be parsed unambiguously and did not suffer from
+   this problem.
+
+ * "git cherry-pick A C B" used to replay changes in A and then B and
+   then C if these three commits had committer timestamps in that
+   order, which is not what the user who said "A C B" naturally
+   expects.
+
+ * "git commit --amend" let the user edit the log message and then
+   died when the human-readable committer name was given
+   insufficiently by getpwent(3).
+
+ * Some capabilities were asked by fetch-pack even when upload-pack
+   did not advertise that they are available.  fetch-pack has been
+   fixed not to do so.
+
+ * "git diff" had a confusion between taking data from a path in the
+   working tree and taking data from an object that happens to have
+   name 0{40} recorded in a tree.
+
+ * "git for-each-ref" did not correctly support more than one --sort
+   option.
+
+ * "git log .." errored out saying it is both rev range and a path
+   when there is no disambiguating "--" is on the command line.
+   Update the command line parser to interpret ".." as a path in such
+   a case.
+
+ * The "--topo-order", "--date-order" (and the lack of either means
+   the default order) options to "rev-list" and "log" family of
+   commands were poorly described in the documentation.
+
+ * "git prune" without "-v" used to warn about leftover temporary
+   files (which is an indication of an earlier aborted operation).
+
+ * Pushing to smart HTTP server with recent Git fails without having
+   the username in the URL to force authentication, if the server is
+   configured to allow GET anonymously, while requiring authentication
+   for POST.
+
+ * The reflog entries left by "git rebase" and "git rebase -i" were
+   inconsistent (the interactive one gave an abbreviated object name).
+
+ * When "git push" triggered the automatic gc on the receiving end, a
+   message from "git prune" that said it was removing cruft leaked to
+   the standard output, breaking the communication protocol.
+
+ * "git show --quiet" ought to be a synonym for "git show -s", but
+   wasn't.
+
+ * "git show --format='%ci'" did not give timestamp correctly for
+   commits created without human readable name on "committer" line.
+
+ * "git send-email" did not unquote encoded words that appear on the
+   header correctly, and lost "_" from strings.
+
+ * The interactive prompt "git send-email" gives was error prone. It
+   asked "What e-mail address do you want to use?" with the address it
+   guessed (correctly) the user would want to use in its prompt,
+   tempting the user to say "y". But the response was taken as "No,
+   please use 'y' as the e-mail address instead", which is most
+   certainly not what the user meant.
+
+ * "gitweb" when used with PATH_INFO failed to notice directories with
+   SP (and other characters that need URL-style quoting) in them.
+
+ * When the user gives an argument that can be taken as both a
+   revision name and a pathname without disambiguating with "--", we
+   used to give a help message "Use '--' to separate".  The message
+   has been clarified to show where that '--' goes on the command
+   line.
+
+ * When the user exports a non-default IFS without HT, scripts that
+   rely on being able to parse "ls-files -s | while read a b c..."
+   started to fail.  Protect them from such a misconfiguration.
+
+ * The attribute system may be asked for a path that itself or its
+   leading directories no longer exists in the working tree, and it is
+   fine if we cannot open .gitattribute file in such a case.  Failure
+   to open per-directory .gitattributes with error status other than
+   ENOENT and ENOTDIR should be diagnosed, but it wasn't.
+
+ * After "gitk" showed the contents of a tag, neither "Reread
+   references" nor "Reload" did not update what is shown as the
+   contents of it, when the user overwrote the tag with "git tag -f".
+
+ * "ciabot" script (in contrib/) has been updated with extensive
+   documentation.
+
+ * "git-jump" script (in contrib/) did not work well when
+   diff.noprefix or diff.mnemonicprefix is in effect.
+
+ * Older parts of the documentation described as if having a regular
+   file in .git/refs/ hierarchy were the only way to have branches and
+   tags, which is not true for quite some time.
+
+ * A utility shell function test_seq has been added as a replacement
+   for the 'seq' utility found on some platforms.
+
+ * Compatibility wrapper to learn the maximum number of file
+   descriptors we can open around sysconf(_SC_OPEN_MAX) and
+   getrlimit(RLIMIT_NO_FILE) has been introduced for portability.
+
+ * We used curl_easy_strerror() without checking version of cURL,
+   breaking the build for versions before curl 7.12.0.
+
+ * Code to work around MacOS X UTF-8 gotcha has been cleaned up.
+
+ * Fallback 'getpass' implementation made unportable use of stdio API.
+
+ * The "--rebase" option to "git pull" can be abbreviated to "-r",
+   but we didn't document it.
+
+ * It was generally understood that "--long-option"s to many of our
+   subcommands can be abbreviated to the unique prefix, but it was not
+   easy to find it described for new readers of the documentation set.
+
+ * The synopsis said "checkout [-B branch]" to make it clear the
+   branch name is a parameter to the option, but the heading for the
+   option description was "-B::", not "-B branch::", making the
+   documentation misleading.
+
+Also contains numerous documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.12.2.txt b/third_party/git/Documentation/RelNotes/1.7.12.2.txt
new file mode 100644
index 0000000000..69255745e6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.12.2.txt
@@ -0,0 +1,40 @@
+Git 1.7.12.2 Release Notes
+==========================
+
+Fixes since v1.7.12.1
+---------------------
+
+ * When "git am" is fed an input that has multiple "Content-type: ..."
+   header, it did not grok charset= attribute correctly.
+
+ * Even during a conflicted merge, "git blame $path" always meant to
+   blame uncommitted changes to the "working tree" version; make it
+   more useful by showing cleanly merged parts as coming from the other
+   branch that is being merged.
+
+ * "git blame MAKEFILE" run in a history that has "Makefile" but not
+   "MAKEFILE" should say "No such file MAKEFILE in HEAD", but got
+   confused on a case insensitive filesystem and failed to do so.
+
+ * "git fetch --all", when passed "--no-tags", did not honor the
+   "--no-tags" option while fetching from individual remotes (the same
+   issue existed with "--tags", but combination "--all --tags" makes
+   much less sense than "--all --no-tags").
+
+ * "git log/diff/format-patch --stat" showed the "N line(s) added"
+   comment in user's locale and caused careless submitters to send
+   patches with such a line in them to projects whose project language
+   is not their language, mildly irritating others. Localization to
+   the line has been disabled for now.
+
+ * "git log --all-match --grep=A --grep=B" ought to show commits that
+   mention both A and B, but when these three options are used with
+   --author or --committer, it showed commits that mention either A or
+   B (or both) instead.
+
+ * The subcommand to remove the definition of a remote in "git remote"
+   was named "rm" even though all other subcommands were spelled out.
+   Introduce "git remote remove" to remove confusion, and keep "rm" as
+   a backward compatible synonym.
+
+Also contains a handful of documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.12.3.txt b/third_party/git/Documentation/RelNotes/1.7.12.3.txt
new file mode 100644
index 0000000000..ecda427a35
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.12.3.txt
@@ -0,0 +1,34 @@
+Git 1.7.12.3 Release Notes
+==========================
+
+Fixes since v1.7.12.2
+---------------------
+
+ * "git am" mishandled a patch attached as application/octet-stream
+   (e.g. not text/*); Content-Transfer-Encoding (e.g. base64) was not
+   honored correctly.
+
+ * It was unclear in the documentation for "git blame" that it is
+   unnecessary for users to use the "--follow" option.
+
+ * A repository created with "git clone --single" had its fetch
+   refspecs set up just like a clone without "--single", leading the
+   subsequent "git fetch" to slurp all the other branches, defeating
+   the whole point of specifying "only this branch".
+
+ * "git fetch" over http had an old workaround for an unlikely server
+   misconfiguration; it turns out that this hurts debuggability of the
+   configuration in general, and has been reverted.
+
+ * "git fetch" over http advertised that it supports "deflate", which
+   is much less common, and did not advertise the more common "gzip" on
+   its Accept-Encoding header.
+
+ * "git receive-pack" (the counterpart to "git push") did not give
+   progress output while processing objects it received to the puser
+   when run over the smart-http protocol.
+
+ * "git status" honored the ignore=dirty settings in .gitmodules but
+   "git commit" didn't.
+
+Also contains a handful of documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.12.4.txt b/third_party/git/Documentation/RelNotes/1.7.12.4.txt
new file mode 100644
index 0000000000..c6da3cc939
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.12.4.txt
@@ -0,0 +1,23 @@
+Git 1.7.12.4 Release Notes
+==========================
+
+Fixes since v1.7.12.3
+---------------------
+
+ * "git fetch" over the dumb-http revision walker could segfault when
+   curl's multi interface was used.
+
+ * It was possible to give specific paths for "asciidoc" and other
+   tools in the documentation toolchain, but not for "xmlto".
+
+ * "gitweb" did not give the correct committer timezone in its feed
+   output due to a typo.
+
+ * The "-Xours" (and similarly -Xtheirs) backend option to "git
+   merge -s recursive" was ignored for binary files.  Now it is
+   honored.
+
+ * The "binary" synthetic attribute made "diff" to treat the path as
+   binary, but not "merge".
+
+Also contains many documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.12.txt b/third_party/git/Documentation/RelNotes/1.7.12.txt
new file mode 100644
index 0000000000..010d8c7de4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.12.txt
@@ -0,0 +1,136 @@
+Git v1.7.12 Release Notes
+=========================
+
+Updates since v1.7.11
+---------------------
+
+UI, Workflows & Features
+
+ * Git can be told to normalize pathnames it read from readdir(3) and
+   all arguments it got from the command line into precomposed UTF-8
+   (assuming that they come as decomposed UTF-8), in order to work
+   around issues on Mac OS.
+
+   I think there still are other places that need conversion
+   (e.g. paths that are read from stdin for some commands), but this
+   should be a good first step in the right direction.
+
+ * Per-user $HOME/.gitconfig file can optionally be stored in
+   $HOME/.config/git/config instead, which is in line with XDG.
+
+ * The value of core.attributesfile and core.excludesfile default to
+   $HOME/.config/git/attributes and $HOME/.config/git/ignore respectively
+   when these files exist.
+
+ * Logic to disambiguate abbreviated object names have been taught to
+   take advantage of object types that are expected in the context,
+   e.g. XXXXXX in the "git describe" output v1.2.3-gXXXXXX must be a
+   commit object, not a blob nor a tree.  This will help us prolong
+   the lifetime of abbreviated object names.
+
+ * "git apply" learned to wiggle the base version and perform three-way
+   merge when a patch does not exactly apply to the version you have.
+
+ * Scripted Porcelain writers now have access to the credential API via
+   the "git credential" plumbing command.
+
+ * "git help" used to always default to "man" format even on platforms
+   where "man" viewer is not widely available.
+
+ * "git clone --local $path" started its life as an experiment to
+   optionally use link/copy when cloning a repository on the disk, but
+   we didn't deprecate it after we made the option a no-op to always
+   use the optimization.  The command learned "--no-local" option to
+   turn this off, as a more explicit alternative over use of file://
+   URL.
+
+ * "git fetch" and friends used to say "remote side hung up
+   unexpectedly" when they failed to get response they expect from the
+   other side, but one common reason why they don't get expected
+   response is that the remote repository does not exist or cannot be
+   read. The error message in this case was updated to give better
+   hints to the user.
+
+ * "git help -w $cmd" can show HTML version of documentation for
+   "git-$cmd" by setting help.htmlpath to somewhere other than the
+   default location where the build procedure installs them locally;
+   the variable can even point at a http:// URL.
+
+ * "git rebase [-i] --root $tip" can now be used to rewrite all the
+   history leading to "$tip" down to the root commit.
+
+ * "git rebase -i" learned "-x <cmd>" to insert "exec <cmd>" after
+   each commit in the resulting history.
+
+ * "git status" gives finer classification to various states of paths
+   in conflicted state and offer advice messages in its output.
+
+ * "git submodule" learned to deal with nested submodule structure
+   where a module is contained within a module whose origin is
+   specified as a relative URL to its superproject's origin.
+
+ * A rather heavy-ish "git completion" script has been split to create
+   a separate "git prompting" script, to help lazy-autoloading of the
+   completion part while making prompting part always available.
+
+ * "gitweb" pays attention to various forms of credits that are
+   similar to "Signed-off-by:" lines in the commit objects and
+   highlights them accordingly.
+
+
+Foreign Interface
+
+ * "mediawiki" remote helper (in contrib/) learned to handle file
+   attachments.
+
+ * "git p4" now uses "Jobs:" and "p4 move" when appropriate.
+
+ * vcs-svn has been updated to clean-up compilation, lift 32-bit
+   limitations, etc.
+
+
+Performance, Internal Implementation, etc. (please report possible regressions)
+
+ * Some tests showed false failures caused by a bug in ecryptofs.
+
+ * We no longer use AsciiDoc7 syntax in our documentation and favor a
+   more modern style.
+
+ * "git am --rebasing" codepath was taught to grab authorship, log
+   message and the patch text directly out of existing commits.  This
+   will help rebasing commits that have confusing "diff" output in
+   their log messages.
+
+ * "git index-pack" and "git pack-objects" use streaming API to read
+   from the object store to avoid having to hold a large blob object
+   in-core while they are doing their thing.
+
+ * Code to match paths with exclude patterns learned to avoid calling
+   fnmatch() by comparing fixed leading substring literally when
+   possible.
+
+ * "git log -n 1 -- rarely-touched-path" was spending unnecessary
+   cycles after showing the first change to find the next one, only to
+   discard it.
+
+ * "git svn" got a large-looking code reorganization at the last
+   minute before the code freeze.
+
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.7.11
+-------------------
+
+Unless otherwise noted, all the fixes since v1.7.11 in the maintenance
+releases are contained in this release (see release notes to them for
+details).
+
+ * "git submodule add" was confused when the superproject did not have
+   its repository in its usual place in the working tree and GIT_DIR
+   and GIT_WORK_TREE was used to access it.
+
+ * "git commit --amend" let the user edit the log message and then died
+   when the human-readable committer name was given insufficiently by
+   getpwent(3).
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.1.txt b/third_party/git/Documentation/RelNotes/1.7.2.1.txt
new file mode 100644
index 0000000000..1103c47a4f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.1.txt
@@ -0,0 +1,25 @@
+Git v1.7.2.1 Release Notes
+==========================
+
+Fixes since v1.7.2
+------------------
+
+ * "git instaweb" wasn't useful when your Apache was installed under a
+   name other than apache2 (e.g. "httpd").
+
+ * Similarly, "git web--browse" (invoked by "git help -w") learned that
+   chrome browser is sometimes called google-chrome.
+
+ * An overlong line after ".gitdir: " in a git file caused out of bounds
+   access to an array on the stack.
+
+ * "git config --path conf.var" to attempt to expand a variable conf.var
+   that uses "~/" short-hand segfaulted when $HOME environment variable
+   was not set.
+
+ * Documentation on Cygwin failed to build.
+
+ * The error message from "git pull blarg" when 'blarg' is an unknown
+   remote name has been improved.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.2.txt b/third_party/git/Documentation/RelNotes/1.7.2.2.txt
new file mode 100644
index 0000000000..71eb6a8b0a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.2.txt
@@ -0,0 +1,22 @@
+Git v1.7.2.2 Release Notes
+==========================
+
+Fixes since v1.7.2.1
+--------------------
+
+ * Object transfer over smart http transport deadlocked the client when
+   the remote HTTP server returned a failure, instead of erroring it out.
+
+ * git-gui honors custom textconv filters when showing diff and blame;
+
+ * git diff --relative=subdir (without the necessary trailing /) did not
+   work well;
+
+ * "git diff-files -p --submodule" was recently broken;
+
+ * "git checkout -b n ':/token'" did not work;
+
+ * "git index-pack" (hence "git fetch/clone/pull/push") enabled the object
+   replacement machinery by mistake (it never should have);
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.3.txt b/third_party/git/Documentation/RelNotes/1.7.2.3.txt
new file mode 100644
index 0000000000..610960cfe1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.3.txt
@@ -0,0 +1,39 @@
+Git v1.7.2.3 Release Notes
+==========================
+
+Fixes since v1.7.2.2
+--------------------
+
+ * When people try insane things such as delta-compressing 4GiB files, we
+   threw an assertion failure.
+
+ * "git archive" gave the full commit ID for "$Format:%h$".
+
+ * "git fetch --tags" did not fetch tags when remote.<nick>.tagopt was set
+   to --no-tags.  The command line option now overrides the configuration
+   setting.
+
+ * "git for-each-ref --format='%(objectname:short)'" has been completely
+   broken for a long time.
+
+ * "git gc" incorrectly pruned a rerere record that was created long
+   time ago but still is actively and repeatedly used.
+
+ * "git log --follow -M -p" was seriously broken in 1.7.2, reporting
+   assertion failure.
+
+ * Running "git log" with an incorrect option started pager nevertheless,
+   forcing the user to dismiss it.
+
+ * "git rebase" did not work well when the user has diff.renames
+   configuration variable set.
+
+ * An earlier (and rather old) fix to "git rebase" against a rebased
+   upstream broke a more normal, non rebased upstream case rather badly,
+   attempting to re-apply patches that are already accepted upstream.
+
+ * "git submodule sync" forgot to update the superproject's config file
+   when submodule URL changed.
+
+ * "git pack-refs --all --prune" did not remove a directory that has
+   become empty.
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.4.txt b/third_party/git/Documentation/RelNotes/1.7.2.4.txt
new file mode 100644
index 0000000000..f7950a4c04
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.4.txt
@@ -0,0 +1,10 @@
+Git v1.7.2.4 Release Notes
+==========================
+
+This is primarily to backport support for the new "add.ignoreErrors"
+name given to the existing "add.ignore-errors" configuration variable.
+
+The next version, Git 1.7.4, and future versions, will support both
+old and incorrect name and the new corrected name, but without this
+backport, users who want to use the new name "add.ignoreErrors" in
+their repositories cannot use older versions of Git.
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.5.txt b/third_party/git/Documentation/RelNotes/1.7.2.5.txt
new file mode 100644
index 0000000000..bf976c40db
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.5.txt
@@ -0,0 +1,8 @@
+Git v1.7.2.5 Release Notes
+==========================
+
+Fixes since v1.7.2.4
+--------------------
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
diff --git a/third_party/git/Documentation/RelNotes/1.7.2.txt b/third_party/git/Documentation/RelNotes/1.7.2.txt
new file mode 100644
index 0000000000..15cf01178c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.2.txt
@@ -0,0 +1,151 @@
+Git v1.7.2 Release Notes
+========================
+
+Updates since v1.7.1
+--------------------
+
+ * core.eol configuration and text/eol attributes are the new way to control
+   the end of line conventions for files in the working tree.
+
+ * core.autocrlf has been made safer - it will now only handle line
+   endings for new files and files that are LF-only in the
+   repository. To normalize content that has been checked in with
+   CRLF, use the new eol/text attributes.
+
+ * The whitespace rules used in "git apply --whitespace" and "git diff"
+   gained a new member in the family (tab-in-indent) to help projects with
+   policy to indent only with spaces.
+
+ * When working from a subdirectory, by default, git does not look for its
+   metadirectory ".git" across filesystems, primarily to help people who
+   have invocations of git in their custom PS1 prompts, as being outside
+   of a git repository would look for ".git" all the way up to the root
+   directory, and NFS mounts are often slow.  DISCOVERY_ACROSS_FILESYSTEM
+   environment variable can be used to tell git not to stop at a
+   filesystem boundary.
+
+ * Usage help messages generated by parse-options library (i.e. most
+   of the Porcelain commands) are sent to the standard output now.
+
+ * ':/<string>' notation to look for a commit now takes regular expression
+   and it is not anchored at the beginning of the commit log message
+   anymore (this is a backward incompatible change).
+
+ * "git" wrapper learned "-c name=value" option to override configuration
+   variable from the command line.
+
+ * Improved portability for various platforms including older SunOS,
+   HP-UX 10/11, AIX, Tru64, etc. and platforms with Python 2.4.
+
+ * The message from "git am -3" has been improved when conflict
+   resolution ended up making the patch a no-op.
+
+ * "git blame" applies the textconv filter to the contents it works
+   on, when available.
+
+ * "git checkout --orphan newbranch" is similar to "-b newbranch" but
+   prepares to create a root commit that is not connected to any existing
+   commit.
+
+ * "git cherry-pick" learned to pick a range of commits
+   (e.g. "cherry-pick A..B" and "cherry-pick --stdin"), so did "git
+   revert"; these do not support the nicer sequencing control "rebase
+   [-i]" has, though.
+
+ * "git cherry-pick" and "git revert" learned --strategy option to specify
+   the merge strategy to be used when performing three-way merges.
+
+ * "git cvsserver" can be told to use pserver; its password file can be
+   stored outside the repository.
+
+ * The output from the textconv filter used by "git diff" can be cached to
+   speed up their reuse.
+
+ * "git diff --word-diff=<mode>" extends the existing "--color-words"
+   option, making it more useful in color-challenged environments.
+
+ * The regexp to detect function headers used by "git diff" for PHP has
+   been enhanced for visibility modifiers (public, protected, etc.) to
+   better support PHP5.
+
+ * "diff.noprefix" configuration variable can be used to implicitly
+   ask for "diff --no-prefix" behaviour.
+
+ * "git for-each-ref" learned "%(objectname:short)" that gives the object
+   name abbreviated.
+
+ * "git format-patch" learned --signature option and format.signature
+   configuration variable to customize the e-mail signature used in the
+   output.
+
+ * Various options to "git grep" (e.g. --count, --name-only) work better
+   with binary files.
+
+ * "git grep" learned "-Ovi" to open the files with hits in your editor.
+
+ * "git help -w" learned "chrome" and "chromium" browsers.
+
+ * "git log --decorate" shows commit decorations in various colours.
+
+ * "git log --follow <path>" follows across copies (it used to only follow
+   renames).  This may make the processing more expensive.
+
+ * "git log --pretty=format:<template>" specifier learned "% <something>"
+   magic that inserts a space only when %<something> expands to a
+   non-empty string; this is similar to "%+<something>" magic, but is
+   useful in a context to generate a single line output.
+
+ * "git notes prune" learned "-n" (dry-run) and "-v" options, similar to
+   what "git prune" has.
+
+ * "git patch-id" can be fed a mbox without getting confused by the
+   signature line in the format-patch output.
+
+ * "git remote" learned "set-branches" subcommand.
+
+ * "git rev-list A..B" learned --ancestry-path option to further limit
+   the result to the commits that are on the ancestry chain between A and
+   B (i.e. commits that are not descendants of A are excluded).
+
+ * "git show -5" is equivalent to "git show --do-walk 5"; this is similar
+   to the update to make "git show master..next" walk the history,
+   introduced in 1.6.4.
+
+ * "git status [-s] --ignored" can be used to list ignored paths.
+
+ * "git status -s -b" shows the current branch in the output.
+
+ * "git status" learned "--ignore-submodules" option.
+
+ * Various "gitweb" enhancements and clean-ups, including syntax
+   highlighting, "plackup" support for instaweb, .fcgi suffix to run
+   it as FastCGI script, etc.
+
+ * The test harness has been updated to produce TAP-friendly output.
+
+ * Many documentation improvement patches are also included.
+
+
+Fixes since v1.7.1
+------------------
+
+All of the fixes in v1.7.1.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * We didn't URL decode "file:///path/to/repo" correctly when path/to/repo
+   had percent-encoded characters (638794c, 9d2e942, ce83eda, 3c73a1d).
+
+ * "git clone" did not configure remote.origin.url correctly for bare
+   clones (df61c889).
+
+ * "git diff --graph" works better with "--color-words" and other options
+   (81fa024..4297c0a).
+
+ * "git diff" could show ambiguous abbreviation of blob object names on
+   its "index" line (3e5a188).
+
+ * "git reset --hard" started from a wrong directory and a working tree in
+   a nonstandard location is in use got confused (560fb6a1).
+
+ * "git read-tree -m A B" used to switch to branch B while retaining
+   local changes added an incorrect cache-tree information (b1f47514).
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.1.txt b/third_party/git/Documentation/RelNotes/1.7.3.1.txt
new file mode 100644
index 0000000000..002c93b961
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.1.txt
@@ -0,0 +1,14 @@
+Git v1.7.3.1 Release Notes
+==========================
+
+Fixes since v1.7.3
+------------------
+
+ * "git stash show stash@{$n}" was accidentally broken in 1.7.3 ("git
+   stash show" without any argument still worked, though).
+
+ * "git stash branch $branch stash@{$n}" was accidentally broken in
+   1.7.3 and started dropping the named stash even when branch creation
+   failed.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.2.txt b/third_party/git/Documentation/RelNotes/1.7.3.2.txt
new file mode 100644
index 0000000000..5c93b85af4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.2.txt
@@ -0,0 +1,5 @@
+Git v1.7.3.2 Release Notes
+==========================
+
+This is primarily to push out many documentation fixes accumulated since
+the 1.7.3.1 release.
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.3.txt b/third_party/git/Documentation/RelNotes/1.7.3.3.txt
new file mode 100644
index 0000000000..9b2b2448df
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.3.txt
@@ -0,0 +1,54 @@
+Git v1.7.3.3 Release Notes
+==========================
+
+In addition to the usual fixes, this release also includes support for
+the new "add.ignoreErrors" name given to the existing "add.ignore-errors"
+configuration variable.
+
+The next version, Git 1.7.4, and future versions, will support both
+old and incorrect name and the new corrected name, but without this
+backport, users who want to use the new name "add.ignoreErrors" in
+their repositories cannot use older versions of Git.
+
+Fixes since v1.7.3.2
+--------------------
+
+ * "git apply" segfaulted when a bogus input is fed to it.
+
+ * Running "git cherry-pick --ff" on a root commit segfaulted.
+
+ * "diff", "blame" and friends incorrectly applied textconv filters to
+   symlinks.
+
+ * Highlighting of whitespace breakage in "diff" output was showing
+   incorrect amount of whitespaces when blank-at-eol is set and the line
+   consisted only of whitespaces and a TAB.
+
+ * "diff" was overly inefficient when trying to find the line to use for
+   the function header (i.e. equivalent to --show-c-function of GNU diff).
+
+ * "git imap-send" depends on libcrypto but our build rule relied on the
+   linker to implicitly link it via libssl, which was wrong.
+
+ * "git merge-file" can be called from within a subdirectory now.
+
+ * "git repack -f" expanded and recompressed non-delta objects in the
+   existing pack, which was wasteful.  Use new "-F" option if you really
+   want to (e.g. when changing the pack.compression level).
+
+ * "git rev-list --format="...%x00..." incorrectly chopped its output
+   at NUL.
+
+ * "git send-email" did not correctly remove duplicate mail addresses from
+   the Cc: header that appear on the To: header.
+
+ * The completion script (in contrib/completion) ignored lightweight tags
+   in __git_ps1().
+
+ * "git-blame" mode (in contrib/emacs) didn't say (require 'format-spec)
+   even though it depends on it; it didn't work with Emacs 22 or older
+   unless Gnus is used.
+
+ * "git-p4" (in contrib/) did not correctly handle deleted files.
+
+Other minor fixes and documentation updates are also included.
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.4.txt b/third_party/git/Documentation/RelNotes/1.7.3.4.txt
new file mode 100644
index 0000000000..e57f7c176d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.4.txt
@@ -0,0 +1,45 @@
+Git v1.7.3.4 Release Notes
+==========================
+
+Fixes since v1.7.3.3
+--------------------
+
+ * Smart HTTP transport used to incorrectly retry redirected POST
+   request with GET request.
+
+ * "git apply" did not correctly handle patches that only change modes
+   if told to apply while stripping leading paths with -p option.
+
+ * "git apply" can deal with patches with timezone formatted with a
+   colon between the hours and minutes part (e.g. "-08:00" instead of
+   "-0800").
+
+ * "git checkout" removed an untracked file "foo" from the working
+   tree when switching to a branch that contains a tracked path
+   "foo/bar".  Prevent this, just like the case where the conflicting
+   path were "foo" (c752e7f..7980872d).
+
+ * "git cherry-pick" or "git revert" refused to work when a path that
+   would be modified by the operation was stat-dirty without a real
+   difference in the contents of the file.
+
+ * "git diff --check" reported an incorrect line number for added
+   blank lines at the end of file.
+
+ * "git imap-send" failed to build under NO_OPENSSL.
+
+ * Setting log.decorate configuration variable to "0" or "1" to mean
+   "false" or "true" did not work.
+
+ * "git push" over dumb HTTP protocol did not work against WebDAV
+   servers that did not terminate a collection name with a slash.
+
+ * "git tag -v" did not work with GPG signatures in rfc1991 mode.
+
+ * The post-receive-email sample hook was accidentally broken in 1.7.3.3
+   update.
+
+ * "gitweb" can sometimes be tricked into parrotting a filename argument
+   given in a request without properly quoting.
+
+Other minor fixes and documentation updates are also included.
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.5.txt b/third_party/git/Documentation/RelNotes/1.7.3.5.txt
new file mode 100644
index 0000000000..40f3ba5795
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.5.txt
@@ -0,0 +1,34 @@
+Git 1.7.3.5 Release Notes
+=========================
+
+ * The xfuncname pattern used by "git diff" and "git grep" to show the
+   last notable line in context were broken for python and ruby for a long
+   time.
+
+ * "git merge" into an unborn branch removed an untracked file "foo" from
+   the working tree when merged branch had "foo" (this fix was already in
+   1.7.3.3 but was omitted from the release notes by mistake).
+
+ * "git status -s" did not quote unprintable characters in paths as
+   documented.
+
+ * "git am --abort" used to always reset to the commit at the beginning of
+   the last "am" invocation that has stopped, losing any unrelated commits
+   that may have been made since then.  Now it refrains from doing so and
+   instead issues a warning.
+
+ * "git blame" incorrectly reused bogusly cached result of textconv
+   filter for files from the working tree.
+
+ * "git commit" used to abort after the user edited the log message
+   when the committer information was not correctly set up.  It now
+   aborts before starting the editor.
+
+ * "git commit --date=invalid" used to silently ignore the incorrectly
+   specified date; it is now diagnosed as an error.
+
+ * "git rebase --skip" to skip the last commit in a series used to fail
+   to run post-rewrite hook and to copy notes from old commits that have
+   successfully been rebased so far.  Now it do (backmerge ef88ad2).
+
+ * "gitweb" tried to show a wrong feed logo when none was specified.
diff --git a/third_party/git/Documentation/RelNotes/1.7.3.txt b/third_party/git/Documentation/RelNotes/1.7.3.txt
new file mode 100644
index 0000000000..309c33181f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.3.txt
@@ -0,0 +1,76 @@
+Git v1.7.3 Release Notes
+========================
+
+Updates since v1.7.2
+--------------------
+
+ * git-gui, now at version 0.13.0, got various updates and a new
+   maintainer, Pat Thoyts.
+
+ * Gitweb allows its configuration to change per each request; it used to
+   read the configuration once upon startup.
+
+ * When git finds a corrupt object, it now reports the file that contains
+   it.
+
+ * "git checkout -B <it>" is a shorter way to say "git branch -f <it>"
+   followed by "git checkout <it>".
+
+ * When "git checkout" or "git merge" refuse to proceed in order to
+   protect local modification to your working tree, they used to stop
+   after showing just one path that might be lost.  They now show all,
+   in a format that is easier to read.
+
+ * "git clean" learned "-e" ("--exclude") option.
+
+ * Hunk headers produced for C# files by "git diff" and friends show more
+   relevant context than before.
+
+ * diff.ignoresubmodules configuration variable can be used to squelch the
+   differences in submodules reported when running commands (e.g. "diff",
+   "status", etc.) at the superproject level.
+
+ * http.useragent configuration can be used to lie who you are to your
+   restrictive firewall.
+
+ * "git rebase --strategy <s>" learned "-X" option to pass extra options
+   that are understood by the chosen merge strategy.
+
+ * "git rebase -i" learned "exec" that you can insert into the insn sheet
+   to run a command between its steps.
+
+ * "git rebase" between branches that have many binary changes that do
+   not conflict should be faster.
+
+ * "git rebase -i" peeks into rebase.autosquash configuration and acts as
+   if you gave --autosquash from the command line.
+
+
+Also contains various documentation updates.
+
+
+Fixes since v1.7.2
+------------------
+
+All of the fixes in v1.7.2.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * "git merge -s recursive" (which is the default) did not handle cases
+   where a directory becomes a file (or vice versa) very well.
+
+ * "git fetch" and friends were accidentally broken for url with "+" in
+   its path, e.g. "git://git.gnome.org/gtk+".
+
+ * "git fetch $url" (i.e. without refspecs) was broken for quite some
+   time, if the current branch happen to be tracking some remote.
+
+ * "git ls-tree dir dirgarbage", when "dir" was a directory,
+   incorrectly recursed into "dir".
+
+ * "git note remove" created unnecessary extra commit when named object
+   did not have any note to begin with.
+
+ * "git rebase" did not work well if you had diff.noprefix configured.
+
+ * "git -c foo=bar subcmd" did not work well for subcmd that is not
+   implemented as a built-in command.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.1.txt b/third_party/git/Documentation/RelNotes/1.7.4.1.txt
new file mode 100644
index 0000000000..79923a6d2f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.1.txt
@@ -0,0 +1,27 @@
+Git v1.7.4.1 Release Notes
+==========================
+
+Fixes since v1.7.4
+------------------
+
+ * On Windows platform, the codepath to spawn a new child process forgot
+   to first flush the output buffer.
+
+ * "git bundle" did not use OFS_DELTA encoding, making its output a few
+   per-cent larger than necessarily.
+
+ * The option to tell "git clone" to recurse into the submodules was
+   misspelled with an underscore "--recurse_submodules".
+
+ * "git diff --cached HEAD" before the first commit does what an end user
+   would expect (namely, show what would be committed without further "git
+   add").
+
+ * "git fast-import" didn't accept the command to ask for "notes" feature
+   to be present in its input stream, even though it was capable of the
+   feature.
+
+ * "git fsck" gave up scanning loose object files in directories with
+   garbage files.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.2.txt b/third_party/git/Documentation/RelNotes/1.7.4.2.txt
new file mode 100644
index 0000000000..ef4ce1fcd3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.2.txt
@@ -0,0 +1,58 @@
+Git v1.7.4.2 Release Notes
+==========================
+
+Fixes since v1.7.4.1
+--------------------
+
+ * Many documentation updates to match "git cmd -h" output and the
+   git-cmd manual page.
+
+ * We used to keep one file descriptor open for each and every packfile
+   that we have a mmap window on it (read: "in use"), even when for very
+   tiny packfiles.  We now close the file descriptor early when the entire
+   packfile fits inside one mmap window.
+
+ * "git bisect visualize" tried to run "gitk" in windowing
+   environments even when "gitk" is not installed, resulting in a
+   strange error message.
+
+ * "git clone /no/such/path" did not fail correctly.
+
+ * "git commit" did not correctly error out when the user asked to use a
+   non existent file as the commit message template.
+
+ * "git diff --stat -B" ran on binary files counted the changes in lines,
+   which was nonsensical.
+
+ * "git diff -M" opportunistically detected copies, which was not
+   necessarily a good thing, especially when it is internally run by
+   recursive merge.
+
+ * "git difftool" didn't tell (g)vimdiff that the files it is reading are
+   to be opened read-only.
+
+ * "git merge" didn't pay attention to prepare-commit-msg hook, even
+   though if a merge is conflicted and manually resolved, the subsequent
+   "git commit" would have triggered the hook, which was inconsistent.
+
+ * "git patch-id" (and commands like "format-patch --ignore-in-upstream"
+   that use it as their internal logic) handled changes to files that end
+   with incomplete lines incorrectly.
+
+ * The official value to tell "git push" to push the current branch back
+   to update the upstream branch it forked from is now called "upstream".
+   The old name "tracking" is and will be supported.
+
+ * "git submodule update" used to honor the --merge/--rebase option (or
+   corresponding configuration variables) even for a newly cloned
+   subproject, which made no sense (so/submodule-no-update-first-time).
+
+ * gitweb's "highlight" interface mishandled tabs.
+
+ * gitweb didn't understand timezones with GMT offset that is not
+   multiple of a whole hour.
+
+ * gitweb had a few forward-incompatible syntactic constructs and
+   also used incorrect variable when showing the file mode in a diff.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.3.txt b/third_party/git/Documentation/RelNotes/1.7.4.3.txt
new file mode 100644
index 0000000000..02a3d5bdf6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.3.txt
@@ -0,0 +1,32 @@
+Git v1.7.4.3 Release Notes
+==========================
+
+Fixes since v1.7.4.2
+--------------------
+
+ * "git apply" used to confuse lines updated by previous hunks as lines
+   that existed before when applying a hunk, contributing misapplication
+   of patches with offsets.
+
+ * "git branch --track" (and "git checkout --track --branch") used to
+   allow setting up a random non-branch that does not make sense to follow
+   as the "upstream".  The command correctly diagnoses it as an error.
+
+ * "git checkout $other_branch" silently removed untracked symbolic links
+   in the working tree that are in the way in order to check out paths
+   under it from the named branch.
+
+ * "git cvsimport" did not bail out immediately when the cvs server cannot
+   be reached, spewing unnecessary error messages that complain about the
+   server response that it never got.
+
+ * "git diff --quiet" did not work very well with the "--diff-filter"
+   option.
+
+ * "git grep -n" lacked a long-hand synonym --line-number.
+
+ * "git stash apply" reported the result of its operation by running
+   "git status" from the top-level of the working tree; it should (and
+   now does) run it from the user's working directory.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.4.txt b/third_party/git/Documentation/RelNotes/1.7.4.4.txt
new file mode 100644
index 0000000000..ff06e04a58
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.4.txt
@@ -0,0 +1,35 @@
+Git v1.7.4.4 Release Notes
+==========================
+
+Fixes since v1.7.4.3
+--------------------
+
+ * Compilation of sha1_file.c on BSD platforms were broken due to our
+   recent use of getrlimit() without including <sys/resource.h>.
+
+ * "git config" did not diagnose incorrect configuration variable names.
+
+ * "git format-patch" did not wrap a long subject line that resulted from
+   rfc2047 encoding.
+
+ * "git instaweb" should work better again with plackup.
+
+ * "git log --max-count=4 -Sfoobar" now shows 4 commits that changes the
+   number of occurrences of string "foobar"; it used to scan only for 4
+   commits and then emitted only matching ones.
+
+ * "git log --first-parent --boundary $c^..$c" segfaulted on a merge.
+
+ * "git pull" into an empty branch should have behaved as if
+   fast-forwarding from emptiness to the version being pulled, with
+   the usual protection against overwriting untracked files.
+
+ * "git submodule" that is run while a merge in the superproject is in
+   conflicted state tried to process each conflicted submodule up to
+   three times.
+
+ * "git status" spent all the effort to notice racily-clean index entries
+   but didn't update the index file to help later operations go faster in
+   some cases.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.5.txt b/third_party/git/Documentation/RelNotes/1.7.4.5.txt
new file mode 100644
index 0000000000..b7a0eeb22f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.5.txt
@@ -0,0 +1,4 @@
+Git v1.7.4.5 Release Notes
+==========================
+
+This contains only minor documentation fixes accumulated since 1.7.4.4.
diff --git a/third_party/git/Documentation/RelNotes/1.7.4.txt b/third_party/git/Documentation/RelNotes/1.7.4.txt
new file mode 100644
index 0000000000..d5bca731b5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.4.txt
@@ -0,0 +1,156 @@
+Git v1.7.4 Release Notes
+========================
+
+Updates since v1.7.3
+--------------------
+
+ * The documentation Makefile now assumes by default asciidoc 8 and
+   docbook-xsl >= 1.73. If you have older versions, you can set
+   ASCIIDOC7 and ASCIIDOC_ROFF, respectively.
+
+ * The option parsers of various commands that create new branches (or
+   rename existing ones to a new name) were too loose and users were
+   allowed to give a branch a name that begins with a dash by creative
+   abuse of their command line options, which only led to burning
+   themselves.  The name of a branch cannot begin with a dash now.
+
+ * System-wide fallback default attributes can be stored in
+   /etc/gitattributes; the core.attributesfile configuration variable can
+   be used to customize the path to this file.
+
+ * The thread structure generated by "git send-email" has changed
+   slightly.  Setting the cover letter of the latest series as a reply
+   to the cover letter of the previous series with --in-reply-to used
+   to make the new cover letter and all the patches replies to the
+   cover letter of the previous series; this has been changed to make
+   the patches in the new series replies to the new cover letter.
+
+ * The Bash completion script in contrib/ has been adjusted to be usable with
+   Bash 4 (options with '=value' didn't complete).  It has been also made
+   usable with zsh.
+
+ * Different pagers can be chosen depending on which subcommand is
+   being run under the pager, using the "pager.<subcommand>" variable.
+
+ * The hardcoded tab-width of 8 that is used in whitespace breakage checks is now
+   configurable via the attributes mechanism.
+
+ * Support of case insensitive filesystems (i.e. "core.ignorecase") has
+   been improved.  For example, the gitignore mechanism didn't pay attention
+   to case insensitivity.
+
+ * The <tree>:<path> syntax for naming a blob in a tree, and the :<path>
+   syntax for naming a blob in the index (e.g. "master:Makefile",
+   ":hello.c") have been extended.  You can start <path> with "./" to
+   implicitly have the (sub)directory you are in prefixed to the
+   lookup.  Similarly, ":../Makefile" from a subdirectory would mean
+   "the Makefile of the parent directory in the index".
+
+ * "git blame" learned the --show-email option to display the e-mail
+   addresses instead of the names of authors.
+
+ * "git commit" learned the --fixup and --squash options to help later invocation
+   of interactive rebase.
+
+ * Command line options to "git cvsimport" whose names are in capital
+   letters (-A, -M, -R and -S) can now be specified as the default in
+   the .git/config file by their longer names (cvsimport.authorsFile,
+   cvsimport.mergeRegex, cvsimport.trackRevisions, cvsimport.ignorePaths).
+
+ * "git daemon" can be built in the MinGW environment.
+
+ * "git daemon" can take more than one --listen option to listen to
+   multiple addresses.
+
+ * "git describe --exact-match" was optimized not to read commit
+   objects unnecessarily.
+
+ * "git diff" and "git grep" learned what functions and subroutines
+   in Fortran, Pascal and Perl look like.
+
+ * "git fetch" learned the "--recurse-submodules" option.
+
+ * "git mergetool" tells vim/gvim to show a three-way diff by default
+   (use vimdiff2/gvimdiff2 as the tool name for old behavior).
+
+ * "git log -G<pattern>" limits the output to commits whose change has
+   added or deleted lines that match the given pattern.
+
+ * "git read-tree" with no argument as a way to empty the index is
+   deprecated; we might want to remove it in the future.  Users can
+   use the new --empty option to be more explicit instead.
+
+ * "git repack -f" does not spend cycles to recompress objects in the
+   non-delta representation anymore (use -F if you really mean it
+   e.g. after you changed the core.compression variable setting).
+
+ * "git merge --log" used to limit the resulting merge log to 20
+   entries; this is now customizable by giving e.g. "--log=47".
+
+ * "git merge" may work better when all files were moved out of a
+   directory in one branch while a new file is created in place of that
+   directory in the other branch.
+
+ * "git merge" learned the "--abort" option, synonymous to
+   "git reset --merge" when a merge is in progress.
+
+ * "git notes" learned the "merge" subcommand to merge notes refs.
+   In addition to the default manual conflict resolution, there are
+   also several notes merge strategies for automatically resolving
+   notes merge conflicts.
+
+ * "git rebase --autosquash" can use SHA-1 object names to name the
+   commit which is to be fixed up (e.g. "fixup! e83c5163").
+
+ * The default "recursive" merge strategy learned the --rename-threshold
+   option to influence the rename detection, similar to the -M option
+   of "git diff".  From the "git merge" frontend, the "-X<strategy option>"
+   interface, e.g. "git merge -Xrename-threshold=50% ...", can be used
+   to trigger this.
+
+ * The "recursive" strategy also learned to ignore various whitespace
+   changes; the most notable is -Xignore-space-at-eol.
+
+ * "git send-email" learned "--to-cmd", similar to "--cc-cmd", to read
+   the recipient list from a command output.
+
+ * "git send-email" learned to read and use "To:" from its input files.
+
+ * you can extend "git shell", which is often used on boxes that allow
+   git-only login over ssh as login shell, with a custom set of
+   commands.
+
+ * The current branch name in "git status" output can be colored differently
+   from the generic header color by setting the "color.status.branch" variable.
+
+ * "git submodule sync" updates metainformation for all submodules,
+   not just the ones that have been checked out.
+
+ * gitweb can use a custom 'highlight' command with its configuration file.
+
+ * other gitweb updates.
+
+
+Also contains various documentation updates.
+
+
+Fixes since v1.7.3
+------------------
+
+All of the fixes in the v1.7.3.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * "git log --author=me --author=her" did not find commits written by
+   me or by her; instead it looked for commits written by me and by
+   her, which is impossible.
+
+ * "git push --progress" shows progress indicators now.
+
+ * "git rebase -i" showed a confusing error message when given a
+   branch name that does not exist.
+
+ * "git repack" places its temporary packs under $GIT_OBJECT_DIRECTORY/pack
+   instead of $GIT_OBJECT_DIRECTORY/ to avoid cross directory renames.
+
+ * "git submodule update --recursive --other-flags" passes flags down
+   to its subinvocations.
diff --git a/third_party/git/Documentation/RelNotes/1.7.5.1.txt b/third_party/git/Documentation/RelNotes/1.7.5.1.txt
new file mode 100644
index 0000000000..c6ebd76d19
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.5.1.txt
@@ -0,0 +1,47 @@
+Git v1.7.5.1 Release Notes
+==========================
+
+Fixes since v1.7.5
+------------------
+
+ * When an object "$tree:$path" does not exist, if $path does exist in the
+   subtree of $tree that corresponds to the subdirectory the user is in,
+   git now suggests using "$tree:./$path" in addition to the advice to use
+   the full path from the root of the working tree.
+
+ * The "--date=relative" output format used to say "X years, 12 months"
+   when it should have said "X+1 years".
+
+ * The smart-HTTP transfer was broken in 1.7.5 when the client needs
+   to issue a small POST (which uses content-length) and then a large
+   POST (which uses chunked) back to back.
+
+ * "git clean" used to fail on an empty directory that is not readable,
+   even though rmdir(2) could remove such a directory.  Now we attempt it
+   as the last resort.
+
+ * The "--dirstat" option of "diff" family of commands used to totally
+   ignore a change that only rearranged lines within a file.  Such a
+   change now counts as at least a minimum but non zero change.
+
+ * The "--dirstat" option of "diff" family of commands used to use the
+   pathname in the original, instead of the pathname in the result,
+   when renames are involved.
+
+ * "git pack-object" did not take core.bigfilethreashold into account
+   (unlike fast-import); now it does.
+
+ * "git reflog" ignored options like "--format=.." on the command line.
+
+ * "git stash apply" used to refuse to work if there was any change in
+   the working tree, even when the change did not overlap with the change
+   the stash recorded.
+
+ * "git stash apply @{99999}" was not diagnosed as an error, even when you
+   did not have that many stash entries.
+
+ * An error message from "git send-email" to diagnose a broken SMTP
+   connection configuration lacked a space between "hello=<smtp-domain>"
+   and "port=<smtp-server-port>".
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.5.2.txt b/third_party/git/Documentation/RelNotes/1.7.5.2.txt
new file mode 100644
index 0000000000..951eb7cb08
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.5.2.txt
@@ -0,0 +1,57 @@
+Git v1.7.5.2 Release Notes
+==========================
+
+The release notes to 1.7.5.1 forgot to mention:
+
+ * "git stash -p --no-keep-index" and "git stash --no-keep-index -p" now
+   mean the same thing.
+
+ * "git upload-pack" (hence "git push" over git native protocol) had a
+   subtle race condition that could lead to a deadlock.
+
+Fixes since v1.7.5.1
+--------------------
+
+ * "git add -p" did not work correctly when a hunk is split and then
+   one of them was given to the editor.
+
+ * "git add -u" did not resolve a conflict where our history deleted and
+   their history modified the same file, and the working tree resolved to
+   keep a file.
+
+ * "git cvsimport" did not know that CVSNT stores its password file in a
+   location different from the traditional CVS.
+
+ * "git diff-files" did not show the mode information from the working
+   tree side of an unmerged path correctly.
+
+ * "git diff -M --cached" used to use unmerged path as a possible rename
+   source candidate, which made no sense.
+
+ * The option name parser in "git fast-import" used prefix matches for
+   some options where it shouldn't, and accepted non-existent options,
+   e.g. "--relative-marksmith" or "--forceps".
+
+ * "git format-patch" did not quote RFC822 special characters in the
+   email address (e.g From: Junio C. Hamano <jch@example.com>, not
+   From: "Junio C. Hamano" <jch@example.com>).
+
+ * "git format-patch" when run with "--quiet" option used to produce a
+   nonsense result that consists of alternating empty output.
+
+ * In "git merge", per-branch branch.<name>.mergeoptions configuration
+   variables did not override the fallback default merge.<option>
+   configuration variables such as merge.ff, merge.log, etc.
+
+ * "git merge-one-file" did not honor GIT_WORK_TREE settings when
+   handling a "both sides added, differently" conflict.
+
+ * "git mergetool" did not handle conflicted submoudules gracefully.
+
+ * "git-p4" (in contrib) used a wrong base image while merge a file that
+   was added on both branches differently.
+
+ * "git rebase -i -p" failed to preserve the history when there is a
+   redundant merge created with the --no-ff option.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.5.3.txt b/third_party/git/Documentation/RelNotes/1.7.5.3.txt
new file mode 100644
index 0000000000..9c03353af2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.5.3.txt
@@ -0,0 +1,32 @@
+Git v1.7.5.3 Release Notes
+==========================
+
+Fixes since v1.7.5.2
+--------------------
+
+ * The bash completion scripts should correctly work using zsh's bash
+   completion emulation layer now.
+
+ * Setting $(prefix) in config.mak did not affect where etc/gitconfig
+   file is read from, even though passing it from the command line of
+   $(MAKE) did.
+
+ * The logic to handle "&" (expand to UNIX username) in GECOS field
+   miscounted the length of the name it formatted.
+
+ * "git cherry-pick -s resolve" failed to cherry-pick a root commit.
+
+ * "git diff --word-diff" misbehaved when diff.suppress-blank-empty was
+   in effect.
+
+ * "git log --stdin path" with an input that has additional pathspec
+   used to corrupt memory.
+
+ * "git send-pack" (hence "git push") over smalt-HTTP protocol could
+   deadlock when the client side pack-object died early.
+
+ * Compressed tarball gitweb generates used to be made with the timestamp
+   of the tarball generation; this was bad because snapshot from the same
+   tree should result in a same tarball.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.5.4.txt b/third_party/git/Documentation/RelNotes/1.7.5.4.txt
new file mode 100644
index 0000000000..7796df3fe4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.5.4.txt
@@ -0,0 +1,21 @@
+Git v1.7.5.4 Release Notes
+==========================
+
+Fixes since v1.7.5.3
+--------------------
+
+ * The single-key mode of "git add -p" was easily fooled into thinking
+   that it was told to add everything ('a') when up-arrow was pressed by
+   mistake.
+
+ * Setting a git command that uses custom configuration via "-c var=val"
+   as an alias caused a crash due to a realloc(3) failure.
+
+ * "git diff -C -C" used to disable the rename detection entirely when
+   there are too many copy candidate paths in the tree; now it falls
+   back to "-C" when doing so would keep the copy candidate paths
+   under the rename detection limit.
+
+ * "git rerere" did not diagnose a corrupt MERGE_RR file in some cases.
+
+And other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.5.txt b/third_party/git/Documentation/RelNotes/1.7.5.txt
new file mode 100644
index 0000000000..987919c321
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.5.txt
@@ -0,0 +1,132 @@
+Git v1.7.5 Release Notes
+========================
+
+Updates since v1.7.4
+--------------------
+
+ * Various MinGW portability fixes.
+
+ * Various git-p4 enhancements (in contrib).
+
+ * Various vcs-svn, git-svn and gitk enhancements and fixes.
+
+ * Various git-gui updates (0.14.0).
+
+ * Update to more modern HP-UX port.
+
+ * The codebase is getting prepared for i18n/l10n; no translated
+   strings nor translation mechanism in the code yet, but the strings
+   are being marked for l10n.
+
+ * The bash completion script can now complete symmetric difference
+   for "git diff" command, e.g. "git diff ...bra<TAB>".
+
+ * The default minimum length of abbreviated and unique object names
+   can now be configured by setting the core.abbrev configuration
+   variable.
+
+ * "git apply -v" reports offset lines when the patch does not apply at
+   the exact location recorded in the diff output.
+
+ * "git config" used to be also known as "git repo-config", but the old
+   name is now officially deprecated.
+
+ * "git checkout --detach <commit>" is a more user friendly synonym for
+   "git checkout <commit>^0".
+
+ * "git checkout" performed on detached HEAD gives a warning and
+   advice when the commit being left behind will become unreachable from
+   any branch or tag.
+
+ * "git cherry-pick" and "git revert" can be told to use a custom merge
+   strategy, similar to "git rebase".
+
+ * "git cherry-pick" remembers which commit failed to apply when it is
+   stopped by conflicts, making it unnecessary to use "commit -c $commit"
+   to conclude it.
+
+ * "git cvsimport" bails out immediately when the cvs server cannot be
+   reached, without spewing unnecessary error messages that complain about
+   the server response it never got.
+
+ * "git fetch" vs "git upload-pack" transfer learned 'no-done'
+   protocol extension to save one round-trip after the content
+   negotiation is done. This saves one HTTP RPC, reducing the overall
+   latency for a trivial fetch.
+
+ * "git fetch" can be told to recursively fetch submodules on-demand.
+
+ * "git grep -f <filename>" learned to treat "-" as "read from the
+   standard input stream".
+
+ * "git grep --no-index" did not honor pathspecs correctly, returning
+   paths outside the specified area.
+
+ * "git init" learned the --separate-git-dir option to allow the git
+   directory for a new repository created elsewhere and linked via the
+   gitdir mechanism. This is primarily to help submodule support later
+   to switch between a branch of superproject that has the submodule
+   and another that does not.
+
+ * "git log" type commands now understand globbing pathspecs.  You
+   can say "git log -- '*.txt'" for example.
+
+ * "git log" family of commands learned --cherry and --cherry-mark
+   options that can be used to view two diverged branches while omitting
+   or highlighting equivalent changes that appear on both sides of a
+   symmetric difference (e.g. "log --cherry A...B").
+
+ * A lazy "git merge" that didn't say what to merge used to be an error.
+   When run on a branch that has an upstream defined, however, the command
+   now merges from the configured upstream.
+
+ * "git mergetool" learned how to drive "beyond compare 3" as well.
+
+ * "git rerere forget" without pathspec used to forget all the saved
+   conflicts that relate to the current merge; it now requires you to
+   give it pathspecs.
+
+ * "git rev-list --objects $revs -- $pathspec" now limits the objects listed
+   in its output properly with the pathspec, in preparation for narrow
+   clones.
+
+ * "git push" with no parameters gives better advice messages when
+   "tracking" is used as the push.default semantics or there is no remote
+   configured yet.
+
+ * A possible value to the "push.default" configuration variable,
+   'tracking', gained a synonym that more naturally describes what it
+   does, 'upstream'.
+
+ * "git rerere" learned a new subcommand "remaining" that is similar to
+   "status" and lists the paths that had conflicts which are known to
+   rerere, but excludes the paths that have already been marked as
+   resolved in the index from its output.  "git mergetool" has been
+   updated to use this facility.
+
+Also contains various documentation updates.
+
+
+Fixes since v1.7.4
+------------------
+
+All of the fixes in the v1.7.4.X maintenance series are included in this
+release, unless otherwise noted.
+
+ * "git fetch" from a client that is mostly following the remote
+   needlessly told all of its refs to the server for both sides to
+   compute the set of objects that need to be transferred efficiently,
+   instead of stopping when the server heard enough. In a project with
+   many tags, this turns out to be extremely wasteful, especially over
+   the smart HTTP transport (sp/maint-{upload,fetch}-pack-stop-early~1).
+
+ * "git fetch" run from a repository that uses the same repository as
+   its alternate object store as the repository it is fetching from
+   did not tell the server that it already has access to objects
+   reachable from the refs in their common alternate object store,
+   causing it to fetch unnecessary objects (jc/maint-fetch-alt).
+
+ * "git remote add --mirror" created a configuration that is suitable for
+   doing both a mirror fetch and a mirror push at the same time, which
+   made little sense.  We now warn and require the command line to specify
+   either --mirror=fetch or --mirror=push.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.1.txt b/third_party/git/Documentation/RelNotes/1.7.6.1.txt
new file mode 100644
index 0000000000..42e46ab17f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.1.txt
@@ -0,0 +1,63 @@
+Git v1.7.6.1 Release Notes
+==========================
+
+Fixes since v1.7.6
+------------------
+
+ * Various codepaths that invoked zlib deflate/inflate assumed that these
+   functions can compress or uncompress more than 4GB data in one call on
+   platforms with 64-bit long, which has been corrected.
+
+ * "git unexecutable" reported that "unexecutable" was not found, even
+   though the actual error was that "unexecutable" was found but did
+   not have a proper she-bang line to be executed.
+
+ * Error exits from $PAGER were silently ignored.
+
+ * "git checkout -b <branch>" was confused when attempting to create a
+   branch whose name ends with "-g" followed by hexadecimal digits,
+   and refused to work.
+
+ * "git checkout -b <branch>" sometimes wrote a bogus reflog entry,
+   causing later "git checkout -" to fail.
+
+ * "git diff --cc" learned to correctly ignore binary files.
+
+ * "git diff -c/--cc" mishandled a deletion that resolves a conflict, and
+   looked in the working tree instead.
+
+ * "git fast-export" forgot to quote pathnames with unsafe characters
+   in its output.
+
+ * "git fetch" over smart-http transport used to abort when the
+   repository was updated between the initial connection and the
+   subsequent object transfer.
+
+ * "git fetch" did not recurse into submodules in subdirectories.
+
+ * "git ls-tree" did not error out when asked to show a corrupt tree.
+
+ * "git pull" without any argument left an extra whitespace after the
+   command name in its reflog.
+
+ * "git push --quiet" was not really quiet.
+
+ * "git rebase -i -p" incorrectly dropped commits from side branches.
+
+ * "git reset [<commit>] paths..." did not reset the index entry correctly
+   for unmerged paths.
+
+ * "git submodule add" did not allow a relative repository path when
+   the superproject did not have any default remote url.
+
+ * "git submodule foreach" failed to correctly give the standard input to
+   the user-supplied command it invoked.
+
+ * submodules that the user has never showed interest in by running
+   "git submodule init" was incorrectly marked as interesting by "git
+   submodule sync".
+
+ * "git submodule update --quiet" was not really quiet.
+
+  * "git tag -l <glob>..." did not take multiple glob patterns from the
+   command line.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.2.txt b/third_party/git/Documentation/RelNotes/1.7.6.2.txt
new file mode 100644
index 0000000000..67ae414965
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.2.txt
@@ -0,0 +1,8 @@
+Git v1.7.6.2 Release Notes
+==========================
+
+Fixes since v1.7.6.1
+--------------------
+
+ * v1.7.6.1 broke "git push --quiet"; it used to be a no-op against an old
+   version of Git running on the other end, but v1.7.6.1 made it abort.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.3.txt b/third_party/git/Documentation/RelNotes/1.7.6.3.txt
new file mode 100644
index 0000000000..95971831b9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.3.txt
@@ -0,0 +1,24 @@
+Git v1.7.6.3 Release Notes
+==========================
+
+Fixes since v1.7.6.2
+--------------------
+
+ * "git -c var=value subcmd" misparsed the custom configuration when
+   value contained an equal sign.
+
+ * "git fetch" had a major performance regression, wasting many
+   needless cycles in a repository where there is no submodules
+   present. This was especially bad, when there were many refs.
+
+ * "git reflog $refname" did not default to the "show" subcommand as
+   the documentation advertised the command to do.
+
+ * "git reset" did not leave meaningful log message in the reflog.
+
+ * "git status --ignored" did not show ignored items when there is no
+   untracked items.
+
+ * "git tag --contains $commit" was unnecessarily inefficient.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.4.txt b/third_party/git/Documentation/RelNotes/1.7.6.4.txt
new file mode 100644
index 0000000000..e19acac2da
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.4.txt
@@ -0,0 +1,32 @@
+Git v1.7.6.4 Release Notes
+==========================
+
+Fixes since v1.7.6.3
+--------------------
+
+ * The error reporting logic of "git am" when the command is fed a file
+   whose mail-storage format is unknown was fixed.
+
+ * "git branch --set-upstream @{-1} foo" did not expand @{-1} correctly.
+
+ * "git check-ref-format --print" used to parrot a candidate string that
+   began with a slash (e.g. /refs/heads/master) without stripping it, to make
+   the result a suitably normalized string the caller can append to "$GIT_DIR/".
+
+ * "git clone" failed to clone locally from a ".git" file that itself
+   is not a directory but is a pointer to one.
+
+ * "git clone" from a local repository that borrows from another
+   object store using a relative path in its objects/info/alternates
+   file did not adjust the alternates in the resulting repository.
+
+ * "git describe --dirty" did not refresh the index before checking the
+   state of the working tree files.
+
+ * "git ls-files ../$path" that is run from a subdirectory reported errors
+   incorrectly when there is no such path that matches the given pathspec.
+
+ * "git mergetool" could loop forever prompting when nothing can be read
+   from the standard input.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.5.txt b/third_party/git/Documentation/RelNotes/1.7.6.5.txt
new file mode 100644
index 0000000000..6713132a9e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.5.txt
@@ -0,0 +1,26 @@
+Git v1.7.6.5 Release Notes
+==========================
+
+Fixes since v1.7.6.4
+--------------------
+
+ * The date parser did not accept timezone designators that lack minutes
+   part and also has a colon between "hh:mm".
+
+ * After fetching from a remote that has very long refname, the reporting
+   output could have corrupted by overrunning a static buffer.
+
+ * "git mergetool" did not use its arguments as pathspec, but as a path to
+   the file that may not even have any conflict.
+
+ * "git name-rev --all" tried to name all _objects_, naturally failing to
+   describe many blobs and trees, instead of showing only commits as
+   advertised in its documentation.
+
+ * "git remote rename $a $b" were not careful to match the remote name
+   against $a (i.e. source side of the remote nickname).
+
+ * "gitweb" used to produce a non-working link while showing the contents
+   of a blob, when JavaScript actions are enabled.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.6.txt b/third_party/git/Documentation/RelNotes/1.7.6.6.txt
new file mode 100644
index 0000000000..5343e00400
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.6.txt
@@ -0,0 +1,16 @@
+Git v1.7.6.6 Release Notes
+==========================
+
+Fixes since v1.7.6.5
+--------------------
+
+ * The code to look up attributes for paths reused entries from a wrong
+   directory when two paths in question are in adjacent directories and
+   the name of the one directory is a prefix of the other.
+
+ * When producing a "thin pack" (primarily used in bundles and smart
+   HTTP transfers) out of a fully packed repository, we unnecessarily
+   avoided sending recent objects as a delta against objects we know
+   the other side has.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.6.txt b/third_party/git/Documentation/RelNotes/1.7.6.txt
new file mode 100644
index 0000000000..9ec498ea39
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.6.txt
@@ -0,0 +1,136 @@
+Git v1.7.6 Release Notes
+========================
+
+Updates since v1.7.5
+--------------------
+
+ * Various git-svn updates.
+
+ * Updates the way content tags are handled in gitweb.  Also adds
+   a UI to choose common timezone for displaying the dates.
+
+ * Similar to branch names, tagnames that begin with "-" are now
+   disallowed.
+
+ * Clean-up of the C part of i18n (but not l10n---please wait)
+   continues.
+
+ * The scripting part of the codebase is getting prepared for i18n/l10n.
+
+ * Pushing and pulling from a repository with large number of refs that
+   point to identical commits are optimized by not listing the same commit
+   during the common ancestor negotiation exchange with the other side.
+
+ * Adding a file larger than core.bigfilethreshold (defaults to 1/2 Gig)
+   using "git add" will send the contents straight to a packfile without
+   having to hold it and its compressed representation both at the same
+   time in memory.
+
+ * Processes spawned by "[alias] <name> = !process" in the configuration
+   can inspect GIT_PREFIX environment variable to learn where in the
+   working tree the original command was invoked.
+
+ * A magic pathspec ":/" tells a command that limits its operation to
+   the current directory when ran from a subdirectory to work on the
+   entire working tree. In general, ":/path/to/file" would be relative
+   to the root of the working tree hierarchy.
+
+   After "git reset --hard; edit Makefile; cd t/", "git add -u" would
+   be a no-op, but "git add -u :/" would add the updated contents of
+   the Makefile at the top level. If you want to name a path in the
+   current subdirectory whose unusual name begins with ":/", you can
+   name it by "./:/that/path" or by "\:/that/path".
+
+ * "git blame" learned "--abbrev[=<n>]" option to control the minimum
+   number of hexdigits shown for commit object names.
+
+ * "git blame" learned "--line-porcelain" that is less efficient but is
+   easier to parse.
+
+ * Aborting "git commit --interactive" discards updates to the index
+   made during the interactive session.
+
+ * "git commit" learned a "--patch" option to directly jump to the
+   per-hunk selection UI of the interactive mode.
+
+ * "git diff" and its family of commands learned --dirstat=0 to show
+   directories that contribute less than 0.1% of changes.
+
+ * "git diff" and its family of commands learned --dirstat=lines mode to
+   assess damage to the directory based on number of lines in the patch
+   output, not based on the similarity numbers.
+
+ * "git format-patch" learned "--quiet" option to suppress the output of
+   the names of generated files.
+
+ * "git format-patch" quotes people's names when it has RFC822 special
+   characters in it, e.g. "Junio C. Hamano" <jch@example.com>.  Earlier
+   it was up to the user to do this when using its output.
+
+ * "git format-patch" can take an empty --subject-prefix now.
+
+ * "git grep" learned the "-P" option to take pcre regular expressions.
+
+ * "git log" and friends learned a new "--notes" option to replace the
+   "--show-notes" option.  Unlike "--show-notes", "--notes=<ref>" does
+   not imply showing the default notes.
+
+ * They also learned a log.abbrevCommit configuration variable to augment
+   the --abbrev-commit command line option.
+
+ * "git ls-remote" learned "--exit-code" option to consider it a
+   different kind of error when no remote ref to be shown.
+
+ * "git merge" learned "-" as a short-hand for "the previous branch", just
+   like the way "git checkout -" works.
+
+ * "git merge" uses "merge.ff" configuration variable to decide to always
+   create a merge commit (i.e. --no-ff, aka merge.ff=no), refuse to create
+   a merge commit (i.e. --ff-only, aka merge.ff=only). Setting merge.ff=yes
+   (or not setting it at all) restores the default behaviour of allowing
+   fast-forward to happen when possible.
+
+ * p4-import (from contrib) learned a new option --preserve-user.
+
+ * "git read-tree -m" learned "--dry-run" option that reports if a merge
+   would fail without touching the index nor the working tree.
+
+ * "git rebase" that does not specify on top of which branch to rebase
+   the current branch now uses @{upstream} of the current branch.
+
+ * "git rebase" finished either normally or with --abort did not
+   update the reflog for HEAD to record the event to come back to
+   where it started from.
+
+ * "git remote add -t only-this-branch --mirror=fetch" is now allowed. Earlier
+   a fetch-mode mirror meant mirror everything, but now it only means refs are
+   not renamed.
+
+ * "git rev-list --count" used with "--cherry-mark" counts the cherry-picked
+   commits separately, producing more a useful output.
+
+ * "git submodule update" learned "--force" option to get rid of local
+   changes in submodules and replace them with the up-to-date version.
+
+ * "git status" and friends ignore .gitmodules file while the file is
+   still in a conflicted state during a merge, to avoid using information
+   that is not final and possibly corrupt with conflict markers.
+
+Also contains various documentation updates and minor miscellaneous
+changes.
+
+
+Fixes since v1.7.5
+------------------
+
+Unless otherwise noted, all the fixes in 1.7.5.X maintenance track are
+included in this release.
+
+ * "git config" used to choke with an insanely long line.
+   (merge ef/maint-strbuf-init later)
+
+ * "git diff --quiet" did not work well with --diff-filter.
+   (merge jk/diff-not-so-quick later)
+
+ * "git status -z" did not default to --porcelain output format.
+   (merge bc/maint-status-z-to-use-porcelain later)
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.1.txt b/third_party/git/Documentation/RelNotes/1.7.7.1.txt
new file mode 100644
index 0000000000..ac9b838e25
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.1.txt
@@ -0,0 +1,60 @@
+Git v1.7.7.1 Release Notes
+==========================
+
+Fixes since v1.7.7
+------------------
+
+ * On some BSD systems, adding +s bit on directories is detrimental
+   (it is not necessary on BSD to begin with). "git init --shared"
+   has been updated to take this into account without extra makefile
+   settings on platforms the Makefile knows about.
+
+ * After incorrectly written third-party tools store a tag object in
+   HEAD, git diagnosed it as a repository corruption and refused to
+   proceed in order to avoid spreading the damage. We now gracefully
+   recover from such a situation by pretending as if the commit that
+   is pointed at by the tag were in HEAD.
+
+ * "git apply --whitespace=error" did not bother to report the exact
+   line number in the patch that introduced new blank lines at the end
+   of the file.
+
+ * "git apply --index" did not check corrupted patch.
+
+ * "git checkout $tree $directory/" resurrected paths locally removed or
+   modified only in the working tree in $directory/ that did not appear
+   in $directory of the given $tree. They should have been kept intact.
+
+ * "git diff $tree $path" used to apply the pathspec at the output stage,
+   reading the whole tree, wasting resources.
+
+ * The code to check for updated submodules during a "git fetch" of the
+   superproject had an unnecessary quadratic loop.
+
+ * "git fetch" from a large bundle did not enable the progress output.
+
+ * When "git fsck --lost-and-found" found that an empty blob object in the
+   object store is unreachable, it incorrectly reported an error after
+   writing the lost blob out successfully.
+
+ * "git filter-branch" did not refresh the index before checking that the
+   working tree was clean.
+
+ * "git grep $tree" when run with multiple threads had an unsafe access to
+   the object database that should have been protected with mutex.
+
+ * The "--ancestry-path" option to "git log" and friends misbehaved in a
+   history with complex criss-cross merges and showed an uninteresting
+   side history as well.
+
+ * Test t1304 assumed LOGNAME is always set, which may not be true on
+   some systems.
+
+ * Tests with --valgrind failed to find "mergetool" scriptlets.
+
+ * "git patch-id" miscomputed the patch-id in a patch that has a line longer
+   than 1kB.
+
+ * When an "exec" insn failed after modifying the index and/or the working
+   tree during "rebase -i", we now check and warn that the changes need to
+   be cleaned up.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.2.txt b/third_party/git/Documentation/RelNotes/1.7.7.2.txt
new file mode 100644
index 0000000000..e6bbef2f01
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.2.txt
@@ -0,0 +1,44 @@
+Git v1.7.7.2 Release Notes
+==========================
+
+Fixes since v1.7.7.1
+--------------------
+
+ * We used to drop error messages from libcurl on certain kinds of
+   errors.
+
+ * Error report from smart HTTP transport, when the connection was
+   broken in the middle of a transfer, showed a useless message on
+   a corrupt packet.
+
+ * "git fetch --prune" was unsafe when used with refspecs from the
+   command line.
+
+ * The attribute mechanism did not use case insensitive match when
+   core.ignorecase was set.
+
+ * "git bisect" did not notice when it failed to update the working tree
+   to the next commit to be tested.
+
+ * "git config --bool --get-regexp" failed to separate the variable name
+   and its value "true" when the variable is defined without "= true".
+
+ * "git remote rename $a $b" were not careful to match the remote name
+   against $a (i.e. source side of the remote nickname).
+
+ * "git mergetool" did not use its arguments as pathspec, but as a path to
+   the file that may not even have any conflict.
+
+ * "git diff --[num]stat" used to use the number of lines of context
+   different from the default, potentially giving different results from
+   "git diff | diffstat" and confusing the users.
+
+ * "git pull" and "git rebase" did not work well even when GIT_WORK_TREE is
+   set correctly with GIT_DIR if the current directory is outside the working
+   tree.
+
+ * "git send-email" did not honor the configured hostname when restarting
+   the HELO/EHLO exchange after switching TLS on.
+
+ * "gitweb" used to produce a non-working link while showing the contents
+   of a blob, when JavaScript actions are enabled.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.3.txt b/third_party/git/Documentation/RelNotes/1.7.7.3.txt
new file mode 100644
index 0000000000..09301f0957
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.3.txt
@@ -0,0 +1,19 @@
+Git v1.7.7.3 Release Notes
+==========================
+
+Fixes since v1.7.7.2
+--------------------
+
+ * Adjust the "quick-install-doc" procedures as preformatted
+   html/manpage are no longer in the source repository.
+
+ * The logic to optimize the locality of the data in a pack introduced in
+   1.7.7 was grossly inefficient.
+
+ * The logic to filter out forked projects in the project list in
+   "gitweb" was broken for some time.
+
+ * "git branch -m/-M" advertised to update RENAME_REF ref in the
+   commit log message that introduced the feature but not anywhere in
+   the documentation, and never did update such a ref anyway. This
+   undocumented misfeature that did not exist has been excised.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.4.txt b/third_party/git/Documentation/RelNotes/1.7.7.4.txt
new file mode 100644
index 0000000000..e5234485e7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.4.txt
@@ -0,0 +1,14 @@
+Git v1.7.7.4 Release Notes
+==========================
+
+Fixes since v1.7.7.3
+--------------------
+
+ * A few header dependencies were missing from the Makefile.
+
+ * Some newer parts of the code used C99 __VA_ARGS__ while we still
+   try to cater to older compilers.
+
+ * "git name-rev --all" tried to name all _objects_, naturally failing to
+   describe many blobs and trees, instead of showing only commits as
+   advertised in its documentation.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.5.txt b/third_party/git/Documentation/RelNotes/1.7.7.5.txt
new file mode 100644
index 0000000000..7b0931987b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.5.txt
@@ -0,0 +1,14 @@
+Git v1.7.7.5 Release Notes
+==========================
+
+Fixes since v1.7.7.4
+--------------------
+
+ * After fetching from a remote that has very long refname, the reporting
+   output could have corrupted by overrunning a static buffer.
+
+ * "git checkout" and "git merge" treated in-tree .gitignore and exclude
+   file in $GIT_DIR/info/ directory inconsistently when deciding which
+   untracked files are ignored and expendable.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.6.txt b/third_party/git/Documentation/RelNotes/1.7.7.6.txt
new file mode 100644
index 0000000000..8df606d452
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.6.txt
@@ -0,0 +1,20 @@
+Git v1.7.7.6 Release Notes
+==========================
+
+Fixes since v1.7.7.5
+--------------------
+
+ * The code to look up attributes for paths reused entries from a wrong
+   directory when two paths in question are in adjacent directories and
+   the name of the one directory is a prefix of the other.
+
+ * A wildcard that matches deeper hierarchy given to the "diff-index" command,
+   e.g. "git diff-index HEAD -- '*.txt'", incorrectly reported additions of
+   matching files even when there is no change.
+
+ * When producing a "thin pack" (primarily used in bundles and smart
+   HTTP transfers) out of a fully packed repository, we unnecessarily
+   avoided sending recent objects as a delta against objects we know
+   the other side has.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.7.txt b/third_party/git/Documentation/RelNotes/1.7.7.7.txt
new file mode 100644
index 0000000000..e79118d063
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.7.txt
@@ -0,0 +1,13 @@
+Git v1.7.7.7 Release Notes
+==========================
+
+Fixes since v1.7.7.6
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * 'git diff --histogram' option was not described.
+
+ * 'git imap-send' carried an unused dead code.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.7.txt b/third_party/git/Documentation/RelNotes/1.7.7.txt
new file mode 100644
index 0000000000..6eff128c80
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.7.txt
@@ -0,0 +1,134 @@
+Git v1.7.7 Release Notes
+========================
+
+Updates since v1.7.6
+--------------------
+
+ * The scripting part of the codebase is getting prepared for i18n/l10n.
+
+ * Interix, Cygwin and Minix ports got updated.
+
+ * Various updates to git-p4 (in contrib/), fast-import, and git-svn.
+
+ * Gitweb learned to read from /etc/gitweb-common.conf when it exists,
+   before reading from gitweb_config.perl or from /etc/gitweb.conf
+   (this last one is read only when per-repository gitweb_config.perl
+   does not exist).
+
+ * Various codepaths that invoked zlib deflate/inflate assumed that these
+   functions can compress or uncompress more than 4GB data in one call on
+   platforms with 64-bit long, which has been corrected.
+
+ * Git now recognizes loose objects written by other implementations that
+   use a non-standard window size for zlib deflation (e.g. Agit running on
+   Android with 4kb window). We used to reject anything that was not
+   deflated with 32kb window.
+
+ * Interaction between the use of pager and coloring of the output has
+   been improved, especially when a command that is not built-in was
+   involved.
+
+ * "git am" learned to pass the "--exclude=<path>" option through to underlying
+   "git apply".
+
+ * You can now feed many empty lines before feeding an mbox file to
+   "git am".
+
+ * "git archive" can be told to pass the output to gzip compression and
+   produce "archive.tar.gz".
+
+ * "git bisect" can be used in a bare repository (provided that the test
+   you perform per each iteration does not need a working tree, of
+   course).
+
+ * The length of abbreviated object names in "git branch -v" output
+   now honors the core.abbrev configuration variable.
+
+ * "git check-attr" can take relative paths from the command line.
+
+ * "git check-attr" learned an "--all" option to list the attributes for a
+   given path.
+
+ * "git checkout" (both the code to update the files upon checking out a
+   different branch and the code to checkout a specific set of files) learned
+   to stream the data from object store when possible, without having to
+   read the entire contents of a file into memory first. An earlier round
+   of this code that is not in any released version had a large leak but
+   now it has been plugged.
+
+ * "git clone" can now take a "--config key=value" option to set the
+   repository configuration options that affect the initial checkout.
+
+ * "git commit <paths>..." now lets you feed relative pathspecs that
+   refer to outside your current subdirectory.
+
+ * "git diff --stat" learned a --stat-count option to limit the output of
+   a diffstat report.
+
+ * "git diff" learned a "--histogram" option to use a different diff
+   generation machinery stolen from jgit, which might give better
+   performance.
+
+ * "git diff" had a weird worst case behaviour that can be triggered
+   when comparing files with potentially many places that could match.
+
+ * "git fetch", "git push" and friends no longer show connection
+   errors for addresses that couldn't be connected to when at least one
+   address succeeds (this is arguably a regression but a deliberate
+   one).
+
+ * "git grep" learned "--break" and "--heading" options, to let users mimic
+   the output format of "ack".
+
+ * "git grep" learned a "-W" option that shows wider context using the same
+   logic used by "git diff" to determine the hunk header.
+
+ * Invoking the low-level "git http-fetch" without "-a" option (which
+   git itself never did--normal users should not have to worry about
+   this) is now deprecated.
+
+ * The "--decorate" option to "git log" and its family learned to
+   highlight grafted and replaced commits.
+
+ * "git rebase master topci" no longer spews usage hints after giving
+   the "fatal: no such branch: topci" error message.
+
+ * The recursive merge strategy implementation got a fairly large
+   fix for many corner cases that may rarely happen in real world
+   projects (it has been verified that none of the 16000+ merges in
+   the Linux kernel history back to v2.6.12 is affected with the
+   corner case bugs this update fixes).
+
+ * "git stash" learned an "--include-untracked option".
+
+ * "git submodule update" used to stop at the first error updating a
+   submodule; it now goes on to update other submodules that can be
+   updated, and reports the ones with errors at the end.
+
+ * "git push" can be told with the "--recurse-submodules=check" option to
+   refuse pushing of the supermodule, if any of its submodules'
+   commits hasn't been pushed out to their remotes.
+
+ * "git upload-pack" and "git receive-pack" learned to pretend that only a
+   subset of the refs exist in a repository. This may help a site to
+   put many tiny repositories into one repository (this would not be
+   useful for larger repositories as repacking would be problematic).
+
+ * "git verify-pack" has been rewritten to use the "index-pack" machinery
+   that is more efficient in reading objects in packfiles.
+
+ * test scripts for gitweb tried to run even when CGI-related perl modules
+   are not installed; they now exit early when the latter are unavailable.
+
+Also contains various documentation updates and minor miscellaneous
+changes.
+
+
+Fixes since v1.7.6
+------------------
+
+Unless otherwise noted, all fixes in the 1.7.6.X maintenance track are
+included in this release.
+
+ * "git branch -m" and "git checkout -b" incorrectly allowed the tip
+   of the branch that is currently checked out updated.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.1.txt b/third_party/git/Documentation/RelNotes/1.7.8.1.txt
new file mode 100644
index 0000000000..33dc948b94
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.1.txt
@@ -0,0 +1,38 @@
+Git v1.7.8.1 Release Notes
+==========================
+
+Fixes since v1.7.8
+------------------
+
+ * In some codepaths (notably, checkout and merge), the ignore patterns
+   recorded in $GIT_DIR/info/exclude were not honored. They now are.
+
+ * "git apply --check" did not error out when given an empty input
+   without any patch.
+
+ * "git archive" mistakenly allowed remote clients to ask for commits
+   that are not at the tip of any ref.
+
+ * "git checkout" and "git merge" treated in-tree .gitignore and exclude
+   file in $GIT_DIR/info/ directory inconsistently when deciding which
+   untracked files are ignored and expendable.
+
+ * LF-to-CRLF streaming filter used when checking out a large-ish blob
+   fell into an infinite loop with a rare input.
+
+ * The function header pattern for files with "diff=cpp" attribute did
+   not consider "type *funcname(type param1,..." as the beginning of a
+   function.
+
+ * The error message from "git diff" and "git status" when they fail
+   to inspect changes in submodules did not report which submodule they
+   had trouble with.
+
+ * After fetching from a remote that has very long refname, the reporting
+   output could have corrupted by overrunning a static buffer.
+
+ * "git pack-objects" avoids creating cyclic dependencies among deltas
+   when seeing a broken packfile that records the same object in both
+   the deflated form and as a delta.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.2.txt b/third_party/git/Documentation/RelNotes/1.7.8.2.txt
new file mode 100644
index 0000000000..b9c66aa1b7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.2.txt
@@ -0,0 +1,71 @@
+Git v1.7.8.2 Release Notes
+==========================
+
+Fixes since v1.7.8.1
+--------------------
+
+ * Porcelain commands like "git reset" did not distinguish deletions
+   and type-changes from ordinary modification, and reported them with
+   the same 'M' moniker. They now use 'D' (for deletion) and 'T' (for
+   type-change) to match "git status -s" and "git diff --name-status".
+
+ * The configuration file parser used for sizes (e.g. bigFileThreshold)
+   did not correctly interpret 'g' suffix.
+
+ * The replacement implementation for snprintf used on platforms with
+   native snprintf that is broken did not use va_copy correctly.
+
+ * LF-to-CRLF streaming filter replaced all LF with CRLF, which might
+   be technically correct but not friendly to people who are trying
+   to recover from earlier mistakes of using CRLF in the repository
+   data in the first place. It now refrains from doing so for LF that
+   follows a CR.
+
+ * git native connection going over TCP (not over SSH) did not set
+   SO_KEEPALIVE option which failed to receive link layer errors.
+
+ * "git branch -m <current branch> HEAD" is an obvious no-op but was not
+   allowed.
+
+ * "git checkout -m" did not recreate the conflicted state in a "both
+   sides added, without any common ancestor version" conflict
+   situation.
+
+ * "git cherry-pick $commit" (not a range) created an unnecessary
+   sequencer state and interfered with valid workflow to use the
+   command during a session to cherry-pick multiple commits.
+
+ * You could make "git commit" segfault by giving the "--no-message"
+   option.
+
+ * "fast-import" did not correctly update an existing notes tree,
+   possibly corrupting the fan-out.
+
+ * "git fetch-pack" accepted unqualified refs that do not begin with
+   refs/ by mistake and compensated it by matching the refspec with
+   tail-match, which was doubly wrong. This broke fetching from a
+   repository with a funny named ref "refs/foo/refs/heads/master" and a
+   'master' branch with "git fetch-pack refs/heads/master", as the
+   command incorrectly considered the former a "match".
+
+ * "git log --follow" did not honor the rename threshold score given
+   with the -M option (e.g. "-M50%").
+
+ * "git mv" gave suboptimal error/warning messages when it overwrites
+   target files. It also did not pay attention to "-v" option.
+
+ * Authenticated "git push" over dumb HTTP were broken with a recent
+   change and failed without asking for password when username is
+   given.
+
+ * "git push" to an empty repository over HTTP were broken with a
+   recent change to the ref handling.
+
+ * "git push -v" forgot how to be verbose by mistake. It now properly
+   becomes verbose when asked to.
+
+ * When a "reword" action in "git rebase -i" failed to run "commit --amend",
+   we did not give the control back to the user to resolve the situation, and
+   instead kept the original commit log message.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.3.txt b/third_party/git/Documentation/RelNotes/1.7.8.3.txt
new file mode 100644
index 0000000000..a92714c14b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.3.txt
@@ -0,0 +1,16 @@
+Git v1.7.8.3 Release Notes
+==========================
+
+Fixes since v1.7.8.2
+--------------------
+
+ * Attempt to fetch from an empty file pretending it to be a bundle did
+   not error out correctly.
+
+ * gitweb did not correctly fall back to configured $fallback_encoding
+   that is not 'latin1'.
+
+ * "git clone --depth $n" did not catch a non-number given as $n as an
+   error.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.4.txt b/third_party/git/Documentation/RelNotes/1.7.8.4.txt
new file mode 100644
index 0000000000..9bebdbf13d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.4.txt
@@ -0,0 +1,23 @@
+Git v1.7.8.4 Release Notes
+==========================
+
+Fixes since v1.7.8.3
+--------------------
+
+ * The code to look up attributes for paths reused entries from a wrong
+   directory when two paths in question are in adjacent directories and
+   the name of the one directory is a prefix of the other.
+
+ * A wildcard that matches deeper hierarchy given to the "diff-index" command,
+   e.g. "git diff-index HEAD -- '*.txt'", incorrectly reported additions of
+   matching files even when there is no change.
+
+ * When producing a "thin pack" (primarily used in bundles and smart
+   HTTP transfers) out of a fully packed repository, we unnecessarily
+   avoided sending recent objects as a delta against objects we know
+   the other side has.
+
+ * "git send-email" did not properly treat sendemail.multiedit as a
+   boolean (e.g. setting it to "false" did not turn it off).
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.5.txt b/third_party/git/Documentation/RelNotes/1.7.8.5.txt
new file mode 100644
index 0000000000..011fd2a428
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.5.txt
@@ -0,0 +1,19 @@
+Git v1.7.8.5 Release Notes
+==========================
+
+Fixes since v1.7.8.4
+--------------------
+
+ * Dependency on our thread-utils.h header file was missing for
+   objects that depend on it in the Makefile.
+
+ * "git am" when fed an empty file did not correctly finish reading it
+   when it attempts to guess the input format.
+
+ * "git grep -P" (when PCRE is enabled in the build) did not match the
+   beginning and the end of the line correctly with ^ and $.
+
+ * "git rebase -m" tried to run "git notes copy" needlessly when
+   nothing was rewritten.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.6.txt b/third_party/git/Documentation/RelNotes/1.7.8.6.txt
new file mode 100644
index 0000000000..d9bf2b741a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.6.txt
@@ -0,0 +1,22 @@
+Git v1.7.8.6 Release Notes
+==========================
+
+Fixes since v1.7.8.5
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * 'git diff --histogram' option was not described.
+
+ * Documentation for 'git rev-list' had minor formatting errors.
+
+ * 'git imap-send' carried an unused dead code.
+
+ * The way 'git fetch' implemented its connectivity check over
+   received objects was overly pessimistic, and wasted a lot of
+   cycles.
+
+ * Various minor backports of fixes from the 'master' and the 'maint'
+   branch.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.8.txt b/third_party/git/Documentation/RelNotes/1.7.8.txt
new file mode 100644
index 0000000000..249311361e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.8.txt
@@ -0,0 +1,161 @@
+Git v1.7.8 Release Notes
+========================
+
+Updates since v1.7.7
+--------------------
+
+ * Some git-svn, git-gui, git-p4 (in contrib) and msysgit updates.
+
+ * Updates to bash completion scripts.
+
+ * The build procedure has been taught to take advantage of computed
+   dependency automatically when the compiler supports it.
+
+ * The date parser now accepts timezone designators that lack minutes
+   part and also has a colon between "hh:mm".
+
+ * The contents of the /etc/mailname file, if exists, is used as the
+   default value of the hostname part of the committer/author e-mail.
+
+ * "git am" learned how to read from patches generated by Hg.
+
+ * "git archive" talking with a remote repository can report errors
+   from the remote side in a more informative way.
+
+ * "git branch" learned an explicit --list option to ask for branches
+   listed, optionally with a glob matching pattern to limit its output.
+
+ * "git check-attr" learned "--cached" option to look at .gitattributes
+   files from the index, not from the working tree.
+
+ * Variants of "git cherry-pick" and "git revert" that take multiple
+   commits learned to "--continue" and "--abort".
+
+ * "git daemon" gives more human readable error messages to clients
+   using ERR packets when appropriate.
+
+ * Errors at the network layer is logged by "git daemon".
+
+ * "git diff" learned "--minimal" option to spend extra cycles to come
+   up with a minimal patch output.
+
+ * "git diff" learned "--function-context" option to show the whole
+   function as context that was affected by a change.
+
+ * "git difftool" can be told to skip launching the tool for a path by
+   answering 'n' to its prompt.
+
+ * "git fetch" learned to honor transfer.fsckobjects configuration to
+   validate the objects that were received from the other end, just like
+   "git receive-pack" (the receiving end of "git push") does.
+
+ * "git fetch" makes sure that the set of objects it received from the
+   other end actually completes the history before updating the refs.
+   "git receive-pack" (the receiving end of "git push") learned to do the
+   same.
+
+ * "git fetch" learned that fetching/cloning from a regular file on the
+   filesystem is not necessarily a request to unpack a bundle file; the
+   file could be ".git" with "gitdir: <path>" in it.
+
+ * "git for-each-ref" learned "%(contents:subject)", "%(contents:body)"
+   and "%(contents:signature)". The last one is useful for signed tags.
+
+ * "git grep" used to incorrectly pay attention to .gitignore files
+   scattered in the directory it was working in even when "--no-index"
+   option was used. It no longer does this. The "--exclude-standard"
+   option needs to be given to explicitly activate the ignore
+   mechanism.
+
+ * "git grep" learned "--untracked" option, where given patterns are
+    searched in untracked (but not ignored) files as well as tracked
+    files in the working tree, so that matches in new but not yet
+    added files do not get missed.
+
+ * The recursive merge backend no longer looks for meaningless
+   existing merges in submodules unless in the outermost merge.
+
+ * "git log" and friends learned "--children" option.
+
+ * "git ls-remote" learned to respond to "-h"(elp) requests.
+
+ * "mediawiki" remote helper can interact with (surprise!) MediaWiki
+   with "git fetch" & "git push".
+
+ * "git merge" learned the "--edit" option to allow users to edit the
+   merge commit log message.
+
+ * "git rebase -i" can be told to use special purpose editor suitable
+   only for its insn sheet via sequence.editor configuration variable.
+
+ * "git send-email" learned to respond to "-h"(elp) requests.
+
+ * "git send-email" allows the value given to sendemail.aliasfile to begin
+   with "~/" to refer to the $HOME directory.
+
+ * "git send-email" forces use of Authen::SASL::Perl to work around
+   issues between Authen::SASL::Cyrus and AUTH PLAIN/LOGIN.
+
+ * "git stash" learned "--include-untracked" option to stash away
+   untracked/ignored cruft from the working tree.
+
+ * "git submodule clone" does not leak an error message to the UI
+   level unnecessarily anymore.
+
+ * "git submodule update" learned to honor "none" as the value for
+   submodule.<name>.update to specify that the named submodule should
+   not be checked out by default.
+
+ * When populating a new submodule directory with "git submodule init",
+   the $GIT_DIR metainformation directory for submodules is created inside
+   $GIT_DIR/modules/<name>/ directory of the superproject and referenced
+   via the gitfile mechanism. This is to make it possible to switch
+   between commits in the superproject that has and does not have the
+   submodule in the tree without re-cloning.
+
+ * "gitweb" leaked unescaped control characters from syntax hiliter
+   outputs.
+
+ * "gitweb" can be told to give custom string at the end of the HTML
+   HEAD element.
+
+ * "gitweb" now has its own manual pages.
+
+
+Also contains other documentation updates and minor code cleanups.
+
+
+Fixes since v1.7.7
+------------------
+
+Unless otherwise noted, all fixes in the 1.7.7.X maintenance track are
+included in this release.
+
+ * HTTP transport did not use pushurl correctly, and also did not tell
+   what host it is trying to authenticate with when asking for
+   credentials.
+   (merge deba493 jk/http-auth later to maint).
+
+ * "git blame" was aborted if started from an uncommitted content and
+   the path had the textconv filter in effect.
+   (merge 8518088 ss/blame-textconv-fake-working-tree later to maint).
+
+ * Adding many refs to the local repository in one go (e.g. "git fetch"
+   that fetches many tags) and looking up a ref by name in a repository
+   with too many refs were unnecessarily slow.
+   (merge 17d68a54d jp/get-ref-dir-unsorted later to maint).
+
+ * Report from "git commit" on untracked files was confused under
+   core.ignorecase option.
+   (merge 395c7356 jk/name-hash-dirent later to maint).
+
+ * "git merge" did not understand ":/<pattern>" as a way to name a commit.
+
+ " "git push" on the receiving end used to call post-receive and post-update
+   hooks for attempted removal of non-existing refs.
+   (merge 160b81ed ph/push-to-delete-nothing later to maint).
+
+ * Help text for "git remote set-url" and "git remote set-branches"
+   were misspelled.
+   (merge c49904e fc/remote-seturl-usage-fix later to maint).
+   (merge 656cdf0 jc/remote-setbranches-usage-fix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.1.txt b/third_party/git/Documentation/RelNotes/1.7.9.1.txt
new file mode 100644
index 0000000000..6957183dbb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.1.txt
@@ -0,0 +1,63 @@
+Git v1.7.9.1 Release Notes
+==========================
+
+Fixes since v1.7.9
+------------------
+
+ * The makefile allowed environment variable X seep into it result in
+   command names suffixed with unnecessary strings.
+
+ * The set of included header files in compat/inet-{ntop,pton}
+   wrappers was updated for Windows some time ago, but in a way that
+   broke Solaris build.
+
+ * rpmbuild noticed an unpackaged but installed *.mo file and failed.
+
+ * Subprocesses spawned from various git programs were often left running
+   to completion even when the top-level process was killed.
+
+ * "git add -e" learned not to show a diff for an otherwise unmodified
+   submodule that only has uncommitted local changes in the patch
+   prepared by for the user to edit.
+
+ * Typo in "git branch --edit-description my-tpoic" was not diagnosed.
+
+ * Using "git grep -l/-L" together with options -W or --break may not
+   make much sense as the output is to only count the number of hits
+   and there is no place for file breaks, but the latter options made
+   "-l/-L" to miscount the hits.
+
+ * "git log --first-parent $pathspec" did not stay on the first parent
+   chain and veered into side branch from which the whole change to the
+   specified paths came.
+
+ * "git merge --no-edit $tag" failed to honor the --no-edit option.
+
+ * "git merge --ff-only $tag" failed because it cannot record the
+   required mergetag without creating a merge, but this is so common
+   operation for branch that is used _only_ to follow the upstream, so
+   it was changed to allow fast-forwarding without recording the mergetag.
+
+ * "git mergetool" now gives an empty file as the common base version
+   to the backend when dealing with the "both sides added, differently"
+   case.
+
+ * "git push -q" was not sufficiently quiet.
+
+ * When "git push" fails to update any refs, the client side did not
+   report an error correctly to the end user.
+
+ * "rebase" and "commit --amend" failed to work on commits with ancient
+   timestamps near year 1970.
+
+ * When asking for a tag to be pulled, "request-pull" did not show the
+   name of the tag prefixed with "tags/", which would have helped older
+   clients.
+
+ * "git submodule add $path" forgot to recompute the name to be stored
+   in .gitmodules when the submodule at $path was once added to the
+   superproject and already initialized.
+
+ * Many small corner case bugs on "git tag -n" was corrected.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.2.txt b/third_party/git/Documentation/RelNotes/1.7.9.2.txt
new file mode 100644
index 0000000000..e500da75dd
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.2.txt
@@ -0,0 +1,69 @@
+Git v1.7.9.2 Release Notes
+==========================
+
+Fixes since v1.7.9.1
+--------------------
+
+ * Bash completion script (in contrib/) did not like a pattern that
+   begins with a dash to be passed to __git_ps1 helper function.
+
+ * Adaptation of the bash completion script (in contrib/) for zsh
+   incorrectly listed all subcommands when "git <TAB><TAB>" was given
+   to ask for list of porcelain subcommands.
+
+ * The build procedure for profile-directed optimized binary was not
+   working very well.
+
+ * Some systems need to explicitly link -lcharset to get locale_charset().
+
+ * t5541 ignored user-supplied port number used for HTTP server testing.
+
+ * The error message emitted when we see an empty loose object was
+   not phrased correctly.
+
+ * The code to ask for password did not fall back to the terminal
+   input when GIT_ASKPASS is set but does not work (e.g. lack of X
+   with GUI askpass helper).
+
+ * We failed to give the true terminal width to any subcommand when
+   they are invoked with the pager, i.e. "git -p cmd".
+
+ * map_user() was not rewriting its output correctly, which resulted
+   in the user visible symptom that "git blame -e" sometimes showed
+   excess '>' at the end of email addresses.
+
+ * "git checkout -b" did not allow switching out of an unborn branch.
+
+ * When you have both .../foo and .../foo.git, "git clone .../foo" did not
+   favor the former but the latter.
+
+ * "git commit" refused to create a commit when entries added with
+   "add -N" remained in the index, without telling Git what their content
+   in the next commit should be. We should have created the commit without
+   these paths.
+
+ * "git diff --stat" said "files", "insertions", and "deletions" even
+   when it is showing one "file", one "insertion" or one "deletion".
+
+ * The output from "git diff --stat" for two paths that have the same
+   amount of changes showed graph bars of different length due to the
+   way we handled rounding errors.
+
+ * "git grep" did not pay attention to -diff (hence -binary) attribute.
+
+ * The transport programs (fetch, push, clone)ignored --no-progress
+   and showed progress when sending their output to a terminal.
+
+ * Sometimes error status detected by a check in an earlier phase of
+   "git receive-pack" (the other end of "git push") was lost by later
+   checks, resulting in false indication of success.
+
+ * "git rev-list --verify" sometimes skipped verification depending on
+   the phase of the moon, which dates back to 1.7.8.x series.
+
+ * Search box in "gitweb" did not accept non-ASCII characters correctly.
+
+ * Search interface of "gitweb" did not show multiple matches in the same file
+   correctly.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.3.txt b/third_party/git/Documentation/RelNotes/1.7.9.3.txt
new file mode 100644
index 0000000000..91c65012f9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.3.txt
@@ -0,0 +1,51 @@
+Git v1.7.9.3 Release Notes
+==========================
+
+Fixes since v1.7.9.2
+--------------------
+
+ * "git p4" (in contrib/) submit the changes to a wrong place when the
+   "--use-client-spec" option is set.
+
+ * The config.mak.autogen generated by optional autoconf support tried
+   to link the binary with -lintl even when libintl.h is missing from
+   the system.
+
+ * When the filter driver exits before reading the content before the
+   main git process writes the contents to be filtered to the pipe to
+   it, the latter could be killed with SIGPIPE instead of ignoring
+   such an event as an error.
+
+ * "git add --refresh <pathspec>" used to warn about unmerged paths
+   outside the given pathspec.
+
+ * The bulk check-in codepath in "git add" streamed contents that
+   needs smudge/clean filters without running them, instead of punting
+   and delegating to the codepath to run filters after slurping
+   everything to core.
+
+ * "git branch --with $that" assumed incorrectly that the user will never
+   ask the question with nonsense value in $that.
+
+ * "git bundle create" produced a corrupt bundle file upon seeing
+   commits with excessively long subject line.
+
+ * When a remote helper exits before reading the blank line from the
+   main git process to signal the end of commands, the latter could be
+   killed with SIGPIPE. Instead we should ignore such event as a
+   non-error.
+
+ * The commit log template given with "git merge --edit" did not have
+   a short instructive text like what "git commit" gives.
+
+ * "git rev-list --verify-objects -q" omitted the extra verification
+   it needs to do over "git rev-list --objects -q" by mistake.
+
+ * "gitweb" used to drop warnings in the log file when "heads" view is
+   accessed in a repository whose HEAD does not point at a valid
+   branch.
+
+ * An invalid regular expression pattern given by an end user made
+   "gitweb" to return garbled response.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.4.txt b/third_party/git/Documentation/RelNotes/1.7.9.4.txt
new file mode 100644
index 0000000000..e5217a1889
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.4.txt
@@ -0,0 +1,24 @@
+Git v1.7.9.4 Release Notes
+==========================
+
+Fixes since v1.7.9.3
+--------------------
+
+ * The code to synthesize the fake ancestor tree used by 3-way merge
+   fallback in "git am" was not prepared to read a patch created with
+   a non-standard -p<num> value.
+
+ * "git bundle" did not record boundary commits correctly when there
+   are many of them.
+
+ * "git diff-index" and its friends at the plumbing level showed the
+   "diff --git" header and nothing else for a path whose cached stat
+   info is dirty without actual difference when asked to produce a
+   patch. This was a longstanding bug that we could have fixed long
+   time ago.
+
+ * "gitweb" did use quotemeta() to prepare search string when asked to
+   do a fixed-string project search, but did not use it by mistake and
+   used the user-supplied string instead.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.5.txt b/third_party/git/Documentation/RelNotes/1.7.9.5.txt
new file mode 100644
index 0000000000..95cc2bbf2c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.5.txt
@@ -0,0 +1,23 @@
+Git v1.7.9.5 Release Notes
+==========================
+
+Fixes since v1.7.9.4
+--------------------
+
+ * When "git config" diagnoses an error in a configuration file and
+   shows the line number for the offending line, it miscounted if the
+   error was at the end of line.
+
+ * "git fast-import" accepted "ls" command with an empty path by
+   mistake.
+
+ * Various new-ish output decoration modes of "git grep" were not
+   documented in the manual's synopsis section.
+
+ * The "remaining" subcommand to "git rerere" was not documented.
+
+ * "gitweb" used to drop warnings in the log file when "heads" view is
+   accessed in a repository whose HEAD does not point at a valid
+   branch.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.6.txt b/third_party/git/Documentation/RelNotes/1.7.9.6.txt
new file mode 100644
index 0000000000..74bf8825e2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.6.txt
@@ -0,0 +1,12 @@
+Git v1.7.9.6 Release Notes
+==========================
+
+Fixes since v1.7.9.5
+--------------------
+
+ * "git merge $tag" to merge an annotated tag always opens the editor
+   during an interactive edit session. v1.7.10 series introduced an
+   environment variable GIT_MERGE_AUTOEDIT to help older scripts decline
+   this behaviour, but the maintenance track should also support it.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.7.txt b/third_party/git/Documentation/RelNotes/1.7.9.7.txt
new file mode 100644
index 0000000000..59667d0f2a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.7.txt
@@ -0,0 +1,13 @@
+Git v1.7.9.7 Release Notes
+==========================
+
+Fixes since v1.7.9.6
+--------------------
+
+ * An error message from 'git bundle' had an unmatched single quote pair in it.
+
+ * The way 'git fetch' implemented its connectivity check over
+   received objects was overly pessimistic, and wasted a lot of
+   cycles.
+
+Also contains minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.7.9.txt b/third_party/git/Documentation/RelNotes/1.7.9.txt
new file mode 100644
index 0000000000..95320aad5d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.7.9.txt
@@ -0,0 +1,112 @@
+Git v1.7.9 Release Notes
+========================
+
+Updates since v1.7.8
+--------------------
+
+ * gitk updates accumulated since early 2011.
+
+ * git-gui updated to 0.16.0.
+
+ * git-p4 (in contrib/) updates.
+
+ * Git uses gettext to translate its most common interface messages
+   into the user's language if translations are available and the
+   locale is appropriately set. Distributors can drop new PO files
+   in po/ to add new translations.
+
+ * The code to handle username/password for HTTP transactions used in
+   "git push" & "git fetch" learned to talk "credential API" to
+   external programs to cache or store them, to allow integration with
+   platform native keychain mechanisms.
+
+ * The input prompts in the terminal use our own getpass() replacement
+   when possible. HTTP transactions used to ask for the username without
+   echoing back what was typed, but with this change you will see it as
+   you type.
+
+ * The internals of "revert/cherry-pick" have been tweaked to prepare
+   building more generic "sequencer" on top of the implementation that
+   drives them.
+
+ * "git rev-parse FETCH_HEAD" after "git fetch" without specifying
+   what to fetch from the command line will now show the commit that
+   would be merged if the command were "git pull".
+
+ * "git add" learned to stream large files directly into a packfile
+   instead of writing them into individual loose object files.
+
+ * "git checkout -B <current branch> <elsewhere>" is a more intuitive
+   way to spell "git reset --keep <elsewhere>".
+
+ * "git checkout" and "git merge" learned "--no-overwrite-ignore" option
+   to tell Git that untracked and ignored files are not expendable.
+
+ * "git commit --amend" learned "--no-edit" option to say that the
+   user is amending the tree being recorded, without updating the
+   commit log message.
+
+ * "git commit" and "git reset" re-learned the optimization to prime
+   the cache-tree information in the index, which makes it faster to
+   write a tree object out after the index entries are updated.
+
+ * "git commit" detects and rejects an attempt to stuff NUL byte in
+   the commit log message.
+
+ * "git commit" learned "-S" to GPG-sign the commit; this can be shown
+   with the "--show-signature" option to "git log".
+
+ * fsck and prune are relatively lengthy operations that still go
+   silent while making the end-user wait. They learned to give progress
+   output like other slow operations.
+
+ * The set of built-in function-header patterns for various languages
+   knows MATLAB.
+
+ * "git log --format='<format>'" learned new %g[nNeE] specifiers to
+   show information from the reflog entries when walking the reflog
+   (i.e. with "-g").
+
+ * "git pull" can be used to fetch and merge an annotated/signed tag,
+   instead of the tip of a topic branch. The GPG signature from the
+   signed tag is recorded in the resulting merge commit for later
+   auditing.
+
+ * "git log" learned "--show-signature" option to show the signed tag
+   that was merged that is embedded in the merge commit. It also can
+   show the signature made on the commit with "git commit -S".
+
+ * "git branch --edit-description" can be used to add descriptive text
+   to explain what a topic branch is about.
+
+ * "git fmt-merge-msg" learned to take the branch description into
+   account when preparing a merge summary that "git merge" records
+   when merging a local branch.
+
+ * "git request-pull" has been updated to convey more information
+   useful for integrators to decide if a topic is worth merging and
+   what is pulled is indeed what the requestor asked to pull,
+   including:
+
+   - the tip of the branch being requested to be merged;
+   - the branch description describing what the topic is about;
+   - the contents of the annotated tag, when requesting to pull a tag.
+
+ * "git pull" learned to notice 'pull.rebase' configuration variable,
+   which serves as a global fallback for setting 'branch.<name>.rebase'
+   configuration variable per branch.
+
+ * "git tag" learned "--cleanup" option to control how the whitespaces
+   and empty lines in tag message are cleaned up.
+
+ * "gitweb" learned to show side-by-side diff.
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.7.8
+------------------
+
+Unless otherwise noted, all the fixes since v1.7.8 in the maintenance
+releases are contained in this release (see release notes to them for
+details).
diff --git a/third_party/git/Documentation/RelNotes/1.8.0.1.txt b/third_party/git/Documentation/RelNotes/1.8.0.1.txt
new file mode 100644
index 0000000000..1f372fa0b5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.0.1.txt
@@ -0,0 +1,64 @@
+Git v1.8.0.1 Release Notes
+==========================
+
+Fixes since v1.8.0
+------------------
+
+ * The configuration parser had an unnecessary hardcoded limit on
+   variable names that was not checked consistently.
+
+ * The "say" function in the test scaffolding incorrectly allowed
+   "echo" to interpret "\a" as if it were a C-string asking for a
+   BEL output.
+
+ * "git mergetool" feeds /dev/null as a common ancestor when dealing
+   with an add/add conflict, but p4merge backend cannot handle
+   it. Work it around by passing a temporary empty file.
+
+ * "git log -F -E --grep='<ere>'" failed to use the given <ere>
+   pattern as extended regular expression, and instead looked for the
+   string literally.
+
+ * "git grep -e pattern <tree>" asked the attribute system to read
+   "<tree>:.gitattributes" file in the working tree, which was
+   nonsense.
+
+ * A symbolic ref refs/heads/SYM was not correctly removed with "git
+   branch -d SYM"; the command removed the ref pointed by SYM
+   instead.
+
+ * Earlier we fixed documentation to hyphenate "remote-tracking branch"
+   to clarify that these are not a remote entity, but unhyphenated
+   spelling snuck in to a few places since then.
+
+ * "git pull --rebase" run while the HEAD is detached tried to find
+   the upstream branch of the detached HEAD (which by definition
+   does not exist) and emitted unnecessary error messages.
+
+ * The refs/replace hierarchy was not mentioned in the
+   repository-layout docs.
+
+ * Sometimes curl_multi_timeout() function suggested a wrong timeout
+   value when there is no file descriptors to wait on and the http
+   transport ended up sleeping for minutes in select(2) system call.
+   A workaround has been added for this.
+
+ * Various rfc2047 quoting issues around a non-ASCII name on the
+   From: line in the output from format-patch have been corrected.
+
+ * "git diff -G<pattern>" did not honor textconv filter when looking
+   for changes.
+
+ * Bash completion script (in contrib/) did not correctly complete a
+   lazy "git checkout $name_of_remote_tracking_branch_that_is_unique"
+   command line.
+
+ * RSS feed from "gitweb" had a xss hole in its title output.
+
+ * "git config --path $key" segfaulted on "[section] key" (a boolean
+   "true" spelled without "=", not "[section] key = true").
+
+ * "git checkout -b foo" while on an unborn branch did not say
+   "Switched to a new branch 'foo'" like other cases.
+
+Also contains other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.8.0.2.txt b/third_party/git/Documentation/RelNotes/1.8.0.2.txt
new file mode 100644
index 0000000000..8497e051de
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.0.2.txt
@@ -0,0 +1,34 @@
+Git v1.8.0.2 Release Notes
+==========================
+
+Fixes since v1.8.0.1
+--------------------
+
+ * Various codepaths have workaround for a common misconfiguration to
+   spell "UTF-8" as "utf8", but it was not used uniformly.  Most
+   notably, mailinfo (which is used by "git am") lacked this support.
+
+ * We failed to mention a file without any content change but whose
+   permission bit was modified, or (worse yet) a new file without any
+   content in the "git diff --stat" output.
+
+ * When "--stat-count" hides a diffstat for binary contents, the total
+   number of added and removed lines at the bottom was computed
+   incorrectly.
+
+ * When "--stat-count" hides a diffstat for unmerged paths, the total
+   number of affected files at the bottom of the "diff --stat" output
+   was computed incorrectly.
+
+ * "diff --shortstat" miscounted the total number of affected files
+   when there were unmerged paths.
+
+ * "git p4" used to try expanding malformed "$keyword$" that spans
+   across multiple lines.
+
+ * "git update-ref -d --deref SYM" to delete a ref through a symbolic
+   ref that points to it did not remove it correctly.
+
+ * Syntax highlighting in "gitweb" was not quite working.
+
+Also contains other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.8.0.3.txt b/third_party/git/Documentation/RelNotes/1.8.0.3.txt
new file mode 100644
index 0000000000..92b1e4b363
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.0.3.txt
@@ -0,0 +1,14 @@
+Git v1.8.0.3 Release Notes
+==========================
+
+Fixes since v1.8.0.2
+--------------------
+
+ * "git log -p -S<string>" did not apply the textconv filter while
+   looking for the <string>.
+
+ * In the documentation, some invalid example e-mail addresses were
+   formatted into mailto: links.
+
+Also contains many documentation updates backported from the 'master'
+branch that is preparing for the upcoming 1.8.1 release.
diff --git a/third_party/git/Documentation/RelNotes/1.8.0.txt b/third_party/git/Documentation/RelNotes/1.8.0.txt
new file mode 100644
index 0000000000..43883c14f0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.0.txt
@@ -0,0 +1,267 @@
+Git v1.8.0 Release Notes
+========================
+
+Backward compatibility notes
+----------------------------
+
+In the next major release (not *this* one), we will change the
+behavior of the "git push" command.
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  We will use the "simple" semantics that pushes the
+current branch to the branch with the same name, only when the current
+branch is set to integrate with that remote branch.  There is a user
+preference configuration variable "push.default" to change this, and
+"git push" will warn about the upcoming change until you set this
+variable in this release.
+
+"git branch --set-upstream" is deprecated and may be removed in a
+relatively distant future.  "git branch [-u|--set-upstream-to]" has
+been introduced with a saner order of arguments.
+
+
+Updates since v1.7.12
+---------------------
+
+UI, Workflows & Features
+
+ * A credential helper for Win32 to allow access to the keychain of
+   the logged-in user has been added.
+
+ * An initial port to HP NonStop.
+
+ * A credential helper to allow access to the Gnome keyring has been
+   added.
+
+ * When "git am" sanitizes the "Subject:" line, we strip the prefix from
+   "Re: subject" and also from a less common "re: subject", but left
+   the even less common "RE: subject" intact.  Now we strip that too.
+
+ * It was tempting to say "git branch --set-upstream origin/master",
+   but that tells Git to arrange the local branch "origin/master" to
+   integrate with the currently checked out branch, which is highly
+   unlikely what the user meant.  The option is deprecated; use the
+   new "--set-upstream-to" (with a short-and-sweet "-u") option
+   instead.
+
+ * "git cherry-pick" learned the "--allow-empty-message" option to
+   allow it to replay a commit without any log message.
+
+ * After "git cherry-pick -s" gave control back to the user asking
+   help to resolve conflicts, concluding "git commit" used to need to
+   be run with "-s" if the user wants to sign it off; now the command
+   leaves the sign-off line in the log template.
+
+ * "git daemon" learned the "--access-hook" option to allow an
+   external command to decline service based on the client address,
+   repository path, etc.
+
+ * "git difftool --dir-diff" learned to use symbolic links to prepare
+   a temporary copy of the working tree when available.
+
+ * "git grep" learned to use a non-standard pattern type by default if
+   a configuration variable tells it to.
+
+ * Accumulated updates to "git gui" has been merged.
+
+ * "git log -g" learned the "--grep-reflog=<pattern>" option to limit
+   its output to commits with a reflog message that matches the given
+   pattern.
+
+ * "git merge-base" learned the "--is-ancestor A B" option to tell if A is
+   an ancestor of B.  The result is indicated by its exit status code.
+
+ * "git mergetool" now allows users to override the actual command used
+   with the mergetool.$name.cmd configuration variable even for built-in
+   mergetool backends.
+
+ * "git rebase -i" learned the "--edit-todo" option to open an editor
+   to edit the instruction sheet.
+
+
+Foreign Interface
+
+ * "git svn" has been updated to work with SVN 1.7.
+
+ * "git p4" learned the "--conflicts" option to specify what to do when
+   encountering a conflict during "p4 submit".
+
+
+Performance, Internal Implementation, etc.
+
+ * Git ships with a fall-back regexp implementation for platforms with
+   buggy regexp library, but it was easy for people to keep using their
+   platform regexp by mistake.  A new test has been added to check this.
+
+ * The "check-docs" build target has been updated and greatly
+   simplified.
+
+ * The test suite is run under MALLOC_CHECK_ when running with a glibc
+   that supports the feature.
+
+ * The documentation in the TeXinfo format was using indented output
+   for materials meant to be examples that are better typeset in
+   monospace.
+
+ * Compatibility wrapper around some mkdir(2) implementations that
+   reject parameters with trailing slash has been introduced.
+
+ * Compatibility wrapper for systems that lack usable setitimer() has
+   been added.
+
+ * The option parsing of "git checkout" had error checking, dwim and
+   defaulting missing options, all mixed in the code, and issuing an
+   appropriate error message with useful context was getting harder.
+   The code has been reorganized to allow giving a proper diagnosis
+   when the user says "git checkout -b -t foo bar" (e.g. "-t" is not a
+   good name for a branch).
+
+ * Many internal uses of a "git merge-base" equivalent were only to see
+   if one commit fast-forwards to the other, which did not need the
+   full set of merge bases to be computed. They have been updated to
+   use less expensive checks.
+
+ * The heuristics to detect and silently convert latin1 to utf8 when
+   we were told to use utf-8 in the log message has been transplanted
+   from "mailinfo" to "commit" and "commit-tree".
+
+ * Messages given by "git <subcommand> -h" from many subcommands have
+   been marked for translation.
+
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.7.12
+-------------------
+
+Unless otherwise noted, all the fixes since v1.7.12 in the
+maintenance track are contained in this release (see release notes
+to them for details).
+
+ * The attribute system may be asked for a path that itself or its
+   leading directories no longer exists in the working tree, and it is
+   fine if we cannot open .gitattribute file in such a case.  Failure
+   to open per-directory .gitattributes with error status other than
+   ENOENT and ENOTDIR should be diagnosed, but it wasn't.
+
+ * When looking for $HOME/.gitconfig etc., it is OK if we cannot read
+   them because they do not exist, but we did not diagnose existing
+   files that we cannot read.
+
+ * When "git am" is fed an input that has multiple "Content-type: ..."
+   header, it did not grok charset= attribute correctly.
+
+ * "git am" mishandled a patch attached as application/octet-stream
+   (e.g. not text/*); Content-Transfer-Encoding (e.g. base64) was not
+   honored correctly.
+
+ * "git blame MAKEFILE" run in a history that has "Makefile" but not
+   "MAKEFILE" should say "No such file MAKEFILE in HEAD", but got
+   confused on a case insensitive filesystem and failed to do so.
+
+ * Even during a conflicted merge, "git blame $path" always meant to
+   blame uncommitted changes to the "working tree" version; make it
+   more useful by showing cleanly merged parts as coming from the other
+   branch that is being merged.
+
+ * It was unclear in the documentation for "git blame" that it is
+   unnecessary for users to use the "--follow" option.
+
+ * Output from "git branch -v" contains "(no branch)" that could be
+   localized, but the code to align it along with the names of
+   branches was counting in bytes, not in display columns.
+
+ * "git cherry-pick A C B" used to replay changes in A and then B and
+   then C if these three commits had committer timestamps in that
+   order, which is not what the user who said "A C B" naturally
+   expects.
+
+ * A repository created with "git clone --single" had its fetch
+   refspecs set up just like a clone without "--single", leading the
+   subsequent "git fetch" to slurp all the other branches, defeating
+   the whole point of specifying "only this branch".
+
+ * Documentation talked about "first line of commit log" when it meant
+   the title of the commit.  The description was clarified by defining
+   how the title is decided and rewording the casual mention of "first
+   line" to "title".
+
+ * "git cvsimport" did not thoroughly cleanse tag names that it
+   inferred from the names of the tags it obtained from CVS, which
+   caused "git tag" to barf and stop the import in the middle.
+
+ * Earlier we made the diffstat summary line that shows the number of
+   lines added/deleted localizable, but it was found irritating having
+   to see them in various languages on a list whose discussion language
+   is English, and this change has been reverted.
+
+ * "git fetch --all", when passed "--no-tags", did not honor the
+   "--no-tags" option while fetching from individual remotes (the same
+   issue existed with "--tags", but the combination "--all --tags" makes
+   much less sense than "--all --no-tags").
+
+ * "git fetch" over http had an old workaround for an unlikely server
+   misconfiguration; it turns out that this hurts debuggability of the
+   configuration in general, and has been reverted.
+
+ * "git fetch" over http advertised that it supports "deflate", which
+   is much less common, and did not advertise the more common "gzip" on
+   its Accept-Encoding header.
+
+ * "git fetch" over the dumb-http revision walker could segfault when
+   curl's multi interface was used.
+
+ * "git gc --auto" notified the user that auto-packing has triggered
+    even under the "--quiet" option.
+
+ * After "gitk" showed the contents of a tag, neither "Reread
+   references" nor "Reload" updated what is shown as the
+   contents of it when the user overwrote the tag with "git tag -f".
+
+ * "git log --all-match --grep=A --grep=B" ought to show commits that
+   mention both A and B, but when these three options are used with
+   --author or --committer, it showed commits that mention either A or
+   B (or both) instead.
+
+ * The "-Xours" backend option to "git merge -s recursive" was ignored
+   for binary files.
+
+ * "git p4", when "--use-client-spec" and "--detect-branches" are used
+   together, misdetected branches.
+
+ * "git receive-pack" (the counterpart to "git push") did not give
+   progress output while processing objects it received to the puser
+   when run over the smart-http protocol.
+
+ * When you misspell the command name you give to the "exec" action in
+   the "git rebase -i" instruction sheet you were told that 'rebase' is not a
+   git subcommand from "git rebase --continue".
+
+ * The subcommand in "git remote" to remove a defined remote was
+   "rm" and the command did not take a fully-spelled "remove".
+
+ * The interactive prompt that "git send-email" gives was error prone. It
+   asked "What e-mail address do you want to use?" with the address it
+   guessed (correctly) the user would want to use in its prompt,
+   tempting the user to say "y". But the response was taken as "No,
+   please use 'y' as the e-mail address instead", which is most
+   certainly not what the user meant.
+
+ * "git show --format='%ci'" did not give the timestamp correctly for
+   commits created without human readable name on the "committer" line.
+
+ * "git show --quiet" ought to be a synonym for "git show -s", but
+   wasn't.
+
+ * "git submodule frotz" was not diagnosed as "frotz" being an unknown
+   subcommand to "git submodule"; the user instead got a complaint
+   that "git submodule status" was run with an unknown path "frotz".
+
+ * "git status" honored the ignore=dirty settings in .gitmodules but
+   "git commit" didn't.
+
+ * "gitweb" did not give the correct committer timezone in its feed
+   output due to a typo.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.1.txt b/third_party/git/Documentation/RelNotes/1.8.1.1.txt
new file mode 100644
index 0000000000..6cde07ba29
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.1.txt
@@ -0,0 +1,87 @@
+Git 1.8.1.1 Release Notes
+=========================
+
+Fixes since v1.8.1
+------------------
+
+ * The attribute mechanism didn't allow limiting attributes to be
+   applied to only a single directory itself with "path/" like the
+   exclude mechanism does.
+
+ * When attempting to read the XDG-style $HOME/.config/git/config and
+   finding that $HOME/.config/git is a file, we gave a wrong error
+   message, instead of treating the case as "a custom config file does
+   not exist there" and moving on.
+
+ * After failing to create a temporary file using mkstemp(), failing
+   pathname was not reported correctly on some platforms.
+
+ * http transport was wrong to ask for the username when the
+   authentication is done by certificate identity.
+
+ * The behaviour visible to the end users was confusing, when they
+   attempt to kill a process spawned in the editor that was in turn
+   launched by Git with SIGINT (or SIGQUIT), as Git would catch that
+   signal and die.  We ignore these signals now.
+
+ * A child process that was killed by a signal (e.g. SIGINT) was
+   reported in an inconsistent way depending on how the process was
+   spawned by us, with or without a shell in between.
+
+ * After "git add -N" and then writing a tree object out of the
+   index, the cache-tree data structure got corrupted.
+
+ * "git apply" misbehaved when fixing whitespace breakages by removing
+   excess trailing blank lines in some corner cases.
+
+ * A tar archive created by "git archive" recorded a directory in a
+   way that made NetBSD's implementation of "tar" sometimes unhappy.
+
+ * When "git clone --separate-git-dir=$over_there" is interrupted, it
+   failed to remove the real location of the $GIT_DIR it created.
+   This was most visible when interrupting a submodule update.
+
+ * "git fetch --mirror" and fetch that uses other forms of refspec
+   with wildcard used to attempt to update a symbolic ref that match
+   the wildcard on the receiving end, which made little sense (the
+   real ref that is pointed at by the symbolic ref would be updated
+   anyway).  Symbolic refs no longer are affected by such a fetch.
+
+ * The "log --graph" codepath fell into infinite loop in some
+   corner cases.
+
+ * "git merge" started calling prepare-commit-msg hook like "git
+   commit" does some time ago, but forgot to pay attention to the exit
+   status of the hook.
+
+ * "git pack-refs" that ran in parallel to another process that
+   created new refs had a race that can lose new ones.
+
+ * When a line to be wrapped has a solid run of non space characters
+   whose length exactly is the wrap width, "git shortlog -w" failed
+   to add a newline after such a line.
+
+ * The way "git svn" asked for password using SSH_ASKPASS and
+   GIT_ASKPASS was not in line with the rest of the system.
+
+ * "gitweb", when sorting by age to show repositories with new
+   activities first, used to sort repositories with absolutely
+   nothing in it early, which was not very useful.
+
+ * "gitweb", when sorting by age to show repositories with new
+   activities first, used to sort repositories with absolutely
+   nothing in it early, which was not very useful.
+
+ * When autoconf is used, any build on a different commit always ran
+   "config.status --recheck" even when unnecessary.
+
+ * Some scripted programs written in Python did not get updated when
+   PYTHON_PATH changed.
+
+ * We have been carrying a translated and long-unmaintained copy of an
+   old version of the tutorial; removed.
+
+ * Portability issues in many self-test scripts have been addressed.
+
+
+Also contains other minor fixes and documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.2.txt b/third_party/git/Documentation/RelNotes/1.8.1.2.txt
new file mode 100644
index 0000000000..5ab7b18906
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.2.txt
@@ -0,0 +1,25 @@
+Git 1.8.1.2 Release Notes
+=========================
+
+Fixes since v1.8.1.1
+--------------------
+
+ * An element on GIT_CEILING_DIRECTORIES list that does not name the
+   real path to a directory (i.e. a symbolic link) could have caused
+   the GIT_DIR discovery logic to escape the ceiling.
+
+ * Command line completion for "tcsh" emitted an unwanted space
+   after completing a single directory name.
+
+ * Command line completion leaked an unnecessary error message while
+   looking for possible matches with paths in <tree-ish>.
+
+ * "git archive" did not record uncompressed size in the header when
+   streaming a zip archive, which confused some implementations of unzip.
+
+ * When users spelled "cc:" in lowercase in the fake "header" in the
+   trailer part, "git send-email" failed to pick up the addresses from
+   there. As e-mail headers field names are case insensitive, this
+   script should follow suit and treat "cc:" and "Cc:" the same way.
+
+Also contains various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.3.txt b/third_party/git/Documentation/RelNotes/1.8.1.3.txt
new file mode 100644
index 0000000000..681cb35c0a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.3.txt
@@ -0,0 +1,47 @@
+Git 1.8.1.3 Release Notes
+=========================
+
+Fixes since v1.8.1.2
+--------------------
+
+ * The attribute mechanism didn't allow limiting attributes to be
+   applied to only a single directory itself with "path/" like the
+   exclude mechanism does.  The fix for this in 1.8.1.2 had
+   performance degradations.
+
+ * Command line completion code was inadvertently made incompatible with
+   older versions of bash by using a newer array notation.
+
+ * Scripts to test bash completion was inherently flaky as it was
+   affected by whatever random things the user may have on $PATH.
+
+ * A fix was added to the build procedure to work around buggy
+   versions of ccache broke the auto-generation of dependencies, which
+   unfortunately is still relevant because some people use ancient
+   distros.
+
+ * We used to stuff "user@" and then append what we read from
+   /etc/mailname to come up with a default e-mail ident, but a bug
+   lost the "user@" part.
+
+ * "git am" did not parse datestamp correctly from Hg generated patch,
+   when it is run in a locale outside C (or en).
+
+ * Attempt to "branch --edit-description" an existing branch, while
+   being on a detached HEAD, errored out.
+
+ * "git cherry-pick" did not replay a root commit to an unborn branch.
+
+ * We forgot to close the file descriptor reading from "gpg" output,
+   killing "git log --show-signature" on a long history.
+
+ * "git rebase --preserve-merges" lost empty merges in recent versions
+   of Git.
+
+ * Rebasing the history of superproject with change in the submodule
+   has been broken since v1.7.12.
+
+ * A failure to push due to non-ff while on an unborn branch
+   dereferenced a NULL pointer when showing an error message.
+
+Also contains various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.4.txt b/third_party/git/Documentation/RelNotes/1.8.1.4.txt
new file mode 100644
index 0000000000..22af1d1643
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.4.txt
@@ -0,0 +1,11 @@
+Git 1.8.1.4 Release Notes
+=========================
+
+Fixes since v1.8.1.3
+--------------------
+
+ * "git imap-send" talking over imaps:// did make sure it received a
+   valid certificate from the other end, but did not check if the
+   certificate matched the host it thought it was talking to.
+
+Also contains various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.5.txt b/third_party/git/Documentation/RelNotes/1.8.1.5.txt
new file mode 100644
index 0000000000..efa68aef22
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.5.txt
@@ -0,0 +1,47 @@
+Git 1.8.1.5 Release Notes
+=========================
+
+Fixes since v1.8.1.4
+--------------------
+
+ * Given a string with a multi-byte character that begins with '-' on
+   the command line where an option is expected, the option parser
+   used just one byte of the unknown letter when reporting an error.
+
+ * In v1.8.1, the attribute parser was tightened too restrictive to
+   error out upon seeing an entry that begins with an ! (exclamation),
+   which may confuse users to expect a "negative match", which does
+   not exist.  This has been demoted to a warning; such an entry is
+   still ignored.
+
+ * "git apply --summary" has been taught to make sure the similarity
+   value shown in its output is sensible, even when the input had a
+   bogus value.
+
+ * "git clean" showed what it was going to do, but sometimes ended
+   up finding that it was not allowed to do so, which resulted in a
+   confusing output (e.g. after saying that it will remove an
+   untracked directory, it found an embedded git repository there
+   which it is not allowed to remove).  It now performs the actions
+   and then reports the outcome more faithfully.
+
+ * "git clone" used to allow --bare and --separate-git-dir=$there
+   options at the same time, which was nonsensical.
+
+ * "git cvsimport" mishandled timestamps at DST boundary.
+
+ * We used to have an arbitrary 32 limit for combined diff input,
+   resulting in incorrect number of leading colons shown when showing
+   the "--raw --cc" output.
+
+ * The smart HTTP clients forgot to verify the content-type that comes
+   back from the server side to make sure that the request is being
+   handled properly.
+
+ * "git help remote-helpers" failed to find the documentation.
+
+ * "gitweb" pages served over HTTPS, when configured to show picon or
+   gravatar, referred to these external resources to be fetched via
+   HTTP, resulting in mixed contents warning in browsers.
+
+Also contains various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.6.txt b/third_party/git/Documentation/RelNotes/1.8.1.6.txt
new file mode 100644
index 0000000000..c15cf2e805
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.6.txt
@@ -0,0 +1,39 @@
+Git 1.8.1.6 Release Notes
+=========================
+
+Fixes since v1.8.1.5
+--------------------
+
+ * An earlier change to the attribute system introduced at v1.8.1.2 by
+   mistake stopped a pattern "dir" (without trailing slash) from
+   matching a directory "dir" (it only wanted to allow pattern "dir/"
+   to also match).
+
+ * The code to keep track of what directory names are known to Git on
+   platforms with case insensitive filesystems can get confused upon a
+   hash collision between these pathnames and looped forever.
+
+ * When the "--prefix" option is used to "checkout-index", the code
+   did not pick the correct output filter based on the attribute
+   setting.
+
+ * Annotated tags outside refs/tags/ hierarchy were not advertised
+   correctly to the ls-remote and fetch with recent version of Git.
+
+ * The logic used by "git diff -M --stat" to shorten the names of
+   files before and after a rename did not work correctly when the
+   common prefix and suffix between the two filenames overlapped.
+
+ * "git update-index -h" did not do the usual "-h(elp)" thing.
+
+ * perl/Git.pm::cat_blob slurped everything in core only to write it
+   out to a file descriptor, which was not a very smart thing to do.
+
+ * The SSL peer verification done by "git imap-send" did not ask for
+   Server Name Indication (RFC 4366), failing to connect SSL/TLS
+   sites that serve multiple hostnames on a single IP.
+
+ * "git bundle verify" did not say "records a complete history" for a
+   bundle that does not have any prerequisites.
+
+Also contains various documentation fixes.
diff --git a/third_party/git/Documentation/RelNotes/1.8.1.txt b/third_party/git/Documentation/RelNotes/1.8.1.txt
new file mode 100644
index 0000000000..d6f9555923
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.1.txt
@@ -0,0 +1,241 @@
+Git v1.8.1 Release Notes
+========================
+
+Backward compatibility notes
+----------------------------
+
+In the next major release (not *this* one), we will change the
+behavior of the "git push" command.
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  We will use the "simple" semantics that pushes the
+current branch to the branch with the same name, only when the current
+branch is set to integrate with that remote branch.  There is a user
+preference configuration variable "push.default" to change this, and
+"git push" will warn about the upcoming change until you set this
+variable in this release.
+
+"git branch --set-upstream" is deprecated and may be removed in a
+relatively distant future.  "git branch [-u|--set-upstream-to]" has
+been introduced with a saner order of arguments to replace it.
+
+
+Updates since v1.8.0
+--------------------
+
+UI, Workflows & Features
+
+ * Command-line completion scripts for tcsh and zsh have been added.
+
+ * "git-prompt" scriptlet (in contrib/completion) can be told to paint
+   pieces of the hints in the prompt string in colors.
+
+ * Some documentation pages that used to ship only in the plain text
+   format are now formatted in HTML as well.
+
+ * We used to have a workaround for a bug in ancient "less" that
+   causes it to exit without any output when the terminal is resized.
+   The bug has been fixed in "less" version 406 (June 2007), and the
+   workaround has been removed in this release.
+
+ * When "git checkout" checks out a branch, it tells the user how far
+   behind (or ahead) the new branch is relative to the remote tracking
+   branch it builds upon.  The message now also advises how to sync
+   them up by pushing or pulling.  This can be disabled with the
+   advice.statusHints configuration variable.
+
+ * "git config --get" used to diagnose presence of multiple
+   definitions of the same variable in the same configuration file as
+   an error, but it now applies the "last one wins" rule used by the
+   internal configuration logic.  Strictly speaking, this may be an
+   API regression but it is expected that nobody will notice it in
+   practice.
+
+ * A new configuration variable "diff.context" can be used to
+   give the default number of context lines in the patch output, to
+   override the hardcoded default of 3 lines.
+
+ * "git format-patch" learned the "--notes=<ref>" option to give
+   notes for the commit after the three-dash lines in its output.
+
+ * "git log -p -S<string>" now looks for the <string> after applying
+   the textconv filter (if defined); earlier it inspected the contents
+   of the blobs without filtering.
+
+ * "git log --grep=<pcre>" learned to honor the "grep.patterntype"
+   configuration set to "perl".
+
+ * "git replace -d <object>" now interprets <object> as an extended
+   SHA-1 (e.g. HEAD~4 is allowed), instead of only accepting full hex
+   object name.
+
+ * "git rm $submodule" used to punt on removing a submodule working
+   tree to avoid losing the repository embedded in it.  Because
+   recent git uses a mechanism to separate the submodule repository
+   from the submodule working tree, "git rm" learned to detect this
+   case and removes the submodule working tree when it is safe to do so.
+
+ * "git send-email" used to prompt for the sender address, even when
+   the committer identity is well specified (e.g. via user.name and
+   user.email configuration variables).  The command no longer gives
+   this prompt when not necessary.
+
+ * "git send-email" did not allow non-address garbage strings to
+   appear after addresses on Cc: lines in the patch files (and when
+   told to pick them up to find more recipients), e.g.
+
+     Cc: Stable Kernel <stable@k.org> # for v3.2 and up
+
+   The command now strips " # for v3.2 and up" part before adding the
+   remainder of this line to the list of recipients.
+
+ * "git submodule add" learned to add a new submodule at the same
+   path as the path where an unrelated submodule was bound to in an
+   existing revision via the "--name" option.
+
+ * "git submodule sync" learned the "--recursive" option.
+
+ * "diff.submodule" configuration variable can be used to give custom
+   default value to the "git diff --submodule" option.
+
+ * "git symbolic-ref" learned the "-d $symref" option to delete the
+   named symbolic ref, which is more intuitive way to spell it than
+   "update-ref -d --no-deref $symref".
+
+
+Foreign Interface
+
+ * "git cvsimport" can be told to record timezones (other than GMT)
+   per-author via its author info file.
+
+ * The remote helper interface to interact with subversion
+   repositories (one of the GSoC 2012 projects) has been merged.
+
+ * A new remote-helper interface for Mercurial has been added to
+   contrib/remote-helpers.
+
+ * The documentation for git(1) was pointing at a page at an external
+   site for the list of authors that no longer existed.  The link has
+   been updated to point at an alternative site.
+
+
+Performance, Internal Implementation, etc.
+
+ * Compilation on Cygwin with newer header files are supported now.
+
+ * A couple of low-level implementation updates on MinGW.
+
+ * The logic to generate the initial advertisement from "upload-pack"
+   (i.e. what is invoked by "git fetch" on the other side of the
+   connection) to list what refs are available in the repository has
+   been optimized.
+
+ * The logic to find set of attributes that match a given path has
+   been optimized.
+
+ * Use preloadindex in "git diff-index" and "git update-index", which
+   has a nice speedup on systems with slow stat calls (and even on
+   Linux).
+
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.8.0
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.0 in the maintenance
+track are contained in this release (see release notes to them for
+details).
+
+ * The configuration parser had an unnecessary hardcoded limit on
+   variable names that was not checked consistently.
+
+ * The "say" function in the test scaffolding incorrectly allowed
+   "echo" to interpret "\a" as if it were a C-string asking for a
+   BEL output.
+
+ * "git mergetool" feeds /dev/null as a common ancestor when dealing
+   with an add/add conflict, but p4merge backend cannot handle
+   it. Work it around by passing a temporary empty file.
+
+ * "git log -F -E --grep='<ere>'" failed to use the given <ere>
+   pattern as extended regular expression, and instead looked for the
+   string literally.
+
+ * "git grep -e pattern <tree>" asked the attribute system to read
+   "<tree>:.gitattributes" file in the working tree, which was
+   nonsense.
+
+ * A symbolic ref refs/heads/SYM was not correctly removed with "git
+   branch -d SYM"; the command removed the ref pointed by SYM
+   instead.
+
+ * Update "remote tracking branch" in the documentation to
+   "remote-tracking branch".
+
+ * "git pull --rebase" run while the HEAD is detached tried to find
+   the upstream branch of the detached HEAD (which by definition
+   does not exist) and emitted unnecessary error messages.
+
+ * The refs/replace hierarchy was not mentioned in the
+   repository-layout docs.
+
+ * Various rfc2047 quoting issues around a non-ASCII name on the
+   From: line in the output from format-patch have been corrected.
+
+ * Sometimes curl_multi_timeout() function suggested a wrong timeout
+   value when there is no file descriptor to wait on and the http
+   transport ended up sleeping for minutes in select(2) system call.
+   A workaround has been added for this.
+
+ * For a fetch refspec (or the result of applying wildcard on one),
+   we always want the RHS to map to something inside "refs/"
+   hierarchy, but the logic to check it was not exactly right.
+   (merge 5c08c1f jc/maint-fetch-tighten-refname-check later to maint).
+
+ * "git diff -G<pattern>" did not honor textconv filter when looking
+   for changes.
+
+ * Some HTTP servers ask for auth only during the actual packing phase
+   (not in ls-remote phase); this is not really a recommended
+   configuration, but the clients used to fail to authenticate with
+   such servers.
+   (merge 2e736fd jk/maint-http-half-auth-fetch later to maint).
+
+ * "git p4" used to try expanding malformed "$keyword$" that spans
+   across multiple lines.
+
+ * Syntax highlighting in "gitweb" was not quite working.
+
+ * RSS feed from "gitweb" had a xss hole in its title output.
+
+ * "git config --path $key" segfaulted on "[section] key" (a boolean
+   "true" spelled without "=", not "[section] key = true").
+
+ * "git checkout -b foo" while on an unborn branch did not say
+   "Switched to a new branch 'foo'" like other cases.
+
+ * Various codepaths have workaround for a common misconfiguration to
+   spell "UTF-8" as "utf8", but it was not used uniformly.  Most
+   notably, mailinfo (which is used by "git am") lacked this support.
+
+ * We failed to mention a file without any content change but whose
+   permission bit was modified, or (worse yet) a new file without any
+   content in the "git diff --stat" output.
+
+ * When "--stat-count" hides a diffstat for binary contents, the total
+   number of added and removed lines at the bottom was computed
+   incorrectly.
+
+ * When "--stat-count" hides a diffstat for unmerged paths, the total
+   number of affected files at the bottom of the "diff --stat" output
+   was computed incorrectly.
+
+ * "diff --shortstat" miscounted the total number of affected files
+   when there were unmerged paths.
+
+ * "update-ref -d --deref SYM" to delete a ref through a symbolic ref
+   that points to it did not remove it correctly.
diff --git a/third_party/git/Documentation/RelNotes/1.8.2.1.txt b/third_party/git/Documentation/RelNotes/1.8.2.1.txt
new file mode 100644
index 0000000000..769a6fc06c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.2.1.txt
@@ -0,0 +1,115 @@
+Git v1.8.2.1 Release Notes
+==========================
+
+Fixes since v1.8.2
+------------------
+
+ * An earlier change to the attribute system introduced at v1.8.1.2 by
+   mistake stopped a pattern "dir" (without trailing slash) from
+   matching a directory "dir" (it only wanted to allow pattern "dir/"
+   to also match).
+
+ * Verification of signed tags were not done correctly when not in C
+   or en/US locale.
+
+ * 'git commit -m "$msg"' used to add an extra newline even when
+   $msg already ended with one.
+
+ * The "--match=<pattern>" option of "git describe", when used with
+   "--all" to allow refs that are not annotated tags to be used as a
+   base of description, did not restrict the output from the command
+   to those that match the given pattern.
+
+ * An aliased command spawned from a bare repository that does not say
+   it is bare with "core.bare = yes" is treated as non-bare by mistake.
+
+ * When "format-patch" quoted a non-ascii strings on the header files,
+   it incorrectly applied rfc2047 and chopped a single character in
+   the middle of it.
+
+ * "git archive" reports a failure when asked to create an archive out
+   of an empty tree.  It would be more intuitive to give an empty
+   archive back in such a case.
+
+ * "git tag -f <tag>" always said "Updated tag '<tag>'" even when
+   creating a new tag (i.e. not overwriting nor updating).
+
+ * "git cmd -- ':(top'" was not diagnosed as an invalid syntax, and
+   instead the parser kept reading beyond the end of the string.
+
+ * Annotated tags outside refs/tags/ hierarchy were not advertised
+   correctly to the ls-remote and fetch with recent version of Git.
+
+ * The code to keep track of what directory names are known to Git on
+   platforms with case insensitive filesystems can get confused upon a
+   hash collision between these pathnames and looped forever.
+
+ * The logic used by "git diff -M --stat" to shorten the names of
+   files before and after a rename did not work correctly when the
+   common prefix and suffix between the two filenames overlapped.
+
+ * "git submodule update", when recursed into sub-submodules, did not
+   accumulate the prefix paths.
+
+ * "git am $maildir/" applied messages in an unexpected order; sort
+   filenames read from the maildir/ in a way that is more likely to
+   sort messages in the order the writing MUA meant to, by sorting
+   numeric segment in numeric order and non-numeric segment in
+   alphabetical order.
+
+ * When export-subst is used, "zip" output recorded incorrect
+   size of the file.
+
+ * Some platforms and users spell UTF-8 differently; retry with the
+   most official "UTF-8" when the system does not understand the
+   user-supplied encoding name that are the common alternative
+   spellings of UTF-8.
+
+ * "git branch" did not bother to check nonsense command line
+   parameters and issue errors in many cases.
+
+ * "git update-index -h" did not do the usual "-h(elp)" thing.
+
+ * perl/Git.pm::cat_blob slurped everything in core only to write it
+   out to a file descriptor, which was not a very smart thing to do.
+
+ * The SSL peer verification done by "git imap-send" did not ask for
+   Server Name Indication (RFC 4366), failing to connect SSL/TLS
+   sites that serve multiple hostnames on a single IP.
+
+ * "git index-pack" had a buffer-overflow while preparing an
+   informational message when the translated version of it was too
+   long.
+
+ * Clarify in the documentation "what" gets pushed to "where" when the
+   command line to "git push" does not say these explicitly.
+
+ * In "git reflog expire", REACHABLE bit was not cleared from the
+   correct objects.
+
+ * The "--color=<when>" argument to the commands in the diff family
+   was described poorly.
+
+ * The arguments given to pre-rebase hook were not documented.
+
+ * The v4 index format was not documented.
+
+ * The "--match=<pattern>" argument "git describe" takes uses glob
+   pattern but it wasn't obvious from the documentation.
+
+ * Some sources failed to compile on systems that lack NI_MAXHOST in
+   their system header (e.g. z/OS).
+
+ * Add an example use of "--env-filter" in "filter-branch"
+   documentation.
+
+ * "git bundle verify" did not say "records a complete history" for a
+   bundle that does not have any prerequisites.
+
+ * In the v1.8.0 era, we changed symbols that do not have to be global
+   to file scope static, but a few functions in graph.c were used by
+   CGit from sideways bypassing the entry points of the API the
+   in-tree users use.
+
+ * "git merge-tree" had a typo in the logic to detect d/f conflicts,
+   which caused it to segfault in some cases.
diff --git a/third_party/git/Documentation/RelNotes/1.8.2.2.txt b/third_party/git/Documentation/RelNotes/1.8.2.2.txt
new file mode 100644
index 0000000000..708df1ae19
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.2.2.txt
@@ -0,0 +1,61 @@
+Git v1.8.2.2 Release Notes
+==========================
+
+Fixes since v1.8.2.1
+--------------------
+
+ * Zsh completion forgot that '%' character used to signal untracked
+   files needs to be escaped with another '%'.
+
+ * A commit object whose author or committer ident are malformed
+   crashed some code that trusted that a name, an email and an
+   timestamp can always be found in it.
+
+ * The new core.commentchar configuration was not applied to a few
+   places.
+
+ * "git pull --rebase" did not pass "-v/-q" options to underlying
+   "git rebase".
+
+ * When receive-pack detects error in the pack header it received in
+   order to decide which of unpack-objects or index-pack to run, it
+   returned without closing the error stream, which led to a hang
+   sideband thread.
+
+ * "git diff --diff-algorithm=algo" was understood by the command line
+   parser, but "git diff --diff-algorithm algo" was not.
+
+ * "git log -S/-G" started paying attention to textconv filter, but
+   there was no way to disable this.  Make it honor --no-textconv
+   option.
+
+ * "git merge $(git rev-parse v1.8.2)" behaved quite differently from
+   "git merge v1.8.2", as if v1.8.2 were written as v1.8.2^0 and did
+   not pay much attention to the annotated tag payload.  Make the code
+   notice the type of the tag object, in addition to the dwim_ref()
+   based classification the current code uses (i.e. the name appears
+   in refs/tags/) to decide when to special case merging of tags.
+
+ * "git cherry-pick" and "git revert" can take more than one commit
+   on the command line these days, but it was not mentioned on the usage
+   text.
+
+ * Perl scripts like "git-svn" closed (not redirecting to /dev/null)
+   the standard error stream, which is not a very smart thing to do.
+   Later open may return file descriptor #2 for unrelated purpose, and
+   error reporting code may write into them.
+
+ * "git apply --whitespace=fix" was not prepared to see a line getting
+   longer after fixing whitespaces (e.g. tab-in-indent aka Python).
+
+ * "git diff/log --cc" did not work well with options that ignore
+   whitespace changes.
+
+ * Documentation on setting up a http server that requires
+   authentication only on the push but not fetch has been clarified.
+
+ * A few bugfixes to "git rerere" working on corner case merge
+   conflicts have been applied.
+
+ * "git bundle" did not like a bundle created using a commit without
+   any message as its one of the prerequisites.
diff --git a/third_party/git/Documentation/RelNotes/1.8.2.3.txt b/third_party/git/Documentation/RelNotes/1.8.2.3.txt
new file mode 100644
index 0000000000..613948251a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.2.3.txt
@@ -0,0 +1,19 @@
+Git v1.8.2.3 Release Notes
+==========================
+
+Fixes since v1.8.2.2
+--------------------
+
+ * "rev-list --stdin" and friends kept bogus pointers into the input
+   buffer around as human readable object names.  This was not a
+   huge problem but was exposed by a new change that uses these
+   names in error output.
+
+ * When "git difftool" drove "kdiff3", it mistakenly passed --auto
+   option that was meant while resolving merge conflicts.
+
+ * "git remote add" command did not diagnose extra command line
+   arguments as an error and silently ignored them.
+
+Also contains a handful of trivial code clean-ups, documentation
+updates, updates to the test suite, etc.
diff --git a/third_party/git/Documentation/RelNotes/1.8.2.txt b/third_party/git/Documentation/RelNotes/1.8.2.txt
new file mode 100644
index 0000000000..fc606ae116
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.2.txt
@@ -0,0 +1,495 @@
+Git v1.8.2 Release Notes
+========================
+
+Backward compatibility notes (this release)
+-------------------------------------------
+
+"git push $there tag v1.2.3" used to allow replacing a tag v1.2.3
+that already exists in the repository $there, if the rewritten tag
+you are pushing points at a commit that is a descendant of a commit
+that the old tag v1.2.3 points at.  This was found to be error prone
+and starting with this release, any attempt to update an existing
+ref under refs/tags/ hierarchy will fail, without "--force".
+
+When "git add -u" and "git add -A" that does not specify what paths
+to add on the command line is run from inside a subdirectory, the
+scope of the operation has always been limited to the subdirectory.
+Many users found this counter-intuitive, given that "git commit -a"
+and other commands operate on the entire tree regardless of where you
+are.  In this release, these commands give a warning message that
+suggests the users to use "git add -u/-A ." when they want to limit
+the scope to the current directory; doing so will squelch the message,
+while training their fingers.
+
+
+Backward compatibility notes (for Git 2.0)
+------------------------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default will change to the "simple"
+semantics that pushes the current branch to the branch with the same
+name, only when the current branch is set to integrate with that
+remote branch.  There is a user preference configuration variable
+"push.default" to change this.  If you are an old-timer who is used
+to the "matching" semantics, you can set it to "matching" to keep the
+traditional behaviour.  If you want to live in the future early,
+you can set it to "simple" today without waiting for Git 2.0.
+
+When "git add -u" and "git add -A", that does not specify what paths
+to add on the command line is run from inside a subdirectory, these
+commands will operate on the entire tree in Git 2.0 for consistency
+with "git commit -a" and other commands. Because there will be no
+mechanism to make "git add -u" behave as if "git add -u .", it is
+important for those who are used to "git add -u" (without pathspec)
+updating the index only for paths in the current subdirectory to start
+training their fingers to explicitly say "git add -u ." when they mean
+it before Git 2.0 comes.
+
+
+Updates since v1.8.1
+--------------------
+
+UI, Workflows & Features
+
+ * Initial ports to QNX and z/OS UNIX System Services have started.
+
+ * Output from the tests is coloured using "green is okay, yellow is
+   questionable, red is bad and blue is informative" scheme.
+
+ * Mention of "GIT/Git/git" in the documentation have been updated to
+   be more uniform and consistent.  The name of the system and the
+   concept it embodies is "Git"; the command the users type is "git".
+   All-caps "GIT" was merely a way to imitate "Git" typeset in small
+   caps in our ASCII text only documentation and to be avoided.
+
+ * The completion script (in contrib/completion) used to let the
+   default completer to suggest pathnames, which gave too many
+   irrelevant choices (e.g. "git add" would not want to add an
+   unmodified path).  It learnt to use a more git-aware logic to
+   enumerate only relevant ones.
+
+ * In bare repositories, "git shortlog" and other commands now read
+   mailmap files from the tip of the history, to help running these
+   tools in server settings.
+
+ * Color specifiers, e.g. "%C(blue)Hello%C(reset)", used in the
+   "--format=" option of "git log" and friends can be disabled when
+   the output is not sent to a terminal by prefixing them with
+   "auto,", e.g. "%C(auto,blue)Hello%C(auto,reset)".
+
+ * Scripts can ask Git that wildcard patterns in pathspecs they give do
+   not have any significance, i.e. take them as literal strings.
+
+ * The patterns in .gitignore and .gitattributes files can have **/,
+   as a pattern that matches 0 or more levels of subdirectory.
+   E.g. "foo/**/bar" matches "bar" in "foo" itself or in a
+   subdirectory of "foo".
+
+ * When giving arguments without "--" disambiguation, object names
+   that come earlier on the command line must not be interpretable as
+   pathspecs and pathspecs that come later on the command line must
+   not be interpretable as object names.  This disambiguation rule has
+   been tweaked so that ":/" (no other string before or after) is
+   always interpreted as a pathspec; "git cmd -- :/" is no longer
+   needed, you can just say "git cmd :/".
+
+ * Various "hint" lines Git gives when it asks the user to edit
+   messages in the editor are commented out with '#' by default. The
+   core.commentchar configuration variable can be used to customize
+   this '#' to a different character.
+
+ * "git add -u" and "git add -A" without pathspec issues warning to
+   make users aware that they are only operating on paths inside the
+   subdirectory they are in.  Use ":/" (everything from the top) or
+   "." (everything from the $cwd) to disambiguate.
+
+ * "git blame" (and "git diff") learned the "--no-follow" option.
+
+ * "git branch" now rejects some nonsense combinations of command line
+   arguments (e.g. giving more than one branch name to rename) with
+   more case-specific error messages.
+
+ * "git check-ignore" command to help debugging .gitignore files has
+   been added.
+
+ * "git cherry-pick" can be used to replay a root commit to an unborn
+   branch.
+
+ * "git commit" can be told to use --cleanup=whitespace by setting the
+   configuration variable commit.cleanup to 'whitespace'.
+
+ * "git diff" and other Porcelain commands can be told to use a
+   non-standard algorithm by setting diff.algorithm configuration
+   variable.
+
+ * "git fetch --mirror" and fetch that uses other forms of refspec
+   with wildcard used to attempt to update a symbolic ref that match
+   the wildcard on the receiving end, which made little sense (the
+   real ref that is pointed at by the symbolic ref would be updated
+   anyway).  Symbolic refs no longer are affected by such a fetch.
+
+ * "git format-patch" now detects more cases in which a whole branch
+   is being exported, and uses the description for the branch, when
+   asked to write a cover letter for the series.
+
+ * "git format-patch" learned "-v $count" option, and prepends a
+   string "v$count-" to the names of its output files, and also
+   automatically sets the subject prefix to "PATCH v$count". This
+   allows patches from rerolled series to be stored under different
+   names and makes it easier to reuse cover letter messages.
+
+ * "git log" and friends can be told with --use-mailmap option to
+   rewrite the names and email addresses of people using the mailmap
+   mechanism.
+
+ * "git log --cc --graph" now shows the combined diff output with the
+   ancestry graph.
+
+ * "git log --grep=<pattern>" honors i18n.logoutputencoding to look
+   for the pattern after fixing the log message to the specified
+   encoding.
+
+ * "git mergetool" and "git difftool" learned to list the available
+   tool backends in a more consistent manner.
+
+ * "git mergetool" is aware of TortoiseGitMerge now and uses it over
+   TortoiseMerge when available.
+
+ * "git push" now requires "-f" to update a tag, even if it is a
+   fast-forward, as tags are meant to be fixed points.
+
+ * Error messages from "git push" when it stops to prevent remote refs
+   from getting overwritten by mistake have been improved to explain
+   various situations separately.
+
+ * "git push" will stop without doing anything if the new "pre-push"
+   hook exists and exits with a failure.
+
+ * When "git rebase" fails to generate patches to be applied (e.g. due
+   to oom), it failed to detect the failure and instead behaved as if
+   there were nothing to do.  A workaround to use a temporary file has
+   been applied, but we probably would want to revisit this later, as
+   it hurts the common case of not failing at all.
+
+ * Input and preconditions to "git reset" has been loosened where
+   appropriate.  "git reset $fromtree Makefile" requires $fromtree to
+   be any tree (it used to require it to be a commit), for example.
+   "git reset" (without options or parameters) used to error out when
+   you do not have any commits in your history, but it now gives you
+   an empty index (to match non-existent commit you are not even on).
+
+ * "git status" says what branch is being bisected or rebased when
+   able, not just "bisecting" or "rebasing".
+
+ * "git submodule" started learning a new mode to integrate with the
+   tip of the remote branch (as opposed to integrating with the commit
+   recorded in the superproject's gitlink).
+
+ * "git upload-pack" which implements the service "ls-remote" and
+   "fetch" talk to can be told to hide ref hierarchies the server
+   side internally uses (and that clients have no business learning
+   about) with transfer.hiderefs configuration.
+
+
+Foreign Interface
+
+ * "git fast-export" has been updated for its use in the context of
+   the remote helper interface.
+
+ * A new remote helper to interact with bzr has been added to contrib/.
+
+ * "git p4" got various bugfixes around its branch handling.  It is
+   also made usable with Python 2.4/2.5.  In addition, its various
+   portability issues for Cygwin have been addressed.
+
+ * The remote helper to interact with Hg in contrib/ has seen a few
+   fixes.
+
+
+Performance, Internal Implementation, etc.
+
+ * "git fsck" has been taught to be pickier about entries in tree
+   objects that should not be there, e.g. ".", ".git", and "..".
+
+ * Matching paths with common forms of pathspecs that contain wildcard
+   characters has been optimized further.
+
+ * We stopped paying attention to $GIT_CONFIG environment that points
+   at a single configuration file from any command other than "git config"
+   quite a while ago, but "git clone" internally set, exported, and
+   then unexported the variable during its operation unnecessarily.
+
+ * "git reset" internals has been reworked and should be faster in
+   general. We tried to be careful not to break any behaviour but
+   there could be corner cases, especially when running the command
+   from a conflicted state, that we may have missed.
+
+ * The implementation of "imap-send" has been updated to reuse xml
+   quoting code from http-push codepath, and lost a lot of unused
+   code.
+
+ * There is a simple-minded checker for the test scripts in t/
+   directory to catch most common mistakes (it is not enabled by
+   default).
+
+ * You can build with USE_WILDMATCH=YesPlease to use a replacement
+   implementation of pattern matching logic used for pathname-like
+   things, e.g. refnames and paths in the repository.  This new
+   implementation is not expected change the existing behaviour of Git
+   in this release, except for "git for-each-ref" where you can now
+   say "refs/**/master" and match with both refs/heads/master and
+   refs/remotes/origin/master.  We plan to use this new implementation
+   in wider places (e.g. "git ls-files '**/Makefile' may find Makefile
+   at the top-level, and "git log '**/t*.sh'" may find commits that
+   touch a shell script whose name begins with "t" at any level) in
+   future versions of Git, but we are not there yet.  By building with
+   USE_WILDMATCH, using the resulting Git daily and reporting when you
+   find breakages, you can help us get closer to that goal.
+
+ * Some reimplementations of Git do not write all the stat info back
+   to the index due to their implementation limitations (e.g. jgit).
+   A configuration option can tell Git to ignore changes to most of
+   the stat fields and only pay attention to mtime and size, which
+   these implementations can reliably update.  This can be used to
+   avoid excessive revalidation of contents.
+
+ * Some platforms ship with old version of expat where xmlparse.h
+   needs to be included instead of expat.h; the build procedure has
+   been taught about this.
+
+ * "make clean" on platforms that cannot compute header dependencies
+   on the fly did not work with implementations of "rm" that do not
+   like an empty argument list.
+
+Also contains minor documentation updates and code clean-ups.
+
+
+Fixes since v1.8.1
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.1 in the maintenance
+track are contained in this release (see release notes to them for
+details).
+
+ * An element on GIT_CEILING_DIRECTORIES list that does not name the
+   real path to a directory (i.e. a symbolic link) could have caused
+   the GIT_DIR discovery logic to escape the ceiling.
+
+ * When attempting to read the XDG-style $HOME/.config/git/config and
+   finding that $HOME/.config/git is a file, we gave a wrong error
+   message, instead of treating the case as "a custom config file does
+   not exist there" and moving on.
+
+ * The behaviour visible to the end users was confusing, when they
+   attempt to kill a process spawned in the editor that was in turn
+   launched by Git with SIGINT (or SIGQUIT), as Git would catch that
+   signal and die.  We ignore these signals now.
+   (merge 0398fc34 pf/editor-ignore-sigint later to maint).
+
+ * A child process that was killed by a signal (e.g. SIGINT) was
+   reported in an inconsistent way depending on how the process was
+   spawned by us, with or without a shell in between.
+
+ * After failing to create a temporary file using mkstemp(), failing
+   pathname was not reported correctly on some platforms.
+
+ * We used to stuff "user@" and then append what we read from
+   /etc/mailname to come up with a default e-mail ident, but a bug
+   lost the "user@" part.
+
+ * The attribute mechanism didn't allow limiting attributes to be
+   applied to only a single directory itself with "path/" like the
+   exclude mechanism does.  The initial implementation of this that
+   was merged to 'maint' and 1.8.1.2 was with a severe performance
+   degradations and needs to merge a fix-up topic.
+
+ * The smart HTTP clients forgot to verify the content-type that comes
+   back from the server side to make sure that the request is being
+   handled properly.
+
+ * "git am" did not parse datestamp correctly from Hg generated patch,
+   when it is run in a locale outside C (or en).
+
+ * "git apply" misbehaved when fixing whitespace breakages by removing
+   excess trailing blank lines.
+
+ * "git apply --summary" has been taught to make sure the similarity
+   value shown in its output is sensible, even when the input had a
+   bogus value.
+
+ * A tar archive created by "git archive" recorded a directory in a
+   way that made NetBSD's implementation of "tar" sometimes unhappy.
+
+ * "git archive" did not record uncompressed size in the header when
+   streaming a zip archive, which confused some implementations of unzip.
+
+ * "git archive" did not parse configuration values in tar.* namespace
+   correctly.
+   (merge b3873c3 jk/config-parsing-cleanup later to maint).
+
+ * Attempt to "branch --edit-description" an existing branch, while
+   being on a detached HEAD, errored out.
+
+ * "git clean" showed what it was going to do, but sometimes end up
+   finding that it was not allowed to do so, which resulted in a
+   confusing output (e.g. after saying that it will remove an
+   untracked directory, it found an embedded git repository there
+   which it is not allowed to remove).  It now performs the actions
+   and then reports the outcome more faithfully.
+
+ * When "git clone --separate-git-dir=$over_there" is interrupted, it
+   failed to remove the real location of the $GIT_DIR it created.
+   This was most visible when interrupting a submodule update.
+
+ * "git cvsimport" mishandled timestamps at DST boundary.
+
+ * We used to have an arbitrary 32 limit for combined diff input,
+   resulting in incorrect number of leading colons shown when showing
+   the "--raw --cc" output.
+
+ * "git fetch --depth" was broken in at least three ways.  The
+   resulting history was deeper than specified by one commit, it was
+   unclear how to wipe the shallowness of the repository with the
+   command, and documentation was misleading.
+   (merge cfb70e1 nd/fetch-depth-is-broken later to maint).
+
+ * "git log --all -p" that walked refs/notes/textconv/ ref can later
+   try to use the textconv data incorrectly after it gets freed.
+
+ * We forgot to close the file descriptor reading from "gpg" output,
+   killing "git log --show-signature" on a long history.
+
+ * The way "git svn" asked for password using SSH_ASKPASS and
+   GIT_ASKPASS was not in line with the rest of the system.
+
+ * The --graph code fell into infinite loop when asked to do what the
+   code did not expect.
+
+ * http transport was wrong to ask for the username when the
+   authentication is done by certificate identity.
+
+ * "git pack-refs" that ran in parallel to another process that
+   created new refs had a nasty race.
+
+ * Rebasing the history of superproject with change in the submodule
+   has been broken since v1.7.12.
+
+ * After "git add -N" and then writing a tree object out of the
+   index, the cache-tree data structure got corrupted.
+
+ * "git clone" used to allow --bare and --separate-git-dir=$there
+   options at the same time, which was nonsensical.
+
+ * "git rebase --preserve-merges" lost empty merges in recent versions
+   of Git.
+
+ * "git merge --no-edit" computed who were involved in the work done
+   on the side branch, even though that information is to be discarded
+   without getting seen in the editor.
+
+ * "git merge" started calling prepare-commit-msg hook like "git
+   commit" does some time ago, but forgot to pay attention to the exit
+   status of the hook.
+
+ * A failure to push due to non-ff while on an unborn branch
+   dereferenced a NULL pointer when showing an error message.
+
+ * When users spell "cc:" in lowercase in the fake "header" in the
+   trailer part, "git send-email" failed to pick up the addresses from
+   there. As e-mail headers field names are case insensitive, this
+   script should follow suit and treat "cc:" and "Cc:" the same way.
+
+ * Output from "git status --ignored" showed an unexpected interaction
+   with "--untracked".
+
+ * "gitweb", when sorting by age to show repositories with new
+   activities first, used to sort repositories with absolutely
+   nothing in it early, which was not very useful.
+
+ * "gitweb"'s code to sanitize control characters before passing it to
+   "highlight" filter lost known-to-be-safe control characters by
+   mistake.
+
+ * "gitweb" pages served over HTTPS, when configured to show picon or
+   gravatar, referred to these external resources to be fetched via
+   HTTP, resulting in mixed contents warning in browsers.
+
+ * When a line to be wrapped has a solid run of non space characters
+   whose length exactly is the wrap width, "git shortlog -w" failed
+   to add a newline after such a line.
+
+ * Command line completion leaked an unnecessary error message while
+   looking for possible matches with paths in <tree-ish>.
+
+ * Command line completion for "tcsh" emitted an unwanted space
+   after completing a single directory name.
+
+ * Command line completion code was inadvertently made incompatible with
+   older versions of bash by using a newer array notation.
+
+ * "git push" was taught to refuse updating the branch that is
+   currently checked out long time ago, but the user manual was left
+   stale.
+   (merge 50995ed wk/man-deny-current-branch-is-default-these-days later to maint).
+
+ * Some shells do not behave correctly when IFS is unset; work it
+   around by explicitly setting it to the default value.
+
+ * Some scripted programs written in Python did not get updated when
+   PYTHON_PATH changed.
+   (cherry-pick 96a4647fca54031974cd6ad1 later to maint).
+
+ * When autoconf is used, any build on a different commit always ran
+   "config.status --recheck" even when unnecessary.
+
+ * A fix was added to the build procedure to work around buggy
+   versions of ccache broke the auto-generation of dependencies, which
+   unfortunately is still relevant because some people use ancient
+   distros.
+
+ * The autoconf subsystem passed --mandir down to generated
+   config.mak.autogen but forgot to do the same for --htmldir.
+   (merge 55d9bf0 ct/autoconf-htmldir later to maint).
+
+ * A change made on v1.8.1.x maintenance track had a nasty regression
+   to break the build when autoconf is used.
+   (merge 7f1b697 jn/less-reconfigure later to maint).
+
+ * We have been carrying a translated and long-unmaintained copy of an
+   old version of the tutorial; removed.
+
+ * t0050 had tests expecting failures from a bug that was fixed some
+   time ago.
+
+ * t4014, t9502 and t0200 tests had various portability issues that
+   broke on OpenBSD.
+
+ * t9020 and t3600 tests had various portability issues.
+
+ * t9200 runs "cvs init" on a directory that already exists, but a
+   platform can configure this fail for the current user (e.g. you
+   need to be in the cvsadmin group on NetBSD 6.0).
+
+ * t9020 and t9810 had a few non-portable shell script construct.
+
+ * Scripts to test bash completion was inherently flaky as it was
+   affected by whatever random things the user may have on $PATH.
+
+ * An element on GIT_CEILING_DIRECTORIES could be a "logical" pathname
+   that uses a symbolic link to point at somewhere else (e.g. /home/me
+   that points at /net/host/export/home/me, and the latter directory
+   is automounted). Earlier when Git saw such a pathname e.g. /home/me
+   on this environment variable, the "ceiling" mechanism did not take
+   effect. With this release (the fix has also been merged to the
+   v1.8.1.x maintenance series), elements on GIT_CEILING_DIRECTORIES
+   are by default checked for such aliasing coming from symbolic
+   links. As this needs to actually resolve symbolic links for each
+   element on the GIT_CEILING_DIRECTORIES, you can disable this
+   mechanism for some elements by listing them after an empty element
+   on the GIT_CEILING_DIRECTORIES. e.g. Setting /home/me::/home/him to
+   GIT_CEILING_DIRECTORIES makes Git resolve symbolic links in
+   /home/me when checking if the current directory is under /home/me,
+   but does not do so for /home/him.
+   (merge 7ec30aa mh/maint-ceil-absolute later to maint).
diff --git a/third_party/git/Documentation/RelNotes/1.8.3.1.txt b/third_party/git/Documentation/RelNotes/1.8.3.1.txt
new file mode 100644
index 0000000000..986637b755
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.3.1.txt
@@ -0,0 +1,14 @@
+Git v1.8.3.1 Release Notes
+==========================
+
+Fixes since v1.8.3
+------------------
+
+ * When $HOME is misconfigured to point at an unreadable directory, we
+   used to complain and die. The check has been loosened.
+
+ * Handling of negative exclude pattern for directories "!dir" was
+   broken in the update to v1.8.3.
+
+Also contains a handful of trivial code clean-ups, documentation
+updates, updates to the test suite, etc.
diff --git a/third_party/git/Documentation/RelNotes/1.8.3.2.txt b/third_party/git/Documentation/RelNotes/1.8.3.2.txt
new file mode 100644
index 0000000000..26ae142c3d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.3.2.txt
@@ -0,0 +1,59 @@
+Git v1.8.3.2 Release Notes
+==========================
+
+Fixes since v1.8.3.1
+--------------------
+
+ * Cloning with "git clone --depth N" while fetch.fsckobjects (or
+   transfer.fsckobjects) is set to true did not tell the cut-off
+   points of the shallow history to the process that validates the
+   objects and the history received, causing the validation to fail.
+
+ * "git checkout foo" DWIMs the intended "upstream" and turns it into
+   "git checkout -t -b foo remotes/origin/foo". This codepath has been
+   updated to correctly take existing remote definitions into account.
+
+ * "git fetch" into a shallow repository from a repository that does
+   not know about the shallow boundary commits (e.g. a different fork
+   from the repository the current shallow repository was cloned from)
+   did not work correctly.
+
+ * "git subtree" (in contrib/) had one codepath with loose error
+   checks to lose data at the remote side.
+
+ * "git log --ancestry-path A...B" did not work as expected, as it did
+   not pay attention to the fact that the merge base between A and B
+   was the bottom of the range being specified.
+
+ * "git diff -c -p" was not showing a deleted line from a hunk when
+   another hunk immediately begins where the earlier one ends.
+
+ * "git merge @{-1}~22" was rewritten to "git merge frotz@{1}~22"
+   incorrectly when your previous branch was "frotz" (it should be
+   rewritten to "git merge frotz~22" instead).
+
+ * "git commit --allow-empty-message -m ''" should not start an
+   editor.
+
+ * "git push --[no-]verify" was not documented.
+
+ * An entry for "file://" scheme in the enumeration of URL types Git
+   can take in the HTML documentation was made into a clickable link
+   by mistake.
+
+ * zsh prompt script that borrowed from bash prompt script did not
+   work due to slight differences in array variable notation between
+   these two shells.
+
+ * The bash prompt code (in contrib/) displayed the name of the branch
+   being rebased when "rebase -i/-m/-p" modes are in use, but not the
+   plain vanilla "rebase".
+
+ * "git push $there HEAD:branch" did not resolve HEAD early enough, so
+   it was easy to flip it around while push is still going on and push
+   out a branch that the user did not originally intended when the
+   command was started.
+
+ * "difftool --dir-diff" did not copy back changes made by the
+   end-user in the diff tool backend to the working tree in some
+   cases.
diff --git a/third_party/git/Documentation/RelNotes/1.8.3.3.txt b/third_party/git/Documentation/RelNotes/1.8.3.3.txt
new file mode 100644
index 0000000000..9ba4f4da0f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.3.3.txt
@@ -0,0 +1,47 @@
+Git v1.8.3.3 Release Notes
+==========================
+
+Fixes since v1.8.3.2
+--------------------
+
+ * "git apply" parsed patches that add new files, generated by programs
+   other than Git, incorrectly.  This is an old breakage in v1.7.11.
+
+ * Older cURL wanted piece of memory we call it with to be stable, but
+   we updated the auth material after handing it to a call.
+
+ * "git pull" into nothing trashed "local changes" that were in the
+   index.
+
+ * Many "git submodule" operations did not work on a submodule at a
+   path whose name is not in ASCII.
+
+ * "cherry-pick" had a small leak in its error codepath.
+
+ * Logic used by git-send-email to suppress cc mishandled names like
+   "A U. Thor" <author@example.xz>, where the human readable part
+   needs to be quoted (the user input may not have the double quotes
+   around the name, and comparison was done between quoted and
+   unquoted strings).  It also mishandled names that need RFC2047
+   quoting.
+
+ * "gitweb" forgot to clear a global variable $search_regexp upon each
+   request, mistakenly carrying over the previous search to a new one
+   when used as a persistent CGI.
+
+ * The wildmatch engine did not honor WM_CASEFOLD option correctly.
+
+ * "git log -c --follow $path" segfaulted upon hitting the commit that
+   renamed the $path being followed.
+
+ * When a reflog notation is used for implicit "current branch",
+   e.g. "git log @{u}", we did not say which branch and worse said
+   "branch ''" in the error messages.
+
+ * Mac OS X does not like to write(2) more than INT_MAX number of
+   bytes; work it around by chopping write(2) into smaller pieces.
+
+ * Newer MacOS X encourages the programs to compile and link with
+   their CommonCrypto, not with OpenSSL.
+
+Also contains various minor documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/1.8.3.4.txt b/third_party/git/Documentation/RelNotes/1.8.3.4.txt
new file mode 100644
index 0000000000..56f106e262
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.3.4.txt
@@ -0,0 +1,20 @@
+Git v1.8.3.4 Release Notes
+==========================
+
+This update is mostly to propagate documentation fixes and test
+updates from the master front back to the maintenance track.
+
+Fixes since v1.8.3.3
+--------------------
+
+ * The bisect log listed incorrect commits when bisection ends with
+   only skipped ones.
+
+ * The test coverage framework was left broken for some time.
+
+ * The test suite for HTTP transport did not run with Apache 2.4.
+
+ * "git diff" used to fail when core.safecrlf is set and the working
+   tree contents had mixed CRLF/LF line endings. Committing such a
+   content must be prohibited, but "git diff" should help the user to
+   locate and fix such problems without failing.
diff --git a/third_party/git/Documentation/RelNotes/1.8.3.txt b/third_party/git/Documentation/RelNotes/1.8.3.txt
new file mode 100644
index 0000000000..ead568e7f1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.3.txt
@@ -0,0 +1,436 @@
+Git v1.8.3 Release Notes
+========================
+
+Backward compatibility notes (for Git 2.0)
+------------------------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default will change to the "simple"
+semantics that pushes only the current branch to the branch with the same
+name, and only when the current branch is set to integrate with that
+remote branch.  Use the user preference configuration variable
+"push.default" to change this.  If you are an old-timer who is used
+to the "matching" semantics, you can set the variable to "matching"
+to keep the traditional behaviour.  If you want to live in the future
+early, you can set it to "simple" today without waiting for Git 2.0.
+
+When "git add -u" (and "git add -A") is run inside a subdirectory and
+does not specify which paths to add on the command line, it
+will operate on the entire tree in Git 2.0 for consistency
+with "git commit -a" and other commands.  There will be no
+mechanism to make plain "git add -u" behave like "git add -u .".
+Current users of "git add -u" (without a pathspec) should start
+training their fingers to explicitly say "git add -u ."
+before Git 2.0 comes.  A warning is issued when these commands are
+run without a pathspec and when you have local changes outside the
+current directory, because the behaviour in Git 2.0 will be different
+from today's version in such a situation.
+
+In Git 2.0, "git add <path>" will behave as "git add -A <path>", so
+that "git add dir/" will notice paths you removed from the directory
+and record the removal.  Versions before Git 2.0, including this
+release, will keep ignoring removals, but the users who rely on this
+behaviour are encouraged to start using "git add --ignore-removal <path>"
+now before 2.0 is released.
+
+
+Updates since v1.8.2
+--------------------
+
+Foreign interface
+
+ * remote-hg and remote-bzr helpers (in contrib/ since v1.8.2) have
+   been updated; especially, the latter has been done in an
+   accelerated schedule (read: we may not have merged to this release
+   if we were following the usual "cook sufficiently in next before
+   unleashing it to the world" workflow) in order to help Emacs folks,
+   whose primary SCM seems to be stagnating.
+
+
+UI, Workflows & Features
+
+ * A handful of updates applied to gitk, including an addition of
+   "revert" action, showing dates in tags in a nicer way, making
+   colors configurable, and support for -G'pickaxe' search.
+
+ * The prompt string generator (in contrib/completion/) learned to
+   show how many changes there are in total and how many have been
+   replayed during a "git rebase" session.
+
+ * "git branch --vv" learned to paint the name of the branch it
+   integrates with in a different color (color.branch.upstream,
+   which defaults to blue).
+
+ * In a sparsely populated working tree, "git checkout <pathspec>" no
+   longer unmarks paths that match the given pathspec that were
+   originally ignored with "--sparse" (use --ignore-skip-worktree-bits
+   option to resurrect these paths out of the index if you really want
+   to).
+
+ * "git log --format" specifier learned %C(auto) token that tells Git
+   to use color when interpolating %d (decoration), %h (short commit
+   object name), etc. for terminal output.
+
+ * "git bisect" leaves the final outcome as a comment in its bisect
+   log file.
+
+ * "git clone --reference" can now refer to a gitfile "textual symlink"
+   that points at the real location of the repository.
+
+ * "git count-objects" learned "--human-readable" aka "-H" option to
+   show various large numbers in Ki/Mi/GiB scaled as necessary.
+
+ * "git cherry-pick $blob" and "git cherry-pick $tree" are nonsense,
+   and a more readable error message e.g. "can't cherry-pick a tree"
+   is given (we used to say "expected exactly one commit").
+
+ * The "--annotate" option to "git send-email" can be turned on (or
+   off) by default with sendemail.annotate configuration variable (you
+   can use --no-annotate from the command line to override it).
+
+ * The "--cover-letter" option to "git format-patch" can be turned on
+   (or off) by default with format.coverLetter configuration
+   variable. By setting it to 'auto', you can turn it on only for a
+   series with two or more patches.
+
+ * The bash completion support (in contrib/) learned that cherry-pick
+   takes a few more options than it already knew about.
+
+ * "git help" learned "-g" option to show the list of guides just like
+   list of commands are given with "-a".
+
+ * A triangular "pull from one place, push to another place" workflow
+   is supported better by new remote.pushdefault (overrides the
+   "origin" thing) and branch.*.pushremote (overrides the
+   branch.*.remote) configuration variables.
+
+ * "git status" learned to report that you are in the middle of a
+   revert session, just like it does for a cherry-pick and a bisect
+   session.
+
+ * The handling by "git branch --set-upstream-to" against various forms
+   of erroneous inputs was suboptimal and has been improved.
+
+ * When the interactive access to git-shell is not enabled, it issues
+   a message meant to help the system administrator to enable it.  An
+   explicit way has been added to issue custom messages to refuse an
+   access over the network to help the end users who connect to the
+   service expecting an interactive shell.
+
+ * In addition to the case where the user edits the log message with
+   the "e)dit" option of "am -i", replace the "Applying: this patch"
+   message with the final log message contents after applymsg hook
+   munges it.
+
+ * "git status" suggests users to look into using --untracked=no option
+   when it takes too long.
+
+ * "git status" shows a bit more information during a rebase/bisect
+   session.
+
+ * "git fetch" learned to fetch a commit at the tip of an unadvertised
+   ref by specifying a raw object name from the command line when the
+   server side supports this feature.
+
+ * Output from "git log --graph" works better with submodule log
+   output now.
+
+ * "git count-objects -v" learned to report leftover temporary
+   packfiles and other garbage in the object store.
+
+ * A new read-only credential helper (in contrib/) to interact with
+   the .netrc/.authinfo files has been added.
+
+ * "git send-email" can be used with the credential helper system.
+
+ * There was no Porcelain way to say "I no longer am interested in
+   this submodule", once you express your interest in a submodule with
+   "submodule init".  "submodule deinit" is the way to do so.
+
+ * "git pull --rebase" learned to pass "-v/-q" options to underlying
+   "git rebase".
+
+ * The new "--follow-tags" option tells "git push" to push relevant
+   annotated tags when pushing branches out.
+
+ * "git merge" and "git pull" can optionally be told to inspect and
+   reject when merging a commit that does not carry a trusted GPG
+   signature.
+
+ * "git mergetool" now feeds files to the "p4merge" backend in the
+   order that matches the p4 convention, where "theirs" is usually
+   shown on the left side, which is the opposite from what other backends
+   expect.
+
+ * "show/log" now honors gpg.program configuration just like other
+   parts of the code that use GnuPG.
+
+ * "git log" that shows the difference between the parent and the
+   child has been optimized somewhat.
+
+ * "git difftool" allows the user to write into the temporary files
+   being shown; if the user makes changes to the working tree at the
+   same time, it now refrains from overwriting the copy in the working
+   tree and leaves the temporary file so that changes can be merged
+   manually.
+
+ * There was no good way to ask "I have a random string that came from
+   outside world. I want to turn it into a 40-hex object name while
+   making sure such an object exists".  A new peeling suffix ^{object}
+   can be used for that purpose, together with "rev-parse --verify".
+
+
+Performance, Internal Implementation, etc.
+
+ * Updates for building under msvc.
+
+ * A handful of issues in the code that traverses the working tree to find
+   untracked and/or ignored files have been fixed, and the general
+   codepath involved in "status -u" and "clean" have been cleaned up
+   and optimized.
+
+ * The stack footprint of some codepaths that access an object from a
+   pack has been shrunk.
+
+ * The logic to coalesce the same lines removed from the parents in
+   the output from "diff -c/--cc" has been updated, but with O(n^2)
+   complexity, so this might turn out to be undesirable.
+
+ * The code to enforce permission bits on files in $GIT_DIR/ for
+   shared repositories has been simplified.
+
+ * A few codepaths know how much data they need to put in the
+   hashtables they use when they start, but still began with small tables
+   and repeatedly grew and rehashed them.
+
+ * The API to walk reflog entries from the latest to older, which was
+   necessary for operations such as "git checkout -", was cumbersome
+   to use correctly and also inefficient.
+
+ * Codepaths that inspect log-message-to-be and decide when to add a
+   new Signed-off-by line in various commands have been consolidated.
+
+ * The pkt-line API, implementation and its callers have been cleaned
+   up to make them more robust.
+
+ * The Cygwin port has a faster-but-lying lstat(2) emulation whose
+   incorrectness does not matter in practice except for a few
+   codepaths, and setting permission bits on directories is a codepath
+   that needs to use a more correct one.
+
+ * "git checkout" had repeated pathspec matches on the same paths,
+   which have been consolidated.  Also a bug in "git checkout dir/"
+   that is started from an unmerged index has been fixed.
+
+ * A few bugfixes to "git rerere" working on corner case merge
+   conflicts have been applied.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v1.8.2
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.2 in the maintenance
+track are contained in this release (see release notes to them for
+details).
+
+ * Recent versions of File::Temp (used by "git svn") started blowing
+   up when its tempfile sub is called as a class method; updated the
+   callsite to call it as a plain vanilla function to fix it.
+   (merge eafc2dd hb/git-pm-tempfile later to maint).
+
+ * Various subcommands of "git remote" simply ignored extraneous
+   command line arguments instead of diagnosing them as errors.
+
+ * When receive-pack detects an error in the pack header it received in
+   order to decide which of unpack-objects or index-pack to run, it
+   returned without closing the error stream, which led to a hung
+   sideband thread.
+
+ * Zsh completion forgot that the '%' character used to signal untracked
+   files needs to be escaped with another '%'.
+
+ * A commit object whose author or committer ident are malformed
+   crashed some code that trusted that a name, an email and a
+   timestamp can always be found in it.
+
+ * When "upload-pack" fails while generating a pack in response to
+   "git fetch" (or "git clone"), the receiving side had
+   a programming error that triggered the die handler
+   recursively.
+
+ * "rev-list --stdin" and friends kept bogus pointers into the input
+   buffer around as human readable object names.  This was not a huge
+   problem but was exposed by a new change that uses these names in
+   error output.
+
+ * Smart-capable HTTP servers were not restricted via the
+   GIT_NAMESPACE mechanism when talking with commit-walking clients,
+   like they are when talking with smart HTTP clients.
+   (merge 6130f86 jk/http-dumb-namespaces later to maint).
+
+ * "git merge-tree" did not omit a merge result that is identical to
+   the "our" side in certain cases.
+   (merge aacecc3 jk/merge-tree-added-identically later to maint).
+
+ * Perl scripts like "git-svn" closed (instead of redirecting to /dev/null)
+   the standard error stream, which is not a very smart thing to do.
+   A later open may return file descriptor #2 for an unrelated purpose, and
+   error reporting code may write into it.
+
+ * "git show-branch" was not prepared to show a very long run of
+   ancestor operators e.g. foobar^2~2^2^2^2...^2~4 correctly.
+
+ * "git diff --diff-algorithm algo" is also understood as "git diff
+   --diff-algorithm=algo".
+
+ * The new core.commentchar configuration was not applied in a few
+   places.
+
+ * "git bundle" erroneously bailed out when parsing a valid bundle
+   containing a prerequisite commit without a commit message.
+
+ * "git log -S/-G" started paying attention to textconv filter, but
+   there was no way to disable this.  Make it honor the --no-textconv
+   option.
+
+ * When used with the "-d temporary-directory" option, "git filter-branch"
+   failed to come back to the original working tree to perform the
+   final clean-up procedure.
+
+ * "git merge $(git rev-parse v1.8.2)" behaved quite differently from
+   "git merge v1.8.2", as if v1.8.2 were written as v1.8.2^0 and did
+   not pay much attention to the annotated tag payload.  Make the code
+   notice the type of the tag object, in addition to the dwim_ref()
+   based classification the current code uses (i.e. the name appears
+   in refs/tags/) to decide when to special-case tag merging.
+
+ * Fix a 1.8.1.x regression that stopped matching "dir" (without a
+   trailing slash) to a directory "dir".
+
+ * "git apply --whitespace=fix" was not prepared to see a line getting
+   longer after fixing whitespaces (e.g. tab-in-indent aka Python).
+
+ * The prompt string generator (in contrib/completion/) did not notice
+   when we are in a middle of a "git revert" session.
+
+ * "submodule summary --summary-limit" option did not support the
+   "--option=value" form.
+
+ * "index-pack --fix-thin" used an uninitialized value to compute
+   the delta depths of objects it appends to the resulting pack.
+
+ * "index-pack --verify-stat" used a few counters outside the protection
+   of a mutex, possibly showing incorrect numbers.
+
+ * The code to keep track of what directory names are known to Git on
+   platforms with case insensitive filesystems could get confused upon a
+   hash collision between these pathnames and would loop forever.
+
+ * Annotated tags outside the refs/tags/ hierarchy were not advertised
+   correctly to ls-remote and fetch with recent versions of Git.
+
+ * Recent optimizations broke shallow clones.
+
+ * "git cmd -- ':(top'" was not diagnosed as an invalid syntax, and
+   instead the parser kept reading beyond the end of the string.
+
+ * "git tag -f <tag>" always said "Updated tag '<tag>'" even when
+   creating a new tag (i.e. neither overwriting nor updating).
+
+ * "git p4" did not behave well when the path to the root of the P4
+   client was not its real path.
+   (merge bbd8486 pw/p4-symlinked-root later to maint).
+
+ * "git archive" reported a failure when asked to create an archive out
+   of an empty tree.  It is more intuitive to give an empty
+   archive back in such a case.
+
+ * When "format-patch" quoted a non-ascii string in header files,
+   it incorrectly applied rfc2047 and chopped a single character in
+   the middle of the string.
+
+ * An aliased command spawned from a bare repository that does not say
+   it is bare with "core.bare = yes" was treated as non-bare by mistake.
+
+ * In "git reflog expire", the REACHABLE bit was not cleared from the
+   correct objects.
+
+ * The logic used by "git diff -M --stat" to shorten the names of
+   files before and after a rename did not work correctly when the
+   common prefix and suffix between the two filenames overlapped.
+
+ * The "--match=<pattern>" option of "git describe", when used with
+   "--all" to allow refs that are not annotated tags to be a
+   base of description, did not restrict the output from the command
+   to those refs that match the given pattern.
+
+ * Clarify in the documentation "what" gets pushed to "where" when the
+   command line to "git push" does not say these explicitly.
+
+ * The "--color=<when>" argument to the commands in the diff family
+   was described poorly.
+
+ * The arguments given to the pre-rebase hook were not documented.
+
+ * The v4 index format was not documented.
+
+ * The "--match=<pattern>" argument "git describe" takes uses glob
+   pattern but it wasn't obvious from the documentation.
+
+ * Some sources failed to compile on systems that lack NI_MAXHOST in
+   their system header (e.g. z/OS).
+
+ * Add an example use of "--env-filter" in "filter-branch"
+   documentation.
+
+ * "git bundle verify" did not say "records a complete history" for a
+   bundle that does not have any prerequisites.
+
+ * In the v1.8.0 era, we changed symbols that do not have to be global
+   to file scope static, but a few functions in graph.c were used by
+   CGit sideways, bypassing the entry points of the API the
+   in-tree users use.
+
+ * "git update-index -h" did not do the usual "-h(elp)" thing.
+
+ * "git index-pack" had a buffer-overflow while preparing an
+   informational message when the translated version of it was too
+   long.
+
+ * 'git commit -m "$msg"' used to add an extra newline even when
+   $msg already ended with one.
+
+ * The SSL peer verification done by "git imap-send" did not ask for
+   Server Name Indication (RFC 4366), failing to connect to SSL/TLS
+   sites that serve multiple hostnames on a single IP.
+
+ * perl/Git.pm::cat_blob slurped everything in core only to write it
+   out to a file descriptor, which was not a very smart thing to do.
+
+ * "git branch" did not bother to check nonsense command line
+   parameters.  It now issues errors in many cases.
+
+ * Verification of signed tags was not done correctly when not in C
+   or en/US locale.
+
+ * Some platforms and users spell UTF-8 differently; retry with the
+   most official "UTF-8" when the system does not understand the
+   user-supplied encoding name that is a common alternative
+   spelling of UTF-8.
+
+ * When export-subst is used, "zip" output recorded an incorrect
+   size of the file.
+
+ * "git am $maildir/" applied messages in an unexpected order; sort
+   filenames read from the maildir/ in a way that is more likely to
+   sort the messages in the order the writing MUA meant to, by sorting
+   numeric segments in numeric order and non-numeric segments in
+   alphabetical order.
+
+ * "git submodule update", when recursed into sub-submodules, did not
+   accumulate the prefix paths.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.1.txt b/third_party/git/Documentation/RelNotes/1.8.4.1.txt
new file mode 100644
index 0000000000..96090ef599
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.1.txt
@@ -0,0 +1,71 @@
+Git v1.8.4.1 Release Notes
+==========================
+
+Fixes since v1.8.4
+------------------
+
+ * Some old versions of bash do not grok some constructs like
+   'printf -v varname' which the prompt and completion code started
+   to use recently.  The completion and prompt scripts have been
+   adjusted to work better with these old versions of bash.
+
+ * In FreeBSD's and NetBSD's "sh", a return in a dot script in a
+   function returns from the function, not only in the dot script,
+   breaking "git rebase" on these platforms (regression introduced
+   in 1.8.4-rc1).
+
+ * "git rebase -i" and other scripted commands were feeding a
+   random, data dependant error message to 'echo' and expecting it
+   to come out literally.
+
+ * Setting the "submodule.<name>.path" variable to the empty
+   "true" caused the configuration parser to segfault.
+
+ * Output from "git log --full-diff -- <pathspec>" looked strange
+   because comparison was done with the previous ancestor that
+   touched the specified <pathspec>, causing the patches for paths
+   outside the pathspec to show more than the single commit has
+   changed.
+
+ * The auto-tag-following code in "git fetch" tries to reuse the
+   same transport twice when the serving end does not cooperate and
+   does not give tags that point to commits that are asked for as
+   part of the primary transfer.  Unfortunately, Git-aware transport
+   helper interface is not designed to be used more than once, hence
+   this did not work over smart-http transfer.  Fixed.
+
+ * Send a large request to read(2)/write(2) as a smaller but still
+   reasonably large chunks, which would improve the latency when the
+   operation needs to be killed and incidentally works around broken
+   64-bit systems that cannot take a 2GB write or read in one go.
+
+ * A ".mailmap" file that ends with an incomplete line, when read
+   from a blob, was not handled properly.
+
+ * The recent "short-cut clone connectivity check" topic broke a
+   shallow repository when a fetch operation tries to auto-follow
+   tags.
+
+ * When send-email comes up with an error message to die with upon
+   failure to start an SSL session, it tried to read the error
+   string from a wrong place.
+
+ * A call to xread() was used without a loop to cope with short
+   read in the codepath to stream large blobs to a pack.
+
+ * On platforms with fgetc() and friends defined as macros, the
+   configuration parser did not compile.
+
+ * New versions of MediaWiki introduced a new API for returning
+   more than 500 results in response to a query, which would cause
+   the MediaWiki remote helper to go into an infinite loop.
+
+ * Subversion's serf access method (the only one available in
+   Subversion 1.8) for http and https URLs in skelta mode tells its
+   caller to open multiple files at a time, which made "git svn
+   fetch" complain that "Temp file with moniker 'svn_delta' already
+   in use" instead of fetching.
+
+
+Also contains a handful of trivial code clean-ups, documentation
+updates, updates to the test suite, etc.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.2.txt b/third_party/git/Documentation/RelNotes/1.8.4.2.txt
new file mode 100644
index 0000000000..bf6fb1a023
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.2.txt
@@ -0,0 +1,77 @@
+Git v1.8.4.2 Release Notes
+==========================
+
+Fixes since v1.8.4.1
+--------------------
+
+ * "git clone" gave some progress messages to the standard output, not
+   to the standard error, and did not allow suppressing them with the
+   "--no-progress" option.
+
+ * "format-patch --from=<whom>" forgot to omit unnecessary in-body
+   from line, i.e. when <whom> is the same as the real author.
+
+ * "git shortlog" used to choke and die when there is a malformed
+   commit (e.g. missing authors); it now simply ignore such a commit
+   and keeps going.
+
+ * "git merge-recursive" did not parse its "--diff-algorithm=" command
+   line option correctly.
+
+ * "git branch --track" had a minor regression in v1.8.3.2 and later
+   that made it impossible to base your local work on anything but a
+   local branch of the upstream repository you are tracking from.
+
+ * "git ls-files -k" needs to crawl only the part of the working tree
+   that may overlap the paths in the index to find killed files, but
+   shared code with the logic to find all the untracked files, which
+   made it unnecessarily inefficient.
+
+ * When there is no sufficient overlap between old and new history
+   during a "git fetch" into a shallow repository, objects that the
+   sending side knows the receiving end has were unnecessarily sent.
+
+ * When running "fetch -q", a long silence while the sender side
+   computes the set of objects to send can be mistaken by proxies as
+   dropped connection.  The server side has been taught to send a
+   small empty messages to keep the connection alive.
+
+ * When the webserver responds with "405 Method Not Allowed", "git
+   http-backend" should tell the client what methods are allowed with
+   the "Allow" header.
+
+ * "git cvsserver" computed the permission mode bits incorrectly for
+   executable files.
+
+ * The implementation of "add -i" has a crippling code to work around
+   ActiveState Perl limitation but it by mistake also triggered on Git
+   for Windows where MSYS perl is used.
+
+ * We made sure that we notice the user-supplied GIT_DIR is actually a
+   gitfile, but did not do the same when the default ".git" is a
+   gitfile.
+
+ * When an object is not found after checking the packfiles and then
+   loose object directory, read_sha1_file() re-checks the packfiles to
+   prevent racing with a concurrent repacker; teach the same logic to
+   has_sha1_file().
+
+ * "git commit --author=$name", when $name is not in the canonical
+   "A. U. Thor <au.thor@example.xz>" format, looks for a matching name
+   from existing history, but did not consult mailmap to grab the
+   preferred author name.
+
+ * The commit object names in the insn sheet that was prepared at the
+   beginning of "rebase -i" session can become ambiguous as the
+   rebasing progresses and the repository gains more commits. Make
+   sure the internal record is kept with full 40-hex object names.
+
+ * "git rebase --preserve-merges" internally used the merge machinery
+   and as a side effect, left merge summary message in the log, but
+   when rebasing, there should not be a need for merge summary.
+
+ * "git rebase -i" forgot that the comment character can be
+   configurable while reading its insn sheet.
+
+Also contains a handful of trivial code clean-ups, documentation
+updates, updates to the test suite, etc.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.3.txt b/third_party/git/Documentation/RelNotes/1.8.4.3.txt
new file mode 100644
index 0000000000..267a1b34b4
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.3.txt
@@ -0,0 +1,54 @@
+Git v1.8.4.3 Release Notes
+==========================
+
+Fixes since v1.8.4.2
+--------------------
+
+ * The interaction between use of Perl in our test suite and NO_PERL
+   has been clarified a bit.
+
+ * A fast-import stream expresses a pathname with funny characters by
+   quoting them in C style; remote-hg remote helper (in contrib/)
+   forgot to unquote such a path.
+
+ * One long-standing flaw in the pack transfer protocol used by "git
+   clone" was that there was no way to tell the other end which branch
+   "HEAD" points at, and the receiving end needed to guess.  A new
+   capability has been defined in the pack protocol to convey this
+   information so that cloning from a repository with more than one
+   branches pointing at the same commit where the HEAD is at now
+   reliably sets the initial branch in the resulting repository.
+
+ * We did not handle cases where http transport gets redirected during
+   the authorization request (e.g. from http:// to https://).
+
+ * "git rev-list --objects ^v1.0^ v1.0" gave v1.0 tag itself in the
+   output, but "git rev-list --objects v1.0^..v1.0" did not.
+
+ * The fall-back parsing of commit objects with broken author or
+   committer lines were less robust than ideal in picking up the
+   timestamps.
+
+ * Bash prompting code to deal with an SVN remote as an upstream
+   were coded in a way not supported by older Bash versions (3.x).
+
+ * "git checkout topic", when there is not yet a local "topic" branch
+   but there is a unique remote-tracking branch for a remote "topic"
+   branch, pretended as if "git checkout -t -b topic remote/$r/topic"
+   (for that unique remote $r) was run. This hack however was not
+   implemented for "git checkout topic --".
+
+ * Coloring around octopus merges in "log --graph" output was screwy.
+
+ * We did not generate HTML version of documentation to "git subtree"
+   in contrib/.
+
+ * The synopsis section of "git unpack-objects" documentation has been
+   clarified a bit.
+
+ * An ancient How-To on serving Git repositories on an HTTP server
+   lacked a warning that it has been mostly superseded with more
+   modern way.
+
+Also contains a handful of trivial code clean-ups, documentation
+updates, updates to the test suite, etc.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.4.txt b/third_party/git/Documentation/RelNotes/1.8.4.4.txt
new file mode 100644
index 0000000000..a7c1ce15c0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.4.txt
@@ -0,0 +1,10 @@
+Git v1.8.4.4 Release Notes
+==========================
+
+Fixes since v1.8.4.3
+--------------------
+
+ * The fix in v1.8.4.3 to the pack transfer protocol to propagate
+   the target of symbolic refs broke "git clone/git fetch" from a
+   repository with too many symbolic refs. As a hotfix/workaround,
+   we transfer only the information on HEAD.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.5.txt b/third_party/git/Documentation/RelNotes/1.8.4.5.txt
new file mode 100644
index 0000000000..215bd1a7a2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.5.txt
@@ -0,0 +1,13 @@
+Git v1.8.4.5 Release Notes
+==========================
+
+Fixes since v1.8.4.4
+--------------------
+
+ * Recent update to remote-hg that attempted to make it work better
+   with non ASCII pathnames fed Unicode strings to the underlying Hg
+   API, which was wrong.
+
+ * "git submodule init" copied "submodule.$name.update" settings from
+   .gitmodules to .git/config without making sure if the suggested
+   value was sensible.
diff --git a/third_party/git/Documentation/RelNotes/1.8.4.txt b/third_party/git/Documentation/RelNotes/1.8.4.txt
new file mode 100644
index 0000000000..02f681b710
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.4.txt
@@ -0,0 +1,486 @@
+Git v1.8.4 Release Notes
+========================
+
+Backward compatibility notes (for Git 2.0)
+------------------------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default will change to the "simple"
+semantics that pushes:
+
+ - only the current branch to the branch with the same name, and only
+   when the current branch is set to integrate with that remote
+   branch, if you are pushing to the same remote as you fetch from; or
+
+ - only the current branch to the branch with the same name, if you
+   are pushing to a remote that is not where you usually fetch from.
+
+Use the user preference configuration variable "push.default" to
+change this.  If you are an old-timer who is used to the "matching"
+semantics, you can set the variable to "matching" to keep the
+traditional behaviour.  If you want to live in the future early, you
+can set it to "simple" today without waiting for Git 2.0.
+
+When "git add -u" (and "git add -A") is run inside a subdirectory and
+does not specify which paths to add on the command line, it
+will operate on the entire tree in Git 2.0 for consistency
+with "git commit -a" and other commands.  There will be no
+mechanism to make plain "git add -u" behave like "git add -u .".
+Current users of "git add -u" (without a pathspec) should start
+training their fingers to explicitly say "git add -u ."
+before Git 2.0 comes.  A warning is issued when these commands are
+run without a pathspec and when you have local changes outside the
+current directory, because the behaviour in Git 2.0 will be different
+from today's version in such a situation.
+
+In Git 2.0, "git add <path>" will behave as "git add -A <path>", so
+that "git add dir/" will notice paths you removed from the directory
+and record the removal.  Versions before Git 2.0, including this
+release, will keep ignoring removals, but the users who rely on this
+behaviour are encouraged to start using "git add --ignore-removal <path>"
+now before 2.0 is released.
+
+
+Updates since v1.8.3
+--------------------
+
+Foreign interfaces, subsystems and ports.
+
+ * Cygwin port has been updated for more recent Cygwin 1.7.
+
+ * "git rebase -i" now honors --strategy and -X options.
+
+ * Git-gui has been updated to its 0.18.0 version.
+
+ * MediaWiki remote helper (in contrib/) has been updated to use the
+   credential helper interface from Git.pm.
+
+ * Update build for Cygwin 1.[57].  Torsten Bögershausen reports that
+   this is fine with Cygwin 1.7 ($gmane/225824) so let's try moving it
+   ahead.
+
+ * The credential helper to talk to keychain on OS X (in contrib/) has
+   been updated to kick in not just when talking http/https but also
+   imap(s) and smtp.
+
+ * Remote transport helper has been updated to report errors and
+   maintain ref hierarchy used to keep track of its own state better.
+
+ * With "export" remote-helper protocol, (1) a push that tries to
+   update a remote ref whose name is different from the pushing side
+   does not work yet, and (2) the helper may not know how to do
+   --dry-run; these problematic cases are disabled for now.
+
+ * git-remote-hg/bzr (in contrib/) updates.
+
+ * git-remote-mw (in contrib/) hints users to check the certificate,
+   when https:// connection failed.
+
+ * git-remote-mw (in contrib/) adds a command to allow previewing the
+   contents locally before pushing it out, when working with a
+   MediaWiki remote.
+
+
+UI, Workflows & Features
+
+ * Sample "post-receive-email" hook script got an enhanced replacement
+   "multimail" (in contrib/).
+
+ * Also in contrib/ is a new "contacts" script that runs "git blame"
+   to find out the people who may be interested in a set of changes.
+
+ * "git clean" command learned an interactive mode.
+
+ * The "--head" option to "git show-ref" was only to add "HEAD" to the
+   list of candidate refs to be filtered by the usual rules
+   (e.g. "--heads" that only show refs under refs/heads).  The meaning
+   of the option has been changed to always show "HEAD" regardless of
+   what filtering will be applied to any other ref.
+
+   This is a backward incompatible change and might cause breakages to
+   people's existing scripts.
+
+ * "git show -s" was less discoverable than it should have been.  It
+   now has a natural synonym "git show --no-patch".
+
+ * "git check-mailmap" is a new command that lets you map usernames
+   and e-mail addresses through the mailmap mechanism, just like many
+   built-in commands do.
+
+ * "git name-rev" learned to name an annotated tag object back to its
+   tagname; "git name-rev $(git rev-parse v1.0.0)" gives "tags/v1.0.0",
+   for example.
+
+ * "git cat-file --batch-check=<format>" is added, primarily to allow
+   on-disk footprint of objects in packfiles (often they are a lot
+   smaller than their true size, when expressed as deltas) to be
+   reported.
+
+ * "git rebase [-i]" used to leave just "rebase" as its reflog messages
+   for some operations. They have been reworded to be more informative.
+
+ * In addition to the choice from "rebase, merge, or checkout-detach",
+   "submodule update" can allow a custom command to be used in to
+   update the working tree of submodules via the "submodule.*.update"
+   configuration variable.
+
+ * "git submodule update" can optionally clone the submodule
+   repositories shallowly.
+
+ * "git format-patch" learned "--from[=whom]" option, which sets the
+   "From: " header to the specified person (or the person who runs the
+   command, if "=whom" part is missing) and move the original author
+   information to an in-body From: header as necessary.
+
+ * The configuration variable "merge.ff" was cleary a tri-state to
+   choose one from "favor fast-forward when possible", "always create
+   a merge even when the history could fast-forward" and "do not
+   create any merge, only update when the history fast-forwards", but
+   the command line parser did not implement the usual convention of
+   "last one wins, and command line overrides the configuration"
+   correctly.
+
+ * "gitweb" learned to optionally place extra links that point at the
+   levels higher than the Gitweb pages themselves in the breadcrumbs,
+   so that it can be used as part of a larger installation.
+
+ * "git log --format=" now honors i18n.logoutputencoding configuration
+   variable.
+
+ * The "push.default=simple" mode of "git push" has been updated to
+   behave like "current" without requiring a remote tracking
+   information, when you push to a remote that is different from where
+   you fetch from (i.e. a triangular workflow).
+
+ * Having multiple "fixup!" on a line in the rebase instruction sheet
+   did not work very well with "git rebase -i --autosquash".
+
+ * "git log" learned the "--author-date-order" option, with which the
+   output is topologically sorted and commits in parallel histories
+   are shown intermixed together based on the author timestamp.
+
+ * Various subcommands of "git submodule" refused to run from anywhere
+   other than the top of the working tree of the superproject, but
+   they have been taught to let you run from a subdirectory.
+
+ * "git diff" learned a mode that ignores hunks whose change consists
+   only of additions and removals of blank lines, which is the same as
+   "diff -B" (ignore blank lines) of GNU diff.
+
+ * "git rm" gives a single message followed by list of paths to report
+   multiple paths that cannot be removed.
+
+ * "git rebase" can be told with ":/look for this string" syntax commits
+   to replay the changes onto and where the work to be replayed begins.
+
+ * Many tutorials teach users to set "color.ui" to "auto" as the first
+   thing after you set "user.name/email" to introduce yourselves to
+   Git.  Now the variable defaults to "auto".
+
+ * On Cygwin, "cygstart" is now recognised as a possible way to start
+   a web browser (used in "help -w" and "instaweb" among others).
+
+ * "git status" learned status.branch and status.short configuration
+   variables to use --branch and --short options by default (override
+   with --no-branch and --no-short options from the command line).
+
+ * "git cmd <name>", when <name> happens to be a 40-hex string,
+   directly uses the 40-hex string as an object name, even if a ref
+   "refs/<some hierarchy>/<name>" exists.  This disambiguation order
+   is unlikely to change, but we should warn about the ambiguity just
+   like we warn when more than one refs/ hierarchies share the same
+   name.
+
+ * "git rebase" learned "--[no-]autostash" option to save local
+   changes instead of refusing to run (to which people's normal
+   response was to stash them and re-run).  This introduced a corner
+   case breakage to "git am --abort" but it has been fixed.
+
+ * "check-ignore" (new feature since 1.8.2) has been updated to work
+   more like "check-attr" over bidi-pipes.
+
+ * "git describe" learned "--first-parent" option to limit its closest
+   tagged commit search to the first-parent chain.
+
+ * "git merge foo" that might have meant "git merge origin/foo" is
+   diagnosed with a more informative error message.
+
+ * "git log -L<line>,<range>:<filename>" has been added.  This may
+   still have leaks and rough edges, though.
+
+ * We used the approxidate() parser for "--expire=<timestamp>" options
+   of various commands, but it is better to treat --expire=all and
+   --expire=now a bit more specially than using the current timestamp.
+   "git gc" and "git reflog" have been updated with a new parsing
+   function for expiry dates.
+
+ * Updates to completion (both bash and zsh) helpers.
+
+ * The behaviour of the "--chain-reply-to" option of "git send-email"
+   have changed at 1.7.0, and we added a warning/advice message to
+   help users adjust to the new behaviour back then, but we kept it
+   around for too long.  The message has finally been removed.
+
+ * "git fetch origin master" unlike "git fetch origin" or "git fetch"
+   did not update "refs/remotes/origin/master"; this was an early
+   design decision to keep the update of remote tracking branches
+   predictable, but in practice it turns out that people find it more
+   convenient to opportunistically update them whenever we have a
+   chance, and we have been updating them when we run "git push" which
+   already breaks the original "predictability" anyway.
+
+ * The configuration variable core.checkstat was advertised in the
+   documentation but the code expected core.statinfo instead.
+   For now, we accept both core.checkstat and core.statinfo, but the
+   latter will be removed in the longer term.
+
+
+Performance, Internal Implementation, etc.
+
+ * On Cygwin, we used to use our own lstat(2) emulation that is
+   allegedly faster than the platform one in codepaths where some of
+   the information it returns did not matter, but it started to bite
+   us in a few codepaths where the trick it uses to cheat does show
+   breakages. This emulation has been removed and we use the native
+   lstat(2) emulation supplied by Cygwin now.
+
+ * The function attributes extensions are used to catch mistakes in
+   use of our own variadic functions that use NULL sentinel at the end
+   (i.e. like execl(3)) and format strings (i.e. like printf(3)).
+
+ * The code to allow configuration data to be read from in-tree blob
+   objects is in.  This may help working in a bare repository and
+   submodule updates.
+
+ * Fetching between repositories with many refs employed O(n^2)
+   algorithm to match up the common objects, which has been corrected.
+
+ * The original way to specify remote repository using .git/branches/
+   used to have a nifty feature.  The code to support the feature was
+   still in a function but the caller was changed not to call it 5
+   years ago, breaking that feature and leaving the supporting code
+   unreachable.  The dead code has been removed.
+
+ * "git pack-refs" that races with new ref creation or deletion have
+   been susceptible to lossage of refs under right conditions, which
+   has been tightened up.
+
+ * We read loose and packed references in two steps, but after
+   deciding to read a loose ref but before actually opening it to read
+   it, another process racing with us can unlink it, which would cause
+   us to barf.  The codepath has been updated to retry when such a
+   race is detected, instead of outright failing.
+
+ * Uses of the platform fnmatch(3) function (many places in the code,
+   matching pathspec, .gitignore and .gitattributes to name a few)
+   have been replaced with wildmatch, allowing "foo/**/bar" that would
+   match foo/bar, foo/a/bar, foo/a/b/bar, etc.
+
+ * Memory ownership and lifetime rules for what for-each-ref feeds to
+   its callbacks have been clarified (in short, "you do not own it, so
+   make a copy if you want to keep it").
+
+ * The revision traversal logic to improve culling of irrelevant
+   parents while traversing a mergy history has been updated.
+
+ * Some leaks in unpack-trees (used in merge, cherry-pick and other
+   codepaths) have been plugged.
+
+ * The codepath to read from marks files in fast-import/export did not
+   have to accept anything but 40-hex representation of the object
+   name.  Further, fast-export did not need full in-core object
+   representation to have parsed wen reading from them.  These
+   codepaths have been optimized by taking advantage of these access
+   patterns.
+
+ * Object lookup logic, when the object hashtable starts to become
+   crowded, has been optimized.
+
+ * When TEST_OUTPUT_DIRECTORY setting is used, it was handled somewhat
+   inconsistently between the test framework and t/Makefile, and logic
+   to summarize the results looked at a wrong place.
+
+ * "git clone" uses a lighter-weight implementation when making sure
+   that the history behind refs are complete.
+
+ * Many warnings from sparse source checker in compat/ area has been
+   squelched.
+
+ * The code to reading and updating packed-refs file has been updated,
+   correcting corner case bugs.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v1.8.3
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.3 in the maintenance
+track are contained in this release (see release notes to them for
+details).
+
+ * Newer Net::SMTP::SSL module does not want the user programs to use
+   the default behaviour to let server certificate go without
+   verification, so by default enable the verification with a
+   mechanism to turn it off if needed.
+   (merge 35035bb rr/send-email-ssl-verify later to maint).
+
+ * When "git" is spawned in such a way that any of the low 3 file
+   descriptors is closed, our first open() may yield file descriptor 2,
+   and writing error message to it would screw things up in a big way.
+   (merge a11c396 tr/protect-low-3-fds later to maint).
+
+ * The mailmap mechanism unnecessarily downcased the e-mail addresses
+   in the output, and also ignored the human name when it is a single
+   character name.
+   (merge bd23794 jc/mailmap-case-insensitivity later to maint).
+
+ * In two places we did not check return value (expected to be a file
+   descriptor) correctly.
+   (merge a77f106 tr/fd-gotcha-fixes later to maint).
+
+ * Logic to auto-detect character encodings in the commit log message
+   did not reject overlong and invalid UTF-8 characters.
+   (merge 81050ac bc/commit-invalid-utf8 later to maint).
+
+ * Pass port number as a separate argument when "send-email" initializes
+   Net::SMTP, instead of as a part of the hostname, i.e. host:port.
+   This allows GSSAPI codepath to match with the hostname given.
+   (merge 1a741bf bc/send-email-use-port-as-separate-param later to maint).
+
+ * "git diff" refused to even show difference when core.safecrlf is
+   set to true (i.e. error out) and there are offending lines in the
+   working tree files.
+   (merge 5430bb2 jc/maint-diff-core-safecrlf later to maint).
+
+ * A test that should have failed but didn't revealed a bug that needs
+   to be corrected.
+   (merge 94d75d1 jc/t1512-fix later to maint).
+
+ * An overlong path to a .git directory may have overflown the
+   temporary path buffer used to create a name for lockfiles.
+   (merge 2fbd4f9 mh/maint-lockfile-overflow later to maint).
+
+ * Invocations of "git checkout" used internally by "git rebase" were
+   counted as "checkout", and affected later "git checkout -" to the
+   the user to an unexpected place.
+   (merge 3bed291 rr/rebase-checkout-reflog later to maint).
+
+ * The configuration variable column.ui was poorly documented.
+   (merge 5e62cc1 rr/column-doc later to maint).
+
+ * "git name-rev --refs=tags/v*" were forbidden, which was a bit
+   inconvenient (you had to give a pattern to match refs fully, like
+   --refs=refs/tags/v*).
+   (merge 98c5c4a nk/name-rev-abbreviated-refs later to maint).
+
+ * "git apply" parsed patches that add new files, generated by
+   programs other than Git, incorrectly.  This is an old breakage in
+   v1.7.11 and will need to be merged down to the maintenance tracks.
+
+ * Older cURL wanted piece of memory we call it with to be stable, but
+   we updated the auth material after handing it to a call.
+
+ * "git pull" into nothing trashed "local changes" that were in the
+   index, and this avoids it.
+
+ * Many "git submodule" operations do not work on a submodule at a
+   path whose name is not in ASCII.
+
+ * "cherry-pick" had a small leak in an error codepath.
+
+ * Logic used by git-send-email to suppress cc mishandled names like
+   "A U. Thor" <author@example.xz>, where the human readable part
+   needs to be quoted (the user input may not have the double quotes
+   around the name, and comparison was done between quoted and
+   unquoted strings).  It also mishandled names that need RFC2047
+   quoting.
+
+ * Call to discard_cache/discard_index (used when we use different
+   contents of the index in-core, in many operations like commit,
+   apply, and merge) used to leak memory that held the array of index
+   entries, which has been plugged.
+   (merge a0fc4db rs/discard-index-discard-array later to maint).
+
+ * "gitweb" forgot to clear a global variable $search_regexp upon each
+   request, mistakenly carrying over the previous search to a new one
+   when used as a persistent CGI.
+
+ * The wildmatch engine did not honor WM_CASEFOLD option correctly.
+
+ * "git log -c --follow $path" segfaulted upon hitting the commit that
+   renamed the $path being followed.
+
+ * When a reflog notation is used for implicit "current branch", we
+   did not say which branch and worse said "branch ''".
+
+ * "difftool --dir-diff" did not copy back changes made by the
+   end-user in the diff tool backend to the working tree in some
+   cases.
+
+ * "git push $there HEAD:branch" did not resolve HEAD early enough, so
+   it was easy to flip it around while push is still going on and push
+   out a branch that the user did not originally intended when the
+   command was started.
+
+ * The bash prompt code (in contrib/) displayed the name of the branch
+   being rebased when "rebase -i/-m/-p" modes are in use, but not the
+   plain vanilla "rebase".
+
+ * Handling of negative exclude pattern for directories "!dir" was
+   broken in the update to v1.8.3.
+
+ * zsh prompt script that borrowed from bash prompt script did not
+   work due to slight differences in array variable notation between
+   these two shells.
+
+ * An entry for "file://" scheme in the enumeration of URL types Git
+   can take in the HTML documentation was made into a clickable link
+   by mistake.
+
+ * "git push --[no-]verify" was not documented.
+
+ * Stop installing the git-remote-testpy script that is only used for
+   testing.
+
+ * "git commit --allow-empty-message -m ''" should not start an
+   editor.
+
+ * "git merge @{-1}~22" was rewritten to "git merge frotz@{1}~22"
+   incorrectly when your previous branch was "frotz" (it should be
+   rewritten to "git merge frotz~22" instead).
+
+ * "git diff -c -p" was not showing a deleted line from a hunk when
+   another hunk immediately begins where the earlier one ends.
+
+ * "git log --ancestry-path A...B" did not work as expected, as it did
+   not pay attention to the fact that the merge base between A and B
+   was the bottom of the range being specified.
+
+ * Mac OS X does not like to write(2) more than INT_MAX number of
+   bytes; work it around by chopping write(2) into smaller pieces.
+
+ * Newer MacOS X encourages the programs to compile and link with
+   their CommonCrypto, not with OpenSSL.
+
+ * "git clone foo/bar:baz" cannot be a request to clone from a remote
+   over git-over-ssh specified in the scp style.  This case is now
+   detected and clones from a local repository at "foo/bar:baz".
+
+ * When $HOME is misconfigured to point at an unreadable directory, we
+   used to complain and die. Loosen the check.
+
+ * "git subtree" (in contrib/) had one codepath with loose error
+   checks to lose data at the remote side.
+
+ * "git fetch" into a shallow repository from a repository that does
+   not know about the shallow boundary commits (e.g. a different fork
+   from the repository the current shallow repository was cloned from)
+   did not work correctly.
+
+ * "git checkout foo" DWIMs the intended "upstream" and turns it into
+   "git checkout -t -b foo remotes/origin/foo". This codepath has been
+   updated to correctly take existing remote definitions into account.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.1.txt b/third_party/git/Documentation/RelNotes/1.8.5.1.txt
new file mode 100644
index 0000000000..7236aaf232
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.1.txt
@@ -0,0 +1,9 @@
+Git v1.8.5.1 Release Notes
+==========================
+
+Fixes since v1.8.5
+------------------
+
+ * "git submodule init" copied "submodule.$name.update" settings from
+   .gitmodules to .git/config without making sure if the suggested
+   value was sensible.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.2.txt b/third_party/git/Documentation/RelNotes/1.8.5.2.txt
new file mode 100644
index 0000000000..3ac4984f10
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.2.txt
@@ -0,0 +1,20 @@
+Git v1.8.5.2 Release Notes
+==========================
+
+Fixes since v1.8.5.1
+--------------------
+
+ * "git diff -- ':(icase)makefile'" was unnecessarily rejected at the
+   command line parser.
+
+ * "git cat-file --batch-check=ok" did not check the existence of
+   the named object.
+
+ * "git am --abort" sometimes complained about not being able to write
+   a tree with an 0{40} object in it.
+
+ * Two processes creating loose objects at the same time could have
+   failed unnecessarily when the name of their new objects started
+   with the same byte value, due to a race condition.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.3.txt b/third_party/git/Documentation/RelNotes/1.8.5.3.txt
new file mode 100644
index 0000000000..3de2dd0f19
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.3.txt
@@ -0,0 +1,27 @@
+Git v1.8.5.3 Release Notes
+==========================
+
+Fixes since v1.8.5.2
+--------------------
+
+ * The "--[no-]informative-errors" options to "git daemon" were parsed
+   a bit too loosely, allowing any other string after these option
+   names.
+
+ * A "gc" process running as a different user should be able to stop a
+   new "gc" process from starting.
+
+ * An earlier "clean-up" introduced an unnecessary memory leak to the
+   credential subsystem.
+
+ * "git mv A B/", when B does not exist as a directory, should error
+   out, but it didn't.
+
+ * "git rev-parse <revs> -- <paths>" did not implement the usual
+   disambiguation rules the commands in the "git log" family used in
+   the same way.
+
+ * "git cat-file --batch=", an admittedly useless command, did not
+   behave very well.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.4.txt b/third_party/git/Documentation/RelNotes/1.8.5.4.txt
new file mode 100644
index 0000000000..d18c40389e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.4.txt
@@ -0,0 +1,48 @@
+Git v1.8.5.4 Release Notes
+==========================
+
+Fixes since v1.8.5.3
+--------------------
+
+ * "git fetch --depth=0" was a no-op, and was silently ignored.
+   Diagnose it as an error.
+
+ * Remote repository URL expressed in scp-style host:path notation are
+   parsed more carefully (e.g. "foo/bar:baz" is local, "[::1]:/~user" asks
+   to connect to user's home directory on host at address ::1.
+
+ * SSL-related options were not passed correctly to underlying socket
+   layer in "git send-email".
+
+ * "git commit -v" appends the patch to the log message before
+   editing, and then removes the patch when the editor returned
+   control. However, the patch was not stripped correctly when the
+   first modified path was a submodule.
+
+ * "git mv A B/", when B does not exist as a directory, should error
+   out, but it didn't.
+
+ * When we figure out how many file descriptors to allocate for
+   keeping packfiles open, a system with non-working getrlimit() could
+   cause us to die(), but because we make this call only to get a
+   rough estimate of how many is available and we do not even attempt
+   to use up all file descriptors available ourselves, it is nicer to
+   fall back to a reasonable low value rather than dying.
+
+ * "git log --decorate" did not handle a tag pointed by another tag
+   nicely.
+
+ * "git add -A" (no other arguments) in a totally empty working tree
+   used to emit an error.
+
+ * There is no reason to have a hardcoded upper limit of the number of
+   parents for an octopus merge, created via the graft mechanism, but
+   there was.
+
+ * The implementation of 'git stash $cmd "stash@{...}"' did not quote
+   the stash argument properly and left it split at IFS whitespace.
+
+ * The documentation to "git pull" hinted there is an "-m" option
+   because it incorrectly shared the documentation with "git merge".
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.5.txt b/third_party/git/Documentation/RelNotes/1.8.5.5.txt
new file mode 100644
index 0000000000..9191ce948f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.5.txt
@@ -0,0 +1,37 @@
+Git v1.8.5.5 Release Notes
+==========================
+
+Fixes since v1.8.5.4
+--------------------
+
+ * The pathspec matching code, while comparing two trees (e.g. "git
+   diff A B -- path1 path2") was too aggressive and failed to match
+   some paths when multiple pathspecs were involved.
+
+ * "git repack --max-pack-size=8g" stopped being parsed correctly when
+   the command was reimplemented in C.
+
+ * A recent update to "git send-email" broke platforms where
+   /etc/ssl/certs/ directory exists but cannot be used as SSL_ca_path
+   (e.g. Fedora rawhide).
+
+ * A handful of bugs around interpreting $branch@{upstream} notation
+   and its lookalike, when $branch part has interesting characters,
+   e.g. "@", and ":", have been fixed.
+
+ * "git clone" would fail to clone from a repository that has a ref
+   directly under "refs/", e.g. "refs/stash", because different
+   validation paths do different things on such a refname.  Loosen the
+   client side's validation to allow such a ref.
+
+ * "git log --left-right A...B" lost the "leftness" of commits
+   reachable from A when A is a tag as a side effect of a recent
+   bugfix.  This is a regression in 1.8.4.x series.
+
+ * "git merge-base --octopus" used to leave cleaning up suboptimal
+   result to the caller, but now it does the clean-up itself.
+
+ * "git mv A B/", when B does not exist as a directory, should error
+   out, but it didn't.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.6.txt b/third_party/git/Documentation/RelNotes/1.8.5.6.txt
new file mode 100644
index 0000000000..92ff92b1e6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.6.txt
@@ -0,0 +1,34 @@
+Git v1.8.5.6 Release Notes
+==========================
+
+Fixes since v1.8.5.5
+--------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/1.8.5.txt b/third_party/git/Documentation/RelNotes/1.8.5.txt
new file mode 100644
index 0000000000..602df0cac2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.8.5.txt
@@ -0,0 +1,456 @@
+Git v1.8.5 Release Notes
+========================
+
+Backward compatibility notes (for Git 2.0)
+------------------------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default will change to the "simple"
+semantics, which pushes:
+
+ - only the current branch to the branch with the same name, and only
+   when the current branch is set to integrate with that remote
+   branch, if you are pushing to the same remote as you fetch from; or
+
+ - only the current branch to the branch with the same name, if you
+   are pushing to a remote that is not where you usually fetch from.
+
+Use the user preference configuration variable "push.default" to
+change this.  If you are an old-timer who is used to the "matching"
+semantics, you can set the variable to "matching" to keep the
+traditional behaviour.  If you want to live in the future early, you
+can set it to "simple" today without waiting for Git 2.0.
+
+When "git add -u" (and "git add -A") is run inside a subdirectory and
+does not specify which paths to add on the command line, it
+will operate on the entire tree in Git 2.0 for consistency
+with "git commit -a" and other commands.  There will be no
+mechanism to make plain "git add -u" behave like "git add -u .".
+Current users of "git add -u" (without a pathspec) should start
+training their fingers to explicitly say "git add -u ."
+before Git 2.0 comes.  A warning is issued when these commands are
+run without a pathspec and when you have local changes outside the
+current directory, because the behaviour in Git 2.0 will be different
+from today's version in such a situation.
+
+In Git 2.0, "git add <path>" will behave as "git add -A <path>", so
+that "git add dir/" will notice paths you removed from the directory
+and record the removal.  Versions before Git 2.0, including this
+release, will keep ignoring removals, but the users who rely on this
+behaviour are encouraged to start using "git add --ignore-removal <path>"
+now before 2.0 is released.
+
+The default prefix for "git svn" will change in Git 2.0.  For a long
+time, "git svn" created its remote-tracking branches directly under
+refs/remotes, but it will place them under refs/remotes/origin/ unless
+it is told otherwise with its --prefix option.
+
+
+Updates since v1.8.4
+--------------------
+
+Foreign interfaces, subsystems and ports.
+
+ * "git-svn" has been taught to use the serf library, which is the
+   only option SVN 1.8.0 offers us when talking the HTTP protocol.
+
+ * "git-svn" talking over an https:// connection using the serf library
+   dumped core due to a bug in the serf library that SVN uses.  Work
+   around it on our side, even though the SVN side is being fixed.
+
+ * On MacOS X, we detected if the filesystem needs the "pre-composed
+   unicode strings" workaround, but did not automatically enable it.
+   Now we do.
+
+ * remote-hg remote helper misbehaved when interacting with a local Hg
+   repository relative to the home directory, e.g. "clone hg::~/there".
+
+ * imap-send ported to OS X uses Apple's security framework instead of
+   OpenSSL's.
+
+ * "git fast-import" treats an empty path given to "ls" as the root of
+   the tree.
+
+
+UI, Workflows & Features
+
+ * xdg-open can be used as a browser backend for "git web-browse"
+   (hence to show "git help -w" output), when available.
+
+ * "git grep" and "git show" pay attention to the "--textconv" option
+   when these commands are told to operate on blob objects (e.g. "git
+   grep -e pattern --textconv HEAD:Makefile").
+
+ * "git replace" helper no longer allows an object to be replaced with
+   another object of a different type to avoid confusion (you can
+   still manually craft such a replacement using "git update-ref", as an
+   escape hatch).
+
+ * "git status" no longer prints the dirty status information of
+   submodules for which submodule.$name.ignore is set to "all".
+
+ * "git rebase -i" honours core.abbrev when preparing the insn sheet
+   for editing.
+
+ * "git status" during a cherry-pick shows which original commit is
+   being picked.
+
+ * Instead of typing four capital letters "HEAD", you can say "@" now,
+   e.g. "git log @".
+
+ * "git check-ignore" follows the same rule as "git add" and "git
+   status" in that the ignore/exclude mechanism does not take effect
+   on paths that are already tracked.  With the "--no-index" option, it
+   can be used to diagnose which paths that should have been ignored
+   have been mistakenly added to the index.
+
+ * Some irrelevant "advice" messages that are shared with "git status"
+   output have been removed from the commit log template.
+
+ * "update-refs" learned a "--stdin" option to read multiple update
+   requests and perform them in an all-or-none fashion.
+
+ * Just like "make -C <directory>", "git -C <directory> ..." tells Git
+   to go there before doing anything else.
+
+ * Just like "git checkout -" knows to check out, and "git merge -"
+   knows to merge, the branch you were previously on, "git cherry-pick"
+   now understands "git cherry-pick -" to pick from the previous
+   branch.
+
+ * "git status" now omits the prefix to make its output a comment in a
+   commit log editor, which is not necessary for human consumption.
+   Scripts that parse the output of "git status" are advised to use
+   "git status --porcelain" instead, as its format is stable and easier
+   to parse.
+
+ * The ref syntax "foo^{tag}" (with the literal string "{tag}") peels a
+   tag ref to itself, i.e. it's a no-op., and fails if
+   "foo" is not a tag.  "git rev-parse --verify v1.0^{tag}" is
+   a more convenient way than "test $(git cat-file -t v1.0) = tag" to
+   check if v1.0 is a tag.
+
+ * "git branch -v -v" (and "git status") did not distinguish among a
+   branch that is not based on any other branch, a branch that is in
+   sync with its upstream branch, and a branch that is configured with an
+   upstream branch that no longer exists.
+
+ * Earlier we started rejecting any attempt to add the 0{40} object name to
+   the index and to tree objects, but it sometimes is necessary to
+   allow this to be able to use tools like filter-branch to correct such
+   broken tree objects.  "filter-branch" can again be used to do this.
+
+ * "git config" did not provide a way to set or access numbers larger
+   than a native "int" on the platform; it now provides 64-bit signed
+   integers on all platforms.
+
+ * "git pull --rebase" always chose to do the bog-standard flattening
+   rebase.  You can tell it to run "rebase --preserve-merges" with
+   "git pull --rebase=preserve" or by
+   setting "pull.rebase" configuration to "preserve".
+
+ * "git push --no-thin" actually disables the "thin pack transfer"
+   optimization.
+
+ * Magic pathspecs like ":(icase)makefile" (matches both Makefile
+   and makefile) and ":(glob)foo/**/bar" (matches "bar" in "foo"
+   and any subdirectory of "foo") can be used in more places.
+
+ * The "http.*" variables can now be specified for individual URLs.
+   For example,
+
+   [http]
+       sslVerify = true
+   [http "https://weak.example.com/"]
+       sslVerify = false
+
+   would flip http.sslVerify off only when talking to that specific
+   site.
+
+ * "git mv A B" when moving a submodule has been taught to
+   relocate the submodule's working tree and to adjust the paths in the
+   .gitmodules file.
+
+ * "git blame" can now take more than one -L option to discover the
+   origin of multiple blocks of lines.
+
+ * The http transport clients can optionally ask to save cookies
+   with the http.savecookies configuration variable.
+
+ * "git push" learned a more fine grained control over a blunt
+   "--force" when requesting a non-fast-forward update with the
+   "--force-with-lease=<refname>:<expected object name>" option.
+
+ * "git diff --diff-filter=<classes of changes>" can now take
+   lowercase letters (e.g. "--diff-filter=d") to mean "show
+   everything but these classes".  "git diff-files -q" is now a
+   deprecated synonym for "git diff-files --diff-filter=d".
+
+ * "git fetch" (hence "git pull" as well) learned to check
+   "fetch.prune" and "remote.*.prune" configuration variables and
+   to behave as if the "--prune" command line option was given.
+
+ * "git check-ignore -z" applied the NUL termination to both its input
+   (with --stdin) and its output, but "git check-attr -z" ignored the
+   option on the output side. Make both honor -z on the input and
+   output side the same way.
+
+ * "git whatchanged" may still be used by old timers, but mention of
+   it in documents meant for new users will only waste readers' time
+   wondering what the difference is between it and "git log".  Make it
+   less prominent in the general part of the documentation and explain
+   that it is merely a "git log" with different default behaviour in
+   its own document.
+
+
+Performance, Internal Implementation, etc.
+
+ * "git for-each-ref" when asking for merely the object name does not
+   have to parse the object pointed at by the refs; the codepath has
+   been optimized.
+
+ * The HTTP transport will try to use TCP keepalive when able.
+
+ * "git repack" is now written in C.
+
+ * Build procedure for MSVC has been updated.
+
+ * If a build-time fallback is set to "cat" instead of "less", we
+   should apply the same "no subprocess or pipe" optimization as we
+   apply to user-supplied GIT_PAGER=cat.
+
+ * Many commands use a --dashed-option as an operation mode selector
+   (e.g. "git tag --delete") that excludes other operation modes
+   (e.g. "git tag --delete --verify" is nonsense) and that cannot be
+   negated (e.g. "git tag --no-delete" is nonsense).  The parse-options
+   API learned a new OPT_CMDMODE macro to make it easier to implement
+   such a set of options.
+
+ * OPT_BOOLEAN() in the parse-options API was misdesigned to be "counting
+   up" but many subcommands expect it to behave as "on/off". Update
+   them to use OPT_BOOL() which is a proper boolean.
+
+ * "git gc" exits early without doing any work when it detects
+   that another instance of itself is already running.
+
+ * Under memory pressure and/or file descriptor pressure, we used to
+   close pack windows that are not used and also closed filehandles to
+   open but unused packfiles. These are now controlled separately
+   to better cope with the load.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v1.8.4
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.4 in the maintenance
+track are contained in this release (see the maintenance releases' notes for
+details).
+
+ * An ancient How-To on serving Git repositories on an HTTP server
+   lacked a warning that it has been mostly superseded with a more
+   modern way.
+   (merge 6d52bc3 sc/doc-howto-dumb-http later to maint).
+
+ * The interaction between the use of Perl in our test suite and NO_PERL
+   has been clarified a bit.
+   (merge f8fc0ee jn/test-prereq-perl-doc later to maint).
+
+ * The synopsis section of the "git unpack-objects" documentation has been
+   clarified a bit.
+   (merge 61e2e22 vd/doc-unpack-objects later to maint).
+
+ * We did not generate the HTML version of the documentation to "git subtree"
+   in contrib/.
+   (merge 95c62fb jk/subtree-install-fix later to maint).
+
+ * A fast-import stream expresses a pathname with funny characters by
+   quoting them in C style; the remote-hg remote helper forgot to unquote
+   such a path.
+   (merge 1136265 ap/remote-hg-unquote-cquote later to maint).
+
+ * "git reset -p HEAD" has a codepath to special-case it to behave
+   differently from resetting to contents of other commits, but a
+   recent change broke it.
+
+ * Coloring around octopus merges in "log --graph" output was screwy.
+   (merge 339c17b hn/log-graph-color-octopus later to maint).
+
+ * "git checkout topic", when there is not yet a local "topic" branch
+   but there is a unique remote-tracking branch for a remote "topic"
+   branch, pretended as if "git checkout -t -b topic remote/$r/topic"
+   (for that unique remote $r) was run. This hack however was not
+   implemented for "git checkout topic --".
+   (merge bca3969 mm/checkout-auto-track-fix later to maint).
+
+ * One long-standing flaw in the pack transfer protocol used by "git
+   clone" was that there was no way to tell the other end which branch
+   "HEAD" points at, and the receiving end needed to guess.  A new
+   capability has been defined in the pack protocol to convey this
+   information so that cloning from a repository with more than one
+   branch pointing at the same commit where the HEAD is at now
+   reliably sets the initial branch in the resulting repository.
+   (merge 360a326 jc/upload-pack-send-symref later to maint).
+
+ * We did not handle cases where the http transport gets redirected during
+   the authorization request (e.g. from http:// to https://).
+   (merge 70900ed jk/http-auth-redirects later to maint).
+
+ * Bash prompting code to deal with an SVN remote as an upstream
+   was coded in a way unsupported by older Bash versions (3.x).
+   (merge 52ec889 sg/prompt-svn-remote-fix later to maint).
+
+ * The fall-back parsing of commit objects with broken author or
+   committer lines was less robust than ideal in picking up the
+   timestamps.
+   (merge 03818a4 jk/split-broken-ident later to maint).
+
+ * "git rev-list --objects ^v1.0^ v1.0" gave the v1.0 tag itself in the
+   output, but "git rev-list --objects v1.0^..v1.0" did not.
+   (merge 895c5ba jc/revision-range-unpeel later to maint).
+
+ * "git clone" wrote some progress messages to standard output, not
+   to standard error, and did not suppress them with the
+   --no-progress option.
+   (merge 643f918 jk/clone-progress-to-stderr later to maint).
+
+ * "format-patch --from=<whom>" forgot to omit an unnecessary in-body
+   from line, i.e. when <whom> is the same as the real author.
+   (merge 662cc30 jk/format-patch-from later to maint).
+
+ * "git shortlog" used to choke and die when there is a malformed
+   commit (e.g. missing authors); it now simply ignores such a commit
+   and keeps going.
+   (merge cd4f09e jk/shortlog-tolerate-broken-commit later to maint).
+
+ * "git merge-recursive" did not parse its "--diff-algorithm=" command
+   line option correctly.
+   (merge 6562928 jk/diff-algo later to maint).
+
+ * When running "fetch -q", a long silence while the sender side
+   computes the set of objects to send can be mistaken by proxies as
+   dropped connection.  The server side has been taught to send a
+   small empty messages to keep the connection alive.
+   (merge 115dedd jk/upload-pack-keepalive later to maint).
+
+ * "git rebase" had a portability regression in v1.8.4 that triggered a
+   bug in some BSD shell implementations.
+   (merge 99855dd mm/rebase-continue-freebsd-WB later to maint).
+
+ * "git branch --track" had a minor regression in v1.8.3.2 and later
+   that made it impossible to base your local work on anything but a
+   local branch of the upstream repository you are tracking.
+   (merge b0f49ff jh/checkout-auto-tracking later to maint).
+
+ * When the web server responds with "405 Method Not Allowed", "git
+   http-backend" should tell the client what methods are allowed with
+   the "Allow" header.
+   (merge 9247be0 bc/http-backend-allow-405 later to maint).
+
+ * When there is no sufficient overlap between old and new history
+   during a "git fetch" into a shallow repository, objects that the
+   sending side knows the receiving end has were unnecessarily sent.
+   (merge f21d2a7 nd/fetch-into-shallow later to maint).
+
+ * "git cvsserver" computed the permission mode bits incorrectly for
+   executable files.
+   (merge 1b48d56 jc/cvsserver-perm-bit-fix later to maint).
+
+ * When send-email obtains an error message to die with upon
+   failure to start an SSL session, it tried to read the error string
+   from a wrong place.
+   (merge 6cb0c88 bc/send-email-ssl-die-message-fix later to maint).
+
+ * The implementation of "add -i" has some crippling code to work around an
+   ActiveState Perl limitation but it by mistake also triggered on Git
+   for Windows where MSYS perl is used.
+   (merge df17e77 js/add-i-mingw later to maint).
+
+ * We made sure that we notice when the user-supplied GIT_DIR is actually a
+   gitfile, but did not do the same when the default ".git" is a
+   gitfile.
+   (merge 487a2b7 nd/git-dir-pointing-at-gitfile later to maint).
+
+ * When an object is not found after checking the packfiles and the
+   loose object directory, read_sha1_file() re-checks the packfiles to
+   prevent racing with a concurrent repacker; teach the same logic to
+   has_sha1_file().
+   (merge 45e8a74 jk/has-sha1-file-retry-packed later to maint).
+
+ * "git commit --author=$name", when $name is not in the canonical
+   "A. U. Thor <au.thor@example.xz>" format, looks for a matching name
+   from existing history, but did not consult mailmap to grab the
+   preferred author name.
+   (merge ea16794 ap/commit-author-mailmap later to maint).
+
+ * "git ls-files -k" needs to crawl only the part of the working tree
+   that may overlap the paths in the index to find killed files, but
+   shared code with the logic to find all the untracked files, which
+   made it unnecessarily inefficient.
+   (merge 680be04 jc/ls-files-killed-optim later to maint).
+
+ * The shortened commit object names in the insn sheet that is prepared at the
+   beginning of a "rebase -i" session can become ambiguous as the
+   rebasing progresses and the repository gains more commits. Make
+   sure the internal record is kept with full 40-hex object names.
+   (merge 75c6976 es/rebase-i-no-abbrev later to maint).
+
+ * "git rebase --preserve-merges" internally used the merge machinery
+   and as a side effect left the merge summary message in the log, but
+   when rebasing there is no need for the merge summary.
+   (merge a9f739c rt/rebase-p-no-merge-summary later to maint).
+
+ * A call to xread() was used without a loop around it to cope with short
+   reads in the codepath to stream new contents to a pack.
+   (merge e92527c js/xread-in-full later to maint).
+
+ * "git rebase -i" forgot that the comment character is
+   configurable while reading its insn sheet.
+   (merge 7bca7af es/rebase-i-respect-core-commentchar later to maint).
+
+ * The mailmap support code read past the allocated buffer when the
+   mailmap file ended with an incomplete line.
+   (merge f972a16 jk/mailmap-incomplete-line later to maint).
+
+ * We used to send a large request to read(2)/write(2) as a single
+   system call, which was bad from the latency point of view when
+   the operation needs to be killed, and also triggered an error on
+   broken 64-bit systems that refuse to read or write more than 2GB
+   in one go.
+   (merge a487916 sp/clip-read-write-to-8mb later to maint).
+
+ * "git fetch" that auto-followed tags incorrectly reused the
+   connection with Git-aware transport helper (like the sample "ext::"
+   helper shipped with Git).
+   (merge 0f73f8b jc/transport-do-not-use-connect-twice-in-fetch later to maint).
+
+ * "git log --full-diff -- <pathspec>" showed a huge diff for paths
+   outside the given <pathspec> for each commit, instead of showing
+   the change relative to the parent of the commit.  "git reflog -p"
+   had a similar problem.
+   (merge 838f9a1 tr/log-full-diff-keep-true-parents later to maint).
+
+ * Setting a submodule.*.path configuration variable to true (without
+   giving "= value") caused Git to segfault.
+   (merge 4b05440 jl/some-submodule-config-are-not-boolean later to maint).
+
+ * "git rebase -i" (there could be others, as the root cause is pretty
+   generic) fed a random, data dependent string to 'echo' and
+   expected it to come out literally, corrupting its error message.
+   (merge 89b0230 mm/no-shell-escape-in-die-message later to maint).
+
+ * Some people still use rather old versions of bash, which cannot
+   grok some constructs like 'printf -v varname' which the prompt and
+   completion code started to use recently.
+   (merge a44aa69 bc/completion-for-bash-3.0 later to maint).
+
+ * Code to read configuration from a blob object did not compile on
+   platforms with fgetc() etc. implemented as macros.
+   (merge 49d6cfa hv/config-from-blob later to maint-1.8.3).
+
+ * The recent "short-cut clone connectivity check" topic broke a
+   shallow repository when a fetch operation tries to auto-follow tags.
+   (merge 6da8bdc nd/fetch-pack-shallow-fix later to maint-1.8.3).
diff --git a/third_party/git/Documentation/RelNotes/1.9.0.txt b/third_party/git/Documentation/RelNotes/1.9.0.txt
new file mode 100644
index 0000000000..4e4b88aa5c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.0.txt
@@ -0,0 +1,345 @@
+Git v1.9.0 Release Notes
+========================
+
+Backward compatibility notes
+----------------------------
+
+"git submodule foreach $cmd $args" used to treat "$cmd $args" the same
+way "ssh" did, concatenating them into a single string and letting the
+shell unquote. Careless users who forget to sufficiently quote $args
+get their argument split at $IFS whitespaces by the shell, and got
+unexpected results due to this. Starting from this release, the
+command line is passed directly to the shell, if it has an argument.
+
+Read-only support for experimental loose-object format, in which users
+could optionally choose to write their loose objects for a short
+while between v1.4.3 and v1.5.3 era, has been dropped.
+
+The meanings of the "--tags" option to "git fetch" has changed; the
+command fetches tags _in addition to_ what is fetched by the same
+command line without the option.
+
+The way "git push $there $what" interprets the $what part given on the
+command line, when it does not have a colon that explicitly tells us
+what ref at the $there repository is to be updated, has been enhanced.
+
+A handful of ancient commands that have long been deprecated are
+finally gone (repo-config, tar-tree, lost-found, and peek-remote).
+
+
+Backward compatibility notes (for Git 2.0.0)
+--------------------------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default will change to the "simple"
+semantics, which pushes:
+
+ - only the current branch to the branch with the same name, and only
+   when the current branch is set to integrate with that remote
+   branch, if you are pushing to the same remote as you fetch from; or
+
+ - only the current branch to the branch with the same name, if you
+   are pushing to a remote that is not where you usually fetch from.
+
+Use the user preference configuration variable "push.default" to
+change this.  If you are an old-timer who is used to the "matching"
+semantics, you can set the variable to "matching" to keep the
+traditional behaviour.  If you want to live in the future early, you
+can set it to "simple" today without waiting for Git 2.0.
+
+When "git add -u" (and "git add -A") is run inside a subdirectory and
+does not specify which paths to add on the command line, it
+will operate on the entire tree in Git 2.0 for consistency
+with "git commit -a" and other commands.  There will be no
+mechanism to make plain "git add -u" behave like "git add -u .".
+Current users of "git add -u" (without a pathspec) should start
+training their fingers to explicitly say "git add -u ."
+before Git 2.0 comes.  A warning is issued when these commands are
+run without a pathspec and when you have local changes outside the
+current directory, because the behaviour in Git 2.0 will be different
+from today's version in such a situation.
+
+In Git 2.0, "git add <path>" will behave as "git add -A <path>", so
+that "git add dir/" will notice paths you removed from the directory
+and record the removal.  Versions before Git 2.0, including this
+release, will keep ignoring removals, but the users who rely on this
+behaviour are encouraged to start using "git add --ignore-removal <path>"
+now before 2.0 is released.
+
+The default prefix for "git svn" will change in Git 2.0.  For a long
+time, "git svn" created its remote-tracking branches directly under
+refs/remotes, but it will place them under refs/remotes/origin/ unless
+it is told otherwise with its --prefix option.
+
+
+Updates since v1.8.5
+--------------------
+
+Foreign interfaces, subsystems and ports.
+
+ * The HTTP transport, when talking GSS-Negotiate, uses "100
+   Continue" response to avoid having to rewind and resend a large
+   payload, which may not be always doable.
+
+ * Various bugfixes to remote-bzr and remote-hg (in contrib/).
+
+ * The build procedure is aware of MirBSD now.
+
+ * Various "git p4", "git svn" and "gitk" updates.
+
+
+UI, Workflows & Features
+
+ * Fetching from a shallowly-cloned repository used to be forbidden,
+   primarily because the codepaths involved were not carefully vetted
+   and we did not bother supporting such usage. This release attempts
+   to allow object transfer out of a shallowly-cloned repository in a
+   more controlled way (i.e. the receiver becomes a shallow repository
+   with a truncated history).
+
+ * Just like we give a reasonable default for "less" via the LESS
+   environment variable, we now specify a reasonable default for "lv"
+   via the "LV" environment variable when spawning the pager.
+
+ * Two-level configuration variable names in "branch.*" and "remote.*"
+   hierarchies, whose variables are predominantly three-level, were
+   not completed by hitting a <TAB> in bash and zsh completions.
+
+ * Fetching a 'frotz' branch with "git fetch", while a 'frotz/nitfol'
+   remote-tracking branch from an earlier fetch was still there, would
+   error out, primarily because the command was not told that it is
+   allowed to lose any information on our side.  "git fetch --prune"
+   now can be used to remove 'frotz/nitfol' to make room for fetching and
+   storing the 'frotz' remote-tracking branch.
+
+ * "diff.orderfile=<file>" configuration variable can be used to
+   pretend as if the "-O<file>" option were given from the command
+   line of "git diff", etc.
+
+ * The negative pathspec syntax allows "git log -- . ':!dir'" to tell
+   us "I am interested in everything but 'dir' directory".
+
+ * "git difftool" shows how many different paths there are in total,
+   and how many of them have been shown so far, to indicate progress.
+
+ * "git push origin master" used to push our 'master' branch to update
+   the 'master' branch at the 'origin' repository.  This has been
+   enhanced to use the same ref mapping "git push origin" would use to
+   determine what ref at the 'origin' to be updated with our 'master'.
+   For example, with this configuration
+
+   [remote "origin"]
+      push = refs/heads/*:refs/review/*
+
+   that would cause "git push origin" to push out our local branches
+   to corresponding refs under refs/review/ hierarchy at 'origin',
+   "git push origin master" would update 'refs/review/master' over
+   there.  Alternatively, if push.default is set to 'upstream' and our
+   'master' is set to integrate with 'topic' from the 'origin' branch,
+   running "git push origin" while on our 'master' would update their
+   'topic' branch, and running "git push origin master" while on any
+   of our branches does the same.
+
+ * "gitweb" learned to treat ref hierarchies other than refs/heads as
+   if they are additional branch namespaces (e.g. refs/changes/ in
+   Gerrit).
+
+ * "git for-each-ref --format=..." learned a few formatting directives;
+   e.g. "%(color:red)%(HEAD)%(color:reset) %(refname:short) %(subject)".
+
+ * The command string given to "git submodule foreach" is passed
+   directly to the shell, without being eval'ed.  This is a backward
+   incompatible change that may break existing users.
+
+ * "git log" and friends learned the "--exclude=<glob>" option, to
+   allow people to say "list history of all branches except those that
+   match this pattern" with "git log --exclude='*/*' --branches".
+
+ * "git rev-parse --parseopt" learned a new "--stuck-long" option to
+   help scripts parse options with an optional parameter.
+
+ * The "--tags" option to "git fetch" no longer tells the command to
+   fetch _only_ the tags. It instead fetches tags _in addition to_
+   what are fetched by the same command line without the option.
+
+
+Performance, Internal Implementation, etc.
+
+ * When parsing a 40-hex string into the object name, the string is
+   checked to see if it can be interpreted as a ref so that a warning
+   can be given for ambiguity. The code kicked in even when the
+   core.warnambiguousrefs is set to false to squelch this warning, in
+   which case the cycles spent to look at the ref namespace were an
+   expensive no-op, as the result was discarded without being used.
+
+ * The naming convention of the packfiles has been updated; it used to
+   be based on the enumeration of names of the objects that are
+   contained in the pack, but now it also depends on how the packed
+   result is represented--packing the same set of objects using
+   different settings (or delta order) would produce a pack with
+   different name.
+
+ * "git diff --no-index" mode used to unnecessarily attempt to read
+   the index when there is one.
+
+ * The deprecated parse-options macro OPT_BOOLEAN has been removed;
+   use OPT_BOOL or OPT_COUNTUP in new code.
+
+ * A few duplicate implementations of prefix/suffix string comparison
+   functions have been unified to starts_with() and ends_with().
+
+ * The new PERLLIB_EXTRA makefile variable can be used to specify
+   additional directories Perl modules (e.g. the ones necessary to run
+   git-svn) are installed on the platform when building.
+
+ * "git merge-base" learned the "--fork-point" mode, that implements
+   the same logic used in "git pull --rebase" to find a suitable fork
+   point out of the reflog entries for the remote-tracking branch the
+   work has been based on.  "git rebase" has the same logic that can be
+   triggered with the "--fork-point" option.
+
+ * A third-party "receive-pack" (the responder to "git push") can
+   advertise the "no-thin" capability to tell "git push" not to use
+   the thin-pack optimization. Our receive-pack has always been
+   capable of accepting and fattening a thin-pack, and will continue
+   not to ask "git push" to use a non-thin pack.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v1.8.5
+------------------
+
+Unless otherwise noted, all the fixes since v1.8.5 in the maintenance
+track are contained in this release (see the maintenance releases' notes
+for details).
+
+ * The pathspec matching code, while comparing two trees (e.g. "git
+   diff A B -- path1 path2") was too aggressive and failed to match
+   some paths when multiple pathspecs were involved.
+
+ * "git repack --max-pack-size=8g" stopped being parsed correctly when
+   the command was reimplemented in C.
+
+ * An earlier update in v1.8.4.x to "git rev-list --objects" with
+   negative ref had a performance regression.
+   (merge 200abe7 jk/mark-edges-uninteresting later to maint).
+
+ * A recent update to "git send-email" broke platforms where
+   /etc/ssl/certs/ directory exists but cannot be used as SSL_ca_path
+   (e.g. Fedora rawhide).
+
+ * A handful of bugs around interpreting $branch@{upstream} notation
+   and its lookalike, when $branch part has interesting characters,
+   e.g. "@", and ":", have been fixed.
+
+ * "git clone" would fail to clone from a repository that has a ref
+   directly under "refs/", e.g. "refs/stash", because different
+   validation paths do different things on such a refname.  Loosen the
+   client side's validation to allow such a ref.
+
+ * "git log --left-right A...B" lost the "leftness" of commits
+   reachable from A when A is a tag as a side effect of a recent
+   bugfix.  This is a regression in 1.8.4.x series.
+
+ * documentations to "git pull" hinted there is an "-m" option because
+   it incorrectly shared the documentation with "git merge".
+
+ * "git diff A B submod" and "git diff A B submod/" ought to have done
+   the same for a submodule "submod", but didn't.
+
+ * "git clone $origin foo\bar\baz" on Windows failed to create the
+   leading directories (i.e. a moral-equivalent of "mkdir -p").
+
+ * "submodule.*.update=checkout", when propagated from .gitmodules to
+   .git/config, turned into a "submodule.*.update=none", which did not
+   make much sense.
+   (merge efa8fd7 fp/submodule-checkout-mode later to maint).
+
+ * The implementation of 'git stash $cmd "stash@{...}"' did not quote
+   the stash argument properly and left it split at IFS whitespace.
+
+ * The "--[no-]informative-errors" options to "git daemon" were parsed
+   a bit too loosely, allowing any other string after these option
+   names.
+
+ * There is no reason to have a hardcoded upper limit for the number of
+   parents of an octopus merge, created via the graft mechanism, but
+   there was.
+
+ * The basic test used to leave unnecessary trash directories in the
+   t/ directory.
+   (merge 738a8be jk/test-framework-updates later to maint).
+
+ * "git merge-base --octopus" used to leave cleaning up suboptimal
+   result to the caller, but now it does the clean-up itself.
+
+ * A "gc" process running as a different user should be able to stop a
+   new "gc" process from starting, but it didn't.
+
+ * An earlier "clean-up" introduced an unnecessary memory leak.
+
+ * "git add -A" (no other arguments) in a totally empty working tree
+   used to emit an error.
+
+ * "git log --decorate" did not handle a tag pointed by another tag
+   nicely.
+
+ * When we figure out how many file descriptors to allocate for
+   keeping packfiles open, a system with non-working getrlimit() could
+   cause us to die(), but because we make this call only to get a
+   rough estimate of how many are available and we do not even attempt
+   to use up all available file descriptors ourselves, it is nicer to
+   fall back to a reasonable low value rather than dying.
+
+ * read_sha1_file(), that is the workhorse to read the contents given
+   an object name, honoured object replacements, but there was no
+   corresponding mechanism to sha1_object_info() that was used to
+   obtain the metainfo (e.g. type & size) about the object.  This led
+   callers to weird inconsistencies.
+   (merge 663a856 cc/replace-object-info later to maint).
+
+ * "git cat-file --batch=", an admittedly useless command, did not
+   behave very well.
+
+ * "git rev-parse <revs> -- <paths>" did not implement the usual
+   disambiguation rules the commands in the "git log" family used in
+   the same way.
+
+ * "git mv A B/", when B does not exist as a directory, should error
+   out, but it didn't.
+
+ * A workaround to an old bug in glibc prior to glibc 2.17 has been
+   retired; this would remove a side effect of the workaround that
+   corrupts system error messages in non-C locales.
+
+ * SSL-related options were not passed correctly to underlying socket
+   layer in "git send-email".
+
+ * "git commit -v" appends the patch to the log message before
+   editing, and then removes the patch when the editor returned
+   control. However, the patch was not stripped correctly when the
+   first modified path was a submodule.
+
+ * "git fetch --depth=0" was a no-op, and was silently ignored.
+   Diagnose it as an error.
+
+ * Remote repository URLs expressed in scp-style host:path notation are
+   parsed more carefully (e.g. "foo/bar:baz" is local, "[::1]:/~user" asks
+   to connect to user's home directory on host at address ::1.
+
+ * "git diff -- ':(icase)makefile'" was unnecessarily rejected at the
+   command line parser.
+
+ * "git cat-file --batch-check=ok" did not check the existence of
+   the named object.
+
+ * "git am --abort" sometimes complained about not being able to write
+   a tree with an 0{40} object in it.
+
+ * Two processes creating loose objects at the same time could have
+   failed unnecessarily when the name of their new objects started
+   with the same byte value, due to a race condition.
diff --git a/third_party/git/Documentation/RelNotes/1.9.1.txt b/third_party/git/Documentation/RelNotes/1.9.1.txt
new file mode 100644
index 0000000000..5b0602053c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.1.txt
@@ -0,0 +1,59 @@
+Git v1.9.1 Release Notes
+========================
+
+Fixes since v1.9.0
+------------------
+
+ * "git clean -d pathspec" did not use the given pathspec correctly
+   and ended up cleaning too much.
+
+ * "git difftool" misbehaved when the repository is bound to the
+   working tree with the ".git file" mechanism, where a textual file
+   ".git" tells us where it is.
+
+ * "git push" did not pay attention to branch.*.pushremote if it is
+   defined earlier than remote.pushdefault; the order of these two
+   variables in the configuration file should not matter, but it did
+   by mistake.
+
+ * Codepaths that parse timestamps in commit objects have been
+   tightened.
+
+ * "git diff --external-diff" incorrectly fed the submodule directory
+   in the working tree to the external diff driver when it knew it is
+   the same as one of the versions being compared.
+
+ * "git reset" needs to refresh the index when working in a working
+   tree (it can also be used to match the index to the HEAD in an
+   otherwise bare repository), but it failed to set up the working
+   tree properly, causing GIT_WORK_TREE to be ignored.
+
+ * "git check-attr" when working on a repository with a working tree
+   did not work well when the working tree was specified via the
+   --work-tree (and obviously with --git-dir) option.
+
+ * "merge-recursive" was broken in 1.7.7 era and stopped working in
+   an empty (temporary) working tree, when there are renames
+   involved.  This has been corrected.
+
+ * "git rev-parse" was loose in rejecting command line arguments
+   that do not make sense, e.g. "--default" without the required
+   value for that option.
+
+ * include.path variable (or any variable that expects a path that
+   can use ~username expansion) in the configuration file is not a
+   boolean, but the code failed to check it.
+
+ * "git diff --quiet -- pathspec1 pathspec2" sometimes did not return
+   correct status value.
+
+ * Attempting to deepen a shallow repository by fetching over smart
+   HTTP transport failed in the protocol exchange, when no-done
+   extension was used.  The fetching side waited for the list of
+   shallow boundary commits after the sending end stopped talking to
+   it.
+
+ * Allow "git cmd path/", when the 'path' is where a submodule is
+   bound to the top-level working tree, to match 'path', despite the
+   extra and unnecessary trailing slash (such a slash is often
+   given by command line completion).
diff --git a/third_party/git/Documentation/RelNotes/1.9.2.txt b/third_party/git/Documentation/RelNotes/1.9.2.txt
new file mode 100644
index 0000000000..47a34ca964
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.2.txt
@@ -0,0 +1,67 @@
+Git v1.9.2 Release Notes
+========================
+
+Fixes since v1.9.1
+------------------
+
+ * Documentation and in-code comments had many instances of mistaken
+   use of "nor", which have been corrected.
+
+ * "git fetch --prune", when the right-hand-side of multiple fetch
+   refspecs overlap (e.g. storing "refs/heads/*" to
+   "refs/remotes/origin/*", while storing "refs/frotz/*" to
+   "refs/remotes/origin/fr/*"), aggressively thought that lack of
+   "refs/heads/fr/otz" on the origin site meant we should remove
+   "refs/remotes/origin/fr/otz" from us, without checking their
+   "refs/frotz/otz" first.
+
+   Note that such a configuration is inherently unsafe (think what
+   should happen when "refs/heads/fr/otz" does appear on the origin
+   site), but that is not a reason not to be extra careful.
+
+ * "git update-ref --stdin" did not fail a request to create a ref
+   when the ref already existed.
+
+ * "git diff --no-index -Mq a b" fell into an infinite loop.
+
+ * When it is not necessary to edit a commit log message (e.g. "git
+   commit -m" is given a message without specifying "-e"), we used to
+   disable the spawning of the editor by overriding GIT_EDITOR, but
+   this means all the uses of the editor, other than to edit the
+   commit log message, are also affected.
+
+ * "git status --porcelain --branch" showed its output with labels
+   "ahead/behind/gone" translated to the user's locale.
+
+ * "git mv" that moves a submodule forgot to adjust the array that
+   uses to keep track of which submodules were to be moved to update
+   its configuration.
+
+ * Length limit for the pathname used when removing a path in a deep
+   subdirectory has been removed to avoid buffer overflows.
+
+ * The test helper lib-terminal always run an actual test_expect_*
+   when included, which screwed up with the use of skil-all that may
+   have to be done later.
+
+ * "git index-pack" used a wrong variable to name the keep-file in an
+   error message when the file cannot be written or closed.
+
+ * "rebase -i" produced a broken insn sheet when the title of a commit
+   happened to contain '\n' (or ended with '\c') due to a careless use
+   of 'echo'.
+
+ * There were a few instances of 'git-foo' remaining in the
+   documentation that should have been spelled 'git foo'.
+
+ * Serving objects from a shallow repository needs to write a
+   new file to hold the temporary shallow boundaries but it was not
+   cleaned when we exit due to die() or a signal.
+
+ * When "git stash pop" stops after failing to apply the stash
+   (e.g. due to conflicting changes), the stash is not dropped. State
+   that explicitly in the output to let the users know.
+
+ * The labels in "git status" output that describe the nature of
+   conflicts (e.g. "both deleted") were limited to 20 bytes, which was
+   too short for some l10n (e.g. fr).
diff --git a/third_party/git/Documentation/RelNotes/1.9.3.txt b/third_party/git/Documentation/RelNotes/1.9.3.txt
new file mode 100644
index 0000000000..17b05ca7b5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.3.txt
@@ -0,0 +1,21 @@
+Git v1.9.3 Release Notes
+========================
+
+Fixes since v1.9.2
+------------------
+
+ * "git p4" dealing with changes in binary files were broken by a
+   change in 1.9 release.
+
+ * The shell prompt script (in contrib/), when using the PROMPT_COMMAND
+   interface, used an unsafe construct when showing the branch name in
+   $PS1.
+
+ * "git rebase" used a POSIX shell construct FreeBSD /bin/sh does not
+   work well with.
+
+ * Some more Unicode codepoints defined in Unicode 6.3 as having
+   zero width have been taught to our display column counting logic.
+
+ * Some tests used shell constructs that did not work well on
+   FreeBSD.
diff --git a/third_party/git/Documentation/RelNotes/1.9.4.txt b/third_party/git/Documentation/RelNotes/1.9.4.txt
new file mode 100644
index 0000000000..e1d1835436
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.4.txt
@@ -0,0 +1,16 @@
+Git v1.9.4 Release Notes
+========================
+
+Fixes since v1.9.3
+------------------
+
+ * Commands that take pathspecs on the command line misbehaved when
+   the pathspec is given as an absolute pathname (which is a
+   practice not particularly encouraged) that points at a symbolic
+   link in the working tree.
+
+ * An earlier fix to the shell prompt script (in contrib/) for using
+   the PROMPT_COMMAND interface did not correctly check if the extra
+   code path needs to trigger, causing the branch name not to appear
+   when 'promptvars' option is disabled in bash or PROMPT_SUBST is
+   unset in zsh.
diff --git a/third_party/git/Documentation/RelNotes/1.9.5.txt b/third_party/git/Documentation/RelNotes/1.9.5.txt
new file mode 100644
index 0000000000..8d6ac0cf53
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/1.9.5.txt
@@ -0,0 +1,34 @@
+Git v1.9.5 Release Notes
+========================
+
+Fixes since v1.9.4
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.0.0.txt b/third_party/git/Documentation/RelNotes/2.0.0.txt
new file mode 100644
index 0000000000..2617372a0c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.0.txt
@@ -0,0 +1,364 @@
+Git v2.0 Release Notes
+======================
+
+Backward compatibility notes
+----------------------------
+
+When "git push [$there]" does not say what to push, we have used the
+traditional "matching" semantics so far (all your branches were sent
+to the remote as long as there already are branches of the same name
+over there).  In Git 2.0, the default is now the "simple" semantics,
+which pushes:
+
+ - only the current branch to the branch with the same name, and only
+   when the current branch is set to integrate with that remote
+   branch, if you are pushing to the same remote as you fetch from; or
+
+ - only the current branch to the branch with the same name, if you
+   are pushing to a remote that is not where you usually fetch from.
+
+You can use the configuration variable "push.default" to change
+this.  If you are an old-timer who wants to keep using the
+"matching" semantics, you can set the variable to "matching", for
+example.  Read the documentation for other possibilities.
+
+When "git add -u" and "git add -A" are run inside a subdirectory
+without specifying which paths to add on the command line, they
+operate on the entire tree for consistency with "git commit -a" and
+other commands (these commands used to operate only on the current
+subdirectory).  Say "git add -u ." or "git add -A ." if you want to
+limit the operation to the current directory.
+
+"git add <path>" is the same as "git add -A <path>" now, so that
+"git add dir/" will notice paths you removed from the directory and
+record the removal.  In older versions of Git, "git add <path>" used
+to ignore removals.  You can say "git add --ignore-removal <path>" to
+add only added or modified paths in <path>, if you really want to.
+
+The "-q" option to "git diff-files", which does *NOT* mean "quiet",
+has been removed (it told Git to ignore deletion, which you can do
+with "git diff-files --diff-filter=d").
+
+"git request-pull" lost a few "heuristics" that often led to mistakes.
+
+The default prefix for "git svn" has changed in Git 2.0.  For a long
+time, "git svn" created its remote-tracking branches directly under
+refs/remotes, but it now places them under refs/remotes/origin/ unless
+it is told otherwise with its "--prefix" option.
+
+
+Updates since v1.9 series
+-------------------------
+
+UI, Workflows & Features
+
+ * The "multi-mail" post-receive hook (in contrib/) has been updated
+   to a more recent version from upstream.
+
+ * The "remote-hg/bzr" remote-helper interfaces (used to be in
+   contrib/) are no more.  They are now maintained separately as
+   third-party plug-ins in their own repositories.
+
+ * "git gc --aggressive" learned "--depth" option and
+   "gc.aggressiveDepth" configuration variable to allow use of a less
+   insane depth than the built-in default value of 250.
+
+ * "git log" learned the "--show-linear-break" option to show where a
+   single strand-of-pearls is broken in its output.
+
+ * The "rev-parse --parseopt" mechanism used by scripted Porcelains to
+   parse command-line options and to give help text learned to take
+   the argv-help (the placeholder string for an option parameter,
+   e.g. "key-id" in "--gpg-sign=<key-id>").
+
+ * The pattern to find where the function begins in C/C++ used in
+   "diff" and "grep -p" has been updated to improve viewing C++
+   sources.
+
+ * "git rebase" learned to interpret a lone "-" as "@{-1}", the
+   branch that we were previously on.
+
+ * "git commit --cleanup=<mode>" learned a new mode, scissors.
+
+ * "git tag --list" output can be sorted using "version sort" with
+   "--sort=version:refname".
+
+ * Discard the accumulated "heuristics" to guess from which branch the
+   result wants to be pulled from and make sure that what the end user
+   specified is not second-guessed by "git request-pull", to avoid
+   mistakes.  When you pushed out your 'master' branch to your public
+   repository as 'for-linus', use the new "master:for-linus" syntax to
+   denote the branch to be pulled.
+
+ * "git grep" learned to behave in a way similar to native grep when
+   "-h" (no header) and "-c" (count) options are given.
+
+ * "git push" via transport-helper interface has been updated to
+   allow forced ref updates in a way similar to the natively
+   supported transports.
+
+ * The "simple" mode is the default for "git push".
+
+ * "git add -u" and "git add -A", when run without any pathspec, is a
+   tree-wide operation even when run inside a subdirectory of a
+   working tree.
+
+ * "git add <path>" is the same as "git add -A <path>" now.
+
+ * "core.statinfo" configuration variable, which is a
+   never-advertised synonym to "core.checkstat", has been removed.
+
+ * The "-q" option to "git diff-files", which does *NOT* mean
+   "quiet", has been removed (it told Git to ignore deletion, which
+   you can do with "git diff-files --diff-filter=d").
+
+ * Server operators can loosen the "tips of refs only" restriction for
+   the remote archive service with the uploadarchive.allowUnreachable
+   configuration option.
+
+ * The progress indicators from various time-consuming commands have
+   been marked for i18n/l10n.
+
+ * "git notes -C <blob>" diagnoses as an error an attempt to use an
+   object that is not a blob.
+
+ * "git config" learned to read from the standard input when "-" is
+   given as the value to its "--file" parameter (attempting an
+   operation to update the configuration in the standard input is
+   rejected, of course).
+
+ * Trailing whitespaces in .gitignore files, unless they are quoted
+   for fnmatch(3), e.g. "path\ ", are warned and ignored.  Strictly
+   speaking, this is a backward-incompatible change, but very unlikely
+   to bite any sane user and adjusting should be obvious and easy.
+
+ * Many commands that create commits, e.g. "pull" and "rebase",
+   learned to take the "--gpg-sign" option on the command line.
+
+ * "git commit" can be told to always GPG sign the resulting commit
+   by setting the "commit.gpgsign" configuration variable to "true"
+   (the command-line option "--no-gpg-sign" should override it).
+
+ * "git pull" can be told to only accept fast-forward by setting the
+   new "pull.ff" configuration variable.
+
+ * "git reset" learned the "-N" option, which does not reset the index
+   fully for paths the index knows about but the tree-ish the command
+   resets to does not (these paths are kept as intend-to-add entries).
+
+
+Performance, Internal Implementation, etc.
+
+ * The compilation options to port to AIX and to MSVC have been
+   updated.
+
+ * We started using wildmatch() in place of fnmatch(3) a few releases
+   ago; complete the process and stop using fnmatch(3).
+
+ * Uses of curl's "multi" interface and "easy" interface do not mix
+   well when we attempt to reuse outgoing connections.  Teach the RPC
+   over HTTP code, used in the smart HTTP transport, not to use the
+   "easy" interface.
+
+ * The bitmap-index feature from JGit has been ported, which should
+   significantly improve performance when serving objects from a
+   repository that uses it.
+
+ * The way "git log --cc" shows a combined diff against multiple
+   parents has been optimized.
+
+ * The prefixcmp() and suffixcmp() functions are gone.  Use
+   starts_with() and ends_with(), and also consider if skip_prefix()
+   suits your needs better when using the former.
+
+
+Also contains various documentation updates and code clean-ups.  Many
+of them came from flurry of activities as GSoC candidate microproject
+exercises.
+
+
+Fixes since v1.9 series
+-----------------------
+
+Unless otherwise noted, all the fixes since v1.9 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git p4" was broken in 1.9 release to deal with changes in binary
+   files.
+   (merge 749b668 cl/p4-use-diff-tree later to maint).
+
+ * The shell prompt script (in contrib/), when using the PROMPT_COMMAND
+   interface, used an unsafe construct when showing the branch name in
+   $PS1.
+   (merge 1e4119c8 rh/prompt-pcmode-avoid-eval-on-refname later to maint).
+
+ * "git rebase" used a POSIX shell construct FreeBSD's /bin/sh does not
+   work well with.
+   (merge 8cd6596 km/avoid-non-function-return-in-rebase later to maint).
+
+ * zsh prompt (in contrib/) leaked unnecessary error messages.
+
+ * Bash completion (in contrib/) did not complete the refs and remotes
+   correctly given "git pu<TAB>" when "pu" is aliased to "push".
+
+ * Some more Unicode code points, defined in Unicode 6.3 as having zero
+   width, have been taught to our display column counting logic.
+   (merge d813ab9 tb/unicode-6.3-zero-width later to maint).
+
+ * Some tests used shell constructs that did not work well on FreeBSD
+   (merge ff7a1c6 km/avoid-bs-in-shell-glob later to maint).
+   (merge 00764ca km/avoid-cp-a later to maint).
+
+ * "git update-ref --stdin" did not fail a request to create a ref
+   when the ref already existed.
+   (merge b9d56b5 mh/update-ref-batch-create-fix later to maint).
+
+ * "git diff --no-index -Mq a b" fell into an infinite loop.
+   (merge ad1c3fb jc/fix-diff-no-index-diff-opt-parse later to maint).
+
+ * "git fetch --prune", when the right-hand side of multiple fetch
+   refspecs overlap (e.g. storing "refs/heads/*" to
+   "refs/remotes/origin/*", while storing "refs/frotz/*" to
+   "refs/remotes/origin/fr/*"), aggressively thought that lack of
+   "refs/heads/fr/otz" on the origin site meant we should remove
+   "refs/remotes/origin/fr/otz" from us, without checking their
+   "refs/frotz/otz" first.
+
+   Note that such a configuration is inherently unsafe (think what
+   should happen when "refs/heads/fr/otz" does appear on the origin
+   site), but that is not a reason not to be extra careful.
+   (merge e6f6371 cn/fetch-prune-overlapping-destination later to maint).
+
+ * "git status --porcelain --branch" showed its output with labels
+   "ahead/behind/gone" translated to the user's locale.
+   (merge 7a76c28 mm/status-porcelain-format-i18n-fix later to maint).
+
+ * A stray environment variable $prefix could have leaked into and
+   affected the behaviour of the "subtree" script (in contrib/).
+
+ * When it is not necessary to edit a commit log message (e.g. "git
+   commit -m" is given a message without specifying "-e"), we used to
+   disable the spawning of the editor by overriding GIT_EDITOR, but
+   this means all the uses of the editor, other than to edit the
+   commit log message, are also affected.
+   (merge b549be0 bp/commit-p-editor later to maint).
+
+ * "git mv" that moves a submodule forgot to adjust the array that
+   uses to keep track of which submodules were to be moved to update
+   its configuration.
+   (merge fb8a4e8 jk/mv-submodules-fix later to maint).
+
+ * Length limit for the pathname used when removing a path in a deep
+   subdirectory has been removed to avoid buffer overflows.
+   (merge 2f29e0c mh/remove-subtree-long-pathname-fix later to maint).
+
+ * The test helper lib-terminal always run an actual test_expect_*
+   when included, which screwed up with the use of skil-all that may
+   have to be done later.
+   (merge 7e27173 jk/lib-terminal-lazy later to maint).
+
+ * "git index-pack" used a wrong variable to name the keep-file in an
+   error message when the file cannot be written or closed.
+   (merge de983a0 nd/index-pack-error-message later to maint).
+
+ * "rebase -i" produced a broken insn sheet when the title of a commit
+   happened to contain '\n' (or ended with '\c') due to a careless use
+   of 'echo'.
+   (merge cb1aefd us/printf-not-echo later to maint).
+
+ * There were a few instances of 'git-foo' remaining in the
+   documentation that should have been spelled 'git foo'.
+   (merge 3c3e6f5 rr/doc-merge-strategies later to maint).
+
+ * Serving objects from a shallow repository needs to write a
+   new file to hold the temporary shallow boundaries, but it was not
+   cleaned when we exit due to die() or a signal.
+   (merge 7839632 jk/shallow-update-fix later to maint).
+
+ * When "git stash pop" stops after failing to apply the stash
+   (e.g. due to conflicting changes), the stash is not dropped. State
+   that explicitly in the output to let the users know.
+   (merge 2d4c993 jc/stash-pop-not-popped later to maint).
+
+ * The labels in "git status" output that describe the nature of
+   conflicts (e.g. "both deleted") were limited to 20 bytes, which was
+   too short for some l10n (e.g. fr).
+   (merge c7cb333 jn/wt-status later to maint).
+
+ * "git clean -d pathspec" did not use the given pathspec correctly
+   and ended up cleaning too much.
+   (merge 1f2e108 jk/clean-d-pathspec later to maint).
+
+ * "git difftool" misbehaved when the repository is bound to the
+   working tree with the ".git file" mechanism, where a textual file
+   ".git" tells us where it is.
+   (merge fcfec8b da/difftool-git-files later to maint).
+
+ * "git push" did not pay attention to "branch.*.pushremote" if it is
+   defined earlier than "remote.pushdefault"; the order of these two
+   variables in the configuration file should not matter, but it did
+   by mistake.
+   (merge 98b406f jk/remote-pushremote-config-reading later to maint).
+
+ * Code paths that parse timestamps in commit objects have been
+   tightened.
+   (merge f80d1f9 jk/commit-dates-parsing-fix later to maint).
+
+ * "git diff --external-diff" incorrectly fed the submodule directory
+   in the working tree to the external diff driver when it knew that it
+   is the same as one of the versions being compared.
+   (merge aba4727 tr/diff-submodule-no-reuse-worktree later to maint).
+
+ * "git reset" needs to refresh the index when working in a working
+   tree (it can also be used to match the index to the HEAD in an
+   otherwise bare repository), but it failed to set up the working
+   tree properly, causing GIT_WORK_TREE to be ignored.
+   (merge b7756d4 nd/reset-setup-worktree later to maint).
+
+ * "git check-attr" when working on a repository with a working tree
+   did not work well when the working tree was specified via the
+   "--work-tree" (and obviously with "--git-dir") option.
+   (merge cdbf623 jc/check-attr-honor-working-tree later to maint).
+
+ * "merge-recursive" was broken in 1.7.7 era and stopped working in
+   an empty (temporary) working tree, when there are renames
+   involved.  This has been corrected.
+   (merge 6e2068a bk/refresh-missing-ok-in-merge-recursive later to maint.)
+
+ * "git rev-parse" was loose in rejecting command-line arguments
+   that do not make sense, e.g. "--default" without the required
+   value for that option.
+   (merge a43219f ds/rev-parse-required-args later to maint.)
+
+ * "include.path" variable (or any variable that expects a path that
+   can use ~username expansion) in the configuration file is not a
+   boolean, but the code failed to check it.
+   (merge 67beb60 jk/config-path-include-fix later to maint.)
+
+ * Commands that take pathspecs on the command line misbehaved when
+   the pathspec is given as an absolute pathname (which is a
+   practice not particularly encouraged) that points at a symbolic
+   link in the working tree.
+   (merge 6127ff6 mw/symlinks later to maint.)
+
+ * "git diff --quiet -- pathspec1 pathspec2" sometimes did not return
+   the correct status value.
+   (merge f34b205 nd/diff-quiet-stat-dirty later to maint.)
+
+ * Attempting to deepen a shallow repository by fetching over smart
+   HTTP transport failed in the protocol exchange, when the no-done
+   extension was used.  The fetching side waited for the list of
+   shallow boundary commits after the sending side stopped talking to
+   it.
+   (merge 0232852 nd/http-fetch-shallow-fix later to maint.)
+
+ * Allow "git cmd path/", when the 'path' is where a submodule is
+   bound to the top-level working tree, to match 'path', despite the
+   extra and unnecessary trailing slash (such a slash is often
+   given by command-line completion).
+   (merge 2e70c01 nd/submodule-pathspec-ending-with-slash later to maint.)
+
+ * Documentation and in-code comments had many instances of mistaken
+   use of "nor", which have been corrected.
+   (merge 235e8d5 jl/nor-or-nand-and later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.0.1.txt b/third_party/git/Documentation/RelNotes/2.0.1.txt
new file mode 100644
index 0000000000..ce5579db3e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.1.txt
@@ -0,0 +1,115 @@
+Git v2.0.1 Release Notes
+========================
+
+ * We used to unconditionally disable the pager in the pager process
+   we spawn to feed out output, but that prevented people who want to
+   run "less" within "less" from doing so.
+
+ * Tools that read diagnostic output in our standard error stream do
+   not want to see terminal control sequence (e.g. erase-to-eol).
+   Detect them by checking if the standard error stream is connected
+   to a tty.
+ * Reworded the error message given upon a failure to open an existing
+   loose object file due to e.g. permission issues; it was reported as
+   the object being corrupt, but that is not quite true.
+
+ * "git log -2master" is a common typo that shows two commits starting
+   from whichever random branch that is not 'master' that happens to
+   be checked out currently.
+
+ * The "%<(10,trunc)%s" pretty format specifier in the log family of
+   commands is used to truncate the string to a given length (e.g. 10
+   in the example) with padding to column-align the output, but did
+   not take into account that number of bytes and number of display
+   columns are different.
+
+ * The "mailmap.file" configuration option did not support the tilde
+   expansion (i.e. ~user/path and ~/path).
+
+ * The completion scripts (in contrib/) did not know about quite a few
+   options that are common between "git merge" and "git pull", and a
+   couple of options unique to "git merge".
+
+ * "--ignore-space-change" option of "git apply" ignored the spaces
+   at the beginning of line too aggressively, which is inconsistent
+   with the option of the same name "diff" and "git diff" have.
+
+ * "git blame" miscounted number of columns needed to show localized
+   timestamps, resulting in jaggy left-side-edge of the source code
+   lines in its output.
+
+ * "git blame" assigned the blame to the copy in the working-tree if
+   the repository is set to core.autocrlf=input and the file used CRLF
+   line endings.
+
+ * "git commit --allow-empty-message -C $commit" did not work when the
+   commit did not have any log message.
+
+ * "git diff --find-copies-harder" sometimes pretended as if the mode
+   bits have changed for paths that are marked with assume-unchanged
+   bit.
+
+ * "git format-patch" did not enforce the rule that the "--follow"
+   option from the log/diff family of commands must be used with
+   exactly one pathspec.
+
+ * "git gc --auto" was recently changed to run in the background to
+   give control back early to the end-user sitting in front of the
+   terminal, but it forgot that housekeeping involving reflogs should
+   be done without other processes competing for accesses to the refs.
+
+ * "git grep -O" to show the lines that hit in the pager did not work
+   well with case insensitive search.  We now spawn "less" with its
+   "-I" option when it is used as the pager (which is the default).
+
+ * We used to disable threaded "git index-pack" on platforms without
+   thread-safe pread(); use a different workaround for such
+   platforms to allow threaded "git index-pack".
+
+ * The error reporting from "git index-pack" has been improved to
+   distinguish missing objects from type errors.
+
+ * "git mailinfo" used to read beyond the end of header string while
+   parsing an incoming e-mail message to extract the patch.
+
+ * On a case insensitive filesystem, merge-recursive incorrectly
+   deleted the file that is to be renamed to a name that is the same
+   except for case differences.
+
+ * "git pack-objects" unnecessarily copied the previous contents when
+   extending the hashtable, even though it will populate the table
+   from scratch anyway.
+
+ * "git rerere forget" did not work well when merge.conflictstyle
+   was set to a non-default value.
+
+ * "git remote rm" and "git remote prune" can involve removing many
+   refs at once, which is not a very efficient thing to do when very
+   many refs exist in the packed-refs file.
+
+ * "git log --exclude=<glob> --all | git shortlog" worked as expected,
+   but "git shortlog --exclude=<glob> --all", which is supposed to be
+   identical to the above pipeline, was not accepted at the command
+   line argument parser level.
+
+ * The autostash mode of "git rebase -i" did not restore the dirty
+   working tree state if the user aborted the interactive rebase by
+   emptying the insn sheet.
+
+ * "git show -s" (i.e. show log message only) used to incorrectly emit
+   an extra blank line after a merge commit.
+
+ * "git status", even though it is a read-only operation, tries to
+   update the index with refreshed lstat(2) info to optimize future
+   accesses to the working tree opportunistically, but this could
+   race with a "read-write" operation that modify the index while it
+   is running.  Detect such a race and avoid overwriting the index.
+
+ * "git status" (and "git commit") behaved as if changes in a modified
+   submodule are not there if submodule.*.ignore configuration is set,
+   which was misleading.  The configuration is only to unclutter diff
+   output during the course of development, and should not to hide
+   changes in the "status" output to cause the users forget to commit
+   them.
+
+ * The mode to run tests with HTTP server tests disabled was broken.
diff --git a/third_party/git/Documentation/RelNotes/2.0.2.txt b/third_party/git/Documentation/RelNotes/2.0.2.txt
new file mode 100644
index 0000000000..8e8321b2ef
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.2.txt
@@ -0,0 +1,32 @@
+Git v2.0.2 Release Notes
+========================
+
+ * Documentation for "git submodule sync" forgot to say that the subcommand
+   can take the "--recursive" option.
+
+ * Mishandling of patterns in .gitignore that has trailing SPs quoted
+   with backslashes (e.g. ones that end with "\ ") have been
+   corrected.
+
+ * Recent updates to "git repack" started to duplicate objects that
+   are in packfiles marked with .keep flag into the new packfile by
+   mistake.
+
+ * "git clone -b brefs/tags/bar" would have mistakenly thought we were
+   following a single tag, even though it was a name of the branch,
+   because it incorrectly used strstr().
+
+ * "%G" (nothing after G) is an invalid pretty format specifier, but
+   the parser did not notice it as garbage.
+
+ * Code to avoid adding the same alternate object store twice was
+   subtly broken for a long time, but nobody seems to have noticed.
+
+ * A handful of code paths had to read the commit object more than
+   once when showing header fields that are usually not parsed.  The
+   internal data structure to keep track of the contents of the commit
+   object has been updated to reduce the need for this double-reading,
+   and to allow the caller find the length of the object.
+
+ * During "git rebase --merge", a conflicted patch could not be
+   skipped with "--skip" if the next one also conflicted.
diff --git a/third_party/git/Documentation/RelNotes/2.0.3.txt b/third_party/git/Documentation/RelNotes/2.0.3.txt
new file mode 100644
index 0000000000..4047b46bbe
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.3.txt
@@ -0,0 +1,17 @@
+Git v2.0.3 Release Notes
+========================
+
+ * An ancient rewrite passed a wrong pointer to a curl library
+   function in a rarely used code path.
+
+ * "filter-branch" left an empty single-parent commit that results when
+   all parents of a merge commit gets mapped to the same commit, even
+   under "--prune-empty".
+
+ * "log --show-signature" incorrectly decided the color to paint a
+   mergetag that was and was not correctly validated.
+
+ * "log --show-signature" did not pay attention to "--graph" option.
+
+Also a lot of fixes to the tests and some updates to the docs are
+included.
diff --git a/third_party/git/Documentation/RelNotes/2.0.4.txt b/third_party/git/Documentation/RelNotes/2.0.4.txt
new file mode 100644
index 0000000000..7e340921a2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.4.txt
@@ -0,0 +1,5 @@
+Git v2.0.4 Release Notes
+========================
+
+ * An earlier update to v2.0.2 broken output from "git diff-tree",
+   which is fixed in this release.
diff --git a/third_party/git/Documentation/RelNotes/2.0.5.txt b/third_party/git/Documentation/RelNotes/2.0.5.txt
new file mode 100644
index 0000000000..3a16f697e8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.0.5.txt
@@ -0,0 +1,34 @@
+Git v2.0.5 Release Notes
+========================
+
+Fixes since v2.0.4
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.1.0.txt b/third_party/git/Documentation/RelNotes/2.1.0.txt
new file mode 100644
index 0000000000..ae4753728e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.1.0.txt
@@ -0,0 +1,391 @@
+Git v2.1 Release Notes
+======================
+
+Backward compatibility notes
+----------------------------
+
+ * The default value we give to the environment variable LESS has been
+   changed from "FRSX" to "FRX", losing "S" (chop long lines instead
+   of wrapping).  Existing users who prefer not to see line-wrapped
+   output may want to set
+
+     $ git config core.pager "less -S"
+
+   to restore the traditional behaviour.  It is expected that people
+   find output from most subcommands easier to read with the new
+   default, except for "blame" which tends to produce really long
+   lines.  To override the new default only for "git blame", you can
+   do this:
+
+     $ git config pager.blame "less -S"
+
+ * A few disused directories in contrib/ have been retired.
+
+
+Updates since v2.0
+------------------
+
+UI, Workflows & Features
+
+ * Since the very beginning of Git, we gave the LESS environment a
+   default value "FRSX" when we spawn "less" as the pager.  "S" (chop
+   long lines instead of wrapping) has been removed from this default
+   set of options, because it is more or less a personal taste thing,
+   as opposed to the others that have good justifications (i.e. "R" is
+   very much justified because many kinds of output we produce are
+   colored and "FX" is justified because output we produce is often
+   shorter than a page).
+
+ * The logic and data used to compute the display width needed for
+   UTF-8 strings have been updated to match Unicode 7.0 better.
+
+ * HTTP-based transports learned to better propagate the error messages from
+   the webserver to the client coming over the HTTP transport.
+
+ * The completion script for bash (in contrib/) has been updated to
+   better handle aliases that define a complex sequence of commands.
+
+ * The "core.preloadindex" configuration variable is enabled by default,
+   allowing modern platforms to take advantage of their
+   multiple cores.
+
+ * "git clone" applies the "if cloning from a local disk, physically
+   copy the repository using hardlinks, unless otherwise told not to with
+   --no-local" optimization when the url.*.insteadOf mechanism rewrites a
+   remote-repository "git clone $URL" into a
+   clone from a local disk.
+
+ * "git commit --date=<date>" option learned more
+   timestamp formats, including "--date=now".
+
+ * The `core.commentChar` configuration variable is used to specify a
+   custom comment character (other than the default "#") for
+   the commit message editor.  This can be set to `auto` to attempt to
+   choose a different character that does not conflict with any that
+   already starts a line in the message being edited, for cases like
+   "git commit --amend".
+
+ * "git format-patch" learned --signature-file=<file> to add the contents
+   of a file as a signature to the mail message it produces.
+
+ * "git grep" learned the grep.fullname configuration variable to force
+   "--full-name" to be the default.  This may cause regressions for
+   scripted users who do not expect this new behaviour.
+
+ * "git imap-send" learned to ask the credential helper for auth
+   material.
+
+ * "git log" and friends now understand the value "auto" for the
+   "log.decorate" configuration variable to enable the "--decorate"
+   option automatically when the output is sent to tty.
+
+ * "git merge" without an argument, even when there is an upstream
+   defined for the current branch, refused to run until
+   merge.defaultToUpstream is set to true.  Flip the default of that
+   configuration variable to true.
+
+ * "git mergetool" learned to drive the vimdiff3 backend.
+
+ * mergetool.prompt used to default to 'true', always asking "do you
+   really want to run the tool on this path?".  The default has been
+   changed to 'false'.  However, the prompt will still appear if
+   mergetool used its autodetection system to guess which tool to use.
+   Users who explicitly specify or configure a tool will no longer see
+   the prompt by default.
+
+   Strictly speaking, this is a backward incompatible change and
+   users need to explicitly set the variable to 'true' if they want
+   to be prompted to confirm running the tool on each path.
+
+ * "git replace" learned the "--edit" subcommand to create a
+   replacement by editing an existing object.
+
+ * "git replace" learned a "--graft" option to rewrite the parents of a
+   commit.
+
+ * "git send-email" learned "--to-cover" and "--cc-cover" options, to
+   tell it to copy To: and Cc: headers found in the first input file
+   when emitting later input files.
+
+ * "git svn" learned to cope with malformed timestamps with only one
+   digit in the hour part, e.g. 2014-01-07T5:01:02.048176Z, emitted
+   by some broken subversion server implementations.
+
+ * "git tag" when editing the tag message shows the name of the tag
+   being edited as a comment in the editor.
+
+ * "git tag" learned to pay attention to "tag.sort" configuration, to
+   be used as the default sort order when no --sort=<value> option
+   is given.
+
+ * A new "git verify-commit" command, to check GPG signatures in signed
+   commits, in a way similar to "git verify-tag" is used to check
+   signed tags, was added.
+
+
+Performance, Internal Implementation, etc.
+
+ * Build procedure for 'subtree' (in contrib/) has been cleaned up.
+
+ * Support for the profile-feedback build, which has
+   bit-rotted for quite a while, has been updated.
+
+ * An experimental format to use two files (the base file and
+   incremental changes relative to it) to represent the index has been
+   introduced; this may reduce I/O cost of rewriting a large index
+   when only small part of the working tree changes.
+
+ * Effort to shrink the size of patches Windows folks maintain on top
+   by upstreaming them continues.  More tests that are not applicable
+   to the Windows environment are identified and either skipped or
+   made more portable.
+
+ * Eradication of "test $condition -a $condition" from our scripts
+   continues.
+
+ * The `core.deltabasecachelimit` used to default to 16 MiB , but this
+   proved to be too small, and has been bumped to 96 MiB.
+
+ * "git blame" has been optimized greatly by reorganising the data
+   structure that is used to keep track of the work to be done.
+
+ * "git diff" that compares 3-or-more trees (e.g. parents and the
+   result of a merge) has been optimized.
+
+ * The API to update/delete references are being converted to handle
+   updates to multiple references in a transactional way.  As an
+   example, "update-ref --stdin [-z]" has been updated to use this
+   API.
+
+ * skip_prefix() and strip_suffix() API functions are used a lot more
+   widely throughout the codebase now.
+
+ * Parts of the test scripts can be skipped by using a range notation,
+   e.g. "sh t1234-test.sh --run='1-4 6 8-'" to omit test piece 5 and 7
+   and run everything else.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.0
+----------------
+
+Unless otherwise noted, all the fixes since v2.0 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * We used to unconditionally disable the pager in the pager process
+   we spawn to feed out output, but that prevented people who want to
+   run "less" within "less" from doing so.
+   (merge c0459ca je/pager-do-not-recurse later to maint).
+
+ * Tools that read diagnostic output in our standard error stream do
+   not want to see terminal control sequence (e.g. erase-to-eol).
+   Detect them by checking if the standard error stream is connected
+   to a tty.
+   (merge 38de156 mn/sideband-no-ansi later to maint).
+
+ * Mishandling of patterns in .gitignore that have trailing SPs quoted
+   with backslashes (e.g. ones that end with "\ ") has been
+   corrected.
+   (merge 97c1364be6b pb/trim-trailing-spaces later to maint).
+
+ * Reworded the error message given upon a failure to open an existing
+   loose object file due to e.g. permission issues; it was reported as
+   the object being corrupt, but that is not quite true.
+   (merge d6c8a05 jk/report-fail-to-read-objects-better later to maint).
+
+ * "git log -2master" is a common typo that shows two commits starting
+   from whichever random branch that is not 'master' that happens to
+   be checked out currently.
+   (merge e3fa568 jc/revision-dash-count-parsing later to maint).
+
+ * Code to avoid adding the same alternate object store twice was
+   subtly broken for a long time, but nobody seems to have noticed.
+   (merge 80b4785 rs/fix-alt-odb-path-comparison later to maint).
+   (merge 539e750 ek/alt-odb-entry-fix later to maint).
+
+ * The "%<(10,trunc)%s" pretty format specifier in the log family of
+   commands is used to truncate the string to a given length (e.g. 10
+   in the example) with padding to column-align the output, but did
+   not take into account that number of bytes and number of display
+   columns are different.
+   (merge 7d50987 as/pretty-truncate later to maint).
+
+ * "%G" (nothing after G) is an invalid pretty format specifier, but
+   the parser did not notice it as garbage.
+   (merge 958b2eb jk/pretty-G-format-fixes later to maint).
+
+ * A handful of code paths had to read the commit object more than
+   once when showing header fields that are usually not parsed.  The
+   internal data structure to keep track of the contents of the commit
+   object has been updated to reduce the need for this double-reading,
+   and to allow the caller find the length of the object.
+   (merge 218aa3a jk/commit-buffer-length later to maint).
+
+ * The "mailmap.file" configuration option did not support tilde
+   expansion (i.e. ~user/path and ~/path).
+   (merge 9352fd5 ow/config-mailmap-pathname later to maint).
+
+ * The completion scripts (in contrib/) did not know about quite a few
+   options that are common between "git merge" and "git pull", and a
+   couple of options unique to "git merge".
+   (merge 8fee872 jk/complete-merge-pull later to maint).
+
+ * The unix-domain socket used by the sample credential cache daemon
+   tried to unlink an existing stale one at a wrong path, if the path
+   to the socket was given as an overlong path that does not fit in
+   the sun_path member of the sockaddr_un structure.
+   (merge 2869b3e rs/fix-unlink-unix-socket later to maint).
+
+ * An ancient rewrite passed a wrong pointer to a curl library
+   function in a rarely used code path.
+   (merge 479eaa8 ah/fix-http-push later to maint).
+
+ * "--ignore-space-change" option of "git apply" ignored the spaces
+   at the beginning of lines too aggressively, which is inconsistent
+   with the option of the same name that "diff" and "git diff" have.
+   (merge 14d3bb4 jc/apply-ignore-whitespace later to maint).
+
+ * "git blame" miscounted the number of columns needed to show localized
+   timestamps, resulting in a jaggy left-side-edge for the source code
+   lines in its output.
+   (merge dd75553 jx/blame-align-relative-time later to maint).
+
+ * "git blame" assigned the blame to the copy in the working-tree if
+   the repository is set to core.autocrlf=input and the file used CRLF
+   line endings.
+   (merge 4d4813a bc/blame-crlf-test later to maint).
+
+ * "git clone -b brefs/tags/bar" would have mistakenly thought we were
+   following a single tag, even though it was a name of the branch,
+   because it incorrectly used strstr().
+   (merge 60a5f5f jc/fix-clone-single-starting-at-a-tag later to maint).
+
+ * "git commit --allow-empty-message -C $commit" did not work when the
+   commit did not have any log message.
+   (merge 076cbd6 jk/commit-C-pick-empty later to maint).
+
+ * "git diff --find-copies-harder" sometimes pretended as if the mode
+   bits have changed for paths that are marked with the assume-unchanged
+   bit.
+   (merge 5304810 jk/diff-files-assume-unchanged later to maint).
+
+ * "filter-branch" left an empty single-parent commit that results when
+   all parents of a merge commit get mapped to the same commit, even
+   under "--prune-empty".
+   (merge 79bc4ef cb/filter-branch-prune-empty-degenerate-merges later to maint).
+
+ * "git format-patch" did not enforce the rule that the "--follow"
+   option from the log/diff family of commands must be used with
+   exactly one pathspec.
+   (merge dd63f16 jk/diff-follow-must-take-one-pathspec later to maint).
+
+ * "git gc --auto" was recently changed to run in the background to
+   give control back early to the end-user sitting in front of the
+   terminal, but it forgot that housekeeping involving reflogs should
+   be done without other processes competing for accesses to the refs.
+   (merge 62aad18 nd/daemonize-gc later to maint).
+
+ * "git grep -O" to show the lines that hit in the pager did not work
+   well with case insensitive search.  We now spawn "less" with its
+   "-I" option when it is used as the pager (which is the default).
+   (merge f7febbe sk/spawn-less-case-insensitively-from-grep-O-i later to maint).
+
+ * We used to disable threaded "git index-pack" on platforms without
+   thread-safe pread(); use a different workaround for such
+   platforms to allow threaded "git index-pack".
+   (merge 3953949 nd/index-pack-one-fd-per-thread later to maint).
+
+ * The error reporting from "git index-pack" has been improved to
+   distinguish missing objects from type errors.
+   (merge 77583e7 jk/index-pack-report-missing later to maint).
+
+ * "log --show-signature" incorrectly decided the color to paint a
+   mergetag that was and was not correctly validated.
+   (merge 42c55ce mg/fix-log-mergetag-color later to maint).
+
+ * "log --show-signature" did not pay attention to the "--graph" option.
+   (merge cf3983d zk/log-graph-showsig later to maint).
+
+ * "git mailinfo" used to read beyond the ends of header strings while
+   parsing an incoming e-mail message to extract the patch.
+   (merge b1a013d rs/mailinfo-header-cmp later to maint).
+
+ * On a case insensitive filesystem, merge-recursive incorrectly
+   deleted the file that is to be renamed to a name that is the same
+   except for case differences.
+   (merge baa37bf dt/merge-recursive-case-insensitive later to maint).
+
+ * Merging changes into a file that ends in an incomplete line made the
+   last line into a complete one, even when the other branch did not
+   change anything around the end of file.
+   (merge ba31180 mk/merge-incomplete-files later to maint).
+
+ * "git pack-objects" unnecessarily copied the previous contents when
+   extending the hashtable, even though it will populate the table
+   from scratch anyway.
+   (merge fb79947 rs/pack-objects-no-unnecessary-realloc later to maint).
+
+ * Recent updates to "git repack" started to duplicate objects that
+   are in packfiles marked with the .keep flag into the new packfile by
+   mistake.
+   (merge d078d85 jk/repack-pack-keep-objects later to maint).
+
+ * "git rerere forget" did not work well when merge.conflictstyle
+   was set to a non-default value.
+   (merge de3d8bb fc/rerere-conflict-style later to maint).
+
+ * "git remote rm" and "git remote prune" can involve removing many
+   refs at once, which is not a very efficient thing to do when very
+   many refs exist in the packed-refs file.
+   (merge e6bea66 jl/remote-rm-prune later to maint).
+
+ * "git log --exclude=<glob> --all | git shortlog" worked as expected,
+   but "git shortlog --exclude=<glob> --all", which is supposed to be
+   identical to the above pipeline, was not accepted at the command
+   line argument parser level.
+   (merge eb07774 jc/shortlog-ref-exclude later to maint).
+
+ * The autostash mode of "git rebase -i" did not restore the dirty
+   working tree state if the user aborted the interactive rebase by
+   emptying the insn sheet.
+   (merge ddb5432 rr/rebase-autostash-fix later to maint).
+
+ * "git rebase --fork-point" did not filter out patch-identical
+   commits correctly.
+
+ * During "git rebase --merge", a conflicted patch could not be
+   skipped with "--skip" if the next one also conflicted.
+   (merge 95104c7 bc/fix-rebase-merge-skip later to maint).
+
+ * "git show -s" (i.e. show log message only) used to incorrectly emit
+   an extra blank line after a merge commit.
+   (merge ad2f725 mk/show-s-no-extra-blank-line-for-merges later to maint).
+
+ * "git status", even though it is a read-only operation, tries to
+   update the index with refreshed lstat(2) info to optimize future
+   accesses to the working tree opportunistically, but this could
+   race with a "read-write" operation that modifies the index while it
+   is running.  Detect such a race and avoid overwriting the index.
+   (merge 426ddee ym/fix-opportunistic-index-update-race later to maint).
+
+ * "git status" (and "git commit") behaved as if changes in a modified
+   submodule are not there if submodule.*.ignore configuration is set,
+   which was misleading.  The configuration is only to unclutter diff
+   output during the course of development, and not to hide
+   changes in the "status" output to cause the users forget to commit
+   them.
+   (merge c215d3d jl/status-added-submodule-is-never-ignored later to maint).
+
+ * Documentation for "git submodule sync" forgot to say that the subcommand
+   can take the "--recursive" option.
+   (merge 9393ae7 mc/doc-submodule-sync-recurse later to maint).
+
+ * "git update-index --cacheinfo" in 2.0 release crashed on a
+   malformed command line.
+   (merge c8e1ee4 jc/rev-parse-argh-dashed-multi-words later to maint).
+
+ * The mode to run tests with HTTP server tests disabled was broken.
+   (merge afa53fe na/no-http-test-in-the-middle later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.1.1.txt b/third_party/git/Documentation/RelNotes/2.1.1.txt
new file mode 100644
index 0000000000..830fc3cc6d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.1.1.txt
@@ -0,0 +1,44 @@
+Git v2.1.1 Release Notes
+========================
+
+ * Git 2.0 had a regression where "git fetch" into a shallowly
+   cloned repository from a repository with bitmap object index
+   enabled did not work correctly.  This has been corrected.
+
+ * Git 2.0 had a regression which broke (rarely used) "git diff-tree
+   -t".  This has been corrected.
+
+ * "git log --pretty/format=" with an empty format string did not
+   mean the more obvious "No output whatsoever" but "Use default
+   format", which was counterintuitive.  Now it means "nothing shown
+   for the log message part".
+
+ * "git -c section.var command" and "git -c section.var= command"
+   should pass the configuration differently (the former should be a
+   boolean true, the latter should be an empty string), but they
+   didn't work that way.  Now it does.
+
+ * Applying a patch not generated by Git in a subdirectory used to
+   check the whitespace breakage using the attributes for incorrect
+   paths. Also whitespace checks were performed even for paths
+   excluded via "git apply --exclude=<path>" mechanism.
+
+ * "git bundle create" with date-range specification were meant to
+   exclude tags outside the range, but it did not work correctly.
+
+ * "git add x" where x that used to be a directory has become a
+   symbolic link to a directory misbehaved.
+
+ * The prompt script checked $GIT_DIR/ref/stash file to see if there
+   is a stash, which was a no-no.
+
+ * "git checkout -m" did not switch to another branch while carrying
+   the local changes forward when a path was deleted from the index.
+
+ * With sufficiently long refnames, fast-import could have overflown
+   an on-stack buffer.
+
+ * After "pack-refs --prune" packed refs at the top-level, it failed
+   to prune them.
+
+ * "git gc --auto" triggered from "git fetch --quiet" was not quiet.
diff --git a/third_party/git/Documentation/RelNotes/2.1.2.txt b/third_party/git/Documentation/RelNotes/2.1.2.txt
new file mode 100644
index 0000000000..abc3b8928a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.1.2.txt
@@ -0,0 +1,20 @@
+Git v2.1.2 Release Notes
+========================
+
+ * "git push" over HTTP transport had an artificial limit on number of
+   refs that can be pushed imposed by the command line length.
+
+ * When receiving an invalid pack stream that records the same object
+   twice, multiple threads got confused due to a race.
+
+ * An attempt to remove the entire tree in the "git fast-import" input
+   stream caused it to misbehave.
+
+ * Reachability check (used in "git prune" and friends) did not add a
+   detached HEAD as a starting point to traverse objects still in use.
+
+ * "git config --add section.var val" used to lose existing
+   section.var whose value was an empty string.
+
+ * "git fsck" failed to report that it found corrupt objects via its
+   exit status in some cases.
diff --git a/third_party/git/Documentation/RelNotes/2.1.3.txt b/third_party/git/Documentation/RelNotes/2.1.3.txt
new file mode 100644
index 0000000000..acc9ebb886
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.1.3.txt
@@ -0,0 +1,26 @@
+Git v2.1.3 Release Notes
+========================
+
+ * Some MUAs mangled a line in a message that begins with "From " to
+   ">From " when writing to a mailbox file and feeding such an input to
+   "git am" used to lose such a line.
+
+ * "git daemon" (with NO_IPV6 build configuration) used to incorrectly
+   use the hostname even when gethostbyname() reported that the given
+   hostname is not found.
+
+ * Newer versions of 'meld' breaks the auto-detection we use to see if
+   they are new enough to support the `--output` option.
+
+ * "git pack-objects" forgot to disable the codepath to generate
+   object recheability bitmap when it needs to split the resulting
+   pack.
+
+ * "gitweb" used deprecated CGI::startfrom, which was removed from
+   CGI.pm as of 4.04; use CGI::start_from instead.
+
+ * "git log" documentation had an example section marked up not
+   quite correctly, which passed AsciiDoc but failed with
+   AsciiDoctor.
+
+Also contains some documentation updates.
diff --git a/third_party/git/Documentation/RelNotes/2.1.4.txt b/third_party/git/Documentation/RelNotes/2.1.4.txt
new file mode 100644
index 0000000000..d16e5f041f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.1.4.txt
@@ -0,0 +1,34 @@
+Git v2.1.4 Release Notes
+========================
+
+Fixes since v2.1.3
+------------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.10.0.txt b/third_party/git/Documentation/RelNotes/2.10.0.txt
new file mode 100644
index 0000000000..f4da28ab66
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.0.txt
@@ -0,0 +1,675 @@
+Git 2.10 Release Notes
+======================
+
+Backward compatibility notes
+----------------------------
+
+Updates since v2.9
+------------------
+
+UI, Workflows & Features
+
+ * "git pull --rebase --verify-signature" learned to warn the user
+   that "--verify-signature" is a no-op when rebasing.
+
+ * An upstream project can make a recommendation to shallowly clone
+   some submodules in the .gitmodules file it ships.
+
+ * "git worktree add" learned that '-' can be used as a short-hand for
+   "@{-1}", the previous branch.
+
+ * Update the funcname definition to support css files.
+
+ * The completion script (in contrib/) learned to complete "git
+   status" options.
+
+ * Messages that are generated by auto gc during "git push" on the
+   receiving end are now passed back to the sending end in such a way
+   that they are shown with "remote: " prefix to avoid confusing the
+   users.
+
+ * "git add -i/-p" learned to honor diff.compactionHeuristic
+   experimental knob, so that the user can work on the same hunk split
+   as "git diff" output.
+
+ * "upload-pack" allows a custom "git pack-objects" replacement when
+   responding to "fetch/clone" via the uploadpack.packObjectsHook.
+   (merge b738396 jk/upload-pack-hook later to maint).
+
+ * Teach format-patch and mailsplit (hence "am") how a line that
+   happens to begin with "From " in the e-mail message is quoted with
+   ">", so that these lines can be restored to their original shape.
+   (merge d9925d1 ew/mboxrd-format-am later to maint).
+
+ * "git repack" learned the "--keep-unreachable" option, which sends
+   loose unreachable objects to a pack instead of leaving them loose.
+   This helps heuristics based on the number of loose objects
+   (e.g. "gc --auto").
+   (merge e26a8c4 jk/repack-keep-unreachable later to maint).
+
+ * "log --graph --format=" learned that "%>|(N)" specifies the width
+   relative to the terminal's left edge, not relative to the area to
+   draw text that is to the right of the ancestry-graph section.  It
+   also now accepts negative N that means the column limit is relative
+   to the right border.
+
+ * A careless invocation of "git send-email directory/" after editing
+   0001-change.patch with an editor often ends up sending both
+   0001-change.patch and its backup file, 0001-change.patch~, causing
+   embarrassment and a minor confusion.  Detect such an input and
+   offer to skip the backup files when sending the patches out.
+   (merge 531220b jc/send-email-skip-backup later to maint).
+
+ * "git submodule update" that drives many "git clone" could
+   eventually hit flaky servers/network conditions on one of the
+   submodules; the command learned to retry the attempt.
+
+ * The output coloring scheme learned two new attributes, italic and
+   strike, in addition to existing bold, reverse, etc.
+
+ * "git log" learns log.showSignature configuration variable, and a
+   command line option "--no-show-signature" to countermand it.
+   (merge fce04c3 mj/log-show-signature-conf later to maint).
+
+ * More markings of messages for i18n, with updates to various tests
+   to pass GETTEXT_POISON tests.
+
+ * "git archive" learned to handle files that are larger than 8GB and
+   commits far in the future than expressible by the traditional US-TAR
+   format.
+   (merge 560b0e8 jk/big-and-future-archive-tar later to maint).
+
+
+ * A new configuration variable core.sshCommand has been added to
+   specify what value for GIT_SSH_COMMAND to use per repository.
+
+ * "git worktree prune" protected worktrees that are marked as
+   "locked" by creating a file in a known location.  "git worktree"
+   command learned a dedicated command pair to create and remove such
+   a file, so that the users do not have to do this with editor.
+
+ * A handful of "git svn" updates.
+
+ * "git push" learned to accept and pass extra options to the
+   receiving end so that hooks can read and react to them.
+
+ * "git status" learned to suggest "merge --abort" during a conflicted
+   merge, just like it already suggests "rebase --abort" during a
+   conflicted rebase.
+
+ * "git jump" script (in contrib/) has been updated a bit.
+   (merge a91e692 jk/git-jump later to maint).
+
+ * "git push" and "git clone" learned to give better progress meters
+   to the end user who is waiting on the terminal.
+
+ * An entry "git log --decorate" for the tip of the current branch is
+   shown as "HEAD -> name" (where "name" is the name of the branch);
+   the arrow is now painted in the same color as "HEAD", not in the
+   color for commits.
+
+ * "git format-patch" learned format.from configuration variable to
+   specify the default settings for its "--from" option.
+
+ * "git am -3" calls "git merge-recursive" when it needs to fall back
+   to a three-way merge; this call has been turned into an internal
+   subroutine call instead of spawning a separate subprocess.
+
+ * The command line completion scripts (in contrib/) now knows about
+   "git branch --delete/--move [--remote]".
+   (merge 2703c22 vs/completion-branch-fully-spelled-d-m-r later to maint).
+
+ * "git rev-parse --git-path hooks/<hook>" learned to take
+   core.hooksPath configuration variable (introduced during 2.9 cycle)
+   into account.
+   (merge 9445b49 ab/hooks later to maint).
+
+ * "git log --show-signature" and other commands that display the
+   verification status of PGP signature now shows the longer key-id,
+   as 32-bit key-id is so last century.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * "git fast-import" learned the same performance trick to avoid
+   creating too small a packfile as "git fetch" and "git push" have,
+   using *.unpackLimit configuration.
+
+ * When "git daemon" is run without --[init-]timeout specified, a
+   connection from a client that silently goes offline can hang around
+   for a long time, wasting resources.  The socket-level KEEPALIVE has
+   been enabled to allow the OS to notice such failed connections.
+
+ * "git upload-pack" command has been updated to use the parse-options
+   API.
+
+ * The "git apply" standalone program is being libified; the first
+   step to move many state variables into a structure that can be
+   explicitly (re)initialized to make the machinery callable more
+   than once has been merged.
+
+ * HTTP transport gained an option to produce more detailed debugging
+   trace.
+   (merge 73e57aa ep/http-curl-trace later to maint).
+
+ * Instead of taking advantage of the fact that a struct string_list
+   that is allocated with all NULs happens to be the INIT_NODUP kind,
+   the users of string_list structures are taught to initialize them
+   explicitly as such, to document their behaviour better.
+   (merge 2721ce2 jk/string-list-static-init later to maint).
+
+ * HTTPd tests learned to show the server error log to help diagnosing
+   a failing tests.
+   (merge 44f243d nd/test-lib-httpd-show-error-log-in-verbose later to maint).
+
+ * The ownership rule for the piece of memory that hold references to
+   be fetched in "git fetch" was screwy, which has been cleaned up.
+
+ * "git bisect" makes an internal call to "git diff-tree" when
+   bisection finds the culprit, but this call did not initialize the
+   data structure to pass to the diff-tree API correctly.
+
+ * Further preparatory clean-up for "worktree" feature continues.
+   (merge 0409e0b nd/worktree-cleanup-post-head-protection later to maint).
+
+ * Formats of the various data (and how to validate them) where we use
+   GPG signature have been documented.
+
+ * A new run-command API function pipe_command() is introduced to
+   sanely feed data to the standard input while capturing data from
+   the standard output and the standard error of an external process,
+   which is cumbersome to hand-roll correctly without deadlocking.
+
+ * The codepath to sign data in a prepared buffer with GPG has been
+   updated to use this API to read from the status-fd to check for
+   errors (instead of relying on GPG's exit status).
+   (merge efee955 jk/gpg-interface-cleanup later to maint).
+
+ * Allow t/perf framework to use the features from the most recent
+   version of Git even when testing an older installed version.
+
+ * The commands in the "log/diff" family have had an FILE* pointer in the
+   data structure they pass around for a long time, but some codepaths
+   used to always write to the standard output.  As a preparatory step
+   to make "git format-patch" available to the internal callers, these
+   codepaths have been updated to consistently write into that FILE*
+   instead.
+
+ * Conversion from unsigned char sha1[20] to struct object_id
+   continues.
+
+ * Improve the look of the way "git fetch" reports what happened to
+   each ref that was fetched.
+
+ * The .c/.h sources are marked as such in our .gitattributes file so
+   that "git diff -W" and friends would work better.
+
+ * Code clean-up to avoid using a variable string that compilers may
+   feel untrustable as printf-style format given to write_file()
+   helper function.
+
+ * "git p4" used a location outside $GIT_DIR/refs/ to place its
+   temporary branches, which has been moved to refs/git-p4-tmp/.
+
+ * Existing autoconf generated test for the need to link with pthread
+   library did not check all the functions from pthread libraries;
+   recent FreeBSD has some functions in libc but not others, and we
+   mistakenly thought linking with libc is enough when it is not.
+
+ * When "git fsck" reports a broken link (e.g. a tree object contains
+   a blob that does not exist), both containing object and the object
+   that is referred to were reported with their 40-hex object names.
+   The command learned the "--name-objects" option to show the path to
+   the containing object from existing refs (e.g. "HEAD~24^2:file.txt").
+
+ * Allow http daemon tests in Travis CI tests.
+
+ * Makefile assumed that -lrt is always available on platforms that
+   want to use clock_gettime() and CLOCK_MONOTONIC, which is not a
+   case for recent Mac OS X.  The necessary symbols are often found in
+   libc on many modern systems and having -lrt on the command line, as
+   long as the library exists, had no effect, but when the platform
+   removes librt.a that is a different matter--having -lrt will break
+   the linkage.
+
+   This change could be seen as a regression for those who do need to
+   specify -lrt, as they now specifically ask for NEEDS_LIBRT when
+   building. Hopefully they are in the minority these days.
+
+ * Further preparatory work on the refs API before the pluggable
+   backend series can land.
+
+ * Error handling in the codepaths that updates refs has been
+   improved.
+
+ * The API to iterate over all the refs (i.e. for_each_ref(), etc.)
+   has been revamped.
+
+ * The handling of the "text=auto" attribute has been corrected.
+   $ echo "* text=auto eol=crlf" >.gitattributes
+   used to have the same effect as
+   $ echo "* text eol=crlf" >.gitattributes
+   i.e. declaring all files are text (ignoring "auto").  The
+   combination has been fixed to be equivalent to doing
+   $ git config core.autocrlf true
+
+ * Documentation has been updated to show better example usage
+   of the updated "text=auto" attribute.
+
+ * A few tests that specifically target "git rebase -i" have been
+   added.
+
+ * Dumb http transport on the client side has been optimized.
+   (merge ecba195 ew/http-walker later to maint).
+
+ * Users of the parse_options_concat() API function need to allocate
+   extra slots in advance and fill them with OPT_END() when they want
+   to decide the set of supported options dynamically, which makes the
+   code error-prone and hard to read.  This has been corrected by tweaking
+   the API to allocate and return a new copy of "struct option" array.
+
+ * "git fetch" exchanges batched have/ack messages between the sender
+   and the receiver, initially doubling every time and then falling
+   back to enlarge the window size linearly.  The "smart http"
+   transport, being an half-duplex protocol, outgrows the preset limit
+   too quickly and becomes inefficient when interacting with a large
+   repository.  The internal mechanism learned to grow the window size
+   more aggressively when working with the "smart http" transport.
+
+ * Tests for "git svn" have been taught to reuse the lib-httpd test
+   infrastructure when testing the subversion integration that
+   interacts with subversion repositories served over the http://
+   protocol.
+   (merge a8a5d25 ew/git-svn-http-tests later to maint).
+
+ * "git pack-objects" has a few options that tell it not to pack
+   objects found in certain packfiles, which require it to scan .idx
+   files of all available packs.  The codepaths involved in these
+   operations have been optimized for a common case of not having any
+   non-local pack and/or any .kept pack.
+
+ * The t3700 test about "add --chmod=-x" have been made a bit more
+   robust and generally cleaned up.
+   (merge 766cdc4 ib/t3700-add-chmod-x-updates later to maint).
+
+ * The build procedure learned PAGER_ENV knob that lists what default
+   environment variable settings to export for popular pagers.  This
+   mechanism is used to tweak the default settings to MORE on FreeBSD.
+   (merge 995bc22 ew/build-time-pager-tweaks later to maint).
+
+ * The http-backend (the server-side component of smart-http
+   transport) used to trickle the HTTP header one at a time.  Now
+   these write(2)s are batched.
+   (merge b36045c ew/http-backend-batch-headers later to maint).
+
+ * When "git rebase" tries to compare set of changes on the updated
+   upstream and our own branch, it computes patch-id for all of these
+   changes and attempts to find matches. This has been optimized by
+   lazily computing the full patch-id (which is expensive) to be
+   compared only for changes that touch the same set of paths.
+   (merge ba67504 kw/patch-ids-optim later to maint).
+
+ * A handful of tests that were broken under gettext-poison build have
+   been fixed.
+
+ * The recent i18n patch we added during this cycle did a bit too much
+   refactoring of the messages to avoid word-legos; the repetition has
+   been reduced to help translators.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.9
+----------------
+
+Unless otherwise noted, all the fixes since v2.8 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * The commands in `git log` family take %C(auto) in a custom format
+   string.  This unconditionally turned the color on, ignoring
+   --no-color or with --color=auto when the output is not connected to
+   a tty; this was corrected to make the format truly behave as
+   "auto".
+
+ * "git rev-list --count" whose walk-length is limited with "-n"
+   option did not work well with the counting optimized to look at the
+   bitmap index.
+
+ * "git show -W" (extend hunks to cover the entire function, delimited
+   by lines that match the "funcname" pattern) used to show the entire
+   file when a change added an entire function at the end of the file,
+   which has been fixed.
+
+ * The documentation set has been updated so that literal commands,
+   configuration variables and environment variables are consistently
+   typeset in fixed-width font and bold in manpages.
+
+ * "git svn propset" subcommand that was added in 2.3 days is
+   documented now.
+
+ * The documentation tries to consistently spell "GPG"; when
+   referring to the specific program name, "gpg" is used.
+
+ * "git reflog" stopped upon seeing an entry that denotes a branch
+   creation event (aka "unborn"), which made it appear as if the
+   reflog was truncated.
+
+ * The git-prompt scriptlet (in contrib/) was not friendly with those
+   who uses "set -u", which has been fixed.
+
+ * compat/regex code did not cleanly compile.
+
+ * A codepath that used alloca(3) to place an unbounded amount of data
+   on the stack has been updated to avoid doing so.
+
+ * "git update-index --add --chmod=+x file" may be usable as an escape
+   hatch, but not a friendly thing to force for people who do need to
+   use it regularly.  "git add --chmod=+x file" can be used instead.
+
+ * Build improvements for gnome-keyring (in contrib/)
+
+ * "git status" used to say "working directory" when it meant "working
+   tree".
+
+ * Comments about misbehaving FreeBSD shells have been clarified with
+   the version number (9.x and before are broken, newer ones are OK).
+
+ * "git cherry-pick A" worked on an unborn branch, but "git
+   cherry-pick A..B" didn't.
+
+ * Fix an unintended regression in v2.9 that breaks "clone --depth"
+   that recurses down to submodules by forcing the submodules to also
+   be cloned shallowly, which many server instances that host upstream
+   of the submodules are not prepared for.
+
+ * Fix unnecessarily waste in the idiomatic use of ': ${VAR=default}'
+   to set the default value, without enclosing it in double quotes.
+
+ * Some platform-specific code had non-ANSI strict declarations of C
+   functions that do not take any parameters, which has been
+   corrected.
+
+ * The internal code used to show local timezone offset is not
+   prepared to handle timestamps beyond year 2100, and gave a
+   bogus offset value to the caller.  Use a more benign looking
+   +0000 instead and let "git log" going in such a case, instead
+   of aborting.
+
+ * One among four invocations of readlink(1) in our test suite has
+   been rewritten so that the test can run on systems without the
+   command (others are in valgrind test framework and t9802).
+
+ * t/perf needs /usr/bin/time with GNU extension; the invocation of it
+   is updated to "gtime" on Darwin.
+
+ * A bug, which caused "git p4" while running under verbose mode to
+   report paths that are omitted due to branch prefix incorrectly, has
+   been fixed; the command said "Ignoring file outside of prefix" for
+   paths that are _inside_.
+
+ * The top level documentation "git help git" still pointed at the
+   documentation set hosted at now-defunct google-code repository.
+   Update it to point to https://git.github.io/htmldocs/git.html
+   instead.
+
+ * A helper function that takes the contents of a commit object and
+   finds its subject line did not ignore leading blank lines, as is
+   commonly done by other codepaths.  Make it ignore leading blank
+   lines to match.
+
+ * For a long time, we carried an in-code comment that said our
+   colored output would work only when we use fprintf/fputs on
+   Windows, which no longer is the case for the past few years.
+
+ * "gc.autoPackLimit" when set to 1 should not trigger a repacking
+   when there is only one pack, but the code counted poorly and did
+   so.
+
+ * Add a test to specify the desired behaviour that currently is not
+   available in "git rebase -Xsubtree=...".
+
+ * More mark-up updates to typeset strings that are expected to
+   literally typed by the end user in fixed-width font.
+
+ * "git commit --amend --allow-empty-message -S" for a commit without
+   any message body could have misidentified where the header of the
+   commit object ends.
+
+ * "git rebase -i --autostash" did not restore the auto-stashed change
+   when the operation was aborted.
+
+ * Git does not know what the contents in the index should be for a
+   path added with "git add -N" yet, so "git grep --cached" should not
+   show hits (or show lack of hits, with -L) in such a path, but that
+   logic does not apply to "git grep", i.e. searching in the working
+   tree files.  But we did so by mistake, which has been corrected.
+
+ * "git blame -M" missed a single line that was moved within the file.
+
+ * Fix recently introduced codepaths that are involved in parallel
+   submodule operations, which gave up on reading too early, and
+   could have wasted CPU while attempting to write under a corner
+   case condition.
+
+ * "git grep -i" has been taught to fold case in non-ascii locales
+   correctly.
+
+ * A test that unconditionally used "mktemp" learned that the command
+   is not necessarily available everywhere.
+
+ * There are certain house-keeping tasks that need to be performed at
+   the very beginning of any Git program, and programs that are not
+   built-in commands had to do them exactly the same way as "git"
+   potty does.  It was easy to make mistakes in one-off standalone
+   programs (like test helpers).  A common "main()" function that
+   calls cmd_main() of individual program has been introduced to
+   make it harder to make mistakes.
+   (merge de61ceb jk/common-main later to maint).
+
+ * The test framework learned a new helper test_match_signal to
+   check an exit code from getting killed by an expected signal.
+
+ * General code clean-up around a helper function to write a
+   single-liner to a file.
+   (merge 7eb6e10 jk/write-file later to maint).
+
+ * One part of "git am" had an oddball helper function that called
+   stuff from outside "his" as opposed to calling what we have "ours",
+   which was not gender-neutral and also inconsistent with the rest of
+   the system where outside stuff is usuall called "theirs" in
+   contrast to "ours".
+
+ * "git blame file" allowed the lineage of lines in the uncommitted,
+   unadded contents of "file" to be inspected, but it refused when
+   "file" did not appear in the current commit.  When "file" was
+   created by renaming an existing file (but the change has not been
+   committed), this restriction was unnecessarily tight.
+
+ * "git add -N dir/file && git write-tree" produced an incorrect tree
+   when there are other paths in the same directory that sorts after
+   "file".
+
+ * "git fetch http://user:pass@host/repo..." scrubbed the userinfo
+   part, but "git push" didn't.
+
+ * "git merge" with renormalization did not work well with
+   merge-recursive, due to "safer crlf" conversion kicking in when it
+   shouldn't.
+   (merge 1335d76 jc/renormalize-merge-kill-safer-crlf later to maint).
+
+ * The use of strbuf in "git rm" to build filename to remove was a bit
+   suboptimal, which has been fixed.
+
+ * An age old bug that caused "git diff --ignore-space-at-eol"
+   misbehave has been fixed.
+
+ * "git notes merge" had a code to see if a path exists (and fails if
+   it does) and then open the path for writing (when it doesn't).
+   Replace it with open with O_EXCL.
+
+ * "git pack-objects" and "git index-pack" mostly operate with off_t
+   when talking about the offset of objects in a packfile, but there
+   were a handful of places that used "unsigned long" to hold that
+   value, leading to an unintended truncation.
+
+ * Recent update to "git daemon" tries to enable the socket-level
+   KEEPALIVE, but when it is spawned via inetd, the standard input
+   file descriptor may not necessarily be connected to a socket.
+   Suppress an ENOTSOCK error from setsockopt().
+
+ * Recent FreeBSD stopped making perl available at /usr/bin/perl;
+   switch the default the built-in path to /usr/local/bin/perl on not
+   too ancient FreeBSD releases.
+
+ * "git commit --help" said "--no-verify" is only about skipping the
+   pre-commit hook, and failed to say that it also skipped the
+   commit-msg hook.
+
+ * "git merge" in Git v2.9 was taught to forbid merging an unrelated
+   lines of history by default, but that is exactly the kind of thing
+   the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
+   "git subtree" has been taught to use the "--allow-unrelated-histories"
+   option to override the default.
+
+ * The build procedure for "git persistent-https" helper (in contrib/)
+   has been updated so that it can be built with more recent versions
+   of Go.
+
+ * There is an optimization used in "git diff $treeA $treeB" to borrow
+   an already checked-out copy in the working tree when it is known to
+   be the same as the blob being compared, expecting that open/mmap of
+   such a file is faster than reading it from the object store, which
+   involves inflating and applying delta.  This however kicked in even
+   when the checked-out copy needs to go through the convert-to-git
+   conversion (including the clean filter), which defeats the whole
+   point of the optimization.  The optimization has been disabled when
+   the conversion is necessary.
+
+ * "git -c grep.patternType=extended log --basic-regexp" misbehaved
+   because the internal API to access the grep machinery was not
+   designed well.
+
+ * Windows port was failing some tests in t4130, due to the lack of
+   inum in the returned values by its lstat(2) emulation.
+
+ * The reflog output format is documented better, and a new format
+   --date=unix to report the seconds-since-epoch (without timezone)
+   has been added.
+   (merge 442f6fd jk/reflog-date later to maint).
+
+ * "git difftool <paths>..." started in a subdirectory failed to
+   interpret the paths relative to that directory, which has been
+   fixed.
+
+ * The characters in the label shown for tags/refs for commits in
+   "gitweb" output are now properly escaped for proper HTML output.
+
+ * FreeBSD can lie when asked mtime of a directory, which made the
+   untracked cache code to fall back to a slow-path, which in turn
+   caused tests in t7063 to fail because it wanted to verify the
+   behaviour of the fast-path.
+
+ * Squelch compiler warnings for nedmalloc (in compat/) library.
+
+ * A small memory leak in the command line parsing of "git blame"
+   has been plugged.
+
+ * The API documentation for hashmap was unclear if hashmap_entry
+   can be safely discarded without any other consideration.  State
+   that it is safe to do so.
+
+ * Not-so-recent rewrite of "git am" that started making internal
+   calls into the commit machinery had an unintended regression, in
+   that no matter how many seconds it took to apply many patches, the
+   resulting committer timestamp for the resulting commits were all
+   the same.
+
+ * "git push --force-with-lease" already had enough logic to allow
+   ensuring that such a push results in creation of a ref (i.e. the
+   receiving end did not have another push from sideways that would be
+   discarded by our force-pushing), but didn't expose this possibility
+   to the users.  It does so now.
+   (merge 9eed4f3 jk/push-force-with-lease-creation later to maint).
+
+ * The mechanism to limit the pack window memory size, when packing is
+   done using multiple threads (which is the default), is per-thread,
+   but this was not documented clearly.
+   (merge 954176c ms/document-pack-window-memory-is-per-thread later to maint).
+
+ * "import-tars" fast-import script (in contrib/) used to ignore a
+   hardlink target and replaced it with an empty file, which has been
+   corrected to record the same blob as the other file the hardlink is
+   shared with.
+   (merge 04e0869 js/import-tars-hardlinks later to maint).
+
+ * "git mv dir non-existing-dir/" did not work in some environments
+   the same way as existing mainstream platforms.  The code now moves
+   "dir" to "non-existing-dir", without relying on rename("A", "B/")
+   that strips the trailing slash of '/'.
+   (merge 189d035 js/mv-dir-to-new-directory later to maint).
+
+ * The "t/" hierarchy is prone to get an unusual pathname; "make test"
+   has been taught to make sure they do not contain paths that cannot
+   be checked out on Windows (and the mechanism can be reusable to
+   catch pathnames that are not portable to other platforms as need
+   arises).
+   (merge c2cafd3 js/test-lint-pathname later to maint).
+
+ * When "git merge-recursive" works on history with many criss-cross
+   merges in "verbose" mode, the names the command assigns to the
+   virtual merge bases could have overwritten each other by unintended
+   reuse of the same piece of memory.
+   (merge 5447a76 rs/pull-signed-tag later to maint).
+
+ * "git checkout --detach <branch>" used to give the same advice
+   message as that is issued when "git checkout <tag>" (or anything
+   that is not a branch name) is given, but asking with "--detach" is
+   an explicit enough sign that the user knows what is going on.  The
+   advice message has been squelched in this case.
+   (merge 779b88a sb/checkout-explit-detach-no-advice later to maint).
+
+ * "git difftool" by default ignores the error exit from the backend
+   commands it spawns, because often they signal that they found
+   differences by exiting with a non-zero status code just like "diff"
+   does; the exit status codes 126 and above however are special in
+   that they are used to signal that the command is not executable,
+   does not exist, or killed by a signal.  "git difftool" has been
+   taught to notice these exit status codes.
+   (merge 45a4f5d jk/difftool-command-not-found later to maint).
+
+ * On Windows, help.browser configuration variable used to be ignored,
+   which has been corrected.
+   (merge 6db5967 js/no-html-bypass-on-windows later to maint).
+
+ * The "git -c var[=val] cmd" facility to append a configuration
+   variable definition at the end of the search order was described in
+   git(1) manual page, but not in git-config(1), which was more likely
+   place for people to look for when they ask "can I make a one-shot
+   override, and if so how?"
+   (merge ae1f709 dg/document-git-c-in-git-config-doc later to maint).
+
+ * The tempfile (hence its user lockfile) API lets the caller to open
+   a file descriptor to a temporary file, write into it and then
+   finalize it by first closing the filehandle and then either
+   removing or renaming the temporary file.  When the process spawns a
+   subprocess after obtaining the file descriptor, and if the
+   subprocess has not exited when the attempt to remove or rename is
+   made, the last step fails on Windows, because the subprocess has
+   the file descriptor still open.  Open tempfile with O_CLOEXEC flag
+   to avoid this (on Windows, this is mapped to O_NOINHERIT).
+   (merge 05d1ed6 bw/mingw-avoid-inheriting-fd-to-lockfile later to maint).
+
+ * Correct an age-old calco (is that a typo-like word for calc)
+   in the documentation.
+   (merge 7841c48 ls/packet-line-protocol-doc-fix later to maint).
+
+ * Other minor clean-ups and documentation updates
+   (merge 02a8cfa rs/merge-add-strategies-simplification later to maint).
+   (merge af4941d rs/merge-recursive-string-list-init later to maint).
+   (merge 1eb47f1 rs/use-strbuf-add-unique-abbrev later to maint).
+   (merge ddd0bfa jk/tighten-alloc later to maint).
+   (merge ecf30b2 rs/mailinfo-lib later to maint).
+   (merge 0eb75ce sg/reflog-past-root later to maint).
+   (merge 4369523 hv/doc-commit-reference-style later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.10.1.txt b/third_party/git/Documentation/RelNotes/2.10.1.txt
new file mode 100644
index 0000000000..70462f7f7e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.1.txt
@@ -0,0 +1,131 @@
+Git v2.10.1 Release Notes
+=========================
+
+Fixes since v2.10
+-----------------
+
+ * Clarify various ways to specify the "revision ranges" in the
+   documentation.
+
+ * "diff-highlight" script (in contrib/) learned to work better with
+   "git log -p --graph" output.
+
+ * The test framework left the number of tests and success/failure
+   count in the t/test-results directory, keyed by the name of the
+   test script plus the process ID.  The latter however turned out not
+   to serve any useful purpose.  The process ID part of the filename
+   has been removed.
+
+ * Having a submodule whose ".git" repository is somehow corrupt
+   caused a few commands that recurse into submodules loop forever.
+
+ * "git symbolic-ref -d HEAD" happily removes the symbolic ref, but
+   the resulting repository becomes an invalid one.  Teach the command
+   to forbid removal of HEAD.
+
+ * A test spawned a short-lived background process, which sometimes
+   prevented the test directory from getting removed at the end of the
+   script on some platforms.
+
+ * Update a few tests that used to use GIT_CURL_VERBOSE to use the
+   newer GIT_TRACE_CURL.
+
+ * Update Japanese translation for "git-gui".
+
+ * "git fetch http::/site/path" did not die correctly and segfaulted
+   instead.
+
+ * "git commit-tree" stopped reading commit.gpgsign configuration
+   variable that was meant for Porcelain "git commit" in Git 2.9; we
+   forgot to update "git gui" to look at the configuration to match
+   this change.
+
+ * "git log --cherry-pick" used to include merge commits as candidates
+   to be matched up with other commits, resulting a lot of wasted time.
+   The patch-id generation logic has been updated to ignore merges to
+   avoid the wastage.
+
+ * The http transport (with curl-multi option, which is the default
+   these days) failed to remove curl-easy handle from a curlm session,
+   which led to unnecessary API failures.
+
+ * "git diff -W" output needs to extend the context backward to
+   include the header line of the current function and also forward to
+   include the body of the entire current function up to the header
+   line of the next one.  This process may have to merge to adjacent
+   hunks, but the code forgot to do so in some cases.
+
+ * Performance tests done via "t/perf" did not use the same set of
+   build configuration if the user relied on autoconf generated
+   configuration.
+
+ * "git format-patch --base=..." feature that was recently added
+   showed the base commit information after "-- " e-mail signature
+   line, which turned out to be inconvenient.  The base information
+   has been moved above the signature line.
+
+ * Even when "git pull --rebase=preserve" (and the underlying "git
+   rebase --preserve") can complete without creating any new commit
+   (i.e. fast-forwards), it still insisted on having a usable ident
+   information (read: user.email is set correctly), which was less
+   than nice.  As the underlying commands used inside "git rebase"
+   would fail with a more meaningful error message and advice text
+   when the bogus ident matters, this extra check was removed.
+
+ * "git gc --aggressive" used to limit the delta-chain length to 250,
+   which is way too deep for gaining additional space savings and is
+   detrimental for runtime performance.  The limit has been reduced to
+   50.
+
+ * Documentation for individual configuration variables to control use
+   of color (like `color.grep`) said that their default value is
+   'false', instead of saying their default is taken from `color.ui`.
+   When we updated the default value for color.ui from 'false' to
+   'auto' quite a while ago, all of them broke.  This has been
+   corrected.
+
+ * A shell script example in check-ref-format documentation has been
+   fixed.
+
+ * "git checkout <word>" does not follow the usual disambiguation
+   rules when the <word> can be both a rev and a path, to allow
+   checking out a branch 'foo' in a project that happens to have a
+   file 'foo' in the working tree without having to disambiguate.
+   This was poorly documented and the check was incorrect when the
+   command was run from a subdirectory.
+
+ * Some codepaths in "git diff" used regexec(3) on a buffer that was
+   mmap(2)ed, which may not have a terminating NUL, leading to a read
+   beyond the end of the mapped region.  This was fixed by introducing
+   a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND
+   extension.
+
+ * The procedure to build Git on Mac OS X for Travis CI hardcoded the
+   internal directory structure we assumed HomeBrew uses, which was a
+   no-no.  The procedure has been updated to ask HomeBrew things we
+   need to know to fix this.
+
+ * When "git rebase -i" is given a broken instruction, it told the
+   user to fix it with "--edit-todo", but didn't say what the step
+   after that was (i.e. "--continue").
+
+ * "git add --chmod=+x" added recently lacked documentation, which has
+   been corrected.
+
+ * "git add --chmod=+x <pathspec>" added recently only toggled the
+   executable bit for paths that are either new or modified. This has
+   been corrected to flip the executable bit for all paths that match
+   the given pathspec.
+
+ * "git pack-objects --include-tag" was taught that when we know that
+   we are sending an object C, we want a tag B that directly points at
+   C but also a tag A that points at the tag B.  We used to miss the
+   intermediate tag B in some cases.
+
+ * Documentation around tools to import from CVS was fairly outdated.
+
+ * In the codepath that comes up with the hostname to be used in an
+   e-mail when the user didn't tell us, we looked at ai_canonname
+   field in struct addrinfo without making sure it is not NULL first.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.10.2.txt b/third_party/git/Documentation/RelNotes/2.10.2.txt
new file mode 100644
index 0000000000..c4d4397023
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.2.txt
@@ -0,0 +1,111 @@
+Git v2.10.2 Release Notes
+=========================
+
+Fixes since v2.10.1
+-------------------
+
+ * The code that parses the format parameter of for-each-ref command
+   has seen a micro-optimization.
+
+ * The "graph" API used in "git log --graph" miscounted the number of
+   output columns consumed so far when drawing a padding line, which
+   has been fixed; this did not affect any existing code as nobody
+   tried to write anything after the padding on such a line, though.
+
+ * Almost everybody uses DEFAULT_ABBREV to refer to the default
+   setting for the abbreviation, but "git blame" peeked into
+   underlying variable bypassing the macro for no good reason.
+
+ * Doc update to clarify what "log -3 --reverse" does.
+
+ * An author name, that spelled a backslash-quoted double quote in the
+   human readable part "My \"double quoted\" name", was not unquoted
+   correctly while applying a patch from a piece of e-mail.
+
+ * The original command line syntax for "git merge", which was "git
+   merge <msg> HEAD <parent>...", has been deprecated for quite some
+   time, and "git gui" was the last in-tree user of the syntax.  This
+   is finally fixed, so that we can move forward with the deprecation.
+
+ * Codepaths that read from an on-disk loose object were too loose in
+   validating what they are reading is a proper object file and
+   sometimes read past the data they read from the disk, which has
+   been corrected.  H/t to Gustavo Grieco for reporting.
+
+ * "git worktree", even though it used the default_abbrev setting that
+   ought to be affected by core.abbrev configuration variable, ignored
+   the variable setting.  The command has been taught to read the
+   default set of configuration variables to correct this.
+
+ * A low-level function verify_packfile() was meant to show errors
+   that were detected without dying itself, but under some conditions
+   it didn't and died instead, which has been fixed.
+
+ * When "git fetch" tries to find where the history of the repository
+   it runs in has diverged from what the other side has, it has a
+   mechanism to avoid digging too deep into irrelevant side branches.
+   This however did not work well over the "smart-http" transport due
+   to a design bug, which has been fixed.
+
+ * When we started cURL to talk to imap server when a new enough
+   version of cURL library is available, we forgot to explicitly add
+   imap(s):// before the destination.  To some folks, that didn't work
+   and the library tried to make HTTP(s) requests instead.
+
+ * The ./configure script generated from configure.ac was taught how
+   to detect support of SSL by libcurl better.
+
+ * http.emptyauth configuration is a way to allow an empty username to
+   pass when attempting to authenticate using mechanisms like
+   Kerberos.  We took an unspecified (NULL) username and sent ":"
+   (i.e. no username, no password) to CURLOPT_USERPWD, but did not do
+   the same when the username is explicitly set to an empty string.
+
+ * "git clone" of a local repository can be done at the filesystem
+   level, but the codepath did not check errors while copying and
+   adjusting the file that lists alternate object stores.
+
+ * Documentation for "git commit" was updated to clarify that "commit
+   -p <paths>" adds to the current contents of the index to come up
+   with what to commit.
+
+ * A stray symbolic link in $GIT_DIR/refs/ directory could make name
+   resolution loop forever, which has been corrected.
+
+ * The "submodule.<name>.path" stored in .gitmodules is never copied
+   to .git/config and such a key in .git/config has no meaning, but
+   the documentation described it and submodule.<name>.url next to
+   each other as if both belong to .git/config.  This has been fixed.
+
+ * Recent git allows submodule.<name>.branch to use a special token
+   "." instead of the branch name; the documentation has been updated
+   to describe it.
+
+ * In a worktree connected to a repository elsewhere, created via "git
+   worktree", "git checkout" attempts to protect users from confusion
+   by refusing to check out a branch that is already checked out in
+   another worktree.  However, this also prevented checking out a
+   branch, which is designated as the primary branch of a bare
+   reopsitory, in a worktree that is connected to the bare
+   repository.  The check has been corrected to allow it.
+
+ * "git rebase" immediately after "git clone" failed to find the fork
+   point from the upstream.
+
+ * When fetching from a remote that has many tags that are irrelevant
+   to branches we are following, we used to waste way too many cycles
+   when checking if the object pointed at by a tag (that we are not
+   going to fetch!) exists in our repository too carefully.
+
+ * The Travis CI configuration we ship ran the tests with --verbose
+   option but this risks non-TAP output that happens to be "ok" to be
+   misinterpreted as TAP signalling a test that passed.  This resulted
+   in unnecessary failure.  This has been corrected by introducing a
+   new mode to run our tests in the test harness to send the verbose
+   output separately to the log file.
+
+ * Some AsciiDoc formatter mishandles a displayed illustration with
+   tabs in it.  Adjust a few of them in merge-base documentation to
+   work around them.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.10.3.txt b/third_party/git/Documentation/RelNotes/2.10.3.txt
new file mode 100644
index 0000000000..ad6a01bf83
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.3.txt
@@ -0,0 +1,55 @@
+Git v2.10.3 Release Notes
+=========================
+
+Fixes since v2.10.2
+-------------------
+
+ * Extract a small helper out of the function that reads the authors
+   script file "git am" internally uses.
+   This by itself is not useful until a second caller appears in the
+   future for "rebase -i" helper.
+
+ * The command-line completion script (in contrib/) learned to
+   complete "git cmd ^mas<HT>" to complete the negative end of
+   reference to "git cmd ^master".
+
+ * "git send-email" attempts to pick up valid e-mails from the
+   trailers, but people in real world write non-addresses there, like
+   "Cc: Stable <add@re.ss> # 4.8+", which broke the output depending
+   on the availability and vintage of Mail::Address perl module.
+
+ * The code that we have used for the past 10+ years to cycle
+   4-element ring buffers turns out to be not quite portable in
+   theoretical world.
+
+ * "git daemon" used fixed-length buffers to turn URL to the
+   repository the client asked for into the server side directory
+   path, using snprintf() to avoid overflowing these buffers, but
+   allowed possibly truncated paths to the directory.  This has been
+   tightened to reject such a request that causes overlong path to be
+   required to serve.
+
+ * Recent update to git-sh-setup (a library of shell functions that
+   are used by our in-tree scripted Porcelain commands) included
+   another shell library git-sh-i18n without specifying where it is,
+   relying on the $PATH.  This has been fixed to be more explicit by
+   prefixing $(git --exec-path) output in front.
+
+ * Fix for a racy false-positive test failure.
+
+ * Portability update and workaround for builds on recent Mac OS X.
+
+ * Update to the test framework made in 2.9 timeframe broke running
+   the tests under valgrind, which has been fixed.
+
+ * Improve the rule to convert "unsigned char [20]" into "struct
+   object_id *" in contrib/coccinelle/
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.10.4.txt b/third_party/git/Documentation/RelNotes/2.10.4.txt
new file mode 100644
index 0000000000..ee8142ad24
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.4.txt
@@ -0,0 +1,4 @@
+Git v2.10.4 Release Notes
+=========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.10.5.txt b/third_party/git/Documentation/RelNotes/2.10.5.txt
new file mode 100644
index 0000000000..a498fd6fdc
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.10.5.txt
@@ -0,0 +1,17 @@
+Git v2.10.5 Release Notes
+=========================
+
+Fixes since v2.10.4
+-------------------
+
+ * "git cvsserver" no longer is invoked by "git daemon" by default,
+   as it is old and largely unmaintained.
+
+ * Various Perl scripts did not use safe_pipe_capture() instead of
+   backticks, leaving them susceptible to end-user input.  They have
+   been corrected.
+
+Credits go to joernchen <joernchen@phenoelit.de> for finding the
+unsafe constructs in "git cvsserver", and to Jeff King at GitHub for
+finding and fixing instances of the same issue in other scripts.
+
diff --git a/third_party/git/Documentation/RelNotes/2.11.0.txt b/third_party/git/Documentation/RelNotes/2.11.0.txt
new file mode 100644
index 0000000000..b7b7dd361e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.11.0.txt
@@ -0,0 +1,593 @@
+Git 2.11 Release Notes
+======================
+
+Backward compatibility notes.
+
+ * An empty string used as a pathspec element has always meant
+   'everything matches', but it is too easy to write a script that
+   finds a path to remove in $path and run 'git rm "$paht"' by
+   mistake (when the user meant to give "$path"), which ends up
+   removing everything.  This release starts warning about the
+   use of an empty string that is used for 'everything matches' and
+   asks users to use a more explicit '.' for that instead.
+
+   The hope is that existing users will not mind this change, and
+   eventually the warning can be turned into a hard error, upgrading
+   the deprecation into removal of this (mis)feature.
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+   has been deprecated for quite some time, and will be removed in the
+   next release (not this one).
+
+ * The default abbreviation length, which has historically been 7, now
+   scales as the repository grows, using the approximate number of
+   objects in the repository and a bit of math around the birthday
+   paradox.  The logic suggests to use 12 hexdigits for the Linux
+   kernel, and 9 to 10 for Git itself.
+
+
+Updates since v2.10
+-------------------
+
+UI, Workflows & Features
+
+ * Comes with new version of git-gui, now at its 0.21.0 tag.
+
+ * "git format-patch --cover-letter HEAD^" to format a single patch
+   with a separate cover letter now numbers the output as [PATCH 0/1]
+   and [PATCH 1/1] by default.
+
+ * An incoming "git push" that attempts to push too many bytes can now
+   be rejected by setting a new configuration variable at the receiving
+   end.
+
+ * "git nosuchcommand --help" said "No manual entry for gitnosuchcommand",
+   which was not intuitive, given that "git nosuchcommand" said "git:
+   'nosuchcommand' is not a git command".
+
+ * "git clone --recurse-submodules --reference $path $URL" is a way to
+   reduce network transfer cost by borrowing objects in an existing
+   $path repository when cloning the superproject from $URL; it
+   learned to also peek into $path for presence of corresponding
+   repositories of submodules and borrow objects from there when able.
+
+ * The "git diff --submodule={short,log}" mechanism has been enhanced
+   to allow "--submodule=diff" to show the patch between the submodule
+   commits bound to the superproject.
+
+ * Even though "git hash-objects", which is a tool to take an
+   on-filesystem data stream and put it into the Git object store,
+   can perform "outside-world-to-Git" conversions (e.g.
+   end-of-line conversions and application of the clean-filter), and
+   it has had this feature on by default from very early days, its reverse
+   operation "git cat-file", which takes an object from the Git object
+   store and externalizes it for consumption by the outside world,
+   lacked an equivalent mechanism to run the "Git-to-outside-world"
+   conversion.  The command learned the "--filters" option to do so.
+
+ * Output from "git diff" can be made easier to read by intelligently selecting
+   which lines are common and which lines are added/deleted
+   when the lines before and after the changed section
+   are the same.  A command line option (--indent-heuristic) and a
+   configuration variable (diff.indentHeuristic) are added to help with the
+   experiment to find good heuristics.
+
+ * In some projects, it is common to use "[RFC PATCH]" as the subject
+   prefix for a patch meant for discussion rather than application.  A
+   new format-patch option "--rfc" is a short-hand for "--subject-prefix=RFC PATCH"
+   to help the participants of such projects.
+
+ * "git add --chmod={+,-}x <pathspec>" only changed the
+   executable bit for paths that are either new or modified. This has
+   been corrected to change the executable bit for all paths that match
+   the given pathspec.
+
+ * When "git format-patch --stdout" output is placed as an in-body
+   header and it uses RFC2822 header folding, "git am" fails to
+   put the header line back into a single logical line.  The
+   underlying "git mailinfo" was taught to handle this properly.
+
+ * "gitweb" can spawn "highlight" to show blob contents with
+   (programming) language-specific syntax highlighting, but only
+   when the language is known.  "highlight" can however be told
+   to guess the language itself by giving it "--force" option, which
+   has been enabled.
+
+ * "git gui" l10n to Portuguese.
+
+ * When given an abbreviated object name that is not (or more
+   realistically, "no longer") unique, we gave a fatal error
+   "ambiguous argument".  This error is now accompanied by a hint that
+   lists the objects beginning with the given prefix.  During the
+   course of development of this new feature, numerous minor bugs were
+   uncovered and corrected, the most notable one of which is that we
+   gave "short SHA1 xxxx is ambiguous." twice without good reason.
+
+ * "git log rev^..rev" is an often-used revision range specification
+   to show what was done on a side branch merged at rev.  This has
+   gained a short-hand "rev^-1".  In general "rev^-$n" is the same as
+   "^rev^$n rev", i.e. what has happened on other branches while the
+   history leading to nth parent was looking the other way.
+
+ * In recent versions of cURL, GSSAPI credential delegation is
+   disabled by default due to CVE-2011-2192; introduce a http.delegation
+   configuration variable to selectively allow enabling this.
+   (merge 26a7b23429 ps/http-gssapi-cred-delegation later to maint).
+
+ * "git mergetool" learned to honor "-O<orderfile>" to control the
+   order of paths to present to the end user.
+
+ * "git diff/log --ws-error-highlight=<kind>" lacked the corresponding
+   configuration variable (diff.wsErrorHighlight) to set it by default.
+
+ * "git ls-files" learned the "--recurse-submodules" option
+   to get a listing of tracked files across submodules (i.e. this
+   only works with the "--cached" option, not for listing untracked or
+   ignored files).  This would be a useful tool to sit on the upstream
+   side of a pipe that is read with xargs to work on all working tree
+   files from the top-level superproject.
+
+ * A new credential helper that talks via "libsecret" with
+   implementations of XDG Secret Service API has been added to
+   contrib/credential/.
+
+ * The GPG verification status shown by the "%G?" pretty format specifier
+   was not rich enough to differentiate a signature made by an expired
+   key, a signature made by a revoked key, etc.  New output letters
+   have been assigned to express them.
+
+ * In addition to purely abbreviated commit object names, "gitweb"
+   learned to turn "git describe" output (e.g. v2.9.3-599-g2376d31787)
+   into clickable links in its output.
+
+ * "git commit" created an empty commit when invoked with an index
+   consisting solely of intend-to-add paths (added with "git add -N").
+   It now requires the "--allow-empty" option to create such a commit.
+   The same logic prevented "git status" from showing such paths as "new files" in the
+   "Changes not staged for commit" section.
+
+ * The smudge/clean filter API spawns an external process
+   to filter the contents of each path that has a filter defined.  A
+   new type of "process" filter API has been added to allow the first
+   request to run the filter for a path to spawn a single process, and
+   all filtering is served by this single process for multiple
+   paths, reducing the process creation overhead.
+
+ * The user always has to say "stash@{$N}" when naming a single
+   element in the default location of the stash, i.e. reflogs in
+   refs/stash.  The "git stash" command learned to accept "git stash
+   apply 4" as a short-hand for "git stash apply stash@{4}".
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The delta-base-cache mechanism has been a key to the performance in
+   a repository with a tightly packed packfile, but it did not scale
+   well even with a larger value of core.deltaBaseCacheLimit.
+
+ * Enhance "git status --porcelain" output by collecting more data on
+   the state of the index and the working tree files, which may
+   further be used to teach git-prompt (in contrib/) to make fewer
+   calls to git.
+
+ * Extract a small helper out of the function that reads the authors
+   script file "git am" internally uses.
+   (merge a77598e jc/am-read-author-file later to maint).
+
+ * Lift calls to exit(2) and die() higher in the callchain in
+   sequencer.c files so that more helper functions in it can be used
+   by callers that want to handle error conditions themselves.
+
+ * "git am" has been taught to make an internal call to "git apply"'s
+   innards without spawning the latter as a separate process.
+
+ * The ref-store abstraction was introduced to the refs API so that we
+   can plug in different backends to store references.
+
+ * The "unsigned char sha1[20]" to "struct object_id" conversion
+   continues.  Notable changes in this round includes that ce->sha1,
+   i.e. the object name recorded in the cache_entry, turns into an
+   object_id.
+
+ * JGit can show a fake ref "capabilities^{}" to "git fetch" when it
+   does not advertise any refs, but "git fetch" was not prepared to
+   see such an advertisement.  When the other side disconnects without
+   giving any ref advertisement, we used to say "there may not be a
+   repository at that URL", but we may have seen other advertisements
+   like "shallow" and ".have" in which case we definitely know that a
+   repository is there.  The code to detect this case has also been
+   updated.
+
+ * Some codepaths in "git pack-objects" were not ready to use an
+   existing pack bitmap; now they are and as a result they have
+   become faster.
+
+ * The codepath in "git fsck" to detect malformed tree objects has
+   been updated not to die but keep going after detecting them.
+
+ * We call "qsort(array, nelem, sizeof(array[0]), fn)", and most of
+   the time third parameter is redundant.  A new QSORT() macro lets us
+   omit it.
+
+ * "git pack-objects" in a repository with many packfiles used to
+   spend a lot of time looking for/at objects in them; the accesses to
+   the packfiles are now optimized by checking the most-recently-used
+   packfile first.
+   (merge c9af708b1a jk/pack-objects-optim-mru later to maint).
+
+ * Codepaths involved in interacting alternate object stores have
+   been cleaned up.
+
+ * In order for the receiving end of "git push" to inspect the
+   received history and decide to reject the push, the objects sent
+   from the sending end need to be made available to the hook and
+   the mechanism for the connectivity check, and this was done
+   traditionally by storing the objects in the receiving repository
+   and letting "git gc" expire them.  Instead, store the newly
+   received objects in a temporary area, and make them available by
+   reusing the alternate object store mechanism to them only while we
+   decide if we accept the check, and once we decide, either migrate
+   them to the repository or purge them immediately.
+
+ * The require_clean_work_tree() helper was recreated in C when "git
+   pull" was rewritten from shell; the helper is now made available to
+   other callers in preparation for upcoming "rebase -i" work.
+
+ * "git upload-pack" had its code cleaned-up and performance improved
+   by reducing use of timestamp-ordered commit-list, which was
+   replaced with a priority queue.
+
+ * "git diff --no-index" codepath has been updated not to try to peek
+   into a .git/ directory that happens to be under the current
+   directory, when we know we are operating outside any repository.
+
+ * Update of the sequencer codebase to make it reusable to reimplement
+   "rebase -i" continues.
+
+ * Git generally does not explicitly close file descriptors that were
+   open in the parent process when spawning a child process, but most
+   of the time the child does not want to access them. As Windows does
+   not allow removing or renaming a file that has a file descriptor
+   open, a slow-to-exit child can even break the parent process by
+   holding onto them.  Use O_CLOEXEC flag to open files in various
+   codepaths.
+
+ * Update "interpret-trailers" machinery and teach it that people in
+   the real world write all sorts of cruft in the "trailer" that was
+   originally designed to have the neat-o "Mail-Header: like thing"
+   and nothing else.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.10
+-----------------
+
+Unless otherwise noted, all the fixes since v2.9 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * Clarify various ways to specify the "revision ranges" in the
+   documentation.
+
+ * "diff-highlight" script (in contrib/) learned to work better with
+   "git log -p --graph" output.
+
+ * The test framework left the number of tests and success/failure
+   count in the t/test-results directory, keyed by the name of the
+   test script plus the process ID.  The latter however turned out not
+   to serve any useful purpose.  The process ID part of the filename
+   has been removed.
+
+ * Having a submodule whose ".git" repository is somehow corrupt
+   caused a few commands that recurse into submodules to loop forever.
+
+ * "git symbolic-ref -d HEAD" happily removes the symbolic ref, but
+   the resulting repository becomes an invalid one.  Teach the command
+   to forbid removal of HEAD.
+
+ * A test spawned a short-lived background process, which sometimes
+   prevented the test directory from getting removed at the end of the
+   script on some platforms.
+
+ * Update a few tests that used to use GIT_CURL_VERBOSE to use the
+   newer GIT_TRACE_CURL.
+
+ * "git pack-objects --include-tag" was taught that when we know that
+   we are sending an object C, we want a tag B that directly points at
+   C but also a tag A that points at the tag B.  We used to miss the
+   intermediate tag B in some cases.
+
+ * Update Japanese translation for "git-gui".
+
+ * "git fetch http::/site/path" did not die correctly and segfaulted
+   instead.
+
+ * "git commit-tree" stopped reading commit.gpgsign configuration
+   variable that was meant for Porcelain "git commit" in Git 2.9; we
+   forgot to update "git gui" to look at the configuration to match
+   this change.
+
+ * "git add --chmod={+,-}x" added recently lacked documentation, which has
+   been corrected.
+
+ * "git log --cherry-pick" used to include merge commits as candidates
+   to be matched up with other commits, resulting a lot of wasted time.
+   The patch-id generation logic has been updated to ignore merges and
+   avoid the wastage.
+
+ * The http transport (with curl-multi option, which is the default
+   these days) failed to remove curl-easy handle from a curlm session,
+   which led to unnecessary API failures.
+
+ * There were numerous corner cases in which the configuration files
+   are read and used or not read at all depending on the directory a
+   Git command was run, leading to inconsistent behaviour.  The code
+   to set-up repository access at the beginning of a Git process has
+   been updated to fix them.
+   (merge 4d0efa1 jk/setup-sequence-update later to maint).
+
+ * "git diff -W" output needs to extend the context backward to
+   include the header line of the current function and also forward to
+   include the body of the entire current function up to the header
+   line of the next one.  This process may have to merge two adjacent
+   hunks, but the code forgot to do so in some cases.
+
+ * Performance tests done via "t/perf" did not use the right
+   build configuration if the user relied on autoconf generated
+   configuration.
+
+ * "git format-patch --base=..." feature that was recently added
+   showed the base commit information after the "-- " e-mail signature
+   line, which turned out to be inconvenient.  The base information
+   has been moved above the signature line.
+
+ * More i18n.
+
+ * Even when "git pull --rebase=preserve" (and the underlying "git
+   rebase --preserve") can complete without creating any new commits
+   (i.e. fast-forwards), it still insisted on having usable ident
+   information (read: user.email is set correctly), which was less
+   than nice.  As the underlying commands used inside "git rebase"
+   would fail with a more meaningful error message and advice text
+   when the bogus ident matters, this extra check was removed.
+
+ * "git gc --aggressive" used to limit the delta-chain length to 250,
+   which is way too deep for gaining additional space savings and is
+   detrimental for runtime performance.  The limit has been reduced to
+   50.
+
+ * Documentation for individual configuration variables to control use
+   of color (like `color.grep`) said that their default value is
+   'false', instead of saying their default is taken from `color.ui`.
+   When we updated the default value for color.ui from 'false' to
+   'auto' quite a while ago, all of them broke.  This has been
+   corrected.
+
+ * The pretty-format specifier "%C(auto)" used by the "log" family of
+   commands to enable coloring of the output is taught to also issue a
+   color-reset sequence to the output.
+
+ * A shell script example in check-ref-format documentation has been
+   fixed.
+
+ * "git checkout <word>" does not follow the usual disambiguation
+   rules when the <word> can be both a rev and a path, to allow
+   checking out a branch 'foo' in a project that happens to have a
+   file 'foo' in the working tree without having to disambiguate.
+   This was poorly documented and the check was incorrect when the
+   command was run from a subdirectory.
+
+ * Some codepaths in "git diff" used regexec(3) on a buffer that was
+   mmap(2)ed, which may not have a terminating NUL, leading to a read
+   beyond the end of the mapped region.  This was fixed by introducing
+   a regexec_buf() helper that takes a <ptr,len> pair with REG_STARTEND
+   extension.
+
+ * The procedure to build Git on Mac OS X for Travis CI hardcoded the
+   internal directory structure we assumed HomeBrew uses, which was a
+   no-no.  The procedure has been updated to ask HomeBrew things we
+   need to know to fix this.
+
+ * When "git rebase -i" is given a broken instruction, it told the
+   user to fix it with "--edit-todo", but didn't say what the step
+   after that was (i.e. "--continue").
+
+ * Documentation around tools to import from CVS was fairly outdated.
+
+ * "git clone --recurse-submodules" lost the progress eye-candy in
+   a recent update, which has been corrected.
+
+ * A low-level function verify_packfile() was meant to show errors
+   that were detected without dying itself, but under some conditions
+   it didn't and died instead, which has been fixed.
+
+ * When "git fetch" tries to find where the history of the repository
+   it runs in has diverged from what the other side has, it has a
+   mechanism to avoid digging too deep into irrelevant side branches.
+   This however did not work well over the "smart-http" transport due
+   to a design bug, which has been fixed.
+
+ * In the codepath that comes up with the hostname to be used in an
+   e-mail when the user didn't tell us, we looked at the ai_canonname
+   field in struct addrinfo without making sure it is not NULL first.
+
+ * "git worktree", even though it used the default_abbrev setting that
+   ought to be affected by the core.abbrev configuration variable, ignored
+   the variable setting.  The command has been taught to read the
+   default set of configuration variables to correct this.
+
+ * "git init" tried to record core.worktree in the repository's
+   'config' file when the GIT_WORK_TREE environment variable was set and
+   it was different from where GIT_DIR appears as ".git" at its top,
+   but the logic was faulty when .git is a "gitdir:" file that points
+   at the real place, causing trouble in working trees that are
+   managed by "git worktree".  This has been corrected.
+
+ * Codepaths that read from an on-disk loose object were too loose in
+   validating that they are reading a proper object file and
+   sometimes read past the data they read from the disk, which has
+   been corrected.  H/t to Gustavo Grieco for reporting.
+
+ * The original command line syntax for "git merge", which was "git
+   merge <msg> HEAD <parent>...", has been deprecated for quite some
+   time, and "git gui" was the last in-tree user of the syntax.  This
+   is finally fixed, so that we can move forward with the deprecation.
+
+ * An author name that has a backslash-quoted double quote in the
+   human readable part ("My \"double quoted\" name"), was not unquoted
+   correctly while applying a patch from a piece of e-mail.
+
+ * Doc update to clarify what "log -3 --reverse" does.
+
+ * Almost everybody uses DEFAULT_ABBREV to refer to the default
+   setting for the abbreviation, but "git blame" peeked into
+   underlying variable bypassing the macro for no good reason.
+
+ * The "graph" API used in "git log --graph" miscounted the number of
+   output columns consumed so far when drawing a padding line, which
+   has been fixed; this did not affect any existing code as nobody
+   tried to write anything after the padding on such a line, though.
+
+ * The code that parses the format parameter of the for-each-ref command
+   has seen a micro-optimization.
+
+ * When we started to use cURL to talk to an imap server, we forgot to explicitly add
+   imap(s):// before the destination.  To some folks, that didn't work
+   and the library tried to make HTTP(s) requests instead.
+
+ * The ./configure script generated from configure.ac was taught how
+   to detect support of SSL by libcurl better.
+
+ * The command-line completion script (in contrib/) learned to
+   complete "git cmd ^mas<HT>" to complete the negative end of
+   reference to "git cmd ^master".
+   (merge 49416ad22a cp/completion-negative-refs later to maint).
+
+ * The existing "git fetch --depth=<n>" option was hard to use
+   correctly when making the history of an existing shallow clone
+   deeper.  A new option, "--deepen=<n>", has been added to make this
+   easier to use.  "git clone" also learned "--shallow-since=<date>"
+   and "--shallow-exclude=<tag>" options to make it easier to specify
+   "I am interested only in the recent N months worth of history" and
+   "Give me only the history since that version".
+   (merge cccf74e2da nd/shallow-deepen later to maint).
+
+ * "git blame --reverse OLD path" is now DWIMmed to show how lines
+   in path in an old revision OLD have survived up to the current
+   commit.
+   (merge e1d09701a4 jc/blame-reverse later to maint).
+
+ * The http.emptyauth configuration variable is a way to allow an empty username to
+   pass when attempting to authenticate using mechanisms like
+   Kerberos.  We took an unspecified (NULL) username and sent ":"
+   (i.e. no username, no password) to CURLOPT_USERPWD, but did not do
+   the same when the username is explicitly set to an empty string.
+
+ * "git clone" of a local repository can be done at the filesystem
+   level, but the codepath did not check errors while copying and
+   adjusting the file that lists alternate object stores.
+
+ * Documentation for "git commit" was updated to clarify that "commit
+   -p <paths>" adds to the current contents of the index to come up
+   with what to commit.
+
+ * A stray symbolic link in the $GIT_DIR/refs/ directory could make name
+   resolution loop forever, which has been corrected.
+
+ * The "submodule.<name>.path" stored in .gitmodules is never copied
+   to .git/config and such a key in .git/config has no meaning, but
+   the documentation described it next to submodule.<name>.url
+   as if both belong to .git/config.  This has been fixed.
+
+ * In a worktree created via "git
+   worktree", "git checkout" attempts to protect users from confusion
+   by refusing to check out a branch that is already checked out in
+   another worktree.  However, this also prevented checking out a
+   branch which is designated as the primary branch of a bare
+   repository, in a worktree that is connected to the bare
+   repository.  The check has been corrected to allow it.
+
+ * "git rebase" immediately after "git clone" failed to find the fork
+   point from the upstream.
+
+ * When fetching from a remote that has many tags that are irrelevant
+   to branches we are following, we used to waste way too many cycles
+   checking if the object pointed at by a tag (that we are not
+   going to fetch!) exists in our repository too carefully.
+
+ * Protect our code from over-eager compilers.
+
+ * Recent git allows submodule.<name>.branch to use a special token
+   "." instead of the branch name; the documentation has been updated
+   to describe it.
+
+ * "git send-email" attempts to pick up valid e-mails from the
+   trailers, but people in the real world write non-addresses there, like
+   "Cc: Stable <add@re.ss> # 4.8+", which broke the output depending
+   on the availability and vintage of the Mail::Address perl module.
+   (merge dcfafc5214 mm/send-email-cc-cruft-after-address later to maint).
+
+ * The Travis CI configuration we ship ran the tests with the --verbose
+   option but this risks non-TAP output that happens to be "ok" to be
+   misinterpreted as TAP signalling a test that passed.  This resulted
+   in unnecessary failures.  This has been corrected by introducing a
+   new mode to run our tests in the test harness to send the verbose
+   output separately to the log file.
+
+ * Some AsciiDoc formatters mishandle a displayed illustration with
+   tabs in it.  Adjust a few of them in merge-base documentation to
+   work around them.
+
+ * Fixed a minor regression in "git submodule" that was introduced
+   when more helper functions were reimplemented in C.
+   (merge 77b63ac31e sb/submodule-ignore-trailing-slash later to maint).
+
+ * The code that we have used for the past 10+ years to cycle
+   4-element ring buffers turns out to be not quite portable in
+   theoretical world.
+   (merge bb84735c80 rs/ring-buffer-wraparound later to maint).
+
+ * "git daemon" used fixed-length buffers to turn URLs to the
+   repository the client asked for into the server side directory
+   paths, using snprintf() to avoid overflowing these buffers, but
+   allowed possibly truncated paths to the directory.  This has been
+   tightened to reject such a request that causes an overlong path to be
+   served.
+   (merge 6bdb0083be jk/daemon-path-ok-check-truncation later to maint).
+
+ * Recent update to git-sh-setup (a library of shell functions that
+   are used by our in-tree scripted Porcelain commands) included
+   another shell library git-sh-i18n without specifying where it is,
+   relying on the $PATH.  This has been fixed to be more explicit by
+   prefixing with $(git --exec-path) output.
+   (merge 1073094f30 ak/sh-setup-dot-source-i18n-fix later to maint).
+
+ * Fix for a racy false-positive test failure.
+   (merge fdf4f6c79b as/merge-attr-sleep later to maint).
+
+ * Portability update and workaround for builds on recent Mac OS X.
+   (merge a296bc0132 ls/macos-update later to maint).
+
+ * Using a %(HEAD) placeholder in "for-each-ref --format=" option
+   caused the command to segfault when on an unborn branch.
+   (merge 84679d470d jc/for-each-ref-head-segfault-fix later to maint).
+
+ * "git rebase -i" did not work well with the core.commentchar
+   configuration variable for two reasons, both of which have been
+   fixed.
+   (merge 882cd23777 js/rebase-i-commentchar-fix later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge 5c238e29a8 jk/common-main later to maint).
+   (merge 5a5749e45b ak/pre-receive-hook-template-modefix later to maint).
+   (merge 6d834ac8f1 jk/rebase-config-insn-fmt-docfix later to maint).
+   (merge de9f7fa3b0 rs/commit-pptr-simplify later to maint).
+   (merge 4259d693fc sc/fmt-merge-msg-doc-markup-fix later to maint).
+   (merge 28fab7b23d nd/test-helpers later to maint).
+   (merge c2bb0c1d1e rs/cocci later to maint).
+   (merge 3285b7badb ps/common-info-doc later to maint).
+   (merge 2b090822e8 nd/worktree-lock later to maint).
+   (merge 4bd488ea7c jk/create-branch-remove-unused-param later to maint).
+   (merge 974e0044d6 tk/diffcore-delta-remove-unused later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.11.1.txt b/third_party/git/Documentation/RelNotes/2.11.1.txt
new file mode 100644
index 0000000000..9cd14c8197
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.11.1.txt
@@ -0,0 +1,168 @@
+Git v2.11.1 Release Notes
+=========================
+
+Fixes since v2.11
+-----------------
+
+ * The default Travis-CI configuration specifies newer P4 and GitLFS.
+
+ * The character width table has been updated to match Unicode 9.0
+
+ * Update the isatty() emulation for Windows by updating the previous
+   hack that depended on internals of (older) MSVC runtime.
+
+ * "git rev-parse --symbolic" failed with a more recent notation like
+   "HEAD^-1" and "HEAD^!".
+
+ * An empty directory in a working tree that can simply be nuked used
+   to interfere while merging or cherry-picking a change to create a
+   submodule directory there, which has been fixed..
+
+ * The code in "git push" to compute if any commit being pushed in the
+   superproject binds a commit in a submodule that hasn't been pushed
+   out was overly inefficient, making it unusable even for a small
+   project that does not have any submodule but have a reasonable
+   number of refs.
+
+ * "git push --dry-run --recurse-submodule=on-demand" wasn't
+   "--dry-run" in the submodules.
+
+ * The output from "git worktree list" was made in readdir() order,
+   and was unstable.
+
+ * mergetool.<tool>.trustExitCode configuration variable did not apply
+   to built-in tools, but now it does.
+
+ * "git p4" LFS support was broken when LFS stores an empty blob.
+
+ * Fix a corner case in merge-recursive regression that crept in
+   during 2.10 development cycle.
+
+ * Update the error messages from the dumb-http client when it fails
+   to obtain loose objects; we used to give sensible error message
+   only upon 404 but we now forbid unexpected redirects that needs to
+   be reported with something sensible.
+
+ * When diff.renames configuration is on (and with Git 2.9 and later,
+   it is enabled by default, which made it worse), "git stash"
+   misbehaved if a file is removed and another file with a very
+   similar content is added.
+
+ * "git diff --no-index" did not take "--no-abbrev" option.
+
+ * "git difftool --dir-diff" had a minor regression when started from
+   a subdirectory, which has been fixed.
+
+ * "git commit --allow-empty --only" (no pathspec) with dirty index
+   ought to be an acceptable way to create a new commit that does not
+   change any paths, but it was forbidden, perhaps because nobody
+   needed it so far.
+
+ * A pathname that begins with "//" or "\\" on Windows is special but
+   path normalization logic was unaware of it.
+
+ * "git pull --rebase", when there is no new commits on our side since
+   we forked from the upstream, should be able to fast-forward without
+   invoking "git rebase", but it didn't.
+
+ * The way to specify hotkeys to "xxdiff" that is used by "git
+   mergetool" has been modernized to match recent versions of xxdiff.
+
+ * Unlike "git am --abort", "git cherry-pick --abort" moved HEAD back
+   to where cherry-pick started while picking multiple changes, when
+   the cherry-pick stopped to ask for help from the user, and the user
+   did "git reset --hard" to a different commit in order to re-attempt
+   the operation.
+
+ * Code cleanup in shallow boundary computation.
+
+ * A recent update to receive-pack to make it easier to drop garbage
+   objects made it clear that GIT_ALTERNATE_OBJECT_DIRECTORIES cannot
+   have a pathname with a colon in it (no surprise!), and this in turn
+   made it impossible to push into a repository at such a path.  This
+   has been fixed by introducing a quoting mechanism used when
+   appending such a path to the colon-separated list.
+
+ * The function usage_msg_opt() has been updated to say "fatal:"
+   before the custom message programs give, when they want to die
+   with a message about wrong command line options followed by the
+   standard usage string.
+
+ * "git index-pack --stdin" needs an access to an existing repository,
+   but "git index-pack file.pack" to generate an .idx file that
+   corresponds to a packfile does not.
+
+ * Fix for NDEBUG builds.
+
+ * A lazy "git push" without refspec did not internally use a fully
+   specified refspec to perform 'current', 'simple', or 'upstream'
+   push, causing unnecessary "ambiguous ref" errors.
+
+ * "git p4" misbehaved when swapping a directory and a symbolic link.
+
+ * Even though an fix was attempted in Git 2.9.3 days, but running
+   "git difftool --dir-diff" from a subdirectory never worked. This
+   has been fixed.
+
+ * "git p4" that tracks multile p4 paths imported a single changelist
+   that touches files in these multiple paths as one commit, followed
+   by many empty commits.  This has been fixed.
+
+ * A potential but unlikely buffer overflow in Windows port has been
+   fixed.
+
+ * When the http server gives an incomplete response to a smart-http
+   rpc call, it could lead to client waiting for a full response that
+   will never come.  Teach the client side to notice this condition
+   and abort the transfer.
+
+ * Some platforms no longer understand "latin-1" that is still seen in
+   the wild in e-mail headers; replace them with "iso-8859-1" that is
+   more widely known when conversion fails from/to it.
+
+ * Update the procedure to generate "tags" for developer support.
+
+ * Update the definition of the MacOSX test environment used by
+   TravisCI.
+
+ * A few git-svn updates.
+
+ * Compression setting for producing packfiles were spread across
+   three codepaths, one of which did not honor any configuration.
+   Unify these so that all of them honor core.compression and
+   pack.compression variables the same way.
+
+ * "git fast-import" sometimes mishandled while rebalancing notes
+   tree, which has been fixed.
+
+ * Recent update to the default abbreviation length that auto-scales
+   lacked documentation update, which has been corrected.
+
+ * Leakage of lockfiles in the config subsystem has been fixed.
+
+ * It is natural that "git gc --auto" may not attempt to pack
+   everything into a single pack, and there is no point in warning
+   when the user has configured the system to use the pack bitmap,
+   leading to disabling further "gc".
+
+ * "git archive" did not read the standard configuration files, and
+   failed to notice a file that is marked as binary via the userdiff
+   driver configuration.
+
+ * "git blame --porcelain" misidentified the "previous" <commit, path>
+   pair (aka "source") when contents came from two or more files.
+
+ * "git rebase -i" with a recent update started showing an incorrect
+   count when squashing more than 10 commits.
+
+ * "git <cmd> @{push}" on a detached HEAD used to segfault; it has
+   been corrected to error out with a message.
+
+ * Tighten a test to avoid mistaking an extended ERE regexp engine as
+   a PRE regexp engine.
+
+ * Typing ^C to pager, which usually does not kill it, killed Git and
+   took the pager down as a collateral damage in certain process-tree
+   structure.  This has been fixed.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.11.2.txt b/third_party/git/Documentation/RelNotes/2.11.2.txt
new file mode 100644
index 0000000000..7428851168
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.11.2.txt
@@ -0,0 +1,12 @@
+Git v2.11.2 Release Notes
+=========================
+
+Fixes since v2.11.1
+-------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
diff --git a/third_party/git/Documentation/RelNotes/2.11.3.txt b/third_party/git/Documentation/RelNotes/2.11.3.txt
new file mode 100644
index 0000000000..4e3b78d0e8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.11.3.txt
@@ -0,0 +1,4 @@
+Git v2.11.3 Release Notes
+=========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.11.4.txt b/third_party/git/Documentation/RelNotes/2.11.4.txt
new file mode 100644
index 0000000000..ad4da8eb09
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.11.4.txt
@@ -0,0 +1,17 @@
+Git v2.11.4 Release Notes
+=========================
+
+Fixes since v2.11.3
+-------------------
+
+ * "git cvsserver" no longer is invoked by "git daemon" by default,
+   as it is old and largely unmaintained.
+
+ * Various Perl scripts did not use safe_pipe_capture() instead of
+   backticks, leaving them susceptible to end-user input.  They have
+   been corrected.
+
+Credits go to joernchen <joernchen@phenoelit.de> for finding the
+unsafe constructs in "git cvsserver", and to Jeff King at GitHub for
+finding and fixing instances of the same issue in other scripts.
+
diff --git a/third_party/git/Documentation/RelNotes/2.12.0.txt b/third_party/git/Documentation/RelNotes/2.12.0.txt
new file mode 100644
index 0000000000..ef8b97da9b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.0.txt
@@ -0,0 +1,500 @@
+Git 2.12 Release Notes
+======================
+
+Backward compatibility notes.
+
+ * Use of an empty string that is used for 'everything matches' is
+   still warned and Git asks users to use a more explicit '.' for that
+   instead.  The hope is that existing users will not mind this
+   change, and eventually the warning can be turned into a hard error,
+   upgrading the deprecation into removal of this (mis)feature.  That
+   is not scheduled to happen in the upcoming release (yet).
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+   has been deprecated for quite some time, and will be removed in a
+   future release.
+
+ * An ancient script "git relink" has been removed.
+
+
+Updates since v2.11
+-------------------
+
+UI, Workflows & Features
+
+ * Various updates to "git p4".
+
+ * "git p4" didn't interact with the internal of .git directory
+   correctly in the modern "git-worktree"-enabled world.
+
+ * "git branch --list" and friends learned "--ignore-case" option to
+   optionally sort branches and tags case insensitively.
+
+ * In addition to %(subject), %(body), "log --pretty=format:..."
+   learned a new placeholder %(trailers).
+
+ * "git rebase" learned "--quit" option, which allows a user to
+   remove the metadata left by an earlier "git rebase" that was
+   manually aborted without using "git rebase --abort".
+
+ * "git clone --reference $there --recurse-submodules $super" has been
+   taught to guess repositories usable as references for submodules of
+   $super that are embedded in $there while making a clone of the
+   superproject borrow objects from $there; extend the mechanism to
+   also allow submodules of these submodules to borrow repositories
+   embedded in these clones of the submodules embedded in the clone of
+   the superproject.
+
+ * Porcelain scripts written in Perl are getting internationalized.
+
+ * "git merge --continue" has been added as a synonym to "git commit"
+   to conclude a merge that has stopped due to conflicts.
+
+ * Finer-grained control of what protocols are allowed for transports
+   during clone/fetch/push have been enabled via a new configuration
+   mechanism.
+
+ * "git shortlog" learned "--committer" option to group commits by
+   committer, instead of author.
+
+ * GitLFS integration with "git p4" has been updated.
+
+ * The isatty() emulation for Windows has been updated to eradicate
+   the previous hack that depended on internals of (older) MSVC
+   runtime.
+
+ * Some platforms no longer understand "latin-1" that is still seen in
+   the wild in e-mail headers; replace them with "iso-8859-1" that is
+   more widely known when conversion fails from/to it.
+
+ * "git grep" has been taught to optionally recurse into submodules.
+
+ * "git rm" used to refuse to remove a submodule when it has its own
+   git repository embedded in its working tree.  It learned to move
+   the repository away to $GIT_DIR/modules/ of the superproject
+   instead, and allow the submodule to be deleted (as long as there
+   will be no loss of local modifications, that is).
+
+ * A recent updates to "git p4" was not usable for older p4 but it
+   could be made to work with minimum changes.  Do so.
+
+ * "git diff" learned diff.interHunkContext configuration variable
+   that gives the default value for its --inter-hunk-context option.
+
+ * The prereleaseSuffix feature of version comparison that is used in
+   "git tag -l" did not correctly when two or more prereleases for the
+   same release were present (e.g. when 2.0, 2.0-beta1, and 2.0-beta2
+   are there and the code needs to compare 2.0-beta1 and 2.0-beta2).
+
+ * "git submodule push" learned "--recurse-submodules=only option to
+   push submodules out without pushing the top-level superproject.
+
+ * "git tag" and "git verify-tag" learned to put GPG verification
+   status in their "--format=<placeholders>" output format.
+
+ * An ancient repository conversion tool left in contrib/ has been
+   removed.
+
+ * "git show-ref HEAD" used with "--verify" because the user is not
+   interested in seeing refs/remotes/origin/HEAD, and used with
+   "--head" because the user does not want HEAD to be filtered out,
+   i.e. "git show-ref --head --verify HEAD", did not work as expected.
+
+ * "git submodule add" used to be confused and refused to add a
+   locally created repository; users can now use "--force" option
+   to add them.
+   (merge 619acfc78c sb/submodule-add-force later to maint).
+
+ * Some people feel the default set of colors used by "git log --graph"
+   rather limiting.  A mechanism to customize the set of colors has
+   been introduced.
+
+ * "git read-tree" and its underlying unpack_trees() machinery learned
+   to report problematic paths prefixed with the --super-prefix option.
+
+ * When a submodule "A", which has another submodule "B" nested within
+   it, is "absorbed" into the top-level superproject, the inner
+   submodule "B" used to be left in a strange state.  The logic to
+   adjust the .git pointers in these submodules has been corrected.
+
+ * The user can specify a custom update method that is run when
+   "submodule update" updates an already checked out submodule.  This
+   was ignored when checking the submodule out for the first time and
+   we instead always just checked out the commit that is bound to the
+   path in the superproject's index.
+
+ * The command line completion (in contrib/) learned that
+   "git diff --submodule=" can take "diff" as a recently added option.
+
+ * The "core.logAllRefUpdates" that used to be boolean has been
+   enhanced to take 'always' as well, to record ref updates to refs
+   other than the ones that are expected to be updated (i.e. branches,
+   remote-tracking branches and notes).
+
+ * Comes with more command line completion (in contrib/) for recently
+   introduced options.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Commands that operate on a log message and add lines to the trailer
+   blocks, such as "format-patch -s", "cherry-pick (-x|-s)", and
+   "commit -s", have been taught to use the logic of and share the
+   code with "git interpret-trailer".
+
+ * The default Travis-CI configuration specifies newer P4 and GitLFS.
+
+ * The "fast hash" that had disastrous performance issues in some
+   corner cases has been retired from the internal diff.
+
+ * The character width table has been updated to match Unicode 9.0
+
+ * Update the procedure to generate "tags" for developer support.
+
+ * The codeflow of setting NOATIME and CLOEXEC on file descriptors Git
+   opens has been simplified.
+
+ * "git diff" and its family had two experimental heuristics to shift
+   the contents of a hunk to make the patch easier to read.  One of
+   them turns out to be better than the other, so leave only the
+   "--indent-heuristic" option and remove the other one.
+
+ * A new submodule helper "git submodule embedgitdirs" to make it
+   easier to move embedded .git/ directory for submodules in a
+   superproject to .git/modules/ (and point the latter with the former
+   that is turned into a "gitdir:" file) has been added.
+
+ * "git push \\server\share\dir" has recently regressed and then
+   fixed.  A test has retroactively been added for this breakage.
+
+ * Build updates for Cygwin.
+
+ * The implementation of "real_path()" was to go there with chdir(2)
+   and call getcwd(3), but this obviously wouldn't be usable in a
+   threaded environment.  Rewrite it to manually resolve relative
+   paths including symbolic links in path components.
+
+ * Adjust documentation to help AsciiDoctor render better while not
+   breaking the rendering done by AsciiDoc.
+
+ * The sequencer machinery has been further enhanced so that a later
+   set of patches can start using it to reimplement "rebase -i".
+
+ * Update the definition of the MacOSX test environment used by
+   TravisCI.
+
+ * Rewrite a scripted porcelain "git difftool" in C.
+
+ * "make -C t failed" will now run only the tests that failed in the
+   previous run.  This is usable only when prove is not use, and gives
+   a useless error message when run after "make clean", but otherwise
+   is serviceable.
+
+ * "uchar [40]" to "struct object_id" conversion continues.
+
+
+Also contains various documentation updates and code clean-ups.
+
+Fixes since v2.10
+-----------------
+
+Unless otherwise noted, all the fixes since v2.9 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * We often decide if a session is interactive by checking if the
+   standard I/O streams are connected to a TTY, but isatty() that
+   comes with Windows incorrectly returned true if it is used on NUL
+   (i.e. an equivalent to /dev/null).  This has been fixed.
+
+ * "git svn" did not work well with path components that are "0", and
+   some configuration variable it uses were not documented.
+
+ * "git rev-parse --symbolic" failed with a more recent notation like
+   "HEAD^-1" and "HEAD^!".
+
+ * An empty directory in a working tree that can simply be nuked used
+   to interfere while merging or cherry-picking a change to create a
+   submodule directory there, which has been fixed..
+
+ * The code in "git push" to compute if any commit being pushed in the
+   superproject binds a commit in a submodule that hasn't been pushed
+   out was overly inefficient, making it unusable even for a small
+   project that does not have any submodule but have a reasonable
+   number of refs.
+
+ * "git push --dry-run --recurse-submodule=on-demand" wasn't
+   "--dry-run" in the submodules.
+
+ * The output from "git worktree list" was made in readdir() order,
+   and was unstable.
+
+ * mergetool.<tool>.trustExitCode configuration variable did not apply
+   to built-in tools, but now it does.
+
+ * "git p4" LFS support was broken when LFS stores an empty blob.
+
+ * A corner case in merge-recursive regression that crept in
+   during 2.10 development cycle has been fixed.
+
+ * Transport with dumb http can be fooled into following foreign URLs
+   that the end user does not intend to, especially with the server
+   side redirects and http-alternates mechanism, which can lead to
+   security issues.  Tighten the redirection and make it more obvious
+   to the end user when it happens.
+
+ * Update the error messages from the dumb-http client when it fails
+   to obtain loose objects; we used to give sensible error message
+   only upon 404 but we now forbid unexpected redirects that needs to
+   be reported with something sensible.
+
+ * When diff.renames configuration is on (and with Git 2.9 and later,
+   it is enabled by default, which made it worse), "git stash"
+   misbehaved if a file is removed and another file with a very
+   similar content is added.
+
+ * "git diff --no-index" did not take "--no-abbrev" option.
+
+ * "git difftool --dir-diff" had a minor regression when started from
+   a subdirectory, which has been fixed.
+
+ * "git commit --allow-empty --only" (no pathspec) with dirty index
+   ought to be an acceptable way to create a new commit that does not
+   change any paths, but it was forbidden, perhaps because nobody
+   needed it so far.
+
+ * Git 2.11 had a minor regression in "merge --ff-only" that competed
+   with another process that simultaneously attempted to update the
+   index. We used to explain what went wrong with an error message,
+   but the new code silently failed.  The error message has been
+   resurrected.
+
+ * A pathname that begins with "//" or "\\" on Windows is special but
+   path normalization logic was unaware of it.
+
+ * "git pull --rebase", when there is no new commits on our side since
+   we forked from the upstream, should be able to fast-forward without
+   invoking "git rebase", but it didn't.
+
+ * The way to specify hotkeys to "xxdiff" that is used by "git
+   mergetool" has been modernized to match recent versions of xxdiff.
+
+ * Unlike "git am --abort", "git cherry-pick --abort" moved HEAD back
+   to where cherry-pick started while picking multiple changes, when
+   the cherry-pick stopped to ask for help from the user, and the user
+   did "git reset --hard" to a different commit in order to re-attempt
+   the operation.
+
+ * Code cleanup in shallow boundary computation.
+
+ * A recent update to receive-pack to make it easier to drop garbage
+   objects made it clear that GIT_ALTERNATE_OBJECT_DIRECTORIES cannot
+   have a pathname with a colon in it (no surprise!), and this in turn
+   made it impossible to push into a repository at such a path.  This
+   has been fixed by introducing a quoting mechanism used when
+   appending such a path to the colon-separated list.
+
+ * The function usage_msg_opt() has been updated to say "fatal:"
+   before the custom message programs give, when they want to die
+   with a message about wrong command line options followed by the
+   standard usage string.
+
+ * "git index-pack --stdin" needs an access to an existing repository,
+   but "git index-pack file.pack" to generate an .idx file that
+   corresponds to a packfile does not.
+
+ * Fix for NDEBUG builds.
+
+ * A lazy "git push" without refspec did not internally use a fully
+   specified refspec to perform 'current', 'simple', or 'upstream'
+   push, causing unnecessary "ambiguous ref" errors.
+
+ * "git p4" misbehaved when swapping a directory and a symbolic link.
+
+ * Even though an fix was attempted in Git 2.9.3 days, but running
+   "git difftool --dir-diff" from a subdirectory never worked. This
+   has been fixed.
+
+ * "git p4" that tracks multile p4 paths imported a single changelist
+   that touches files in these multiple paths as one commit, followed
+   by many empty commits.  This has been fixed.
+
+ * A potential but unlikely buffer overflow in Windows port has been
+   fixed.
+
+ * When the http server gives an incomplete response to a smart-http
+   rpc call, it could lead to client waiting for a full response that
+   will never come.  Teach the client side to notice this condition
+   and abort the transfer.
+
+ * Compression setting for producing packfiles were spread across
+   three codepaths, one of which did not honor any configuration.
+   Unify these so that all of them honor core.compression and
+   pack.compression variables the same way.
+
+ * "git fast-import" sometimes mishandled while rebalancing notes
+   tree, which has been fixed.
+
+ * Recent update to the default abbreviation length that auto-scales
+   lacked documentation update, which has been corrected.
+
+ * Leakage of lockfiles in the config subsystem has been fixed.
+
+ * It is natural that "git gc --auto" may not attempt to pack
+   everything into a single pack, and there is no point in warning
+   when the user has configured the system to use the pack bitmap,
+   leading to disabling further "gc".
+
+ * "git archive" did not read the standard configuration files, and
+   failed to notice a file that is marked as binary via the userdiff
+   driver configuration.
+
+ * "git blame --porcelain" misidentified the "previous" <commit, path>
+   pair (aka "source") when contents came from two or more files.
+
+ * "git rebase -i" with a recent update started showing an incorrect
+   count when squashing more than 10 commits.
+
+ * "git <cmd> @{push}" on a detached HEAD used to segfault; it has
+   been corrected to error out with a message.
+
+ * Running "git add a/b" when "a" is a submodule correctly errored
+   out, but without a meaningful error message.
+   (merge 2d81c48fa7 sb/pathspec-errors later to maint).
+
+ * Typing ^C to pager, which usually does not kill it, killed Git and
+   took the pager down as a collateral damage in certain process-tree
+   structure.  This has been fixed.
+
+ * "git mergetool" without any pathspec on the command line that is
+   run from a subdirectory became no-op in Git v2.11 by mistake, which
+   has been fixed.
+
+ * Retire long unused/unmaintained gitview from the contrib/ area.
+   (merge 3120925c25 sb/remove-gitview later to maint).
+
+ * Tighten a test to avoid mistaking an extended ERE regexp engine as
+   a PRE regexp engine.
+
+ * An error message with an ASCII control character like '\r' in it
+   can alter the message to hide its early part, which is problematic
+   when a remote side gives such an error message that the local side
+   will relay with a "remote: " prefix.
+   (merge f290089879 jk/vreport-sanitize later to maint).
+
+ * "git fsck" inspects loose objects more carefully now.
+   (merge cce044df7f jk/loose-object-fsck later to maint).
+
+ * A crashing bug introduced in v2.11 timeframe has been found (it is
+   triggerable only in fast-import) and fixed.
+   (merge abd5a00268 jk/clear-delta-base-cache-fix later to maint).
+
+ * With an anticipatory tweak for remotes defined in ~/.gitconfig
+   (e.g. "remote.origin.prune" set to true, even though there may or
+   may not actually be "origin" remote defined in a particular Git
+   repository), "git remote rename" and other commands misinterpreted
+   and behaved as if such a non-existing remote actually existed.
+   (merge e459b073fb js/remote-rename-with-half-configured-remote later to maint).
+
+ * A few codepaths had to rely on a global variable when sorting
+   elements of an array because sort(3) API does not allow extra data
+   to be passed to the comparison function.  Use qsort_s() when
+   natively available, and a fallback implementation of it when not,
+   to eliminate the need, which is a prerequisite for making the
+   codepath reentrant.
+
+ * "git fsck --connectivity-check" was not working at all.
+   (merge a2b22854bd jk/fsck-connectivity-check-fix later to maint).
+
+ * After starting "git rebase -i", which first opens the user's editor
+   to edit the series of patches to apply, but before saving the
+   contents of that file, "git status" failed to show the current
+   state (i.e. you are in an interactive rebase session, but you have
+   applied no steps yet) correctly.
+   (merge df9ded4984 js/status-pre-rebase-i later to maint).
+
+ * Test tweak for FreeBSD where /usr/bin/unzip is unsuitable to run
+   our tests but /usr/local/bin/unzip is usable.
+   (merge d98b2c5fce js/unzip-in-usr-bin-workaround later to maint).
+
+ * "git p4" did not work well with multiple git-p4.mapUser entries on
+   Windows.
+   (merge c3c2b05776 gv/mingw-p4-mapuser later to maint).
+
+ * "git help" enumerates executable files in $PATH; the implementation
+   of "is this file executable?" on Windows has been optimized.
+   (merge c755015f79 hv/mingw-help-is-executable later to maint).
+
+ * Test tweaks for those who have default ACL in their git source tree
+   that interfere with the umask test.
+   (merge d549d21307 mm/reset-facl-before-umask-test later to maint).
+
+ * Names of the various hook scripts must be spelled exactly, but on
+   Windows, an .exe binary must be named with .exe suffix; notice
+   $GIT_DIR/hooks/<hookname>.exe as a valid <hookname> hook.
+   (merge 235be51fbe js/mingw-hooks-with-exe-suffix later to maint).
+
+ * Asciidoctor, an alternative reimplementation of AsciiDoc, still
+   needs some changes to work with documents meant to be formatted
+   with AsciiDoc.  "make USE_ASCIIDOCTOR=YesPlease" to use it out of
+   the box to document our pages is getting closer to reality.
+
+ * Correct command line completion (in contrib/) on "git svn"
+   (merge 2cbad17642 ew/complete-svn-authorship-options later to maint).
+
+ * Incorrect usage help message for "git worktree prune" has been fixed.
+   (merge 2488dcab22 ps/worktree-prune-help-fix later to maint).
+
+ * Adjust a perf test to new world order where commands that do
+   require a repository are really strict about having a repository.
+   (merge c86000c1a7 rs/p5302-create-repositories-before-tests later to maint).
+
+ * "git log --graph" did not work well with "--name-only", even though
+   other forms of "diff" output were handled correctly.
+   (merge f5022b5fed jk/log-graph-name-only later to maint).
+
+ * The push-options given via the "--push-options" option were not
+   passed through to external remote helpers such as "smart HTTP" that
+   are invoked via the transport helper.
+
+ * The documentation explained what "git stash" does to the working
+   tree (after stashing away the local changes) in terms of "reset
+   --hard", which was exposing an unnecessary implementation detail.
+   (merge 20a7e06172 tg/stash-doc-cleanup later to maint).
+
+ * When "git p4" imports changelist that removes paths, it failed to
+   convert pathnames when the p4 used encoding different from the one
+   used on the Git side.  This has been corrected.
+   (merge a8b05162e8 ls/p4-path-encoding later to maint).
+
+ * A new coccinelle rule that catches a check of !pointer before the
+   pointer is free(3)d, which most likely is a bug.
+   (merge ec6cd14c7a rs/cocci-check-free-only-null later to maint).
+
+ * "ls-files" run with pathspec has been micro-optimized to avoid
+   having to memmove(3) unnecessary bytes.
+   (merge 96f6d3f61a rs/ls-files-partial-optim later to maint).
+
+ * A hotfix for a topic already in 'master'.
+   (merge a4d92d579f js/mingw-isatty later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge f2627d9b19 sb/submodule-config-cleanup later to maint).
+   (merge 384f1a167b sb/unpack-trees-cleanup later to maint).
+   (merge 874444b704 rh/diff-orderfile-doc later to maint).
+   (merge eafd5d9483 cw/doc-sign-off later to maint).
+   (merge 0aaad415bc rs/absolute-pathdup later to maint).
+   (merge 4432dd6b5b rs/receive-pack-cleanup later to maint).
+   (merge 540a398e9c sg/mailmap-self later to maint).
+   (merge 209df269a6 nd/rev-list-all-includes-HEAD-doc later to maint).
+   (merge 941b9c5270 sb/doc-unify-bottom later to maint).
+   (merge 2aaf37b62c jk/doc-remote-helpers-markup-fix later to maint).
+   (merge e91461b332 jk/doc-submodule-markup-fix later to maint).
+   (merge 8ab9740d9f dp/submodule-doc-markup-fix later to maint).
+   (merge 0838cbc22f jk/tempfile-ferror-fclose-confusion later to maint).
+   (merge 115a40add6 dr/doc-check-ref-format-normalize later to maint).
+   (merge 133f0a299d gp/document-dotfiles-in-templates-are-not-copied later to maint).
+   (merge 2b35a9f4c7 bc/blame-doc-fix later to maint).
+   (merge 7e82388024 ps/doc-gc-aggressive-depth-update later to maint).
+   (merge 9993a7c5f1 bc/worktree-doc-fix-detached later to maint).
+   (merge e519eccdf4 rt/align-add-i-help-text later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.12.1.txt b/third_party/git/Documentation/RelNotes/2.12.1.txt
new file mode 100644
index 0000000000..a74f7db747
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.1.txt
@@ -0,0 +1,41 @@
+Git v2.12.1 Release Notes
+=========================
+
+Fixes since v2.12
+-----------------
+
+ * Reduce authentication round-trip over HTTP when the server supports
+   just a single authentication method.  This also improves the
+   behaviour when Git is misconfigured to enable http.emptyAuth
+   against a server that does not authenticate without a username
+   (i.e. not using Kerberos etc., which makes http.emptyAuth
+   pointless).
+
+ * Windows port wants to use OpenSSL's implementation of SHA-1
+   routines, so let them.
+
+ * Add 32-bit Linux variant to the set of platforms to be tested with
+   Travis CI.
+
+ * When a redirected http transport gets an error during the
+   redirected request, we ignored the error we got from the server,
+   and ended up giving a not-so-useful error message.
+
+ * The patch subcommand of "git add -i" was meant to have paths
+   selection prompt just like other subcommand, unlike "git add -p"
+   directly jumps to hunk selection.  Recently, this was broken and
+   "add -i" lost the paths selection dialog, but it now has been
+   fixed.
+
+ * Git v2.12 was shipped with an embarrassing breakage where various
+   operations that verify paths given from the user stopped dying when
+   seeing an issue, and instead later triggering segfault.
+
+ * The code to parse "git log -L..." command line was buggy when there
+   are many ranges specified with -L; overrun of the allocated buffer
+   has been fixed.
+
+ * The command-line parsing of "git log -L" copied internal data
+   structures using incorrect size on ILP32 systems.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.12.2.txt b/third_party/git/Documentation/RelNotes/2.12.2.txt
new file mode 100644
index 0000000000..441939709c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.2.txt
@@ -0,0 +1,83 @@
+Git v2.12.2 Release Notes
+=========================
+
+Fixes since v2.12.1
+-------------------
+
+ * "git status --porcelain" is supposed to give a stable output, but a
+   few strings were left as translatable by mistake.
+
+ * "Dumb http" transport used to misparse a nonsense http-alternates
+   response, which has been fixed.
+
+ * "git diff --quiet" relies on the size field in diff_filespec to be
+   correctly populated, but diff_populate_filespec() helper function
+   made an incorrect short-cut when asked only to populate the size
+   field for paths that need to go through convert_to_git() (e.g. CRLF
+   conversion).
+
+ * There is no need for Python only to give a few messages to the
+   standard error stream, but we somehow did.
+
+ * A leak in a codepath to read from a packed object in (rare) cases
+   has been plugged.
+
+ * "git upload-pack", which is a counter-part of "git fetch", did not
+   report a request for a ref that was not advertised as invalid.
+   This is generally not a problem (because "git fetch" will stop
+   before making such a request), but is the right thing to do.
+
+ * A "gc.log" file left by a backgrounded "gc --auto" disables further
+   automatic gc; it has been taught to run at least once a day (by
+   default) by ignoring a stale "gc.log" file that is too old.
+
+ * "git remote rm X", when a branch has remote X configured as the
+   value of its branch.*.remote, tried to remove branch.*.remote and
+   branch.*.merge and failed if either is unset.
+
+ * A caller of tempfile API that uses stdio interface to write to
+   files may ignore errors while writing, which is detected when
+   tempfile is closed (with a call to ferror()).  By that time, the
+   original errno that may have told us what went wrong is likely to
+   be long gone and was overwritten by an irrelevant value.
+   close_tempfile() now resets errno to EIO to make errno at least
+   predictable.
+
+ * "git show-branch" expected there were only very short branch names
+   in the repository and used a fixed-length buffer to hold them
+   without checking for overflow.
+
+ * The code that parses header fields in the commit object has been
+   updated for (micro)performance and code hygiene.
+
+ * A test that creates a confusing branch whose name is HEAD has been
+   corrected not to do so.
+
+ * "Cc:" on the trailer part does not have to conform to RFC strictly,
+   unlike in the e-mail header.  "git send-email" has been updated to
+   ignore anything after '>' when picking addresses, to allow non-address
+   cruft like " # stable 4.4" after the address.
+
+ * "git push" had a handful of codepaths that could lead to a deadlock
+   when unexpected error happened, which has been fixed.
+
+ * Code to read submodule.<name>.ignore config did not state the
+   variable name correctly when giving an error message diagnosing
+   misconfiguration.
+
+ * "git ls-remote" and "git archive --remote" are designed to work
+   without being in a directory under Git's control.  However, recent
+   updates revealed that we randomly look into a directory called
+   .git/ without actually doing necessary set-up when working in a
+   repository.  Stop doing so.
+
+ * The code to parse the command line "git grep <patterns>... <rev>
+   [[--] <pathspec>...]" has been cleaned up, and a handful of bugs
+   have been fixed (e.g. we used to check "--" if it is a rev).
+
+ * The code to parse "git -c VAR=VAL cmd" and set configuration
+   variable for the duration of cmd had two small bugs, which have
+   been fixed.
+   This supersedes jc/config-case-cmdline topic that has been discarded.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.12.3.txt b/third_party/git/Documentation/RelNotes/2.12.3.txt
new file mode 100644
index 0000000000..ebca846d5d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.3.txt
@@ -0,0 +1,64 @@
+Git v2.12.3 Release Notes
+=========================
+
+Fixes since v2.12.2
+-------------------
+
+ * The "parse_config_key()" API function has been cleaned up.
+
+ * An helper function to make it easier to append the result from
+   real_path() to a strbuf has been added.
+
+ * The t/perf performance test suite was not prepared to test not so
+   old versions of Git, but now it covers versions of Git that are not
+   so ancient.
+
+ * Picking two versions of Git and running tests to make sure the
+   older one and the newer one interoperate happily has now become
+   possible.
+
+ * Teach the "debug" helper used in the test framework that allows a
+   command to run under "gdb" to make the session interactive.
+
+ * "git repack --depth=<n>" for a long time busted the specified depth
+   when reusing delta from existing packs.  This has been corrected.
+
+ * user.email that consists of only cruft chars should consistently
+   error out, but didn't.
+
+ * A few tests were run conditionally under (rare) conditions where
+   they cannot be run (like running cvs tests under 'root' account).
+
+ * "git branch @" created refs/heads/@ as a branch, and in general the
+   code that handled @{-1} and @{upstream} was a bit too loose in
+   disambiguating.
+
+ * "git fetch" that requests a commit by object name, when the other
+   side does not allow such an request, failed without much
+   explanation.
+
+ * "git filter-branch --prune-empty" drops a single-parent commit that
+   becomes a no-op, but did not drop a root commit whose tree is empty.
+
+ * Recent versions of Git treats http alternates (used in dumb http
+   transport) just like HTTP redirects and requires the client to
+   enable following it, due to security concerns.  But we forgot to
+   give a warning when we decide not to honor the alternates.
+
+ * NO_PTHREADS build has been broken for some time; now fixed.
+
+ * Fix for potential segv introduced in v2.11.0 and later (also
+   v2.10.2).
+
+ * A few unterminated here documents in tests were fixed, which in
+   turn revealed incorrect expectations the tests make. These tests
+   have been updated.
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.12.4.txt b/third_party/git/Documentation/RelNotes/2.12.4.txt
new file mode 100644
index 0000000000..3f56938221
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.4.txt
@@ -0,0 +1,4 @@
+Git v2.12.4 Release Notes
+=========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.12.5.txt b/third_party/git/Documentation/RelNotes/2.12.5.txt
new file mode 100644
index 0000000000..8fa73cfce7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.12.5.txt
@@ -0,0 +1,17 @@
+Git v2.12.5 Release Notes
+=========================
+
+Fixes since v2.12.4
+-------------------
+
+ * "git cvsserver" no longer is invoked by "git daemon" by default,
+   as it is old and largely unmaintained.
+
+ * Various Perl scripts did not use safe_pipe_capture() instead of
+   backticks, leaving them susceptible to end-user input.  They have
+   been corrected.
+
+Credits go to joernchen <joernchen@phenoelit.de> for finding the
+unsafe constructs in "git cvsserver", and to Jeff King at GitHub for
+finding and fixing instances of the same issue in other scripts.
+
diff --git a/third_party/git/Documentation/RelNotes/2.13.0.txt b/third_party/git/Documentation/RelNotes/2.13.0.txt
new file mode 100644
index 0000000000..aa99d4b3ce
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.0.txt
@@ -0,0 +1,618 @@
+Git 2.13 Release Notes
+======================
+
+Backward compatibility notes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is still warned and Git asks users to use a
+   more explicit '.' for that instead.  The hope is that existing
+   users will not mind this change, and eventually the warning can be
+   turned into a hard error, upgrading the deprecation into removal of
+   this (mis)feature.  That is not scheduled to happen in the upcoming
+   release (yet).
+
+ * The historical argument order "git merge <msg> HEAD <commit>..."
+   has been deprecated for quite some time, and is now removed.
+
+ * The default location "~/.git-credential-cache/socket" for the
+   socket used to communicate with the credential-cache daemon has
+   been moved to "~/.cache/git/credential/socket".
+
+ * Git now avoids blindly falling back to ".git" when the setup
+   sequence said we are _not_ in Git repository.  A corner case that
+   happens to work right now may be broken by a call to die("BUG").
+   We've tried hard to locate such cases and fixed them, but there
+   might still be cases that need to be addressed--bug reports are
+   greatly appreciated.
+
+
+Updates since v2.12
+-------------------
+
+UI, Workflows & Features
+
+ * "git describe" and "git name-rev" have been taught to take more
+   than one refname patterns to restrict the set of refs to base their
+   naming output on, and also learned to take negative patterns to
+   name refs not to be used for naming via their "--exclude" option.
+
+ * Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
+   once there no longer is any other branch whose name begins with
+   "foo/", but we didn't do so so far.  Now we do.
+
+ * When "git merge" detects a path that is renamed in one history
+   while the other history deleted (or modified) it, it now reports
+   both paths to help the user understand what is going on in the two
+   histories being merged.
+
+ * The <url> part in "http.<url>.<variable>" configuration variable
+   can now be spelled with '*' that serves as wildcard.
+   E.g. "http.https://*.example.com.proxy" can be used to specify the
+   proxy used for https://a.example.com, https://b.example.com, etc.,
+   i.e. any host in the example.com domain.
+
+ * "git tag" did not leave useful message when adding a new entry to
+   reflog; this was left unnoticed for a long time because refs/tags/*
+   doesn't keep reflog by default.
+
+ * The "negative" pathspec feature was somewhat more cumbersome to use
+   than necessary in that its short-hand used "!" which needed to be
+   escaped from shells, and it required "exclude from what?" specified.
+
+ * The command line options for ssh invocation needs to be tweaked for
+   some implementations of SSH (e.g. PuTTY plink wants "-P <port>"
+   while OpenSSH wants "-p <port>" to specify port to connect to), and
+   the variant was guessed when GIT_SSH environment variable is used
+   to specify it.  The logic to guess now applies to the command
+   specified by the newer GIT_SSH_COMMAND and also core.sshcommand
+   configuration variable, and comes with an escape hatch for users to
+   deal with misdetected cases.
+
+ * The "--git-path", "--git-common-dir", and "--shared-index-path"
+   options of "git rev-parse" did not produce usable output.  They are
+   now updated to show the path to the correct file, relative to where
+   the caller is.
+
+ * "git diff -W" has been taught to handle the case where a new
+   function is added at the end of the file better.
+
+ * "git update-ref -d" and other operations to delete references did
+   not leave any entry in HEAD's reflog when the reference being
+   deleted was the current branch.  This is not a problem in practice
+   because you do not want to delete the branch you are currently on,
+   but caused renaming of the current branch to something else not to
+   be logged in a useful way.
+
+ * "Cc:" on the trailer part does not have to conform to RFC strictly,
+   unlike in the e-mail header.  "git send-email" has been updated to
+   ignore anything after '>' when picking addresses, to allow non-address
+   cruft like " # stable 4.4" after the address.
+
+ * When "git submodule init" decides that the submodule in the working
+   tree is its upstream, it now gives a warning as it is not a very
+   common setup.
+
+ * "git stash push" takes a pathspec so that the local changes can be
+   stashed away only partially.
+
+ * Documentation for "git ls-files" did not refer to core.quotePath.
+
+ * The experimental "split index" feature has gained a few
+   configuration variables to make it easier to use.
+
+ * From a working tree of a repository, a new option of "rev-parse"
+   lets you ask if the repository is used as a submodule of another
+   project, and where the root level of the working tree of that
+   project (i.e. your superproject) is.
+
+ * The pathspec mechanism learned to further limit the paths that
+   match the pattern to those that have specified attributes attached
+   via the gitattributes mechanism.
+
+ * Our source code has used the SHA1_HEADER cpp macro after "#include"
+   in the C code to switch among the SHA-1 implementations. Instead,
+   list the exact header file names and switch among implementations
+   using "#ifdef BLK_SHA1/#include "block-sha1/sha1.h"/.../#endif";
+   this helps some IDE tools.
+
+ * The start-up sequence of "git" needs to figure out some configured
+   settings before it finds and set itself up in the location of the
+   repository and was quite messy due to its "chicken-and-egg" nature.
+   The code has been restructured.
+
+ * The command line prompt (in contrib/) learned a new 'tag' style
+   that can be specified with GIT_PS1_DESCRIBE_STYLE, to describe a
+   detached HEAD with "git describe --tags".
+
+ * The configuration file learned a new "includeIf.<condition>.path"
+   that includes the contents of the given path only when the
+   condition holds.  This allows you to say "include this work-related
+   bit only in the repositories under my ~/work/ directory".
+
+ * Recent update to "rebase -i" started showing a message that is not
+   a warning with "warning:" prefix by mistake.  This has been fixed.
+
+ * Recently we started passing the "--push-options" through the
+   external remote helper interface; now the "smart HTTP" remote
+   helper understands what to do with the passed information.
+
+ * "git describe --dirty" dies when it cannot be determined if the
+   state in the working tree matches that of HEAD (e.g. broken
+   repository or broken submodule).  The command learned a new option
+   "git describe --broken" to give "$name-broken" (where $name is the
+   description of HEAD) in such a case.
+
+ * "git checkout" is taught the "--recurse-submodules" option.
+
+ * Recent enhancement to "git stash push" command to support pathspec
+   to allow only a subset of working tree changes to be stashed away
+   was found to be too chatty and exposed the internal implementation
+   detail (e.g. when it uses reset to match the index to HEAD before
+   doing other things, output from reset seeped out).  These, and
+   other chattyness has been fixed.
+
+ * "git merge <message> HEAD <commit>" syntax that has been deprecated
+   since October 2007 has been removed.
+
+ * The refs completion for large number of refs has been sped up,
+   partly by giving up disambiguating ambiguous refs and partly by
+   eliminating most of the shell processing between 'git for-each-ref'
+   and 'ls-remote' and Bash's completion facility.
+
+ * On many keyboards, typing "@{" involves holding down SHIFT key and
+   one can easily end up with "@{Up..." when typing "@{upstream}".  As
+   the upstream/push keywords do not appear anywhere else in the syntax,
+   we can safely accept them case insensitively without introducing
+   ambiguity or confusion to solve this.
+
+ * "git tag/branch/for-each-ref" family of commands long allowed to
+   filter the refs by "--contains X" (show only the refs that are
+   descendants of X), "--merged X" (show only the refs that are
+   ancestors of X), "--no-merged X" (show only the refs that are not
+   ancestors of X).  One curious omission, "--no-contains X" (show
+   only the refs that are not descendants of X) has been added to
+   them.
+
+ * The default behaviour of "git log" in an interactive session has
+   been changed to enable "--decorate".
+
+ * The output from "git status --short" has been extended to show
+   various kinds of dirtyness in submodules differently; instead of to
+   "M" for modified, 'm' and '?' can be shown to signal changes only
+   to the working tree of the submodule but not the commit that is
+   checked out.
+
+ * Allow the http.postbuffer configuration variable to be set to a
+   size that can be expressed in size_t, which can be larger than
+   ulong on some platforms.
+
+ * "git rebase" learns "--signoff" option.
+
+ * The completion script (in contrib/) learned to complete "git push
+   --delete b<TAB>" to complete branch name to be deleted.
+
+ * "git worktree add --lock" allows to lock a worktree immediately
+   after it's created. This helps prevent a race between "git worktree
+   add; git worktree lock" and "git worktree prune".
+
+ * Completion for "git checkout <branch>" that auto-creates the branch
+   out of a remote tracking branch can now be disabled, as this
+   completion often gets in the way when completing to checkout an
+   existing local branch that happens to share the same prefix with
+   bunch of remote tracking branches.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The code to list branches in "git branch" has been consolidated
+   with the more generic ref-filter API.
+
+ * Resource usage while enumerating refs from alternate object store
+   has been optimized to help receiving end of "push" that hosts a
+   repository with many "forks".
+
+ * The gitattributes machinery is being taught to work better in a
+   multi-threaded environment.
+
+ * "git rebase -i" starts using the recently updated "sequencer" code.
+
+ * Code and design clean-up for the refs API.
+
+ * The preload-index code has been taught not to bother with the index
+   entries that are paths that are not checked out by "sparse checkout".
+
+ * Some warning() messages from "git clean" were updated to show the
+   errno from failed system calls.
+
+ * The "parse_config_key()" API function has been cleaned up.
+
+ * A test that creates a confusing branch whose name is HEAD has been
+   corrected not to do so.
+
+ * The code that parses header fields in the commit object has been
+   updated for (micro)performance and code hygiene.
+
+ * An helper function to make it easier to append the result from
+   real_path() to a strbuf has been added.
+
+ * Reduce authentication round-trip over HTTP when the server supports
+   just a single authentication method.  This also improves the
+   behaviour when Git is misconfigured to enable http.emptyAuth
+   against a server that does not authenticate without a username
+   (i.e. not using Kerberos etc., which makes http.emptyAuth
+   pointless).
+
+ * Windows port wants to use OpenSSL's implementation of SHA-1
+   routines, so let them.
+
+ * The t/perf performance test suite was not prepared to test not so
+   old versions of Git, but now it covers versions of Git that are not
+   so ancient.
+
+ * Add 32-bit Linux variant to the set of platforms to be tested with
+   Travis CI.
+
+ * "git branch --list" takes the "--abbrev" and "--no-abbrev" options
+   to control the output of the object name in its "-v"(erbose)
+   output, but a recent update started ignoring them; fix it before
+   the breakage reaches to any released version.
+
+ * Picking two versions of Git and running tests to make sure the
+   older one and the newer one interoperate happily has now become
+   possible.
+
+ * "git tag --contains" used to (ab)use the object bits to keep track
+   of the state of object reachability without clearing them after
+   use; this has been cleaned up and made to use the newer commit-slab
+   facility.
+
+ * The "debug" helper used in the test framework learned to run
+   a command under "gdb" interactively.
+
+ * The "detect attempt to create collisions" variant of SHA-1
+   implementation by Marc Stevens (CWI) and Dan Shumow (Microsoft)
+   has been integrated and made the default.
+
+ * The test framework learned to detect unterminated here documents.
+
+ * The name-hash used for detecting paths that are different only in
+   cases (which matter on case insensitive filesystems) has been
+   optimized to take advantage of multi-threading when it makes sense.
+
+ * An earlier version of sha1dc/sha1.c that was merged to 'master'
+   compiled incorrectly on Windows, which has been fixed.
+
+ * "what URL do we want to update this submodule?" and "are we
+   interested in this submodule?" are split into two distinct
+   concepts, and then the way used to express the latter got extended,
+   paving a way to make it easier to manage a project with many
+   submodules and make it possible to later extend use of multiple
+   worktrees for a project with submodules.
+
+ * Some debugging output from "git describe" were marked for l10n,
+   but some weren't.  Mark missing ones for l10n.
+
+ * Define a new task in .travis.yml that triggers a test session on
+   Windows run elsewhere.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * The "submodule" specific field in the ref_store structure is
+   replaced with a more generic "gitdir" that can later be used also
+   when dealing with ref_store that represents the set of refs visible
+   from the other worktrees.
+
+ * The string-list API used a custom reallocation strategy that was
+   very inefficient, instead of using the usual ALLOC_GROW() macro,
+   which has been fixed.
+   (merge 950a234cbd jh/string-list-micro-optim later to maint).
+
+ * In a 2- and 3-way merge of trees, more than one source trees often
+   end up sharing an identical subtree; optimize by not reading the
+   same tree multiple times in such a case.
+   (merge d12a8cf0af jh/unpack-trees-micro-optim later to maint).
+
+ * The index file has a trailing SHA-1 checksum to detect file
+   corruption, and historically we checked it every time the index
+   file is used.  Omit the validation during normal use, and instead
+   verify only in "git fsck".
+
+ * Having a git command on the upstream side of a pipe in a test
+   script will hide the exit status from the command, which may cause
+   us to fail to notice a breakage; rewrite tests in a script to avoid
+   this issue.
+
+ * Travis CI learns to run coccicheck.
+
+ * "git checkout" that handles a lot of paths has been optimized by
+   reducing the number of unnecessary checks of paths in the
+   has_dir_name() function.
+
+ * The internals of the refs API around the cached refs has been
+   streamlined.
+
+ * Output from perf tests have been updated to align their titles.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.12
+-----------------
+
+Unless otherwise noted, all the fixes since v2.12 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git repack --depth=<n>" for a long time busted the specified depth
+   when reusing delta from existing packs.  This has been corrected.
+
+ * The code to parse the command line "git grep <patterns>... <rev>
+   [[--] <pathspec>...]" has been cleaned up, and a handful of bugs
+   have been fixed (e.g. we used to check "--" if it is a rev).
+
+ * "git ls-remote" and "git archive --remote" are designed to work
+   without being in a directory under Git's control.  However, recent
+   updates revealed that we randomly look into a directory called
+   .git/ without actually doing necessary set-up when working in a
+   repository.  Stop doing so.
+
+ * "git show-branch" expected there were only very short branch names
+   in the repository and used a fixed-length buffer to hold them
+   without checking for overflow.
+
+ * A caller of tempfile API that uses stdio interface to write to
+   files may ignore errors while writing, which is detected when
+   tempfile is closed (with a call to ferror()).  By that time, the
+   original errno that may have told us what went wrong is likely to
+   be long gone and was overwritten by an irrelevant value.
+   close_tempfile() now resets errno to EIO to make errno at least
+   predictable.
+
+ * "git remote rm X", when a branch has remote X configured as the
+   value of its branch.*.remote, tried to remove branch.*.remote and
+   branch.*.merge and failed if either is unset.
+
+ * A "gc.log" file left by a backgrounded "gc --auto" disables further
+   automatic gc; it has been taught to run at least once a day (by
+   default) by ignoring a stale "gc.log" file that is too old.
+
+ * The code to parse "git -c VAR=VAL cmd" and set configuration
+   variable for the duration of cmd had two small bugs, which have
+   been fixed.
+
+ * user.email that consists of only cruft chars should consistently
+   error out, but didn't.
+
+ * "git upload-pack", which is a counter-part of "git fetch", did not
+   report a request for a ref that was not advertised as invalid.
+   This is generally not a problem (because "git fetch" will stop
+   before making such a request), but is the right thing to do.
+
+ * A leak in a codepath to read from a packed object in (rare) cases
+   has been plugged.
+
+ * When a redirected http transport gets an error during the
+   redirected request, we ignored the error we got from the server,
+   and ended up giving a not-so-useful error message.
+
+ * The patch subcommand of "git add -i" was meant to have paths
+   selection prompt just like other subcommand, unlike "git add -p"
+   directly jumps to hunk selection.  Recently, this was broken and
+   "add -i" lost the paths selection dialog, but it now has been
+   fixed.
+
+ * Git v2.12 was shipped with an embarrassing breakage where various
+   operations that verify paths given from the user stopped dying when
+   seeing an issue, and instead later triggering segfault.
+
+ * There is no need for Python only to give a few messages to the
+   standard error stream, but we somehow did.
+
+ * The code to parse "git log -L..." command line was buggy when there
+   are many ranges specified with -L; overrun of the allocated buffer
+   has been fixed.
+
+ * The command-line parsing of "git log -L" copied internal data
+   structures using incorrect size on ILP32 systems.
+
+ * "git diff --quiet" relies on the size field in diff_filespec to be
+   correctly populated, but diff_populate_filespec() helper function
+   made an incorrect short-cut when asked only to populate the size
+   field for paths that need to go through convert_to_git() (e.g. CRLF
+   conversion).
+
+ * A few tests were run conditionally under (rare) conditions where
+   they cannot be run (like running cvs tests under 'root' account).
+
+ * "git branch @" created refs/heads/@ as a branch, and in general the
+   code that handled @{-1} and @{upstream} was a bit too loose in
+   disambiguating.
+
+ * "git fetch" that requests a commit by object name, when the other
+   side does not allow such an request, failed without much
+   explanation.
+
+ * "git filter-branch --prune-empty" drops a single-parent commit that
+   becomes a no-op, but did not drop a root commit whose tree is empty.
+
+ * Recent versions of Git treats http alternates (used in dumb http
+   transport) just like HTTP redirects and requires the client to
+   enable following it, due to security concerns.  But we forgot to
+   give a warning when we decide not to honor the alternates.
+
+ * "git push" had a handful of codepaths that could lead to a deadlock
+   when unexpected error happened, which has been fixed.
+
+ * "Dumb http" transport used to misparse a nonsense http-alternates
+   response, which has been fixed.
+
+ * "git add -p <pathspec>" unnecessarily expanded the pathspec to a
+   list of individual files that matches the pathspec by running "git
+   ls-files <pathspec>", before feeding it to "git diff-index" to see
+   which paths have changes, because historically the pathspec
+   language supported by "diff-index" was weaker.  These days they are
+   equivalent and there is no reason to internally expand it.  This
+   helps both performance and avoids command line argument limit on
+   some platforms.
+   (merge 7288e12cce jk/add-i-use-pathspecs later to maint).
+
+ * "git status --porcelain" is supposed to give a stable output, but a
+   few strings were left as translatable by mistake.
+
+ * "git revert -m 0 $merge_commit" complained that reverting a merge
+   needs to say relative to which parent the reversion needs to
+   happen, as if "-m 0" weren't given.  The correct diagnosis is that
+   "-m 0" does not refer to the first parent ("-m 1" does).  This has
+   been fixed.
+
+ * Code to read submodule.<name>.ignore config did not state the
+   variable name correctly when giving an error message diagnosing
+   misconfiguration.
+
+ * Fix for NO_PTHREADS build.
+
+ * Fix for potential segv introduced in v2.11.0 and later (also
+   v2.10.2) to "git log --pickaxe-regex -S".
+
+ * A few unterminated here documents in tests were fixed, which in
+   turn revealed incorrect expectations the tests make. These tests
+   have been updated.
+
+ * Fix for NO_PTHREADS option.
+   (merge 2225e1ea20 bw/grep-recurse-submodules later to maint).
+
+ * Git now avoids blindly falling back to ".git" when the setup
+   sequence said we are _not_ in Git repository.  A corner case that
+   happens to work right now may be broken by a call to die("BUG").
+   (merge b1ef400eec jk/no-looking-at-dotgit-outside-repo-final later to maint).
+
+ * A few commands that recently learned the "--recurse-submodule"
+   option misbehaved when started from a subdirectory of the
+   superproject.
+   (merge b2dfeb7c00 bw/recurse-submodules-relative-fix later to maint).
+
+ * FreeBSD implementation of getcwd(3) behaved differently when an
+   intermediate directory is unreadable/unsearchable depending on the
+   length of the buffer provided, which our strbuf_getcwd() was not
+   aware of.  strbuf_getcwd() has been taught to cope with it better.
+   (merge a54e938e5b rs/freebsd-getcwd-workaround later to maint).
+
+ * A recent update to "rebase -i" stopped running hooks for the "git
+   commit" command during "reword" action, which has been fixed.
+
+ * Removing an entry from a notes tree and then looking another note
+   entry from the resulting tree using the internal notes API
+   functions did not work as expected.  No in-tree users of the API
+   has such access pattern, but it still is worth fixing.
+
+ * "git receive-pack" could have been forced to die by attempting
+   allocate an unreasonably large amount of memory with a crafted push
+   certificate; this has been fixed.
+   (merge f2214dede9 bc/push-cert-receive-fix later to maint).
+
+ * Update error handling for codepath that deals with corrupt loose
+   objects.
+   (merge 51054177b3 jk/loose-object-info-report-error later to maint).
+
+ * "git diff --submodule=diff" learned to work better in a project
+   with a submodule that in turn has its own submodules.
+   (merge 17b254cda6 sb/show-diff-for-submodule-in-diff-fix later to maint).
+
+ * Update the build dependency so that an update to /usr/bin/perl
+   etc. result in recomputation of perl.mak file.
+   (merge c59c4939c2 ab/regen-perl-mak-with-different-perl later to maint).
+
+ * "git push --recurse-submodules --push-option=<string>" learned to
+   propagate the push option recursively down to pushes in submodules.
+
+ * If a patch e-mail had its first paragraph after an in-body header
+   indented (even after a blank line after the in-body header line),
+   the indented line was mistook as a continuation of the in-body
+   header.  This has been fixed.
+   (merge fd1062e52e lt/mailinfo-in-body-header-continuation later to maint).
+
+ * Clean up fallouts from recent tightening of the set-up sequence,
+   where Git barfs when repository information is accessed without
+   first ensuring that it was started in a repository.
+   (merge bccb22cbb1 jk/no-looking-at-dotgit-outside-repo later to maint).
+
+ * "git p4" used "name-rev HEAD" when it wants to learn what branch is
+   checked out; it should use "symbolic-ref HEAD".
+   (merge eff451101d ld/p4-current-branch-fix later to maint).
+
+ * "http.proxy" set to an empty string is used to disable the usage of
+   proxy.  We broke this early last year.
+   (merge ae51d91105 sr/http-proxy-configuration-fix later to maint).
+
+ * $GIT_DIR may in some cases be normalized with all symlinks resolved
+   while "gitdir" path expansion in the pattern does not receive the
+   same treatment, leading to incorrect mismatch.  This has been fixed.
+
+ * "git submodule" script does not work well with strange pathnames.
+   Protect it from a path with slashes in them, at least.
+
+ * "git fetch-pack" was not prepared to accept ERR packet that the
+   upload-pack can send with a human-readable error message.  It
+   showed the packet contents with ERR prefix, so there was no data
+   loss, but it was redundant to say "ERR" in an error message.
+   (merge 8e2c7bef03 jt/fetch-pack-error-reporting later to maint).
+
+ * "ls-files --recurse-submodules" did not quite work well in a
+   project with nested submodules.
+
+ * gethostname(2) may not NUL terminate the buffer if hostname does
+   not fit; unfortunately there is no easy way to see if our buffer
+   was too small, but at least this will make sure we will not end up
+   using garbage past the end of the buffer.
+   (merge 5781a9a270 dt/xgethostname-nul-termination later to maint).
+
+ * A recent update broke "git add -p ../foo" from a subdirectory.
+
+ * While handy, "git_path()" is a dangerous function to use as a
+   callsite that uses it safely one day can be broken by changes
+   to other code that calls it.  Reduction of its use continues.
+   (merge 16d2676c9e jk/war-on-git-path later to maint).
+
+ * The split-index code configuration code used an unsafe git_path()
+   function without copying its result out.
+
+ * Many stale HTTP(s) links have been updated in our documentation.
+   (merge 613416f0be jk/update-links-in-docs later to maint).
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge df2a6e38b7 jk/pager-in-use later to maint).
+   (merge 75ec4a6cb0 ab/branch-list-doc later to maint).
+   (merge 3e5b36c637 sg/skip-prefix-in-prettify-refname later to maint).
+   (merge 2c5e2865cc jk/fast-import-cleanup later to maint).
+   (merge 4473060bc2 ab/test-readme-updates later to maint).
+   (merge 48a96972fd ab/doc-submitting later to maint).
+   (merge f5c2bc2b96 jk/make-coccicheck-detect-errors later to maint).
+   (merge c105f563d1 cc/untracked later to maint).
+   (merge 8668976b53 jc/unused-symbols later to maint).
+   (merge fba275dc93 jc/bs-t-is-not-a-tab-for-sed later to maint).
+   (merge be6ed145de mm/ls-files-s-doc later to maint).
+   (merge 60b091c679 qp/bisect-docfix later to maint).
+   (merge 47242cd103 ah/diff-files-ours-theirs-doc later to maint).
+   (merge 35ad44cbd8 sb/submodule-rm-absorb later to maint).
+   (merge 0301f1fd92 va/i18n-perl-scripts later to maint).
+   (merge 733e064d98 vn/revision-shorthand-for-side-branch-log later to maint).
+   (merge 85999743e7 tb/doc-eol-normalization later to maint).
+   (merge 0747fb49fd jk/loose-object-fsck later to maint).
+   (merge d8f4481c4f jk/quarantine-received-objects later to maint).
+   (merge 7ba1ceef95 xy/format-patch-base later to maint).
+   (merge fa1912c89a rs/misc-cppcheck-fixes later to maint).
+   (merge f17d642d3b ab/push-cas-doc-n-test later to maint).
+   (merge 61e282425a ss/gitmodules-ignore-doc later to maint).
+   (merge 8d3047cd5b ss/submodule-shallow-doc later to maint).
+   (merge 1f9e18b772 jk/prio-queue-avoid-swap-with-self later to maint).
+   (merge 627fde1025 jk/submodule-init-segv-fix later to maint).
+   (merge d395745d81 rg/doc-pull-typofix later to maint).
+   (merge 01e60a9a22 rg/doc-submittingpatches-wordfix later to maint).
+   (merge 501d3cd7b8 sr/hooks-cwd-doc later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.13.1.txt b/third_party/git/Documentation/RelNotes/2.13.1.txt
new file mode 100644
index 0000000000..ed7cd976d9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.1.txt
@@ -0,0 +1,114 @@
+Git v2.13.1 Release Notes
+=========================
+
+Fixes since v2.13
+-----------------
+
+ * The Web interface to gmane news archive is long gone, even though
+   the articles are still accessible via NTTP.  Replace the links with
+   ones to public-inbox.org.  Because their message identification is
+   based on the actual message-id, it is likely that it will be easier
+   to migrate away from it if/when necessary.
+
+ * Update tests to pass under GETTEXT_POISON (a mechanism to ensure
+   that output strings that should not be translated are not
+   translated by mistake), and tell TravisCI to run them.
+
+ * Setting "log.decorate=false" in the configuration file did not take
+   effect in v2.13, which has been corrected.
+
+ * An earlier update to test 7400 needed to be skipped on CYGWIN.
+
+ * Git sometimes gives an advice in a rhetorical question that does
+   not require an answer, which can confuse new users and non native
+   speakers.  Attempt to rephrase them.
+
+ * "git read-tree -m" (no tree-ish) gave a nonsense suggestion "use
+   --empty if you want to clear the index".  With "-m", such a request
+   will still fail anyway, as you'd need to name at least one tree-ish
+   to be merged.
+
+ * The codepath in "git am" that is used when running "git rebase"
+   leaked memory held for the log message of the commits being rebased.
+
+ * "pack-objects" can stream a slice of an existing packfile out when
+   the pack bitmap can tell that the reachable objects are all needed
+   in the output, without inspecting individual objects.  This
+   strategy however would not work well when "--local" and other
+   options are in use, and need to be disabled.
+
+ * Clarify documentation for include.path and includeIf.<condition>.path
+   configuration variables.
+
+ * Tag objects, which are not reachable from any ref, that point at
+   missing objects were mishandled by "git gc" and friends (they
+   should silently be ignored instead)
+
+ * A few http:// links that are redirected to https:// in the
+   documentation have been updated to https:// links.
+
+ * Make sure our tests would pass when the sources are checked out
+   with "platform native" line ending convention by default on
+   Windows.  Some "text" files out tests use and the test scripts
+   themselves that are meant to be run with /bin/sh, ought to be
+   checked out with eol=LF even on Windows.
+
+ * Fix memory leaks pointed out by Coverity (and people).
+
+ * The receive-pack program now makes sure that the push certificate
+   records the same set of push options used for pushing.
+
+ * "git cherry-pick" and other uses of the sequencer machinery
+   mishandled a trailer block whose last line is an incomplete line.
+   This has been fixed so that an additional sign-off etc. are added
+   after completing the existing incomplete line.
+
+ * The shell completion script (in contrib/) learned "git stash" has
+   a new "push" subcommand.
+
+ * Travis CI gained a task to format the documentation with both
+   AsciiDoc and AsciiDoctor.
+
+ * Update the C style recommendation for notes for translators, as
+   recent versions of gettext tools can work with our style of
+   multi-line comments.
+
+ * "git clone --config var=val" is a way to populate the
+   per-repository configuration file of the new repository, but it did
+   not work well when val is an empty string.  This has been fixed.
+
+ * A few codepaths in "checkout" and "am" working on an unborn branch
+   tried to access an uninitialized piece of memory.
+
+ * "git for-each-ref --format=..." with %(HEAD) in the format used to
+   resolve the HEAD symref as many times as it had processed refs,
+   which was wasteful, and "git branch" shared the same problem.
+
+ * "git interpret-trailers", when used as GIT_EDITOR for "git commit
+   -v", looked for and appended to a trailer block at the very end,
+   i.e. at the end of the "diff" output.  The command has been
+   corrected to pay attention to the cut-mark line "commit -v" adds to
+   the buffer---the real trailer block should appear just before it.
+
+ * A test allowed both "git push" and "git receive-pack" on the other
+   end write their traces into the same file.  This is OK on platforms
+   that allows atomically appending to a file opened with O_APPEND,
+   but on other platforms led to a mangled output, causing
+   intermittent test failures.  This has been fixed by disabling
+   traces from "receive-pack" in the test.
+
+ * "foo\bar\baz" in "git fetch foo\bar\baz", even though there is no
+   slashes in it, cannot be a nickname for a remote on Windows, as
+   that is likely to be a pathname on a local filesystem.
+
+ * The "collision detecting" SHA-1 implementation shipped with 2.13
+   was quite broken on some big-endian platforms and/or platforms that
+   do not like unaligned fetches.  Update to the upstream code which
+   has already fixed these issues.
+
+ * "git am -h" triggered a BUG().
+
+ * The interaction of "url.*.insteadOf" and custom URL scheme's
+   whitelisting is now documented better.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.13.2.txt b/third_party/git/Documentation/RelNotes/2.13.2.txt
new file mode 100644
index 0000000000..8c2b20071e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.2.txt
@@ -0,0 +1,54 @@
+Git v2.13.2 Release Notes
+=========================
+
+Fixes since v2.13.1
+-------------------
+
+ * The "collision detecting" SHA-1 implementation shipped with 2.13.1
+   was still broken on some platforms.  Update to the upstream code
+   again to take their fix.
+
+ * "git checkout --recurse-submodules" did not quite work with a
+   submodule that itself has submodules.
+
+ * Introduce the BUG() macro to improve die("BUG: ...").
+
+ * The "run-command" API implementation has been made more robust
+   against dead-locking in a threaded environment.
+
+ * A recent update to t5545-push-options.sh started skipping all the
+   tests in the script when a web server testing is disabled or
+   unavailable, not just the ones that require a web server.  Non HTTP
+   tests have been salvaged to always run in this script.
+
+ * "git clean -d" used to clean directories that has ignored files,
+   even though the command should not lose ignored ones without "-x".
+   "git status --ignored"  did not list ignored and untracked files
+   without "-uall".  These have been corrected.
+
+ * The timestamp of the index file is now taken after the file is
+   closed, to help Windows, on which a stale timestamp is reported by
+   fstat() on a file that is opened for writing and data was written
+   but not yet closed.
+
+ * "git pull --rebase --autostash" didn't auto-stash when the local history
+   fast-forwards to the upstream.
+
+ * "git describe --contains" penalized light-weight tags so much that
+   they were almost never considered.  Instead, give them about the
+   same chance to be considered as an annotated tag that is the same
+   age as the underlying commit would.
+
+ * The result from "git diff" that compares two blobs, e.g. "git diff
+   $commit1:$path $commit2:$path", used to be shown with the full
+   object name as given on the command line, but it is more natural to
+   use the $path in the output and use it to look up .gitattributes.
+
+ * A flaky test has been corrected.
+
+ * Help contributors that visit us at GitHub.
+
+ * "git stash push <pathspec>" did not work from a subdirectory at all.
+   Bugfix for a topic in v2.13
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.13.3.txt b/third_party/git/Documentation/RelNotes/2.13.3.txt
new file mode 100644
index 0000000000..5d76ad5310
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.3.txt
@@ -0,0 +1,62 @@
+Git v2.13.3 Release Notes
+=========================
+
+Fixes since v2.13.2
+-------------------
+
+ * The "collision detecting" SHA-1 implementation shipped with 2.13.2
+   was still broken on some platforms.  Update to the upstream code
+   again to take their fix.
+
+ * The 'diff-highlight' program (in contrib/) has been restructured
+   for easier reuse by an external project 'diff-so-fancy'.
+
+ * "git mergetool" learned to work around a wrapper MacOS X adds
+   around underlying meld.
+
+ * An example in documentation that does not work in multi worktree
+   configuration has been corrected.
+
+ * The pretty-format specifiers like '%h', '%t', etc. had an
+   optimization that no longer works correctly.  In preparation/hope
+   of getting it correctly implemented, first discard the optimization
+   that is broken.
+
+ * The code to pick up and execute command alias definition from the
+   configuration used to switch to the top of the working tree and
+   then come back when the expanded alias was executed, which was
+   unnecessarilyl complex.  Attempt to simplify the logic by using the
+   early-config mechanism that does not chdir around.
+
+ * "git add -p" were updated in 2.12 timeframe to cope with custom
+   core.commentchar but the implementation was buggy and a
+   metacharacter like $ and * did not work.
+
+ * Fix a recent regression to "git rebase -i" and add tests that would
+   have caught it and others.
+
+ * An unaligned 32-bit access in pack-bitmap code ahs been corrected.
+
+ * Tighten error checks for invalid "git apply" input.
+
+ * The split index code did not honor core.sharedrepository setting
+   correctly.
+
+ * The Makefile rule in contrib/subtree for building documentation
+   learned to honour USE_ASCIIDOCTOR just like the main documentation
+   set does.
+
+ * A few tests that tried to verify the contents of push certificates
+   did not use 'git rev-parse' to formulate the line to look for in
+   the certificate correctly.
+
+ * After "git branch --move" of the currently checked out branch, the
+   code to walk the reflog of HEAD via "log -g" and friends
+   incorrectly stopped at the reflog entry that records the renaming
+   of the branch.
+
+ * The rewrite of "git branch --list" using for-each-ref's internals
+   that happened in v2.13 regressed its handling of color.branch.local;
+   this has been fixed.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.13.4.txt b/third_party/git/Documentation/RelNotes/2.13.4.txt
new file mode 100644
index 0000000000..9a9f8f9599
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.4.txt
@@ -0,0 +1,28 @@
+Git v2.13.4 Release Notes
+=========================
+
+Fixes since v2.13.3
+-------------------
+
+ * Update the character width tables.
+
+ * A recent update broke an alias that contained an uppercase letter,
+   which has been fixed.
+
+ * On Cygwin, similar to Windows, "git push //server/share/repository"
+   ought to mean a repository on a network share that can be accessed
+   locally, but this did not work correctly due to stripping the double
+   slashes at the beginning.
+
+ * The progress meter did not give a useful output when we haven't had
+   0.5 seconds to measure the throughput during the interval.  Instead
+   show the overall throughput rate at the end, which is a much more
+   useful number.
+
+ * We run an early part of "git gc" that deals with refs before
+   daemonising (and not under lock) even when running a background
+   auto-gc, which caused multiple gc processes attempting to run the
+   early part at the same time.  This is now prevented by running the
+   early part also under the GC lock.
+
+Also contains a handful of small code and documentation clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.13.5.txt b/third_party/git/Documentation/RelNotes/2.13.5.txt
new file mode 100644
index 0000000000..6949fcda78
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.5.txt
@@ -0,0 +1,4 @@
+Git v2.13.5 Release Notes
+=========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.13.6.txt b/third_party/git/Documentation/RelNotes/2.13.6.txt
new file mode 100644
index 0000000000..afcae9c808
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.6.txt
@@ -0,0 +1,17 @@
+Git v2.13.6 Release Notes
+=========================
+
+Fixes since v2.13.5
+-------------------
+
+ * "git cvsserver" no longer is invoked by "git daemon" by default,
+   as it is old and largely unmaintained.
+
+ * Various Perl scripts did not use safe_pipe_capture() instead of
+   backticks, leaving them susceptible to end-user input.  They have
+   been corrected.
+
+Credits go to joernchen <joernchen@phenoelit.de> for finding the
+unsafe constructs in "git cvsserver", and to Jeff King at GitHub for
+finding and fixing instances of the same issue in other scripts.
+
diff --git a/third_party/git/Documentation/RelNotes/2.13.7.txt b/third_party/git/Documentation/RelNotes/2.13.7.txt
new file mode 100644
index 0000000000..09fc01406c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.13.7.txt
@@ -0,0 +1,20 @@
+Git v2.13.7 Release Notes
+=========================
+
+Fixes since v2.13.6
+-------------------
+
+ * Submodule "names" come from the untrusted .gitmodules file, but we
+   blindly append them to $GIT_DIR/modules to create our on-disk repo
+   paths. This means you can do bad things by putting "../" into the
+   name. We now enforce some rules for submodule names which will cause
+   Git to ignore these malicious names (CVE-2018-11235).
+
+   Credit for finding this vulnerability and the proof of concept from
+   which the test script was adapted goes to Etienne Stalmans.
+
+ * It was possible to trick the code that sanity-checks paths on NTFS
+   into reading random piece of memory (CVE-2018-11233).
+
+Credit for fixing for these bugs goes to Jeff King, Johannes
+Schindelin and others.
diff --git a/third_party/git/Documentation/RelNotes/2.14.0.txt b/third_party/git/Documentation/RelNotes/2.14.0.txt
new file mode 100644
index 0000000000..4246c68ff5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.0.txt
@@ -0,0 +1,517 @@
+Git 2.14 Release Notes
+======================
+
+Backward compatibility notes and other notable changes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is still warned and Git asks users to use a
+   more explicit '.' for that instead.  The hope is that existing
+   users will not mind this change, and eventually the warning can be
+   turned into a hard error, upgrading the deprecation into removal of
+   this (mis)feature.  That is not scheduled to happen in the upcoming
+   release (yet).
+
+ * Git now avoids blindly falling back to ".git" when the setup
+   sequence said we are _not_ in Git repository.  A corner case that
+   happens to work right now may be broken by a call to die("BUG").
+   We've tried hard to locate such cases and fixed them, but there
+   might still be cases that need to be addressed--bug reports are
+   greatly appreciated.
+
+ * The experiment to improve the hunk-boundary selection of textual
+   diff output has finished, and the "indent heuristics" has now
+   become the default.
+
+ * Git can now be built with PCRE v2 instead of v1 of the PCRE
+   library. Replace USE_LIBPCRE=YesPlease with USE_LIBPCRE2=YesPlease
+   in existing build scripts to build against the new version.  As the
+   upstream PCRE maintainer has abandoned v1 maintenance for all but
+   the most critical bug fixes, use of v2 is recommended.
+
+
+Updates since v2.13
+-------------------
+
+UI, Workflows & Features
+
+ * The colors in which "git status --short --branch" showed the names
+   of the current branch and its remote-tracking branch are now
+   configurable.
+
+ * "git clone" learned the "--no-tags" option not to fetch all tags
+   initially, and also set up the tagopt not to follow any tags in
+   subsequent fetches.
+
+ * "git archive --format=zip" learned to use zip64 extension when
+   necessary to go beyond the 4GB limit.
+
+ * "git reset" learned "--recurse-submodules" option.
+
+ * "git diff --submodule=diff" now recurses into nested submodules.
+
+ * "git repack" learned to accept the --threads=<n> option and pass it
+   to pack-objects.
+
+ * "git send-email" learned to run sendemail-validate hook to inspect
+   and reject a message before sending it out.
+
+ * There is no good reason why "git fetch $there $sha1" should fail
+   when the $sha1 names an object at the tip of an advertised ref,
+   even when the other side hasn't enabled allowTipSHA1InWant.
+
+ * The "[includeIf "gitdir:$dir"] path=..." mechanism introduced in
+   2.13.0 would canonicalize the path of the gitdir being matched,
+   and did not match e.g. "gitdir:~/work/*" against a repo in
+   "~/work/main" if "~/work" was a symlink to "/mnt/storage/work".
+   Now we match both the resolved canonical path and what "pwd" would
+   show. The include will happen if either one matches.
+
+ * The "indent" heuristics is now the default in "diff". The
+   diff.indentHeuristic configuration variable can be set to "false"
+   for those who do not want it.
+
+ * Many commands learned to pay attention to submodule.recurse
+   configuration.
+
+ * The convention for a command line is to follow "git cmdname
+   --options" with revisions followed by an optional "--"
+   disambiguator and then finally pathspecs.  When "--" is not there,
+   we make sure early ones are all interpretable as revs (and do not
+   look like paths) and later ones are the other way around.  A
+   pathspec with "magic" (e.g. ":/p/a/t/h" that matches p/a/t/h from
+   the top-level of the working tree, no matter what subdirectory you
+   are working from) are conservatively judged as "not a path", which
+   required disambiguation more often.  The command line parser
+   learned to say "it's a pathspec" a bit more often when the syntax
+   looks like so.
+
+ * Update "perl-compatible regular expression" support to enable JIT
+   and also allow linking with the newer PCRE v2 library.
+
+ * "filter-branch" learned a pseudo filter "--setup" that can be used
+   to define common functions/variables that can be used by other
+   filters.
+
+ * Using "git add d/i/r" when d/i/r is the top of the working tree of
+   a separate repository would create a gitlink in the index, which
+   would appear as a not-quite-initialized submodule to others.  We
+   learned to give warnings when this happens.
+
+ * "git status" learned to optionally give how many stash entries there
+   are in its output.
+
+ * "git status" has long shown essentially the same message as "git
+   commit"; the message it gives while preparing for the root commit,
+   i.e. "Initial commit", was hard to understand for some new users.
+   Now it says "No commits yet" to stress more on the current status
+   (rather than the commit the user is preparing for, which is more in
+   line with the focus of "git commit").
+
+ * "git send-email" now has --batch-size and --relogin-delay options
+    which can be used to overcome limitations on SMTP servers that
+    restrict on how many of e-mails can be sent in a single session.
+
+ * An old message shown in the commit log template was removed, as it
+   has outlived its usefulness.
+
+ * "git pull --rebase --recurse-submodules" learns to rebase the
+   branch in the submodules to an updated base.
+
+ * "git log" learned -P as a synonym for --perl-regexp, "git grep"
+   already had such a synonym.
+
+ * "git log" didn't understand --regexp-ignore-case when combined with
+   --perl-regexp. This has been fixed.
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The default packed-git limit value has been raised on larger
+   platforms to save "git fetch" from a (recoverable) failure while
+   "gc" is running in parallel.
+
+ * Code to update the cache-tree has been tightened so that we won't
+   accidentally write out any 0{40} entry in the tree object.
+
+ * Attempt to allow us notice "fishy" situation where we fail to
+   remove the temporary directory used during the test.
+
+ * Travis CI gained a task to format the documentation with both
+   AsciiDoc and AsciiDoctor.
+
+ * Some platforms have ulong that is smaller than time_t, and our
+   historical use of ulong for timestamp would mean they cannot
+   represent some timestamp that the platform allows.  Invent a
+   separate and dedicated timestamp_t (so that we can distingiuish
+   timestamps and a vanilla ulongs, which along is already a good
+   move), and then declare uintmax_t is the type to be used as the
+   timestamp_t.
+
+ * We can trigger Windows auto-build tester (credits: Dscho &
+   Microsoft) from our existing Travis CI tester now.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * Simplify parse_pathspec() codepath and stop it from looking at the
+   default in-core index.
+
+ * Add perf-test for wildmatch.
+
+ * Code from "conversion using external process" codepath has been
+   extracted to a separate sub-process.[ch] module.
+
+ * When "git checkout", "git merge", etc. manipulates the in-core
+   index, various pieces of information in the index extensions are
+   discarded from the original state, as it is usually not the case
+   that they are kept up-to-date and in-sync with the operation on the
+   main index.  The untracked cache extension is copied across these
+   operations now, which would speed up "git status" (as long as the
+   cache is properly invalidated).
+
+ * The internal implementation of "git grep" has seen some clean-up.
+
+ * Update the C style recommendation for notes for translators, as
+   recent versions of gettext tools can work with our style of
+   multi-line comments.
+
+ * The implementation of "ref" API around the "packed refs" have been
+   cleaned up, in preparation for further changes.
+
+ * The internal logic used in "git blame" has been libified to make it
+   easier to use by cgit.
+
+ * Our code often opens a path to an optional file, to work on its
+   contents when we can successfully open it.  We can ignore a failure
+   to open if such an optional file does not exist, but we do want to
+   report a failure in opening for other reasons (e.g. we got an I/O
+   error, or the file is there, but we lack the permission to open).
+
+   The exact errors we need to ignore are ENOENT (obviously) and
+   ENOTDIR (less obvious).  Instead of repeating comparison of errno
+   with these two constants, introduce a helper function to do so.
+
+ * We often try to open a file for reading whose existence is
+   optional, and silently ignore errors from open/fopen; report such
+   errors if they are not due to missing files.
+
+ * When an existing repository is used for t/perf testing, we first
+   create bit-for-bit copy of it, which may grab a transient state of
+   the repository and freeze it into the repository used for testing,
+   which then may cause Git operations to fail.  Single out "the index
+   being locked" case and forcibly drop the lock from the copy.
+
+ * Three instances of the same helper function have been consolidated
+   to one.
+
+ * "fast-import" uses a default pack chain depth that is consistent
+   with other parts of the system.
+
+ * A new test to show the interaction between the pattern [^a-z]
+   (which matches '/') and a slash in a path has been added.  The
+   pattern should not match the slash with "pathmatch", but should
+   with "wildmatch".
+
+ * The 'diff-highlight' program (in contrib/) has been restructured
+   for easier reuse by an external project 'diff-so-fancy'.
+
+ * A common pattern to free a piece of memory and assign NULL to the
+   pointer that used to point at it has been replaced with a new
+   FREE_AND_NULL() macro.
+
+ * Traditionally, the default die() routine had a code to prevent it
+   from getting called multiple times, which interacted badly when a
+   threaded program used it (one downside is that the real error may
+   be hidden and instead the only error message given to the user may
+   end up being "die recursion detected", which is not very useful).
+
+ * Introduce a "repository" object to eventually make it easier to
+   work in multiple repositories (the primary focus is to work with
+   the superproject and its submodules) in a single process.
+
+ * Optimize "what are the object names already taken in an alternate
+   object database?" query that is used to derive the length of prefix
+   an object name is uniquely abbreviated to.
+
+ * The hashmap API has been updated so that data to customize the
+   behaviour of the comparison function can be specified at the time a
+   hashmap is initialized.
+
+ * The "collision detecting" SHA-1 implementation shipped with 2.13 is
+   now integrated into git.git as a submodule (the first submodule to
+   ship with git.git). Clone git.git with --recurse-submodules to get
+   it. For now a non-submodule copy of the same code is also shipped
+   as part of the tree.
+
+ * A recent update made it easier to use "-fsanitize=" option while
+   compiling but supported only one sanitize option.  Allow more than
+   one to be combined, joined with a comma, like "make SANITIZE=foo,bar".
+
+ * Use "p4 -G" to make "p4 changes" output more Python-friendly
+   to parse.
+
+ * We started using "%" PRItime, imitating "%" PRIuMAX and friends, as
+   a way to format the internal timestamp value, but this does not
+   play well with gettext(1) i18n framework, and causes "make pot"
+   that is run by the l10n coordinator to create a broken po/git.pot
+   file.  This is a possible workaround for that problem.
+
+ * It turns out that Cygwin also needs the fopen() wrapper that
+   returns failure when a directory is opened for reading.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.13
+-----------------
+
+Unless otherwise noted, all the fixes since v2.13 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git gc" did not interact well with "git worktree"-managed
+   per-worktree refs.
+
+ * "git cherry-pick" and other uses of the sequencer machinery
+   mishandled a trailer block whose last line is an incomplete line.
+   This has been fixed so that an additional sign-off etc. are added
+   after completing the existing incomplete line.
+
+ * The codepath in "git am" that is used when running "git rebase"
+   leaked memory held for the log message of the commits being rebased.
+
+ * "git clone --config var=val" is a way to populate the
+   per-repository configuration file of the new repository, but it did
+   not work well when val is an empty string.  This has been fixed.
+
+ * Setting "log.decorate=false" in the configuration file did not take
+   effect in v2.13, which has been corrected.
+
+ * A few codepaths in "checkout" and "am" working on an unborn branch
+   tried to access an uninitialized piece of memory.
+
+ * The Web interface to gmane news archive is long gone, even though
+   the articles are still accessible via NTTP.  Replace the links with
+   ones to public-inbox.org.  Because their message identification is
+   based on the actual message-id, it is likely that it will be easier
+   to migrate away from it if/when necessary.
+
+ * The receive-pack program now makes sure that the push certificate
+   records the same set of push options used for pushing.
+
+ * Tests have been updated to pass under GETTEXT_POISON (a mechanism
+   to ensure that output strings that should not be translated are
+   not translated by mistake), and TravisCI is told to run them.
+
+ * "git checkout --recurse-submodules" did not quite work with a
+   submodule that itself has submodules.
+
+ * "pack-objects" can stream a slice of an existing packfile out when
+   the pack bitmap can tell that the reachable objects are all needed
+   in the output, without inspecting individual objects.  This
+   strategy however would not work well when "--local" and other
+   options are in use, and need to be disabled.
+
+ * Fix memory leaks pointed out by Coverity (and people).
+
+ * "git read-tree -m" (no tree-ish) gave a nonsense suggestion "use
+   --empty if you want to clear the index".  With "-m", such a request
+   will still fail anyway, as you'd need to name at least one tree-ish
+   to be merged.
+
+ * Make sure our tests would pass when the sources are checked out
+   with "platform native" line ending convention by default on
+   Windows.  Some "text" files out tests use and the test scripts
+   themselves that are meant to be run with /bin/sh, ought to be
+   checked out with eol=LF even on Windows.
+
+ * Introduce the BUG() macro to improve die("BUG: ...").
+
+ * Clarify documentation for include.path and includeIf.<condition>.path
+   configuration variables.
+
+ * Git sometimes gives an advice in a rhetorical question that does
+   not require an answer, which can confuse new users and non native
+   speakers.  Attempt to rephrase them.
+
+ * A few http:// links that are redirected to https:// in the
+   documentation have been updated to https:// links.
+
+ * "git for-each-ref --format=..." with %(HEAD) in the format used to
+   resolve the HEAD symref as many times as it had processed refs,
+   which was wasteful, and "git branch" shared the same problem.
+
+ * Regression fix to topic recently merged to 'master'.
+
+ * The shell completion script (in contrib/) learned "git stash" has
+   a new "push" subcommand.
+
+ * "git interpret-trailers", when used as GIT_EDITOR for "git commit
+   -v", looked for and appended to a trailer block at the very end,
+   i.e. at the end of the "diff" output.  The command has been
+   corrected to pay attention to the cut-mark line "commit -v" adds to
+   the buffer---the real trailer block should appear just before it.
+
+ * A test allowed both "git push" and "git receive-pack" on the other
+   end write their traces into the same file.  This is OK on platforms
+   that allows atomically appending to a file opened with O_APPEND,
+   but on other platforms led to a mangled output, causing
+   intermittent test failures.  This has been fixed by disabling
+   traces from "receive-pack" in the test.
+
+ * Tag objects, which are not reachable from any ref, that point at
+   missing objects were mishandled by "git gc" and friends (they
+   should silently be ignored instead)
+
+ * "git describe --contains" penalized light-weight tags so much that
+   they were almost never considered.  Instead, give them about the
+   same chance to be considered as an annotated tag that is the same
+   age as the underlying commit would.
+
+ * The "run-command" API implementation has been made more robust
+   against dead-locking in a threaded environment.
+
+ * A recent update to t5545-push-options.sh started skipping all the
+   tests in the script when a web server testing is disabled or
+   unavailable, not just the ones that require a web server.  Non HTTP
+   tests have been salvaged to always run in this script.
+
+ * "git send-email" now uses Net::SMTP::SSL, which is obsolete, only
+   when needed.  Recent versions of Net::SMTP can do TLS natively.
+
+ * "foo\bar\baz" in "git fetch foo\bar\baz", even though there is no
+   slashes in it, cannot be a nickname for a remote on Windows, as
+   that is likely to be a pathname on a local filesystem.
+
+ * "git clean -d" used to clean directories that has ignored files,
+   even though the command should not lose ignored ones without "-x".
+   "git status --ignored"  did not list ignored and untracked files
+   without "-uall".  These have been corrected.
+
+ * The result from "git diff" that compares two blobs, e.g. "git diff
+   $commit1:$path $commit2:$path", used to be shown with the full
+   object name as given on the command line, but it is more natural to
+   use the $path in the output and use it to look up .gitattributes.
+
+ * The "collision detecting" SHA-1 implementation shipped with 2.13
+   was quite broken on some big-endian platforms and/or platforms that
+   do not like unaligned fetches.  Update to the upstream code which
+   has already fixed these issues.
+
+ * "git am -h" triggered a BUG().
+
+ * The interaction of "url.*.insteadOf" and custom URL scheme's
+   whitelisting is now documented better.
+
+ * The timestamp of the index file is now taken after the file is
+   closed, to help Windows, on which a stale timestamp is reported by
+   fstat() on a file that is opened for writing and data was written
+   but not yet closed.
+
+ * "git pull --rebase --autostash" didn't auto-stash when the local history
+   fast-forwards to the upstream.
+
+ * A flaky test has been corrected.
+
+ * "git $cmd -h" for builtin commands calls the implementation of the
+   command (i.e. cmd_$cmd() function) without doing any repository
+   set-up, and the commands that expect RUN_SETUP is done by the Git
+   potty needs to be prepared to show the help text without barfing.
+   (merge d691551192 jk/consistent-h later to maint).
+
+ * Help contributors that visit us at GitHub.
+
+ * "git stash push <pathspec>" did not work from a subdirectory at all.
+   Bugfix for a topic in v2.13
+
+ * As there is no portable way to pass timezone information to
+   strftime, some output format from "git log" and friends are
+   impossible to produce.  Teach our own strbuf_addftime to replace %z
+   and %Z with caller-supplied values to help working around this.
+   (merge 6eced3ec5e rs/strbuf-addftime-zZ later to maint).
+
+ * "git mergetool" learned to work around a wrapper MacOS X adds
+   around underlying meld.
+
+ * An example in documentation that does not work in multi worktree
+   configuration has been corrected.
+
+ * The pretty-format specifiers like '%h', '%t', etc. had an
+   optimization that no longer works correctly.  In preparation/hope
+   of getting it correctly implemented, first discard the optimization
+   that is broken.
+
+ * The code to pick up and execute command alias definition from the
+   configuration used to switch to the top of the working tree and
+   then come back when the expanded alias was executed, which was
+   unnecessarilyl complex.  Attempt to simplify the logic by using the
+   early-config mechanism that does not chdir around.
+
+ * Fix configuration codepath to pay proper attention to commondir
+   that is used in multi-worktree situation, and isolate config API
+   into its own header file.
+   (merge dc8441fdb4 bw/config-h later to maint).
+
+ * "git add -p" were updated in 2.12 timeframe to cope with custom
+   core.commentchar but the implementation was buggy and a
+   metacharacter like $ and * did not work.
+
+ * A recent regression in "git rebase -i" has been fixed and tests
+   that would have caught it and others have been added.
+
+ * An unaligned 32-bit access in pack-bitmap code has been corrected.
+
+ * Tighten error checks for invalid "git apply" input.
+
+ * The split index code did not honor core.sharedRepository setting
+   correctly.
+
+ * The Makefile rule in contrib/subtree for building documentation
+   learned to honour USE_ASCIIDOCTOR just like the main documentation
+   set does.
+
+ * Code clean-up to fix possible buffer over-reading.
+
+ * A few tests that tried to verify the contents of push certificates
+   did not use 'git rev-parse' to formulate the line to look for in
+   the certificate correctly.
+
+ * Update the character width tables.
+
+ * After "git branch --move" of the currently checked out branch, the
+   code to walk the reflog of HEAD via "log -g" and friends
+   incorrectly stopped at the reflog entry that records the renaming
+   of the branch.
+
+ * The rewrite of "git branch --list" using for-each-ref's internals
+   that happened in v2.13 regressed its handling of color.branch.local;
+   this has been fixed.
+
+ * The build procedure has been improved to allow building and testing
+   Git with address sanitizer more easily.
+   (merge 425ca6710b jk/build-with-asan later to maint).
+
+ * On Cygwin, similar to Windows, "git push //server/share/repository"
+   ought to mean a repository on a network share that can be accessed
+   locally, but this did not work correctly due to stripping the double
+   slashes at the beginning.
+
+ * The progress meter did not give a useful output when we haven't had
+   0.5 seconds to measure the throughput during the interval.  Instead
+   show the overall throughput rate at the end, which is a much more
+   useful number.
+
+ * Code clean-up, that makes us in sync with Debian by one patch.
+
+ * We run an early part of "git gc" that deals with refs before
+   daemonising (and not under lock) even when running a background
+   auto-gc, which caused multiple gc processes attempting to run the
+   early part at the same time.  This is now prevented by running the
+   early part also under the GC lock.
+
+ * A recent update broke an alias that contained an uppercase letter.
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge 5053313562 rs/urlmatch-cleanup later to maint).
+   (merge 42c78a216e rs/use-div-round-up later to maint).
+   (merge 5e8d2729ae rs/wt-status-cleanup later to maint).
+   (merge bc9b7e207f as/diff-options-grammofix later to maint).
+   (merge ac05222b31 ah/patch-id-doc later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.14.1.txt b/third_party/git/Documentation/RelNotes/2.14.1.txt
new file mode 100644
index 0000000000..9403340f7f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.1.txt
@@ -0,0 +1,4 @@
+Git v2.14.1 Release Notes
+=========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.14.2.txt b/third_party/git/Documentation/RelNotes/2.14.2.txt
new file mode 100644
index 0000000000..bec9186ade
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.2.txt
@@ -0,0 +1,105 @@
+Git v2.14.2 Release Notes
+=========================
+
+Fixes since v2.14.1
+-------------------
+
+ * Because recent Git for Windows do come with a real msgfmt, the
+   build procedure for git-gui has been updated to use it instead of a
+   hand-rolled substitute.
+
+ * "%C(color name)" in the pretty print format always produced ANSI
+   color escape codes, which was an early design mistake.  They now
+   honor the configuration (e.g. "color.ui = never") and also tty-ness
+   of the output medium.
+
+ * The http.{sslkey,sslCert} configuration variables are to be
+   interpreted as a pathname that honors "~[username]/" prefix, but
+   weren't, which has been fixed.
+
+ * Numerous bugs in walking of reflogs via "log -g" and friends have
+   been fixed.
+
+ * "git commit" when seeing an totally empty message said "you did not
+   edit the message", which is clearly wrong.  The message has been
+   corrected.
+
+ * When a directory is not readable, "gitweb" fails to build the
+   project list.  Work this around by skipping such a directory.
+
+ * A recently added test for the "credential-cache" helper revealed
+   that EOF detection done around the time the connection to the cache
+   daemon is torn down were flaky.  This was fixed by reacting to
+   ECONNRESET and behaving as if we got an EOF.
+
+ * Some versions of GnuPG fail to kill gpg-agent it auto-spawned
+   and such a left-over agent can interfere with a test.  Work it
+   around by attempting to kill one before starting a new test.
+
+ * "git log --tag=no-such-tag" showed log starting from HEAD, which
+   has been fixed---it now shows nothing.
+
+ * The "tag.pager" configuration variable was useless for those who
+   actually create tag objects, as it interfered with the use of an
+   editor.  A new mechanism has been introduced for commands to enable
+   pager depending on what operation is being carried out to fix this,
+   and then "git tag -l" is made to run pager by default.
+
+ * "git push --recurse-submodules $there HEAD:$target" was not
+   propagated down to the submodules, but now it is.
+
+ * Commands like "git rebase" accepted the --rerere-autoupdate option
+   from the command line, but did not always use it.  This has been
+   fixed.
+
+ * "git clone --recurse-submodules --quiet" did not pass the quiet
+   option down to submodules.
+
+ * "git am -s" has been taught that some input may end with a trailer
+   block that is not Signed-off-by: and it should refrain from adding
+   an extra blank line before adding a new sign-off in such a case.
+
+ * "git svn" used with "--localtime" option did not compute the tz
+   offset for the timestamp in question and instead always used the
+   current time, which has been corrected.
+
+ * Memory leaks in a few error codepaths have been plugged.
+
+ * bash 4.4 or newer gave a warning on NUL byte in command
+   substitution done in "git stash"; this has been squelched.
+
+ * "git grep -L" and "git grep --quiet -L" reported different exit
+   codes; this has been corrected.
+
+ * When handshake with a subprocess filter notices that the process
+   asked for an unknown capability, Git did not report what program
+   the offending subprocess was running.  This has been corrected.
+
+ * "git apply" that is used as a better "patch -p1" failed to apply a
+   taken from a file with CRLF line endings to a file with CRLF line
+   endings.  The root cause was because it misused convert_to_git()
+   that tried to do "safe-crlf" processing by looking at the index
+   entry at the same path, which is a nonsense---in that mode, "apply"
+   is not working on the data in (or derived from) the index at all.
+   This has been fixed.
+
+ * Killing "git merge --edit" before the editor returns control left
+   the repository in a state with MERGE_MSG but without MERGE_HEAD,
+   which incorrectly tells the subsequent "git commit" that there was
+   a squash merge in progress.  This has been fixed.
+
+ * "git archive" did not work well with pathspecs and the
+   export-ignore attribute.
+
+ * "git cvsserver" no longer is invoked by "git daemon" by default,
+   as it is old and largely unmaintained.
+
+ * Various Perl scripts did not use safe_pipe_capture() instead of
+   backticks, leaving them susceptible to end-user input.  They have
+   been corrected.
+
+Also contains various documentation updates and code clean-ups.
+
+Credits go to joernchen <joernchen@phenoelit.de> for finding the
+unsafe constructs in "git cvsserver", and to Jeff King at GitHub for
+finding and fixing instances of the same issue in other scripts.
diff --git a/third_party/git/Documentation/RelNotes/2.14.3.txt b/third_party/git/Documentation/RelNotes/2.14.3.txt
new file mode 100644
index 0000000000..977c9e857c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.3.txt
@@ -0,0 +1,99 @@
+Git v2.14.3 Release Notes
+=========================
+
+Fixes since v2.14.2
+-------------------
+
+ * A helper function to read a single whole line into strbuf
+   mistakenly triggered OOM error at EOF under certain conditions,
+   which has been fixed.
+
+ * In addition to "cc: <a@dd.re.ss> # cruft", "cc: a@dd.re.ss # cruft"
+   was taught to "git send-email" as a valid way to tell it that it
+   needs to also send a carbon copy to <a@dd.re.ss> in the trailer
+   section.
+
+ * Fix regression to "gitk --bisect" by a recent update.
+
+ * Unlike "git commit-tree < file", "git commit-tree -F file" did not
+   pass the contents of the file verbatim and instead completed an
+   incomplete line at the end, if exists.  The latter has been updated
+   to match the behaviour of the former.
+
+ * "git archive", especially when used with pathspec, stored an empty
+   directory in its output, even though Git itself never does so.
+   This has been fixed.
+
+ * API error-proofing which happens to also squelch warnings from GCC.
+
+ * "git gc" tries to avoid running two instances at the same time by
+   reading and writing pid/host from and to a lock file; it used to
+   use an incorrect fscanf() format when reading, which has been
+   corrected.
+
+ * The test linter has been taught that we do not like "echo -e".
+
+ * Code cmp.std.c nitpick.
+
+ * "git describe --match" learned to take multiple patterns in v2.13
+   series, but the feature ignored the patterns after the first one
+   and did not work at all.  This has been fixed.
+
+ * "git cat-file --textconv" started segfaulting recently, which
+   has been corrected.
+
+ * The built-in pattern to detect the "function header" for HTML did
+   not match <H1>..<H6> elements without any attributes, which has
+   been fixed.
+
+ * "git mailinfo" was loose in decoding quoted printable and produced
+   garbage when the two letters after the equal sign are not
+   hexadecimal.  This has been fixed.
+
+ * The documentation for '-X<option>' for merges was misleadingly
+   written to suggest that "-s theirs" exists, which is not the case.
+
+ * Spell the name of our system as "Git" in the output from
+   request-pull script.
+
+ * Fixes for a handful memory access issues identified by valgrind.
+
+ * Backports a moral equivalent of 2015 fix to the poll emulation from
+   the upstream gnulib to fix occasional breakages on HPE NonStop.
+
+ * In the "--format=..." option of the "git for-each-ref" command (and
+   its friends, i.e. the listing mode of "git branch/tag"), "%(atom:)"
+   (e.g. "%(refname:)", "%(body:)" used to error out.  Instead, treat
+   them as if the colon and an empty string that follows it were not
+   there.
+
+ * Users with "color.ui = always" in their configuration were broken
+   by a recent change that made plumbing commands to pay attention to
+   them as the patch created internally by "git add -p" were colored
+   (heh) and made unusable.  This has been fixed.
+
+ * "git branch -M a b" while on a branch that is completely unrelated
+   to either branch a or branch b misbehaved when multiple worktree
+   was in use.  This has been fixed.
+
+ * "git fast-export" with -M/-C option issued "copy" instruction on a
+   path that is simultaneously modified, which was incorrect.
+
+ * The checkpoint command "git fast-import" did not flush updates to
+   refs and marks unless at least one object was created since the
+   last checkpoint, which has been corrected, as these things can
+   happen without any new object getting created.
+
+ * The scripts to drive TravisCI has been reorganized and then an
+   optimization to avoid spending cycles on a branch whose tip is
+   tagged has been implemented.
+
+ * "git fetch <there> <src>:<dst>" allows an object name on the <src>
+   side when the other side accepts such a request since Git v2.5, but
+   the documentation was left stale.
+
+ * A regression in 2.11 that made the code to read the list of
+   alternate object stores overrun the end of the string has been
+   fixed.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.14.4.txt b/third_party/git/Documentation/RelNotes/2.14.4.txt
new file mode 100644
index 0000000000..97755a89d9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.4.txt
@@ -0,0 +1,5 @@
+Git v2.14.4 Release Notes
+=========================
+
+This release is to forward-port the fixes made in the v2.13.7 version
+of Git.  See its release notes for details.
diff --git a/third_party/git/Documentation/RelNotes/2.14.5.txt b/third_party/git/Documentation/RelNotes/2.14.5.txt
new file mode 100644
index 0000000000..130645fb29
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.14.5.txt
@@ -0,0 +1,16 @@
+Git v2.14.5 Release Notes
+=========================
+
+This release is to address the recently reported CVE-2018-17456.
+
+Fixes since v2.14.4
+-------------------
+
+ * Submodules' "URL"s come from the untrusted .gitmodules file, but
+   we blindly gave it to "git clone" to clone submodules when "git
+   clone --recurse-submodules" was used to clone a project that has
+   such a submodule.  The code has been hardened to reject such
+   malformed URLs (e.g. one that begins with a dash).
+
+Credit for finding and fixing this vulnerability goes to joernchen
+and Jeff King, respectively.
diff --git a/third_party/git/Documentation/RelNotes/2.15.0.txt b/third_party/git/Documentation/RelNotes/2.15.0.txt
new file mode 100644
index 0000000000..cdd761bcc2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.15.0.txt
@@ -0,0 +1,508 @@
+Git 2.15 Release Notes
+======================
+
+Backward compatibility notes and other notable changes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is still warned and Git asks users to use a
+   more explicit '.' for that instead.  The hope is that existing
+   users will not mind this change, and eventually the warning can be
+   turned into a hard error, upgrading the deprecation into removal of
+   this (mis)feature.  That is now scheduled to happen in Git v2.16,
+   the next major release after this one.
+
+ * Git now avoids blindly falling back to ".git" when the setup
+   sequence said we are _not_ in Git repository.  A corner case that
+   happens to work right now may be broken by a call to BUG().
+   We've tried hard to locate such cases and fixed them, but there
+   might still be cases that need to be addressed--bug reports are
+   greatly appreciated.
+
+ * "branch --set-upstream" that has been deprecated in Git 1.8 has
+   finally been retired.
+
+
+Updates since v2.14
+-------------------
+
+UI, Workflows & Features
+
+ * An example that is now obsolete has been removed from a sample hook,
+   and an old example in it that added a sign-off manually has been
+   improved to use the interpret-trailers command.
+
+ * The advice message given when "git rebase" stops for conflicting
+   changes has been improved.
+
+ * The "rerere-train" script (in contrib/) learned the "--overwrite"
+   option to allow overwriting existing recorded resolutions.
+
+ * "git contacts" (in contrib/) now lists the address on the
+   "Reported-by:" trailer to its output, in addition to those on
+   S-o-b: and other trailers, to make it easier to notify (and thank)
+   the original bug reporter.
+
+ * "git rebase", especially when it is run by mistake and ends up
+   trying to replay many changes, spent long time in silence.  The
+   command has been taught to show progress report when it spends
+   long time preparing these many changes to replay (which would give
+   the user a chance to abort with ^C).
+
+ * "git merge" learned a "--signoff" option to add the Signed-off-by:
+   trailer with the committer's name.
+
+ * "git diff" learned to optionally paint new lines that are the same
+   as deleted lines elsewhere differently from genuinely new lines.
+
+ * "git interpret-trailers" learned to take the trailer specifications
+   from the command line that overrides the configured values.
+
+ * "git interpret-trailers" has been taught a "--parse" and a few
+   other options to make it easier for scripts to grab existing
+   trailer lines from a commit log message.
+
+ * The "--format=%(trailers)" option "git log" and its friends take
+   learned to take the 'unfold' and 'only' modifiers to normalize its
+   output, e.g. "git log --format=%(trailers:only,unfold)".
+
+ * "gitweb" shows a link to visit the 'raw' contents of blobs in the
+   history overview page.
+
+ * "[gc] rerereResolved = 5.days" used to be invalid, as the variable
+   is defined to take an integer counting the number of days.  It now
+   is allowed.
+
+ * The code to acquire a lock on a reference (e.g. while accepting a
+   push from a client) used to immediately fail when the reference is
+   already locked---now it waits for a very short while and retries,
+   which can make it succeed if the lock holder was holding it during
+   a read-only operation.
+
+ * "branch --set-upstream" that has been deprecated in Git 1.8 has
+   finally been retired.
+
+ * The codepath to call external process filter for smudge/clean
+   operation learned to show the progress meter.
+
+ * "git rev-parse" learned "--is-shallow-repository", that is to be
+   used in a way similar to existing "--is-bare-repository" and
+   friends.
+
+ * "git describe --match <pattern>" has been taught to play well with
+   the "--all" option.
+
+ * "git branch" learned "-c/-C" to create a new branch by copying an
+   existing one.
+
+ * Some commands (most notably "git status") makes an opportunistic
+   update when performing a read-only operation to help optimize later
+   operations in the same repository.  The new "--no-optional-locks"
+   option can be passed to Git to disable them.
+
+ * "git for-each-ref --format=..." learned a new format element,
+   %(trailers), to show only the commit log trailer part of the log
+   message.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * Start using selected c99 constructs in small, stable and
+   essential part of the system to catch people who care about
+   older compilers that do not grok them.
+
+ * The filter-process interface learned to allow a process with long
+   latency give a "delayed" response.
+
+ * Many uses of comparison callback function the hashmap API uses
+   cast the callback function type when registering it to
+   hashmap_init(), which defeats the compile time type checking when
+   the callback interface changes (e.g. gaining more parameters).
+   The callback implementations have been updated to take "void *"
+   pointers and cast them to the type they expect instead.
+
+ * Because recent Git for Windows do come with a real msgfmt, the
+   build procedure for git-gui has been updated to use it instead of a
+   hand-rolled substitute.
+
+ * "git grep --recurse-submodules" has been reworked to give a more
+   consistent output across submodule boundary (and do its thing
+   without having to fork a separate process).
+
+ * A helper function to read a single whole line into strbuf
+   mistakenly triggered OOM error at EOF under certain conditions,
+   which has been fixed.
+
+ * The "ref-store" code reorganization continues.
+
+ * "git commit" used to discard the index and re-read from the filesystem
+   just in case the pre-commit hook has updated it in the middle; this
+   has been optimized out when we know we do not run the pre-commit hook.
+   (merge 680ee550d7 kw/commit-keep-index-when-pre-commit-is-not-run later to maint).
+
+ * Updates to the HTTP layer we made recently unconditionally used
+   features of libCurl without checking the existence of them, causing
+   compilation errors, which has been fixed.  Also migrate the code to
+   check feature macros, not version numbers, to cope better with
+   libCurl that vendor ships with backported features.
+
+ * The API to start showing progress meter after a short delay has
+   been simplified.
+   (merge 8aade107dd jc/simplify-progress later to maint).
+
+ * Code clean-up to avoid mixing values read from the .gitmodules file
+   and values read from the .git/config file.
+
+ * We used to spend more than necessary cycles allocating and freeing
+   piece of memory while writing each index entry out.  This has been
+   optimized.
+
+ * Platforms that ship with a separate sha1 with collision detection
+   library can link to it instead of using the copy we ship as part of
+   our source tree.
+
+ * Code around "notes" have been cleaned up.
+   (merge 3964281524 mh/notes-cleanup later to maint).
+
+ * The long-standing rule that an in-core lockfile instance, once it
+   is used, must not be freed, has been lifted and the lockfile and
+   tempfile APIs have been updated to reduce the chance of programming
+   errors.
+
+ * Our hashmap implementation in hashmap.[ch] is not thread-safe when
+   adding a new item needs to expand the hashtable by rehashing; add
+   an API to disable the automatic rehashing to work it around.
+
+ * Many of our programs consider that it is OK to release dynamic
+   storage that is used throughout the life of the program by simply
+   exiting, but this makes it harder to leak detection tools to avoid
+   reporting false positives.  Plug many existing leaks and introduce
+   a mechanism for developers to mark that the region of memory
+   pointed by a pointer is not lost/leaking to help these tools.
+
+ * As "git commit" to conclude a conflicted "git merge" honors the
+   commit-msg hook, "git merge" that records a merge commit that
+   cleanly auto-merges should, but it didn't.
+
+ * The codepath for "git merge-recursive" has been cleaned up.
+
+ * Many leaks of strbuf have been fixed.
+
+ * "git imap-send" has our own implementation of the protocol and also
+   can use more recent libCurl with the imap protocol support.  Update
+   the latter so that it can use the credential subsystem, and then
+   make it the default option to use, so that we can eventually
+   deprecate and remove the former.
+
+ * "make style" runs git-clang-format to help developers by pointing
+   out coding style issues.
+
+ * A test to demonstrate "git mv" failing to adjust nested submodules
+   has been added.
+   (merge c514167df2 hv/mv-nested-submodules-test later to maint).
+
+ * On Cygwin, "ulimit -s" does not report failure but it does not work
+   at all, which causes an unexpected success of some tests that
+   expect failures under a limited stack situation.  This has been
+   fixed.
+
+ * Many codepaths have been updated to squelch -Wimplicit-fallthrough
+   warnings from Gcc 7 (which is a good code hygiene).
+
+ * Add a helper for DLL loading in anticipation for its need in a
+   future topic RSN.
+
+ * "git status --ignored", when noticing that a directory without any
+   tracked path is ignored, still enumerated all the ignored paths in
+   the directory, which is unnecessary.  The codepath has been
+   optimized to avoid this overhead.
+
+ * The final batch to "git rebase -i" updates to move more code from
+   the shell script to C has been merged.
+
+ * Operations that do not touch (majority of) packed refs have been
+   optimized by making accesses to packed-refs file lazy; we no longer
+   pre-parse everything, and an access to a single ref in the
+   packed-refs does not touch majority of irrelevant refs, either.
+
+ * Add comment to clarify that the style file is meant to be used with
+   clang-5 and the rules are still work in progress.
+
+ * Many variables that points at a region of memory that will live
+   throughout the life of the program have been marked with UNLEAK
+   marker to help the leak checkers concentrate on real leaks..
+
+ * Plans for weaning us off of SHA-1 has been documented.
+
+ * A new "oidmap" API has been introduced and oidset API has been
+   rewritten to use it.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.14
+-----------------
+
+ * "%C(color name)" in the pretty print format always produced ANSI
+   color escape codes, which was an early design mistake.  They now
+   honor the configuration (e.g. "color.ui = never") and also tty-ness
+   of the output medium.
+
+ * The http.{sslkey,sslCert} configuration variables are to be
+   interpreted as a pathname that honors "~[username]/" prefix, but
+   weren't, which has been fixed.
+
+ * Numerous bugs in walking of reflogs via "log -g" and friends have
+   been fixed.
+
+ * "git commit" when seeing an totally empty message said "you did not
+   edit the message", which is clearly wrong.  The message has been
+   corrected.
+
+ * When a directory is not readable, "gitweb" fails to build the
+   project list.  Work this around by skipping such a directory.
+
+ * Some versions of GnuPG fails to kill gpg-agent it auto-spawned
+   and such a left-over agent can interfere with a test.  Work it
+   around by attempting to kill one before starting a new test.
+
+ * A recently added test for the "credential-cache" helper revealed
+   that EOF detection done around the time the connection to the cache
+   daemon is torn down were flaky.  This was fixed by reacting to
+   ECONNRESET and behaving as if we got an EOF.
+
+ * "git log --tag=no-such-tag" showed log starting from HEAD, which
+   has been fixed---it now shows nothing.
+
+ * The "tag.pager" configuration variable was useless for those who
+   actually create tag objects, as it interfered with the use of an
+   editor.  A new mechanism has been introduced for commands to enable
+   pager depending on what operation is being carried out to fix this,
+   and then "git tag -l" is made to run pager by default.
+
+ * "git push --recurse-submodules $there HEAD:$target" was not
+   propagated down to the submodules, but now it is.
+
+ * Commands like "git rebase" accepted the --rerere-autoupdate option
+   from the command line, but did not always use it.  This has been
+   fixed.
+
+ * "git clone --recurse-submodules --quiet" did not pass the quiet
+   option down to submodules.
+
+ * Test portability fix for OBSD.
+
+ * Portability fix for OBSD.
+
+ * "git am -s" has been taught that some input may end with a trailer
+   block that is not Signed-off-by: and it should refrain from adding
+   an extra blank line before adding a new sign-off in such a case.
+
+ * "git svn" used with "--localtime" option did not compute the tz
+   offset for the timestamp in question and instead always used the
+   current time, which has been corrected.
+
+ * Memory leak in an error codepath has been plugged.
+
+ * "git stash -u" used the contents of the committed version of the
+   ".gitignore" file to decide which paths are ignored, even when the
+   file has local changes.  The command has been taught to instead use
+   the locally modified contents.
+
+ * bash 4.4 or newer gave a warning on NUL byte in command
+   substitution done in "git stash"; this has been squelched.
+
+ * "git grep -L" and "git grep --quiet -L" reported different exit
+   codes; this has been corrected.
+
+ * When handshake with a subprocess filter notices that the process
+   asked for an unknown capability, Git did not report what program
+   the offending subprocess was running.  This has been corrected.
+
+ * "git apply" that is used as a better "patch -p1" failed to apply a
+   taken from a file with CRLF line endings to a file with CRLF line
+   endings.  The root cause was because it misused convert_to_git()
+   that tried to do "safe-crlf" processing by looking at the index
+   entry at the same path, which is a nonsense---in that mode, "apply"
+   is not working on the data in (or derived from) the index at all.
+   This has been fixed.
+
+ * Killing "git merge --edit" before the editor returns control left
+   the repository in a state with MERGE_MSG but without MERGE_HEAD,
+   which incorrectly tells the subsequent "git commit" that there was
+   a squash merge in progress.  This has been fixed.
+
+ * "git archive" did not work well with pathspecs and the
+   export-ignore attribute.
+
+ * In addition to "cc: <a@dd.re.ss> # cruft", "cc: a@dd.re.ss # cruft"
+   was taught to "git send-email" as a valid way to tell it that it
+   needs to also send a carbon copy to <a@dd.re.ss> in the trailer
+   section.
+
+ * "git branch -M a b" while on a branch that is completely unrelated
+   to either branch a or branch b misbehaved when multiple worktree
+   was in use.  This has been fixed.
+   (merge 31824d180d nd/worktree-kill-parse-ref later to maint).
+
+ * "git gc" and friends when multiple worktrees are used off of a
+   single repository did not consider the index and per-worktree refs
+   of other worktrees as the root for reachability traversal, making
+   objects that are in use only in other worktrees to be subject to
+   garbage collection.
+
+ * A regression to "gitk --bisect" by a recent update has been fixed.
+
+ * "git -c submodule.recurse=yes pull" did not work as if the
+   "--recurse-submodules" option was given from the command line.
+   This has been corrected.
+
+ * Unlike "git commit-tree < file", "git commit-tree -F file" did not
+   pass the contents of the file verbatim and instead completed an
+   incomplete line at the end, if exists.  The latter has been updated
+   to match the behaviour of the former.
+
+ * Many codepaths did not diagnose write failures correctly when disks
+   go full, due to their misuse of write_in_full() helper function,
+   which have been corrected.
+   (merge f48ecd38cb jk/write-in-full-fix later to maint).
+
+ * "git help co" now says "co is aliased to ...", not "git co is".
+   (merge b3a8076e0d ks/help-alias-label later to maint).
+
+ * "git archive", especially when used with pathspec, stored an empty
+   directory in its output, even though Git itself never does so.
+   This has been fixed.
+
+ * API error-proofing which happens to also squelch warnings from GCC.
+
+ * The explanation of the cut-line in the commit log editor has been
+   slightly tweaked.
+   (merge 8c4b1a3593 ks/commit-do-not-touch-cut-line later to maint).
+
+ * "git gc" tries to avoid running two instances at the same time by
+   reading and writing pid/host from and to a lock file; it used to
+   use an incorrect fscanf() format when reading, which has been
+   corrected.
+
+ * The scripts to drive TravisCI has been reorganized and then an
+   optimization to avoid spending cycles on a branch whose tip is
+   tagged has been implemented.
+   (merge 8376eb4a8f ls/travis-scriptify later to maint).
+
+ * The test linter has been taught that we do not like "echo -e".
+
+ * Code cmp.std.c nitpick.
+
+ * A regression fix for 2.11 that made the code to read the list of
+   alternate object stores overrun the end of the string.
+   (merge f0f7bebef7 jk/info-alternates-fix later to maint).
+
+ * "git describe --match" learned to take multiple patterns in v2.13
+   series, but the feature ignored the patterns after the first one
+   and did not work at all.  This has been fixed.
+
+ * "git filter-branch" cannot reproduce a history with a tag without
+   the tagger field, which only ancient versions of Git allowed to be
+   created.  This has been corrected.
+   (merge b2c1ca6b4b ic/fix-filter-branch-to-handle-tag-without-tagger later to maint).
+
+ * "git cat-file --textconv" started segfaulting recently, which
+   has been corrected.
+
+ * The built-in pattern to detect the "function header" for HTML did
+   not match <H1>..<H6> elements without any attributes, which has
+   been fixed.
+
+ * "git mailinfo" was loose in decoding quoted printable and produced
+   garbage when the two letters after the equal sign are not
+   hexadecimal.  This has been fixed.
+
+ * The machinery to create xdelta used in pack files received the
+   sizes of the data in size_t, but lost the higher bits of them by
+   storing them in "unsigned int" during the computation, which is
+   fixed.
+
+ * The delta format used in the packfile cannot reference data at
+   offset larger than what can be expressed in 4-byte, but the
+   generator for the data failed to make sure the offset does not
+   overflow.  This has been corrected.
+
+ * The documentation for '-X<option>' for merges was misleadingly
+   written to suggest that "-s theirs" exists, which is not the case.
+
+ * "git fast-export" with -M/-C option issued "copy" instruction on a
+   path that is simultaneously modified, which was incorrect.
+   (merge b3e8ca89cf jt/fast-export-copy-modify-fix later to maint).
+
+ * Many codepaths have been updated to squelch -Wsign-compare
+   warnings.
+   (merge 071bcaab64 rj/no-sign-compare later to maint).
+
+ * Memory leaks in various codepaths have been plugged.
+   (merge 4d01a7fa65 ma/leakplugs later to maint).
+
+ * Recent versions of "git rev-parse --parseopt" did not parse the
+   option specification that does not have the optional flags (*=?!)
+   correctly, which has been corrected.
+   (merge a6304fa4c2 bc/rev-parse-parseopt-fix later to maint).
+
+ * The checkpoint command "git fast-import" did not flush updates to
+   refs and marks unless at least one object was created since the
+   last checkpoint, which has been corrected, as these things can
+   happen without any new object getting created.
+   (merge 30e215a65c er/fast-import-dump-refs-on-checkpoint later to maint).
+
+ * Spell the name of our system as "Git" in the output from
+   request-pull script.
+
+ * Fixes for a handful memory access issues identified by valgrind.
+
+ * Backports a moral equivalent of 2015 fix to the poll() emulation
+   from the upstream gnulib to fix occasional breakages on HPE NonStop.
+
+ * Users with "color.ui = always" in their configuration were broken
+   by a recent change that made plumbing commands to pay attention to
+   them as the patch created internally by "git add -p" were colored
+   (heh) and made unusable.  This has been fixed by reverting the
+   offending change.
+
+ * In the "--format=..." option of the "git for-each-ref" command (and
+   its friends, i.e. the listing mode of "git branch/tag"), "%(atom:)"
+   (e.g. "%(refname:)", "%(body:)" used to error out.  Instead, treat
+   them as if the colon and an empty string that follows it were not
+   there.
+
+ * An ancient bug that made Git misbehave with creation/renaming of
+   refs has been fixed.
+
+ * "git fetch <there> <src>:<dst>" allows an object name on the <src>
+   side when the other side accepts such a request since Git v2.5, but
+   the documentation was left stale.
+   (merge 83558a412a jc/fetch-refspec-doc-update later to maint).
+
+ * Update the documentation for "git filter-branch" so that the filter
+   options are listed in the same order as they are applied, as
+   described in an earlier part of the doc.
+   (merge 07c4984508 dg/filter-branch-filter-order-doc later to maint).
+
+ * A possible oom error is now caught as a fatal error, instead of
+   continuing and dereferencing NULL.
+   (merge 55d7d15847 ao/path-use-xmalloc later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge f094b89a4d ma/parse-maybe-bool later to maint).
+   (merge 6cdf8a7929 ma/ts-cleanups later to maint).
+   (merge 7560f547e6 ma/up-to-date later to maint).
+   (merge 0db3dc75f3 rs/apply-epoch later to maint).
+   (merge 276d0e35c0 ma/split-symref-update-fix later to maint).
+   (merge f777623514 ks/branch-tweak-error-message-for-extra-args later to maint).
+   (merge 33f3c683ec ks/verify-filename-non-option-error-message-tweak later to maint).
+   (merge 7cbbf9d6a2 ls/filter-process-delayed later to maint).
+   (merge 488aa65c8f wk/merge-options-gpg-sign-doc later to maint).
+   (merge e61cb19a27 jc/branch-force-doc-readability-fix later to maint).
+   (merge 32fceba3fd np/config-path-doc later to maint).
+   (merge e38c681fb7 sb/rev-parse-show-superproject-root later to maint).
+   (merge 4f851dc883 sg/rev-list-doc-reorder-fix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.15.1.txt b/third_party/git/Documentation/RelNotes/2.15.1.txt
new file mode 100644
index 0000000000..ec06704e63
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.15.1.txt
@@ -0,0 +1,88 @@
+Git v2.15.1 Release Notes
+=========================
+
+Fixes since v2.15
+-----------------
+
+ * TravisCI build updates.
+
+ * "auto" as a value for the columnar output configuration ought to
+   judge "is the output consumed by humans?" with the same criteria as
+   "auto" for coloured output configuration, i.e. either the standard
+   output stream is going to tty, or a pager is in use.  We forgot the
+   latter, which has been fixed.
+
+ * The experimental "color moved lines differently in diff output"
+   feature was buggy around "ignore whitespace changes" edges, which
+   has been corrected.
+
+ * Instead of using custom line comparison and hashing functions to
+   implement "moved lines" coloring in the diff output, use the pair
+   of these functions from lower-layer xdiff/ code.
+
+ * Some codepaths did not check for errors when asking what branch the
+   HEAD points at, which have been fixed.
+
+ * "git commit", after making a commit, did not check for errors when
+   asking on what branch it made the commit, which has been corrected.
+
+ * "git status --ignored -u" did not stop at a working tree of a
+   separate project that is embedded in an ignored directory and
+   listed files in that other project, instead of just showing the
+   directory itself as ignored.
+
+ * A broken access to object databases in recent update to "git grep
+   --recurse-submodules" has been fixed.
+
+ * A recent regression in "git rebase -i" that broke execution of git
+   commands from subdirectories via "exec" instruction has been fixed.
+
+ * "git check-ref-format --branch @{-1}" bit a "BUG()" when run
+   outside a repository for obvious reasons; clarify the documentation
+   and make sure we do not even try to expand the at-mark magic in
+   such a case, but still call the validation logic for branch names.
+
+ * Command line completion (in contrib/) update.
+
+ * Description of blame.{showroot,blankboundary,showemail,date}
+   configuration variables have been added to "git config --help".
+
+ * After an error from lstat(), diff_populate_filespec() function
+   sometimes still went ahead and used invalid data in struct stat,
+   which has been fixed.
+
+ * UNC paths are also relevant in Cygwin builds and they are now
+   tested just like Mingw builds.
+
+ * Correct start-up sequence so that a repository could be placed
+   immediately under the root directory again (which was broken at
+   around Git 2.13).
+
+ * The credential helper for libsecret (in contrib/) has been improved
+   to allow possibly prompting the end user to unlock secrets that are
+   currently locked (otherwise the secrets may not be loaded).
+
+ * Updates from GfW project.
+
+ * "git rebase -i" recently started misbehaving when a submodule that
+   is configured with 'submodule.<name>.ignore' is dirty; this has
+   been corrected.
+
+ * Some error messages did not quote filenames shown in it, which have
+   been fixed.
+
+ * Building with NO_LIBPCRE1_JIT did not disable it, which has been fixed.
+
+ * We used to add an empty alternate object database to the system
+   that does not help anything; it has been corrected.
+
+ * Error checking in "git imap-send" for empty response has been
+   improved.
+
+ * An ancient bug in "git apply --ignore-space-change" codepath has
+   been fixed.
+
+ * There was a recent semantic mismerge in the codepath to write out a
+   section of a configuration section, which has been corrected.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.15.2.txt b/third_party/git/Documentation/RelNotes/2.15.2.txt
new file mode 100644
index 0000000000..b480e56b68
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.15.2.txt
@@ -0,0 +1,50 @@
+Git v2.15.2 Release Notes
+=========================
+
+Fixes since v2.15.1
+-------------------
+
+ * Recent update to the refs infrastructure implementation started
+   rewriting packed-refs file more often than before; this has been
+   optimized again for most trivial cases.
+
+ * The SubmittingPatches document has been converted to produce an
+   HTML version via AsciiDoc/Asciidoctor.
+
+ * Contrary to the documentation, "git pull -4/-6 other-args" did not
+   ask the underlying "git fetch" to go over IPv4/IPv6, which has been
+   corrected.
+
+ * When "git rebase" prepared an mailbox of changes and fed it to "git
+   am" to replay them, it was confused when a stray "From " happened
+   to be in the log message of one of the replayed changes.  This has
+   been corrected.
+
+ * Command line completion (in contrib/) has been taught about the
+   "--copy" option of "git branch".
+
+ * "git apply --inaccurate-eof" when used with "--ignore-space-change"
+   triggered an internal sanity check, which has been fixed.
+
+ * The sequencer machinery (used by "git cherry-pick A..B", and "git
+   rebase -i", among other things) would have lost a commit if stopped
+   due to an unlockable index file, which has been fixed.
+
+ * The three-way merge performed by "git cherry-pick" was confused
+   when a new submodule was added in the meantime, which has been
+   fixed (or "papered over").
+
+ * "git notes" sent its error message to its standard output stream,
+   which was corrected.
+
+ * A few scripts (both in production and tests) incorrectly redirected
+   their error output.  These have been corrected.
+
+ * Clarify and enhance documentation for "merge-base --fork-point", as
+   it was clear what it computed but not why/what for.
+
+ * This release also contains the fixes made in the v2.13.7 version of
+   Git.  See its release notes for details.
+
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.15.3.txt b/third_party/git/Documentation/RelNotes/2.15.3.txt
new file mode 100644
index 0000000000..fd2e6f8df7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.15.3.txt
@@ -0,0 +1,6 @@
+Git v2.15.3 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
diff --git a/third_party/git/Documentation/RelNotes/2.16.0.txt b/third_party/git/Documentation/RelNotes/2.16.0.txt
new file mode 100644
index 0000000000..0c81c5915f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.0.txt
@@ -0,0 +1,482 @@
+Git 2.16 Release Notes
+======================
+
+Backward compatibility notes and other notable changes.
+
+ * Use of an empty string as a pathspec element that is used for
+   'everything matches' is now an error.
+
+
+Updates since v2.15
+-------------------
+
+UI, Workflows & Features
+
+ * An empty string as a pathspec element that means "everything"
+   i.e. 'git add ""', is now illegal.  We started this by first
+   deprecating and warning a pathspec that has such an element in
+   2.11 (Nov 2016).
+
+ * A hook script that is set unexecutable is simply ignored.  Git
+   notifies when such a file is ignored, unless the message is
+   squelched via advice.ignoredHook configuration.
+
+ * "git pull" has been taught to accept "--[no-]signoff" option and
+   pass it down to "git merge".
+
+ * The "--push-option=<string>" option to "git push" now defaults to a
+   list of strings configured via push.pushOption variable.
+
+ * "gitweb" checks if a directory is searchable with Perl's "-x"
+   operator, which can be enhanced by using "filetest 'access'"
+   pragma, which now we do.
+
+ * "git stash save" has been deprecated in favour of "git stash push".
+
+ * The set of paths output from "git status --ignored" was tied
+   closely with its "--untracked=<mode>" option, but now it can be
+   controlled more flexibly.  Most notably, a directory that is
+   ignored because it is listed to be ignored in the ignore/exclude
+   mechanism can be handled differently from a directory that ends up
+   to be ignored only because all files in it are ignored.
+
+ * The remote-helper for talking to MediaWiki has been updated to
+   truncate an overlong pagename so that ".mw" suffix can still be
+   added.
+
+ * The remote-helper for talking to MediaWiki has been updated to
+   work with mediawiki namespaces.
+
+ * The "--format=..." option "git for-each-ref" takes learned to show
+   the name of the 'remote' repository and the ref at the remote side
+   that is affected for 'upstream' and 'push' via "%(push:remotename)"
+   and friends.
+
+ * Doc and message updates to teach users "bisect view" is a synonym
+   for "bisect visualize".
+
+ * "git bisect run" that did not specify any command to run used to go
+   ahead and treated all commits to be tested as 'good'.  This has
+   been corrected by making the command error out.
+
+ * The SubmittingPatches document has been converted to produce an
+   HTML version via AsciiDoc/Asciidoctor.
+
+ * We learned to optionally talk to a file system monitor via new
+   fsmonitor extension to speed up "git status" and other operations
+   that need to see which paths have been modified.  Currently we only
+   support "watchman".  See File System Monitor section of
+   git-update-index(1) for more detail.
+
+ * The "diff" family of commands learned to ignore differences in
+   carriage return at the end of line.
+
+ * Places that know about "sendemail.to", like documentation and shell
+   completion (in contrib/) have been taught about "sendemail.tocmd",
+   too.
+
+ * "git add --renormalize ." is a new and safer way to record the fact
+   that you are correcting the end-of-line convention and other
+   "convert_to_git()" glitches in the in-repository data.
+
+ * "git branch" and "git checkout -b" are now forbidden from creating
+   a branch whose name is "HEAD".
+
+ * "git branch --list" learned to show its output through the pager by
+   default when the output is going to a terminal, which is controlled
+   by the pager.branch configuration variable.  This is similar to a
+   recent change to "git tag --list".
+
+ * "git grep -W", "git diff -W" and their friends learned a heuristic
+   to extend a pre-context beyond the line that matches the "function
+   pattern" (aka "diff.*.xfuncname") to include a comment block, if
+   exists, that immediately precedes it.
+
+ * "git config --expiry-date gc.reflogexpire" can read "2.weeks" from
+   the configuration and report it as a timestamp, just like "--int"
+   would read "1k" and report 1024, to help consumption by scripts.
+
+ * The shell completion (in contrib/) learned that "git pull" can take
+   the "--autostash" option.
+
+ * The tagnames "git log --decorate" uses to annotate the commits can
+   now be limited to subset of available refs with the two additional
+   options, --decorate-refs[-exclude]=<pattern>.
+
+ * "git grep" compiled with libpcre2 sometimes triggered a segfault,
+   which is being fixed.
+
+ * "git send-email" tries to see if the sendmail program is available
+   in /usr/lib and /usr/sbin; extend the list of locations to be
+   checked to also include directories on $PATH.
+
+ * "git diff" learned, "--anchored", a variant of the "--patience"
+   algorithm, to which the user can specify which 'unique' line to be
+   used as anchoring points.
+
+ * The way "git worktree add" determines what branch to create from
+   where and checkout in the new worktree has been updated a bit.
+
+ * Ancient part of codebase still shows dots after an abbreviated
+   object name just to show that it is not a full object name, but
+   these ellipses are confusing to people who newly discovered Git
+   who are used to seeing abbreviated object names and find them
+   confusing with the range syntax.
+
+ * With a configuration variable rebase.abbreviateCommands set,
+   "git rebase -i" produces the todo list with a single-letter
+   command names.
+
+ * "git worktree add" learned to run the post-checkout hook, just like
+   "git checkout" does, after the initial checkout.
+
+ * "git svn" has been updated to strip CRs in the commit messages, as
+   recent versions of Subversion rejects them.
+
+ * "git imap-send" did not correctly quote the folder name when
+   making a request to the server, which has been corrected.
+
+ * Error messages from "git rebase" have been somewhat cleaned up.
+
+ * Git has been taught to support an https:// URL used for http.proxy
+   when using recent versions of libcurl.
+
+ * "git merge" learned to pay attention to merge.verifySignatures
+   configuration variable and pretend as if '--verify-signatures'
+   option was given from the command line.
+
+ * "git describe" was taught to dig trees deeper to find a
+   <commit-ish>:<path> that refers to a given blob object.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * An earlier update made it possible to use an on-stack in-core
+   lockfile structure (as opposed to having to deliberately leak an
+   on-heap one).  Many codepaths have been updated to take advantage
+   of this new facility.
+
+ * Calling cmd_foo() as if it is a general purpose helper function is
+   a no-no.  Correct two instances of such to set an example.
+
+ * We try to see if somebody runs our test suite with a shell that
+   does not support "local" like bash/dash does.
+
+ * An early part of piece-by-piece rewrite of "git bisect" in C.
+
+ * GSoC to piece-by-piece rewrite "git submodule" in C.
+
+ * Optimize the code to find shortest unique prefix of object names.
+
+ * Pathspec-limited revision traversal was taught not to keep finding
+   unneeded differences once it knows two trees are different inside
+   given pathspec.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * Code cleanup.
+
+ * A single-word "unsigned flags" in the diff options is being split
+   into a structure with many bitfields.
+
+ * TravisCI build updates.
+
+ * Parts of a test to drive the long-running content filter interface
+   has been split into its own module, hopefully to eventually become
+   reusable.
+
+ * Drop (perhaps overly cautious) sanity check before using the index
+   read from the filesystem at runtime.
+
+ * The build procedure has been taught to avoid some unnecessary
+   instability in the build products.
+
+ * A new mechanism to upgrade the wire protocol in place is proposed
+   and demonstrated that it works with the older versions of Git
+   without harming them.
+
+ * An infrastructure to define what hash function is used in Git is
+   introduced, and an effort to plumb that throughout various
+   codepaths has been started.
+
+ * The code to iterate over loose object files got optimized.
+
+ * An internal function that was left for backward compatibility has
+   been removed, as there is no remaining callers.
+
+ * Historically, the diff machinery for rename detection had a
+   hardcoded limit of 32k paths; this is being lifted to allow users
+   trade cycles with a (possibly) easier to read result.
+
+ * The tracing infrastructure has been optimized for cases where no
+   tracing is requested.
+
+ * In preparation for implementing narrow/partial clone, the object
+   walking machinery has been taught a way to tell it to "filter" some
+   objects from enumeration.
+
+ * A few structures and variables that are implementation details of
+   the decorate API have been renamed and then the API got documented
+   better.
+
+ * Assorted updates for TravisCI integration.
+   (merge 4f26366679 sg/travis-fixes later to maint).
+
+ * Introduce a helper to simplify code to parse a common pattern that
+   expects either "--key" or "--key=<something>".
+
+ * "git version --build-options" learned to report the host CPU and
+   the exact commit object name the binary was built from.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.15
+-----------------
+
+ * "auto" as a value for the columnar output configuration ought to
+   judge "is the output consumed by humans?" with the same criteria as
+   "auto" for coloured output configuration, i.e. either the standard
+   output stream is going to tty, or a pager is in use.  We forgot the
+   latter, which has been fixed.
+
+ * The experimental "color moved lines differently in diff output"
+   feature was buggy around "ignore whitespace changes" edges, which
+   has been corrected.
+
+ * Instead of using custom line comparison and hashing functions to
+   implement "moved lines" coloring in the diff output, use the pair
+   of these functions from lower-layer xdiff/ code.
+
+ * Some codepaths did not check for errors when asking what branch the
+   HEAD points at, which have been fixed.
+
+ * "git commit", after making a commit, did not check for errors when
+   asking on what branch it made the commit, which has been corrected.
+
+ * "git status --ignored -u" did not stop at a working tree of a
+   separate project that is embedded in an ignored directory and
+   listed files in that other project, instead of just showing the
+   directory itself as ignored.
+
+ * A broken access to object databases in recent update to "git grep
+   --recurse-submodules" has been fixed.
+
+ * A recent regression in "git rebase -i" that broke execution of git
+   commands from subdirectories via "exec" instruction has been fixed.
+
+ * A (possibly flakey) test fix.
+
+ * "git check-ref-format --branch @{-1}" bit a "BUG()" when run
+   outside a repository for obvious reasons; clarify the documentation
+   and make sure we do not even try to expand the at-mark magic in
+   such a case, but still call the validation logic for branch names.
+
+ * "git fetch --recurse-submodules" now knows that submodules can be
+   moved around in the superproject in addition to getting updated,
+   and finds the ones that need to be fetched accordingly.
+
+ * Command line completion (in contrib/) update.
+
+ * Description of blame.{showroot,blankboundary,showemail,date}
+   configuration variables have been added to "git config --help".
+
+ * After an error from lstat(), diff_populate_filespec() function
+   sometimes still went ahead and used invalid data in struct stat,
+   which has been fixed.
+
+ * UNC paths are also relevant in Cygwin builds and they are now
+   tested just like Mingw builds.
+
+ * Correct start-up sequence so that a repository could be placed
+   immediately under the root directory again (which was broken at
+   around Git 2.13).
+
+ * The credential helper for libsecret (in contrib/) has been improved
+   to allow possibly prompting the end user to unlock secrets that are
+   currently locked (otherwise the secrets may not be loaded).
+
+ * MinGW updates.
+
+ * Error checking in "git imap-send" for empty response has been
+   improved.
+
+ * Recent update to the refs infrastructure implementation started
+   rewriting packed-refs file more often than before; this has been
+   optimized again for most trivial cases.
+
+ * Some error messages did not quote filenames shown in it, which have
+   been fixed.
+
+ * "git rebase -i" recently started misbehaving when a submodule that
+   is configured with 'submodule.<name>.ignore' is dirty; this has
+   been corrected.
+
+ * Building with NO_LIBPCRE1_JIT did not disable it, which has been fixed.
+
+ * We used to add an empty alternate object database to the system
+   that does not help anything; it has been corrected.
+
+ * Doc update around use of "format-patch --subject-prefix" etc.
+
+ * A fix for an ancient bug in "git apply --ignore-space-change" codepath.
+
+ * Clarify and enhance documentation for "merge-base --fork-point", as
+   it was clear what it computed but not why/what for.
+
+ * A few scripts (both in production and tests) incorrectly redirected
+   their error output.  These have been corrected.
+
+ * "git notes" sent its error message to its standard output stream,
+   which was corrected.
+
+ * The three-way merge performed by "git cherry-pick" was confused
+   when a new submodule was added in the meantime, which has been
+   fixed (or "papered over").
+
+ * The sequencer machinery (used by "git cherry-pick A..B", and "git
+   rebase -i", among other things) would have lost a commit if stopped
+   due to an unlockable index file, which has been fixed.
+
+ * "git apply --inaccurate-eof" when used with "--ignore-space-change"
+   triggered an internal sanity check, which has been fixed.
+
+ * Command line completion (in contrib/) has been taught about the
+   "--copy" option of "git branch".
+
+ * When "git rebase" prepared a mailbox of changes and fed it to "git
+   am" to replay them, it was confused when a stray "From " happened
+   to be in the log message of one of the replayed changes.  This has
+   been corrected.
+
+ * There was a recent semantic mismerge in the codepath to write out a
+   section of a configuration section, which has been corrected.
+
+ * Mentions of "git-rebase" and "git-am" (dashed form) still remained
+   in end-user visible strings emitted by the "git rebase" command;
+   they have been corrected.
+
+ * Contrary to the documentation, "git pull -4/-6 other-args" did not
+   ask the underlying "git fetch" to go over IPv4/IPv6, which has been
+   corrected.
+
+ * "git checkout --recursive" may overwrite and rewind the history of
+   the branch that happens to be checked out in submodule
+   repositories, which might not be desirable.  Detach the HEAD but
+   still allow the recursive checkout to succeed in such a case.
+   (merge 57f22bf997 sb/submodule-recursive-checkout-detach-head later to maint).
+
+ * "git branch --set-upstream" has been deprecated and (sort of)
+   removed, as "--set-upstream-to" is the preferred one these days.
+   The documentation still had "--set-upstream" listed on its
+   synopsis section, which has been corrected.
+   (merge a060f3d3d8 tz/branch-doc-remove-set-upstream later to maint).
+
+ * Internally we use 0{40} as a placeholder object name to signal the
+   codepath that there is no such object (e.g. the fast-forward check
+   while "git fetch" stores a new remote-tracking ref says "we know
+   there is no 'old' thing pointed at by the ref, as we are creating
+   it anew" by passing 0{40} for the 'old' side), and expect that a
+   codepath to locate an in-core object to return NULL as a sign that
+   the object does not exist.  A look-up for an object that does not
+   exist however is quite costly with a repository with large number
+   of packfiles.  This access pattern has been optimized.
+   (merge 87b5e236a1 jk/fewer-pack-rescan later to maint).
+
+ * In addition to "git stash -m message", the command learned to
+   accept "git stash -mmessage" form.
+   (merge 5675473fcb ph/stash-save-m-option-fix later to maint).
+
+ * @{-N} in "git checkout @{-N}" may refer to a detached HEAD state,
+   but the documentation was not clear about it, which has been fixed.
+   (merge 75ce149575 ks/doc-checkout-previous later to maint).
+
+ * A regression in the progress eye-candy was fixed.
+   (merge 9c5951cacf jk/progress-delay-fix later to maint).
+
+ * The code internal to the recursive merge strategy was not fully
+   prepared to see a path that is renamed to try overwriting another
+   path that is only different in case on case insensitive systems.
+   This does not matter in the current code, but will start to matter
+   once the rename detection logic starts taking hints from nearby
+   paths moving to some directory and moves a new path along with them.
+   (merge 4cba2b0108 en/merge-recursive-icase-removal later to maint).
+
+ * An v2.12-era regression in pathspec match logic, which made it look
+   into submodule tree even when it is not desired, has been fixed.
+   (merge eef3df5a93 bw/pathspec-match-submodule-boundary later to maint).
+
+ * Amending commits in git-gui broke the author name that is non-ascii
+   due to incorrect enconding conversion.
+
+ * Recent update to the submodule configuration code broke "diff-tree"
+   by accidentally stopping to read from the index upfront.
+   (merge fd66bcc31f bw/submodule-config-cleanup later to maint).
+
+ * Git shows a message to tell the user that it is waiting for the
+   user to finish editing when spawning an editor, in case the editor
+   opens to a hidden window or somewhere obscure and the user gets
+   lost.
+   (merge abfb04d0c7 ls/editor-waiting-message later to maint).
+
+ * The "safe crlf" check incorrectly triggered for contents that does
+   not use CRLF as line endings, which has been corrected.
+   (merge 649f1f0948 tb/check-crlf-for-safe-crlf later to maint).
+
+ * "git clone --shared" to borrow from a (secondary) worktree did not
+   work, even though "git clone --local" did.  Both are now accepted.
+   (merge b3b05971c1 es/clone-shared-worktree later to maint).
+
+ * The build procedure now allows not just the repositories but also
+   the refs to be used to take pre-formatted manpages and html
+   documents to install.
+   (merge 65289e9dcd rb/quick-install-doc later to maint).
+
+ * Update the shell prompt script (in contrib/) to strip trailing CR
+   from strings read from various "state" files.
+   (merge 041fe8fc83 ra/prompt-eread-fix later to maint).
+
+ * "git merge -s recursive" did not correctly abort when the index is
+   dirty, if the merged tree happened to be the same as the current
+   HEAD, which has been fixed.
+
+ * Bytes with high-bit set were encoded incorrectly and made
+   credential helper fail.
+   (merge 4c267f2ae3 jd/fix-strbuf-add-urlencode-bytes later to maint).
+
+ * "git rebase -p -X<option>" did not propagate the option properly
+   down to underlying merge strategy backend.
+   (merge dd6fb0053c js/fix-merge-arg-quoting-in-rebase-p later to maint).
+
+ * "git merge -s recursive" did not correctly abort when the index is
+   dirty, if the merged tree happened to be the same as the current
+   HEAD, which has been fixed.
+   (merge f309e8e768 ew/empty-merge-with-dirty-index-maint later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge 1a1fc2d5b5 rd/man-prune-progress later to maint).
+   (merge 0ba014035a rd/man-reflog-add-n later to maint).
+   (merge e54b63359f rd/doc-notes-prune-fix later to maint).
+   (merge ff4c9b413a sp/doc-info-attributes later to maint).
+   (merge 7db2cbf4f1 jc/receive-pack-hook-doc later to maint).
+   (merge 5a0526264b tg/t-readme-updates later to maint).
+   (merge 5e83cca0b8 jk/no-optional-locks later to maint).
+   (merge 826c778f7c js/hashmap-update-sample later to maint).
+   (merge 176b2d328c sg/setup-doc-update later to maint).
+   (merge 1b09073514 rs/am-builtin-leakfix later to maint).
+   (merge addcf6cfde rs/fmt-merge-msg-string-leak-fix later to maint).
+   (merge c3ff8f6c14 rs/strbuf-read-once-reset-length later to maint).
+   (merge 6b0eb884f9 db/doc-workflows-neuter-the-maintainer later to maint).
+   (merge 8c87bdfb21 jk/cvsimport-quoting later to maint).
+   (merge 176cb979fe rs/fmt-merge-msg-leakfix later to maint).
+   (merge 5a03360e73 tb/delimit-pretty-trailers-args-with-comma later to maint).
+   (merge d0e6326026 ot/pretty later to maint).
+   (merge 44103f4197 sb/test-helper-excludes later to maint).
+   (merge 170078693f jt/transport-no-more-rsync later to maint).
+   (merge c07b3adff1 bw/path-doc later to maint).
+   (merge bf9d7df950 tz/lib-git-svn-svnserve-tests later to maint).
+   (merge dec366c9a8 sr/http-sslverify-config-doc later to maint).
+   (merge 3f824e91c8 jk/test-suite-tracing later to maint).
+   (merge 1feb061701 db/doc-config-section-names-with-bs later to maint).
+   (merge 74dea0e13c jh/memihash-opt later to maint).
+   (merge 2e9fdc795c ma/bisect-leakfix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.16.1.txt b/third_party/git/Documentation/RelNotes/2.16.1.txt
new file mode 100644
index 0000000000..66e64361fd
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.1.txt
@@ -0,0 +1,11 @@
+Git v2.16.1 Release Notes
+=========================
+
+Fixes since v2.16
+-----------------
+
+ * "git clone" segfaulted when cloning a project that happens to
+   track two paths that differ only in case on a case insensitive
+   filesystem.
+
+Does not contain any other documentation updates or code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.16.2.txt b/third_party/git/Documentation/RelNotes/2.16.2.txt
new file mode 100644
index 0000000000..a216466d3d
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.2.txt
@@ -0,0 +1,30 @@
+Git v2.16.2 Release Notes
+=========================
+
+Fixes since v2.16.1
+-------------------
+
+ * An old regression in "git describe --all $annotated_tag^0" has been
+   fixed.
+
+ * "git svn dcommit" did not take into account the fact that a
+   svn+ssh:// URL with a username@ (typically used for pushing) refers
+   to the same SVN repository without the username@ and failed when
+   svn.pushmergeinfo option is set.
+
+ * "git merge -Xours/-Xtheirs" learned to use our/their version when
+   resolving a conflicting updates to a symbolic link.
+
+ * "git clone $there $here" is allowed even when here directory exists
+   as long as it is an empty directory, but the command incorrectly
+   removed it upon a failure of the operation.
+
+ * "git stash -- <pathspec>" incorrectly blew away untracked files in
+   the directory that matched the pathspec, which has been corrected.
+
+ * "git add -p" was taught to ignore local changes to submodules as
+   they do not interfere with the partial addition of regular changes
+   anyway.
+
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.16.3.txt b/third_party/git/Documentation/RelNotes/2.16.3.txt
new file mode 100644
index 0000000000..64a0bcb0d2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.3.txt
@@ -0,0 +1,49 @@
+Git v2.16.3 Release Notes
+=========================
+
+Fixes since v2.16.2
+-------------------
+
+ * "git status" after moving a path in the working tree (hence making
+   it appear "removed") and then adding with the -N option (hence
+   making that appear "added") detected it as a rename, but did not
+   report the  old and new pathnames correctly.
+
+ * "git commit --fixup" did not allow "-m<message>" option to be used
+   at the same time; allow it to annotate resulting commit with more
+   text.
+
+ * When resetting the working tree files recursively, the working tree
+   of submodules are now also reset to match.
+
+ * Fix for a commented-out code to adjust it to a rather old API change
+   around object ID.
+
+ * When there are too many changed paths, "git diff" showed a warning
+   message but in the middle of a line.
+
+ * The http tracing code, often used to debug connection issues,
+   learned to redact potentially sensitive information from its output
+   so that it can be more safely sharable.
+
+ * Crash fix for a corner case where an error codepath tried to unlock
+   what it did not acquire lock on.
+
+ * The split-index mode had a few corner case bugs fixed.
+
+ * Assorted fixes to "git daemon".
+
+ * Completion of "git merge -s<strategy>" (in contrib/) did not work
+   well in non-C locale.
+
+ * Workaround for segfault with more recent versions of SVN.
+
+ * Recently introduced leaks in fsck have been plugged.
+
+ * Travis CI integration now builds the executable in 'script' phase
+   to follow the established practice, rather than during
+   'before_script' phase.  This allows the CI categorize the failures
+   better ('failed' is project's fault, 'errored' is build
+   environment's).
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.16.4.txt b/third_party/git/Documentation/RelNotes/2.16.4.txt
new file mode 100644
index 0000000000..6be538ba30
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.4.txt
@@ -0,0 +1,5 @@
+Git v2.16.4 Release Notes
+=========================
+
+This release is to forward-port the fixes made in the v2.13.7 version
+of Git.  See its release notes for details.
diff --git a/third_party/git/Documentation/RelNotes/2.16.5.txt b/third_party/git/Documentation/RelNotes/2.16.5.txt
new file mode 100644
index 0000000000..cb8ee02a9a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.16.5.txt
@@ -0,0 +1,6 @@
+Git v2.16.5 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
diff --git a/third_party/git/Documentation/RelNotes/2.17.0.txt b/third_party/git/Documentation/RelNotes/2.17.0.txt
new file mode 100644
index 0000000000..c2cf891f71
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.17.0.txt
@@ -0,0 +1,398 @@
+Git 2.17 Release Notes
+======================
+
+Updates since v2.16
+-------------------
+
+UI, Workflows & Features
+
+ * "diff" family of commands learned "--find-object=<object-id>" option
+   to limit the findings to changes that involve the named object.
+
+ * "git format-patch" learned to give 72-cols to diffstat, which is
+   consistent with other line length limits the subcommand uses for
+   its output meant for e-mails.
+
+ * The log from "git daemon" can be redirected with a new option; one
+   relevant use case is to send the log to standard error (instead of
+   syslog) when running it from inetd.
+
+ * "git rebase" learned to take "--allow-empty-message" option.
+
+ * "git am" has learned the "--quit" option, in addition to the
+   existing "--abort" option; having the pair mirrors a few other
+   commands like "rebase" and "cherry-pick".
+
+ * "git worktree add" learned to run the post-checkout hook, just like
+   "git clone" runs it upon the initial checkout.
+
+ * "git tag" learned an explicit "--edit" option that allows the
+   message given via "-m" and "-F" to be further edited.
+
+ * "git fetch --prune-tags" may be used as a handy short-hand for
+   getting rid of stale tags that are locally held.
+
+ * The new "--show-current-patch" option gives an end-user facing way
+   to get the diff being applied when "git rebase" (and "git am")
+   stops with a conflict.
+
+ * "git add -p" used to offer "/" (look for a matching hunk) as a
+   choice, even there was only one hunk, which has been corrected.
+   Also the single-key help is now given only for keys that are
+   enabled (e.g. help for '/' won't be shown when there is only one
+   hunk).
+
+ * Since Git 1.7.9, "git merge" defaulted to --no-ff (i.e. even when
+   the side branch being merged is a descendant of the current commit,
+   create a merge commit instead of fast-forwarding) when merging a
+   tag object.  This was appropriate default for integrators who pull
+   signed tags from their downstream contributors, but caused an
+   unnecessary merges when used by downstream contributors who
+   habitually "catch up" their topic branches with tagged releases
+   from the upstream.  Update "git merge" to default to --no-ff only
+   when merging a tag object that does *not* sit at its usual place in
+   refs/tags/ hierarchy, and allow fast-forwarding otherwise, to
+   mitigate the problem.
+
+ * "git status" can spend a lot of cycles to compute the relation
+   between the current branch and its upstream, which can now be
+   disabled with "--no-ahead-behind" option.
+
+ * "git diff" and friends learned funcname patterns for Go language
+   source files.
+
+ * "git send-email" learned "--reply-to=<address>" option.
+
+ * Funcname pattern used for C# now recognizes "async" keyword.
+
+ * In a way similar to how "git tag" learned to honor the pager
+   setting only in the list mode, "git config" learned to ignore the
+   pager setting when it is used for setting values (i.e. when the
+   purpose of the operation is not to "show").
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * More perf tests for threaded grep
+
+ * "perf" test output can be sent to codespeed server.
+
+ * The build procedure for perl/ part has been greatly simplified by
+   weaning ourselves off of MakeMaker.
+
+ * Perl 5.8 or greater has been required since Git 1.7.4 released in
+   2010, but we continued to assume some core modules may not exist and
+   used a conditional "eval { require <<module>> }"; we no longer do
+   this.  Some platforms (Fedora/RedHat/CentOS, for example) ship Perl
+   without all core modules by default (e.g. Digest::MD5, File::Temp,
+   File::Spec, Net::Domain, Net::SMTP).  Users on such platforms may
+   need to install these additional modules.
+
+ * As a convenience, we install copies of Perl modules we require which
+   are not part of the core Perl distribution (e.g. Error and
+   Mail::Address).  Users and packagers whose operating system provides
+   these modules can set NO_PERL_CPAN_FALLBACKS to avoid installing the
+   bundled modules.
+
+ * In preparation for implementing narrow/partial clone, the machinery
+   for checking object connectivity used by gc and fsck has been
+   taught that a missing object is OK when it is referenced by a
+   packfile specially marked as coming from trusted repository that
+   promises to make them available on-demand and lazily.
+
+ * The machinery to clone & fetch, which in turn involves packing and
+   unpacking objects, has been told how to omit certain objects using
+   the filtering mechanism introduced by another topic.  It now knows
+   to mark the resulting pack as a promisor pack to tolerate missing
+   objects, laying foundation for "narrow" clones.
+
+ * The first step to getting rid of mru API and using the
+   doubly-linked list API directly instead.
+
+ * Retire mru API as it does not give enough abstraction over
+   underlying list API to be worth it.
+
+ * Rewrite two more "git submodule" subcommands in C.
+
+ * The tracing machinery learned to report tweaking of environment
+   variables as well.
+
+ * Update Coccinelle rules to catch and optimize strbuf_addf(&buf, "%s", str)
+
+ * Prevent "clang-format" from breaking line after function return type.
+
+ * The sequencer infrastructure is shared across "git cherry-pick",
+   "git rebase -i", etc., and has always spawned "git commit" when it
+   needs to create a commit.  It has been taught to do so internally,
+   when able, by reusing the codepath "git commit" itself uses, which
+   gives performance boost for a few tens of percents in some sample
+   scenarios.
+
+ * Push the submodule version of collision-detecting SHA-1 hash
+   implementation a bit harder on builders.
+
+ * Avoid mmapping small files while using packed refs (especially ones
+   with zero size, which would cause later munmap() to fail).
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * More tests for wildmatch functions.
+
+ * The code to binary search starting from a fan-out table (which is
+   how the packfile is indexed with object names) has been refactored
+   into a reusable helper.
+
+ * We now avoid using identifiers that clash with C++ keywords.  Even
+   though it is not a goal to compile Git with C++ compilers, changes
+   like this help use of code analysis tools that targets C++ on our
+   codebase.
+
+ * The executable is now built in 'script' phase in Travis CI integration,
+   to follow the established practice, rather than during 'before_script'
+   phase.  This allows the CI categorize the failures better ('failed'
+   is project's fault, 'errored' is build environment's).
+   (merge 3c93b82920 sg/travis-build-during-script-phase later to maint).
+
+ * Writing out the index file when the only thing that changed in it
+   is the untracked cache information is often wasteful, and this has
+   been optimized out.
+
+ * Various pieces of Perl code we have have been cleaned up.
+
+ * Internal API clean-up to allow write_locked_index() optionally skip
+   writing the in-core index when it is not modified.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.16
+-----------------
+
+ * An old regression in "git describe --all $annotated_tag^0" has been
+   fixed.
+
+ * "git status" after moving a path in the working tree (hence making
+   it appear "removed") and then adding with the -N option (hence
+   making that appear "added") detected it as a rename, but did not
+   report the  old and new pathnames correctly.
+
+ * "git svn dcommit" did not take into account the fact that a
+   svn+ssh:// URL with a username@ (typically used for pushing) refers
+   to the same SVN repository without the username@ and failed when
+   svn.pushmergeinfo option is set.
+
+ * API clean-up around revision traversal.
+
+ * "git merge -Xours/-Xtheirs" learned to use our/their version when
+   resolving a conflicting updates to a symbolic link.
+
+ * "git clone $there $here" is allowed even when here directory exists
+   as long as it is an empty directory, but the command incorrectly
+   removed it upon a failure of the operation.
+
+ * "git commit --fixup" did not allow "-m<message>" option to be used
+   at the same time; allow it to annotate resulting commit with more
+   text.
+
+ * When resetting the working tree files recursively, the working tree
+   of submodules are now also reset to match.
+
+ * "git stash -- <pathspec>" incorrectly blew away untracked files in
+   the directory that matched the pathspec, which has been corrected.
+
+ * Instead of maintaining home-grown email address parsing code, ship
+   a copy of reasonably recent Mail::Address to be used as a fallback
+   in 'git send-email' when the platform lacks it.
+   (merge d60be8acab mm/send-email-fallback-to-local-mail-address later to maint).
+
+ * "git add -p" was taught to ignore local changes to submodules as
+   they do not interfere with the partial addition of regular changes
+   anyway.
+
+ * Avoid showing a warning message in the middle of a line of "git
+   diff" output.
+   (merge 4e056c989f nd/diff-flush-before-warning later to maint).
+
+ * The http tracing code, often used to debug connection issues,
+   learned to redact potentially sensitive information from its output
+   so that it can be more safely sharable.
+   (merge 8ba18e6fa4 jt/http-redact-cookies later to maint).
+
+ * Crash fix for a corner case where an error codepath tried to unlock
+   what it did not acquire lock on.
+   (merge 81fcb698e0 mr/packed-ref-store-fix later to maint).
+
+ * The split-index mode had a few corner case bugs fixed.
+   (merge ae59a4e44f tg/split-index-fixes later to maint).
+
+ * Assorted fixes to "git daemon".
+   (merge ed15e58efe jk/daemon-fixes later to maint).
+
+ * Completion of "git merge -s<strategy>" (in contrib/) did not work
+   well in non-C locale.
+   (merge 7cc763aaa3 nd/list-merge-strategy later to maint).
+
+ * Workaround for segfault with more recent versions of SVN.
+   (merge 7f6f75e97a ew/svn-branch-segfault-fix later to maint).
+
+ * Plug recently introduced leaks in fsck.
+   (merge ba3a08ca0e jt/fsck-code-cleanup later to maint).
+
+ * "git pull --rebase" did not pass verbosity setting down when
+   recursing into a submodule.
+   (merge a56771a668 sb/pull-rebase-submodule later to maint).
+
+ * The way "git reset --hard" reports the commit the updated HEAD
+   points at is made consistent with the way how the commit title is
+   generated by the other parts of the system.  This matters when the
+   title is spread across physically multiple lines.
+   (merge 1cf823fb68 tg/reset-hard-show-head-with-pretty later to maint).
+
+ * Test fixes.
+   (merge 63b1a175ee sg/test-i18ngrep later to maint).
+
+ * Some bugs around "untracked cache" feature have been fixed.  This
+   will notice corrupt data in the untracked cache left by old and
+   buggy code and issue a warning---the index can be fixed by clearing
+   the untracked cache from it.
+   (merge 0cacebf099 nd/fix-untracked-cache-invalidation later to maint).
+   (merge 7bf0be7501 ab/untracked-cache-invalidation-docs later to maint).
+
+ * "git blame HEAD COPYING" in a bare repository failed to run, while
+   "git blame HEAD -- COPYING" run just fine.  This has been corrected.
+
+ * "git add" files in the same directory, but spelling the directory
+   path in different cases on case insensitive filesystem, corrupted
+   the name hash data structure and led to unexpected results.  This
+   has been corrected.
+   (merge c95525e90d bp/name-hash-dirname-fix later to maint).
+
+ * "git rebase -p" mangled log messages of a merge commit, which is
+   now fixed.
+   (merge ed5144d7eb js/fix-merge-arg-quoting-in-rebase-p later to maint).
+
+ * Some low level protocol codepath could crash when they get an
+   unexpected flush packet, which is now fixed.
+   (merge bb1356dc64 js/packet-read-line-check-null later to maint).
+
+ * "git check-ignore" with multiple paths got confused when one is a
+   file and the other is a directory, which has been fixed.
+   (merge d60771e930 rs/check-ignore-multi later to maint).
+
+ * "git describe $garbage" stopped giving any errors when the garbage
+   happens to be a string with 40 hexadecimal letters.
+   (merge a8e7a2bf0f sb/describe-blob later to maint).
+
+ * Code to unquote single-quoted string (used in the parser for
+   configuration files, etc.) did not diagnose bogus input correctly
+   and produced bogus results instead.
+   (merge ddbbf8eb25 jk/sq-dequote-on-bogus-input later to maint).
+
+ * Many places in "git apply" knew that "/dev/null" that signals
+   "there is no such file on this side of the diff" can be followed by
+   whitespace and garbage when parsing a patch, except for one, which
+   made an otherwise valid patch (e.g. ones from subversion) rejected.
+   (merge e454ad4bec tk/apply-dev-null-verify-name-fix later to maint).
+
+ * We no longer create any *.spec file, so "make clean" should not
+   remove it.
+   (merge 4321bdcabb tz/do-not-clean-spec-file later to maint).
+
+ * "git push" over http transport did not unquote the push-options
+   correctly.
+   (merge 90dce21eb0 jk/push-options-via-transport-fix later to maint).
+
+ * "git send-email" learned to complain when the batch-size option is
+   not defined when the relogin-delay option is, since these two are
+   mutually required.
+   (merge 9caa70697b xz/send-email-batch-size later to maint).
+
+ * Y2k20 fix ;-) for our perl scripts.
+   (merge a40e06ee33 bw/perl-timegm-timelocal-fix later to maint).
+
+ * Threaded "git grep" has been optimized to avoid allocation in code
+   section that is covered under a mutex.
+   (merge 38ef24dccf rv/grep-cleanup later to maint).
+
+ * "git subtree" script (in contrib/) scripted around "git log", whose
+   output got affected by end-user configuration like log.showsignature
+   (merge 8841b5222c sg/subtree-signed-commits later to maint).
+
+ * While finding unique object name abbreviation, the code may
+   accidentally have read beyond the end of the array of object names
+   in a pack.
+   (merge 21abed500c ds/find-unique-abbrev-optim later to maint).
+
+ * Micro optimization in revision traversal code.
+   (merge ebbed3ba04 ds/mark-parents-uninteresting-optim later to maint).
+
+ * "git commit" used to run "gc --auto" near the end, which was lost
+   when the command was reimplemented in C by mistake.
+   (merge 095c741edd ab/gc-auto-in-commit later to maint).
+
+ * Allow running a couple of tests with "sh -x".
+   (merge c20bf94abc sg/cvs-tests-with-x later to maint).
+
+ * The codepath to replace an existing entry in the index had a bug in
+   updating the name hash structure, which has been fixed.
+   (merge 0e267b7a24 bp/refresh-cache-ent-rehash-fix later to maint).
+
+ * The transfer.fsckobjects configuration tells "git fetch" to
+   validate the data and connected-ness of objects in the received
+   pack; the code to perform this check has been taught about the
+   narrow clone's convention that missing objects that are reachable
+   from objects in a pack that came from a promisor remote is OK.
+
+ * There was an unused file-scope static variable left in http.c when
+   building for versions of libCURL that is older than 7.19.4, which
+   has been fixed.
+   (merge b8fd6008ec rj/http-code-cleanup later to maint).
+
+ * Shell script portability fix.
+   (merge 206a6ae013 ml/filter-branch-portability-fix later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge e2a5a028c7 bw/oidmap-autoinit later to maint).
+   (merge ec3b4b06f8 cl/t9001-cleanup later to maint).
+   (merge e1b3f3dd38 ks/submodule-doc-updates later to maint).
+   (merge fbac558a9b rs/describe-unique-abbrev later to maint).
+   (merge 8462ff43e4 tb/crlf-conv-flags later to maint).
+   (merge 7d68bb0766 rb/hashmap-h-compilation-fix later to maint).
+   (merge 3449847168 cc/sha1-file-name later to maint).
+   (merge ad622a256f ds/use-get-be64 later to maint).
+   (merge f919ffebed sg/cocci-move-array later to maint).
+   (merge 4e801463c7 jc/mailinfo-cleanup-fix later to maint).
+   (merge ef5b3a6c5e nd/shared-index-fix later to maint).
+   (merge 9f5258cbb8 tz/doc-show-defaults-to-head later to maint).
+   (merge b780e4407d jc/worktree-add-short-help later to maint).
+   (merge ae239fc8e5 rs/cocci-strbuf-addf-to-addstr later to maint).
+   (merge 2e22a85e5c nd/ignore-glob-doc-update later to maint).
+   (merge 3738031581 jk/gettext-poison later to maint).
+   (merge 54360a1956 rj/sparse-updates later to maint).
+   (merge 12e31a6b12 sg/doc-test-must-fail-args later to maint).
+   (merge 760f1ad101 bc/doc-interpret-trailers-grammofix later to maint).
+   (merge 4ccf461f56 bp/fsmonitor later to maint).
+   (merge a6119f82b1 jk/test-hashmap-updates later to maint).
+   (merge 5aea9fe6cc rd/typofix later to maint).
+   (merge e4e5da2796 sb/status-doc-fix later to maint).
+   (merge 7976e901c8 gs/test-unset-xdg-cache-home later to maint).
+   (merge d023df1ee6 tg/worktree-create-tracking later to maint).
+   (merge 4cbe92fd41 sm/mv-dry-run-update later to maint).
+   (merge 75e5e9c3f7 sb/color-h-cleanup later to maint).
+   (merge 2708ef4af6 sg/t6300-modernize later to maint).
+   (merge d88e92d4e0 bw/doc-submodule-recurse-config-with-clone later to maint).
+   (merge f74bbc8dd2 jk/cached-commit-buffer later to maint).
+   (merge 1316416903 ms/non-ascii-ticks later to maint).
+   (merge 878056005e rs/strbuf-read-file-or-whine later to maint).
+   (merge 79f0ba1547 jk/strbuf-read-file-close-error later to maint).
+   (merge edfb8ba068 ot/ref-filter-cleanup later to maint).
+   (merge 11395a3b4b jc/test-must-be-empty later to maint).
+   (merge 768b9d6db7 mk/doc-pretty-fill later to maint).
+   (merge 2caa7b8d27 ab/man-sec-list later to maint).
+   (merge 40c17eb184 ks/t3200-typofix later to maint).
+   (merge bd9958c358 dp/merge-strategy-doc-fix later to maint).
+   (merge 9ee0540a40 js/ming-strftime later to maint).
+   (merge 1775e990f7 tz/complete-tag-delete-tagname later to maint).
+   (merge 00a4b03501 rj/warning-uninitialized-fix later to maint).
+   (merge b635ed97a0 jk/attributes-path-doc later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.17.1.txt b/third_party/git/Documentation/RelNotes/2.17.1.txt
new file mode 100644
index 0000000000..e01384fe8e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.17.1.txt
@@ -0,0 +1,16 @@
+Git v2.17.1 Release Notes
+=========================
+
+Fixes since v2.17
+-----------------
+
+ * This release contains the same fixes made in the v2.13.7 version of
+   Git, covering CVE-2018-11233 and 11235, and forward-ported to
+   v2.14.4, v2.15.2 and v2.16.4 releases.  See release notes to
+   v2.13.7 for details.
+
+ * In addition to the above fixes, this release has support on the
+   server side to reject pushes to repositories that attempt to create
+   such problematic .gitmodules file etc. as tracked contents, to help
+   hosting sites protect their customers by preventing malicious
+   contents from spreading.
diff --git a/third_party/git/Documentation/RelNotes/2.17.2.txt b/third_party/git/Documentation/RelNotes/2.17.2.txt
new file mode 100644
index 0000000000..ef021be870
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.17.2.txt
@@ -0,0 +1,12 @@
+Git v2.17.2 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 to address
+the recently reported CVE-2018-17456; see the release notes for that
+version for details.
+
+In addition, this release also teaches "fsck" and the server side
+logic to reject pushes to repositories that attempt to create such a
+problematic ".gitmodules" file as tracked contents, to help hosting
+sites protect their customers by preventing malicious contents from
+spreading.
diff --git a/third_party/git/Documentation/RelNotes/2.18.0.txt b/third_party/git/Documentation/RelNotes/2.18.0.txt
new file mode 100644
index 0000000000..3ea280cf68
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.18.0.txt
@@ -0,0 +1,583 @@
+Git 2.18 Release Notes
+======================
+
+Updates since v2.17
+-------------------
+
+UI, Workflows & Features
+
+ * Rename detection logic that is used in "merge" and "cherry-pick" has
+   learned to guess when all of x/a, x/b and x/c have moved to z/a,
+   z/b and z/c, it is likely that x/d added in the meantime would also
+   want to move to z/d by taking the hint that the entire directory
+   'x' moved to 'z'.  A bug causing dirty files involved in a rename
+   to be overwritten during merge has also been fixed as part of this
+   work.  Incidentally, this also avoids updating a file in the
+   working tree after a (non-trivial) merge whose result matches what
+   our side originally had.
+
+ * "git filter-branch" learned to use a different exit code to allow
+   the callers to tell the case where there was no new commits to
+   rewrite from other error cases.
+
+ * When built with more recent cURL, GIT_SSL_VERSION can now specify
+   "tlsv1.3" as its value.
+
+ * "git gui" learned that "~/.ssh/id_ecdsa.pub" and
+   "~/.ssh/id_ed25519.pub" are also possible SSH key files.
+   (merge 2e2f0288ef bb/git-gui-ssh-key-files later to maint).
+
+ * "git gui" performs commit upon CTRL/CMD+ENTER but the
+   CTRL/CMD+KP_ENTER (i.e. enter key on the numpad) did not have the
+   same key binding.  It now does.
+   (merge 28a1d94a06 bp/git-gui-bind-kp-enter later to maint).
+
+ * "git gui" has been taught to work with old versions of tk (like
+   8.5.7) that do not support "ttk::style theme use" as a way to query
+   the current theme.
+   (merge 4891961105 cb/git-gui-ttk-style later to maint).
+
+ * "git rebase" has learned to honor "--signoff" option when using
+   backends other than "am" (but not "--preserve-merges").
+
+ * "git branch --list" during an interrupted "rebase -i" now lets
+   users distinguish the case where a detached HEAD is being rebased
+   and a normal branch is being rebased.
+
+ * "git mergetools" learned talking to guiffy.
+
+ * The scripts in contrib/emacs/ have outlived their usefulness and
+   have been replaced with a stub that errors out and tells the user
+   there are replacements.
+
+ * The new "working-tree-encoding" attribute can ask Git to convert the
+   contents to the specified encoding when checking out to the working
+   tree (and the other way around when checking in).
+
+ * The "git config" command uses separate options e.g. "--int",
+   "--bool", etc. to specify what type the caller wants the value to
+   be interpreted as.  A new "--type=<typename>" option has been
+   introduced, which would make it cleaner to define new types.
+
+ * "git config --get" learned the "--default" option, to help the
+   calling script.  Building on top of the above changes, the
+   "git config" learns "--type=color" type.  Taken together, you can
+   do things like "git config --get foo.color --default blue" and get
+   the ANSI color sequence for the color given to foo.color variable,
+   or "blue" if the variable does not exist.
+
+ * "git ls-remote" learned an option to allow sorting its output based
+   on the refnames being shown.
+
+ * The command line completion (in contrib/) has been taught that "git
+   stash save" has been deprecated ("git stash push" is the preferred
+   spelling in the new world) and does not offer it as a possible
+   completion candidate when "git stash push" can be.
+
+ * "git gc --prune=nonsense" spent long time repacking and then
+   silently failed when underlying "git prune --expire=nonsense"
+   failed to parse its command line.  This has been corrected.
+
+ * Error messages from "git push" can be painted for more visibility.
+
+ * "git http-fetch" (deprecated) had an optional and experimental
+   "feature" to fetch only commits and/or trees, which nobody used.
+   This has been removed.
+
+ * The functionality of "$GIT_DIR/info/grafts" has been superseded by
+   the "refs/replace/" mechanism for some time now, but the internal
+   code had support for it in many places, which has been cleaned up
+   in order to drop support of the "grafts" mechanism.
+
+ * "git worktree add" learned to check out an existing branch.
+
+ * "git --no-pager cmd" did not have short-and-sweet single letter
+   option. Now it does as "-P".
+   (merge 7213c28818 js/no-pager-shorthand later to maint).
+
+ * "git rebase" learned "--rebase-merges" to transplant the whole
+   topology of commit graph elsewhere.
+
+ * "git status" learned to pay attention to UI related diff
+   configuration variables such as diff.renames.
+
+ * The command line completion mechanism (in contrib/) learned to load
+   custom completion file for "git $command" where $command is a
+   custom "git-$command" that the end user has on the $PATH when using
+   newer version of bash-completion.
+
+ * "git send-email" can sometimes offer confirmation dialog "Send this
+   email?" with choices 'Yes', 'No', 'Quit', and 'All'.  A new action
+   'Edit' has been added to this dialog's choice.
+
+ * With merge.renames configuration set to false, the recursive merge
+   strategy can be told not to spend cycles trying to find renamed
+   paths and merge them accordingly.
+
+ * "git status" learned to honor a new status.renames configuration to
+   skip rename detection, which could be useful for those who want to
+   do so without disabling the default rename detection done by the
+   "git diff" command.
+
+ * Command line completion (in contrib/) learned to complete pathnames
+   for various commands better.
+
+ * "git blame" learns to unhighlight uninteresting metadata from the
+   originating commit on lines that are the same as the previous one,
+   and also paint lines in different colors depending on the age of
+   the commit.
+
+ * Transfer protocol v2 learned to support the partial clone.
+
+ * When a short hexadecimal string is used to name an object but there
+   are multiple objects that share the string as the prefix of their
+   names, the code lists these ambiguous candidates in a help message.
+   These object names are now sorted according to their types for
+   easier eyeballing.
+
+ * "git fetch $there $refspec" that talks over protocol v2 can take
+   advantage of server-side ref filtering; the code has been extended
+   so that this mechanism triggers also when fetching with configured
+   refspec.
+
+ * Our HTTP client code used to advertise that we accept gzip encoding
+   from the other side; instead, just let cURL library to advertise
+   and negotiate the best one.
+
+ * "git p4" learned to "unshelve" shelved commit from P4.
+   (merge 123f631761 ld/p4-unshelve later to maint).
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * A "git fetch" from a repository with insane number of refs into a
+   repository that is already up-to-date still wasted too many cycles
+   making many lstat(2) calls to see if these objects at the tips
+   exist as loose objects locally.  These lstat(2) calls are optimized
+   away by enumerating all loose objects beforehand.
+   It is unknown if the new strategy negatively affects existing use
+   cases, fetching into a repository with many loose objects from a
+   repository with small number of refs.
+
+ * Git can be built to use either v1 or v2 of the PCRE library, and so
+   far, the build-time configuration USE_LIBPCRE=YesPlease instructed
+   the build procedure to use v1, but now it means v2.  USE_LIBPCRE1
+   and USE_LIBPCRE2 can be used to explicitly choose which version to
+   use, as before.
+
+ * The build procedure learned to optionally use symbolic links
+   (instead of hardlinks and copies) to install "git-foo" for built-in
+   commands, whose binaries are all identical.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * The way "git worktree prune" worked internally has been simplified,
+   by assuming how "git worktree move" moves an existing worktree to a
+   different place.
+
+ * Code clean-up for the "repository" abstraction.
+   (merge 00a3da2a13 nd/remove-ignore-env-field later to maint).
+
+ * Code to find the length to uniquely abbreviate object names based
+   on packfile content, which is a relatively recent addtion, has been
+   optimized to use the same fan-out table.
+
+ * The mechanism to use parse-options API to automate the command line
+   completion continues to get extended and polished.
+
+ * Copies of old scripted Porcelain commands in contrib/examples/ have
+   been removed.
+
+ * Some tests that rely on the exact hardcoded values of object names
+   have been updated in preparation for hash function migration.
+
+ * Perf-test update.
+
+ * Test helper update.
+
+ * The effort continues to refactor the internal global data structure
+   to make it possible to open multiple repositories, work with and
+   then close them,
+
+ * Small test-helper programs have been consolidated into a single
+   binary.
+
+ * API clean-up around ref-filter code.
+
+ * Shell completion (in contrib) that gives list of paths have been
+   optimized somewhat.
+
+ * The index file is updated to record the fsmonitor section after a
+   full scan was made, to avoid wasting the effort that has already
+   spent.
+
+ * Performance measuring framework in t/perf learned to help bisecting
+   performance regressions.
+
+ * Some multi-word source filenames are being renamed to separate
+   words with dashes instead of underscores.
+
+ * An reusable "memory pool" implementation has been extracted from
+   fast-import.c, which in turn has become the first user of the
+   mem-pool API.
+
+ * A build-time option has been added to allow Git to be told to refer
+   to its associated files relative to the main binary, in the same
+   way that has been possible on Windows for quite some time, for
+   Linux, BSDs and Darwin.
+
+ * Precompute and store information necessary for ancestry traversal
+   in a separate file to optimize graph walking.
+
+ * The effort to pass the repository in-core structure throughout the
+   API continues.  This round deals with the code that implements the
+   refs/replace/ mechanism.
+
+ * The build procedure "make DEVELOPER=YesPlease" learned to enable a
+   bit more warning options depending on the compiler used to help
+   developers more.  There also is "make DEVOPTS=tokens" knob
+   available now, for those who want to help fixing warnings we
+   usually ignore, for example.
+
+ * A new version of the transport protocol is being worked on.
+
+ * The code to interface to GPG has been restructured somewhat to make
+   it cleaner to integrate with other types of signature systems later.
+
+ * The code has been taught to use the duplicated information stored
+   in the commit-graph file to learn the tree object name for a commit
+   to avoid opening and parsing the commit object when it makes sense
+   to do so.
+
+ * "git gc" in a large repository takes a lot of time as it considers
+   to repack all objects into one pack by default.  The command has
+   been taught to pretend as if the largest existing packfile is
+   marked with ".keep" so that it is left untouched while objects in
+   other packs and loose ones are repacked.
+
+ * The transport protocol v2 is getting updated further.
+
+ * The codepath around object-info API has been taught to take the
+   repository object (which in turn tells the API which object store
+   the objects are to be located).
+
+ * "git pack-objects" needs to allocate tons of "struct object_entry"
+   while doing its work, and shrinking its size helps the performance
+   quite a bit.
+
+ * The implementation of "git rebase -i --root" has been updated to use
+   the sequencer machinery more.
+
+ * Developer support update, by using BUG() macro instead of die() to
+   mark codepaths that should not happen more clearly.
+
+ * Developer support.  Use newer GCC on one of the builds done at
+   TravisCI.org to get more warnings and errors diagnosed.
+
+ * Conversion from uchar[20] to struct object_id continues.
+
+ * By code restructuring of submodule merge in merge-recursive,
+   informational messages from the codepath are now given using the
+   same mechanism as other output, and honor the merge.verbosity
+   configuration.  The code also learned to give a few new messages
+   when a submodule three-way merge resolves cleanly when one side
+   records a descendant of the commit chosen by the other side.
+
+ * Avoid unchecked snprintf() to make future code auditing easier.
+   (merge ac4896f007 jk/snprintf-truncation later to maint).
+
+ * Many tests hardcode the raw object names, which would change once
+   we migrate away from SHA-1.  While some of them must test against
+   exact object names, most of them do not have to use hardcoded
+   constants in the test.  The latter kind of tests have been updated
+   to test the moral equivalent of the original without hardcoding the
+   actual object names.
+
+ * The list of commands with their various attributes were spread
+   across a few places in the build procedure, but it now is getting a
+   bit more consolidated to allow more automation.
+
+ * Quite a many tests assumed that newly created refs are made as
+   loose refs using the files backend, which have been updated to use
+   proper plumbing like rev-parse and update-ref, to avoid breakage
+   once we start using different ref backends.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.17
+-----------------
+
+ * "git shortlog cruft" aborted with a BUG message when run outside a
+   Git repository.  The command has been taught to complain about
+   extra and unwanted arguments on its command line instead in such a
+   case.
+   (merge 4aa0161e83 ma/shortlog-revparse later to maint).
+
+ * "git stash push -u -- <pathspec>" gave an unnecessary and confusing
+   error message when there was no tracked files that match the
+   <pathspec>, which has been fixed.
+   (merge 353278687e tg/stash-untracked-with-pathspec-fix later to maint).
+
+ * "git tag --contains no-such-commit" gave a full list of options
+   after giving an error message.
+   (merge 3bb0923f06 ps/contains-id-error-message later to maint).
+
+ * "diff-highlight" filter (in contrib/) learned to understand "git log
+   --graph" output better.
+   (merge 4551fbba14 jk/diff-highlight-graph-fix later to maint).
+
+ * when refs that do not point at committish are given, "git
+   filter-branch" gave a misleading error messages.  This has been
+   corrected.
+   (merge f78ab355e7 yk/filter-branch-non-committish-refs later to maint).
+
+ * "git submodule status" misbehaved on a submodule that has been
+   removed from the working tree.
+   (merge 74b6bda32f rs/status-with-removed-submodule later to maint).
+
+ * When credential helper exits very quickly without reading its
+   input, it used to cause Git to die with SIGPIPE, which has been
+   fixed.
+   (merge a0d51e8d0e eb/cred-helper-ignore-sigpipe later to maint).
+
+ * "git rebase --keep-empty" still removed an empty commit if the
+   other side contained an empty commit (due to the "does an
+   equivalent patch exist already?" check), which has been corrected.
+   (merge 3d946165e1 pw/rebase-keep-empty-fixes later to maint).
+
+ * Some codepaths, including the refs API, get and keep relative
+   paths, that go out of sync when the process does chdir(2).  The
+   chdir-notify API is introduced to let these codepaths adjust these
+   cached paths to the new current directory.
+   (merge fb9c2d2703 jk/relative-directory-fix later to maint).
+
+ * "cd sub/dir && git commit ../path" ought to record the changes to
+   the file "sub/path", but this regressed long time ago.
+   (merge 86238e07ef bw/commit-partial-from-subdirectory-fix later to maint).
+
+ * Recent introduction of "--log-destination" option to "git daemon"
+   did not work well when the daemon was run under "--inetd" mode.
+   (merge e67d906d73 lw/daemon-log-destination later to maint).
+
+ * Small fix to the autoconf build procedure.
+   (merge 249482daf0 es/fread-reads-dir-autoconf-fix later to maint).
+
+ * Fix an unexploitable (because the oversized contents are not under
+   attacker's control) buffer overflow.
+   (merge d8579accfa bp/fsmonitor-bufsize-fix later to maint).
+
+ * Recent simplification of build procedure forgot a bit of tweak to
+   the build procedure of contrib/mw-to-git/
+   (merge d8698987f3 ab/simplify-perl-makefile later to maint).
+
+ * Moving a submodule that itself has submodule in it with "git mv"
+   forgot to make necessary adjustment to the nested sub-submodules;
+   now the codepath learned to recurse into the submodules.
+
+ * "git config --unset a.b", when "a.b" is the last variable in an
+   otherwise empty section "a", left an empty section "a" behind, and
+   worse yet, a subsequent "git config a.c value" did not reuse that
+   empty shell and instead created a new one.  These have been
+   (partially) corrected.
+   (merge c71d8bb38a js/empty-config-section-fix later to maint).
+
+ * "git worktree remove" learned that "-f" is a shorthand for
+   "--force" option, just like for "git worktree add".
+   (merge d228eea514 sb/worktree-remove-opt-force later to maint).
+
+ * The completion script (in contrib/) learned to clear cached list of
+   command line options upon dot-sourcing it again in a more efficient
+   way.
+   (merge 94408dc71c sg/completion-clear-cached later to maint).
+
+ * "git svn" had a minor thinko/typo which has been fixed.
+   (merge 51db271587 ab/git-svn-get-record-typofix later to maint).
+
+ * During a "rebase -i" session, the code could give older timestamp
+   to commits created by later "pick" than an earlier "reword", which
+   has been corrected.
+   (merge 12f7babd6b js/ident-date-fix later to maint).
+
+ * "git submodule status" did not check the symbolic revision name it
+   computed for the submodule HEAD is not the NULL, and threw it at
+   printf routines, which has been corrected.
+   (merge 0b5e2ea7cf nd/submodule-status-fix later to maint).
+
+ * When fed input that already has In-Reply-To: and/or References:
+   headers and told to add the same information, "git send-email"
+   added these headers separately, instead of appending to an existing
+   one, which is a violation of the RFC.  This has been corrected.
+   (merge 256be1d3f0 sa/send-email-dedup-some-headers later to maint).
+
+ * "git fast-export" had a regression in v2.15.0 era where it skipped
+   some merge commits in certain cases, which has been corrected.
+   (merge be011bbe00 ma/fast-export-skip-merge-fix later to maint).
+
+ * The code did not propagate the terminal width to subprocesses via
+   COLUMNS environment variable, which it now does.  This caused
+   trouble to "git column" helper subprocess when "git tag --column=row"
+   tried to list the existing tags on a display with non-default width.
+   (merge b5d5a567fb nd/term-columns later to maint).
+
+ * We learned that our source files with ".pl" and ".py" extensions
+   are Perl and Python files respectively and changes to them are
+   better viewed as such with appropriate diff drivers.
+   (merge 7818b619e2 ab/perl-python-attrs later to maint).
+
+ * "git rebase -i" sometimes left intermediate "# This is a
+   combination of N commits" message meant for the human consumption
+   inside an editor in the final result in certain corner cases, which
+   has been fixed.
+   (merge 15ef69314d js/rebase-i-clean-msg-after-fixup-continue later to maint).
+
+ * A test to see if the filesystem normalizes UTF-8 filename has been
+   updated to check what we need to know in a more direct way, i.e. a
+   path created in NFC form can be accessed with NFD form (or vice
+   versa) to cope with APFS as well as HFS.
+   (merge 742ae10e35 tb/test-apfs-utf8-normalization later to maint).
+
+ * "git format-patch --cover --attach" created a broken MIME multipart
+   message for the cover letter, which has been fixed by keeping the
+   cover letter as plain text file.
+   (merge 50cd54ef4e bc/format-patch-cover-no-attach later to maint).
+
+ * The split-index feature had a long-standing and dormant bug in
+   certain use of the in-core merge machinery, which has been fixed.
+   (merge 7db118303a en/unpack-trees-split-index-fix later to maint).
+
+ * Asciidoctor gives a reasonable imitation for AsciiDoc, but does not
+   render illustration in a literal block correctly when indented with
+   HT by default. The problem is fixed by forcing 8-space tabs.
+   (merge 379805051d bc/asciidoctor-tab-width later to maint).
+
+ * Code clean-up to adjust to a more recent lockfile API convention that
+   allows lockfile instances kept on the stack.
+   (merge 0fa5a2ed8d ma/lockfile-cleanup later to maint).
+
+ * the_repository->index is not a allocated piece of memory but
+   repo_clear() indiscriminately attempted to free(3) it, which has
+   been corrected.
+   (merge 74373b5f10 nd/repo-clear-keep-the-index later to maint).
+
+ * Code clean-up to avoid non-standard-conformant pointer arithmetic.
+   (merge c112084af9 rs/no-null-ptr-arith-in-fast-export later to maint).
+
+ * Code clean-up to turn history traversal more robust in a
+   semi-corrupt repository.
+   (merge 8702b30fd7 jk/unavailable-can-be-missing later to maint).
+
+ * "git update-ref A B" is supposed to ensure that ref A does not yet
+   exist when B is a NULL OID, but this check was not done correctly
+   for pseudo-refs outside refs/ hierarchy, e.g. MERGE_HEAD.
+
+ * "git submodule update" and "git submodule add" supported the
+   "--reference" option to borrow objects from a neighbouring local
+   repository like "git clone" does, but lacked the more recent
+   invention "--dissociate".  Also "git submodule add" has been taught
+   to take the "--progress" option.
+   (merge a0ef29341a cf/submodule-progress-dissociate later to maint).
+
+ * Update credential-netrc helper (in contrib/) to allow customizing
+   the GPG used to decrypt the encrypted .netrc file.
+   (merge 786ef50a23 lm/credential-netrc later to maint).
+
+ * "git submodule update" attempts two different kinds of "git fetch"
+   against the upstream repository to grab a commit bound at the
+   submodule's path, but it incorrectly gave up if the first kind
+   (i.e. a normal fetch) failed, making the second "last resort" one
+   (i.e. fetching an exact commit object by object name) ineffective.
+   This has been corrected.
+   (merge e30d833671 sb/submodule-update-try-harder later to maint).
+
+ * Error behaviour of "git grep" when it cannot read the index was
+   inconsistent with other commands that uses the index, which has
+   been corrected to error out early.
+   (merge b2aa84c789 sb/grep-die-on-unreadable-index later to maint).
+
+ * We used to call regfree() after regcomp() failed in some codepaths,
+   which have been corrected.
+   (merge 17154b1576 ma/regex-no-regfree-after-comp-fail later to maint).
+
+ * The import-tars script (in contrib/) has been taught to handle
+   tarballs with overly long paths that use PAX extended headers.
+   (merge 12ecea46e3 pa/import-tars-long-names later to maint).
+
+ * "git rev-parse Y..." etc. misbehaved when given endpoints were
+   not committishes.
+   (merge 0ed556d38f en/rev-parse-invalid-range later to maint).
+
+ * "git pull --recurse-submodules --rebase", when the submodule
+   repository's history did not have anything common between ours and
+   the upstream's, failed to execute.  We need to fetch from them to
+   continue even in such a case.
+   (merge 4d36f88be7 jt/submodule-pull-recurse-rebase later to maint).
+
+ * "git remote update" can take both a single remote nickname and a
+   nickname for remote groups, but only one of them was documented.
+   (merge a97447a42a nd/remote-update-doc later to maint).
+
+ * "index-pack --strict" has been taught to make sure that it runs the
+   final object integrity checks after making the freshly indexed
+   packfile available to itself.
+   (merge 3737746120 jk/index-pack-maint later to maint).
+
+ * Make zlib inflate codepath more robust against versions of zlib
+   that clobber unused portion of outbuf.
+   (merge b611396e97 jl/zlib-restore-nul-termination later to maint).
+
+ * Fix old merge glitch in Documentation during v2.13-rc0 era.
+   (merge 28cb06020b mw/doc-merge-enumfix later to maint).
+
+ * The code to read compressed bitmap was not careful to avoid reading
+   past the end of the file, which has been corrected.
+   (merge 1140bf01ec jk/ewah-bounds-check later to maint).
+
+ * "make NO_ICONV=NoThanks" did not override NEEDS_LIBICONV
+   (i.e. linkage of -lintl, -liconv, etc. that are platform-specific
+   tweaks), which has been corrected.
+   (merge fdb1fbbc7d es/make-no-iconv later to maint).
+
+ * Other minor doc, test and build updates and code cleanups.
+   (merge 248f66ed8e nd/trace-with-env later to maint).
+   (merge 14ced5562c ys/bisect-object-id-missing-conversion-fix later to maint).
+   (merge 5988eb631a ab/doc-hash-brokenness later to maint).
+   (merge a4d4e32a70 pk/test-avoid-pipe-hiding-exit-status later to maint).
+   (merge 05e293c1ac jk/flockfile-stdio later to maint).
+   (merge e9184b0789 jk/t5561-missing-curl later to maint).
+   (merge b1801b85a3 nd/worktree-move later to maint).
+   (merge bbd374dd20 ak/bisect-doc-typofix later to maint).
+   (merge 4855f06fb3 mn/send-email-credential-doc later to maint).
+   (merge 8523b1e355 en/doc-typoes later to maint).
+   (merge 43b44ccfe7 js/t5404-path-fix later to maint).
+   (merge decf711fc1 ps/test-chmtime-get later to maint).
+   (merge 22d11a6e8e es/worktree-docs later to maint).
+   (merge 92a5dbbc22 tg/use-git-contacts later to maint).
+   (merge adc887221f tq/t1510 later to maint).
+   (merge bed21a8ad6 sg/doc-gc-quote-mismatch-fix later to maint).
+   (merge 73364e4f10 tz/doc-git-urls-reference later to maint).
+   (merge cd1e606bad bc/mailmap-self later to maint).
+   (merge f7997e3682 ao/config-api-doc later to maint).
+   (merge ee930754d8 jk/apply-p-doc later to maint).
+   (merge 011b648646 nd/pack-format-doc later to maint).
+   (merge 87a6bb701a sg/t5310-jgit-bitmap-test later to maint).
+   (merge f6b82970aa sg/t5516-fixes later to maint).
+   (merge 4362da078e sg/t7005-spaces-in-filenames-cleanup later to maint).
+   (merge 7d0ee47c11 js/test-unset-prereq later to maint).
+   (merge 5356a3c354 ah/misc-doc-updates later to maint).
+   (merge 92c4a7a129 nd/completion-aliasfiletype-typofix later to maint).
+   (merge 58bd77b66a nd/pack-unreachable-objects-doc later to maint).
+   (merge 4ed79d5203 sg/t6500-no-redirect-of-stdin later to maint).
+   (merge 17b8a2d6cd jk/config-blob-sans-repo later to maint).
+   (merge 590551ca2c rd/tag-doc-lightweight later to maint).
+   (merge 44f560fc16 rd/init-typo later to maint).
+   (merge f156a0934a rd/p4-doc-markup-env later to maint).
+   (merge 2a00502b14 tg/doc-sec-list later to maint).
+   (merge 47cc91310a jk/submodule-fsck-loose-fixup later to maint).
+   (merge efde7b725c rd/comment-typofix-in-sha1-file later to maint).
+   (merge 7eedad15df rd/diff-options-typofix later to maint).
+   (merge 58ebd936cc km/doc-workflows-typofix later to maint).
+   (merge 30aa96cdf8 rd/doc-remote-tracking-with-hyphen later to maint).
+   (merge cf317877e3 ks/branch-set-upstream later to maint).
+   (merge 8de19d6be8 sg/t7406-chain-fix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.18.1.txt b/third_party/git/Documentation/RelNotes/2.18.1.txt
new file mode 100644
index 0000000000..2098cdd776
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.18.1.txt
@@ -0,0 +1,6 @@
+Git v2.18.1 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 and in
+v2.17.2 to address the recently reported CVE-2018-17456; see the
+release notes for those versions for details.
diff --git a/third_party/git/Documentation/RelNotes/2.19.0.txt b/third_party/git/Documentation/RelNotes/2.19.0.txt
new file mode 100644
index 0000000000..a06ccf6e2a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.19.0.txt
@@ -0,0 +1,615 @@
+Git 2.19 Release Notes
+======================
+
+Updates since v2.18
+-------------------
+
+UI, Workflows & Features
+
+ * "git diff" compares the index and the working tree.  For paths
+   added with intent-to-add bit, the command shows the full contents
+   of them as added, but the paths themselves were not marked as new
+   files.  They are now shown as new by default.
+
+   "git apply" learned the "--intent-to-add" option so that an
+   otherwise working-tree-only application of a patch will add new
+   paths to the index marked with the "intent-to-add" bit.
+
+ * "git grep" learned the "--column" option that gives not just the
+   line number but the column number of the hit.
+
+ * The "-l" option in "git branch -l" is an unfortunate short-hand for
+   "--create-reflog", but many users, both old and new, somehow expect
+   it to be something else, perhaps "--list".  This step warns when "-l"
+   is used as a short-hand for "--create-reflog" and warns about the
+   future repurposing of the it when it is used.
+
+ * The userdiff pattern for .php has been updated.
+
+ * The content-transfer-encoding of the message "git send-email" sends
+   out by default was 8bit, which can cause trouble when there is an
+   overlong line to bust RFC 5322/2822 limit.  A new option 'auto' to
+   automatically switch to quoted-printable when there is such a line
+   in the payload has been introduced and is made the default.
+
+ * "git checkout" and "git worktree add" learned to honor
+   checkout.defaultRemote when auto-vivifying a local branch out of a
+   remote tracking branch in a repository with multiple remotes that
+   have tracking branches that share the same names.
+   (merge 8d7b558bae ab/checkout-default-remote later to maint).
+
+ * "git grep" learned the "--only-matching" option.
+
+ * "git rebase --rebase-merges" mode now handles octopus merges as
+   well.
+
+ * Add a server-side knob to skip commits in exponential/fibbonacci
+   stride in an attempt to cover wider swath of history with a smaller
+   number of iterations, potentially accepting a larger packfile
+   transfer, instead of going back one commit a time during common
+   ancestor discovery during the "git fetch" transaction.
+   (merge 42cc7485a2 jt/fetch-negotiator-skipping later to maint).
+
+ * A new configuration variable core.usereplacerefs has been added,
+   primarily to help server installations that want to ignore the
+   replace mechanism altogether.
+
+ * Teach "git tag -s" etc. a few configuration variables (gpg.format
+   that can be set to "openpgp" or "x509", and gpg.<format>.program
+   that is used to specify what program to use to deal with the format)
+   to allow x.509 certs with CMS via "gpgsm" to be used instead of
+   openpgp via "gnupg".
+
+ * Many more strings are prepared for l10n.
+
+ * "git p4 submit" learns to ask its own pre-submit hook if it should
+   continue with submitting.
+
+ * The test performed at the receiving end of "git push" to prevent
+   bad objects from entering repository can be customized via
+   receive.fsck.* configuration variables; we now have gained a
+   counterpart to do the same on the "git fetch" side, with
+   fetch.fsck.* configuration variables.
+
+ * "git pull --rebase=interactive" learned "i" as a short-hand for
+   "interactive".
+
+ * "git instaweb" has been adjusted to run better with newer Apache on
+   RedHat based distros.
+
+ * "git range-diff" is a reimplementation of "git tbdiff" that lets us
+   compare individual patches in two iterations of a topic.
+
+ * The sideband code learned to optionally paint selected keywords at
+   the beginning of incoming lines on the receiving end.
+
+ * "git branch --list" learned to take the default sort order from the
+   'branch.sort' configuration variable, just like "git tag --list"
+   pays attention to 'tag.sort'.
+
+ * "git worktree" command learned "--quiet" option to make it less
+   verbose.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The bulk of "git submodule foreach" has been rewritten in C.
+
+ * The in-core "commit" object had an all-purpose "void *util" field,
+   which was tricky to use especially in library-ish part of the
+   code.  All of the existing uses of the field has been migrated to a
+   more dedicated "commit-slab" mechanism and the field is eliminated.
+
+ * A less often used command "git show-index" has been modernized.
+   (merge fb3010c31f jk/show-index later to maint).
+
+ * The conversion to pass "the_repository" and then "a_repository"
+   throughout the object access API continues.
+
+ * Continuing with the idea to programatically enumerate various
+   pieces of data required for command line completion, teach the
+   codebase to report the list of configuration variables
+   subcommands care about to help complete them.
+
+ * Separate "rebase -p" codepath out of "rebase -i" implementation to
+   slim down the latter and make it easier to manage.
+
+ * Make refspec parsing codepath more robust.
+
+ * Some flaky tests have been fixed.
+
+ * Continuing with the idea to programmatically enumerate various
+   pieces of data required for command line completion, the codebase
+   has been taught to enumerate options prefixed with "--no-" to
+   negate them.
+
+ * Build and test procedure for netrc credential helper (in contrib/)
+   has been updated.
+
+ * Remove unused function definitions and declarations from ewah
+   bitmap subsystem.
+
+ * Code preparation to make "git p4" closer to be usable with Python 3.
+
+ * Tighten the API to make it harder to misuse in-tree .gitmodules
+   file, even though it shares the same syntax with configuration
+   files, to read random configuration items from it.
+
+ * "git fast-import" has been updated to avoid attempting to create
+   delta against a zero-byte-long string, which is pointless.
+
+ * The codebase has been updated to compile cleanly with -pedantic
+   option.
+   (merge 2b647a05d7 bb/pedantic later to maint).
+
+ * The character display width table has been updated to match the
+   latest Unicode standard.
+   (merge 570951eea2 bb/unicode-11-width later to maint).
+
+ * test-lint now looks for broken use of "VAR=VAL shell_func" in test
+   scripts.
+
+ * Conversion from uchar[40] to struct object_id continues.
+
+ * Recent "security fix" to pay attention to contents of ".gitmodules"
+   while accepting "git push" was a bit overly strict than necessary,
+   which has been adjusted.
+
+ * "git fsck" learns to make sure the optional commit-graph file is in
+   a sane state.
+
+ * "git diff --color-moved" feature has further been tweaked.
+
+ * Code restructuring and a small fix to transport protocol v2 during
+   fetching.
+
+ * Parsing of -L[<N>][,[<M>]] parameters "git blame" and "git log"
+   take has been tweaked.
+
+ * lookup_commit_reference() and friends have been updated to find
+   in-core object for a specific in-core repository instance.
+
+ * Various glitches in the heuristics of merge-recursive strategy have
+   been documented in new tests.
+
+ * "git fetch" learned a new option "--negotiation-tip" to limit the
+   set of commits it tells the other end as "have", to reduce wasted
+   bandwidth and cycles, which would be helpful when the receiving
+   repository has a lot of refs that have little to do with the
+   history at the remote it is fetching from.
+
+ * For a large tree, the index needs to hold many cache entries
+   allocated on heap.  These cache entries are now allocated out of a
+   dedicated memory pool to amortize malloc(3) overhead.
+
+ * Tests to cover various conflicting cases have been added for
+   merge-recursive.
+
+ * Tests to cover conflict cases that involve submodules have been
+   added for merge-recursive.
+
+ * Look for broken "&&" chains that are hidden in subshell, many of
+   which have been found and corrected.
+
+ * The singleton commit-graph in-core instance is made per in-core
+   repository instance.
+
+ * "make DEVELOPER=1 DEVOPTS=pedantic" allows developers to compile
+   with -pedantic option, which may catch more problematic program
+   constructs and potential bugs.
+
+ * Preparatory code to later add json output for telemetry data has
+   been added.
+
+ * Update the way we use Coccinelle to find out-of-style code that
+   need to be modernised.
+
+ * It is too easy to misuse system API functions such as strcat();
+   these selected functions are now forbidden in this codebase and
+   will cause a compilation failure.
+
+ * Add a script (in contrib/) to help users of VSCode work better with
+   our codebase.
+
+ * The Travis CI scripts were taught to ship back the test data from
+   failed tests.
+   (merge aea8879a6a sg/travis-retrieve-trash-upon-failure later to maint).
+
+ * The parse-options machinery learned to refrain from enclosing
+   placeholder string inside a "<bra" and "ket>" pair automatically
+   without PARSE_OPT_LITERAL_ARGHELP.  Existing help text for option
+   arguments that are not formatted correctly have been identified and
+   fixed.
+   (merge 5f0df44cd7 rs/parse-opt-lithelp later to maint).
+
+ * Noiseword "extern" has been removed from function decls in the
+   header files.
+
+ * A few atoms like %(objecttype) and %(objectsize) in the format
+   specifier of "for-each-ref --format=<format>" can be filled without
+   getting the full contents of the object, but just with the object
+   header.  These cases have been optimized by calling
+   oid_object_info() API (instead of reading and inspecting the data).
+
+ * The end result of documentation update has been made to be
+   inspected more easily to help developers.
+
+ * The API to iterate over all objects learned to optionally list
+   objects in the order they appear in packfiles, which helps locality
+   of access if the caller accesses these objects while as objects are
+   enumerated.
+
+ * Improve built-in facility to catch broken &&-chain in the tests.
+
+ * The more library-ish parts of the codebase learned to work on the
+   in-core index-state instance that is passed in by their callers,
+   instead of always working on the singleton "the_index" instance.
+
+ * A test prerequisite defined by various test scripts with slightly
+   different semantics has been consolidated into a single copy and
+   made into a lazily defined one.
+   (merge 6ec633059a wc/make-funnynames-shared-lazy-prereq later to maint).
+
+ * After a partial clone, repeated fetches from promisor remote would
+   have accumulated many packfiles marked with .promisor bit without
+   getting them coalesced into fewer packfiles, hurting performance.
+   "git repack" now learned to repack them.
+
+ * Partially revert the support for multiple hash functions to regain
+   hash comparison performance; we'd think of a way to do this better
+   in the next cycle.
+
+ * "git help --config" (which is used in command line completion)
+   missed the configuration variables not described in the main
+   config.txt file but are described in another file that is included
+   by it, which has been corrected.
+
+ * The test linter code has learned that the end of here-doc mark
+   "EOF" can be quoted in a double-quote pair, not just in a
+   single-quote pair.
+
+
+Fixes since v2.18
+-----------------
+
+ * "git remote update" can take both a single remote nickname and a
+   nickname for remote groups, and the completion script (in contrib/)
+   has been taught about it.
+   (merge 9cd4382ad5 ls/complete-remote-update-names later to maint).
+
+ * "git fetch --shallow-since=<cutoff>" that specifies the cut-off
+   point that is newer than the existing history used to end up
+   grabbing the entire history.  Such a request now errors out.
+   (merge e34de73c56 nd/reject-empty-shallow-request later to maint).
+
+ * Fix for 2.17-era regression around `core.safecrlf`.
+   (merge 6cb09125be as/safecrlf-quiet-fix later to maint).
+
+ * The recent addition of "partial clone" experimental feature kicked
+   in when it shouldn't, namely, when there is no partial-clone filter
+   defined even if extensions.partialclone is set.
+   (merge cac1137dc4 jh/partial-clone later to maint).
+
+ * "git send-pack --signed" (hence "git push --signed" over the http
+   transport) did not read user ident from the config mechanism to
+   determine whom to sign the push certificate as, which has been
+   corrected.
+   (merge d067d98887 ms/send-pack-honor-config later to maint).
+
+ * "git fetch-pack --all" used to unnecessarily fail upon seeing an
+   annotated tag that points at an object other than a commit.
+   (merge c12c9df527 jk/fetch-all-peeled-fix later to maint).
+
+ * When user edits the patch in "git add -p" and the user's editor is
+   set to strip trailing whitespaces indiscriminately, an empty line
+   that is unchanged in the patch would become completely empty
+   (instead of a line with a sole SP on it).  The code introduced in
+   Git 2.17 timeframe failed to parse such a patch, but now it learned
+   to notice the situation and cope with it.
+   (merge f4d35a6b49 pw/add-p-recount later to maint).
+
+ * The code to try seeing if a fetch is necessary in a submodule
+   during a fetch with --recurse-submodules got confused when the path
+   to the submodule was changed in the range of commits in the
+   superproject, sometimes showing "(null)".  This has been corrected.
+
+ * Bugfix for "rebase -i" corner case regression.
+   (merge a9279c6785 pw/rebase-i-keep-reword-after-conflict later to maint).
+
+ * Recently added "--base" option to "git format-patch" command did
+   not correctly generate prereq patch ids.
+   (merge 15b76c1fb3 xy/format-patch-prereq-patch-id-fix later to maint).
+
+ * POSIX portability fix in Makefile to fix a glitch introduced a few
+   releases ago.
+   (merge 6600054e9b dj/runtime-prefix later to maint).
+
+ * "git filter-branch" when used with the "--state-branch" option
+   still attempted to rewrite the commits whose filtered result is
+   known from the previous attempt (which is recorded on the state
+   branch); the command has been corrected not to waste cycles doing
+   so.
+   (merge 709cfe848a mb/filter-branch-optim later to maint).
+
+ * Clarify that setting core.ignoreCase to deviate from reality would
+   not turn a case-incapable filesystem into a case-capable one.
+   (merge 48294b512a ms/core-icase-doc later to maint).
+
+ * "fsck.skipList" did not prevent a blob object listed there from
+   being inspected for is contents (e.g. we recently started to
+   inspect the contents of ".gitmodules" for certain malicious
+   patterns), which has been corrected.
+   (merge fb16287719 rj/submodule-fsck-skip later to maint).
+
+ * "git checkout --recurse-submodules another-branch" did not report
+   in which submodule it failed to update the working tree, which
+   resulted in an unhelpful error message.
+   (merge ba95d4e4bd sb/submodule-move-head-error-msg later to maint).
+
+ * "git rebase" behaved slightly differently depending on which one of
+   the three backends gets used; this has been documented and an
+   effort to make them more uniform has begun.
+   (merge b00bf1c9a8 en/rebase-consistency later to maint).
+
+ * The "--ignore-case" option of "git for-each-ref" (and its friends)
+   did not work correctly, which has been fixed.
+   (merge e674eb2528 jk/for-each-ref-icase later to maint).
+
+ * "git fetch" failed to correctly validate the set of objects it
+   received when making a shallow history deeper, which has been
+   corrected.
+   (merge cf1e7c0770 jt/connectivity-check-after-unshallow later to maint).
+
+ * Partial clone support of "git clone" has been updated to correctly
+   validate the objects it receives from the other side.  The server
+   side has been corrected to send objects that are directly
+   requested, even if they may match the filtering criteria (e.g. when
+   doing a "lazy blob" partial clone).
+   (merge a7e67c11b8 jt/partial-clone-fsck-connectivity later to maint).
+
+ * Handling of an empty range by "git cherry-pick" was inconsistent
+   depending on how the range ended up to be empty, which has been
+   corrected.
+   (merge c5e358d073 jk/empty-pick-fix later to maint).
+
+ * "git reset --merge" (hence "git merge ---abort") and "git reset --hard"
+   had trouble working correctly in a sparsely checked out working
+   tree after a conflict, which has been corrected.
+   (merge b33fdfc34c mk/merge-in-sparse-checkout later to maint).
+
+ * Correct a broken use of "VAR=VAL shell_func" in a test.
+   (merge 650161a277 jc/t3404-one-shot-export-fix later to maint).
+
+ * "git rev-parse ':/substring'" did not consider the history leading
+   only to HEAD when looking for a commit with the given substring,
+   when the HEAD is detached.  This has been fixed.
+   (merge 6b3351e799 wc/find-commit-with-pattern-on-detached-head later to maint).
+
+ * Build doc update for Windows.
+   (merge ede8d89bb1 nd/command-list later to maint).
+
+ * core.commentchar is now honored when preparing the list of commits
+   to replay in "rebase -i".
+
+ * "git pull --rebase" on a corrupt HEAD caused a segfault.  In
+   general we substitute an empty tree object when running the in-core
+   equivalent of the diff-index command, and the codepath has been
+   corrected to do so as well to fix this issue.
+   (merge 3506dc9445 jk/has-uncommitted-changes-fix later to maint).
+
+ * httpd tests saw occasional breakage due to the way its access log
+   gets inspected by the tests, which has been updated to make them
+   less flaky.
+   (merge e8b3b2e275 sg/httpd-test-unflake later to maint).
+
+ * Tests to cover more D/F conflict cases have been added for
+   merge-recursive.
+
+ * "git gc --auto" opens file descriptors for the packfiles before
+   spawning "git repack/prune", which would upset Windows that does
+   not want a process to work on a file that is open by another
+   process.  The issue has been worked around.
+   (merge 12e73a3ce4 kg/gc-auto-windows-workaround later to maint).
+
+ * The recursive merge strategy did not properly ensure there was no
+   change between HEAD and the index before performing its operation,
+   which has been corrected.
+   (merge 55f39cf755 en/dirty-merge-fixes later to maint).
+
+ * "git rebase" started exporting GIT_DIR environment variable and
+   exposing it to hook scripts when part of it got rewritten in C.
+   Instead of matching the old scripted Porcelains' behaviour,
+   compensate by also exporting GIT_WORK_TREE environment as well to
+   lessen the damage.  This can harm existing hooks that want to
+   operate on different repository, but the current behaviour is
+   already broken for them anyway.
+   (merge ab5e67d751 bc/sequencer-export-work-tree-as-well later to maint).
+
+ * "git send-email" when using in a batched mode that limits the
+   number of messages sent in a single SMTP session lost the contents
+   of the variable used to choose between tls/ssl, unable to send the
+   second and later batches, which has been fixed.
+   (merge 636f3d7ac5 jm/send-email-tls-auth-on-batch later to maint).
+
+ * The lazy clone support had a few places where missing but promised
+   objects were not correctly tolerated, which have been fixed.
+
+ * One of the "diff --color-moved" mode "dimmed_zebra" that was named
+   in an unusual way has been deprecated and replaced by
+   "dimmed-zebra".
+   (merge e3f2f5f9cd es/diff-color-moved-fix later to maint).
+
+ * The wire-protocol v2 relies on the client to send "ref prefixes" to
+   limit the bandwidth spent on the initial ref advertisement.  "git
+   clone" when learned to speak v2 forgot to do so, which has been
+   corrected.
+   (merge 402c47d939 bw/clone-ref-prefixes later to maint).
+
+ * "git diff --histogram" had a bad memory usage pattern, which has
+   been rearranged to reduce the peak usage.
+   (merge 79cb2ebb92 sb/histogram-less-memory later to maint).
+
+ * Code clean-up to use size_t/ssize_t when they are the right type.
+   (merge 7726d360b5 jk/size-t later to maint).
+
+ * The wire-protocol v2 relies on the client to send "ref prefixes" to
+   limit the bandwidth spent on the initial ref advertisement.  "git
+   fetch $remote branch:branch" that asks tags that point into the
+   history leading to the "branch" automatically followed sent to
+   narrow prefix and broke the tag following, which has been fixed.
+   (merge 2b554353a5 jt/tag-following-with-proto-v2-fix later to maint).
+
+ * When the sparse checkout feature is in use, "git cherry-pick" and
+   other mergy operations lost the skip_worktree bit when a path that
+   is excluded from checkout requires content level merge, which is
+   resolved as the same as the HEAD version, without materializing the
+   merge result in the working tree, which made the path appear as
+   deleted.  This has been corrected by preserving the skip_worktree
+   bit (and not materializing the file in the working tree).
+   (merge 2b75fb601c en/merge-recursive-skip-fix later to maint).
+
+ * The "author-script" file "git rebase -i" creates got broken when
+   we started to move the command away from shell script, which is
+   getting fixed now.
+   (merge 5522bbac20 es/rebase-i-author-script-fix later to maint).
+
+ * The automatic tree-matching in "git merge -s subtree" was broken 5
+   years ago and nobody has noticed since then, which is now fixed.
+   (merge 2ec4150713 jk/merge-subtree-heuristics later to maint).
+
+ * "git fetch $there refs/heads/s" ought to fetch the tip of the
+   branch 's', but when "refs/heads/refs/heads/s", i.e. a branch whose
+   name is "refs/heads/s" exists at the same time, fetched that one
+   instead by mistake.  This has been corrected to honor the usual
+   disambiguation rules for abbreviated refnames.
+   (merge 60650a48c0 jt/refspec-dwim-precedence-fix later to maint).
+
+ * Futureproofing a helper function that can easily be misused.
+   (merge 65bb21e77e es/want-color-fd-defensive later to maint).
+
+ * The http-backend (used for smart-http transport) used to slurp the
+   whole input until EOF, without paying attention to CONTENT_LENGTH
+   that is supplied in the environment and instead expecting the Web
+   server to close the input stream.  This has been fixed.
+   (merge eebfe40962 mk/http-backend-content-length later to maint).
+
+ * "git merge --abort" etc. did not clean things up properly when
+   there were conflicted entries in the index in certain order that
+   are involved in D/F conflicts.  This has been corrected.
+   (merge ad3762042a en/abort-df-conflict-fixes later to maint).
+
+ * "git diff --indent-heuristic" had a bad corner case performance.
+   (merge 301ef85401 sb/indent-heuristic-optim later to maint).
+
+ * The "--exec" option to "git rebase --rebase-merges" placed the exec
+   commands at wrong places, which has been corrected.
+
+ * "git verify-tag" and "git verify-commit" have been taught to use
+   the exit status of underlying "gpg --verify" to signal bad or
+   untrusted signature they found.
+   (merge 4e5dc9ca17 jc/gpg-status later to maint).
+
+ * "git mergetool" stopped and gave an extra prompt to continue after
+   the last path has been handled, which did not make much sense.
+   (merge d651a54b8a ng/mergetool-lose-final-prompt later to maint).
+
+ * Among the three codepaths we use O_APPEND to open a file for
+   appending, one used for writing GIT_TRACE output requires O_APPEND
+   implementation that behaves sensibly when multiple processes are
+   writing to the same file.  POSIX emulation used in the Windows port
+   has been updated to improve in this area.
+   (merge d641097589 js/mingw-o-append later to maint).
+
+ * "git pull --rebase -v" in a repository with a submodule barfed as
+   an intermediate process did not understand what "-v(erbose)" flag
+   meant, which has been fixed.
+   (merge e84c3cf3dc sb/pull-rebase-submodule later to maint).
+
+ * Recent update to "git config" broke updating variable in a
+   subsection, which has been corrected.
+   (merge bff7df7a87 sb/config-write-fix later to maint).
+
+ * When "git rebase -i" is told to squash two or more commits into
+   one, it labeled the log message for each commit with its number.
+   It correctly called the first one "1st commit", but the next one
+   was "commit #1", which was off-by-one.  This has been corrected.
+   (merge dd2e36ebac pw/rebase-i-squash-number-fix later to maint).
+
+ * "git rebase -i", when a 'merge <branch>' insn in its todo list
+   fails, segfaulted, which has been (minimally) corrected.
+   (merge bc9238bb09 pw/rebase-i-merge-segv-fix later to maint).
+
+ * "git cherry-pick --quit" failed to remove CHERRY_PICK_HEAD even
+   though we won't be in a cherry-pick session after it returns, which
+   has been corrected.
+   (merge 3e7dd99208 nd/cherry-pick-quit-fix later to maint).
+
+ * In a recent update in 2.18 era, "git pack-objects" started
+   producing a larger than necessary packfiles by missing
+   opportunities to use large deltas.  This has been corrected.
+
+ * The meaning of the possible values the "core.checkStat"
+   configuration variable can take were not adequately documented,
+   which has been fixed.
+   (merge 9bf5d4c4e2 nd/config-core-checkstat-doc later to maint).
+
+ * Recent "git rebase -i" update started to write bogusly formatted
+   author-script, with a matching broken reading code.  These are
+   fixed.
+
+ * Recent addition of "directory rename" heuristics to the
+   merge-recursive backend makes the command susceptible to false
+   positives and false negatives.  In the context of "git am -3",
+   which does not know about surrounding unmodified paths and thus
+   cannot inform the merge machinery about the full trees involved,
+   this risk is particularly severe.  As such, the heuristic is
+   disabled for "git am -3" to keep the machinery "more stupid but
+   predictable".
+
+ * "git merge-base" in 2.19-rc1 has performance regression when the
+   (experimental) commit-graph feature is in use, which has been
+   mitigated.
+
+ * Code cleanup, docfix, build fix, etc.
+   (merge aee9be2ebe sg/update-ref-stdin-cleanup later to maint).
+   (merge 037714252f jc/clean-after-sanity-tests later to maint).
+   (merge 5b26c3c941 en/merge-recursive-cleanup later to maint).
+   (merge 0dcbc0392e bw/config-refer-to-gitsubmodules-doc later to maint).
+   (merge bb4d000e87 bw/protocol-v2 later to maint).
+   (merge 928f0ab4ba vs/typofixes later to maint).
+   (merge d7f590be84 en/rebase-i-microfixes later to maint).
+   (merge 81d395cc85 js/rebase-recreate-merge later to maint).
+   (merge 51d1863168 tz/exclude-doc-smallfixes later to maint).
+   (merge a9aa3c0927 ds/commit-graph later to maint).
+   (merge 5cf8e06474 js/enhanced-version-info later to maint).
+   (merge 6aaded5509 tb/config-default later to maint).
+   (merge 022d2ac1f3 sb/blame-color later to maint).
+   (merge 5a06a20e0c bp/test-drop-caches-for-windows later to maint).
+   (merge dd61cc1c2e jk/ui-color-always-to-auto later to maint).
+   (merge 1e83b9bfdd sb/trailers-docfix later to maint).
+   (merge ab29f1b329 sg/fast-import-dump-refs-on-checkpoint-fix later to maint).
+   (merge 6a8ad880f0 jn/subtree-test-fixes later to maint).
+   (merge ffbd51cc60 nd/pack-objects-threading-doc later to maint).
+   (merge e9dac7be60 es/mw-to-git-chain-fix later to maint).
+   (merge fe583c6c7a rs/remote-mv-leakfix later to maint).
+   (merge 69885ab015 en/t3031-title-fix later to maint).
+   (merge 8578037bed nd/config-blame-sort later to maint).
+   (merge 8ad169c4ba hn/config-in-code-comment later to maint).
+   (merge b7446fcfdf ar/t4150-am-scissors-test-fix later to maint).
+   (merge a8132410ee js/typofixes later to maint).
+   (merge 388d0ff6e5 en/update-index-doc later to maint).
+   (merge e05aa688dd jc/update-index-doc later to maint).
+   (merge 10c600172c sg/t5310-empty-input-fix later to maint).
+   (merge 5641eb9465 jh/partial-clone-doc later to maint).
+   (merge 2711b1ad5e ab/submodule-relative-url-tests later to maint).
+   (merge ce528de023 ab/unconditional-free-and-null later to maint).
+   (merge bbc072f5d8 rs/opt-updates later to maint).
+   (merge 69d846f053 jk/use-compat-util-in-test-tool later to maint).
+   (merge 1820703045 js/larger-timestamps later to maint).
+   (merge c8b35b95e1 sg/t4051-fix later to maint).
+   (merge 30612cb670 sg/t0020-conversion-fix later to maint).
+   (merge 15da753709 sg/t7501-thinkofix later to maint).
+   (merge 79b04f9b60 sg/t3903-missing-fix later to maint).
+   (merge 2745817028 sg/t3420-autostash-fix later to maint).
+   (merge 7afb0d6777 sg/test-rebase-editor-fix later to maint).
+   (merge 6c6ce21baa es/freebsd-iconv-portability later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.19.1.txt b/third_party/git/Documentation/RelNotes/2.19.1.txt
new file mode 100644
index 0000000000..da7672674e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.19.1.txt
@@ -0,0 +1,6 @@
+Git v2.19.1 Release Notes
+=========================
+
+This release merges up the fixes that appear in v2.14.5 and in
+v2.17.2 to address the recently reported CVE-2018-17456; see the
+release notes for those versions for details.
diff --git a/third_party/git/Documentation/RelNotes/2.19.2.txt b/third_party/git/Documentation/RelNotes/2.19.2.txt
new file mode 100644
index 0000000000..759e6ca957
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.19.2.txt
@@ -0,0 +1,108 @@
+Git v2.19.2 Release Notes
+=========================
+
+Fixes since v2.19.1
+-------------------
+
+ * "git interpret-trailers" and its underlying machinery had a buggy
+   code that attempted to ignore patch text after commit log message,
+   which triggered in various codepaths that will always get the log
+   message alone and never get such an input.
+
+ * "git rebase -i" did not clear the state files correctly when a run
+   of "squash/fixup" is aborted and then the user manually amended the
+   commit instead, which has been corrected.
+
+ * When fsmonitor is in use, after operation on submodules updates
+   .gitmodules, we lost track of the fact that we did so and relied on
+   stale fsmonitor data.
+
+ * Fix for a long-standing bug that leaves the index file corrupt when
+   it shrinks during a partial commit.
+
+ * Further fix for O_APPEND emulation on Windows
+
+ * A corner case bugfix in "git rerere" code.
+
+ * "git add ':(attr:foo)'" is not supported and is supposed to be
+   rejected while the command line arguments are parsed, but we fail
+   to reject such a command line upfront.
+
+ * "git rebase" etc. in Git 2.19 fails to abort when given an empty
+   commit log message as result of editing, which has been corrected.
+
+ * The code to backfill objects in lazily cloned repository did not
+   work correctly, which has been corrected.
+
+ * Update error messages given by "git remote" and make them consistent.
+
+ * "git update-ref" learned to make both "--no-deref" and "--stdin"
+   work at the same time.
+
+ * Recently added "range-diff" had a corner-case bug to cause it
+   segfault, which has been corrected.
+
+ * The recently introduced commit-graph auxiliary data is incompatible
+   with mechanisms such as replace & grafts that "breaks" immutable
+   nature of the object reference relationship.  Disable optimizations
+   based on its use (and updating existing commit-graph) when these
+   incompatible features are in use in the repository.
+
+ * The mailmap file update.
+
+ * The code in "git status" sometimes hit an assertion failure.  This
+   was caused by a structure that was reused without cleaning the data
+   used for the first run, which has been corrected.
+
+ * A corner-case bugfix.
+
+ * A partial clone that is configured to lazily fetch missing objects
+   will on-demand issue a "git fetch" request to the originating
+   repository to fill not-yet-obtained objects.  The request has been
+   optimized for requesting a tree object (and not the leaf blob
+   objects contained in it) by telling the originating repository that
+   no blobs are needed.
+
+ * The codepath to support the experimental split-index mode had
+   remaining "racily clean" issues fixed.
+
+ * "git log --graph" showing an octopus merge sometimes miscounted the
+   number of display columns it is consuming to show the merge and its
+   parent commits, which has been corrected.
+
+ * The implementation of run_command() API on the UNIX platforms had a
+   bug that caused a command not on $PATH to be found in the current
+   directory.
+
+ * A mutex used in "git pack-objects" were not correctly initialized
+   and this caused "git repack" to dump core on Windows.
+
+ * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on
+   Windows would strip initial parts from the paths because they
+   were not recognized as absolute, which has been corrected.
+
+ * The receive.denyCurrentBranch=updateInstead codepath kicked in even
+   when the push should have been rejected due to other reasons, such
+   as it does not fast-forward or the update-hook rejects it, which
+   has been corrected.
+
+ * "git repack" in a shallow clone did not correctly update the
+   shallow points in the repository, leading to a repository that
+   does not pass fsck.
+
+ * Operations on promisor objects make sense in the context of only a
+   small subset of the commands that internally use the revisions
+   machinery, but the "--exclude-promisor-objects" option were taken
+   and led to nonsense results by commands like "log", to which it
+   didn't make much sense.  This has been corrected.
+
+ * The "container" mode of TravisCI is going away.  Our .travis.yml
+   file is getting prepared for the transition.
+
+ * Our test scripts can now take the '-V' option as a synonym for the
+   '--verbose-log' option.
+
+ * A regression in Git 2.12 era made "git fsck" fall into an infinite
+   loop while processing truncated loose objects.
+
+Also contains various documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.2.0.txt b/third_party/git/Documentation/RelNotes/2.2.0.txt
new file mode 100644
index 0000000000..e98ecbcff6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.2.0.txt
@@ -0,0 +1,313 @@
+Git v2.2 Release Notes
+======================
+
+Updates since v2.1
+------------------
+
+Ports
+
+ * Building on older MacOS X systems automatically sets
+   the necessary NO_APPLE_COMMON_CRYPTO build-time option.
+
+ * Building with NO_PTHREADS has been resurrected.
+
+ * Compilation options have been updated a bit to better support the
+   z/OS port.
+
+
+UI, Workflows & Features
+
+ * "git archive" learned to filter what gets archived with a pathspec.
+
+ * "git config --edit --global" starts from a skeletal per-user
+   configuration file contents, instead of a total blank, when the
+   user does not already have any global config.  This immediately
+   reduces the need to later ask "Have you forgotten to set
+   core.user?", and we can add more to the template as we gain
+   more experience.
+
+ * "git stash list -p" used to be almost always a no-op because each
+   stash entry is represented as a merge commit.  It learned to show
+   the difference between the base commit version and the working tree
+   version, which is in line with what "git stash show" gives.
+
+ * Sometimes users want to report a bug they experience on their
+   repository, but they are not at liberty to share the contents of
+   the repository.  "fast-export" was taught an "--anonymize" option
+   to replace blob contents, names of people, paths and log
+   messages with bland and simple strings to help them.
+
+ * "git difftool" learned an option to stop feeding paths to the
+   diff backend when it exits with a non-zero status.
+
+ * "git grep" learned to paint (or not paint) partial matches on
+   context lines when showing "grep -C<num>" output in color.
+
+ * "log --date=iso" uses a slight variant of the ISO 8601 format that is
+   more human readable.  A new "--date=iso-strict" option gives
+   datetime output that conforms more strictly.
+
+ * The logic "git prune" uses is more resilient against various corner
+   cases.
+
+ * A broken reimplementation of Git could write an invalid index that
+   records both stage #0 and higher-stage entries for the same path.
+   We now notice and reject such an index, as there is no sensible
+   fallback (we do not know if the broken tool wanted to resolve and
+   forgot to remove the higher-stage entries, or if it wanted to unresolve
+   and forgot to remove the stage #0 entry).
+
+ * The temporary files "git mergetool" uses are renamed to avoid too
+   many dots in them (e.g. a temporary file for "hello.c" used to be
+   named e.g. "hello.BASE.4321.c" but now uses underscore instead,
+   e.g. "hello_BASE_4321.c", to allow us to have multiple variants).
+
+ * The temporary files "git mergetool" uses can be placed in a newly
+   created temporary directory, instead of the current directory, by
+   setting the mergetool.writeToTemp configuration variable.
+
+ * "git mergetool" understands "--tool bc" now, as version 4 of
+   BeyondCompare can be driven the same way as its version 3 and it
+   feels awkward to say "--tool bc3" to run version 4.
+
+ * The "pre-receive" and "post-receive" hooks are no longer required
+   to consume their input fully (not following this requirement used
+   to result in intermittent errors in "git push").
+
+ * The pretty-format specifier "%d", which expands to " (tagname)"
+   for a tagged commit, gained a cousin "%D" that just gives the
+   "tagname" without frills.
+
+ * "git push" learned "--signed" push, that allows a push (i.e.
+   request to update the refs on the other side to point at a new
+   history, together with the transmission of necessary objects) to be
+   signed, so that it can be verified and audited, using the GPG
+   signature of the person who pushed, that the tips of branches at a
+   public repository really point the commits the pusher wanted to,
+   without having to "trust" the server.
+
+ * "git interpret-trailers" is a new filter to programmatically edit
+   the tail end of the commit log messages, e.g. "Signed-off-by:".
+
+ * "git help everyday" shows the "Everyday Git in 20 commands or so"
+   document, whose contents have been updated to match more modern
+   Git practice.
+
+ * On the "git svn" front, work progresses to reduce memory consumption and
+   to improve handling of mergeinfo.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The API to manipulate the "refs" has been restructured to make it
+   more transactional, with the eventual goal to allow all-or-none
+   atomic updates and migrating the storage to something other than
+   the traditional filesystem based one (e.g. databases).
+
+ * The lockfile API and its users have been cleaned up.
+
+ * We no longer attempt to keep track of individual dependencies to
+   the header files in the build procedure, relying instead on automated
+   dependency generation support from modern compilers.
+
+ * In tests, we have been using NOT_{MINGW,CYGWIN} test prerequisites
+   long before negated prerequisites e.g. !MINGW were invented.
+   The former has been converted to the latter to avoid confusion.
+
+ * Optimized looking up a remote's configuration in a repository with very many
+   remotes defined.
+
+ * There are cases where you lock and open to write a file, close it
+   to show the updated contents to an external processes, and then have
+   to update the file again while still holding the lock; now the
+   lockfile API has support for such an access pattern.
+
+ * The API to allocate the structure to keep track of commit
+   decoration has been updated to make it less cumbersome to use.
+
+ * An in-core caching layer to let us avoid reading the same
+   configuration files several times has been added.  A few commands
+   have been converted to use this subsystem.
+
+ * Various code paths have been cleaned up and simplified by using
+   the "strbuf", "starts_with()", and "skip_prefix()" APIs more.
+
+ * A few codepaths that died when large blobs that would not fit in
+   core are involved in their operation have been taught to punt
+   instead, by e.g. marking a too-large blob as not to be diffed.
+
+ * A few more code paths in "commit" and "checkout" have been taught
+   to repopulate the cache-tree in the index, to help speed up later
+   "write-tree" (used in "commit") and "diff-index --cached" (used in
+   "status").
+
+ * A common programming mistake to assign the same short option name
+   to two separate options is detected by the parse_options() API to help
+   developers.
+
+ * The code path to write out the packed-refs file has been optimized,
+   which especially matters in a repository with a large number of
+   refs.
+
+ * The check to see if a ref $F can be created by making sure no
+   existing ref has $F/ as its prefix has been optimized, which
+   especially matters in a repository with a large number of existing
+   refs.
+
+ * "git fsck" was taught to check the contents of tag objects a bit more.
+
+ * "git hash-object" was taught a "--literally" option to help
+   debugging.
+
+ * When running a required clean filter, we do not have to mmap the
+   original before feeding the filter.  Instead, stream the file
+   contents directly to the filter and process its output.
+
+ * The scripts in the test suite can be run with the "-x" option to show
+   a shell-trace of each command they run.
+
+ * The "run-command" API learned to manage the argv and environment
+   arrays for child process, alleviating the need for the callers to
+   allocate and deallocate them.
+
+ * Some people use AsciiDoctor, instead of AsciiDoc, to format our
+   documentation set; the documentation has been adjusted to be usable
+   by both, as AsciiDoctor is pickier than AsciiDoc about its input
+   mark-up.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.1
+----------------
+
+Unless otherwise noted, all the fixes since v2.1 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git log --pretty/format=" with an empty format string did not
+   mean the more obvious "No output whatsoever" but "Use default
+   format", which was counterintuitive.
+
+ * "git -c section.var command" and "git -c section.var= command"
+   should pass the configuration value differently (the former should be a
+   boolean true, the latter should be an empty string).
+
+ * Applying a patch not generated by Git in a subdirectory used to
+   check for whitespace breakage using the attributes of incorrect
+   paths. Also whitespace checks were performed even for paths
+   excluded via the "git apply --exclude=<path>" mechanism.
+
+ * "git bundle create" with a date-range specification was meant to
+   exclude tags outside the range, but it didn't.
+
+ * "git add x" where x used to be a directory and is now a
+   symbolic link to a directory misbehaved.
+
+ * The prompt script checked the $GIT_DIR/ref/stash file to see if there
+   is a stash, which was a no-no.
+
+ * Pack-protocol documentation had a minor typo.
+
+ * "git checkout -m" did not switch to another branch while carrying
+   the local changes forward when a path was deleted from the index.
+
+ * "git daemon" (with NO_IPV6 build configuration) used to incorrectly
+   use the hostname even when gethostbyname() reported that the given
+   hostname is not found.
+   (merge 107efbe rs/daemon-fixes later to maint).
+
+ * With sufficiently long refnames, "git fast-import" could have
+   overflowed an on-stack buffer.
+
+ * After "pack-refs --prune" packed refs at the top-level, it failed
+   to prune them.
+
+ * Progress output from "git gc --auto" was visible in "git fetch -q".
+
+ * We used to pass -1000 to poll(2), expecting it to also mean "no
+   timeout", which should be spelled as -1.
+
+ * "git rebase" documentation was unclear that it is required to
+   specify on what <upstream> the rebase is to be done when telling it
+   to first check out <branch>.
+   (merge 95c6826 so/rebase-doc later to maint).
+
+ * "git push" over HTTP transport had an artificial limit on the number of
+   refs that can be pushed, imposed by the command line length.
+   (merge 26be19b jk/send-pack-many-refspecs later to maint).
+
+ * When receiving an invalid pack stream that records the same object
+   twice, multiple threads got confused due to a race.
+   (merge ab791dd jk/index-pack-threading-races later to maint).
+
+ * An attempt to remove the entire tree in the "git fast-import" input
+   stream caused it to misbehave.
+   (merge 2668d69 mb/fast-import-delete-root later to maint).
+
+ * Reachability check (used in "git prune" and friends) did not add a
+   detached HEAD as a starting point to traverse objects still in use.
+   (merge c40fdd0 mk/reachable-protect-detached-head later to maint).
+
+ * "git config --add section.var val" when section.var already has an
+   empty-string value used to lose the empty-string value.
+   (merge c1063be ta/config-add-to-empty-or-true-fix later to maint).
+
+ * "git fsck" failed to report that it found corrupt objects via its
+   exit status in some cases.
+   (merge 30d1038 jk/fsck-exit-code-fix later to maint).
+
+ * Use of the "--verbose" option used to break "git branch --merged".
+   (merge 12994dd jk/maint-branch-verbose-merged later to maint).
+
+ * Some MUAs mangle a line in a message that begins with "From " to
+   ">From " when writing to a mailbox file, and feeding such an input
+   to "git am" used to lose such a line.
+   (merge 85de86a jk/mbox-from-line later to maint).
+
+ * "rev-parse --verify --quiet $name" is meant to quietly exit with a
+   non-zero status when $name is not a valid object name, but still
+   gave error messages in some cases.
+
+ * A handful of C source files have been updated to include
+   "git-compat-util.h" as the first thing, to conform better to our
+   coding guidelines.
+   (merge 1c4b660 da/include-compat-util-first-in-c later to maint).
+
+ * The t7004 test, which tried to run Git with small stack space, has been
+   updated to use a bit larger stack to avoid false breakage on some
+   platforms.
+   (merge b9a1907 sk/tag-contains-wo-recursion later to maint).
+
+ * A few documentation pages had example sections marked up not quite
+   correctly, which passed AsciiDoc but failed with AsciiDoctor.
+   (merge c30c43c bc/asciidoc-pretty-formats-fix later to maint).
+   (merge f8a48af bc/asciidoc later to maint).
+
+ * "gitweb" used deprecated CGI::startfrom, which was removed from
+   CGI.pm as of 4.04; use CGI::start_from instead.
+   (merge 4750f4b rm/gitweb-start-form later to maint).
+
+ * Newer versions of 'meld' break the auto-detection we use to see if
+   they are new enough to support the `--output` option.
+   (merge b12d045 da/mergetool-meld later to maint).
+
+ * "git pack-objects" forgot to disable the codepath to generate the
+   object reachability bitmap when it needs to split the resulting
+   pack.
+   (merge 2113471 jk/pack-objects-no-bitmap-when-splitting later to maint).
+
+ * The code to use cache-tree trusted the on-disk data too much and
+   fell into an infinite loop upon seeing an incorrectly recorded
+   index file.
+   (merge 729dbbd jk/cache-tree-protect-from-broken-libgit2 later to maint).
+
+ * "git fetch" into a repository where branch B was deleted earlier,
+   back when it had reflog enabled, and then branch B/C is fetched
+   into it without reflog enabled, which is arguably an unlikely
+   corner case, unnecessarily failed.
+   (merge aae828b jk/fetch-reflog-df-conflict later to maint).
+
+ * "git log --first-parent -L..." used to crash.
+   (merge a8787c5 tm/line-log-first-parent later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.2.1.txt b/third_party/git/Documentation/RelNotes/2.2.1.txt
new file mode 100644
index 0000000000..d5a3cd9e73
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.2.1.txt
@@ -0,0 +1,34 @@
+Git v2.2.1 Release Notes
+========================
+
+Fixes since v2.2
+----------------
+
+ * We used to allow committing a path ".Git/config" with Git that is
+   running on a case sensitive filesystem, but an attempt to check out
+   such a path with Git that runs on a case insensitive filesystem
+   would have clobbered ".git/config", which is definitely not what
+   the user would have expected.  Git now prevents you from tracking
+   a path with ".Git" (in any case combination) as a path component.
+
+ * On Windows, certain path components that are different from ".git"
+   are mapped to ".git", e.g. "git~1/config" is treated as if it were
+   ".git/config".  HFS+ has a similar issue, where certain unicode
+   codepoints are ignored, e.g. ".g\u200cit/config" is treated as if
+   it were ".git/config".  Pathnames with these potential issues are
+   rejected on the affected systems.  Git on systems that are not
+   affected by this issue (e.g. Linux) can also be configured to
+   reject them to ensure cross platform interoperability of the hosted
+   projects.
+
+ * "git fsck" notices a tree object that records such a path that can
+   be confused with ".git", and with receive.fsckObjects configuration
+   set to true, an attempt to "git push" such a tree object will be
+   rejected.  Such a path may not be a problem on a well behaving
+   filesystem but in order to protect those on HFS+ and on case
+   insensitive filesystems, this check is enabled on all platforms.
+
+A big "thanks!" for bringing this issue to us goes to our friends in
+the Mercurial land, namely, Matt Mackall and Augie Fackler.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.2.2.txt b/third_party/git/Documentation/RelNotes/2.2.2.txt
new file mode 100644
index 0000000000..b19a35d94f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.2.2.txt
@@ -0,0 +1,63 @@
+Git v2.2.2 Release Notes
+========================
+
+Fixes since v2.2.1
+------------------
+
+ * "git checkout $treeish $path", when $path in the index and the
+   working tree already matched what is in $treeish at the $path,
+   still overwrote the $path unnecessarily.
+
+ * "git config --get-color" did not parse its command line arguments
+   carefully.
+
+ * open() emulated on Windows platforms did not give EISDIR upon
+   an attempt to open a directory for writing.
+
+ * A few code paths used abs() when they should have used labs() on
+   long integers.
+
+ * "gitweb" used to depend on a behaviour recent CGI.pm deprecated.
+
+ * "git init" (hence "git clone") initialized the per-repository
+   configuration file .git/config with x-bit by mistake.
+
+ * Git 2.0 was supposed to make the "simple" mode for the default of
+   "git push", but it didn't.
+
+ * "Everyday" document had a broken link.
+
+ * The build procedure did not bother fixing perl and python scripts
+   when NO_PERL and NO_PYTHON build-time configuration changed.
+
+ * The code that reads the reflog from the newer to the older entries
+   did not handle an entry that crosses a boundary of block it uses to
+   read them correctly.
+
+ * "git apply" was described in the documentation to take --ignore-date
+   option, which it does not.
+
+ * Traditionally we tried to avoid interpreting date strings given by
+   the user as future dates, e.g. GIT_COMMITTER_DATE=2014-12-10 when
+   used early November 2014 was taken as "October 12, 2014" because it
+   is likely that a date in the future, December 10, is a mistake.
+   This heuristics has been loosened to allow people to express future
+   dates (most notably, --until=<date> may want to be far in the
+   future) and we no longer tiebreak by future-ness of the date when
+
+    (1) ISO-like format is used, and
+    (2) the string can make sense interpreted as both y-m-d and y-d-m.
+
+   Git may still have to use the heuristics to tiebreak between dd/mm/yy
+   and mm/dd/yy, though.
+
+ * The code to abbreviate an object name to its short unique prefix
+   has been optimized when no abbreviation was requested.
+
+ * "git add --ignore-errors ..." did not ignore an error to
+   give a file that did not exist.
+
+ * Git did not correctly read an overlong refname from a packed refs
+   file.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.2.3.txt b/third_party/git/Documentation/RelNotes/2.2.3.txt
new file mode 100644
index 0000000000..5bfffa4106
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.2.3.txt
@@ -0,0 +1,9 @@
+Git v2.2.3 Release Notes
+========================
+
+Fixes since v2.2.2
+------------------
+
+ * A handful of codepaths that used to use fixed-sized arrays to hold
+   pathnames have been corrected to use strbuf and other mechanisms to
+   allow longer pathnames without fearing overflows.
diff --git a/third_party/git/Documentation/RelNotes/2.20.0.txt b/third_party/git/Documentation/RelNotes/2.20.0.txt
new file mode 100644
index 0000000000..e71fe3dee1
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.20.0.txt
@@ -0,0 +1,700 @@
+Git 2.20 Release Notes
+======================
+
+Backward Compatibility Notes
+----------------------------
+
+ * "git branch -l <foo>" used to be a way to ask a reflog to be
+   created while creating a new branch, but that is no longer the
+   case.  It is a short-hand for "git branch --list <foo>" now.
+
+ * "git push" into refs/tags/* hierarchy is rejected without getting
+   forced, but "git fetch" (misguidedly) used the "fast forwarding"
+   rule used for the refs/heads/* hierarchy; this has been corrected,
+   which means some fetches of tags that did not fail with older
+   version of Git will fail without "--force" with this version.
+
+ * "git help -a" now gives verbose output (same as "git help -av").
+   Those who want the old output may say "git help --no-verbose -a"..
+
+ * "git cpn --help", when "cpn" is an alias to, say, "cherry-pick -n",
+   reported only the alias expansion of "cpn" in earlier versions of
+   Git.  It now runs "git cherry-pick --help" to show the manual page
+   of the command, while sending the alias expansion to the standard
+   error stream.
+
+ * "git send-email" learned to grab address-looking string on any
+   trailer whose name ends with "-by". This is a backward-incompatible
+   change.  Adding "--suppress-cc=misc-by" on the command line, or
+   setting sendemail.suppresscc configuration variable to "misc-by",
+   can be used to disable this behaviour.
+
+
+Updates since v2.19
+-------------------
+
+UI, Workflows & Features
+
+ * Running "git clone" against a project that contain two files with
+   pathnames that differ only in cases on a case insensitive
+   filesystem would result in one of the files lost because the
+   underlying filesystem is incapable of holding both at the same
+   time.  An attempt is made to detect such a case and warn.
+
+ * "git checkout -b newbranch [HEAD]" should not have to do as much as
+   checking out a commit different from HEAD.  An attempt is made to
+   optimize this special case.
+
+ * "git rev-list --stdin </dev/null" used to be an error; it now shows
+   no output without an error.  "git rev-list --stdin --default HEAD"
+   still falls back to the given default when nothing is given on the
+   standard input.
+
+ * Lift code from GitHub to restrict delta computation so that an
+   object that exists in one fork is not made into a delta against
+   another object that does not appear in the same forked repository.
+
+ * "git format-patch" learned new "--interdiff" and "--range-diff"
+   options to explain the difference between this version and the
+   previous attempt in the cover letter (or after the three-dashes as
+   a comment).
+
+ * "git mailinfo" used in "git am" learned to make a best-effort
+   recovery of a patch corrupted by MUA that sends text/plain with
+   format=flawed option.
+   (merge 3aa4d81f88 rs/mailinfo-format-flowed later to maint).
+
+ * The rules used by "git push" and "git fetch" to determine if a ref
+   can or cannot be updated were inconsistent; specifically, fetching
+   to update existing tags were allowed even though tags are supposed
+   to be unmoving anchoring points.  "git fetch" was taught to forbid
+   updates to existing tags without the "--force" option.
+
+ * "git multi-pack-index" learned to detect corruption in the .midx
+   file it uses, and this feature has been integrated into "git fsck".
+
+ * Generation of (experimental) commit-graph files have so far been
+   fairly silent, even though it takes noticeable amount of time in a
+   meaningfully large repository.  The users will now see progress
+   output.
+
+ * The minimum version of Windows supported by Windows port of Git is
+   now set to Vista.
+
+ * The completion script (in contrib/) learned to complete a handful of
+   options "git stash list" command takes.
+
+ * The completion script (in contrib/) learned that "git fetch
+   --multiple" only takes remote names as arguments and no refspecs.
+
+ * "git status" learns to show progress bar when refreshing the index
+   takes a long time.
+   (merge ae9af12287 nd/status-refresh-progress later to maint).
+
+ * "git help -a" and "git help -av" give different pieces of
+   information, and generally the "verbose" version is more friendly
+   to the new users.  "git help -a" by default now uses the more
+   verbose output (with "--no-verbose", you can go back to the
+   original).  Also "git help -av" now lists aliases and external
+   commands, which it did not used to.
+
+ * Unlike "grep", "git grep" by default recurses to the whole tree.
+   The command learned "git grep --recursive" option, so that "git
+   grep --no-recursive" can serve as a synonym to setting the
+   max-depth to 0.
+
+ * When pushing into a repository that borrows its objects from an
+   alternate object store, "git receive-pack" that responds to the
+   push request on the other side lists the tips of refs in the
+   alternate to reduce the amount of objects transferred.  This
+   sometimes is detrimental when the number of refs in the alternate
+   is absurdly large, in which case the bandwidth saved in potentially
+   fewer objects transferred is wasted in excessively large ref
+   advertisement.  The alternate refs that are advertised are now
+   configurable with a pair of configuration variables.
+
+ * "git cmd --help" when "cmd" is aliased used to only say "cmd is
+   aliased to ...".  Now it shows that to the standard error stream
+   and runs "git $cmd --help" where $cmd is the first word of the
+   alias expansion.
+
+ * The documentation of "git gc" has been updated to mention that it
+   is no longer limited to "pruning away crufts" but also updates
+   ancillary files like commit-graph as a part of repository
+   optimization.
+
+ * "git p4 unshelve" improvements.
+
+ * The logic to select the default user name and e-mail on Windows has
+   been improved.
+   (merge 501afcb8b0 js/mingw-default-ident later to maint).
+
+ * The "rev-list --filter" feature learned to exclude all trees via
+   "tree:0" filter.
+
+ * "git send-email" learned to grab address-looking string on any
+   trailer whose name ends with "-by"; --suppress-cc=misc-by on the
+   command line, or setting sendemail.suppresscc configuration
+   variable to "misc-by", can be used to disable this behaviour.
+
+ * "git mergetool" learned to take the "--[no-]gui" option, just like
+   "git difftool" does.
+
+ * "git rebase -i" learned a new insn, 'break', that the user can
+   insert in the to-do list.  Upon hitting it, the command returns
+   control back to the user.
+
+ * New "--pretty=format:" placeholders %GF and %GP that show the GPG
+   key fingerprints have been invented.
+
+ * On platforms with recent cURL library, http.sslBackend configuration
+   variable can be used to choose a different SSL backend at runtime.
+   The Windows port uses this mechanism to switch between OpenSSL and
+   Secure Channel while talking over the HTTPS protocol.
+
+ * "git send-email" learned to disable SMTP authentication via the
+   "--smtp-auth=none" option, even when the smtp username is given
+   (which turns the authentication on by default).
+
+ * A fourth class of configuration files (in addition to the
+   traditional "system wide", "per user in the $HOME directory" and
+   "per repository in the $GIT_DIR/config") has been introduced so
+   that different worktrees that share the same repository (hence the
+   same $GIT_DIR/config file) can use different customization.
+
+ * A pattern with '**' that does not have a slash on either side used
+   to be an invalid one, but the code now treats such double-asterisks
+   the same way as two normal asterisks that happen to be adjacent to
+   each other.
+   (merge e5bbe09e88 nd/wildmatch-double-asterisk later to maint).
+
+ * The "--no-patch" option, which can be used to get a high-level
+   overview without the actual line-by-line patch difference shown, of
+   the "range-diff" command was earlier broken, which has been
+   corrected.
+
+ * The recently merged "rebase in C" has an escape hatch to use the
+   scripted version when necessary, but it hasn't been documented,
+   which has been corrected.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Developer builds now use -Wunused-function compilation option.
+
+ * One of our CI tests to run with "unusual/experimental/random"
+   settings now also uses commit-graph and midx.
+
+ * When there are too many packfiles in a repository (which is not
+   recommended), looking up an object in these would require
+   consulting many pack .idx files; a new mechanism to have a single
+   file that consolidates all of these .idx files is introduced.
+
+ * "git submodule update" is getting rewritten piece-by-piece into C.
+
+ * The code for computing history reachability has been shuffled,
+   obtained a bunch of new tests to cover them, and then being
+   improved.
+
+ * The unpack_trees() API used in checking out a branch and merging
+   walks one or more trees along with the index.  When the cache-tree
+   in the index tells us that we are walking a tree whose flattened
+   contents is known (i.e. matches a span in the index), as linearly
+   scanning a span in the index is much more efficient than having to
+   open tree objects recursively and listing their entries, the walk
+   can be optimized, which has been done.
+
+ * When creating a thin pack, which allows objects to be made into a
+   delta against another object that is not in the resulting pack but
+   is known to be present on the receiving end, the code learned to
+   take advantage of the reachability bitmap; this allows the server
+   to send a delta against a base beyond the "boundary" commit.
+
+ * spatch transformation to replace boolean uses of !hashcmp() to
+   newly introduced oideq() is added, and applied, to regain
+   performance lost due to support of multiple hash algorithms.
+
+ * Fix a bug in which the same path could be registered under multiple
+   worktree entries if the path was missing (for instance, was removed
+   manually).  Also, as a convenience, expand the number of cases in
+   which --force is applicable.
+
+ * Split Documentation/config.txt for easier maintenance.
+   (merge 6014363f0b nd/config-split later to maint).
+
+ * Test helper binaries clean-up.
+   (merge c9a1f4161f nd/test-tool later to maint).
+
+ * Various tests have been updated to make it easier to swap the
+   hash function used for object identification.
+   (merge ae0c89d41b bc/hash-independent-tests later to maint).
+
+ * Update fsck.skipList implementation and documentation.
+   (merge 371a655074 ab/fsck-skiplist later to maint).
+
+ * An alias that expands to another alias has so far been forbidden,
+   but now it is allowed to create such an alias.
+
+ * Various test scripts have been updated for style and also correct
+   handling of exit status of various commands.
+
+ * "gc --auto" ended up calling exit(-1) upon error, which has been
+   corrected to use exit(1).  Also the error reporting behaviour when
+   daemonized has been updated to exit with zero status when stopping
+   due to a previously discovered error (which implies there is no
+   point running gc to improve the situation); we used to exit with
+   failure in such a case.
+
+ * Various codepaths in the core-ish part learned to work on an
+   arbitrary in-core index structure, not necessarily the default
+   instance "the_index".
+   (merge b3c7eef9b0 nd/the-index later to maint).
+
+ * Code clean-up in the internal machinery used by "git status" and
+   "git commit --dry-run".
+   (merge 73ba5d78b4 ss/wt-status-committable later to maint).
+
+ * Some environment variables that control the runtime options of Git
+   used during tests are getting renamed for consistency.
+   (merge 4231d1ba99 bp/rename-test-env-var later to maint).
+
+ * A pair of new extensions to the index file have been introduced.
+   They allow the index file to be read in parallel for performance.
+
+ * The oidset API was built on top of the oidmap API which in turn is
+   on the hashmap API.  Replace the implementation to build on top of
+   the khash API and gain performance.
+
+ * Over some transports, fetching objects with an exact commit object
+   name can be done without first seeing the ref advertisements.  The
+   code has been optimized to exploit this.
+
+ * In a partial clone that will lazily be hydrated from the
+   originating repository, we generally want to avoid "does this
+   object exist (locally)?" on objects that we deliberately omitted
+   when we created the clone.  The cache-tree codepath (which is used
+   to write a tree object out of the index) however insisted that the
+   object exists, even for paths that are outside of the partial
+   checkout area.  The code has been updated to avoid such a check.
+
+ * To help developers, an EditorConfig file that attempts to follow
+   the project convention has been added.
+   (merge b548d698a0 bc/editorconfig later to maint).
+
+ * The result of coverage test can be combined with "git blame" to
+   check the test coverage of code introduced recently with a new
+   'coverage-diff' tool (in contrib/).
+   (merge 783faedd65 ds/coverage-diff later to maint).
+
+ * An experiment to fuzz test a few areas, hopefully we can gain more
+   coverage to various areas.
+
+ * More codepaths are moving away from hardcoded hash sizes.
+
+ * The way the Windows port figures out the current directory has been
+   improved.
+
+ * The way DLLs are loaded on the Windows port has been improved.
+
+ * Some tests have been reorganized and renamed; "ls t/" now gives a
+   better overview of what is tested for these scripts than before.
+
+ * "git rebase" and "git rebase -i" have been reimplemented in C.
+
+ * Windows port learned to use nano-second resolution file timestamps.
+
+ * The overly large Documentation/config.txt file have been split into
+   million little pieces.  This potentially allows each individual piece
+   to be included into the manual page of the command it affects more easily.
+
+ * Replace three string-list instances used as look-up tables in "git
+   fetch" with hashmaps.
+
+ * Unify code to read the author-script used in "git am" and the
+   commands that use the sequencer machinery, e.g. "git rebase -i".
+
+ * In preparation to the day when we can deprecate and remove the
+   "rebase -p", make sure we can skip and later remove tests for
+   it.
+
+ * The history traversal used to implement the tag-following has been
+   optimized by introducing a new helper.
+
+ * The helper function to refresh the cached stat information in the
+   in-core index has learned to perform the lstat() part of the
+   operation in parallel on multi-core platforms.
+
+ * The code to traverse objects for reachability, used to decide what
+   objects are unreferenced and expendable, have been taught to also
+   consider per-worktree refs of other worktrees as starting points to
+   prevent data loss.
+
+ * "git add" needs to internally run "diff-files" equivalent, and the
+   codepath learned the same optimization as "diff-files" has to run
+   lstat(2) in parallel to find which paths have been updated in the
+   working tree.
+
+ * The procedure to install dependencies before testing at Travis CI
+   is getting revamped for both simplicity and flexibility, taking
+   advantage of the recent move to the vm-based environment.
+
+ * The support for format-patch (and send-email) by the command-line
+   completion script (in contrib/) has been simplified a bit.
+
+ * The revision walker machinery learned to take advantage of the
+   commit generation numbers stored in the commit-graph file.
+
+ * The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".
+
+ * The way -lcurl library gets linked has been simplified by taking
+   advantage of the fact that we can just ask curl-config command how.
+
+ * Various functions have been audited for "-Wunused-parameter" warnings
+   and bugs in them got fixed.
+
+ * A sanity check for start-up sequence has been added in the config
+   API codepath.
+
+ * The build procedure to link for fuzzing test has been made
+   customizable with a new Makefile variable.
+
+ * The way "git rebase" parses and forwards the command line options
+   meant for underlying "git am" has been revamped, which fixed for
+   options with parameters that were not passed correctly.
+
+ * Our testing framework uses a special i18n "poisoned localization"
+   feature to find messages that ought to stay constant but are
+   incorrectly marked to be translated.  This feature has been made
+   into a runtime option (it used to be a compile-time option).
+
+ * "git push" used to check ambiguities between object-names and
+   refnames while processing the list of refs' old and new values,
+   which was unnecessary (as it knew that it is feeding raw object
+   names).  This has been optimized out.
+
+ * The xcurl_off_t() helper function is used to cast size_t to
+   curl_off_t, but some compilers gave warnings against the code to
+   ensure the casting is done without wraparound, when size_t is
+   narrower than curl_off_t.  This warning has been squelched.
+
+ * Code preparation to replace ulong vars with size_t vars where
+   appropriate continues.
+
+ * The "test installed Git" mode of our test suite has been updated to
+   work better.
+
+ * A coding convention around the Coccinelle semantic patches to have
+   two classes to ease code migration process has been proposed and
+   its support has been added to the Makefile.
+
+ * The "container" mode of TravisCI is going away.  Our .travis.yml
+   file is getting prepared for the transition.
+   (merge 32ee384be8 ss/travis-ci-force-vm-mode later to maint).
+
+ * Our test scripts can now take the '-V' option as a synonym for the
+   '--verbose-log' option.
+   (merge a5f52c6dab sg/test-verbose-log later to maint).
+
+
+Fixes since v2.19
+-----------------
+
+ * "git interpret-trailers" and its underlying machinery had a buggy
+   code that attempted to ignore patch text after commit log message,
+   which triggered in various codepaths that will always get the log
+   message alone and never get such an input.
+   (merge 66e83d9b41 jk/trailer-fixes later to maint).
+
+ * Malformed or crafted data in packstream can make our code attempt
+   to read or write past the allocated buffer and abort, instead of
+   reporting an error, which has been fixed.
+
+ * "git rebase -i" did not clear the state files correctly when a run
+   of "squash/fixup" is aborted and then the user manually amended the
+   commit instead, which has been corrected.
+   (merge 10d2f35436 js/rebase-i-autosquash-fix later to maint).
+
+ * When fsmonitor is in use, after operation on submodules updates
+   .gitmodules, we lost track of the fact that we did so and relied on
+   stale fsmonitor data.
+   (merge 43f1180814 bp/mv-submodules-with-fsmonitor later to maint).
+
+ * Fix for a long-standing bug that leaves the index file corrupt when
+   it shrinks during a partial commit.
+   (merge 6c003d6ffb jk/reopen-tempfile-truncate later to maint).
+
+ * Further fix for O_APPEND emulation on Windows
+   (merge eeaf7ddac7 js/mingw-o-append later to maint).
+
+ * A corner case bugfix in "git rerere" code.
+   (merge ad2bf0d9b4 en/rerere-multi-stage-1-fix later to maint).
+
+ * "git add ':(attr:foo)'" is not supported and is supposed to be
+   rejected while the command line arguments are parsed, but we fail
+   to reject such a command line upfront.
+   (merge 84d938b732 nd/attr-pathspec-fix later to maint).
+
+ * Recent update broke the reachability algorithm when refs (e.g.
+   tags) that point at objects that are not commit were involved,
+   which has been fixed.
+
+ * "git rebase" etc. in Git 2.19 fails to abort when given an empty
+   commit log message as result of editing, which has been corrected.
+   (merge a3ec9eaf38 en/sequencer-empty-edit-result-aborts later to maint).
+
+ * The code to backfill objects in lazily cloned repository did not
+   work correctly, which has been corrected.
+   (merge e68302011c jt/lazy-object-fetch-fix later to maint).
+
+ * Update error messages given by "git remote" and make them consistent.
+   (merge 5025425dff ms/remote-error-message-update later to maint).
+
+ * "git update-ref" learned to make both "--no-deref" and "--stdin"
+   work at the same time.
+   (merge d345e9fbe7 en/update-ref-no-deref-stdin later to maint).
+
+ * Recently added "range-diff" had a corner-case bug to cause it
+   segfault, which has been corrected.
+   (merge e467a90c7a tg/range-diff-corner-case-fix later to maint).
+
+ * The recently introduced commit-graph auxiliary data is incompatible
+   with mechanisms such as replace & grafts that "breaks" immutable
+   nature of the object reference relationship.  Disable optimizations
+   based on its use (and updating existing commit-graph) when these
+   incompatible features are in use in the repository.
+   (merge 829a321569 ds/commit-graph-with-grafts later to maint).
+
+ * The mailmap file update.
+   (merge 255eb03edf jn/mailmap-update later to maint).
+
+ * The code in "git status" sometimes hit an assertion failure.  This
+   was caused by a structure that was reused without cleaning the data
+   used for the first run, which has been corrected.
+   (merge 3e73cc62c0 en/status-multiple-renames-to-the-same-target-fix later to maint).
+
+ * "git fetch $repo $object" in a partial clone did not correctly
+   fetch the asked-for object that is referenced by an object in
+   promisor packfile, which has been fixed.
+
+ * A corner-case bugfix.
+   (merge c5cbb27cb5 sm/show-superproject-while-conflicted later to maint).
+
+ * Various fixes to "diff --color-moved-ws".
+
+ * A partial clone that is configured to lazily fetch missing objects
+   will on-demand issue a "git fetch" request to the originating
+   repository to fill not-yet-obtained objects.  The request has been
+   optimized for requesting a tree object (and not the leaf blob
+   objects contained in it) by telling the originating repository that
+   no blobs are needed.
+   (merge 4c7f9567ea jt/non-blob-lazy-fetch later to maint).
+
+ * The codepath to support the experimental split-index mode had
+   remaining "racily clean" issues fixed.
+   (merge 4c490f3d32 sg/split-index-racefix later to maint).
+
+ * "git log --graph" showing an octopus merge sometimes miscounted the
+   number of display columns it is consuming to show the merge and its
+   parent commits, which has been corrected.
+   (merge 04005834ed np/log-graph-octopus-fix later to maint).
+
+ * "git range-diff" did not work well when the compared ranges had
+   changes in submodules and the "--submodule=log" was used.
+
+ * The implementation of run_command() API on the UNIX platforms had a
+   bug that caused a command not on $PATH to be found in the current
+   directory.
+   (merge f67b980771 jk/run-command-notdot later to maint).
+
+ * A mutex used in "git pack-objects" were not correctly initialized
+   and this caused "git repack" to dump core on Windows.
+   (merge 34204c8166 js/pack-objects-mutex-init-fix later to maint).
+
+ * Under certain circumstances, "git diff D:/a/b/c D:/a/b/d" on
+   Windows would strip initial parts from the paths because they
+   were not recognized as absolute, which has been corrected.
+   (merge ffd04e92e2 js/diff-notice-has-drive-prefix later to maint).
+
+ * The receive.denyCurrentBranch=updateInstead codepath kicked in even
+   when the push should have been rejected due to other reasons, such
+   as it does not fast-forward or the update-hook rejects it, which
+   has been corrected.
+   (merge b072a25fad jc/receive-deny-current-branch-fix later to maint).
+
+ * The logic to determine the archive type "git archive" uses did not
+   correctly kick in for "git archive --remote", which has been
+   corrected.
+
+ * "git repack" in a shallow clone did not correctly update the
+   shallow points in the repository, leading to a repository that
+   does not pass fsck.
+   (merge 5dcfbf564c js/shallow-and-fetch-prune later to maint).
+
+ * Some codepaths failed to form a proper URL when .gitmodules record
+   the URL to a submodule repository as relative to the repository of
+   superproject, which has been corrected.
+   (merge e0a862fdaf sb/submodule-url-to-absolute later to maint).
+
+ * "git fetch" over protocol v2 into a shallow repository failed to
+   fetch full history behind a new tip of history that was diverged
+   before the cut-off point of the history that was previously fetched
+   shallowly.
+
+ * The command line completion machinery (in contrib/) has been
+   updated to allow the completion script to tweak the list of options
+   that are reported by the parse-options machinery correctly.
+   (merge 276b49ff34 nd/completion-negation later to maint).
+
+ * Operations on promisor objects make sense in the context of only a
+   small subset of the commands that internally use the revisions
+   machinery, but the "--exclude-promisor-objects" option were taken
+   and led to nonsense results by commands like "log", to which it
+   didn't make much sense.  This has been corrected.
+   (merge 669b1d2aae md/exclude-promisor-objects-fix later to maint).
+
+ * A regression in Git 2.12 era made "git fsck" fall into an infinite
+   loop while processing truncated loose objects.
+   (merge 18ad13e5b2 jk/detect-truncated-zlib-input later to maint).
+
+ * "git ls-remote $there foo" was broken by recent update for the
+   protocol v2 and stopped showing refs that match 'foo' that are not
+   refs/{heads,tags}/foo, which has been fixed.
+   (merge 6a139cdd74 jk/proto-v2-ref-prefix-fix later to maint).
+
+ * Additional comment on a tricky piece of code to help developers.
+   (merge 0afbe3e806 jk/stream-pack-non-delta-clarification later to maint).
+
+ * A couple of tests used to leave the repository in a state that is
+   deliberately corrupt, which have been corrected.
+   (merge aa984dbe5e ab/pack-tests-cleanup later to maint).
+
+ * The submodule support has been updated to read from the blob at
+   HEAD:.gitmodules when the .gitmodules file is missing from the
+   working tree.
+   (merge 2b1257e463 ao/submodule-wo-gitmodules-checked-out later to maint).
+
+ * "git fetch" was a bit loose in parsing responses from the other side
+   when talking over the protocol v2.
+
+ * "git rev-parse --exclude=* --branches --branches"  (i.e. first
+   saying "add only things that do not match '*' out of all branches"
+   and then adding all branches, without any exclusion this time)
+   worked as expected, but "--exclude=* --all --all" did not work the
+   same way, which has been fixed.
+   (merge 5221048092 ag/rev-parse-all-exclude-fix later to maint).
+
+ * "git send-email --transfer-encoding=..." in recent versions of Git
+   sometimes produced an empty "Content-Transfer-Encoding:" header,
+   which has been corrected.
+   (merge 3c88e46f1a al/send-email-auto-cte-fixup later to maint).
+
+ * The interface into "xdiff" library used to discover the offset and
+   size of a generated patch hunk by first formatting it into the
+   textual hunk header "@@ -n,m +k,l @@" and then parsing the numbers
+   out.  A new interface has been introduced to allow callers a more
+   direct access to them.
+   (merge 5eade0746e jk/xdiff-interface later to maint).
+
+ * Pathspec matching against a tree object were buggy when negative
+   pathspec elements were involved, which has been fixed.
+   (merge b7845cebc0 nd/tree-walk-path-exclusion later to maint).
+
+ * "git merge" and "git pull" that merges into an unborn branch used
+   to completely ignore "--verify-signatures", which has been
+   corrected.
+   (merge 01a31f3bca jk/verify-sig-merge-into-void later to maint).
+
+ * "git rebase --autostash" did not correctly re-attach the HEAD at times.
+
+ * "rev-parse --exclude=<pattern> --branches=<pattern>" etc. did not
+   quite work, which has been corrected.
+   (merge 9ab9b5df0e ra/rev-parse-exclude-glob later to maint).
+
+ * When editing a patch in a "git add -i" session, a hunk could be
+   made to no-op.  The "git apply" program used to reject a patch with
+   such a no-op hunk to catch user mistakes, but it is now updated to
+   explicitly allow a no-op hunk in an edited patch.
+   (merge 22cb3835b9 js/apply-recount-allow-noop later to maint).
+
+ * The URL to an MSDN page in a comment has been updated.
+   (merge 2ef2ae2917 js/mingw-msdn-url later to maint).
+
+ * "git ls-remote --sort=<thing>" can feed an object that is not yet
+   available into the comparison machinery and segfault, which has
+   been corrected to check such a request upfront and reject it.
+
+ * When "git bundle" aborts due to an empty commit ranges
+   (i.e. resulting in an empty pack), it left a file descriptor to an
+   lockfile open, which resulted in leftover lockfile on Windows where
+   you cannot remove a file with an open file descriptor.  This has
+   been corrected.
+   (merge 2c8ee1f53c jk/close-duped-fd-before-unlock-for-bundle later to maint).
+
+ * "git format-patch --stat=<width>" can be used to specify the width
+   used by the diffstat (shown in the cover letter).
+   (merge 284aeb7e60 nd/format-patch-cover-letter-stat-width later to maint).
+
+ * The way .git/index and .git/sharedindex* files were initially
+   created gave these files different perm bits until they were
+   adjusted for shared repository settings.  This was made consistent.
+   (merge c9d6c78870 cc/shared-index-permbits later to maint).
+
+ * "git rebase --stat" to transplant a piece of history onto a totally
+   unrelated history were not working before and silently showed wrong
+   result.  With the recent reimplementation in C, it started to instead
+   die with an error message, as the original logic was not prepared
+   to cope with this case.  This has now been fixed.
+
+ * The advice message to tell the user to migrate an existing graft
+   file to the replace system when a graft file was read was shown
+   even when "git replace --convert-graft-file" command, which is the
+   way the message suggests to use, was running, which made little
+   sense.
+   (merge 8821e90a09 ab/replace-graft-with-replace-advice later to maint).
+
+ * "git diff --raw" lost ellipses to adjust the output columns for
+   some time now, but the documentation still showed them.
+
+ * Code cleanup, docfix, build fix, etc.
+   (merge 96a7501aad ts/doc-build-manpage-xsl-quietly later to maint).
+   (merge b9b07efdb2 tg/conflict-marker-size later to maint).
+   (merge fa0aeea770 sg/doc-trace-appends later to maint).
+   (merge d64324cb60 tb/void-check-attr later to maint).
+   (merge c3b9bc94b9 en/double-semicolon-fix later to maint).
+   (merge 79336116f5 sg/t3701-tighten-trace later to maint).
+   (merge 801fa63a90 jk/dev-build-format-security later to maint).
+   (merge 0597dd62ba sb/string-list-remove-unused later to maint).
+   (merge db2d36fad8 bw/protocol-v2 later to maint).
+   (merge 456d7cd3a9 sg/split-index-test later to maint).
+   (merge 7b6057c852 tq/refs-internal-comment-fix later to maint).
+   (merge 29e8dc50ad tg/t5551-with-curl-7.61.1 later to maint).
+   (merge 55f6bce2c9 fe/doc-updates later to maint).
+   (merge 7987d2232d jk/check-everything-connected-is-long-gone later to maint).
+   (merge 4ba3c9be47 dz/credential-doc-url-matching-rules later to maint).
+   (merge 4c399442f7 ma/commit-graph-docs later to maint).
+   (merge fc0503b04e ma/t1400-undebug-test later to maint).
+   (merge e56b53553a nd/packobjectshook-doc-fix later to maint).
+   (merge c56170a0c4 ma/mailing-list-address-in-git-help later to maint).
+   (merge 6e8fc70fce rs/sequencer-oidset-insert-avoids-dups later to maint).
+   (merge ad0b8f9575 mw/doc-typofixes later to maint).
+   (merge d9f079ad1a jc/how-to-document-api later to maint).
+   (merge b1492bf315 ma/t7005-bash-workaround later to maint).
+   (merge ac1f98a0df du/rev-parse-is-plumbing later to maint).
+   (merge ca8ed443a5 mm/doc-no-dashed-git later to maint).
+   (merge ce366a8144 du/get-tar-commit-id-is-plumbing later to maint).
+   (merge 61018fe9e0 du/cherry-is-plumbing later to maint).
+   (merge c7e5fe79b9 sb/strbuf-h-update later to maint).
+   (merge 8d2008196b tq/branch-create-wo-branch-get later to maint).
+   (merge 2e3c894f4b tq/branch-style-fix later to maint).
+   (merge c5d844af9c sg/doc-show-branch-typofix later to maint).
+   (merge 081d91618b ah/doc-updates later to maint).
+   (merge b84c783882 jc/cocci-preincr later to maint).
+   (merge 5e495f8122 uk/merge-subtree-doc-update later to maint).
+   (merge aaaa881822 jk/uploadpack-packobjectshook-fix later to maint).
+   (merge 3063477445 tb/char-may-be-unsigned later to maint).
+   (merge 8c64bc9420 sg/test-rebase-editor-fix later to maint).
+   (merge 71571cd7d6 ma/sequencer-do-reset-saner-loop-termination later to maint).
+   (merge 9a4cb8781e cb/notes-freeing-always-null-fix later to maint).
+   (merge 3006f5ee16 ma/reset-doc-rendering-fix later to maint).
+   (merge 4c2eb06419 sg/daemon-test-signal-fix later to maint).
+   (merge d27525e519 ss/msvc-strcasecmp later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.20.1.txt b/third_party/git/Documentation/RelNotes/2.20.1.txt
new file mode 100644
index 0000000000..dcba888dba
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.20.1.txt
@@ -0,0 +1,20 @@
+Git v2.20.1 Release Notes
+=========================
+
+This release is primarily to fix brown-paper-bag breakages in the
+2.20.0 release.
+
+Fixes since v2.20
+-----------------
+
+ * A few newly added tests were not portable and caused minority
+   platforms to report false breakages, which have been fixed.
+
+ * Portability fix for a recent update to parse-options API.
+
+ * "git help -a" did not work well when an overly long alias is
+   defined, which has been corrected.
+
+ * A recent update accidentally squelched an error message when the
+   run_command API failed to run a missing command, which has been
+   corrected.
diff --git a/third_party/git/Documentation/RelNotes/2.21.0.txt b/third_party/git/Documentation/RelNotes/2.21.0.txt
new file mode 100644
index 0000000000..7a49deddf3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.21.0.txt
@@ -0,0 +1,451 @@
+Git 2.21 Release Notes
+======================
+
+Backward Compatibility Notes
+----------------------------
+
+ * Historically, the "-m" (mainline) option can only be used for "git
+   cherry-pick" and "git revert" when working with a merge commit.
+   This version of Git no longer warns or errors out when working with
+   a single-parent commit, as long as the argument to the "-m" option
+   is 1 (i.e. it has only one parent, and the request is to pick or
+   revert relative to that first parent).  Scripts that relied on the
+   behaviour may get broken with this change.
+
+
+Updates since v2.20
+-------------------
+
+UI, Workflows & Features
+
+ * The "http.version" configuration variable can be used with recent
+   enough versions of cURL library to force the version of HTTP used
+   to talk when fetching and pushing.
+
+ * Small fixes and features for fast-export and fast-import, mostly on
+   the fast-export side has been made.
+
+ * "git push $there $src:$dst" rejects when $dst is not a fully
+   qualified refname and it is not clear what the end user meant.  The
+   codepath has been taught to give a clearer error message, and also
+   guess where the push should go by taking the type of the pushed
+   object into account (e.g. a tag object would want to go under
+   refs/tags/).
+
+ * "git checkout [<tree-ish>] path..." learned to report the number of
+   paths that have been checked out of the index or the tree-ish,
+   which gives it the same degree of noisy-ness as the case in which
+   the command checks out a branch.  "git checkout -m <pathspec>" to
+   undo conflict resolution gives a similar message.
+
+ * "git quiltimport" learned "--keep-non-patch" option.
+
+ * "git worktree remove" and "git worktree move" refused to work when
+   there is a submodule involved.  This has been loosened to ignore
+   uninitialized submodules.
+
+ * "git cherry-pick -m1" was forbidden when picking a non-merge
+   commit, even though there _is_ parent number 1 for such a commit.
+   This was done to avoid mistakes back when "cherry-pick" was about
+   picking a single commit, but is no longer useful with "cherry-pick"
+   that can pick a range of commits.  Now the "-m$num" option is
+   allowed when picking any commit, as long as $num names an existing
+   parent of the commit.
+
+ * Update "git multimail" from the upstream.
+
+ * "git p4" update.
+
+ * The "--format=<placeholder>" option of for-each-ref, branch and tag
+   learned to show a few more traits of objects that can be learned by
+   the object_info API.
+
+ * "git rebase -i" learned to re-execute a command given with 'exec'
+   to run after it failed the last time.
+
+ * "git diff --color-moved-ws" updates.
+
+ * Custom userformat "log --format" learned %S atom that stands for
+   the tip the traversal reached the commit from, i.e. --source.
+
+ * "git instaweb" learned to drive http.server that comes with
+   "batteries included" Python installation (both Python2 & 3).
+
+ * A new encoding UTF-16LE-BOM has been invented to force encoding to
+   UTF-16 with BOM in little endian byte order, which cannot be directly
+   generated by using iconv.
+
+ * A new date format "--date=human" that morphs its output depending
+   on how far the time is from the current time has been introduced.
+   "--date=auto:human" can be used to use this new format (or any
+   existing format) when the output is going to the pager or to the
+   terminal, and otherwise the default format.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Code clean-up with optimization for the codepath that checks
+   (non-)existence of loose objects.
+
+ * More codepaths have become aware of working with in-core repository
+   instances other than the default "the_repository".
+
+ * The "strncat()" function is now among the banned functions.
+
+ * Portability updates for the HPE NonStop platform.
+
+ * Earlier we added "-Wformat-security" to developer builds, assuming
+   that "-Wall" (which includes "-Wformat" which in turn is required
+   to use "-Wformat-security") is always in effect.  This is not true
+   when config.mak.autogen is in use, unfortunately.  This has been
+   fixed by unconditionally adding "-Wall" to developer builds.
+
+ * The loose object cache used to optimize existence look-up has been
+   updated.
+
+ * Flaky tests can now be repeatedly run under load with the
+   "--stress" option.
+
+ * Documentation/Makefile is getting prepared for manpage
+   localization.
+
+ * "git fetch-pack" now can talk the version 2 protocol.
+
+ * sha-256 hash has been added and plumbed through the code to allow
+   building Git with the "NewHash".
+
+ * Debugging help for http transport.
+
+ * "git fetch --deepen=<more>" has been corrected to work over v2
+   protocol.
+
+ * The code to walk tree objects has been taught that we may be
+   working with object names that are not computed with SHA-1.
+
+ * The in-core repository instances are passed through more codepaths.
+
+ * Update the protocol message specification to allow only the limited
+   use of scaled quantities.  This is to ensure potential compatibility
+   issues will not get out of hand.
+
+ * Micro-optimize the code that prepares commit objects to be walked
+   by "git rev-list" when the commit-graph is available.
+
+ * "git fetch" and "git upload-pack" learned to send all exchanges over
+   the sideband channel while talking the v2 protocol.
+
+ * The codepath to write out commit-graph has been optimized by
+   following the usual pattern of visiting objects in in-pack order.
+
+ * The codepath to show progress meter while writing out commit-graph
+   file has been improved.
+
+ * Cocci rules have been updated to encourage use of strbuf_addbuf().
+
+ * "git rebase --merge" has been reimplemented by reusing the internal
+   machinery used for "git rebase -i".
+
+ * More code in "git bisect" has been rewritten in C.
+
+ * Instead of going through "git-rebase--am" scriptlet to use the "am"
+   backend, the built-in version of "git rebase" learned to drive the
+   "am" backend directly.
+
+ * The assumption to work on the single "in-core index" instance has
+   been reduced from the library-ish part of the codebase.
+
+ * The test lint learned to catch non-portable "sed" options.
+
+ * "git pack-objects" learned another algorithm to compute the set of
+   objects to send, that trades the resulting packfile off to save
+   traversal cost to favor small pushes.
+
+ * The travis CI scripts have been corrected to build Git with the
+   compiler(s) of our choice.
+
+ * "git submodule update" learned to abort early when core.worktree
+   for the submodule is not set correctly to prevent spreading damage.
+
+ * Test suite has been adjusted to run on Azure Pipeline.
+
+ * Running "Documentation/doc-diff x" from anywhere other than the
+   top-level of the working tree did not show the usage string
+   correctly, which has been fixed.
+
+ * Use of the sparse tool got easier to customize from the command
+   line to help developers.
+
+ * A new target "coverage-prove" to run the coverage test under
+   "prove" has been added.
+
+ * A flakey "p4" test has been removed.
+
+ * The code and tests assume that the system supplied iconv() would
+   always use BOM in its output when asked to encode to UTF-16 (or
+   UTF-32), but apparently some implementations output big-endian
+   without BOM.  A compile-time knob has been added to help such
+   systems (e.g. NonStop) to add BOM to the output to increase
+   portability.
+
+
+Fixes since v2.20
+-----------------
+
+ * Updates for corner cases in merge-recursive.
+   (merge cc4cb0902c en/merge-path-collision later to maint).
+
+ * "git checkout frotz" (without any double-dash) avoids ambiguity by
+   making sure 'frotz' cannot be interpreted as a revision and as a
+   path at the same time.  This safety has been updated to check also
+   a unique remote-tracking branch 'frotz' in a remote, when dwimming
+   to create a local branch 'frotz' out of a remote-tracking branch
+   'frotz' from a remote.
+   (merge be4908f103 nd/checkout-dwim-fix later to maint).
+
+ * Refspecs configured with "git -c var=val clone" did not propagate
+   to the resulting repository, which has been corrected.
+   (merge 7eae4a3ac4 sg/clone-initial-fetch-configuration later to maint).
+
+ * A properly configured username/email is required under
+   user.useConfigOnly in order to create commits; now "git stash"
+   (even though it creates commit objects to represent stash entries)
+   command is exempt from the requirement.
+   (merge 3bc2111fc2 sd/stash-wo-user-name later to maint).
+
+ * The http-backend CGI process did not correctly clean up the child
+   processes it spawns to run upload-pack etc. when it dies itself,
+   which has been corrected.
+   (merge 02818a98d7 mk/http-backend-kill-children-before-exit later to maint).
+
+ * "git rev-list --exclude-promisor-objects" had to take an object
+   that does not exist locally (and is lazily available) from the
+   command line without barfing, but the code dereferenced NULL.
+   (merge 4cf67869b2 md/list-lazy-objects-fix later to maint).
+
+ * The traversal over tree objects has learned to honor
+   ":(attr:label)" pathspec match, which has been implemented only for
+   enumerating paths on the filesystem.
+   (merge 5a0b97b34c nd/attr-pathspec-in-tree-walk later to maint).
+
+ * BSD port updates.
+   (merge 4e3ecbd439 cb/openbsd-allows-reading-directory later to maint).
+   (merge b6bdc2a0f5 cb/t5004-empty-tar-archive-fix later to maint).
+   (merge 82cbc8cde2 cb/test-lint-cp-a later to maint).
+
+ * Lines that begin with a certain keyword that come over the wire, as
+   well as lines that consist only of one of these keywords, ought to
+   be painted in color for easier eyeballing, but the latter was
+   broken ever since the feature was introduced in 2.19, which has
+   been corrected.
+   (merge 1f67290450 hn/highlight-sideband-keywords later to maint).
+
+ * "git log -G<regex>" looked for a hunk in the "git log -p" patch
+   output that contained a string that matches the given pattern.
+   Optimize this code to ignore binary files, which by default will
+   not show any hunk that would match any pattern (unless textconv or
+   the --text option is in effect, that is).
+   (merge e0e7cb8080 tb/log-G-binary later to maint).
+
+ * "git submodule update" ought to use a single job unless asked, but
+   by mistake used multiple jobs, which has been fixed.
+   (merge e3a9d1aca9 sb/submodule-fetchjobs-default-to-one later to maint).
+
+ * "git stripspace" should be usable outside a git repository, but
+   under the "-s" or "-c" mode, it didn't.
+   (merge 957da75802 jn/stripspace-wo-repository later to maint).
+
+ * Some of the documentation pages formatted incorrectly with
+   Asciidoctor, which have been fixed.
+   (merge b62eb1d2f4 ma/asciidoctor later to maint).
+
+ * The core.worktree setting in a submodule repository should not be
+   pointing at a directory when the submodule loses its working tree
+   (e.g. getting deinit'ed), but the code did not properly maintain
+   this invariant.
+
+ * With zsh, "git cmd path<TAB>" was completed to "git cmd path name"
+   when the completed path has a special character like SP in it,
+   without any attempt to keep "path name" a single filename.  This
+   has been fixed to complete it to "git cmd path\ name" just like
+   Bash completion does.
+
+ * The test suite tried to see if it is run under bash, but the check
+   itself failed under some other implementations of shell (notably
+   under NetBSD).  This has been corrected.
+   (merge 54ea72f09c sg/test-bash-version-fix later to maint).
+
+ * "git gc" and "git repack" did not close the open packfiles that
+   they found unneeded before removing them, which didn't work on a
+   platform incapable of removing an open file.  This has been
+   corrected.
+   (merge 5bdece0d70 js/gc-repack-close-before-remove later to maint).
+
+ * The code to drive GIT_EXTERNAL_DIFF command relied on the string
+   returned from getenv() to be non-volatile, which is not true, that
+   has been corrected.
+   (merge 6776a84dae kg/external-diff-save-env later to maint).
+
+ * There were many places the code relied on the string returned from
+   getenv() to be non-volatile, which is not true, that have been
+   corrected.
+   (merge 0da0e9268b jk/save-getenv-result later to maint).
+
+ * The v2 upload-pack protocol implementation failed to honor
+   hidden-ref configuration, which has been corrected.
+   (merge e20b4192a3 jk/proto-v2-hidden-refs-fix later to maint).
+
+ * "git fetch --recurse-submodules" may not fetch the necessary commit
+   that is bound to the superproject, which is getting corrected.
+   (merge be76c21282 sb/submodule-recursive-fetch-gets-the-tip later to maint).
+
+ * "git rebase" internally runs "checkout" to switch between branches,
+   and the command used to call the post-checkout hook, but the
+   reimplementation stopped doing so, which is getting fixed.
+
+ * "git add -e" got confused when the change it wants to let the user
+   edit is smaller than the previous change that was left over in a
+   temporary file.
+   (merge fa6f225e01 js/add-e-clear-patch-before-stating later to maint).
+
+ * "git p4" failed to update a shelved change when there were moved
+   files, which has been corrected.
+   (merge 7a10946ab9 ld/git-p4-shelve-update-fix later to maint).
+
+ * The codepath to read from the commit-graph file attempted to read
+   past the end of it when the file's table-of-contents was corrupt.
+
+ * The compat/obstack code had casts that -Wcast-function-type
+   compilation option found questionable.
+   (merge 764473d257 sg/obstack-cast-function-type-fix later to maint).
+
+ * An obvious typo in an assertion error message has been fixed.
+   (merge 3c27e2e059 cc/test-ref-store-typofix later to maint).
+
+ * In Git for Windows, "git clone \\server\share\path" etc. that uses
+   UNC paths from command line had bad interaction with its shell
+   emulation.
+
+ * "git add --ignore-errors" did not work as advertised and instead
+   worked as an unintended synonym for "git add --renormalize", which
+   has been fixed.
+   (merge e2c2a37545 jk/add-ignore-errors-bit-assignment-fix later to maint).
+
+ * On a case-insensitive filesystem, we failed to compare the part of
+   the path that is above the worktree directory in an absolute
+   pathname, which has been corrected.
+
+ * Asking "git check-attr" about a macro (e.g. "binary") on a specific
+   path did not work correctly, even though "git check-attr -a" listed
+   such a macro correctly.  This has been corrected.
+   (merge 7b95849be4 jk/attr-macro-fix later to maint).
+
+ * "git pack-objects" incorrectly used uninitialized mutex, which has
+   been corrected.
+   (merge edb673cf10 ph/pack-objects-mutex-fix later to maint).
+
+ * "git checkout -b <new> [HEAD]" to create a new branch from the
+   current commit and check it out ought to be a no-op in the index
+   and the working tree in normal cases, but there are corner cases
+   that do require updates to the index and the working tree.  Running
+   it immediately after "git clone --no-checkout" is one of these
+   cases that an earlier optimization kicked in incorrectly, which has
+   been fixed.
+   (merge 8424bfd45b bp/checkout-new-branch-optim later to maint).
+
+ * "git diff --color-moved --cc --stat -p" did not work well due to
+   funny interaction between a bug in color-moved and the rest, which
+   has been fixed.
+   (merge dac03b5518 jk/diff-cc-stat-fixes later to maint).
+
+ * When GIT_SEQUENCE_EDITOR is set, the command was incorrectly
+   started when modes of "git rebase" that implicitly uses the
+   machinery for the interactive rebase are run, which has been
+   corrected.
+   (merge 891d4a0313 pw/no-editor-in-rebase-i-implicit later to maint).
+
+ * The commit-graph facility did not work when in-core objects that
+   are promoted from unknown type to commit (e.g. a commit that is
+   accessed via a tag that refers to it) were involved, which has been
+   corrected.
+   (merge 4468d4435c sg/object-as-type-commit-graph-fix later to maint).
+
+ * "git fetch" output cleanup.
+   (merge dc40b24df4 nd/fetch-compact-update later to maint).
+
+ * "git cat-file --batch" reported a dangling symbolic link by
+   mistake, when it wanted to report that a given name is ambiguous.
+
+ * Documentation around core.crlf has been updated.
+   (merge c9446f0504 jk/autocrlf-overrides-eol-doc later to maint).
+
+ * The documentation of "git commit-tree" said that the command
+   understands "--gpg-sign" in addition to "-S", but the command line
+   parser did not know about the longhand, which has been corrected.
+
+ * "git rebase -x $cmd" did not reject multi-line command, even though
+   the command is incapable of handling such a command.  It now is
+   rejected upfront.
+   (merge c762aada1a pw/rebase-x-sanity-check later to maint).
+
+ * Output from "git help" was not correctly aligned, which has been
+   fixed.
+   (merge 6195a76da4 nd/help-align-command-desc later to maint).
+
+ * The "git submodule summary" subcommand showed shortened commit
+   object names by mechanically truncating them at 7-hexdigit, which
+   has been improved to let "rev-parse --short" scale the length of
+   the abbreviation with the size of the repository.
+   (merge 0586a438f6 sh/submodule-summary-abbrev-fix later to maint).
+
+ * The way the OSX build jobs updates its build environment used the
+   "--quiet" option to "brew update" command, but it wasn't all that
+   quiet to be useful.  The use of the option has been replaced with
+   an explicit redirection to the /dev/null (which incidentally would
+   have worked around a breakage by recent updates to homebrew, which
+   has fixed itself already).
+   (merge a1ccaedd62 sg/travis-osx-brew-breakage-workaround later to maint).
+
+ * "git --work-tree=$there --git-dir=$here describe --dirty" did not
+   work correctly as it did not pay attention to the location of the
+   worktree specified by the user by mistake, which has been
+   corrected.
+   (merge c801170b0c ss/describe-dirty-in-the-right-directory later to maint).
+
+ * "git fetch" over protocol v2 that needs to make a second connection
+   to backfill tags did not clear a variable that holds shallow
+   repository information correctly, leading to an access of freed
+   piece of memory.
+
+ * Some errors from the other side coming over smart HTTP transport
+   were not noticed, which has been corrected.
+
+ * Code cleanup, docfix, build fix, etc.
+   (merge 89ba9a79ae hb/t0061-dot-in-path-fix later to maint).
+   (merge d173e799ea sb/diff-color-moved-config-option-fixup later to maint).
+   (merge a8f5a59067 en/directory-renames-nothanks-doc-update later to maint).
+   (merge ec36c42a63 nd/indentation-fix later to maint).
+   (merge f116ee21cd do/gitweb-strict-export-conf-doc later to maint).
+   (merge 112ea42663 fd/gitweb-snapshot-conf-doc-fix later to maint).
+   (merge 1cadad6f65 tb/use-common-win32-pathfuncs-on-cygwin later to maint).
+   (merge 57e9dcaa65 km/rebase-doc-typofix later to maint).
+   (merge b8b4cb27e6 ds/gc-doc-typofix later to maint).
+   (merge 3b3357626e nd/style-opening-brace later to maint).
+   (merge b4583d5595 es/doc-worktree-guessremote-config later to maint).
+   (merge cce99cd8c6 ds/commit-graph-assert-missing-parents later to maint).
+   (merge 0650614982 cy/completion-typofix later to maint).
+   (merge 6881925ef5 rs/sha1-file-close-mapped-file-on-error later to maint).
+   (merge bd8d6f0def en/show-ref-doc-fix later to maint).
+   (merge 1747125e2c cc/partial-clone-doc-typofix later to maint).
+   (merge e01378753d cc/fetch-error-message-fix later to maint).
+   (merge 54e8c11215 jk/remote-insteadof-cleanup later to maint).
+   (merge d609615f48 js/test-git-installed later to maint).
+   (merge ba170517be ja/doc-style-fix later to maint).
+   (merge 86fb1c4e77 km/init-doc-typofix later to maint).
+   (merge 5cfd4a9d10 nd/commit-doc later to maint).
+   (merge 9fce19a431 ab/diff-tree-doc-fix later to maint).
+   (merge 2e285e7803 tz/gpg-test-fix later to maint).
+   (merge 5427de960b kl/pretty-doc-markup-fix later to maint).
+   (merge 3815f64b0d js/mingw-host-cpu later to maint).
+   (merge 5fe81438b5 rj/sequencer-sign-off-header-static later to maint).
+   (merge 18a4f6be6b nd/fileno-may-be-macro later to maint).
+   (merge 99e9ab54ab kd/t0028-octal-del-is-377-not-777 later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.22.0.txt b/third_party/git/Documentation/RelNotes/2.22.0.txt
new file mode 100644
index 0000000000..91e6ae9887
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.22.0.txt
@@ -0,0 +1,597 @@
+Git 2.22 Release Notes
+======================
+
+Updates since v2.21
+-------------------
+
+Backward compatibility note
+
+ * The filter specification "--filter=sparse:path=<path>" used to
+   create a lazy/partial clone has been removed.  Using a blob that is
+   part of the project as sparse specification is still supported with
+   the "--filter=sparse:oid=<blob>" option.
+
+UI, Workflows & Features
+
+ * "git checkout --no-overlay" can be used to trigger a new mode of
+   checking out paths out of the tree-ish, that allows paths that
+   match the pathspec that are in the current index and working tree
+   and are not in the tree-ish.
+
+ * The %(trailers) formatter in "git log --format=..."  now allows to
+   optionally pick trailers selectively by keyword, show only values,
+   etc.
+
+ * Four new configuration variables {author,committer}.{name,email}
+   have been introduced to override user.{name,email} in more specific
+   cases.
+
+ * Command-line completion (in contrib/) learned to tab-complete the
+   "git submodule absorbgitdirs" subcommand.
+
+ * "git branch" learned a new subcommand "--show-current".
+
+ * Output from "diff --cc" did not show the original paths when the
+   merge involved renames.  A new option adds the paths in the
+   original trees to the output.
+
+ * The command line completion (in contrib/) has been taught to
+   complete more subcommand parameters.
+
+ * The final report from "git bisect" used to show the suspected
+   culprit using a raw "diff-tree", with which there is no output for
+   a merge commit.  This has been updated to use a more modern and
+   human readable output that still is concise enough.
+
+ * "git rebase --rebase-merges" replaces its old "--preserve-merges"
+   option; the latter is now marked as deprecated.
+
+ * Error message given while cloning with --recurse-submodules has
+   been updated.
+
+ * The completion helper code now pays attention to repository-local
+   configuration (when available), which allows --list-cmds to honour
+   a repository specific setting of completion.commands, for example.
+
+ * "git mergetool" learned to offer Sublime Merge (smerge) as one of
+   its backends.
+
+ * A new hook "post-index-change" is called when the on-disk index
+   file changes, which can help e.g. a virtualized working tree
+   implementation.
+
+ * "git difftool" can now run outside a repository.
+
+ * "git checkout -m <other>" was about carrying the differences
+   between HEAD and the working-tree files forward while checking out
+   another branch, and ignored the differences between HEAD and the
+   index.  The command has been taught to abort when the index and the
+   HEAD are different.
+
+ * A progress indicator has been added to the "index-pack" step, which
+   often makes users wait for completion during "git clone".
+
+ * "git submodule" learns "set-branch" subcommand that allows the
+   submodule.*.branch settings to be modified.
+
+ * "git merge-recursive" backend recently learned a new heuristics to
+   infer file movement based on how other files in the same directory
+   moved.  As this is inherently less robust heuristics than the one
+   based on the content similarity of the file itself (rather than
+   based on what its neighbours are doing), it sometimes gives an
+   outcome unexpected by the end users.  This has been toned down to
+   leave the renamed paths in higher/conflicted stages in the index so
+   that the user can examine and confirm the result.
+
+ * "git tag" learned to give an advice suggesting it might be a
+   mistake when creating an annotated or signed tag that points at
+   another tag.
+
+ * The "git pack-objects" command learned to report the number of
+   objects it packed via the trace2 mechanism.
+
+ * The list of conflicted paths shown in the editor while concluding a
+   conflicted merge was shown above the scissors line when the
+   clean-up mode is set to "scissors", even though it was commented
+   out just like the list of updated paths and other information to
+   help the user explain the merge better.
+
+ * The trace2 tracing facility learned to auto-generate a filename
+   when told to log to a directory.
+
+ * "git clone" learned a new --server-option option when talking over
+   the protocol version 2.
+
+ * The connectivity bitmaps are created by default in bare
+   repositories now; also the pathname hash-cache is created by
+   default to avoid making crappy deltas when repacking.
+
+ * "git branch new A...B" and "git checkout -b new A...B" have been
+   taught that in their contexts, the notation A...B means "the merge
+   base between these two commits", just like "git checkout A...B"
+   detaches HEAD at that commit.
+
+ * Update "git difftool" and "git mergetool" so that the combinations
+   of {diff,merge}.{tool,guitool} configuration variables serve as
+   fallback settings of each other in a sensible order.
+
+ * The "--dir-diff" mode of "git difftool" is not useful in "--no-index"
+   mode; they are now explicitly marked as mutually incompatible.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The diff machinery, one of the oldest parts of the system, which
+   long predates the parse-options API, uses fairly long and complex
+   handcrafted option parser.  This is being rewritten to use the
+   parse-options API.
+
+ * The implementation of pack-redundant has been updated for
+   performance in a repository with many packfiles.
+
+ * A more structured way to obtain execution trace has been added.
+
+ * "git prune" has been taught to take advantage of reachability
+   bitmap when able.
+
+ * The command line parser of "git commit-tree" has been rewritten to
+   use the parse-options API.
+
+ * Suggest GitGitGadget instead of submitGit as a way to submit
+   patches based on GitHub PR to us.
+
+ * The test framework has been updated to help developers by making it
+   easier to run most of the tests under different versions of
+   over-the-wire protocols.
+
+ * Dev support update to make it easier to compare two formatted
+   results from our documentation.
+
+ * The scripted "git rebase" implementation has been retired.
+
+ * "git multi-pack-index verify" did not scale well with the number of
+   packfiles, which is being improved.
+
+ * "git stash" has been rewritten in C.
+
+ * The "check-docs" Makefile target to support developers has been
+   updated.
+
+ * The tests have been updated not to rely on the abbreviated option
+   names the parse-options API offers, to protect us from an
+   abbreviated form of an option that used to be unique within the
+   command getting non-unique when a new option that share the same
+   prefix is added.
+
+ * The scripted version of "git rebase -i" wrote and rewrote the todo
+   list many times during a single step of its operation, and the
+   recent C-rewrite made a faithful conversion of the logic to C.  The
+   implementation has been updated to carry necessary information
+   around in-core to avoid rewriting the same file over and over
+   unnecessarily.
+
+ * Test framework update to more robustly clean up leftover files and
+   processes after tests are done.
+
+ * Conversion from unsigned char[20] to struct object_id continues.
+
+ * While running "git diff" in a lazy clone, we can upfront know which
+   missing blobs we will need, instead of waiting for the on-demand
+   machinery to discover them one by one.  The code learned to aim to
+   achieve better performance by batching the request for these
+   promised blobs.
+
+ * During an initial "git clone --depth=..." partial clone, it is
+   pointless to spend cycles for a large portion of the connectivity
+   check that enumerates and skips promisor objects (which by
+   definition is all objects fetched from the other side).  This has
+   been optimized out.
+
+ * Mechanically and systematically drop "extern" from function
+   declaration.
+
+ * The script to aggregate perf result unconditionally depended on
+   libjson-perl even though it did not have to, which has been
+   corrected.
+
+ * The internal implementation of "git rebase -i" has been updated to
+   avoid forking a separate "rebase--interactive" process.
+
+ * Allow DEP and ASLR for Windows build to for security hardening.
+
+ * Performance test framework has been broken and measured the version
+   of Git that happens to be on $PATH, not the specified one to
+   measure, for a while, which has been corrected.
+
+ * Optionally "make coccicheck" can feed multiple source files to
+   spatch, gaining performance while spending more memory.
+
+ * Attempt to use an abbreviated option in "git clone --recurs" is
+   responded by a request to disambiguate between --recursive and
+   --recurse-submodules, which is bad because these two are synonyms.
+   The parse-options API has been extended to define such synonyms
+   more easily and not produce an unnecessary failure.
+
+ * A pair of private functions in http.c that had names similar to
+   fread/fwrite did not return the number of elements, which was found
+   to be confusing.
+
+ * Update collision-detecting SHA-1 code to build properly on HP-UX.
+
+
+Fixes since v2.21
+-----------------
+
+ * "git prune-packed" did not notice and complain against excess
+   arguments given from the command line, which now it does.
+   (merge 9b0bd87ed2 rj/prune-packed-excess-args later to maint).
+
+ * Split-index fix.
+   (merge 6e37c8ed3c nd/split-index-null-base-fix later to maint).
+
+ * "git diff --no-index" may still want to access Git goodies like
+   --ext-diff and --textconv, but so far these have been ignored,
+   which has been corrected.
+   (merge 287ab28bfa jk/diff-no-index-initialize later to maint).
+
+ * Unify RPC code for smart http in protocol v0/v1 and v2, which fixes
+   a bug in the latter (lack of authentication retry) and generally
+   improves the code base.
+   (merge a97d00799a jt/http-auth-proto-v2-fix later to maint).
+
+ * The include file compat/bswap.h has been updated so that it is safe
+   to (accidentally) include it more than once.
+   (merge 33aa579a55 jk/guard-bswap-header later to maint).
+
+ * The set of header files used by "make hdr-check" unconditionally
+   included sha256/gcrypt.h, even when it is not used, causing the
+   make target to fail.  We now skip it when GCRYPT_SHA256 is not in
+   use.
+   (merge f23aa18e7f rj/hdr-check-gcrypt-fix later to maint).
+
+ * The Makefile uses 'find' utility to enumerate all the *.h header
+   files, which is expensive on platforms with slow filesystems; it
+   now optionally uses "ls-files" if working within a repository,
+   which is a trick similar to how all sources are enumerated to run
+   ETAGS on.
+   (merge 92b88eba9f js/find-lib-h-with-ls-files-when-possible later to maint).
+
+ * "git rebase" that was reimplemented in C did not set ORIG_HEAD
+   correctly, which has been corrected.
+   (merge cbd29ead92 js/rebase-orig-head-fix later to maint).
+
+ * Dev support.
+   (merge f545737144 js/stress-test-ui-tweak later to maint).
+
+ * CFLAGS now can be tweaked when invoking Make while using
+   DEVELOPER=YesPlease; this did not work well before.
+   (merge 6d5d4b4e93 ab/makefile-help-devs-more later to maint).
+
+ * "git fsck --connectivity-only" omits computation necessary to sift
+   the objects that are not reachable from any of the refs into
+   unreachable and dangling.  This is now enabled when dangling
+   objects are requested (which is done by default, but can be
+   overridden with the "--no-dangling" option).
+   (merge 8d8c2a5aef jk/fsck-doc later to maint).
+
+ * On platforms where "git fetch" is killed with SIGPIPE (e.g. OSX),
+   the upload-pack that runs on the other end that hangs up after
+   detecting an error could cause "git fetch" to die with a signal,
+   which led to a flaky test.  "git fetch" now ignores SIGPIPE during
+   the network portion of its operation (this is not a problem as we
+   check the return status from our write(2)s).
+   (merge 143588949c jk/no-sigpipe-during-network-transport later to maint).
+
+ * A recent update broke "is this object available to us?" check for
+   well-known objects like an empty tree (which should yield "yes",
+   even when there is no on-disk object for an empty tree), which has
+   been corrected.
+   (merge f06ab027ef jk/virtual-objects-do-exist later to maint).
+
+ * The setup code has been cleaned up to avoid leaks around the
+   repository_format structure.
+   (merge e8805af1c3 ma/clear-repository-format later to maint).
+
+ * "git config --type=color ..." is meant to replace "git config --get-color"
+   but there is a slight difference that wasn't documented, which is
+   now fixed.
+   (merge cd8e7593b9 jk/config-type-color-ends-with-lf later to maint).
+
+ * When the "clean" filter can reduce the size of a huge file in the
+   working tree down to a small "token" (a la Git LFS), there is no
+   point in allocating a huge scratch area upfront, but the buffer is
+   sized based on the original file size.  The convert mechanism now
+   allocates very minimum and reallocates as it receives the output
+   from the clean filter process.
+   (merge 02156ab031 jh/resize-convert-scratch-buffer later to maint).
+
+ * "git rebase" uses the refs/rewritten/ hierarchy to store its
+   intermediate states, which inherently makes the hierarchy per
+   worktree, but it didn't quite work well.
+   (merge b9317d55a3 nd/rewritten-ref-is-per-worktree later to maint).
+
+ * "git log -L<from>,<to>:<path>" with "-s" did not suppress the patch
+   output as it should.  This has been corrected.
+   (merge 05314efaea jk/line-log-with-patch later to maint).
+
+ * "git worktree add" used to do a "find an available name with stat
+   and then mkdir", which is race-prone.  This has been fixed by using
+   mkdir and reacting to EEXIST in a loop.
+   (merge 7af01f2367 ms/worktree-add-atomic-mkdir later to maint).
+
+ * Build update for SHA-1 with collision detection.
+   (merge 07a20f569b jk/sha1dc later to maint).
+
+ * Build procedure has been fixed around use of asciidoctor instead of
+   asciidoc.
+   (merge 185f9a0ea0 ma/asciidoctor-fixes later to maint).
+
+ * remote-http transport did not anonymize URLs reported in its error
+   messages at places.
+   (merge c1284b21f2 js/anonymize-remote-curl-diag later to maint).
+
+ * Error messages given from the http transport have been updated so
+   that they can be localized.
+   (merge ed8b4132c8 js/remote-curl-i18n later to maint).
+
+ * "git init" forgot to read platform-specific repository
+   configuration, which made Windows port to ignore settings of
+   core.hidedotfiles, for example.
+
+ * A corner-case object name ambiguity while the sequencer machinery
+   is working (e.g. "rebase -i -x") has been fixed.
+
+ * "git format-patch" did not diagnose an error while opening the
+   output file for the cover-letter, which has been corrected.
+   (merge 2fe95f494c jc/format-patch-error-check later to maint).
+
+ * "git checkout -f <branch>" while the index has an unmerged path
+   incorrectly left some paths in an unmerged state, which has been
+   corrected.
+
+ * A corner case bug in the refs API has been corrected.
+   (merge d3322eb28b jk/refs-double-abort later to maint).
+
+ * Unicode update.
+   (merge 584b62c37b bb/unicode-12 later to maint).
+
+ * dumb-http walker has been updated to share more error recovery
+   strategy with the normal codepath.
+
+ * A buglet in configuration parser has been fixed.
+   (merge 19e7fdaa58 nd/include-if-wildmatch later to maint).
+
+ * The documentation for "git read-tree --reset -u" has been updated.
+   (merge b5a0bd694c nd/read-tree-reset-doc later to maint).
+
+ * Code clean-up around a much-less-important-than-it-used-to-be
+   update_server_info() function.
+   (merge b3223761c8 jk/server-info-rabbit-hole later to maint).
+
+ * The message given when "git commit -a <paths>" errors out has been
+   updated.
+   (merge 5a1dbd48bc nd/commit-a-with-paths-msg-update later to maint).
+
+ * "git cherry-pick --options A..B", after giving control back to the
+   user to ask help resolving a conflicted step, did not honor the
+   options it originally received, which has been corrected.
+
+ * Various glitches in "git gc" around reflog handling have been fixed.
+
+ * The code to read from commit-graph file has been cleanup with more
+   careful error checking before using data read from it.
+
+ * Performance fix around "git fetch" that grabs many refs.
+   (merge b764300912 jt/fetch-pack-wanted-refs-optim later to maint).
+
+ * Protocol v2 support in "git fetch-pack" of shallow clones has been
+   corrected.
+
+ * Performance fix around "git blame", especially in a linear history
+   (which is the norm we should optimize for).
+   (merge f892014943 dk/blame-keep-origin-blob later to maint).
+
+ * Performance fix for "rev-list --parents -- pathspec".
+   (merge 8320b1dbe7 jk/revision-rewritten-parents-in-prio-queue later to maint).
+
+ * Updating the display with progress message has been cleaned up to
+   deal better with overlong messages.
+   (merge 545dc345eb sg/overlong-progress-fix later to maint).
+
+ * "git blame -- path" in a non-bare repository starts blaming from
+   the working tree, and the same command in a bare repository errors
+   out because there is no working tree by definition.  The command
+   has been taught to instead start blaming from the commit at HEAD,
+   which is more useful.
+   (merge a544fb08f8 sg/blame-in-bare-start-at-head later to maint).
+
+ * An underallocation in the code to read the untracked cache
+   extension has been corrected.
+   (merge 3a7b45a623 js/untracked-cache-allocfix later to maint).
+
+ * The code is updated to check the result of memory allocation before
+   it is used in more places, by using xmalloc and/or xcalloc calls.
+   (merge 999b951b28 jk/xmalloc later to maint).
+
+ * The GETTEXT_POISON test option has been quite broken ever since it
+   was made runtime-tunable, which has been fixed.
+   (merge f88b9cb603 jc/gettext-test-fix later to maint).
+
+ * Test fix on APFS that is incapable of store paths in Latin-1.
+   (merge 3889149619 js/iso8895-test-on-apfs later to maint).
+
+ * "git submodule foreach <command> --quiet" did not pass the option
+   down correctly, which has been corrected.
+   (merge a282f5a906 nd/submodule-foreach-quiet later to maint).
+
+ * "git send-email" has been taught to use quoted-printable when the
+   payload contains carriage-return.  The use of the mechanism is in
+   line with the design originally added the codepath that chooses QP
+   when the payload has overly long lines.
+   (merge 74d76a1701 bc/send-email-qp-cr later to maint).
+
+ * The recently added feature to add addresses that are on
+   anything-by: trailers in 'git send-email' was found to be way too
+   eager and considered nonsense strings as if they can be legitimate
+   beginning of *-by: trailer.  This has been tightened.
+
+ * Builds with gettext broke on recent macOS w/ Homebrew, which
+   seems to have stopped including from /usr/local/include; this
+   has been corrected.
+   (merge 92a1377a2a js/macos-gettext-build later to maint).
+
+ * Running "git add" on a repository created inside the current
+   repository is an explicit indication that the user wants to add it
+   as a submodule, but when the HEAD of the inner repository is on an
+   unborn branch, it cannot be added as a submodule.  Worse, the files
+   in its working tree can be added as if they are a part of the outer
+   repository, which is not what the user wants.  These problems are
+   being addressed.
+   (merge f937bc2f86 km/empty-repo-is-still-a-repo later to maint).
+
+ * "git cherry-pick" run with the "-x" or the "--signoff" option used
+   to (and more importantly, ought to) clean up the commit log message
+   with the --cleanup=space option by default, but this has been
+   broken since late 2017.  This has been fixed.
+
+ * When given a tag that points at a commit-ish, "git replace --graft"
+   failed to peel the tag before writing a replace ref, which did not
+   make sense because the old graft mechanism the feature wants to
+   mimic only allowed to replace one commit object with another.
+   This has been fixed.
+   (merge ee521ec4cb cc/replace-graft-peel-tags later to maint).
+
+ * Code tightening against a "wrong" object appearing where an object
+   of a different type is expected, instead of blindly assuming that
+   the connection between objects are correctly made.
+   (merge 97dd512af7 tb/unexpected later to maint).
+
+ * An earlier update for MinGW and Cygwin accidentally broke MSVC build,
+   which has been fixed.
+   (merge 22c3634c0f ss/msvc-path-utils-fix later to maint).
+
+ * %(push:track) token used in the --format option to "git
+   for-each-ref" and friends was not showing the right branch, which
+   has been fixed.
+   (merge c646d0934e dr/ref-filter-push-track-fix later to maint).
+
+ * "make check-docs", "git help -a", etc. did not account for cases
+   where a particular build may deliberately omit some subcommands,
+   which has been corrected.
+
+ * The logic to tell if a Git repository has a working tree protects
+   "git branch -D" from removing the branch that is currently checked
+   out by mistake.  The implementation of this logic was broken for
+   repositories with unusual name, which unfortunately is the norm for
+   submodules these days.  This has been fixed.
+   (merge f3534c98e4 jt/submodule-repo-is-with-worktree later to maint).
+
+ * AIX shared the same build issues with other BSDs around fileno(fp),
+   which has been corrected.
+   (merge ee662bf5c6 cc/aix-has-fileno-as-a-macro later to maint).
+
+ * The autoconf generated configure script failed to use the right
+   gettext() implementations from -libintl by ignoring useless stub
+   implementations shipped in some C library, which has been
+   corrected.
+   (merge b71e56a683 vk/autoconf-gettext later to maint).
+
+ * Fix index-pack perf test so that the repeated invocations always
+   run in an empty repository, which emulates the initial clone
+   situation better.
+   (merge 775c71e16d jk/p5302-avoid-collision-check-cost later to maint).
+
+ * A "ls-files" that emulates "find" to enumerate files in the working
+   tree resulted in duplicated Makefile rules that caused the build to
+   issue an unnecessary warning during a trial build after merge
+   conflicts are resolved in working tree *.h files but before the
+   resolved results are added to the index.  This has been corrected.
+
+ * "git cherry-pick" (and "revert" that shares the same runtime engine)
+   that deals with multiple commits got confused when the final step
+   gets stopped with a conflict and the user concluded the sequence
+   with "git commit".  Attempt to fix it by cleaning up the state
+   files used by these commands in such a situation.
+   (merge 4a72486de9 pw/clean-sequencer-state-upon-final-commit later to maint).
+
+ * On a filesystem like HFS+, the names of the refs stored as filesystem
+   entities may become different from what the end-user expects, just
+   like files in the working tree get "renamed".  Work around the
+   mismatch by paying attention to the core.precomposeUnicode
+   configuration.
+   (merge 8e712ef6fc en/unicode-in-refnames later to maint).
+
+ * The code to generate the multi-pack idx file was not prepared to
+   see too many packfiles and ran out of open file descriptor, which
+   has been corrected.
+
+ * To run tests for Git SVN, our scripts for CI used to install the
+   git-svn package (in the hope that it would bring in the right
+   dependencies).  This has been updated to install the more direct
+   dependency, namely, libsvn-perl.
+   (merge db864306cf sg/ci-libsvn-perl later to maint).
+
+ * "git cvsexportcommit" running on msys did not expect cvsnt showed
+   "cvs status" output with CRLF line endings.
+
+ * The fsmonitor interface got out of sync after the in-core index
+   file gets discarded, which has been corrected.
+   (merge 398a3b0899 js/fsmonitor-refresh-after-discarding-index later to maint).
+
+ * "git status" did not know that the "label" instruction in the
+   todo-list "rebase -i -r" uses should not be shown as a hex object
+   name.
+
+ * A prerequisite check in the test suite to see if a working jgit is
+   available was made more robust.
+   (merge abd0f28983 tz/test-lib-check-working-jgit later to maint).
+
+ * The codepath to parse :<path> that obtains the object name for an
+   indexed object has been made more robust.
+
+ * Code cleanup, docfix, build fix, etc.
+   (merge 11f470aee7 jc/test-yes-doc later to maint).
+   (merge 90503a240b js/doc-symref-in-proto-v1 later to maint).
+   (merge 5c326d1252 jk/unused-params later to maint).
+   (merge 68cabbfda3 dl/doc-submodule-wo-subcommand later to maint).
+   (merge 9903623761 ab/receive-pack-use-after-free-fix later to maint).
+   (merge 1ede45e44b en/merge-options-doc later to maint).
+   (merge 3e14dd2c8e rd/doc-hook-used-in-sample later to maint).
+   (merge c271dc28fd nd/no-more-check-racy later to maint).
+   (merge e6e15194a8 yb/utf-16le-bom-spellfix later to maint).
+   (merge bb101aaf0c rd/attr.c-comment-typofix later to maint).
+   (merge 716a5af812 rd/gc-prune-doc-fix later to maint).
+   (merge 50b206371d js/untravis-windows later to maint).
+   (merge dbf47215e3 js/rebase-recreate-merge later to maint).
+   (merge 56cb2d30f8 dl/reset-doc-no-wrt-abbrev later to maint).
+   (merge 64eca306a2 ja/dir-rename-doc-markup-fix later to maint).
+   (merge af91b0230c dl/ignore-docs later to maint).
+   (merge 59a06e947b ra/t3600-test-path-funcs later to maint).
+   (merge e041d0781b ar/t4150-remove-cruft later to maint).
+   (merge 8d75a1d183 ma/asciidoctor-fixes-more later to maint).
+   (merge 74cc547b0f mh/pack-protocol-doc-fix later to maint).
+   (merge ed31851fa6 ab/doc-misc-typofixes later to maint).
+   (merge a7256debd4 nd/checkout-m-doc-update later to maint).
+   (merge 3a9e1ad78d jt/t5551-protocol-v2-does-not-have-half-auth later to maint).
+   (merge 0b918b75af sg/t5318-cleanup later to maint).
+   (merge 68ed71b53c cb/doco-mono later to maint).
+   (merge a34dca2451 nd/interpret-trailers-docfix later to maint).
+   (merge cf7b857a77 en/fast-import-parsing-fix later to maint).
+   (merge fe61ccbc35 po/rerere-doc-fmt later to maint).
+   (merge ffea0248bf po/describe-not-necessarily-7 later to maint).
+   (merge 7cb7283adb tg/ls-files-debug-format-fix later to maint).
+   (merge f64a21bd82 tz/doc-apostrophe-no-longer-needed later to maint).
+   (merge dbe7b41019 js/t3301-unbreak-notes-test later to maint).
+   (merge d8083e4180 km/t3000-retitle later to maint).
+   (merge 9e4cbccbd7 tz/git-svn-doc-markup-fix later to maint).
+   (merge da9ca955a7 jk/ls-files-doc-markup-fix later to maint).
+   (merge 6804ba3a58 cw/diff-highlight later to maint).
+   (merge 1a8787144d nd/submodule-helper-incomplete-line-fix later to maint).
+   (merge d9ef573837 jk/apache-lsan later to maint).
+   (merge c871fbee2b js/t6500-use-windows-pid-on-mingw later to maint).
+   (merge ce4c7bfc90 bl/t4253-exit-code-from-format-patch later to maint).
+   (merge 397a46db78 js/t5580-unc-alternate-test later to maint).
+   (merge d4907720a2 cm/notes-comment-fix later to maint).
+   (merge 9dde06de13 cb/http-push-null-in-message-fix later to maint).
+   (merge 4c785c0edc js/rebase-config-bitfix later to maint).
+   (merge 8e9fe16c87 es/doc-gitsubmodules-markup later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.22.1.txt b/third_party/git/Documentation/RelNotes/2.22.1.txt
new file mode 100644
index 0000000000..432762f270
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.22.1.txt
@@ -0,0 +1,150 @@
+Git 2.22.1 Release Notes
+========================
+
+Fixes since v2.22
+-----------------
+
+ * A relative pathname given to "git init --template=<path> <repo>"
+   ought to be relative to the directory "git init" gets invoked in,
+   but it instead was made relative to the repository, which has been
+   corrected.
+
+ * "git worktree add" used to fail when another worktree connected to
+   the same repository was corrupt, which has been corrected.
+
+ * The ownership rule for the file descriptor to fast-import remote
+   backend was mixed up, leading to unrelated file descriptor getting
+   closed, which has been fixed.
+
+ * "git update-server-info" used to leave stale packfiles in its
+   output, which has been corrected.
+
+ * The server side support for "git fetch" used to show incorrect
+   value for the HEAD symbolic ref when the namespace feature is in
+   use, which has been corrected.
+
+ * "git am -i --resolved" segfaulted after trying to see a commit as
+   if it were a tree, which has been corrected.
+
+ * "git bundle verify" needs to see if prerequisite objects exist in
+   the receiving repository, but the command did not check if we are
+   in a repository upfront, which has been corrected.
+
+ * "git merge --squash" is designed to update the working tree and the
+   index without creating the commit, and this cannot be countermanded
+   by adding the "--commit" option; the command now refuses to work
+   when both options are given.
+
+ * The data collected by fsmonitor was not properly written back to
+   the on-disk index file, breaking t7519 tests occasionally, which
+   has been corrected.
+
+ * Update to Unicode 12.1 width table.
+
+ * The command line to invoke a "git cat-file" command from inside
+   "git p4" was not properly quoted to protect a caret and running a
+   broken command on Windows, which has been corrected.
+
+ * "git request-pull" learned to warn when the ref we ask them to pull
+   from in the local repository and in the published repository are
+   different.
+
+ * When creating a partial clone, the object filtering criteria is
+   recorded for the origin of the clone, but this incorrectly used a
+   hardcoded name "origin" to name that remote; it has been corrected
+   to honor the "--origin <name>" option.
+
+ * "git fetch" into a lazy clone forgot to fetch base objects that are
+   necessary to complete delta in a thin packfile, which has been
+   corrected.
+
+ * The filter_data used in the list-objects-filter (which manages a
+   lazily sparse clone repository) did not use the dynamic array API
+   correctly---'nr' is supposed to point at one past the last element
+   of the array in use.  This has been corrected.
+
+ * The description about slashes in gitignore patterns (used to
+   indicate things like "anchored to this level only" and "only
+   matches directories") has been revamped.
+
+ * The URL decoding code has been updated to avoid going past the end
+   of the string while parsing %-<hex>-<hex> sequence.
+
+ * The list of for-each like macros used by clang-format has been
+   updated.
+
+ * "git push --atomic" that goes over the transport-helper (namely,
+   the smart http transport) failed to prevent refs to be pushed when
+   it can locally tell that one of the ref update will fail without
+   having to consult the other end, which has been corrected.
+
+ * "git clean" silently skipped a path when it cannot lstat() it; now
+   it gives a warning.
+
+ * A codepath that reads from GPG for signed object verification read
+   past the end of allocated buffer, which has been fixed.
+
+ * "git rm" to resolve a conflicted path leaked an internal message
+   "needs merge" before actually removing the path, which was
+   confusing.  This has been corrected.
+
+ * The "git clone" documentation refers to command line options in its
+   description in the short form; they have been replaced with long
+   forms to make them more recognisable.
+
+ * The configuration variable rebase.rescheduleFailedExec should be
+   effective only while running an interactive rebase and should not
+   affect anything when running a non-interactive one, which was not
+   the case.  This has been corrected.
+
+ * "git submodule foreach" did not protect command line options passed
+   to the command to be run in each submodule correctly, when the
+   "--recursive" option was in use.
+
+ * Use "Erase in Line" CSI sequence that is already used in the editor
+   support to clear cruft in the progress output.
+
+ * The codepath to compute delta islands used to spew progress output
+   without giving the callers any way to squelch it, which has been
+   fixed.
+
+ * The code to parse scaled numbers out of configuration files has
+   been made more robust and also easier to follow.
+
+ * An incorrect list of options was cached after command line
+   completion failed (e.g. trying to complete a command that requires
+   a repository outside one), which has been corrected.
+
+ * "git rebase --abort" used to leave refs/rewritten/ when concluding
+   "git rebase -r", which has been corrected.
+
+ * "git stash show 23" used to work, but no more after getting
+   rewritten in C; this regression has been corrected.
+
+ * "git interpret-trailers" always treated '#' as the comment
+   character, regardless of core.commentChar setting, which has been
+   corrected.
+
+ * Code clean-up to avoid signed integer overlaps during binary search.
+
+ * "git checkout -p" needs to selectively apply a patch in reverse,
+   which did not work well.
+
+ * The commit-graph file is now part of the "files that the runtime
+   may keep open file descriptors on, all of which would need to be
+   closed when done with the object store", and the file descriptor to
+   an existing commit-graph file now is closed before "gc" finalizes a
+   new instance to replace it.
+
+ * Code restructuring during 2.20 period broke fetching tags via
+   "import" based transports.
+
+ * We have been trying out a few language features outside c89; the
+   coding guidelines document did not talk about them and instead had
+   a blanket ban against them.
+
+ * The internal diff machinery can be made to read out of bounds while
+   looking for --funcion-context line in a corner case, which has been
+   corrected.
+
+Also contains various documentation updates, code clean-ups and minor fixups.
diff --git a/third_party/git/Documentation/RelNotes/2.23.0.txt b/third_party/git/Documentation/RelNotes/2.23.0.txt
new file mode 100644
index 0000000000..e3c4e78265
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.23.0.txt
@@ -0,0 +1,348 @@
+Git 2.23 Release Notes
+======================
+
+Updates since v2.22
+-------------------
+
+Backward compatibility note
+
+ * The "--base" option of "format-patch" computed the patch-ids for
+   prerequisite patches in an unstable way, which has been updated to
+   compute in a way that is compatible with "git patch-id --stable".
+
+ * The "git log" command by default behaves as if the --mailmap option
+   was given.
+
+
+UI, Workflows & Features
+
+ * The "git fast-export/import" pair has been taught to handle commits
+   with log messages in encoding other than UTF-8 better.
+
+ * In recent versions of Git, per-worktree refs are exposed in
+   refs/worktrees/<wtname>/ hierarchy, which means that worktree names
+   must be a valid refname component.  The code now sanitizes the names
+   given to worktrees, to make sure these refs are well-formed.
+
+ * "git merge" learned "--quit" option that cleans up the in-progress
+   merge while leaving the working tree and the index still in a mess.
+
+ * "git format-patch" learns a configuration to set the default for
+   its --notes=<ref> option.
+
+ * The code to show args with potential typo that cannot be
+   interpreted as a commit-ish has been improved.
+
+ * "git clone --recurse-submodules" learned to set up the submodules
+   to ignore commit object names recorded in the superproject gitlink
+   and instead use the commits that happen to be at the tip of the
+   remote-tracking branches from the get-go, by passing the new
+   "--remote-submodules" option.
+
+ * The pattern "git diff/grep" use to extract funcname and words
+   boundary for Matlab has been extend to cover Octave, which is more
+   or less equivalent.
+
+ * "git help git" was hard to discover (well, at least for some
+   people).
+
+ * The pattern "git diff/grep" use to extract funcname and words
+   boundary for Rust has been added.
+
+ * "git status" can be told a non-standard default value for the
+   "--[no-]ahead-behind" option with a new configuration variable
+   status.aheadBehind.
+
+ * "git fetch" and "git pull" reports when a fetch results in
+   non-fast-forward updates to let the user notice unusual situation.
+   The commands learned "--no-show-forced-updates" option to disable
+   this safety feature.
+
+ * Two new commands "git switch" and "git restore" are introduced to
+   split "checking out a branch to work on advancing its history" and
+   "checking out paths out of the index and/or a tree-ish to work on
+   advancing the current history" out of the single "git checkout"
+   command.
+
+ * "git branch --list" learned to always output the detached HEAD as
+   the first item (when the HEAD is detached, of course), regardless
+   of the locale.
+
+ * The conditional inclusion mechanism learned to base the choice on
+   the branch the HEAD currently is on.
+
+ * "git rev-list --objects" learned the "--no-object-names" option to
+   squelch the path to the object that is used as a grouping hint for
+   pack-objects.
+
+ * A new tag.gpgSign configuration variable turns "git tag -a" into
+   "git tag -s".
+
+ * "git multi-pack-index" learned expire and repack subcommands.
+
+ * "git blame" learned to "ignore" commits in the history, whose
+   effects (as well as their presence) get ignored.
+
+ * "git cherry-pick/revert" learned a new "--skip" action.
+
+ * The tips of refs from the alternate object store can be used as
+   starting point for reachability computation now.
+
+ * Extra blank lines in "git status" output have been reduced.
+
+ * The commits in a repository can be described by multiple
+   commit-graph files now, which allows the commit-graph files to be
+   updated incrementally.
+
+ * "git range-diff" output has been tweaked for easier identification
+   of which part of what file the patch shown is about.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Update supporting parts of "git rebase" to remove code that should
+   no longer be used.
+
+ * Developer support to emulate unsatisfied prerequisites in tests to
+   ensure that the remainder of the tests still succeeds when tests
+   with prerequisites are skipped.
+
+ * "git update-server-info" learned not to rewrite the file with the
+   same contents.
+
+ * The way of specifying the path to find dynamic libraries at runtime
+   has been simplified.  The old default to pass -R/path/to/dir has been
+   replaced with the new default to pass -Wl,-rpath,/path/to/dir,
+   which is the more recent GCC uses.  Those who need to build with an
+   old GCC can still use "CC_LD_DYNPATH=-R"
+
+ * Prepare use of reachability index in topological walker that works
+   on a range (A..B).
+
+ * A new tutorial targeting specifically aspiring git-core
+   developers has been added.
+
+ * Auto-detect how to tell HP-UX aCC where to use dynamically linked
+   libraries from at runtime.
+
+ * "git mergetool" and its tests now spawn fewer subprocesses.
+
+ * Dev support update to help tracing out tests.
+
+ * Support to build with MSVC has been updated.
+
+ * "git fetch" that grabs from a group of remotes learned to run the
+   auto-gc only once at the very end.
+
+ * A handful of Windows build patches have been upstreamed.
+
+ * The code to read state files used by the sequencer machinery for
+   "git status" has been made more robust against a corrupt or stale
+   state files.
+
+ * "git for-each-ref" with multiple patterns have been optimized.
+
+ * The tree-walk API learned to pass an in-core repository
+   instance throughout more codepaths.
+
+ * When one step in multi step cherry-pick or revert is reset or
+   committed, the command line prompt script failed to notice the
+   current status, which has been improved.
+
+ * Many GIT_TEST_* environment variables control various aspects of
+   how our tests are run, but a few followed "non-empty is true, empty
+   or unset is false" while others followed the usual "there are a few
+   ways to spell true, like yes, on, etc., and also ways to spell
+   false, like no, off, etc." convention.
+
+ * Adjust the dir-iterator API and apply it to the local clone
+   optimization codepath.
+
+ * We have been trying out a few language features outside c89; the
+   coding guidelines document did not talk about them and instead had
+   a blanket ban against them.
+
+ * A test helper has been introduced to optimize preparation of test
+   repositories with many simple commits, and a handful of test
+   scripts have been updated to use it.
+
+
+Fixes since v2.22
+-----------------
+
+ * A relative pathname given to "git init --template=<path> <repo>"
+   ought to be relative to the directory "git init" gets invoked in,
+   but it instead was made relative to the repository, which has been
+   corrected.
+
+ * "git worktree add" used to fail when another worktree connected to
+   the same repository was corrupt, which has been corrected.
+
+ * The ownership rule for the file descriptor to fast-import remote
+   backend was mixed up, leading to an unrelated file descriptor getting
+   closed, which has been fixed.
+
+ * A "merge -c" instruction during "git rebase --rebase-merges" should
+   give the user a chance to edit the log message, even when there is
+   otherwise no need to create a new merge and replace the existing
+   one (i.e. fast-forward instead), but did not.  Which has been
+   corrected.
+
+ * Code cleanup and futureproof.
+
+ * More parameter validation.
+
+ * "git update-server-info" used to leave stale packfiles in its
+   output, which has been corrected.
+
+ * The server side support for "git fetch" used to show incorrect
+   value for the HEAD symbolic ref when the namespace feature is in
+   use, which has been corrected.
+
+ * "git am -i --resolved" segfaulted after trying to see a commit as
+   if it were a tree, which has been corrected.
+
+ * "git bundle verify" needs to see if prerequisite objects exist in
+   the receiving repository, but the command did not check if we are
+   in a repository upfront, which has been corrected.
+
+ * "git merge --squash" is designed to update the working tree and the
+   index without creating the commit, and this cannot be countermanded
+   by adding the "--commit" option; the command now refuses to work
+   when both options are given.
+
+ * The data collected by fsmonitor was not properly written back to
+   the on-disk index file, breaking t7519 tests occasionally, which
+   has been corrected.
+
+ * Update to Unicode 12.1 width table.
+
+ * The command line to invoke a "git cat-file" command from inside
+   "git p4" was not properly quoted to protect a caret and running a
+   broken command on Windows, which has been corrected.
+
+ * "git request-pull" learned to warn when the ref we ask them to pull
+   from in the local repository and in the published repository are
+   different.
+
+ * When creating a partial clone, the object filtering criteria is
+   recorded for the origin of the clone, but this incorrectly used a
+   hardcoded name "origin" to name that remote; it has been corrected
+   to honor the "--origin <name>" option.
+
+ * "git fetch" into a lazy clone forgot to fetch base objects that are
+   necessary to complete delta in a thin packfile, which has been
+   corrected.
+
+ * The filter_data used in the list-objects-filter (which manages a
+   lazily sparse clone repository) did not use the dynamic array API
+   correctly---'nr' is supposed to point at one past the last element
+   of the array in use.  This has been corrected.
+
+ * The description about slashes in gitignore patterns (used to
+   indicate things like "anchored to this level only" and "only
+   matches directories") has been revamped.
+
+ * The URL decoding code has been updated to avoid going past the end
+   of the string while parsing %-<hex>-<hex> sequence.
+
+ * The list of for-each like macros used by clang-format has been
+   updated.
+
+ * "git branch --list" learned to show branches that are checked out
+   in other worktrees connected to the same repository prefixed with
+   '+', similar to the way the currently checked out branch is shown
+   with '*' in front.
+   (merge 6e9381469e nb/branch-show-other-worktrees-head later to maint).
+
+ * Code restructuring during 2.20 period broke fetching tags via
+   "import" based transports.
+
+ * The commit-graph file is now part of the "files that the runtime
+   may keep open file descriptors on, all of which would need to be
+   closed when done with the object store", and the file descriptor to
+   an existing commit-graph file now is closed before "gc" finalizes a
+   new instance to replace it.
+
+ * "git checkout -p" needs to selectively apply a patch in reverse,
+   which did not work well.
+
+ * Code clean-up to avoid signed integer wraparounds during binary search.
+
+ * "git interpret-trailers" always treated '#' as the comment
+   character, regardless of core.commentChar setting, which has been
+   corrected.
+
+ * "git stash show 23" used to work, but no more after getting
+   rewritten in C; this regression has been corrected.
+
+ * "git rebase --abort" used to leave refs/rewritten/ when concluding
+   "git rebase -r", which has been corrected.
+
+ * An incorrect list of options was cached after command line
+   completion failed (e.g. trying to complete a command that requires
+   a repository outside one), which has been corrected.
+
+ * The code to parse scaled numbers out of configuration files has
+   been made more robust and also easier to follow.
+
+ * The codepath to compute delta islands used to spew progress output
+   without giving the callers any way to squelch it, which has been
+   fixed.
+
+ * Protocol capabilities that go over wire should never be translated,
+   but it was incorrectly marked for translation, which has been
+   corrected.  The output of protocol capabilities for debugging has
+   been tweaked a bit.
+
+ * Use "Erase in Line" CSI sequence that is already used in the editor
+   support to clear cruft in the progress output.
+
+ * "git submodule foreach" did not protect command line options passed
+   to the command to be run in each submodule correctly, when the
+   "--recursive" option was in use.
+
+ * The configuration variable rebase.rescheduleFailedExec should be
+   effective only while running an interactive rebase and should not
+   affect anything when running a non-interactive one, which was not
+   the case.  This has been corrected.
+
+ * The "git clone" documentation refers to command line options in its
+   description in the short form; they have been replaced with long
+   forms to make them more recognisable.
+
+ * Generation of pack bitmaps are now disabled when .keep files exist,
+   as these are mutually exclusive features.
+   (merge 7328482253 ew/repack-with-bitmaps-by-default later to maint).
+
+ * "git rm" to resolve a conflicted path leaked an internal message
+   "needs merge" before actually removing the path, which was
+   confusing.  This has been corrected.
+
+ * "git stash --keep-index" did not work correctly on paths that have
+   been removed, which has been fixed.
+   (merge b932f6a5e8 tg/stash-keep-index-with-removed-paths later to maint).
+
+ * Window 7 update ;-)
+
+ * A codepath that reads from GPG for signed object verification read
+   past the end of allocated buffer, which has been fixed.
+
+ * "git clean" silently skipped a path when it cannot lstat() it; now
+   it gives a warning.
+
+ * "git push --atomic" that goes over the transport-helper (namely,
+   the smart http transport) failed to prevent refs to be pushed when
+   it can locally tell that one of the ref update will fail without
+   having to consult the other end, which has been corrected.
+
+ * The internal diff machinery can be made to read out of bounds while
+   looking for --function-context line in a corner case, which has been
+   corrected.
+   (merge b777f3fd61 jk/xdiff-clamp-funcname-context-index later to maint).
+
+ * Other code cleanup, docfix, build fix, etc.
+   (merge fbec05c210 cc/test-oidmap later to maint).
+   (merge 7a06fb038c jk/no-system-includes-in-dot-c later to maint).
+   (merge 81ed2b405c cb/xdiff-no-system-includes-in-dot-c later to maint).
+   (merge d61e6ce1dd sg/fsck-config-in-doc later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.3.0.txt b/third_party/git/Documentation/RelNotes/2.3.0.txt
new file mode 100644
index 0000000000..e3c639c840
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.0.txt
@@ -0,0 +1,300 @@
+Git v2.3 Release Notes
+======================
+
+This one ended up to be a release with lots of small corrections and
+improvements without big uncomfortably exciting features.  The recent
+security fix that went to 2.2.1 and older maintenance tracks is also
+contained in this update.
+
+
+Updates since v2.2
+------------------
+
+Ports
+
+ * Recent gcc toolchain on Cygwin started throwing compilation warning,
+   which has been squelched.
+
+ * A few updates to build on platforms that lack tv_nsec,
+   clock_gettime, CLOCK_MONOTONIC and HMAC_CTX_cleanup (e.g. older
+   RHEL) have been added.
+
+
+UI, Workflows & Features
+
+ * It was cumbersome to use "GIT_SSH" mechanism when the user wanted
+   to pass an extra set of arguments to the underlying ssh.  A new
+   environment variable GIT_SSH_COMMAND can be used for this.
+
+ * A request to store an empty note via "git notes" meant to remove
+   note from the object but with --allow-empty we will store a
+   (surprise!)  note that is empty.
+
+ * "git interpret-trailers" learned to properly handle the
+   "Conflicts:" block at the end.
+
+ * "git am" learned "--message-id" option to copy the message ID of
+   the incoming e-mail to the log message of resulting commit.
+
+ * "git clone --reference=<over there>" learned the "--dissociate"
+   option to go with it; it borrows objects from the reference object
+   store while cloning only to reduce network traffic and then
+   dissociates the resulting clone from the reference by performing
+   local copies of borrowed objects.
+
+ * "git send-email" learned "--transfer-encoding" option to force a
+   non-fault Content-Transfer-Encoding header (e.g. base64).
+
+ * "git send-email" normally identifies itself via X-Mailer: header in
+   the message it sends out.  A new command line flag --no-xmailer
+   allows the user to squelch the header.
+
+ * "git push" into a repository with a working tree normally refuses
+   to modify the branch that is checked out.  The command learned to
+   optionally do an equivalent of "git reset --hard" only when there
+   is no change to the working tree and the index instead, which would
+   be useful to "deploy" by pushing into a repository.
+
+ * "git new-workdir" (in contrib/) can be used to populate an empty
+   and existing directory now.
+
+ * Credential helpers are asked in turn until one of them give
+   positive response, which is cumbersome to turn off when you need to
+   run Git in an automated setting.  The credential helper interface
+   learned to allow a helper to say "stop, don't ask other helpers."
+   Also GIT_TERMINAL_PROMPT environment can be set to false to disable
+   our built-in prompt mechanism for passwords.
+
+ * "git branch -d" (delete) and "git branch -m" (move) learned to
+   honor "-f" (force) flag; unlike many other subcommands, the way to
+   force these have been with separate "-D/-M" options, which was
+   inconsistent.
+
+ * "diff-highlight" filter (in contrib/) allows its color output to be
+   customized via configuration variables.
+
+ * "git imap-send" learned to take "-v" (verbose) and "-q" (quiet)
+   command line options.
+
+ * "git remote add $name $URL" is now allowed when "url.$URL.insteadOf"
+   is already defined.
+
+ * "git imap-send" now can be built to use cURL library to talk to
+   IMAP servers (if the library is recent enough, of course).
+   This allows you to use authenticate method other than CRAM-MD5,
+   among other things.
+
+ * "git imap-send" now allows GIT_CURL_VERBOSE environment variable to
+   control the verbosity when talking via the cURL library.
+
+ * The prompt script (in contrib/) learned to optionally hide prompt
+   when in an ignored directory by setting GIT_PS1_HIDE_IF_PWD_IGNORED
+   shell variable.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Earlier we made "rev-list --object-edge" more aggressively list the
+   objects at the edge commits, in order to reduce number of objects　
+   fetched into a shallow repository, but the change affected cases
+   other than "fetching into a shallow repository" and made it
+   unusably slow (e.g. fetching into a normal repository should not
+   have to suffer the overhead from extra processing).  Limit it to a
+   more specific case by introducing --objects-edge-aggressive, a new
+   option to rev-list.
+
+ * Squelched useless compiler warnings on Mac OS X regarding the
+   crypto API.
+
+ * The procedure to generate unicode table has been simplified.
+
+ * Some filesystems assign filemodes in a strange way, fooling then
+   automatic "filemode trustability" check done during a new
+   repository creation.  The initialization codepath has been hardened
+   against this issue.
+
+ * The codepath in "git remote update --prune" to drop many refs has
+   been optimized.
+
+ * The API into get_merge_bases*() family of functions was easy to
+   misuse, which has been corrected to make it harder to do so.
+
+ * Long overdue departure from the assumption that S_IFMT is shared by
+   everybody made in 2005, which was necessary to port to z/OS.
+
+ * "git push" and "git fetch" did not communicate an overlong refname
+   correctly.  Now it uses 64kB sideband to accommodate longer ones.
+
+ * Recent GPG changes the keyring format and drops support for RFC1991
+   formatted signatures, breaking our existing tests.
+
+ * "git-prompt" (in contrib/) used a variable from the global scope,
+   possibly contaminating end-user's namespace.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.2
+----------------
+
+Unless otherwise noted, all the fixes since v2.2 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git http-push" over WebDAV (aka dumb http-push) was broken in
+   v2.2.2 when parsing a symbolic ref, resulting in a bogus request
+   that gets rejected by recent versions of cURL library.
+   (merge f6786c8 jk/http-push-symref-fix later to maint).
+
+ * The logic in "git bisect bad HEAD" etc. to avoid forcing the test
+   of the common ancestor of bad and good commits was broken.
+   (merge 07913d5 cc/bisect-rev-parsing later to maint).
+
+ * "git checkout-index --temp=$target $path" did not work correctly
+   for paths outside the current subdirectory in the project.
+   (merge 74c4de5 es/checkout-index-temp later to maint).
+
+ * The report from "git checkout" on a branch that builds on another
+   local branch by setting its branch.*.merge to branch name (not a
+   full refname) incorrectly said that the upstream is gone.
+   (merge 05e7368 jc/checkout-local-track-report later to maint).
+
+ * With The git-prompt support (in contrib/), using the exit status of
+   the last command in the prompt, e.g.  PS1='$(__git_ps1) $? ', did
+   not work well, because the helper function stomped on the exit
+   status.
+   (merge 6babe76 tf/prompt-preserve-exit-status later to maint).
+
+ * Recent update to "git commit" broke amending an existing commit
+   with bogus author/committer lines without a valid e-mail address.
+   (merge c83a509 jk/commit-date-approxidate later to maint).
+
+ * The lockfile API used to get confused which file to clean up when
+   the process moved the $cwd after creating a lockfile.
+   (merge fa137f6 nd/lockfile-absolute later to maint).
+
+ * Traditionally we tried to avoid interpreting date strings given by
+   the user as future dates, e.g. GIT_COMMITTER_DATE=2014-12-10 when
+   used early November 2014 was taken as "October 12, 2014" because it
+   is likely that a date in the future, December 10, is a mistake.
+   This heuristics has been loosened to allow people to express future
+   dates (most notably, --until=<date> may want to be far in the
+   future) and we no longer tiebreak by future-ness of the date when
+
+    (1) ISO-like format is used, and
+    (2) the string can make sense interpreted as both y-m-d and y-d-m.
+
+   Git may still have to use the heuristics to tiebreak between dd/mm/yy
+   and mm/dd/yy, though.
+   (merge d372395 jk/approxidate-avoid-y-d-m-over-future-dates later to maint).
+
+ * Git did not correctly read an overlong refname from a packed refs
+   file.
+   (merge ea41783 jk/read-packed-refs-without-path-max later to maint).
+
+ * "git apply" was described in the documentation to take --ignore-date
+   option, which it does not.
+   (merge 0cef4e7 rw/apply-does-not-take-ignore-date later to maint).
+
+ * "git add -i" did not notice when the interactive command input
+   stream went away and kept asking the same question.
+   (merge a8bec7a jk/add-i-read-error later to maint).
+
+ * "git send-email" did not handle RFC 2047 encoded headers quite
+   right.
+   (merge ab47e2a rd/send-email-2047-fix later to maint).
+
+ * New tag object format validation added in 2.2 showed garbage after
+   a tagname it reported in its error message.
+   (merge a1e920a js/fsck-tag-validation later to maint).
+
+ * The code that reads the reflog from the newer to the older entries
+   did not handle an entry that crosses a boundary of block it uses to
+   read them correctly.
+   (merge 69216bf jk/for-each-reflog-ent-reverse later to maint).
+
+ * "git diff -B -M" after making a new copy B out of an existing file
+   A and then editing A extensively ought to report that B was created
+   by copying A and A was modified, which is what "git diff -C"
+   reports, but it instead said A was renamed to B and A was edited
+   heavily in place.  This was not just incoherent but also failed to
+   apply with "git apply".  The report has been corrected to match what
+   "git diff -C" produces for this case.
+   (merge 6936b58 jc/diff-b-m later to maint).
+
+ * In files we pre-populate for the user to edit with commented hints,
+   a line of hint that is indented with a tab used to show as '#' (or
+   any comment char), ' ' (space), and then the hint text that began
+   with the tab, which some editors flag as an indentation error (tab
+   following space).  We now omit the space after the comment char in
+   such a case.
+   (merge d55aeb7 jc/strbuf-add-lines-avoid-sp-ht-sequence later to maint).
+
+ * "git ls-tree" does not support path selection based on negative
+   pathspecs, but did not error out when negative pathspecs are given.
+   (merge f1f6224 nd/ls-tree-pathspec later to maint).
+
+ * The function sometimes returned a non-freeable memory and some
+   other times returned a piece of memory that must be freed, leading
+   to inevitable leaks.
+   (merge 59362e5 jc/exec-cmd-system-path-leak-fix later to maint).
+
+ * The code to abbreviate an object name to its short unique prefix
+   has been optimized when no abbreviation was requested.
+   (merge 61e704e mh/find-uniq-abbrev later to maint).
+
+ * "git add --ignore-errors ..." did not ignore an error to
+   give a file that did not exist.
+   (merge 1d31e5a mg/add-ignore-errors later to maint).
+
+ * "git checkout $treeish $path", when $path in the index and the
+   working tree already matched what is in $treeish at the $path,
+   still overwrote the $path unnecessarily.
+   (merge c5326bd jk/checkout-from-tree later to maint).
+
+ * "git config --get-color" did not parse its command line arguments
+   carefully.
+   (merge cb35722 jk/colors-fix later to maint).
+
+ * open() emulated on Windows platforms did not give EISDIR upon
+   an attempt to open a directory for writing.
+   (merge ba6fad0 js/windows-open-eisdir-error later to maint).
+
+ * A few code paths used abs() when they should have used labs() on
+   long integers.
+   (merge 83915ba rs/maint-config-use-labs later to maint).
+   (merge 31a8aa1 rs/receive-pack-use-labs later to maint).
+
+ * "gitweb" used to depend on a behaviour recent CGI.pm deprecated.
+   (merge 13dbf46 jk/gitweb-with-newer-cgi-multi-param later to maint).
+
+ * "git init" (hence "git clone") initialized the per-repository
+   configuration file .git/config with x-bit by mistake.
+   (merge 1f32ecf mh/config-flip-xbit-back-after-checking later to maint).
+
+ * Recent update in Git 2.2 started creating objects/info/packs and
+   info/refs files with permission bits tighter than user's umask.
+   (merge d91175b jk/prune-packed-server-info later to maint).
+
+ * Git 2.0 was supposed to make the "simple" mode for the default of
+   "git push", but it didn't.
+   (merge 00a6fa0 jk/push-simple later to maint).
+
+ * "Everyday" document had a broken link.
+   (merge 366c8d4 po/everyday-doc later to maint).
+
+ * A few test fixes.
+   (merge 880ef58 jk/no-perl-tests later to maint).
+
+ * The build procedure did not bother fixing perl and python scripts
+   when NO_PERL and NO_PYTHON build-time configuration changed.
+   (merge ca2051d jk/rebuild-perl-scripts-with-no-perl-seting-change later to maint).
+
+ * The usage string of "git log" command was marked incorrectly for
+   l10n.
+   (merge e66dc0c km/log-usage-string-i18n later to maint).
+
+ * "git for-each-ref" mishandled --format="%(upstream:track)" when a
+   branch is marked to have forked from a non-existing branch.
+   (merge b6160d9 rc/for-each-ref-tracking later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.3.1.txt b/third_party/git/Documentation/RelNotes/2.3.1.txt
new file mode 100644
index 0000000000..cf96186288
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.1.txt
@@ -0,0 +1,52 @@
+Git v2.3.1 Release Notes
+========================
+
+Fixes since v2.3
+----------------
+
+ * The interactive "show a list and let the user choose from it"
+   interface "add -i" used showed and prompted to the user even when
+   the candidate list was empty, against which the only "choice" the
+   user could have made was to choose nothing.
+
+ * "git apply --whitespace=fix" used to under-allocate the memory
+   when the fix resulted in a longer text than the original patch.
+
+ * "git log --help" used to show rev-list options that are irrelevant
+   to the "log" command.
+
+ * The error message from "git commit", when a non-existing author
+   name was given as value to the "--author=" parameter, has been
+   reworded to avoid misunderstanding.
+
+ * A broken pack .idx file in the receiving repository prevented the
+   dumb http transport from fetching a good copy of it from the other
+   side.
+
+ * The documentation incorrectly said that C(opy) and R(ename) are the
+   only ones that can be followed by the score number in the output in
+   the --raw format.
+
+ * Fix a misspelled conditional that is always true.
+
+ * Code to read branch name from various files in .git/ directory
+   would have misbehaved if the code to write them left an empty file.
+
+ * The "git push" documentation made the "--repo=<there>" option
+   easily misunderstood.
+
+ * After attempting and failing a password-less authentication
+   (e.g. kerberos), libcURL refuses to fall back to password based
+   Basic authentication without a bit of help/encouragement.
+
+ * Setting diff.submodule to 'log' made "git format-patch" produce
+   broken patches.
+
+ * "git rerere" (invoked internally from many mergy operations) did
+   not correctly signal errors when told to update the working tree
+   files and failed to do so for whatever reason.
+
+ * "git blame HEAD -- missing" failed to correctly say "HEAD" when it
+   tried to say "No such path 'missing' in HEAD".
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.10.txt b/third_party/git/Documentation/RelNotes/2.3.10.txt
new file mode 100644
index 0000000000..20c2d2cacc
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.10.txt
@@ -0,0 +1,18 @@
+Git v2.3.10 Release Notes
+=========================
+
+Fixes since v2.3.9
+------------------
+
+ * xdiff code we use to generate diffs is not prepared to handle
+   extremely large files.  It uses "int" in many places, which can
+   overflow if we have a very large number of lines or even bytes in
+   our input files, for example.  Cap the input size to somewhere
+   around 1GB for now.
+
+ * Some protocols (like git-remote-ext) can execute arbitrary code
+   found in the URL.  The URLs that submodules use may come from
+   arbitrary sources (e.g., .gitmodules files in a remote
+   repository), and can hurt those who blindly enable recursive
+   fetch.  Restrict the allowed protocols to well known and safe
+   ones.
diff --git a/third_party/git/Documentation/RelNotes/2.3.2.txt b/third_party/git/Documentation/RelNotes/2.3.2.txt
new file mode 100644
index 0000000000..93462e45c2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.2.txt
@@ -0,0 +1,79 @@
+Git v2.3.2 Release Notes
+========================
+
+Fixes since v2.3.1
+------------------
+
+ * "update-index --refresh" used to leak when an entry cannot be
+   refreshed for whatever reason.
+
+ * "git fast-import" used to crash when it could not close and
+   conclude the resulting packfile cleanly.
+
+ * "git blame" died, trying to free an uninitialized piece of memory.
+
+ * "git merge-file" did not work correctly in a subdirectory.
+
+ * "git submodule add" failed to squash "path/to/././submodule" to
+   "path/to/submodule".
+
+ * In v2.2.0, we broke "git prune" that runs in a repository that
+   borrows from an alternate object store.
+
+ * Certain older vintages of cURL give irregular output from
+   "curl-config --vernum", which confused our build system.
+
+ * An earlier workaround to squelch unhelpful deprecation warnings
+   from the compiler on Mac OSX unnecessarily set minimum required
+   version of the OS, which the user might want to raise (or lower)
+   for other reasons.
+
+ * Longstanding configuration variable naming rules has been added to
+   the documentation.
+
+ * The credential helper for Windows (in contrib/) used to mishandle
+   a user name with an at-sign in it.
+
+ * Older GnuPG implementations may not correctly import the keyring
+   material we prepare for the tests to use.
+
+ * Clarify in the documentation that "remote.<nick>.pushURL" and
+   "remote.<nick>.URL" are there to name the same repository accessed
+   via different transports, not two separate repositories.
+
+ * The pack bitmap support did not build with older versions of GCC.
+
+ * Reading configuration from a blob object, when it ends with a lone
+   CR, use to confuse the configuration parser.
+
+ * We didn't format an integer that wouldn't fit in "int" but in
+   "uintmax_t" correctly.
+
+ * "git push --signed" gave an incorrectly worded error message when
+   the other side did not support the capability.
+
+ * "git fetch" over a remote-helper that cannot respond to "list"
+   command could not fetch from a symbolic reference e.g. HEAD.
+
+ * The insn sheet "git rebase -i" creates did not fully honor
+   core.abbrev settings.
+
+ * The tests that wanted to see that file becomes unreadable after
+   running "chmod a-r file", and the tests that wanted to make sure it
+   is not run as root, we used "can we write into the / directory?" as
+   a cheap substitute, but on some platforms that is not a good
+   heuristics.  The tests and their prerequisites have been updated to
+   check what they really require.
+
+ * The configuration variable 'mailinfo.scissors' was hard to
+   discover in the documentation.
+
+ * Correct a breakage to git-svn around v2.2 era that triggers
+   premature closing of FileHandle.
+
+ * Even though we officially haven't dropped Perl 5.8 support, the
+   Getopt::Long package that came with it does not support "--no-"
+   prefix to negate a boolean option; manually add support to help
+   people with older Getopt::Long package.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.3.txt b/third_party/git/Documentation/RelNotes/2.3.3.txt
new file mode 100644
index 0000000000..5ef12644c2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.3.txt
@@ -0,0 +1,39 @@
+Git v2.3.3 Release Notes
+========================
+
+Fixes since v2.3.2
+------------------
+
+ * A corrupt input to "git diff -M" used cause us to segfault.
+
+ * The borrowed code in kwset API did not follow our usual convention
+   to use "unsigned char" to store values that range from 0-255.
+
+ * Description given by "grep -h" for its --exclude-standard option
+   was phrased poorly.
+
+ * Documentaton for "git remote add" mentioned "--tags" and
+   "--no-tags" and it was not clear that fetch from the remote in
+   the future will use the default behaviour when neither is given
+   to override it.
+
+ * "git diff --shortstat --dirstat=changes" showed a dirstat based on
+   lines that was never asked by the end user in addition to the
+   dirstat that the user asked for.
+
+ * The interaction between "git submodule update" and the
+   submodule.*.update configuration was not clearly documented.
+
+ * "git apply" was not very careful about reading from, removing,
+   updating and creating paths outside the working tree (under
+   --index/--cached) or the current directory (when used as a
+   replacement for GNU patch).
+
+ * "git daemon" looked up the hostname even when "%CH" and "%IP"
+   interpolations are not requested, which was unnecessary.
+
+ * The "interpolated-path" option of "git daemon" inserted any string
+   client declared on the "host=" capability request without checking.
+   Sanitize and limit %H and %CH to a saner and a valid DNS name.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.4.txt b/third_party/git/Documentation/RelNotes/2.3.4.txt
new file mode 100644
index 0000000000..094c7b853b
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.4.txt
@@ -0,0 +1,32 @@
+Git v2.3.4 Release Notes
+========================
+
+Fixes since v2.3.3
+------------------
+
+ * The 'color.status.unmerged' configuration was not described.
+
+ * "git log --decorate" did not reset colors correctly around the
+   branch names.
+
+ * "git -C '' subcmd" refused to work in the current directory, unlike
+   "cd ''" which silently behaves as a no-op.
+
+ * "git imap-send" learned to optionally talk with an IMAP server via
+   libcURL; because there is no other option when Git is built with
+   NO_OPENSSL option, use that codepath by default under such
+   configuration.
+
+ * A workaround for certain build of GPG that triggered false breakage
+   in a test has been added.
+
+ * "git rebase -i" recently started to include the number of
+   commits in the insn sheet to be processed, but on a platform
+   that prepends leading whitespaces to "wc -l" output, the numbers
+   are shown with extra whitespaces that aren't necessary.
+
+ * We did not parse username followed by literal IPv6 address in SSH
+   transport URLs, e.g. ssh://user@[2001:db8::1]:22/repo.git
+   correctly.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.5.txt b/third_party/git/Documentation/RelNotes/2.3.5.txt
new file mode 100644
index 0000000000..5b309db689
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.5.txt
@@ -0,0 +1,44 @@
+Git v2.3.5 Release Notes
+========================
+
+Fixes since v2.3.4
+------------------
+
+ * The prompt script (in contrib/) did not show the untracked sign
+   when working in a subdirectory without any untracked files.
+
+ * Even though "git grep --quiet" is run merely to ask for the exit
+   status, we spawned the pager regardless.  Stop doing that.
+
+ * Recommend format-patch and send-email for those who want to submit
+   patches to this project.
+
+ * An failure early in the "git clone" that started creating the
+   working tree and repository could have resulted in some directories
+   and files left without getting cleaned up.
+
+ * "git fetch" that fetches a commit using the allow-tip-sha1-in-want
+   extension could have failed to fetch all the requested refs.
+
+ * The split-index mode introduced at v2.3.0-rc0~41 was broken in the
+   codepath to protect us against a broken reimplementation of Git
+   that writes an invalid index with duplicated index entries, etc.
+
+ * "git prune" used to largely ignore broken refs when deciding which
+   objects are still being used, which could spread an existing small
+   damage and make it a larger one.
+
+ * "git tag -h" used to show the "--column" and "--sort" options
+   that are about listing in a wrong section.
+
+ * The transfer.hiderefs support did not quite work for smart-http
+   transport.
+
+ * The code that reads from the ctags file in the completion script
+   (in contrib/) did not spell ${param/pattern/string} substitution
+   correctly, which happened to work with bash but not with zsh.
+
+ * The explanation on "rebase --preserve-merges", "pull --rebase=preserve",
+   and "push --force-with-lease" in the documentation was unclear.
+
+Also contains typofixes, documentation updates and trivial code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.6.txt b/third_party/git/Documentation/RelNotes/2.3.6.txt
new file mode 100644
index 0000000000..432f770ef3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.6.txt
@@ -0,0 +1,13 @@
+Git v2.3.6 Release Notes
+========================
+
+Fixes since v2.3.5
+------------------
+
+ * "diff-highlight" (in contrib/) used to show byte-by-byte
+   differences, which meant that multi-byte characters can be chopped
+   in the middle.  It learned to pay attention to character boundaries
+   (assuming the UTF-8 payload).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.7.txt b/third_party/git/Documentation/RelNotes/2.3.7.txt
new file mode 100644
index 0000000000..fc95812cb3
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.7.txt
@@ -0,0 +1,21 @@
+Git v2.3.7 Release Notes
+========================
+
+Fixes since v2.3.6
+------------------
+
+ * An earlier update to the parser that disects a URL broke an
+   address, followed by a colon, followed by an empty string (instead
+   of the port number), e.g. ssh://example.com:/path/to/repo.
+
+ * The completion script (in contrib/) contaminated global namespace
+   and clobbered on a shell variable $x.
+
+ * The "git push --signed" protocol extension did not limit what the
+   "nonce" that is a server-chosen string can contain or how long it
+   can be, which was unnecessarily lax.  Limit both the length and the
+   alphabet to a reasonably small space that can still have enough
+   entropy.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.8.txt b/third_party/git/Documentation/RelNotes/2.3.8.txt
new file mode 100644
index 0000000000..0b67268a96
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.8.txt
@@ -0,0 +1,22 @@
+Git v2.3.8 Release Notes
+========================
+
+Fixes since v2.3.7
+------------------
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.3.9.txt b/third_party/git/Documentation/RelNotes/2.3.9.txt
new file mode 100644
index 0000000000..1a2ad3235a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.3.9.txt
@@ -0,0 +1,9 @@
+Git v2.3.9 Release Notes
+========================
+
+Fixes since v2.3.8
+------------------
+
+ * A handful of codepaths that used to use fixed-sized arrays to hold
+   pathnames have been corrected to use strbuf and other mechanisms to
+   allow longer pathnames without fearing overflows.
diff --git a/third_party/git/Documentation/RelNotes/2.4.0.txt b/third_party/git/Documentation/RelNotes/2.4.0.txt
new file mode 100644
index 0000000000..cde64be535
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.0.txt
@@ -0,0 +1,514 @@
+Git 2.4 Release Notes
+=====================
+
+Backward compatibility warning(s)
+---------------------------------
+
+This release has a few changes in the user-visible output from
+Porcelain commands. These are not meant to be parsed by scripts, but
+users still may want to be aware of the changes:
+
+ * The output from "git log --decorate" (and, more generally, the "%d"
+   format specifier used in the "--format=<string>" parameter to the
+   "git log" family of commands) has changed. It used to list "HEAD"
+   just like other branches; e.g.,
+
+     $ git log --decorate -1 master
+     commit bdb0f6788fa5e3cacc4315e9ff318a27b2676ff4 (HEAD, master)
+     ...
+
+   This release changes the output slightly when HEAD refers to a
+   branch whose name is also shown in the output. The above is now
+   shown as:
+
+     $ git log --decorate -1 master
+     commit bdb0f6788fa5e3cacc4315e9ff318a27b2676ff4 (HEAD -> master)
+     ...
+
+ * The phrasing "git branch" uses to describe a detached HEAD has been
+   updated to agree with the phrasing used by "git status":
+
+    - When HEAD is at the same commit as when it was originally
+      detached, they now both show "detached at <commit object name>".
+
+    - When HEAD has moved since it was originally detached, they now
+      both show "detached from <commit object name>".
+
+   Previously, "git branch" always used "from".
+
+
+Updates since v2.3
+------------------
+
+Ports
+
+ * Our default I/O size (8 MiB) for large files was too large for some
+   platforms with smaller SSIZE_MAX, leading to read(2)/write(2)
+   failures.
+
+ * We did not check the curl library version before using the
+   CURLOPT_PROXYAUTH feature, which did not exist in older versions of
+   the library.
+
+ * We now detect number of CPUs on older BSD-derived systems.
+
+ * Portability fixes and workarounds for shell scripts have been added
+   to help BSD-derived systems.
+
+
+UI, Workflows & Features
+
+ * The command usage info strings given by "git cmd -h" and in
+   documentation have been tweaked for consistency.
+
+ * The "sync" subcommand of "git p4" now allows users to exclude
+   subdirectories like its "clone" subcommand does.
+
+ * "git log --invert-grep --grep=WIP" will show only commits that do
+   not have the string "WIP" in their messages.
+
+ * "git push" has been taught an "--atomic" option that makes a push
+   that updates more than one ref an "all-or-none" affair.
+
+ * Extending the "push to deploy" feature that was added in 2.3, the
+   behaviour of "git push" when updating the branch that is checked
+   out can now be tweaked by a "push-to-checkout" hook.
+
+ * HTTP-based transports now send Accept-Language when making
+   requests. The languages to accept are inferred from environment
+   variables on the client side (LANGUAGE, etc).
+
+ * "git send-email" used to accept a mistaken "y" (or "yes") as an
+   answer to "What encoding do you want to use [UTF-8]?" without
+   questioning. Now it asks for confirmation when the answer looks too
+   short to be a valid encoding name.
+
+ * When "git apply --whitespace=fix" fixed whitespace errors in the
+   common context lines, the command reports that it did so.
+
+ * "git status" now allows the "-v" option to be given twice, in which
+   case it also shows the differences in the working tree that are not
+   staged to be committed.
+
+ * "git cherry-pick" used to clean up the log message even when it is
+   merely replaying an existing commit. It now replays the message
+   verbatim unless you are editing the message of the resulting
+   commit.
+
+ * "git archive" can now be told to set the 'text' attribute in the
+   resulting zip archive.
+
+ * Output from "git log --decorate" now distinguishes between a
+   detached HEAD vs. a HEAD that points at a branch.
+
+   This is a potentially backward-incompatible change; see above for
+   more information.
+
+ * When HEAD was detached when at commit xyz and hasn't been moved
+   since it was detached, "git status" would report "detached at xyz"
+   whereas "git branch" would report "detached from xyz". Now the
+   output of "git branch" agrees with that of "git status".
+
+   This is a potentially backward-incompatible change; see above for
+   more information.
+
+ * "git -C '' subcmd" now works in the current directory (analogously
+   to "cd ''") rather than dying with an error message.
+   (merge 6a536e2 kn/git-cd-to-empty later to maint).
+
+ * The versionsort.prereleaseSuffix configuration variable can be used
+   to specify that, for example, v1.0-pre1 comes before v1.0.
+
+ * A new "push.followTags" configuration turns the "--follow-tags"
+   option on by default for the "git push" command.
+
+ * "git log --graph --no-walk A B..." is a nonsensical combination of
+   options: "--no-walk" requests discrete points in the history, while
+   "--graph" asks to draw connections between these discrete points.
+   Forbid the use of these options together.
+
+ * "git rev-list --bisect --first-parent" does not work (yet) and can
+   even cause SEGV; forbid it. "git log --bisect --first-parent" would
+   not be useful until "git bisect --first-parent" materializes, so
+   also forbid it for now.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Slightly change the implementation of the N_() macro to help us
+   detect mistakes.
+
+ * Restructure the implementation of "reflog expire" to fit better
+   with the recently updated reference API.
+
+ * The transport-helper did not pass transport options such as
+   verbosity, progress, cloning, etc. to import and export based
+   helpers, like it did for fetch and push based helpers, robbing them
+   of the chance to honor the wish of the end-users better.
+
+ * The tests that wanted to see that a file becomes unreadable after
+   running "chmod a-r file", and the tests that wanted to make sure
+   that they are not run as root, used "can we write into the /
+   directory?" as a cheap substitute. But on some platforms that is
+   not a good heuristic. The tests and their prerequisites have been
+   updated to check what they really require.
+   (merge f400e51 jk/sanity later to maint).
+
+ * Various issues around "reflog expire", e.g. using --updateref when
+   expiring a reflog for a symbolic reference, have been corrected
+   and/or made saner.
+
+ * The documentation for the strbuf API had been split between the API
+   documentation and the header file. Consolidate the documentation in
+   strbuf.h.
+
+ * The error handling functions and conventions are now documented in
+   the API manual (in api-error-handling.txt).
+
+ * Optimize gitattribute look-up, mostly useful in "git grep" on a
+   project that does not use many attributes, by avoiding it when we
+   (should) know that the attributes are not defined in the first
+   place.
+
+ * Typofix in comments.
+   (merge ef2956a ak/git-pm-typofix later to maint).
+
+ * Code clean-up.
+   (merge 0b868f0 sb/hex-object-name-is-at-most-41-bytes-long later to maint).
+   (merge 5d30851 dp/remove-duplicated-header-inclusion later to maint).
+
+ * Simplify the ref transaction API for verifying that "the ref should
+   be pointing at this object".
+
+ * Simplify the code in "git daemon" that parses out and holds
+   hostnames used in request interpolation.
+
+ * Restructure the "git push" codepath to make it easier to add new
+   configuration bits.
+
+ * The run-command interface made it easy to make a pipe for us to
+   read from a process, wait for the process to finish, and then
+   attempt to read its output. But this pattern can lead to deadlock.
+   So introduce a helper to do this correctly (i.e., first read, and
+   then wait the process to finish) and also add code to prevent such
+   abuse in the run-command helper.
+
+ * People often forget to chain the commands in their test together
+   with &&, letting a failure from an earlier command in the test go
+   unnoticed. The new GIT_TEST_CHAIN_LINT mechanism allows you to
+   catch such a mistake more easily.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.3
+----------------
+
+Unless otherwise noted, all the fixes since v2.3 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git blame HEAD -- missing" failed to correctly say "HEAD" when it
+   tried to say "No such path 'missing' in HEAD".
+   (merge a46442f jk/blame-commit-label later to maint).
+
+ * "git rerere" (invoked internally from many mergy operations) did
+   not correctly signal errors when it attempted to update the working
+   tree files but failed for whatever reason.
+   (merge 89ea903 jn/rerere-fail-on-auto-update-failure later to maint).
+
+ * Setting diff.submodule to 'log' made "git format-patch" produce
+   broken patches.
+   (merge 339de50 dk/format-patch-ignore-diff-submodule later to maint).
+
+ * After attempting and failing a password-less authentication (e.g.,
+   Kerberos), libcURL refuses to fall back to password-based Basic
+   authentication without a bit of help/encouragement.
+   (merge 4dbe664 bc/http-fallback-to-password-after-krb-fails later to maint).
+
+ * The "git push" documentation for the "--repo=<there>" option was
+   easily misunderstood.
+   (merge 57b92a7 mg/push-repo-option-doc later to maint).
+
+ * Code to read a branch name from various files in the .git/
+   directory would have overrun array limits if asked to read an empty
+   file.
+   (merge 66ec904 jk/status-read-branch-name-fix later to maint).
+
+ * Remove a superfluous conditional that is always true.
+   (merge 94ee8e2 jk/remote-curl-an-array-in-struct-cannot-be-null later to maint).
+
+ * The "git diff --raw" documentation incorrectly implied that C(opy)
+   and R(ename) are the only statuses that can be followed by a score
+   number.
+   (merge ac1c2d9 jc/diff-format-doc later to maint).
+
+ * A broken pack .idx file in the receiving repository prevented the
+   dumb http transport from fetching a good copy of it from the other
+   side.
+   (merge 8b9c2dd jk/dumb-http-idx-fetch-fix later to maint).
+
+ * The error message from "git commit", when a non-existing author
+   name was given as value to the "--author=" parameter, has been
+   reworded to avoid misunderstanding.
+   (merge 1044b1f mg/commit-author-no-match-malformed-message later to maint).
+
+ * "git log --help" used to show rev-list options that are irrelevant
+   to the "log" command.
+   (merge 3cab02d jc/doc-log-rev-list-options later to maint).
+
+ * "git apply --whitespace=fix" used to under-allocate memory when the
+   fix resulted in a longer text than the original patch.
+   (merge 407a792 jc/apply-ws-fix-expands later to maint).
+
+ * The interactive "show a list and let the user choose from it"
+   interface used by "git add -i" unnecessarily prompted the user even
+   when the candidate list was empty, against which the only "choice"
+   the user could have made was to choose nothing.
+   (merge a9c4641 ak/add-i-empty-candidates later to maint).
+
+ * The todo list created by "git rebase -i" did not fully honor
+   core.abbrev settings.
+   (merge edb72d5 ks/rebase-i-abbrev later to maint).
+
+ * "git fetch" over a remote-helper that cannot respond to the "list"
+   command could not fetch from a symbolic reference (e.g., HEAD).
+   (merge 33cae54 mh/deref-symref-over-helper-transport later to maint).
+
+ * "git push --signed" gave an incorrectly worded error message when
+   the other side did not support the capability.
+
+ * The "git push --signed" protocol extension did not limit what the
+   "nonce" (a server-chosen string) could contain nor how long it
+   could be, which was unnecessarily lax. Limit both the length and
+   the alphabet to a reasonably small space that can still have enough
+   entropy.
+   (merge afcb6ee jc/push-cert later to maint).
+
+ * The completion script (in contrib/) clobbered the shell variable $x
+   in the global shell namespace.
+   (merge 852ff1c ma/bash-completion-leaking-x later to maint).
+
+ * We incorrectly formatted a "uintmax_t" integer that doesn't fit in
+   "int".
+   (merge d306f3d jk/decimal-width-for-uintmax later to maint).
+
+ * The configuration parser used to be confused when reading
+   configuration from a blob object that ends with a lone CR.
+   (merge 1d0655c jk/config-no-ungetc-eof later to maint).
+
+ * The pack bitmap support did not build with older versions of GCC.
+   (merge bd4e882 jk/pack-bitmap later to maint).
+
+ * The documentation wasn't clear that "remote.<nick>.pushURL" and
+   "remote.<nick>.URL" are there to name the same repository accessed
+   via different transports, not two separate repositories.
+   (merge 697f652 jc/remote-set-url-doc later to maint).
+
+ * Older GnuPG implementations may not correctly import the keyring
+   material we prepare for the tests to use.
+   (merge 1f985d6 ch/new-gpg-drops-rfc-1991 later to maint).
+
+ * The credential helper for Windows (in contrib/) used to mishandle
+   user names that contain an at-sign.
+   (merge 13d261e av/wincred-with-at-in-username-fix later to maint).
+
+ * "diff-highlight" (in contrib/) used to show byte-by-byte
+   differences, which could cause multi-byte characters to be chopped
+   in the middle. It learned to pay attention to character boundaries
+   (assuming UTF-8).
+   (merge 8d00662 jk/colors later to maint).
+
+ * Document longstanding configuration variable naming rules in
+   CodingGuidelines.
+   (merge 35840a3 jc/conf-var-doc later to maint).
+
+ * An earlier workaround to squelch unhelpful deprecation warnings
+   from the compiler on OS X unnecessarily set a minimum required
+   version of the OS, which the user might want to raise (or lower)
+   for other reasons.
+   (merge 88c03eb es/squelch-openssl-warnings-on-macosx later to maint).
+
+ * Certain older vintages of cURL give irregular output from
+   "curl-config --vernum", which confused our build system.
+   (merge 3af6792 tc/curl-vernum-output-broken-in-7.11 later to maint).
+
+ * In v2.2.0, we broke "git prune" that runs in a repository that
+   borrows from an alternate object store.
+   (merge b0a4264 jk/prune-mtime later to maint).
+
+ * "git submodule add" failed to squash "path/to/././submodule" to
+   "path/to/submodule".
+   (merge 8196e72 ps/submodule-sanitize-path-upon-add later to maint).
+
+ * "git merge-file" did not work correctly when invoked in a
+   subdirectory.
+   (merge 204a8ff ab/merge-file-prefix later to maint).
+
+ * "git blame" could die trying to free an uninitialized piece of
+   memory.
+   (merge e600592 es/blame-commit-info-fix later to maint).
+
+ * "git fast-import" used to crash when it could not close and
+   finalize the resulting packfile cleanly.
+   (merge 5e915f3 jk/fast-import-die-nicely-fix later to maint).
+
+ * "update-index --refresh" used to leak memory when an entry could
+   not be refreshed for whatever reason.
+   (merge bc1c2ca sb/plug-leak-in-make-cache-entry later to maint).
+
+ * The "interpolated-path" option of "git daemon" inserted any string
+   the client declared on the "host=" capability request without
+   checking. Sanitize and limit %H and %CH to a saner and a valid DNS
+   name.
+   (merge b485373 jk/daemon-interpolate later to maint).
+
+ * "git daemon" unnecessarily looked up the hostname even when "%CH"
+   and "%IP" interpolations were not requested.
+   (merge dc8edc8 rs/daemon-interpolate later to maint).
+
+ * We relied on "--no-" prefix handling in Perl's Getopt::Long
+   package, even though that support didn't exist in Perl 5.8 (which
+   we still support). Manually add support to help people with older
+   Getopt::Long packages.
+   (merge f471494 km/send-email-getopt-long-workarounds later to maint).
+
+ * "git apply" was not very careful about reading from, removing,
+   updating and creating paths outside the working tree (under
+   --index/--cached) or the current directory (when used as a
+   replacement for GNU patch).
+   (merge e0d201b jc/apply-beyond-symlink later to maint).
+
+ * Correct a breakage in git-svn, introduced around the v2.2 era, that
+   can cause FileHandles to be closed prematurely.
+   (merge e426311 ew/svn-maint-fixes later to maint).
+
+ * We did not parse usernames followed by literal IPv6 addresses
+   correctly in SSH transport URLs; e.g.,
+   ssh://user@[2001:db8::1]:22/repo.git.
+   (merge 6b6c5f7 tb/connect-ipv6-parse-fix later to maint).
+
+ * The configuration variable 'mailinfo.scissors' was hard to
+   discover in the documentation.
+   (merge afb5de7 mm/am-c-doc later to maint).
+
+ * The interaction between "git submodule update" and the
+   submodule.*.update configuration was not clearly documented.
+   (merge 5c31acf ms/submodule-update-config-doc later to maint).
+
+ * "git diff --shortstat" used together with "--dirstat=changes" or
+   "--dirstat=files" incorrectly output dirstat information twice.
+   (merge ab27389 mk/diff-shortstat-dirstat-fix later to maint).
+
+ * The manpage for "git remote add" mentioned "--tags" and "--no-tags"
+   but did not explain what happens if neither option is provided.
+   (merge aaba0ab mg/doc-remote-tags-or-not later to maint).
+
+ * The description of "--exclude-standard option" in the output of
+   "git grep -h" was phrased poorly.
+   (merge 77fdb8a nd/grep-exclude-standard-help-fix later to maint).
+
+ * "git rebase -i" recently started to include the number of commits
+   in the todo list, but that output included extraneous whitespace on
+   a platform that prepends leading whitespaces to its "wc -l" output.
+   (merge 2185d3b es/rebase-i-count-todo later to maint).
+
+ * The borrowed code in the kwset API did not follow our usual
+   convention to use "unsigned char" to store values that range from
+   0-255.
+   (merge 189c860 bw/kwset-use-unsigned later to maint).
+
+ * A corrupt input to "git diff -M" used to cause it to segfault.
+   (merge 4d6be03 jk/diffcore-rename-duplicate later to maint).
+
+ * Certain builds of GPG triggered false breakages in a test.
+   (merge 3f88c1b mg/verify-commit later to maint).
+
+ * "git imap-send" learned to optionally talk with an IMAP server via
+   libcURL. Because there is no other option when Git is built with
+   the NO_OPENSSL option, use libcURL by default in that case.
+   (merge dcd01ea km/imap-send-libcurl-options later to maint).
+
+ * "git log --decorate" did not reset colors correctly around the
+   branch names.
+   (merge 5ee8758 jc/decorate-leaky-separator-color later to maint).
+
+ * The code that reads from the ctags file in the completion script
+   (in contrib/) did not spell ${param/pattern/string} substitution
+   correctly, which happened to work with bash but not with zsh.
+   (merge db8d750 js/completion-ctags-pattern-substitution-fix later to maint).
+
+ * The transfer.hiderefs support did not quite work for smart-http
+   transport.
+   (merge 8ddf3ca jk/smart-http-hide-refs later to maint).
+
+ * In the "git tag -h" output, move the documentation for the
+   "--column" and "--sort" options to the "Tag listing options"
+   section.
+   (merge dd059c6 jk/tag-h-column-is-a-listing-option later to maint).
+
+ * "git prune" used to largely ignore broken refs when deciding which
+   objects are still being used, which could cause reference
+   corruption to lead to object loss.
+   (merge ea56c4e jk/prune-with-corrupt-refs later to maint).
+
+ * The split-index mode introduced in v2.3.0-rc0~41 was broken in the
+   codepath to protect us against a broken reimplementation of Git
+   that writes an invalid index with duplicated index entries, etc.
+   (merge 03f15a7 tg/fix-check-order-with-split-index later to maint).
+
+ * "git fetch", when fetching a commit using the
+   allow-tip-sha1-in-want extension, could have failed to fetch all of
+   the requested refs.
+   (merge 32d0462 jk/fetch-pack later to maint).
+
+ * An failure early in the "git clone" that started creating the
+   working tree and repository could have resulted in the failure to
+   clean up some directories and files.
+   (merge 16eff6c jk/cleanup-failed-clone later to maint).
+
+ * Recommend format-patch and send-email for those who want to submit
+   patches to this project.
+   (merge b25c469 jc/submitting-patches-mention-send-email later to maint).
+
+ * Do not spawn the pager when "git grep" is run with "--quiet".
+   (merge c2048f0 ws/grep-quiet-no-pager later to maint).
+
+ * The prompt script (in contrib/) did not show the untracked sign
+   when working in a subdirectory without any untracked files.
+   (merge 9bdc517 ct/prompt-untracked-fix later to maint).
+
+ * An earlier update to the URL parser broke an address that contains
+   a colon but an empty string for the port number, like
+   ssh://example.com:/path/to/repo.
+   (merge 6b6c5f7 tb/connect-ipv6-parse-fix later to maint).
+
+ * Code cleanups and documentation updates.
+   (merge 2ce63e9 rs/simple-cleanups later to maint).
+   (merge 33baa69 rj/no-xopen-source-for-cygwin later to maint).
+   (merge 817d03e jc/diff-test-updates later to maint).
+   (merge eb32c66 ak/t5516-typofix later to maint).
+   (merge bcd57cb mr/doc-clean-f-f later to maint).
+   (merge 0d6accc mg/doc-status-color-slot later to maint).
+   (merge 53e53c7 sg/completion-remote later to maint).
+   (merge 8fa7975 ak/git-done-help-cleanup later to maint).
+   (merge 9a6f128 rs/deflate-init-cleanup later to maint).
+   (merge 6f75d45 rs/use-isxdigit later to maint).
+   (merge 376e4b3 jk/test-annoyances later to maint).
+   (merge 7032054 nd/doc-git-index-version later to maint).
+   (merge e869c5e tg/test-index-v4 later to maint).
+   (merge 599d223 jk/simplify-csum-file-sha1fd-check later to maint).
+   (merge 260d585 sg/completion-gitcomp-nl-for-refs later to maint).
+   (merge 777c55a jc/report-path-error-to-dir later to maint).
+   (merge fddfaf8 ph/push-doc-cas later to maint).
+   (merge d50d31e ss/pull-rebase-preserve later to maint).
+   (merge c8c3f1d pt/enter-repo-comment-fix later to maint).
+   (merge d7bfb9e jz/gitweb-conf-doc-fix later to maint).
+   (merge f907282 jk/cherry-pick-docfix later to maint).
+   (merge d3c0811 iu/fix-parse-options-h-comment later to maint).
+   (merge 6c3b2af jg/cguide-we-cannot-count later to maint).
+   (merge 2b8bd44 jk/pack-corruption-post-mortem later to maint).
+   (merge 9585cb8 jn/doc-fast-import-no-16-octopus-limit later to maint).
+   (merge 5dcd1b1 ps/grep-help-all-callback-arg later to maint).
+   (merge f1f4c84 va/fix-git-p4-tests later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.4.1.txt b/third_party/git/Documentation/RelNotes/2.4.1.txt
new file mode 100644
index 0000000000..a65a6c5829
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.1.txt
@@ -0,0 +1,40 @@
+Git v2.4.1 Release Notes
+========================
+
+Fixes since v2.4
+----------------
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+
+ * "git cat-file bl $blob" failed to barf even though there is no
+   object type that is "bl".
+
+ * Teach the codepaths that read .gitignore and .gitattributes files
+   that these files encoded in UTF-8 may have UTF-8 BOM marker at the
+   beginning; this makes it in line with what we do for configuration
+   files already.
+
+ * Access to objects in repositories that borrow from another one on a
+   slow NFS server unnecessarily got more expensive due to recent code
+   becoming more cautious in a naive way not to lose objects to pruning.
+
+ * We avoid setting core.worktree when the repository location is the
+   ".git" directory directly at the top level of the working tree, but
+   the code misdetected the case in which the working tree is at the
+   root level of the filesystem (which arguably is a silly thing to
+   do, but still valid).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.10.txt b/third_party/git/Documentation/RelNotes/2.4.10.txt
new file mode 100644
index 0000000000..702d8d4e22
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.10.txt
@@ -0,0 +1,18 @@
+Git v2.4.10 Release Notes
+=========================
+
+Fixes since v2.4.9
+------------------
+
+ * xdiff code we use to generate diffs is not prepared to handle
+   extremely large files.  It uses "int" in many places, which can
+   overflow if we have a very large number of lines or even bytes in
+   our input files, for example.  Cap the input size to somewhere
+   around 1GB for now.
+
+ * Some protocols (like git-remote-ext) can execute arbitrary code
+   found in the URL.  The URLs that submodules use may come from
+   arbitrary sources (e.g., .gitmodules files in a remote
+   repository), and can hurt those who blindly enable recursive
+   fetch.  Restrict the allowed protocols to well known and safe
+   ones.
diff --git a/third_party/git/Documentation/RelNotes/2.4.11.txt b/third_party/git/Documentation/RelNotes/2.4.11.txt
new file mode 100644
index 0000000000..723360295c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.11.txt
@@ -0,0 +1,11 @@
+Git v2.4.11 Release Notes
+=========================
+
+Fixes since v2.4.10
+-------------------
+
+ * Bugfix patches were backported from the 'master' front to plug heap
+   corruption holes, to catch integer overflow in the computation of
+   pathname lengths, and to get rid of the name_path API.  Both of
+   these would have resulted in writing over an under-allocated buffer
+   when formulating pathnames while tree traversal.
diff --git a/third_party/git/Documentation/RelNotes/2.4.12.txt b/third_party/git/Documentation/RelNotes/2.4.12.txt
new file mode 100644
index 0000000000..7d15f94725
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.12.txt
@@ -0,0 +1,12 @@
+Git v2.4.12 Release Notes
+=========================
+
+Fixes since v2.4.11
+-------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
diff --git a/third_party/git/Documentation/RelNotes/2.4.2.txt b/third_party/git/Documentation/RelNotes/2.4.2.txt
new file mode 100644
index 0000000000..250cdc423c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.2.txt
@@ -0,0 +1,45 @@
+Git v2.4.2 Release Notes
+========================
+
+Fixes since v2.4.1
+------------------
+
+ * "git rev-list --objects $old --not --all" to see if everything that
+   is reachable from $old is already connected to the existing refs
+   was very inefficient.
+
+ * "hash-object --literally" introduced in v2.2 was not prepared to
+   take a really long object type name.
+
+ * "git rebase --quiet" was not quite quiet when there is nothing to
+   do.
+
+ * The completion for "log --decorate=" parameter value was incorrect.
+
+ * "filter-branch" corrupted commit log message that ends with an
+   incomplete line on platforms with some "sed" implementations that
+   munge such a line.  Work it around by avoiding to use "sed".
+
+ * "git daemon" fails to build from the source under NO_IPV6
+   configuration (regression in 2.4).
+
+ * "git stash pop/apply" forgot to make sure that not just the working
+   tree is clean but also the index is clean. The latter is important
+   as a stash application can conflict and the index will be used for
+   conflict resolution.
+
+ * We have prepended $GIT_EXEC_PATH and the path "git" is installed in
+   (typically "/usr/bin") to $PATH when invoking subprograms and hooks
+   for almost eternity, but the original use case the latter tried to
+   support was semi-bogus (i.e. install git to /opt/foo/git and run it
+   without having /opt/foo on $PATH), and more importantly it has
+   become less and less relevant as Git grew more mainstream (i.e. the
+   users would _want_ to have it on their $PATH).  Stop prepending the
+   path in which "git" is installed to users' $PATH, as that would
+   interfere the command search order people depend on (e.g. they may
+   not like versions of programs that are unrelated to Git in /usr/bin
+   and want to override them by having different ones in /usr/local/bin
+   and have the latter directory earlier in their $PATH).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.3.txt b/third_party/git/Documentation/RelNotes/2.4.3.txt
new file mode 100644
index 0000000000..914d2c1860
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.3.txt
@@ -0,0 +1,76 @@
+Git v2.4.3 Release Notes
+========================
+
+Fixes since v2.4.3
+------------------
+
+ * Error messages from "git branch" called remote-tracking branches as
+   "remote branches".
+
+ * "git rerere forget" in a repository without rerere enabled gave a
+   cryptic error message; it should be a silent no-op instead.
+
+ * "git pull --log" and "git pull --no-log" worked as expected, but
+   "git pull --log=20" did not.
+
+ * The pull.ff configuration was supposed to override the merge.ff
+   configuration, but it didn't.
+
+ * The code to read pack-bitmap wanted to allocate a few hundred
+   pointers to a structure, but by mistake allocated and leaked memory
+   enough to hold that many actual structures.  Correct the allocation
+   size and also have it on stack, as it is small enough.
+
+ * Various documentation mark-up fixes to make the output more
+   consistent in general and also make AsciiDoctor (an alternative
+   formatter) happier.
+
+ * "git bundle verify" did not diagnose extra parameters on the
+   command line.
+
+ * Multi-ref transaction support we merged a few releases ago
+   unnecessarily kept many file descriptors open, risking to fail with
+   resource exhaustion.
+
+ * The ref API did not handle cases where 'refs/heads/xyzzy/frotz' is
+   removed at the same time as 'refs/heads/xyzzy' is added (or vice
+   versa) very well.
+
+ * The "log --decorate" enhancement in Git 2.4 that shows the commit
+   at the tip of the current branch e.g. "HEAD -> master", did not
+   work with --decorate=full.
+
+ * There was a commented-out (instead of being marked to expect
+   failure) test that documented a breakage that was fixed since the
+   test was written; turn it into a proper test.
+
+ * core.excludesfile (defaulting to $XDG_HOME/git/ignore) is supposed
+   to be overridden by repository-specific .git/info/exclude file, but
+   the order was swapped from the beginning. This belatedly fixes it.
+
+ * The connection initiation code for "ssh" transport tried to absorb
+   differences between the stock "ssh" and Putty-supplied "plink" and
+   its derivatives, but the logic to tell that we are using "plink"
+   variants were too loose and falsely triggered when "plink" appeared
+   anywhere in the path (e.g. "/home/me/bin/uplink/ssh").
+
+ * "git rebase -i" moved the "current" command from "todo" to "done" a
+   bit too prematurely, losing a step when a "pick" did not even start.
+
+ * "git add -e" did not allow the user to abort the operation by
+   killing the editor.
+
+ * Git 2.4 broke setting verbosity and progress levels on "git clone"
+   with native transports.
+
+ * Some time ago, "git blame" (incorrectly) lost the convert_to_git()
+   call when synthesizing a fake "tip" commit that represents the
+   state in the working tree, which broke folks who record the history
+   with LF line ending to make their project portabile across
+   platforms while terminating lines in their working tree files with
+   CRLF for their platform.
+
+ * Code clean-up for xdg configuration path support.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.4.txt b/third_party/git/Documentation/RelNotes/2.4.4.txt
new file mode 100644
index 0000000000..f1ccd001be
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.4.txt
@@ -0,0 +1,35 @@
+Git v2.4.4 Release Notes
+========================
+
+Fixes since v2.4.3
+------------------
+
+ * l10n updates for German.
+
+ * An earlier leakfix to bitmap testing code was incomplete.
+
+ * "git clean pathspec..." tried to lstat(2) and complain even for
+   paths outside the given pathspec.
+
+ * Communication between the HTTP server and http_backend process can
+   lead to a dead-lock when relaying a large ref negotiation request.
+   Diagnose the situation better, and mitigate it by reading such a
+   request first into core (to a reasonable limit).
+
+ * The clean/smudge interface did not work well when filtering an
+   empty contents (failed and then passed the empty input through).
+   It can be argued that a filter that produces anything but empty for
+   an empty input is nonsense, but if the user wants to do strange
+   things, then why not?
+
+ * Make "git stash something --help" error out, so that users can
+   safely say "git stash drop --help".
+
+ * Clarify that "log --raw" and "log --format=raw" are unrelated
+   concepts.
+
+ * Catch a programmer mistake to feed a pointer not an array to
+   ARRAY_SIZE() macro, by using a couple of GCC extensions.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.5.txt b/third_party/git/Documentation/RelNotes/2.4.5.txt
new file mode 100644
index 0000000000..568297ccb7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.5.txt
@@ -0,0 +1,28 @@
+Git v2.4.5 Release Notes
+========================
+
+Fixes since v2.4.4
+------------------
+
+ * The setup code used to die when core.bare and core.worktree are set
+   inconsistently, even for commands that do not need working tree.
+
+ * There was a dead code that used to handle "git pull --tags" and
+   show special-cased error message, which was made irrelevant when
+   the semantics of the option changed back in Git 1.9 days.
+
+ * "color.diff.plain" was a misnomer; give it 'color.diff.context' as
+   a more logical synonym.
+
+ * The configuration reader/writer uses mmap(2) interface to access
+   the files; when we find a directory, it barfed with "Out of memory?".
+
+ * Recent "git prune" traverses young unreachable objects to safekeep
+   old objects in the reachability chain from them, which sometimes
+   showed unnecessary error messages that are alarming.
+
+ * "git rebase -i" fired post-rewrite hook when it shouldn't (namely,
+   when it was told to stop sequencing with 'exec' insn).
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.6.txt b/third_party/git/Documentation/RelNotes/2.4.6.txt
new file mode 100644
index 0000000000..b53f353939
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.6.txt
@@ -0,0 +1,23 @@
+Git v2.4.6 Release Notes
+========================
+
+Fixes since v2.4.5
+------------------
+
+ * "git fetch --depth=<depth>" and "git clone --depth=<depth>" issued
+   a shallow transfer request even to an upload-pack that does not
+   support the capability.
+
+ * "git fsck" used to ignore missing or invalid objects recorded in reflog.
+
+ * The tcsh completion writes a bash scriptlet but that would have
+   failed for users with noclobber set.
+
+ * Recent Mac OS X updates breaks the logic to detect that the machine
+   is on the AC power in the sample pre-auto-gc script.
+
+ * "git format-patch --ignore-if-upstream A..B" did not like to be fed
+   tags as boundary commits.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.7.txt b/third_party/git/Documentation/RelNotes/2.4.7.txt
new file mode 100644
index 0000000000..b3ac412b82
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.7.txt
@@ -0,0 +1,53 @@
+Git v2.4.7 Release Notes
+========================
+
+Fixes since v2.4.6
+------------------
+
+ * A minor regression to "git fsck" in v2.2 era was fixed; it
+   complained about a body-less tag object when it lacked a
+   separator empty line after its header to separate it with a
+   non-existent body.
+
+ * We used to ask libCURL to use the most secure authentication method
+   available when talking to an HTTP proxy only when we were told to
+   talk to one via configuration variables.  We now ask libCURL to
+   always use the most secure authentication method, because the user
+   can tell libCURL to use an HTTP proxy via an environment variable
+   without using configuration variables.
+
+ * When you say "!<ENTER>" while running say "git log", you'd confuse
+   yourself in the resulting shell, that may look as if you took
+   control back to the original shell you spawned "git log" from but
+   that isn't what is happening.  To that new shell, we leaked
+   GIT_PAGER_IN_USE environment variable that was meant as a local
+   communication between the original "Git" and subprocesses that was
+   spawned by it after we launched the pager, which caused many
+   "interesting" things to happen, e.g. "git diff | cat" still paints
+   its output in color by default.
+
+   Stop leaking that environment variable to the pager's half of the
+   fork; we only need it on "Git" side when we spawn the pager.
+
+ * Avoid possible ssize_t to int truncation.
+
+ * "git config" failed to update the configuration file when the
+   underlying filesystem is incapable of renaming a file that is still
+   open.
+
+ * A minor bugfix when pack bitmap is used with "rev-list --count".
+
+ * An ancient test framework enhancement to allow color was not
+   entirely correct; this makes it work even when tput needs to read
+   from the ~/.terminfo under the user's real HOME directory.
+
+ * Fix a small bug in our use of umask() return value.
+
+ * "git rebase" did not exit with failure when format-patch it invoked
+   failed for whatever reason.
+
+ * Disable "have we lost a race with competing repack?" check while
+   receiving a huge object transfer that runs index-pack.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.8.txt b/third_party/git/Documentation/RelNotes/2.4.8.txt
new file mode 100644
index 0000000000..ad946b2673
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.8.txt
@@ -0,0 +1,21 @@
+Git v2.4.8 Release Notes
+========================
+
+Fixes since v2.4.7
+------------------
+
+ * Abandoning an already applied change in "git rebase -i" with
+   "--continue" left CHERRY_PICK_HEAD and confused later steps.
+
+ * Various fixes around "git am" that applies a patch to a history
+   that is not there yet.
+
+ * "git for-each-ref" reported "missing object" for 0{40} when it
+   encounters a broken ref.  The lack of object whose name is 0{40} is
+   not the problem; the ref being broken is.
+
+ * "git commit --cleanup=scissors" was not careful enough to protect
+   against getting fooled by a line that looked like scissors.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.4.9.txt b/third_party/git/Documentation/RelNotes/2.4.9.txt
new file mode 100644
index 0000000000..09af9ddbc7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.4.9.txt
@@ -0,0 +1,9 @@
+Git v2.4.9 Release Notes
+========================
+
+Fixes since v2.4.9
+------------------
+
+ * A handful of codepaths that used to use fixed-sized arrays to hold
+   pathnames have been corrected to use strbuf and other mechanisms to
+   allow longer pathnames without fearing overflows.
diff --git a/third_party/git/Documentation/RelNotes/2.5.0.txt b/third_party/git/Documentation/RelNotes/2.5.0.txt
new file mode 100644
index 0000000000..87044504c5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.0.txt
@@ -0,0 +1,563 @@
+Git 2.5 Release Notes
+=====================
+
+Updates since v2.4
+------------------
+
+UI, Workflows & Features
+
+ * The bash completion script (in contrib/) learned a few options that
+   "git revert" takes.
+
+ * Whitespace breakages in deleted and context lines can also be
+   painted in the output of "git diff" and friends with the new
+   --ws-error-highlight option.
+
+ * List of commands shown by "git help" are grouped along the workflow
+   elements to help early learners.
+
+ * "git p4" now detects the filetype (e.g. binary) correctly even when
+   the files are opened exclusively.
+
+ * git p4 attempts to better handle branches in Perforce.
+
+ * "git p4" learned "--changes-block-size <n>" to read the changes in
+   chunks from Perforce, instead of making one call to "p4 changes"
+   that may trigger "too many rows scanned" error from Perforce.
+
+ * More workaround for Perforce's row number limit in "git p4".
+
+ * Unlike "$EDITOR" and "$GIT_EDITOR" that can hold the path to the
+   command and initial options (e.g. "/path/to/emacs -nw"), 'git p4'
+   did not let the shell interpolate the contents of the environment
+   variable that name the editor "$P4EDITOR" (and "$EDITOR", too).
+   This release makes it in line with the rest of Git, as well as with
+   Perforce.
+
+ * A new short-hand <branch>@{push} denotes the remote-tracking branch
+   that tracks the branch at the remote the <branch> would be pushed
+   to.
+
+ * "git show-branch --topics HEAD" (with no other arguments) did not
+   do anything interesting.  Instead, contrast the given revision
+   against all the local branches by default.
+
+ * A replacement for contrib/workdir/git-new-workdir that does not
+   rely on symbolic links and make sharing of objects and refs safer
+   by making the borrowee and borrowers aware of each other.
+
+   Consider this as still an experimental feature; its UI is still
+   likely to change.
+
+ * Tweak the sample "store" backend of the credential helper to honor
+   XDG configuration file locations when specified.
+
+ * A heuristic we use to catch mistyped paths on the command line
+   "git <cmd> <revs> <pathspec>" is to make sure that all the non-rev
+   parameters in the later part of the command line are names of the
+   files in the working tree, but that means "git grep $str -- \*.c"
+   must always be disambiguated with "--", because nobody sane will
+   create a file whose name literally is asterisk-dot-see.  Loosen the
+   heuristic to declare that with a wildcard string the user likely
+   meant to give us a pathspec.
+
+ * "git merge FETCH_HEAD" learned that the previous "git fetch" could
+   be to create an Octopus merge, i.e. recording multiple branches
+   that are not marked as "not-for-merge"; this allows us to lose an
+   old style invocation "git merge <msg> HEAD $commits..." in the
+   implementation of "git pull" script; the old style syntax can now
+   be deprecated (but not removed yet).
+
+ * Filter scripts were run with SIGPIPE disabled on the Git side,
+   expecting that they may not read what Git feeds them to filter.
+   We however treated a filter that does not read its input fully
+   before exiting as an error.  We no longer do and ignore EPIPE
+   when writing to feed the filter scripts.
+
+   This changes semantics, but arguably in a good way.  If a filter
+   can produce its output without fully consuming its input using
+   whatever magic, we now let it do so, instead of diagnosing it
+   as a programming error.
+
+ * Instead of dying immediately upon failing to obtain a lock, the
+   locking (of refs etc) retries after a short while with backoff.
+
+ * Introduce http.<url>.SSLCipherList configuration variable to tweak
+   the list of cipher suite to be used with libcURL when talking with
+   https:// sites.
+
+ * "git subtree" script (in contrib/) used "echo -n" to produce
+   progress messages in a non-portable way.
+
+ * "git subtree" script (in contrib/) does not have --squash option
+   when pushing, but the documentation and help text pretended as if
+   it did.
+
+ * The Git subcommand completion (in contrib/) no longer lists credential
+   helpers among candidates; they are not something the end user would
+   invoke interactively.
+
+ * The index file can be taught with "update-index --untracked-cache"
+   to optionally remember already seen untracked files, in order to
+   speed up "git status" in a working tree with tons of cruft.
+
+ * "git mergetool" learned to drive WinMerge as a backend.
+
+ * "git upload-pack" that serves "git fetch" can be told to serve
+   commits that are not at the tip of any ref, as long as they are
+   reachable from a ref, with uploadpack.allowReachableSHA1InWant
+   configuration variable.
+
+ * "git cat-file --batch(-check)" learned the "--follow-symlinks"
+   option that follows an in-tree symbolic link when asked about an
+   object via extended SHA-1 syntax, e.g. HEAD:RelNotes that points at
+   Documentation/RelNotes/2.5.0.txt.  With the new option, the command
+   behaves as if HEAD:Documentation/RelNotes/2.5.0.txt was given as
+   input instead.
+
+   Consider this as still an experimental and incomplete feature:
+
+    - We may want to do the same for in-index objects, e.g.
+      asking for :RelNotes with this option should give
+      :Documentation/RelNotes/2.5.0.txt, too
+
+    - "git cat-file --follow-symlinks blob HEAD:RelNotes"
+      may also be something we want to allow in the future.
+
+ * "git send-email" learned the alias file format used by the sendmail
+   program (in a simplified form; we obviously do not feed pipes).
+
+ * Traditionally, external low-level 3-way merge drivers are expected
+   to produce their results based solely on the contents of the three
+   variants given in temporary files named by %O, %A and %B on their
+   command line.  Additionally allow them to look at the final path
+   (given by %P).
+
+ * "git blame" learned blame.showEmail configuration variable.
+
+ * "git apply" cannot diagnose a patch corruption when the breakage is
+   to mark the length of the hunk shorter than it really is on the
+   hunk header line "@@ -l,k +m,n @@"; one special case it could is
+   when the hunk becomes no-op (e.g. k == n == 2 for two-line context
+   patch output), and it learned to do so in this special case.
+
+ * Add the "--allow-unknown-type" option to "cat-file" to allow
+   inspecting loose objects of an experimental or a broken type.
+
+ * Many long-running operations show progress eye-candy, even when
+   they are later backgrounded.  Hide the eye-candy when the process
+   is sent to the background instead.
+   (merge a4fb76c lm/squelch-bg-progress later to maint).
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * "unsigned char [20]" used throughout the code to represent object
+   names are being converted into a semi-opaque "struct object_id".
+   This effort is expected to interfere with other topics in flight,
+   but hopefully will give us one extra level of abstraction in the
+   end, when completed.
+
+ * for_each_ref() callback functions were taught to name the objects
+   not with "unsigned char sha1[20]" but with "struct object_id".
+
+ * Catch a programmer mistake to feed a pointer not an array to
+   ARRAY_SIZE() macro, by using a couple of GCC extensions.
+
+ * Some error messages in "git config" were emitted without calling
+   the usual error() facility.
+
+ * When "add--interactive" splits a hunk into two overlapping hunks
+   and then let the user choose only one, it sometimes feeds an
+   incorrect patch text to "git apply".  Add tests to demonstrate
+   this.
+
+   I have a slight suspicion that this may be $gmane/87202 coming back
+   and biting us (I seem to have said "let's run with this and see
+   what happens" back then).
+
+ * More line-ending tests.
+
+ * An earlier rewrite to use strbuf_getwholeline() instead of fgets(3)
+   to read packed-refs file revealed that the former is unacceptably
+   inefficient.  It has been optimized by using getdelim(3) when
+   available.
+
+ * The refs API uses ref_lock struct which had its own "int fd", even
+   though the same file descriptor was in the lock struct it contains.
+   Clean-up the code to lose this redundant field.
+
+ * There was a dead code that used to handle "git pull --tags" and
+   show special-cased error message, which was made irrelevant when
+   the semantics of the option changed back in Git 1.9 days.
+   (merge 19d122b pt/pull-tags-error-diag later to maint).
+
+ * Help us to find broken test script that splits the body part of the
+   test by mistaken use of wrong kind of quotes.
+   (merge d93d5d5 jc/test-prereq-validate later to maint).
+
+ * Developer support to automatically detect broken &&-chain in the
+   test scripts is now turned on by default.
+   (merge 92b269f jk/test-chain-lint later to maint).
+
+ * Error reporting mechanism used in "refs" API has been made more
+   consistent.
+
+ * "git pull" has more test coverage now.
+
+ * "git pull" has become more aware of the options meant for
+   underlying "git fetch" and then learned to use parse-options
+   parser.
+
+ * Clarify in the Makefile a guideline to decide use of USE_NSEC.
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.4
+----------------
+
+Unless otherwise noted, all the fixes since v2.4 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * Git 2.4 broke setting verbosity and progress levels on "git clone"
+   with native transports.
+   (merge 822f0c4 mh/clone-verbosity-fix later to maint).
+
+ * "git add -e" did not allow the user to abort the operation by
+   killing the editor.
+   (merge cb64800 jk/add-e-kill-editor later to maint).
+
+ * Memory usage of "git index-pack" has been trimmed by tens of
+   per-cent.
+   (merge f0e7f11 nd/slim-index-pack-memory-usage later to maint).
+
+ * "git rev-list --objects $old --not --all" to see if everything that
+   is reachable from $old is already connected to the existing refs
+   was very inefficient.
+   (merge b6e8a3b jk/still-interesting later to maint).
+
+ * "hash-object --literally" introduced in v2.2 was not prepared to
+   take a really long object type name.
+   (merge 1427a7f jc/hash-object later to maint).
+
+ * "git rebase --quiet" was not quite quiet when there is nothing to
+   do.
+   (merge 22946a9 jk/rebase-quiet-noop later to maint).
+
+ * The completion for "log --decorate=" parameter value was incorrect.
+   (merge af16bda sg/complete-decorate-full-not-long later to maint).
+
+ * "filter-branch" corrupted commit log message that ends with an
+   incomplete line on platforms with some "sed" implementations that
+   munge such a line.  Work it around by avoiding to use "sed".
+   (merge df06201 jk/filter-branch-use-of-sed-on-incomplete-line later to maint).
+
+ * "git daemon" fails to build from the source under NO_IPV6
+   configuration (regression in 2.4).
+   (merge d358f77 jc/daemon-no-ipv6-for-2.4.1 later to maint).
+
+ * Some time ago, "git blame" (incorrectly) lost the convert_to_git()
+   call when synthesizing a fake "tip" commit that represents the
+   state in the working tree, which broke folks who record the history
+   with LF line ending to make their project portable across platforms
+   while terminating lines in their working tree files with CRLF for
+   their platform.
+   (merge 4bf256d tb/blame-resurrect-convert-to-git later to maint).
+
+ * We avoid setting core.worktree when the repository location is the
+   ".git" directory directly at the top level of the working tree, but
+   the code misdetected the case in which the working tree is at the
+   root level of the filesystem (which arguably is a silly thing to
+   do, but still valid).
+   (merge 84ccad8 jk/init-core-worktree-at-root later to maint).
+
+ * "git commit --date=now" or anything that relies on approxidate lost
+   the daylight-saving-time offset.
+   (merge f6e6362 jc/epochtime-wo-tz later to maint).
+
+ * Access to objects in repositories that borrow from another one on a
+   slow NFS server unnecessarily got more expensive due to recent code
+   becoming more cautious in a naive way not to lose objects to pruning.
+   (merge ee1c6c3 jk/prune-mtime later to maint).
+
+ * The codepaths that read .gitignore and .gitattributes files have been
+   taught that these files encoded in UTF-8 may have UTF-8 BOM marker at
+   the beginning; this makes it in line with what we do for configuration
+   files already.
+   (merge 27547e5 cn/bom-in-gitignore later to maint).
+
+ * a few helper scripts in the test suite did not report errors
+   correctly.
+   (merge de248e9 ep/fix-test-lib-functions-report later to maint).
+
+ * The default $HOME/.gitconfig file created upon "git config --global"
+   that edits it had incorrectly spelled user.name and user.email
+   entries in it.
+   (merge 7e11052 oh/fix-config-default-user-name-section later to maint).
+
+ * "git cat-file bl $blob" failed to barf even though there is no
+   object type that is "bl".
+   (merge b7994af jk/type-from-string-gently later to maint).
+
+ * The usual "git diff" when seeing a file turning into a directory
+   showed a patchset to remove the file and create all files in the
+   directory, but "git diff --no-index" simply refused to work.  Also,
+   when asked to compare a file and a directory, imitate POSIX "diff"
+   and compare the file with the file with the same name in the
+   directory, instead of refusing to run.
+   (merge 0615173 jc/diff-no-index-d-f later to maint).
+
+ * "git rebase -i" moved the "current" command from "todo" to "done" a
+   bit too prematurely, losing a step when a "pick" did not even start.
+   (merge 8cbc57c ph/rebase-i-redo later to maint).
+
+ * The connection initiation code for "ssh" transport tried to absorb
+   differences between the stock "ssh" and Putty-supplied "plink" and
+   its derivatives, but the logic to tell that we are using "plink"
+   variants were too loose and falsely triggered when "plink" appeared
+   anywhere in the path (e.g. "/home/me/bin/uplink/ssh").
+   (merge baaf233 bc/connect-plink later to maint).
+
+ * We have prepended $GIT_EXEC_PATH and the path "git" is installed in
+   (typically "/usr/bin") to $PATH when invoking subprograms and hooks
+   for almost eternity, but the original use case the latter tried to
+   support was semi-bogus (i.e. install git to /opt/foo/git and run it
+   without having /opt/foo on $PATH), and more importantly it has
+   become less and less relevant as Git grew more mainstream (i.e. the
+   users would _want_ to have it on their $PATH).  Stop prepending the
+   path in which "git" is installed to users' $PATH, as that would
+   interfere the command search order people depend on (e.g. they may
+   not like versions of programs that are unrelated to Git in /usr/bin
+   and want to override them by having different ones in /usr/local/bin
+   and have the latter directory earlier in their $PATH).
+   (merge a0b4507 jk/git-no-more-argv0-path-munging later to maint).
+
+ * core.excludesfile (defaulting to $XDG_HOME/git/ignore) is supposed
+   to be overridden by repository-specific .git/info/exclude file, but
+   the order was swapped from the beginning. This belatedly fixes it.
+   (merge 099d2d8 jc/gitignore-precedence later to maint).
+
+ * There was a commented-out (instead of being marked to expect
+   failure) test that documented a breakage that was fixed since the
+   test was written; turn it into a proper test.
+   (merge 66d2e04 sb/t1020-cleanup later to maint).
+
+ * The "log --decorate" enhancement in Git 2.4 that shows the commit
+   at the tip of the current branch e.g. "HEAD -> master", did not
+   work with --decorate=full.
+   (merge 429ad20 mg/log-decorate-HEAD later to maint).
+
+ * The ref API did not handle cases where 'refs/heads/xyzzy/frotz' is
+   removed at the same time as 'refs/heads/xyzzy' is added (or vice
+   versa) very well.
+   (merge c628edf mh/ref-directory-file later to maint).
+
+ * Multi-ref transaction support we merged a few releases ago
+   unnecessarily kept many file descriptors open, risking to fail with
+   resource exhaustion.  This is for 2.4.x track.
+   (merge 185ce3a mh/write-refs-sooner-2.4 later to maint).
+
+ * "git bundle verify" did not diagnose extra parameters on the
+   command line.
+   (merge 7886cfa ps/bundle-verify-arg later to maint).
+
+ * Various documentation mark-up fixes to make the output more
+   consistent in general and also make AsciiDoctor (an alternative
+   formatter) happier.
+   (merge d0258b9 jk/asciidoc-markup-fix later to maint).
+   (merge ad3967a jk/stripspace-asciidoctor-fix later to maint).
+   (merge 975e382 ja/tutorial-asciidoctor-fix later to maint).
+
+ * The code to read pack-bitmap wanted to allocate a few hundred
+   pointers to a structure, but by mistake allocated and leaked memory
+   enough to hold that many actual structures.  Correct the allocation
+   size and also have it on stack, as it is small enough.
+   (merge 599dc76 rs/plug-leak-in-pack-bitmaps later to maint).
+
+ * The pull.ff configuration was supposed to override the merge.ff
+   configuration, but it didn't.
+   (merge db9bb28 pt/pull-ff-vs-merge-ff later to maint).
+
+ * "git pull --log" and "git pull --no-log" worked as expected, but
+   "git pull --log=20" did not.
+   (merge 5061a44 pt/pull-log-n later to maint).
+
+ * "git rerere forget" in a repository without rerere enabled gave a
+   cryptic error message; it should be a silent no-op instead.
+   (merge 0544574 jk/rerere-forget-check-enabled later to maint).
+
+ * "git rebase -i" fired post-rewrite hook when it shouldn't (namely,
+   when it was told to stop sequencing with 'exec' insn).
+   (merge 141ff8f mm/rebase-i-post-rewrite-exec later to maint).
+
+ * Clarify that "log --raw" and "log --format=raw" are unrelated
+   concepts.
+   (merge 92de921 mm/log-format-raw-doc later to maint).
+
+ * Make "git stash something --help" error out, so that users can
+   safely say "git stash drop --help".
+   (merge 5ba2831 jk/stash-options later to maint).
+
+ * The clean/smudge interface did not work well when filtering an
+   empty contents (failed and then passed the empty input through).
+   It can be argued that a filter that produces anything but empty for
+   an empty input is nonsense, but if the user wants to do strange
+   things, then why not?
+   (merge f6a1e1e jh/filter-empty-contents later to maint).
+
+ * Communication between the HTTP server and http_backend process can
+   lead to a dead-lock when relaying a large ref negotiation request.
+   Diagnose the situation better, and mitigate it by reading such a
+   request first into core (to a reasonable limit).
+   (merge 636614f jk/http-backend-deadlock later to maint).
+
+ * "git clean pathspec..." tried to lstat(2) and complain even for
+   paths outside the given pathspec.
+   (merge 838d6a9 dt/clean-pathspec-filter-then-lstat later to maint).
+
+ * Recent "git prune" traverses young unreachable objects to safekeep
+   old objects in the reachability chain from them, which sometimes
+   caused error messages that are unnecessarily alarming.
+   (merge ce4e7b2 jk/squelch-missing-link-warning-for-unreachable later to maint).
+
+ * The configuration reader/writer uses mmap(2) interface to access
+   the files; when we find a directory, it barfed with "Out of memory?".
+   (merge 9ca0aaf jk/diagnose-config-mmap-failure later to maint).
+
+ * "color.diff.plain" was a misnomer; give it 'color.diff.context' as
+   a more logical synonym.
+   (merge 8dbf3eb jk/color-diff-plain-is-context later to maint).
+
+ * The setup code used to die when core.bare and core.worktree are set
+   inconsistently, even for commands that do not need working tree.
+   (merge fada767 jk/die-on-bogus-worktree-late later to maint).
+
+ * Recent Mac OS X updates breaks the logic to detect that the machine
+   is on the AC power in the sample pre-auto-gc script.
+   (merge c54c7b3 pa/auto-gc-mac-osx later to maint).
+
+ * "git commit --cleanup=scissors" was not careful enough to protect
+   against getting fooled by a line that looked like scissors.
+   (merge fbfa097 sg/commit-cleanup-scissors later to maint).
+
+ * "Have we lost a race with competing repack?" check was too
+   expensive, especially while receiving a huge object transfer
+   that runs index-pack (e.g. "clone" or "fetch").
+   (merge 0eeb077 jk/index-pack-reduce-recheck later to maint).
+
+ * The tcsh completion writes a bash scriptlet but that would have
+   failed for users with noclobber set.
+   (merge 0b1f688 af/tcsh-completion-noclobber later to maint).
+
+ * "git for-each-ref" reported "missing object" for 0{40} when it
+   encounters a broken ref.  The lack of object whose name is 0{40} is
+   not the problem; the ref being broken is.
+   (merge 501cf47 mh/reporting-broken-refs-from-for-each-ref later to maint).
+
+ * Various fixes around "git am" that applies a patch to a history
+   that is not there yet.
+   (merge 6ea3b67 pt/am-abort-fix later to maint).
+
+ * "git fsck" used to ignore missing or invalid objects recorded in reflog.
+   (merge 19bf6c9 mh/fsck-reflog-entries later to maint).
+
+ * "git format-patch --ignore-if-upstream A..B" did not like to be fed
+   tags as boundary commits.
+   (merge 9b7a61d jc/do-not-feed-tags-to-clear-commit-marks later to maint).
+
+ * "git fetch --depth=<depth>" and "git clone --depth=<depth>" issued
+   a shallow transfer request even to an upload-pack that does not
+   support the capability.
+   (merge eb86a50 me/fetch-into-shallow-safety later to maint).
+
+ * "git rebase" did not exit with failure when format-patch it invoked
+   failed for whatever reason.
+   (merge 60d708b cb/rebase-am-exit-code later to maint).
+
+ * Fix a small bug in our use of umask() return value.
+   (merge 3096b2e jk/fix-refresh-utime later to maint).
+
+ * An ancient test framework enhancement to allow color was not
+   entirely correct; this makes it work even when tput needs to read
+   from the ~/.terminfo under the user's real HOME directory.
+   (merge d5c1b7c rh/test-color-avoid-terminfo-in-original-home later to maint).
+
+ * A minor bugfix when pack bitmap is used with "rev-list --count".
+   (merge c8a70d3 jk/rev-list-no-bitmap-while-pruning later to maint).
+
+ * "git config" failed to update the configuration file when the
+   underlying filesystem is incapable of renaming a file that is still
+   open.
+   (merge 7a64592 kb/config-unmap-before-renaming later to maint).
+
+ * Avoid possible ssize_t to int truncation.
+   (merge 6c8afe4 mh/strbuf-read-file-returns-ssize-t later to maint).
+
+ * When you say "!<ENTER>" while running say "git log", you'd confuse
+   yourself in the resulting shell, that may look as if you took
+   control back to the original shell you spawned "git log" from but
+   that isn't what is happening.  To that new shell, we leaked
+   GIT_PAGER_IN_USE environment variable that was meant as a local
+   communication between the original "Git" and subprocesses that was
+   spawned by it after we launched the pager, which caused many
+   "interesting" things to happen, e.g. "git diff | cat" still paints
+   its output in color by default.
+
+   Stop leaking that environment variable to the pager's half of the
+   fork; we only need it on "Git" side when we spawn the pager.
+   (merge 124b519 jc/unexport-git-pager-in-use-in-pager later to maint).
+
+ * Abandoning an already applied change in "git rebase -i" with
+   "--continue" left CHERRY_PICK_HEAD and confused later steps.
+   (merge 0e0aff4 js/rebase-i-clean-up-upon-continue-to-skip later to maint).
+
+ * We used to ask libCURL to use the most secure authentication method
+   available when talking to an HTTP proxy only when we were told to
+   talk to one via configuration variables.  We now ask libCURL to
+   always use the most secure authentication method, because the user
+   can tell libCURL to use an HTTP proxy via an environment variable
+   without using configuration variables.
+   (merge 5841520 et/http-proxyauth later to maint).
+
+ * A fix to a minor regression to "git fsck" in v2.2 era that started
+   complaining about a body-less tag object when it lacks a separator
+   empty line after its header to separate it with a non-existent body.
+   (merge 84d18c0 jc/fsck-retire-require-eoh later to maint).
+
+ * Code cleanups and documentation updates.
+   (merge 0269f96 mm/usage-log-l-can-take-regex later to maint).
+   (merge 64f2589 nd/t1509-chroot-test later to maint).
+   (merge d201a1e sb/test-bitmap-free-at-end later to maint).
+   (merge 05bfc7d sb/line-log-plug-pairdiff-leak later to maint).
+   (merge 846e5df pt/xdg-config-path later to maint).
+   (merge 1154aa4 jc/plug-fmt-merge-msg-leak later to maint).
+   (merge 319b678 jk/sha1-file-reduce-useless-warnings later to maint).
+   (merge 9a35c14 fg/document-commit-message-stripping later to maint).
+   (merge bbf431c ps/doc-packfile-vs-pack-file later to maint).
+   (merge 309a9e3 jk/skip-http-tests-under-no-curl later to maint).
+   (merge ccd593c dl/branch-error-message later to maint).
+   (merge 22570b6 rs/janitorial later to maint).
+   (merge 5c2a581 mc/commit-doc-grammofix later to maint).
+   (merge ce41720 ah/usage-strings later to maint).
+   (merge e6a268c sb/glossary-submodule later to maint).
+   (merge ec48a76 sb/submodule-doc-intro later to maint).
+   (merge 14f8b9b jk/clone-dissociate later to maint).
+   (merge 055c7e9 sb/pack-protocol-mention-smart-http later to maint).
+   (merge 7c37a5d jk/make-fix-dependencies later to maint).
+   (merge fc0aa39 sg/merge-summary-config later to maint).
+   (merge 329af6c pt/t0302-needs-sanity later to maint).
+   (merge d614f07 fk/doc-format-patch-vn later to maint).
+   (merge 72dbb36 sg/completion-commit-cleanup later to maint).
+   (merge e654eb2 es/utf8-stupid-compiler-workaround later to maint).
+   (merge 34b935c es/osx-header-pollutes-mask-macro later to maint).
+   (merge ab7fade jc/prompt-document-ps1-state-separator later to maint).
+   (merge 25f600e mm/describe-doc later to maint).
+   (merge 83fe167 mm/branch-doc-updates later to maint).
+   (merge 75d2e5a ls/hint-rev-list-count later to maint).
+   (merge edc8f71 cb/subtree-tests-update later to maint).
+   (merge 5330e6e sb/p5310-and-chain later to maint).
+   (merge c4ac525 tb/checkout-doc later to maint).
+   (merge e479c5f jk/pretty-encoding-doc later to maint).
+   (merge 7e837c6 ss/clone-guess-dir-name-simplify later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.5.1.txt b/third_party/git/Documentation/RelNotes/2.5.1.txt
new file mode 100644
index 0000000000..b70553308a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.1.txt
@@ -0,0 +1,65 @@
+Git v2.5.1 Release Notes
+========================
+
+Fixes since v2.5
+----------------
+
+ * Running an aliased command from a subdirectory when the .git thing
+   in the working tree is a gitfile pointing elsewhere did not work.
+
+ * Often a fast-import stream builds a new commit on top of the
+   previous commit it built, and it often unconditionally emits a
+   "from" command to specify the first parent, which can be omitted in
+   such a case.  This caused fast-import to forget the tree of the
+   previous commit and then re-read it from scratch, which was
+   inefficient.  Optimize for this common case.
+
+ * The "rev-parse --parseopt" mode parsed the option specification
+   and the argument hint in a strange way to allow '=' and other
+   special characters in the option name while forbidding them from
+   the argument hint.  This made it impossible to define an option
+   like "--pair <key>=<value>" with "pair=key=value" specification,
+   which instead would have defined a "--pair=key <value>" option.
+
+ * A "rebase" replays changes of the local branch on top of something
+   else, as such they are placed in stage #3 and referred to as
+   "theirs", while the changes in the new base, typically a foreign
+   work, are placed in stage #2 and referred to as "ours".  Clarify
+   the "checkout --ours/--theirs".
+
+ * An experimental "untracked cache" feature used uname(2) in a
+   slightly unportable way.
+
+ * "sparse checkout" misbehaved for a path that is excluded from the
+   checkout when switching between branches that differ at the path.
+
+ * The low-level "git send-pack" did not honor 'user.signingkey'
+   configuration variable when sending a signed-push.
+
+ * An attempt to delete a ref by pushing into a repository whose HEAD
+   symbolic reference points at an unborn branch that cannot be
+   created due to ref D/F conflict (e.g. refs/heads/a/b exists, HEAD
+   points at refs/heads/a) failed.
+
+ * "git subtree" (in contrib/) depended on "git log" output to be
+   stable, which was a no-no.  Apply a workaround to force a
+   particular date format.
+
+ * "git clone $URL" in recent releases of Git contains a regression in
+   the code that invents a new repository name incorrectly based on
+   the $URL.  This has been corrected.
+   (merge db2e220 jk/guess-repo-name-regression-fix later to maint).
+
+ * Running tests with the "-x" option to make them verbose had some
+   unpleasant interactions with other features of the test suite.
+   (merge 9b5fe78 jk/test-with-x later to maint).
+
+ * "git pull" in recent releases of Git has a regression in the code
+   that allows custom path to the --upload-pack=<program>.  This has
+   been corrected.
+
+ * pipe() emulation used in Git for Windows looked at a wrong variable
+   when checking for an error from an _open_osfhandle() call.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.5.2.txt b/third_party/git/Documentation/RelNotes/2.5.2.txt
new file mode 100644
index 0000000000..3f749398bb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.2.txt
@@ -0,0 +1,63 @@
+Git v2.5.2 Release Notes
+========================
+
+Fixes since v2.5.1
+------------------
+
+ * "git init empty && git -C empty log" said "bad default revision 'HEAD'",
+   which was found to be a bit confusing to new users.
+
+ * The "interpret-trailers" helper mistook a multi-paragraph title of
+   a commit log message with a colon in it as the end of the trailer
+   block.
+
+ * When re-priming the cache-tree opportunistically while committing
+   the in-core index as-is, we mistakenly invalidated the in-core
+   index too aggressively, causing the experimental split-index code
+   to unnecessarily rewrite the on-disk index file(s).
+
+ * "git archive" did not use zip64 extension when creating an archive
+   with more than 64k entries, which nobody should need, right ;-)?
+
+ * The code in "multiple-worktree" support that attempted to recover
+   from an inconsistent state updated an incorrect file.
+
+ * "git rev-list" does not take "--notes" option, but did not complain
+   when one is given.
+
+ * Because the configuration system does not allow "alias.0foo" and
+   "pager.0foo" as the configuration key, the user cannot use '0foo'
+   as a custom command name anyway, but "git 0foo" tried to look these
+   keys up and emitted useless warnings before saying '0foo is not a
+   git command'.  These warning messages have been squelched.
+
+ * We recently rewrote one of the build scripts in Perl, which made it
+   necessary to have Perl to build Git.  Reduced Perl dependency by
+   rewriting it again using sed.
+
+ * t1509 test that requires a dedicated VM environment had some
+   bitrot, which has been corrected.
+
+ * strbuf_read() used to have one extra iteration (and an unnecessary
+   strbuf_grow() of 8kB), which was eliminated.
+
+ * The codepath to produce error messages had a hard-coded limit to
+   the size of the message, primarily to avoid memory allocation while
+   calling die().
+
+ * When trying to see that an object does not exist, a state errno
+   leaked from our "first try to open a packfile with O_NOATIME and
+   then if it fails retry without it" logic on a system that refuses
+   O_NOATIME.  This confused us and caused us to die, saying that the
+   packfile is unreadable, when we should have just reported that the
+   object does not exist in that packfile to the caller.
+
+ * An off-by-one error made "git remote" to mishandle a remote with a
+   single letter nickname.
+
+ * A handful of codepaths that used to use fixed-sized arrays to hold
+   pathnames have been corrected to use strbuf and other mechanisms to
+   allow longer pathnames without fearing overflows.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.5.3.txt b/third_party/git/Documentation/RelNotes/2.5.3.txt
new file mode 100644
index 0000000000..d1436857cb
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.3.txt
@@ -0,0 +1,17 @@
+Git v2.5.3 Release Notes
+========================
+
+Fixes since v2.5.2
+------------------
+
+ * The experimental untracked-cache feature were buggy when paths with
+   a few levels of subdirectories are involved.
+
+ * Recent versions of scripted "git am" has a performance regression
+   in "git am --skip" codepath, which no longer exists in the
+   built-in version on the 'master' front.  Fix the regression in
+   the last scripted version that appear in 2.5.x maintenance track
+   and older.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.5.4.txt b/third_party/git/Documentation/RelNotes/2.5.4.txt
new file mode 100644
index 0000000000..b8a2f93ee7
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.4.txt
@@ -0,0 +1,18 @@
+Git v2.5.4 Release Notes
+========================
+
+Fixes since v2.5.4
+------------------
+
+ * xdiff code we use to generate diffs is not prepared to handle
+   extremely large files.  It uses "int" in many places, which can
+   overflow if we have a very large number of lines or even bytes in
+   our input files, for example.  Cap the input size to somewhere
+   around 1GB for now.
+
+ * Some protocols (like git-remote-ext) can execute arbitrary code
+   found in the URL.  The URLs that submodules use may come from
+   arbitrary sources (e.g., .gitmodules files in a remote
+   repository), and can hurt those who blindly enable recursive
+   fetch.  Restrict the allowed protocols to well known and safe
+   ones.
diff --git a/third_party/git/Documentation/RelNotes/2.5.5.txt b/third_party/git/Documentation/RelNotes/2.5.5.txt
new file mode 100644
index 0000000000..37eae9a2d9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.5.txt
@@ -0,0 +1,11 @@
+Git v2.5.5 Release Notes
+========================
+
+Fixes since v2.5.4
+------------------
+
+ * Bugfix patches were backported from the 'master' front to plug heap
+   corruption holes, to catch integer overflow in the computation of
+   pathname lengths, and to get rid of the name_path API.  Both of
+   these would have resulted in writing over an under-allocated buffer
+   when formulating pathnames while tree traversal.
diff --git a/third_party/git/Documentation/RelNotes/2.5.6.txt b/third_party/git/Documentation/RelNotes/2.5.6.txt
new file mode 100644
index 0000000000..9cd025bb1c
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.5.6.txt
@@ -0,0 +1,12 @@
+Git v2.5.6 Release Notes
+========================
+
+Fixes since v2.5.5
+------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
diff --git a/third_party/git/Documentation/RelNotes/2.6.0.txt b/third_party/git/Documentation/RelNotes/2.6.0.txt
new file mode 100644
index 0000000000..7288aaf716
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.0.txt
@@ -0,0 +1,370 @@
+Git 2.6 Release Notes
+=====================
+
+Updates since v2.5
+------------------
+
+UI, Workflows & Features
+
+ * An asterisk as a substring (as opposed to the entirety) of a path
+   component for both side of a refspec, e.g.
+   "refs/heads/o*:refs/remotes/heads/i*", is now allowed.
+
+ * New userdiff pattern definition for fountain screenwriting markup
+   format has been added.
+
+ * "git log" and friends learned a new "--date=format:..." option to
+   format timestamps using system's strftime(3).
+
+ * "git fast-import" learned to respond to the get-mark command via
+   its cat-blob-fd interface.
+
+ * "git rebase -i" learned "drop commit-object-name subject" command
+   as another way to skip replaying of a commit.
+
+ * A new configuration variable can enable "--follow" automatically
+   when "git log" is run with one pathspec argument.
+
+ * "git status" learned to show a more detailed information regarding
+   the "rebase -i" session in progress.
+
+ * "git cat-file" learned "--batch-all-objects" option to enumerate all
+   available objects in the repository more quickly than "rev-list
+   --all --objects" (the output includes unreachable objects, though).
+
+ * "git fsck" learned to ignore errors on a set of known-to-be-bad
+   objects, and also allows the warning levels of various kinds of
+   non-critical breakages to be tweaked.
+
+ * "git rebase -i"'s list of todo is made configurable.
+
+ * "git send-email" now performs alias-expansion on names that are
+   given via --cccmd, etc.
+
+ * An environment variable GIT_REPLACE_REF_BASE tells Git to look into
+   refs hierarchy other than refs/replace/ for the object replacement
+   data.
+
+ * Allow untracked cache (experimental) to be used when sparse
+   checkout (experimental) is also in use.
+
+ * "git pull --rebase" has been taught to pay attention to
+   rebase.autostash configuration.
+
+ * The command-line completion script (in contrib/) has been updated.
+
+ * A negative !ref entry in multi-value transfer.hideRefs
+   configuration can be used to say "don't hide this one".
+
+ * After "git am" without "-3" stops, running "git am -3" pays attention
+   to "-3" only for the patch that caused the original invocation
+   to stop.
+
+ * When linked worktree is used, simultaneous "notes merge" instances
+   for the same ref in refs/notes/* are prevented from stomping on
+   each other.
+
+ * "git send-email" learned a new option --smtp-auth to limit the SMTP
+   AUTH mechanisms to be used to a subset of what the system library
+   supports.
+
+ * A new configuration variable http.sslVersion can be used to specify
+   what specific version of SSL/TLS to use to make a connection.
+
+ * "git notes merge" can be told with "--strategy=<how>" option how to
+   automatically handle conflicts; this can now be configured by
+   setting notes.mergeStrategy configuration variable.
+
+ * "git log --cc" did not show any patch, even though most of the time
+   the user meant "git log --cc -p -m" to see patch output for commits
+   with a single parent, and combined diff for merge commits.  The
+   command is taught to DWIM "--cc" (without "--raw" and other forms
+   of output specification) to "--cc -p -m".
+
+ * "git config --list" output was hard to parse when values consist of
+   multiple lines.  "--name-only" option is added to help this.
+
+ * A handful of usability & cosmetic fixes to gitk and l10n updates.
+
+ * A completely empty e-mail address <> is now allowed in the authors
+   file used by git-svn, to match the way it accepts the output from
+   authors-prog.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * In preparation for allowing different "backends" to store the refs
+   in a way different from the traditional "one ref per file in
+   $GIT_DIR or in a $GIT_DIR/packed-refs file" filesystem storage,
+   direct filesystem access to ref-like things like CHERRY_PICK_HEAD
+   from scripts and programs has been reduced.
+
+ * Computation of untracked status indicator by bash prompt
+   script (in contrib/) has been optimized.
+
+ * Memory use reduction when commit-slab facility is used to annotate
+   sparsely (which is not recommended in the first place).
+
+ * Clean up refs API and make "git clone" less intimate with the
+   implementation detail.
+
+ * "git pull" was reimplemented in C.
+
+ * The packet tracing machinery allows to capture an incoming pack
+   data to a file for debugging.
+
+ * Move machinery to parse human-readable scaled numbers like 1k, 4M,
+   and 2G as an option parameter's value from pack-objects to
+   parse-options API, to make it available to other codepaths.
+
+ * "git verify-tag" and "git verify-commit" have been taught to share
+   more code, and then learned to optionally show the verification
+   message from the underlying GPG implementation.
+
+ * Various enhancements around "git am" reading patches generated by
+   foreign SCM have been made.
+
+ * Ref listing by "git branch -l" and "git tag -l" commands has
+   started to be rebuilt, based on the for-each-ref machinery.
+
+ * The code to perform multi-tree merges has been taught to repopulate
+   the cache-tree upon a successful merge into the index, so that
+   subsequent "diff-index --cached" (hence "status") and "write-tree"
+   (hence "commit") will go faster.
+
+   The same logic in "git checkout" may now be removed, but that is a
+   separate issue.
+
+ * Tests that assume how reflogs are represented on the filesystem too
+   much have been corrected.
+
+ * "git am" has been rewritten in "C".
+
+ * git_path() and mkpath() are handy helper functions but it is easy
+   to misuse, as the callers need to be careful to keep the number of
+   active results below 4.  Their uses have been reduced.
+
+ * The "lockfile" API has been rebuilt on top of a new "tempfile" API.
+
+ * To prepare for allowing a different "ref" backend to be plugged in
+   to the system, update_ref()/delete_ref() have been taught about
+   ref-like things like MERGE_HEAD that are per-worktree (they will
+   always be written to the filesystem inside $GIT_DIR).
+
+ * The gitmodules API that is accessed from the C code learned to
+   cache stuff lazily.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.5
+----------------
+
+Unless otherwise noted, all the fixes since v2.5 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git subtree" (in contrib/) depended on "git log" output to be
+   stable, which was a no-no.  Apply a workaround to force a
+   particular date format.
+   (merge e7aac44 da/subtree-date-confusion later to maint).
+
+ * An attempt to delete a ref by pushing into a repository whose HEAD
+   symbolic reference points at an unborn branch that cannot be
+   created due to ref D/F conflict (e.g. refs/heads/a/b exists, HEAD
+   points at refs/heads/a) failed.
+   (merge b112b14 jx/do-not-crash-receive-pack-wo-head later to maint).
+
+ * The low-level "git send-pack" did not honor 'user.signingkey'
+   configuration variable when sending a signed-push.
+   (merge d830d39 db/send-pack-user-signingkey later to maint).
+
+ * "sparse checkout" misbehaved for a path that is excluded from the
+   checkout when switching between branches that differ at the path.
+   (merge 7d78241 as/sparse-checkout-removal later to maint).
+
+ * An experimental "untracked cache" feature used uname(2) in a
+   slightly unportable way.
+   (merge 100e433 cb/uname-in-untracked later to maint).
+
+ * A "rebase" replays changes of the local branch on top of something
+   else, as such they are placed in stage #3 and referred to as
+   "theirs", while the changes in the new base, typically a foreign
+   work, are placed in stage #2 and referred to as "ours".  Clarify
+   the "checkout --ours/--theirs".
+   (merge f303016 se/doc-checkout-ours-theirs later to maint).
+
+ * The "rev-parse --parseopt" mode parsed the option specification
+   and the argument hint in a strange way to allow '=' and other
+   special characters in the option name while forbidding them from
+   the argument hint.  This made it impossible to define an option
+   like "--pair <key>=<value>" with "pair=key=value" specification,
+   which instead would have defined a "--pair=key <value>" option.
+   (merge 2d893df ib/scripted-parse-opt-better-hint-string later to maint).
+
+ * Often a fast-import stream builds a new commit on top of the
+   previous commit it built, and it often unconditionally emits a
+   "from" command to specify the first parent, which can be omitted in
+   such a case.  This caused fast-import to forget the tree of the
+   previous commit and then re-read it from scratch, which was
+   inefficient.  Optimize for this common case.
+   (merge 0df3245 mh/fast-import-optimize-current-from later to maint).
+
+ * Running an aliased command from a subdirectory when the .git thing
+   in the working tree is a gitfile pointing elsewhere did not work.
+   (merge d95138e nd/export-worktree later to maint).
+
+ * "Is this subdirectory a separate repository that should not be
+   touched?" check "git clean" was inefficient.  This was replaced
+   with a more optimized check.
+   (merge fbf2fec ee/clean-remove-dirs later to maint).
+
+ * The "new-worktree-mode" hack in "checkout" that was added in
+   nd/multiple-work-trees topic has been removed by updating the
+   implementation of new "worktree add".
+   (merge 65f9b75 es/worktree-add-cleanup later to maint).
+
+ * Remove remaining cruft from  "git checkout --to", which
+   transitioned to "git worktree add".
+   (merge 114ff88 es/worktree-add later to maint).
+
+ * An off-by-one error made "git remote" to mishandle a remote with a
+   single letter nickname.
+   (merge bc598c3 mh/get-remote-group-fix later to maint).
+
+ * "git clone $URL", when cloning from a site whose sole purpose is to
+   host a single repository (hence, no path after <scheme>://<site>/),
+   tried to use the site name as the new repository name, but did not
+   remove username or password when <site> part was of the form
+   <user>@<pass>:<host>.  The code is taught to redact these.
+   (merge adef956 ps/guess-repo-name-at-root later to maint).
+
+ * Running tests with the "-x" option to make them verbose had some
+   unpleasant interactions with other features of the test suite.
+   (merge 9b5fe78 jk/test-with-x later to maint).
+
+ * t1509 test that requires a dedicated VM environment had some
+   bitrot, which has been corrected.
+   (merge faacc5a ps/t1509-chroot-test-fixup later to maint).
+
+ * "git pull" in recent releases of Git has a regression in the code
+   that allows custom path to the --upload-pack=<program>.  This has
+   been corrected.
+
+   Note that this is irrelevant for 'master' with "git pull" rewritten
+   in C.
+   (merge 13e0e28 mm/pull-upload-pack later to maint).
+
+ * When trying to see that an object does not exist, a state errno
+   leaked from our "first try to open a packfile with O_NOATIME and
+   then if it fails retry without it" logic on a system that refuses
+   O_NOATIME.  This confused us and caused us to die, saying that the
+   packfile is unreadable, when we should have just reported that the
+   object does not exist in that packfile to the caller.
+   (merge dff6f28 cb/open-noatime-clear-errno later to maint).
+
+ * The codepath to produce error messages had a hard-coded limit to
+   the size of the message, primarily to avoid memory allocation while
+   calling die().
+   (merge f4c3edc jk/long-error-messages later to maint).
+
+ * strbuf_read() used to have one extra iteration (and an unnecessary
+   strbuf_grow() of 8kB), which was eliminated.
+   (merge 3ebbd00 jh/strbuf-read-use-read-in-full later to maint).
+
+ * We rewrote one of the build scripts in Perl but this reimplements
+   in Bourne shell.
+   (merge 57cee8a sg/help-group later to maint).
+
+ * The experimental untracked-cache feature were buggy when paths with
+   a few levels of subdirectories are involved.
+   (merge 73f9145 dt/untracked-subdir later to maint).
+
+ * "interpret-trailers" helper mistook a single-liner log message that
+   has a colon as the end of existing trailer.
+
+ * The "interpret-trailers" helper mistook a multi-paragraph title of
+   a commit log message with a colon in it as the end of the trailer
+   block.
+   (merge 5c99995 cc/trailers-corner-case-fix later to maint).
+
+ * "git describe" without argument defaulted to describe the HEAD
+   commit, but "git describe --contains" didn't.  Arguably, in a
+   repository used for active development, such defaulting would not
+   be very useful as the tip of branch is typically not tagged, but it
+   is better to be consistent.
+   (merge 2bd0706 sg/describe-contains later to maint).
+
+ * The client side codepaths in "git push" have been cleaned up
+   and the user can request to perform an optional "signed push",
+   i.e. sign only when the other end accepts signed push.
+   (merge 68c757f db/push-sign-if-asked later to maint).
+
+ * Because the configuration system does not allow "alias.0foo" and
+   "pager.0foo" as the configuration key, the user cannot use '0foo'
+   as a custom command name anyway, but "git 0foo" tried to look these
+   keys up and emitted useless warnings before saying '0foo is not a
+   git command'.  These warning messages have been squelched.
+   (merge 9e9de18 jk/fix-alias-pager-config-key-warnings later to maint).
+
+ * "git rev-list" does not take "--notes" option, but did not complain
+   when one is given.
+   (merge 2aea7a5 jk/rev-list-has-no-notes later to maint).
+
+ * When re-priming the cache-tree opportunistically while committing
+   the in-core index as-is, we mistakenly invalidated the in-core
+   index too aggressively, causing the experimental split-index code
+   to unnecessarily rewrite the on-disk index file(s).
+   (merge 475a344 dt/commit-preserve-base-index-upon-opportunistic-cache-tree-update later to maint).
+
+ * "git archive" did not use zip64 extension when creating an archive
+   with more than 64k entries, which nobody should need, right ;-)?
+   (merge 88329ca rs/archive-zip-many later to maint).
+
+ * The code in "multiple-worktree" support that attempted to recover
+   from an inconsistent state updated an incorrect file.
+   (merge 82fde87 nd/fixup-linked-gitdir later to maint).
+
+ * On case insensitive systems, "git p4" did not work well with client
+   specs.
+
+ * "git init empty && git -C empty log" said "bad default revision 'HEAD'",
+   which was found to be a bit confusing to new users.
+   (merge ce11360 jk/log-missing-default-HEAD later to maint).
+
+ * Recent versions of scripted "git am" has a performance regression in
+   "git am --skip" codepath, which no longer exists in the built-in
+   version on the 'master' front.  Fix the regression in the last
+   scripted version that appear in 2.5.x maintenance track and older.
+   (merge b9d6689 js/maint-am-skip-performance-regression later to maint).
+
+ * The branch descriptions that are set with "git branch --edit-description"
+   option were used in many places but they weren't clearly documented.
+   (merge 561d2b7 po/doc-branch-desc later to maint).
+
+ * Code cleanups and documentation updates.
+   (merge 1c601af es/doc-clean-outdated-tools later to maint).
+   (merge 3581304 kn/tag-doc-fix later to maint).
+   (merge 3a59e59 kb/i18n-doc later to maint).
+   (merge 45abdee sb/remove-unused-var-from-builtin-add later to maint).
+   (merge 14691e3 sb/parse-options-codeformat later to maint).
+   (merge 4a6ada3 ad/bisect-cleanup later to maint).
+   (merge da4c5ad ta/docfix-index-format-tech later to maint).
+   (merge ae25fd3 sb/check-return-from-read-ref later to maint).
+   (merge b3325df nd/dwim-wildcards-as-pathspecs later to maint).
+   (merge 7aa9b9b sg/wt-status-header-inclusion later to maint).
+   (merge f04c690 as/docfix-reflog-expire-unreachable later to maint).
+   (merge 1269847 sg/t3020-typofix later to maint).
+   (merge 8b54c23 jc/calloc-pathspec later to maint).
+   (merge a6926b8 po/po-readme later to maint).
+   (merge 54d160e ss/fix-config-fd-leak later to maint).
+   (merge b80fa84 ah/submodule-typofix-in-error later to maint).
+   (merge 99885bc ah/reflog-typofix-in-error later to maint).
+   (merge 9476c2c ah/read-tree-usage-string later to maint).
+   (merge b8c1d27 ah/pack-objects-usage-strings later to maint).
+   (merge 486e1e1 br/svn-doc-include-paths-config later to maint).
+   (merge 1733ed3 ee/clean-test-fixes later to maint).
+   (merge 5fcadc3 gb/apply-comment-typofix later to maint).
+   (merge b894d3e mp/t7060-diff-index-test later to maint).
+   (merge d238710 as/config-doc-markup-fix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.6.1.txt b/third_party/git/Documentation/RelNotes/2.6.1.txt
new file mode 100644
index 0000000000..f37ea89cda
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.1.txt
@@ -0,0 +1,18 @@
+Git v2.6.1 Release Notes
+========================
+
+Fixes since v2.6
+----------------
+
+ * xdiff code we use to generate diffs is not prepared to handle
+   extremely large files.  It uses "int" in many places, which can
+   overflow if we have a very large number of lines or even bytes in
+   our input files, for example.  Cap the input size to somewhere
+   around 1GB for now.
+
+ * Some protocols (like git-remote-ext) can execute arbitrary code
+   found in the URL.  The URLs that submodules use may come from
+   arbitrary sources (e.g., .gitmodules files in a remote
+   repository), and can hurt those who blindly enable recursive
+   fetch.  Restrict the allowed protocols to well known and safe
+   ones.
diff --git a/third_party/git/Documentation/RelNotes/2.6.2.txt b/third_party/git/Documentation/RelNotes/2.6.2.txt
new file mode 100644
index 0000000000..5b65e35245
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.2.txt
@@ -0,0 +1,65 @@
+Git v2.6.2 Release Notes
+========================
+
+Fixes since v2.6.1
+------------------
+
+ * There were some classes of errors that "git fsck" diagnosed to its
+   standard error that did not cause it to exit with non-zero status.
+
+ * A test script for the HTTP service had a timing dependent bug,
+   which was fixed.
+
+ * Performance-measurement tests did not work without an installed Git.
+
+ * On a case insensitive filesystems, setting GIT_WORK_TREE variable
+   using a random cases that does not agree with what the filesystem
+   thinks confused Git that it wasn't inside the working tree.
+
+ * When "git am" was rewritten as a built-in, it stopped paying
+   attention to user.signingkey, which was fixed.
+
+ * After "git checkout --detach", "git status" reported a fairly
+   useless "HEAD detached at HEAD", instead of saying at which exact
+   commit.
+
+ * "git rebase -i" had a minor regression recently, which stopped
+   considering a line that begins with an indented '#' in its insn
+   sheet not a comment, which is now fixed.
+
+ * Description of the "log.follow" configuration variable in "git log"
+   documentation is now also copied to "git config" documentation.
+
+ * Allocation related functions and stdio are unsafe things to call
+   inside a signal handler, and indeed killing the pager can cause
+   glibc to deadlock waiting on allocation mutex as our signal handler
+   tries to free() some data structures in wait_for_pager().  Reduce
+   these unsafe calls.
+
+ * The way how --ref/--notes to specify the notes tree reference are
+   DWIMmed was not clearly documented.
+
+ * Customization to change the behaviour with "make -w" and "make -s"
+   in our Makefile was broken when they were used together.
+
+ * The Makefile always runs the library archiver with hardcoded "crs"
+   options, which was inconvenient for exotic platforms on which
+   people want to use programs with totally different set of command
+   line options.
+
+ * The ssh transport, just like any other transport over the network,
+   did not clear GIT_* environment variables, but it is possible to
+   use SendEnv and AcceptEnv to leak them to the remote invocation of
+   Git, which is not a good idea at all.  Explicitly clear them just
+   like we do for the local transport.
+
+ * "git blame --first-parent v1.0..v2.0" was not rejected but did not
+   limit the blame to commits on the first parent chain.
+
+ * Very small number of options take a parameter that is optional
+   (which is not a great UI element as they can only appear at the end
+   of the command line).  Add notice to documentation of each and
+   every one of them.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.6.3.txt b/third_party/git/Documentation/RelNotes/2.6.3.txt
new file mode 100644
index 0000000000..fc6fe1711f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.3.txt
@@ -0,0 +1,111 @@
+Git v2.6.3 Release Notes
+========================
+
+Fixes since v2.6.2
+------------------
+
+ * The error message from "git blame --contents --reverse" incorrectly
+   talked about "--contents --children".
+
+ * "git merge-file" tried to signal how many conflicts it found, which
+   obviously would not work well when there are too many of them.
+
+ * The name-hash subsystem that is used to cope with case insensitive
+   filesystems keeps track of directories and their on-filesystem
+   cases for all the paths in the index by holding a pointer to a
+   randomly chosen cache entry that is inside the directory (for its
+   ce->ce_name component).  This pointer was not updated even when the
+   cache entry was removed from the index, leading to use after free.
+   This was fixed by recording the path for each directory instead of
+   borrowing cache entries and restructuring the API somewhat.
+
+ * When the "git am" command was reimplemented in C, "git am -3" had a
+   small regression where it is aborted in its error handling codepath
+   when underlying merge-recursive failed in some ways.
+
+ * The synopsis text and the usage string of subcommands that read
+   list of things from the standard input are often shown as if they
+   only take input from a file on a filesystem, which was misleading.
+
+ * A couple of commands still showed "[options]" in their usage string
+   to note where options should come on their command line, but we
+   spell that "[<options>]" in most places these days.
+
+ * The submodule code has been taught to work better with separate
+   work trees created via "git worktree add".
+
+ * When "git gc --auto" is backgrounded, its diagnosis message is
+   lost.  It now is saved to a file in $GIT_DIR and is shown next time
+   the "gc --auto" is run.
+
+ * Work around "git p4" failing when the P4 depot records the contents
+   in UTF-16 without UTF-16 BOM.
+
+ * Recent update to "rebase -i" that tries to sanity check the edited
+   insn sheet before it uses it has become too picky on Windows where
+   CRLF left by the editor is turned into a trailing CR on the line
+   read via the "read" built-in command.
+
+ * "git clone --dissociate" runs a big "git repack" process at the
+   end, and it helps to close file descriptors that are open on the
+   packs and their idx files before doing so on filesystems that
+   cannot remove a file that is still open.
+
+ * Correct "git p4 --detect-labels" so that it does not fail to create
+   a tag that points at a commit that is also being imported.
+
+ * The internal stripspace() function has been moved to where it
+   logically belongs to, i.e. strbuf API, and the command line parser
+   of "git stripspace" has been updated to use the parse_options API.
+
+ * Prepare for Git on-disk repository representation to undergo
+   backward incompatible changes by introducing a new repository
+   format version "1", with an extension mechanism.
+
+ * "git gc" used to barf when a symbolic ref has gone dangling
+   (e.g. the branch that used to be your upstream's default when you
+   cloned from it is now gone, and you did "fetch --prune").
+
+ * The normalize_ceiling_entry() function does not muck with the end
+   of the path it accepts, and the real world callers do rely on that,
+   but a test insisted that the function drops a trailing slash.
+
+ * "git gc" is safe to run anytime only because it has the built-in
+   grace period to protect young objects.  In order to run with no
+   grace period, the user must make sure that the repository is
+   quiescent.
+
+ * A recent "filter-branch --msg-filter" broke skipping of the commit
+   object header, which is fixed.
+
+ * "git --literal-pathspecs add -u/-A" without any command line
+   argument misbehaved ever since Git 2.0.
+
+ * Merging a branch that removes a path and another that changes the
+   mode bits on the same path should have conflicted at the path, but
+   it didn't and silently favoured the removal.
+
+ * "git imap-send" did not compile well with older version of cURL library.
+
+ * The linkage order of libraries was wrong in places around libcurl.
+
+ * It was not possible to use a repository-lookalike created by "git
+   worktree add" as a local source of "git clone".
+
+ * When "git send-email" wanted to talk over Net::SMTP::SSL,
+   Net::Cmd::datasend() did not like to be fed too many bytes at the
+   same time and failed to send messages.  Send the payload one line
+   at a time to work around the problem.
+
+ * We peek objects from submodule's object store by linking it to the
+   list of alternate object databases, but the code to do so forgot to
+   correctly initialize the list.
+
+ * "git status --branch --short" accessed beyond the constant string
+   "HEAD", which has been corrected.
+
+ * "git daemon" uses "run_command()" without "finish_command()", so it
+   needs to release resources itself, which it forgot to do.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.6.4.txt b/third_party/git/Documentation/RelNotes/2.6.4.txt
new file mode 100644
index 0000000000..b0256a2dc9
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.4.txt
@@ -0,0 +1,63 @@
+Git v2.6.4 Release Notes
+========================
+
+Fixes since v2.6.3
+------------------
+
+ * The "configure" script did not test for -lpthread correctly, which
+   upset some linkers.
+
+ * Add support for talking http/https over socks proxy.
+
+ * Portability fix for Windows, which may rewrite $SHELL variable using
+   non-POSIX paths.
+
+ * We now consistently allow all hooks to ignore their standard input,
+   rather than having git complain of SIGPIPE.
+
+ * Fix shell quoting in contrib script.
+
+ * Test portability fix for a topic in v2.6.1.
+
+ * Allow tilde-expansion in some http config variables.
+
+ * Give a useful special case "diff/show --word-diff-regex=." as an
+   example in the documentation.
+
+ * Fix for a corner case in filter-branch.
+
+ * Make git-p4 work on a detached head.
+
+ * Documentation clarification for "check-ignore" without "--verbose".
+
+ * Just like the working tree is cleaned up when the user cancelled
+   submission in P4Submit.applyCommit(), clean up the mess if "p4
+   submit" fails.
+
+ * Having a leftover .idx file without corresponding .pack file in
+   the repository hurts performance; "git gc" learned to prune them.
+
+ * The code to prepare the working tree side of temporary directory
+   for the "dir-diff" feature forgot that symbolic links need not be
+   copied (or symlinked) to the temporary area, as the code already
+   special cases and overwrites them.  Besides, it was wrong to try
+   computing the object name of the target of symbolic link, which may
+   not even exist or may be a directory.
+
+ * There was no way to defeat a configured rebase.autostash variable
+   from the command line, as "git rebase --no-autostash" was missing.
+
+ * Allow "git interpret-trailers" to run outside of a Git repository.
+
+ * Produce correct "dirty" marker for shell prompts, even when we
+   are on an orphan or an unborn branch.
+
+ * Some corner cases have been fixed in string-matching done in "git
+   status".
+
+ * Apple's common crypto implementation of SHA1_Update() does not take
+   more than 4GB at a time, and we now have a compile-time workaround
+   for it.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.6.5.txt b/third_party/git/Documentation/RelNotes/2.6.5.txt
new file mode 100644
index 0000000000..f0924b62e0
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.5.txt
@@ -0,0 +1,58 @@
+Git v2.6.5 Release Notes
+========================
+
+Fixes since v2.6.4
+------------------
+
+ * Because "test_when_finished" in our test framework queues the
+   clean-up tasks to be done in a shell variable, it should not be
+   used inside a subshell.  Add a mechanism to allow 'bash' to catch
+   such uses, and fix the ones that were found.
+
+ * Update "git subtree" (in contrib/) so that it can take whitespaces
+   in the pathnames, not only in the in-tree pathname but the name of
+   the directory that the repository is in.
+
+ * Cosmetic improvement to lock-file error messages.
+
+ * mark_tree_uninteresting() has code to handle the case where it gets
+   passed a NULL pointer in its 'tree' parameter, but the function had
+   'object = &tree->object' assignment before checking if tree is
+   NULL.  This gives a compiler an excuse to declare that tree will
+   never be NULL and apply a wrong optimization.  Avoid it.
+
+ * The helper used to iterate over loose object directories to prune
+   stale objects did not closedir() immediately when it is done with a
+   directory--a callback such as the one used for "git prune" may want
+   to do rmdir(), but it would fail on open directory on platforms
+   such as WinXP.
+
+ * "git p4" used to import Perforce CLs that touch only paths outside
+   the client spec as empty commits.  It has been corrected to ignore
+   them instead, with a new configuration git-p4.keepEmptyCommits as a
+   backward compatibility knob.
+
+ * The exit code of git-fsck did not reflect some types of errors
+   found in packed objects, which has been corrected.
+
+ * The completion script (in contrib/) used to list "git column"
+   (which is not an end-user facing command) as one of the choices
+
+ * Improve error reporting when SMTP TLS fails.
+
+ * When getpwuid() on the system returned NULL (e.g. the user is not
+   in the /etc/passwd file or other uid-to-name mappings), the
+   codepath to find who the user is to record it in the reflog barfed
+   and died.  Loosen the check in this codepath, which already accepts
+   questionable ident string (e.g. host part of the e-mail address is
+   obviously bogus), and in general when we operate fmt_ident() function
+   in non-strict mode.
+
+ * "git symbolic-ref" forgot to report a failure with its exit status.
+
+ * History traversal with "git log --source" that starts with an
+   annotated tag failed to report the tag as "source", due to an
+   old regression in the command line parser back in v2.2 days.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.6.6.txt b/third_party/git/Documentation/RelNotes/2.6.6.txt
new file mode 100644
index 0000000000..023ad85ec6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.6.txt
@@ -0,0 +1,11 @@
+Git v2.6.6 Release Notes
+========================
+
+Fixes since v2.6.5
+------------------
+
+ * Bugfix patches were backported from the 'master' front to plug heap
+   corruption holes, to catch integer overflow in the computation of
+   pathname lengths, and to get rid of the name_path API.  Both of
+   these would have resulted in writing over an under-allocated buffer
+   when formulating pathnames while tree traversal.
diff --git a/third_party/git/Documentation/RelNotes/2.6.7.txt b/third_party/git/Documentation/RelNotes/2.6.7.txt
new file mode 100644
index 0000000000..1335de49a6
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.6.7.txt
@@ -0,0 +1,12 @@
+Git v2.6.7 Release Notes
+========================
+
+Fixes since v2.6.6
+------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
diff --git a/third_party/git/Documentation/RelNotes/2.7.0.txt b/third_party/git/Documentation/RelNotes/2.7.0.txt
new file mode 100644
index 0000000000..563dadc57e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.0.txt
@@ -0,0 +1,414 @@
+Git 2.7 Release Notes
+=====================
+
+Updates since v2.6
+------------------
+
+UI, Workflows & Features
+
+ * The appearance of "gitk", particularly on high DPI monitors, have
+   been improved.  "gitk" also comes with an undated translation for
+   Swedish and Japanese.
+
+ * "git remote" learned "get-url" subcommand to show the URL for a
+   given remote name used for fetching and pushing.
+
+ * There was no way to defeat a configured rebase.autostash variable
+   from the command line, as "git rebase --no-autostash" was missing.
+
+ * "git log --date=local" used to only show the normal (default)
+   format in the local timezone.  The command learned to take 'local'
+   as an instruction to use the local timezone with other formats,
+
+ * The refs used during a "git bisect" session is now per-worktree so
+   that independent bisect sessions can be done in different worktrees
+   created with "git worktree add".
+
+ * Users who are too busy to type three extra keystrokes to ask for
+   "git stash show -p" can now set stash.showPatch configuration
+   variable to true to always see the actual patch, not just the list
+   of paths affected with feel for the extent of damage via diffstat.
+
+ * "quiltimport" allows to specify the series file by honoring the
+   $QUILT_SERIES environment and also --series command line option.
+
+ * The use of 'good/bad' in "git bisect" made it confusing to use when
+   hunting for a state change that is not a regression (e.g. bugfix).
+   The command learned 'old/new' and then allows the end user to
+   say e.g. "bisect start --term-old=fast --term-new=slow" to find a
+   performance regression.
+
+ * "git interpret-trailers" can now run outside of a Git repository.
+
+ * "git p4" learned to reencode the pathname it uses to communicate
+   with the p4 depot with a new option.
+
+ * Give progress meter to "git filter-branch".
+
+ * Allow a later "!/abc/def" to override an earlier "/abc" that
+   appears in the same .gitignore file to make it easier to express
+   "everything in /abc directory is ignored, except for ...".
+
+ * Teach "git p4" to send large blobs outside the repository by
+   talking to Git LFS.
+
+ * Prepare for Git on-disk repository representation to undergo
+   backward incompatible changes by introducing a new repository
+   format version "1", with an extension mechanism.
+
+ * "git worktree" learned a "list" subcommand.
+
+ * "git clone --dissociate" learned that it can be used even when
+   "--reference" was not used at the same time.
+
+ * "git blame" learnt to take "--first-parent" and "--reverse" at the
+   same time when it makes sense.
+
+ * "git checkout" did not follow the usual "--[no-]progress"
+   convention and implemented only "--quiet" that is essentially
+   a superset of "--no-progress".  Extend the command to support the
+   usual "--[no-]progress".
+
+ * The semantics of transfer.hideRefs configuration variable have been
+   extended to work better with the ref "namespace" feature that lets
+   you throw unrelated bunches of repositories in a single physical
+   repository and virtually serve them as separate ones.
+
+ * send-email config variables whose values are pathnames now go
+   through the ~username/ expansion.
+
+ * bash completion learnt to TAB-complete recipient addresses given
+   to send-email.
+
+ * The credential-cache daemon can be told to ignore SIGHUP to work
+   around issue when running Git from inside emacs.
+
+ * "git push" learned new configuration for doing "--recurse-submodules"
+   on each push.
+
+ * "format-patch" has learned a new option to zero-out the commit
+   object name on the mbox "From " line.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The infrastructure to rewrite "git submodule" in C is being built
+   incrementally.  Let's polish these early parts well enough and make
+   them graduate to 'next' and 'master', so that the more involved
+   follow-up can start cooking on a solid ground.
+
+ * Some features from "git tag -l" and "git branch -l" have been made
+   available to "git for-each-ref" so that eventually the unified
+   implementation can be shared across all three.  The version merged
+   to the 'master' branch earlier had a performance regression in "tag
+   --contains", which has since been corrected.
+
+ * Because "test_when_finished" in our test framework queues the
+   clean-up tasks to be done in a shell variable, it should not be
+   used inside a subshell.  Add a mechanism to allow 'bash' to catch
+   such uses, and fix the ones that were found.
+
+ * The debugging infrastructure for pkt-line based communication has
+   been improved to mark the side-band communication specifically.
+
+ * Update "git branch" that list existing branches, using the
+   ref-filter API that is shared with "git tag" and "git
+   for-each-ref".
+
+ * The test for various line-ending conversions has been enhanced.
+
+ * A few test scripts around "git p4" have been improved for
+   portability.
+
+ * Many allocations that is manually counted (correctly) that are
+   followed by strcpy/sprintf have been replaced with a less error
+   prone constructs such as xstrfmt.
+
+ * The internal stripspace() function has been moved to where it
+   logically belongs to, i.e. strbuf API, and the command line parser
+   of "git stripspace" has been updated to use the parse_options API.
+
+ * "git am" used to spawn "git mailinfo" via run_command() API once
+   per each patch, but learned to make a direct call to mailinfo()
+   instead.
+
+ * The implementation of "git mailinfo" was refactored so that a
+   mailinfo() function can be directly called from inside a process.
+
+ * With a "debug" helper, debugging of a single "git" invocation in
+   our test scripts has become a lot easier.
+
+ * The "configure" script did not test for -lpthread correctly, which
+   upset some linkers.
+
+ * Cross completed task off of subtree project's todo list.
+
+ * Test cleanups for the subtree project.
+
+ * Clean up style in an ancient test t9300.
+
+ * Work around some test flakiness with p4d.
+
+ * Fsck did not correctly detect a NUL-truncated header in a tag.
+
+ * Use a safer behavior when we hit errors verifying remote certificates.
+
+ * Speed up filter-branch for cases where we only care about rewriting
+   commits, not tree data.
+
+ * The parse-options API has been updated to make "-h" command line
+   option work more consistently in all commands.
+
+ * "git svn rebase/mkdirs" got optimized by keeping track of empty
+   directories better.
+
+ * Fix some racy client/server tests by treating SIGPIPE the same as a
+   normal non-zero exit.
+
+ * The necessary infrastructure to build topics using the free Travis
+   CI has been added. Developers forking from this topic (and enabling
+   Travis) can do their own builds, and we can turn on auto-builds for
+   git/git (including build-status for pull requests that people
+   open).
+
+ * The write(2) emulation for Windows learned to set errno to EPIPE
+   when necessary.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.6
+----------------
+
+Unless otherwise noted, all the fixes since v2.6 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * Very small number of options take a parameter that is optional
+   (which is not a great UI element as they can only appear at the end
+   of the command line).  Add notice to documentation of each and
+   every one of them.
+
+ * "git blame --first-parent v1.0..v2.0" was not rejected but did not
+   limit the blame to commits on the first parent chain.
+
+ * "git subtree" (in contrib/) now can take whitespaces in the
+   pathnames, not only in the in-tree pathname but the name of the
+   directory that the repository is in.
+
+ * The ssh transport, just like any other transport over the network,
+   did not clear GIT_* environment variables, but it is possible to
+   use SendEnv and AcceptEnv to leak them to the remote invocation of
+   Git, which is not a good idea at all.  Explicitly clear them just
+   like we do for the local transport.
+
+ * Correct "git p4 --detect-labels" so that it does not fail to create
+   a tag that points at a commit that is also being imported.
+
+ * The Makefile always runs the library archiver with hardcoded "crs"
+   options, which was inconvenient for exotic platforms on which
+   people want to use programs with totally different set of command
+   line options.
+
+ * Customization to change the behaviour with "make -w" and "make -s"
+   in our Makefile was broken when they were used together.
+
+ * Allocation related functions and stdio are unsafe things to call
+   inside a signal handler, and indeed killing the pager can cause
+   glibc to deadlock waiting on allocation mutex as our signal handler
+   tries to free() some data structures in wait_for_pager().  Reduce
+   these unsafe calls.
+
+ * The way how --ref/--notes to specify the notes tree reference are
+   DWIMmed was not clearly documented.
+
+ * "git gc" used to barf when a symbolic ref has gone dangling
+   (e.g. the branch that used to be your upstream's default when you
+   cloned from it is now gone, and you did "fetch --prune").
+
+ * "git clone --dissociate" runs a big "git repack" process at the
+   end, and it helps to close file descriptors that are open on the
+   packs and their idx files before doing so on filesystems that
+   cannot remove a file that is still open.
+
+ * Description of the "log.follow" configuration variable in "git log"
+   documentation is now also copied to "git config" documentation.
+
+ * "git rebase -i" had a minor regression recently, which stopped
+   considering a line that begins with an indented '#' in its insn
+   sheet not a comment. Further, the code was still too picky on
+   Windows where CRLF left by the editor is turned into a trailing CR
+   on the line read via the "read" built-in command of bash.  Both of
+   these issues are now fixed.
+
+ * After "git checkout --detach", "git status" reported a fairly
+   useless "HEAD detached at HEAD", instead of saying at which exact
+   commit.
+
+ * When "git send-email" wanted to talk over Net::SMTP::SSL,
+   Net::Cmd::datasend() did not like to be fed too many bytes at the
+   same time and failed to send messages.  Send the payload one line
+   at a time to work around the problem.
+
+ * When "git am" was rewritten as a built-in, it stopped paying
+   attention to user.signingkey, which was fixed.
+
+ * It was not possible to use a repository-lookalike created by "git
+   worktree add" as a local source of "git clone".
+
+ * On a case insensitive filesystems, setting GIT_WORK_TREE variable
+   using a random cases that does not agree with what the filesystem
+   thinks confused Git that it wasn't inside the working tree.
+
+ * Performance-measurement tests did not work without an installed Git.
+
+ * A test script for the HTTP service had a timing dependent bug,
+   which was fixed.
+
+ * There were some classes of errors that "git fsck" diagnosed to its
+   standard error that did not cause it to exit with non-zero status.
+
+ * Work around "git p4" failing when the P4 depot records the contents
+   in UTF-16 without UTF-16 BOM.
+
+ * When "git gc --auto" is backgrounded, its diagnosis message is
+   lost.  Save it to a file in $GIT_DIR and show it next time the "gc
+   --auto" is run.
+
+ * The submodule code has been taught to work better with separate
+   work trees created via "git worktree add".
+
+ * "git gc" is safe to run anytime only because it has the built-in
+   grace period to protect young objects.  In order to run with no
+   grace period, the user must make sure that the repository is
+   quiescent.
+
+ * A recent "filter-branch --msg-filter" broke skipping of the commit
+   object header, which is fixed.
+
+ * The normalize_ceiling_entry() function does not muck with the end
+   of the path it accepts, and the real world callers do rely on that,
+   but a test insisted that the function drops a trailing slash.
+
+ * A test for interaction between untracked cache and sparse checkout
+   added in Git 2.5 days were flaky.
+
+ * A couple of commands still showed "[options]" in their usage string
+   to note where options should come on their command line, but we
+   spell that "[<options>]" in most places these days.
+
+ * The synopsis text and the usage string of subcommands that read
+   list of things from the standard input are often shown as if they
+   only take input from a file on a filesystem, which was misleading.
+
+ * "git am -3" had a small regression where it is aborted in its error
+   handling codepath when underlying merge-recursive failed in certain
+   ways, as it assumed that the internal call to merge-recursive will
+   never die, which is not the case (yet).
+
+ * The linkage order of libraries was wrong in places around libcurl.
+
+ * The name-hash subsystem that is used to cope with case insensitive
+   filesystems keeps track of directories and their on-filesystem
+   cases for all the paths in the index by holding a pointer to a
+   randomly chosen cache entry that is inside the directory (for its
+   ce->ce_name component).  This pointer was not updated even when the
+   cache entry was removed from the index, leading to use after free.
+   This was fixed by recording the path for each directory instead of
+   borrowing cache entries and restructuring the API somewhat.
+
+ * "git merge-file" tried to signal how many conflicts it found, which
+   obviously would not work well when there are too many of them.
+
+ * The error message from "git blame --contents --reverse" incorrectly
+   talked about "--contents --children".
+
+ * "git imap-send" did not compile well with older version of cURL library.
+
+ * Merging a branch that removes a path and another that changes the
+   mode bits on the same path should have conflicted at the path, but
+   it didn't and silently favoured the removal.
+
+ * "git --literal-pathspecs add -u/-A" without any command line
+   argument misbehaved ever since Git 2.0.
+
+ * "git daemon" uses "run_command()" without "finish_command()", so it
+   needs to release resources itself, which it forgot to do.
+
+ * "git status --branch --short" accessed beyond the constant string
+   "HEAD", which has been corrected.
+
+ * We peek objects from submodule's object store by linking it to the
+   list of alternate object databases, but the code to do so forgot to
+   correctly initialize the list.
+
+ * The code to prepare the working tree side of temporary directory
+   for the "dir-diff" feature forgot that symbolic links need not be
+   copied (or symlinked) to the temporary area, as the code already
+   special cases and overwrites them.  Besides, it was wrong to try
+   computing the object name of the target of symbolic link, which may
+   not even exist or may be a directory.
+
+ * A Range: request can be responded with a full response and when
+   asked properly libcurl knows how to strip the result down to the
+   requested range.  However, we were hand-crafting a range request
+   and it did not kick in.
+
+ * Having a leftover .idx file without corresponding .pack file in
+   the repository hurts performance; "git gc" learned to prune them.
+
+ * Apple's common crypto implementation of SHA1_Update() does not take
+   more than 4GB at a time, and we now have a compile-time workaround
+   for it.
+
+ * Produce correct "dirty" marker for shell prompts, even when we
+   are on an orphan or an unborn branch.
+
+ * A build without NO_IPv6 used to use gethostbyname() when guessing
+   user's hostname, instead of getaddrinfo() that is used in other
+   codepaths in such a build.
+
+ * The exit code of git-fsck did not reflect some types of errors
+   found in packed objects, which has been corrected.
+
+ * The helper used to iterate over loose object directories to prune
+   stale objects did not closedir() immediately when it is done with a
+   directory--a callback such as the one used for "git prune" may want
+   to do rmdir(), but it would fail on open directory on platforms
+   such as WinXP.
+
+ * "git p4" used to import Perforce CLs that touch only paths outside
+   the client spec as empty commits.  It has been corrected to ignore
+   them instead, with a new configuration git-p4.keepEmptyCommits as a
+   backward compatibility knob.
+
+ * The completion script (in contrib/) used to list "git column"
+   (which is not an end-user facing command) as one of the choices
+   (merge 160fcdb sg/completion-no-column later to maint).
+
+ * The error reporting from "git send-email", when SMTP TLS fails, has
+   been improved.
+   (merge 9d60524 jk/send-email-ssl-errors later to maint).
+
+ * When getpwuid() on the system returned NULL (e.g. the user is not
+   in the /etc/passwd file or other uid-to-name mappings), the
+   codepath to find who the user is to record it in the reflog barfed
+   and died.  Loosen the check in this codepath, which already accepts
+   questionable ident string (e.g. host part of the e-mail address is
+   obviously bogus), and in general when we operate fmt_ident() function
+   in non-strict mode.
+   (merge 92bcbb9 jk/ident-loosen-getpwuid later to maint).
+
+ * "git symbolic-ref" forgot to report a failure with its exit status.
+   (merge f91b273 jk/symbolic-ref-maint later to maint).
+
+ * History traversal with "git log --source" that starts with an
+   annotated tag failed to report the tag as "source", due to an
+   old regression in the command line parser back in v2.2 days.
+   (merge 728350b jk/pending-keep-tag-name later to maint).
+
+ * "git p4" when interacting with multiple depots at the same time
+   used to incorrectly drop changes.
+
+ * Code clean-up, minor fixes etc.
diff --git a/third_party/git/Documentation/RelNotes/2.7.1.txt b/third_party/git/Documentation/RelNotes/2.7.1.txt
new file mode 100644
index 0000000000..6553d69e33
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.1.txt
@@ -0,0 +1,87 @@
+Git v2.7.1 Release Notes
+========================
+
+Fixes since v2.7
+----------------
+
+ * An earlier change in 2.5.x-era broke users' hooks and aliases by
+   exporting GIT_WORK_TREE to point at the root of the working tree,
+   interfering when they tried to use a different working tree without
+   setting GIT_WORK_TREE environment themselves.
+
+ * The "exclude_list" structure has the usual "alloc, nr" pair of
+   fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot
+   to reset 'alloc' to 0 when it cleared 'nr' to discard the managed
+   array.
+
+ * "git send-email" was confused by escaped quotes stored in the alias
+   files saved by "mutt", which has been corrected.
+
+ * A few unportable C construct have been spotted by clang compiler
+   and have been fixed.
+
+ * The documentation has been updated to hint the connection between
+   the '--signoff' option and DCO.
+
+ * "git reflog" incorrectly assumed that all objects that used to be
+   at the tip of a ref must be commits, which caused it to segfault.
+
+ * The ignore mechanism saw a few regressions around untracked file
+   listing and sparse checkout selection areas in 2.7.0; the change
+   that is responsible for the regression has been reverted.
+
+ * Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR
+   (e.g. COMMIT_EDITMSG) that is meant to be left after the command is
+   done.  This however did not work well if the repository is set to
+   be shared with core.sharedRepository and the umask of the previous
+   user is tighter.  They have been made to work better by calling
+   unlink(2) and retrying after fopen(3) fails with EPERM.
+
+ * Asking gitweb for a nonexistent commit left a warning in the server
+   log.
+
+ * "git rebase", unlike all other callers of "gc --auto", did not
+   ignore the exit code from "gc --auto".
+
+ * Many codepaths that run "gc --auto" before exiting kept packfiles
+   mapped and left the file descriptors to them open, which was not
+   friendly to systems that cannot remove files that are open.  They
+   now close the packs before doing so.
+
+ * A recent optimization to filter-branch in v2.7.0 introduced a
+   regression when --prune-empty filter is used, which has been
+   corrected.
+
+ * The description for SANITY prerequisite the test suite uses has
+   been clarified both in the comment and in the implementation.
+
+ * "git tag" started listing a tag "foo" as "tags/foo" when a branch
+   named "foo" exists in the same repository; remove this unnecessary
+   disambiguation, which is a regression introduced in v2.7.0.
+
+ * The way "git svn" uses auth parameter was broken by Subversion
+   1.9.0 and later.
+
+ * The "split" subcommand of "git subtree" (in contrib/) incorrectly
+   skipped merges when it shouldn't, which was corrected.
+
+ * A few options of "git diff" did not work well when the command was
+   run from a subdirectory.
+
+ * dirname() emulation has been added, as Msys2 lacks it.
+
+ * The underlying machinery used by "ls-files -o" and other commands
+   have been taught not to create empty submodule ref cache for a
+   directory that is not a submodule.  This removes a ton of wasted
+   CPU cycles.
+
+ * Drop a few old "todo" items by deciding that the change one of them
+   suggests is not such a good idea, and doing the change the other
+   one suggested to do.
+
+ * Documentation for "git fetch --depth" has been updated for clarity.
+
+ * The command line completion learned a handful of additional options
+   and command specific syntax.
+
+Also includes a handful of documentation and test updates.
diff --git a/third_party/git/Documentation/RelNotes/2.7.2.txt b/third_party/git/Documentation/RelNotes/2.7.2.txt
new file mode 100644
index 0000000000..4feef76704
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.2.txt
@@ -0,0 +1,41 @@
+Git v2.7.2 Release Notes
+========================
+
+Fixes since v2.7.1
+------------------
+
+ * The low-level merge machinery has been taught to use CRLF line
+   termination when inserting conflict markers to merged contents that
+   are themselves CRLF line-terminated.
+
+ * "git worktree" had a broken code that attempted to auto-fix
+   possible inconsistency that results from end-users moving a
+   worktree to different places without telling Git (the original
+   repository needs to maintain backpointers to its worktrees, but
+   "mv" run by end-users who are not familiar with that fact will
+   obviously not adjust them), which actually made things worse
+   when triggered.
+
+ * "git push --force-with-lease" has been taught to report if the push
+   needed to force (or fast-forwarded).
+
+ * The emulated "yes" command used in our test scripts has been
+   tweaked not to spend too much time generating unnecessary output
+   that is not used, to help those who test on Windows where it would
+   not stop until it fills the pipe buffer due to lack of SIGPIPE.
+
+ * The vimdiff backend for "git mergetool" has been tweaked to arrange
+   and number buffers in the order that would match the expectation of
+   majority of people who read left to right, then top down and assign
+   buffers 1 2 3 4 "mentally" to local base remote merge windows based
+   on that order.
+
+ * The documentation for "git clean" has been corrected; it mentioned
+   that .git/modules/* are removed by giving two "-f", which has never
+   been the case.
+
+ * Paths that have been told the index about with "add -N" are not
+   quite yet in the index, but a few commands behaved as if they
+   already are in a harmful way.
+
+Also includes tiny documentation and test updates.
diff --git a/third_party/git/Documentation/RelNotes/2.7.3.txt b/third_party/git/Documentation/RelNotes/2.7.3.txt
new file mode 100644
index 0000000000..6adf038915
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.3.txt
@@ -0,0 +1,62 @@
+Git v2.7.3 Release Notes
+========================
+
+Fixes since v2.7.2
+------------------
+
+ * Traditionally, the tests that try commands that work on the
+   contents in the working tree were named with "worktree" in their
+   filenames, but with the recent addition of "git worktree"
+   subcommand, whose tests are also named similarly, it has become
+   harder to tell them apart.  The traditional tests have been renamed
+   to use "work-tree" instead in an attempt to differentiate them.
+
+ * Many codepaths forget to check return value from git_config_set();
+   the function is made to die() to make sure we do not proceed when
+   setting a configuration variable failed.
+
+ * Handling of errors while writing into our internal asynchronous
+   process has been made more robust, which reduces flakiness in our
+   tests.
+
+ * "git show 'HEAD:Foo[BAR]Baz'" did not interpret the argument as a
+   rev, i.e. the object named by the the pathname with wildcard
+   characters in a tree object.
+
+ * "git rev-parse --git-common-dir" used in the worktree feature
+   misbehaved when run from a subdirectory.
+
+ * The "v(iew)" subcommand of the interactive "git am -i" command was
+   broken in 2.6.0 timeframe when the command was rewritten in C.
+
+ * "git merge-tree" used to mishandle "both sides added" conflict with
+   its own "create a fake ancestor file that has the common parts of
+   what both sides have added and do a 3-way merge" logic; this has
+   been updated to use the usual "3-way merge with an empty blob as
+   the fake common ancestor file" approach used in the rest of the
+   system.
+
+ * The memory ownership rule of fill_textconv() API, which was a bit
+   tricky, has been documented a bit better.
+
+ * The documentation did not clearly state that the 'simple' mode is
+   now the default for "git push" when push.default configuration is
+   not set.
+
+ * Recent versions of GNU grep are pickier when their input contains
+   arbitrary binary data, which some of our tests uses.  Rewrite the
+   tests to sidestep the problem.
+
+ * A helper function "git submodule" uses since v2.7.0 to list the
+   modules that match the pathspec argument given to its subcommands
+   (e.g. "submodule add <repo> <path>") has been fixed.
+
+ * "git config section.var value" to set a value in per-repository
+   configuration file failed when it was run outside any repository,
+   but didn't say the reason correctly.
+
+ * The code to read the pack data using the offsets stored in the pack
+   idx file has been made more carefully check the validity of the
+   data in the idx.
+
+Also includes documentation and test updates.
diff --git a/third_party/git/Documentation/RelNotes/2.7.4.txt b/third_party/git/Documentation/RelNotes/2.7.4.txt
new file mode 100644
index 0000000000..883ae896fe
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.4.txt
@@ -0,0 +1,11 @@
+Git v2.7.4 Release Notes
+========================
+
+Fixes since v2.7.3
+------------------
+
+ * Bugfix patches were backported from the 'master' front to plug heap
+   corruption holes, to catch integer overflow in the computation of
+   pathname lengths, and to get rid of the name_path API.  Both of
+   these would have resulted in writing over an under-allocated buffer
+   when formulating pathnames while tree traversal.
diff --git a/third_party/git/Documentation/RelNotes/2.7.5.txt b/third_party/git/Documentation/RelNotes/2.7.5.txt
new file mode 100644
index 0000000000..83559ce3b2
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.5.txt
@@ -0,0 +1,14 @@
+Git v2.7.5 Release Notes
+========================
+
+Fixes since v2.7.4
+------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
+Also contains a few fixes backported from later development tracks.
diff --git a/third_party/git/Documentation/RelNotes/2.7.6.txt b/third_party/git/Documentation/RelNotes/2.7.6.txt
new file mode 100644
index 0000000000..4c6d1dcd4a
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.7.6.txt
@@ -0,0 +1,25 @@
+Git v2.7.6 Release Notes
+========================
+
+Fixes since v2.7.5
+------------------
+
+ * A "ssh://..." URL can result in a "ssh" command line with a
+   hostname that begins with a dash "-", which would cause the "ssh"
+   command to instead (mis)treat it as an option.  This is now
+   prevented by forbidding such a hostname (which will not be
+   necessary in the real world).
+
+ * Similarly, when GIT_PROXY_COMMAND is configured, the command is
+   run with host and port that are parsed out from "ssh://..." URL;
+   a poorly written GIT_PROXY_COMMAND could be tricked into treating
+   a string that begins with a dash "-".  This is now prevented by
+   forbidding such a hostname and port number (again, which will not
+   be necessary in the real world).
+
+ * In the same spirit, a repository name that begins with a dash "-"
+   is also forbidden now.
+
+Credits go to Brian Neel at GitLab, Joern Schneeweisz of Recurity
+Labs and Jeff King at GitHub.
+
diff --git a/third_party/git/Documentation/RelNotes/2.8.0.txt b/third_party/git/Documentation/RelNotes/2.8.0.txt
new file mode 100644
index 0000000000..25079710fa
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.0.txt
@@ -0,0 +1,439 @@
+Git 2.8 Release Notes
+=====================
+
+Backward compatibility note
+---------------------------
+
+The rsync:// transport has been removed.
+
+
+Updates since v2.7
+------------------
+
+UI, Workflows & Features
+
+ * It turns out "git clone" over rsync transport has been broken when
+   the source repository has packed references for a long time, and
+   nobody noticed nor complained about it.
+
+ * "push" learned that its "--delete" option can be shortened to
+   "-d", just like "branch --delete" and "branch -d" are the same
+   thing.
+
+ * "git blame" learned to produce the progress eye-candy when it takes
+   too much time before emitting the first line of the result.
+
+ * "git grep" can now be configured (or told from the command line)
+   how many threads to use when searching in the working tree files.
+
+ * Some "git notes" operations, e.g. "git log --notes=<note>", should
+   be able to read notes from any tree-ish that is shaped like a notes
+   tree, but the notes infrastructure required that the argument must
+   be a ref under refs/notes/.  Loosen it to require a valid ref only
+   when the operation would update the notes (in which case we must
+   have a place to store the updated notes tree, iow, a ref).
+
+ * "git grep" by default does not fall back to its "--no-index"
+   behavior outside a directory under Git's control (otherwise the
+   user may by mistake end up running a huge recursive search); with a
+   new configuration (set in $HOME/.gitconfig--by definition this
+   cannot be set in the config file per project), this safety can be
+   disabled.
+
+ * "git pull --rebase" has been extended to allow invoking
+   "rebase -i".
+
+ * "git p4" learned to cope with the type of a file getting changed.
+
+ * "git format-patch" learned to notice format.outputDirectory
+   configuration variable.  This allows "-o <dir>" option to be
+   omitted on the command line if you always use the same directory in
+   your workflow.
+
+ * "interpret-trailers" has been taught to optionally update a file in
+   place, instead of always writing the result to the standard output.
+
+ * Many commands that read files that are expected to contain text
+   that is generated (or can be edited) by the end user to control
+   their behavior (e.g. "git grep -f <filename>") have been updated
+   to be more tolerant to lines that are terminated with CRLF (they
+   used to treat such a line to contain payload that ends with CR,
+   which is usually not what the users expect).
+
+ * "git notes merge" used to limit the source of the merged notes tree
+   to somewhere under refs/notes/ hierarchy, which was too limiting
+   when inventing a workflow to exchange notes with remote
+   repositories using remote-tracking notes trees (located in e.g.
+   refs/remote-notes/ or somesuch).
+
+ * "git ls-files" learned a new "--eol" option to help diagnose
+   end-of-line problems.
+
+ * "ls-remote" learned an option to show which branch the remote
+   repository advertises as its primary by pointing its HEAD at.
+
+ * New http.proxyAuthMethod configuration variable can be used to
+   specify what authentication method to use, as a way to work around
+   proxies that do not give error response expected by libcurl when
+   CURLAUTH_ANY is used.  Also, the codepath for proxy authentication
+   has been taught to use credential API to store the authentication
+   material in user's keyrings.
+
+ * Update the untracked cache subsystem and change its primary UI from
+   "git update-index" to "git config".
+
+ * There were a few "now I am doing this thing" progress messages in
+   the TCP connection code that can be triggered by setting a verbose
+   option internally in the code, but "git fetch -v" and friends never
+   passed the verbose option down to that codepath.
+
+ * Clean/smudge filters defined in a configuration file of lower
+   precedence can now be overridden to be a pass-through no-op by
+   setting the variable to an empty string.
+
+ * A new "<branch>^{/!-<pattern>}" notation can be used to name a
+   commit that is reachable from <branch> that does not match the
+   given <pattern>.
+
+ * The "user.useConfigOnly" configuration variable can be used to
+   force the user to always set user.email & user.name configuration
+   variables, serving as a reminder for those who work on multiple
+   projects and do not want to put these in their $HOME/.gitconfig.
+
+ * "git fetch" and friends that make network connections can now be
+   told to only use ipv4 (or ipv6).
+
+ * Some authentication methods do not need username or password, but
+   libcurl needs some hint that it needs to perform authentication.
+   Supplying an empty username and password string is a valid way to
+   do so, but you can set the http.[<url>.]emptyAuth configuration
+   variable to achieve the same, if you find it cleaner.
+
+ * You can now set http.[<url>.]pinnedpubkey to specify the pinned
+   public key when building with recent enough versions of libcURL.
+
+ * The configuration system has been taught to phrase where it found a
+   bad configuration variable in a better way in its error messages.
+   "git config" learnt a new "--show-origin" option to indicate where
+   the values come from.
+
+ * The "credential-cache" daemon process used to run in whatever
+   directory it happened to start in, but this made umount(2)ing the
+   filesystem that houses the repository harder; now the process
+   chdir()s to the directory that house its own socket on startup.
+
+ * When "git submodule update" did not result in fetching the commit
+   object in the submodule that is referenced by the superproject, the
+   command learned to retry another fetch, specifically asking for
+   that commit that may not be connected to the refs it usually
+   fetches.
+
+ * "git merge-recursive" learned "--no-renames" option to disable its
+   rename detection logic.
+
+ * Across the transition at around Git version 2.0, the user used to
+   get a pretty loud warning when running "git push" without setting
+   push.default configuration variable.  We no longer warn because the
+   transition was completed a long time ago.
+
+ * README has been renamed to README.md and its contents got tweaked
+   slightly to make it easier on the eyes.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * Add a framework to spawn a group of processes in parallel, and use
+   it to run "git fetch --recurse-submodules" in parallel.
+
+ * A slight update to the Makefile to mark ".PHONY" targets as such
+   correctly.
+
+ * In-core storage of the reverse index for .pack files (which lets
+   you go from a pack offset to an object name) has been streamlined.
+
+ * d95138e6 (setup: set env $GIT_WORK_TREE when work tree is set, like
+   $GIT_DIR, 2015-06-26) attempted to work around a glitch in alias
+   handling by overwriting GIT_WORK_TREE environment variable to
+   affect subprocesses when set_git_work_tree() gets called, which
+   resulted in a rather unpleasant regression to "clone" and "init".
+   Try to address the same issue by always restoring the environment
+   and respawning the real underlying command when handling alias.
+
+ * The low-level code that is used to create symbolic references has
+   been updated to share more code with the code that deals with
+   normal references.
+
+ * strbuf_getline() and friends have been redefined to make it easier
+   to identify which callsite of (new) strbuf_getline_lf() should
+   allow and silently ignore carriage-return at the end of the line to
+   help users on DOSsy systems.
+
+ * "git shortlog" used to accumulate various pieces of information
+   regardless of what was asked to be shown in the final output.  It
+   has been optimized by noticing what need not to be collected
+   (e.g. there is no need to collect the log messages when showing
+   only the number of changes).
+
+ * "git checkout $branch" (and other operations that share the same
+   underlying machinery) has been optimized.
+
+ * Automated tests in Travis CI environment has been optimized by
+   persisting runtime statistics of previous "prove" run, executing
+   tests that take longer before other ones; this reduces the total
+   wallclock time.
+
+ * Test scripts have been updated to remove assumptions that are not
+   portable between Git for POSIX and Git for Windows, or to skip ones
+   with expectations that are not satisfiable on Git for Windows.
+
+ * Some calls to strcpy(3) triggers a false warning from static
+   analyzers that are less intelligent than humans, and reducing the
+   number of these false hits helps us notice real issues.  A few
+   calls to strcpy(3) in a couple of protrams that are already safe
+   has been rewritten to avoid false warnings.
+
+ * The "name_path" API was an attempt to reduce the need to construct
+   the full path out of a series of path components while walking a
+   tree hierarchy, but over time made less efficient because the path
+   needs to be flattened, e.g. to be compared with another path that
+   is already flat.  The API has been removed and its users have been
+   rewritten to simplify the overall code complexity.
+
+ * Help those who debug http(s) part of the system.
+   (merge 0054045 sp/remote-curl-ssl-strerror later to maint).
+
+ * The internal API to interact with "remote.*" configuration
+   variables has been streamlined.
+
+ * The ref-filter's format-parsing code has been refactored, in
+   preparation for "branch --format" and friends.
+
+ * Traditionally, the tests that try commands that work on the
+   contents in the working tree were named with "worktree" in their
+   filenames, but with the recent addition of "git worktree"
+   subcommand, whose tests are also named similarly, it has become
+   harder to tell them apart.  The traditional tests have been renamed
+   to use "work-tree" instead in an attempt to differentiate them.
+   (merge 5549029 mg/work-tree-tests later to maint).
+
+ * Many codepaths forget to check return value from git_config_set();
+   the function is made to die() to make sure we do not proceed when
+   setting a configuration variable failed.
+   (merge 3d18064 ps/config-error later to maint).
+
+ * Handling of errors while writing into our internal asynchronous
+   process has been made more robust, which reduces flakiness in our
+   tests.
+   (merge 43f3afc jk/epipe-in-async later to maint).
+
+ * There is a new DEVELOPER knob that enables many compiler warning
+   options in the Makefile.
+
+ * The way the test scripts configure the Apache web server has been
+   updated to work also for Apache 2.4 running on RedHat derived
+   distros.
+
+ * Out of maintenance gcc on OSX 10.6 fails to compile the code in
+   'master'; work it around by using clang by default on the platform.
+
+ * The "name_path" API was an attempt to reduce the need to construct
+   the full path out of a series of path components while walking a
+   tree hierarchy, but over time made less efficient because the path
+   needs to be flattened, e.g. to be compared with another path that
+   is already flat, in many cases.  The API has been removed and its
+   users have been rewritten to simplify the overall code complexity.
+   This incidentally also closes some heap-corruption holes.
+
+ * Recent versions of GNU grep is pickier than before to decide if a
+   file is "binary" and refuse to give line-oriented hits when we
+   expect it to, unless explicitly told with "-a" option.  As our
+   scripted Porcelains use sane_grep wrapper for line-oriented data,
+   even when the line may contain non-ASCII payload we took from
+   end-user data, use "grep -a" to implement sane_grep wrapper when
+   using an implementation of "grep" that takes the "-a" option.
+
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.7
+----------------
+
+Unless otherwise noted, all the fixes since v2.7 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * An earlier change in 2.5.x-era broke users' hooks and aliases by
+   exporting GIT_WORK_TREE to point at the root of the working tree,
+   interfering when they tried to use a different working tree without
+   setting GIT_WORK_TREE environment themselves.
+
+ * The "exclude_list" structure has the usual "alloc, nr" pair of
+   fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot
+   to reset 'alloc' to 0 when it cleared 'nr' to discard the managed
+   array.
+
+ * Paths that have been told the index about with "add -N" are not
+   quite yet in the index, but a few commands behaved as if they
+   already are in a harmful way.
+
+ * "git send-email" was confused by escaped quotes stored in the alias
+   files saved by "mutt", which has been corrected.
+
+ * A few non-portable C construct have been spotted by clang compiler
+   and have been fixed.
+
+ * The documentation has been updated to hint the connection between
+   the '--signoff' option and DCO.
+
+ * "git reflog" incorrectly assumed that all objects that used to be
+   at the tip of a ref must be commits, which caused it to segfault.
+
+ * The ignore mechanism saw a few regressions around untracked file
+   listing and sparse checkout selection areas in 2.7.0; the change
+   that is responsible for the regression has been reverted.
+
+ * Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR
+   (e.g. COMMIT_EDITMSG) that is meant to be left after the command is
+   done.  This however did not work well if the repository is set to
+   be shared with core.sharedRepository and the umask of the previous
+   user is tighter.  They have been made to work better by calling
+   unlink(2) and retrying after fopen(3) fails with EPERM.
+
+ * Asking gitweb for a nonexistent commit left a warning in the server
+   log.
+
+   Somebody may want to follow this up with an additional test, perhaps?
+   IIRC, we do test that no Perl warnings are given to the server log,
+   so this should have been caught if our test coverage were good.
+
+ * "git rebase", unlike all other callers of "gc --auto", did not
+   ignore the exit code from "gc --auto".
+
+ * Many codepaths that run "gc --auto" before exiting kept packfiles
+   mapped and left the file descriptors to them open, which was not
+   friendly to systems that cannot remove files that are open.  They
+   now close the packs before doing so.
+
+ * A recent optimization to filter-branch in v2.7.0 introduced a
+   regression when --prune-empty filter is used, which has been
+   corrected.
+
+ * The description for SANITY prerequisite the test suite uses has
+   been clarified both in the comment and in the implementation.
+
+ * "git tag" started listing a tag "foo" as "tags/foo" when a branch
+   named "foo" exists in the same repository; remove this unnecessary
+   disambiguation, which is a regression introduced in v2.7.0.
+
+ * The way "git svn" uses auth parameter was broken by Subversion
+   1.9.0 and later.
+
+ * The "split" subcommand of "git subtree" (in contrib/) incorrectly
+   skipped merges when it shouldn't, which was corrected.
+
+ * A few options of "git diff" did not work well when the command was
+   run from a subdirectory.
+
+ * The command line completion learned a handful of additional options
+   and command specific syntax.
+
+ * dirname() emulation has been added, as Msys2 lacks it.
+
+ * The underlying machinery used by "ls-files -o" and other commands
+   has been taught not to create empty submodule ref cache for a
+   directory that is not a submodule.  This removes a ton of wasted
+   CPU cycles.
+
+ * "git worktree" had a broken code that attempted to auto-fix
+   possible inconsistency that results from end-users moving a
+   worktree to different places without telling Git (the original
+   repository needs to maintain back-pointers to its worktrees,
+   but "mv" run by end-users who are not familiar with that fact
+   will obviously not adjust them), which actually made things
+   worse when triggered.
+
+ * The low-level merge machinery has been taught to use CRLF line
+   termination when inserting conflict markers to merged contents that
+   are themselves CRLF line-terminated.
+
+ * "git push --force-with-lease" has been taught to report if the push
+   needed to force (or fast-forwarded).
+
+ * The emulated "yes" command used in our test scripts has been
+   tweaked not to spend too much time generating unnecessary output
+   that is not used, to help those who test on Windows where it would
+   not stop until it fills the pipe buffer due to lack of SIGPIPE.
+
+ * The documentation for "git clean" has been corrected; it mentioned
+   that .git/modules/* are removed by giving two "-f", which has never
+   been the case.
+
+ * The vimdiff backend for "git mergetool" has been tweaked to arrange
+   and number buffers in the order that would match the expectation of
+   majority of people who read left to right, then top down and assign
+   buffers 1 2 3 4 "mentally" to local base remote merge windows based
+   on that order.
+
+ * "git show 'HEAD:Foo[BAR]Baz'" did not interpret the argument as a
+   rev, i.e. the object named by the the pathname with wildcard
+   characters in a tree object.
+   (merge aac4fac nd/dwim-wildcards-as-pathspecs later to maint).
+
+ * "git rev-parse --git-common-dir" used in the worktree feature
+   misbehaved when run from a subdirectory.
+   (merge 17f1365 nd/git-common-dir-fix later to maint).
+
+ * "git worktree add -B <branchname>" did not work.
+
+ * The "v(iew)" subcommand of the interactive "git am -i" command was
+   broken in 2.6.0 timeframe when the command was rewritten in C.
+   (merge 708b8cc jc/am-i-v-fix later to maint).
+
+ * "git merge-tree" used to mishandle "both sides added" conflict with
+   its own "create a fake ancestor file that has the common parts of
+   what both sides have added and do a 3-way merge" logic; this has
+   been updated to use the usual "3-way merge with an empty blob as
+   the fake common ancestor file" approach used in the rest of the
+   system.
+   (merge 907681e jk/no-diff-emit-common later to maint).
+
+ * The memory ownership rule of fill_textconv() API, which was a bit
+   tricky, has been documented a bit better.
+   (merge a64e6a4 jk/more-comments-on-textconv later to maint).
+
+ * Update various codepaths to avoid manually-counted malloc().
+   (merge 08c95df jk/tighten-alloc later to maint).
+
+ * The documentation did not clearly state that the 'simple' mode is
+   now the default for "git push" when push.default configuration is
+   not set.
+   (merge f6b1fb3 mm/push-simple-doc later to maint).
+
+ * Recent versions of GNU grep are pickier when their input contains
+   arbitrary binary data, which some of our tests uses.  Rewrite the
+   tests to sidestep the problem.
+   (merge 3b1442d jk/grep-binary-workaround-in-test later to maint).
+
+ * A helper function "git submodule" uses since v2.7.0 to list the
+   modules that match the pathspec argument given to its subcommands
+   (e.g. "submodule add <repo> <path>") has been fixed.
+   (merge 2b56bb7 sb/submodule-module-list-fix later to maint).
+
+ * "git config section.var value" to set a value in per-repository
+   configuration file failed when it was run outside any repository,
+   but didn't say the reason correctly.
+   (merge 638fa62 js/config-set-in-non-repository later to maint).
+
+ * The code to read the pack data using the offsets stored in the pack
+   idx file has been made more carefully check the validity of the
+   data in the idx.
+   (merge 7465feb jk/pack-idx-corruption-safety later to maint).
+
+ * Other minor clean-ups and documentation updates
+   (merge f459823 ak/extract-argv0-last-dir-sep later to maint).
+   (merge 63ca1c0 ak/git-strip-extension-from-dashed-command later to maint).
+   (merge 4867f11 ps/plug-xdl-merge-leak later to maint).
+   (merge 4938686 dt/initial-ref-xn-commit-doc later to maint).
+   (merge 9537f21 ma/update-hooks-sample-typofix later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.8.1.txt b/third_party/git/Documentation/RelNotes/2.8.1.txt
new file mode 100644
index 0000000000..ef6d80b008
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.1.txt
@@ -0,0 +1,9 @@
+Git v2.8.1 Release Notes
+========================
+
+Fixes since v2.8
+----------------
+
+ * "make rpmbuild" target was broken as its input, git.spec.in, was
+   not updated to match a file it describes that has been renamed
+   recently.  This has been fixed.
diff --git a/third_party/git/Documentation/RelNotes/2.8.2.txt b/third_party/git/Documentation/RelNotes/2.8.2.txt
new file mode 100644
index 0000000000..447b1933a8
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.2.txt
@@ -0,0 +1,70 @@
+Git v2.8.2 Release Notes
+========================
+
+Fixes since v2.8.1
+------------------
+
+ * The embedded args argv-array in the child process is used to build
+   the command line to run pack-objects instead of using a separate
+   array of strings.
+
+ * Bunch of tests on "git clone" has been renumbered for better
+   organization.
+
+ * The tests that involve running httpd leaked the system-wide
+   configuration in /etc/gitconfig to the tested environment.
+
+ * "index-pack --keep=<msg>" was broken since v2.1.0 timeframe.
+
+ * "git config --get-urlmatch", unlike other variants of the "git
+   config --get" family, did not signal error with its exit status
+   when there was no matching configuration.
+
+ * The "--local-env-vars" and "--resolve-git-dir" options of "git
+   rev-parse" failed to work outside a repository when the command's
+   option parsing was rewritten in 1.8.5 era.
+
+ * Fetching of history by naming a commit object name directly didn't
+   work across remote-curl transport.
+
+ * A small memory leak in an error codepath has been plugged in xdiff
+   code.
+
+ * strbuf_getwholeline() did not NUL-terminate the buffer on certain
+   corner cases in its error codepath.
+
+ * The startup_info data, which records if we are working inside a
+   repository (among other things), are now uniformly available to Git
+   subcommand implementations, and Git avoids attempting to touch
+   references when we are not in a repository.
+
+ * "git mergetool" did not work well with conflicts that both sides
+   deleted.
+
+ * "git send-email" had trouble parsing alias file in mailrc format
+   when lines in it had trailing whitespaces on them.
+
+ * When "git merge --squash" stopped due to conflict, the concluding
+   "git commit" failed to read in the SQUASH_MSG that shows the log
+   messages from all the squashed commits.
+
+ * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
+   nothing into an unborn history (which is arguably unusual usage,
+   which perhaps was the reason why nobody noticed it).
+
+ * Build updates for MSVC.
+
+ * "git diff -M" used to work better when two originally identical
+   files A and B got renamed to X/A and X/B by pairing A to X/A and B
+   to X/B, but this was broken in the 2.0 timeframe.
+
+ * "git send-pack --all <there>" was broken when its command line
+   option parsing was written in the 2.6 timeframe.
+
+ * When running "git blame $path" with unnormalized data in the index
+   for the path, the data in the working tree was blamed, even though
+   "git add" would not have changed what is already in the index, due
+   to "safe crlf" that disables the line-end conversion.  It has been
+   corrected.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.8.3.txt b/third_party/git/Documentation/RelNotes/2.8.3.txt
new file mode 100644
index 0000000000..fedd9968e5
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.3.txt
@@ -0,0 +1,101 @@
+Git v2.8.3 Release Notes
+========================
+
+Fixes since v2.8.2
+------------------
+
+ * "git send-email" now uses a more readable timestamps when
+   formulating a message ID.
+
+ * The repository set-up sequence has been streamlined (the biggest
+   change is that there is no longer git_config_early()), so that we
+   do not attempt to look into refs/* when we know we do not have a
+   Git repository.
+
+ * When "git worktree" feature is in use, "git branch -d" allowed
+   deletion of a branch that is checked out in another worktree
+
+ * When "git worktree" feature is in use, "git branch -m" renamed a
+   branch that is checked out in another worktree without adjusting
+   the HEAD symbolic ref for the worktree.
+
+ * "git format-patch --help" showed `-s` and `--no-patch` as if these
+   are valid options to the command.  We already hide `--patch` option
+   from the documentation, because format-patch is about showing the
+   diff, and the documentation now hides these options as well.
+
+ * A change back in version 2.7 to "git branch" broke display of a
+   symbolic ref in a non-standard place in the refs/ hierarchy (we
+   expect symbolic refs to appear in refs/remotes/*/HEAD to point at
+   the primary branch the remote has, and as .git/HEAD to point at the
+   branch we locally checked out).
+
+ * A partial rewrite of "git submodule" in the 2.7 timeframe changed
+   the way the gitdir: pointer in the submodules point at the real
+   repository location to use absolute paths by accident.  This has
+   been corrected.
+
+ * "git commit" misbehaved in a few minor ways when an empty message
+   is given via -m '', all of which has been corrected.
+
+ * Support for CRAM-MD5 authentication method in "git imap-send" did
+   not work well.
+
+ * The socks5:// proxy support added back in 2.6.4 days was not aware
+   that socks5h:// proxies behave differently.
+
+ * "git config" had a codepath that tried to pass a NULL to
+   printf("%s"), which nobody seems to have noticed.
+
+ * On Cygwin, object creation uses the "create a temporary and then
+   rename it to the final name" pattern, not "create a temporary,
+   hardlink it to the final name and then unlink the temporary"
+   pattern.
+
+   This is necessary to use Git on Windows shared directories, and is
+   already enabled for the MinGW and plain Windows builds.  It also
+   has been used in Cygwin packaged versions of Git for quite a while.
+   See http://thread.gmane.org/gmane.comp.version-control.git/291853
+   and http://thread.gmane.org/gmane.comp.version-control.git/275680.
+
+ * "git replace -e" did not honour "core.editor" configuration.
+
+ * Upcoming OpenSSL 1.1.0 will break compilation b updating a few APIs
+   we use in imap-send, which has been adjusted for the change.
+
+ * "git submodule" reports the paths of submodules the command
+   recurses into, but this was incorrect when the command was not run
+   from the root level of the superproject.
+
+ * The test scripts for "git p4" (but not "git p4" implementation
+   itself) has been updated so that they would work even on a system
+   where the installed version of Python is python 3.
+
+ * The "user.useConfigOnly" configuration variable makes it an error
+   if users do not explicitly set user.name and user.email.  However,
+   its check was not done early enough and allowed another error to
+   trigger, reporting that the default value we guessed from the
+   system setting was unusable.  This was a suboptimal end-user
+   experience as we want the users to set user.name/user.email without
+   relying on the auto-detection at all.
+
+ * "git mv old new" did not adjust the path for a submodule that lives
+   as a subdirectory inside old/ directory correctly.
+
+ * "git push" from a corrupt repository that attempts to push a large
+   number of refs deadlocked; the thread to relay rejection notices
+   for these ref updates blocked on writing them to the main thread,
+   after the main thread at the receiving end notices that the push
+   failed and decides not to read these notices and return a failure.
+
+ * A question by "git send-email" to ask the identity of the sender
+   has been updated.
+
+ * Recent update to Git LFS broke "git p4" by changing the output from
+   its "lfs pointer" subcommand.
+
+ * Some multi-byte encoding can have a backslash byte as a later part
+   of one letter, which would confuse "highlight" filter used in
+   gitweb.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.8.4.txt b/third_party/git/Documentation/RelNotes/2.8.4.txt
new file mode 100644
index 0000000000..f4e2552836
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.4.txt
@@ -0,0 +1,69 @@
+Git v2.8.4 Release Notes
+========================
+
+Fixes since v2.8.3
+------------------
+
+ * Documentation for "git merge --verify-signatures" has been updated
+   to clarify that the signature of only the commit at the tip is
+   verified.  Also the phrasing used for signature and key validity is
+   adjusted to align with that used by OpenPGP.
+
+ * On Windows, .git and optionally any files whose name starts with a
+   dot are now marked as hidden, with a core.hideDotFiles knob to
+   customize this behaviour.
+
+ * Portability enhancement for "rebase -i" to help platforms whose
+   shell does not like "for i in <empty>" (which is not POSIX-kosher).
+
+ * "git fsck" learned to catch NUL byte in a commit object as
+   potential error and warn.
+
+ * CI test was taught to build documentation pages.
+
+ * Many 'linkgit:<git documentation page>' references were broken,
+   which are all fixed with this.
+
+ * "git describe --contains" often made a hard-to-justify choice of
+   tag to give name to a given commit, because it tried to come up
+   with a name with smallest number of hops from a tag, causing an old
+   commit whose close descendant that is recently tagged were not
+   described with respect to an old tag but with a newer tag.  It did
+   not help that its computation of "hop" count was further tweaked to
+   penalize being on a side branch of a merge.  The logic has been
+   updated to favor using the tag with the oldest tagger date, which
+   is a lot easier to explain to the end users: "We describe a commit
+   in terms of the (chronologically) oldest tag that contains the
+   commit."
+
+ * Running tests with '-x' option to trace the individual command
+   executions is a useful way to debug test scripts, but some tests
+   that capture the standard error stream and check what the command
+   said can be broken with the trace output mixed in.  When running
+   our tests under "bash", however, we can redirect the trace output
+   to another file descriptor to keep the standard error of programs
+   being tested intact.
+
+ * "http.cookieFile" configuration variable clearly wants a pathname,
+   but we forgot to treat it as such by e.g. applying tilde expansion.
+
+ * When de-initialising all submodules, "git submodule deinit" gave a
+   faulty recommendation to use "git submodule deinit .", which would
+   result in a strange error message in a pathological corner case.
+   This has been corrected to suggest "submodule deinit --all" instead.
+
+ * Many commands normalize command line arguments from NFD to NFC
+   variant of UTF-8 on OSX, but commands in the "diff" family did
+   not, causing "git diff $path" to complain that no such path is
+   known to Git.  They have been taught to do the normalization.
+
+ * A couple of bugs around core.autocrlf have been fixed.
+
+ * "git difftool" learned to handle unmerged paths correctly in
+   dir-diff mode.
+
+ * The "are we talking with TTY, doing an interactive session?"
+   detection has been updated to work better for "Git for Windows".
+
+
+Also contains other minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.8.5.txt b/third_party/git/Documentation/RelNotes/2.8.5.txt
new file mode 100644
index 0000000000..7bd179fa12
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.5.txt
@@ -0,0 +1,12 @@
+Git v2.8.5 Release Notes
+========================
+
+Fixes since v2.8.4
+------------------
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
diff --git a/third_party/git/Documentation/RelNotes/2.8.6.txt b/third_party/git/Documentation/RelNotes/2.8.6.txt
new file mode 100644
index 0000000000..d8db55d920
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.8.6.txt
@@ -0,0 +1,4 @@
+Git v2.8.6 Release Notes
+========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/RelNotes/2.9.0.txt b/third_party/git/Documentation/RelNotes/2.9.0.txt
new file mode 100644
index 0000000000..b61d36712f
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.0.txt
@@ -0,0 +1,512 @@
+Git 2.9 Release Notes
+=====================
+
+Backward compatibility notes
+----------------------------
+
+The end-user facing Porcelain level commands in the "git diff" and
+"git log" family by default enable the rename detection; you can still
+use "diff.renames" configuration variable to disable this.
+
+Merging two branches that have no common ancestor with "git merge" is
+by default forbidden now to prevent creating such an unusual merge by
+mistake.
+
+The output formats of "git log" that indents the commit log message by
+4 spaces now expands HT in the log message by default.  You can use
+the "--no-expand-tabs" option to disable this.
+
+"git commit-tree" plumbing command required the user to always sign
+its result when the user sets the commit.gpgsign configuration
+variable, which was an ancient mistake, which this release corrects.
+A script that drives commit-tree, if it relies on this mistake, now
+needs to read commit.gpgsign and pass the -S option as necessary.
+
+
+Updates since v2.8
+------------------
+
+UI, Workflows & Features
+
+ * Comes with git-multimail 1.3.1 (in contrib/).
+
+ * The end-user facing commands like "git diff" and "git log"
+   now enable the rename detection by default.
+
+ * The credential.helper configuration variable is cumulative and
+   there is no good way to override it from the command line.  As
+   a special case, giving an empty string as its value now serves
+   as the signal to clear the values specified in various files.
+
+ * A new "interactive.diffFilter" configuration can be used to
+   customize the diff shown in "git add -i" sessions.
+
+ * "git p4" now allows P4 author names to be mapped to Git author
+   names.
+
+ * "git rebase -x" can be used without passing "-i" option.
+
+ * "git -c credential.<var>=<value> submodule" can now be used to
+   propagate configuration variables related to credential helper
+   down to the submodules.
+
+ * "git tag" can create an annotated tag without explicitly given an
+   "-a" (or "-s") option (i.e. when a tag message is given).  A new
+   configuration variable, tag.forceSignAnnotated, can be used to tell
+   the command to create signed tag in such a situation.
+
+ * "git merge" used to allow merging two branches that have no common
+   base by default, which led to a brand new history of an existing
+   project created and then get pulled by an unsuspecting maintainer,
+   which allowed an unnecessary parallel history merged into the
+   existing project.  The command has been taught not to allow this by
+   default, with an escape hatch "--allow-unrelated-histories" option
+   to be used in a rare event that merges histories of two projects
+   that started their lives independently.
+
+ * "git pull" has been taught to pass the "--allow-unrelated-histories"
+   option to underlying "git merge".
+
+ * "git apply -v" learned to report paths in the patch that were
+   skipped via --include/--exclude mechanism or being outside the
+   current working directory.
+
+ * Shell completion (in contrib/) updates.
+
+ * The commit object name reported when "rebase -i" stops has been
+   shortened.
+
+ * "git worktree add" can be given "--no-checkout" option to only
+   create an empty worktree without checking out the files.
+
+ * "git mergetools" learned to drive ExamDiff.
+
+ * "git pull --rebase" learned "--[no-]autostash" option, so that
+   the rebase.autostash configuration variable set to true can be
+   overridden from the command line.
+
+ * When "git log" shows the log message indented by 4-spaces, the
+   remainder of a line after a HT does not align in the way the author
+   originally intended.  The command now expands tabs by default to help
+   such a case, and allows the users to override it with a new option,
+   "--no-expand-tabs".
+
+ * "git send-email" now uses a more readable timestamps when
+   formulating a message ID.
+
+ * "git rerere" can encounter two or more files with the same conflict
+   signature that have to be resolved in different ways, but there was
+   no way to record these separate resolutions.
+
+ * "git p4" learned to record P4 jobs in Git commit that imports from
+   the history in Perforce.
+
+ * "git describe --contains" often made a hard-to-justify choice of
+   tag to name a given commit, because it tried to come up
+   with a name with smallest number of hops from a tag, causing an old
+   commit whose close descendant that is recently tagged were not
+   described with respect to an old tag but with a newer tag.  It did
+   not help that its computation of "hop" count was further tweaked to
+   penalize being on a side branch of a merge.  The logic has been
+   updated to favor using the tag with the oldest tagger date, which
+   is a lot easier to explain to the end users: "We describe a commit
+   in terms of the (chronologically) oldest tag that contains the
+   commit."
+
+ * "git clone" learned the "--shallow-submodules" option.
+
+ * HTTP transport clients learned to throw extra HTTP headers at the
+   server, specified via http.extraHeader configuration variable.
+
+ * The "--compaction-heuristic" option to "git diff" family of
+   commands enables a heuristic to make the patch output more readable
+   by using a blank line as a strong hint that the contents before and
+   after it belong to logically separate units.  It is still
+   experimental.
+
+ * A new configuration variable core.hooksPath allows customizing
+   where the hook directory is.
+
+ * An earlier addition of "sanitize_submodule_env" with 14111fc4 (git:
+   submodule honor -c credential.* from command line, 2016-02-29)
+   turned out to be a convoluted no-op; implement what it wanted to do
+   correctly, and stop filtering settings given via "git -c var=val".
+
+ * "git commit --dry-run" reported "No, no, you cannot commit." in one
+   case where "git commit" would have allowed you to commit, and this
+   improves it a little bit ("git commit --dry-run --short" still does
+   not give you the correct answer, for example).  This is a stop-gap
+   measure in that "commit --short --dry-run" still gives an incorrect
+   result.
+
+ * The experimental "multiple worktree" feature gains more safety to
+   forbid operations on a branch that is checked out or being actively
+   worked on elsewhere, by noticing that e.g. it is being rebased.
+
+ * "git format-patch" learned a new "--base" option to record what
+   (public, well-known) commit the original series was built on in
+   its output.
+
+ * "git commit" learned to pay attention to the "commit.verbose"
+   configuration variable and act as if the "--verbose" option
+   was given from the command line.
+
+ * Updated documentation gives hints to GMail users with two-factor
+   auth enabled that they need app-specific-password when using
+   "git send-email".
+
+ * The manpage output of our documentation did not render well in
+   terminal; typeset literals in bold by default to make them stand
+   out more.
+
+ * The mark-up in the top-level README.md file has been updated to
+   typeset CLI command names differently from the body text.
+
+
+Performance, Internal Implementation, Development Support etc.
+
+ * The embedded args argv-array in the child process is used to build
+   the command line to run pack-objects instead of using a separate
+   array of strings.
+
+ * A test for tags has been restructured so that more parts of it can
+   easily be run on a platform without a working GnuPG.
+
+ * The startup_info data, which records if we are working inside a
+   repository (among other things), are now uniformly available to Git
+   subcommand implementations, and Git avoids attempting to touch
+   references when we are not in a repository.
+
+ * The command line argument parser for "receive-pack" has been
+   rewritten to use parse-options.
+
+ * A major part of "git submodule update" has been ported to C to take
+   advantage of the recently added framework to run download tasks in
+   parallel.  Other updates to "git submodule" that move pieces of
+   logic to C continues.
+
+ * Rename bunch of tests on "git clone" for better organization.
+
+ * The tests that involve running httpd leaked the system-wide
+   configuration in /etc/gitconfig to the tested environment.
+
+ * Build updates for MSVC.
+
+ * The repository set-up sequence has been streamlined (the biggest
+   change is that there is no longer git_config_early()), so that we
+   do not attempt to look into refs/* when we know we do not have a
+   Git repository.
+
+ * Code restructuring around the "refs" API to prepare for pluggable
+   refs backends.
+
+ * Sources to many test helper binaries and the generated helpers
+   have been moved to t/helper/ subdirectory to reduce clutter at the
+   top level of the tree.
+
+ * Unify internal logic between "git tag -v" and "git verify-tag"
+   commands by making one directly call into the other.
+
+ * "merge-recursive" strategy incorrectly checked if a path that is
+   involved in its internal merge exists in the working tree.
+
+ * The test scripts for "git p4" (but not "git p4" implementation
+   itself) has been updated so that they would work even on a system
+   where the installed version of Python is python 3.
+
+ * As nobody maintains our in-tree git.spec.in and distros use their
+   own spec file, we stopped pretending that we support "make rpm".
+
+ * Move from "unsigned char[20]" to "struct object_id" continues.
+
+ * The code for warning_errno/die_errno has been refactored and a new
+   error_errno() reporting helper is introduced.
+   (merge 1da045f nd/error-errno later to maint).
+
+ * Running tests with '-x' option to trace the individual command
+   executions is a useful way to debug test scripts, but some tests
+   that capture the standard error stream and check what the command
+   said can be broken with the trace output mixed in.  When running
+   our tests under "bash", however, we can redirect the trace output
+   to another file descriptor to keep the standard error of programs
+   being tested intact.
+
+ * t0040 had too many unnecessary repetitions in its test data.  Teach
+   test-parse-options program so that a caller can tell what it
+   expects in its output, so that these repetitions can be cleaned up.
+
+ * Add perf test for "rebase -i".
+
+ * Common mistakes when writing gitlink: in our documentation are
+   found by "make check-docs".
+
+ * t9xxx series has been updated primarily for readability, while
+   fixing small bugs in it.  A few scripted Porcelain commands have
+   also been updated to fix possible bugs around their use of
+   "test -z" and "test -n".
+
+ * CI test was taught to run git-svn tests.
+
+ * "git cat-file --batch-all" has been sped up, by taking advantage
+   of the fact that it does not have to read a list of objects, in two
+   ways.
+
+ * test updates to make it more readable and maintainable.
+   (merge e6273f4 es/t1500-modernize later to maint).
+
+ * "make DEVELOPER=1" worked as expected; setting DEVELOPER=1 in
+   config.mak didn't.
+   (merge 51dd3e8 mm/makefile-developer-can-be-in-config-mak later to maint).
+
+ * The way how "submodule--helper list" signals unmatch error to its
+   callers has been updated.
+
+ * A bash-ism "local" has been removed from "git submodule" scripted
+   Porcelain.
+
+
+Also contains various documentation updates and code clean-ups.
+
+
+Fixes since v2.8
+----------------
+
+Unless otherwise noted, all the fixes since v2.8 in the maintenance
+track are contained in this release (see the maintenance releases'
+notes for details).
+
+ * "git config --get-urlmatch", unlike other variants of the "git
+   config --get" family, did not signal error with its exit status
+   when there was no matching configuration.
+
+ * The "--local-env-vars" and "--resolve-git-dir" options of "git
+   rev-parse" failed to work outside a repository when the command's
+   option parsing was rewritten in 1.8.5 era.
+
+ * "git index-pack --keep[=<msg>] pack-$name.pack" simply did not work.
+
+ * Fetching of history by naming a commit object name directly didn't
+   work across remote-curl transport.
+
+ * A small memory leak in an error codepath has been plugged in xdiff
+   code.
+
+ * strbuf_getwholeline() did not NUL-terminate the buffer on certain
+   corner cases in its error codepath.
+
+ * "git mergetool" did not work well with conflicts that both sides
+   deleted.
+
+ * "git send-email" had trouble parsing alias file in mailrc format
+   when lines in it had trailing whitespaces on them.
+
+ * When "git merge --squash" stopped due to conflict, the concluding
+   "git commit" failed to read in the SQUASH_MSG that shows the log
+   messages from all the squashed commits.
+
+ * "git merge FETCH_HEAD" dereferenced NULL pointer when merging
+   nothing into an unborn history (which is arguably unusual usage,
+   which perhaps was the reason why nobody noticed it).
+
+ * When "git worktree" feature is in use, "git branch -d" allowed
+   deletion of a branch that is checked out in another worktree,
+   which was wrong.
+
+ * When "git worktree" feature is in use, "git branch -m" renamed a
+   branch that is checked out in another worktree without adjusting
+   the HEAD symbolic ref for the worktree.
+
+ * "git diff -M" used to work better when two originally identical
+   files A and B got renamed to X/A and X/B by pairing A to X/A and B
+   to X/B, but this was broken in the 2.0 timeframe.
+
+ * "git send-pack --all <there>" was broken when its command line
+   option parsing was written in the 2.6 timeframe.
+
+ * "git format-patch --help" showed `-s` and `--no-patch` as if these
+   are valid options to the command.  We already hide `--patch` option
+   from the documentation, because format-patch is about showing the
+   diff, and the documentation now hides these options as well.
+
+ * When running "git blame $path" with unnormalized data in the index
+   for the path, the data in the working tree was blamed, even though
+   "git add" would not have changed what is already in the index, due
+   to "safe crlf" that disables the line-end conversion.  It has been
+   corrected.
+
+ * A change back in version 2.7 to "git branch" broke display of a
+   symbolic ref in a non-standard place in the refs/ hierarchy (we
+   expect symbolic refs to appear in refs/remotes/*/HEAD to point at
+   the primary branch the remote has, and as .git/HEAD to point at the
+   branch we locally checked out).
+
+ * A partial rewrite of "git submodule" in the 2.7 timeframe changed
+   the way the gitdir: pointer in the submodules point at the real
+   repository location to use absolute paths by accident.  This has
+   been corrected.
+
+ * "git commit" misbehaved in a few minor ways when an empty message
+   is given via -m '', all of which has been corrected.
+
+ * Support for CRAM-MD5 authentication method in "git imap-send" did
+   not work well.
+
+ * Upcoming OpenSSL 1.1.0 will break compilation by updating a few API
+   elements we use in imap-send, which has been adjusted for the change.
+
+ * The socks5:// proxy support added back in 2.6.4 days was not aware
+   that socks5h:// proxies behave differently from socks5:// proxies.
+
+ * "git config" had a codepath that tried to pass a NULL to
+   printf("%s"), which nobody seems to have noticed.
+
+ * On Cygwin, object creation uses the "create a temporary and then
+   rename it to the final name" pattern, not "create a temporary,
+   hardlink it to the final name and then unlink the temporary"
+   pattern.
+
+   This is necessary to use Git on Windows shared directories, and is
+   already enabled for the MinGW and plain Windows builds.  It also
+   has been used in Cygwin packaged versions of Git for quite a while.
+   See http://thread.gmane.org/gmane.comp.version-control.git/291853
+
+ * "merge-octopus" strategy did not ensure that the index is clean
+   when merge begins.
+
+ * When "git merge" notices that the merge can be resolved purely at
+   the tree level (without having to merge blobs) and the resulting
+   tree happens to already exist in the object store, it forgot to
+   update the index, which left an inconsistent state that would
+   break later operations.
+
+ * "git submodule" reports the paths of submodules the command
+   recurses into, but these paths were incorrectly reported when
+   the command was not run from the root level of the superproject.
+
+ * The "user.useConfigOnly" configuration variable makes it an error
+   if users do not explicitly set user.name and user.email.  However,
+   its check was not done early enough and allowed another error to
+   trigger, reporting that the default value we guessed from the
+   system setting was unusable.  This was a suboptimal end-user
+   experience as we want the users to set user.name/user.email without
+   relying on the auto-detection at all.
+
+ * "git mv old new" did not adjust the path for a submodule that lives
+   as a subdirectory inside old/ directory correctly.
+
+ * "git replace -e" did not honour "core.editor" configuration.
+
+ * "git push" from a corrupt repository that attempts to push a large
+   number of refs deadlocked; the thread to relay rejection notices
+   for these ref updates blocked on writing them to the main thread,
+   after the main thread at the receiving end notices that the push
+   failed and decides not to read these notices and return a failure.
+
+ * mmap emulation on Windows has been optimized and work better without
+   consuming paging store when not needed.
+
+ * A question by "git send-email" to ask the identity of the sender
+   has been updated.
+
+ * UI consistency improvements for "git mergetool".
+
+ * "git rebase -m" could be asked to rebase an entire branch starting
+   from the root, but failed by assuming that there always is a parent
+   commit to the first commit on the branch.
+
+ * Fix a broken "p4 lfs" test.
+
+ * Recent update to Git LFS broke "git p4" by changing the output from
+   its "lfs pointer" subcommand.
+
+ * "git fetch" test t5510 was flaky while running a (forced) automagic
+   garbage collection.
+
+ * Documentation updates to help contributors setting up Travis CI
+   test for their patches.
+
+ * Some multi-byte encoding can have a backslash byte as a later part
+   of one letter, which would confuse "highlight" filter used in
+   gitweb.
+
+ * "git commit-tree" plumbing command required the user to always sign
+   its result when the user sets the commit.gpgsign configuration
+   variable, which was an ancient mistake.  Rework "git rebase" that
+   relied on this mistake so that it reads commit.gpgsign and pass (or
+   not pass) the -S option to "git commit-tree" to keep the end-user
+   expectation the same, while teaching "git commit-tree" to ignore
+   the configuration variable.  This will stop requiring the users to
+   sign commit objects used internally as an implementation detail of
+   "git stash".
+
+ * "http.cookieFile" configuration variable clearly wants a pathname,
+   but we forgot to treat it as such by e.g. applying tilde expansion.
+
+ * Consolidate description of tilde-expansion that is done to
+   configuration variables that take pathname to a single place.
+
+ * Correct faulty recommendation to use "git submodule deinit ." when
+   de-initialising all submodules, which would result in a strange
+   error message in a pathological corner case.
+
+ * Many 'linkgit:<git documentation page>' references were broken,
+   which are all fixed with this.
+
+ * "git rerere" can get confused by conflict markers deliberately left
+   by the inner merge step, because they are indistinguishable from
+   the real conflict markers left by the outermost merge which are
+   what the end user and "rerere" need to look at.  This was fixed by
+   making the conflict markers left by the inner merges a bit longer.
+   (merge 0f9fd5c jc/ll-merge-internal later to maint).
+
+ * CI test was taught to build documentation pages.
+
+ * "git fsck" learned to catch NUL byte in a commit object as
+   potential error and warn.
+
+ * Portability enhancement for "rebase -i" to help platforms whose
+   shell does not like "for i in <empty>" (which is not POSIX-kosher).
+
+ * On Windows, .git and optionally any files whose name starts with a
+   dot are now marked as hidden, with a core.hideDotFiles knob to
+   customize this behaviour.
+
+ * Documentation for "git merge --verify-signatures" has been updated
+   to clarify that the signature of only the commit at the tip is
+   verified.  Also the phrasing used for signature and key validity is
+   adjusted to align with that used by OpenPGP.
+
+ * A couple of bugs around core.autocrlf have been fixed.
+
+ * Many commands normalize command line arguments from NFD to NFC
+   variant of UTF-8 on OSX, but commands in the "diff" family did
+   not, causing "git diff $path" to complain that no such path is
+   known to Git.  They have been taught to do the normalization.
+
+ * "git difftool" learned to handle unmerged paths correctly in
+   dir-diff mode.
+
+ * The "are we talking with TTY, doing an interactive session?"
+   detection has been updated to work better for "Git for Windows".
+
+ * We forgot to add "git log --decorate=auto" to documentation when we
+   added the feature back in v2.1.0 timeframe.
+   (merge 462cbb4 rj/log-decorate-auto later to maint).
+
+ * "git fast-import --export-marks" would overwrite the existing marks
+   file even when it makes a dump from its custom die routine.
+   Prevent it from doing so when we have an import-marks file but
+   haven't finished reading it.
+   (merge f4beed6 fc/fast-import-broken-marks-file later to maint).
+
+ * "git rebase -i", after it fails to auto-resolve the conflict, had
+   an unnecessary call to "git rerere" from its very early days, which
+   was spotted recently; the call has been removed.
+   (merge 7063693 js/rebase-i-dedup-call-to-rerere later to maint).
+
+ * Other minor clean-ups and documentation updates
+   (merge cd82b7a pa/cherry-pick-doc-typo later to maint).
+   (merge 2bb73ae rs/patch-id-use-skip-prefix later to maint).
+   (merge aa20cbc rs/apply-name-terminate later to maint).
+   (merge fe17fc0 jc/t2300-setup later to maint).
+   (merge e256eec jk/shell-portability later to maint).
diff --git a/third_party/git/Documentation/RelNotes/2.9.1.txt b/third_party/git/Documentation/RelNotes/2.9.1.txt
new file mode 100644
index 0000000000..338394097e
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.1.txt
@@ -0,0 +1,117 @@
+Git v2.9.1 Release Notes
+========================
+
+Fixes since v2.9
+----------------
+
+ * When "git daemon" is run without --[init-]timeout specified, a
+   connection from a client that silently goes offline can hang around
+   for a long time, wasting resources.  The socket-level KEEPALIVE has
+   been enabled to allow the OS to notice such failed connections.
+
+ * The commands in `git log` family take %C(auto) in a custom format
+   string.  This unconditionally turned the color on, ignoring
+   --no-color or with --color=auto when the output is not connected to
+   a tty; this was corrected to make the format truly behave as
+   "auto".
+
+ * "git rev-list --count" whose walk-length is limited with "-n"
+   option did not work well with the counting optimized to look at the
+   bitmap index.
+
+ * "git show -W" (extend hunks to cover the entire function, delimited
+   by lines that match the "funcname" pattern) used to show the entire
+   file when a change added an entire function at the end of the file,
+   which has been fixed.
+
+ * The documentation set has been updated so that literal commands,
+   configuration variables and environment variables are consistently
+   typeset in fixed-width font and bold in manpages.
+
+ * "git svn propset" subcommand that was added in 2.3 days is
+   documented now.
+
+ * The documentation tries to consistently spell "GPG"; when
+   referring to the specific program name, "gpg" is used.
+
+ * "git reflog" stopped upon seeing an entry that denotes a branch
+   creation event (aka "unborn"), which made it appear as if the
+   reflog was truncated.
+
+ * The git-prompt scriptlet (in contrib/) was not friendly with those
+   who uses "set -u", which has been fixed.
+
+ * A codepath that used alloca(3) to place an unbounded amount of data
+   on the stack has been updated to avoid doing so.
+
+ * "git update-index --add --chmod=+x file" may be usable as an escape
+   hatch, but not a friendly thing to force for people who do need to
+   use it regularly.  "git add --chmod=+x file" can be used instead.
+
+ * Build improvements for gnome-keyring (in contrib/)
+
+ * "git status" used to say "working directory" when it meant "working
+   tree".
+
+ * Comments about misbehaving FreeBSD shells have been clarified with
+   the version number (9.x and before are broken, newer ones are OK).
+
+ * "git cherry-pick A" worked on an unborn branch, but "git
+   cherry-pick A..B" didn't.
+
+ * "git add -i/-p" learned to honor diff.compactionHeuristic
+   experimental knob, so that the user can work on the same hunk split
+   as "git diff" output.
+
+ * "log --graph --format=" learned that "%>|(N)" specifies the width
+   relative to the terminal's left edge, not relative to the area to
+   draw text that is to the right of the ancestry-graph section.  It
+   also now accepts negative N that means the column limit is relative
+   to the right border.
+
+ * The ownership rule for the piece of memory that hold references to
+   be fetched in "git fetch" was screwy, which has been cleaned up.
+
+ * "git bisect" makes an internal call to "git diff-tree" when
+   bisection finds the culprit, but this call did not initialize the
+   data structure to pass to the diff-tree API correctly.
+
+ * Formats of the various data (and how to validate them) where we use
+   GPG signature have been documented.
+
+ * Fix an unintended regression in v2.9 that breaks "clone --depth"
+   that recurses down to submodules by forcing the submodules to also
+   be cloned shallowly, which many server instances that host upstream
+   of the submodules are not prepared for.
+
+ * Fix unnecessarily waste in the idiomatic use of ': ${VAR=default}'
+   to set the default value, without enclosing it in double quotes.
+
+ * Some platform-specific code had non-ANSI strict declarations of C
+   functions that do not take any parameters, which has been
+   corrected.
+
+ * The internal code used to show local timezone offset is not
+   prepared to handle timestamps beyond year 2100, and gave a
+   bogus offset value to the caller.  Use a more benign looking
+   +0000 instead and let "git log" going in such a case, instead
+   of aborting.
+
+ * One among four invocations of readlink(1) in our test suite has
+   been rewritten so that the test can run on systems without the
+   command (others are in valgrind test framework and t9802).
+
+ * t/perf needs /usr/bin/time with GNU extension; the invocation of it
+   is updated to "gtime" on Darwin.
+
+ * A bug, which caused "git p4" while running under verbose mode to
+   report paths that are omitted due to branch prefix incorrectly, has
+   been fixed; the command said "Ignoring file outside of prefix" for
+   paths that are _inside_.
+
+ * The top level documentation "git help git" still pointed at the
+   documentation set hosted at now-defunct google-code repository.
+   Update it to point to https://git.github.io/htmldocs/git.html
+   instead.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.9.2.txt b/third_party/git/Documentation/RelNotes/2.9.2.txt
new file mode 100644
index 0000000000..2620003dcf
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.2.txt
@@ -0,0 +1,13 @@
+Git v2.9.2 Release Notes
+========================
+
+Fixes since v2.9.1
+------------------
+
+ * A fix merged to v2.9.1 had a few tests that are not meant to be
+   run on platforms without 64-bit long, which caused unnecessary
+   test failures on them because we didn't detect the platform and
+   skip them.  These tests are now skipped on platforms that they
+   are not applicable to.
+
+No other change is included in this update.
diff --git a/third_party/git/Documentation/RelNotes/2.9.3.txt b/third_party/git/Documentation/RelNotes/2.9.3.txt
new file mode 100644
index 0000000000..695b86f612
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.3.txt
@@ -0,0 +1,170 @@
+Git v2.9.3 Release Notes
+========================
+
+Fixes since v2.9.2
+------------------
+
+ * A helper function that takes the contents of a commit object and
+   finds its subject line did not ignore leading blank lines, as is
+   commonly done by other codepaths.  Make it ignore leading blank
+   lines to match.
+
+ * Git does not know what the contents in the index should be for a
+   path added with "git add -N" yet, so "git grep --cached" should not
+   show hits (or show lack of hits, with -L) in such a path, but that
+   logic does not apply to "git grep", i.e. searching in the working
+   tree files.  But we did so by mistake, which has been corrected.
+
+ * "git rebase -i --autostash" did not restore the auto-stashed change
+   when the operation was aborted.
+
+ * "git commit --amend --allow-empty-message -S" for a commit without
+   any message body could have misidentified where the header of the
+   commit object ends.
+
+ * More mark-up updates to typeset strings that are expected to
+   literally typed by the end user in fixed-width font.
+
+ * For a long time, we carried an in-code comment that said our
+   colored output would work only when we use fprintf/fputs on
+   Windows, which no longer is the case for the past few years.
+
+ * "gc.autoPackLimit" when set to 1 should not trigger a repacking
+   when there is only one pack, but the code counted poorly and did
+   so.
+
+ * One part of "git am" had an oddball helper function that called
+   stuff from outside "his" as opposed to calling what we have "ours",
+   which was not gender-neutral and also inconsistent with the rest of
+   the system where outside stuff is usuall called "theirs" in
+   contrast to "ours".
+
+ * The test framework learned a new helper test_match_signal to
+   check an exit code from getting killed by an expected signal.
+
+ * "git blame -M" missed a single line that was moved within the file.
+
+ * Fix recently introduced codepaths that are involved in parallel
+   submodule operations, which gave up on reading too early, and
+   could have wasted CPU while attempting to write under a corner
+   case condition.
+
+ * "git grep -i" has been taught to fold case in non-ascii locales
+   correctly.
+
+ * A test that unconditionally used "mktemp" learned that the command
+   is not necessarily available everywhere.
+
+ * "git blame file" allowed the lineage of lines in the uncommitted,
+   unadded contents of "file" to be inspected, but it refused when
+   "file" did not appear in the current commit.  When "file" was
+   created by renaming an existing file (but the change has not been
+   committed), this restriction was unnecessarily tight.
+
+ * "git add -N dir/file && git write-tree" produced an incorrect tree
+   when there are other paths in the same directory that sorts after
+   "file".
+
+ * "git fetch http://user:pass@host/repo..." scrubbed the userinfo
+   part, but "git push" didn't.
+
+ * An age old bug that caused "git diff --ignore-space-at-eol"
+   misbehave has been fixed.
+
+ * "git notes merge" had a code to see if a path exists (and fails if
+   it does) and then open the path for writing (when it doesn't).
+   Replace it with open with O_EXCL.
+
+ * "git pack-objects" and "git index-pack" mostly operate with off_t
+   when talking about the offset of objects in a packfile, but there
+   were a handful of places that used "unsigned long" to hold that
+   value, leading to an unintended truncation.
+
+ * Recent update to "git daemon" tries to enable the socket-level
+   KEEPALIVE, but when it is spawned via inetd, the standard input
+   file descriptor may not necessarily be connected to a socket.
+   Suppress an ENOTSOCK error from setsockopt().
+
+ * Recent FreeBSD stopped making perl available at /usr/bin/perl;
+   switch the default the built-in path to /usr/local/bin/perl on not
+   too ancient FreeBSD releases.
+
+ * "git status" learned to suggest "merge --abort" during a conflicted
+   merge, just like it already suggests "rebase --abort" during a
+   conflicted rebase.
+
+ * The .c/.h sources are marked as such in our .gitattributes file so
+   that "git diff -W" and friends would work better.
+
+ * Existing autoconf generated test for the need to link with pthread
+   library did not check all the functions from pthread libraries;
+   recent FreeBSD has some functions in libc but not others, and we
+   mistakenly thought linking with libc is enough when it is not.
+
+ * Allow http daemon tests in Travis CI tests.
+
+ * Users of the parse_options_concat() API function need to allocate
+   extra slots in advance and fill them with OPT_END() when they want
+   to decide the set of supported options dynamically, which makes the
+   code error-prone and hard to read.  This has been corrected by tweaking
+   the API to allocate and return a new copy of "struct option" array.
+
+ * The use of strbuf in "git rm" to build filename to remove was a bit
+   suboptimal, which has been fixed.
+
+ * "git commit --help" said "--no-verify" is only about skipping the
+   pre-commit hook, and failed to say that it also skipped the
+   commit-msg hook.
+
+ * "git merge" in Git v2.9 was taught to forbid merging an unrelated
+   lines of history by default, but that is exactly the kind of thing
+   the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
+   "git subtree" has been taught to use the "--allow-unrelated-histories"
+   option to override the default.
+
+ * The build procedure for "git persistent-https" helper (in contrib/)
+   has been updated so that it can be built with more recent versions
+   of Go.
+
+ * There is an optimization used in "git diff $treeA $treeB" to borrow
+   an already checked-out copy in the working tree when it is known to
+   be the same as the blob being compared, expecting that open/mmap of
+   such a file is faster than reading it from the object store, which
+   involves inflating and applying delta.  This however kicked in even
+   when the checked-out copy needs to go through the convert-to-git
+   conversion (including the clean filter), which defeats the whole
+   point of the optimization.  The optimization has been disabled when
+   the conversion is necessary.
+
+ * "git -c grep.patternType=extended log --basic-regexp" misbehaved
+   because the internal API to access the grep machinery was not
+   designed well.
+
+ * Windows port was failing some tests in t4130, due to the lack of
+   inum in the returned values by its lstat(2) emulation.
+
+ * The characters in the label shown for tags/refs for commits in
+   "gitweb" output are now properly escaped for proper HTML output.
+
+ * FreeBSD can lie when asked mtime of a directory, which made the
+   untracked cache code to fall back to a slow-path, which in turn
+   caused tests in t7063 to fail because it wanted to verify the
+   behaviour of the fast-path.
+
+ * Squelch compiler warnings for netmalloc (in compat/) library.
+
+ * The API documentation for hashmap was unclear if hashmap_entry
+   can be safely discarded without any other consideration.  State
+   that it is safe to do so.
+
+ * Not-so-recent rewrite of "git am" that started making internal
+   calls into the commit machinery had an unintended regression, in
+   that no matter how many seconds it took to apply many patches, the
+   resulting committer timestamp for the resulting commits were all
+   the same.
+
+ * "git difftool <paths>..." started in a subdirectory failed to
+   interpret the paths relative to that directory, which has been
+   fixed.
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.9.4.txt b/third_party/git/Documentation/RelNotes/2.9.4.txt
new file mode 100644
index 0000000000..9768293831
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.4.txt
@@ -0,0 +1,90 @@
+Git v2.9.4 Release Notes
+========================
+
+Fixes since v2.9.3
+------------------
+
+ * There are certain house-keeping tasks that need to be performed at
+   the very beginning of any Git program, and programs that are not
+   built-in commands had to do them exactly the same way as "git"
+   potty does.  It was easy to make mistakes in one-off standalone
+   programs (like test helpers).  A common "main()" function that
+   calls cmd_main() of individual program has been introduced to
+   make it harder to make mistakes.
+
+ * "git merge" with renormalization did not work well with
+   merge-recursive, due to "safer crlf" conversion kicking in when it
+   shouldn't.
+
+ * The reflog output format is documented better, and a new format
+   --date=unix to report the seconds-since-epoch (without timezone)
+   has been added.
+
+ * "git push --force-with-lease" already had enough logic to allow
+   ensuring that such a push results in creation of a ref (i.e. the
+   receiving end did not have another push from sideways that would be
+   discarded by our force-pushing), but didn't expose this possibility
+   to the users.  It does so now.
+
+ * "import-tars" fast-import script (in contrib/) used to ignore a
+   hardlink target and replaced it with an empty file, which has been
+   corrected to record the same blob as the other file the hardlink is
+   shared with.
+
+ * "git mv dir non-existing-dir/" did not work in some environments
+   the same way as existing mainstream platforms.  The code now moves
+   "dir" to "non-existing-dir", without relying on rename("A", "B/")
+   that strips the trailing slash of '/'.
+
+ * The "t/" hierarchy is prone to get an unusual pathname; "make test"
+   has been taught to make sure they do not contain paths that cannot
+   be checked out on Windows (and the mechanism can be reusable to
+   catch pathnames that are not portable to other platforms as need
+   arises).
+
+ * When "git merge-recursive" works on history with many criss-cross
+   merges in "verbose" mode, the names the command assigns to the
+   virtual merge bases could have overwritten each other by unintended
+   reuse of the same piece of memory.
+
+ * "git checkout --detach <branch>" used to give the same advice
+   message as that is issued when "git checkout <tag>" (or anything
+   that is not a branch name) is given, but asking with "--detach" is
+   an explicit enough sign that the user knows what is going on.  The
+   advice message has been squelched in this case.
+
+ * "git difftool" by default ignores the error exit from the backend
+   commands it spawns, because often they signal that they found
+   differences by exiting with a non-zero status code just like "diff"
+   does; the exit status codes 126 and above however are special in
+   that they are used to signal that the command is not executable,
+   does not exist, or killed by a signal.  "git difftool" has been
+   taught to notice these exit status codes.
+
+ * On Windows, help.browser configuration variable used to be ignored,
+   which has been corrected.
+
+ * The "git -c var[=val] cmd" facility to append a configuration
+   variable definition at the end of the search order was described in
+   git(1) manual page, but not in git-config(1), which was more likely
+   place for people to look for when they ask "can I make a one-shot
+   override, and if so how?"
+
+ * The tempfile (hence its user lockfile) API lets the caller to open
+   a file descriptor to a temporary file, write into it and then
+   finalize it by first closing the filehandle and then either
+   removing or renaming the temporary file.  When the process spawns a
+   subprocess after obtaining the file descriptor, and if the
+   subprocess has not exited when the attempt to remove or rename is
+   made, the last step fails on Windows, because the subprocess has
+   the file descriptor still open.  Open tempfile with O_CLOEXEC flag
+   to avoid this (on Windows, this is mapped to O_NOINHERIT).
+
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
+Also contains minor documentation updates and code clean-ups.
diff --git a/third_party/git/Documentation/RelNotes/2.9.5.txt b/third_party/git/Documentation/RelNotes/2.9.5.txt
new file mode 100644
index 0000000000..668313ae55
--- /dev/null
+++ b/third_party/git/Documentation/RelNotes/2.9.5.txt
@@ -0,0 +1,4 @@
+Git v2.9.5 Release Notes
+========================
+
+This release forward-ports the fix for "ssh://..." URL from Git v2.7.6
diff --git a/third_party/git/Documentation/SubmittingPatches b/third_party/git/Documentation/SubmittingPatches
new file mode 100644
index 0000000000..6d589e118c
--- /dev/null
+++ b/third_party/git/Documentation/SubmittingPatches
@@ -0,0 +1,569 @@
+Submitting Patches
+==================
+
+== Guidelines
+
+Here are some guidelines for people who want to contribute their code
+to this software.
+
+[[base-branch]]
+=== Decide what to base your work on.
+
+In general, always base your work on the oldest branch that your
+change is relevant to.
+
+* A bugfix should be based on `maint` in general. If the bug is not
+  present in `maint`, base it on `master`. For a bug that's not yet
+  in `master`, find the topic that introduces the regression, and
+  base your work on the tip of the topic.
+
+* A new feature should be based on `master` in general. If the new
+  feature depends on a topic that is in `pu`, but not in `master`,
+  base your work on the tip of that topic.
+
+* Corrections and enhancements to a topic not yet in `master` should
+  be based on the tip of that topic. If the topic has not been merged
+  to `next`, it's alright to add a note to squash minor corrections
+  into the series.
+
+* In the exceptional case that a new feature depends on several topics
+  not in `master`, start working on `next` or `pu` privately and send
+  out patches for discussion. Before the final merge, you may have to
+  wait until some of the dependent topics graduate to `master`, and
+  rebase your work.
+
+* Some parts of the system have dedicated maintainers with their own
+  repositories (see the section "Subsystems" below).  Changes to
+  these parts should be based on their trees.
+
+To find the tip of a topic branch, run `git log --first-parent
+master..pu` and look for the merge commit. The second parent of this
+commit is the tip of the topic branch.
+
+[[separate-commits]]
+=== Make separate commits for logically separate changes.
+
+Unless your patch is really trivial, you should not be sending
+out a patch that was generated between your working tree and
+your commit head.  Instead, always make a commit with complete
+commit message and generate a series of patches from your
+repository.  It is a good discipline.
+
+Give an explanation for the change(s) that is detailed enough so
+that people can judge if it is good thing to do, without reading
+the actual patch text to determine how well the code does what
+the explanation promises to do.
+
+If your description starts to get too long, that's a sign that you
+probably need to split up your commit to finer grained pieces.
+That being said, patches which plainly describe the things that
+help reviewers check the patch, and future maintainers understand
+the code, are the most beautiful patches.  Descriptions that summarize
+the point in the subject well, and describe the motivation for the
+change, the approach taken by the change, and if relevant how this
+differs substantially from the prior version, are all good things
+to have.
+
+Make sure that you have tests for the bug you are fixing.  See
+`t/README` for guidance.
+
+[[tests]]
+When adding a new feature, make sure that you have new tests to show
+the feature triggers the new behavior when it should, and to show the
+feature does not trigger when it shouldn't.  After any code change, make
+sure that the entire test suite passes.
+
+If you have an account at GitHub (and you can get one for free to work
+on open source projects), you can use their Travis CI integration to
+test your changes on Linux, Mac (and hopefully soon Windows).  See
+GitHub-Travis CI hints section for details.
+
+Do not forget to update the documentation to describe the updated
+behavior and make sure that the resulting documentation set formats
+well (try the Documentation/doc-diff script).
+
+We currently have a liberal mixture of US and UK English norms for
+spelling and grammar, which is somewhat unfortunate.  A huge patch that
+touches the files all over the place only to correct the inconsistency
+is not welcome, though.  Potential clashes with other changes that can
+result from such a patch are not worth it.  We prefer to gradually
+reconcile the inconsistencies in favor of US English, with small and
+easily digestible patches, as a side effect of doing some other real
+work in the vicinity (e.g. rewriting a paragraph for clarity, while
+turning en_UK spelling to en_US).  Obvious typographical fixes are much
+more welcomed ("teh -> "the"), preferably submitted as independent
+patches separate from other documentation changes.
+
+[[whitespace-check]]
+Oh, another thing.  We are picky about whitespaces.  Make sure your
+changes do not trigger errors with the sample pre-commit hook shipped
+in `templates/hooks--pre-commit`.  To help ensure this does not happen,
+run `git diff --check` on your changes before you commit.
+
+[[describe-changes]]
+=== Describe your changes well.
+
+The first line of the commit message should be a short description (50
+characters is the soft limit, see DISCUSSION in linkgit:git-commit[1]),
+and should skip the full stop.  It is also conventional in most cases to
+prefix the first line with "area: " where the area is a filename or
+identifier for the general area of the code being modified, e.g.
+
+* doc: clarify distinction between sign-off and pgp-signing
+* githooks.txt: improve the intro section
+
+If in doubt which identifier to use, run `git log --no-merges` on the
+files you are modifying to see the current conventions.
+
+[[summary-section]]
+It's customary to start the remainder of the first line after "area: "
+with a lower-case letter. E.g. "doc: clarify...", not "doc:
+Clarify...", or "githooks.txt: improve...", not "githooks.txt:
+Improve...".
+
+[[meaningful-message]]
+The body should provide a meaningful commit message, which:
+
+. explains the problem the change tries to solve, i.e. what is wrong
+  with the current code without the change.
+
+. justifies the way the change solves the problem, i.e. why the
+  result with the change is better.
+
+. alternate solutions considered but discarded, if any.
+
+[[imperative-mood]]
+Describe your changes in imperative mood, e.g. "make xyzzy do frotz"
+instead of "[This patch] makes xyzzy do frotz" or "[I] changed xyzzy
+to do frotz", as if you are giving orders to the codebase to change
+its behavior.  Try to make sure your explanation can be understood
+without external resources. Instead of giving a URL to a mailing list
+archive, summarize the relevant points of the discussion.
+
+[[commit-reference]]
+If you want to reference a previous commit in the history of a stable
+branch, use the format "abbreviated sha1 (subject, date)",
+with the subject enclosed in a pair of double-quotes, like this:
+
+....
+	Commit f86a374 ("pack-bitmap.c: fix a memleak", 2015-03-30)
+	noticed that ...
+....
+
+The "Copy commit summary" command of gitk can be used to obtain this
+format, or this invocation of `git show`:
+
+....
+	git show -s --date=short --pretty='format:%h ("%s", %ad)' <commit>
+....
+
+[[git-tools]]
+=== Generate your patch using Git tools out of your commits.
+
+Git based diff tools generate unidiff which is the preferred format.
+
+You do not have to be afraid to use `-M` option to `git diff` or
+`git format-patch`, if your patch involves file renames.  The
+receiving end can handle them just fine.
+
+[[review-patch]]
+Please make sure your patch does not add commented out debugging code,
+or include any extra files which do not relate to what your patch
+is trying to achieve. Make sure to review
+your patch after generating it, to ensure accuracy.  Before
+sending out, please make sure it cleanly applies to the `master`
+branch head.  If you are preparing a work based on "next" branch,
+that is fine, but please mark it as such.
+
+[[send-patches]]
+=== Sending your patches.
+
+:security-ml: footnoteref:[security-ml,The Git Security mailing list: git-security@googlegroups.com]
+
+Before sending any patches, please note that patches that may be
+security relevant should be submitted privately to the Git Security
+mailing list{security-ml}, instead of the public mailing list.
+
+Learn to use format-patch and send-email if possible.  These commands
+are optimized for the workflow of sending patches, avoiding many ways
+your existing e-mail client that is optimized for "multipart/*" mime
+type e-mails to corrupt and render your patches unusable.
+
+People on the Git mailing list need to be able to read and
+comment on the changes you are submitting.  It is important for
+a developer to be able to "quote" your changes, using standard
+e-mail tools, so that they may comment on specific portions of
+your code.  For this reason, each patch should be submitted
+"inline" in a separate message.
+
+Multiple related patches should be grouped into their own e-mail
+thread to help readers find all parts of the series.  To that end,
+send them as replies to either an additional "cover letter" message
+(see below), the first patch, or the respective preceding patch.
+
+If your log message (including your name on the
+Signed-off-by line) is not writable in ASCII, make sure that
+you send off a message in the correct encoding.
+
+WARNING: Be wary of your MUAs word-wrap
+corrupting your patch.  Do not cut-n-paste your patch; you can
+lose tabs that way if you are not careful.
+
+It is a common convention to prefix your subject line with
+[PATCH].  This lets people easily distinguish patches from other
+e-mail discussions.  Use of markers in addition to PATCH within
+the brackets to describe the nature of the patch is also
+encouraged.  E.g. [RFC PATCH] (where RFC stands for "request for
+comments") is often used to indicate a patch needs further
+discussion before being accepted, [PATCH v2], [PATCH v3] etc.
+are often seen when you are sending an update to what you have
+previously sent.
+
+The `git format-patch` command follows the best current practice to
+format the body of an e-mail message.  At the beginning of the
+patch should come your commit message, ending with the
+Signed-off-by: lines, and a line that consists of three dashes,
+followed by the diffstat information and the patch itself.  If
+you are forwarding a patch from somebody else, optionally, at
+the beginning of the e-mail message just before the commit
+message starts, you can put a "From: " line to name that person.
+To change the default "[PATCH]" in the subject to "[<text>]", use
+`git format-patch --subject-prefix=<text>`.  As a shortcut, you
+can use `--rfc` instead of `--subject-prefix="RFC PATCH"`, or
+`-v <n>` instead of `--subject-prefix="PATCH v<n>"`.
+
+You often want to add additional explanation about the patch,
+other than the commit message itself.  Place such "cover letter"
+material between the three-dash line and the diffstat.  For
+patches requiring multiple iterations of review and discussion,
+an explanation of changes between each iteration can be kept in
+Git-notes and inserted automatically following the three-dash
+line via `git format-patch --notes`.
+
+[[attachment]]
+Do not attach the patch as a MIME attachment, compressed or not.
+Do not let your e-mail client send quoted-printable.  Do not let
+your e-mail client send format=flowed which would destroy
+whitespaces in your patches. Many
+popular e-mail applications will not always transmit a MIME
+attachment as plain text, making it impossible to comment on
+your code.  A MIME attachment also takes a bit more time to
+process.  This does not decrease the likelihood of your
+MIME-attached change being accepted, but it makes it more likely
+that it will be postponed.
+
+Exception:  If your mailer is mangling patches then someone may ask
+you to re-send them using MIME, that is OK.
+
+[[pgp-signature]]
+Do not PGP sign your patch. Most likely, your maintainer or other people on the
+list would not have your PGP key and would not bother obtaining it anyway.
+Your patch is not judged by who you are; a good patch from an unknown origin
+has a far better chance of being accepted than a patch from a known, respected
+origin that is done poorly or does incorrect things.
+
+If you really really really really want to do a PGP signed
+patch, format it as "multipart/signed", not a text/plain message
+that starts with `-----BEGIN PGP SIGNED MESSAGE-----`.  That is
+not a text/plain, it's something else.
+
+:security-ml-ref: footnoteref:[security-ml]
+
+As mentioned at the beginning of the section, patches that may be
+security relevant should not be submitted to the public mailing list
+mentioned below, but should instead be sent privately to the Git
+Security mailing list{security-ml-ref}.
+
+Send your patch with "To:" set to the mailing list, with "cc:" listing
+people who are involved in the area you are touching (the `git
+contacts` command in `contrib/contacts/` can help to
+identify them), to solicit comments and reviews.
+
+:current-maintainer: footnote:[The current maintainer: gitster@pobox.com]
+:git-ml: footnote:[The mailing list: git@vger.kernel.org]
+
+After the list reached a consensus that it is a good idea to apply the
+patch, re-send it with "To:" set to the maintainer{current-maintainer} and "cc:" the
+list{git-ml} for inclusion.
+
+Do not forget to add trailers such as `Acked-by:`, `Reviewed-by:` and
+`Tested-by:` lines as necessary to credit people who helped your
+patch.
+
+[[sign-off]]
+=== Certify your work by adding your "Signed-off-by: " line
+
+To improve tracking of who did what, we've borrowed the
+"sign-off" procedure from the Linux kernel project on patches
+that are being emailed around.  Although core Git is a lot
+smaller project it is a good discipline to follow it.
+
+The sign-off is a simple line at the end of the explanation for
+the patch, which certifies that you wrote it or otherwise have
+the right to pass it on as an open-source patch.  The rules are
+pretty simple: if you can certify the below D-C-O:
+
+[[dco]]
+.Developer's Certificate of Origin 1.1
+____
+By making a contribution to this project, I certify that:
+
+a. The contribution was created in whole or in part by me and I
+   have the right to submit it under the open source license
+   indicated in the file; or
+
+b. The contribution is based upon previous work that, to the best
+   of my knowledge, is covered under an appropriate open source
+   license and I have the right under that license to submit that
+   work with modifications, whether created in whole or in part
+   by me, under the same open source license (unless I am
+   permitted to submit under a different license), as indicated
+   in the file; or
+
+c. The contribution was provided directly to me by some other
+   person who certified (a), (b) or (c) and I have not modified
+   it.
+
+d. I understand and agree that this project and the contribution
+   are public and that a record of the contribution (including all
+   personal information I submit with it, including my sign-off) is
+   maintained indefinitely and may be redistributed consistent with
+   this project or the open source license(s) involved.
+____
+
+then you just add a line saying
+
+....
+	Signed-off-by: Random J Developer <random@developer.example.org>
+....
+
+This line can be automatically added by Git if you run the git-commit
+command with the -s option.
+
+Notice that you can place your own Signed-off-by: line when
+forwarding somebody else's patch with the above rules for
+D-C-O.  Indeed you are encouraged to do so.  Do not forget to
+place an in-body "From: " line at the beginning to properly attribute
+the change to its true author (see (2) above).
+
+[[real-name]]
+Also notice that a real name is used in the Signed-off-by: line. Please
+don't hide your real name.
+
+[[commit-trailers]]
+If you like, you can put extra tags at the end:
+
+. `Reported-by:` is used to credit someone who found the bug that
+  the patch attempts to fix.
+. `Acked-by:` says that the person who is more familiar with the area
+  the patch attempts to modify liked the patch.
+. `Reviewed-by:`, unlike the other tags, can only be offered by the
+  reviewer and means that she is completely satisfied that the patch
+  is ready for application.  It is usually offered only after a
+  detailed review.
+. `Tested-by:` is used to indicate that the person applied the patch
+  and found it to have the desired effect.
+
+You can also create your own tag or use one that's in common usage
+such as "Thanks-to:", "Based-on-patch-by:", or "Mentored-by:".
+
+== Subsystems with dedicated maintainers
+
+Some parts of the system have dedicated maintainers with their own
+repositories.
+
+- `git-gui/` comes from git-gui project, maintained by Pat Thoyts:
+
+	git://repo.or.cz/git-gui.git
+
+- `gitk-git/` comes from Paul Mackerras's gitk project:
+
+	git://ozlabs.org/~paulus/gitk
+
+- `po/` comes from the localization coordinator, Jiang Xin:
+
+	https://github.com/git-l10n/git-po/
+
+Patches to these parts should be based on their trees.
+
+[[patch-flow]]
+== An ideal patch flow
+
+Here is an ideal patch flow for this project the current maintainer
+suggests to the contributors:
+
+. You come up with an itch.  You code it up.
+
+. Send it to the list and cc people who may need to know about
+  the change.
++
+The people who may need to know are the ones whose code you
+are butchering.  These people happen to be the ones who are
+most likely to be knowledgeable enough to help you, but
+they have no obligation to help you (i.e. you ask for help,
+don't demand).  +git log -p {litdd} _$area_you_are_modifying_+ would
+help you find out who they are.
+
+. You get comments and suggestions for improvements.  You may
+  even get them in an "on top of your change" patch form.
+
+. Polish, refine, and re-send to the list and the people who
+  spend their time to improve your patch.  Go back to step (2).
+
+. The list forms consensus that the last round of your patch is
+  good.  Send it to the maintainer and cc the list.
+
+. A topic branch is created with the patch and is merged to `next`,
+  and cooked further and eventually graduates to `master`.
+
+In any time between the (2)-(3) cycle, the maintainer may pick it up
+from the list and queue it to `pu`, in order to make it easier for
+people play with it without having to pick up and apply the patch to
+their trees themselves.
+
+[[patch-status]]
+== Know the status of your patch after submission
+
+* You can use Git itself to find out when your patch is merged in
+  master. `git pull --rebase` will automatically skip already-applied
+  patches, and will let you know. This works only if you rebase on top
+  of the branch in which your patch has been merged (i.e. it will not
+  tell you if your patch is merged in pu if you rebase on top of
+  master).
+
+* Read the Git mailing list, the maintainer regularly posts messages
+  entitled "What's cooking in git.git" and "What's in git.git" giving
+  the status of various proposed changes.
+
+[[travis]]
+== GitHub-Travis CI hints
+
+With an account at GitHub (you can get one for free to work on open
+source projects), you can use Travis CI to test your changes on Linux,
+Mac (and hopefully soon Windows).  You can find a successful example
+test build here: https://travis-ci.org/git/git/builds/120473209
+
+Follow these steps for the initial setup:
+
+. Fork https://github.com/git/git to your GitHub account.
+  You can find detailed instructions how to fork here:
+  https://help.github.com/articles/fork-a-repo/
+
+. Open the Travis CI website: https://travis-ci.org
+
+. Press the "Sign in with GitHub" button.
+
+. Grant Travis CI permissions to access your GitHub account.
+  You can find more information about the required permissions here:
+  https://docs.travis-ci.com/user/github-oauth-scopes
+
+. Open your Travis CI profile page: https://travis-ci.org/profile
+
+. Enable Travis CI builds for your Git fork.
+
+After the initial setup, Travis CI will run whenever you push new changes
+to your fork of Git on GitHub.  You can monitor the test state of all your
+branches here: https://travis-ci.org/__<Your GitHub handle>__/git/branches
+
+If a branch did not pass all test cases then it is marked with a red
+cross.  In that case you can click on the failing Travis CI job and
+scroll all the way down in the log.  Find the line "<-- Click here to see
+detailed test output!" and click on the triangle next to the log line
+number to expand the detailed test output.  Here is such a failing
+example: https://travis-ci.org/git/git/jobs/122676187
+
+Fix the problem and push your fix to your Git fork.  This will trigger
+a new Travis CI build to ensure all tests pass.
+
+[[mua]]
+== MUA specific hints
+
+Some of patches I receive or pick up from the list share common
+patterns of breakage.  Please make sure your MUA is set up
+properly not to corrupt whitespaces.
+
+See the DISCUSSION section of linkgit:git-format-patch[1] for hints on
+checking your patch by mailing it to yourself and applying with
+linkgit:git-am[1].
+
+While you are at it, check the resulting commit log message from
+a trial run of applying the patch.  If what is in the resulting
+commit is not exactly what you would want to see, it is very
+likely that your maintainer would end up hand editing the log
+message when he applies your patch.  Things like "Hi, this is my
+first patch.\n", if you really want to put in the patch e-mail,
+should come after the three-dash line that signals the end of the
+commit message.
+
+
+=== Pine
+
+(Johannes Schindelin)
+
+....
+I don't know how many people still use pine, but for those poor
+souls it may be good to mention that the quell-flowed-text is
+needed for recent versions.
+
+... the "no-strip-whitespace-before-send" option, too. AFAIK it
+was introduced in 4.60.
+....
+
+(Linus Torvalds)
+
+....
+And 4.58 needs at least this.
+
+diff-tree 8326dd8350be64ac7fc805f6563a1d61ad10d32c (from e886a61f76edf5410573e92e38ce22974f9c40f1)
+Author: Linus Torvalds <torvalds@g5.osdl.org>
+Date:   Mon Aug 15 17:23:51 2005 -0700
+
+    Fix pine whitespace-corruption bug
+
+    There's no excuse for unconditionally removing whitespace from
+    the pico buffers on close.
+
+diff --git a/pico/pico.c b/pico/pico.c
+--- a/pico/pico.c
++++ b/pico/pico.c
+@@ -219,7 +219,9 @@ PICO *pm;
+	    switch(pico_all_done){	/* prepare for/handle final events */
+	      case COMP_EXIT :		/* already confirmed */
+		packheader();
++#if 0
+		stripwhitespace();
++#endif
+		c |= COMP_EXIT;
+		break;
+....
+
+(Daniel Barkalow)
+
+....
+> A patch to SubmittingPatches, MUA specific help section for
+> users of Pine 4.63 would be very much appreciated.
+
+Ah, it looks like a recent version changed the default behavior to do the
+right thing, and inverted the sense of the configuration option. (Either
+that or Gentoo did it.) So you need to set the
+"no-strip-whitespace-before-send" option, unless the option you have is
+"strip-whitespace-before-send", in which case you should avoid checking
+it.
+....
+
+=== Thunderbird, KMail, GMail
+
+See the MUA-SPECIFIC HINTS section of linkgit:git-format-patch[1].
+
+=== Gnus
+
+"|" in the `*Summary*` buffer can be used to pipe the current
+message to an external program, and this is a handy way to drive
+`git am`.  However, if the message is MIME encoded, what is
+piped into the program is the representation you see in your
+`*Article*` buffer after unwrapping MIME.  This is often not what
+you would want for two reasons.  It tends to screw up non ASCII
+characters (most notably in people's names), and also
+whitespaces (fatal in patches).  Running "C-u g" to display the
+message in raw form before using "|" to run the pipe can work
+this problem around.
diff --git a/third_party/git/Documentation/asciidoc.conf b/third_party/git/Documentation/asciidoc.conf
new file mode 100644
index 0000000000..2c16c536ba
--- /dev/null
+++ b/third_party/git/Documentation/asciidoc.conf
@@ -0,0 +1,97 @@
+## linkgit: macro
+#
+# Usage: linkgit:command[manpage-section]
+#
+# Note, {0} is the manpage section, while {target} is the command.
+#
+# Show Git link as: <command>(<section>); if section is defined, else just show
+# the command.
+
+[macros]
+(?su)[\\]?(?P<name>linkgit):(?P<target>\S*?)\[(?P<attrlist>.*?)\]=
+
+[attributes]
+asterisk=&#42;
+plus=&#43;
+caret=&#94;
+startsb=&#91;
+endsb=&#93;
+backslash=&#92;
+tilde=&#126;
+apostrophe=&#39;
+backtick=&#96;
+litdd=&#45;&#45;
+
+ifdef::backend-docbook[]
+[linkgit-inlinemacro]
+{0%{target}}
+{0#<citerefentry>}
+{0#<refentrytitle>{target}</refentrytitle><manvolnum>{0}</manvolnum>}
+{0#</citerefentry>}
+endif::backend-docbook[]
+
+ifdef::backend-docbook[]
+ifndef::git-asciidoc-no-roff[]
+# "unbreak" docbook-xsl v1.68 for manpages. v1.69 works with or without this.
+# v1.72 breaks with this because it replaces dots not in roff requests.
+[listingblock]
+<example><title>{title}</title>
+<literallayout class="monospaced">
+ifdef::doctype-manpage[]
+&#10;.ft C&#10;
+endif::doctype-manpage[]
+|
+ifdef::doctype-manpage[]
+&#10;.ft&#10;
+endif::doctype-manpage[]
+</literallayout>
+{title#}</example>
+endif::git-asciidoc-no-roff[]
+
+ifdef::git-asciidoc-no-roff[]
+ifdef::doctype-manpage[]
+# The following two small workarounds insert a simple paragraph after screen
+[listingblock]
+<example><title>{title}</title>
+<literallayout class="monospaced">
+|
+</literallayout><simpara></simpara>
+{title#}</example>
+
+[verseblock]
+<formalpara{id? id="{id}"}><title>{title}</title><para>
+{title%}<literallayout{id? id="{id}"}>
+{title#}<literallayout>
+|
+</literallayout>
+{title#}</para></formalpara>
+{title%}<simpara></simpara>
+endif::doctype-manpage[]
+endif::git-asciidoc-no-roff[]
+endif::backend-docbook[]
+
+ifdef::doctype-manpage[]
+ifdef::backend-docbook[]
+[header]
+template::[header-declarations]
+<refentry>
+<refmeta>
+<refentrytitle>{mantitle}</refentrytitle>
+<manvolnum>{manvolnum}</manvolnum>
+<refmiscinfo class="source">Git</refmiscinfo>
+<refmiscinfo class="version">{git_version}</refmiscinfo>
+<refmiscinfo class="manual">Git Manual</refmiscinfo>
+</refmeta>
+<refnamediv>
+  <refname>{manname}</refname>
+  <refpurpose>{manpurpose}</refpurpose>
+</refnamediv>
+endif::backend-docbook[]
+endif::doctype-manpage[]
+
+ifdef::backend-xhtml11[]
+[attributes]
+git-relative-html-prefix=
+[linkgit-inlinemacro]
+<a href="{git-relative-html-prefix}{target}.html">{target}{0?({0})}</a>
+endif::backend-xhtml11[]
diff --git a/third_party/git/Documentation/asciidoctor-extensions.rb b/third_party/git/Documentation/asciidoctor-extensions.rb
new file mode 100644
index 0000000000..0089e0cfb8
--- /dev/null
+++ b/third_party/git/Documentation/asciidoctor-extensions.rb
@@ -0,0 +1,28 @@
+require 'asciidoctor'
+require 'asciidoctor/extensions'
+
+module Git
+  module Documentation
+    class LinkGitProcessor < Asciidoctor::Extensions::InlineMacroProcessor
+      use_dsl
+
+      named :chrome
+
+      def process(parent, target, attrs)
+        if parent.document.basebackend? 'html'
+          prefix = parent.document.attr('git-relative-html-prefix')
+          %(<a href="#{prefix}#{target}.html">#{target}(#{attrs[1]})</a>)
+        elsif parent.document.basebackend? 'docbook'
+          "<citerefentry>\n" \
+            "<refentrytitle>#{target}</refentrytitle>" \
+            "<manvolnum>#{attrs[1]}</manvolnum>\n" \
+          "</citerefentry>"
+        end
+      end
+    end
+  end
+end
+
+Asciidoctor::Extensions.register do
+  inline_macro Git::Documentation::LinkGitProcessor, :linkgit
+end
diff --git a/third_party/git/Documentation/blame-options.txt b/third_party/git/Documentation/blame-options.txt
new file mode 100644
index 0000000000..5d122db6e9
--- /dev/null
+++ b/third_party/git/Documentation/blame-options.txt
@@ -0,0 +1,133 @@
+-b::
+	Show blank SHA-1 for boundary commits.  This can also
+	be controlled via the `blame.blankboundary` config option.
+
+--root::
+	Do not treat root commits as boundaries.  This can also be
+	controlled via the `blame.showRoot` config option.
+
+--show-stats::
+	Include additional statistics at the end of blame output.
+
+-L <start>,<end>::
+-L :<funcname>::
+	Annotate only the given line range. May be specified multiple times.
+	Overlapping ranges are allowed.
++
+<start> and <end> are optional. ``-L <start>'' or ``-L <start>,'' spans from
+<start> to end of file. ``-L ,<end>'' spans from start of file to <end>.
++
+include::line-range-format.txt[]
+
+-l::
+	Show long rev (Default: off).
+
+-t::
+	Show raw timestamp (Default: off).
+
+-S <revs-file>::
+	Use revisions from revs-file instead of calling linkgit:git-rev-list[1].
+
+--reverse <rev>..<rev>::
+	Walk history forward instead of backward. Instead of showing
+	the revision in which a line appeared, this shows the last
+	revision in which a line has existed. This requires a range of
+	revision like START..END where the path to blame exists in
+	START.  `git blame --reverse START` is taken as `git blame
+	--reverse START..HEAD` for convenience.
+
+-p::
+--porcelain::
+	Show in a format designed for machine consumption.
+
+--line-porcelain::
+	Show the porcelain format, but output commit information for
+	each line, not just the first time a commit is referenced.
+	Implies --porcelain.
+
+--incremental::
+	Show the result incrementally in a format designed for
+	machine consumption.
+
+--encoding=<encoding>::
+	Specifies the encoding used to output author names
+	and commit summaries. Setting it to `none` makes blame
+	output unconverted data. For more information see the
+	discussion about encoding in the linkgit:git-log[1]
+	manual page.
+
+--contents <file>::
+	When <rev> is not specified, the command annotates the
+	changes starting backwards from the working tree copy.
+	This flag makes the command pretend as if the working
+	tree copy has the contents of the named file (specify
+	`-` to make the command read from the standard input).
+
+--date <format>::
+	Specifies the format used to output dates. If --date is not
+	provided, the value of the blame.date config variable is
+	used. If the blame.date config variable is also not set, the
+	iso format is used. For supported values, see the discussion
+	of the --date option at linkgit:git-log[1].
+
+--[no-]progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal. This flag
+	enables progress reporting even if not attached to a
+	terminal. Can't use `--progress` together with `--porcelain`
+	or `--incremental`.
+
+-M[<num>]::
+	Detect moved or copied lines within a file. When a commit
+	moves or copies a block of lines (e.g. the original file
+	has A and then B, and the commit changes it to B and then
+	A), the traditional 'blame' algorithm notices only half of
+	the movement and typically blames the lines that were moved
+	up (i.e. B) to the parent and assigns blame to the lines that
+	were moved down (i.e. A) to the child commit.  With this
+	option, both groups of lines are blamed on the parent by
+	running extra passes of inspection.
++
+<num> is optional but it is the lower bound on the number of
+alphanumeric characters that Git must detect as moving/copying
+within a file for it to associate those lines with the parent
+commit. The default value is 20.
+
+-C[<num>]::
+	In addition to `-M`, detect lines moved or copied from other
+	files that were modified in the same commit.  This is
+	useful when you reorganize your program and move code
+	around across files.  When this option is given twice,
+	the command additionally looks for copies from other
+	files in the commit that creates the file. When this
+	option is given three times, the command additionally
+	looks for copies from other files in any commit.
++
+<num> is optional but it is the lower bound on the number of
+alphanumeric characters that Git must detect as moving/copying
+between files for it to associate those lines with the parent
+commit. And the default value is 40. If there are more than one
+`-C` options given, the <num> argument of the last `-C` will
+take effect.
+
+--ignore-rev <rev>::
+	Ignore changes made by the revision when assigning blame, as if the
+	change never happened.  Lines that were changed or added by an ignored
+	commit will be blamed on the previous commit that changed that line or
+	nearby lines.  This option may be specified multiple times to ignore
+	more than one revision.  If the `blame.markIgnoredLines` config option
+	is set, then lines that were changed by an ignored commit and attributed to
+	another commit will be marked with a `?` in the blame output.  If the
+	`blame.markUnblamableLines` config option is set, then those lines touched
+	by an ignored commit that we could not attribute to another revision are
+	marked with a '*'.
+
+--ignore-revs-file <file>::
+	Ignore revisions listed in `file`, which must be in the same format as an
+	`fsck.skipList`.  This option may be repeated, and these files will be
+	processed after any files specified with the `blame.ignoreRevsFile` config
+	option.  An empty file name, `""`, will clear the list of revs from
+	previously processed files.
+
+-h::
+	Show help message.
diff --git a/third_party/git/Documentation/build-docdep.perl b/third_party/git/Documentation/build-docdep.perl
new file mode 100755
index 0000000000..ba4205e030
--- /dev/null
+++ b/third_party/git/Documentation/build-docdep.perl
@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+my %include = ();
+my %included = ();
+
+for my $text (<*.txt>) {
+    open I, '<', $text || die "cannot read: $text";
+    while (<I>) {
+	if (/^include::/) {
+	    chomp;
+	    s/^include::\s*//;
+	    s/\[\]//;
+	    $include{$text}{$_} = 1;
+	    $included{$_} = 1;
+	}
+    }
+    close I;
+}
+
+# Do we care about chained includes???
+my $changed = 1;
+while ($changed) {
+    $changed = 0;
+    while (my ($text, $included) = each %include) {
+	for my $i (keys %$included) {
+	    # $text has include::$i; if $i includes $j
+	    # $text indirectly includes $j.
+	    if (exists $include{$i}) {
+		for my $j (keys %{$include{$i}}) {
+		    if (!exists $include{$text}{$j}) {
+			$include{$text}{$j} = 1;
+			$included{$j} = 1;
+			$changed = 1;
+		    }
+		}
+	    }
+	}
+    }
+}
+
+while (my ($text, $included) = each %include) {
+    if (! exists $included{$text} &&
+	(my $base = $text) =~ s/\.txt$//) {
+	print "$base.html $base.xml : ", join(" ", keys %$included), "\n";
+    }
+}
diff --git a/third_party/git/Documentation/cat-texi.perl b/third_party/git/Documentation/cat-texi.perl
new file mode 100755
index 0000000000..14d2f83415
--- /dev/null
+++ b/third_party/git/Documentation/cat-texi.perl
@@ -0,0 +1,46 @@
+#!/usr/bin/perl -w
+
+use strict;
+use warnings;
+
+my @menu = ();
+my $output = $ARGV[0];
+
+open my $tmp, '>', "$output.tmp";
+
+while (<STDIN>) {
+	next if (/^\\input texinfo/../\@node Top/);
+	next if (/^\@bye/ || /^\.ft/);
+	if (s/^\@top (.*)/\@node $1,,,Top/) {
+		push @menu, $1;
+	}
+	s/\(\@pxref\{\[(URLS|REMOTES)\]}\)//;
+	s/\@anchor\{[^{}]*\}//g;
+	print $tmp $_;
+}
+close $tmp;
+
+print '\input texinfo
+@setfilename gitman.info
+@documentencoding UTF-8
+@dircategory Development
+@direntry
+* Git Man Pages: (gitman).  Manual pages for Git revision control system
+@end direntry
+@node Top,,, (dir)
+@top Git Manual Pages
+@documentlanguage en
+@menu
+';
+
+for (@menu) {
+	print "* ${_}::\n";
+}
+print "\@end menu\n";
+open $tmp, '<', "$output.tmp";
+while (<$tmp>) {
+	print;
+}
+close $tmp;
+print "\@bye\n";
+unlink "$output.tmp";
diff --git a/third_party/git/Documentation/cmd-list.perl b/third_party/git/Documentation/cmd-list.perl
new file mode 100755
index 0000000000..5aa73cfe45
--- /dev/null
+++ b/third_party/git/Documentation/cmd-list.perl
@@ -0,0 +1,78 @@
+#!/usr/bin/perl -w
+
+use File::Compare qw(compare);
+
+sub format_one {
+	my ($out, $nameattr) = @_;
+	my ($name, $attr) = @$nameattr;
+	my ($state, $description);
+	$state = 0;
+	open I, '<', "$name.txt" or die "No such file $name.txt";
+	while (<I>) {
+		if (/^NAME$/) {
+			$state = 1;
+			next;
+		}
+		if ($state == 1 && /^----$/) {
+			$state = 2;
+			next;
+		}
+		next if ($state != 2);
+		chomp;
+		$description = $_;
+		last;
+	}
+	close I;
+	if (!defined $description) {
+		die "No description found in $name.txt";
+	}
+	if (my ($verify_name, $text) = ($description =~ /^($name) - (.*)/)) {
+		print $out "linkgit:$name\[1\]::\n\t";
+		if ($attr =~ / deprecated /) {
+			print $out "(deprecated) ";
+		}
+		print $out "$text.\n\n";
+	}
+	else {
+		die "Description does not match $name: $description";
+	}
+}
+
+while (<>) {
+	last if /^### command list/;
+}
+
+my %cmds = ();
+for (sort <>) {
+	next if /^#/;
+
+	chomp;
+	my ($name, $cat, $attr) = /^(\S+)\s+(.*?)(?:\s+(.*))?$/;
+	$attr = '' unless defined $attr;
+	push @{$cmds{$cat}}, [$name, " $attr "];
+}
+
+for my $cat (qw(ancillaryinterrogators
+		ancillarymanipulators
+		mainporcelain
+		plumbinginterrogators
+		plumbingmanipulators
+		synchingrepositories
+		foreignscminterface
+		purehelpers
+		synchelpers)) {
+	my $out = "cmds-$cat.txt";
+	open O, '>', "$out+" or die "Cannot open output file $out+";
+	for (@{$cmds{$cat}}) {
+		format_one(\*O, $_);
+	}
+	close O;
+
+	if (-f "$out" && compare("$out", "$out+") == 0) {
+		unlink "$out+";
+	}
+	else {
+		print STDERR "$out\n";
+		rename "$out+", "$out";
+	}
+}
diff --git a/third_party/git/Documentation/config.txt b/third_party/git/Documentation/config.txt
new file mode 100644
index 0000000000..e3f5bc3396
--- /dev/null
+++ b/third_party/git/Documentation/config.txt
@@ -0,0 +1,460 @@
+CONFIGURATION FILE
+------------------
+
+The Git configuration file contains a number of variables that affect
+the Git commands' behavior. The files `.git/config` and optionally
+`config.worktree` (see `extensions.worktreeConfig` below) in each
+repository are used to store the configuration for that repository, and
+`$HOME/.gitconfig` is used to store a per-user configuration as
+fallback values for the `.git/config` file. The file `/etc/gitconfig`
+can be used to store a system-wide default configuration.
+
+The configuration variables are used by both the Git plumbing
+and the porcelains. The variables are divided into sections, wherein
+the fully qualified variable name of the variable itself is the last
+dot-separated segment and the section name is everything before the last
+dot. The variable names are case-insensitive, allow only alphanumeric
+characters and `-`, and must start with an alphabetic character.  Some
+variables may appear multiple times; we say then that the variable is
+multivalued.
+
+Syntax
+~~~~~~
+
+The syntax is fairly flexible and permissive; whitespaces are mostly
+ignored.  The '#' and ';' characters begin comments to the end of line,
+blank lines are ignored.
+
+The file consists of sections and variables.  A section begins with
+the name of the section in square brackets and continues until the next
+section begins.  Section names are case-insensitive.  Only alphanumeric
+characters, `-` and `.` are allowed in section names.  Each variable
+must belong to some section, which means that there must be a section
+header before the first setting of a variable.
+
+Sections can be further divided into subsections.  To begin a subsection
+put its name in double quotes, separated by space from the section name,
+in the section header, like in the example below:
+
+--------
+	[section "subsection"]
+
+--------
+
+Subsection names are case sensitive and can contain any characters except
+newline and the null byte. Doublequote `"` and backslash can be included
+by escaping them as `\"` and `\\`, respectively. Backslashes preceding
+other characters are dropped when reading; for example, `\t` is read as
+`t` and `\0` is read as `0` Section headers cannot span multiple lines.
+Variables may belong directly to a section or to a given subsection. You
+can have `[section]` if you have `[section "subsection"]`, but you don't
+need to.
+
+There is also a deprecated `[section.subsection]` syntax. With this
+syntax, the subsection name is converted to lower-case and is also
+compared case sensitively. These subsection names follow the same
+restrictions as section names.
+
+All the other lines (and the remainder of the line after the section
+header) are recognized as setting variables, in the form
+'name = value' (or just 'name', which is a short-hand to say that
+the variable is the boolean "true").
+The variable names are case-insensitive, allow only alphanumeric characters
+and `-`, and must start with an alphabetic character.
+
+A line that defines a value can be continued to the next line by
+ending it with a `\`; the backquote and the end-of-line are
+stripped.  Leading whitespaces after 'name =', the remainder of the
+line after the first comment character '#' or ';', and trailing
+whitespaces of the line are discarded unless they are enclosed in
+double quotes.  Internal whitespaces within the value are retained
+verbatim.
+
+Inside double quotes, double quote `"` and backslash `\` characters
+must be escaped: use `\"` for `"` and `\\` for `\`.
+
+The following escape sequences (beside `\"` and `\\`) are recognized:
+`\n` for newline character (NL), `\t` for horizontal tabulation (HT, TAB)
+and `\b` for backspace (BS).  Other char escape sequences (including octal
+escape sequences) are invalid.
+
+
+Includes
+~~~~~~~~
+
+The `include` and `includeIf` sections allow you to include config
+directives from another source. These sections behave identically to
+each other with the exception that `includeIf` sections may be ignored
+if their condition does not evaluate to true; see "Conditional includes"
+below.
+
+You can include a config file from another by setting the special
+`include.path` (or `includeIf.*.path`) variable to the name of the file
+to be included. The variable takes a pathname as its value, and is
+subject to tilde expansion. These variables can be given multiple times.
+
+The contents of the included file are inserted immediately, as if they
+had been found at the location of the include directive. If the value of the
+variable is a relative path, the path is considered to
+be relative to the configuration file in which the include directive
+was found.  See below for examples.
+
+Conditional includes
+~~~~~~~~~~~~~~~~~~~~
+
+You can include a config file from another conditionally by setting a
+`includeIf.<condition>.path` variable to the name of the file to be
+included.
+
+The condition starts with a keyword followed by a colon and some data
+whose format and meaning depends on the keyword. Supported keywords
+are:
+
+`gitdir`::
+
+	The data that follows the keyword `gitdir:` is used as a glob
+	pattern. If the location of the .git directory matches the
+	pattern, the include condition is met.
++
+The .git location may be auto-discovered, or come from `$GIT_DIR`
+environment variable. If the repository is auto discovered via a .git
+file (e.g. from submodules, or a linked worktree), the .git location
+would be the final location where the .git directory is, not where the
+.git file is.
++
+The pattern can contain standard globbing wildcards and two additional
+ones, `**/` and `/**`, that can match multiple path components. Please
+refer to linkgit:gitignore[5] for details. For convenience:
+
+ * If the pattern starts with `~/`, `~` will be substituted with the
+   content of the environment variable `HOME`.
+
+ * If the pattern starts with `./`, it is replaced with the directory
+   containing the current config file.
+
+ * If the pattern does not start with either `~/`, `./` or `/`, `**/`
+   will be automatically prepended. For example, the pattern `foo/bar`
+   becomes `**/foo/bar` and would match `/any/path/to/foo/bar`.
+
+ * If the pattern ends with `/`, `**` will be automatically added. For
+   example, the pattern `foo/` becomes `foo/**`. In other words, it
+   matches "foo" and everything inside, recursively.
+
+`gitdir/i`::
+	This is the same as `gitdir` except that matching is done
+	case-insensitively (e.g. on case-insensitive file sytems)
+
+`onbranch`::
+	The data that follows the keyword `onbranch:` is taken to be a
+	pattern with standard globbing wildcards and two additional
+	ones, `**/` and `/**`, that can match multiple path components.
+	If we are in a worktree where the name of the branch that is
+	currently checked out matches the pattern, the include condition
+	is met.
++
+If the pattern ends with `/`, `**` will be automatically added. For
+example, the pattern `foo/` becomes `foo/**`. In other words, it matches
+all branches that begin with `foo/`. This is useful if your branches are
+organized hierarchically and you would like to apply a configuration to
+all the branches in that hierarchy.
+
+A few more notes on matching via `gitdir` and `gitdir/i`:
+
+ * Symlinks in `$GIT_DIR` are not resolved before matching.
+
+ * Both the symlink & realpath versions of paths will be matched
+   outside of `$GIT_DIR`. E.g. if ~/git is a symlink to
+   /mnt/storage/git, both `gitdir:~/git` and `gitdir:/mnt/storage/git`
+   will match.
++
+This was not the case in the initial release of this feature in
+v2.13.0, which only matched the realpath version. Configuration that
+wants to be compatible with the initial release of this feature needs
+to either specify only the realpath version, or both versions.
+
+ * Note that "../" is not special and will match literally, which is
+   unlikely what you want.
+
+Example
+~~~~~~~
+
+	# Core variables
+	[core]
+		; Don't trust file modes
+		filemode = false
+
+	# Our diff algorithm
+	[diff]
+		external = /usr/local/bin/diff-wrapper
+		renames = true
+
+	[branch "devel"]
+		remote = origin
+		merge = refs/heads/devel
+
+	# Proxy settings
+	[core]
+		gitProxy="ssh" for "kernel.org"
+		gitProxy=default-proxy ; for the rest
+
+	[include]
+		path = /path/to/foo.inc ; include by absolute path
+		path = foo.inc ; find "foo.inc" relative to the current file
+		path = ~/foo.inc ; find "foo.inc" in your `$HOME` directory
+
+	; include if $GIT_DIR is /path/to/foo/.git
+	[includeIf "gitdir:/path/to/foo/.git"]
+		path = /path/to/foo.inc
+
+	; include for all repositories inside /path/to/group
+	[includeIf "gitdir:/path/to/group/"]
+		path = /path/to/foo.inc
+
+	; include for all repositories inside $HOME/to/group
+	[includeIf "gitdir:~/to/group/"]
+		path = /path/to/foo.inc
+
+	; relative paths are always relative to the including
+	; file (if the condition is true); their location is not
+	; affected by the condition
+	[includeIf "gitdir:/path/to/group/"]
+		path = foo.inc
+
+	; include only if we are in a worktree where foo-branch is
+	; currently checked out
+	[includeIf "onbranch:foo-branch"]
+		path = foo.inc
+
+Values
+~~~~~~
+
+Values of many variables are treated as a simple string, but there
+are variables that take values of specific types and there are rules
+as to how to spell them.
+
+boolean::
+
+       When a variable is said to take a boolean value, many
+       synonyms are accepted for 'true' and 'false'; these are all
+       case-insensitive.
+
+	true;; Boolean true literals are `yes`, `on`, `true`,
+		and `1`.  Also, a variable defined without `= <value>`
+		is taken as true.
+
+	false;; Boolean false literals are `no`, `off`, `false`,
+		`0` and the empty string.
++
+When converting a value to its canonical form using the `--type=bool` type
+specifier, 'git config' will ensure that the output is "true" or
+"false" (spelled in lowercase).
+
+integer::
+       The value for many variables that specify various sizes can
+       be suffixed with `k`, `M`,... to mean "scale the number by
+       1024", "by 1024x1024", etc.
+
+color::
+       The value for a variable that takes a color is a list of
+       colors (at most two, one for foreground and one for background)
+       and attributes (as many as you want), separated by spaces.
++
+The basic colors accepted are `normal`, `black`, `red`, `green`, `yellow`,
+`blue`, `magenta`, `cyan` and `white`.  The first color given is the
+foreground; the second is the background.
++
+Colors may also be given as numbers between 0 and 255; these use ANSI
+256-color mode (but note that not all terminals may support this).  If
+your terminal supports it, you may also specify 24-bit RGB values as
+hex, like `#ff0ab3`.
++
+The accepted attributes are `bold`, `dim`, `ul`, `blink`, `reverse`,
+`italic`, and `strike` (for crossed-out or "strikethrough" letters).
+The position of any attributes with respect to the colors
+(before, after, or in between), doesn't matter. Specific attributes may
+be turned off by prefixing them with `no` or `no-` (e.g., `noreverse`,
+`no-ul`, etc).
++
+An empty color string produces no color effect at all. This can be used
+to avoid coloring specific elements without disabling color entirely.
++
+For git's pre-defined color slots, the attributes are meant to be reset
+at the beginning of each item in the colored output. So setting
+`color.decorate.branch` to `black` will paint that branch name in a
+plain `black`, even if the previous thing on the same output line (e.g.
+opening parenthesis before the list of branch names in `log --decorate`
+output) is set to be painted with `bold` or some other attribute.
+However, custom log formats may do more complicated and layered
+coloring, and the negated forms may be useful there.
+
+pathname::
+	A variable that takes a pathname value can be given a
+	string that begins with "`~/`" or "`~user/`", and the usual
+	tilde expansion happens to such a string: `~/`
+	is expanded to the value of `$HOME`, and `~user/` to the
+	specified user's home directory.
+
+
+Variables
+~~~~~~~~~
+
+Note that this list is non-comprehensive and not necessarily complete.
+For command-specific variables, you will find a more detailed description
+in the appropriate manual page.
+
+Other git-related tools may and do use their own variables.  When
+inventing new variables for use in your own tool, make sure their
+names do not conflict with those that are used by Git itself and
+other popular tools, and describe them in your documentation.
+
+include::config/advice.txt[]
+
+include::config/core.txt[]
+
+include::config/add.txt[]
+
+include::config/alias.txt[]
+
+include::config/am.txt[]
+
+include::config/apply.txt[]
+
+include::config/blame.txt[]
+
+include::config/branch.txt[]
+
+include::config/browser.txt[]
+
+include::config/checkout.txt[]
+
+include::config/clean.txt[]
+
+include::config/color.txt[]
+
+include::config/column.txt[]
+
+include::config/commit.txt[]
+
+include::config/credential.txt[]
+
+include::config/completion.txt[]
+
+include::config/diff.txt[]
+
+include::config/difftool.txt[]
+
+include::config/fastimport.txt[]
+
+include::config/fetch.txt[]
+
+include::config/format.txt[]
+
+include::config/filter.txt[]
+
+include::config/fsck.txt[]
+
+include::config/gc.txt[]
+
+include::config/gitcvs.txt[]
+
+include::config/gitweb.txt[]
+
+include::config/grep.txt[]
+
+include::config/gpg.txt[]
+
+include::config/gui.txt[]
+
+include::config/guitool.txt[]
+
+include::config/help.txt[]
+
+include::config/http.txt[]
+
+include::config/i18n.txt[]
+
+include::config/imap.txt[]
+
+include::config/index.txt[]
+
+include::config/init.txt[]
+
+include::config/instaweb.txt[]
+
+include::config/interactive.txt[]
+
+include::config/log.txt[]
+
+include::config/mailinfo.txt[]
+
+include::config/mailmap.txt[]
+
+include::config/man.txt[]
+
+include::config/merge.txt[]
+
+include::config/mergetool.txt[]
+
+include::config/notes.txt[]
+
+include::config/pack.txt[]
+
+include::config/pager.txt[]
+
+include::config/pretty.txt[]
+
+include::config/protocol.txt[]
+
+include::config/pull.txt[]
+
+include::config/push.txt[]
+
+include::config/rebase.txt[]
+
+include::config/receive.txt[]
+
+include::config/remote.txt[]
+
+include::config/remotes.txt[]
+
+include::config/repack.txt[]
+
+include::config/rerere.txt[]
+
+include::config/reset.txt[]
+
+include::config/sendemail.txt[]
+
+include::config/sequencer.txt[]
+
+include::config/showbranch.txt[]
+
+include::config/splitindex.txt[]
+
+include::config/ssh.txt[]
+
+include::config/status.txt[]
+
+include::config/stash.txt[]
+
+include::config/submodule.txt[]
+
+include::config/tag.txt[]
+
+include::config/trace2.txt[]
+
+include::config/transfer.txt[]
+
+include::config/uploadarchive.txt[]
+
+include::config/uploadpack.txt[]
+
+include::config/url.txt[]
+
+include::config/user.txt[]
+
+include::config/versionsort.txt[]
+
+include::config/web.txt[]
+
+include::config/worktree.txt[]
diff --git a/third_party/git/Documentation/config/add.txt b/third_party/git/Documentation/config/add.txt
new file mode 100644
index 0000000000..4d753f006e
--- /dev/null
+++ b/third_party/git/Documentation/config/add.txt
@@ -0,0 +1,7 @@
+add.ignoreErrors::
+add.ignore-errors (deprecated)::
+	Tells 'git add' to continue adding files when some files cannot be
+	added due to indexing errors. Equivalent to the `--ignore-errors`
+	option of linkgit:git-add[1].  `add.ignore-errors` is deprecated,
+	as it does not follow the usual naming convention for configuration
+	variables.
diff --git a/third_party/git/Documentation/config/advice.txt b/third_party/git/Documentation/config/advice.txt
new file mode 100644
index 0000000000..6aaa360202
--- /dev/null
+++ b/third_party/git/Documentation/config/advice.txt
@@ -0,0 +1,110 @@
+advice.*::
+	These variables control various optional help messages designed to
+	aid new users. All 'advice.*' variables default to 'true', and you
+	can tell Git that you do not need help by setting these to 'false':
++
+--
+	fetchShowForcedUpdates::
+		Advice shown when linkgit:git-fetch[1] takes a long time
+		to calculate forced updates after ref updates, or to warn
+		that the check is disabled.
+	pushUpdateRejected::
+		Set this variable to 'false' if you want to disable
+		'pushNonFFCurrent',
+		'pushNonFFMatching', 'pushAlreadyExists',
+		'pushFetchFirst', and 'pushNeedsForce'
+		simultaneously.
+	pushNonFFCurrent::
+		Advice shown when linkgit:git-push[1] fails due to a
+		non-fast-forward update to the current branch.
+	pushNonFFMatching::
+		Advice shown when you ran linkgit:git-push[1] and pushed
+		'matching refs' explicitly (i.e. you used ':', or
+		specified a refspec that isn't your current branch) and
+		it resulted in a non-fast-forward error.
+	pushAlreadyExists::
+		Shown when linkgit:git-push[1] rejects an update that
+		does not qualify for fast-forwarding (e.g., a tag.)
+	pushFetchFirst::
+		Shown when linkgit:git-push[1] rejects an update that
+		tries to overwrite a remote ref that points at an
+		object we do not have.
+	pushNeedsForce::
+		Shown when linkgit:git-push[1] rejects an update that
+		tries to overwrite a remote ref that points at an
+		object that is not a commit-ish, or make the remote
+		ref point at an object that is not a commit-ish.
+	pushUnqualifiedRefname::
+		Shown when linkgit:git-push[1] gives up trying to
+		guess based on the source and destination refs what
+		remote ref namespace the source belongs in, but where
+		we can still suggest that the user push to either
+		refs/heads/* or refs/tags/* based on the type of the
+		source object.
+	statusAheadBehind::
+		Shown when linkgit:git-status[1] computes the ahead/behind
+		counts for a local ref compared to its remote tracking ref,
+		and that calculation takes longer than expected. Will not
+		appear if `status.aheadBehind` is false or the option
+		`--no-ahead-behind` is given.
+	statusHints::
+		Show directions on how to proceed from the current
+		state in the output of linkgit:git-status[1], in
+		the template shown when writing commit messages in
+		linkgit:git-commit[1], and in the help message shown
+		by linkgit:git-switch[1] or
+		linkgit:git-checkout[1] when switching branch.
+	statusUoption::
+		Advise to consider using the `-u` option to linkgit:git-status[1]
+		when the command takes more than 2 seconds to enumerate untracked
+		files.
+	commitBeforeMerge::
+		Advice shown when linkgit:git-merge[1] refuses to
+		merge to avoid overwriting local changes.
+	resetQuiet::
+		Advice to consider using the `--quiet` option to linkgit:git-reset[1]
+		when the command takes more than 2 seconds to enumerate unstaged
+		changes after reset.
+	resolveConflict::
+		Advice shown by various commands when conflicts
+		prevent the operation from being performed.
+	sequencerInUse::
+		Advice shown when a sequencer command is already in progress.
+	implicitIdentity::
+		Advice on how to set your identity configuration when
+		your information is guessed from the system username and
+		domain name.
+	detachedHead::
+		Advice shown when you used
+		linkgit:git-switch[1] or linkgit:git-checkout[1]
+		to move to the detach HEAD state, to instruct how to
+		create a local branch after the fact.
+	checkoutAmbiguousRemoteBranchName::
+		Advice shown when the argument to
+		linkgit:git-checkout[1] and linkgit:git-switch[1]
+		ambiguously resolves to a
+		remote tracking branch on more than one remote in
+		situations where an unambiguous argument would have
+		otherwise caused a remote-tracking branch to be
+		checked out. See the `checkout.defaultRemote`
+		configuration variable for how to set a given remote
+		to used by default in some situations where this
+		advice would be printed.
+	amWorkDir::
+		Advice that shows the location of the patch file when
+		linkgit:git-am[1] fails to apply it.
+	rmHints::
+		In case of failure in the output of linkgit:git-rm[1],
+		show directions on how to proceed from the current state.
+	addEmbeddedRepo::
+		Advice on what to do when you've accidentally added one
+		git repo inside of another.
+	ignoredHook::
+		Advice shown if a hook is ignored because the hook is not
+		set as executable.
+	waitingForEditor::
+		Print a message to the terminal whenever Git is waiting for
+		editor input from the user.
+	nestedTag::
+		Advice shown if a user attempts to recursively tag a tag object.
+--
diff --git a/third_party/git/Documentation/config/alias.txt b/third_party/git/Documentation/config/alias.txt
new file mode 100644
index 0000000000..f1ca739d57
--- /dev/null
+++ b/third_party/git/Documentation/config/alias.txt
@@ -0,0 +1,28 @@
+alias.*::
+	Command aliases for the linkgit:git[1] command wrapper - e.g.
+	after defining `alias.last = cat-file commit HEAD`, the invocation
+	`git last` is equivalent to `git cat-file commit HEAD`. To avoid
+	confusion and troubles with script usage, aliases that
+	hide existing Git commands are ignored. Arguments are split by
+	spaces, the usual shell quoting and escaping is supported.
+	A quote pair or a backslash can be used to quote them.
++
+Note that the first word of an alias does not necessarily have to be a
+command. It can be a command-line option that will be passed into the
+invocation of `git`. In particular, this is useful when used with `-c`
+to pass in one-time configurations or `-p` to force pagination. For example,
+`loud-rebase = -c commit.verbose=true rebase` can be defined such that
+running `git loud-rebase` would be equivalent to
+`git -c commit.verbose=true rebase`. Also, `ps = -p status` would be a
+helpful alias since `git ps` would paginate the output of `git status`
+where the original command does not.
++
+If the alias expansion is prefixed with an exclamation point,
+it will be treated as a shell command.  For example, defining
+`alias.new = !gitk --all --not ORIG_HEAD`, the invocation
+`git new` is equivalent to running the shell command
+`gitk --all --not ORIG_HEAD`.  Note that shell commands will be
+executed from the top-level directory of a repository, which may
+not necessarily be the current directory.
+`GIT_PREFIX` is set as returned by running `git rev-parse --show-prefix`
+from the original current directory. See linkgit:git-rev-parse[1].
diff --git a/third_party/git/Documentation/config/am.txt b/third_party/git/Documentation/config/am.txt
new file mode 100644
index 0000000000..5bcad2efb1
--- /dev/null
+++ b/third_party/git/Documentation/config/am.txt
@@ -0,0 +1,14 @@
+am.keepcr::
+	If true, git-am will call git-mailsplit for patches in mbox format
+	with parameter `--keep-cr`. In this case git-mailsplit will
+	not remove `\r` from lines ending with `\r\n`. Can be overridden
+	by giving `--no-keep-cr` from the command line.
+	See linkgit:git-am[1], linkgit:git-mailsplit[1].
+
+am.threeWay::
+	By default, `git am` will fail if the patch does not apply cleanly. When
+	set to true, this setting tells `git am` to fall back on 3-way merge if
+	the patch records the identity of blobs it is supposed to apply to and
+	we have those blobs available locally (equivalent to giving the `--3way`
+	option from the command line). Defaults to `false`.
+	See linkgit:git-am[1].
diff --git a/third_party/git/Documentation/config/apply.txt b/third_party/git/Documentation/config/apply.txt
new file mode 100644
index 0000000000..8fb8ef763d
--- /dev/null
+++ b/third_party/git/Documentation/config/apply.txt
@@ -0,0 +1,11 @@
+apply.ignoreWhitespace::
+	When set to 'change', tells 'git apply' to ignore changes in
+	whitespace, in the same way as the `--ignore-space-change`
+	option.
+	When set to one of: no, none, never, false tells 'git apply' to
+	respect all whitespace differences.
+	See linkgit:git-apply[1].
+
+apply.whitespace::
+	Tells 'git apply' how to handle whitespaces, in the same way
+	as the `--whitespace` option. See linkgit:git-apply[1].
diff --git a/third_party/git/Documentation/config/blame.txt b/third_party/git/Documentation/config/blame.txt
new file mode 100644
index 0000000000..9468e8599c
--- /dev/null
+++ b/third_party/git/Documentation/config/blame.txt
@@ -0,0 +1,37 @@
+blame.blankBoundary::
+	Show blank commit object name for boundary commits in
+	linkgit:git-blame[1]. This option defaults to false.
+
+blame.coloring::
+	This determines the coloring scheme to be applied to blame
+	output. It can be 'repeatedLines', 'highlightRecent',
+	or 'none' which is the default.
+
+blame.date::
+	Specifies the format used to output dates in linkgit:git-blame[1].
+	If unset the iso format is used. For supported values,
+	see the discussion of the `--date` option at linkgit:git-log[1].
+
+blame.showEmail::
+	Show the author email instead of author name in linkgit:git-blame[1].
+	This option defaults to false.
+
+blame.showRoot::
+	Do not treat root commits as boundaries in linkgit:git-blame[1].
+	This option defaults to false.
+
+blame.ignoreRevsFile::
+	Ignore revisions listed in the file, one unabbreviated object name per
+	line, in linkgit:git-blame[1].  Whitespace and comments beginning with
+	`#` are ignored.  This option may be repeated multiple times.  Empty
+	file names will reset the list of ignored revisions.  This option will
+	be handled before the command line option `--ignore-revs-file`.
+
+blame.markUnblamables::
+	Mark lines that were changed by an ignored revision that we could not
+	attribute to another commit with a '*' in the output of
+	linkgit:git-blame[1].
+
+blame.markIgnoredLines::
+	Mark lines that were changed by an ignored revision that we attributed to
+	another commit with a '?' in the output of linkgit:git-blame[1].
diff --git a/third_party/git/Documentation/config/branch.txt b/third_party/git/Documentation/config/branch.txt
new file mode 100644
index 0000000000..a592d522a7
--- /dev/null
+++ b/third_party/git/Documentation/config/branch.txt
@@ -0,0 +1,102 @@
+branch.autoSetupMerge::
+	Tells 'git branch', 'git switch' and 'git checkout' to set up new branches
+	so that linkgit:git-pull[1] will appropriately merge from the
+	starting point branch. Note that even if this option is not set,
+	this behavior can be chosen per-branch using the `--track`
+	and `--no-track` options. The valid settings are: `false` -- no
+	automatic setup is done; `true` -- automatic setup is done when the
+	starting point is a remote-tracking branch; `always` --
+	automatic setup is done when the starting point is either a
+	local branch or remote-tracking
+	branch. This option defaults to true.
+
+branch.autoSetupRebase::
+	When a new branch is created with 'git branch', 'git switch' or 'git checkout'
+	that tracks another branch, this variable tells Git to set
+	up pull to rebase instead of merge (see "branch.<name>.rebase").
+	When `never`, rebase is never automatically set to true.
+	When `local`, rebase is set to true for tracked branches of
+	other local branches.
+	When `remote`, rebase is set to true for tracked branches of
+	remote-tracking branches.
+	When `always`, rebase will be set to true for all tracking
+	branches.
+	See "branch.autoSetupMerge" for details on how to set up a
+	branch to track another branch.
+	This option defaults to never.
+
+branch.sort::
+	This variable controls the sort ordering of branches when displayed by
+	linkgit:git-branch[1]. Without the "--sort=<value>" option provided, the
+	value of this variable will be used as the default.
+	See linkgit:git-for-each-ref[1] field names for valid values.
+
+branch.<name>.remote::
+	When on branch <name>, it tells 'git fetch' and 'git push'
+	which remote to fetch from/push to.  The remote to push to
+	may be overridden with `remote.pushDefault` (for all branches).
+	The remote to push to, for the current branch, may be further
+	overridden by `branch.<name>.pushRemote`.  If no remote is
+	configured, or if you are not on any branch, it defaults to
+	`origin` for fetching and `remote.pushDefault` for pushing.
+	Additionally, `.` (a period) is the current local repository
+	(a dot-repository), see `branch.<name>.merge`'s final note below.
+
+branch.<name>.pushRemote::
+	When on branch <name>, it overrides `branch.<name>.remote` for
+	pushing.  It also overrides `remote.pushDefault` for pushing
+	from branch <name>.  When you pull from one place (e.g. your
+	upstream) and push to another place (e.g. your own publishing
+	repository), you would want to set `remote.pushDefault` to
+	specify the remote to push to for all branches, and use this
+	option to override it for a specific branch.
+
+branch.<name>.merge::
+	Defines, together with branch.<name>.remote, the upstream branch
+	for the given branch. It tells 'git fetch'/'git pull'/'git rebase' which
+	branch to merge and can also affect 'git push' (see push.default).
+	When in branch <name>, it tells 'git fetch' the default
+	refspec to be marked for merging in FETCH_HEAD. The value is
+	handled like the remote part of a refspec, and must match a
+	ref which is fetched from the remote given by
+	"branch.<name>.remote".
+	The merge information is used by 'git pull' (which at first calls
+	'git fetch') to lookup the default branch for merging. Without
+	this option, 'git pull' defaults to merge the first refspec fetched.
+	Specify multiple values to get an octopus merge.
+	If you wish to setup 'git pull' so that it merges into <name> from
+	another branch in the local repository, you can point
+	branch.<name>.merge to the desired branch, and use the relative path
+	setting `.` (a period) for branch.<name>.remote.
+
+branch.<name>.mergeOptions::
+	Sets default options for merging into branch <name>. The syntax and
+	supported options are the same as those of linkgit:git-merge[1], but
+	option values containing whitespace characters are currently not
+	supported.
+
+branch.<name>.rebase::
+	When true, rebase the branch <name> on top of the fetched branch,
+	instead of merging the default branch from the default remote when
+	"git pull" is run. See "pull.rebase" for doing this in a non
+	branch-specific manner.
++
+When `merges`, pass the `--rebase-merges` option to 'git rebase'
+so that the local merge commits are included in the rebase (see
+linkgit:git-rebase[1] for details).
++
+When `preserve` (deprecated in favor of `merges`), also pass
+`--preserve-merges` along to 'git rebase' so that locally committed merge
+commits will not be flattened by running 'git pull'.
++
+When the value is `interactive`, the rebase is run in interactive mode.
++
+*NOTE*: this is a possibly dangerous operation; do *not* use
+it unless you understand the implications (see linkgit:git-rebase[1]
+for details).
+
+branch.<name>.description::
+	Branch description, can be edited with
+	`git branch --edit-description`. Branch description is
+	automatically added in the format-patch cover letter or
+	request-pull summary.
diff --git a/third_party/git/Documentation/config/browser.txt b/third_party/git/Documentation/config/browser.txt
new file mode 100644
index 0000000000..195df207a6
--- /dev/null
+++ b/third_party/git/Documentation/config/browser.txt
@@ -0,0 +1,9 @@
+browser.<tool>.cmd::
+	Specify the command to invoke the specified browser. The
+	specified command is evaluated in shell with the URLs passed
+	as arguments. (See linkgit:git-web{litdd}browse[1].)
+
+browser.<tool>.path::
+	Override the path for the given tool that may be used to
+	browse HTML help (see `-w` option in linkgit:git-help[1]) or a
+	working repository in gitweb (see linkgit:git-instaweb[1]).
diff --git a/third_party/git/Documentation/config/checkout.txt b/third_party/git/Documentation/config/checkout.txt
new file mode 100644
index 0000000000..6b646813ab
--- /dev/null
+++ b/third_party/git/Documentation/config/checkout.txt
@@ -0,0 +1,18 @@
+checkout.defaultRemote::
+	When you run 'git checkout <something>'
+	or 'git switch <something>' and only have one
+	remote, it may implicitly fall back on checking out and
+	tracking e.g. 'origin/<something>'. This stops working as soon
+	as you have more than one remote with a '<something>'
+	reference. This setting allows for setting the name of a
+	preferred remote that should always win when it comes to
+	disambiguation. The typical use-case is to set this to
+	`origin`.
++
+Currently this is used by linkgit:git-switch[1] and
+linkgit:git-checkout[1] when 'git checkout <something>'
+or 'git switch <something>'
+will checkout the '<something>' branch on another remote,
+and by linkgit:git-worktree[1] when 'git worktree add' refers to a
+remote branch. This setting might be used for other checkout-like
+commands or functionality in the future.
diff --git a/third_party/git/Documentation/config/clean.txt b/third_party/git/Documentation/config/clean.txt
new file mode 100644
index 0000000000..a807c925b9
--- /dev/null
+++ b/third_party/git/Documentation/config/clean.txt
@@ -0,0 +1,3 @@
+clean.requireForce::
+	A boolean to make git-clean do nothing unless given -f,
+	-i or -n.   Defaults to true.
diff --git a/third_party/git/Documentation/config/color.txt b/third_party/git/Documentation/config/color.txt
new file mode 100644
index 0000000000..d5daacb13a
--- /dev/null
+++ b/third_party/git/Documentation/config/color.txt
@@ -0,0 +1,201 @@
+color.advice::
+	A boolean to enable/disable color in hints (e.g. when a push
+	failed, see `advice.*` for a list).  May be set to `always`,
+	`false` (or `never`) or `auto` (or `true`), in which case colors
+	are used only when the error output goes to a terminal. If
+	unset, then the value of `color.ui` is used (`auto` by default).
+
+color.advice.hint::
+	Use customized color for hints.
+
+color.blame.highlightRecent::
+	This can be used to color the metadata of a blame line depending
+	on age of the line.
++
+This setting should be set to a comma-separated list of color and date settings,
+starting and ending with a color, the dates should be set from oldest to newest.
+The metadata will be colored given the colors if the line was introduced
+before the given timestamp, overwriting older timestamped colors.
++
+Instead of an absolute timestamp relative timestamps work as well, e.g.
+2.weeks.ago is valid to address anything older than 2 weeks.
++
+It defaults to 'blue,12 month ago,white,1 month ago,red', which colors
+everything older than one year blue, recent changes between one month and
+one year old are kept white, and lines introduced within the last month are
+colored red.
+
+color.blame.repeatedLines::
+	Use the customized color for the part of git-blame output that
+	is repeated meta information per line (such as commit id,
+	author name, date and timezone). Defaults to cyan.
+
+color.branch::
+	A boolean to enable/disable color in the output of
+	linkgit:git-branch[1]. May be set to `always`,
+	`false` (or `never`) or `auto` (or `true`), in which case colors are used
+	only when the output is to a terminal. If unset, then the
+	value of `color.ui` is used (`auto` by default).
+
+color.branch.<slot>::
+	Use customized color for branch coloration. `<slot>` is one of
+	`current` (the current branch), `local` (a local branch),
+	`remote` (a remote-tracking branch in refs/remotes/),
+	`upstream` (upstream tracking branch), `plain` (other
+	refs).
+
+color.diff::
+	Whether to use ANSI escape sequences to add color to patches.
+	If this is set to `always`, linkgit:git-diff[1],
+	linkgit:git-log[1], and linkgit:git-show[1] will use color
+	for all patches.  If it is set to `true` or `auto`, those
+	commands will only use color when output is to the terminal.
+	If unset, then the value of `color.ui` is used (`auto` by
+	default).
++
+This does not affect linkgit:git-format-patch[1] or the
+'git-diff-{asterisk}' plumbing commands.  Can be overridden on the
+command line with the `--color[=<when>]` option.
+
+color.diff.<slot>::
+	Use customized color for diff colorization.  `<slot>` specifies
+	which part of the patch to use the specified color, and is one
+	of `context` (context text - `plain` is a historical synonym),
+	`meta` (metainformation), `frag`
+	(hunk header), 'func' (function in hunk header), `old` (removed lines),
+	`new` (added lines), `commit` (commit headers), `whitespace`
+	(highlighting whitespace errors), `oldMoved` (deleted lines),
+	`newMoved` (added lines), `oldMovedDimmed`, `oldMovedAlternative`,
+	`oldMovedAlternativeDimmed`, `newMovedDimmed`, `newMovedAlternative`
+	`newMovedAlternativeDimmed` (See the '<mode>'
+	setting of '--color-moved' in linkgit:git-diff[1] for details),
+	`contextDimmed`, `oldDimmed`, `newDimmed`, `contextBold`,
+	`oldBold`, and `newBold` (see linkgit:git-range-diff[1] for details).
+
+color.decorate.<slot>::
+	Use customized color for 'git log --decorate' output.  `<slot>` is one
+	of `branch`, `remoteBranch`, `tag`, `stash` or `HEAD` for local
+	branches, remote-tracking branches, tags, stash and HEAD, respectively
+	and `grafted` for grafted commits.
+
+color.grep::
+	When set to `always`, always highlight matches.  When `false` (or
+	`never`), never.  When set to `true` or `auto`, use color only
+	when the output is written to the terminal.  If unset, then the
+	value of `color.ui` is used (`auto` by default).
+
+color.grep.<slot>::
+	Use customized color for grep colorization.  `<slot>` specifies which
+	part of the line to use the specified color, and is one of
++
+--
+`context`;;
+	non-matching text in context lines (when using `-A`, `-B`, or `-C`)
+`filename`;;
+	filename prefix (when not using `-h`)
+`function`;;
+	function name lines (when using `-p`)
+`lineNumber`;;
+	line number prefix (when using `-n`)
+`column`;;
+	column number prefix (when using `--column`)
+`match`;;
+	matching text (same as setting `matchContext` and `matchSelected`)
+`matchContext`;;
+	matching text in context lines
+`matchSelected`;;
+	matching text in selected lines
+`selected`;;
+	non-matching text in selected lines
+`separator`;;
+	separators between fields on a line (`:`, `-`, and `=`)
+	and between hunks (`--`)
+--
+
+color.interactive::
+	When set to `always`, always use colors for interactive prompts
+	and displays (such as those used by "git-add --interactive" and
+	"git-clean --interactive"). When false (or `never`), never.
+	When set to `true` or `auto`, use colors only when the output is
+	to the terminal. If unset, then the value of `color.ui` is
+	used (`auto` by default).
+
+color.interactive.<slot>::
+	Use customized color for 'git add --interactive' and 'git clean
+	--interactive' output. `<slot>` may be `prompt`, `header`, `help`
+	or `error`, for four distinct types of normal output from
+	interactive commands.
+
+color.pager::
+	A boolean to enable/disable colored output when the pager is in
+	use (default is true).
+
+color.push::
+	A boolean to enable/disable color in push errors. May be set to
+	`always`, `false` (or `never`) or `auto` (or `true`), in which
+	case colors are used only when the error output goes to a terminal.
+	If unset, then the value of `color.ui` is used (`auto` by default).
+
+color.push.error::
+	Use customized color for push errors.
+
+color.remote::
+	If set, keywords at the start of the line are highlighted. The
+	keywords are "error", "warning", "hint" and "success", and are
+	matched case-insensitively. May be set to `always`, `false` (or
+	`never`) or `auto` (or `true`). If unset, then the value of
+	`color.ui` is used (`auto` by default).
+
+color.remote.<slot>::
+	Use customized color for each remote keyword. `<slot>` may be
+	`hint`, `warning`, `success` or `error` which match the
+	corresponding keyword.
+
+color.showBranch::
+	A boolean to enable/disable color in the output of
+	linkgit:git-show-branch[1]. May be set to `always`,
+	`false` (or `never`) or `auto` (or `true`), in which case colors are used
+	only when the output is to a terminal. If unset, then the
+	value of `color.ui` is used (`auto` by default).
+
+color.status::
+	A boolean to enable/disable color in the output of
+	linkgit:git-status[1]. May be set to `always`,
+	`false` (or `never`) or `auto` (or `true`), in which case colors are used
+	only when the output is to a terminal. If unset, then the
+	value of `color.ui` is used (`auto` by default).
+
+color.status.<slot>::
+	Use customized color for status colorization. `<slot>` is
+	one of `header` (the header text of the status message),
+	`added` or `updated` (files which are added but not committed),
+	`changed` (files which are changed but not added in the index),
+	`untracked` (files which are not tracked by Git),
+	`branch` (the current branch),
+	`nobranch` (the color the 'no branch' warning is shown in, defaulting
+	to red),
+	`localBranch` or `remoteBranch` (the local and remote branch names,
+	respectively, when branch and tracking information is displayed in the
+	status short-format), or
+	`unmerged` (files which have unmerged changes).
+
+color.transport::
+	A boolean to enable/disable color when pushes are rejected. May be
+	set to `always`, `false` (or `never`) or `auto` (or `true`), in which
+	case colors are used only when the error output goes to a terminal.
+	If unset, then the value of `color.ui` is used (`auto` by default).
+
+color.transport.rejected::
+	Use customized color when a push was rejected.
+
+color.ui::
+	This variable determines the default value for variables such
+	as `color.diff` and `color.grep` that control the use of color
+	per command family. Its scope will expand as more commands learn
+	configuration to set a default for the `--color` option.  Set it
+	to `false` or `never` if you prefer Git commands not to use
+	color unless enabled explicitly with some other configuration
+	or the `--color` option. Set it to `always` if you want all
+	output not intended for machine consumption to use color, to
+	`true` or `auto` (this is the default since Git 1.8.4) if you
+	want such output to use color when written to the terminal.
diff --git a/third_party/git/Documentation/config/column.txt b/third_party/git/Documentation/config/column.txt
new file mode 100644
index 0000000000..76aa2f29dc
--- /dev/null
+++ b/third_party/git/Documentation/config/column.txt
@@ -0,0 +1,55 @@
+column.ui::
+	Specify whether supported commands should output in columns.
+	This variable consists of a list of tokens separated by spaces
+	or commas:
++
+These options control when the feature should be enabled
+(defaults to 'never'):
++
+--
+`always`;;
+	always show in columns
+`never`;;
+	never show in columns
+`auto`;;
+	show in columns if the output is to the terminal
+--
++
+These options control layout (defaults to 'column').  Setting any
+of these implies 'always' if none of 'always', 'never', or 'auto' are
+specified.
++
+--
+`column`;;
+	fill columns before rows
+`row`;;
+	fill rows before columns
+`plain`;;
+	show in one column
+--
++
+Finally, these options can be combined with a layout option (defaults
+to 'nodense'):
++
+--
+`dense`;;
+	make unequal size columns to utilize more space
+`nodense`;;
+	make equal size columns
+--
+
+column.branch::
+	Specify whether to output branch listing in `git branch` in columns.
+	See `column.ui` for details.
+
+column.clean::
+	Specify the layout when list items in `git clean -i`, which always
+	shows files and directories in columns. See `column.ui` for details.
+
+column.status::
+	Specify whether to output untracked files in `git status` in columns.
+	See `column.ui` for details.
+
+column.tag::
+	Specify whether to output tag listing in `git tag` in columns.
+	See `column.ui` for details.
diff --git a/third_party/git/Documentation/config/commit.txt b/third_party/git/Documentation/config/commit.txt
new file mode 100644
index 0000000000..2c95573930
--- /dev/null
+++ b/third_party/git/Documentation/config/commit.txt
@@ -0,0 +1,29 @@
+commit.cleanup::
+	This setting overrides the default of the `--cleanup` option in
+	`git commit`. See linkgit:git-commit[1] for details. Changing the
+	default can be useful when you always want to keep lines that begin
+	with comment character `#` in your log message, in which case you
+	would do `git config commit.cleanup whitespace` (note that you will
+	have to remove the help lines that begin with `#` in the commit log
+	template yourself, if you do this).
+
+commit.gpgSign::
+
+	A boolean to specify whether all commits should be GPG signed.
+	Use of this option when doing operations such as rebase can
+	result in a large number of commits being signed. It may be
+	convenient to use an agent to avoid typing your GPG passphrase
+	several times.
+
+commit.status::
+	A boolean to enable/disable inclusion of status information in the
+	commit message template when using an editor to prepare the commit
+	message.  Defaults to true.
+
+commit.template::
+	Specify the pathname of a file to use as the template for
+	new commit messages.
+
+commit.verbose::
+	A boolean or int to specify the level of verbose with `git commit`.
+	See linkgit:git-commit[1].
diff --git a/third_party/git/Documentation/config/completion.txt b/third_party/git/Documentation/config/completion.txt
new file mode 100644
index 0000000000..4d99bf33c9
--- /dev/null
+++ b/third_party/git/Documentation/config/completion.txt
@@ -0,0 +1,7 @@
+completion.commands::
+	This is only used by git-completion.bash to add or remove
+	commands from the list of completed commands. Normally only
+	porcelain commands and a few select others are completed. You
+	can add more commands, separated by space, in this
+	variable. Prefixing the command with '-' will remove it from
+	the existing list.
diff --git a/third_party/git/Documentation/config/core.txt b/third_party/git/Documentation/config/core.txt
new file mode 100644
index 0000000000..75538d27e7
--- /dev/null
+++ b/third_party/git/Documentation/config/core.txt
@@ -0,0 +1,603 @@
+core.fileMode::
+	Tells Git if the executable bit of files in the working tree
+	is to be honored.
++
+Some filesystems lose the executable bit when a file that is
+marked as executable is checked out, or checks out a
+non-executable file with executable bit on.
+linkgit:git-clone[1] or linkgit:git-init[1] probe the filesystem
+to see if it handles the executable bit correctly
+and this variable is automatically set as necessary.
++
+A repository, however, may be on a filesystem that handles
+the filemode correctly, and this variable is set to 'true'
+when created, but later may be made accessible from another
+environment that loses the filemode (e.g. exporting ext4 via
+CIFS mount, visiting a Cygwin created repository with
+Git for Windows or Eclipse).
+In such a case it may be necessary to set this variable to 'false'.
+See linkgit:git-update-index[1].
++
+The default is true (when core.filemode is not specified in the config file).
+
+core.hideDotFiles::
+	(Windows-only) If true, mark newly-created directories and files whose
+	name starts with a dot as hidden.  If 'dotGitOnly', only the `.git/`
+	directory is hidden, but no other files starting with a dot.  The
+	default mode is 'dotGitOnly'.
+
+core.ignoreCase::
+	Internal variable which enables various workarounds to enable
+	Git to work better on filesystems that are not case sensitive,
+	like APFS, HFS+, FAT, NTFS, etc. For example, if a directory listing
+	finds "makefile" when Git expects "Makefile", Git will assume
+	it is really the same file, and continue to remember it as
+	"Makefile".
++
+The default is false, except linkgit:git-clone[1] or linkgit:git-init[1]
+will probe and set core.ignoreCase true if appropriate when the repository
+is created.
++
+Git relies on the proper configuration of this variable for your operating
+and file system. Modifying this value may result in unexpected behavior.
+
+core.precomposeUnicode::
+	This option is only used by Mac OS implementation of Git.
+	When core.precomposeUnicode=true, Git reverts the unicode decomposition
+	of filenames done by Mac OS. This is useful when sharing a repository
+	between Mac OS and Linux or Windows.
+	(Git for Windows 1.7.10 or higher is needed, or Git under cygwin 1.7).
+	When false, file names are handled fully transparent by Git,
+	which is backward compatible with older versions of Git.
+
+core.protectHFS::
+	If set to true, do not allow checkout of paths that would
+	be considered equivalent to `.git` on an HFS+ filesystem.
+	Defaults to `true` on Mac OS, and `false` elsewhere.
+
+core.protectNTFS::
+	If set to true, do not allow checkout of paths that would
+	cause problems with the NTFS filesystem, e.g. conflict with
+	8.3 "short" names.
+	Defaults to `true` on Windows, and `false` elsewhere.
+
+core.fsmonitor::
+	If set, the value of this variable is used as a command which
+	will identify all files that may have changed since the
+	requested date/time. This information is used to speed up git by
+	avoiding unnecessary processing of files that have not changed.
+	See the "fsmonitor-watchman" section of linkgit:githooks[5].
+
+core.trustctime::
+	If false, the ctime differences between the index and the
+	working tree are ignored; useful when the inode change time
+	is regularly modified by something outside Git (file system
+	crawlers and some backup systems).
+	See linkgit:git-update-index[1]. True by default.
+
+core.splitIndex::
+	If true, the split-index feature of the index will be used.
+	See linkgit:git-update-index[1]. False by default.
+
+core.untrackedCache::
+	Determines what to do about the untracked cache feature of the
+	index. It will be kept, if this variable is unset or set to
+	`keep`. It will automatically be added if set to `true`. And
+	it will automatically be removed, if set to `false`. Before
+	setting it to `true`, you should check that mtime is working
+	properly on your system.
+	See linkgit:git-update-index[1]. `keep` by default.
+
+core.checkStat::
+	When missing or is set to `default`, many fields in the stat
+	structure are checked to detect if a file has been modified
+	since Git looked at it.  When this configuration variable is
+	set to `minimal`, sub-second part of mtime and ctime, the
+	uid and gid of the owner of the file, the inode number (and
+	the device number, if Git was compiled to use it), are
+	excluded from the check among these fields, leaving only the
+	whole-second part of mtime (and ctime, if `core.trustCtime`
+	is set) and the filesize to be checked.
++
+There are implementations of Git that do not leave usable values in
+some fields (e.g. JGit); by excluding these fields from the
+comparison, the `minimal` mode may help interoperability when the
+same repository is used by these other systems at the same time.
+
+core.quotePath::
+	Commands that output paths (e.g. 'ls-files', 'diff'), will
+	quote "unusual" characters in the pathname by enclosing the
+	pathname in double-quotes and escaping those characters with
+	backslashes in the same way C escapes control characters (e.g.
+	`\t` for TAB, `\n` for LF, `\\` for backslash) or bytes with
+	values larger than 0x80 (e.g. octal `\302\265` for "micro" in
+	UTF-8).  If this variable is set to false, bytes higher than
+	0x80 are not considered "unusual" any more. Double-quotes,
+	backslash and control characters are always escaped regardless
+	of the setting of this variable.  A simple space character is
+	not considered "unusual".  Many commands can output pathnames
+	completely verbatim using the `-z` option. The default value
+	is true.
+
+core.eol::
+	Sets the line ending type to use in the working directory for
+	files that are marked as text (either by having the `text`
+	attribute set, or by having `text=auto` and Git auto-detecting
+	the contents as text).
+	Alternatives are 'lf', 'crlf' and 'native', which uses the platform's
+	native line ending.  The default value is `native`.  See
+	linkgit:gitattributes[5] for more information on end-of-line
+	conversion. Note that this value is ignored if `core.autocrlf`
+	is set to `true` or `input`.
+
+core.safecrlf::
+	If true, makes Git check if converting `CRLF` is reversible when
+	end-of-line conversion is active.  Git will verify if a command
+	modifies a file in the work tree either directly or indirectly.
+	For example, committing a file followed by checking out the
+	same file should yield the original file in the work tree.  If
+	this is not the case for the current setting of
+	`core.autocrlf`, Git will reject the file.  The variable can
+	be set to "warn", in which case Git will only warn about an
+	irreversible conversion but continue the operation.
++
+CRLF conversion bears a slight chance of corrupting data.
+When it is enabled, Git will convert CRLF to LF during commit and LF to
+CRLF during checkout.  A file that contains a mixture of LF and
+CRLF before the commit cannot be recreated by Git.  For text
+files this is the right thing to do: it corrects line endings
+such that we have only LF line endings in the repository.
+But for binary files that are accidentally classified as text the
+conversion can corrupt data.
++
+If you recognize such corruption early you can easily fix it by
+setting the conversion type explicitly in .gitattributes.  Right
+after committing you still have the original file in your work
+tree and this file is not yet corrupted.  You can explicitly tell
+Git that this file is binary and Git will handle the file
+appropriately.
++
+Unfortunately, the desired effect of cleaning up text files with
+mixed line endings and the undesired effect of corrupting binary
+files cannot be distinguished.  In both cases CRLFs are removed
+in an irreversible way.  For text files this is the right thing
+to do because CRLFs are line endings, while for binary files
+converting CRLFs corrupts data.
++
+Note, this safety check does not mean that a checkout will generate a
+file identical to the original file for a different setting of
+`core.eol` and `core.autocrlf`, but only for the current one.  For
+example, a text file with `LF` would be accepted with `core.eol=lf`
+and could later be checked out with `core.eol=crlf`, in which case the
+resulting file would contain `CRLF`, although the original file
+contained `LF`.  However, in both work trees the line endings would be
+consistent, that is either all `LF` or all `CRLF`, but never mixed.  A
+file with mixed line endings would be reported by the `core.safecrlf`
+mechanism.
+
+core.autocrlf::
+	Setting this variable to "true" is the same as setting
+	the `text` attribute to "auto" on all files and core.eol to "crlf".
+	Set to true if you want to have `CRLF` line endings in your
+	working directory and the repository has LF line endings.
+	This variable can be set to 'input',
+	in which case no output conversion is performed.
+
+core.checkRoundtripEncoding::
+	A comma and/or whitespace separated list of encodings that Git
+	performs UTF-8 round trip checks on if they are used in an
+	`working-tree-encoding` attribute (see linkgit:gitattributes[5]).
+	The default value is `SHIFT-JIS`.
+
+core.symlinks::
+	If false, symbolic links are checked out as small plain files that
+	contain the link text. linkgit:git-update-index[1] and
+	linkgit:git-add[1] will not change the recorded type to regular
+	file. Useful on filesystems like FAT that do not support
+	symbolic links.
++
+The default is true, except linkgit:git-clone[1] or linkgit:git-init[1]
+will probe and set core.symlinks false if appropriate when the repository
+is created.
+
+core.gitProxy::
+	A "proxy command" to execute (as 'command host port') instead
+	of establishing direct connection to the remote server when
+	using the Git protocol for fetching. If the variable value is
+	in the "COMMAND for DOMAIN" format, the command is applied only
+	on hostnames ending with the specified domain string. This variable
+	may be set multiple times and is matched in the given order;
+	the first match wins.
++
+Can be overridden by the `GIT_PROXY_COMMAND` environment variable
+(which always applies universally, without the special "for"
+handling).
++
+The special string `none` can be used as the proxy command to
+specify that no proxy be used for a given domain pattern.
+This is useful for excluding servers inside a firewall from
+proxy use, while defaulting to a common proxy for external domains.
+
+core.sshCommand::
+	If this variable is set, `git fetch` and `git push` will
+	use the specified command instead of `ssh` when they need to
+	connect to a remote system. The command is in the same form as
+	the `GIT_SSH_COMMAND` environment variable and is overridden
+	when the environment variable is set.
+
+core.ignoreStat::
+	If true, Git will avoid using lstat() calls to detect if files have
+	changed by setting the "assume-unchanged" bit for those tracked files
+	which it has updated identically in both the index and working tree.
++
+When files are modified outside of Git, the user will need to stage
+the modified files explicitly (e.g. see 'Examples' section in
+linkgit:git-update-index[1]).
+Git will not normally detect changes to those files.
++
+This is useful on systems where lstat() calls are very slow, such as
+CIFS/Microsoft Windows.
++
+False by default.
+
+core.preferSymlinkRefs::
+	Instead of the default "symref" format for HEAD
+	and other symbolic reference files, use symbolic links.
+	This is sometimes needed to work with old scripts that
+	expect HEAD to be a symbolic link.
+
+core.alternateRefsCommand::
+	When advertising tips of available history from an alternate, use the shell to
+	execute the specified command instead of linkgit:git-for-each-ref[1]. The
+	first argument is the absolute path of the alternate. Output must contain one
+	hex object id per line (i.e., the same as produced by `git for-each-ref
+	--format='%(objectname)'`).
++
+Note that you cannot generally put `git for-each-ref` directly into the config
+value, as it does not take a repository path as an argument (but you can wrap
+the command above in a shell script).
+
+core.alternateRefsPrefixes::
+	When listing references from an alternate, list only references that begin
+	with the given prefix. Prefixes match as if they were given as arguments to
+	linkgit:git-for-each-ref[1]. To list multiple prefixes, separate them with
+	whitespace. If `core.alternateRefsCommand` is set, setting
+	`core.alternateRefsPrefixes` has no effect.
+
+core.bare::
+	If true this repository is assumed to be 'bare' and has no
+	working directory associated with it.  If this is the case a
+	number of commands that require a working directory will be
+	disabled, such as linkgit:git-add[1] or linkgit:git-merge[1].
++
+This setting is automatically guessed by linkgit:git-clone[1] or
+linkgit:git-init[1] when the repository was created.  By default a
+repository that ends in "/.git" is assumed to be not bare (bare =
+false), while all other repositories are assumed to be bare (bare
+= true).
+
+core.worktree::
+	Set the path to the root of the working tree.
+	If `GIT_COMMON_DIR` environment variable is set, core.worktree
+	is ignored and not used for determining the root of working tree.
+	This can be overridden by the `GIT_WORK_TREE` environment
+	variable and the `--work-tree` command-line option.
+	The value can be an absolute path or relative to the path to
+	the .git directory, which is either specified by --git-dir
+	or GIT_DIR, or automatically discovered.
+	If --git-dir or GIT_DIR is specified but none of
+	--work-tree, GIT_WORK_TREE and core.worktree is specified,
+	the current working directory is regarded as the top level
+	of your working tree.
++
+Note that this variable is honored even when set in a configuration
+file in a ".git" subdirectory of a directory and its value differs
+from the latter directory (e.g. "/path/to/.git/config" has
+core.worktree set to "/different/path"), which is most likely a
+misconfiguration.  Running Git commands in the "/path/to" directory will
+still use "/different/path" as the root of the work tree and can cause
+confusion unless you know what you are doing (e.g. you are creating a
+read-only snapshot of the same index to a location different from the
+repository's usual working tree).
+
+core.logAllRefUpdates::
+	Enable the reflog. Updates to a ref <ref> is logged to the file
+	"`$GIT_DIR/logs/<ref>`", by appending the new and old
+	SHA-1, the date/time and the reason of the update, but
+	only when the file exists.  If this configuration
+	variable is set to `true`, missing "`$GIT_DIR/logs/<ref>`"
+	file is automatically created for branch heads (i.e. under
+	`refs/heads/`), remote refs (i.e. under `refs/remotes/`),
+	note refs (i.e. under `refs/notes/`), and the symbolic ref `HEAD`.
+	If it is set to `always`, then a missing reflog is automatically
+	created for any ref under `refs/`.
++
+This information can be used to determine what commit
+was the tip of a branch "2 days ago".
++
+This value is true by default in a repository that has
+a working directory associated with it, and false by
+default in a bare repository.
+
+core.repositoryFormatVersion::
+	Internal variable identifying the repository format and layout
+	version.
+
+core.sharedRepository::
+	When 'group' (or 'true'), the repository is made shareable between
+	several users in a group (making sure all the files and objects are
+	group-writable). When 'all' (or 'world' or 'everybody'), the
+	repository will be readable by all users, additionally to being
+	group-shareable. When 'umask' (or 'false'), Git will use permissions
+	reported by umask(2). When '0xxx', where '0xxx' is an octal number,
+	files in the repository will have this mode value. '0xxx' will override
+	user's umask value (whereas the other options will only override
+	requested parts of the user's umask value). Examples: '0660' will make
+	the repo read/write-able for the owner and group, but inaccessible to
+	others (equivalent to 'group' unless umask is e.g. '0022'). '0640' is a
+	repository that is group-readable but not group-writable.
+	See linkgit:git-init[1]. False by default.
+
+core.warnAmbiguousRefs::
+	If true, Git will warn you if the ref name you passed it is ambiguous
+	and might match multiple refs in the repository. True by default.
+
+core.compression::
+	An integer -1..9, indicating a default compression level.
+	-1 is the zlib default. 0 means no compression,
+	and 1..9 are various speed/size tradeoffs, 9 being slowest.
+	If set, this provides a default to other compression variables,
+	such as `core.looseCompression` and `pack.compression`.
+
+core.looseCompression::
+	An integer -1..9, indicating the compression level for objects that
+	are not in a pack file. -1 is the zlib default. 0 means no
+	compression, and 1..9 are various speed/size tradeoffs, 9 being
+	slowest.  If not set,  defaults to core.compression.  If that is
+	not set,  defaults to 1 (best speed).
+
+core.packedGitWindowSize::
+	Number of bytes of a pack file to map into memory in a
+	single mapping operation.  Larger window sizes may allow
+	your system to process a smaller number of large pack files
+	more quickly.  Smaller window sizes will negatively affect
+	performance due to increased calls to the operating system's
+	memory manager, but may improve performance when accessing
+	a large number of large pack files.
++
+Default is 1 MiB if NO_MMAP was set at compile time, otherwise 32
+MiB on 32 bit platforms and 1 GiB on 64 bit platforms.  This should
+be reasonable for all users/operating systems.  You probably do
+not need to adjust this value.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
+core.packedGitLimit::
+	Maximum number of bytes to map simultaneously into memory
+	from pack files.  If Git needs to access more than this many
+	bytes at once to complete an operation it will unmap existing
+	regions to reclaim virtual address space within the process.
++
+Default is 256 MiB on 32 bit platforms and 32 TiB (effectively
+unlimited) on 64 bit platforms.
+This should be reasonable for all users/operating systems, except on
+the largest projects.  You probably do not need to adjust this value.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
+core.deltaBaseCacheLimit::
+	Maximum number of bytes to reserve for caching base objects
+	that may be referenced by multiple deltified objects.  By storing the
+	entire decompressed base objects in a cache Git is able
+	to avoid unpacking and decompressing frequently used base
+	objects multiple times.
++
+Default is 96 MiB on all platforms.  This should be reasonable
+for all users/operating systems, except on the largest projects.
+You probably do not need to adjust this value.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
+core.bigFileThreshold::
+	Files larger than this size are stored deflated, without
+	attempting delta compression.  Storing large files without
+	delta compression avoids excessive memory usage, at the
+	slight expense of increased disk usage. Additionally files
+	larger than this size are always treated as binary.
++
+Default is 512 MiB on all platforms.  This should be reasonable
+for most projects as source code and other text files can still
+be delta compressed, but larger binary media files won't be.
++
+Common unit suffixes of 'k', 'm', or 'g' are supported.
+
+core.excludesFile::
+	Specifies the pathname to the file that contains patterns to
+	describe paths that are not meant to be tracked, in addition
+	to `.gitignore` (per-directory) and `.git/info/exclude`.
+	Defaults to `$XDG_CONFIG_HOME/git/ignore`.
+	If `$XDG_CONFIG_HOME` is either not set or empty, `$HOME/.config/git/ignore`
+	is used instead. See linkgit:gitignore[5].
+
+core.askPass::
+	Some commands (e.g. svn and http interfaces) that interactively
+	ask for a password can be told to use an external program given
+	via the value of this variable. Can be overridden by the `GIT_ASKPASS`
+	environment variable. If not set, fall back to the value of the
+	`SSH_ASKPASS` environment variable or, failing that, a simple password
+	prompt. The external program shall be given a suitable prompt as
+	command-line argument and write the password on its STDOUT.
+
+core.attributesFile::
+	In addition to `.gitattributes` (per-directory) and
+	`.git/info/attributes`, Git looks into this file for attributes
+	(see linkgit:gitattributes[5]). Path expansions are made the same
+	way as for `core.excludesFile`. Its default value is
+	`$XDG_CONFIG_HOME/git/attributes`. If `$XDG_CONFIG_HOME` is either not
+	set or empty, `$HOME/.config/git/attributes` is used instead.
+
+core.hooksPath::
+	By default Git will look for your hooks in the
+	`$GIT_DIR/hooks` directory. Set this to different path,
+	e.g. `/etc/git/hooks`, and Git will try to find your hooks in
+	that directory, e.g. `/etc/git/hooks/pre-receive` instead of
+	in `$GIT_DIR/hooks/pre-receive`.
++
+The path can be either absolute or relative. A relative path is
+taken as relative to the directory where the hooks are run (see
+the "DESCRIPTION" section of linkgit:githooks[5]).
++
+This configuration variable is useful in cases where you'd like to
+centrally configure your Git hooks instead of configuring them on a
+per-repository basis, or as a more flexible and centralized
+alternative to having an `init.templateDir` where you've changed
+default hooks.
+
+core.editor::
+	Commands such as `commit` and `tag` that let you edit
+	messages by launching an editor use the value of this
+	variable when it is set, and the environment variable
+	`GIT_EDITOR` is not set.  See linkgit:git-var[1].
+
+core.commentChar::
+	Commands such as `commit` and `tag` that let you edit
+	messages consider a line that begins with this character
+	commented, and removes them after the editor returns
+	(default '#').
++
+If set to "auto", `git-commit` would select a character that is not
+the beginning character of any line in existing commit messages.
+
+core.filesRefLockTimeout::
+	The length of time, in milliseconds, to retry when trying to
+	lock an individual reference. Value 0 means not to retry at
+	all; -1 means to try indefinitely. Default is 100 (i.e.,
+	retry for 100ms).
+
+core.packedRefsTimeout::
+	The length of time, in milliseconds, to retry when trying to
+	lock the `packed-refs` file. Value 0 means not to retry at
+	all; -1 means to try indefinitely. Default is 1000 (i.e.,
+	retry for 1 second).
+
+core.pager::
+	Text viewer for use by Git commands (e.g., 'less').  The value
+	is meant to be interpreted by the shell.  The order of preference
+	is the `$GIT_PAGER` environment variable, then `core.pager`
+	configuration, then `$PAGER`, and then the default chosen at
+	compile time (usually 'less').
++
+When the `LESS` environment variable is unset, Git sets it to `FRX`
+(if `LESS` environment variable is set, Git does not change it at
+all).  If you want to selectively override Git's default setting
+for `LESS`, you can set `core.pager` to e.g. `less -S`.  This will
+be passed to the shell by Git, which will translate the final
+command to `LESS=FRX less -S`. The environment does not set the
+`S` option but the command line does, instructing less to truncate
+long lines. Similarly, setting `core.pager` to `less -+F` will
+deactivate the `F` option specified by the environment from the
+command-line, deactivating the "quit if one screen" behavior of
+`less`.  One can specifically activate some flags for particular
+commands: for example, setting `pager.blame` to `less -S` enables
+line truncation only for `git blame`.
++
+Likewise, when the `LV` environment variable is unset, Git sets it
+to `-c`.  You can override this setting by exporting `LV` with
+another value or setting `core.pager` to `lv +c`.
+
+core.whitespace::
+	A comma separated list of common whitespace problems to
+	notice.  'git diff' will use `color.diff.whitespace` to
+	highlight them, and 'git apply --whitespace=error' will
+	consider them as errors.  You can prefix `-` to disable
+	any of them (e.g. `-trailing-space`):
++
+* `blank-at-eol` treats trailing whitespaces at the end of the line
+  as an error (enabled by default).
+* `space-before-tab` treats a space character that appears immediately
+  before a tab character in the initial indent part of the line as an
+  error (enabled by default).
+* `indent-with-non-tab` treats a line that is indented with space
+  characters instead of the equivalent tabs as an error (not enabled by
+  default).
+* `tab-in-indent` treats a tab character in the initial indent part of
+  the line as an error (not enabled by default).
+* `blank-at-eof` treats blank lines added at the end of file as an error
+  (enabled by default).
+* `trailing-space` is a short-hand to cover both `blank-at-eol` and
+  `blank-at-eof`.
+* `cr-at-eol` treats a carriage-return at the end of line as
+  part of the line terminator, i.e. with it, `trailing-space`
+  does not trigger if the character before such a carriage-return
+  is not a whitespace (not enabled by default).
+* `tabwidth=<n>` tells how many character positions a tab occupies; this
+  is relevant for `indent-with-non-tab` and when Git fixes `tab-in-indent`
+  errors. The default tab width is 8. Allowed values are 1 to 63.
+
+core.fsyncObjectFiles::
+	This boolean will enable 'fsync()' when writing object files.
++
+This is a total waste of time and effort on a filesystem that orders
+data writes properly, but can be useful for filesystems that do not use
+journalling (traditional UNIX filesystems) or that only journal metadata
+and not file contents (OS X's HFS+, or Linux ext3 with "data=writeback").
+
+core.preloadIndex::
+	Enable parallel index preload for operations like 'git diff'
++
+This can speed up operations like 'git diff' and 'git status' especially
+on filesystems like NFS that have weak caching semantics and thus
+relatively high IO latencies.  When enabled, Git will do the
+index comparison to the filesystem data in parallel, allowing
+overlapping IO's.  Defaults to true.
+
+core.unsetenvvars::
+	Windows-only: comma-separated list of environment variables'
+	names that need to be unset before spawning any other process.
+	Defaults to `PERL5LIB` to account for the fact that Git for
+	Windows insists on using its own Perl interpreter.
+
+core.createObject::
+	You can set this to 'link', in which case a hardlink followed by
+	a delete of the source are used to make sure that object creation
+	will not overwrite existing objects.
++
+On some file system/operating system combinations, this is unreliable.
+Set this config setting to 'rename' there; However, This will remove the
+check that makes sure that existing object files will not get overwritten.
+
+core.notesRef::
+	When showing commit messages, also show notes which are stored in
+	the given ref.  The ref must be fully qualified.  If the given
+	ref does not exist, it is not an error but means that no
+	notes should be printed.
++
+This setting defaults to "refs/notes/commits", and it can be overridden by
+the `GIT_NOTES_REF` environment variable.  See linkgit:git-notes[1].
+
+core.commitGraph::
+	If true, then git will read the commit-graph file (if it exists)
+	to parse the graph structure of commits. Defaults to false. See
+	linkgit:git-commit-graph[1] for more information.
+
+core.useReplaceRefs::
+	If set to `false`, behave as if the `--no-replace-objects`
+	option was given on the command line. See linkgit:git[1] and
+	linkgit:git-replace[1] for more information.
+
+core.multiPackIndex::
+	Use the multi-pack-index file to track multiple packfiles using a
+	single index. See link:technical/multi-pack-index.html[the
+	multi-pack-index design document].
+
+core.sparseCheckout::
+	Enable "sparse checkout" feature. See section "Sparse checkout" in
+	linkgit:git-read-tree[1] for more information.
+
+core.abbrev::
+	Set the length object names are abbreviated to.  If
+	unspecified or set to "auto", an appropriate value is
+	computed based on the approximate number of packed objects
+	in your repository, which hopefully is enough for
+	abbreviated object names to stay unique for some time.
+	The minimum length is 4.
diff --git a/third_party/git/Documentation/config/credential.txt b/third_party/git/Documentation/config/credential.txt
new file mode 100644
index 0000000000..60fb3189e1
--- /dev/null
+++ b/third_party/git/Documentation/config/credential.txt
@@ -0,0 +1,26 @@
+credential.helper::
+	Specify an external helper to be called when a username or
+	password credential is needed; the helper may consult external
+	storage to avoid prompting the user for the credentials. Note
+	that multiple helpers may be defined. See linkgit:gitcredentials[7]
+	for details.
+
+credential.useHttpPath::
+	When acquiring credentials, consider the "path" component of an http
+	or https URL to be important. Defaults to false. See
+	linkgit:gitcredentials[7] for more information.
+
+credential.username::
+	If no username is set for a network authentication, use this username
+	by default. See credential.<context>.* below, and
+	linkgit:gitcredentials[7].
+
+credential.<url>.*::
+	Any of the credential.* options above can be applied selectively to
+	some credentials. For example "credential.https://example.com.username"
+	would set the default username only for https connections to
+	example.com. See linkgit:gitcredentials[7] for details on how URLs are
+	matched.
+
+credentialCache.ignoreSIGHUP::
+	Tell git-credential-cache--daemon to ignore SIGHUP, instead of quitting.
diff --git a/third_party/git/Documentation/config/diff.txt b/third_party/git/Documentation/config/diff.txt
new file mode 100644
index 0000000000..5afb5a2cbc
--- /dev/null
+++ b/third_party/git/Documentation/config/diff.txt
@@ -0,0 +1,231 @@
+diff.autoRefreshIndex::
+	When using 'git diff' to compare with work tree
+	files, do not consider stat-only change as changed.
+	Instead, silently run `git update-index --refresh` to
+	update the cached stat information for paths whose
+	contents in the work tree match the contents in the
+	index.  This option defaults to true.  Note that this
+	affects only 'git diff' Porcelain, and not lower level
+	'diff' commands such as 'git diff-files'.
+
+diff.dirstat::
+	A comma separated list of `--dirstat` parameters specifying the
+	default behavior of the `--dirstat` option to linkgit:git-diff[1]
+	and friends. The defaults can be overridden on the command line
+	(using `--dirstat=<param1,param2,...>`). The fallback defaults
+	(when not changed by `diff.dirstat`) are `changes,noncumulative,3`.
+	The following parameters are available:
++
+--
+`changes`;;
+	Compute the dirstat numbers by counting the lines that have been
+	removed from the source, or added to the destination. This ignores
+	the amount of pure code movements within a file.  In other words,
+	rearranging lines in a file is not counted as much as other changes.
+	This is the default behavior when no parameter is given.
+`lines`;;
+	Compute the dirstat numbers by doing the regular line-based diff
+	analysis, and summing the removed/added line counts. (For binary
+	files, count 64-byte chunks instead, since binary files have no
+	natural concept of lines). This is a more expensive `--dirstat`
+	behavior than the `changes` behavior, but it does count rearranged
+	lines within a file as much as other changes. The resulting output
+	is consistent with what you get from the other `--*stat` options.
+`files`;;
+	Compute the dirstat numbers by counting the number of files changed.
+	Each changed file counts equally in the dirstat analysis. This is
+	the computationally cheapest `--dirstat` behavior, since it does
+	not have to look at the file contents at all.
+`cumulative`;;
+	Count changes in a child directory for the parent directory as well.
+	Note that when using `cumulative`, the sum of the percentages
+	reported may exceed 100%. The default (non-cumulative) behavior can
+	be specified with the `noncumulative` parameter.
+<limit>;;
+	An integer parameter specifies a cut-off percent (3% by default).
+	Directories contributing less than this percentage of the changes
+	are not shown in the output.
+--
++
+Example: The following will count changed files, while ignoring
+directories with less than 10% of the total amount of changed files,
+and accumulating child directory counts in the parent directories:
+`files,10,cumulative`.
+
+diff.statGraphWidth::
+	Limit the width of the graph part in --stat output. If set, applies
+	to all commands generating --stat output except format-patch.
+
+diff.context::
+	Generate diffs with <n> lines of context instead of the default
+	of 3. This value is overridden by the -U option.
+
+diff.interHunkContext::
+	Show the context between diff hunks, up to the specified number
+	of lines, thereby fusing the hunks that are close to each other.
+	This value serves as the default for the `--inter-hunk-context`
+	command line option.
+
+diff.external::
+	If this config variable is set, diff generation is not
+	performed using the internal diff machinery, but using the
+	given command.  Can be overridden with the `GIT_EXTERNAL_DIFF'
+	environment variable.  The command is called with parameters
+	as described under "git Diffs" in linkgit:git[1].  Note: if
+	you want to use an external diff program only on a subset of
+	your files, you might want to use linkgit:gitattributes[5] instead.
+
+diff.ignoreSubmodules::
+	Sets the default value of --ignore-submodules. Note that this
+	affects only 'git diff' Porcelain, and not lower level 'diff'
+	commands such as 'git diff-files'. 'git checkout'
+	and 'git switch' also honor
+	this setting when reporting uncommitted changes. Setting it to
+	'all' disables the submodule summary normally shown by 'git commit'
+	and 'git status' when `status.submoduleSummary` is set unless it is
+	overridden by using the --ignore-submodules command-line option.
+	The 'git submodule' commands are not affected by this setting.
+
+diff.mnemonicPrefix::
+	If set, 'git diff' uses a prefix pair that is different from the
+	standard "a/" and "b/" depending on what is being compared.  When
+	this configuration is in effect, reverse diff output also swaps
+	the order of the prefixes:
+`git diff`;;
+	compares the (i)ndex and the (w)ork tree;
+`git diff HEAD`;;
+	 compares a (c)ommit and the (w)ork tree;
+`git diff --cached`;;
+	compares a (c)ommit and the (i)ndex;
+`git diff HEAD:file1 file2`;;
+	compares an (o)bject and a (w)ork tree entity;
+`git diff --no-index a b`;;
+	compares two non-git things (1) and (2).
+
+diff.noprefix::
+	If set, 'git diff' does not show any source or destination prefix.
+
+diff.orderFile::
+	File indicating how to order files within a diff.
+	See the '-O' option to linkgit:git-diff[1] for details.
+	If `diff.orderFile` is a relative pathname, it is treated as
+	relative to the top of the working tree.
+
+diff.renameLimit::
+	The number of files to consider when performing the copy/rename
+	detection; equivalent to the 'git diff' option `-l`. This setting
+	has no effect if rename detection is turned off.
+
+diff.renames::
+	Whether and how Git detects renames.  If set to "false",
+	rename detection is disabled. If set to "true", basic rename
+	detection is enabled.  If set to "copies" or "copy", Git will
+	detect copies, as well.  Defaults to true.  Note that this
+	affects only 'git diff' Porcelain like linkgit:git-diff[1] and
+	linkgit:git-log[1], and not lower level commands such as
+	linkgit:git-diff-files[1].
+
+diff.suppressBlankEmpty::
+	A boolean to inhibit the standard behavior of printing a space
+	before each empty output line. Defaults to false.
+
+diff.submodule::
+	Specify the format in which differences in submodules are
+	shown.  The "short" format just shows the names of the commits
+	at the beginning and end of the range. The "log" format lists
+	the commits in the range like linkgit:git-submodule[1] `summary`
+	does. The "diff" format shows an inline diff of the changed
+	contents of the submodule. Defaults to "short".
+
+diff.wordRegex::
+	A POSIX Extended Regular Expression used to determine what is a "word"
+	when performing word-by-word difference calculations.  Character
+	sequences that match the regular expression are "words", all other
+	characters are *ignorable* whitespace.
+
+diff.<driver>.command::
+	The custom diff driver command.  See linkgit:gitattributes[5]
+	for details.
+
+diff.<driver>.xfuncname::
+	The regular expression that the diff driver should use to
+	recognize the hunk header.  A built-in pattern may also be used.
+	See linkgit:gitattributes[5] for details.
+
+diff.<driver>.binary::
+	Set this option to true to make the diff driver treat files as
+	binary.  See linkgit:gitattributes[5] for details.
+
+diff.<driver>.textconv::
+	The command that the diff driver should call to generate the
+	text-converted version of a file.  The result of the
+	conversion is used to generate a human-readable diff.  See
+	linkgit:gitattributes[5] for details.
+
+diff.<driver>.wordRegex::
+	The regular expression that the diff driver should use to
+	split words in a line.  See linkgit:gitattributes[5] for
+	details.
+
+diff.<driver>.cachetextconv::
+	Set this option to true to make the diff driver cache the text
+	conversion outputs.  See linkgit:gitattributes[5] for details.
+
+diff.tool::
+	Controls which diff tool is used by linkgit:git-difftool[1].
+	This variable overrides the value configured in `merge.tool`.
+	The list below shows the valid built-in values.
+	Any other value is treated as a custom diff tool and requires
+	that a corresponding difftool.<tool>.cmd variable is defined.
+
+diff.guitool::
+	Controls which diff tool is used by linkgit:git-difftool[1] when
+	the -g/--gui flag is specified. This variable overrides the value
+	configured in `merge.guitool`. The list below shows the valid
+	built-in values. Any other value is treated as a custom diff tool
+	and requires that a corresponding difftool.<guitool>.cmd variable
+	is defined.
+
+include::../mergetools-diff.txt[]
+
+diff.indentHeuristic::
+	Set this option to `true` to enable experimental heuristics
+	that shift diff hunk boundaries to make patches easier to read.
+
+diff.algorithm::
+	Choose a diff algorithm.  The variants are as follows:
++
+--
+`default`, `myers`;;
+	The basic greedy diff algorithm. Currently, this is the default.
+`minimal`;;
+	Spend extra time to make sure the smallest possible diff is
+	produced.
+`patience`;;
+	Use "patience diff" algorithm when generating patches.
+`histogram`;;
+	This algorithm extends the patience algorithm to "support
+	low-occurrence common elements".
+--
++
+
+diff.wsErrorHighlight::
+	Highlight whitespace errors in the `context`, `old` or `new`
+	lines of the diff.  Multiple values are separated by comma,
+	`none` resets previous values, `default` reset the list to
+	`new` and `all` is a shorthand for `old,new,context`.  The
+	whitespace errors are colored with `color.diff.whitespace`.
+	The command line option `--ws-error-highlight=<kind>`
+	overrides this setting.
+
+diff.colorMoved::
+	If set to either a valid `<mode>` or a true value, moved lines
+	in a diff are colored differently, for details of valid modes
+	see '--color-moved' in linkgit:git-diff[1]. If simply set to
+	true the default color mode will be used. When set to false,
+	moved lines are not colored.
+
+diff.colorMovedWS::
+	When moved lines are colored using e.g. the `diff.colorMoved` setting,
+	this option controls the `<mode>` how spaces are treated
+	for details of valid modes see '--color-moved-ws' in linkgit:git-diff[1].
diff --git a/third_party/git/Documentation/config/difftool.txt b/third_party/git/Documentation/config/difftool.txt
new file mode 100644
index 0000000000..6762594480
--- /dev/null
+++ b/third_party/git/Documentation/config/difftool.txt
@@ -0,0 +1,14 @@
+difftool.<tool>.path::
+	Override the path for the given tool.  This is useful in case
+	your tool is not in the PATH.
+
+difftool.<tool>.cmd::
+	Specify the command to invoke the specified diff tool.
+	The specified command is evaluated in shell with the following
+	variables available:  'LOCAL' is set to the name of the temporary
+	file containing the contents of the diff pre-image and 'REMOTE'
+	is set to the name of the temporary file containing the contents
+	of the diff post-image.
+
+difftool.prompt::
+	Prompt before each invocation of the diff tool.
diff --git a/third_party/git/Documentation/config/fastimport.txt b/third_party/git/Documentation/config/fastimport.txt
new file mode 100644
index 0000000000..c1166e330d
--- /dev/null
+++ b/third_party/git/Documentation/config/fastimport.txt
@@ -0,0 +1,8 @@
+fastimport.unpackLimit::
+	If the number of objects imported by linkgit:git-fast-import[1]
+	is below this limit, then the objects will be unpacked into
+	loose object files.  However if the number of imported objects
+	equals or exceeds this limit then the pack will be stored as a
+	pack.  Storing the pack from a fast-import can make the import
+	operation complete faster, especially on slow filesystems.  If
+	not set, the value of `transfer.unpackLimit` is used instead.
diff --git a/third_party/git/Documentation/config/fetch.txt b/third_party/git/Documentation/config/fetch.txt
new file mode 100644
index 0000000000..ba890b5884
--- /dev/null
+++ b/third_party/git/Documentation/config/fetch.txt
@@ -0,0 +1,70 @@
+fetch.recurseSubmodules::
+	This option can be either set to a boolean value or to 'on-demand'.
+	Setting it to a boolean changes the behavior of fetch and pull to
+	unconditionally recurse into submodules when set to true or to not
+	recurse at all when set to false. When set to 'on-demand' (the default
+	value), fetch and pull will only recurse into a populated submodule
+	when its superproject retrieves a commit that updates the submodule's
+	reference.
+
+fetch.fsckObjects::
+	If it is set to true, git-fetch-pack will check all fetched
+	objects. See `transfer.fsckObjects` for what's
+	checked. Defaults to false. If not set, the value of
+	`transfer.fsckObjects` is used instead.
+
+fetch.fsck.<msg-id>::
+	Acts like `fsck.<msg-id>`, but is used by
+	linkgit:git-fetch-pack[1] instead of linkgit:git-fsck[1]. See
+	the `fsck.<msg-id>` documentation for details.
+
+fetch.fsck.skipList::
+	Acts like `fsck.skipList`, but is used by
+	linkgit:git-fetch-pack[1] instead of linkgit:git-fsck[1]. See
+	the `fsck.skipList` documentation for details.
+
+fetch.unpackLimit::
+	If the number of objects fetched over the Git native
+	transfer is below this
+	limit, then the objects will be unpacked into loose object
+	files. However if the number of received objects equals or
+	exceeds this limit then the received pack will be stored as
+	a pack, after adding any missing delta bases.  Storing the
+	pack from a push can make the push operation complete faster,
+	especially on slow filesystems.  If not set, the value of
+	`transfer.unpackLimit` is used instead.
+
+fetch.prune::
+	If true, fetch will automatically behave as if the `--prune`
+	option was given on the command line.  See also `remote.<name>.prune`
+	and the PRUNING section of linkgit:git-fetch[1].
+
+fetch.pruneTags::
+	If true, fetch will automatically behave as if the
+	`refs/tags/*:refs/tags/*` refspec was provided when pruning,
+	if not set already. This allows for setting both this option
+	and `fetch.prune` to maintain a 1=1 mapping to upstream
+	refs. See also `remote.<name>.pruneTags` and the PRUNING
+	section of linkgit:git-fetch[1].
+
+fetch.output::
+	Control how ref update status is printed. Valid values are
+	`full` and `compact`. Default value is `full`. See section
+	OUTPUT in linkgit:git-fetch[1] for detail.
+
+fetch.negotiationAlgorithm::
+	Control how information about the commits in the local repository is
+	sent when negotiating the contents of the packfile to be sent by the
+	server. Set to "skipping" to use an algorithm that skips commits in an
+	effort to converge faster, but may result in a larger-than-necessary
+	packfile; The default is "default" which instructs Git to use the default algorithm
+	that never skips commits (unless the server has acknowledged it or one
+	of its descendants).
+	Unknown values will cause 'git fetch' to error out.
++
+See also the `--negotiation-tip` option for linkgit:git-fetch[1].
+
+fetch.showForcedUpdates::
+	Set to false to enable `--no-show-forced-updates` in
+	linkgit:git-fetch[1] and linkgit:git-pull[1] commands.
+	Defaults to true.
diff --git a/third_party/git/Documentation/config/filter.txt b/third_party/git/Documentation/config/filter.txt
new file mode 100644
index 0000000000..90dfe0ba5a
--- /dev/null
+++ b/third_party/git/Documentation/config/filter.txt
@@ -0,0 +1,9 @@
+filter.<driver>.clean::
+	The command which is used to convert the content of a worktree
+	file to a blob upon checkin.  See linkgit:gitattributes[5] for
+	details.
+
+filter.<driver>.smudge::
+	The command which is used to convert the content of a blob
+	object to a worktree file upon checkout.  See
+	linkgit:gitattributes[5] for details.
diff --git a/third_party/git/Documentation/config/fmt-merge-msg.txt b/third_party/git/Documentation/config/fmt-merge-msg.txt
new file mode 100644
index 0000000000..c73cfa90b7
--- /dev/null
+++ b/third_party/git/Documentation/config/fmt-merge-msg.txt
@@ -0,0 +1,10 @@
+merge.branchdesc::
+	In addition to branch names, populate the log message with
+	the branch description text associated with them.  Defaults
+	to false.
+
+merge.log::
+	In addition to branch names, populate the log message with at
+	most the specified number of one-line descriptions from the
+	actual commits that are being merged.  Defaults to false, and
+	true is a synonym for 20.
diff --git a/third_party/git/Documentation/config/format.txt b/third_party/git/Documentation/config/format.txt
new file mode 100644
index 0000000000..414a5a8a9d
--- /dev/null
+++ b/third_party/git/Documentation/config/format.txt
@@ -0,0 +1,102 @@
+format.attach::
+	Enable multipart/mixed attachments as the default for
+	'format-patch'.  The value can also be a double quoted string
+	which will enable attachments as the default and set the
+	value as the boundary.  See the --attach option in
+	linkgit:git-format-patch[1].
+
+format.from::
+	Provides the default value for the `--from` option to format-patch.
+	Accepts a boolean value, or a name and email address.  If false,
+	format-patch defaults to `--no-from`, using commit authors directly in
+	the "From:" field of patch mails.  If true, format-patch defaults to
+	`--from`, using your committer identity in the "From:" field of patch
+	mails and including a "From:" field in the body of the patch mail if
+	different.  If set to a non-boolean value, format-patch uses that
+	value instead of your committer identity.  Defaults to false.
+
+format.numbered::
+	A boolean which can enable or disable sequence numbers in patch
+	subjects.  It defaults to "auto" which enables it only if there
+	is more than one patch.  It can be enabled or disabled for all
+	messages by setting it to "true" or "false".  See --numbered
+	option in linkgit:git-format-patch[1].
+
+format.headers::
+	Additional email headers to include in a patch to be submitted
+	by mail.  See linkgit:git-format-patch[1].
+
+format.to::
+format.cc::
+	Additional recipients to include in a patch to be submitted
+	by mail.  See the --to and --cc options in
+	linkgit:git-format-patch[1].
+
+format.subjectPrefix::
+	The default for format-patch is to output files with the '[PATCH]'
+	subject prefix. Use this variable to change that prefix.
+
+format.signature::
+	The default for format-patch is to output a signature containing
+	the Git version number. Use this variable to change that default.
+	Set this variable to the empty string ("") to suppress
+	signature generation.
+
+format.signatureFile::
+	Works just like format.signature except the contents of the
+	file specified by this variable will be used as the signature.
+
+format.suffix::
+	The default for format-patch is to output files with the suffix
+	`.patch`. Use this variable to change that suffix (make sure to
+	include the dot if you want it).
+
+format.pretty::
+	The default pretty format for log/show/whatchanged command,
+	See linkgit:git-log[1], linkgit:git-show[1],
+	linkgit:git-whatchanged[1].
+
+format.thread::
+	The default threading style for 'git format-patch'.  Can be
+	a boolean value, or `shallow` or `deep`.  `shallow` threading
+	makes every mail a reply to the head of the series,
+	where the head is chosen from the cover letter, the
+	`--in-reply-to`, and the first patch mail, in this order.
+	`deep` threading makes every mail a reply to the previous one.
+	A true boolean value is the same as `shallow`, and a false
+	value disables threading.
+
+format.signOff::
+	A boolean value which lets you enable the `-s/--signoff` option of
+	format-patch by default. *Note:* Adding the Signed-off-by: line to a
+	patch should be a conscious act and means that you certify you have
+	the rights to submit this work under the same open source license.
+	Please see the 'SubmittingPatches' document for further discussion.
+
+format.coverLetter::
+	A boolean that controls whether to generate a cover-letter when
+	format-patch is invoked, but in addition can be set to "auto", to
+	generate a cover-letter only when there's more than one patch.
+
+format.outputDirectory::
+	Set a custom directory to store the resulting files instead of the
+	current working directory.
+
+format.useAutoBase::
+	A boolean value which lets you enable the `--base=auto` option of
+	format-patch by default.
+
+format.notes::
+	Provides the default value for the `--notes` option to
+	format-patch. Accepts a boolean value, or a ref which specifies
+	where to get notes. If false, format-patch defaults to
+	`--no-notes`. If true, format-patch defaults to `--notes`. If
+	set to a non-boolean value, format-patch defaults to
+	`--notes=<ref>`, where `ref` is the non-boolean value. Defaults
+	to false.
++
+If one wishes to use the ref `ref/notes/true`, please use that literal
+instead.
++
+This configuration can be specified multiple times in order to allow
+multiple notes refs to be included.
diff --git a/third_party/git/Documentation/config/fsck.txt b/third_party/git/Documentation/config/fsck.txt
new file mode 100644
index 0000000000..450e8c38e3
--- /dev/null
+++ b/third_party/git/Documentation/config/fsck.txt
@@ -0,0 +1,67 @@
+fsck.<msg-id>::
+	During fsck git may find issues with legacy data which
+	wouldn't be generated by current versions of git, and which
+	wouldn't be sent over the wire if `transfer.fsckObjects` was
+	set. This feature is intended to support working with legacy
+	repositories containing such data.
++
+Setting `fsck.<msg-id>` will be picked up by linkgit:git-fsck[1], but
+to accept pushes of such data set `receive.fsck.<msg-id>` instead, or
+to clone or fetch it set `fetch.fsck.<msg-id>`.
++
+The rest of the documentation discusses `fsck.*` for brevity, but the
+same applies for the corresponding `receive.fsck.*` and
+`fetch.<msg-id>.*`. variables.
++
+Unlike variables like `color.ui` and `core.editor` the
+`receive.fsck.<msg-id>` and `fetch.fsck.<msg-id>` variables will not
+fall back on the `fsck.<msg-id>` configuration if they aren't set. To
+uniformly configure the same fsck settings in different circumstances
+all three of them they must all set to the same values.
++
+When `fsck.<msg-id>` is set, errors can be switched to warnings and
+vice versa by configuring the `fsck.<msg-id>` setting where the
+`<msg-id>` is the fsck message ID and the value is one of `error`,
+`warn` or `ignore`. For convenience, fsck prefixes the error/warning
+with the message ID, e.g. "missingEmail: invalid author/committer
+line - missing email" means that setting `fsck.missingEmail = ignore`
+will hide that issue.
++
+In general, it is better to enumerate existing objects with problems
+with `fsck.skipList`, instead of listing the kind of breakages these
+problematic objects share to be ignored, as doing the latter will
+allow new instances of the same breakages go unnoticed.
++
+Setting an unknown `fsck.<msg-id>` value will cause fsck to die, but
+doing the same for `receive.fsck.<msg-id>` and `fetch.fsck.<msg-id>`
+will only cause git to warn.
+
+fsck.skipList::
+	The path to a list of object names (i.e. one unabbreviated SHA-1 per
+	line) that are known to be broken in a non-fatal way and should
+	be ignored. On versions of Git 2.20 and later comments ('#'), empty
+	lines, and any leading and trailing whitespace is ignored. Everything
+	but a SHA-1 per line will error out on older versions.
++
+This feature is useful when an established project should be accepted
+despite early commits containing errors that can be safely ignored
+such as invalid committer email addresses.  Note: corrupt objects
+cannot be skipped with this setting.
++
+Like `fsck.<msg-id>` this variable has corresponding
+`receive.fsck.skipList` and `fetch.fsck.skipList` variants.
++
+Unlike variables like `color.ui` and `core.editor` the
+`receive.fsck.skipList` and `fetch.fsck.skipList` variables will not
+fall back on the `fsck.skipList` configuration if they aren't set. To
+uniformly configure the same fsck settings in different circumstances
+all three of them they must all set to the same values.
++
+Older versions of Git (before 2.20) documented that the object names
+list should be sorted. This was never a requirement, the object names
+could appear in any order, but when reading the list we tracked whether
+the list was sorted for the purposes of an internal binary search
+implementation, which could save itself some work with an already sorted
+list. Unless you had a humongous list there was no reason to go out of
+your way to pre-sort the list. After Git version 2.20 a hash implementation
+is used instead, so there's now no reason to pre-sort the list.
diff --git a/third_party/git/Documentation/config/gc.txt b/third_party/git/Documentation/config/gc.txt
new file mode 100644
index 0000000000..02b92b18b5
--- /dev/null
+++ b/third_party/git/Documentation/config/gc.txt
@@ -0,0 +1,136 @@
+gc.aggressiveDepth::
+	The depth parameter used in the delta compression
+	algorithm used by 'git gc --aggressive'.  This defaults
+	to 50, which is the default for the `--depth` option when
+	`--aggressive` isn't in use.
++
+See the documentation for the `--depth` option in
+linkgit:git-repack[1] for more details.
+
+gc.aggressiveWindow::
+	The window size parameter used in the delta compression
+	algorithm used by 'git gc --aggressive'.  This defaults
+	to 250, which is a much more aggressive window size than
+	the default `--window` of 10.
++
+See the documentation for the `--window` option in
+linkgit:git-repack[1] for more details.
+
+gc.auto::
+	When there are approximately more than this many loose
+	objects in the repository, `git gc --auto` will pack them.
+	Some Porcelain commands use this command to perform a
+	light-weight garbage collection from time to time.  The
+	default value is 6700.
++
+Setting this to 0 disables not only automatic packing based on the
+number of loose objects, but any other heuristic `git gc --auto` will
+otherwise use to determine if there's work to do, such as
+`gc.autoPackLimit`.
+
+gc.autoPackLimit::
+	When there are more than this many packs that are not
+	marked with `*.keep` file in the repository, `git gc
+	--auto` consolidates them into one larger pack.  The
+	default value is 50.  Setting this to 0 disables it.
+	Setting `gc.auto` to 0 will also disable this.
++
+See the `gc.bigPackThreshold` configuration variable below. When in
+use, it'll affect how the auto pack limit works.
+
+gc.autoDetach::
+	Make `git gc --auto` return immediately and run in background
+	if the system supports it. Default is true.
+
+gc.bigPackThreshold::
+	If non-zero, all packs larger than this limit are kept when
+	`git gc` is run. This is very similar to `--keep-base-pack`
+	except that all packs that meet the threshold are kept, not
+	just the base pack. Defaults to zero. Common unit suffixes of
+	'k', 'm', or 'g' are supported.
++
+Note that if the number of kept packs is more than gc.autoPackLimit,
+this configuration variable is ignored, all packs except the base pack
+will be repacked. After this the number of packs should go below
+gc.autoPackLimit and gc.bigPackThreshold should be respected again.
++
+If the amount of memory estimated for `git repack` to run smoothly is
+not available and `gc.bigPackThreshold` is not set, the largest pack
+will also be excluded (this is the equivalent of running `git gc` with
+`--keep-base-pack`).
+
+gc.writeCommitGraph::
+	If true, then gc will rewrite the commit-graph file when
+	linkgit:git-gc[1] is run. When using `git gc --auto`
+	the commit-graph will be updated if housekeeping is
+	required. Default is false. See linkgit:git-commit-graph[1]
+	for details.
+
+gc.logExpiry::
+	If the file gc.log exists, then `git gc --auto` will print
+	its content and exit with status zero instead of running
+	unless that file is more than 'gc.logExpiry' old.  Default is
+	"1.day".  See `gc.pruneExpire` for more ways to specify its
+	value.
+
+gc.packRefs::
+	Running `git pack-refs` in a repository renders it
+	unclonable by Git versions prior to 1.5.1.2 over dumb
+	transports such as HTTP.  This variable determines whether
+	'git gc' runs `git pack-refs`. This can be set to `notbare`
+	to enable it within all non-bare repos or it can be set to a
+	boolean value.  The default is `true`.
+
+gc.pruneExpire::
+	When 'git gc' is run, it will call 'prune --expire 2.weeks.ago'.
+	Override the grace period with this config variable.  The value
+	"now" may be used to disable this grace period and always prune
+	unreachable objects immediately, or "never" may be used to
+	suppress pruning.  This feature helps prevent corruption when
+	'git gc' runs concurrently with another process writing to the
+	repository; see the "NOTES" section of linkgit:git-gc[1].
+
+gc.worktreePruneExpire::
+	When 'git gc' is run, it calls
+	'git worktree prune --expire 3.months.ago'.
+	This config variable can be used to set a different grace
+	period. The value "now" may be used to disable the grace
+	period and prune `$GIT_DIR/worktrees` immediately, or "never"
+	may be used to suppress pruning.
+
+gc.reflogExpire::
+gc.<pattern>.reflogExpire::
+	'git reflog expire' removes reflog entries older than
+	this time; defaults to 90 days. The value "now" expires all
+	entries immediately, and "never" suppresses expiration
+	altogether. With "<pattern>" (e.g.
+	"refs/stash") in the middle the setting applies only to
+	the refs that match the <pattern>.
+
+gc.reflogExpireUnreachable::
+gc.<pattern>.reflogExpireUnreachable::
+	'git reflog expire' removes reflog entries older than
+	this time and are not reachable from the current tip;
+	defaults to 30 days. The value "now" expires all entries
+	immediately, and "never" suppresses expiration altogether.
+	With "<pattern>" (e.g. "refs/stash")
+	in the middle, the setting applies only to the refs that
+	match the <pattern>.
++
+These types of entries are generally created as a result of using `git
+commit --amend` or `git rebase` and are the commits prior to the amend
+or rebase occurring.  Since these changes are not part of the current
+project most users will want to expire them sooner, which is why the
+default is more aggressive than `gc.reflogExpire`.
+
+gc.rerereResolved::
+	Records of conflicted merge you resolved earlier are
+	kept for this many days when 'git rerere gc' is run.
+	You can also use more human-readable "1.month.ago", etc.
+	The default is 60 days.  See linkgit:git-rerere[1].
+
+gc.rerereUnresolved::
+	Records of conflicted merge you have not resolved are
+	kept for this many days when 'git rerere gc' is run.
+	You can also use more human-readable "1.month.ago", etc.
+	The default is 15 days.  See linkgit:git-rerere[1].
diff --git a/third_party/git/Documentation/config/gitcvs.txt b/third_party/git/Documentation/config/gitcvs.txt
new file mode 100644
index 0000000000..02da427fd9
--- /dev/null
+++ b/third_party/git/Documentation/config/gitcvs.txt
@@ -0,0 +1,67 @@
+gitcvs.commitMsgAnnotation::
+	Append this string to each commit message. Set to empty string
+	to disable this feature. Defaults to "via git-CVS emulator".
+
+gitcvs.enabled::
+	Whether the CVS server interface is enabled for this repository.
+	See linkgit:git-cvsserver[1].
+
+gitcvs.logFile::
+	Path to a log file where the CVS server interface well... logs
+	various stuff. See linkgit:git-cvsserver[1].
+
+gitcvs.usecrlfattr::
+	If true, the server will look up the end-of-line conversion
+	attributes for files to determine the `-k` modes to use. If
+	the attributes force Git to treat a file as text,
+	the `-k` mode will be left blank so CVS clients will
+	treat it as text. If they suppress text conversion, the file
+	will be set with '-kb' mode, which suppresses any newline munging
+	the client might otherwise do. If the attributes do not allow
+	the file type to be determined, then `gitcvs.allBinary` is
+	used. See linkgit:gitattributes[5].
+
+gitcvs.allBinary::
+	This is used if `gitcvs.usecrlfattr` does not resolve
+	the correct '-kb' mode to use. If true, all
+	unresolved files are sent to the client in
+	mode '-kb'. This causes the client to treat them
+	as binary files, which suppresses any newline munging it
+	otherwise might do. Alternatively, if it is set to "guess",
+	then the contents of the file are examined to decide if
+	it is binary, similar to `core.autocrlf`.
+
+gitcvs.dbName::
+	Database used by git-cvsserver to cache revision information
+	derived from the Git repository. The exact meaning depends on the
+	used database driver, for SQLite (which is the default driver) this
+	is a filename. Supports variable substitution (see
+	linkgit:git-cvsserver[1] for details). May not contain semicolons (`;`).
+	Default: '%Ggitcvs.%m.sqlite'
+
+gitcvs.dbDriver::
+	Used Perl DBI driver. You can specify any available driver
+	for this here, but it might not work. git-cvsserver is tested
+	with 'DBD::SQLite', reported to work with 'DBD::Pg', and
+	reported *not* to work with 'DBD::mysql'. Experimental feature.
+	May not contain double colons (`:`). Default: 'SQLite'.
+	See linkgit:git-cvsserver[1].
+
+gitcvs.dbUser, gitcvs.dbPass::
+	Database user and password. Only useful if setting `gitcvs.dbDriver`,
+	since SQLite has no concept of database users and/or passwords.
+	'gitcvs.dbUser' supports variable substitution (see
+	linkgit:git-cvsserver[1] for details).
+
+gitcvs.dbTableNamePrefix::
+	Database table name prefix.  Prepended to the names of any
+	database tables used, allowing a single database to be used
+	for several repositories.  Supports variable substitution (see
+	linkgit:git-cvsserver[1] for details).  Any non-alphabetic
+	characters will be replaced with underscores.
+
+All gitcvs variables except for `gitcvs.usecrlfattr` and
+`gitcvs.allBinary` can also be specified as
+'gitcvs.<access_method>.<varname>' (where 'access_method'
+is one of "ext" and "pserver") to make them apply only for the given
+access method.
diff --git a/third_party/git/Documentation/config/gitweb.txt b/third_party/git/Documentation/config/gitweb.txt
new file mode 100644
index 0000000000..1b51475108
--- /dev/null
+++ b/third_party/git/Documentation/config/gitweb.txt
@@ -0,0 +1,16 @@
+gitweb.category::
+gitweb.description::
+gitweb.owner::
+gitweb.url::
+	See linkgit:gitweb[1] for description.
+
+gitweb.avatar::
+gitweb.blame::
+gitweb.grep::
+gitweb.highlight::
+gitweb.patches::
+gitweb.pickaxe::
+gitweb.remote_heads::
+gitweb.showSizes::
+gitweb.snapshot::
+	See linkgit:gitweb.conf[5] for description.
diff --git a/third_party/git/Documentation/config/gpg.txt b/third_party/git/Documentation/config/gpg.txt
new file mode 100644
index 0000000000..cce2c89245
--- /dev/null
+++ b/third_party/git/Documentation/config/gpg.txt
@@ -0,0 +1,20 @@
+gpg.program::
+	Use this custom program instead of "`gpg`" found on `$PATH` when
+	making or verifying a PGP signature. The program must support the
+	same command-line interface as GPG, namely, to verify a detached
+	signature, "`gpg --verify $signature - <$file`" is run, and the
+	program is expected to signal a good signature by exiting with
+	code 0, and to generate an ASCII-armored detached signature, the
+	standard input of "`gpg -bsau $key`" is fed with the contents to be
+	signed, and the program is expected to send the result to its
+	standard output.
+
+gpg.format::
+	Specifies which key format to use when signing with `--gpg-sign`.
+	Default is "openpgp" and another possible value is "x509".
+
+gpg.<format>.program::
+	Use this to customize the program used for the signing format you
+	chose. (see `gpg.program` and `gpg.format`) `gpg.program` can still
+	be used as a legacy synonym for `gpg.openpgp.program`. The default
+	value for `gpg.x509.program` is "gpgsm".
diff --git a/third_party/git/Documentation/config/grep.txt b/third_party/git/Documentation/config/grep.txt
new file mode 100644
index 0000000000..44abe45a7c
--- /dev/null
+++ b/third_party/git/Documentation/config/grep.txt
@@ -0,0 +1,24 @@
+grep.lineNumber::
+	If set to true, enable `-n` option by default.
+
+grep.column::
+	If set to true, enable the `--column` option by default.
+
+grep.patternType::
+	Set the default matching behavior. Using a value of 'basic', 'extended',
+	'fixed', or 'perl' will enable the `--basic-regexp`, `--extended-regexp`,
+	`--fixed-strings`, or `--perl-regexp` option accordingly, while the
+	value 'default' will return to the default matching behavior.
+
+grep.extendedRegexp::
+	If set to true, enable `--extended-regexp` option by default. This
+	option is ignored when the `grep.patternType` option is set to a value
+	other than 'default'.
+
+grep.threads::
+	Number of grep worker threads to use.
+	See `grep.threads` in linkgit:git-grep[1] for more information.
+
+grep.fallbackToNoIndex::
+	If set to true, fall back to git grep --no-index if git grep
+	is executed outside of a git repository.  Defaults to false.
diff --git a/third_party/git/Documentation/config/gui.txt b/third_party/git/Documentation/config/gui.txt
new file mode 100644
index 0000000000..d30831a130
--- /dev/null
+++ b/third_party/git/Documentation/config/gui.txt
@@ -0,0 +1,57 @@
+gui.commitMsgWidth::
+	Defines how wide the commit message window is in the
+	linkgit:git-gui[1]. "75" is the default.
+
+gui.diffContext::
+	Specifies how many context lines should be used in calls to diff
+	made by the linkgit:git-gui[1]. The default is "5".
+
+gui.displayUntracked::
+	Determines if linkgit:git-gui[1] shows untracked files
+	in the file list. The default is "true".
+
+gui.encoding::
+	Specifies the default encoding to use for displaying of
+	file contents in linkgit:git-gui[1] and linkgit:gitk[1].
+	It can be overridden by setting the 'encoding' attribute
+	for relevant files (see linkgit:gitattributes[5]).
+	If this option is not set, the tools default to the
+	locale encoding.
+
+gui.matchTrackingBranch::
+	Determines if new branches created with linkgit:git-gui[1] should
+	default to tracking remote branches with matching names or
+	not. Default: "false".
+
+gui.newBranchTemplate::
+	Is used as suggested name when creating new branches using the
+	linkgit:git-gui[1].
+
+gui.pruneDuringFetch::
+	"true" if linkgit:git-gui[1] should prune remote-tracking branches when
+	performing a fetch. The default value is "false".
+
+gui.trustmtime::
+	Determines if linkgit:git-gui[1] should trust the file modification
+	timestamp or not. By default the timestamps are not trusted.
+
+gui.spellingDictionary::
+	Specifies the dictionary used for spell checking commit messages in
+	the linkgit:git-gui[1]. When set to "none" spell checking is turned
+	off.
+
+gui.fastCopyBlame::
+	If true, 'git gui blame' uses `-C` instead of `-C -C` for original
+	location detection. It makes blame significantly faster on huge
+	repositories at the expense of less thorough copy detection.
+
+gui.copyBlameThreshold::
+	Specifies the threshold to use in 'git gui blame' original location
+	detection, measured in alphanumeric characters. See the
+	linkgit:git-blame[1] manual for more information on copy detection.
+
+gui.blamehistoryctx::
+	Specifies the radius of history context in days to show in
+	linkgit:gitk[1] for the selected commit, when the `Show History
+	Context` menu item is invoked from 'git gui blame'. If this
+	variable is set to zero, the whole history is shown.
diff --git a/third_party/git/Documentation/config/guitool.txt b/third_party/git/Documentation/config/guitool.txt
new file mode 100644
index 0000000000..43fb9466ff
--- /dev/null
+++ b/third_party/git/Documentation/config/guitool.txt
@@ -0,0 +1,50 @@
+guitool.<name>.cmd::
+	Specifies the shell command line to execute when the corresponding item
+	of the linkgit:git-gui[1] `Tools` menu is invoked. This option is
+	mandatory for every tool. The command is executed from the root of
+	the working directory, and in the environment it receives the name of
+	the tool as `GIT_GUITOOL`, the name of the currently selected file as
+	'FILENAME', and the name of the current branch as 'CUR_BRANCH' (if
+	the head is detached, 'CUR_BRANCH' is empty).
+
+guitool.<name>.needsFile::
+	Run the tool only if a diff is selected in the GUI. It guarantees
+	that 'FILENAME' is not empty.
+
+guitool.<name>.noConsole::
+	Run the command silently, without creating a window to display its
+	output.
+
+guitool.<name>.noRescan::
+	Don't rescan the working directory for changes after the tool
+	finishes execution.
+
+guitool.<name>.confirm::
+	Show a confirmation dialog before actually running the tool.
+
+guitool.<name>.argPrompt::
+	Request a string argument from the user, and pass it to the tool
+	through the `ARGS` environment variable. Since requesting an
+	argument implies confirmation, the 'confirm' option has no effect
+	if this is enabled. If the option is set to 'true', 'yes', or '1',
+	the dialog uses a built-in generic prompt; otherwise the exact
+	value of the variable is used.
+
+guitool.<name>.revPrompt::
+	Request a single valid revision from the user, and set the
+	`REVISION` environment variable. In other aspects this option
+	is similar to 'argPrompt', and can be used together with it.
+
+guitool.<name>.revUnmerged::
+	Show only unmerged branches in the 'revPrompt' subdialog.
+	This is useful for tools similar to merge or rebase, but not
+	for things like checkout or reset.
+
+guitool.<name>.title::
+	Specifies the title to use for the prompt dialog. The default
+	is the tool name.
+
+guitool.<name>.prompt::
+	Specifies the general prompt string to display at the top of
+	the dialog, before subsections for 'argPrompt' and 'revPrompt'.
+	The default value includes the actual command.
diff --git a/third_party/git/Documentation/config/help.txt b/third_party/git/Documentation/config/help.txt
new file mode 100644
index 0000000000..224bbf5a28
--- /dev/null
+++ b/third_party/git/Documentation/config/help.txt
@@ -0,0 +1,23 @@
+help.browser::
+	Specify the browser that will be used to display help in the
+	'web' format. See linkgit:git-help[1].
+
+help.format::
+	Override the default help format used by linkgit:git-help[1].
+	Values 'man', 'info', 'web' and 'html' are supported. 'man' is
+	the default. 'web' and 'html' are the same.
+
+help.autoCorrect::
+	Automatically correct and execute mistyped commands after
+	waiting for the given number of deciseconds (0.1 sec). If more
+	than one command can be deduced from the entered text, nothing
+	will be executed.  If the value of this option is negative,
+	the corrected command will be executed immediately. If the
+	value is 0 - the command will be just shown but not executed.
+	This is the default.
+
+help.htmlPath::
+	Specify the path where the HTML documentation resides. File system paths
+	and URLs are supported. HTML pages will be prefixed with this path when
+	help is displayed in the 'web' format. This defaults to the documentation
+	path of your Git installation.
diff --git a/third_party/git/Documentation/config/http.txt b/third_party/git/Documentation/config/http.txt
new file mode 100644
index 0000000000..5a32f5b0a5
--- /dev/null
+++ b/third_party/git/Documentation/config/http.txt
@@ -0,0 +1,280 @@
+http.proxy::
+	Override the HTTP proxy, normally configured using the 'http_proxy',
+	'https_proxy', and 'all_proxy' environment variables (see `curl(1)`). In
+	addition to the syntax understood by curl, it is possible to specify a
+	proxy string with a user name but no password, in which case git will
+	attempt to acquire one in the same way it does for other credentials. See
+	linkgit:gitcredentials[7] for more information. The syntax thus is
+	'[protocol://][user[:password]@]proxyhost[:port]'. This can be overridden
+	on a per-remote basis; see remote.<name>.proxy
+
+http.proxyAuthMethod::
+	Set the method with which to authenticate against the HTTP proxy. This
+	only takes effect if the configured proxy string contains a user name part
+	(i.e. is of the form 'user@host' or 'user@host:port'). This can be
+	overridden on a per-remote basis; see `remote.<name>.proxyAuthMethod`.
+	Both can be overridden by the `GIT_HTTP_PROXY_AUTHMETHOD` environment
+	variable.  Possible values are:
++
+--
+* `anyauth` - Automatically pick a suitable authentication method. It is
+  assumed that the proxy answers an unauthenticated request with a 407
+  status code and one or more Proxy-authenticate headers with supported
+  authentication methods. This is the default.
+* `basic` - HTTP Basic authentication
+* `digest` - HTTP Digest authentication; this prevents the password from being
+  transmitted to the proxy in clear text
+* `negotiate` - GSS-Negotiate authentication (compare the --negotiate option
+  of `curl(1)`)
+* `ntlm` - NTLM authentication (compare the --ntlm option of `curl(1)`)
+--
+
+http.emptyAuth::
+	Attempt authentication without seeking a username or password.  This
+	can be used to attempt GSS-Negotiate authentication without specifying
+	a username in the URL, as libcurl normally requires a username for
+	authentication.
+
+http.delegation::
+	Control GSSAPI credential delegation. The delegation is disabled
+	by default in libcurl since version 7.21.7. Set parameter to tell
+	the server what it is allowed to delegate when it comes to user
+	credentials. Used with GSS/kerberos. Possible values are:
++
+--
+* `none` - Don't allow any delegation.
+* `policy` - Delegates if and only if the OK-AS-DELEGATE flag is set in the
+  Kerberos service ticket, which is a matter of realm policy.
+* `always` - Unconditionally allow the server to delegate.
+--
+
+
+http.extraHeader::
+	Pass an additional HTTP header when communicating with a server.  If
+	more than one such entry exists, all of them are added as extra
+	headers.  To allow overriding the settings inherited from the system
+	config, an empty value will reset the extra headers to the empty list.
+
+http.cookieFile::
+	The pathname of a file containing previously stored cookie lines,
+	which should be used
+	in the Git http session, if they match the server. The file format
+	of the file to read cookies from should be plain HTTP headers or
+	the Netscape/Mozilla cookie file format (see `curl(1)`).
+	NOTE that the file specified with http.cookieFile is used only as
+	input unless http.saveCookies is set.
+
+http.saveCookies::
+	If set, store cookies received during requests to the file specified by
+	http.cookieFile. Has no effect if http.cookieFile is unset.
+
+http.version::
+	Use the specified HTTP protocol version when communicating with a server.
+	If you want to force the default. The available and default version depend
+	on libcurl. Actually the possible values of
+	this option are:
+
+	- HTTP/2
+	- HTTP/1.1
+
+http.sslVersion::
+	The SSL version to use when negotiating an SSL connection, if you
+	want to force the default.  The available and default version
+	depend on whether libcurl was built against NSS or OpenSSL and the
+	particular configuration of the crypto library in use. Internally
+	this sets the 'CURLOPT_SSL_VERSION' option; see the libcurl
+	documentation for more details on the format of this option and
+	for the ssl version supported. Actually the possible values of
+	this option are:
+
+	- sslv2
+	- sslv3
+	- tlsv1
+	- tlsv1.0
+	- tlsv1.1
+	- tlsv1.2
+	- tlsv1.3
+
++
+Can be overridden by the `GIT_SSL_VERSION` environment variable.
+To force git to use libcurl's default ssl version and ignore any
+explicit http.sslversion option, set `GIT_SSL_VERSION` to the
+empty string.
+
+http.sslCipherList::
+  A list of SSL ciphers to use when negotiating an SSL connection.
+  The available ciphers depend on whether libcurl was built against
+  NSS or OpenSSL and the particular configuration of the crypto
+  library in use.  Internally this sets the 'CURLOPT_SSL_CIPHER_LIST'
+  option; see the libcurl documentation for more details on the format
+  of this list.
++
+Can be overridden by the `GIT_SSL_CIPHER_LIST` environment variable.
+To force git to use libcurl's default cipher list and ignore any
+explicit http.sslCipherList option, set `GIT_SSL_CIPHER_LIST` to the
+empty string.
+
+http.sslVerify::
+	Whether to verify the SSL certificate when fetching or pushing
+	over HTTPS. Defaults to true. Can be overridden by the
+	`GIT_SSL_NO_VERIFY` environment variable.
+
+http.sslCert::
+	File containing the SSL certificate when fetching or pushing
+	over HTTPS. Can be overridden by the `GIT_SSL_CERT` environment
+	variable.
+
+http.sslKey::
+	File containing the SSL private key when fetching or pushing
+	over HTTPS. Can be overridden by the `GIT_SSL_KEY` environment
+	variable.
+
+http.sslCertPasswordProtected::
+	Enable Git's password prompt for the SSL certificate.  Otherwise
+	OpenSSL will prompt the user, possibly many times, if the
+	certificate or private key is encrypted.  Can be overridden by the
+	`GIT_SSL_CERT_PASSWORD_PROTECTED` environment variable.
+
+http.sslCAInfo::
+	File containing the certificates to verify the peer with when
+	fetching or pushing over HTTPS. Can be overridden by the
+	`GIT_SSL_CAINFO` environment variable.
+
+http.sslCAPath::
+	Path containing files with the CA certificates to verify the peer
+	with when fetching or pushing over HTTPS. Can be overridden
+	by the `GIT_SSL_CAPATH` environment variable.
+
+http.sslBackend::
+	Name of the SSL backend to use (e.g. "openssl" or "schannel").
+	This option is ignored if cURL lacks support for choosing the SSL
+	backend at runtime.
+
+http.schannelCheckRevoke::
+	Used to enforce or disable certificate revocation checks in cURL
+	when http.sslBackend is set to "schannel". Defaults to `true` if
+	unset. Only necessary to disable this if Git consistently errors
+	and the message is about checking the revocation status of a
+	certificate. This option is ignored if cURL lacks support for
+	setting the relevant SSL option at runtime.
+
+http.schannelUseSSLCAInfo::
+	As of cURL v7.60.0, the Secure Channel backend can use the
+	certificate bundle provided via `http.sslCAInfo`, but that would
+	override the Windows Certificate Store. Since this is not desirable
+	by default, Git will tell cURL not to use that bundle by default
+	when the `schannel` backend was configured via `http.sslBackend`,
+	unless `http.schannelUseSSLCAInfo` overrides this behavior.
+
+http.pinnedpubkey::
+	Public key of the https service. It may either be the filename of
+	a PEM or DER encoded public key file or a string starting with
+	'sha256//' followed by the base64 encoded sha256 hash of the
+	public key. See also libcurl 'CURLOPT_PINNEDPUBLICKEY'. git will
+	exit with an error if this option is set but not supported by
+	cURL.
+
+http.sslTry::
+	Attempt to use AUTH SSL/TLS and encrypted data transfers
+	when connecting via regular FTP protocol. This might be needed
+	if the FTP server requires it for security reasons or you wish
+	to connect securely whenever remote FTP server supports it.
+	Default is false since it might trigger certificate verification
+	errors on misconfigured servers.
+
+http.maxRequests::
+	How many HTTP requests to launch in parallel. Can be overridden
+	by the `GIT_HTTP_MAX_REQUESTS` environment variable. Default is 5.
+
+http.minSessions::
+	The number of curl sessions (counted across slots) to be kept across
+	requests. They will not be ended with curl_easy_cleanup() until
+	http_cleanup() is invoked. If USE_CURL_MULTI is not defined, this
+	value will be capped at 1. Defaults to 1.
+
+http.postBuffer::
+	Maximum size in bytes of the buffer used by smart HTTP
+	transports when POSTing data to the remote system.
+	For requests larger than this buffer size, HTTP/1.1 and
+	Transfer-Encoding: chunked is used to avoid creating a
+	massive pack file locally.  Default is 1 MiB, which is
+	sufficient for most requests.
+
+http.lowSpeedLimit, http.lowSpeedTime::
+	If the HTTP transfer speed is less than 'http.lowSpeedLimit'
+	for longer than 'http.lowSpeedTime' seconds, the transfer is aborted.
+	Can be overridden by the `GIT_HTTP_LOW_SPEED_LIMIT` and
+	`GIT_HTTP_LOW_SPEED_TIME` environment variables.
+
+http.noEPSV::
+	A boolean which disables using of EPSV ftp command by curl.
+	This can helpful with some "poor" ftp servers which don't
+	support EPSV mode. Can be overridden by the `GIT_CURL_FTP_NO_EPSV`
+	environment variable. Default is false (curl will use EPSV).
+
+http.userAgent::
+	The HTTP USER_AGENT string presented to an HTTP server.  The default
+	value represents the version of the client Git such as git/1.7.1.
+	This option allows you to override this value to a more common value
+	such as Mozilla/4.0.  This may be necessary, for instance, if
+	connecting through a firewall that restricts HTTP connections to a set
+	of common USER_AGENT strings (but not including those like git/1.7.1).
+	Can be overridden by the `GIT_HTTP_USER_AGENT` environment variable.
+
+http.followRedirects::
+	Whether git should follow HTTP redirects. If set to `true`, git
+	will transparently follow any redirect issued by a server it
+	encounters. If set to `false`, git will treat all redirects as
+	errors. If set to `initial`, git will follow redirects only for
+	the initial request to a remote, but not for subsequent
+	follow-up HTTP requests. Since git uses the redirected URL as
+	the base for the follow-up requests, this is generally
+	sufficient. The default is `initial`.
+
+http.<url>.*::
+	Any of the http.* options above can be applied selectively to some URLs.
+	For a config key to match a URL, each element of the config key is
+	compared to that of the URL, in the following order:
++
+--
+. Scheme (e.g., `https` in `https://example.com/`). This field
+  must match exactly between the config key and the URL.
+
+. Host/domain name (e.g., `example.com` in `https://example.com/`).
+  This field must match between the config key and the URL. It is
+  possible to specify a `*` as part of the host name to match all subdomains
+  at this level. `https://*.example.com/` for example would match
+  `https://foo.example.com/`, but not `https://foo.bar.example.com/`.
+
+. Port number (e.g., `8080` in `http://example.com:8080/`).
+  This field must match exactly between the config key and the URL.
+  Omitted port numbers are automatically converted to the correct
+  default for the scheme before matching.
+
+. Path (e.g., `repo.git` in `https://example.com/repo.git`). The
+  path field of the config key must match the path field of the URL
+  either exactly or as a prefix of slash-delimited path elements.  This means
+  a config key with path `foo/` matches URL path `foo/bar`.  A prefix can only
+  match on a slash (`/`) boundary.  Longer matches take precedence (so a config
+  key with path `foo/bar` is a better match to URL path `foo/bar` than a config
+  key with just path `foo/`).
+
+. User name (e.g., `user` in `https://user@example.com/repo.git`). If
+  the config key has a user name it must match the user name in the
+  URL exactly. If the config key does not have a user name, that
+  config key will match a URL with any user name (including none),
+  but at a lower precedence than a config key with a user name.
+--
++
+The list above is ordered by decreasing precedence; a URL that matches
+a config key's path is preferred to one that matches its user name. For example,
+if the URL is `https://user@example.com/foo/bar` a config key match of
+`https://example.com/foo` will be preferred over a config key match of
+`https://user@example.com`.
++
+All URLs are normalized before attempting any matching (the password part,
+if embedded in the URL, is always ignored for matching purposes) so that
+equivalent URLs that are simply spelled differently will match properly.
+Environment variable settings always override any matches.  The URLs that are
+matched against are those given directly to Git commands.  This means any URLs
+visited as a result of a redirection do not participate in matching.
diff --git a/third_party/git/Documentation/config/i18n.txt b/third_party/git/Documentation/config/i18n.txt
new file mode 100644
index 0000000000..cc25621731
--- /dev/null
+++ b/third_party/git/Documentation/config/i18n.txt
@@ -0,0 +1,10 @@
+i18n.commitEncoding::
+	Character encoding the commit messages are stored in; Git itself
+	does not care per se, but this information is necessary e.g. when
+	importing commits from emails or in the gitk graphical history
+	browser (and possibly at other places in the future or in other
+	porcelains). See e.g. linkgit:git-mailinfo[1]. Defaults to 'utf-8'.
+
+i18n.logOutputEncoding::
+	Character encoding the commit messages are converted to when
+	running 'git log' and friends.
diff --git a/third_party/git/Documentation/config/imap.txt b/third_party/git/Documentation/config/imap.txt
new file mode 100644
index 0000000000..06166fb5c0
--- /dev/null
+++ b/third_party/git/Documentation/config/imap.txt
@@ -0,0 +1,44 @@
+imap.folder::
+	The folder to drop the mails into, which is typically the Drafts
+	folder. For example: "INBOX.Drafts", "INBOX/Drafts" or
+	"[Gmail]/Drafts". Required.
+
+imap.tunnel::
+	Command used to setup a tunnel to the IMAP server through which
+	commands will be piped instead of using a direct network connection
+	to the server. Required when imap.host is not set.
+
+imap.host::
+	A URL identifying the server. Use an `imap://` prefix for non-secure
+	connections and an `imaps://` prefix for secure connections.
+	Ignored when imap.tunnel is set, but required otherwise.
+
+imap.user::
+	The username to use when logging in to the server.
+
+imap.pass::
+	The password to use when logging in to the server.
+
+imap.port::
+	An integer port number to connect to on the server.
+	Defaults to 143 for imap:// hosts and 993 for imaps:// hosts.
+	Ignored when imap.tunnel is set.
+
+imap.sslverify::
+	A boolean to enable/disable verification of the server certificate
+	used by the SSL/TLS connection. Default is `true`. Ignored when
+	imap.tunnel is set.
+
+imap.preformattedHTML::
+	A boolean to enable/disable the use of html encoding when sending
+	a patch.  An html encoded patch will be bracketed with <pre>
+	and have a content type of text/html.  Ironically, enabling this
+	option causes Thunderbird to send the patch as a plain/text,
+	format=fixed email.  Default is `false`.
+
+imap.authMethod::
+	Specify authenticate method for authentication with IMAP server.
+	If Git was built with the NO_CURL option, or if your curl version is older
+	than 7.34.0, or if you're running git-imap-send with the `--no-curl`
+	option, the only supported method is 'CRAM-MD5'. If this is not set
+	then 'git imap-send' uses the basic IMAP plaintext LOGIN command.
diff --git a/third_party/git/Documentation/config/index.txt b/third_party/git/Documentation/config/index.txt
new file mode 100644
index 0000000000..f181503041
--- /dev/null
+++ b/third_party/git/Documentation/config/index.txt
@@ -0,0 +1,26 @@
+index.recordEndOfIndexEntries::
+	Specifies whether the index file should include an "End Of Index
+	Entry" section. This reduces index load time on multiprocessor
+	machines but produces a message "ignoring EOIE extension" when
+	reading the index using Git versions before 2.20. Defaults to
+	'true' if index.threads has been explicitly enabled, 'false'
+	otherwise.
+
+index.recordOffsetTable::
+	Specifies whether the index file should include an "Index Entry
+	Offset Table" section. This reduces index load time on
+	multiprocessor machines but produces a message "ignoring IEOT
+	extension" when reading the index using Git versions before 2.20.
+	Defaults to 'true' if index.threads has been explicitly enabled,
+	'false' otherwise.
+
+index.threads::
+	Specifies the number of threads to spawn when loading the index.
+	This is meant to reduce index load time on multiprocessor machines.
+	Specifying 0 or 'true' will cause Git to auto-detect the number of
+	CPU's and set the number of threads accordingly. Specifying 1 or
+	'false' will disable multithreading. Defaults to 'true'.
+
+index.version::
+	Specify the version with which new index files should be
+	initialized.  This does not affect existing repositories.
diff --git a/third_party/git/Documentation/config/init.txt b/third_party/git/Documentation/config/init.txt
new file mode 100644
index 0000000000..46fa8c6a08
--- /dev/null
+++ b/third_party/git/Documentation/config/init.txt
@@ -0,0 +1,3 @@
+init.templateDir::
+	Specify the directory from which templates will be copied.
+	(See the "TEMPLATE DIRECTORY" section of linkgit:git-init[1].)
diff --git a/third_party/git/Documentation/config/instaweb.txt b/third_party/git/Documentation/config/instaweb.txt
new file mode 100644
index 0000000000..50cb2f7d62
--- /dev/null
+++ b/third_party/git/Documentation/config/instaweb.txt
@@ -0,0 +1,20 @@
+instaweb.browser::
+	Specify the program that will be used to browse your working
+	repository in gitweb. See linkgit:git-instaweb[1].
+
+instaweb.httpd::
+	The HTTP daemon command-line to start gitweb on your working
+	repository. See linkgit:git-instaweb[1].
+
+instaweb.local::
+	If true the web server started by linkgit:git-instaweb[1] will
+	be bound to the local IP (127.0.0.1).
+
+instaweb.modulePath::
+	The default module path for linkgit:git-instaweb[1] to use
+	instead of /usr/lib/apache2/modules.  Only used if httpd
+	is Apache.
+
+instaweb.port::
+	The port number to bind the gitweb httpd to. See
+	linkgit:git-instaweb[1].
diff --git a/third_party/git/Documentation/config/interactive.txt b/third_party/git/Documentation/config/interactive.txt
new file mode 100644
index 0000000000..a2d3c7ec44
--- /dev/null
+++ b/third_party/git/Documentation/config/interactive.txt
@@ -0,0 +1,17 @@
+interactive.singleKey::
+	In interactive commands, allow the user to provide one-letter
+	input with a single key (i.e., without hitting enter).
+	Currently this is used by the `--patch` mode of
+	linkgit:git-add[1], linkgit:git-checkout[1],
+	linkgit:git-restore[1], linkgit:git-commit[1],
+	linkgit:git-reset[1], and linkgit:git-stash[1]. Note that this
+	setting is silently ignored if portable keystroke input
+	is not available; requires the Perl module Term::ReadKey.
+
+interactive.diffFilter::
+	When an interactive command (such as `git add --patch`) shows
+	a colorized diff, git will pipe the diff through the shell
+	command defined by this configuration variable. The command may
+	mark up the diff further for human consumption, provided that it
+	retains a one-to-one correspondence with the lines in the
+	original diff. Defaults to disabled (no filtering).
diff --git a/third_party/git/Documentation/config/log.txt b/third_party/git/Documentation/config/log.txt
new file mode 100644
index 0000000000..e9e1e397f3
--- /dev/null
+++ b/third_party/git/Documentation/config/log.txt
@@ -0,0 +1,44 @@
+log.abbrevCommit::
+	If true, makes linkgit:git-log[1], linkgit:git-show[1], and
+	linkgit:git-whatchanged[1] assume `--abbrev-commit`. You may
+	override this option with `--no-abbrev-commit`.
+
+log.date::
+	Set the default date-time mode for the 'log' command.
+	Setting a value for log.date is similar to using 'git log''s
+	`--date` option.  See linkgit:git-log[1] for details.
+
+log.decorate::
+	Print out the ref names of any commits that are shown by the log
+	command. If 'short' is specified, the ref name prefixes 'refs/heads/',
+	'refs/tags/' and 'refs/remotes/' will not be printed. If 'full' is
+	specified, the full ref name (including prefix) will be printed.
+	If 'auto' is specified, then if the output is going to a terminal,
+	the ref names are shown as if 'short' were given, otherwise no ref
+	names are shown. This is the same as the `--decorate` option
+	of the `git log`.
+
+log.follow::
+	If `true`, `git log` will act as if the `--follow` option was used when
+	a single <path> is given.  This has the same limitations as `--follow`,
+	i.e. it cannot be used to follow multiple files and does not work well
+	on non-linear history.
+
+log.graphColors::
+	A list of colors, separated by commas, that can be used to draw
+	history lines in `git log --graph`.
+
+log.showRoot::
+	If true, the initial commit will be shown as a big creation event.
+	This is equivalent to a diff against an empty tree.
+	Tools like linkgit:git-log[1] or linkgit:git-whatchanged[1], which
+	normally hide the root commit will now show it. True by default.
+
+log.showSignature::
+	If true, makes linkgit:git-log[1], linkgit:git-show[1], and
+	linkgit:git-whatchanged[1] assume `--show-signature`.
+
+log.mailmap::
+	If true, makes linkgit:git-log[1], linkgit:git-show[1], and
+	linkgit:git-whatchanged[1] assume `--use-mailmap`, otherwise
+	assume `--no-use-mailmap`. True by default.
diff --git a/third_party/git/Documentation/config/mailinfo.txt b/third_party/git/Documentation/config/mailinfo.txt
new file mode 100644
index 0000000000..3854d4ae37
--- /dev/null
+++ b/third_party/git/Documentation/config/mailinfo.txt
@@ -0,0 +1,6 @@
+mailinfo.scissors::
+	If true, makes linkgit:git-mailinfo[1] (and therefore
+	linkgit:git-am[1]) act by default as if the --scissors option
+	was provided on the command-line. When active, this features
+	removes everything from the message body before a scissors
+	line (i.e. consisting mainly of ">8", "8<" and "-").
diff --git a/third_party/git/Documentation/config/mailmap.txt b/third_party/git/Documentation/config/mailmap.txt
new file mode 100644
index 0000000000..48cbc30722
--- /dev/null
+++ b/third_party/git/Documentation/config/mailmap.txt
@@ -0,0 +1,15 @@
+mailmap.file::
+	The location of an augmenting mailmap file. The default
+	mailmap, located in the root of the repository, is loaded
+	first, then the mailmap file pointed to by this variable.
+	The location of the mailmap file may be in a repository
+	subdirectory, or somewhere outside of the repository itself.
+	See linkgit:git-shortlog[1] and linkgit:git-blame[1].
+
+mailmap.blob::
+	Like `mailmap.file`, but consider the value as a reference to a
+	blob in the repository. If both `mailmap.file` and
+	`mailmap.blob` are given, both are parsed, with entries from
+	`mailmap.file` taking precedence. In a bare repository, this
+	defaults to `HEAD:.mailmap`. In a non-bare repository, it
+	defaults to empty.
diff --git a/third_party/git/Documentation/config/man.txt b/third_party/git/Documentation/config/man.txt
new file mode 100644
index 0000000000..a727d987a8
--- /dev/null
+++ b/third_party/git/Documentation/config/man.txt
@@ -0,0 +1,12 @@
+man.viewer::
+	Specify the programs that may be used to display help in the
+	'man' format. See linkgit:git-help[1].
+
+man.<tool>.cmd::
+	Specify the command to invoke the specified man viewer. The
+	specified command is evaluated in shell with the man page
+	passed as argument. (See linkgit:git-help[1].)
+
+man.<tool>.path::
+	Override the path for the given tool that may be used to
+	display help in the 'man' format. See linkgit:git-help[1].
diff --git a/third_party/git/Documentation/config/merge.txt b/third_party/git/Documentation/config/merge.txt
new file mode 100644
index 0000000000..6a313937f8
--- /dev/null
+++ b/third_party/git/Documentation/config/merge.txt
@@ -0,0 +1,106 @@
+merge.conflictStyle::
+	Specify the style in which conflicted hunks are written out to
+	working tree files upon merge.  The default is "merge", which
+	shows a `<<<<<<<` conflict marker, changes made by one side,
+	a `=======` marker, changes made by the other side, and then
+	a `>>>>>>>` marker.  An alternate style, "diff3", adds a `|||||||`
+	marker and the original text before the `=======` marker.
+
+merge.defaultToUpstream::
+	If merge is called without any commit argument, merge the upstream
+	branches configured for the current branch by using their last
+	observed values stored in their remote-tracking branches.
+	The values of the `branch.<current branch>.merge` that name the
+	branches at the remote named by `branch.<current branch>.remote`
+	are consulted, and then they are mapped via `remote.<remote>.fetch`
+	to their corresponding remote-tracking branches, and the tips of
+	these tracking branches are merged.
+
+merge.ff::
+	By default, Git does not create an extra merge commit when merging
+	a commit that is a descendant of the current commit. Instead, the
+	tip of the current branch is fast-forwarded. When set to `false`,
+	this variable tells Git to create an extra merge commit in such
+	a case (equivalent to giving the `--no-ff` option from the command
+	line). When set to `only`, only such fast-forward merges are
+	allowed (equivalent to giving the `--ff-only` option from the
+	command line).
+
+merge.verifySignatures::
+	If true, this is equivalent to the --verify-signatures command
+	line option. See linkgit:git-merge[1] for details.
+
+include::fmt-merge-msg.txt[]
+
+merge.renameLimit::
+	The number of files to consider when performing rename detection
+	during a merge; if not specified, defaults to the value of
+	diff.renameLimit. This setting has no effect if rename detection
+	is turned off.
+
+merge.renames::
+	Whether Git detects renames.  If set to "false", rename detection
+	is disabled. If set to "true", basic rename detection is enabled.
+	Defaults to the value of diff.renames.
+
+merge.directoryRenames::
+	Whether Git detects directory renames, affecting what happens at
+	merge time to new files added to a directory on one side of
+	history when that directory was renamed on the other side of
+	history.  If merge.directoryRenames is set to "false", directory
+	rename detection is disabled, meaning that such new files will be
+	left behind in the old directory.  If set to "true", directory
+	rename detection is enabled, meaning that such new files will be
+	moved into the new directory.  If set to "conflict", a conflict
+	will be reported for such paths.  If merge.renames is false,
+	merge.directoryRenames is ignored and treated as false.  Defaults
+	to "conflict".
+
+merge.renormalize::
+	Tell Git that canonical representation of files in the
+	repository has changed over time (e.g. earlier commits record
+	text files with CRLF line endings, but recent ones use LF line
+	endings).  In such a repository, Git can convert the data
+	recorded in commits to a canonical form before performing a
+	merge to reduce unnecessary conflicts.  For more information,
+	see section "Merging branches with differing checkin/checkout
+	attributes" in linkgit:gitattributes[5].
+
+merge.stat::
+	Whether to print the diffstat between ORIG_HEAD and the merge result
+	at the end of the merge.  True by default.
+
+merge.tool::
+	Controls which merge tool is used by linkgit:git-mergetool[1].
+	The list below shows the valid built-in values.
+	Any other value is treated as a custom merge tool and requires
+	that a corresponding mergetool.<tool>.cmd variable is defined.
+
+merge.guitool::
+	Controls which merge tool is used by linkgit:git-mergetool[1] when the
+	-g/--gui flag is specified. The list below shows the valid built-in values.
+	Any other value is treated as a custom merge tool and requires that a
+	corresponding mergetool.<guitool>.cmd variable is defined.
+
+include::../mergetools-merge.txt[]
+
+merge.verbosity::
+	Controls the amount of output shown by the recursive merge
+	strategy.  Level 0 outputs nothing except a final error
+	message if conflicts were detected. Level 1 outputs only
+	conflicts, 2 outputs conflicts and file changes.  Level 5 and
+	above outputs debugging information.  The default is level 2.
+	Can be overridden by the `GIT_MERGE_VERBOSITY` environment variable.
+
+merge.<driver>.name::
+	Defines a human-readable name for a custom low-level
+	merge driver.  See linkgit:gitattributes[5] for details.
+
+merge.<driver>.driver::
+	Defines the command that implements a custom low-level
+	merge driver.  See linkgit:gitattributes[5] for details.
+
+merge.<driver>.recursive::
+	Names a low-level merge driver to be used when
+	performing an internal merge between common ancestors.
+	See linkgit:gitattributes[5] for details.
diff --git a/third_party/git/Documentation/config/mergetool.txt b/third_party/git/Documentation/config/mergetool.txt
new file mode 100644
index 0000000000..09ed31dbfa
--- /dev/null
+++ b/third_party/git/Documentation/config/mergetool.txt
@@ -0,0 +1,53 @@
+mergetool.<tool>.path::
+	Override the path for the given tool.  This is useful in case
+	your tool is not in the PATH.
+
+mergetool.<tool>.cmd::
+	Specify the command to invoke the specified merge tool.  The
+	specified command is evaluated in shell with the following
+	variables available: 'BASE' is the name of a temporary file
+	containing the common base of the files to be merged, if available;
+	'LOCAL' is the name of a temporary file containing the contents of
+	the file on the current branch; 'REMOTE' is the name of a temporary
+	file containing the contents of the file from the branch being
+	merged; 'MERGED' contains the name of the file to which the merge
+	tool should write the results of a successful merge.
+
+mergetool.<tool>.trustExitCode::
+	For a custom merge command, specify whether the exit code of
+	the merge command can be used to determine whether the merge was
+	successful.  If this is not set to true then the merge target file
+	timestamp is checked and the merge assumed to have been successful
+	if the file has been updated, otherwise the user is prompted to
+	indicate the success of the merge.
+
+mergetool.meld.hasOutput::
+	Older versions of `meld` do not support the `--output` option.
+	Git will attempt to detect whether `meld` supports `--output`
+	by inspecting the output of `meld --help`.  Configuring
+	`mergetool.meld.hasOutput` will make Git skip these checks and
+	use the configured value instead.  Setting `mergetool.meld.hasOutput`
+	to `true` tells Git to unconditionally use the `--output` option,
+	and `false` avoids using `--output`.
+
+mergetool.keepBackup::
+	After performing a merge, the original file with conflict markers
+	can be saved as a file with a `.orig` extension.  If this variable
+	is set to `false` then this file is not preserved.  Defaults to
+	`true` (i.e. keep the backup files).
+
+mergetool.keepTemporaries::
+	When invoking a custom merge tool, Git uses a set of temporary
+	files to pass to the tool. If the tool returns an error and this
+	variable is set to `true`, then these temporary files will be
+	preserved, otherwise they will be removed after the tool has
+	exited. Defaults to `false`.
+
+mergetool.writeToTemp::
+	Git writes temporary 'BASE', 'LOCAL', and 'REMOTE' versions of
+	conflicting files in the worktree by default.  Git will attempt
+	to use a temporary directory for these files when set `true`.
+	Defaults to `false`.
+
+mergetool.prompt::
+	Prompt before each invocation of the merge resolution program.
diff --git a/third_party/git/Documentation/config/notes.txt b/third_party/git/Documentation/config/notes.txt
new file mode 100644
index 0000000000..aeef56d49a
--- /dev/null
+++ b/third_party/git/Documentation/config/notes.txt
@@ -0,0 +1,59 @@
+notes.mergeStrategy::
+	Which merge strategy to choose by default when resolving notes
+	conflicts.  Must be one of `manual`, `ours`, `theirs`, `union`, or
+	`cat_sort_uniq`.  Defaults to `manual`.  See "NOTES MERGE STRATEGIES"
+	section of linkgit:git-notes[1] for more information on each strategy.
+
+notes.<name>.mergeStrategy::
+	Which merge strategy to choose when doing a notes merge into
+	refs/notes/<name>.  This overrides the more general
+	"notes.mergeStrategy".  See the "NOTES MERGE STRATEGIES" section in
+	linkgit:git-notes[1] for more information on the available strategies.
+
+notes.displayRef::
+	The (fully qualified) refname from which to show notes when
+	showing commit messages.  The value of this variable can be set
+	to a glob, in which case notes from all matching refs will be
+	shown.  You may also specify this configuration variable
+	several times.  A warning will be issued for refs that do not
+	exist, but a glob that does not match any refs is silently
+	ignored.
++
+This setting can be overridden with the `GIT_NOTES_DISPLAY_REF`
+environment variable, which must be a colon separated list of refs or
+globs.
++
+The effective value of "core.notesRef" (possibly overridden by
+GIT_NOTES_REF) is also implicitly added to the list of refs to be
+displayed.
+
+notes.rewrite.<command>::
+	When rewriting commits with <command> (currently `amend` or
+	`rebase`) and this variable is set to `true`, Git
+	automatically copies your notes from the original to the
+	rewritten commit.  Defaults to `true`, but see
+	"notes.rewriteRef" below.
+
+notes.rewriteMode::
+	When copying notes during a rewrite (see the
+	"notes.rewrite.<command>" option), determines what to do if
+	the target commit already has a note.  Must be one of
+	`overwrite`, `concatenate`, `cat_sort_uniq`, or `ignore`.
+	Defaults to `concatenate`.
++
+This setting can be overridden with the `GIT_NOTES_REWRITE_MODE`
+environment variable.
+
+notes.rewriteRef::
+	When copying notes during a rewrite, specifies the (fully
+	qualified) ref whose notes should be copied.  The ref may be a
+	glob, in which case notes in all matching refs will be copied.
+	You may also specify this configuration several times.
++
+Does not have a default value; you must configure this variable to
+enable note rewriting.  Set it to `refs/notes/commits` to enable
+rewriting for the default commit notes.
++
+This setting can be overridden with the `GIT_NOTES_REWRITE_REF`
+environment variable, which must be a colon separated list of refs or
+globs.
diff --git a/third_party/git/Documentation/config/pack.txt b/third_party/git/Documentation/config/pack.txt
new file mode 100644
index 0000000000..9cdcfa7324
--- /dev/null
+++ b/third_party/git/Documentation/config/pack.txt
@@ -0,0 +1,127 @@
+pack.window::
+	The size of the window used by linkgit:git-pack-objects[1] when no
+	window size is given on the command line. Defaults to 10.
+
+pack.depth::
+	The maximum delta depth used by linkgit:git-pack-objects[1] when no
+	maximum depth is given on the command line. Defaults to 50.
+	Maximum value is 4095.
+
+pack.windowMemory::
+	The maximum size of memory that is consumed by each thread
+	in linkgit:git-pack-objects[1] for pack window memory when
+	no limit is given on the command line.  The value can be
+	suffixed with "k", "m", or "g".  When left unconfigured (or
+	set explicitly to 0), there will be no limit.
+
+pack.compression::
+	An integer -1..9, indicating the compression level for objects
+	in a pack file. -1 is the zlib default. 0 means no
+	compression, and 1..9 are various speed/size tradeoffs, 9 being
+	slowest.  If not set,  defaults to core.compression.  If that is
+	not set,  defaults to -1, the zlib default, which is "a default
+	compromise between speed and compression (currently equivalent
+	to level 6)."
++
+Note that changing the compression level will not automatically recompress
+all existing objects. You can force recompression by passing the -F option
+to linkgit:git-repack[1].
+
+pack.island::
+	An extended regular expression configuring a set of delta
+	islands. See "DELTA ISLANDS" in linkgit:git-pack-objects[1]
+	for details.
+
+pack.islandCore::
+	Specify an island name which gets to have its objects be
+	packed first. This creates a kind of pseudo-pack at the front
+	of one pack, so that the objects from the specified island are
+	hopefully faster to copy into any pack that should be served
+	to a user requesting these objects. In practice this means
+	that the island specified should likely correspond to what is
+	the most commonly cloned in the repo. See also "DELTA ISLANDS"
+	in linkgit:git-pack-objects[1].
+
+pack.deltaCacheSize::
+	The maximum memory in bytes used for caching deltas in
+	linkgit:git-pack-objects[1] before writing them out to a pack.
+	This cache is used to speed up the writing object phase by not
+	having to recompute the final delta result once the best match
+	for all objects is found.  Repacking large repositories on machines
+	which are tight with memory might be badly impacted by this though,
+	especially if this cache pushes the system into swapping.
+	A value of 0 means no limit. The smallest size of 1 byte may be
+	used to virtually disable this cache. Defaults to 256 MiB.
+
+pack.deltaCacheLimit::
+	The maximum size of a delta, that is cached in
+	linkgit:git-pack-objects[1]. This cache is used to speed up the
+	writing object phase by not having to recompute the final delta
+	result once the best match for all objects is found.
+	Defaults to 1000. Maximum value is 65535.
+
+pack.threads::
+	Specifies the number of threads to spawn when searching for best
+	delta matches.  This requires that linkgit:git-pack-objects[1]
+	be compiled with pthreads otherwise this option is ignored with a
+	warning. This is meant to reduce packing time on multiprocessor
+	machines. The required amount of memory for the delta search window
+	is however multiplied by the number of threads.
+	Specifying 0 will cause Git to auto-detect the number of CPU's
+	and set the number of threads accordingly.
+
+pack.indexVersion::
+	Specify the default pack index version.  Valid values are 1 for
+	legacy pack index used by Git versions prior to 1.5.2, and 2 for
+	the new pack index with capabilities for packs larger than 4 GB
+	as well as proper protection against the repacking of corrupted
+	packs.  Version 2 is the default.  Note that version 2 is enforced
+	and this config option ignored whenever the corresponding pack is
+	larger than 2 GB.
++
+If you have an old Git that does not understand the version 2 `*.idx` file,
+cloning or fetching over a non native protocol (e.g. "http")
+that will copy both `*.pack` file and corresponding `*.idx` file from the
+other side may give you a repository that cannot be accessed with your
+older version of Git. If the `*.pack` file is smaller than 2 GB, however,
+you can use linkgit:git-index-pack[1] on the *.pack file to regenerate
+the `*.idx` file.
+
+pack.packSizeLimit::
+	The maximum size of a pack.  This setting only affects
+	packing to a file when repacking, i.e. the git:// protocol
+	is unaffected.  It can be overridden by the `--max-pack-size`
+	option of linkgit:git-repack[1].  Reaching this limit results
+	in the creation of multiple packfiles; which in turn prevents
+	bitmaps from being created.
+	The minimum size allowed is limited to 1 MiB.
+	The default is unlimited.
+	Common unit suffixes of 'k', 'm', or 'g' are
+	supported.
+
+pack.useBitmaps::
+	When true, git will use pack bitmaps (if available) when packing
+	to stdout (e.g., during the server side of a fetch). Defaults to
+	true. You should not generally need to turn this off unless
+	you are debugging pack bitmaps.
+
+pack.useSparse::
+	When true, git will default to using the '--sparse' option in
+	'git pack-objects' when the '--revs' option is present. This
+	algorithm only walks trees that appear in paths that introduce new
+	objects. This can have significant performance benefits when
+	computing a pack to send a small change. However, it is possible
+	that extra objects are added to the pack-file if the included
+	commits contain certain types of direct renames.
+
+pack.writeBitmaps (deprecated)::
+	This is a deprecated synonym for `repack.writeBitmaps`.
+
+pack.writeBitmapHashCache::
+	When true, git will include a "hash cache" section in the bitmap
+	index (if one is written). This cache can be used to feed git's
+	delta heuristics, potentially leading to better deltas between
+	bitmapped and non-bitmapped objects (e.g., when serving a fetch
+	between an older, bitmapped pack and objects that have been
+	pushed since the last gc). The downside is that it consumes 4
+	bytes per object of disk space. Defaults to true.
diff --git a/third_party/git/Documentation/config/pager.txt b/third_party/git/Documentation/config/pager.txt
new file mode 100644
index 0000000000..d3731cf66c
--- /dev/null
+++ b/third_party/git/Documentation/config/pager.txt
@@ -0,0 +1,8 @@
+pager.<cmd>::
+	If the value is boolean, turns on or off pagination of the
+	output of a particular Git subcommand when writing to a tty.
+	Otherwise, turns on pagination for the subcommand using the
+	pager specified by the value of `pager.<cmd>`.  If `--paginate`
+	or `--no-pager` is specified on the command line, it takes
+	precedence over this option.  To disable pagination for all
+	commands, set `core.pager` or `GIT_PAGER` to `cat`.
diff --git a/third_party/git/Documentation/config/pretty.txt b/third_party/git/Documentation/config/pretty.txt
new file mode 100644
index 0000000000..063c6b63d9
--- /dev/null
+++ b/third_party/git/Documentation/config/pretty.txt
@@ -0,0 +1,9 @@
+pretty.<name>::
+	Alias for a --pretty= format string, as specified in
+	linkgit:git-log[1]. Any aliases defined here can be used just
+	as the built-in pretty formats could. For example,
+	running `git config pretty.changelog "format:* %H %s"`
+	would cause the invocation `git log --pretty=changelog`
+	to be equivalent to running `git log "--pretty=format:* %H %s"`.
+	Note that an alias with the same name as a built-in format
+	will be silently ignored.
diff --git a/third_party/git/Documentation/config/protocol.txt b/third_party/git/Documentation/config/protocol.txt
new file mode 100644
index 0000000000..bfccc07491
--- /dev/null
+++ b/third_party/git/Documentation/config/protocol.txt
@@ -0,0 +1,64 @@
+protocol.allow::
+	If set, provide a user defined default policy for all protocols which
+	don't explicitly have a policy (`protocol.<name>.allow`).  By default,
+	if unset, known-safe protocols (http, https, git, ssh, file) have a
+	default policy of `always`, known-dangerous protocols (ext) have a
+	default policy of `never`, and all other protocols have a default
+	policy of `user`.  Supported policies:
++
+--
+
+* `always` - protocol is always able to be used.
+
+* `never` - protocol is never able to be used.
+
+* `user` - protocol is only able to be used when `GIT_PROTOCOL_FROM_USER` is
+  either unset or has a value of 1.  This policy should be used when you want a
+  protocol to be directly usable by the user but don't want it used by commands which
+  execute clone/fetch/push commands without user input, e.g. recursive
+  submodule initialization.
+
+--
+
+protocol.<name>.allow::
+	Set a policy to be used by protocol `<name>` with clone/fetch/push
+	commands. See `protocol.allow` above for the available policies.
++
+The protocol names currently used by git are:
++
+--
+  - `file`: any local file-based path (including `file://` URLs,
+    or local paths)
+
+  - `git`: the anonymous git protocol over a direct TCP
+    connection (or proxy, if configured)
+
+  - `ssh`: git over ssh (including `host:path` syntax,
+    `ssh://`, etc).
+
+  - `http`: git over http, both "smart http" and "dumb http".
+    Note that this does _not_ include `https`; if you want to configure
+    both, you must do so individually.
+
+  - any external helpers are named by their protocol (e.g., use
+    `hg` to allow the `git-remote-hg` helper)
+--
+
+protocol.version::
+	Experimental. If set, clients will attempt to communicate with a
+	server using the specified protocol version.  If unset, no
+	attempt will be made by the client to communicate using a
+	particular protocol version, this results in protocol version 0
+	being used.
+	Supported versions:
++
+--
+
+* `0` - the original wire protocol.
+
+* `1` - the original wire protocol with the addition of a version string
+  in the initial response from the server.
+
+* `2` - link:technical/protocol-v2.html[wire protocol version 2].
+
+--
diff --git a/third_party/git/Documentation/config/pull.txt b/third_party/git/Documentation/config/pull.txt
new file mode 100644
index 0000000000..b87cab31b3
--- /dev/null
+++ b/third_party/git/Documentation/config/pull.txt
@@ -0,0 +1,36 @@
+pull.ff::
+	By default, Git does not create an extra merge commit when merging
+	a commit that is a descendant of the current commit. Instead, the
+	tip of the current branch is fast-forwarded. When set to `false`,
+	this variable tells Git to create an extra merge commit in such
+	a case (equivalent to giving the `--no-ff` option from the command
+	line). When set to `only`, only such fast-forward merges are
+	allowed (equivalent to giving the `--ff-only` option from the
+	command line). This setting overrides `merge.ff` when pulling.
+
+pull.rebase::
+	When true, rebase branches on top of the fetched branch, instead
+	of merging the default branch from the default remote when "git
+	pull" is run. See "branch.<name>.rebase" for setting this on a
+	per-branch basis.
++
+When `merges`, pass the `--rebase-merges` option to 'git rebase'
+so that the local merge commits are included in the rebase (see
+linkgit:git-rebase[1] for details).
++
+When `preserve` (deprecated in favor of `merges`), also pass
+`--preserve-merges` along to 'git rebase' so that locally committed merge
+commits will not be flattened by running 'git pull'.
++
+When the value is `interactive`, the rebase is run in interactive mode.
++
+*NOTE*: this is a possibly dangerous operation; do *not* use
+it unless you understand the implications (see linkgit:git-rebase[1]
+for details).
+
+pull.octopus::
+	The default merge strategy to use when pulling multiple branches
+	at once.
+
+pull.twohead::
+	The default merge strategy to use when pulling a single branch.
diff --git a/third_party/git/Documentation/config/push.txt b/third_party/git/Documentation/config/push.txt
new file mode 100644
index 0000000000..0a0e000569
--- /dev/null
+++ b/third_party/git/Documentation/config/push.txt
@@ -0,0 +1,113 @@
+push.default::
+	Defines the action `git push` should take if no refspec is
+	explicitly given.  Different values are well-suited for
+	specific workflows; for instance, in a purely central workflow
+	(i.e. the fetch source is equal to the push destination),
+	`upstream` is probably what you want.  Possible values are:
++
+--
+
+* `nothing` - do not push anything (error out) unless a refspec is
+  explicitly given. This is primarily meant for people who want to
+  avoid mistakes by always being explicit.
+
+* `current` - push the current branch to update a branch with the same
+  name on the receiving end.  Works in both central and non-central
+  workflows.
+
+* `upstream` - push the current branch back to the branch whose
+  changes are usually integrated into the current branch (which is
+  called `@{upstream}`).  This mode only makes sense if you are
+  pushing to the same repository you would normally pull from
+  (i.e. central workflow).
+
+* `tracking` - This is a deprecated synonym for `upstream`.
+
+* `simple` - in centralized workflow, work like `upstream` with an
+  added safety to refuse to push if the upstream branch's name is
+  different from the local one.
++
+When pushing to a remote that is different from the remote you normally
+pull from, work as `current`.  This is the safest option and is suited
+for beginners.
++
+This mode has become the default in Git 2.0.
+
+* `matching` - push all branches having the same name on both ends.
+  This makes the repository you are pushing to remember the set of
+  branches that will be pushed out (e.g. if you always push 'maint'
+  and 'master' there and no other branches, the repository you push
+  to will have these two branches, and your local 'maint' and
+  'master' will be pushed there).
++
+To use this mode effectively, you have to make sure _all_ the
+branches you would push out are ready to be pushed out before
+running 'git push', as the whole point of this mode is to allow you
+to push all of the branches in one go.  If you usually finish work
+on only one branch and push out the result, while other branches are
+unfinished, this mode is not for you.  Also this mode is not
+suitable for pushing into a shared central repository, as other
+people may add new branches there, or update the tip of existing
+branches outside your control.
++
+This used to be the default, but not since Git 2.0 (`simple` is the
+new default).
+
+--
+
+push.followTags::
+	If set to true enable `--follow-tags` option by default.  You
+	may override this configuration at time of push by specifying
+	`--no-follow-tags`.
+
+push.gpgSign::
+	May be set to a boolean value, or the string 'if-asked'. A true
+	value causes all pushes to be GPG signed, as if `--signed` is
+	passed to linkgit:git-push[1]. The string 'if-asked' causes
+	pushes to be signed if the server supports it, as if
+	`--signed=if-asked` is passed to 'git push'. A false value may
+	override a value from a lower-priority config file. An explicit
+	command-line flag always overrides this config option.
+
+push.pushOption::
+	When no `--push-option=<option>` argument is given from the
+	command line, `git push` behaves as if each <value> of
+	this variable is given as `--push-option=<value>`.
++
+This is a multi-valued variable, and an empty value can be used in a
+higher priority configuration file (e.g. `.git/config` in a
+repository) to clear the values inherited from a lower priority
+configuration files (e.g. `$HOME/.gitconfig`).
++
+--
+
+Example:
+
+/etc/gitconfig
+  push.pushoption = a
+  push.pushoption = b
+
+~/.gitconfig
+  push.pushoption = c
+
+repo/.git/config
+  push.pushoption =
+  push.pushoption = b
+
+This will result in only b (a and c are cleared).
+
+--
+
+push.recurseSubmodules::
+	Make sure all submodule commits used by the revisions to be pushed
+	are available on a remote-tracking branch. If the value is 'check'
+	then Git will verify that all submodule commits that changed in the
+	revisions to be pushed are available on at least one remote of the
+	submodule. If any commits are missing, the push will be aborted and
+	exit with non-zero status. If the value is 'on-demand' then all
+	submodules that changed in the revisions to be pushed will be
+	pushed. If on-demand was not able to push all necessary revisions
+	it will also be aborted and exit with non-zero status. If the value
+	is 'no' then default behavior of ignoring submodules when pushing
+	is retained. You may override this configuration at time of push by
+	specifying '--recurse-submodules=check|on-demand|no'.
diff --git a/third_party/git/Documentation/config/rebase.txt b/third_party/git/Documentation/config/rebase.txt
new file mode 100644
index 0000000000..d98e32d812
--- /dev/null
+++ b/third_party/git/Documentation/config/rebase.txt
@@ -0,0 +1,64 @@
+rebase.useBuiltin::
+	Unused configuration variable. Used in Git versions 2.20 and
+	2.21 as an escape hatch to enable the legacy shellscript
+	implementation of rebase. Now the built-in rewrite of it in C
+	is always used. Setting this will emit a warning, to alert any
+	remaining users that setting this now does nothing.
+
+rebase.stat::
+	Whether to show a diffstat of what changed upstream since the last
+	rebase. False by default.
+
+rebase.autoSquash::
+	If set to true enable `--autosquash` option by default.
+
+rebase.autoStash::
+	When set to true, automatically create a temporary stash entry
+	before the operation begins, and apply it after the operation
+	ends.  This means that you can run rebase on a dirty worktree.
+	However, use with care: the final stash application after a
+	successful rebase might result in non-trivial conflicts.
+	This option can be overridden by the `--no-autostash` and
+	`--autostash` options of linkgit:git-rebase[1].
+	Defaults to false.
+
+rebase.missingCommitsCheck::
+	If set to "warn", git rebase -i will print a warning if some
+	commits are removed (e.g. a line was deleted), however the
+	rebase will still proceed. If set to "error", it will print
+	the previous warning and stop the rebase, 'git rebase
+	--edit-todo' can then be used to correct the error. If set to
+	"ignore", no checking is done.
+	To drop a commit without warning or error, use the `drop`
+	command in the todo list.
+	Defaults to "ignore".
+
+rebase.instructionFormat::
+	A format string, as specified in linkgit:git-log[1], to be used for the
+	todo list during an interactive rebase.  The format will
+	automatically have the long commit hash prepended to the format.
+
+rebase.abbreviateCommands::
+	If set to true, `git rebase` will use abbreviated command names in the
+	todo list resulting in something like this:
++
+-------------------------------------------
+	p deadbee The oneline of the commit
+	p fa1afe1 The oneline of the next commit
+	...
+-------------------------------------------
++
+instead of:
++
+-------------------------------------------
+	pick deadbee The oneline of the commit
+	pick fa1afe1 The oneline of the next commit
+	...
+-------------------------------------------
++
+Defaults to false.
+
+rebase.rescheduleFailedExec::
+	Automatically reschedule `exec` commands that failed. This only makes
+	sense in interactive mode (or when an `--exec` option was provided).
+	This is the same as specifying the `--reschedule-failed-exec` option.
diff --git a/third_party/git/Documentation/config/receive.txt b/third_party/git/Documentation/config/receive.txt
new file mode 100644
index 0000000000..65f78aac37
--- /dev/null
+++ b/third_party/git/Documentation/config/receive.txt
@@ -0,0 +1,123 @@
+receive.advertiseAtomic::
+	By default, git-receive-pack will advertise the atomic push
+	capability to its clients. If you don't want to advertise this
+	capability, set this variable to false.
+
+receive.advertisePushOptions::
+	When set to true, git-receive-pack will advertise the push options
+	capability to its clients. False by default.
+
+receive.autogc::
+	By default, git-receive-pack will run "git-gc --auto" after
+	receiving data from git-push and updating refs.  You can stop
+	it by setting this variable to false.
+
+receive.certNonceSeed::
+	By setting this variable to a string, `git receive-pack`
+	will accept a `git push --signed` and verifies it by using
+	a "nonce" protected by HMAC using this string as a secret
+	key.
+
+receive.certNonceSlop::
+	When a `git push --signed` sent a push certificate with a
+	"nonce" that was issued by a receive-pack serving the same
+	repository within this many seconds, export the "nonce"
+	found in the certificate to `GIT_PUSH_CERT_NONCE` to the
+	hooks (instead of what the receive-pack asked the sending
+	side to include).  This may allow writing checks in
+	`pre-receive` and `post-receive` a bit easier.  Instead of
+	checking `GIT_PUSH_CERT_NONCE_SLOP` environment variable
+	that records by how many seconds the nonce is stale to
+	decide if they want to accept the certificate, they only
+	can check `GIT_PUSH_CERT_NONCE_STATUS` is `OK`.
+
+receive.fsckObjects::
+	If it is set to true, git-receive-pack will check all received
+	objects. See `transfer.fsckObjects` for what's checked.
+	Defaults to false. If not set, the value of
+	`transfer.fsckObjects` is used instead.
+
+receive.fsck.<msg-id>::
+	Acts like `fsck.<msg-id>`, but is used by
+	linkgit:git-receive-pack[1] instead of
+	linkgit:git-fsck[1]. See the `fsck.<msg-id>` documentation for
+	details.
+
+receive.fsck.skipList::
+	Acts like `fsck.skipList`, but is used by
+	linkgit:git-receive-pack[1] instead of
+	linkgit:git-fsck[1]. See the `fsck.skipList` documentation for
+	details.
+
+receive.keepAlive::
+	After receiving the pack from the client, `receive-pack` may
+	produce no output (if `--quiet` was specified) while processing
+	the pack, causing some networks to drop the TCP connection.
+	With this option set, if `receive-pack` does not transmit
+	any data in this phase for `receive.keepAlive` seconds, it will
+	send a short keepalive packet.  The default is 5 seconds; set
+	to 0 to disable keepalives entirely.
+
+receive.unpackLimit::
+	If the number of objects received in a push is below this
+	limit then the objects will be unpacked into loose object
+	files. However if the number of received objects equals or
+	exceeds this limit then the received pack will be stored as
+	a pack, after adding any missing delta bases.  Storing the
+	pack from a push can make the push operation complete faster,
+	especially on slow filesystems.  If not set, the value of
+	`transfer.unpackLimit` is used instead.
+
+receive.maxInputSize::
+	If the size of the incoming pack stream is larger than this
+	limit, then git-receive-pack will error out, instead of
+	accepting the pack file. If not set or set to 0, then the size
+	is unlimited.
+
+receive.denyDeletes::
+	If set to true, git-receive-pack will deny a ref update that deletes
+	the ref. Use this to prevent such a ref deletion via a push.
+
+receive.denyDeleteCurrent::
+	If set to true, git-receive-pack will deny a ref update that
+	deletes the currently checked out branch of a non-bare repository.
+
+receive.denyCurrentBranch::
+	If set to true or "refuse", git-receive-pack will deny a ref update
+	to the currently checked out branch of a non-bare repository.
+	Such a push is potentially dangerous because it brings the HEAD
+	out of sync with the index and working tree. If set to "warn",
+	print a warning of such a push to stderr, but allow the push to
+	proceed. If set to false or "ignore", allow such pushes with no
+	message. Defaults to "refuse".
++
+Another option is "updateInstead" which will update the working
+tree if pushing into the current branch.  This option is
+intended for synchronizing working directories when one side is not easily
+accessible via interactive ssh (e.g. a live web site, hence the requirement
+that the working directory be clean). This mode also comes in handy when
+developing inside a VM to test and fix code on different Operating Systems.
++
+By default, "updateInstead" will refuse the push if the working tree or
+the index have any difference from the HEAD, but the `push-to-checkout`
+hook can be used to customize this.  See linkgit:githooks[5].
+
+receive.denyNonFastForwards::
+	If set to true, git-receive-pack will deny a ref update which is
+	not a fast-forward. Use this to prevent such an update via a push,
+	even if that push is forced. This configuration variable is
+	set when initializing a shared repository.
+
+receive.hideRefs::
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `receive-pack` (and so affects pushes, but not fetches).
+	An attempt to update or delete a hidden ref by `git push` is
+	rejected.
+
+receive.updateServerInfo::
+	If set to true, git-receive-pack will run git-update-server-info
+	after receiving data from git-push and updating refs.
+
+receive.shallowUpdate::
+	If set to true, .git/shallow can be updated when new refs
+	require new shallow roots. Otherwise those refs are rejected.
diff --git a/third_party/git/Documentation/config/remote.txt b/third_party/git/Documentation/config/remote.txt
new file mode 100644
index 0000000000..6c4cad83a2
--- /dev/null
+++ b/third_party/git/Documentation/config/remote.txt
@@ -0,0 +1,78 @@
+remote.pushDefault::
+	The remote to push to by default.  Overrides
+	`branch.<name>.remote` for all branches, and is overridden by
+	`branch.<name>.pushRemote` for specific branches.
+
+remote.<name>.url::
+	The URL of a remote repository.  See linkgit:git-fetch[1] or
+	linkgit:git-push[1].
+
+remote.<name>.pushurl::
+	The push URL of a remote repository.  See linkgit:git-push[1].
+
+remote.<name>.proxy::
+	For remotes that require curl (http, https and ftp), the URL to
+	the proxy to use for that remote.  Set to the empty string to
+	disable proxying for that remote.
+
+remote.<name>.proxyAuthMethod::
+	For remotes that require curl (http, https and ftp), the method to use for
+	authenticating against the proxy in use (probably set in
+	`remote.<name>.proxy`). See `http.proxyAuthMethod`.
+
+remote.<name>.fetch::
+	The default set of "refspec" for linkgit:git-fetch[1]. See
+	linkgit:git-fetch[1].
+
+remote.<name>.push::
+	The default set of "refspec" for linkgit:git-push[1]. See
+	linkgit:git-push[1].
+
+remote.<name>.mirror::
+	If true, pushing to this remote will automatically behave
+	as if the `--mirror` option was given on the command line.
+
+remote.<name>.skipDefaultUpdate::
+	If true, this remote will be skipped by default when updating
+	using linkgit:git-fetch[1] or the `update` subcommand of
+	linkgit:git-remote[1].
+
+remote.<name>.skipFetchAll::
+	If true, this remote will be skipped by default when updating
+	using linkgit:git-fetch[1] or the `update` subcommand of
+	linkgit:git-remote[1].
+
+remote.<name>.receivepack::
+	The default program to execute on the remote side when pushing.  See
+	option --receive-pack of linkgit:git-push[1].
+
+remote.<name>.uploadpack::
+	The default program to execute on the remote side when fetching.  See
+	option --upload-pack of linkgit:git-fetch-pack[1].
+
+remote.<name>.tagOpt::
+	Setting this value to --no-tags disables automatic tag following when
+	fetching from remote <name>. Setting it to --tags will fetch every
+	tag from remote <name>, even if they are not reachable from remote
+	branch heads. Passing these flags directly to linkgit:git-fetch[1] can
+	override this setting. See options --tags and --no-tags of
+	linkgit:git-fetch[1].
+
+remote.<name>.vcs::
+	Setting this to a value <vcs> will cause Git to interact with
+	the remote with the git-remote-<vcs> helper.
+
+remote.<name>.prune::
+	When set to true, fetching from this remote by default will also
+	remove any remote-tracking references that no longer exist on the
+	remote (as if the `--prune` option was given on the command line).
+	Overrides `fetch.prune` settings, if any.
+
+remote.<name>.pruneTags::
+	When set to true, fetching from this remote by default will also
+	remove any local tags that no longer exist on the remote if pruning
+	is activated in general via `remote.<name>.prune`, `fetch.prune` or
+	`--prune`. Overrides `fetch.pruneTags` settings, if any.
++
+See also `remote.<name>.prune` and the PRUNING section of
+linkgit:git-fetch[1].
diff --git a/third_party/git/Documentation/config/remotes.txt b/third_party/git/Documentation/config/remotes.txt
new file mode 100644
index 0000000000..4cfe03221e
--- /dev/null
+++ b/third_party/git/Documentation/config/remotes.txt
@@ -0,0 +1,3 @@
+remotes.<group>::
+	The list of remotes which are fetched by "git remote update
+	<group>".  See linkgit:git-remote[1].
diff --git a/third_party/git/Documentation/config/repack.txt b/third_party/git/Documentation/config/repack.txt
new file mode 100644
index 0000000000..9c413e177e
--- /dev/null
+++ b/third_party/git/Documentation/config/repack.txt
@@ -0,0 +1,27 @@
+repack.useDeltaBaseOffset::
+	By default, linkgit:git-repack[1] creates packs that use
+	delta-base offset. If you need to share your repository with
+	Git older than version 1.4.4, either directly or via a dumb
+	protocol such as http, then you need to set this option to
+	"false" and repack. Access from old Git versions over the
+	native protocol are unaffected by this option.
+
+repack.packKeptObjects::
+	If set to true, makes `git repack` act as if
+	`--pack-kept-objects` was passed. See linkgit:git-repack[1] for
+	details. Defaults to `false` normally, but `true` if a bitmap
+	index is being written (either via `--write-bitmap-index` or
+	`repack.writeBitmaps`).
+
+repack.useDeltaIslands::
+	If set to true, makes `git repack` act as if `--delta-islands`
+	was passed. Defaults to `false`.
+
+repack.writeBitmaps::
+	When true, git will write a bitmap index when packing all
+	objects to disk (e.g., when `git repack -a` is run).  This
+	index can speed up the "counting objects" phase of subsequent
+	packs created for clones and fetches, at the cost of some disk
+	space and extra time spent on the initial repack.  This has
+	no effect if multiple packfiles are created.
+	Defaults to true on bare repos, false otherwise.
diff --git a/third_party/git/Documentation/config/rerere.txt b/third_party/git/Documentation/config/rerere.txt
new file mode 100644
index 0000000000..40abdf6a6b
--- /dev/null
+++ b/third_party/git/Documentation/config/rerere.txt
@@ -0,0 +1,12 @@
+rerere.autoUpdate::
+	When set to true, `git-rerere` updates the index with the
+	resulting contents after it cleanly resolves conflicts using
+	previously recorded resolution.  Defaults to false.
+
+rerere.enabled::
+	Activate recording of resolved conflicts, so that identical
+	conflict hunks can be resolved automatically, should they be
+	encountered again.  By default, linkgit:git-rerere[1] is
+	enabled if there is an `rr-cache` directory under the
+	`$GIT_DIR`, e.g. if "rerere" was previously used in the
+	repository.
diff --git a/third_party/git/Documentation/config/reset.txt b/third_party/git/Documentation/config/reset.txt
new file mode 100644
index 0000000000..63b7c45aac
--- /dev/null
+++ b/third_party/git/Documentation/config/reset.txt
@@ -0,0 +1,2 @@
+reset.quiet::
+	When set to true, 'git reset' will default to the '--quiet' option.
diff --git a/third_party/git/Documentation/config/sendemail.txt b/third_party/git/Documentation/config/sendemail.txt
new file mode 100644
index 0000000000..0006faf800
--- /dev/null
+++ b/third_party/git/Documentation/config/sendemail.txt
@@ -0,0 +1,63 @@
+sendemail.identity::
+	A configuration identity. When given, causes values in the
+	'sendemail.<identity>' subsection to take precedence over
+	values in the 'sendemail' section. The default identity is
+	the value of `sendemail.identity`.
+
+sendemail.smtpEncryption::
+	See linkgit:git-send-email[1] for description.  Note that this
+	setting is not subject to the 'identity' mechanism.
+
+sendemail.smtpssl (deprecated)::
+	Deprecated alias for 'sendemail.smtpEncryption = ssl'.
+
+sendemail.smtpsslcertpath::
+	Path to ca-certificates (either a directory or a single file).
+	Set it to an empty string to disable certificate verification.
+
+sendemail.<identity>.*::
+	Identity-specific versions of the 'sendemail.*' parameters
+	found below, taking precedence over those when this
+	identity is selected, through either the command-line or
+	`sendemail.identity`.
+
+sendemail.aliasesFile::
+sendemail.aliasFileType::
+sendemail.annotate::
+sendemail.bcc::
+sendemail.cc::
+sendemail.ccCmd::
+sendemail.chainReplyTo::
+sendemail.confirm::
+sendemail.envelopeSender::
+sendemail.from::
+sendemail.multiEdit::
+sendemail.signedoffbycc::
+sendemail.smtpPass::
+sendemail.suppresscc::
+sendemail.suppressFrom::
+sendemail.to::
+sendemail.tocmd::
+sendemail.smtpDomain::
+sendemail.smtpServer::
+sendemail.smtpServerPort::
+sendemail.smtpServerOption::
+sendemail.smtpUser::
+sendemail.thread::
+sendemail.transferEncoding::
+sendemail.validate::
+sendemail.xmailer::
+	See linkgit:git-send-email[1] for description.
+
+sendemail.signedoffcc (deprecated)::
+	Deprecated alias for `sendemail.signedoffbycc`.
+
+sendemail.smtpBatchSize::
+	Number of messages to be sent per connection, after that a relogin
+	will happen.  If the value is 0 or undefined, send all messages in
+	one connection.
+	See also the `--batch-size` option of linkgit:git-send-email[1].
+
+sendemail.smtpReloginDelay::
+	Seconds wait before reconnecting to smtp server.
+	See also the `--relogin-delay` option of linkgit:git-send-email[1].
diff --git a/third_party/git/Documentation/config/sequencer.txt b/third_party/git/Documentation/config/sequencer.txt
new file mode 100644
index 0000000000..b48d532a96
--- /dev/null
+++ b/third_party/git/Documentation/config/sequencer.txt
@@ -0,0 +1,5 @@
+sequence.editor::
+	Text editor used by `git rebase -i` for editing the rebase instruction file.
+	The value is meant to be interpreted by the shell when it is used.
+	It can be overridden by the `GIT_SEQUENCE_EDITOR` environment variable.
+	When not configured the default commit message editor is used instead.
diff --git a/third_party/git/Documentation/config/showbranch.txt b/third_party/git/Documentation/config/showbranch.txt
new file mode 100644
index 0000000000..e79ecd9ee9
--- /dev/null
+++ b/third_party/git/Documentation/config/showbranch.txt
@@ -0,0 +1,3 @@
+showBranch.default::
+	The default set of branches for linkgit:git-show-branch[1].
+	See linkgit:git-show-branch[1].
diff --git a/third_party/git/Documentation/config/splitindex.txt b/third_party/git/Documentation/config/splitindex.txt
new file mode 100644
index 0000000000..afdb186df8
--- /dev/null
+++ b/third_party/git/Documentation/config/splitindex.txt
@@ -0,0 +1,24 @@
+splitIndex.maxPercentChange::
+	When the split index feature is used, this specifies the
+	percent of entries the split index can contain compared to the
+	total number of entries in both the split index and the shared
+	index before a new shared index is written.
+	The value should be between 0 and 100. If the value is 0 then
+	a new shared index is always written, if it is 100 a new
+	shared index is never written.
+	By default the value is 20, so a new shared index is written
+	if the number of entries in the split index would be greater
+	than 20 percent of the total number of entries.
+	See linkgit:git-update-index[1].
+
+splitIndex.sharedIndexExpire::
+	When the split index feature is used, shared index files that
+	were not modified since the time this variable specifies will
+	be removed when a new shared index file is created. The value
+	"now" expires all entries immediately, and "never" suppresses
+	expiration altogether.
+	The default value is "2.weeks.ago".
+	Note that a shared index file is considered modified (for the
+	purpose of expiration) each time a new split-index file is
+	either created based on it or read from it.
+	See linkgit:git-update-index[1].
diff --git a/third_party/git/Documentation/config/ssh.txt b/third_party/git/Documentation/config/ssh.txt
new file mode 100644
index 0000000000..2ca4bf93e1
--- /dev/null
+++ b/third_party/git/Documentation/config/ssh.txt
@@ -0,0 +1,35 @@
+ssh.variant::
+	By default, Git determines the command line arguments to use
+	based on the basename of the configured SSH command (configured
+	using the environment variable `GIT_SSH` or `GIT_SSH_COMMAND` or
+	the config setting `core.sshCommand`). If the basename is
+	unrecognized, Git will attempt to detect support of OpenSSH
+	options by first invoking the configured SSH command with the
+	`-G` (print configuration) option and will subsequently use
+	OpenSSH options (if that is successful) or no options besides
+	the host and remote command (if it fails).
++
+The config variable `ssh.variant` can be set to override this detection.
+Valid values are `ssh` (to use OpenSSH options), `plink`, `putty`,
+`tortoiseplink`, `simple` (no options except the host and remote command).
+The default auto-detection can be explicitly requested using the value
+`auto`.  Any other value is treated as `ssh`.  This setting can also be
+overridden via the environment variable `GIT_SSH_VARIANT`.
++
+The current command-line parameters used for each variant are as
+follows:
++
+--
+
+* `ssh` - [-p port] [-4] [-6] [-o option] [username@]host command
+
+* `simple` - [username@]host command
+
+* `plink` or `putty` - [-P port] [-4] [-6] [username@]host command
+
+* `tortoiseplink` - [-P port] [-4] [-6] -batch [username@]host command
+
+--
++
+Except for the `simple` variant, command-line parameters are likely to
+change as git gains new features.
diff --git a/third_party/git/Documentation/config/stash.txt b/third_party/git/Documentation/config/stash.txt
new file mode 100644
index 0000000000..abc7ef4a3a
--- /dev/null
+++ b/third_party/git/Documentation/config/stash.txt
@@ -0,0 +1,24 @@
+stash.useBuiltin::
+       Set to `false` to use the legacy shell script implementation of
+       linkgit:git-stash[1]. Is `true` by default, which means use
+       the built-in rewrite of it in C.
++
+The C rewrite is first included with Git version 2.22 (and Git for Windows
+version 2.19). This option serves as an escape hatch to re-enable the
+legacy version in case any bugs are found in the rewrite. This option and
+the shell script version of linkgit:git-stash[1] will be removed in some
+future release.
++
+If you find some reason to set this option to `false`, other than
+one-off testing, you should report the behavior difference as a bug in
+Git (see https://git-scm.com/community for details).
+
+stash.showPatch::
+	If this is set to true, the `git stash show` command without an
+	option will show the stash entry in patch form.  Defaults to false.
+	See description of 'show' command in linkgit:git-stash[1].
+
+stash.showStat::
+	If this is set to true, the `git stash show` command without an
+	option will show diffstat of the stash entry.  Defaults to true.
+	See description of 'show' command in linkgit:git-stash[1].
diff --git a/third_party/git/Documentation/config/status.txt b/third_party/git/Documentation/config/status.txt
new file mode 100644
index 0000000000..0fc704ab80
--- /dev/null
+++ b/third_party/git/Documentation/config/status.txt
@@ -0,0 +1,77 @@
+status.relativePaths::
+	By default, linkgit:git-status[1] shows paths relative to the
+	current directory. Setting this variable to `false` shows paths
+	relative to the repository root (this was the default for Git
+	prior to v1.5.4).
+
+status.short::
+	Set to true to enable --short by default in linkgit:git-status[1].
+	The option --no-short takes precedence over this variable.
+
+status.branch::
+	Set to true to enable --branch by default in linkgit:git-status[1].
+	The option --no-branch takes precedence over this variable.
+
+status.aheadBehind::
+	Set to true to enable `--ahead-behind` and false to enable
+	`--no-ahead-behind` by default in linkgit:git-status[1] for
+	non-porcelain status formats.  Defaults to true.
+
+status.displayCommentPrefix::
+	If set to true, linkgit:git-status[1] will insert a comment
+	prefix before each output line (starting with
+	`core.commentChar`, i.e. `#` by default). This was the
+	behavior of linkgit:git-status[1] in Git 1.8.4 and previous.
+	Defaults to false.
+
+status.renameLimit::
+	The number of files to consider when performing rename detection
+	in linkgit:git-status[1] and linkgit:git-commit[1]. Defaults to
+	the value of diff.renameLimit.
+
+status.renames::
+	Whether and how Git detects renames in linkgit:git-status[1] and
+	linkgit:git-commit[1] .  If set to "false", rename detection is
+	disabled. If set to "true", basic rename detection is enabled.
+	If set to "copies" or "copy", Git will detect copies, as well.
+	Defaults to the value of diff.renames.
+
+status.showStash::
+	If set to true, linkgit:git-status[1] will display the number of
+	entries currently stashed away.
+	Defaults to false.
+
+status.showUntrackedFiles::
+	By default, linkgit:git-status[1] and linkgit:git-commit[1] show
+	files which are not currently tracked by Git. Directories which
+	contain only untracked files, are shown with the directory name
+	only. Showing untracked files means that Git needs to lstat() all
+	the files in the whole repository, which might be slow on some
+	systems. So, this variable controls how the commands displays
+	the untracked files. Possible values are:
++
+--
+* `no` - Show no untracked files.
+* `normal` - Show untracked files and directories.
+* `all` - Show also individual files in untracked directories.
+--
++
+If this variable is not specified, it defaults to 'normal'.
+This variable can be overridden with the -u|--untracked-files option
+of linkgit:git-status[1] and linkgit:git-commit[1].
+
+status.submoduleSummary::
+	Defaults to false.
+	If this is set to a non zero number or true (identical to -1 or an
+	unlimited number), the submodule summary will be enabled and a
+	summary of commits for modified submodules will be shown (see
+	--summary-limit option of linkgit:git-submodule[1]). Please note
+	that the summary output command will be suppressed for all
+	submodules when `diff.ignoreSubmodules` is set to 'all' or only
+	for those submodules where `submodule.<name>.ignore=all`. The only
+	exception to that rule is that status and commit will show staged
+	submodule changes. To
+	also view the summary for ignored submodules you can either use
+	the --ignore-submodules=dirty command-line option or the 'git
+	submodule summary' command, which shows a similar output but does
+	not honor these settings.
diff --git a/third_party/git/Documentation/config/submodule.txt b/third_party/git/Documentation/config/submodule.txt
new file mode 100644
index 0000000000..0a1293b051
--- /dev/null
+++ b/third_party/git/Documentation/config/submodule.txt
@@ -0,0 +1,82 @@
+submodule.<name>.url::
+	The URL for a submodule. This variable is copied from the .gitmodules
+	file to the git config via 'git submodule init'. The user can change
+	the configured URL before obtaining the submodule via 'git submodule
+	update'. If neither submodule.<name>.active or submodule.active are
+	set, the presence of this variable is used as a fallback to indicate
+	whether the submodule is of interest to git commands.
+	See linkgit:git-submodule[1] and linkgit:gitmodules[5] for details.
+
+submodule.<name>.update::
+	The method by which a submodule is updated by 'git submodule update',
+	which is the only affected command, others such as
+	'git checkout --recurse-submodules' are unaffected. It exists for
+	historical reasons, when 'git submodule' was the only command to
+	interact with submodules; settings like `submodule.active`
+	and `pull.rebase` are more specific. It is populated by
+	`git submodule init` from the linkgit:gitmodules[5] file.
+	See description of 'update' command in linkgit:git-submodule[1].
+
+submodule.<name>.branch::
+	The remote branch name for a submodule, used by `git submodule
+	update --remote`.  Set this option to override the value found in
+	the `.gitmodules` file.  See linkgit:git-submodule[1] and
+	linkgit:gitmodules[5] for details.
+
+submodule.<name>.fetchRecurseSubmodules::
+	This option can be used to control recursive fetching of this
+	submodule. It can be overridden by using the --[no-]recurse-submodules
+	command-line option to "git fetch" and "git pull".
+	This setting will override that from in the linkgit:gitmodules[5]
+	file.
+
+submodule.<name>.ignore::
+	Defines under what circumstances "git status" and the diff family show
+	a submodule as modified. When set to "all", it will never be considered
+	modified (but it will nonetheless show up in the output of status and
+	commit when it has been staged), "dirty" will ignore all changes
+	to the submodules work tree and
+	takes only differences between the HEAD of the submodule and the commit
+	recorded in the superproject into account. "untracked" will additionally
+	let submodules with modified tracked files in their work tree show up.
+	Using "none" (the default when this option is not set) also shows
+	submodules that have untracked files in their work tree as changed.
+	This setting overrides any setting made in .gitmodules for this submodule,
+	both settings can be overridden on the command line by using the
+	"--ignore-submodules" option. The 'git submodule' commands are not
+	affected by this setting.
+
+submodule.<name>.active::
+	Boolean value indicating if the submodule is of interest to git
+	commands.  This config option takes precedence over the
+	submodule.active config option. See linkgit:gitsubmodules[7] for
+	details.
+
+submodule.active::
+	A repeated field which contains a pathspec used to match against a
+	submodule's path to determine if the submodule is of interest to git
+	commands. See linkgit:gitsubmodules[7] for details.
+
+submodule.recurse::
+	Specifies if commands recurse into submodules by default. This
+	applies to all commands that have a `--recurse-submodules` option,
+	except `clone`.
+	Defaults to false.
+
+submodule.fetchJobs::
+	Specifies how many submodules are fetched/cloned at the same time.
+	A positive integer allows up to that number of submodules fetched
+	in parallel. A value of 0 will give some reasonable default.
+	If unset, it defaults to 1.
+
+submodule.alternateLocation::
+	Specifies how the submodules obtain alternates when submodules are
+	cloned. Possible values are `no`, `superproject`.
+	By default `no` is assumed, which doesn't add references. When the
+	value is set to `superproject` the submodule to be cloned computes
+	its alternates location relative to the superprojects alternate.
+
+submodule.alternateErrorStrategy::
+	Specifies how to treat errors with the alternates for a submodule
+	as computed via `submodule.alternateLocation`. Possible values are
+	`ignore`, `info`, `die`. Default is `die`.
diff --git a/third_party/git/Documentation/config/tag.txt b/third_party/git/Documentation/config/tag.txt
new file mode 100644
index 0000000000..ef5adb3f42
--- /dev/null
+++ b/third_party/git/Documentation/config/tag.txt
@@ -0,0 +1,24 @@
+tag.forceSignAnnotated::
+	A boolean to specify whether annotated tags created should be GPG signed.
+	If `--annotate` is specified on the command line, it takes
+	precedence over this option.
+
+tag.sort::
+	This variable controls the sort ordering of tags when displayed by
+	linkgit:git-tag[1]. Without the "--sort=<value>" option provided, the
+	value of this variable will be used as the default.
+
+tag.gpgSign::
+	A boolean to specify whether all tags should be GPG signed.
+	Use of this option when running in an automated script can
+	result in a large number of tags being signed. It is therefore
+	convenient to use an agent to avoid typing your gpg passphrase
+	several times. Note that this option doesn't affects tag signing
+	behavior enabled by "-u <keyid>" or "--local-user=<keyid>" options.
+
+tar.umask::
+	This variable can be used to restrict the permission bits of
+	tar archive entries.  The default is 0002, which turns off the
+	world write bit.  The special value "user" indicates that the
+	archiving user's umask will be used instead.  See umask(2) and
+	linkgit:git-archive[1].
diff --git a/third_party/git/Documentation/config/trace2.txt b/third_party/git/Documentation/config/trace2.txt
new file mode 100644
index 0000000000..2edbfb02fe
--- /dev/null
+++ b/third_party/git/Documentation/config/trace2.txt
@@ -0,0 +1,56 @@
+Trace2 config settings are only read from the system and global
+config files; repository local and worktree config files and `-c`
+command line arguments are not respected.
+
+trace2.normalTarget::
+	This variable controls the normal target destination.
+	It may be overridden by the `GIT_TRACE2` environment variable.
+	The following table shows possible values.
+
+trace2.perfTarget::
+	This variable controls the performance target destination.
+	It may be overridden by the `GIT_TRACE2_PERF` environment variable.
+	The following table shows possible values.
+
+trace2.eventTarget::
+	This variable controls the event target destination.
+	It may be overridden by the `GIT_TRACE2_EVENT` environment variable.
+	The following table shows possible values.
++
+include::../trace2-target-values.txt[]
+
+trace2.normalBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from normal output.  May be overridden by the
+	`GIT_TRACE2_BRIEF` environment variable.  Defaults to false.
+
+trace2.perfBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from PERF output.  May be overridden by the
+	`GIT_TRACE2_PERF_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventBrief::
+	Boolean.  When true `time`, `filename`, and `line` fields are
+	omitted from event output.  May be overridden by the
+	`GIT_TRACE2_EVENT_BRIEF` environment variable.  Defaults to false.
+
+trace2.eventNesting::
+	Integer.  Specifies desired depth of nested regions in the
+	event output.  Regions deeper than this value will be
+	omitted.  May be overridden by the `GIT_TRACE2_EVENT_NESTING`
+	environment variable.  Defaults to 2.
+
+trace2.configParams::
+	A comma-separated list of patterns of "important" config
+	settings that should be recorded in the trace2 output.
+	For example, `core.*,remote.*.url` would cause the trace2
+	output to contain events listing each configured remote.
+	May be overridden by the `GIT_TRACE2_CONFIG_PARAMS` environment
+	variable.  Unset by default.
+
+trace2.destinationDebug::
+	Boolean.  When true Git will print error messages when a
+	trace target destination cannot be opened for writing.
+	By default, these errors are suppressed and tracing is
+	silently disabled.  May be overridden by the
+	`GIT_TRACE2_DST_DEBUG` environment variable.
diff --git a/third_party/git/Documentation/config/transfer.txt b/third_party/git/Documentation/config/transfer.txt
new file mode 100644
index 0000000000..f5b6245270
--- /dev/null
+++ b/third_party/git/Documentation/config/transfer.txt
@@ -0,0 +1,71 @@
+transfer.fsckObjects::
+	When `fetch.fsckObjects` or `receive.fsckObjects` are
+	not set, the value of this variable is used instead.
+	Defaults to false.
++
+When set, the fetch or receive will abort in the case of a malformed
+object or a link to a nonexistent object. In addition, various other
+issues are checked for, including legacy issues (see `fsck.<msg-id>`),
+and potential security issues like the existence of a `.GIT` directory
+or a malicious `.gitmodules` file (see the release notes for v2.2.1
+and v2.17.1 for details). Other sanity and security checks may be
+added in future releases.
++
+On the receiving side, failing fsckObjects will make those objects
+unreachable, see "QUARANTINE ENVIRONMENT" in
+linkgit:git-receive-pack[1]. On the fetch side, malformed objects will
+instead be left unreferenced in the repository.
++
+Due to the non-quarantine nature of the `fetch.fsckObjects`
+implementation it cannot be relied upon to leave the object store
+clean like `receive.fsckObjects` can.
++
+As objects are unpacked they're written to the object store, so there
+can be cases where malicious objects get introduced even though the
+"fetch" failed, only to have a subsequent "fetch" succeed because only
+new incoming objects are checked, not those that have already been
+written to the object store. That difference in behavior should not be
+relied upon. In the future, such objects may be quarantined for
+"fetch" as well.
++
+For now, the paranoid need to find some way to emulate the quarantine
+environment if they'd like the same protection as "push". E.g. in the
+case of an internal mirror do the mirroring in two steps, one to fetch
+the untrusted objects, and then do a second "push" (which will use the
+quarantine) to another internal repo, and have internal clients
+consume this pushed-to repository, or embargo internal fetches and
+only allow them once a full "fsck" has run (and no new fetches have
+happened in the meantime).
+
+transfer.hideRefs::
+	String(s) `receive-pack` and `upload-pack` use to decide which
+	refs to omit from their initial advertisements.  Use more than
+	one definition to specify multiple prefix strings. A ref that is
+	under the hierarchies listed in the value of this variable is
+	excluded, and is hidden when responding to `git push` or `git
+	fetch`.  See `receive.hideRefs` and `uploadpack.hideRefs` for
+	program-specific versions of this config.
++
+You may also include a `!` in front of the ref name to negate the entry,
+explicitly exposing it, even if an earlier entry marked it as hidden.
+If you have multiple hideRefs values, later entries override earlier ones
+(and entries in more-specific config files override less-specific ones).
++
+If a namespace is in use, the namespace prefix is stripped from each
+reference before it is matched against `transfer.hiderefs` patterns.
+For example, if `refs/heads/master` is specified in `transfer.hideRefs` and
+the current namespace is `foo`, then `refs/namespaces/foo/refs/heads/master`
+is omitted from the advertisements but `refs/heads/master` and
+`refs/namespaces/bar/refs/heads/master` are still advertised as so-called
+"have" lines. In order to match refs before stripping, add a `^` in front of
+the ref name. If you combine `!` and `^`, `!` must be specified first.
++
+Even if you hide refs, a client may still be able to steal the target
+objects via the techniques described in the "SECURITY" section of the
+linkgit:gitnamespaces[7] man page; it's best to keep private data in a
+separate repository.
+
+transfer.unpackLimit::
+	When `fetch.unpackLimit` or `receive.unpackLimit` are
+	not set, the value of this variable is used instead.
+	The default value is 100.
diff --git a/third_party/git/Documentation/config/uploadarchive.txt b/third_party/git/Documentation/config/uploadarchive.txt
new file mode 100644
index 0000000000..e0698e8c1d
--- /dev/null
+++ b/third_party/git/Documentation/config/uploadarchive.txt
@@ -0,0 +1,6 @@
+uploadarchive.allowUnreachable::
+	If true, allow clients to use `git archive --remote` to request
+	any tree, whether reachable from the ref tips or not. See the
+	discussion in the "SECURITY" section of
+	linkgit:git-upload-archive[1] for more details. Defaults to
+	`false`.
diff --git a/third_party/git/Documentation/config/uploadpack.txt b/third_party/git/Documentation/config/uploadpack.txt
new file mode 100644
index 0000000000..ed1c835695
--- /dev/null
+++ b/third_party/git/Documentation/config/uploadpack.txt
@@ -0,0 +1,65 @@
+uploadpack.hideRefs::
+	This variable is the same as `transfer.hideRefs`, but applies
+	only to `upload-pack` (and so affects only fetches, not pushes).
+	An attempt to fetch a hidden ref by `git fetch` will fail.  See
+	also `uploadpack.allowTipSHA1InWant`.
+
+uploadpack.allowTipSHA1InWant::
+	When `uploadpack.hideRefs` is in effect, allow `upload-pack`
+	to accept a fetch request that asks for an object at the tip
+	of a hidden ref (by default, such a request is rejected).
+	See also `uploadpack.hideRefs`.  Even if this is false, a client
+	may be able to steal objects via the techniques described in the
+	"SECURITY" section of the linkgit:gitnamespaces[7] man page; it's
+	best to keep private data in a separate repository.
+
+uploadpack.allowReachableSHA1InWant::
+	Allow `upload-pack` to accept a fetch request that asks for an
+	object that is reachable from any ref tip. However, note that
+	calculating object reachability is computationally expensive.
+	Defaults to `false`.  Even if this is false, a client may be able
+	to steal objects via the techniques described in the "SECURITY"
+	section of the linkgit:gitnamespaces[7] man page; it's best to
+	keep private data in a separate repository.
+
+uploadpack.allowAnySHA1InWant::
+	Allow `upload-pack` to accept a fetch request that asks for any
+	object at all.
+	Defaults to `false`.
+
+uploadpack.keepAlive::
+	When `upload-pack` has started `pack-objects`, there may be a
+	quiet period while `pack-objects` prepares the pack. Normally
+	it would output progress information, but if `--quiet` was used
+	for the fetch, `pack-objects` will output nothing at all until
+	the pack data begins. Some clients and networks may consider
+	the server to be hung and give up. Setting this option instructs
+	`upload-pack` to send an empty keepalive packet every
+	`uploadpack.keepAlive` seconds. Setting this option to 0
+	disables keepalive packets entirely. The default is 5 seconds.
+
+uploadpack.packObjectsHook::
+	If this option is set, when `upload-pack` would run
+	`git pack-objects` to create a packfile for a client, it will
+	run this shell command instead.  The `pack-objects` command and
+	arguments it _would_ have run (including the `git pack-objects`
+	at the beginning) are appended to the shell command. The stdin
+	and stdout of the hook are treated as if `pack-objects` itself
+	was run. I.e., `upload-pack` will feed input intended for
+	`pack-objects` to the hook, and expects a completed packfile on
+	stdout.
++
+Note that this configuration variable is ignored if it is seen in the
+repository-level config (this is a safety measure against fetching from
+untrusted repositories).
+
+uploadpack.allowFilter::
+	If this option is set, `upload-pack` will support partial
+	clone and partial fetch object filtering.
+
+uploadpack.allowRefInWant::
+	If this option is set, `upload-pack` will support the `ref-in-want`
+	feature of the protocol version 2 `fetch` command.  This feature
+	is intended for the benefit of load-balanced servers which may
+	not have the same view of what OIDs their refs point to due to
+	replication delay.
diff --git a/third_party/git/Documentation/config/url.txt b/third_party/git/Documentation/config/url.txt
new file mode 100644
index 0000000000..e5566c371d
--- /dev/null
+++ b/third_party/git/Documentation/config/url.txt
@@ -0,0 +1,30 @@
+url.<base>.insteadOf::
+	Any URL that starts with this value will be rewritten to
+	start, instead, with <base>. In cases where some site serves a
+	large number of repositories, and serves them with multiple
+	access methods, and some users need to use different access
+	methods, this feature allows people to specify any of the
+	equivalent URLs and have Git automatically rewrite the URL to
+	the best alternative for the particular user, even for a
+	never-before-seen repository on the site.  When more than one
+	insteadOf strings match a given URL, the longest match is used.
++
+Note that any protocol restrictions will be applied to the rewritten
+URL. If the rewrite changes the URL to use a custom protocol or remote
+helper, you may need to adjust the `protocol.*.allow` config to permit
+the request.  In particular, protocols you expect to use for submodules
+must be set to `always` rather than the default of `user`. See the
+description of `protocol.allow` above.
+
+url.<base>.pushInsteadOf::
+	Any URL that starts with this value will not be pushed to;
+	instead, it will be rewritten to start with <base>, and the
+	resulting URL will be pushed to. In cases where some site serves
+	a large number of repositories, and serves them with multiple
+	access methods, some of which do not allow push, this feature
+	allows people to specify a pull-only URL and have Git
+	automatically use an appropriate URL to push, even for a
+	never-before-seen repository on the site.  When more than one
+	pushInsteadOf strings match a given URL, the longest match is
+	used.  If a remote has an explicit pushurl, Git will ignore this
+	setting for that remote.
diff --git a/third_party/git/Documentation/config/user.txt b/third_party/git/Documentation/config/user.txt
new file mode 100644
index 0000000000..0557cbbceb
--- /dev/null
+++ b/third_party/git/Documentation/config/user.txt
@@ -0,0 +1,33 @@
+user.name::
+user.email::
+author.name::
+author.email::
+committer.name::
+committer.email::
+	The `user.name` and `user.email` variables determine what ends
+	up in the `author` and `committer` field of commit
+	objects.
+	If you need the `author` or `committer` to be different, the
+	`author.name`, `author.email`, `committer.name` or
+	`committer.email` variables can be set.
+	Also, all of these can be overridden by the `GIT_AUTHOR_NAME`,
+	`GIT_AUTHOR_EMAIL`, `GIT_COMMITTER_NAME`,
+	`GIT_COMMITTER_EMAIL` and `EMAIL` environment variables.
+	See linkgit:git-commit-tree[1] for more information.
+
+user.useConfigOnly::
+	Instruct Git to avoid trying to guess defaults for `user.email`
+	and `user.name`, and instead retrieve the values only from the
+	configuration. For example, if you have multiple email addresses
+	and would like to use a different one for each repository, then
+	with this configuration option set to `true` in the global config
+	along with a name, Git will prompt you to set up an email before
+	making new commits in a newly cloned repository.
+	Defaults to `false`.
+
+user.signingKey::
+	If linkgit:git-tag[1] or linkgit:git-commit[1] is not selecting the
+	key you want it to automatically when creating a signed tag or
+	commit, you can override the default selection with this variable.
+	This option is passed unchanged to gpg's --local-user parameter,
+	so you may specify a key using any method that gpg supports.
diff --git a/third_party/git/Documentation/config/versionsort.txt b/third_party/git/Documentation/config/versionsort.txt
new file mode 100644
index 0000000000..6c7cc054fa
--- /dev/null
+++ b/third_party/git/Documentation/config/versionsort.txt
@@ -0,0 +1,33 @@
+versionsort.prereleaseSuffix (deprecated)::
+	Deprecated alias for `versionsort.suffix`.  Ignored if
+	`versionsort.suffix` is set.
+
+versionsort.suffix::
+	Even when version sort is used in linkgit:git-tag[1], tagnames
+	with the same base version but different suffixes are still sorted
+	lexicographically, resulting e.g. in prerelease tags appearing
+	after the main release (e.g. "1.0-rc1" after "1.0").  This
+	variable can be specified to determine the sorting order of tags
+	with different suffixes.
++
+By specifying a single suffix in this variable, any tagname containing
+that suffix will appear before the corresponding main release.  E.g. if
+the variable is set to "-rc", then all "1.0-rcX" tags will appear before
+"1.0".  If specified multiple times, once per suffix, then the order of
+suffixes in the configuration will determine the sorting order of tagnames
+with those suffixes.  E.g. if "-pre" appears before "-rc" in the
+configuration, then all "1.0-preX" tags will be listed before any
+"1.0-rcX" tags.  The placement of the main release tag relative to tags
+with various suffixes can be determined by specifying the empty suffix
+among those other suffixes.  E.g. if the suffixes "-rc", "", "-ck" and
+"-bfs" appear in the configuration in this order, then all "v4.8-rcX" tags
+are listed first, followed by "v4.8", then "v4.8-ckX" and finally
+"v4.8-bfsX".
++
+If more than one suffixes match the same tagname, then that tagname will
+be sorted according to the suffix which starts at the earliest position in
+the tagname.  If more than one different matching suffixes start at
+that earliest position, then that tagname will be sorted according to the
+longest of those suffixes.
+The sorting order between different suffixes is undefined if they are
+in multiple config files.
diff --git a/third_party/git/Documentation/config/web.txt b/third_party/git/Documentation/config/web.txt
new file mode 100644
index 0000000000..beec8d1303
--- /dev/null
+++ b/third_party/git/Documentation/config/web.txt
@@ -0,0 +1,4 @@
+web.browser::
+	Specify a web browser that may be used by some commands.
+	Currently only linkgit:git-instaweb[1] and linkgit:git-help[1]
+	may use it.
diff --git a/third_party/git/Documentation/config/worktree.txt b/third_party/git/Documentation/config/worktree.txt
new file mode 100644
index 0000000000..048e349482
--- /dev/null
+++ b/third_party/git/Documentation/config/worktree.txt
@@ -0,0 +1,9 @@
+worktree.guessRemote::
+	If no branch is specified and neither `-b` nor `-B` nor
+	`--detach` is used, then `git worktree add` defaults to
+	creating a new branch from HEAD.  If `worktree.guessRemote` is
+	set to true, `worktree add` tries to find a remote-tracking
+	branch whose name uniquely matches the new branch name.  If
+	such a branch exists, it is checked out and set as "upstream"
+	for the new branch.  If no such match can be found, it falls
+	back to creating a new branch from the current HEAD.
diff --git a/third_party/git/Documentation/date-formats.txt b/third_party/git/Documentation/date-formats.txt
new file mode 100644
index 0000000000..6926e0a4c8
--- /dev/null
+++ b/third_party/git/Documentation/date-formats.txt
@@ -0,0 +1,26 @@
+DATE FORMATS
+------------
+
+The `GIT_AUTHOR_DATE`, `GIT_COMMITTER_DATE` environment variables
+ifdef::git-commit[]
+and the `--date` option
+endif::git-commit[]
+support the following date formats:
+
+Git internal format::
+	It is `<unix timestamp> <time zone offset>`, where `<unix
+	timestamp>` is the number of seconds since the UNIX epoch.
+	`<time zone offset>` is a positive or negative offset from UTC.
+	For example CET (which is 1 hour ahead of UTC) is `+0100`.
+
+RFC 2822::
+	The standard email format as described by RFC 2822, for example
+	`Thu, 07 Apr 2005 22:13:13 +0200`.
+
+ISO 8601::
+	Time and date specified by the ISO 8601 standard, for example
+	`2005-04-07T22:13:13`. The parser accepts a space instead of the
+	`T` character as well.
++
+NOTE: In addition, the date part is accepted in the following formats:
+`YYYY.MM.DD`, `MM/DD/YYYY` and `DD.MM.YYYY`.
diff --git a/third_party/git/Documentation/diff-format.txt b/third_party/git/Documentation/diff-format.txt
new file mode 100644
index 0000000000..4d846d7346
--- /dev/null
+++ b/third_party/git/Documentation/diff-format.txt
@@ -0,0 +1,185 @@
+Raw output format
+-----------------
+
+The raw output format from "git-diff-index", "git-diff-tree",
+"git-diff-files" and "git diff --raw" are very similar.
+
+These commands all compare two sets of things; what is
+compared differs:
+
+git-diff-index <tree-ish>::
+        compares the <tree-ish> and the files on the filesystem.
+
+git-diff-index --cached <tree-ish>::
+        compares the <tree-ish> and the index.
+
+git-diff-tree [-r] <tree-ish-1> <tree-ish-2> [<pattern>...]::
+        compares the trees named by the two arguments.
+
+git-diff-files [<pattern>...]::
+        compares the index and the files on the filesystem.
+
+The "git-diff-tree" command begins its output by printing the hash of
+what is being compared. After that, all the commands print one output
+line per changed file.
+
+An output line is formatted this way:
+
+------------------------------------------------
+in-place edit  :100644 100644 bcd1234 0123456 M file0
+copy-edit      :100644 100644 abcd123 1234567 C68 file1 file2
+rename-edit    :100644 100644 abcd123 1234567 R86 file1 file3
+create         :000000 100644 0000000 1234567 A file4
+delete         :100644 000000 1234567 0000000 D file5
+unmerged       :000000 000000 0000000 0000000 U file6
+------------------------------------------------
+
+That is, from the left to the right:
+
+. a colon.
+. mode for "src"; 000000 if creation or unmerged.
+. a space.
+. mode for "dst"; 000000 if deletion or unmerged.
+. a space.
+. sha1 for "src"; 0\{40\} if creation or unmerged.
+. a space.
+. sha1 for "dst"; 0\{40\} if creation, unmerged or "look at work tree".
+. a space.
+. status, followed by optional "score" number.
+. a tab or a NUL when `-z` option is used.
+. path for "src"
+. a tab or a NUL when `-z` option is used; only exists for C or R.
+. path for "dst"; only exists for C or R.
+. an LF or a NUL when `-z` option is used, to terminate the record.
+
+Possible status letters are:
+
+- A: addition of a file
+- C: copy of a file into a new one
+- D: deletion of a file
+- M: modification of the contents or mode of a file
+- R: renaming of a file
+- T: change in the type of the file
+- U: file is unmerged (you must complete the merge before it can
+be committed)
+- X: "unknown" change type (most probably a bug, please report it)
+
+Status letters C and R are always followed by a score (denoting the
+percentage of similarity between the source and target of the move or
+copy).  Status letter M may be followed by a score (denoting the
+percentage of dissimilarity) for file rewrites.
+
+<sha1> is shown as all 0's if a file is new on the filesystem
+and it is out of sync with the index.
+
+Example:
+
+------------------------------------------------
+:100644 100644 5be4a4a 0000000 M file.c
+------------------------------------------------
+
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
+
+diff format for merges
+----------------------
+
+"git-diff-tree", "git-diff-files" and "git-diff --raw"
+can take `-c` or `--cc` option
+to generate diff output also for merge commits.  The output differs
+from the format described above in the following way:
+
+. there is a colon for each parent
+. there are more "src" modes and "src" sha1
+. status is concatenated status characters for each parent
+. no optional "score" number
+. tab-separated pathname(s) of the file
+
+For `-c` and `--cc`, only the destination or final path is shown even
+if the file was renamed on any side of history.  With
+`--combined-all-paths`, the name of the path in each parent is shown
+followed by the name of the path in the merge commit.
+
+Examples for `-c` and `--cc` without `--combined-all-paths`:
+------------------------------------------------
+::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c
+::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	bar.sh
+::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	phooey.c
+------------------------------------------------
+
+Examples when `--combined-all-paths` added to either `-c` or `--cc`:
+
+------------------------------------------------
+::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c	desc.c	desc.c
+::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	foo.sh	bar.sh	bar.sh
+::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	fooey.c	fuey.c	phooey.c
+------------------------------------------------
+
+Note that 'combined diff' lists only files which were modified from
+all parents.
+
+
+include::diff-generate-patch.txt[]
+
+
+other diff formats
+------------------
+
+The `--summary` option describes newly added, deleted, renamed and
+copied files.  The `--stat` option adds diffstat(1) graph to the
+output.  These options can be combined with other options, such as
+`-p`, and are meant for human consumption.
+
+When showing a change that involves a rename or a copy, `--stat` output
+formats the pathnames compactly by combining common prefix and suffix of
+the pathnames.  For example, a change that moves `arch/i386/Makefile` to
+`arch/x86/Makefile` while modifying 4 lines will be shown like this:
+
+------------------------------------
+arch/{i386 => x86}/Makefile    |   4 +--
+------------------------------------
+
+The `--numstat` option gives the diffstat(1) information but is designed
+for easier machine consumption.  An entry in `--numstat` output looks
+like this:
+
+----------------------------------------
+1	2	README
+3	1	arch/{i386 => x86}/Makefile
+----------------------------------------
+
+That is, from left to right:
+
+. the number of added lines;
+. a tab;
+. the number of deleted lines;
+. a tab;
+. pathname (possibly with rename/copy information);
+. a newline.
+
+When `-z` output option is in effect, the output is formatted this way:
+
+----------------------------------------
+1	2	README NUL
+3	1	NUL arch/i386/Makefile NUL arch/x86/Makefile NUL
+----------------------------------------
+
+That is:
+
+. the number of added lines;
+. a tab;
+. the number of deleted lines;
+. a tab;
+. a NUL (only exists if renamed/copied);
+. pathname in preimage;
+. a NUL (only exists if renamed/copied);
+. pathname in postimage (only exists if renamed/copied);
+. a NUL.
+
+The extra `NUL` before the preimage path in renamed case is to allow
+scripts that read the output to tell if the current record being read is
+a single-path record or a rename/copy record without reading ahead.
+After reading added and deleted lines, reading up to `NUL` would yield
+the pathname, but if that is `NUL`, the record will show two paths.
diff --git a/third_party/git/Documentation/diff-generate-patch.txt b/third_party/git/Documentation/diff-generate-patch.txt
new file mode 100644
index 0000000000..f10ca410ad
--- /dev/null
+++ b/third_party/git/Documentation/diff-generate-patch.txt
@@ -0,0 +1,197 @@
+Generating patches with -p
+--------------------------
+
+When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
+with a `-p` option, "git diff" without the `--raw` option, or
+"git log" with the "-p" option, they
+do not produce the output described above; instead they produce a
+patch file.  You can customize the creation of such patches via the
+`GIT_EXTERNAL_DIFF` and the `GIT_DIFF_OPTS` environment variables.
+
+What the -p option produces is slightly different from the traditional
+diff format:
+
+1.   It is preceded with a "git diff" header that looks like this:
+
+       diff --git a/file1 b/file2
++
+The `a/` and `b/` filenames are the same unless rename/copy is
+involved.  Especially, even for a creation or a deletion,
+`/dev/null` is _not_ used in place of the `a/` or `b/` filenames.
++
+When rename/copy is involved, `file1` and `file2` show the
+name of the source file of the rename/copy and the name of
+the file that rename/copy produces, respectively.
+
+2.   It is followed by one or more extended header lines:
+
+       old mode <mode>
+       new mode <mode>
+       deleted file mode <mode>
+       new file mode <mode>
+       copy from <path>
+       copy to <path>
+       rename from <path>
+       rename to <path>
+       similarity index <number>
+       dissimilarity index <number>
+       index <hash>..<hash> <mode>
++
+File modes are printed as 6-digit octal numbers including the file type
+and file permission bits.
++
+Path names in extended headers do not include the `a/` and `b/` prefixes.
++
+The similarity index is the percentage of unchanged lines, and
+the dissimilarity index is the percentage of changed lines.  It
+is a rounded down integer, followed by a percent sign.  The
+similarity index value of 100% is thus reserved for two equal
+files, while 100% dissimilarity means that no line from the old
+file made it into the new one.
++
+The index line includes the SHA-1 checksum before and after the change.
+The <mode> is included if the file mode does not change; otherwise,
+separate lines indicate the old and the new mode.
+
+3.  Pathnames with "unusual" characters are quoted as explained for
+    the configuration variable `core.quotePath` (see
+    linkgit:git-config[1]).
+
+4.  All the `file1` files in the output refer to files before the
+    commit, and all the `file2` files refer to files after the commit.
+    It is incorrect to apply each change to each file sequentially.  For
+    example, this patch will swap a and b:
+
+      diff --git a/a b/b
+      rename from a
+      rename to b
+      diff --git a/b b/a
+      rename from b
+      rename to a
+
+
+combined diff format
+--------------------
+
+Any diff-generating command can take the `-c` or `--cc` option to
+produce a 'combined diff' when showing a merge. This is the default
+format when showing merges with linkgit:git-diff[1] or
+linkgit:git-show[1]. Note also that you can give the `-m` option to any
+of these commands to force generation of diffs with individual parents
+of a merge.
+
+A 'combined diff' format looks like this:
+
+------------
+diff --combined describe.c
+index fabadb8,cc95eb0..4866510
+--- a/describe.c
++++ b/describe.c
+@@@ -98,20 -98,12 +98,20 @@@
+	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
+  }
+
+- static void describe(char *arg)
+ -static void describe(struct commit *cmit, int last_one)
+++static void describe(char *arg, int last_one)
+  {
+ +	unsigned char sha1[20];
+ +	struct commit *cmit;
+	struct commit_list *list;
+	static int initialized = 0;
+	struct commit_name *n;
+
+ +	if (get_sha1(arg, sha1) < 0)
+ +		usage(describe_usage);
+ +	cmit = lookup_commit_reference(sha1);
+ +	if (!cmit)
+ +		usage(describe_usage);
+ +
+	if (!initialized) {
+		initialized = 1;
+		for_each_ref(get_name);
+------------
+
+1.   It is preceded with a "git diff" header, that looks like
+     this (when `-c` option is used):
+
+       diff --combined file
++
+or like this (when `--cc` option is used):
+
+       diff --cc file
+
+2.   It is followed by one or more extended header lines
+     (this example shows a merge with two parents):
+
+       index <hash>,<hash>..<hash>
+       mode <mode>,<mode>..<mode>
+       new file mode <mode>
+       deleted file mode <mode>,<mode>
++
+The `mode <mode>,<mode>..<mode>` line appears only if at least one of
+the <mode> is different from the rest. Extended headers with
+information about detected contents movement (renames and
+copying detection) are designed to work with diff of two
+<tree-ish> and are not used by combined diff format.
+
+3.   It is followed by two-line from-file/to-file header
+
+       --- a/file
+       +++ b/file
++
+Similar to two-line header for traditional 'unified' diff
+format, `/dev/null` is used to signal created or deleted
+files.
++
+However, if the --combined-all-paths option is provided, instead of a
+two-line from-file/to-file you get a N+1 line from-file/to-file header,
+where N is the number of parents in the merge commit
+
+       --- a/file
+       --- a/file
+       --- a/file
+       +++ b/file
++
+This extended format can be useful if rename or copy detection is
+active, to allow you to see the original name of the file in different
+parents.
+
+4.   Chunk header format is modified to prevent people from
+     accidentally feeding it to `patch -p1`. Combined diff format
+     was created for review of merge commit changes, and was not
+     meant for apply. The change is similar to the change in the
+     extended 'index' header:
+
+       @@@ <from-file-range> <from-file-range> <to-file-range> @@@
++
+There are (number of parents + 1) `@` characters in the chunk
+header for combined diff format.
+
+Unlike the traditional 'unified' diff format, which shows two
+files A and B with a single column that has `-` (minus --
+appears in A but removed in B), `+` (plus -- missing in A but
+added to B), or `" "` (space -- unchanged) prefix, this format
+compares two or more files file1, file2,... with one file X, and
+shows how X differs from each of fileN.  One column for each of
+fileN is prepended to the output line to note how X's line is
+different from it.
+
+A `-` character in the column N means that the line appears in
+fileN but it does not appear in the result.  A `+` character
+in the column N means that the line appears in the result,
+and fileN does not have that line (in other words, the line was
+added, from the point of view of that parent).
+
+In the above example output, the function signature was changed
+from both files (hence two `-` removals from both file1 and
+file2, plus `++` to mean one line that was added does not appear
+in either file1 or file2).  Also eight other lines are the same
+from file1 but do not appear in file2 (hence prefixed with `+`).
+
+When shown by `git diff-tree -c`, it compares the parents of a
+merge commit with the merge result (i.e. file1..fileN are the
+parents).  When shown by `git diff-files -c`, it compares the
+two unresolved merge parents with the working tree file
+(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
+"their version").
diff --git a/third_party/git/Documentation/diff-options.txt b/third_party/git/Documentation/diff-options.txt
new file mode 100644
index 0000000000..09faee3b44
--- /dev/null
+++ b/third_party/git/Documentation/diff-options.txt
@@ -0,0 +1,756 @@
+// Please don't remove this comment as asciidoc behaves badly when
+// the first non-empty line is ifdef/ifndef. The symptom is that
+// without this comment the <git-diff-core> attribute conditionally
+// defined below ends up being defined unconditionally.
+// Last checked with asciidoc 7.0.2.
+
+ifndef::git-format-patch[]
+ifndef::git-diff[]
+ifndef::git-log[]
+:git-diff-core: 1
+endif::git-log[]
+endif::git-diff[]
+endif::git-format-patch[]
+
+ifdef::git-format-patch[]
+-p::
+--no-stat::
+	Generate plain patches without any diffstats.
+endif::git-format-patch[]
+
+ifndef::git-format-patch[]
+-p::
+-u::
+--patch::
+	Generate patch (see section on generating patches).
+ifdef::git-diff[]
+	This is the default.
+endif::git-diff[]
+
+-s::
+--no-patch::
+	Suppress diff output. Useful for commands like `git show` that
+	show the patch by default, or to cancel the effect of `--patch`.
+endif::git-format-patch[]
+
+-U<n>::
+--unified=<n>::
+	Generate diffs with <n> lines of context instead of
+	the usual three. Implies `--patch`.
+ifndef::git-format-patch[]
+	Implies `-p`.
+endif::git-format-patch[]
+
+--output=<file>::
+	Output to a specific file instead of stdout.
+
+--output-indicator-new=<char>::
+--output-indicator-old=<char>::
+--output-indicator-context=<char>::
+	Specify the character used to indicate new, old or context
+	lines in the generated patch. Normally they are '+', '-' and
+	' ' respectively.
+
+ifndef::git-format-patch[]
+--raw::
+ifndef::git-log[]
+	Generate the diff in raw format.
+ifdef::git-diff-core[]
+	This is the default.
+endif::git-diff-core[]
+endif::git-log[]
+ifdef::git-log[]
+	For each commit, show a summary of changes using the raw diff
+	format. See the "RAW OUTPUT FORMAT" section of
+	linkgit:git-diff[1]. This is different from showing the log
+	itself in raw format, which you can achieve with
+	`--format=raw`.
+endif::git-log[]
+endif::git-format-patch[]
+
+ifndef::git-format-patch[]
+--patch-with-raw::
+	Synonym for `-p --raw`.
+endif::git-format-patch[]
+
+--indent-heuristic::
+	Enable the heuristic that shifts diff hunk boundaries to make patches
+	easier to read. This is the default.
+
+--no-indent-heuristic::
+	Disable the indent heuristic.
+
+--minimal::
+	Spend extra time to make sure the smallest possible
+	diff is produced.
+
+--patience::
+	Generate a diff using the "patience diff" algorithm.
+
+--histogram::
+	Generate a diff using the "histogram diff" algorithm.
+
+--anchored=<text>::
+	Generate a diff using the "anchored diff" algorithm.
++
+This option may be specified more than once.
++
+If a line exists in both the source and destination, exists only once,
+and starts with this text, this algorithm attempts to prevent it from
+appearing as a deletion or addition in the output. It uses the "patience
+diff" algorithm internally.
+
+--diff-algorithm={patience|minimal|histogram|myers}::
+	Choose a diff algorithm. The variants are as follows:
++
+--
+`default`, `myers`;;
+	The basic greedy diff algorithm. Currently, this is the default.
+`minimal`;;
+	Spend extra time to make sure the smallest possible diff is
+	produced.
+`patience`;;
+	Use "patience diff" algorithm when generating patches.
+`histogram`;;
+	This algorithm extends the patience algorithm to "support
+	low-occurrence common elements".
+--
++
+For instance, if you configured the `diff.algorithm` variable to a
+non-default value and want to use the default one, then you
+have to use `--diff-algorithm=default` option.
+
+--stat[=<width>[,<name-width>[,<count>]]]::
+	Generate a diffstat. By default, as much space as necessary
+	will be used for the filename part, and the rest for the graph
+	part. Maximum width defaults to terminal width, or 80 columns
+	if not connected to a terminal, and can be overridden by
+	`<width>`. The width of the filename part can be limited by
+	giving another width `<name-width>` after a comma. The width
+	of the graph part can be limited by using
+	`--stat-graph-width=<width>` (affects all commands generating
+	a stat graph) or by setting `diff.statGraphWidth=<width>`
+	(does not affect `git format-patch`).
+	By giving a third parameter `<count>`, you can limit the
+	output to the first `<count>` lines, followed by `...` if
+	there are more.
++
+These parameters can also be set individually with `--stat-width=<width>`,
+`--stat-name-width=<name-width>` and `--stat-count=<count>`.
+
+--compact-summary::
+	Output a condensed summary of extended header information such
+	as file creations or deletions ("new" or "gone", optionally "+l"
+	if it's a symlink) and mode changes ("+x" or "-x" for adding
+	or removing executable bit respectively) in diffstat. The
+	information is put between the filename part and the graph
+	part. Implies `--stat`.
+
+--numstat::
+	Similar to `--stat`, but shows number of added and
+	deleted lines in decimal notation and pathname without
+	abbreviation, to make it more machine friendly.  For
+	binary files, outputs two `-` instead of saying
+	`0 0`.
+
+--shortstat::
+	Output only the last line of the `--stat` format containing total
+	number of modified files, as well as number of added and deleted
+	lines.
+
+-X[<param1,param2,...>]::
+--dirstat[=<param1,param2,...>]::
+	Output the distribution of relative amount of changes for each
+	sub-directory. The behavior of `--dirstat` can be customized by
+	passing it a comma separated list of parameters.
+	The defaults are controlled by the `diff.dirstat` configuration
+	variable (see linkgit:git-config[1]).
+	The following parameters are available:
++
+--
+`changes`;;
+	Compute the dirstat numbers by counting the lines that have been
+	removed from the source, or added to the destination. This ignores
+	the amount of pure code movements within a file.  In other words,
+	rearranging lines in a file is not counted as much as other changes.
+	This is the default behavior when no parameter is given.
+`lines`;;
+	Compute the dirstat numbers by doing the regular line-based diff
+	analysis, and summing the removed/added line counts. (For binary
+	files, count 64-byte chunks instead, since binary files have no
+	natural concept of lines). This is a more expensive `--dirstat`
+	behavior than the `changes` behavior, but it does count rearranged
+	lines within a file as much as other changes. The resulting output
+	is consistent with what you get from the other `--*stat` options.
+`files`;;
+	Compute the dirstat numbers by counting the number of files changed.
+	Each changed file counts equally in the dirstat analysis. This is
+	the computationally cheapest `--dirstat` behavior, since it does
+	not have to look at the file contents at all.
+`cumulative`;;
+	Count changes in a child directory for the parent directory as well.
+	Note that when using `cumulative`, the sum of the percentages
+	reported may exceed 100%. The default (non-cumulative) behavior can
+	be specified with the `noncumulative` parameter.
+<limit>;;
+	An integer parameter specifies a cut-off percent (3% by default).
+	Directories contributing less than this percentage of the changes
+	are not shown in the output.
+--
++
+Example: The following will count changed files, while ignoring
+directories with less than 10% of the total amount of changed files,
+and accumulating child directory counts in the parent directories:
+`--dirstat=files,10,cumulative`.
+
+--cumulative::
+	Synonym for --dirstat=cumulative
+
+--dirstat-by-file[=<param1,param2>...]::
+	Synonym for --dirstat=files,param1,param2...
+
+--summary::
+	Output a condensed summary of extended header information
+	such as creations, renames and mode changes.
+
+ifndef::git-format-patch[]
+--patch-with-stat::
+	Synonym for `-p --stat`.
+endif::git-format-patch[]
+
+ifndef::git-format-patch[]
+
+-z::
+ifdef::git-log[]
+	Separate the commits with NULs instead of with new newlines.
++
+Also, when `--raw` or `--numstat` has been given, do not munge
+pathnames and use NULs as output field terminators.
+endif::git-log[]
+ifndef::git-log[]
+	When `--raw`, `--numstat`, `--name-only` or `--name-status` has been
+	given, do not munge pathnames and use NULs as output field terminators.
+endif::git-log[]
++
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
+
+--name-only::
+	Show only names of changed files.
+
+--name-status::
+	Show only names and status of changed files. See the description
+	of the `--diff-filter` option on what the status letters mean.
+
+--submodule[=<format>]::
+	Specify how differences in submodules are shown.  When specifying
+	`--submodule=short` the 'short' format is used.  This format just
+	shows the names of the commits at the beginning and end of the range.
+	When `--submodule` or `--submodule=log` is specified, the 'log'
+	format is used.  This format lists the commits in the range like
+	linkgit:git-submodule[1] `summary` does.  When `--submodule=diff`
+	is specified, the 'diff' format is used.  This format shows an
+	inline diff of the changes in the submodule contents between the
+	commit range.  Defaults to `diff.submodule` or the 'short' format
+	if the config option is unset.
+
+--color[=<when>]::
+	Show colored diff.
+	`--color` (i.e. without '=<when>') is the same as `--color=always`.
+	'<when>' can be one of `always`, `never`, or `auto`.
+ifdef::git-diff[]
+	It can be changed by the `color.ui` and `color.diff`
+	configuration settings.
+endif::git-diff[]
+
+--no-color::
+	Turn off colored diff.
+ifdef::git-diff[]
+	This can be used to override configuration settings.
+endif::git-diff[]
+	It is the same as `--color=never`.
+
+--color-moved[=<mode>]::
+	Moved lines of code are colored differently.
+ifdef::git-diff[]
+	It can be changed by the `diff.colorMoved` configuration setting.
+endif::git-diff[]
+	The <mode> defaults to 'no' if the option is not given
+	and to 'zebra' if the option with no mode is given.
+	The mode must be one of:
++
+--
+no::
+	Moved lines are not highlighted.
+default::
+	Is a synonym for `zebra`. This may change to a more sensible mode
+	in the future.
+plain::
+	Any line that is added in one location and was removed
+	in another location will be colored with 'color.diff.newMoved'.
+	Similarly 'color.diff.oldMoved' will be used for removed lines
+	that are added somewhere else in the diff. This mode picks up any
+	moved line, but it is not very useful in a review to determine
+	if a block of code was moved without permutation.
+blocks::
+	Blocks of moved text of at least 20 alphanumeric characters
+	are detected greedily. The detected blocks are
+	painted using either the 'color.diff.{old,new}Moved' color.
+	Adjacent blocks cannot be told apart.
+zebra::
+	Blocks of moved text are detected as in 'blocks' mode. The blocks
+	are painted using either the 'color.diff.{old,new}Moved' color or
+	'color.diff.{old,new}MovedAlternative'. The change between
+	the two colors indicates that a new block was detected.
+dimmed-zebra::
+	Similar to 'zebra', but additional dimming of uninteresting parts
+	of moved code is performed. The bordering lines of two adjacent
+	blocks are considered interesting, the rest is uninteresting.
+	`dimmed_zebra` is a deprecated synonym.
+--
+
+--no-color-moved::
+	Turn off move detection. This can be used to override configuration
+	settings. It is the same as `--color-moved=no`.
+
+--color-moved-ws=<modes>::
+	This configures how whitespace is ignored when performing the
+	move detection for `--color-moved`.
+ifdef::git-diff[]
+	It can be set by the `diff.colorMovedWS` configuration setting.
+endif::git-diff[]
+	These modes can be given as a comma separated list:
++
+--
+no::
+	Do not ignore whitespace when performing move detection.
+ignore-space-at-eol::
+	Ignore changes in whitespace at EOL.
+ignore-space-change::
+	Ignore changes in amount of whitespace.  This ignores whitespace
+	at line end, and considers all other sequences of one or
+	more whitespace characters to be equivalent.
+ignore-all-space::
+	Ignore whitespace when comparing lines. This ignores differences
+	even if one line has whitespace where the other line has none.
+allow-indentation-change::
+	Initially ignore any whitespace in the move detection, then
+	group the moved code blocks only into a block if the change in
+	whitespace is the same per line. This is incompatible with the
+	other modes.
+--
+
+--no-color-moved-ws::
+	Do not ignore whitespace when performing move detection. This can be
+	used to override configuration settings. It is the same as
+	`--color-moved-ws=no`.
+
+--word-diff[=<mode>]::
+	Show a word diff, using the <mode> to delimit changed words.
+	By default, words are delimited by whitespace; see
+	`--word-diff-regex` below.  The <mode> defaults to 'plain', and
+	must be one of:
++
+--
+color::
+	Highlight changed words using only colors.  Implies `--color`.
+plain::
+	Show words as `[-removed-]` and `{+added+}`.  Makes no
+	attempts to escape the delimiters if they appear in the input,
+	so the output may be ambiguous.
+porcelain::
+	Use a special line-based format intended for script
+	consumption.  Added/removed/unchanged runs are printed in the
+	usual unified diff format, starting with a `+`/`-`/` `
+	character at the beginning of the line and extending to the
+	end of the line.  Newlines in the input are represented by a
+	tilde `~` on a line of its own.
+none::
+	Disable word diff again.
+--
++
+Note that despite the name of the first mode, color is used to
+highlight the changed parts in all modes if enabled.
+
+--word-diff-regex=<regex>::
+	Use <regex> to decide what a word is, instead of considering
+	runs of non-whitespace to be a word.  Also implies
+	`--word-diff` unless it was already enabled.
++
+Every non-overlapping match of the
+<regex> is considered a word.  Anything between these matches is
+considered whitespace and ignored(!) for the purposes of finding
+differences.  You may want to append `|[^[:space:]]` to your regular
+expression to make sure that it matches all non-whitespace characters.
+A match that contains a newline is silently truncated(!) at the
+newline.
++
+For example, `--word-diff-regex=.` will treat each character as a word
+and, correspondingly, show differences character by character.
++
+The regex can also be set via a diff driver or configuration option, see
+linkgit:gitattributes[5] or linkgit:git-config[1].  Giving it explicitly
+overrides any diff driver or configuration setting.  Diff drivers
+override configuration settings.
+
+--color-words[=<regex>]::
+	Equivalent to `--word-diff=color` plus (if a regex was
+	specified) `--word-diff-regex=<regex>`.
+endif::git-format-patch[]
+
+--no-renames::
+	Turn off rename detection, even when the configuration
+	file gives the default to do so.
+
+--[no-]rename-empty::
+	Whether to use empty blobs as rename source.
+
+ifndef::git-format-patch[]
+--check::
+	Warn if changes introduce conflict markers or whitespace errors.
+	What are considered whitespace errors is controlled by `core.whitespace`
+	configuration.  By default, trailing whitespaces (including
+	lines that consist solely of whitespaces) and a space character
+	that is immediately followed by a tab character inside the
+	initial indent of the line are considered whitespace errors.
+	Exits with non-zero status if problems are found. Not compatible
+	with --exit-code.
+
+--ws-error-highlight=<kind>::
+	Highlight whitespace errors in the `context`, `old` or `new`
+	lines of the diff.  Multiple values are separated by comma,
+	`none` resets previous values, `default` reset the list to
+	`new` and `all` is a shorthand for `old,new,context`.  When
+	this option is not given, and the configuration variable
+	`diff.wsErrorHighlight` is not set, only whitespace errors in
+	`new` lines are highlighted. The whitespace errors are colored
+	with `color.diff.whitespace`.
+
+endif::git-format-patch[]
+
+--full-index::
+	Instead of the first handful of characters, show the full
+	pre- and post-image blob object names on the "index"
+	line when generating patch format output.
+
+--binary::
+	In addition to `--full-index`, output a binary diff that
+	can be applied with `git-apply`. Implies `--patch`.
+
+--abbrev[=<n>]::
+	Instead of showing the full 40-byte hexadecimal object
+	name in diff-raw format output and diff-tree header
+	lines, show only a partial prefix.  This is
+	independent of the `--full-index` option above, which controls
+	the diff-patch output format.  Non default number of
+	digits can be specified with `--abbrev=<n>`.
+
+-B[<n>][/<m>]::
+--break-rewrites[=[<n>][/<m>]]::
+	Break complete rewrite changes into pairs of delete and
+	create. This serves two purposes:
++
+It affects the way a change that amounts to a total rewrite of a file
+not as a series of deletion and insertion mixed together with a very
+few lines that happen to match textually as the context, but as a
+single deletion of everything old followed by a single insertion of
+everything new, and the number `m` controls this aspect of the -B
+option (defaults to 60%). `-B/70%` specifies that less than 30% of the
+original should remain in the result for Git to consider it a total
+rewrite (i.e. otherwise the resulting patch will be a series of
+deletion and insertion mixed together with context lines).
++
+When used with -M, a totally-rewritten file is also considered as the
+source of a rename (usually -M only considers a file that disappeared
+as the source of a rename), and the number `n` controls this aspect of
+the -B option (defaults to 50%). `-B20%` specifies that a change with
+addition and deletion compared to 20% or more of the file's size are
+eligible for being picked up as a possible source of a rename to
+another file.
+
+-M[<n>]::
+--find-renames[=<n>]::
+ifndef::git-log[]
+	Detect renames.
+endif::git-log[]
+ifdef::git-log[]
+	If generating diffs, detect and report renames for each commit.
+	For following files across renames while traversing history, see
+	`--follow`.
+endif::git-log[]
+	If `n` is specified, it is a threshold on the similarity
+	index (i.e. amount of addition/deletions compared to the
+	file's size). For example, `-M90%` means Git should consider a
+	delete/add pair to be a rename if more than 90% of the file
+	hasn't changed.  Without a `%` sign, the number is to be read as
+	a fraction, with a decimal point before it.  I.e., `-M5` becomes
+	0.5, and is thus the same as `-M50%`.  Similarly, `-M05` is
+	the same as `-M5%`.  To limit detection to exact renames, use
+	`-M100%`.  The default similarity index is 50%.
+
+-C[<n>]::
+--find-copies[=<n>]::
+	Detect copies as well as renames.  See also `--find-copies-harder`.
+	If `n` is specified, it has the same meaning as for `-M<n>`.
+
+--find-copies-harder::
+	For performance reasons, by default, `-C` option finds copies only
+	if the original file of the copy was modified in the same
+	changeset.  This flag makes the command
+	inspect unmodified files as candidates for the source of
+	copy.  This is a very expensive operation for large
+	projects, so use it with caution.  Giving more than one
+	`-C` option has the same effect.
+
+-D::
+--irreversible-delete::
+	Omit the preimage for deletes, i.e. print only the header but not
+	the diff between the preimage and `/dev/null`. The resulting patch
+	is not meant to be applied with `patch` or `git apply`; this is
+	solely for people who want to just concentrate on reviewing the
+	text after the change. In addition, the output obviously lacks
+	enough information to apply such a patch in reverse, even manually,
+	hence the name of the option.
++
+When used together with `-B`, omit also the preimage in the deletion part
+of a delete/create pair.
+
+-l<num>::
+	The `-M` and `-C` options require O(n^2) processing time where n
+	is the number of potential rename/copy targets.  This
+	option prevents rename/copy detection from running if
+	the number of rename/copy targets exceeds the specified
+	number.
+
+ifndef::git-format-patch[]
+--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]::
+	Select only files that are Added (`A`), Copied (`C`),
+	Deleted (`D`), Modified (`M`), Renamed (`R`), have their
+	type (i.e. regular file, symlink, submodule, ...) changed (`T`),
+	are Unmerged (`U`), are
+	Unknown (`X`), or have had their pairing Broken (`B`).
+	Any combination of the filter characters (including none) can be used.
+	When `*` (All-or-none) is added to the combination, all
+	paths are selected if there is any file that matches
+	other criteria in the comparison; if there is no file
+	that matches other criteria, nothing is selected.
++
+Also, these upper-case letters can be downcased to exclude.  E.g.
+`--diff-filter=ad` excludes added and deleted paths.
++
+Note that not all diffs can feature all types. For instance, diffs
+from the index to the working tree can never have Added entries
+(because the set of paths included in the diff is limited by what is in
+the index).  Similarly, copied and renamed entries cannot appear if
+detection for those types is disabled.
+
+-S<string>::
+	Look for differences that change the number of occurrences of
+	the specified string (i.e. addition/deletion) in a file.
+	Intended for the scripter's use.
++
+It is useful when you're looking for an exact block of code (like a
+struct), and want to know the history of that block since it first
+came into being: use the feature iteratively to feed the interesting
+block in the preimage back into `-S`, and keep going until you get the
+very first version of the block.
++
+Binary files are searched as well.
+
+-G<regex>::
+	Look for differences whose patch text contains added/removed
+	lines that match <regex>.
++
+To illustrate the difference between `-S<regex> --pickaxe-regex` and
+`-G<regex>`, consider a commit with the following diff in the same
+file:
++
+----
++    return !regexec(regexp, two->ptr, 1, &regmatch, 0);
+...
+-    hit = !regexec(regexp, mf2.ptr, 1, &regmatch, 0);
+----
++
+While `git log -G"regexec\(regexp"` will show this commit, `git log
+-S"regexec\(regexp" --pickaxe-regex` will not (because the number of
+occurrences of that string did not change).
++
+Unless `--text` is supplied patches of binary files without a textconv
+filter will be ignored.
++
+See the 'pickaxe' entry in linkgit:gitdiffcore[7] for more
+information.
+
+--find-object=<object-id>::
+	Look for differences that change the number of occurrences of
+	the specified object. Similar to `-S`, just the argument is different
+	in that it doesn't search for a specific string but for a specific
+	object id.
++
+The object can be a blob or a submodule commit. It implies the `-t` option in
+`git-log` to also find trees.
+
+--pickaxe-all::
+	When `-S` or `-G` finds a change, show all the changes in that
+	changeset, not just the files that contain the change
+	in <string>.
+
+--pickaxe-regex::
+	Treat the <string> given to `-S` as an extended POSIX regular
+	expression to match.
+
+endif::git-format-patch[]
+
+-O<orderfile>::
+	Control the order in which files appear in the output.
+	This overrides the `diff.orderFile` configuration variable
+	(see linkgit:git-config[1]).  To cancel `diff.orderFile`,
+	use `-O/dev/null`.
++
+The output order is determined by the order of glob patterns in
+<orderfile>.
+All files with pathnames that match the first pattern are output
+first, all files with pathnames that match the second pattern (but not
+the first) are output next, and so on.
+All files with pathnames that do not match any pattern are output
+last, as if there was an implicit match-all pattern at the end of the
+file.
+If multiple pathnames have the same rank (they match the same pattern
+but no earlier patterns), their output order relative to each other is
+the normal order.
++
+<orderfile> is parsed as follows:
++
+--
+ - Blank lines are ignored, so they can be used as separators for
+   readability.
+
+ - Lines starting with a hash ("`#`") are ignored, so they can be used
+   for comments.  Add a backslash ("`\`") to the beginning of the
+   pattern if it starts with a hash.
+
+ - Each other line contains a single pattern.
+--
++
+Patterns have the same syntax and semantics as patterns used for
+fnmatch(3) without the FNM_PATHNAME flag, except a pathname also
+matches a pattern if removing any number of the final pathname
+components matches the pattern.  For example, the pattern "`foo*bar`"
+matches "`fooasdfbar`" and "`foo/bar/baz/asdf`" but not "`foobarx`".
+
+ifndef::git-format-patch[]
+-R::
+	Swap two inputs; that is, show differences from index or
+	on-disk file to tree contents.
+
+--relative[=<path>]::
+	When run from a subdirectory of the project, it can be
+	told to exclude changes outside the directory and show
+	pathnames relative to it with this option.  When you are
+	not in a subdirectory (e.g. in a bare repository), you
+	can name which subdirectory to make the output relative
+	to by giving a <path> as an argument.
+endif::git-format-patch[]
+
+-a::
+--text::
+	Treat all files as text.
+
+--ignore-cr-at-eol::
+	Ignore carriage-return at the end of line when doing a comparison.
+
+--ignore-space-at-eol::
+	Ignore changes in whitespace at EOL.
+
+-b::
+--ignore-space-change::
+	Ignore changes in amount of whitespace.  This ignores whitespace
+	at line end, and considers all other sequences of one or
+	more whitespace characters to be equivalent.
+
+-w::
+--ignore-all-space::
+	Ignore whitespace when comparing lines.  This ignores
+	differences even if one line has whitespace where the other
+	line has none.
+
+--ignore-blank-lines::
+	Ignore changes whose lines are all blank.
+
+--inter-hunk-context=<lines>::
+	Show the context between diff hunks, up to the specified number
+	of lines, thereby fusing hunks that are close to each other.
+	Defaults to `diff.interHunkContext` or 0 if the config option
+	is unset.
+
+-W::
+--function-context::
+	Show whole surrounding functions of changes.
+
+ifndef::git-format-patch[]
+ifndef::git-log[]
+--exit-code::
+	Make the program exit with codes similar to diff(1).
+	That is, it exits with 1 if there were differences and
+	0 means no differences.
+
+--quiet::
+	Disable all output of the program. Implies `--exit-code`.
+endif::git-log[]
+endif::git-format-patch[]
+
+--ext-diff::
+	Allow an external diff helper to be executed. If you set an
+	external diff driver with linkgit:gitattributes[5], you need
+	to use this option with linkgit:git-log[1] and friends.
+
+--no-ext-diff::
+	Disallow external diff drivers.
+
+--textconv::
+--no-textconv::
+	Allow (or disallow) external text conversion filters to be run
+	when comparing binary files. See linkgit:gitattributes[5] for
+	details. Because textconv filters are typically a one-way
+	conversion, the resulting diff is suitable for human
+	consumption, but cannot be applied. For this reason, textconv
+	filters are enabled by default only for linkgit:git-diff[1] and
+	linkgit:git-log[1], but not for linkgit:git-format-patch[1] or
+	diff plumbing commands.
+
+--ignore-submodules[=<when>]::
+	Ignore changes to submodules in the diff generation. <when> can be
+	either "none", "untracked", "dirty" or "all", which is the default.
+	Using "none" will consider the submodule modified when it either contains
+	untracked or modified files or its HEAD differs from the commit recorded
+	in the superproject and can be used to override any settings of the
+	'ignore' option in linkgit:git-config[1] or linkgit:gitmodules[5]. When
+	"untracked" is used submodules are not considered dirty when they only
+	contain untracked content (but they are still scanned for modified
+	content). Using "dirty" ignores all changes to the work tree of submodules,
+	only changes to the commits stored in the superproject are shown (this was
+	the behavior until 1.7.0). Using "all" hides all changes to submodules.
+
+--src-prefix=<prefix>::
+	Show the given source prefix instead of "a/".
+
+--dst-prefix=<prefix>::
+	Show the given destination prefix instead of "b/".
+
+--no-prefix::
+	Do not show any source or destination prefix.
+
+--line-prefix=<prefix>::
+	Prepend an additional prefix to every line of output.
+
+--ita-invisible-in-index::
+	By default entries added by "git add -N" appear as an existing
+	empty file in "git diff" and a new file in "git diff --cached".
+	This option makes the entry appear as a new file in "git diff"
+	and non-existent in "git diff --cached". This option could be
+	reverted with `--ita-visible-in-index`. Both options are
+	experimental and could be removed in future.
+
+For more detailed explanation on these common options, see also
+linkgit:gitdiffcore[7].
diff --git a/third_party/git/Documentation/doc-diff b/third_party/git/Documentation/doc-diff
new file mode 100755
index 0000000000..3355be4798
--- /dev/null
+++ b/third_party/git/Documentation/doc-diff
@@ -0,0 +1,187 @@
+#!/bin/sh
+#
+# Build two documentation trees and diff the resulting formatted output.
+# Compared to a source diff, this can reveal mistakes in the formatting.
+# For example:
+#
+#   ./doc-diff origin/master HEAD
+#
+# would show the differences introduced by a branch based on master.
+
+OPTIONS_SPEC="\
+doc-diff [options] <from> <to> [-- <diff-options>]
+doc-diff (-c|--clean)
+--
+j=n			parallel argument to pass to make
+f			force rebuild; do not rely on cached results
+c,clean			cleanup temporary working files
+from-asciidoc		use asciidoc with the 'from'-commit
+from-asciidoctor	use asciidoctor with the 'from'-commit
+asciidoc		use asciidoc with both commits
+to-asciidoc		use asciidoc with the 'to'-commit
+to-asciidoctor		use asciidoctor with the 'to'-commit
+asciidoctor		use asciidoctor with both commits
+cut-header-footer	cut away header and footer
+"
+SUBDIRECTORY_OK=1
+. "$(git --exec-path)/git-sh-setup"
+
+parallel=
+force=
+clean=
+from_program=
+to_program=
+cut_header_footer=
+while test $# -gt 0
+do
+	case "$1" in
+	-j)
+		parallel=$2; shift ;;
+	-c|--clean)
+		clean=t ;;
+	-f)
+		force=t ;;
+	--from-asciidoctor)
+		from_program=-asciidoctor ;;
+	--to-asciidoctor)
+		to_program=-asciidoctor ;;
+	--asciidoctor)
+		from_program=-asciidoctor
+		to_program=-asciidoctor ;;
+	--from-asciidoc)
+		from_program=-asciidoc ;;
+	--to-asciidoc)
+		to_program=-asciidoc ;;
+	--asciidoc)
+		from_program=-asciidoc
+		to_program=-asciidoc ;;
+	--cut-header-footer)
+		cut_header_footer=-cut-header-footer ;;
+	--)
+		shift; break ;;
+	*)
+		usage ;;
+	esac
+	shift
+done
+
+tmp="$(git rev-parse --show-toplevel)/Documentation/tmp-doc-diff" || exit 1
+
+if test -n "$clean"
+then
+	test $# -eq 0 || usage
+	git worktree remove --force "$tmp/worktree" 2>/dev/null
+	rm -rf "$tmp"
+	exit 0
+fi
+
+if test -z "$parallel"
+then
+	parallel=$(getconf _NPROCESSORS_ONLN 2>/dev/null)
+	if test $? != 0 || test -z "$parallel"
+	then
+		parallel=1
+	fi
+fi
+
+test $# -gt 1 || usage
+from=$1; shift
+to=$1; shift
+
+from_oid=$(git rev-parse --verify "$from") || exit 1
+to_oid=$(git rev-parse --verify "$to") || exit 1
+
+if test -n "$force"
+then
+	rm -rf "$tmp"
+fi
+
+# We'll do both builds in a single worktree, which lets "make" reuse
+# results that don't differ between the two trees.
+if ! test -d "$tmp/worktree"
+then
+	git worktree add -f --detach "$tmp/worktree" "$from" &&
+	dots=$(echo "$tmp/worktree" | sed 's#[^/]*#..#g') &&
+	ln -s "$dots/config.mak" "$tmp/worktree/config.mak"
+fi
+
+construct_makemanflags () {
+	if test "$1" = "-asciidoc"
+	then
+		echo USE_ASCIIDOCTOR=
+	elif test "$1" = "-asciidoctor"
+	then
+		echo USE_ASCIIDOCTOR=YesPlease
+	fi
+}
+
+from_makemanflags=$(construct_makemanflags "$from_program") &&
+to_makemanflags=$(construct_makemanflags "$to_program") &&
+
+from_dir=$from_oid$from_program$cut_header_footer &&
+to_dir=$to_oid$to_program$cut_header_footer &&
+
+# generate_render_makefile <srcdir> <dstdir>
+generate_render_makefile () {
+	find "$1" -type f |
+	while read src
+	do
+		dst=$2/${src#$1/}
+		printf 'all:: %s\n' "$dst"
+		printf '%s: %s\n' "$dst" "$src"
+		printf '\t@echo >&2 "  RENDER $(notdir $@)" && \\\n'
+		printf '\tmkdir -p $(dir $@) && \\\n'
+		printf '\tMANWIDTH=80 man $< >$@+ && \\\n'
+		printf '\tmv $@+ $@\n'
+	done
+}
+
+# render_tree <committish_oid> <directory_name> <makemanflags>
+render_tree () {
+	# Skip install-man entirely if we already have an installed directory.
+	# We can't rely on make here, since "install-man" unconditionally
+	# copies the files (spending effort, but also updating timestamps that
+	# we then can't rely on during the render step). We use "mv" to make
+	# sure we don't get confused by a previous run that failed partway
+	# through.
+	oid=$1 &&
+	dname=$2 &&
+	makemanflags=$3 &&
+	if ! test -d "$tmp/installed/$dname"
+	then
+		git -C "$tmp/worktree" checkout --detach "$oid" &&
+		make -j$parallel -C "$tmp/worktree" \
+			$makemanflags \
+			GIT_VERSION=omitted \
+			SOURCE_DATE_EPOCH=0 \
+			DESTDIR="$tmp/installed/$dname+" \
+			install-man &&
+		mv "$tmp/installed/$dname+" "$tmp/installed/$dname"
+	fi &&
+
+	# As with "installed" above, we skip the render if it's already been
+	# done.  So using make here is primarily just about running in
+	# parallel.
+	if ! test -d "$tmp/rendered/$dname"
+	then
+		generate_render_makefile "$tmp/installed/$dname" \
+			"$tmp/rendered/$dname+" |
+		make -j$parallel -f - &&
+		mv "$tmp/rendered/$dname+" "$tmp/rendered/$dname"
+
+		if test "$cut_header_footer" = "-cut-header-footer"
+		then
+			for f in $(find "$tmp/rendered/$dname" -type f)
+			do
+				tail -n +3 "$f" | head -n -2 |
+				sed -e '1{/^$/d}' -e '${/^$/d}' >"$f+" &&
+				mv "$f+" "$f" ||
+				return 1
+			done
+		fi
+	fi
+}
+
+render_tree $from_oid $from_dir $from_makemanflags &&
+render_tree $to_oid $to_dir $to_makemanflags &&
+git -C $tmp/rendered diff --no-index "$@" $from_dir $to_dir
diff --git a/third_party/git/Documentation/docbook-xsl.css b/third_party/git/Documentation/docbook-xsl.css
new file mode 100644
index 0000000000..e11c8f053a
--- /dev/null
+++ b/third_party/git/Documentation/docbook-xsl.css
@@ -0,0 +1,296 @@
+/*
+  CSS stylesheet for XHTML produced by DocBook XSL stylesheets.
+  Tested with XSL stylesheets 1.61.2, 1.67.2
+*/
+
+span.strong {
+  font-weight: bold;
+}
+
+body blockquote {
+  margin-top: .75em;
+  line-height: 1.5;
+  margin-bottom: .75em;
+}
+
+html body {
+  margin: 1em 5% 1em 5%;
+  line-height: 1.2;
+  font-family: sans-serif;
+}
+
+body div {
+  margin: 0;
+}
+
+h1, h2, h3, h4, h5, h6,
+div.toc p b,
+div.list-of-figures p b,
+div.list-of-tables p b,
+div.abstract p.title
+{
+  color: #527bbd;
+  font-family: tahoma, verdana, sans-serif;
+}
+
+div.toc p:first-child,
+div.list-of-figures p:first-child,
+div.list-of-tables p:first-child,
+div.example p.title
+{
+  margin-bottom: 0.2em;
+}
+
+body h1 {
+  margin: .0em 0 0 -4%;
+  line-height: 1.3;
+  border-bottom: 2px solid silver;
+}
+
+body h2 {
+  margin: 0.5em 0 0 -4%;
+  line-height: 1.3;
+  border-bottom: 2px solid silver;
+}
+
+body h3 {
+  margin: .8em 0 0 -3%;
+  line-height: 1.3;
+}
+
+body h4 {
+  margin: .8em 0 0 -3%;
+  line-height: 1.3;
+}
+
+body h5 {
+  margin: .8em 0 0 -2%;
+  line-height: 1.3;
+}
+
+body h6 {
+  margin: .8em 0 0 -1%;
+  line-height: 1.3;
+}
+
+body hr {
+  border: none; /* Broken on IE6 */
+}
+div.footnotes hr {
+  border: 1px solid silver;
+}
+
+div.navheader th, div.navheader td, div.navfooter td {
+  font-family: sans-serif;
+  font-size: 0.9em;
+  font-weight: bold;
+  color: #527bbd;
+}
+div.navheader img, div.navfooter img {
+  border-style: none;
+}
+div.navheader a, div.navfooter a {
+  font-weight: normal;
+}
+div.navfooter hr {
+  border: 1px solid silver;
+}
+
+body td {
+  line-height: 1.2
+}
+
+body th {
+  line-height: 1.2;
+}
+
+ol {
+  line-height: 1.2;
+}
+
+ul, body dir, body menu {
+  line-height: 1.2;
+}
+
+html {
+  margin: 0;
+  padding: 0;
+}
+
+body h1, body h2, body h3, body h4, body h5, body h6 {
+  margin-left: 0
+}
+
+body pre {
+  margin: 0.5em 10% 0.5em 1em;
+  line-height: 1.0;
+  color: navy;
+}
+
+tt.literal, code.literal {
+  color: navy;
+  font-family: sans-serif;
+}
+
+code.literal:before { content: "'"; }
+code.literal:after { content: "'"; }
+
+em {
+  font-style: italic;
+  color: #064;
+}
+
+div.literallayout p {
+  padding: 0em;
+  margin: 0em;
+}
+
+div.literallayout {
+  font-family: monospace;
+  margin: 0em;
+  color: navy;
+  border: 1px solid silver;
+  background: #f4f4f4;
+  padding: 0.5em;
+}
+
+.programlisting, .screen {
+  border: 1px solid silver;
+  background: #f4f4f4;
+  margin: 0.5em 10% 0.5em 0;
+  padding: 0.5em 1em;
+}
+
+div.sidebar {
+  background: #ffffee;
+  margin: 1.0em 10% 0.5em 0;
+  padding: 0.5em 1em;
+  border: 1px solid silver;
+}
+div.sidebar * { padding: 0; }
+div.sidebar div { margin: 0; }
+div.sidebar p.title {
+  font-family: sans-serif;
+  margin-top: 0.5em;
+  margin-bottom: 0.2em;
+}
+
+div.bibliomixed {
+  margin: 0.5em 5% 0.5em 1em;
+}
+
+div.glossary dt {
+  font-weight: bold;
+}
+div.glossary dd p {
+  margin-top: 0.2em;
+}
+
+dl {
+  margin: .8em 0;
+  line-height: 1.2;
+}
+
+dt {
+  margin-top: 0.5em;
+}
+
+dt span.term {
+  font-style: normal;
+  color: navy;
+}
+
+div.variablelist dd p {
+  margin-top: 0;
+}
+
+div.itemizedlist li, div.orderedlist li {
+  margin-left: -0.8em;
+  margin-top: 0.5em;
+}
+
+ul, ol {
+    list-style-position: outside;
+}
+
+div.sidebar ul, div.sidebar ol {
+    margin-left: 2.8em;
+}
+
+div.itemizedlist p.title,
+div.orderedlist p.title,
+div.variablelist p.title
+{
+  margin-bottom: -0.8em;
+}
+
+div.revhistory table {
+  border-collapse: collapse;
+  border: none;
+}
+div.revhistory th {
+  border: none;
+  color: #527bbd;
+  font-family: tahoma, verdana, sans-serif;
+}
+div.revhistory td {
+  border: 1px solid silver;
+}
+
+/* Keep TOC and index lines close together. */
+div.toc dl, div.toc dt,
+div.list-of-figures dl, div.list-of-figures dt,
+div.list-of-tables dl, div.list-of-tables dt,
+div.indexdiv dl, div.indexdiv dt
+{
+  line-height: normal;
+  margin-top: 0;
+  margin-bottom: 0;
+}
+
+/*
+  Table styling does not work because of overriding attributes in
+  generated HTML.
+*/
+div.table table,
+div.informaltable table
+{
+    margin-left: 0;
+    margin-right: 5%;
+    margin-bottom: 0.8em;
+}
+div.informaltable table
+{
+    margin-top: 0.4em
+}
+div.table thead,
+div.table tfoot,
+div.table tbody,
+div.informaltable thead,
+div.informaltable tfoot,
+div.informaltable tbody
+{
+    /* No effect in IE6. */
+    border-top: 2px solid #527bbd;
+    border-bottom: 2px solid #527bbd;
+}
+div.table thead, div.table tfoot,
+div.informaltable thead, div.informaltable tfoot
+{
+    font-weight: bold;
+}
+
+div.mediaobject img {
+    border: 1px solid silver;
+    margin-bottom: 0.8em;
+}
+div.figure p.title,
+div.table p.title
+{
+  margin-top: 1em;
+  margin-bottom: 0.4em;
+}
+
+@media print {
+  div.navheader, div.navfooter { display: none; }
+}
diff --git a/third_party/git/Documentation/docbook.xsl b/third_party/git/Documentation/docbook.xsl
new file mode 100644
index 0000000000..da8b05b922
--- /dev/null
+++ b/third_party/git/Documentation/docbook.xsl
@@ -0,0 +1,8 @@
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version='1.0'>
+ <xsl:import href="http://docbook.sourceforge.net/release/xsl/current/html/docbook.xsl"/>
+ <xsl:output method="html"
+     encoding="UTF-8" indent="no"
+     doctype-public="-//W3C//DTD HTML 4.01//EN"
+     doctype-system="http://www.w3.org/TR/html4/strict.dtd" />
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/everyday.txto b/third_party/git/Documentation/everyday.txto
new file mode 100644
index 0000000000..ae555bd47e
--- /dev/null
+++ b/third_party/git/Documentation/everyday.txto
@@ -0,0 +1,9 @@
+Everyday Git With 20 Commands Or So
+===================================
+
+This document has been moved to linkgit:giteveryday[7].
+
+Please let the owners of the referring site know so that they can update the
+link you clicked to get here.
+
+Thanks.
diff --git a/third_party/git/Documentation/fetch-options.txt b/third_party/git/Documentation/fetch-options.txt
new file mode 100644
index 0000000000..3c9b4f9e09
--- /dev/null
+++ b/third_party/git/Documentation/fetch-options.txt
@@ -0,0 +1,247 @@
+--all::
+	Fetch all remotes.
+
+-a::
+--append::
+	Append ref names and object names of fetched refs to the
+	existing contents of `.git/FETCH_HEAD`.  Without this
+	option old data in `.git/FETCH_HEAD` will be overwritten.
+
+--depth=<depth>::
+	Limit fetching to the specified number of commits from the tip of
+	each remote branch history. If fetching to a 'shallow' repository
+	created by `git clone` with `--depth=<depth>` option (see
+	linkgit:git-clone[1]), deepen or shorten the history to the specified
+	number of commits. Tags for the deepened commits are not fetched.
+
+--deepen=<depth>::
+	Similar to --depth, except it specifies the number of commits
+	from the current shallow boundary instead of from the tip of
+	each remote branch history.
+
+--shallow-since=<date>::
+	Deepen or shorten the history of a shallow repository to
+	include all reachable commits after <date>.
+
+--shallow-exclude=<revision>::
+	Deepen or shorten the history of a shallow repository to
+	exclude commits reachable from a specified remote branch or tag.
+	This option can be specified multiple times.
+
+--unshallow::
+	If the source repository is complete, convert a shallow
+	repository to a complete one, removing all the limitations
+	imposed by shallow repositories.
++
+If the source repository is shallow, fetch as much as possible so that
+the current repository has the same history as the source repository.
+
+--update-shallow::
+	By default when fetching from a shallow repository,
+	`git fetch` refuses refs that require updating
+	.git/shallow. This option updates .git/shallow and accept such
+	refs.
+
+--negotiation-tip=<commit|glob>::
+	By default, Git will report, to the server, commits reachable
+	from all local refs to find common commits in an attempt to
+	reduce the size of the to-be-received packfile. If specified,
+	Git will only report commits reachable from the given tips.
+	This is useful to speed up fetches when the user knows which
+	local ref is likely to have commits in common with the
+	upstream ref being fetched.
++
+This option may be specified more than once; if so, Git will report
+commits reachable from any of the given commits.
++
+The argument to this option may be a glob on ref names, a ref, or the (possibly
+abbreviated) SHA-1 of a commit. Specifying a glob is equivalent to specifying
+this option multiple times, one for each matching ref name.
++
+See also the `fetch.negotiationAlgorithm` configuration variable
+documented in linkgit:git-config[1].
+
+ifndef::git-pull[]
+--dry-run::
+	Show what would be done, without making any changes.
+endif::git-pull[]
+
+-f::
+--force::
+	When 'git fetch' is used with `<src>:<dst>` refspec it may
+	refuse to update the local branch as discussed
+ifdef::git-pull[]
+	in the `<refspec>` part of the linkgit:git-fetch[1]
+	documentation.
+endif::git-pull[]
+ifndef::git-pull[]
+	in the `<refspec>` part below.
+endif::git-pull[]
+	This option overrides that check.
+
+-k::
+--keep::
+	Keep downloaded pack.
+
+ifndef::git-pull[]
+--multiple::
+	Allow several <repository> and <group> arguments to be
+	specified. No <refspec>s may be specified.
+
+--[no-]auto-gc::
+	Run `git gc --auto` at the end to perform garbage collection
+	if needed. This is enabled by default.
+
+-p::
+--prune::
+	Before fetching, remove any remote-tracking references that no
+	longer exist on the remote.  Tags are not subject to pruning
+	if they are fetched only because of the default tag
+	auto-following or due to a --tags option.  However, if tags
+	are fetched due to an explicit refspec (either on the command
+	line or in the remote configuration, for example if the remote
+	was cloned with the --mirror option), then they are also
+	subject to pruning. Supplying `--prune-tags` is a shorthand for
+	providing the tag refspec.
++
+See the PRUNING section below for more details.
+
+-P::
+--prune-tags::
+	Before fetching, remove any local tags that no longer exist on
+	the remote if `--prune` is enabled. This option should be used
+	more carefully, unlike `--prune` it will remove any local
+	references (local tags) that have been created. This option is
+	a shorthand for providing the explicit tag refspec along with
+	`--prune`, see the discussion about that in its documentation.
++
+See the PRUNING section below for more details.
+
+endif::git-pull[]
+
+ifndef::git-pull[]
+-n::
+endif::git-pull[]
+--no-tags::
+	By default, tags that point at objects that are downloaded
+	from the remote repository are fetched and stored locally.
+	This option disables this automatic tag following. The default
+	behavior for a remote may be specified with the remote.<name>.tagOpt
+	setting. See linkgit:git-config[1].
+
+ifndef::git-pull[]
+--refmap=<refspec>::
+	When fetching refs listed on the command line, use the
+	specified refspec (can be given more than once) to map the
+	refs to remote-tracking branches, instead of the values of
+	`remote.*.fetch` configuration variables for the remote
+	repository.  See section on "Configured Remote-tracking
+	Branches" for details.
+
+-t::
+--tags::
+	Fetch all tags from the remote (i.e., fetch remote tags
+	`refs/tags/*` into local tags with the same name), in addition
+	to whatever else would otherwise be fetched.  Using this
+	option alone does not subject tags to pruning, even if --prune
+	is used (though tags may be pruned anyway if they are also the
+	destination of an explicit refspec; see `--prune`).
+
+--recurse-submodules[=yes|on-demand|no]::
+	This option controls if and under what conditions new commits of
+	populated submodules should be fetched too. It can be used as a
+	boolean option to completely disable recursion when set to 'no' or to
+	unconditionally recurse into all populated submodules when set to
+	'yes', which is the default when this option is used without any
+	value. Use 'on-demand' to only recurse into a populated submodule
+	when the superproject retrieves a commit that updates the submodule's
+	reference to a commit that isn't already in the local submodule
+	clone.
+
+-j::
+--jobs=<n>::
+	Number of parallel children to be used for fetching submodules.
+	Each will fetch from different submodules, such that fetching many
+	submodules will be faster. By default submodules will be fetched
+	one at a time.
+
+--no-recurse-submodules::
+	Disable recursive fetching of submodules (this has the same effect as
+	using the `--recurse-submodules=no` option).
+
+--submodule-prefix=<path>::
+	Prepend <path> to paths printed in informative messages
+	such as "Fetching submodule foo".  This option is used
+	internally when recursing over submodules.
+
+--recurse-submodules-default=[yes|on-demand]::
+	This option is used internally to temporarily provide a
+	non-negative default value for the --recurse-submodules
+	option.  All other methods of configuring fetch's submodule
+	recursion (such as settings in linkgit:gitmodules[5] and
+	linkgit:git-config[1]) override this option, as does
+	specifying --[no-]recurse-submodules directly.
+endif::git-pull[]
+
+-u::
+--update-head-ok::
+	By default 'git fetch' refuses to update the head which
+	corresponds to the current branch.  This flag disables the
+	check.  This is purely for the internal use for 'git pull'
+	to communicate with 'git fetch', and unless you are
+	implementing your own Porcelain you are not supposed to
+	use it.
+
+--upload-pack <upload-pack>::
+	When given, and the repository to fetch from is handled
+	by 'git fetch-pack', `--exec=<upload-pack>` is passed to
+	the command to specify non-default path for the command
+	run on the other end.
+
+ifndef::git-pull[]
+-q::
+--quiet::
+	Pass --quiet to git-fetch-pack and silence any other internally
+	used git commands. Progress is not reported to the standard error
+	stream.
+
+-v::
+--verbose::
+	Be verbose.
+endif::git-pull[]
+
+--progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless -q
+	is specified. This flag forces progress status even if the
+	standard error stream is not directed to a terminal.
+
+-o <option>::
+--server-option=<option>::
+	Transmit the given string to the server when communicating using
+	protocol version 2.  The given string must not contain a NUL or LF
+	character.  The server's handling of server options, including
+	unknown ones, is server-specific.
+	When multiple `--server-option=<option>` are given, they are all
+	sent to the other side in the order listed on the command line.
+
+--show-forced-updates::
+	By default, git checks if a branch is force-updated during
+	fetch. This can be disabled through fetch.showForcedUpdates, but
+	the --show-forced-updates option guarantees this check occurs.
+	See linkgit:git-config[1].
+
+--no-show-forced-updates::
+	By default, git checks if a branch is force-updated during
+	fetch. Pass --no-show-forced-updates or set fetch.showForcedUpdates
+	to false to skip this check for performance reasons. If used during
+	'git-pull' the --ff-only option will still check for forced updates
+	before attempting a fast-forward update. See linkgit:git-config[1].
+
+-4::
+--ipv4::
+	Use IPv4 addresses only, ignoring IPv6 addresses.
+
+-6::
+--ipv6::
+	Use IPv6 addresses only, ignoring IPv4 addresses.
diff --git a/third_party/git/Documentation/fix-texi.perl b/third_party/git/Documentation/fix-texi.perl
new file mode 100755
index 0000000000..ff7d78f620
--- /dev/null
+++ b/third_party/git/Documentation/fix-texi.perl
@@ -0,0 +1,15 @@
+#!/usr/bin/perl -w
+
+while (<>) {
+	if (/^\@setfilename/) {
+		$_ = "\@setfilename git.info\n";
+	} elsif (/^\@direntry/) {
+		print '@dircategory Development
+@direntry
+* Git: (git).           A fast distributed revision control system
+@end direntry
+';	}
+	unless (/^\@direntry/../^\@end direntry/) {
+		print;
+	}
+}
diff --git a/third_party/git/Documentation/git-add.txt b/third_party/git/Documentation/git-add.txt
new file mode 100644
index 0000000000..8b0e4c7fa8
--- /dev/null
+++ b/third_party/git/Documentation/git-add.txt
@@ -0,0 +1,424 @@
+git-add(1)
+==========
+
+NAME
+----
+git-add - Add file contents to the index
+
+SYNOPSIS
+--------
+[verse]
+'git add' [--verbose | -v] [--dry-run | -n] [--force | -f] [--interactive | -i] [--patch | -p]
+	  [--edit | -e] [--[no-]all | --[no-]ignore-removal | [--update | -u]]
+	  [--intent-to-add | -N] [--refresh] [--ignore-errors] [--ignore-missing] [--renormalize]
+	  [--chmod=(+|-)x] [--] [<pathspec>...]
+
+DESCRIPTION
+-----------
+This command updates the index using the current content found in
+the working tree, to prepare the content staged for the next commit.
+It typically adds the current content of existing paths as a whole,
+but with some options it can also be used to add content with
+only part of the changes made to the working tree files applied, or
+remove paths that do not exist in the working tree anymore.
+
+The "index" holds a snapshot of the content of the working tree, and it
+is this snapshot that is taken as the contents of the next commit.  Thus
+after making any changes to the working tree, and before running
+the commit command, you must use the `add` command to add any new or
+modified files to the index.
+
+This command can be performed multiple times before a commit.  It only
+adds the content of the specified file(s) at the time the add command is
+run; if you want subsequent changes included in the next commit, then
+you must run `git add` again to add the new content to the index.
+
+The `git status` command can be used to obtain a summary of which
+files have changes that are staged for the next commit.
+
+The `git add` command will not add ignored files by default.  If any
+ignored files were explicitly specified on the command line, `git add`
+will fail with a list of ignored files.  Ignored files reached by
+directory recursion or filename globbing performed by Git (quote your
+globs before the shell) will be silently ignored.  The 'git add' command can
+be used to add ignored files with the `-f` (force) option.
+
+Please see linkgit:git-commit[1] for alternative ways to add content to a
+commit.
+
+
+OPTIONS
+-------
+<pathspec>...::
+	Files to add content from.  Fileglobs (e.g. `*.c`) can
+	be given to add all matching files.  Also a
+	leading directory name (e.g. `dir` to add `dir/file1`
+	and `dir/file2`) can be given to update the index to
+	match the current state of the directory as a whole (e.g.
+	specifying `dir` will record not just a file `dir/file1`
+	modified in the working tree, a file `dir/file2` added to
+	the working tree, but also a file `dir/file3` removed from
+	the working tree). Note that older versions of Git used
+	to ignore removed files; use `--no-all` option if you want
+	to add modified or new files but ignore removed ones.
++
+For more details about the <pathspec> syntax, see the 'pathspec' entry
+in linkgit:gitglossary[7].
+
+-n::
+--dry-run::
+	Don't actually add the file(s), just show if they exist and/or will
+	be ignored.
+
+-v::
+--verbose::
+        Be verbose.
+
+-f::
+--force::
+	Allow adding otherwise ignored files.
+
+-i::
+--interactive::
+	Add modified contents in the working tree interactively to
+	the index. Optional path arguments may be supplied to limit
+	operation to a subset of the working tree. See ``Interactive
+	mode'' for details.
+
+-p::
+--patch::
+	Interactively choose hunks of patch between the index and the
+	work tree and add them to the index. This gives the user a chance
+	to review the difference before adding modified contents to the
+	index.
++
+This effectively runs `add --interactive`, but bypasses the
+initial command menu and directly jumps to the `patch` subcommand.
+See ``Interactive mode'' for details.
+
+-e::
+--edit::
+	Open the diff vs. the index in an editor and let the user
+	edit it.  After the editor was closed, adjust the hunk headers
+	and apply the patch to the index.
++
+The intent of this option is to pick and choose lines of the patch to
+apply, or even to modify the contents of lines to be staged. This can be
+quicker and more flexible than using the interactive hunk selector.
+However, it is easy to confuse oneself and create a patch that does not
+apply to the index. See EDITING PATCHES below.
+
+-u::
+--update::
+	Update the index just where it already has an entry matching
+	<pathspec>.  This removes as well as modifies index entries to
+	match the working tree, but adds no new files.
++
+If no <pathspec> is given when `-u` option is used, all
+tracked files in the entire working tree are updated (old versions
+of Git used to limit the update to the current directory and its
+subdirectories).
+
+-A::
+--all::
+--no-ignore-removal::
+	Update the index not only where the working tree has a file
+	matching <pathspec> but also where the index already has an
+	entry. This adds, modifies, and removes index entries to
+	match the working tree.
++
+If no <pathspec> is given when `-A` option is used, all
+files in the entire working tree are updated (old versions
+of Git used to limit the update to the current directory and its
+subdirectories).
+
+--no-all::
+--ignore-removal::
+	Update the index by adding new files that are unknown to the
+	index and files modified in the working tree, but ignore
+	files that have been removed from the working tree.  This
+	option is a no-op when no <pathspec> is used.
++
+This option is primarily to help users who are used to older
+versions of Git, whose "git add <pathspec>..." was a synonym
+for "git add --no-all <pathspec>...", i.e. ignored removed files.
+
+-N::
+--intent-to-add::
+	Record only the fact that the path will be added later. An entry
+	for the path is placed in the index with no content. This is
+	useful for, among other things, showing the unstaged content of
+	such files with `git diff` and committing them with `git commit
+	-a`.
+
+--refresh::
+	Don't add the file(s), but only refresh their stat()
+	information in the index.
+
+--ignore-errors::
+	If some files could not be added because of errors indexing
+	them, do not abort the operation, but continue adding the
+	others. The command shall still exit with non-zero status.
+	The configuration variable `add.ignoreErrors` can be set to
+	true to make this the default behaviour.
+
+--ignore-missing::
+	This option can only be used together with --dry-run. By using
+	this option the user can check if any of the given files would
+	be ignored, no matter if they are already present in the work
+	tree or not.
+
+--no-warn-embedded-repo::
+	By default, `git add` will warn when adding an embedded
+	repository to the index without using `git submodule add` to
+	create an entry in `.gitmodules`. This option will suppress the
+	warning (e.g., if you are manually performing operations on
+	submodules).
+
+--renormalize::
+	Apply the "clean" process freshly to all tracked files to
+	forcibly add them again to the index.  This is useful after
+	changing `core.autocrlf` configuration or the `text` attribute
+	in order to correct files added with wrong CRLF/LF line endings.
+	This option implies `-u`.
+
+--chmod=(+|-)x::
+	Override the executable bit of the added files.  The executable
+	bit is only changed in the index, the files on disk are left
+	unchanged.
+
+\--::
+	This option can be used to separate command-line options from
+	the list of files, (useful when filenames might be mistaken
+	for command-line options).
+
+
+EXAMPLES
+--------
+
+* Adds content from all `*.txt` files under `Documentation` directory
+  and its subdirectories:
++
+------------
+$ git add Documentation/\*.txt
+------------
++
+Note that the asterisk `*` is quoted from the shell in this
+example; this lets the command include the files from
+subdirectories of `Documentation/` directory.
+
+* Considers adding content from all git-*.sh scripts:
++
+------------
+$ git add git-*.sh
+------------
++
+Because this example lets the shell expand the asterisk (i.e. you are
+listing the files explicitly), it does not consider
+`subdir/git-foo.sh`.
+
+INTERACTIVE MODE
+----------------
+When the command enters the interactive mode, it shows the
+output of the 'status' subcommand, and then goes into its
+interactive command loop.
+
+The command loop shows the list of subcommands available, and
+gives a prompt "What now> ".  In general, when the prompt ends
+with a single '>', you can pick only one of the choices given
+and type return, like this:
+
+------------
+    *** Commands ***
+      1: status       2: update       3: revert       4: add untracked
+      5: patch        6: diff         7: quit         8: help
+    What now> 1
+------------
+
+You also could say `s` or `sta` or `status` above as long as the
+choice is unique.
+
+The main command loop has 6 subcommands (plus help and quit).
+
+status::
+
+   This shows the change between HEAD and index (i.e. what will be
+   committed if you say `git commit`), and between index and
+   working tree files (i.e. what you could stage further before
+   `git commit` using `git add`) for each path.  A sample output
+   looks like this:
++
+------------
+              staged     unstaged path
+     1:       binary      nothing foo.png
+     2:     +403/-35        +1/-1 git-add--interactive.perl
+------------
++
+It shows that foo.png has differences from HEAD (but that is
+binary so line count cannot be shown) and there is no
+difference between indexed copy and the working tree
+version (if the working tree version were also different,
+'binary' would have been shown in place of 'nothing').  The
+other file, git-add{litdd}interactive.perl, has 403 lines added
+and 35 lines deleted if you commit what is in the index, but
+working tree file has further modifications (one addition and
+one deletion).
+
+update::
+
+   This shows the status information and issues an "Update>>"
+   prompt.  When the prompt ends with double '>>', you can
+   make more than one selection, concatenated with whitespace or
+   comma.  Also you can say ranges.  E.g. "2-5 7,9" to choose
+   2,3,4,5,7,9 from the list.  If the second number in a range is
+   omitted, all remaining patches are taken.  E.g. "7-" to choose
+   7,8,9 from the list.  You can say '*' to choose everything.
++
+What you chose are then highlighted with '*',
+like this:
++
+------------
+           staged     unstaged path
+  1:       binary      nothing foo.png
+* 2:     +403/-35        +1/-1 git-add--interactive.perl
+------------
++
+To remove selection, prefix the input with `-`
+like this:
++
+------------
+Update>> -2
+------------
++
+After making the selection, answer with an empty line to stage the
+contents of working tree files for selected paths in the index.
+
+revert::
+
+  This has a very similar UI to 'update', and the staged
+  information for selected paths are reverted to that of the
+  HEAD version.  Reverting new paths makes them untracked.
+
+add untracked::
+
+  This has a very similar UI to 'update' and
+  'revert', and lets you add untracked paths to the index.
+
+patch::
+
+  This lets you choose one path out of a 'status' like selection.
+  After choosing the path, it presents the diff between the index
+  and the working tree file and asks you if you want to stage
+  the change of each hunk.  You can select one of the following
+  options and type return:
+
+       y - stage this hunk
+       n - do not stage this hunk
+       q - quit; do not stage this hunk or any of the remaining ones
+       a - stage this hunk and all later hunks in the file
+       d - do not stage this hunk or any of the later hunks in the file
+       g - select a hunk to go to
+       / - search for a hunk matching the given regex
+       j - leave this hunk undecided, see next undecided hunk
+       J - leave this hunk undecided, see next hunk
+       k - leave this hunk undecided, see previous undecided hunk
+       K - leave this hunk undecided, see previous hunk
+       s - split the current hunk into smaller hunks
+       e - manually edit the current hunk
+       ? - print help
++
+After deciding the fate for all hunks, if there is any hunk
+that was chosen, the index is updated with the selected hunks.
++
+You can omit having to type return here, by setting the configuration
+variable `interactive.singleKey` to `true`.
+
+diff::
+
+  This lets you review what will be committed (i.e. between
+  HEAD and index).
+
+
+EDITING PATCHES
+---------------
+
+Invoking `git add -e` or selecting `e` from the interactive hunk
+selector will open a patch in your editor; after the editor exits, the
+result is applied to the index. You are free to make arbitrary changes
+to the patch, but note that some changes may have confusing results, or
+even result in a patch that cannot be applied.  If you want to abort the
+operation entirely (i.e., stage nothing new in the index), simply delete
+all lines of the patch. The list below describes some common things you
+may see in a patch, and which editing operations make sense on them.
+
+--
+added content::
+
+Added content is represented by lines beginning with "{plus}". You can
+prevent staging any addition lines by deleting them.
+
+removed content::
+
+Removed content is represented by lines beginning with "-". You can
+prevent staging their removal by converting the "-" to a " " (space).
+
+modified content::
+
+Modified content is represented by "-" lines (removing the old content)
+followed by "{plus}" lines (adding the replacement content). You can
+prevent staging the modification by converting "-" lines to " ", and
+removing "{plus}" lines. Beware that modifying only half of the pair is
+likely to introduce confusing changes to the index.
+--
+
+There are also more complex operations that can be performed. But beware
+that because the patch is applied only to the index and not the working
+tree, the working tree will appear to "undo" the change in the index.
+For example, introducing a new line into the index that is in neither
+the HEAD nor the working tree will stage the new line for commit, but
+the line will appear to be reverted in the working tree.
+
+Avoid using these constructs, or do so with extreme caution.
+
+--
+removing untouched content::
+
+Content which does not differ between the index and working tree may be
+shown on context lines, beginning with a " " (space).  You can stage
+context lines for removal by converting the space to a "-". The
+resulting working tree file will appear to re-add the content.
+
+modifying existing content::
+
+One can also modify context lines by staging them for removal (by
+converting " " to "-") and adding a "{plus}" line with the new content.
+Similarly, one can modify "{plus}" lines for existing additions or
+modifications. In all cases, the new modification will appear reverted
+in the working tree.
+
+new content::
+
+You may also add new content that does not exist in the patch; simply
+add new lines, each starting with "{plus}". The addition will appear
+reverted in the working tree.
+--
+
+There are also several operations which should be avoided entirely, as
+they will make the patch impossible to apply:
+
+* adding context (" ") or removal ("-") lines
+* deleting context or removal lines
+* modifying the contents of context or removal lines
+
+SEE ALSO
+--------
+linkgit:git-status[1]
+linkgit:git-rm[1]
+linkgit:git-reset[1]
+linkgit:git-mv[1]
+linkgit:git-commit[1]
+linkgit:git-update-index[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-am.txt b/third_party/git/Documentation/git-am.txt
new file mode 100644
index 0000000000..fc3b993c33
--- /dev/null
+++ b/third_party/git/Documentation/git-am.txt
@@ -0,0 +1,245 @@
+git-am(1)
+=========
+
+NAME
+----
+git-am - Apply a series of patches from a mailbox
+
+
+SYNOPSIS
+--------
+[verse]
+'git am' [--signoff] [--keep] [--[no-]keep-cr] [--[no-]utf8]
+	 [--[no-]3way] [--interactive] [--committer-date-is-author-date]
+	 [--ignore-date] [--ignore-space-change | --ignore-whitespace]
+	 [--whitespace=<option>] [-C<n>] [-p<n>] [--directory=<dir>]
+	 [--exclude=<path>] [--include=<path>] [--reject] [-q | --quiet]
+	 [--[no-]scissors] [-S[<keyid>]] [--patch-format=<format>]
+	 [(<mbox> | <Maildir>)...]
+'git am' (--continue | --skip | --abort | --quit | --show-current-patch)
+
+DESCRIPTION
+-----------
+Splits mail messages in a mailbox into commit log message,
+authorship information and patches, and applies them to the
+current branch.
+
+OPTIONS
+-------
+(<mbox>|<Maildir>)...::
+	The list of mailbox files to read patches from. If you do not
+	supply this argument, the command reads from the standard input.
+	If you supply directories, they will be treated as Maildirs.
+
+-s::
+--signoff::
+	Add a `Signed-off-by:` line to the commit message, using
+	the committer identity of yourself.
+	See the signoff option in linkgit:git-commit[1] for more information.
+
+-k::
+--keep::
+	Pass `-k` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+
+--keep-non-patch::
+	Pass `-b` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+
+--[no-]keep-cr::
+	With `--keep-cr`, call 'git mailsplit' (see linkgit:git-mailsplit[1])
+	with the same option, to prevent it from stripping CR at the end of
+	lines. `am.keepcr` configuration variable can be used to specify the
+	default behaviour.  `--no-keep-cr` is useful to override `am.keepcr`.
+
+-c::
+--scissors::
+	Remove everything in body before a scissors line (see
+	linkgit:git-mailinfo[1]). Can be activated by default using
+	the `mailinfo.scissors` configuration variable.
+
+--no-scissors::
+	Ignore scissors lines (see linkgit:git-mailinfo[1]).
+
+-m::
+--message-id::
+	Pass the `-m` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]),
+	so that the Message-ID header is added to the commit message.
+	The `am.messageid` configuration variable can be used to specify
+	the default behaviour.
+
+--no-message-id::
+	Do not add the Message-ID header to the commit message.
+	`no-message-id` is useful to override `am.messageid`.
+
+-q::
+--quiet::
+	Be quiet. Only print error messages.
+
+-u::
+--utf8::
+	Pass `-u` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+	The proposed commit log message taken from the e-mail
+	is re-coded into UTF-8 encoding (configuration variable
+	`i18n.commitencoding` can be used to specify project's
+	preferred encoding if it is not UTF-8).
++
+This was optional in prior versions of git, but now it is the
+default.   You can use `--no-utf8` to override this.
+
+--no-utf8::
+	Pass `-n` flag to 'git mailinfo' (see
+	linkgit:git-mailinfo[1]).
+
+-3::
+--3way::
+--no-3way::
+	When the patch does not apply cleanly, fall back on
+	3-way merge if the patch records the identity of blobs
+	it is supposed to apply to and we have those blobs
+	available locally. `--no-3way` can be used to override
+	am.threeWay configuration variable. For more information,
+	see am.threeWay in linkgit:git-config[1].
+
+--rerere-autoupdate::
+--no-rerere-autoupdate::
+	Allow the rerere mechanism to update the index with the
+	result of auto-conflict resolution if possible.
+
+--ignore-space-change::
+--ignore-whitespace::
+--whitespace=<option>::
+-C<n>::
+-p<n>::
+--directory=<dir>::
+--exclude=<path>::
+--include=<path>::
+--reject::
+	These flags are passed to the 'git apply' (see linkgit:git-apply[1])
+	program that applies
+	the patch.
+
+--patch-format::
+	By default the command will try to detect the patch format
+	automatically. This option allows the user to bypass the automatic
+	detection and specify the patch format that the patch(es) should be
+	interpreted as. Valid formats are mbox, mboxrd,
+	stgit, stgit-series and hg.
+
+-i::
+--interactive::
+	Run interactively.
+
+--committer-date-is-author-date::
+	By default the command records the date from the e-mail
+	message as the commit author date, and uses the time of
+	commit creation as the committer date. This allows the
+	user to lie about the committer date by using the same
+	value as the author date.
+
+--ignore-date::
+	By default the command records the date from the e-mail
+	message as the commit author date, and uses the time of
+	commit creation as the committer date. This allows the
+	user to lie about the author date by using the same
+	value as the committer date.
+
+--skip::
+	Skip the current patch.  This is only meaningful when
+	restarting an aborted patch.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+--continue::
+-r::
+--resolved::
+	After a patch failure (e.g. attempting to apply
+	conflicting patch), the user has applied it by hand and
+	the index file stores the result of the application.
+	Make a commit using the authorship and commit log
+	extracted from the e-mail message and the current index
+	file, and continue.
+
+--resolvemsg=<msg>::
+	When a patch failure occurs, <msg> will be printed
+	to the screen before exiting.  This overrides the
+	standard message informing you to use `--continue`
+	or `--skip` to handle the failure.  This is solely
+	for internal use between 'git rebase' and 'git am'.
+
+--abort::
+	Restore the original branch and abort the patching operation.
+
+--quit::
+	Abort the patching operation but keep HEAD and the index
+	untouched.
+
+--show-current-patch::
+	Show the patch being applied when "git am" is stopped because
+	of conflicts.
+
+DISCUSSION
+----------
+
+The commit author name is taken from the "From: " line of the
+message, and commit author date is taken from the "Date: " line
+of the message.  The "Subject: " line is used as the title of
+the commit, after stripping common prefix "[PATCH <anything>]".
+The "Subject: " line is supposed to concisely describe what the
+commit is about in one line of text.
+
+"From: " and "Subject: " lines starting the body override the respective
+commit author name and title values taken from the headers.
+
+The commit message is formed by the title taken from the
+"Subject: ", a blank line and the body of the message up to
+where the patch begins.  Excess whitespace at the end of each
+line is automatically stripped.
+
+The patch is expected to be inline, directly following the
+message.  Any line that is of the form:
+
+* three-dashes and end-of-line, or
+* a line that begins with "diff -", or
+* a line that begins with "Index: "
+
+is taken as the beginning of a patch, and the commit log message
+is terminated before the first occurrence of such a line.
+
+When initially invoking `git am`, you give it the names of the mailboxes
+to process.  Upon seeing the first patch that does not apply, it
+aborts in the middle.  You can recover from this in one of two ways:
+
+. skip the current patch by re-running the command with the `--skip`
+  option.
+
+. hand resolve the conflict in the working directory, and update
+  the index file to bring it into a state that the patch should
+  have produced.  Then run the command with the `--continue` option.
+
+The command refuses to process new mailboxes until the current
+operation is finished, so if you decide to start over from scratch,
+run `git am --abort` before running the command with mailbox
+names.
+
+Before any patches are applied, ORIG_HEAD is set to the tip of the
+current branch.  This is useful if you have problems with multiple
+commits, like running 'git am' on the wrong branch or an error in the
+commits that is more easily fixed by changing the mailbox (e.g.
+errors in the "From:" lines).
+
+HOOKS
+-----
+This command can run `applypatch-msg`, `pre-applypatch`,
+and `post-applypatch` hooks.  See linkgit:githooks[5] for more
+information.
+
+SEE ALSO
+--------
+linkgit:git-apply[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-annotate.txt b/third_party/git/Documentation/git-annotate.txt
new file mode 100644
index 0000000000..e44a831339
--- /dev/null
+++ b/third_party/git/Documentation/git-annotate.txt
@@ -0,0 +1,33 @@
+git-annotate(1)
+===============
+
+NAME
+----
+git-annotate - Annotate file lines with commit information
+
+SYNOPSIS
+--------
+[verse]
+'git annotate' [<options>] <file> [<revision>]
+
+DESCRIPTION
+-----------
+Annotates each line in the given file with information from the commit
+which introduced the line. Optionally annotates from a given revision.
+
+The only difference between this command and linkgit:git-blame[1] is that
+they use slightly different output formats, and this command exists only
+for backward compatibility to support existing scripts, and provide a more
+familiar command name for people coming from other SCM systems.
+
+OPTIONS
+-------
+include::blame-options.txt[]
+
+SEE ALSO
+--------
+linkgit:git-blame[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-apply.txt b/third_party/git/Documentation/git-apply.txt
new file mode 100644
index 0000000000..b9aa39000f
--- /dev/null
+++ b/third_party/git/Documentation/git-apply.txt
@@ -0,0 +1,285 @@
+git-apply(1)
+============
+
+NAME
+----
+git-apply - Apply a patch to files and/or to the index
+
+
+SYNOPSIS
+--------
+[verse]
+'git apply' [--stat] [--numstat] [--summary] [--check] [--index | --intent-to-add] [--3way]
+	  [--apply] [--no-add] [--build-fake-ancestor=<file>] [-R | --reverse]
+	  [--allow-binary-replacement | --binary] [--reject] [-z]
+	  [-p<n>] [-C<n>] [--inaccurate-eof] [--recount] [--cached]
+	  [--ignore-space-change | --ignore-whitespace]
+	  [--whitespace=(nowarn|warn|fix|error|error-all)]
+	  [--exclude=<path>] [--include=<path>] [--directory=<root>]
+	  [--verbose] [--unsafe-paths] [<patch>...]
+
+DESCRIPTION
+-----------
+Reads the supplied diff output (i.e. "a patch") and applies it to files.
+When running from a subdirectory in a repository, patched paths
+outside the directory are ignored.
+With the `--index` option the patch is also applied to the index, and
+with the `--cached` option the patch is only applied to the index.
+Without these options, the command applies the patch only to files,
+and does not require them to be in a Git repository.
+
+This command applies the patch but does not create a commit.  Use
+linkgit:git-am[1] to create commits from patches generated by
+linkgit:git-format-patch[1] and/or received by email.
+
+OPTIONS
+-------
+<patch>...::
+	The files to read the patch from.  '-' can be used to read
+	from the standard input.
+
+--stat::
+	Instead of applying the patch, output diffstat for the
+	input.  Turns off "apply".
+
+--numstat::
+	Similar to `--stat`, but shows the number of added and
+	deleted lines in decimal notation and the pathname without
+	abbreviation, to make it more machine friendly.  For
+	binary files, outputs two `-` instead of saying
+	`0 0`.  Turns off "apply".
+
+--summary::
+	Instead of applying the patch, output a condensed
+	summary of information obtained from git diff extended
+	headers, such as creations, renames and mode changes.
+	Turns off "apply".
+
+--check::
+	Instead of applying the patch, see if the patch is
+	applicable to the current working tree and/or the index
+	file and detects errors.  Turns off "apply".
+
+--index::
+	When `--check` is in effect, or when applying the patch
+	(which is the default when none of the options that
+	disables it is in effect), make sure the patch is
+	applicable to what the current index file records.  If
+	the file to be patched in the working tree is not
+	up to date, it is flagged as an error.  This flag also
+	causes the index file to be updated.
+
+--cached::
+	Apply a patch without touching the working tree. Instead take the
+	cached data, apply the patch, and store the result in the index
+	without using the working tree. This implies `--index`.
+
+--intent-to-add::
+	When applying the patch only to the working tree, mark new
+	files to be added to the index later (see `--intent-to-add`
+	option in linkgit:git-add[1]). This option is ignored unless
+	running in a Git repository and `--index` is not specified.
+	Note that `--index` could be implied by other options such
+	as `--cached` or `--3way`.
+
+-3::
+--3way::
+	When the patch does not apply cleanly, fall back on 3-way merge if
+	the patch records the identity of blobs it is supposed to apply to,
+	and we have those blobs available locally, possibly leaving the
+	conflict markers in the files in the working tree for the user to
+	resolve.  This option implies the `--index` option, and is incompatible
+	with the `--reject` and the `--cached` options.
+
+--build-fake-ancestor=<file>::
+	Newer 'git diff' output has embedded 'index information'
+	for each blob to help identify the original version that
+	the patch applies to.  When this flag is given, and if
+	the original versions of the blobs are available locally,
+	builds a temporary index containing those blobs.
++
+When a pure mode change is encountered (which has no index information),
+the information is read from the current index instead.
+
+-R::
+--reverse::
+	Apply the patch in reverse.
+
+--reject::
+	For atomicity, 'git apply' by default fails the whole patch and
+	does not touch the working tree when some of the hunks
+	do not apply.  This option makes it apply
+	the parts of the patch that are applicable, and leave the
+	rejected hunks in corresponding *.rej files.
+
+-z::
+	When `--numstat` has been given, do not munge pathnames,
+	but use a NUL-terminated machine-readable format.
++
+Without this option, pathnames with "unusual" characters are quoted as
+explained for the configuration variable `core.quotePath` (see
+linkgit:git-config[1]).
+
+-p<n>::
+	Remove <n> leading path components (separated by slashes) from
+	traditional diff paths. E.g., with `-p2`, a patch against
+	`a/dir/file` will be applied directly to `file`. The default is
+	1.
+
+-C<n>::
+	Ensure at least <n> lines of surrounding context match before
+	and after each change.  When fewer lines of surrounding
+	context exist they all must match.  By default no context is
+	ever ignored.
+
+--unidiff-zero::
+	By default, 'git apply' expects that the patch being
+	applied is a unified diff with at least one line of context.
+	This provides good safety measures, but breaks down when
+	applying a diff generated with `--unified=0`. To bypass these
+	checks use `--unidiff-zero`.
++
+Note, for the reasons stated above usage of context-free patches is
+discouraged.
+
+--apply::
+	If you use any of the options marked "Turns off
+	'apply'" above, 'git apply' reads and outputs the
+	requested information without actually applying the
+	patch.  Give this flag after those flags to also apply
+	the patch.
+
+--no-add::
+	When applying a patch, ignore additions made by the
+	patch.  This can be used to extract the common part between
+	two files by first running 'diff' on them and applying
+	the result with this option, which would apply the
+	deletion part but not the addition part.
+
+--allow-binary-replacement::
+--binary::
+	Historically we did not allow binary patch applied
+	without an explicit permission from the user, and this
+	flag was the way to do so.  Currently we always allow binary
+	patch application, so this is a no-op.
+
+--exclude=<path-pattern>::
+	Don't apply changes to files matching the given path pattern. This can
+	be useful when importing patchsets, where you want to exclude certain
+	files or directories.
+
+--include=<path-pattern>::
+	Apply changes to files matching the given path pattern. This can
+	be useful when importing patchsets, where you want to include certain
+	files or directories.
++
+When `--exclude` and `--include` patterns are used, they are examined in the
+order they appear on the command line, and the first match determines if a
+patch to each path is used.  A patch to a path that does not match any
+include/exclude pattern is used by default if there is no include pattern
+on the command line, and ignored if there is any include pattern.
+
+--ignore-space-change::
+--ignore-whitespace::
+	When applying a patch, ignore changes in whitespace in context
+	lines if necessary.
+	Context lines will preserve their whitespace, and they will not
+	undergo whitespace fixing regardless of the value of the
+	`--whitespace` option. New lines will still be fixed, though.
+
+--whitespace=<action>::
+	When applying a patch, detect a new or modified line that has
+	whitespace errors.  What are considered whitespace errors is
+	controlled by `core.whitespace` configuration.  By default,
+	trailing whitespaces (including lines that solely consist of
+	whitespaces) and a space character that is immediately followed
+	by a tab character inside the initial indent of the line are
+	considered whitespace errors.
++
+By default, the command outputs warning messages but applies the patch.
+When `git-apply` is used for statistics and not applying a
+patch, it defaults to `nowarn`.
++
+You can use different `<action>` values to control this
+behavior:
++
+* `nowarn` turns off the trailing whitespace warning.
+* `warn` outputs warnings for a few such errors, but applies the
+  patch as-is (default).
+* `fix` outputs warnings for a few such errors, and applies the
+  patch after fixing them (`strip` is a synonym --- the tool
+  used to consider only trailing whitespace characters as errors, and the
+  fix involved 'stripping' them, but modern Gits do more).
+* `error` outputs warnings for a few such errors, and refuses
+  to apply the patch.
+* `error-all` is similar to `error` but shows all errors.
+
+--inaccurate-eof::
+	Under certain circumstances, some versions of 'diff' do not correctly
+	detect a missing new-line at the end of the file. As a result, patches
+	created by such 'diff' programs do not record incomplete lines
+	correctly. This option adds support for applying such patches by
+	working around this bug.
+
+-v::
+--verbose::
+	Report progress to stderr. By default, only a message about the
+	current patch being applied will be printed. This option will cause
+	additional information to be reported.
+
+--recount::
+	Do not trust the line counts in the hunk headers, but infer them
+	by inspecting the patch (e.g. after editing the patch without
+	adjusting the hunk headers appropriately).
+
+--directory=<root>::
+	Prepend <root> to all filenames.  If a "-p" argument was also passed,
+	it is applied before prepending the new root.
++
+For example, a patch that talks about updating `a/git-gui.sh` to `b/git-gui.sh`
+can be applied to the file in the working tree `modules/git-gui/git-gui.sh` by
+running `git apply --directory=modules/git-gui`.
+
+--unsafe-paths::
+	By default, a patch that affects outside the working area
+	(either a Git controlled working tree, or the current working
+	directory when "git apply" is used as a replacement of GNU
+	patch) is rejected as a mistake (or a mischief).
++
+When `git apply` is used as a "better GNU patch", the user can pass
+the `--unsafe-paths` option to override this safety check.  This option
+has no effect when `--index` or `--cached` is in use.
+
+CONFIGURATION
+-------------
+
+apply.ignoreWhitespace::
+	Set to 'change' if you want changes in whitespace to be ignored by default.
+	Set to one of: no, none, never, false if you want changes in
+	whitespace to be significant.
+apply.whitespace::
+	When no `--whitespace` flag is given from the command
+	line, this configuration item is used as the default.
+
+SUBMODULES
+----------
+If the patch contains any changes to submodules then 'git apply'
+treats these changes as follows.
+
+If `--index` is specified (explicitly or implicitly), then the submodule
+commits must match the index exactly for the patch to apply.  If any
+of the submodules are checked-out, then these check-outs are completely
+ignored, i.e., they are not required to be up to date or clean and they
+are not updated.
+
+If `--index` is not specified, then the submodule commits in the patch
+are ignored and only the absence or presence of the corresponding
+subdirectory is checked and (if possible) updated.
+
+SEE ALSO
+--------
+linkgit:git-am[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-archimport.txt b/third_party/git/Documentation/git-archimport.txt
new file mode 100644
index 0000000000..a595a0ffee
--- /dev/null
+++ b/third_party/git/Documentation/git-archimport.txt
@@ -0,0 +1,113 @@
+git-archimport(1)
+=================
+
+NAME
+----
+git-archimport - Import a GNU Arch repository into Git
+
+
+SYNOPSIS
+--------
+[verse]
+'git archimport' [-h] [-v] [-o] [-a] [-f] [-T] [-D depth] [-t tempdir]
+               <archive/branch>[:<git-branch>] ...
+
+DESCRIPTION
+-----------
+Imports a project from one or more GNU Arch repositories.
+It will follow branches
+and repositories within the namespaces defined by the <archive/branch>
+parameters supplied. If it cannot find the remote branch a merge comes from
+it will just import it as a regular commit. If it can find it, it will mark it
+as a merge whenever possible (see discussion below).
+
+The script expects you to provide the key roots where it can start the import
+from an 'initial import' or 'tag' type of Arch commit. It will follow and
+import new branches within the provided roots.
+
+It expects to be dealing with one project only. If it sees
+branches that have different roots, it will refuse to run. In that case,
+edit your <archive/branch> parameters to define clearly the scope of the
+import.
+
+'git archimport' uses `tla` extensively in the background to access the
+Arch repository.
+Make sure you have a recent version of `tla` available in the path. `tla` must
+know about the repositories you pass to 'git archimport'.
+
+For the initial import, 'git archimport' expects to find itself in an empty
+directory. To follow the development of a project that uses Arch, rerun
+'git archimport' with the same parameters as the initial import to perform
+incremental imports.
+
+While 'git archimport' will try to create sensible branch names for the
+archives that it imports, it is also possible to specify Git branch names
+manually.  To do so, write a Git branch name after each <archive/branch>
+parameter, separated by a colon.  This way, you can shorten the Arch
+branch names and convert Arch jargon to Git jargon, for example mapping a
+"PROJECT{litdd}devo{litdd}VERSION" branch to "master".
+
+Associating multiple Arch branches to one Git branch is possible; the
+result will make the most sense only if no commits are made to the first
+branch, after the second branch is created.  Still, this is useful to
+convert Arch repositories that had been rotated periodically.
+
+
+MERGES
+------
+Patch merge data from Arch is used to mark merges in Git as well. Git
+does not care much about tracking patches, and only considers a merge when a
+branch incorporates all the commits since the point they forked. The end result
+is that Git will have a good idea of how far branches have diverged. So the
+import process does lose some patch-trading metadata.
+
+Fortunately, when you try and merge branches imported from Arch,
+Git will find a good merge base, and it has a good chance of identifying
+patches that have been traded out-of-sequence between the branches.
+
+OPTIONS
+-------
+
+-h::
+	Display usage.
+
+-v::
+	Verbose output.
+
+-T::
+	Many tags. Will create a tag for every commit, reflecting the commit
+	name in the Arch repository.
+
+-f::
+	Use the fast patchset import strategy.  This can be significantly
+	faster for large trees, but cannot handle directory renames or
+	permissions changes.  The default strategy is slow and safe.
+
+-o::
+	Use this for compatibility with old-style branch names used by
+	earlier versions of 'git archimport'.  Old-style branch names
+	were category{litdd}branch, whereas new-style branch names are
+	archive,category{litdd}branch{litdd}version.  In both cases, names given
+	on the command-line will override the automatically-generated
+	ones.
+
+-D <depth>::
+	Follow merge ancestry and attempt to import trees that have been
+	merged from.  Specify a depth greater than 1 if patch logs have been
+	pruned.
+
+-a::
+	Attempt to auto-register archives at `http://mirrors.sourcecontrol.net`
+	This is particularly useful with the -D option.
+
+-t <tmpdir>::
+	Override the default tempdir.
+
+
+<archive/branch>::
+	Archive/branch identifier in a format that `tla log` understands.
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-archive.txt b/third_party/git/Documentation/git-archive.txt
new file mode 100644
index 0000000000..cfa1e4ebe4
--- /dev/null
+++ b/third_party/git/Documentation/git-archive.txt
@@ -0,0 +1,197 @@
+git-archive(1)
+==============
+
+NAME
+----
+git-archive - Create an archive of files from a named tree
+
+
+SYNOPSIS
+--------
+[verse]
+'git archive' [--format=<fmt>] [--list] [--prefix=<prefix>/] [<extra>]
+	      [-o <file> | --output=<file>] [--worktree-attributes]
+	      [--remote=<repo> [--exec=<git-upload-archive>]] <tree-ish>
+	      [<path>...]
+
+DESCRIPTION
+-----------
+Creates an archive of the specified format containing the tree
+structure for the named tree, and writes it out to the standard
+output.  If <prefix> is specified it is
+prepended to the filenames in the archive.
+
+'git archive' behaves differently when given a tree ID versus when
+given a commit ID or tag ID.  In the first case the current time is
+used as the modification time of each file in the archive.  In the latter
+case the commit time as recorded in the referenced commit object is
+used instead.  Additionally the commit ID is stored in a global
+extended pax header if the tar format is used; it can be extracted
+using 'git get-tar-commit-id'. In ZIP files it is stored as a file
+comment.
+
+OPTIONS
+-------
+
+--format=<fmt>::
+	Format of the resulting archive: 'tar' or 'zip'. If this option
+	is not given, and the output file is specified, the format is
+	inferred from the filename if possible (e.g. writing to "foo.zip"
+	makes the output to be in the zip format). Otherwise the output
+	format is `tar`.
+
+-l::
+--list::
+	Show all available formats.
+
+-v::
+--verbose::
+	Report progress to stderr.
+
+--prefix=<prefix>/::
+	Prepend <prefix>/ to each filename in the archive.
+
+-o <file>::
+--output=<file>::
+	Write the archive to <file> instead of stdout.
+
+--worktree-attributes::
+	Look for attributes in .gitattributes files in the working tree
+	as well (see <<ATTRIBUTES>>).
+
+<extra>::
+	This can be any options that the archiver backend understands.
+	See next section.
+
+--remote=<repo>::
+	Instead of making a tar archive from the local repository,
+	retrieve a tar archive from a remote repository. Note that the
+	remote repository may place restrictions on which sha1
+	expressions may be allowed in `<tree-ish>`. See
+	linkgit:git-upload-archive[1] for details.
+
+--exec=<git-upload-archive>::
+	Used with --remote to specify the path to the
+	'git-upload-archive' on the remote side.
+
+<tree-ish>::
+	The tree or commit to produce an archive for.
+
+<path>::
+	Without an optional path parameter, all files and subdirectories
+	of the current working directory are included in the archive.
+	If one or more paths are specified, only these are included.
+
+BACKEND EXTRA OPTIONS
+---------------------
+
+zip
+~~~
+-0::
+	Store the files instead of deflating them.
+-9::
+	Highest and slowest compression level.  You can specify any
+	number from 1 to 9 to adjust compression speed and ratio.
+
+
+CONFIGURATION
+-------------
+
+tar.umask::
+	This variable can be used to restrict the permission bits of
+	tar archive entries.  The default is 0002, which turns off the
+	world write bit.  The special value "user" indicates that the
+	archiving user's umask will be used instead.  See umask(2) for
+	details.  If `--remote` is used then only the configuration of
+	the remote repository takes effect.
+
+tar.<format>.command::
+	This variable specifies a shell command through which the tar
+	output generated by `git archive` should be piped. The command
+	is executed using the shell with the generated tar file on its
+	standard input, and should produce the final output on its
+	standard output. Any compression-level options will be passed
+	to the command (e.g., "-9"). An output file with the same
+	extension as `<format>` will be use this format if no other
+	format is given.
++
+The "tar.gz" and "tgz" formats are defined automatically and default to
+`gzip -cn`. You may override them with custom commands.
+
+tar.<format>.remote::
+	If true, enable `<format>` for use by remote clients via
+	linkgit:git-upload-archive[1]. Defaults to false for
+	user-defined formats, but true for the "tar.gz" and "tgz"
+	formats.
+
+[[ATTRIBUTES]]
+ATTRIBUTES
+----------
+
+export-ignore::
+	Files and directories with the attribute export-ignore won't be
+	added to archive files.  See linkgit:gitattributes[5] for details.
+
+export-subst::
+	If the attribute export-subst is set for a file then Git will
+	expand several placeholders when adding this file to an archive.
+	See linkgit:gitattributes[5] for details.
+
+Note that attributes are by default taken from the `.gitattributes` files
+in the tree that is being archived.  If you want to tweak the way the
+output is generated after the fact (e.g. you committed without adding an
+appropriate export-ignore in its `.gitattributes`), adjust the checked out
+`.gitattributes` file as necessary and use `--worktree-attributes`
+option.  Alternatively you can keep necessary attributes that should apply
+while archiving any tree in your `$GIT_DIR/info/attributes` file.
+
+EXAMPLES
+--------
+`git archive --format=tar --prefix=junk/ HEAD | (cd /var/tmp/ && tar xf -)`::
+
+	Create a tar archive that contains the contents of the
+	latest commit on the current branch, and extract it in the
+	`/var/tmp/junk` directory.
+
+`git archive --format=tar --prefix=git-1.4.0/ v1.4.0 | gzip >git-1.4.0.tar.gz`::
+
+	Create a compressed tarball for v1.4.0 release.
+
+`git archive --format=tar.gz --prefix=git-1.4.0/ v1.4.0 >git-1.4.0.tar.gz`::
+
+	Same as above, but using the builtin tar.gz handling.
+
+`git archive --prefix=git-1.4.0/ -o git-1.4.0.tar.gz v1.4.0`::
+
+	Same as above, but the format is inferred from the output file.
+
+`git archive --format=tar --prefix=git-1.4.0/ v1.4.0^{tree} | gzip >git-1.4.0.tar.gz`::
+
+	Create a compressed tarball for v1.4.0 release, but without a
+	global extended pax header.
+
+`git archive --format=zip --prefix=git-docs/ HEAD:Documentation/ > git-1.4.0-docs.zip`::
+
+	Put everything in the current head's Documentation/ directory
+	into 'git-1.4.0-docs.zip', with the prefix 'git-docs/'.
+
+`git archive -o latest.zip HEAD`::
+
+	Create a Zip archive that contains the contents of the latest
+	commit on the current branch. Note that the output format is
+	inferred by the extension of the output file.
+
+`git config tar.tar.xz.command "xz -c"`::
+
+	Configure a "tar.xz" format for making LZMA-compressed tarfiles.
+	You can use it specifying `--format=tar.xz`, or by creating an
+	output file like `-o foo.tar.xz`.
+
+
+SEE ALSO
+--------
+linkgit:gitattributes[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-bisect-lk2009.txt b/third_party/git/Documentation/git-bisect-lk2009.txt
new file mode 100644
index 0000000000..e99925184d
--- /dev/null
+++ b/third_party/git/Documentation/git-bisect-lk2009.txt
@@ -0,0 +1,1358 @@
+Fighting regressions with git bisect
+====================================
+:Author: Christian Couder
+:Email: chriscool@tuxfamily.org
+:Date: 2009/11/08
+
+Abstract
+--------
+
+"git bisect" enables software users and developers to easily find the
+commit that introduced a regression. We show why it is important to
+have good tools to fight regressions. We describe how "git bisect"
+works from the outside and the algorithms it uses inside. Then we
+explain how to take advantage of "git bisect" to improve current
+practices. And we discuss how "git bisect" could improve in the
+future.
+
+
+Introduction to "git bisect"
+----------------------------
+
+Git is a Distributed Version Control system (DVCS) created by Linus
+Torvalds and maintained by Junio Hamano.
+
+In Git like in many other Version Control Systems (VCS), the different
+states of the data that is managed by the system are called
+commits. And, as VCS are mostly used to manage software source code,
+sometimes "interesting" changes of behavior in the software are
+introduced in some commits.
+
+In fact people are specially interested in commits that introduce a
+"bad" behavior, called a bug or a regression. They are interested in
+these commits because a commit (hopefully) contains a very small set
+of source code changes. And it's much easier to understand and
+properly fix a problem when you only need to check a very small set of
+changes, than when you don't know where look in the first place.
+
+So to help people find commits that introduce a "bad" behavior, the
+"git bisect" set of commands was invented. And it follows of course
+that in "git bisect" parlance, commits where the "interesting
+behavior" is present are called "bad" commits, while other commits are
+called "good" commits. And a commit that introduce the behavior we are
+interested in is called a "first bad commit". Note that there could be
+more than one "first bad commit" in the commit space we are searching.
+
+So "git bisect" is designed to help find a "first bad commit". And to
+be as efficient as possible, it tries to perform a binary search.
+
+
+Fighting regressions overview
+-----------------------------
+
+Regressions: a big problem
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Regressions are a big problem in the software industry. But it's
+difficult to put some real numbers behind that claim.
+
+There are some numbers about bugs in general, like a NIST study in
+2002 <<1>> that said:
+
+_____________
+Software bugs, or errors, are so prevalent and so detrimental that
+they cost the U.S. economy an estimated $59.5 billion annually, or
+about 0.6 percent of the gross domestic product, according to a newly
+released study commissioned by the Department of Commerce's National
+Institute of Standards and Technology (NIST). At the national level,
+over half of the costs are borne by software users and the remainder
+by software developers/vendors.  The study also found that, although
+all errors cannot be removed, more than a third of these costs, or an
+estimated $22.2 billion, could be eliminated by an improved testing
+infrastructure that enables earlier and more effective identification
+and removal of software defects. These are the savings associated with
+finding an increased percentage (but not 100 percent) of errors closer
+to the development stages in which they are introduced. Currently,
+over half of all errors are not found until "downstream" in the
+development process or during post-sale software use.
+_____________
+
+And then:
+
+_____________
+Software developers already spend approximately 80 percent of
+development costs on identifying and correcting defects, and yet few
+products of any type other than software are shipped with such high
+levels of errors.
+_____________
+
+Eventually the conclusion started with:
+
+_____________
+The path to higher software quality is significantly improved software
+testing.
+_____________
+
+There are other estimates saying that 80% of the cost related to
+software is about maintenance <<2>>.
+
+Though, according to Wikipedia <<3>>:
+
+_____________
+A common perception of maintenance is that it is merely fixing
+bugs. However, studies and surveys over the years have indicated that
+the majority, over 80%, of the maintenance effort is used for
+non-corrective actions (Pigosky 1997). This perception is perpetuated
+by users submitting problem reports that in reality are functionality
+enhancements to the system.
+_____________
+
+But we can guess that improving on existing software is very costly
+because you have to watch out for regressions. At least this would
+make the above studies consistent among themselves.
+
+Of course some kind of software is developed, then used during some
+time without being improved on much, and then finally thrown away. In
+this case, of course, regressions may not be a big problem. But on the
+other hand, there is a lot of big software that is continually
+developed and maintained during years or even tens of years by a lot
+of people. And as there are often many people who depend (sometimes
+critically) on such software, regressions are a really big problem.
+
+One such software is the Linux kernel. And if we look at the Linux
+kernel, we can see that a lot of time and effort is spent to fight
+regressions. The release cycle start with a 2 weeks long merge
+window. Then the first release candidate (rc) version is tagged. And
+after that about 7 or 8 more rc versions will appear with around one
+week between each of them, before the final release.
+
+The time between the first rc release and the final release is
+supposed to be used to test rc versions and fight bugs and especially
+regressions. And this time is more than 80% of the release cycle
+time. But this is not the end of the fight yet, as of course it
+continues after the release.
+
+And then this is what Ingo Molnar (a well known Linux kernel
+developer) says about his use of git bisect:
+
+_____________
+I most actively use it during the merge window (when a lot of trees
+get merged upstream and when the influx of bugs is the highest) - and
+yes, there have been cases that i used it multiple times a day. My
+average is roughly once a day.
+_____________
+
+So regressions are fought all the time by developers, and indeed it is
+well known that bugs should be fixed as soon as possible, so as soon
+as they are found. That's why it is interesting to have good tools for
+this purpose.
+
+Other tools to fight regressions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+So what are the tools used to fight regressions? They are nearly the
+same as those used to fight regular bugs. The only specific tools are
+test suites and tools similar as "git bisect".
+
+Test suites are very nice. But when they are used alone, they are
+supposed to be used so that all the tests are checked after each
+commit. This means that they are not very efficient, because many
+tests are run for no interesting result, and they suffer from
+combinational explosion.
+
+In fact the problem is that big software often has many different
+configuration options and that each test case should pass for each
+configuration after each commit. So if you have for each release: N
+configurations, M commits and T test cases, you should perform:
+
+-------------
+N * M * T tests
+-------------
+
+where N, M and T are all growing with the size your software.
+
+So very soon it will not be possible to completely test everything.
+
+And if some bugs slip through your test suite, then you can add a test
+to your test suite. But if you want to use your new improved test
+suite to find where the bug slipped in, then you will either have to
+emulate a bisection process or you will perhaps bluntly test each
+commit backward starting from the "bad" commit you have which may be
+very wasteful.
+
+"git bisect" overview
+---------------------
+
+Starting a bisection
+~~~~~~~~~~~~~~~~~~~~
+
+The first "git bisect" subcommand to use is "git bisect start" to
+start the search. Then bounds must be set to limit the commit
+space. This is done usually by giving one "bad" and at least one
+"good" commit. They can be passed in the initial call to "git bisect
+start" like this:
+
+-------------
+$ git bisect start [BAD [GOOD...]]
+-------------
+
+or they can be set using:
+
+-------------
+$ git bisect bad [COMMIT]
+-------------
+
+and:
+
+-------------
+$ git bisect good [COMMIT...]
+-------------
+
+where BAD, GOOD and COMMIT are all names that can be resolved to a
+commit.
+
+Then "git bisect" will checkout a commit of its choosing and ask the
+user to test it, like this:
+
+-------------
+$ git bisect start v2.6.27 v2.6.25
+Bisecting: 10928 revisions left to test after this (roughly 14 steps)
+[2ec65f8b89ea003c27ff7723525a2ee335a2b393] x86: clean up using max_low_pfn on 32-bit
+-------------
+
+Note that the example that we will use is really a toy example, we
+will be looking for the first commit that has a version like
+"2.6.26-something", that is the commit that has a "SUBLEVEL = 26" line
+in the top level Makefile. This is a toy example because there are
+better ways to find this commit with Git than using "git bisect" (for
+example "git blame" or "git log -S<string>").
+
+Driving a bisection manually
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+At this point there are basically 2 ways to drive the search. It can
+be driven manually by the user or it can be driven automatically by a
+script or a command.
+
+If the user is driving it, then at each step of the search, the user
+will have to test the current commit and say if it is "good" or "bad"
+using the "git bisect good" or "git bisect bad" commands respectively
+that have been described above. For example:
+
+-------------
+$ git bisect bad
+Bisecting: 5480 revisions left to test after this (roughly 13 steps)
+[66c0b394f08fd89236515c1c84485ea712a157be] KVM: kill file->f_count abuse in kvm
+-------------
+
+And after a few more steps like that, "git bisect" will eventually
+find a first bad commit:
+
+-------------
+$ git bisect bad
+2ddcca36c8bcfa251724fe342c8327451988be0d is the first bad commit
+commit 2ddcca36c8bcfa251724fe342c8327451988be0d
+Author: Linus Torvalds <torvalds@linux-foundation.org>
+Date:   Sat May 3 11:59:44 2008 -0700
+
+    Linux 2.6.26-rc1
+
+:100644 100644 5cf82581... 4492984e... M      Makefile
+-------------
+
+At this point we can see what the commit does, check it out (if it's
+not already checked out) or tinker with it, for example:
+
+-------------
+$ git show HEAD
+commit 2ddcca36c8bcfa251724fe342c8327451988be0d
+Author: Linus Torvalds <torvalds@linux-foundation.org>
+Date:   Sat May 3 11:59:44 2008 -0700
+
+    Linux 2.6.26-rc1
+
+diff --git a/Makefile b/Makefile
+index 5cf8258..4492984 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1,7 +1,7 @@
+ VERSION = 2
+ PATCHLEVEL = 6
+-SUBLEVEL = 25
+-EXTRAVERSION =
++SUBLEVEL = 26
++EXTRAVERSION = -rc1
+ NAME = Funky Weasel is Jiggy wit it
+
+ # *DOCUMENTATION*
+-------------
+
+And when we are finished we can use "git bisect reset" to go back to
+the branch we were in before we started bisecting:
+
+-------------
+$ git bisect reset
+Checking out files: 100% (21549/21549), done.
+Previous HEAD position was 2ddcca3... Linux 2.6.26-rc1
+Switched to branch 'master'
+-------------
+
+Driving a bisection automatically
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The other way to drive the bisection process is to tell "git bisect"
+to launch a script or command at each bisection step to know if the
+current commit is "good" or "bad". To do that, we use the "git bisect
+run" command. For example:
+
+-------------
+$ git bisect start v2.6.27 v2.6.25
+Bisecting: 10928 revisions left to test after this (roughly 14 steps)
+[2ec65f8b89ea003c27ff7723525a2ee335a2b393] x86: clean up using max_low_pfn on 32-bit
+$
+$ git bisect run grep '^SUBLEVEL = 25' Makefile
+running grep ^SUBLEVEL = 25 Makefile
+Bisecting: 5480 revisions left to test after this (roughly 13 steps)
+[66c0b394f08fd89236515c1c84485ea712a157be] KVM: kill file->f_count abuse in kvm
+running grep ^SUBLEVEL = 25 Makefile
+SUBLEVEL = 25
+Bisecting: 2740 revisions left to test after this (roughly 12 steps)
+[671294719628f1671faefd4882764886f8ad08cb] V4L/DVB(7879): Adding cx18 Support for mxl5005s
+...
+...
+running grep ^SUBLEVEL = 25 Makefile
+Bisecting: 0 revisions left to test after this (roughly 0 steps)
+[2ddcca36c8bcfa251724fe342c8327451988be0d] Linux 2.6.26-rc1
+running grep ^SUBLEVEL = 25 Makefile
+2ddcca36c8bcfa251724fe342c8327451988be0d is the first bad commit
+commit 2ddcca36c8bcfa251724fe342c8327451988be0d
+Author: Linus Torvalds <torvalds@linux-foundation.org>
+Date:   Sat May 3 11:59:44 2008 -0700
+
+    Linux 2.6.26-rc1
+
+:100644 100644 5cf82581... 4492984e... M      Makefile
+bisect run success
+-------------
+
+In this example, we passed "grep '^SUBLEVEL = 25' Makefile" as
+parameter to "git bisect run". This means that at each step, the grep
+command we passed will be launched. And if it exits with code 0 (that
+means success) then git bisect will mark the current state as
+"good". If it exits with code 1 (or any code between 1 and 127
+included, except the special code 125), then the current state will be
+marked as "bad".
+
+Exit code between 128 and 255 are special to "git bisect run". They
+make it stop immediately the bisection process. This is useful for
+example if the command passed takes too long to complete, because you
+can kill it with a signal and it will stop the bisection process.
+
+It can also be useful in scripts passed to "git bisect run" to "exit
+255" if some very abnormal situation is detected.
+
+Avoiding untestable commits
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Sometimes it happens that the current state cannot be tested, for
+example if it does not compile because there was a bug preventing it
+at that time. This is what the special exit code 125 is for. It tells
+"git bisect run" that the current commit should be marked as
+untestable and that another one should be chosen and checked out.
+
+If the bisection process is driven manually, you can use "git bisect
+skip" to do the same thing. (In fact the special exit code 125 makes
+"git bisect run" use "git bisect skip" in the background.)
+
+Or if you want more control, you can inspect the current state using
+for example "git bisect visualize". It will launch gitk (or "git log"
+if the `DISPLAY` environment variable is not set) to help you find a
+better bisection point.
+
+Either way, if you have a string of untestable commits, it might
+happen that the regression you are looking for has been introduced by
+one of these untestable commits. In this case it's not possible to
+tell for sure which commit introduced the regression.
+
+So if you used "git bisect skip" (or the run script exited with
+special code 125) you could get a result like this:
+
+-------------
+There are only 'skip'ped commits left to test.
+The first bad commit could be any of:
+15722f2fa328eaba97022898a305ffc8172db6b1
+78e86cf3e850bd755bb71831f42e200626fbd1e0
+e15b73ad3db9b48d7d1ade32f8cd23a751fe0ace
+070eab2303024706f2924822bfec8b9847e4ac1b
+We cannot bisect more!
+-------------
+
+Saving a log and replaying it
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you want to show other people your bisection process, you can get a
+log using for example:
+
+-------------
+$ git bisect log > bisect_log.txt
+-------------
+
+And it is possible to replay it using:
+
+-------------
+$ git bisect replay bisect_log.txt
+-------------
+
+
+"git bisect" details
+--------------------
+
+Bisection algorithm
+~~~~~~~~~~~~~~~~~~~
+
+As the Git commits form a directed acyclic graph (DAG), finding the
+best bisection commit to test at each step is not so simple. Anyway
+Linus found and implemented a "truly stupid" algorithm, later improved
+by Junio Hamano, that works quite well.
+
+So the algorithm used by "git bisect" to find the best bisection
+commit when there are no skipped commits is the following:
+
+1) keep only the commits that:
+
+a) are ancestor of the "bad" commit (including the "bad" commit itself),
+b) are not ancestor of a "good" commit (excluding the "good" commits).
+
+This means that we get rid of the uninteresting commits in the DAG.
+
+For example if we start with a graph like this:
+
+-------------
+G-Y-G-W-W-W-X-X-X-X
+	   \ /
+	    W-W-B
+	   /
+Y---G-W---W
+ \ /   \
+Y-Y     X-X-X-X
+
+-> time goes this way ->
+-------------
+
+where B is the "bad" commit, "G" are "good" commits and W, X, and Y
+are other commits, we will get the following graph after this first
+step:
+
+-------------
+W-W-W
+     \
+      W-W-B
+     /
+W---W
+-------------
+
+So only the W and B commits will be kept. Because commits X and Y will
+have been removed by rules a) and b) respectively, and because commits
+G are removed by rule b) too.
+
+Note for Git users, that it is equivalent as keeping only the commit
+given by:
+
+-------------
+git rev-list BAD --not GOOD1 GOOD2...
+-------------
+
+Also note that we don't require the commits that are kept to be
+descendants of a "good" commit. So in the following example, commits W
+and Z will be kept:
+
+-------------
+G-W-W-W-B
+   /
+Z-Z
+-------------
+
+2) starting from the "good" ends of the graph, associate to each
+commit the number of ancestors it has plus one
+
+For example with the following graph where H is the "bad" commit and A
+and D are some parents of some "good" commits:
+
+-------------
+A-B-C
+     \
+      F-G-H
+     /
+D---E
+-------------
+
+this will give:
+
+-------------
+1 2 3
+A-B-C
+     \6 7 8
+      F-G-H
+1   2/
+D---E
+-------------
+
+3) associate to each commit: min(X, N - X)
+
+where X is the value associated to the commit in step 2) and N is the
+total number of commits in the graph.
+
+In the above example we have N = 8, so this will give:
+
+-------------
+1 2 3
+A-B-C
+     \2 1 0
+      F-G-H
+1   2/
+D---E
+-------------
+
+4) the best bisection point is the commit with the highest associated
+number
+
+So in the above example the best bisection point is commit C.
+
+5) note that some shortcuts are implemented to speed up the algorithm
+
+As we know N from the beginning, we know that min(X, N - X) can't be
+greater than N/2. So during steps 2) and 3), if we would associate N/2
+to a commit, then we know this is the best bisection point. So in this
+case we can just stop processing any other commit and return the
+current commit.
+
+Bisection algorithm debugging
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For any commit graph, you can see the number associated with each
+commit using "git rev-list --bisect-all".
+
+For example, for the above graph, a command like:
+
+-------------
+$ git rev-list --bisect-all BAD --not GOOD1 GOOD2
+-------------
+
+would output something like:
+
+-------------
+e15b73ad3db9b48d7d1ade32f8cd23a751fe0ace (dist=3)
+15722f2fa328eaba97022898a305ffc8172db6b1 (dist=2)
+78e86cf3e850bd755bb71831f42e200626fbd1e0 (dist=2)
+a1939d9a142de972094af4dde9a544e577ddef0e (dist=2)
+070eab2303024706f2924822bfec8b9847e4ac1b (dist=1)
+a3864d4f32a3bf5ed177ddef598490a08760b70d (dist=1)
+a41baa717dd74f1180abf55e9341bc7a0bb9d556 (dist=1)
+9e622a6dad403b71c40979743bb9d5be17b16bd6 (dist=0)
+-------------
+
+Bisection algorithm discussed
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+First let's define "best bisection point". We will say that a commit X
+is a best bisection point or a best bisection commit if knowing its
+state ("good" or "bad") gives as much information as possible whether
+the state of the commit happens to be "good" or "bad".
+
+This means that the best bisection commits are the commits where the
+following function is maximum:
+
+-------------
+f(X) = min(information_if_good(X), information_if_bad(X))
+-------------
+
+where information_if_good(X) is the information we get if X is good
+and information_if_bad(X) is the information we get if X is bad.
+
+Now we will suppose that there is only one "first bad commit". This
+means that all its descendants are "bad" and all the other commits are
+"good". And we will suppose that all commits have an equal probability
+of being good or bad, or of being the first bad commit, so knowing the
+state of c commits gives always the same amount of information
+wherever these c commits are on the graph and whatever c is. (So we
+suppose that these commits being for example on a branch or near a
+good or a bad commit does not give more or less information).
+
+Let's also suppose that we have a cleaned up graph like one after step
+1) in the bisection algorithm above. This means that we can measure
+the information we get in terms of number of commit we can remove from
+the graph..
+
+And let's take a commit X in the graph.
+
+If X is found to be "good", then we know that its ancestors are all
+"good", so we want to say that:
+
+-------------
+information_if_good(X) = number_of_ancestors(X)  (TRUE)
+-------------
+
+And this is true because at step 1) b) we remove the ancestors of the
+"good" commits.
+
+If X is found to be "bad", then we know that its descendants are all
+"bad", so we want to say that:
+
+-------------
+information_if_bad(X) = number_of_descendants(X)  (WRONG)
+-------------
+
+But this is wrong because at step 1) a) we keep only the ancestors of
+the bad commit. So we get more information when a commit is marked as
+"bad", because we also know that the ancestors of the previous "bad"
+commit that are not ancestors of the new "bad" commit are not the
+first bad commit. We don't know if they are good or bad, but we know
+that they are not the first bad commit because they are not ancestor
+of the new "bad" commit.
+
+So when a commit is marked as "bad" we know we can remove all the
+commits in the graph except those that are ancestors of the new "bad"
+commit. This means that:
+
+-------------
+information_if_bad(X) = N - number_of_ancestors(X)  (TRUE)
+-------------
+
+where N is the number of commits in the (cleaned up) graph.
+
+So in the end this means that to find the best bisection commits we
+should maximize the function:
+
+-------------
+f(X) = min(number_of_ancestors(X), N - number_of_ancestors(X))
+-------------
+
+And this is nice because at step 2) we compute number_of_ancestors(X)
+and so at step 3) we compute f(X).
+
+Let's take the following graph as an example:
+
+-------------
+            G-H-I-J
+           /       \
+A-B-C-D-E-F         O
+           \       /
+            K-L-M-N
+-------------
+
+If we compute the following non optimal function on it:
+
+-------------
+g(X) = min(number_of_ancestors(X), number_of_descendants(X))
+-------------
+
+we get:
+
+-------------
+            4 3 2 1
+            G-H-I-J
+1 2 3 4 5 6/       \0
+A-B-C-D-E-F         O
+           \       /
+            K-L-M-N
+            4 3 2 1
+-------------
+
+but with the algorithm used by git bisect we get:
+
+-------------
+            7 7 6 5
+            G-H-I-J
+1 2 3 4 5 6/       \0
+A-B-C-D-E-F         O
+           \       /
+            K-L-M-N
+            7 7 6 5
+-------------
+
+So we chose G, H, K or L as the best bisection point, which is better
+than F. Because if for example L is bad, then we will know not only
+that L, M and N are bad but also that G, H, I and J are not the first
+bad commit (since we suppose that there is only one first bad commit
+and it must be an ancestor of L).
+
+So the current algorithm seems to be the best possible given what we
+initially supposed.
+
+Skip algorithm
+~~~~~~~~~~~~~~
+
+When some commits have been skipped (using "git bisect skip"), then
+the bisection algorithm is the same for step 1) to 3). But then we use
+roughly the following steps:
+
+6) sort the commit by decreasing associated value
+
+7) if the first commit has not been skipped, we can return it and stop
+here
+
+8) otherwise filter out all the skipped commits in the sorted list
+
+9) use a pseudo random number generator (PRNG) to generate a random
+number between 0 and 1
+
+10) multiply this random number with its square root to bias it toward
+0
+
+11) multiply the result by the number of commits in the filtered list
+to get an index into this list
+
+12) return the commit at the computed index
+
+Skip algorithm discussed
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+After step 7) (in the skip algorithm), we could check if the second
+commit has been skipped and return it if it is not the case. And in
+fact that was the algorithm we used from when "git bisect skip" was
+developed in Git version 1.5.4 (released on February 1st 2008) until
+Git version 1.6.4 (released July 29th 2009).
+
+But Ingo Molnar and H. Peter Anvin (another well known linux kernel
+developer) both complained that sometimes the best bisection points
+all happened to be in an area where all the commits are
+untestable. And in this case the user was asked to test many
+untestable commits, which could be very inefficient.
+
+Indeed untestable commits are often untestable because a breakage was
+introduced at one time, and that breakage was fixed only after many
+other commits were introduced.
+
+This breakage is of course most of the time unrelated to the breakage
+we are trying to locate in the commit graph. But it prevents us to
+know if the interesting "bad behavior" is present or not.
+
+So it is a fact that commits near an untestable commit have a high
+probability of being untestable themselves. And the best bisection
+commits are often found together too (due to the bisection algorithm).
+
+This is why it is a bad idea to just chose the next best unskipped
+bisection commit when the first one has been skipped.
+
+We found that most commits on the graph may give quite a lot of
+information when they are tested. And the commits that will not on
+average give a lot of information are the one near the good and bad
+commits.
+
+So using a PRNG with a bias to favor commits away from the good and
+bad commits looked like a good choice.
+
+One obvious improvement to this algorithm would be to look for a
+commit that has an associated value near the one of the best bisection
+commit, and that is on another branch, before using the PRNG. Because
+if such a commit exists, then it is not very likely to be untestable
+too, so it will probably give more information than a nearly randomly
+chosen one.
+
+Checking merge bases
+~~~~~~~~~~~~~~~~~~~~
+
+There is another tweak in the bisection algorithm that has not been
+described in the "bisection algorithm" above.
+
+We supposed in the previous examples that the "good" commits were
+ancestors of the "bad" commit. But this is not a requirement of "git
+bisect".
+
+Of course the "bad" commit cannot be an ancestor of a "good" commit,
+because the ancestors of the good commits are supposed to be
+"good". And all the "good" commits must be related to the bad commit.
+They cannot be on a branch that has no link with the branch of the
+"bad" commit. But it is possible for a good commit to be related to a
+bad commit and yet not be neither one of its ancestor nor one of its
+descendants.
+
+For example, there can be a "main" branch, and a "dev" branch that was
+forked of the main branch at a commit named "D" like this:
+
+-------------
+A-B-C-D-E-F-G  <--main
+       \
+        H-I-J  <--dev
+-------------
+
+The commit "D" is called a "merge base" for branch "main" and "dev"
+because it's the best common ancestor for these branches for a merge.
+
+Now let's suppose that commit J is bad and commit G is good and that
+we apply the bisection algorithm like it has been previously
+described.
+
+As described in step 1) b) of the bisection algorithm, we remove all
+the ancestors of the good commits because they are supposed to be good
+too.
+
+So we would be left with only:
+
+-------------
+H-I-J
+-------------
+
+But what happens if the first bad commit is "B" and if it has been
+fixed in the "main" branch by commit "F"?
+
+The result of such a bisection would be that we would find that H is
+the first bad commit, when in fact it's B. So that would be wrong!
+
+And yes it can happen in practice that people working on one branch
+are not aware that people working on another branch fixed a bug! It
+could also happen that F fixed more than one bug or that it is a
+revert of some big development effort that was not ready to be
+released.
+
+In fact development teams often maintain both a development branch and
+a maintenance branch, and it would be quite easy for them if "git
+bisect" just worked when they want to bisect a regression on the
+development branch that is not on the maintenance branch. They should
+be able to start bisecting using:
+
+-------------
+$ git bisect start dev main
+-------------
+
+To enable that additional nice feature, when a bisection is started
+and when some good commits are not ancestors of the bad commit, we
+first compute the merge bases between the bad and the good commits and
+we chose these merge bases as the first commits that will be checked
+out and tested.
+
+If it happens that one merge base is bad, then the bisection process
+is stopped with a message like:
+
+-------------
+The merge base BBBBBB is bad.
+This means the bug has been fixed between BBBBBB and [GGGGGG,...].
+-------------
+
+where BBBBBB is the sha1 hash of the bad merge base and [GGGGGG,...]
+is a comma separated list of the sha1 of the good commits.
+
+If some of the merge bases are skipped, then the bisection process
+continues, but the following message is printed for each skipped merge
+base:
+
+-------------
+Warning: the merge base between BBBBBB and [GGGGGG,...] must be skipped.
+So we cannot be sure the first bad commit is between MMMMMM and BBBBBB.
+We continue anyway.
+-------------
+
+where BBBBBB is the sha1 hash of the bad commit, MMMMMM is the sha1
+hash of the merge base that is skipped and [GGGGGG,...]  is a comma
+separated list of the sha1 of the good commits.
+
+So if there is no bad merge base, the bisection process continues as
+usual after this step.
+
+Best bisecting practices
+------------------------
+
+Using test suites and git bisect together
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you both have a test suite and use git bisect, then it becomes less
+important to check that all tests pass after each commit. Though of
+course it is probably a good idea to have some checks to avoid
+breaking too many things because it could make bisecting other bugs
+more difficult.
+
+You can focus your efforts to check at a few points (for example rc
+and beta releases) that all the T test cases pass for all the N
+configurations. And when some tests don't pass you can use "git
+bisect" (or better "git bisect run"). So you should perform roughly:
+
+-------------
+c * N * T + b * M * log2(M) tests
+-------------
+
+where c is the number of rounds of test (so a small constant) and b is
+the ratio of bug per commit (hopefully a small constant too).
+
+So of course it's much better as it's O(N * T) vs O(N * T * M) if
+you would test everything after each commit.
+
+This means that test suites are good to prevent some bugs from being
+committed and they are also quite good to tell you that you have some
+bugs. But they are not so good to tell you where some bugs have been
+introduced. To tell you that efficiently, git bisect is needed.
+
+The other nice thing with test suites, is that when you have one, you
+already know how to test for bad behavior. So you can use this
+knowledge to create a new test case for "git bisect" when it appears
+that there is a regression. So it will be easier to bisect the bug and
+fix it. And then you can add the test case you just created to your
+test suite.
+
+So if you know how to create test cases and how to bisect, you will be
+subject to a virtuous circle:
+
+more tests => easier to create tests => easier to bisect => more tests
+
+So test suites and "git bisect" are complementary tools that are very
+powerful and efficient when used together.
+
+Bisecting build failures
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can very easily automatically bisect broken builds using something
+like:
+
+-------------
+$ git bisect start BAD GOOD
+$ git bisect run make
+-------------
+
+Passing sh -c "some commands" to "git bisect run"
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For example:
+
+-------------
+$ git bisect run sh -c "make || exit 125; ./my_app | grep 'good output'"
+-------------
+
+On the other hand if you do this often, then it can be worth having
+scripts to avoid too much typing.
+
+Finding performance regressions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Here is an example script that comes slightly modified from a real
+world script used by Junio Hamano <<4>>.
+
+This script can be passed to "git bisect run" to find the commit that
+introduced a performance regression:
+
+-------------
+#!/bin/sh
+
+# Build errors are not what I am interested in.
+make my_app || exit 255
+
+# We are checking if it stops in a reasonable amount of time, so
+# let it run in the background...
+
+./my_app >log 2>&1 &
+
+# ... and grab its process ID.
+pid=$!
+
+# ... and then wait for sufficiently long.
+sleep $NORMAL_TIME
+
+# ... and then see if the process is still there.
+if kill -0 $pid
+then
+	# It is still running -- that is bad.
+	kill $pid; sleep 1; kill $pid;
+	exit 1
+else
+	# It has already finished (the $pid process was no more),
+	# and we are happy.
+	exit 0
+fi
+-------------
+
+Following general best practices
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It is obviously a good idea not to have commits with changes that
+knowingly break things, even if some other commits later fix the
+breakage.
+
+It is also a good idea when using any VCS to have only one small
+logical change in each commit.
+
+The smaller the changes in your commit, the most effective "git
+bisect" will be. And you will probably need "git bisect" less in the
+first place, as small changes are easier to review even if they are
+only reviewed by the committer.
+
+Another good idea is to have good commit messages. They can be very
+helpful to understand why some changes were made.
+
+These general best practices are very helpful if you bisect often.
+
+Avoiding bug prone merges
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+First merges by themselves can introduce some regressions even when
+the merge needs no source code conflict resolution. This is because a
+semantic change can happen in one branch while the other branch is not
+aware of it.
+
+For example one branch can change the semantic of a function while the
+other branch add more calls to the same function.
+
+This is made much worse if many files have to be fixed to resolve
+conflicts. That's why such merges are called "evil merges". They can
+make regressions very difficult to track down. It can even be
+misleading to know the first bad commit if it happens to be such a
+merge, because people might think that the bug comes from bad conflict
+resolution when it comes from a semantic change in one branch.
+
+Anyway "git rebase" can be used to linearize history. This can be used
+either to avoid merging in the first place. Or it can be used to
+bisect on a linear history instead of the non linear one, as this
+should give more information in case of a semantic change in one
+branch.
+
+Merges can be also made simpler by using smaller branches or by using
+many topic branches instead of only long version related branches.
+
+And testing can be done more often in special integration branches
+like linux-next for the linux kernel.
+
+Adapting your work-flow
+~~~~~~~~~~~~~~~~~~~~~~~
+
+A special work-flow to process regressions can give great results.
+
+Here is an example of a work-flow used by Andreas Ericsson:
+
+* write, in the test suite, a test script that exposes the regression
+* use "git bisect run" to find the commit that introduced it
+* fix the bug that is often made obvious by the previous step
+* commit both the fix and the test script (and if needed more tests)
+
+And here is what Andreas said about this work-flow <<5>>:
+
+_____________
+To give some hard figures, we used to have an average report-to-fix
+cycle of 142.6 hours (according to our somewhat weird bug-tracker
+which just measures wall-clock time). Since we moved to Git, we've
+lowered that to 16.2 hours. Primarily because we can stay on top of
+the bug fixing now, and because everyone's jockeying to get to fix
+bugs (we're quite proud of how lazy we are to let Git find the bugs
+for us). Each new release results in ~40% fewer bugs (almost certainly
+due to how we now feel about writing tests).
+_____________
+
+Clearly this work-flow uses the virtuous circle between test suites
+and "git bisect". In fact it makes it the standard procedure to deal
+with regression.
+
+In other messages Andreas says that they also use the "best practices"
+described above: small logical commits, topic branches, no evil
+merge,... These practices all improve the bisectability of the commit
+graph, by making it easier and more useful to bisect.
+
+So a good work-flow should be designed around the above points. That
+is making bisecting easier, more useful and standard.
+
+Involving QA people and if possible end users
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+One nice about "git bisect" is that it is not only a developer
+tool. It can effectively be used by QA people or even end users (if
+they have access to the source code or if they can get access to all
+the builds).
+
+There was a discussion at one point on the linux kernel mailing list
+of whether it was ok to always ask end user to bisect, and very good
+points were made to support the point of view that it is ok.
+
+For example David Miller wrote <<6>>:
+
+_____________
+What people don't get is that this is a situation where the "end node
+principle" applies. When you have limited resources (here: developers)
+you don't push the bulk of the burden upon them. Instead you push
+things out to the resource you have a lot of, the end nodes (here:
+users), so that the situation actually scales.
+_____________
+
+This means that it is often "cheaper" if QA people or end users can do
+it.
+
+What is interesting too is that end users that are reporting bugs (or
+QA people that reproduced a bug) have access to the environment where
+the bug happens. So they can often more easily reproduce a
+regression. And if they can bisect, then more information will be
+extracted from the environment where the bug happens, which means that
+it will be easier to understand and then fix the bug.
+
+For open source projects it can be a good way to get more useful
+contributions from end users, and to introduce them to QA and
+development activities.
+
+Using complex scripts
+~~~~~~~~~~~~~~~~~~~~~
+
+In some cases like for kernel development it can be worth developing
+complex scripts to be able to fully automate bisecting.
+
+Here is what Ingo Molnar says about that <<7>>:
+
+_____________
+i have a fully automated bootup-hang bisection script. It is based on
+"git-bisect run". I run the script, it builds and boots kernels fully
+automatically, and when the bootup fails (the script notices that via
+the serial log, which it continuously watches - or via a timeout, if
+the system does not come up within 10 minutes it's a "bad" kernel),
+the script raises my attention via a beep and i power cycle the test
+box. (yeah, i should make use of a managed power outlet to 100%
+automate it)
+_____________
+
+Combining test suites, git bisect and other systems together
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+We have seen that test suites and git bisect are very powerful when
+used together. It can be even more powerful if you can combine them
+with other systems.
+
+For example some test suites could be run automatically at night with
+some unusual (or even random) configurations. And if a regression is
+found by a test suite, then "git bisect" can be automatically
+launched, and its result can be emailed to the author of the first bad
+commit found by "git bisect", and perhaps other people too. And a new
+entry in the bug tracking system could be automatically created too.
+
+
+The future of bisecting
+-----------------------
+
+"git replace"
+~~~~~~~~~~~~~
+
+We saw earlier that "git bisect skip" is now using a PRNG to try to
+avoid areas in the commit graph where commits are untestable. The
+problem is that sometimes the first bad commit will be in an
+untestable area.
+
+To simplify the discussion we will suppose that the untestable area is
+a simple string of commits and that it was created by a breakage
+introduced by one commit (let's call it BBC for bisect breaking
+commit) and later fixed by another one (let's call it BFC for bisect
+fixing commit).
+
+For example:
+
+-------------
+...-Y-BBC-X1-X2-X3-X4-X5-X6-BFC-Z-...
+-------------
+
+where we know that Y is good and BFC is bad, and where BBC and X1 to
+X6 are untestable.
+
+In this case if you are bisecting manually, what you can do is create
+a special branch that starts just before the BBC. The first commit in
+this branch should be the BBC with the BFC squashed into it. And the
+other commits in the branch should be the commits between BBC and BFC
+rebased on the first commit of the branch and then the commit after
+BFC also rebased on.
+
+For example:
+
+-------------
+      (BBC+BFC)-X1'-X2'-X3'-X4'-X5'-X6'-Z'
+     /
+...-Y-BBC-X1-X2-X3-X4-X5-X6-BFC-Z-...
+-------------
+
+where commits quoted with ' have been rebased.
+
+You can easily create such a branch with Git using interactive rebase.
+
+For example using:
+
+-------------
+$ git rebase -i Y Z
+-------------
+
+and then moving BFC after BBC and squashing it.
+
+After that you can start bisecting as usual in the new branch and you
+should eventually find the first bad commit.
+
+For example:
+
+-------------
+$ git bisect start Z' Y
+-------------
+
+If you are using "git bisect run", you can use the same manual fix up
+as above, and then start another "git bisect run" in the special
+branch. Or as the "git bisect" man page says, the script passed to
+"git bisect run" can apply a patch before it compiles and test the
+software <<8>>. The patch should turn a current untestable commits
+into a testable one. So the testing will result in "good" or "bad" and
+"git bisect" will be able to find the first bad commit. And the script
+should not forget to remove the patch once the testing is done before
+exiting from the script.
+
+(Note that instead of a patch you can use "git cherry-pick BFC" to
+apply the fix, and in this case you should use "git reset --hard
+HEAD^" to revert the cherry-pick after testing and before returning
+from the script.)
+
+But the above ways to work around untestable areas are a little bit
+clunky. Using special branches is nice because these branches can be
+shared by developers like usual branches, but the risk is that people
+will get many such branches. And it disrupts the normal "git bisect"
+work-flow. So, if you want to use "git bisect run" completely
+automatically, you have to add special code in your script to restart
+bisection in the special branches.
+
+Anyway one can notice in the above special branch example that the Z'
+and Z commits should point to the same source code state (the same
+"tree" in git parlance). That's because Z' result from applying the
+same changes as Z just in a slightly different order.
+
+So if we could just "replace" Z by Z' when we bisect, then we would
+not need to add anything to a script. It would just work for anyone in
+the project sharing the special branches and the replacements.
+
+With the example above that would give:
+
+-------------
+      (BBC+BFC)-X1'-X2'-X3'-X4'-X5'-X6'-Z'-...
+     /
+...-Y-BBC-X1-X2-X3-X4-X5-X6-BFC-Z
+-------------
+
+That's why the "git replace" command was created. Technically it
+stores replacements "refs" in the "refs/replace/" hierarchy. These
+"refs" are like branches (that are stored in "refs/heads/") or tags
+(that are stored in "refs/tags"), and that means that they can
+automatically be shared like branches or tags among developers.
+
+"git replace" is a very powerful mechanism. It can be used to fix
+commits in already released history, for example to change the commit
+message or the author. And it can also be used instead of git "grafts"
+to link a repository with another old repository.
+
+In fact it's this last feature that "sold" it to the Git community, so
+it is now in the "master" branch of Git's Git repository and it should
+be released in Git 1.6.5 in October or November 2009.
+
+One problem with "git replace" is that currently it stores all the
+replacements refs in "refs/replace/", but it would be perhaps better
+if the replacement refs that are useful only for bisecting would be in
+"refs/replace/bisect/". This way the replacement refs could be used
+only for bisecting, while other refs directly in "refs/replace/" would
+be used nearly all the time.
+
+Bisecting sporadic bugs
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Another possible improvement to "git bisect" would be to optionally
+add some redundancy to the tests performed so that it would be more
+reliable when tracking sporadic bugs.
+
+This has been requested by some kernel developers because some bugs
+called sporadic bugs do not appear in all the kernel builds because
+they are very dependent on the compiler output.
+
+The idea is that every 3 test for example, "git bisect" could ask the
+user to test a commit that has already been found to be "good" or
+"bad" (because one of its descendants or one of its ancestors has been
+found to be "good" or "bad" respectively). If it happens that a commit
+has been previously incorrectly classified then the bisection can be
+aborted early, hopefully before too many mistakes have been made. Then
+the user will have to look at what happened and then restart the
+bisection using a fixed bisect log.
+
+There is already a project called BBChop created by Ealdwulf Wuffinga
+on Github that does something like that using Bayesian Search Theory
+<<9>>:
+
+_____________
+BBChop is like 'git bisect' (or equivalent), but works when your bug
+is intermittent. That is, it works in the presence of false negatives
+(when a version happens to work this time even though it contains the
+bug). It assumes that there are no false positives (in principle, the
+same approach would work, but adding it may be non-trivial).
+_____________
+
+But BBChop is independent of any VCS and it would be easier for Git
+users to have something integrated in Git.
+
+Conclusion
+----------
+
+We have seen that regressions are an important problem, and that "git
+bisect" has nice features that complement very well practices and
+other tools, especially test suites, that are generally used to fight
+regressions. But it might be needed to change some work-flows and
+(bad) habits to get the most out of it.
+
+Some improvements to the algorithms inside "git bisect" are possible
+and some new features could help in some cases, but overall "git
+bisect" works already very well, is used a lot, and is already very
+useful. To back up that last claim, let's give the final word to Ingo
+Molnar when he was asked by the author how much time does he think
+"git bisect" saves him when he uses it:
+
+_____________
+a _lot_.
+
+About ten years ago did i do my first 'bisection' of a Linux patch
+queue. That was prior the Git (and even prior the BitKeeper) days. I
+literally days spent sorting out patches, creating what in essence
+were standalone commits that i guessed to be related to that bug.
+
+It was a tool of absolute last resort. I'd rather spend days looking
+at printk output than do a manual 'patch bisection'.
+
+With Git bisect it's a breeze: in the best case i can get a ~15 step
+kernel bisection done in 20-30 minutes, in an automated way. Even with
+manual help or when bisecting multiple, overlapping bugs, it's rarely
+more than an hour.
+
+In fact it's invaluable because there are bugs i would never even
+_try_ to debug if it wasn't for git bisect. In the past there were bug
+patterns that were immediately hopeless for me to debug - at best i
+could send the crash/bug signature to lkml and hope that someone else
+can think of something.
+
+And even if a bisection fails today it tells us something valuable
+about the bug: that it's non-deterministic - timing or kernel image
+layout dependent.
+
+So git bisect is unconditional goodness - and feel free to quote that
+;-)
+_____________
+
+Acknowledgments
+---------------
+
+Many thanks to Junio Hamano for his help in reviewing this paper, for
+reviewing the patches I sent to the Git mailing list, for discussing
+some ideas and helping me improve them, for improving "git bisect" a
+lot and for his awesome work in maintaining and developing Git.
+
+Many thanks to Ingo Molnar for giving me very useful information that
+appears in this paper, for commenting on this paper, for his
+suggestions to improve "git bisect" and for evangelizing "git bisect"
+on the linux kernel mailing lists.
+
+Many thanks to Linus Torvalds for inventing, developing and
+evangelizing "git bisect", Git and Linux.
+
+Many thanks to the many other great people who helped one way or
+another when I worked on Git, especially to Andreas Ericsson, Johannes
+Schindelin, H. Peter Anvin, Daniel Barkalow, Bill Lear, John Hawley,
+Shawn O. Pierce, Jeff King, Sam Vilain, Jon Seymour.
+
+Many thanks to the Linux-Kongress program committee for choosing the
+author to given a talk and for publishing this paper.
+
+References
+----------
+
+- [[[1]]] https://www.nist.gov/sites/default/files/documents/director/planning/report02-3.pdf['The Economic Impacts of Inadequate Infratructure for Software Testing'.  Nist Planning Report 02-3], see Executive Summary and Chapter 8.
+- [[[2]]] http://www.oracle.com/technetwork/java/codeconvtoc-136057.html['Code Conventions for the Java Programming Language'. Sun Microsystems.]
+- [[[3]]] https://en.wikipedia.org/wiki/Software_maintenance['Software maintenance'. Wikipedia.]
+- [[[4]]] https://public-inbox.org/git/7vps5xsbwp.fsf_-_@assigned-by-dhcp.cox.net/[Junio C Hamano. 'Automated bisect success story'.]
+- [[[5]]] https://lwn.net/Articles/317154/[Christian Couder. 'Fully automated bisecting with "git bisect run"'. LWN.net.]
+- [[[6]]] https://lwn.net/Articles/277872/[Jonathan Corbet. 'Bisection divides users and developers'. LWN.net.]
+- [[[7]]] http://marc.info/?l=linux-kernel&m=119702753411680&w=2[Ingo Molnar. 'Re: BUG 2.6.23-rc3 can't see sd partitions on Alpha'. Linux-kernel mailing list.]
+- [[[8]]] https://www.kernel.org/pub/software/scm/git/docs/git-bisect.html[Junio C Hamano and the git-list. 'git-bisect(1) Manual Page'. Linux Kernel Archives.]
+- [[[9]]] https://github.com/Ealdwulf/bbchop[Ealdwulf. 'bbchop'. GitHub.]
diff --git a/third_party/git/Documentation/git-bisect.txt b/third_party/git/Documentation/git-bisect.txt
new file mode 100644
index 0000000000..4b45d837a7
--- /dev/null
+++ b/third_party/git/Documentation/git-bisect.txt
@@ -0,0 +1,499 @@
+git-bisect(1)
+=============
+
+NAME
+----
+git-bisect - Use binary search to find the commit that introduced a bug
+
+
+SYNOPSIS
+--------
+[verse]
+'git bisect' <subcommand> <options>
+
+DESCRIPTION
+-----------
+The command takes various subcommands, and different options depending
+on the subcommand:
+
+ git bisect start [--term-{old,good}=<term> --term-{new,bad}=<term>]
+		  [--no-checkout] [<bad> [<good>...]] [--] [<paths>...]
+ git bisect (bad|new|<term-new>) [<rev>]
+ git bisect (good|old|<term-old>) [<rev>...]
+ git bisect terms [--term-good | --term-bad]
+ git bisect skip [(<rev>|<range>)...]
+ git bisect reset [<commit>]
+ git bisect (visualize|view)
+ git bisect replay <logfile>
+ git bisect log
+ git bisect run <cmd>...
+ git bisect help
+
+This command uses a binary search algorithm to find which commit in
+your project's history introduced a bug. You use it by first telling
+it a "bad" commit that is known to contain the bug, and a "good"
+commit that is known to be before the bug was introduced. Then `git
+bisect` picks a commit between those two endpoints and asks you
+whether the selected commit is "good" or "bad". It continues narrowing
+down the range until it finds the exact commit that introduced the
+change.
+
+In fact, `git bisect` can be used to find the commit that changed
+*any* property of your project; e.g., the commit that fixed a bug, or
+the commit that caused a benchmark's performance to improve. To
+support this more general usage, the terms "old" and "new" can be used
+in place of "good" and "bad", or you can choose your own terms. See
+section "Alternate terms" below for more information.
+
+Basic bisect commands: start, bad, good
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+As an example, suppose you are trying to find the commit that broke a
+feature that was known to work in version `v2.6.13-rc2` of your
+project. You start a bisect session as follows:
+
+------------------------------------------------
+$ git bisect start
+$ git bisect bad                 # Current version is bad
+$ git bisect good v2.6.13-rc2    # v2.6.13-rc2 is known to be good
+------------------------------------------------
+
+Once you have specified at least one bad and one good commit, `git
+bisect` selects a commit in the middle of that range of history,
+checks it out, and outputs something similar to the following:
+
+------------------------------------------------
+Bisecting: 675 revisions left to test after this (roughly 10 steps)
+------------------------------------------------
+
+You should now compile the checked-out version and test it. If that
+version works correctly, type
+
+------------------------------------------------
+$ git bisect good
+------------------------------------------------
+
+If that version is broken, type
+
+------------------------------------------------
+$ git bisect bad
+------------------------------------------------
+
+Then `git bisect` will respond with something like
+
+------------------------------------------------
+Bisecting: 337 revisions left to test after this (roughly 9 steps)
+------------------------------------------------
+
+Keep repeating the process: compile the tree, test it, and depending
+on whether it is good or bad run `git bisect good` or `git bisect bad`
+to ask for the next commit that needs testing.
+
+Eventually there will be no more revisions left to inspect, and the
+command will print out a description of the first bad commit. The
+reference `refs/bisect/bad` will be left pointing at that commit.
+
+
+Bisect reset
+~~~~~~~~~~~~
+
+After a bisect session, to clean up the bisection state and return to
+the original HEAD, issue the following command:
+
+------------------------------------------------
+$ git bisect reset
+------------------------------------------------
+
+By default, this will return your tree to the commit that was checked
+out before `git bisect start`.  (A new `git bisect start` will also do
+that, as it cleans up the old bisection state.)
+
+With an optional argument, you can return to a different commit
+instead:
+
+------------------------------------------------
+$ git bisect reset <commit>
+------------------------------------------------
+
+For example, `git bisect reset bisect/bad` will check out the first
+bad revision, while `git bisect reset HEAD` will leave you on the
+current bisection commit and avoid switching commits at all.
+
+
+Alternate terms
+~~~~~~~~~~~~~~~
+
+Sometimes you are not looking for the commit that introduced a
+breakage, but rather for a commit that caused a change between some
+other "old" state and "new" state. For example, you might be looking
+for the commit that introduced a particular fix. Or you might be
+looking for the first commit in which the source-code filenames were
+finally all converted to your company's naming standard. Or whatever.
+
+In such cases it can be very confusing to use the terms "good" and
+"bad" to refer to "the state before the change" and "the state after
+the change". So instead, you can use the terms "old" and "new",
+respectively, in place of "good" and "bad". (But note that you cannot
+mix "good" and "bad" with "old" and "new" in a single session.)
+
+In this more general usage, you provide `git bisect` with a "new"
+commit that has some property and an "old" commit that doesn't have that
+property. Each time `git bisect` checks out a commit, you test if that
+commit has the property. If it does, mark the commit as "new";
+otherwise, mark it as "old". When the bisection is done, `git bisect`
+will report which commit introduced the property.
+
+To use "old" and "new" instead of "good" and bad, you must run `git
+bisect start` without commits as argument and then run the following
+commands to add the commits:
+
+------------------------------------------------
+git bisect old [<rev>]
+------------------------------------------------
+
+to indicate that a commit was before the sought change, or
+
+------------------------------------------------
+git bisect new [<rev>...]
+------------------------------------------------
+
+to indicate that it was after.
+
+To get a reminder of the currently used terms, use
+
+------------------------------------------------
+git bisect terms
+------------------------------------------------
+
+You can get just the old (respectively new) term with `git bisect terms
+--term-old` or `git bisect terms --term-good`.
+
+If you would like to use your own terms instead of "bad"/"good" or
+"new"/"old", you can choose any names you like (except existing bisect
+subcommands like `reset`, `start`, ...) by starting the
+bisection using
+
+------------------------------------------------
+git bisect start --term-old <term-old> --term-new <term-new>
+------------------------------------------------
+
+For example, if you are looking for a commit that introduced a
+performance regression, you might use
+
+------------------------------------------------
+git bisect start --term-old fast --term-new slow
+------------------------------------------------
+
+Or if you are looking for the commit that fixed a bug, you might use
+
+------------------------------------------------
+git bisect start --term-new fixed --term-old broken
+------------------------------------------------
+
+Then, use `git bisect <term-old>` and `git bisect <term-new>` instead
+of `git bisect good` and `git bisect bad` to mark commits.
+
+Bisect visualize/view
+~~~~~~~~~~~~~~~~~~~~~
+
+To see the currently remaining suspects in 'gitk', issue the following
+command during the bisection process (the subcommand `view` can be used
+as an alternative to `visualize`):
+
+------------
+$ git bisect visualize
+------------
+
+If the `DISPLAY` environment variable is not set, 'git log' is used
+instead.  You can also give command-line options such as `-p` and
+`--stat`.
+
+------------
+$ git bisect visualize --stat
+------------
+
+Bisect log and bisect replay
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+After having marked revisions as good or bad, issue the following
+command to show what has been done so far:
+
+------------
+$ git bisect log
+------------
+
+If you discover that you made a mistake in specifying the status of a
+revision, you can save the output of this command to a file, edit it to
+remove the incorrect entries, and then issue the following commands to
+return to a corrected state:
+
+------------
+$ git bisect reset
+$ git bisect replay that-file
+------------
+
+Avoiding testing a commit
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If, in the middle of a bisect session, you know that the suggested
+revision is not a good one to test (e.g. it fails to build and you
+know that the failure does not have anything to do with the bug you
+are chasing), you can manually select a nearby commit and test that
+one instead.
+
+For example:
+
+------------
+$ git bisect good/bad			# previous round was good or bad.
+Bisecting: 337 revisions left to test after this (roughly 9 steps)
+$ git bisect visualize			# oops, that is uninteresting.
+$ git reset --hard HEAD~3		# try 3 revisions before what
+					# was suggested
+------------
+
+Then compile and test the chosen revision, and afterwards mark
+the revision as good or bad in the usual manner.
+
+Bisect skip
+~~~~~~~~~~~
+
+Instead of choosing a nearby commit by yourself, you can ask Git to do
+it for you by issuing the command:
+
+------------
+$ git bisect skip                 # Current version cannot be tested
+------------
+
+However, if you skip a commit adjacent to the one you are looking for,
+Git will be unable to tell exactly which of those commits was the
+first bad one.
+
+You can also skip a range of commits, instead of just one commit,
+using range notation. For example:
+
+------------
+$ git bisect skip v2.5..v2.6
+------------
+
+This tells the bisect process that no commit after `v2.5`, up to and
+including `v2.6`, should be tested.
+
+Note that if you also want to skip the first commit of the range you
+would issue the command:
+
+------------
+$ git bisect skip v2.5 v2.5..v2.6
+------------
+
+This tells the bisect process that the commits between `v2.5` and
+`v2.6` (inclusive) should be skipped.
+
+
+Cutting down bisection by giving more parameters to bisect start
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can further cut down the number of trials, if you know what part of
+the tree is involved in the problem you are tracking down, by specifying
+path parameters when issuing the `bisect start` command:
+
+------------
+$ git bisect start -- arch/i386 include/asm-i386
+------------
+
+If you know beforehand more than one good commit, you can narrow the
+bisect space down by specifying all of the good commits immediately after
+the bad commit when issuing the `bisect start` command:
+
+------------
+$ git bisect start v2.6.20-rc6 v2.6.20-rc4 v2.6.20-rc1 --
+                   # v2.6.20-rc6 is bad
+                   # v2.6.20-rc4 and v2.6.20-rc1 are good
+------------
+
+Bisect run
+~~~~~~~~~~
+
+If you have a script that can tell if the current source code is good
+or bad, you can bisect by issuing the command:
+
+------------
+$ git bisect run my_script arguments
+------------
+
+Note that the script (`my_script` in the above example) should exit
+with code 0 if the current source code is good/old, and exit with a
+code between 1 and 127 (inclusive), except 125, if the current source
+code is bad/new.
+
+Any other exit code will abort the bisect process. It should be noted
+that a program that terminates via `exit(-1)` leaves $? = 255, (see the
+exit(3) manual page), as the value is chopped with `& 0377`.
+
+The special exit code 125 should be used when the current source code
+cannot be tested. If the script exits with this code, the current
+revision will be skipped (see `git bisect skip` above). 125 was chosen
+as the highest sensible value to use for this purpose, because 126 and 127
+are used by POSIX shells to signal specific error status (127 is for
+command not found, 126 is for command found but not executable--these
+details do not matter, as they are normal errors in the script, as far as
+`bisect run` is concerned).
+
+You may often find that during a bisect session you want to have
+temporary modifications (e.g. s/#define DEBUG 0/#define DEBUG 1/ in a
+header file, or "revision that does not have this commit needs this
+patch applied to work around another problem this bisection is not
+interested in") applied to the revision being tested.
+
+To cope with such a situation, after the inner 'git bisect' finds the
+next revision to test, the script can apply the patch
+before compiling, run the real test, and afterwards decide if the
+revision (possibly with the needed patch) passed the test and then
+rewind the tree to the pristine state.  Finally the script should exit
+with the status of the real test to let the `git bisect run` command loop
+determine the eventual outcome of the bisect session.
+
+OPTIONS
+-------
+--no-checkout::
++
+Do not checkout the new working tree at each iteration of the bisection
+process. Instead just update a special reference named `BISECT_HEAD` to make
+it point to the commit that should be tested.
++
+This option may be useful when the test you would perform in each step
+does not require a checked out tree.
++
+If the repository is bare, `--no-checkout` is assumed.
+
+EXAMPLES
+--------
+
+* Automatically bisect a broken build between v1.2 and HEAD:
++
+------------
+$ git bisect start HEAD v1.2 --      # HEAD is bad, v1.2 is good
+$ git bisect run make                # "make" builds the app
+$ git bisect reset                   # quit the bisect session
+------------
+
+* Automatically bisect a test failure between origin and HEAD:
++
+------------
+$ git bisect start HEAD origin --    # HEAD is bad, origin is good
+$ git bisect run make test           # "make test" builds and tests
+$ git bisect reset                   # quit the bisect session
+------------
+
+* Automatically bisect a broken test case:
++
+------------
+$ cat ~/test.sh
+#!/bin/sh
+make || exit 125                     # this skips broken builds
+~/check_test_case.sh                 # does the test case pass?
+$ git bisect start HEAD HEAD~10 --   # culprit is among the last 10
+$ git bisect run ~/test.sh
+$ git bisect reset                   # quit the bisect session
+------------
++
+Here we use a `test.sh` custom script. In this script, if `make`
+fails, we skip the current commit.
+`check_test_case.sh` should `exit 0` if the test case passes,
+and `exit 1` otherwise.
++
+It is safer if both `test.sh` and `check_test_case.sh` are
+outside the repository to prevent interactions between the bisect,
+make and test processes and the scripts.
+
+* Automatically bisect with temporary modifications (hot-fix):
++
+------------
+$ cat ~/test.sh
+#!/bin/sh
+
+# tweak the working tree by merging the hot-fix branch
+# and then attempt a build
+if	git merge --no-commit hot-fix &&
+	make
+then
+	# run project specific test and report its status
+	~/check_test_case.sh
+	status=$?
+else
+	# tell the caller this is untestable
+	status=125
+fi
+
+# undo the tweak to allow clean flipping to the next commit
+git reset --hard
+
+# return control
+exit $status
+------------
++
+This applies modifications from a hot-fix branch before each test run,
+e.g. in case your build or test environment changed so that older
+revisions may need a fix which newer ones have already. (Make sure the
+hot-fix branch is based off a commit which is contained in all revisions
+which you are bisecting, so that the merge does not pull in too much, or
+use `git cherry-pick` instead of `git merge`.)
+
+* Automatically bisect a broken test case:
++
+------------
+$ git bisect start HEAD HEAD~10 --   # culprit is among the last 10
+$ git bisect run sh -c "make || exit 125; ~/check_test_case.sh"
+$ git bisect reset                   # quit the bisect session
+------------
++
+This shows that you can do without a run script if you write the test
+on a single line.
+
+* Locate a good region of the object graph in a damaged repository
++
+------------
+$ git bisect start HEAD <known-good-commit> [ <boundary-commit> ... ] --no-checkout
+$ git bisect run sh -c '
+	GOOD=$(git for-each-ref "--format=%(objectname)" refs/bisect/good-*) &&
+	git rev-list --objects BISECT_HEAD --not $GOOD >tmp.$$ &&
+	git pack-objects --stdout >/dev/null <tmp.$$
+	rc=$?
+	rm -f tmp.$$
+	test $rc = 0'
+
+$ git bisect reset                   # quit the bisect session
+------------
++
+In this case, when 'git bisect run' finishes, bisect/bad will refer to a commit that
+has at least one parent whose reachable graph is fully traversable in the sense
+required by 'git pack objects'.
+
+* Look for a fix instead of a regression in the code
++
+------------
+$ git bisect start
+$ git bisect new HEAD    # current commit is marked as new
+$ git bisect old HEAD~10 # the tenth commit from now is marked as old
+------------
++
+or:
+------------
+$ git bisect start --term-old broken --term-new fixed
+$ git bisect fixed
+$ git bisect broken HEAD~10
+------------
+
+Getting help
+~~~~~~~~~~~~
+
+Use `git bisect` to get a short usage description, and `git bisect
+help` or `git bisect -h` to get a long usage description.
+
+SEE ALSO
+--------
+link:git-bisect-lk2009.html[Fighting regressions with git bisect],
+linkgit:git-blame[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-blame.txt b/third_party/git/Documentation/git-blame.txt
new file mode 100644
index 0000000000..7e81541996
--- /dev/null
+++ b/third_party/git/Documentation/git-blame.txt
@@ -0,0 +1,236 @@
+git-blame(1)
+============
+
+NAME
+----
+git-blame - Show what revision and author last modified each line of a file
+
+SYNOPSIS
+--------
+[verse]
+'git blame' [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-e] [-p] [-w] [--incremental]
+	    [-L <range>] [-S <revs-file>] [-M] [-C] [-C] [-C] [--since=<date>]
+	    [--ignore-rev <rev>] [--ignore-revs-file <file>]
+	    [--progress] [--abbrev=<n>] [<rev> | --contents <file> | --reverse <rev>..<rev>]
+	    [--] <file>
+
+DESCRIPTION
+-----------
+
+Annotates each line in the given file with information from the revision which
+last modified the line. Optionally, start annotating from the given revision.
+
+When specified one or more times, `-L` restricts annotation to the requested
+lines.
+
+The origin of lines is automatically followed across whole-file
+renames (currently there is no option to turn the rename-following
+off). To follow lines moved from one file to another, or to follow
+lines that were copied and pasted from another file, etc., see the
+`-C` and `-M` options.
+
+The report does not tell you anything about lines which have been deleted or
+replaced; you need to use a tool such as 'git diff' or the "pickaxe"
+interface briefly mentioned in the following paragraph.
+
+Apart from supporting file annotation, Git also supports searching the
+development history for when a code snippet occurred in a change. This makes it
+possible to track when a code snippet was added to a file, moved or copied
+between files, and eventually deleted or replaced. It works by searching for
+a text string in the diff. A small example of the pickaxe interface
+that searches for `blame_usage`:
+
+-----------------------------------------------------------------------------
+$ git log --pretty=oneline -S'blame_usage'
+5040f17eba15504bad66b14a645bddd9b015ebb7 blame -S <ancestry-file>
+ea4c7f9bf69e781dd0cd88d2bccb2bf5cc15c9a7 git-blame: Make the output
+-----------------------------------------------------------------------------
+
+OPTIONS
+-------
+include::blame-options.txt[]
+
+-c::
+	Use the same output mode as linkgit:git-annotate[1] (Default: off).
+
+--score-debug::
+	Include debugging information related to the movement of
+	lines between files (see `-C`) and lines moved within a
+	file (see `-M`).  The first number listed is the score.
+	This is the number of alphanumeric characters detected
+	as having been moved between or within files.  This must be above
+	a certain threshold for 'git blame' to consider those lines
+	of code to have been moved.
+
+-f::
+--show-name::
+	Show the filename in the original commit.  By default
+	the filename is shown if there is any line that came from a
+	file with a different name, due to rename detection.
+
+-n::
+--show-number::
+	Show the line number in the original commit (Default: off).
+
+-s::
+	Suppress the author name and timestamp from the output.
+
+-e::
+--show-email::
+	Show the author email instead of author name (Default: off).
+	This can also be controlled via the `blame.showEmail` config
+	option.
+
+-w::
+	Ignore whitespace when comparing the parent's version and
+	the child's to find where the lines came from.
+
+--abbrev=<n>::
+	Instead of using the default 7+1 hexadecimal digits as the
+	abbreviated object name, use <n>+1 digits. Note that 1 column
+	is used for a caret to mark the boundary commit.
+
+
+THE PORCELAIN FORMAT
+--------------------
+
+In this format, each line is output after a header; the
+header at the minimum has the first line which has:
+
+- 40-byte SHA-1 of the commit the line is attributed to;
+- the line number of the line in the original file;
+- the line number of the line in the final file;
+- on a line that starts a group of lines from a different
+  commit than the previous one, the number of lines in this
+  group.  On subsequent lines this field is absent.
+
+This header line is followed by the following information
+at least once for each commit:
+
+- the author name ("author"), email ("author-mail"), time
+  ("author-time"), and time zone ("author-tz"); similarly
+  for committer.
+- the filename in the commit that the line is attributed to.
+- the first line of the commit log message ("summary").
+
+The contents of the actual line is output after the above
+header, prefixed by a TAB. This is to allow adding more
+header elements later.
+
+The porcelain format generally suppresses commit information that has
+already been seen. For example, two lines that are blamed to the same
+commit will both be shown, but the details for that commit will be shown
+only once. This is more efficient, but may require more state be kept by
+the reader. The `--line-porcelain` option can be used to output full
+commit information for each line, allowing simpler (but less efficient)
+usage like:
+
+	# count the number of lines attributed to each author
+	git blame --line-porcelain file |
+	sed -n 's/^author //p' |
+	sort | uniq -c | sort -rn
+
+
+SPECIFYING RANGES
+-----------------
+
+Unlike 'git blame' and 'git annotate' in older versions of git, the extent
+of the annotation can be limited to both line ranges and revision
+ranges. The `-L` option, which limits annotation to a range of lines, may be
+specified multiple times.
+
+When you are interested in finding the origin for
+lines 40-60 for file `foo`, you can use the `-L` option like so
+(they mean the same thing -- both ask for 21 lines starting at
+line 40):
+
+	git blame -L 40,60 foo
+	git blame -L 40,+21 foo
+
+Also you can use a regular expression to specify the line range:
+
+	git blame -L '/^sub hello {/,/^}$/' foo
+
+which limits the annotation to the body of the `hello` subroutine.
+
+When you are not interested in changes older than version
+v2.6.18, or changes older than 3 weeks, you can use revision
+range specifiers  similar to 'git rev-list':
+
+	git blame v2.6.18.. -- foo
+	git blame --since=3.weeks -- foo
+
+When revision range specifiers are used to limit the annotation,
+lines that have not changed since the range boundary (either the
+commit v2.6.18 or the most recent commit that is more than 3
+weeks old in the above example) are blamed for that range
+boundary commit.
+
+A particularly useful way is to see if an added file has lines
+created by copy-and-paste from existing files.  Sometimes this
+indicates that the developer was being sloppy and did not
+refactor the code properly.  You can first find the commit that
+introduced the file with:
+
+	git log --diff-filter=A --pretty=short -- foo
+
+and then annotate the change between the commit and its
+parents, using `commit^!` notation:
+
+	git blame -C -C -f $commit^! -- foo
+
+
+INCREMENTAL OUTPUT
+------------------
+
+When called with `--incremental` option, the command outputs the
+result as it is built.  The output generally will talk about
+lines touched by more recent commits first (i.e. the lines will
+be annotated out of order) and is meant to be used by
+interactive viewers.
+
+The output format is similar to the Porcelain format, but it
+does not contain the actual lines from the file that is being
+annotated.
+
+. Each blame entry always starts with a line of:
+
+	<40-byte hex sha1> <sourceline> <resultline> <num_lines>
++
+Line numbers count from 1.
+
+. The first time that a commit shows up in the stream, it has various
+  other information about it printed out with a one-word tag at the
+  beginning of each line describing the extra commit information (author,
+  email, committer, dates, summary, etc.).
+
+. Unlike the Porcelain format, the filename information is always
+  given and terminates the entry:
+
+	"filename" <whitespace-quoted-filename-goes-here>
++
+and thus it is really quite easy to parse for some line- and word-oriented
+parser (which should be quite natural for most scripting languages).
++
+[NOTE]
+For people who do parsing: to make it more robust, just ignore any
+lines between the first and last one ("<sha1>" and "filename" lines)
+where you do not recognize the tag words (or care about that particular
+one) at the beginning of the "extended information" lines. That way, if
+there is ever added information (like the commit encoding or extended
+commit commentary), a blame viewer will not care.
+
+
+MAPPING AUTHORS
+---------------
+
+include::mailmap.txt[]
+
+
+SEE ALSO
+--------
+linkgit:git-annotate[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-branch.txt b/third_party/git/Documentation/git-branch.txt
new file mode 100644
index 0000000000..135206ff4a
--- /dev/null
+++ b/third_party/git/Documentation/git-branch.txt
@@ -0,0 +1,383 @@
+git-branch(1)
+=============
+
+NAME
+----
+git-branch - List, create, or delete branches
+
+SYNOPSIS
+--------
+[verse]
+'git branch' [--color[=<when>] | --no-color] [--show-current]
+	[-v [--abbrev=<length> | --no-abbrev]]
+	[--column[=<options>] | --no-column] [--sort=<key>]
+	[(--merged | --no-merged) [<commit>]]
+	[--contains [<commit]] [--no-contains [<commit>]]
+	[--points-at <object>] [--format=<format>]
+	[(-r | --remotes) | (-a | --all)]
+	[--list] [<pattern>...]
+'git branch' [--track | --no-track] [-f] <branchname> [<start-point>]
+'git branch' (--set-upstream-to=<upstream> | -u <upstream>) [<branchname>]
+'git branch' --unset-upstream [<branchname>]
+'git branch' (-m | -M) [<oldbranch>] <newbranch>
+'git branch' (-c | -C) [<oldbranch>] <newbranch>
+'git branch' (-d | -D) [-r] <branchname>...
+'git branch' --edit-description [<branchname>]
+
+DESCRIPTION
+-----------
+
+If `--list` is given, or if there are no non-option arguments, existing
+branches are listed; the current branch will be highlighted in green and
+marked with an asterisk.  Any branches checked out in linked worktrees will
+be highlighted in cyan and marked with a plus sign. Option `-r` causes the
+remote-tracking branches to be listed,
+and option `-a` shows both local and remote branches.
+
+If a `<pattern>`
+is given, it is used as a shell wildcard to restrict the output to
+matching branches. If multiple patterns are given, a branch is shown if
+it matches any of the patterns.
+
+Note that when providing a
+`<pattern>`, you must use `--list`; otherwise the command may be interpreted
+as branch creation.
+
+With `--contains`, shows only the branches that contain the named commit
+(in other words, the branches whose tip commits are descendants of the
+named commit), `--no-contains` inverts it. With `--merged`, only branches
+merged into the named commit (i.e. the branches whose tip commits are
+reachable from the named commit) will be listed.  With `--no-merged` only
+branches not merged into the named commit will be listed.  If the <commit>
+argument is missing it defaults to `HEAD` (i.e. the tip of the current
+branch).
+
+The command's second form creates a new branch head named <branchname>
+which points to the current `HEAD`, or <start-point> if given. As a
+special case, for <start-point>, you may use `"A...B"` as a shortcut for
+the merge base of `A` and `B` if there is exactly one merge base. You
+can leave out at most one of `A` and `B`, in which case it defaults to
+`HEAD`.
+
+Note that this will create the new branch, but it will not switch the
+working tree to it; use "git switch <newbranch>" to switch to the
+new branch.
+
+When a local branch is started off a remote-tracking branch, Git sets up the
+branch (specifically the `branch.<name>.remote` and `branch.<name>.merge`
+configuration entries) so that 'git pull' will appropriately merge from
+the remote-tracking branch. This behavior may be changed via the global
+`branch.autoSetupMerge` configuration flag. That setting can be
+overridden by using the `--track` and `--no-track` options, and
+changed later using `git branch --set-upstream-to`.
+
+With a `-m` or `-M` option, <oldbranch> will be renamed to <newbranch>.
+If <oldbranch> had a corresponding reflog, it is renamed to match
+<newbranch>, and a reflog entry is created to remember the branch
+renaming. If <newbranch> exists, -M must be used to force the rename
+to happen.
+
+The `-c` and `-C` options have the exact same semantics as `-m` and
+`-M`, except instead of the branch being renamed it along with its
+config and reflog will be copied to a new name.
+
+With a `-d` or `-D` option, `<branchname>` will be deleted.  You may
+specify more than one branch for deletion.  If the branch currently
+has a reflog then the reflog will also be deleted.
+
+Use `-r` together with `-d` to delete remote-tracking branches. Note, that it
+only makes sense to delete remote-tracking branches if they no longer exist
+in the remote repository or if 'git fetch' was configured not to fetch
+them again. See also the 'prune' subcommand of linkgit:git-remote[1] for a
+way to clean up all obsolete remote-tracking branches.
+
+
+OPTIONS
+-------
+-d::
+--delete::
+	Delete a branch. The branch must be fully merged in its
+	upstream branch, or in `HEAD` if no upstream was set with
+	`--track` or `--set-upstream-to`.
+
+-D::
+	Shortcut for `--delete --force`.
+
+--create-reflog::
+	Create the branch's reflog.  This activates recording of
+	all changes made to the branch ref, enabling use of date
+	based sha1 expressions such as "<branchname>@\{yesterday}".
+	Note that in non-bare repositories, reflogs are usually
+	enabled by default by the `core.logAllRefUpdates` config option.
+	The negated form `--no-create-reflog` only overrides an earlier
+	`--create-reflog`, but currently does not negate the setting of
+	`core.logAllRefUpdates`.
+
+-f::
+--force::
+	Reset <branchname> to <startpoint>, even if <branchname> exists
+	already. Without `-f`, 'git branch' refuses to change an existing branch.
+	In combination with `-d` (or `--delete`), allow deleting the
+	branch irrespective of its merged status. In combination with
+	`-m` (or `--move`), allow renaming the branch even if the new
+	branch name already exists, the same applies for `-c` (or `--copy`).
+
+-m::
+--move::
+	Move/rename a branch and the corresponding reflog.
+
+-M::
+	Shortcut for `--move --force`.
+
+-c::
+--copy::
+	Copy a branch and the corresponding reflog.
+
+-C::
+	Shortcut for `--copy --force`.
+
+--color[=<when>]::
+	Color branches to highlight current, local, and
+	remote-tracking branches.
+	The value must be always (the default), never, or auto.
+
+--no-color::
+	Turn off branch colors, even when the configuration file gives the
+	default to color output.
+	Same as `--color=never`.
+
+-i::
+--ignore-case::
+	Sorting and filtering branches are case insensitive.
+
+--column[=<options>]::
+--no-column::
+	Display branch listing in columns. See configuration variable
+	column.branch for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never' respectively.
++
+This option is only applicable in non-verbose mode.
+
+-r::
+--remotes::
+	List or delete (if used with -d) the remote-tracking branches.
+	Combine with `--list` to match the optional pattern(s).
+
+-a::
+--all::
+	List both remote-tracking branches and local branches.
+	Combine with `--list` to match optional pattern(s).
+
+-l::
+--list::
+	List branches.  With optional `<pattern>...`, e.g. `git
+	branch --list 'maint-*'`, list only the branches that match
+	the pattern(s).
+
+--show-current::
+	Print the name of the current branch. In detached HEAD state,
+	nothing is printed.
+
+-v::
+-vv::
+--verbose::
+	When in list mode,
+	show sha1 and commit subject line for each head, along with
+	relationship to upstream branch (if any). If given twice, print
+	the path of the linked worktree (if any) and the name of the upstream
+	branch, as well (see also `git remote show <remote>`).  Note that the
+	current worktree's HEAD will not have its path printed (it will always
+	be your current directory).
+
+-q::
+--quiet::
+	Be more quiet when creating or deleting a branch, suppressing
+	non-error messages.
+
+--abbrev=<length>::
+	Alter the sha1's minimum display length in the output listing.
+	The default value is 7 and can be overridden by the `core.abbrev`
+	config option.
+
+--no-abbrev::
+	Display the full sha1s in the output listing rather than abbreviating them.
+
+-t::
+--track::
+	When creating a new branch, set up `branch.<name>.remote` and
+	`branch.<name>.merge` configuration entries to mark the
+	start-point branch as "upstream" from the new branch. This
+	configuration will tell git to show the relationship between the
+	two branches in `git status` and `git branch -v`. Furthermore,
+	it directs `git pull` without arguments to pull from the
+	upstream when the new branch is checked out.
++
+This behavior is the default when the start point is a remote-tracking branch.
+Set the branch.autoSetupMerge configuration variable to `false` if you
+want `git switch`, `git checkout` and `git branch` to always behave as if `--no-track`
+were given. Set it to `always` if you want this behavior when the
+start-point is either a local or remote-tracking branch.
+
+--no-track::
+	Do not set up "upstream" configuration, even if the
+	branch.autoSetupMerge configuration variable is true.
+
+--set-upstream::
+	As this option had confusing syntax, it is no longer supported.
+	Please use `--track` or `--set-upstream-to` instead.
+
+-u <upstream>::
+--set-upstream-to=<upstream>::
+	Set up <branchname>'s tracking information so <upstream> is
+	considered <branchname>'s upstream branch. If no <branchname>
+	is specified, then it defaults to the current branch.
+
+--unset-upstream::
+	Remove the upstream information for <branchname>. If no branch
+	is specified it defaults to the current branch.
+
+--edit-description::
+	Open an editor and edit the text to explain what the branch is
+	for, to be used by various other commands (e.g. `format-patch`,
+	`request-pull`, and `merge` (if enabled)). Multi-line explanations
+	may be used.
+
+--contains [<commit>]::
+	Only list branches which contain the specified commit (HEAD
+	if not specified). Implies `--list`.
+
+--no-contains [<commit>]::
+	Only list branches which don't contain the specified commit
+	(HEAD if not specified). Implies `--list`.
+
+--merged [<commit>]::
+	Only list branches whose tips are reachable from the
+	specified commit (HEAD if not specified). Implies `--list`,
+	incompatible with `--no-merged`.
+
+--no-merged [<commit>]::
+	Only list branches whose tips are not reachable from the
+	specified commit (HEAD if not specified). Implies `--list`,
+	incompatible with `--merged`.
+
+<branchname>::
+	The name of the branch to create or delete.
+	The new branch name must pass all checks defined by
+	linkgit:git-check-ref-format[1].  Some of these checks
+	may restrict the characters allowed in a branch name.
+
+<start-point>::
+	The new branch head will point to this commit.  It may be
+	given as a branch name, a commit-id, or a tag.  If this
+	option is omitted, the current HEAD will be used instead.
+
+<oldbranch>::
+	The name of an existing branch to rename.
+
+<newbranch>::
+	The new name for an existing branch. The same restrictions as for
+	<branchname> apply.
+
+--sort=<key>::
+	Sort based on the key given. Prefix `-` to sort in descending
+	order of the value. You may use the --sort=<key> option
+	multiple times, in which case the last key becomes the primary
+	key. The keys supported are the same as those in `git
+	for-each-ref`. Sort order defaults to the value configured for the
+	`branch.sort` variable if exists, or to sorting based on the
+	full refname (including `refs/...` prefix). This lists
+	detached HEAD (if present) first, then local branches and
+	finally remote-tracking branches. See linkgit:git-config[1].
+
+
+--points-at <object>::
+	Only list branches of the given object.
+
+--format <format>::
+	A string that interpolates `%(fieldname)` from a branch ref being shown
+	and the object it points at.  The format is the same as
+	that of linkgit:git-for-each-ref[1].
+
+CONFIGURATION
+-------------
+`pager.branch` is only respected when listing branches, i.e., when
+`--list` is used or implied. The default is to use a pager.
+See linkgit:git-config[1].
+
+EXAMPLES
+--------
+
+Start development from a known tag::
++
+------------
+$ git clone git://git.kernel.org/pub/scm/.../linux-2.6 my2.6
+$ cd my2.6
+$ git branch my2.6.14 v2.6.14   <1>
+$ git switch my2.6.14
+------------
++
+<1> This step and the next one could be combined into a single step with
+    "checkout -b my2.6.14 v2.6.14".
+
+Delete an unneeded branch::
++
+------------
+$ git clone git://git.kernel.org/.../git.git my.git
+$ cd my.git
+$ git branch -d -r origin/todo origin/html origin/man   <1>
+$ git branch -D test                                    <2>
+------------
++
+<1> Delete the remote-tracking branches "todo", "html" and "man". The next
+    'fetch' or 'pull' will create them again unless you configure them not to.
+    See linkgit:git-fetch[1].
+<2> Delete the "test" branch even if the "master" branch (or whichever branch
+    is currently checked out) does not have all commits from the test branch.
+
+Listing branches from a specific remote::
++
+------------
+$ git branch -r -l '<remote>/<pattern>'                 <1>
+$ git for-each-ref 'refs/remotes/<remote>/<pattern>'    <2>
+------------
++
+<1> Using `-a` would conflate <remote> with any local branches you happen to
+    have been prefixed with the same <remote> pattern.
+<2> `for-each-ref` can take a wide range of options. See linkgit:git-for-each-ref[1]
+
+Patterns will normally need quoting.
+
+NOTES
+-----
+
+If you are creating a branch that you want to switch to immediately,
+it is easier to use the "git switch" command with its `-c` option to
+do the same thing with a single command.
+
+The options `--contains`, `--no-contains`, `--merged` and `--no-merged`
+serve four related but different purposes:
+
+- `--contains <commit>` is used to find all branches which will need
+  special attention if <commit> were to be rebased or amended, since those
+  branches contain the specified <commit>.
+
+- `--no-contains <commit>` is the inverse of that, i.e. branches that don't
+  contain the specified <commit>.
+
+- `--merged` is used to find all branches which can be safely deleted,
+  since those branches are fully contained by HEAD.
+
+- `--no-merged` is used to find branches which are candidates for merging
+  into HEAD, since those branches are not fully contained by HEAD.
+
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1],
+linkgit:git-fetch[1],
+linkgit:git-remote[1],
+link:user-manual.html#what-is-a-branch[``Understanding history: What is
+a branch?''] in the Git User's Manual.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-bundle.txt b/third_party/git/Documentation/git-bundle.txt
new file mode 100644
index 0000000000..7d6c9dcd17
--- /dev/null
+++ b/third_party/git/Documentation/git-bundle.txt
@@ -0,0 +1,205 @@
+git-bundle(1)
+=============
+
+NAME
+----
+git-bundle - Move objects and refs by archive
+
+
+SYNOPSIS
+--------
+[verse]
+'git bundle' create <file> <git-rev-list-args>
+'git bundle' verify <file>
+'git bundle' list-heads <file> [<refname>...]
+'git bundle' unbundle <file> [<refname>...]
+
+DESCRIPTION
+-----------
+
+Some workflows require that one or more branches of development on one
+machine be replicated on another machine, but the two machines cannot
+be directly connected, and therefore the interactive Git protocols (git,
+ssh, http) cannot be used.  This command provides support for
+'git fetch' and 'git pull' to operate by packaging objects and references
+in an archive at the originating machine, then importing those into
+another repository using 'git fetch' and 'git pull'
+after moving the archive by some means (e.g., by sneakernet).  As no
+direct connection between the repositories exists, the user must specify a
+basis for the bundle that is held by the destination repository: the
+bundle assumes that all objects in the basis are already in the
+destination repository.
+
+OPTIONS
+-------
+
+create <file>::
+	Used to create a bundle named 'file'.  This requires the
+	'git-rev-list-args' arguments to define the bundle contents.
+
+verify <file>::
+	Used to check that a bundle file is valid and will apply
+	cleanly to the current repository.  This includes checks on the
+	bundle format itself as well as checking that the prerequisite
+	commits exist and are fully linked in the current repository.
+	'git bundle' prints a list of missing commits, if any, and exits
+	with a non-zero status.
+
+list-heads <file>::
+	Lists the references defined in the bundle.  If followed by a
+	list of references, only references matching those given are
+	printed out.
+
+unbundle <file>::
+	Passes the objects in the bundle to 'git index-pack'
+	for storage in the repository, then prints the names of all
+	defined references. If a list of references is given, only
+	references matching those in the list are printed. This command is
+	really plumbing, intended to be called only by 'git fetch'.
+
+<git-rev-list-args>::
+	A list of arguments, acceptable to 'git rev-parse' and
+	'git rev-list' (and containing a named ref, see SPECIFYING REFERENCES
+	below), that specifies the specific objects and references
+	to transport.  For example, `master~10..master` causes the
+	current master reference to be packaged along with all objects
+	added since its 10th ancestor commit.  There is no explicit
+	limit to the number of references and objects that may be
+	packaged.
+
+
+[<refname>...]::
+	A list of references used to limit the references reported as
+	available. This is principally of use to 'git fetch', which
+	expects to receive only those references asked for and not
+	necessarily everything in the pack (in this case, 'git bundle' acts
+	like 'git fetch-pack').
+
+SPECIFYING REFERENCES
+---------------------
+
+'git bundle' will only package references that are shown by
+'git show-ref': this includes heads, tags, and remote heads.  References
+such as `master~1` cannot be packaged, but are perfectly suitable for
+defining the basis.  More than one reference may be packaged, and more
+than one basis can be specified.  The objects packaged are those not
+contained in the union of the given bases.  Each basis can be
+specified explicitly (e.g. `^master~10`), or implicitly (e.g.
+`master~10..master`, `--since=10.days.ago master`).
+
+It is very important that the basis used be held by the destination.
+It is okay to err on the side of caution, causing the bundle file
+to contain objects already in the destination, as these are ignored
+when unpacking at the destination.
+
+EXAMPLES
+--------
+
+Assume you want to transfer the history from a repository R1 on machine A
+to another repository R2 on machine B.
+For whatever reason, direct connection between A and B is not allowed,
+but we can move data from A to B via some mechanism (CD, email, etc.).
+We want to update R2 with development made on the branch master in R1.
+
+To bootstrap the process, you can first create a bundle that does not have
+any basis. You can use a tag to remember up to what commit you last
+processed, in order to make it easy to later update the other repository
+with an incremental bundle:
+
+----------------
+machineA$ cd R1
+machineA$ git bundle create file.bundle master
+machineA$ git tag -f lastR2bundle master
+----------------
+
+Then you transfer file.bundle to the target machine B. Because this
+bundle does not require any existing object to be extracted, you can
+create a new repository on machine B by cloning from it:
+
+----------------
+machineB$ git clone -b master /home/me/tmp/file.bundle R2
+----------------
+
+This will define a remote called "origin" in the resulting repository that
+lets you fetch and pull from the bundle. The $GIT_DIR/config file in R2 will
+have an entry like this:
+
+------------------------
+[remote "origin"]
+    url = /home/me/tmp/file.bundle
+    fetch = refs/heads/*:refs/remotes/origin/*
+------------------------
+
+To update the resulting mine.git repository, you can fetch or pull after
+replacing the bundle stored at /home/me/tmp/file.bundle with incremental
+updates.
+
+After working some more in the original repository, you can create an
+incremental bundle to update the other repository:
+
+----------------
+machineA$ cd R1
+machineA$ git bundle create file.bundle lastR2bundle..master
+machineA$ git tag -f lastR2bundle master
+----------------
+
+You then transfer the bundle to the other machine to replace
+/home/me/tmp/file.bundle, and pull from it.
+
+----------------
+machineB$ cd R2
+machineB$ git pull
+----------------
+
+If you know up to what commit the intended recipient repository should
+have the necessary objects, you can use that knowledge to specify the
+basis, giving a cut-off point to limit the revisions and objects that go
+in the resulting bundle. The previous example used the lastR2bundle tag
+for this purpose, but you can use any other options that you would give to
+the linkgit:git-log[1] command. Here are more examples:
+
+You can use a tag that is present in both:
+
+----------------
+$ git bundle create mybundle v1.0.0..master
+----------------
+
+You can use a basis based on time:
+
+----------------
+$ git bundle create mybundle --since=10.days master
+----------------
+
+You can use the number of commits:
+
+----------------
+$ git bundle create mybundle -10 master
+----------------
+
+You can run `git-bundle verify` to see if you can extract from a bundle
+that was created with a basis:
+
+----------------
+$ git bundle verify mybundle
+----------------
+
+This will list what commits you must have in order to extract from the
+bundle and will error out if you do not have them.
+
+A bundle from a recipient repository's point of view is just like a
+regular repository which it fetches or pulls from. You can, for example, map
+references when fetching:
+
+----------------
+$ git fetch mybundle master:localRef
+----------------
+
+You can also see what references it offers:
+
+----------------
+$ git ls-remote mybundle
+----------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-cat-file.txt b/third_party/git/Documentation/git-cat-file.txt
new file mode 100644
index 0000000000..8eca671b82
--- /dev/null
+++ b/third_party/git/Documentation/git-cat-file.txt
@@ -0,0 +1,319 @@
+git-cat-file(1)
+===============
+
+NAME
+----
+git-cat-file - Provide content or type and size information for repository objects
+
+
+SYNOPSIS
+--------
+[verse]
+'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv | --filters ) [--path=<path>] <object>
+'git cat-file' (--batch | --batch-check) [ --textconv | --filters ] [--follow-symlinks]
+
+DESCRIPTION
+-----------
+In its first form, the command provides the content or the type of an object in
+the repository. The type is required unless `-t` or `-p` is used to find the
+object type, or `-s` is used to find the object size, or `--textconv` or
+`--filters` is used (which imply type "blob").
+
+In the second form, a list of objects (separated by linefeeds) is provided on
+stdin, and the SHA-1, type, and size of each object is printed on stdout. The
+output format can be overridden using the optional `<format>` argument. If
+either `--textconv` or `--filters` was specified, the input is expected to
+list the object names followed by the path name, separated by a single
+whitespace, so that the appropriate drivers can be determined.
+
+OPTIONS
+-------
+<object>::
+	The name of the object to show.
+	For a more complete list of ways to spell object names, see
+	the "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
+
+-t::
+	Instead of the content, show the object type identified by
+	<object>.
+
+-s::
+	Instead of the content, show the object size identified by
+	<object>.
+
+-e::
+	Exit with zero status if <object> exists and is a valid
+	object. If <object> is of an invalid format exit with non-zero and
+	emits an error on stderr.
+
+-p::
+	Pretty-print the contents of <object> based on its type.
+
+<type>::
+	Typically this matches the real type of <object> but asking
+	for a type that can trivially be dereferenced from the given
+	<object> is also permitted.  An example is to ask for a
+	"tree" with <object> being a commit object that contains it,
+	or to ask for a "blob" with <object> being a tag object that
+	points at it.
+
+--textconv::
+	Show the content as transformed by a textconv filter. In this case,
+	<object> has to be of the form <tree-ish>:<path>, or :<path> in
+	order to apply the filter to the content recorded in the index at
+	<path>.
+
+--filters::
+	Show the content as converted by the filters configured in
+	the current working tree for the given <path> (i.e. smudge filters,
+	end-of-line conversion, etc). In this case, <object> has to be of
+	the form <tree-ish>:<path>, or :<path>.
+
+--path=<path>::
+	For use with --textconv or --filters, to allow specifying an object
+	name and a path separately, e.g. when it is difficult to figure out
+	the revision from which the blob came.
+
+--batch::
+--batch=<format>::
+	Print object information and contents for each object provided
+	on stdin.  May not be combined with any other options or arguments
+	except `--textconv` or `--filters`, in which case the input lines
+	also need to specify the path, separated by whitespace.  See the
+	section `BATCH OUTPUT` below for details.
+
+--batch-check::
+--batch-check=<format>::
+	Print object information for each object provided on stdin.  May
+	not be combined with any other options or arguments except
+	`--textconv` or `--filters`, in which case the input lines also
+	need to specify the path, separated by whitespace.  See the
+	section `BATCH OUTPUT` below for details.
+
+--batch-all-objects::
+	Instead of reading a list of objects on stdin, perform the
+	requested batch operation on all objects in the repository and
+	any alternate object stores (not just reachable objects).
+	Requires `--batch` or `--batch-check` be specified. Note that
+	the objects are visited in order sorted by their hashes.
+
+--buffer::
+	Normally batch output is flushed after each object is output, so
+	that a process can interactively read and write from
+	`cat-file`. With this option, the output uses normal stdio
+	buffering; this is much more efficient when invoking
+	`--batch-check` on a large number of objects.
+
+--unordered::
+	When `--batch-all-objects` is in use, visit objects in an
+	order which may be more efficient for accessing the object
+	contents than hash order. The exact details of the order are
+	unspecified, but if you do not require a specific order, this
+	should generally result in faster output, especially with
+	`--batch`.  Note that `cat-file` will still show each object
+	only once, even if it is stored multiple times in the
+	repository.
+
+--allow-unknown-type::
+	Allow -s or -t to query broken/corrupt objects of unknown type.
+
+--follow-symlinks::
+	With --batch or --batch-check, follow symlinks inside the
+	repository when requesting objects with extended SHA-1
+	expressions of the form tree-ish:path-in-tree.  Instead of
+	providing output about the link itself, provide output about
+	the linked-to object.  If a symlink points outside the
+	tree-ish (e.g. a link to /foo or a root-level link to ../foo),
+	the portion of the link which is outside the tree will be
+	printed.
++
+This option does not (currently) work correctly when an object in the
+index is specified (e.g. `:link` instead of `HEAD:link`) rather than
+one in the tree.
++
+This option cannot (currently) be used unless `--batch` or
+`--batch-check` is used.
++
+For example, consider a git repository containing:
++
+--
+	f: a file containing "hello\n"
+	link: a symlink to f
+	dir/link: a symlink to ../f
+	plink: a symlink to ../f
+	alink: a symlink to /etc/passwd
+--
++
+For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print
++
+--
+	ce013625030ba8dba906f756967f9e9ca394464a blob 6
+--
++
+And `echo HEAD:link | git cat-file --batch --follow-symlinks` would
+print the same thing, as would `HEAD:dir/link`, as they both point at
+`HEAD:f`.
++
+Without `--follow-symlinks`, these would print data about the symlink
+itself.  In the case of `HEAD:link`, you would see
++
+--
+	4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1
+--
++
+Both `plink` and `alink` point outside the tree, so they would
+respectively print:
++
+--
+	symlink 4
+	../f
+
+	symlink 11
+	/etc/passwd
+--
+
+
+OUTPUT
+------
+If `-t` is specified, one of the <type>.
+
+If `-s` is specified, the size of the <object> in bytes.
+
+If `-e` is specified, no output, unless the <object> is malformed.
+
+If `-p` is specified, the contents of <object> are pretty-printed.
+
+If <type> is specified, the raw (though uncompressed) contents of the <object>
+will be returned.
+
+BATCH OUTPUT
+------------
+
+If `--batch` or `--batch-check` is given, `cat-file` will read objects
+from stdin, one per line, and print information about them. By default,
+the whole line is considered as an object, as if it were fed to
+linkgit:git-rev-parse[1].
+
+You can specify the information shown for each object by using a custom
+`<format>`. The `<format>` is copied literally to stdout for each
+object, with placeholders of the form `%(atom)` expanded, followed by a
+newline. The available atoms are:
+
+`objectname`::
+	The 40-hex object name of the object.
+
+`objecttype`::
+	The type of the object (the same as `cat-file -t` reports).
+
+`objectsize`::
+	The size, in bytes, of the object (the same as `cat-file -s`
+	reports).
+
+`objectsize:disk`::
+	The size, in bytes, that the object takes up on disk. See the
+	note about on-disk sizes in the `CAVEATS` section below.
+
+`deltabase`::
+	If the object is stored as a delta on-disk, this expands to the
+	40-hex sha1 of the delta base object. Otherwise, expands to the
+	null sha1 (40 zeroes). See `CAVEATS` below.
+
+`rest`::
+	If this atom is used in the output string, input lines are split
+	at the first whitespace boundary. All characters before that
+	whitespace are considered to be the object name; characters
+	after that first run of whitespace (i.e., the "rest" of the
+	line) are output in place of the `%(rest)` atom.
+
+If no format is specified, the default format is `%(objectname)
+%(objecttype) %(objectsize)`.
+
+If `--batch` is specified, the object information is followed by the
+object contents (consisting of `%(objectsize)` bytes), followed by a
+newline.
+
+For example, `--batch` without a custom format would produce:
+
+------------
+<sha1> SP <type> SP <size> LF
+<contents> LF
+------------
+
+Whereas `--batch-check='%(objectname) %(objecttype)'` would produce:
+
+------------
+<sha1> SP <type> LF
+------------
+
+If a name is specified on stdin that cannot be resolved to an object in
+the repository, then `cat-file` will ignore any custom format and print:
+
+------------
+<object> SP missing LF
+------------
+
+If a name is specified that might refer to more than one object (an ambiguous short sha), then `cat-file` will ignore any custom format and print:
+
+------------
+<object> SP ambiguous LF
+------------
+
+If --follow-symlinks is used, and a symlink in the repository points
+outside the repository, then `cat-file` will ignore any custom format
+and print:
+
+------------
+symlink SP <size> LF
+<symlink> LF
+------------
+
+The symlink will either be absolute (beginning with a /), or relative
+to the tree root.  For instance, if dir/link points to ../../foo, then
+<symlink> will be ../foo.  <size> is the size of the symlink in bytes.
+
+If --follow-symlinks is used, the following error messages will be
+displayed:
+
+------------
+<object> SP missing LF
+------------
+is printed when the initial symlink requested does not exist.
+
+------------
+dangling SP <size> LF
+<object> LF
+------------
+is printed when the initial symlink exists, but something that
+it (transitive-of) points to does not.
+
+------------
+loop SP <size> LF
+<object> LF
+------------
+is printed for symlink loops (or any symlinks that
+require more than 40 link resolutions to resolve).
+
+------------
+notdir SP <size> LF
+<object> LF
+------------
+is printed when, during symlink resolution, a file is used as a
+directory name.
+
+CAVEATS
+-------
+
+Note that the sizes of objects on disk are reported accurately, but care
+should be taken in drawing conclusions about which refs or objects are
+responsible for disk usage. The size of a packed non-delta object may be
+much larger than the size of objects which delta against it, but the
+choice of which object is the base and which is the delta is arbitrary
+and is subject to change during a repack.
+
+Note also that multiple copies of an object may be present in the object
+database; in this case, it is undefined which copy's size or delta base
+will be reported.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-check-attr.txt b/third_party/git/Documentation/git-check-attr.txt
new file mode 100644
index 0000000000..3c0578217b
--- /dev/null
+++ b/third_party/git/Documentation/git-check-attr.txt
@@ -0,0 +1,120 @@
+git-check-attr(1)
+=================
+
+NAME
+----
+git-check-attr - Display gitattributes information
+
+
+SYNOPSIS
+--------
+[verse]
+'git check-attr' [-a | --all | <attr>...] [--] <pathname>...
+'git check-attr' --stdin [-z] [-a | --all | <attr>...]
+
+DESCRIPTION
+-----------
+For every pathname, this command will list if each attribute is 'unspecified',
+'set', or 'unset' as a gitattribute on that pathname.
+
+OPTIONS
+-------
+-a, --all::
+	List all attributes that are associated with the specified
+	paths.  If this option is used, then 'unspecified' attributes
+	will not be included in the output.
+
+--cached::
+	Consider `.gitattributes` in the index only, ignoring the working tree.
+
+--stdin::
+	Read pathnames from the standard input, one per line,
+	instead of from the command-line.
+
+-z::
+	The output format is modified to be machine-parseable.
+	If `--stdin` is also given, input paths are separated
+	with a NUL character instead of a linefeed character.
+
+\--::
+	Interpret all preceding arguments as attributes and all following
+	arguments as path names.
+
+If none of `--stdin`, `--all`, or `--` is used, the first argument
+will be treated as an attribute and the rest of the arguments as
+pathnames.
+
+OUTPUT
+------
+
+The output is of the form:
+<path> COLON SP <attribute> COLON SP <info> LF
+
+unless `-z` is in effect, in which case NUL is used as delimiter:
+<path> NUL <attribute> NUL <info> NUL
+
+
+<path> is the path of a file being queried, <attribute> is an attribute
+being queried and <info> can be either:
+
+'unspecified';; when the attribute is not defined for the path.
+'unset';;	when the attribute is defined as false.
+'set';;		when the attribute is defined as true.
+<value>;;	when a value has been assigned to the attribute.
+
+Buffering happens as documented under the `GIT_FLUSH` option in
+linkgit:git[1].  The caller is responsible for avoiding deadlocks
+caused by overfilling an input buffer or reading from an empty output
+buffer.
+
+EXAMPLES
+--------
+
+In the examples, the following '.gitattributes' file is used:
+---------------
+*.java diff=java -crlf myAttr
+NoMyAttr.java !myAttr
+README caveat=unspecified
+---------------
+
+* Listing a single attribute:
+---------------
+$ git check-attr diff org/example/MyClass.java
+org/example/MyClass.java: diff: java
+---------------
+
+* Listing multiple attributes for a file:
+---------------
+$ git check-attr crlf diff myAttr -- org/example/MyClass.java
+org/example/MyClass.java: crlf: unset
+org/example/MyClass.java: diff: java
+org/example/MyClass.java: myAttr: set
+---------------
+
+* Listing all attributes for a file:
+---------------
+$ git check-attr --all -- org/example/MyClass.java
+org/example/MyClass.java: diff: java
+org/example/MyClass.java: myAttr: set
+---------------
+
+* Listing an attribute for multiple files:
+---------------
+$ git check-attr myAttr -- org/example/MyClass.java org/example/NoMyAttr.java
+org/example/MyClass.java: myAttr: set
+org/example/NoMyAttr.java: myAttr: unspecified
+---------------
+
+* Not all values are equally unambiguous:
+---------------
+$ git check-attr caveat README
+README: caveat: unspecified
+---------------
+
+SEE ALSO
+--------
+linkgit:gitattributes[5].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-check-ignore.txt b/third_party/git/Documentation/git-check-ignore.txt
new file mode 100644
index 0000000000..8b42cb3fb2
--- /dev/null
+++ b/third_party/git/Documentation/git-check-ignore.txt
@@ -0,0 +1,120 @@
+git-check-ignore(1)
+===================
+
+NAME
+----
+git-check-ignore - Debug gitignore / exclude files
+
+
+SYNOPSIS
+--------
+[verse]
+'git check-ignore' [<options>] <pathname>...
+'git check-ignore' [<options>] --stdin
+
+DESCRIPTION
+-----------
+
+For each pathname given via the command-line or from a file via
+`--stdin`, check whether the file is excluded by .gitignore (or other
+input files to the exclude mechanism) and output the path if it is
+excluded.
+
+By default, tracked files are not shown at all since they are not
+subject to exclude rules; but see `--no-index'.
+
+OPTIONS
+-------
+-q, --quiet::
+	Don't output anything, just set exit status.  This is only
+	valid with a single pathname.
+
+-v, --verbose::
+	Also output details about the matching pattern (if any)
+	for each given pathname. For precedence rules within and
+	between exclude sources, see linkgit:gitignore[5].
+
+--stdin::
+	Read pathnames from the standard input, one per line,
+	instead of from the command-line.
+
+-z::
+	The output format is modified to be machine-parseable (see
+	below).  If `--stdin` is also given, input paths are separated
+	with a NUL character instead of a linefeed character.
+
+-n, --non-matching::
+	Show given paths which don't match any pattern.	 This only
+	makes sense when `--verbose` is enabled, otherwise it would
+	not be possible to distinguish between paths which match a
+	pattern and those which don't.
+
+--no-index::
+	Don't look in the index when undertaking the checks. This can
+	be used to debug why a path became tracked by e.g. `git add .`
+	and was not ignored by the rules as expected by the user or when
+	developing patterns including negation to match a path previously
+	added with `git add -f`.
+
+OUTPUT
+------
+
+By default, any of the given pathnames which match an ignore pattern
+will be output, one per line.  If no pattern matches a given path,
+nothing will be output for that path; this means that path will not be
+ignored.
+
+If `--verbose` is specified, the output is a series of lines of the form:
+
+<source> <COLON> <linenum> <COLON> <pattern> <HT> <pathname>
+
+<pathname> is the path of a file being queried, <pattern> is the
+matching pattern, <source> is the pattern's source file, and <linenum>
+is the line number of the pattern within that source.  If the pattern
+contained a `!` prefix or `/` suffix, it will be preserved in the
+output.  <source> will be an absolute path when referring to the file
+configured by `core.excludesFile`, or relative to the repository root
+when referring to `.git/info/exclude` or a per-directory exclude file.
+
+If `-z` is specified, the pathnames in the output are delimited by the
+null character; if `--verbose` is also specified then null characters
+are also used instead of colons and hard tabs:
+
+<source> <NULL> <linenum> <NULL> <pattern> <NULL> <pathname> <NULL>
+
+If `-n` or `--non-matching` are specified, non-matching pathnames will
+also be output, in which case all fields in each output record except
+for <pathname> will be empty.  This can be useful when running
+non-interactively, so that files can be incrementally streamed to
+STDIN of a long-running check-ignore process, and for each of these
+files, STDOUT will indicate whether that file matched a pattern or
+not.  (Without this option, it would be impossible to tell whether the
+absence of output for a given file meant that it didn't match any
+pattern, or that the output hadn't been generated yet.)
+
+Buffering happens as documented under the `GIT_FLUSH` option in
+linkgit:git[1].  The caller is responsible for avoiding deadlocks
+caused by overfilling an input buffer or reading from an empty output
+buffer.
+
+EXIT STATUS
+-----------
+
+0::
+	One or more of the provided paths is ignored.
+
+1::
+	None of the provided paths are ignored.
+
+128::
+	A fatal error was encountered.
+
+SEE ALSO
+--------
+linkgit:gitignore[5]
+linkgit:git-config[1]
+linkgit:git-ls-files[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-check-mailmap.txt b/third_party/git/Documentation/git-check-mailmap.txt
new file mode 100644
index 0000000000..aa2055dbeb
--- /dev/null
+++ b/third_party/git/Documentation/git-check-mailmap.txt
@@ -0,0 +1,47 @@
+git-check-mailmap(1)
+====================
+
+NAME
+----
+git-check-mailmap - Show canonical names and email addresses of contacts
+
+
+SYNOPSIS
+--------
+[verse]
+'git check-mailmap' [<options>] <contact>...
+
+
+DESCRIPTION
+-----------
+
+For each ``Name $$<user@host>$$'' or ``$$<user@host>$$'' from the command-line
+or standard input (when using `--stdin`), look up the person's canonical name
+and email address (see "Mapping Authors" below). If found, print them;
+otherwise print the input as-is.
+
+
+OPTIONS
+-------
+--stdin::
+	Read contacts, one per line, from the standard input after exhausting
+	contacts provided on the command-line.
+
+
+OUTPUT
+------
+
+For each contact, a single line is output, terminated by a newline.  If the
+name is provided or known to the 'mailmap', ``Name $$<user@host>$$'' is
+printed; otherwise only ``$$<user@host>$$'' is printed.
+
+
+MAPPING AUTHORS
+---------------
+
+include::mailmap.txt[]
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-check-ref-format.txt b/third_party/git/Documentation/git-check-ref-format.txt
new file mode 100644
index 0000000000..ee6a4144fb
--- /dev/null
+++ b/third_party/git/Documentation/git-check-ref-format.txt
@@ -0,0 +1,140 @@
+git-check-ref-format(1)
+=======================
+
+NAME
+----
+git-check-ref-format - Ensures that a reference name is well formed
+
+SYNOPSIS
+--------
+[verse]
+'git check-ref-format' [--normalize]
+       [--[no-]allow-onelevel] [--refspec-pattern]
+       <refname>
+'git check-ref-format' --branch <branchname-shorthand>
+
+DESCRIPTION
+-----------
+Checks if a given 'refname' is acceptable, and exits with a non-zero
+status if it is not.
+
+A reference is used in Git to specify branches and tags.  A
+branch head is stored in the `refs/heads` hierarchy, while
+a tag is stored in the `refs/tags` hierarchy of the ref namespace
+(typically in `$GIT_DIR/refs/heads` and `$GIT_DIR/refs/tags`
+directories or, as entries in file `$GIT_DIR/packed-refs`
+if refs are packed by `git gc`).
+
+Git imposes the following rules on how references are named:
+
+. They can include slash `/` for hierarchical (directory)
+  grouping, but no slash-separated component can begin with a
+  dot `.` or end with the sequence `.lock`.
+
+. They must contain at least one `/`. This enforces the presence of a
+  category like `heads/`, `tags/` etc. but the actual names are not
+  restricted.  If the `--allow-onelevel` option is used, this rule
+  is waived.
+
+. They cannot have two consecutive dots `..` anywhere.
+
+. They cannot have ASCII control characters (i.e. bytes whose
+  values are lower than \040, or \177 `DEL`), space, tilde `~`,
+  caret `^`, or colon `:` anywhere.
+
+. They cannot have question-mark `?`, asterisk `*`, or open
+  bracket `[` anywhere.  See the `--refspec-pattern` option below for
+  an exception to this rule.
+
+. They cannot begin or end with a slash `/` or contain multiple
+  consecutive slashes (see the `--normalize` option below for an
+  exception to this rule)
+
+. They cannot end with a dot `.`.
+
+. They cannot contain a sequence `@{`.
+
+. They cannot be the single character `@`.
+
+. They cannot contain a `\`.
+
+These rules make it easy for shell script based tools to parse
+reference names, pathname expansion by the shell when a reference name is used
+unquoted (by mistake), and also avoid ambiguities in certain
+reference name expressions (see linkgit:gitrevisions[7]):
+
+. A double-dot `..` is often used as in `ref1..ref2`, and in some
+  contexts this notation means `^ref1 ref2` (i.e. not in
+  `ref1` and in `ref2`).
+
+. A tilde `~` and caret `^` are used to introduce the postfix
+  'nth parent' and 'peel onion' operation.
+
+. A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
+  value and store it in dstref" in fetch and push operations.
+  It may also be used to select a specific object such as with
+  'git cat-file': "git cat-file blob v1.3.3:refs.c".
+
+. at-open-brace `@{` is used as a notation to access a reflog entry.
+
+With the `--branch` option, the command takes a name and checks if
+it can be used as a valid branch name (e.g. when creating a new
+branch). But be cautious when using the
+previous checkout syntax that may refer to a detached HEAD state.
+The rule `git check-ref-format --branch $name` implements
+may be stricter than what `git check-ref-format refs/heads/$name`
+says (e.g. a dash may appear at the beginning of a ref component,
+but it is explicitly forbidden at the beginning of a branch name).
+When run with `--branch` option in a repository, the input is first
+expanded for the ``previous checkout syntax''
+`@{-n}`.  For example, `@{-1}` is a way to refer the last thing that
+was checked out using "git switch" or "git checkout" operation.
+This option should be
+used by porcelains to accept this syntax anywhere a branch name is
+expected, so they can act as if you typed the branch name. As an
+exception note that, the ``previous checkout operation'' might result
+in a commit object name when the N-th last thing checked out was not
+a branch.
+
+OPTIONS
+-------
+--[no-]allow-onelevel::
+	Controls whether one-level refnames are accepted (i.e.,
+	refnames that do not contain multiple `/`-separated
+	components).  The default is `--no-allow-onelevel`.
+
+--refspec-pattern::
+	Interpret <refname> as a reference name pattern for a refspec
+	(as used with remote repositories).  If this option is
+	enabled, <refname> is allowed to contain a single `*`
+	in the refspec (e.g., `foo/bar*/baz` or `foo/bar*baz/`
+	but not `foo/bar*/baz*`).
+
+--normalize::
+	Normalize 'refname' by removing any leading slash (`/`)
+	characters and collapsing runs of adjacent slashes between
+	name components into a single slash.  If the normalized
+	refname is valid then print it to standard output and exit
+	with a status of 0, otherwise exit with a non-zero status.
+	(`--print` is a deprecated way to spell `--normalize`.)
+
+
+EXAMPLES
+--------
+
+* Print the name of the previous thing checked out:
++
+------------
+$ git check-ref-format --branch @{-1}
+------------
+
+* Determine the reference name to use for a new branch:
++
+------------
+$ ref=$(git check-ref-format --normalize "refs/heads/$newbranch")||
+{ echo "we do not like '$newbranch' as a branch name." >&2 ; exit 1 ; }
+------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-checkout-index.txt b/third_party/git/Documentation/git-checkout-index.txt
new file mode 100644
index 0000000000..4d33e7be0f
--- /dev/null
+++ b/third_party/git/Documentation/git-checkout-index.txt
@@ -0,0 +1,177 @@
+git-checkout-index(1)
+=====================
+
+NAME
+----
+git-checkout-index - Copy files from the index to the working tree
+
+
+SYNOPSIS
+--------
+[verse]
+'git checkout-index' [-u] [-q] [-a] [-f] [-n] [--prefix=<string>]
+		   [--stage=<number>|all]
+		   [--temp]
+		   [-z] [--stdin]
+		   [--] [<file>...]
+
+DESCRIPTION
+-----------
+Will copy all files listed from the index to the working directory
+(not overwriting existing files).
+
+OPTIONS
+-------
+-u::
+--index::
+	update stat information for the checked out entries in
+	the index file.
+
+-q::
+--quiet::
+	be quiet if files exist or are not in the index
+
+-f::
+--force::
+	forces overwrite of existing files
+
+-a::
+--all::
+	checks out all files in the index.  Cannot be used
+	together with explicit filenames.
+
+-n::
+--no-create::
+	Don't checkout new files, only refresh files already checked
+	out.
+
+--prefix=<string>::
+	When creating files, prepend <string> (usually a directory
+	including a trailing /)
+
+--stage=<number>|all::
+	Instead of checking out unmerged entries, copy out the
+	files from named stage.  <number> must be between 1 and 3.
+	Note: --stage=all automatically implies --temp.
+
+--temp::
+	Instead of copying the files to the working directory
+	write the content to temporary files.  The temporary name
+	associations will be written to stdout.
+
+--stdin::
+	Instead of taking list of paths from the command line,
+	read list of paths from the standard input.  Paths are
+	separated by LF (i.e. one path per line) by default.
+
+-z::
+	Only meaningful with `--stdin`; paths are separated with
+	NUL character instead of LF.
+
+\--::
+	Do not interpret any more arguments as options.
+
+The order of the flags used to matter, but not anymore.
+
+Just doing `git checkout-index` does nothing. You probably meant
+`git checkout-index -a`. And if you want to force it, you want
+`git checkout-index -f -a`.
+
+Intuitiveness is not the goal here. Repeatability is. The reason for
+the "no arguments means no work" behavior is that from scripts you are
+supposed to be able to do:
+
+----------------
+$ find . -name '*.h' -print0 | xargs -0 git checkout-index -f --
+----------------
+
+which will force all existing `*.h` files to be replaced with their
+cached copies. If an empty command line implied "all", then this would
+force-refresh everything in the index, which was not the point.  But
+since 'git checkout-index' accepts --stdin it would be faster to use:
+
+----------------
+$ find . -name '*.h' -print0 | git checkout-index -f -z --stdin
+----------------
+
+The `--` is just a good idea when you know the rest will be filenames;
+it will prevent problems with a filename of, for example,  `-a`.
+Using `--` is probably a good policy in scripts.
+
+
+Using --temp or --stage=all
+---------------------------
+When `--temp` is used (or implied by `--stage=all`)
+'git checkout-index' will create a temporary file for each index
+entry being checked out.  The index will not be updated with stat
+information.  These options can be useful if the caller needs all
+stages of all unmerged entries so that the unmerged files can be
+processed by an external merge tool.
+
+A listing will be written to stdout providing the association of
+temporary file names to tracked path names.  The listing format
+has two variations:
+
+    . tempname TAB path RS
++
+The first format is what gets used when `--stage` is omitted or
+is not `--stage=all`. The field tempname is the temporary file
+name holding the file content and path is the tracked path name in
+the index.  Only the requested entries are output.
+
+    . stage1temp SP stage2temp SP stage3tmp TAB path RS
++
+The second format is what gets used when `--stage=all`.  The three
+stage temporary fields (stage1temp, stage2temp, stage3temp) list the
+name of the temporary file if there is a stage entry in the index
+or `.` if there is no stage entry.  Paths which only have a stage 0
+entry will always be omitted from the output.
+
+In both formats RS (the record separator) is newline by default
+but will be the null byte if -z was passed on the command line.
+The temporary file names are always safe strings; they will never
+contain directory separators or whitespace characters.  The path
+field is always relative to the current directory and the temporary
+file names are always relative to the top level directory.
+
+If the object being copied out to a temporary file is a symbolic
+link the content of the link will be written to a normal file.  It is
+up to the end-user or the Porcelain to make use of this information.
+
+
+EXAMPLES
+--------
+To update and refresh only the files already checked out::
++
+----------------
+$ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
+----------------
+
+Using 'git checkout-index' to "export an entire tree"::
+	The prefix ability basically makes it trivial to use
+	'git checkout-index' as an "export as tree" function.
+	Just read the desired tree into the index, and do:
++
+----------------
+$ git checkout-index --prefix=git-export-dir/ -a
+----------------
++
+`git checkout-index` will "export" the index into the specified
+directory.
++
+The final "/" is important. The exported name is literally just
+prefixed with the specified string.  Contrast this with the
+following example.
+
+Export files with a prefix::
++
+----------------
+$ git checkout-index --prefix=.merged- Makefile
+----------------
++
+This will check out the currently cached copy of `Makefile`
+into the file `.merged-Makefile`.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-checkout.txt b/third_party/git/Documentation/git-checkout.txt
new file mode 100644
index 0000000000..cf3cac0a2b
--- /dev/null
+++ b/third_party/git/Documentation/git-checkout.txt
@@ -0,0 +1,584 @@
+git-checkout(1)
+===============
+
+NAME
+----
+git-checkout - Switch branches or restore working tree files
+
+SYNOPSIS
+--------
+[verse]
+'git checkout' [-q] [-f] [-m] [<branch>]
+'git checkout' [-q] [-f] [-m] --detach [<branch>]
+'git checkout' [-q] [-f] [-m] [--detach] <commit>
+'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]
+'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
+'git checkout' [<tree-ish>] [--] <pathspec>...
+'git checkout' (-p|--patch) [<tree-ish>] [--] [<paths>...]
+
+DESCRIPTION
+-----------
+Updates files in the working tree to match the version in the index
+or the specified tree.  If no paths are given, 'git checkout' will
+also update `HEAD` to set the specified branch as the current
+branch.
+
+'git checkout' [<branch>]::
+	To prepare for working on `<branch>`, switch to it by updating
+	the index and the files in the working tree, and by pointing
+	`HEAD` at the branch. Local modifications to the files in the
+	working tree are kept, so that they can be committed to the
+	`<branch>`.
++
+If `<branch>` is not found but there does exist a tracking branch in
+exactly one remote (call it `<remote>`) with a matching name and
+`--no-guess` is not specified, treat as equivalent to
++
+------------
+$ git checkout -b <branch> --track <remote>/<branch>
+------------
++
+You could omit `<branch>`, in which case the command degenerates to
+"check out the current branch", which is a glorified no-op with
+rather expensive side-effects to show only the tracking information,
+if exists, for the current branch.
+
+'git checkout' -b|-B <new_branch> [<start point>]::
+
+	Specifying `-b` causes a new branch to be created as if
+	linkgit:git-branch[1] were called and then checked out.  In
+	this case you can use the `--track` or `--no-track` options,
+	which will be passed to 'git branch'.  As a convenience,
+	`--track` without `-b` implies branch creation; see the
+	description of `--track` below.
++
+If `-B` is given, `<new_branch>` is created if it doesn't exist; otherwise, it
+is reset. This is the transactional equivalent of
++
+------------
+$ git branch -f <branch> [<start point>]
+$ git checkout <branch>
+------------
++
+that is to say, the branch is not reset/created unless "git checkout" is
+successful.
+
+'git checkout' --detach [<branch>]::
+'git checkout' [--detach] <commit>::
+
+	Prepare to work on top of `<commit>`, by detaching `HEAD` at it
+	(see "DETACHED HEAD" section), and updating the index and the
+	files in the working tree.  Local modifications to the files
+	in the working tree are kept, so that the resulting working
+	tree will be the state recorded in the commit plus the local
+	modifications.
++
+When the `<commit>` argument is a branch name, the `--detach` option can
+be used to detach `HEAD` at the tip of the branch (`git checkout
+<branch>` would check out that branch without detaching `HEAD`).
++
+Omitting `<branch>` detaches `HEAD` at the tip of the current branch.
+
+'git checkout' [<tree-ish>] [--] <pathspec>...::
+
+	Overwrite paths in the working tree by replacing with the
+	contents in the index or in the `<tree-ish>` (most often a
+	commit).  When a `<tree-ish>` is given, the paths that
+	match the `<pathspec>` are updated both in the index and in
+	the working tree.
++
+The index may contain unmerged entries because of a previous failed merge.
+By default, if you try to check out such an entry from the index, the
+checkout operation will fail and nothing will be checked out.
+Using `-f` will ignore these unmerged entries.  The contents from a
+specific side of the merge can be checked out of the index by
+using `--ours` or `--theirs`.  With `-m`, changes made to the working tree
+file can be discarded to re-create the original conflicted merge result.
+
+'git checkout' (-p|--patch) [<tree-ish>] [--] [<pathspec>...]::
+	This is similar to the "check out paths to the working tree
+	from either the index or from a tree-ish" mode described
+	above, but lets you use the interactive interface to show
+	the "diff" output and choose which hunks to use in the
+	result.  See below for the description of `--patch` option.
+
+
+OPTIONS
+-------
+-q::
+--quiet::
+	Quiet, suppress feedback messages.
+
+--progress::
+--no-progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
+-f::
+--force::
+	When switching branches, proceed even if the index or the
+	working tree differs from `HEAD`.  This is used to throw away
+	local changes.
++
+When checking out paths from the index, do not fail upon unmerged
+entries; instead, unmerged entries are ignored.
+
+--ours::
+--theirs::
+	When checking out paths from the index, check out stage #2
+	('ours') or #3 ('theirs') for unmerged paths.
++
+Note that during `git rebase` and `git pull --rebase`, 'ours' and
+'theirs' may appear swapped; `--ours` gives the version from the
+branch the changes are rebased onto, while `--theirs` gives the
+version from the branch that holds your work that is being rebased.
++
+This is because `rebase` is used in a workflow that treats the
+history at the remote as the shared canonical one, and treats the
+work done on the branch you are rebasing as the third-party work to
+be integrated, and you are temporarily assuming the role of the
+keeper of the canonical history during the rebase.  As the keeper of
+the canonical history, you need to view the history from the remote
+as `ours` (i.e. "our shared canonical history"), while what you did
+on your side branch as `theirs` (i.e. "one contributor's work on top
+of it").
+
+-b <new_branch>::
+	Create a new branch named `<new_branch>` and start it at
+	`<start_point>`; see linkgit:git-branch[1] for details.
+
+-B <new_branch>::
+	Creates the branch `<new_branch>` and start it at `<start_point>`;
+	if it already exists, then reset it to `<start_point>`. This is
+	equivalent to running "git branch" with "-f"; see
+	linkgit:git-branch[1] for details.
+
+-t::
+--track::
+	When creating a new branch, set up "upstream" configuration. See
+	"--track" in linkgit:git-branch[1] for details.
++
+If no `-b` option is given, the name of the new branch will be
+derived from the remote-tracking branch, by looking at the local part of
+the refspec configured for the corresponding remote, and then stripping
+the initial part up to the "*".
+This would tell us to use `hack` as the local branch when branching
+off of `origin/hack` (or `remotes/origin/hack`, or even
+`refs/remotes/origin/hack`).  If the given name has no slash, or the above
+guessing results in an empty name, the guessing is aborted.  You can
+explicitly give a name with `-b` in such a case.
+
+--no-track::
+	Do not set up "upstream" configuration, even if the
+	`branch.autoSetupMerge` configuration variable is true.
+
+--guess::
+--no-guess::
+	If `<branch>` is not found but there does exist a tracking
+	branch in exactly one remote (call it `<remote>`) with a
+	matching name, treat as equivalent to
++
+------------
+$ git checkout -b <branch> --track <remote>/<branch>
+------------
++
+If the branch exists in multiple remotes and one of them is named by
+the `checkout.defaultRemote` configuration variable, we'll use that
+one for the purposes of disambiguation, even if the `<branch>` isn't
+unique across all remotes. Set it to
+e.g. `checkout.defaultRemote=origin` to always checkout remote
+branches from there if `<branch>` is ambiguous but exists on the
+'origin' remote. See also `checkout.defaultRemote` in
+linkgit:git-config[1].
++
+Use `--no-guess` to disable this.
+
+-l::
+	Create the new branch's reflog; see linkgit:git-branch[1] for
+	details.
+
+--detach::
+	Rather than checking out a branch to work on it, check out a
+	commit for inspection and discardable experiments.
+	This is the default behavior of `git checkout <commit>` when
+	`<commit>` is not a branch name.  See the "DETACHED HEAD" section
+	below for details.
+
+--orphan <new_branch>::
+	Create a new 'orphan' branch, named `<new_branch>`, started from
+	`<start_point>` and switch to it.  The first commit made on this
+	new branch will have no parents and it will be the root of a new
+	history totally disconnected from all the other branches and
+	commits.
++
+The index and the working tree are adjusted as if you had previously run
+`git checkout <start_point>`.  This allows you to start a new history
+that records a set of paths similar to `<start_point>` by easily running
+`git commit -a` to make the root commit.
++
+This can be useful when you want to publish the tree from a commit
+without exposing its full history. You might want to do this to publish
+an open source branch of a project whose current tree is "clean", but
+whose full history contains proprietary or otherwise encumbered bits of
+code.
++
+If you want to start a disconnected history that records a set of paths
+that is totally different from the one of `<start_point>`, then you should
+clear the index and the working tree right after creating the orphan
+branch by running `git rm -rf .` from the top level of the working tree.
+Afterwards you will be ready to prepare your new files, repopulating the
+working tree, by copying them from elsewhere, extracting a tarball, etc.
+
+--ignore-skip-worktree-bits::
+	In sparse checkout mode, `git checkout -- <paths>` would
+	update only entries matched by `<paths>` and sparse patterns
+	in `$GIT_DIR/info/sparse-checkout`. This option ignores
+	the sparse patterns and adds back any files in `<paths>`.
+
+-m::
+--merge::
+	When switching branches,
+	if you have local modifications to one or more files that
+	are different between the current branch and the branch to
+	which you are switching, the command refuses to switch
+	branches in order to preserve your modifications in context.
+	However, with this option, a three-way merge between the current
+	branch, your working tree contents, and the new branch
+	is done, and you will be on the new branch.
++
+When a merge conflict happens, the index entries for conflicting
+paths are left unmerged, and you need to resolve the conflicts
+and mark the resolved paths with `git add` (or `git rm` if the merge
+should result in deletion of the path).
++
+When checking out paths from the index, this option lets you recreate
+the conflicted merge in the specified paths.
++
+When switching branches with `--merge`, staged changes may be lost.
+
+--conflict=<style>::
+	The same as `--merge` option above, but changes the way the
+	conflicting hunks are presented, overriding the
+	`merge.conflictStyle` configuration variable.  Possible values are
+	"merge" (default) and "diff3" (in addition to what is shown by
+	"merge" style, shows the original contents).
+
+-p::
+--patch::
+	Interactively select hunks in the difference between the
+	`<tree-ish>` (or the index, if unspecified) and the working
+	tree.  The chosen hunks are then applied in reverse to the
+	working tree (and if a `<tree-ish>` was specified, the index).
++
+This means that you can use `git checkout -p` to selectively discard
+edits from your current working tree. See the ``Interactive Mode''
+section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
++
+Note that this option uses the no overlay mode by default (see also
+`--overlay`), and currently doesn't support overlay mode.
+
+--ignore-other-worktrees::
+	`git checkout` refuses when the wanted ref is already checked
+	out by another worktree. This option makes it check the ref
+	out anyway. In other words, the ref can be held by more than one
+	worktree.
+
+--overwrite-ignore::
+--no-overwrite-ignore::
+	Silently overwrite ignored files when switching branches. This
+	is the default behavior. Use `--no-overwrite-ignore` to abort
+	the operation when the new branch contains ignored files.
+
+--recurse-submodules::
+--no-recurse-submodules::
+	Using `--recurse-submodules` will update the content of all initialized
+	submodules according to the commit recorded in the superproject. If
+	local modifications in a submodule would be overwritten the checkout
+	will fail unless `-f` is used. If nothing (or `--no-recurse-submodules`)
+	is used, the work trees of submodules will not be updated.
+	Just like linkgit:git-submodule[1], this will detach `HEAD` of the
+	submodule.
+
+--overlay::
+--no-overlay::
+	In the default overlay mode, `git checkout` never
+	removes files from the index or the working tree.  When
+	specifying `--no-overlay`, files that appear in the index and
+	working tree, but not in `<tree-ish>` are removed, to make them
+	match `<tree-ish>` exactly.
+
+<branch>::
+	Branch to checkout; if it refers to a branch (i.e., a name that,
+	when prepended with "refs/heads/", is a valid ref), then that
+	branch is checked out. Otherwise, if it refers to a valid
+	commit, your `HEAD` becomes "detached" and you are no longer on
+	any branch (see below for details).
++
+You can use the `@{-N}` syntax to refer to the N-th last
+branch/commit checked out using "git checkout" operation. You may
+also specify `-` which is synonymous to `@{-1}`.
++
+As a special case, you may use `A...B` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
+
+<new_branch>::
+	Name for the new branch.
+
+<start_point>::
+	The name of a commit at which to start the new branch; see
+	linkgit:git-branch[1] for details. Defaults to `HEAD`.
++
+As a special case, you may use `"A...B"` as a shortcut for the
+merge base of `A` and `B` if there is exactly one merge base. You can
+leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
+
+<tree-ish>::
+	Tree to checkout from (when paths are given). If not specified,
+	the index will be used.
+
+
+
+DETACHED HEAD
+-------------
+`HEAD` normally refers to a named branch (e.g. `master`). Meanwhile, each
+branch refers to a specific commit. Let's look at a repo with three
+commits, one of them tagged, and with branch `master` checked out:
+
+------------
+           HEAD (refers to branch 'master')
+            |
+            v
+a---b---c  branch 'master' (refers to commit 'c')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+When a commit is created in this state, the branch is updated to refer to
+the new commit. Specifically, 'git commit' creates a new commit `d`, whose
+parent is commit `c`, and then updates branch `master` to refer to new
+commit `d`. `HEAD` still refers to branch `master` and so indirectly now refers
+to commit `d`:
+
+------------
+$ edit; git add; git commit
+
+               HEAD (refers to branch 'master')
+                |
+                v
+a---b---c---d  branch 'master' (refers to commit 'd')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+It is sometimes useful to be able to checkout a commit that is not at
+the tip of any named branch, or even to create a new commit that is not
+referenced by a named branch. Let's look at what happens when we
+checkout commit `b` (here we show two ways this may be done):
+
+------------
+$ git checkout v2.0  # or
+$ git checkout master^^
+
+   HEAD (refers to commit 'b')
+    |
+    v
+a---b---c---d  branch 'master' (refers to commit 'd')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+Notice that regardless of which checkout command we use, `HEAD` now refers
+directly to commit `b`. This is known as being in detached `HEAD` state.
+It means simply that `HEAD` refers to a specific commit, as opposed to
+referring to a named branch. Let's see what happens when we create a commit:
+
+------------
+$ edit; git add; git commit
+
+     HEAD (refers to commit 'e')
+      |
+      v
+      e
+     /
+a---b---c---d  branch 'master' (refers to commit 'd')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+There is now a new commit `e`, but it is referenced only by `HEAD`. We can
+of course add yet another commit in this state:
+
+------------
+$ edit; git add; git commit
+
+	 HEAD (refers to commit 'f')
+	  |
+	  v
+      e---f
+     /
+a---b---c---d  branch 'master' (refers to commit 'd')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+In fact, we can perform all the normal Git operations. But, let's look
+at what happens when we then checkout `master`:
+
+------------
+$ git checkout master
+
+               HEAD (refers to branch 'master')
+      e---f     |
+     /          v
+a---b---c---d  branch 'master' (refers to commit 'd')
+    ^
+    |
+  tag 'v2.0' (refers to commit 'b')
+------------
+
+It is important to realize that at this point nothing refers to commit
+`f`. Eventually commit `f` (and by extension commit `e`) will be deleted
+by the routine Git garbage collection process, unless we create a reference
+before that happens. If we have not yet moved away from commit `f`,
+any of these will create a reference to it:
+
+------------
+$ git checkout -b foo   <1>
+$ git branch foo        <2>
+$ git tag foo           <3>
+------------
+
+<1> creates a new branch `foo`, which refers to commit `f`, and then
+    updates `HEAD` to refer to branch `foo`. In other words, we'll no longer
+    be in detached `HEAD` state after this command.
+
+<2> similarly creates a new branch `foo`, which refers to commit `f`,
+    but leaves `HEAD` detached.
+
+<3> creates a new tag `foo`, which refers to commit `f`,
+    leaving `HEAD` detached.
+
+If we have moved away from commit `f`, then we must first recover its object
+name (typically by using git reflog), and then we can create a reference to
+it. For example, to see the last two commits to which `HEAD` referred, we
+can use either of these commands:
+
+------------
+$ git reflog -2 HEAD # or
+$ git log -g -2 HEAD
+------------
+
+ARGUMENT DISAMBIGUATION
+-----------------------
+
+When there is only one argument given and it is not `--` (e.g. `git
+checkout abc`), and when the argument is both a valid `<tree-ish>`
+(e.g. a branch `abc` exists) and a valid `<pathspec>` (e.g. a file
+or a directory whose name is "abc" exists), Git would usually ask
+you to disambiguate.  Because checking out a branch is so common an
+operation, however, `git checkout abc` takes "abc" as a `<tree-ish>`
+in such a situation.  Use `git checkout -- <pathspec>` if you want
+to checkout these paths out of the index.
+
+EXAMPLES
+--------
+
+. The following sequence checks out the `master` branch, reverts
+  the `Makefile` to two revisions back, deletes `hello.c` by
+  mistake, and gets it back from the index.
++
+------------
+$ git checkout master             <1>
+$ git checkout master~2 Makefile  <2>
+$ rm -f hello.c
+$ git checkout hello.c            <3>
+------------
++
+<1> switch branch
+<2> take a file out of another commit
+<3> restore `hello.c` from the index
++
+If you want to check out _all_ C source files out of the index,
+you can say
++
+------------
+$ git checkout -- '*.c'
+------------
++
+Note the quotes around `*.c`.  The file `hello.c` will also be
+checked out, even though it is no longer in the working tree,
+because the file globbing is used to match entries in the index
+(not in the working tree by the shell).
++
+If you have an unfortunate branch that is named `hello.c`, this
+step would be confused as an instruction to switch to that branch.
+You should instead write:
++
+------------
+$ git checkout -- hello.c
+------------
+
+. After working in the wrong branch, switching to the correct
+  branch would be done using:
++
+------------
+$ git checkout mytopic
+------------
++
+However, your "wrong" branch and correct `mytopic` branch may
+differ in files that you have modified locally, in which case
+the above checkout would fail like this:
++
+------------
+$ git checkout mytopic
+error: You have local changes to 'frotz'; not switching branches.
+------------
++
+You can give the `-m` flag to the command, which would try a
+three-way merge:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+------------
++
+After this three-way merge, the local modifications are _not_
+registered in your index file, so `git diff` would show you what
+changes you made since the tip of the new branch.
+
+. When a merge conflict happens during switching branches with
+  the `-m` option, you would see something like this:
++
+------------
+$ git checkout -m mytopic
+Auto-merging frotz
+ERROR: Merge conflict in frotz
+fatal: merge program failed
+------------
++
+At this point, `git diff` shows the changes cleanly merged as in
+the previous example, as well as the changes in the conflicted
+files.  Edit and resolve the conflict and mark it resolved with
+`git add` as usual:
++
+------------
+$ edit frotz
+$ git add frotz
+------------
+
+SEE ALSO
+--------
+linkgit:git-switch[1],
+linkgit:git-restore[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-cherry-pick.txt b/third_party/git/Documentation/git-cherry-pick.txt
new file mode 100644
index 0000000000..83ce51aedf
--- /dev/null
+++ b/third_party/git/Documentation/git-cherry-pick.txt
@@ -0,0 +1,243 @@
+git-cherry-pick(1)
+==================
+
+NAME
+----
+git-cherry-pick - Apply the changes introduced by some existing commits
+
+SYNOPSIS
+--------
+[verse]
+'git cherry-pick' [--edit] [-n] [-m parent-number] [-s] [-x] [--ff]
+		  [-S[<keyid>]] <commit>...
+'git cherry-pick' (--continue | --skip | --abort | --quit)
+
+DESCRIPTION
+-----------
+
+Given one or more existing commits, apply the change each one
+introduces, recording a new commit for each.  This requires your
+working tree to be clean (no modifications from the HEAD commit).
+
+When it is not obvious how to apply a change, the following
+happens:
+
+1. The current branch and `HEAD` pointer stay at the last commit
+   successfully made.
+2. The `CHERRY_PICK_HEAD` ref is set to point at the commit that
+   introduced the change that is difficult to apply.
+3. Paths in which the change applied cleanly are updated both
+   in the index file and in your working tree.
+4. For conflicting paths, the index file records up to three
+   versions, as described in the "TRUE MERGE" section of
+   linkgit:git-merge[1].  The working tree files will include
+   a description of the conflict bracketed by the usual
+   conflict markers `<<<<<<<` and `>>>>>>>`.
+5. No other modifications are made.
+
+See linkgit:git-merge[1] for some hints on resolving such
+conflicts.
+
+OPTIONS
+-------
+<commit>...::
+	Commits to cherry-pick.
+	For a more complete list of ways to spell commits, see
+	linkgit:gitrevisions[7].
+	Sets of commits can be passed but no traversal is done by
+	default, as if the `--no-walk` option was specified, see
+	linkgit:git-rev-list[1]. Note that specifying a range will
+	feed all <commit>... arguments to a single revision walk
+	(see a later example that uses 'maint master..next').
+
+-e::
+--edit::
+	With this option, 'git cherry-pick' will let you edit the commit
+	message prior to committing.
+
+--cleanup=<mode>::
+	This option determines how the commit message will be cleaned up before
+	being passed on to the commit machinery. See linkgit:git-commit[1] for more
+	details. In particular, if the '<mode>' is given a value of `scissors`,
+	scissors will be appended to `MERGE_MSG` before being passed on in the case
+	of a conflict.
+
+-x::
+	When recording the commit, append a line that says
+	"(cherry picked from commit ...)" to the original commit
+	message in order to indicate which commit this change was
+	cherry-picked from.  This is done only for cherry
+	picks without conflicts.  Do not use this option if
+	you are cherry-picking from your private branch because
+	the information is useless to the recipient.  If on the
+	other hand you are cherry-picking between two publicly
+	visible branches (e.g. backporting a fix to a
+	maintenance branch for an older release from a
+	development branch), adding this information can be
+	useful.
+
+-r::
+	It used to be that the command defaulted to do `-x`
+	described above, and `-r` was to disable it.  Now the
+	default is not to do `-x` so this option is a no-op.
+
+-m parent-number::
+--mainline parent-number::
+	Usually you cannot cherry-pick a merge because you do not know which
+	side of the merge should be considered the mainline.  This
+	option specifies the parent number (starting from 1) of
+	the mainline and allows cherry-pick to replay the change
+	relative to the specified parent.
+
+-n::
+--no-commit::
+	Usually the command automatically creates a sequence of commits.
+	This flag applies the changes necessary to cherry-pick
+	each named commit to your working tree and the index,
+	without making any commit.  In addition, when this
+	option is used, your index does not have to match the
+	HEAD commit.  The cherry-pick is done against the
+	beginning state of your index.
++
+This is useful when cherry-picking more than one commits'
+effect to your index in a row.
+
+-s::
+--signoff::
+	Add Signed-off-by line at the end of the commit message.
+	See the signoff option in linkgit:git-commit[1] for more information.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+--ff::
+	If the current HEAD is the same as the parent of the
+	cherry-pick'ed commit, then a fast forward to this commit will
+	be performed.
+
+--allow-empty::
+	By default, cherry-picking an empty commit will fail,
+	indicating that an explicit invocation of `git commit
+	--allow-empty` is required. This option overrides that
+	behavior, allowing empty commits to be preserved automatically
+	in a cherry-pick. Note that when "--ff" is in effect, empty
+	commits that meet the "fast-forward" requirement will be kept
+	even without this option.  Note also, that use of this option only
+	keeps commits that were initially empty (i.e. the commit recorded the
+	same tree as its parent).  Commits which are made empty due to a
+	previous commit are dropped.  To force the inclusion of those commits
+	use `--keep-redundant-commits`.
+
+--allow-empty-message::
+	By default, cherry-picking a commit with an empty message will fail.
+	This option overrides that behavior, allowing commits with empty
+	messages to be cherry picked.
+
+--keep-redundant-commits::
+	If a commit being cherry picked duplicates a commit already in the
+	current history, it will become empty.  By default these
+	redundant commits cause `cherry-pick` to stop so the user can
+	examine the commit. This option overrides that behavior and
+	creates an empty commit object.  Implies `--allow-empty`.
+
+--strategy=<strategy>::
+	Use the given merge strategy.  Should only be used once.
+	See the MERGE STRATEGIES section in linkgit:git-merge[1]
+	for details.
+
+-X<option>::
+--strategy-option=<option>::
+	Pass the merge strategy-specific option through to the
+	merge strategy.  See linkgit:git-merge[1] for details.
+
+--rerere-autoupdate::
+--no-rerere-autoupdate::
+	Allow the rerere mechanism to update the index with the
+	result of auto-conflict resolution if possible.
+
+SEQUENCER SUBCOMMANDS
+---------------------
+include::sequencer.txt[]
+
+EXAMPLES
+--------
+`git cherry-pick master`::
+
+	Apply the change introduced by the commit at the tip of the
+	master branch and create a new commit with this change.
+
+`git cherry-pick ..master`::
+`git cherry-pick ^HEAD master`::
+
+	Apply the changes introduced by all commits that are ancestors
+	of master but not of HEAD to produce new commits.
+
+`git cherry-pick maint next ^master`::
+`git cherry-pick maint master..next`::
+
+	Apply the changes introduced by all commits that are
+	ancestors of maint or next, but not master or any of its
+	ancestors.  Note that the latter does not mean `maint` and
+	everything between `master` and `next`; specifically,
+	`maint` will not be used if it is included in `master`.
+
+`git cherry-pick master~4 master~2`::
+
+	Apply the changes introduced by the fifth and third last
+	commits pointed to by master and create 2 new commits with
+	these changes.
+
+`git cherry-pick -n master~1 next`::
+
+	Apply to the working tree and the index the changes introduced
+	by the second last commit pointed to by master and by the last
+	commit pointed to by next, but do not create any commit with
+	these changes.
+
+`git cherry-pick --ff ..next`::
+
+	If history is linear and HEAD is an ancestor of next, update
+	the working tree and advance the HEAD pointer to match next.
+	Otherwise, apply the changes introduced by those commits that
+	are in next but not HEAD to the current branch, creating a new
+	commit for each new change.
+
+`git rev-list --reverse master -- README | git cherry-pick -n --stdin`::
+
+	Apply the changes introduced by all commits on the master
+	branch that touched README to the working tree and index,
+	so the result can be inspected and made into a single new
+	commit if suitable.
+
+The following sequence attempts to backport a patch, bails out because
+the code the patch applies to has changed too much, and then tries
+again, this time exercising more care about matching up context lines.
+
+------------
+$ git cherry-pick topic^             <1>
+$ git diff                           <2>
+$ git reset --merge ORIG_HEAD        <3>
+$ git cherry-pick -Xpatience topic^  <4>
+------------
+<1> apply the change that would be shown by `git show topic^`.
+    In this example, the patch does not apply cleanly, so
+    information about the conflict is written to the index and
+    working tree and no new commit results.
+<2> summarize changes to be reconciled
+<3> cancel the cherry-pick.  In other words, return to the
+    pre-cherry-pick state, preserving any local modifications
+    you had in the working tree.
+<4> try to apply the change introduced by `topic^` again,
+    spending extra time to avoid mistakes based on incorrectly
+    matching context lines.
+
+SEE ALSO
+--------
+linkgit:git-revert[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-cherry.txt b/third_party/git/Documentation/git-cherry.txt
new file mode 100644
index 0000000000..0ea921a593
--- /dev/null
+++ b/third_party/git/Documentation/git-cherry.txt
@@ -0,0 +1,145 @@
+git-cherry(1)
+=============
+
+NAME
+----
+git-cherry - Find commits yet to be applied to upstream
+
+SYNOPSIS
+--------
+[verse]
+'git cherry' [-v] [<upstream> [<head> [<limit>]]]
+
+DESCRIPTION
+-----------
+Determine whether there are commits in `<head>..<upstream>` that are
+equivalent to those in the range `<limit>..<head>`.
+
+The equivalence test is based on the diff, after removing whitespace
+and line numbers.  git-cherry therefore detects when commits have been
+"copied" by means of linkgit:git-cherry-pick[1], linkgit:git-am[1] or
+linkgit:git-rebase[1].
+
+Outputs the SHA1 of every commit in `<limit>..<head>`, prefixed with
+`-` for commits that have an equivalent in <upstream>, and `+` for
+commits that do not.
+
+OPTIONS
+-------
+-v::
+	Show the commit subjects next to the SHA1s.
+
+<upstream>::
+	Upstream branch to search for equivalent commits.
+	Defaults to the upstream branch of HEAD.
+
+<head>::
+	Working branch; defaults to HEAD.
+
+<limit>::
+	Do not report commits up to (and including) limit.
+
+EXAMPLES
+--------
+
+Patch workflows
+~~~~~~~~~~~~~~~
+
+git-cherry is frequently used in patch-based workflows (see
+linkgit:gitworkflows[7]) to determine if a series of patches has been
+applied by the upstream maintainer.  In such a workflow you might
+create and send a topic branch like this:
+
+------------
+$ git checkout -b topic origin/master
+# work and create some commits
+$ git format-patch origin/master
+$ git send-email ... 00*
+------------
+
+Later, you can see whether your changes have been applied by saying
+(still on `topic`):
+
+------------
+$ git fetch  # update your notion of origin/master
+$ git cherry -v
+------------
+
+Concrete example
+~~~~~~~~~~~~~~~~
+
+In a situation where topic consisted of three commits, and the
+maintainer applied two of them, the situation might look like:
+
+------------
+$ git log --graph --oneline --decorate --boundary origin/master...topic
+* 7654321 (origin/master) upstream tip commit
+[... snip some other commits ...]
+* cccc111 cherry-pick of C
+* aaaa111 cherry-pick of A
+[... snip a lot more that has happened ...]
+| * cccc000 (topic) commit C
+| * bbbb000 commit B
+| * aaaa000 commit A
+|/
+o 1234567 branch point
+------------
+
+In such cases, git-cherry shows a concise summary of what has yet to
+be applied:
+
+------------
+$ git cherry origin/master topic
+- cccc000... commit C
++ bbbb000... commit B
+- aaaa000... commit A
+------------
+
+Here, we see that the commits A and C (marked with `-`) can be
+dropped from your `topic` branch when you rebase it on top of
+`origin/master`, while the commit B (marked with `+`) still needs to
+be kept so that it will be sent to be applied to `origin/master`.
+
+
+Using a limit
+~~~~~~~~~~~~~
+
+The optional <limit> is useful in cases where your topic is based on
+other work that is not in upstream.  Expanding on the previous
+example, this might look like:
+
+------------
+$ git log --graph --oneline --decorate --boundary origin/master...topic
+* 7654321 (origin/master) upstream tip commit
+[... snip some other commits ...]
+* cccc111 cherry-pick of C
+* aaaa111 cherry-pick of A
+[... snip a lot more that has happened ...]
+| * cccc000 (topic) commit C
+| * bbbb000 commit B
+| * aaaa000 commit A
+| * 0000fff (base) unpublished stuff F
+[... snip ...]
+| * 0000aaa unpublished stuff A
+|/
+o 1234567 merge-base between upstream and topic
+------------
+
+By specifying `base` as the limit, you can avoid listing commits
+between `base` and `topic`:
+
+------------
+$ git cherry origin/master topic base
+- cccc000... commit C
++ bbbb000... commit B
+- aaaa000... commit A
+------------
+
+
+SEE ALSO
+--------
+linkgit:git-patch-id[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-citool.txt b/third_party/git/Documentation/git-citool.txt
new file mode 100644
index 0000000000..c7a11c36c1
--- /dev/null
+++ b/third_party/git/Documentation/git-citool.txt
@@ -0,0 +1,25 @@
+git-citool(1)
+=============
+
+NAME
+----
+git-citool - Graphical alternative to git-commit
+
+SYNOPSIS
+--------
+[verse]
+'git citool'
+
+DESCRIPTION
+-----------
+A Tcl/Tk based graphical interface to review modified files, stage
+them into the index, enter a commit message and record the new
+commit onto the current branch.  This interface is an alternative
+to the less interactive 'git commit' program.
+
+'git citool' is actually a standard alias for `git gui citool`.
+See linkgit:git-gui[1] for more details.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-clean.txt b/third_party/git/Documentation/git-clean.txt
new file mode 100644
index 0000000000..0028ff12d1
--- /dev/null
+++ b/third_party/git/Documentation/git-clean.txt
@@ -0,0 +1,140 @@
+git-clean(1)
+============
+
+NAME
+----
+git-clean - Remove untracked files from the working tree
+
+SYNOPSIS
+--------
+[verse]
+'git clean' [-d] [-f] [-i] [-n] [-q] [-e <pattern>] [-x | -X] [--] <path>...
+
+DESCRIPTION
+-----------
+
+Cleans the working tree by recursively removing files that are not
+under version control, starting from the current directory.
+
+Normally, only files unknown to Git are removed, but if the `-x`
+option is specified, ignored files are also removed. This can, for
+example, be useful to remove all build products.
+
+If any optional `<path>...` arguments are given, only those paths
+are affected.
+
+OPTIONS
+-------
+-d::
+	Remove untracked directories in addition to untracked files.
+	If an untracked directory is managed by a different Git
+	repository, it is not removed by default.  Use -f option twice
+	if you really want to remove such a directory.
+
+-f::
+--force::
+	If the Git configuration variable clean.requireForce is not set
+	to false, 'git clean' will refuse to delete files or directories
+	unless given -f, -n or -i. Git will refuse to delete directories
+	with .git sub directory or file unless a second -f
+	is given.
+
+-i::
+--interactive::
+	Show what would be done and clean files interactively. See
+	``Interactive mode'' for details.
+
+-n::
+--dry-run::
+	Don't actually remove anything, just show what would be done.
+
+-q::
+--quiet::
+	Be quiet, only report errors, but not the files that are
+	successfully removed.
+
+-e <pattern>::
+--exclude=<pattern>::
+	Use the given exclude pattern in addition to the standard ignore rules
+	(see linkgit:gitignore[5]).
+
+-x::
+	Don't use the standard ignore rules (see linkgit:gitignore[5]), but
+	still use the ignore rules given with `-e` options from the command
+	line.  This allows removing all untracked
+	files, including build products.  This can be used (possibly in
+	conjunction with 'git restore' or 'git reset') to create a pristine
+	working directory to test a clean build.
+
+-X::
+	Remove only files ignored by Git.  This may be useful to rebuild
+	everything from scratch, but keep manually created files.
+
+Interactive mode
+----------------
+When the command enters the interactive mode, it shows the
+files and directories to be cleaned, and goes into its
+interactive command loop.
+
+The command loop shows the list of subcommands available, and
+gives a prompt "What now> ".  In general, when the prompt ends
+with a single '>', you can pick only one of the choices given
+and type return, like this:
+
+------------
+    *** Commands ***
+	1: clean                2: filter by pattern    3: select by numbers
+	4: ask each             5: quit                 6: help
+    What now> 1
+------------
+
+You also could say `c` or `clean` above as long as the choice is unique.
+
+The main command loop has 6 subcommands.
+
+clean::
+
+   Start cleaning files and directories, and then quit.
+
+filter by pattern::
+
+   This shows the files and directories to be deleted and issues an
+   "Input ignore patterns>>" prompt. You can input space-separated
+   patterns to exclude files and directories from deletion.
+   E.g. "*.c *.h" will excludes files end with ".c" and ".h" from
+   deletion. When you are satisfied with the filtered result, press
+   ENTER (empty) back to the main menu.
+
+select by numbers::
+
+   This shows the files and directories to be deleted and issues an
+   "Select items to delete>>" prompt. When the prompt ends with double
+   '>>' like this, you can make more than one selection, concatenated
+   with whitespace or comma.  Also you can say ranges.  E.g. "2-5 7,9"
+   to choose 2,3,4,5,7,9 from the list.  If the second number in a
+   range is omitted, all remaining items are selected.  E.g. "7-" to
+   choose 7,8,9 from the list.  You can say '*' to choose everything.
+   Also when you are satisfied with the filtered result, press ENTER
+   (empty) back to the main menu.
+
+ask each::
+
+  This will start to clean, and you must confirm one by one in order
+  to delete items. Please note that this action is not as efficient
+  as the above two actions.
+
+quit::
+
+  This lets you quit without do cleaning.
+
+help::
+
+  Show brief usage of interactive git-clean.
+
+SEE ALSO
+--------
+linkgit:gitignore[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-clone.txt b/third_party/git/Documentation/git-clone.txt
new file mode 100644
index 0000000000..34011c2940
--- /dev/null
+++ b/third_party/git/Documentation/git-clone.txt
@@ -0,0 +1,337 @@
+git-clone(1)
+============
+
+NAME
+----
+git-clone - Clone a repository into a new directory
+
+
+SYNOPSIS
+--------
+[verse]
+'git clone' [--template=<template_directory>]
+	  [-l] [-s] [--no-hardlinks] [-q] [-n] [--bare] [--mirror]
+	  [-o <name>] [-b <name>] [-u <upload-pack>] [--reference <repository>]
+	  [--dissociate] [--separate-git-dir <git dir>]
+	  [--depth <depth>] [--[no-]single-branch] [--no-tags]
+	  [--recurse-submodules[=<pathspec>]] [--[no-]shallow-submodules]
+	  [--[no-]remote-submodules] [--jobs <n>] [--] <repository>
+	  [<directory>]
+
+DESCRIPTION
+-----------
+
+Clones a repository into a newly created directory, creates
+remote-tracking branches for each branch in the cloned repository
+(visible using `git branch --remotes`), and creates and checks out an
+initial branch that is forked from the cloned repository's
+currently active branch.
+
+After the clone, a plain `git fetch` without arguments will update
+all the remote-tracking branches, and a `git pull` without
+arguments will in addition merge the remote master branch into the
+current master branch, if any (this is untrue when "--single-branch"
+is given; see below).
+
+This default configuration is achieved by creating references to
+the remote branch heads under `refs/remotes/origin` and
+by initializing `remote.origin.url` and `remote.origin.fetch`
+configuration variables.
+
+
+OPTIONS
+-------
+-l::
+--local::
+	When the repository to clone from is on a local machine,
+	this flag bypasses the normal "Git aware" transport
+	mechanism and clones the repository by making a copy of
+	HEAD and everything under objects and refs directories.
+	The files under `.git/objects/` directory are hardlinked
+	to save space when possible.
++
+If the repository is specified as a local path (e.g., `/path/to/repo`),
+this is the default, and --local is essentially a no-op.  If the
+repository is specified as a URL, then this flag is ignored (and we
+never use the local optimizations).  Specifying `--no-local` will
+override the default when `/path/to/repo` is given, using the regular
+Git transport instead.
+
+--no-hardlinks::
+	Force the cloning process from a repository on a local
+	filesystem to copy the files under the `.git/objects`
+	directory instead of using hardlinks. This may be desirable
+	if you are trying to make a back-up of your repository.
+
+-s::
+--shared::
+	When the repository to clone is on the local machine,
+	instead of using hard links, automatically setup
+	`.git/objects/info/alternates` to share the objects
+	with the source repository.  The resulting repository
+	starts out without any object of its own.
++
+*NOTE*: this is a possibly dangerous operation; do *not* use
+it unless you understand what it does. If you clone your
+repository using this option and then delete branches (or use any
+other Git command that makes any existing commit unreferenced) in the
+source repository, some objects may become unreferenced (or dangling).
+These objects may be removed by normal Git operations (such as `git commit`)
+which automatically call `git gc --auto`. (See linkgit:git-gc[1].)
+If these objects are removed and were referenced by the cloned repository,
+then the cloned repository will become corrupt.
++
+Note that running `git repack` without the `--local` option in a repository
+cloned with `--shared` will copy objects from the source repository into a pack
+in the cloned repository, removing the disk space savings of `clone --shared`.
+It is safe, however, to run `git gc`, which uses the `--local` option by
+default.
++
+If you want to break the dependency of a repository cloned with `--shared` on
+its source repository, you can simply run `git repack -a` to copy all
+objects from the source repository into a pack in the cloned repository.
+
+--reference[-if-able] <repository>::
+	If the reference repository is on the local machine,
+	automatically setup `.git/objects/info/alternates` to
+	obtain objects from the reference repository.  Using
+	an already existing repository as an alternate will
+	require fewer objects to be copied from the repository
+	being cloned, reducing network and local storage costs.
+	When using the `--reference-if-able`, a non existing
+	directory is skipped with a warning instead of aborting
+	the clone.
++
+*NOTE*: see the NOTE for the `--shared` option, and also the
+`--dissociate` option.
+
+--dissociate::
+	Borrow the objects from reference repositories specified
+	with the `--reference` options only to reduce network
+	transfer, and stop borrowing from them after a clone is made
+	by making necessary local copies of borrowed objects.  This
+	option can also be used when cloning locally from a
+	repository that already borrows objects from another
+	repository--the new repository will borrow objects from the
+	same repository, and this option can be used to stop the
+	borrowing.
+
+-q::
+--quiet::
+	Operate quietly.  Progress is not reported to the standard
+	error stream.
+
+-v::
+--verbose::
+	Run verbosely. Does not affect the reporting of progress status
+	to the standard error stream.
+
+--progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag forces progress status even if the
+	standard error stream is not directed to a terminal.
+
+--server-option=<option>::
+	Transmit the given string to the server when communicating using
+	protocol version 2.  The given string must not contain a NUL or LF
+	character.  The server's handling of server options, including
+	unknown ones, is server-specific.
+	When multiple `--server-option=<option>` are given, they are all
+	sent to the other side in the order listed on the command line.
+
+-n::
+--no-checkout::
+	No checkout of HEAD is performed after the clone is complete.
+
+--bare::
+	Make a 'bare' Git repository.  That is, instead of
+	creating `<directory>` and placing the administrative
+	files in `<directory>/.git`, make the `<directory>`
+	itself the `$GIT_DIR`. This obviously implies the `--no-checkout`
+	because there is nowhere to check out the working tree.
+	Also the branch heads at the remote are copied directly
+	to corresponding local branch heads, without mapping
+	them to `refs/remotes/origin/`.  When this option is
+	used, neither remote-tracking branches nor the related
+	configuration variables are created.
+
+--mirror::
+	Set up a mirror of the source repository.  This implies `--bare`.
+	Compared to `--bare`, `--mirror` not only maps local branches of the
+	source to local branches of the target, it maps all refs (including
+	remote-tracking branches, notes etc.) and sets up a refspec configuration such
+	that all these refs are overwritten by a `git remote update` in the
+	target repository.
+
+-o <name>::
+--origin <name>::
+	Instead of using the remote name `origin` to keep track
+	of the upstream repository, use `<name>`.
+
+-b <name>::
+--branch <name>::
+	Instead of pointing the newly created HEAD to the branch pointed
+	to by the cloned repository's HEAD, point to `<name>` branch
+	instead. In a non-bare repository, this is the branch that will
+	be checked out.
+	`--branch` can also take tags and detaches the HEAD at that commit
+	in the resulting repository.
+
+-u <upload-pack>::
+--upload-pack <upload-pack>::
+	When given, and the repository to clone from is accessed
+	via ssh, this specifies a non-default path for the command
+	run on the other end.
+
+--template=<template_directory>::
+	Specify the directory from which templates will be used;
+	(See the "TEMPLATE DIRECTORY" section of linkgit:git-init[1].)
+
+-c <key>=<value>::
+--config <key>=<value>::
+	Set a configuration variable in the newly-created repository;
+	this takes effect immediately after the repository is
+	initialized, but before the remote history is fetched or any
+	files checked out.  The key is in the same format as expected by
+	linkgit:git-config[1] (e.g., `core.eol=true`). If multiple
+	values are given for the same key, each value will be written to
+	the config file. This makes it safe, for example, to add
+	additional fetch refspecs to the origin remote.
++
+Due to limitations of the current implementation, some configuration
+variables do not take effect until after the initial fetch and checkout.
+Configuration variables known to not take effect are:
+`remote.<name>.mirror` and `remote.<name>.tagOpt`.  Use the
+corresponding `--mirror` and `--no-tags` options instead.
+
+--depth <depth>::
+	Create a 'shallow' clone with a history truncated to the
+	specified number of commits. Implies `--single-branch` unless
+	`--no-single-branch` is given to fetch the histories near the
+	tips of all branches. If you want to clone submodules shallowly,
+	also pass `--shallow-submodules`.
+
+--shallow-since=<date>::
+	Create a shallow clone with a history after the specified time.
+
+--shallow-exclude=<revision>::
+	Create a shallow clone with a history, excluding commits
+	reachable from a specified remote branch or tag.  This option
+	can be specified multiple times.
+
+--[no-]single-branch::
+	Clone only the history leading to the tip of a single branch,
+	either specified by the `--branch` option or the primary
+	branch remote's `HEAD` points at.
+	Further fetches into the resulting repository will only update the
+	remote-tracking branch for the branch this option was used for the
+	initial cloning.  If the HEAD at the remote did not point at any
+	branch when `--single-branch` clone was made, no remote-tracking
+	branch is created.
+
+--no-tags::
+	Don't clone any tags, and set
+	`remote.<remote>.tagOpt=--no-tags` in the config, ensuring
+	that future `git pull` and `git fetch` operations won't follow
+	any tags. Subsequent explicit tag fetches will still work,
+	(see linkgit:git-fetch[1]).
++
+Can be used in conjunction with `--single-branch` to clone and
+maintain a branch with no references other than a single cloned
+branch. This is useful e.g. to maintain minimal clones of the default
+branch of some repository for search indexing.
+
+--recurse-submodules[=<pathspec]::
+	After the clone is created, initialize and clone submodules
+	within based on the provided pathspec.  If no pathspec is
+	provided, all submodules are initialized and cloned.
+	This option can be given multiple times for pathspecs consisting
+	of multiple entries.  The resulting clone has `submodule.active` set to
+	the provided pathspec, or "." (meaning all submodules) if no
+	pathspec is provided.
++
+Submodules are initialized and cloned using their default settings. This is
+equivalent to running
+`git submodule update --init --recursive <pathspec>` immediately after
+the clone is finished. This option is ignored if the cloned repository does
+not have a worktree/checkout (i.e. if any of `--no-checkout`/`-n`, `--bare`,
+or `--mirror` is given)
+
+--[no-]shallow-submodules::
+	All submodules which are cloned will be shallow with a depth of 1.
+
+--[no-]remote-submodules::
+	All submodules which are cloned will use the status of the submodule’s
+	remote-tracking branch to update the submodule, rather than the
+	superproject’s recorded SHA-1. Equivalent to passing `--remote` to
+	`git submodule update`.
+
+--separate-git-dir=<git dir>::
+	Instead of placing the cloned repository where it is supposed
+	to be, place the cloned repository at the specified directory,
+	then make a filesystem-agnostic Git symbolic link to there.
+	The result is Git repository can be separated from working
+	tree.
+
+-j <n>::
+--jobs <n>::
+	The number of submodules fetched at the same time.
+	Defaults to the `submodule.fetchJobs` option.
+
+<repository>::
+	The (possibly remote) repository to clone from.  See the
+	<<URLS,GIT URLS>> section below for more information on specifying
+	repositories.
+
+<directory>::
+	The name of a new directory to clone into.  The "humanish"
+	part of the source repository is used if no directory is
+	explicitly given (`repo` for `/path/to/repo.git` and `foo`
+	for `host.xz:foo/.git`).  Cloning into an existing directory
+	is only allowed if the directory is empty.
+
+:git-clone: 1
+include::urls.txt[]
+
+EXAMPLES
+--------
+
+* Clone from upstream:
++
+------------
+$ git clone git://git.kernel.org/pub/scm/.../linux.git my-linux
+$ cd my-linux
+$ make
+------------
+
+
+* Make a local clone that borrows from the current directory, without checking things out:
++
+------------
+$ git clone -l -s -n . ../copy
+$ cd ../copy
+$ git show-branch
+------------
+
+
+* Clone from upstream while borrowing from an existing local directory:
++
+------------
+$ git clone --reference /git/linux.git \
+	git://git.kernel.org/pub/scm/.../linux.git \
+	my-linux
+$ cd my-linux
+------------
+
+
+* Create a bare repository to publish your changes to the public:
++
+------------
+$ git clone --bare -l /home/proj/.git /pub/scm/proj.git
+------------
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-column.txt b/third_party/git/Documentation/git-column.txt
new file mode 100644
index 0000000000..f58e9c43e6
--- /dev/null
+++ b/third_party/git/Documentation/git-column.txt
@@ -0,0 +1,79 @@
+git-column(1)
+=============
+
+NAME
+----
+git-column - Display data in columns
+
+SYNOPSIS
+--------
+[verse]
+'git column' [--command=<name>] [--[raw-]mode=<mode>] [--width=<width>]
+	     [--indent=<string>] [--nl=<string>] [--padding=<n>]
+
+DESCRIPTION
+-----------
+This command formats the lines of its standard input into a table with
+multiple columns. Each input line occupies one cell of the table. It
+is used internally by other git commands to format output into
+columns.
+
+OPTIONS
+-------
+--command=<name>::
+	Look up layout mode using configuration variable column.<name> and
+	column.ui.
+
+--mode=<mode>::
+	Specify layout mode. See configuration variable column.ui for option
+	syntax in linkgit:git-config[1].
+
+--raw-mode=<n>::
+	Same as --mode but take mode encoded as a number. This is mainly used
+	by other commands that have already parsed layout mode.
+
+--width=<width>::
+	Specify the terminal width. By default 'git column' will detect the
+	terminal width, or fall back to 80 if it is unable to do so.
+
+--indent=<string>::
+	String to be printed at the beginning of each line.
+
+--nl=<N>::
+	String to be printed at the end of each line,
+	including newline character.
+
+--padding=<N>::
+	The number of spaces between columns. One space by default.
+
+EXAMPLES
+--------
+
+Format data by columns:
+------------
+$ seq 1 24 | git column --mode=column --padding=5
+1      4      7      10     13     16     19     22
+2      5      8      11     14     17     20     23
+3      6      9      12     15     18     21     24
+------------
+
+Format data by rows:
+------------
+$ seq 1 21 | git column --mode=row --padding=5
+1      2      3      4      5      6      7
+8      9      10     11     12     13     14
+15     16     17     18     19     20     21
+------------
+
+List some tags in a table with unequal column widths:
+------------
+$ git tag --list 'v2.4.*' --column=row,dense
+v2.4.0  v2.4.0-rc0  v2.4.0-rc1  v2.4.0-rc2  v2.4.0-rc3
+v2.4.1  v2.4.10     v2.4.11     v2.4.12     v2.4.2
+v2.4.3  v2.4.4      v2.4.5      v2.4.6      v2.4.7
+v2.4.8  v2.4.9
+------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-commit-graph.txt b/third_party/git/Documentation/git-commit-graph.txt
new file mode 100644
index 0000000000..eb5e7865f0
--- /dev/null
+++ b/third_party/git/Documentation/git-commit-graph.txt
@@ -0,0 +1,127 @@
+git-commit-graph(1)
+===================
+
+NAME
+----
+git-commit-graph - Write and verify Git commit-graph files
+
+
+SYNOPSIS
+--------
+[verse]
+'git commit-graph read' [--object-dir <dir>]
+'git commit-graph verify' [--object-dir <dir>] [--shallow]
+'git commit-graph write' <options> [--object-dir <dir>]
+
+
+DESCRIPTION
+-----------
+
+Manage the serialized commit-graph file.
+
+
+OPTIONS
+-------
+--object-dir::
+	Use given directory for the location of packfiles and commit-graph
+	file. This parameter exists to specify the location of an alternate
+	that only has the objects directory, not a full `.git` directory. The
+	commit-graph file is expected to be in the `<dir>/info` directory and
+	the packfiles are expected to be in `<dir>/pack`.
+
+
+COMMANDS
+--------
+'write'::
+
+Write a commit-graph file based on the commits found in packfiles.
++
+With the `--stdin-packs` option, generate the new commit graph by
+walking objects only in the specified pack-indexes. (Cannot be combined
+with `--stdin-commits` or `--reachable`.)
++
+With the `--stdin-commits` option, generate the new commit graph by
+walking commits starting at the commits specified in stdin as a list
+of OIDs in hex, one OID per line. (Cannot be combined with
+`--stdin-packs` or `--reachable`.)
++
+With the `--reachable` option, generate the new commit graph by walking
+commits starting at all refs. (Cannot be combined with `--stdin-commits`
+or `--stdin-packs`.)
++
+With the `--append` option, include all commits that are present in the
+existing commit-graph file.
++
+With the `--split` option, write the commit-graph as a chain of multiple
+commit-graph files stored in `<dir>/info/commit-graphs`. The new commits
+not already in the commit-graph are added in a new "tip" file. This file
+is merged with the existing file if the following merge conditions are
+met:
++
+* If `--size-multiple=<X>` is not specified, let `X` equal 2. If the new
+tip file would have `N` commits and the previous tip has `M` commits and
+`X` times `N` is greater than  `M`, instead merge the two files into a
+single file.
++
+* If `--max-commits=<M>` is specified with `M` a positive integer, and the
+new tip file would have more than `M` commits, then instead merge the new
+tip with the previous tip.
++
+Finally, if `--expire-time=<datetime>` is not specified, let `datetime`
+be the current time. After writing the split commit-graph, delete all
+unused commit-graph whose modified times are older than `datetime`.
+
+'read'::
+
+Read the commit-graph file and output basic details about it.
+Used for debugging purposes.
+
+'verify'::
+
+Read the commit-graph file and verify its contents against the object
+database. Used to check for corrupted data.
++
+With the `--shallow` option, only check the tip commit-graph file in
+a chain of split commit-graphs.
+
+
+EXAMPLES
+--------
+
+* Write a commit-graph file for the packed commits in your local `.git`
+  directory.
++
+------------------------------------------------
+$ git commit-graph write
+------------------------------------------------
+
+* Write a commit-graph file, extending the current commit-graph file
+  using commits in `<pack-index>`.
++
+------------------------------------------------
+$ echo <pack-index> | git commit-graph write --stdin-packs
+------------------------------------------------
+
+* Write a commit-graph file containing all reachable commits.
++
+------------------------------------------------
+$ git show-ref -s | git commit-graph write --stdin-commits
+------------------------------------------------
+
+* Write a commit-graph file containing all commits in the current
+  commit-graph file along with those reachable from `HEAD`.
++
+------------------------------------------------
+$ git rev-parse HEAD | git commit-graph write --stdin-commits --append
+------------------------------------------------
+
+* Read basic information from the commit-graph file.
++
+------------------------------------------------
+$ git commit-graph read
+------------------------------------------------
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-commit-tree.txt b/third_party/git/Documentation/git-commit-tree.txt
new file mode 100644
index 0000000000..4b90b9c12a
--- /dev/null
+++ b/third_party/git/Documentation/git-commit-tree.txt
@@ -0,0 +1,123 @@
+git-commit-tree(1)
+==================
+
+NAME
+----
+git-commit-tree - Create a new commit object
+
+
+SYNOPSIS
+--------
+[verse]
+'git commit-tree' <tree> [(-p <parent>)...]
+'git commit-tree' [(-p <parent>)...] [-S[<keyid>]] [(-m <message>)...]
+		  [(-F <file>)...] <tree>
+
+
+DESCRIPTION
+-----------
+This is usually not what an end user wants to run directly.  See
+linkgit:git-commit[1] instead.
+
+Creates a new commit object based on the provided tree object and
+emits the new commit object id on stdout. The log message is read
+from the standard input, unless `-m` or `-F` options are given.
+
+The `-m` and `-F` options can be given any number of times, in any
+order. The commit log message will be composed in the order in which
+the options are given.
+
+A commit object may have any number of parents. With exactly one
+parent, it is an ordinary commit. Having more than one parent makes
+the commit a merge between several lines of history. Initial (root)
+commits have no parents.
+
+While a tree represents a particular directory state of a working
+directory, a commit represents that state in "time", and explains how
+to get there.
+
+Normally a commit would identify a new "HEAD" state, and while Git
+doesn't care where you save the note about that state, in practice we
+tend to just write the result to the file that is pointed at by
+`.git/HEAD`, so that we can always see what the last committed
+state was.
+
+OPTIONS
+-------
+<tree>::
+	An existing tree object.
+
+-p <parent>::
+	Each `-p` indicates the id of a parent commit object.
+
+-m <message>::
+	A paragraph in the commit log message. This can be given more than
+	once and each <message> becomes its own paragraph.
+
+-F <file>::
+	Read the commit log message from the given file. Use `-` to read
+	from the standard input. This can be given more than once and the
+	content of each file becomes its own paragraph.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+--no-gpg-sign::
+	Do not GPG-sign commit, to countermand a `--gpg-sign` option
+	given earlier on the command line.
+
+
+Commit Information
+------------------
+
+A commit encapsulates:
+
+- all parent object ids
+- author name, email and date
+- committer name and email and the commit time.
+
+While parent object ids are provided on the command line, author and
+committer information is taken from the following environment variables,
+if set:
+
+	GIT_AUTHOR_NAME
+	GIT_AUTHOR_EMAIL
+	GIT_AUTHOR_DATE
+	GIT_COMMITTER_NAME
+	GIT_COMMITTER_EMAIL
+	GIT_COMMITTER_DATE
+
+(nb "<", ">" and "\n"s are stripped)
+
+In case (some of) these environment variables are not set, the information
+is taken from the configuration items user.name and user.email, or, if not
+present, the environment variable EMAIL, or, if that is not set,
+system user name and the hostname used for outgoing mail (taken
+from `/etc/mailname` and falling back to the fully qualified hostname when
+that file does not exist).
+
+A commit comment is read from stdin. If a changelog
+entry is not provided via "<" redirection, 'git commit-tree' will just wait
+for one to be entered and terminated with ^D.
+
+include::date-formats.txt[]
+
+Discussion
+----------
+
+include::i18n.txt[]
+
+FILES
+-----
+/etc/mailname
+
+SEE ALSO
+--------
+linkgit:git-write-tree[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-commit.txt b/third_party/git/Documentation/git-commit.txt
new file mode 100644
index 0000000000..7628193284
--- /dev/null
+++ b/third_party/git/Documentation/git-commit.txt
@@ -0,0 +1,496 @@
+git-commit(1)
+=============
+
+NAME
+----
+git-commit - Record changes to the repository
+
+SYNOPSIS
+--------
+[verse]
+'git commit' [-a | --interactive | --patch] [-s] [-v] [-u<mode>] [--amend]
+	   [--dry-run] [(-c | -C | --fixup | --squash) <commit>]
+	   [-F <file> | -m <msg>] [--reset-author] [--allow-empty]
+	   [--allow-empty-message] [--no-verify] [-e] [--author=<author>]
+	   [--date=<date>] [--cleanup=<mode>] [--[no-]status]
+	   [-i | -o] [-S[<keyid>]] [--] [<file>...]
+
+DESCRIPTION
+-----------
+Create a new commit containing the current contents of the index and
+the given log message describing the changes. The new commit is a
+direct child of HEAD, usually the tip of the current branch, and the
+branch is updated to point to it (unless no branch is associated with
+the working tree, in which case HEAD is "detached" as described in
+linkgit:git-checkout[1]).
+
+The content to be committed can be specified in several ways:
+
+1. by using linkgit:git-add[1] to incrementally "add" changes to the
+   index before using the 'commit' command (Note: even modified files
+   must be "added");
+
+2. by using linkgit:git-rm[1] to remove files from the working tree
+   and the index, again before using the 'commit' command;
+
+3. by listing files as arguments to the 'commit' command
+   (without --interactive or --patch switch), in which
+   case the commit will ignore changes staged in the index, and instead
+   record the current content of the listed files (which must already
+   be known to Git);
+
+4. by using the -a switch with the 'commit' command to automatically
+   "add" changes from all known files (i.e. all files that are already
+   listed in the index) and to automatically "rm" files in the index
+   that have been removed from the working tree, and then perform the
+   actual commit;
+
+5. by using the --interactive or --patch switches with the 'commit' command
+   to decide one by one which files or hunks should be part of the commit
+   in addition to contents in the index,
+   before finalizing the operation. See the ``Interactive Mode'' section of
+   linkgit:git-add[1] to learn how to operate these modes.
+
+The `--dry-run` option can be used to obtain a
+summary of what is included by any of the above for the next
+commit by giving the same set of parameters (options and paths).
+
+If you make a commit and then find a mistake immediately after
+that, you can recover from it with 'git reset'.
+
+
+OPTIONS
+-------
+-a::
+--all::
+	Tell the command to automatically stage files that have
+	been modified and deleted, but new files you have not
+	told Git about are not affected.
+
+-p::
+--patch::
+	Use the interactive patch selection interface to chose
+	which changes to commit. See linkgit:git-add[1] for
+	details.
+
+-C <commit>::
+--reuse-message=<commit>::
+	Take an existing commit object, and reuse the log message
+	and the authorship information (including the timestamp)
+	when creating the commit.
+
+-c <commit>::
+--reedit-message=<commit>::
+	Like '-C', but with `-c` the editor is invoked, so that
+	the user can further edit the commit message.
+
+--fixup=<commit>::
+	Construct a commit message for use with `rebase --autosquash`.
+	The commit message will be the subject line from the specified
+	commit with a prefix of "fixup! ".  See linkgit:git-rebase[1]
+	for details.
+
+--squash=<commit>::
+	Construct a commit message for use with `rebase --autosquash`.
+	The commit message subject line is taken from the specified
+	commit with a prefix of "squash! ".  Can be used with additional
+	commit message options (`-m`/`-c`/`-C`/`-F`). See
+	linkgit:git-rebase[1] for details.
+
+--reset-author::
+	When used with -C/-c/--amend options, or when committing after a
+	conflicting cherry-pick, declare that the authorship of the
+	resulting commit now belongs to the committer. This also renews
+	the author timestamp.
+
+--short::
+	When doing a dry-run, give the output in the short-format. See
+	linkgit:git-status[1] for details. Implies `--dry-run`.
+
+--branch::
+	Show the branch and tracking info even in short-format.
+
+--porcelain::
+	When doing a dry-run, give the output in a porcelain-ready
+	format. See linkgit:git-status[1] for details. Implies
+	`--dry-run`.
+
+--long::
+	When doing a dry-run, give the output in the long-format.
+	Implies `--dry-run`.
+
+-z::
+--null::
+	When showing `short` or `porcelain` status output, print the
+	filename verbatim and terminate the entries with NUL, instead of LF.
+	If no format is given, implies the `--porcelain` output format.
+	Without the `-z` option, filenames with "unusual" characters are
+	quoted as explained for the configuration variable `core.quotePath`
+	(see linkgit:git-config[1]).
+
+-F <file>::
+--file=<file>::
+	Take the commit message from the given file.  Use '-' to
+	read the message from the standard input.
+
+--author=<author>::
+	Override the commit author. Specify an explicit author using the
+	standard `A U Thor <author@example.com>` format. Otherwise <author>
+	is assumed to be a pattern and is used to search for an existing
+	commit by that author (i.e. rev-list --all -i --author=<author>);
+	the commit author is then copied from the first such commit found.
+
+--date=<date>::
+	Override the author date used in the commit.
+
+-m <msg>::
+--message=<msg>::
+	Use the given <msg> as the commit message.
+	If multiple `-m` options are given, their values are
+	concatenated as separate paragraphs.
++
+The `-m` option is mutually exclusive with `-c`, `-C`, and `-F`.
+
+-t <file>::
+--template=<file>::
+	When editing the commit message, start the editor with the
+	contents in the given file.  The `commit.template` configuration
+	variable is often used to give this option implicitly to the
+	command.  This mechanism can be used by projects that want to
+	guide participants with some hints on what to write in the message
+	in what order.  If the user exits the editor without editing the
+	message, the commit is aborted.  This has no effect when a message
+	is given by other means, e.g. with the `-m` or `-F` options.
+
+-s::
+--signoff::
+	Add Signed-off-by line by the committer at the end of the commit
+	log message.  The meaning of a signoff depends on the project,
+	but it typically certifies that committer has
+	the rights to submit this work under the same license and
+	agrees to a Developer Certificate of Origin
+	(see http://developercertificate.org/ for more information).
+
+-n::
+--no-verify::
+	This option bypasses the pre-commit and commit-msg hooks.
+	See also linkgit:githooks[5].
+
+--allow-empty::
+	Usually recording a commit that has the exact same tree as its
+	sole parent commit is a mistake, and the command prevents you
+	from making such a commit.  This option bypasses the safety, and
+	is primarily for use by foreign SCM interface scripts.
+
+--allow-empty-message::
+       Like --allow-empty this command is primarily for use by foreign
+       SCM interface scripts. It allows you to create a commit with an
+       empty commit message without using plumbing commands like
+       linkgit:git-commit-tree[1].
+
+--cleanup=<mode>::
+	This option determines how the supplied commit message should be
+	cleaned up before committing.  The '<mode>' can be `strip`,
+	`whitespace`, `verbatim`, `scissors` or `default`.
++
+--
+strip::
+	Strip leading and trailing empty lines, trailing whitespace,
+	commentary and collapse consecutive empty lines.
+whitespace::
+	Same as `strip` except #commentary is not removed.
+verbatim::
+	Do not change the message at all.
+scissors::
+	Same as `whitespace` except that everything from (and including)
+	the line found below is truncated, if the message is to be edited.
+	"`#`" can be customized with core.commentChar.
+
+		# ------------------------ >8 ------------------------
+
+default::
+	Same as `strip` if the message is to be edited.
+	Otherwise `whitespace`.
+--
++
+The default can be changed by the `commit.cleanup` configuration
+variable (see linkgit:git-config[1]).
+
+-e::
+--edit::
+	The message taken from file with `-F`, command line with
+	`-m`, and from commit object with `-C` are usually used as
+	the commit log message unmodified. This option lets you
+	further edit the message taken from these sources.
+
+--no-edit::
+	Use the selected commit message without launching an editor.
+	For example, `git commit --amend --no-edit` amends a commit
+	without changing its commit message.
+
+--amend::
+	Replace the tip of the current branch by creating a new
+	commit. The recorded tree is prepared as usual (including
+	the effect of the `-i` and `-o` options and explicit
+	pathspec), and the message from the original commit is used
+	as the starting point, instead of an empty message, when no
+	other message is specified from the command line via options
+	such as `-m`, `-F`, `-c`, etc.  The new commit has the same
+	parents and author as the current one (the `--reset-author`
+	option can countermand this).
++
+--
+It is a rough equivalent for:
+------
+	$ git reset --soft HEAD^
+	$ ... do something else to come up with the right tree ...
+	$ git commit -c ORIG_HEAD
+
+------
+but can be used to amend a merge commit.
+--
++
+You should understand the implications of rewriting history if you
+amend a commit that has already been published.  (See the "RECOVERING
+FROM UPSTREAM REBASE" section in linkgit:git-rebase[1].)
+
+--no-post-rewrite::
+	Bypass the post-rewrite hook.
+
+-i::
+--include::
+	Before making a commit out of staged contents so far,
+	stage the contents of paths given on the command line
+	as well.  This is usually not what you want unless you
+	are concluding a conflicted merge.
+
+-o::
+--only::
+	Make a commit by taking the updated working tree contents
+	of the paths specified on the
+	command line, disregarding any contents that have been
+	staged for other paths. This is the default mode of operation of
+	'git commit' if any paths are given on the command line,
+	in which case this option can be omitted.
+	If this option is specified together with `--amend`, then
+	no paths need to be specified, which can be used to amend
+	the last commit without committing changes that have
+	already been staged. If used together with `--allow-empty`
+	paths are also not required, and an empty commit will be created.
+
+-u[<mode>]::
+--untracked-files[=<mode>]::
+	Show untracked files.
++
+The mode parameter is optional (defaults to 'all'), and is used to
+specify the handling of untracked files; when -u is not used, the
+default is 'normal', i.e. show untracked files and directories.
++
+The possible options are:
++
+	- 'no'     - Show no untracked files
+	- 'normal' - Shows untracked files and directories
+	- 'all'    - Also shows individual files in untracked directories.
++
+The default can be changed using the status.showUntrackedFiles
+configuration variable documented in linkgit:git-config[1].
+
+-v::
+--verbose::
+	Show unified diff between the HEAD commit and what
+	would be committed at the bottom of the commit message
+	template to help the user describe the commit by reminding
+	what changes the commit has.
+	Note that this diff output doesn't have its
+	lines prefixed with '#'. This diff will not be a part
+	of the commit message. See the `commit.verbose` configuration
+	variable in linkgit:git-config[1].
++
+If specified twice, show in addition the unified diff between
+what would be committed and the worktree files, i.e. the unstaged
+changes to tracked files.
+
+-q::
+--quiet::
+	Suppress commit summary message.
+
+--dry-run::
+	Do not create a commit, but show a list of paths that are
+	to be committed, paths with local changes that will be left
+	uncommitted and paths that are untracked.
+
+--status::
+	Include the output of linkgit:git-status[1] in the commit
+	message template when using an editor to prepare the commit
+	message.  Defaults to on, but can be used to override
+	configuration variable commit.status.
+
+--no-status::
+	Do not include the output of linkgit:git-status[1] in the
+	commit message template when using an editor to prepare the
+	default commit message.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+--no-gpg-sign::
+	Countermand `commit.gpgSign` configuration variable that is
+	set to force each and every commit to be signed.
+
+\--::
+	Do not interpret any more arguments as options.
+
+<file>...::
+	When files are given on the command line, the command
+	commits the contents of the named files, without
+	recording the changes already staged.  The contents of
+	these files are also staged for the next commit on top
+	of what have been staged before.
+
+:git-commit: 1
+include::date-formats.txt[]
+
+EXAMPLES
+--------
+When recording your own work, the contents of modified files in
+your working tree are temporarily stored to a staging area
+called the "index" with 'git add'.  A file can be
+reverted back, only in the index but not in the working tree,
+to that of the last commit with `git restore --staged <file>`,
+which effectively reverts 'git add' and prevents the changes to
+this file from participating in the next commit.  After building
+the state to be committed incrementally with these commands,
+`git commit` (without any pathname parameter) is used to record what
+has been staged so far.  This is the most basic form of the
+command.  An example:
+
+------------
+$ edit hello.c
+$ git rm goodbye.c
+$ git add hello.c
+$ git commit
+------------
+
+Instead of staging files after each individual change, you can
+tell `git commit` to notice the changes to the files whose
+contents are tracked in
+your working tree and do corresponding `git add` and `git rm`
+for you.  That is, this example does the same as the earlier
+example if there is no other change in your working tree:
+
+------------
+$ edit hello.c
+$ rm goodbye.c
+$ git commit -a
+------------
+
+The command `git commit -a` first looks at your working tree,
+notices that you have modified hello.c and removed goodbye.c,
+and performs necessary `git add` and `git rm` for you.
+
+After staging changes to many files, you can alter the order the
+changes are recorded in, by giving pathnames to `git commit`.
+When pathnames are given, the command makes a commit that
+only records the changes made to the named paths:
+
+------------
+$ edit hello.c hello.h
+$ git add hello.c hello.h
+$ edit Makefile
+$ git commit Makefile
+------------
+
+This makes a commit that records the modification to `Makefile`.
+The changes staged for `hello.c` and `hello.h` are not included
+in the resulting commit.  However, their changes are not lost --
+they are still staged and merely held back.  After the above
+sequence, if you do:
+
+------------
+$ git commit
+------------
+
+this second commit would record the changes to `hello.c` and
+`hello.h` as expected.
+
+After a merge (initiated by 'git merge' or 'git pull') stops
+because of conflicts, cleanly merged
+paths are already staged to be committed for you, and paths that
+conflicted are left in unmerged state.  You would have to first
+check which paths are conflicting with 'git status'
+and after fixing them manually in your working tree, you would
+stage the result as usual with 'git add':
+
+------------
+$ git status | grep unmerged
+unmerged: hello.c
+$ edit hello.c
+$ git add hello.c
+------------
+
+After resolving conflicts and staging the result, `git ls-files -u`
+would stop mentioning the conflicted path.  When you are done,
+run `git commit` to finally record the merge:
+
+------------
+$ git commit
+------------
+
+As with the case to record your own changes, you can use `-a`
+option to save typing.  One difference is that during a merge
+resolution, you cannot use `git commit` with pathnames to
+alter the order the changes are committed, because the merge
+should be recorded as a single commit.  In fact, the command
+refuses to run when given pathnames (but see `-i` option).
+
+
+DISCUSSION
+----------
+
+Though not required, it's a good idea to begin the commit message
+with a single short (less than 50 character) line summarizing the
+change, followed by a blank line and then a more thorough description.
+The text up to the first blank line in a commit message is treated
+as the commit title, and that title is used throughout Git.
+For example, linkgit:git-format-patch[1] turns a commit into email, and it uses
+the title on the Subject line and the rest of the commit in the body.
+
+include::i18n.txt[]
+
+ENVIRONMENT AND CONFIGURATION VARIABLES
+---------------------------------------
+The editor used to edit the commit log message will be chosen from the
+`GIT_EDITOR` environment variable, the core.editor configuration variable, the
+`VISUAL` environment variable, or the `EDITOR` environment variable (in that
+order).  See linkgit:git-var[1] for details.
+
+HOOKS
+-----
+This command can run `commit-msg`, `prepare-commit-msg`, `pre-commit`,
+`post-commit` and `post-rewrite` hooks.  See linkgit:githooks[5] for more
+information.
+
+FILES
+-----
+
+`$GIT_DIR/COMMIT_EDITMSG`::
+	This file contains the commit message of a commit in progress.
+	If `git commit` exits due to an error before creating a commit,
+	any commit message that has been provided by the user (e.g., in
+	an editor session) will be available in this file, but will be
+	overwritten by the next invocation of `git commit`.
+
+SEE ALSO
+--------
+linkgit:git-add[1],
+linkgit:git-rm[1],
+linkgit:git-mv[1],
+linkgit:git-merge[1],
+linkgit:git-commit-tree[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-config.txt b/third_party/git/Documentation/git-config.txt
new file mode 100644
index 0000000000..ff9310f958
--- /dev/null
+++ b/third_party/git/Documentation/git-config.txt
@@ -0,0 +1,493 @@
+git-config(1)
+=============
+
+NAME
+----
+git-config - Get and set repository or global options
+
+
+SYNOPSIS
+--------
+[verse]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] name [value [value_regex]]
+'git config' [<file-option>] [--type=<type>] --add name value
+'git config' [<file-option>] [--type=<type>] --replace-all name value [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] --get-all name [value_regex]
+'git config' [<file-option>] [--type=<type>] [--show-origin] [-z|--null] [--name-only] --get-regexp name_regex [value_regex]
+'git config' [<file-option>] [--type=<type>] [-z|--null] --get-urlmatch name URL
+'git config' [<file-option>] --unset name [value_regex]
+'git config' [<file-option>] --unset-all name [value_regex]
+'git config' [<file-option>] --rename-section old_name new_name
+'git config' [<file-option>] --remove-section name
+'git config' [<file-option>] [--show-origin] [-z|--null] [--name-only] -l | --list
+'git config' [<file-option>] --get-color name [default]
+'git config' [<file-option>] --get-colorbool name [stdout-is-tty]
+'git config' [<file-option>] -e | --edit
+
+DESCRIPTION
+-----------
+You can query/set/replace/unset options with this command. The name is
+actually the section and the key separated by a dot, and the value will be
+escaped.
+
+Multiple lines can be added to an option by using the `--add` option.
+If you want to update or unset an option which can occur on multiple
+lines, a POSIX regexp `value_regex` needs to be given.  Only the
+existing values that match the regexp are updated or unset.  If
+you want to handle the lines that do *not* match the regex, just
+prepend a single exclamation mark in front (see also <<EXAMPLES>>).
+
+The `--type=<type>` option instructs 'git config' to ensure that incoming and
+outgoing values are canonicalize-able under the given <type>.  If no
+`--type=<type>` is given, no canonicalization will be performed. Callers may
+unset an existing `--type` specifier with `--no-type`.
+
+When reading, the values are read from the system, global and
+repository local configuration files by default, and options
+`--system`, `--global`, `--local`, `--worktree` and
+`--file <filename>` can be used to tell the command to read from only
+that location (see <<FILES>>).
+
+When writing, the new value is written to the repository local
+configuration file by default, and options `--system`, `--global`,
+`--worktree`, `--file <filename>` can be used to tell the command to
+write to that location (you can say `--local` but that is the
+default).
+
+This command will fail with non-zero status upon error.  Some exit
+codes are:
+
+- The section or key is invalid (ret=1),
+- no section or name was provided (ret=2),
+- the config file is invalid (ret=3),
+- the config file cannot be written (ret=4),
+- you try to unset an option which does not exist (ret=5),
+- you try to unset/set an option for which multiple lines match (ret=5), or
+- you try to use an invalid regexp (ret=6).
+
+On success, the command returns the exit code 0.
+
+OPTIONS
+-------
+
+--replace-all::
+	Default behavior is to replace at most one line. This replaces
+	all lines matching the key (and optionally the value_regex).
+
+--add::
+	Adds a new line to the option without altering any existing
+	values.  This is the same as providing '^$' as the value_regex
+	in `--replace-all`.
+
+--get::
+	Get the value for a given key (optionally filtered by a regex
+	matching the value). Returns error code 1 if the key was not
+	found and the last value if multiple key values were found.
+
+--get-all::
+	Like get, but returns all values for a multi-valued key.
+
+--get-regexp::
+	Like --get-all, but interprets the name as a regular expression and
+	writes out the key names.  Regular expression matching is currently
+	case-sensitive and done against a canonicalized version of the key
+	in which section and variable names are lowercased, but subsection
+	names are not.
+
+--get-urlmatch name URL::
+	When given a two-part name section.key, the value for
+	section.<url>.key whose <url> part matches the best to the
+	given URL is returned (if no such key exists, the value for
+	section.key is used as a fallback).  When given just the
+	section as name, do so for all the keys in the section and
+	list them.  Returns error code 1 if no value is found.
+
+--global::
+	For writing options: write to global `~/.gitconfig` file
+	rather than the repository `.git/config`, write to
+	`$XDG_CONFIG_HOME/git/config` file if this file exists and the
+	`~/.gitconfig` file doesn't.
++
+For reading options: read only from global `~/.gitconfig` and from
+`$XDG_CONFIG_HOME/git/config` rather than from all available files.
++
+See also <<FILES>>.
+
+--system::
+	For writing options: write to system-wide
+	`$(prefix)/etc/gitconfig` rather than the repository
+	`.git/config`.
++
+For reading options: read only from system-wide `$(prefix)/etc/gitconfig`
+rather than from all available files.
++
+See also <<FILES>>.
+
+--local::
+	For writing options: write to the repository `.git/config` file.
+	This is the default behavior.
++
+For reading options: read only from the repository `.git/config` rather than
+from all available files.
++
+See also <<FILES>>.
+
+--worktree::
+	Similar to `--local` except that `.git/config.worktree` is
+	read from or written to if `extensions.worktreeConfig` is
+	present. If not it's the same as `--local`.
+
+-f config-file::
+--file config-file::
+	Use the given config file instead of the one specified by GIT_CONFIG.
+
+--blob blob::
+	Similar to `--file` but use the given blob instead of a file. E.g.
+	you can use 'master:.gitmodules' to read values from the file
+	'.gitmodules' in the master branch. See "SPECIFYING REVISIONS"
+	section in linkgit:gitrevisions[7] for a more complete list of
+	ways to spell blob names.
+
+--remove-section::
+	Remove the given section from the configuration file.
+
+--rename-section::
+	Rename the given section to a new name.
+
+--unset::
+	Remove the line matching the key from config file.
+
+--unset-all::
+	Remove all lines matching the key from config file.
+
+-l::
+--list::
+	List all variables set in config file, along with their values.
+
+--type <type>::
+  'git config' will ensure that any input or output is valid under the given
+  type constraint(s), and will canonicalize outgoing values in `<type>`'s
+  canonical form.
++
+Valid `<type>`'s include:
++
+- 'bool': canonicalize values as either "true" or "false".
+- 'int': canonicalize values as simple decimal numbers. An optional suffix of
+  'k', 'm', or 'g' will cause the value to be multiplied by 1024, 1048576, or
+  1073741824 upon input.
+- 'bool-or-int': canonicalize according to either 'bool' or 'int', as described
+  above.
+- 'path': canonicalize by adding a leading `~` to the value of `$HOME` and
+  `~user` to the home directory for the specified user. This specifier has no
+  effect when setting the value (but you can use `git config section.variable
+  ~/` from the command line to let your shell do the expansion.)
+- 'expiry-date': canonicalize by converting from a fixed or relative date-string
+  to a timestamp. This specifier has no effect when setting the value.
+- 'color': When getting a value, canonicalize by converting to an ANSI color
+  escape sequence. When setting a value, a sanity-check is performed to ensure
+  that the given value is canonicalize-able as an ANSI color, but it is written
+  as-is.
++
+
+--bool::
+--int::
+--bool-or-int::
+--path::
+--expiry-date::
+  Historical options for selecting a type specifier. Prefer instead `--type`
+  (see above).
+
+--no-type::
+  Un-sets the previously set type specifier (if one was previously set). This
+  option requests that 'git config' not canonicalize the retrieved variable.
+  `--no-type` has no effect without `--type=<type>` or `--<type>`.
+
+-z::
+--null::
+	For all options that output values and/or keys, always
+	end values with the null character (instead of a
+	newline). Use newline instead as a delimiter between
+	key and value. This allows for secure parsing of the
+	output without getting confused e.g. by values that
+	contain line breaks.
+
+--name-only::
+	Output only the names of config variables for `--list` or
+	`--get-regexp`.
+
+--show-origin::
+	Augment the output of all queried config options with the
+	origin type (file, standard input, blob, command line) and
+	the actual origin (config file path, ref, or blob id if
+	applicable).
+
+--get-colorbool name [stdout-is-tty]::
+
+	Find the color setting for `name` (e.g. `color.diff`) and output
+	"true" or "false".  `stdout-is-tty` should be either "true" or
+	"false", and is taken into account when configuration says
+	"auto".  If `stdout-is-tty` is missing, then checks the standard
+	output of the command itself, and exits with status 0 if color
+	is to be used, or exits with status 1 otherwise.
+	When the color setting for `name` is undefined, the command uses
+	`color.ui` as fallback.
+
+--get-color name [default]::
+
+	Find the color configured for `name` (e.g. `color.diff.new`) and
+	output it as the ANSI color escape sequence to the standard
+	output.  The optional `default` parameter is used instead, if
+	there is no color configured for `name`.
++
+`--type=color [--default=<default>]` is preferred over `--get-color`
+(but note that `--get-color` will omit the trailing newline printed by
+`--type=color`).
+
+-e::
+--edit::
+	Opens an editor to modify the specified config file; either
+	`--system`, `--global`, or repository (default).
+
+--[no-]includes::
+	Respect `include.*` directives in config files when looking up
+	values. Defaults to `off` when a specific file is given (e.g.,
+	using `--file`, `--global`, etc) and `on` when searching all
+	config files.
+
+--default <value>::
+  When using `--get`, and the requested variable is not found, behave as if
+  <value> were the value assigned to the that variable.
+
+CONFIGURATION
+-------------
+`pager.config` is only respected when listing configuration, i.e., when
+using `--list` or any of the `--get-*` which may return multiple results.
+The default is to use a pager.
+
+[[FILES]]
+FILES
+-----
+
+If not set explicitly with `--file`, there are four files where
+'git config' will search for configuration options:
+
+$(prefix)/etc/gitconfig::
+	System-wide configuration file.
+
+$XDG_CONFIG_HOME/git/config::
+	Second user-specific configuration file. If $XDG_CONFIG_HOME is not set
+	or empty, `$HOME/.config/git/config` will be used. Any single-valued
+	variable set in this file will be overwritten by whatever is in
+	`~/.gitconfig`.  It is a good idea not to create this file if
+	you sometimes use older versions of Git, as support for this
+	file was added fairly recently.
+
+~/.gitconfig::
+	User-specific configuration file. Also called "global"
+	configuration file.
+
+$GIT_DIR/config::
+	Repository specific configuration file.
+
+$GIT_DIR/config.worktree::
+	This is optional and is only searched when
+	`extensions.worktreeConfig` is present in $GIT_DIR/config.
+
+If no further options are given, all reading options will read all of these
+files that are available. If the global or the system-wide configuration
+file are not available they will be ignored. If the repository configuration
+file is not available or readable, 'git config' will exit with a non-zero
+error code. However, in neither case will an error message be issued.
+
+The files are read in the order given above, with last value found taking
+precedence over values read earlier.  When multiple values are taken then all
+values of a key from all files will be used.
+
+You may override individual configuration parameters when running any git
+command by using the `-c` option. See linkgit:git[1] for details.
+
+All writing options will per default write to the repository specific
+configuration file. Note that this also affects options like `--replace-all`
+and `--unset`. *'git config' will only ever change one file at a time*.
+
+You can override these rules either by command-line options or by environment
+variables. The `--global`, `--system` and `--worktree` options will limit
+the file used to the global, system-wide or per-worktree file respectively.
+The `GIT_CONFIG` environment variable has a similar effect, but you
+can specify any filename you want.
+
+
+ENVIRONMENT
+-----------
+
+GIT_CONFIG::
+	Take the configuration from the given file instead of .git/config.
+	Using the "--global" option forces this to ~/.gitconfig. Using the
+	"--system" option forces this to $(prefix)/etc/gitconfig.
+
+GIT_CONFIG_NOSYSTEM::
+	Whether to skip reading settings from the system-wide
+	$(prefix)/etc/gitconfig file. See linkgit:git[1] for details.
+
+See also <<FILES>>.
+
+
+[[EXAMPLES]]
+EXAMPLES
+--------
+
+Given a .git/config like this:
+
+	#
+	# This is the config file, and
+	# a '#' or ';' character indicates
+	# a comment
+	#
+
+	; core variables
+	[core]
+		; Don't trust file modes
+		filemode = false
+
+	; Our diff algorithm
+	[diff]
+		external = /usr/local/bin/diff-wrapper
+		renames = true
+
+	; Proxy settings
+	[core]
+		gitproxy=proxy-command for kernel.org
+		gitproxy=default-proxy ; for all the rest
+
+	; HTTP
+	[http]
+		sslVerify
+	[http "https://weak.example.com"]
+		sslVerify = false
+		cookieFile = /tmp/cookie.txt
+
+you can set the filemode to true with
+
+------------
+% git config core.filemode true
+------------
+
+The hypothetical proxy command entries actually have a postfix to discern
+what URL they apply to. Here is how to change the entry for kernel.org
+to "ssh".
+
+------------
+% git config core.gitproxy '"ssh" for kernel.org' 'for kernel.org$'
+------------
+
+This makes sure that only the key/value pair for kernel.org is replaced.
+
+To delete the entry for renames, do
+
+------------
+% git config --unset diff.renames
+------------
+
+If you want to delete an entry for a multivar (like core.gitproxy above),
+you have to provide a regex matching the value of exactly one line.
+
+To query the value for a given key, do
+
+------------
+% git config --get core.filemode
+------------
+
+or
+
+------------
+% git config core.filemode
+------------
+
+or, to query a multivar:
+
+------------
+% git config --get core.gitproxy "for kernel.org$"
+------------
+
+If you want to know all the values for a multivar, do:
+
+------------
+% git config --get-all core.gitproxy
+------------
+
+If you like to live dangerously, you can replace *all* core.gitproxy by a
+new one with
+
+------------
+% git config --replace-all core.gitproxy ssh
+------------
+
+However, if you really only want to replace the line for the default proxy,
+i.e. the one without a "for ..." postfix, do something like this:
+
+------------
+% git config core.gitproxy ssh '! for '
+------------
+
+To actually match only values with an exclamation mark, you have to
+
+------------
+% git config section.key value '[!]'
+------------
+
+To add a new proxy, without altering any of the existing ones, use
+
+------------
+% git config --add core.gitproxy '"proxy-command" for example.com'
+------------
+
+An example to use customized color from the configuration in your
+script:
+
+------------
+#!/bin/sh
+WS=$(git config --get-color color.diff.whitespace "blue reverse")
+RESET=$(git config --get-color "" "reset")
+echo "${WS}your whitespace color or blue reverse${RESET}"
+------------
+
+For URLs in `https://weak.example.com`, `http.sslVerify` is set to
+false, while it is set to `true` for all others:
+
+------------
+% git config --type=bool --get-urlmatch http.sslverify https://good.example.com
+true
+% git config --type=bool --get-urlmatch http.sslverify https://weak.example.com
+false
+% git config --get-urlmatch http https://weak.example.com
+http.cookieFile /tmp/cookie.txt
+http.sslverify false
+------------
+
+include::config.txt[]
+
+BUGS
+----
+When using the deprecated `[section.subsection]` syntax, changing a value
+will result in adding a multi-line key instead of a change, if the subsection
+is given with at least one uppercase character. For example when the config
+looks like
+
+--------
+  [section.subsection]
+    key = value1
+--------
+
+and running `git config section.Subsection.key value2` will result in
+
+--------
+  [section.subsection]
+    key = value1
+    key = value2
+--------
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-count-objects.txt b/third_party/git/Documentation/git-count-objects.txt
new file mode 100644
index 0000000000..cb9b4d2e46
--- /dev/null
+++ b/third_party/git/Documentation/git-count-objects.txt
@@ -0,0 +1,54 @@
+git-count-objects(1)
+====================
+
+NAME
+----
+git-count-objects - Count unpacked number of objects and their disk consumption
+
+SYNOPSIS
+--------
+[verse]
+'git count-objects' [-v] [-H | --human-readable]
+
+DESCRIPTION
+-----------
+This counts the number of unpacked object files and disk space consumed by
+them, to help you decide when it is a good time to repack.
+
+
+OPTIONS
+-------
+-v::
+--verbose::
+	Report in more detail:
++
+count: the number of loose objects
++
+size: disk space consumed by loose objects, in KiB (unless -H is specified)
++
+in-pack: the number of in-pack objects
++
+size-pack: disk space consumed by the packs, in KiB (unless -H is specified)
++
+prune-packable: the number of loose objects that are also present in
+the packs. These objects could be pruned using `git prune-packed`.
++
+garbage: the number of files in object database that are neither valid loose
+objects nor valid packs
++
+size-garbage: disk space consumed by garbage files, in KiB (unless -H is
+specified)
++
+alternate: absolute path of alternate object databases; may appear
+multiple times, one line per path. Note that if the path contains
+non-printable characters, it may be surrounded by double-quotes and
+contain C-style backslashed escape sequences.
+
+-H::
+--human-readable::
+
+Print sizes in human readable format
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-credential-cache--daemon.txt b/third_party/git/Documentation/git-credential-cache--daemon.txt
new file mode 100644
index 0000000000..7051c6bdf8
--- /dev/null
+++ b/third_party/git/Documentation/git-credential-cache--daemon.txt
@@ -0,0 +1,30 @@
+git-credential-cache--daemon(1)
+===============================
+
+NAME
+----
+git-credential-cache--daemon - Temporarily store user credentials in memory
+
+SYNOPSIS
+--------
+[verse]
+git credential-cache--daemon [--debug] <socket>
+
+DESCRIPTION
+-----------
+
+NOTE: You probably don't want to invoke this command yourself; it is
+started automatically when you use linkgit:git-credential-cache[1].
+
+This command listens on the Unix domain socket specified by `<socket>`
+for `git-credential-cache` clients. Clients may store and retrieve
+credentials. Each credential is held for a timeout specified by the
+client; once no credentials are held, the daemon exits.
+
+If the `--debug` option is specified, the daemon does not close its
+stderr stream, and may output extra diagnostics to it even after it has
+begun listening for clients.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-credential-cache.txt b/third_party/git/Documentation/git-credential-cache.txt
new file mode 100644
index 0000000000..0216c18ef8
--- /dev/null
+++ b/third_party/git/Documentation/git-credential-cache.txt
@@ -0,0 +1,80 @@
+git-credential-cache(1)
+=======================
+
+NAME
+----
+git-credential-cache - Helper to temporarily store passwords in memory
+
+SYNOPSIS
+--------
+-----------------------------
+git config credential.helper 'cache [<options>]'
+-----------------------------
+
+DESCRIPTION
+-----------
+
+This command caches credentials in memory for use by future Git
+programs. The stored credentials never touch the disk, and are forgotten
+after a configurable timeout.  The cache is accessible over a Unix
+domain socket, restricted to the current user by filesystem permissions.
+
+You probably don't want to invoke this command directly; it is meant to
+be used as a credential helper by other parts of Git. See
+linkgit:gitcredentials[7] or `EXAMPLES` below.
+
+OPTIONS
+-------
+
+--timeout <seconds>::
+
+	Number of seconds to cache credentials (default: 900).
+
+--socket <path>::
+
+	Use `<path>` to contact a running cache daemon (or start a new
+	cache daemon if one is not started).
+	Defaults to `$XDG_CACHE_HOME/git/credential/socket` unless
+	`~/.git-credential-cache/` exists in which case
+	`~/.git-credential-cache/socket` is used instead.
+	If your home directory is on a network-mounted filesystem, you
+	may need to change this to a local filesystem. You must specify
+	an absolute path.
+
+CONTROLLING THE DAEMON
+----------------------
+
+If you would like the daemon to exit early, forgetting all cached
+credentials before their timeout, you can issue an `exit` action:
+
+--------------------------------------
+git credential-cache exit
+--------------------------------------
+
+EXAMPLES
+--------
+
+The point of this helper is to reduce the number of times you must type
+your username or password. For example:
+
+------------------------------------
+$ git config credential.helper cache
+$ git push http://example.com/repo.git
+Username: <type your username>
+Password: <type your password>
+
+[work for 5 more minutes]
+$ git push http://example.com/repo.git
+[your credentials are used automatically]
+------------------------------------
+
+You can provide options via the credential.helper configuration
+variable (this example drops the cache time to 5 minutes):
+
+-------------------------------------------------------
+$ git config credential.helper 'cache --timeout=300'
+-------------------------------------------------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-credential-store.txt b/third_party/git/Documentation/git-credential-store.txt
new file mode 100644
index 0000000000..693dd9d9d7
--- /dev/null
+++ b/third_party/git/Documentation/git-credential-store.txt
@@ -0,0 +1,106 @@
+git-credential-store(1)
+=======================
+
+NAME
+----
+git-credential-store - Helper to store credentials on disk
+
+SYNOPSIS
+--------
+-------------------
+git config credential.helper 'store [<options>]'
+-------------------
+
+DESCRIPTION
+-----------
+
+NOTE: Using this helper will store your passwords unencrypted on disk,
+protected only by filesystem permissions. If this is not an acceptable
+security tradeoff, try linkgit:git-credential-cache[1], or find a helper
+that integrates with secure storage provided by your operating system.
+
+This command stores credentials indefinitely on disk for use by future
+Git programs.
+
+You probably don't want to invoke this command directly; it is meant to
+be used as a credential helper by other parts of git. See
+linkgit:gitcredentials[7] or `EXAMPLES` below.
+
+OPTIONS
+-------
+
+--file=<path>::
+
+	Use `<path>` to lookup and store credentials. The file will have its
+	filesystem permissions set to prevent other users on the system
+	from reading it, but will not be encrypted or otherwise
+	protected. If not specified, credentials will be searched for from
+	`~/.git-credentials` and `$XDG_CONFIG_HOME/git/credentials`, and
+	credentials will be written to `~/.git-credentials` if it exists, or
+	`$XDG_CONFIG_HOME/git/credentials` if it exists and the former does
+	not. See also <<FILES>>.
+
+[[FILES]]
+FILES
+-----
+
+If not set explicitly with `--file`, there are two files where
+git-credential-store will search for credentials in order of precedence:
+
+~/.git-credentials::
+	User-specific credentials file.
+
+$XDG_CONFIG_HOME/git/credentials::
+	Second user-specific credentials file. If '$XDG_CONFIG_HOME' is not set
+	or empty, `$HOME/.config/git/credentials` will be used. Any credentials
+	stored in this file will not be used if `~/.git-credentials` has a
+	matching credential as well. It is a good idea not to create this file
+	if you sometimes use older versions of Git that do not support it.
+
+For credential lookups, the files are read in the order given above, with the
+first matching credential found taking precedence over credentials found in
+files further down the list.
+
+Credential storage will by default write to the first existing file in the
+list. If none of these files exist, `~/.git-credentials` will be created and
+written to.
+
+When erasing credentials, matching credentials will be erased from all files.
+
+EXAMPLES
+--------
+
+The point of this helper is to reduce the number of times you must type
+your username or password. For example:
+
+------------------------------------------
+$ git config credential.helper store
+$ git push http://example.com/repo.git
+Username: <type your username>
+Password: <type your password>
+
+[several days later]
+$ git push http://example.com/repo.git
+[your credentials are used automatically]
+------------------------------------------
+
+STORAGE FORMAT
+--------------
+
+The `.git-credentials` file is stored in plaintext. Each credential is
+stored on its own line as a URL like:
+
+------------------------------
+https://user:pass@example.com
+------------------------------
+
+When Git needs authentication for a particular URL context,
+credential-store will consider that context a pattern to match against
+each entry in the credentials file.  If the protocol, hostname, and
+username (if we already have one) match, then the password is returned
+to Git. See the discussion of configuration in linkgit:gitcredentials[7]
+for more information.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-credential.txt b/third_party/git/Documentation/git-credential.txt
new file mode 100644
index 0000000000..b211440373
--- /dev/null
+++ b/third_party/git/Documentation/git-credential.txt
@@ -0,0 +1,154 @@
+git-credential(1)
+=================
+
+NAME
+----
+git-credential - Retrieve and store user credentials
+
+SYNOPSIS
+--------
+------------------
+git credential <fill|approve|reject>
+------------------
+
+DESCRIPTION
+-----------
+
+Git has an internal interface for storing and retrieving credentials
+from system-specific helpers, as well as prompting the user for
+usernames and passwords. The git-credential command exposes this
+interface to scripts which may want to retrieve, store, or prompt for
+credentials in the same manner as Git. The design of this scriptable
+interface models the internal C API; see
+link:technical/api-credentials.html[the Git credential API] for more
+background on the concepts.
+
+git-credential takes an "action" option on the command-line (one of
+`fill`, `approve`, or `reject`) and reads a credential description
+on stdin (see <<IOFMT,INPUT/OUTPUT FORMAT>>).
+
+If the action is `fill`, git-credential will attempt to add "username"
+and "password" attributes to the description by reading config files,
+by contacting any configured credential helpers, or by prompting the
+user. The username and password attributes of the credential
+description are then printed to stdout together with the attributes
+already provided.
+
+If the action is `approve`, git-credential will send the description
+to any configured credential helpers, which may store the credential
+for later use.
+
+If the action is `reject`, git-credential will send the description to
+any configured credential helpers, which may erase any stored
+credential matching the description.
+
+If the action is `approve` or `reject`, no output should be emitted.
+
+TYPICAL USE OF GIT CREDENTIAL
+-----------------------------
+
+An application using git-credential will typically use `git
+credential` following these steps:
+
+  1. Generate a credential description based on the context.
++
+For example, if we want a password for
+`https://example.com/foo.git`, we might generate the following
+credential description (don't forget the blank line at the end; it
+tells `git credential` that the application finished feeding all the
+information it has):
+
+	 protocol=https
+	 host=example.com
+	 path=foo.git
+
+  2. Ask git-credential to give us a username and password for this
+     description. This is done by running `git credential fill`,
+     feeding the description from step (1) to its standard input. The complete
+     credential description (including the credential per se, i.e. the
+     login and password) will be produced on standard output, like:
+
+	protocol=https
+	host=example.com
+	username=bob
+	password=secr3t
++
+In most cases, this means the attributes given in the input will be
+repeated in the output, but Git may also modify the credential
+description, for example by removing the `path` attribute when the
+protocol is HTTP(s) and `credential.useHttpPath` is false.
++
+If the `git credential` knew about the password, this step may
+not have involved the user actually typing this password (the
+user may have typed a password to unlock the keychain instead,
+or no user interaction was done if the keychain was already
+unlocked) before it returned `password=secr3t`.
+
+  3. Use the credential (e.g., access the URL with the username and
+     password from step (2)), and see if it's accepted.
+
+  4. Report on the success or failure of the password. If the
+     credential allowed the operation to complete successfully, then
+     it can be marked with an "approve" action to tell `git
+     credential` to reuse it in its next invocation. If the credential
+     was rejected during the operation, use the "reject" action so
+     that `git credential` will ask for a new password in its next
+     invocation. In either case, `git credential` should be fed with
+     the credential description obtained from step (2) (which also
+     contain the ones provided in step (1)).
+
+[[IOFMT]]
+INPUT/OUTPUT FORMAT
+-------------------
+
+`git credential` reads and/or writes (depending on the action used)
+credential information in its standard input/output. This information
+can correspond either to keys for which `git credential` will obtain
+the login/password information (e.g. host, protocol, path), or to the
+actual credential data to be obtained (login/password).
+
+The credential is split into a set of named attributes, with one
+attribute per line. Each attribute is
+specified by a key-value pair, separated by an `=` (equals) sign,
+followed by a newline. The key may contain any bytes except `=`,
+newline, or NUL. The value may contain any bytes except newline or NUL.
+In both cases, all bytes are treated as-is (i.e., there is no quoting,
+and one cannot transmit a value with newline or NUL in it). The list of
+attributes is terminated by a blank line or end-of-file.
+Git understands the following attributes:
+
+`protocol`::
+
+	The protocol over which the credential will be used (e.g.,
+	`https`).
+
+`host`::
+
+	The remote hostname for a network credential.
+
+`path`::
+
+	The path with which the credential will be used. E.g., for
+	accessing a remote https repository, this will be the
+	repository's path on the server.
+
+`username`::
+
+	The credential's username, if we already have one (e.g., from a
+	URL, from the user, or from a previously run helper).
+
+`password`::
+
+	The credential's password, if we are asking it to be stored.
+
+`url`::
+
+	When this special attribute is read by `git credential`, the
+	value is parsed as a URL and treated as if its constituent parts
+	were read (e.g., `url=https://example.com` would behave as if
+	`protocol=https` and `host=example.com` had been provided). This
+	can help callers avoid parsing URLs themselves.  Note that any
+	components which are missing from the URL (e.g., there is no
+	username in the example above) will be set to empty; if you want
+	to provide a URL and override some attributes, provide the URL
+	attribute first, followed by any overrides.
diff --git a/third_party/git/Documentation/git-cvsexportcommit.txt b/third_party/git/Documentation/git-cvsexportcommit.txt
new file mode 100644
index 0000000000..00154b6c85
--- /dev/null
+++ b/third_party/git/Documentation/git-cvsexportcommit.txt
@@ -0,0 +1,118 @@
+git-cvsexportcommit(1)
+======================
+
+NAME
+----
+git-cvsexportcommit - Export a single commit to a CVS checkout
+
+
+SYNOPSIS
+--------
+[verse]
+'git cvsexportcommit' [-h] [-u] [-v] [-c] [-P] [-p] [-a] [-d cvsroot]
+	[-w cvsworkdir] [-W] [-f] [-m msgprefix] [PARENTCOMMIT] COMMITID
+
+
+DESCRIPTION
+-----------
+Exports a commit from Git to a CVS checkout, making it easier
+to merge patches from a Git repository into a CVS repository.
+
+Specify the name of a CVS checkout using the -w switch or execute it
+from the root of the CVS working copy. In the latter case GIT_DIR must
+be defined. See examples below.
+
+It does its best to do the safe thing, it will check that the files are
+unchanged and up to date in the CVS checkout, and it will not autocommit
+by default.
+
+Supports file additions, removals, and commits that affect binary files.
+
+If the commit is a merge commit, you must tell 'git cvsexportcommit' what
+parent the changeset should be done against.
+
+OPTIONS
+-------
+
+-c::
+	Commit automatically if the patch applied cleanly. It will not
+	commit if any hunks fail to apply or there were other problems.
+
+-p::
+	Be pedantic (paranoid) when applying patches. Invokes patch with
+	--fuzz=0
+
+-a::
+	Add authorship information. Adds Author line, and Committer (if
+	different from Author) to the message.
+
+-d::
+	Set an alternative CVSROOT to use.  This corresponds to the CVS
+	-d parameter.  Usually users will not want to set this, except
+	if using CVS in an asymmetric fashion.
+
+-f::
+	Force the merge even if the files are not up to date.
+
+-P::
+	Force the parent commit, even if it is not a direct parent.
+
+-m::
+	Prepend the commit message with the provided prefix.
+	Useful for patch series and the like.
+
+-u::
+	Update affected files from CVS repository before attempting export.
+
+-k::
+	Reverse CVS keyword expansion (e.g. $Revision: 1.2.3.4$
+	becomes $Revision$) in working CVS checkout before applying patch.
+
+-w::
+	Specify the location of the CVS checkout to use for the export. This
+	option does not require GIT_DIR to be set before execution if the
+	current directory is within a Git repository.  The default is the
+	value of 'cvsexportcommit.cvsdir'.
+
+-W::
+	Tell cvsexportcommit that the current working directory is not only
+	a Git checkout, but also the CVS checkout.  Therefore, Git will
+	reset the working directory to the parent commit before proceeding.
+
+-v::
+	Verbose.
+
+CONFIGURATION
+-------------
+cvsexportcommit.cvsdir::
+	The default location of the CVS checkout to use for the export.
+
+EXAMPLES
+--------
+
+Merge one patch into CVS::
++
+------------
+$ export GIT_DIR=~/project/.git
+$ cd ~/project_cvs_checkout
+$ git cvsexportcommit -v <commit-sha1>
+$ cvs commit -F .msg <files>
+------------
+
+Merge one patch into CVS (-c and -w options). The working directory is within the Git Repo::
++
+------------
+	$ git cvsexportcommit -v -c -w ~/project_cvs_checkout <commit-sha1>
+------------
+
+Merge pending patches into CVS automatically -- only if you really know what you are doing::
++
+------------
+$ export GIT_DIR=~/project/.git
+$ cd ~/project_cvs_checkout
+$ git cherry cvshead myhead | sed -n 's/^+ //p' | xargs -l1 git cvsexportcommit -c -p -v
+------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-cvsimport.txt b/third_party/git/Documentation/git-cvsimport.txt
new file mode 100644
index 0000000000..de1ebed67d
--- /dev/null
+++ b/third_party/git/Documentation/git-cvsimport.txt
@@ -0,0 +1,228 @@
+git-cvsimport(1)
+================
+
+NAME
+----
+git-cvsimport - Salvage your data out of another SCM people love to hate
+
+
+SYNOPSIS
+--------
+[verse]
+'git cvsimport' [-o <branch-for-HEAD>] [-h] [-v] [-d <CVSROOT>]
+	      [-A <author-conv-file>] [-p <options-for-cvsps>] [-P <file>]
+	      [-C <git_repository>] [-z <fuzz>] [-i] [-k] [-u] [-s <subst>]
+	      [-a] [-m] [-M <regex>] [-S <regex>] [-L <commitlimit>]
+	      [-r <remote>] [-R] [<CVS_module>]
+
+
+DESCRIPTION
+-----------
+*WARNING:* `git cvsimport` uses cvsps version 2, which is considered
+deprecated; it does not work with cvsps version 3 and later.  If you are
+performing a one-shot import of a CVS repository consider using
+http://cvs2svn.tigris.org/cvs2git.html[cvs2git] or
+http://www.catb.org/esr/cvs-fast-export/[cvs-fast-export].
+
+Imports a CVS repository into Git. It will either create a new
+repository, or incrementally import into an existing one.
+
+Splitting the CVS log into patch sets is done by 'cvsps'.
+At least version 2.1 is required.
+
+*WARNING:* for certain situations the import leads to incorrect results.
+Please see the section <<issues,ISSUES>> for further reference.
+
+You should *never* do any work of your own on the branches that are
+created by 'git cvsimport'.  By default initial import will create and populate a
+"master" branch from the CVS repository's main branch which you're free
+to work with; after that, you need to 'git merge' incremental imports, or
+any CVS branches, yourself.  It is advisable to specify a named remote via
+-r to separate and protect the incoming branches.
+
+If you intend to set up a shared public repository that all developers can
+read/write, or if you want to use linkgit:git-cvsserver[1], then you
+probably want to make a bare clone of the imported repository,
+and use the clone as the shared repository.
+See linkgit:gitcvs-migration[7].
+
+
+OPTIONS
+-------
+-v::
+	Verbosity: let 'cvsimport' report what it is doing.
+
+-d <CVSROOT>::
+	The root of the CVS archive. May be local (a simple path) or remote;
+	currently, only the :local:, :ext: and :pserver: access methods
+	are supported. If not given, 'git cvsimport' will try to read it
+	from `CVS/Root`. If no such file exists, it checks for the
+	`CVSROOT` environment variable.
+
+<CVS_module>::
+	The CVS module you want to import. Relative to <CVSROOT>.
+	If not given, 'git cvsimport' tries to read it from
+	`CVS/Repository`.
+
+-C <target-dir>::
+	The Git repository to import to.  If the directory doesn't
+        exist, it will be created.  Default is the current directory.
+
+-r <remote>::
+	The Git remote to import this CVS repository into.
+	Moves all CVS branches into remotes/<remote>/<branch>
+	akin to the way 'git clone' uses 'origin' by default.
+
+-o <branch-for-HEAD>::
+	When no remote is specified (via -r) the `HEAD` branch
+	from CVS is imported to the 'origin' branch within the Git
+	repository, as `HEAD` already has a special meaning for Git.
+	When a remote is specified the `HEAD` branch is named
+	remotes/<remote>/master mirroring 'git clone' behaviour.
+	Use this option if you want to import into a different
+	branch.
++
+Use '-o master' for continuing an import that was initially done by
+the old cvs2git tool.
+
+-i::
+	Import-only: don't perform a checkout after importing.  This option
+	ensures the working directory and index remain untouched and will
+	not create them if they do not exist.
+
+-k::
+	Kill keywords: will extract files with '-kk' from the CVS archive
+	to avoid noisy changesets. Highly recommended, but off by default
+	to preserve compatibility with early imported trees.
+
+-u::
+	Convert underscores in tag and branch names to dots.
+
+-s <subst>::
+	Substitute the character "/" in branch names with <subst>
+
+-p <options-for-cvsps>::
+	Additional options for cvsps.
+	The options `-u` and '-A' are implicit and should not be used here.
++
+If you need to pass multiple options, separate them with a comma.
+
+-z <fuzz>::
+	Pass the timestamp fuzz factor to cvsps, in seconds. If unset,
+	cvsps defaults to 300s.
+
+-P <cvsps-output-file>::
+	Instead of calling cvsps, read the provided cvsps output file. Useful
+	for debugging or when cvsps is being handled outside cvsimport.
+
+-m::
+	Attempt to detect merges based on the commit message. This option
+	will enable default regexes that try to capture the source
+	branch name from the commit message.
+
+-M <regex>::
+	Attempt to detect merges based on the commit message with a custom
+	regex. It can be used with `-m` to enable the default regexes
+	as well. You must escape forward slashes.
++
+The regex must capture the source branch name in $1.
++
+This option can be used several times to provide several detection regexes.
+
+-S <regex>::
+	Skip paths matching the regex.
+
+-a::
+	Import all commits, including recent ones. cvsimport by default
+	skips commits that have a timestamp less than 10 minutes ago.
+
+-L <limit>::
+	Limit the number of commits imported. Workaround for cases where
+	cvsimport leaks memory.
+
+-A <author-conv-file>::
+	CVS by default uses the Unix username when writing its
+	commit logs. Using this option and an author-conv-file
+	maps the name recorded in CVS to author name, e-mail and
+	optional time zone:
++
+---------
+	exon=Andreas Ericsson <ae@op5.se>
+	spawn=Simon Pawn <spawn@frog-pond.org> America/Chicago
+
+---------
++
+'git cvsimport' will make it appear as those authors had
+their GIT_AUTHOR_NAME and GIT_AUTHOR_EMAIL set properly
+all along.  If a time zone is specified, GIT_AUTHOR_DATE will
+have the corresponding offset applied.
++
+For convenience, this data is saved to `$GIT_DIR/cvs-authors`
+each time the '-A' option is provided and read from that same
+file each time 'git cvsimport' is run.
++
+It is not recommended to use this feature if you intend to
+export changes back to CVS again later with
+'git cvsexportcommit'.
+
+-R::
+	Generate a `$GIT_DIR/cvs-revisions` file containing a mapping from CVS
+	revision numbers to newly-created Git commit IDs.  The generated file
+	will contain one line for each (filename, revision) pair imported;
+	each line will look like
++
+---------
+src/widget.c 1.1 1d862f173cdc7325b6fa6d2ae1cfd61fd1b512b7
+---------
++
+The revision data is appended to the file if it already exists, for use when
+doing incremental imports.
++
+This option may be useful if you have CVS revision numbers stored in commit
+messages, bug-tracking systems, email archives, and the like.
+
+-h::
+	Print a short usage message and exit.
+
+OUTPUT
+------
+If `-v` is specified, the script reports what it is doing.
+
+Otherwise, success is indicated the Unix way, i.e. by simply exiting with
+a zero exit status.
+
+[[issues]]
+ISSUES
+------
+Problems related to timestamps:
+
+ * If timestamps of commits in the CVS repository are not stable enough
+   to be used for ordering commits changes may show up in the wrong
+   order.
+ * If any files were ever "cvs import"ed more than once (e.g., import of
+   more than one vendor release) the HEAD contains the wrong content.
+ * If the timestamp order of different files cross the revision order
+   within the commit matching time window the order of commits may be
+   wrong.
+
+Problems related to branches:
+
+ * Branches on which no commits have been made are not imported.
+ * All files from the branching point are added to a branch even if
+   never added in CVS.
+ * This applies to files added to the source branch *after* a daughter
+   branch was created: if previously no commit was made on the daughter
+   branch they will erroneously be added to the daughter branch in git.
+
+Problems related to tags:
+
+* Multiple tags on the same revision are not imported.
+
+If you suspect that any of these issues may apply to the repository you
+want to import, consider using cvs2git:
+
+* cvs2git (part of cvs2svn), `http://subversion.apache.org/`
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-cvsserver.txt b/third_party/git/Documentation/git-cvsserver.txt
new file mode 100644
index 0000000000..79e22b1f3a
--- /dev/null
+++ b/third_party/git/Documentation/git-cvsserver.txt
@@ -0,0 +1,433 @@
+git-cvsserver(1)
+================
+
+NAME
+----
+git-cvsserver - A CVS server emulator for Git
+
+SYNOPSIS
+--------
+
+SSH:
+
+[verse]
+export CVS_SERVER="git cvsserver"
+'cvs' -d :ext:user@server/path/repo.git co <HEAD_name>
+
+pserver (/etc/inetd.conf):
+
+[verse]
+cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver
+
+Usage:
+
+[verse]
+'git-cvsserver' [<options>] [pserver|server] [<directory> ...]
+
+OPTIONS
+-------
+
+All these options obviously only make sense if enforced by the server side.
+They have been implemented to resemble the linkgit:git-daemon[1] options as
+closely as possible.
+
+--base-path <path>::
+Prepend 'path' to requested CVSROOT
+
+--strict-paths::
+Don't allow recursing into subdirectories
+
+--export-all::
+Don't check for `gitcvs.enabled` in config. You also have to specify a list
+of allowed directories (see below) if you want to use this option.
+
+-V::
+--version::
+Print version information and exit
+
+-h::
+-H::
+--help::
+Print usage information and exit
+
+<directory>::
+You can specify a list of allowed directories. If no directories
+are given, all are allowed. This is an additional restriction, gitcvs
+access still needs to be enabled by the `gitcvs.enabled` config option
+unless `--export-all` was given, too.
+
+
+DESCRIPTION
+-----------
+
+This application is a CVS emulation layer for Git.
+
+It is highly functional. However, not all methods are implemented,
+and for those methods that are implemented,
+not all switches are implemented.
+
+Testing has been done using both the CLI CVS client, and the Eclipse CVS
+plugin. Most functionality works fine with both of these clients.
+
+LIMITATIONS
+-----------
+
+CVS clients cannot tag, branch or perform Git merges.
+
+'git-cvsserver' maps Git branches to CVS modules. This is very different
+from what most CVS users would expect since in CVS modules usually represent
+one or more directories.
+
+INSTALLATION
+------------
+
+1. If you are going to offer CVS access via pserver, add a line in
+   /etc/inetd.conf like
++
+--
+------
+   cvspserver stream tcp nowait nobody git-cvsserver pserver
+
+------
+Note: Some inetd servers let you specify the name of the executable
+independently of the value of argv[0] (i.e. the name the program assumes
+it was executed with). In this case the correct line in /etc/inetd.conf
+looks like
+
+------
+   cvspserver stream tcp nowait nobody /usr/bin/git-cvsserver git-cvsserver pserver
+
+------
+
+Only anonymous access is provided by pserve by default. To commit you
+will have to create pserver accounts, simply add a gitcvs.authdb
+setting in the config file of the repositories you want the cvsserver
+to allow writes to, for example:
+
+------
+
+   [gitcvs]
+	authdb = /etc/cvsserver/passwd
+
+------
+The format of these files is username followed by the encrypted password,
+for example:
+
+------
+   myuser:$1Oyx5r9mdGZ2
+   myuser:$1$BA)@$vbnMJMDym7tA32AamXrm./
+------
+You can use the 'htpasswd' facility that comes with Apache to make these
+files, but Apache's MD5 crypt method differs from the one used by most C
+library's crypt() function, so don't use the -m option.
+
+Alternatively you can produce the password with perl's crypt() operator:
+-----
+   perl -e 'my ($user, $pass) = @ARGV; printf "%s:%s\n", $user, crypt($user, $pass)' $USER password
+-----
+
+Then provide your password via the pserver method, for example:
+------
+   cvs -d:pserver:someuser:somepassword <at> server/path/repo.git co <HEAD_name>
+------
+No special setup is needed for SSH access, other than having Git tools
+in the PATH. If you have clients that do not accept the CVS_SERVER
+environment variable, you can rename 'git-cvsserver' to `cvs`.
+
+Note: Newer CVS versions (>= 1.12.11) also support specifying
+CVS_SERVER directly in CVSROOT like
+
+------
+cvs -d ":ext;CVS_SERVER=git cvsserver:user@server/path/repo.git" co <HEAD_name>
+------
+This has the advantage that it will be saved in your 'CVS/Root' files and
+you don't need to worry about always setting the correct environment
+variable.  SSH users restricted to 'git-shell' don't need to override the default
+with CVS_SERVER (and shouldn't) as 'git-shell' understands `cvs` to mean
+'git-cvsserver' and pretends that the other end runs the real 'cvs' better.
+--
+2. For each repo that you want accessible from CVS you need to edit config in
+   the repo and add the following section.
++
+--
+------
+   [gitcvs]
+        enabled=1
+        # optional for debugging
+	logFile=/path/to/logfile
+
+------
+Note: you need to ensure each user that is going to invoke 'git-cvsserver' has
+write access to the log file and to the database (see
+<<dbbackend,Database Backend>>. If you want to offer write access over
+SSH, the users of course also need write access to the Git repository itself.
+
+You also need to ensure that each repository is "bare" (without a Git index
+file) for `cvs commit` to work. See linkgit:gitcvs-migration[7].
+
+[[configaccessmethod]]
+All configuration variables can also be overridden for a specific method of
+access. Valid method names are "ext" (for SSH access) and "pserver". The
+following example configuration would disable pserver access while still
+allowing access over SSH.
+------
+   [gitcvs]
+        enabled=0
+
+   [gitcvs "ext"]
+        enabled=1
+------
+--
+3. If you didn't specify the CVSROOT/CVS_SERVER directly in the checkout command,
+   automatically saving it in your 'CVS/Root' files, then you need to set them
+   explicitly in your environment.  CVSROOT should be set as per normal, but the
+   directory should point at the appropriate Git repo.  As above, for SSH clients
+   _not_ restricted to 'git-shell', CVS_SERVER should be set to 'git-cvsserver'.
++
+--
+------
+     export CVSROOT=:ext:user@server:/var/git/project.git
+     export CVS_SERVER="git cvsserver"
+------
+--
+4. For SSH clients that will make commits, make sure their server-side
+   .ssh/environment files (or .bashrc, etc., according to their specific shell)
+   export appropriate values for GIT_AUTHOR_NAME, GIT_AUTHOR_EMAIL,
+   GIT_COMMITTER_NAME, and GIT_COMMITTER_EMAIL.  For SSH clients whose login
+   shell is bash, .bashrc may be a reasonable alternative.
+
+5. Clients should now be able to check out the project. Use the CVS 'module'
+   name to indicate what Git 'head' you want to check out.  This also sets the
+   name of your newly checked-out directory, unless you tell it otherwise with
+   `-d <dir_name>`.  For example, this checks out 'master' branch to the
+   `project-master` directory:
++
+------
+     cvs co -d project-master master
+------
+
+[[dbbackend]]
+DATABASE BACKEND
+----------------
+
+'git-cvsserver' uses one database per Git head (i.e. CVS module) to
+store information about the repository to maintain consistent
+CVS revision numbers. The database needs to be
+updated (i.e. written to) after every commit.
+
+If the commit is done directly by using `git` (as opposed to
+using 'git-cvsserver') the update will need to happen on the
+next repository access by 'git-cvsserver', independent of
+access method and requested operation.
+
+That means that even if you offer only read access (e.g. by using
+the pserver method), 'git-cvsserver' should have write access to
+the database to work reliably (otherwise you need to make sure
+that the database is up to date any time 'git-cvsserver' is executed).
+
+By default it uses SQLite databases in the Git directory, named
+`gitcvs.<module_name>.sqlite`. Note that the SQLite backend creates
+temporary files in the same directory as the database file on
+write so it might not be enough to grant the users using
+'git-cvsserver' write access to the database file without granting
+them write access to the directory, too.
+
+The database cannot be reliably regenerated in a
+consistent form after the branch it is tracking has changed.
+Example: For merged branches, 'git-cvsserver' only tracks
+one branch of development, and after a 'git merge' an
+incrementally updated database may track a different branch
+than a database regenerated from scratch, causing inconsistent
+CVS revision numbers. `git-cvsserver` has no way of knowing which
+branch it would have picked if it had been run incrementally
+pre-merge. So if you have to fully or partially (from old
+backup) regenerate the database, you should be suspicious
+of pre-existing CVS sandboxes.
+
+You can configure the database backend with the following
+configuration variables:
+
+Configuring database backend
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+'git-cvsserver' uses the Perl DBI module. Please also read
+its documentation if changing these variables, especially
+about `DBI->connect()`.
+
+gitcvs.dbName::
+	Database name. The exact meaning depends on the
+	selected database driver, for SQLite this is a filename.
+	Supports variable substitution (see below). May
+	not contain semicolons (`;`).
+	Default: '%Ggitcvs.%m.sqlite'
+
+gitcvs.dbDriver::
+	Used DBI driver. You can specify any available driver
+	for this here, but it might not work. cvsserver is tested
+	with 'DBD::SQLite', reported to work with
+	'DBD::Pg', and reported *not* to work with 'DBD::mysql'.
+	Please regard this as an experimental feature. May not
+	contain colons (`:`).
+	Default: 'SQLite'
+
+gitcvs.dbuser::
+	Database user. Only useful if setting `dbDriver`, since
+	SQLite has no concept of database users. Supports variable
+	substitution (see below).
+
+gitcvs.dbPass::
+	Database password.  Only useful if setting `dbDriver`, since
+	SQLite has no concept of database passwords.
+
+gitcvs.dbTableNamePrefix::
+	Database table name prefix.  Supports variable substitution
+	(see below).  Any non-alphabetic characters will be replaced
+	with underscores.
+
+All variables can also be set per access method, see <<configaccessmethod,above>>.
+
+Variable substitution
+^^^^^^^^^^^^^^^^^^^^^
+In `dbDriver` and `dbUser` you can use the following variables:
+
+%G::
+	Git directory name
+%g::
+	Git directory name, where all characters except for
+	alpha-numeric ones, `.`, and `-` are replaced with
+	`_` (this should make it easier to use the directory
+	name in a filename if wanted)
+%m::
+	CVS module/Git head name
+%a::
+	access method (one of "ext" or "pserver")
+%u::
+	Name of the user running 'git-cvsserver'.
+	If no name can be determined, the
+	numeric uid is used.
+
+ENVIRONMENT
+-----------
+
+These variables obviate the need for command-line options in some
+circumstances, allowing easier restricted usage through git-shell.
+
+GIT_CVSSERVER_BASE_PATH takes the place of the argument to --base-path.
+
+GIT_CVSSERVER_ROOT specifies a single-directory whitelist. The
+repository must still be configured to allow access through
+git-cvsserver, as described above.
+
+When these environment variables are set, the corresponding
+command-line arguments may not be used.
+
+ECLIPSE CVS CLIENT NOTES
+------------------------
+
+To get a checkout with the Eclipse CVS client:
+
+1. Select "Create a new project -> From CVS checkout"
+2. Create a new location. See the notes below for details on how to choose the
+   right protocol.
+3. Browse the 'modules' available. It will give you a list of the heads in
+   the repository. You will not be able to browse the tree from there. Only
+   the heads.
+4. Pick `HEAD` when it asks what branch/tag to check out. Untick the
+   "launch commit wizard" to avoid committing the .project file.
+
+Protocol notes: If you are using anonymous access via pserver, just select that.
+Those using SSH access should choose the 'ext' protocol, and configure 'ext'
+access on the Preferences->Team->CVS->ExtConnection pane. Set CVS_SERVER to
+"`git cvsserver`". Note that password support is not good when using 'ext',
+you will definitely want to have SSH keys setup.
+
+Alternatively, you can just use the non-standard extssh protocol that Eclipse
+offer. In that case CVS_SERVER is ignored, and you will have to replace
+the cvs utility on the server with 'git-cvsserver' or manipulate your `.bashrc`
+so that calling 'cvs' effectively calls 'git-cvsserver'.
+
+CLIENTS KNOWN TO WORK
+---------------------
+
+- CVS 1.12.9 on Debian
+- CVS 1.11.17 on MacOSX (from Fink package)
+- Eclipse 3.0, 3.1.2 on MacOSX (see Eclipse CVS Client Notes)
+- TortoiseCVS
+
+OPERATIONS SUPPORTED
+--------------------
+
+All the operations required for normal use are supported, including
+checkout, diff, status, update, log, add, remove, commit.
+
+Most CVS command arguments that read CVS tags or revision numbers
+(typically -r) work, and also support any git refspec
+(tag, branch, commit ID, etc).
+However, CVS revision numbers for non-default branches are not well
+emulated, and cvs log does not show tags or branches at
+all.  (Non-main-branch CVS revision numbers superficially resemble CVS
+revision numbers, but they actually encode a git commit ID directly,
+rather than represent the number of revisions since the branch point.)
+
+Note that there are two ways to checkout a particular branch.
+As described elsewhere on this page, the "module" parameter
+of cvs checkout is interpreted as a branch name, and it becomes
+the main branch.  It remains the main branch for a given sandbox
+even if you temporarily make another branch sticky with
+cvs update -r.  Alternatively, the -r argument can indicate
+some other branch to actually checkout, even though the module
+is still the "main" branch.  Tradeoffs (as currently
+implemented): Each new "module" creates a new database on disk with
+a history for the given module, and after the database is created,
+operations against that main branch are fast.  Or alternatively,
+-r doesn't take any extra disk space, but may be significantly slower for
+many operations, like cvs update.
+
+If you want to refer to a git refspec that has characters that are
+not allowed by CVS, you have two options.  First, it may just work
+to supply the git refspec directly to the appropriate CVS -r argument;
+some CVS clients don't seem to do much sanity checking of the argument.
+Second, if that fails, you can use a special character escape mechanism
+that only uses characters that are valid in CVS tags.  A sequence
+of 4 or 5 characters of the form (underscore (`"_"`), dash (`"-"`),
+one or two characters, and dash (`"-"`)) can encode various characters based
+on the one or two letters: `"s"` for slash (`"/"`), `"p"` for
+period (`"."`), `"u"` for underscore (`"_"`), or two hexadecimal digits
+for any byte value at all (typically an ASCII number, or perhaps a part
+of a UTF-8 encoded character).
+
+Legacy monitoring operations are not supported (edit, watch and related).
+Exports and tagging (tags and branches) are not supported at this stage.
+
+CRLF Line Ending Conversions
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default the server leaves the `-k` mode blank for all files,
+which causes the CVS client to treat them as a text files, subject
+to end-of-line conversion on some platforms.
+
+You can make the server use the end-of-line conversion attributes to
+set the `-k` modes for files by setting the `gitcvs.usecrlfattr`
+config variable.  See linkgit:gitattributes[5] for more information
+about end-of-line conversion.
+
+Alternatively, if `gitcvs.usecrlfattr` config is not enabled
+or the attributes do not allow automatic detection for a filename, then
+the server uses the `gitcvs.allBinary` config for the default setting.
+If `gitcvs.allBinary` is set, then file not otherwise
+specified will default to '-kb' mode. Otherwise the `-k` mode
+is left blank. But if `gitcvs.allBinary` is set to "guess", then
+the correct `-k` mode will be guessed based on the contents of
+the file.
+
+For best consistency with 'cvs', it is probably best to override the
+defaults by setting `gitcvs.usecrlfattr` to true,
+and `gitcvs.allBinary` to "guess".
+
+DEPENDENCIES
+------------
+'git-cvsserver' depends on DBD::SQLite.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-daemon.txt b/third_party/git/Documentation/git-daemon.txt
new file mode 100644
index 0000000000..fdc28c041c
--- /dev/null
+++ b/third_party/git/Documentation/git-daemon.txt
@@ -0,0 +1,340 @@
+git-daemon(1)
+=============
+
+NAME
+----
+git-daemon - A really simple server for Git repositories
+
+SYNOPSIS
+--------
+[verse]
+'git daemon' [--verbose] [--syslog] [--export-all]
+	     [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]
+	     [--strict-paths] [--base-path=<path>] [--base-path-relaxed]
+	     [--user-path | --user-path=<path>]
+	     [--interpolated-path=<pathtemplate>]
+	     [--reuseaddr] [--detach] [--pid-file=<file>]
+	     [--enable=<service>] [--disable=<service>]
+	     [--allow-override=<service>] [--forbid-override=<service>]
+	     [--access-hook=<path>] [--[no-]informative-errors]
+	     [--inetd |
+	      [--listen=<host_or_ipaddr>] [--port=<n>]
+	      [--user=<user> [--group=<group>]]]
+	     [--log-destination=(stderr|syslog|none)]
+	     [<directory>...]
+
+DESCRIPTION
+-----------
+A really simple TCP Git daemon that normally listens on port "DEFAULT_GIT_PORT"
+aka 9418.  It waits for a connection asking for a service, and will serve
+that service if it is enabled.
+
+It verifies that the directory has the magic file "git-daemon-export-ok", and
+it will refuse to export any Git directory that hasn't explicitly been marked
+for export this way (unless the `--export-all` parameter is specified). If you
+pass some directory paths as 'git daemon' arguments, you can further restrict
+the offers to a whitelist comprising of those.
+
+By default, only `upload-pack` service is enabled, which serves
+'git fetch-pack' and 'git ls-remote' clients, which are invoked
+from 'git fetch', 'git pull', and 'git clone'.
+
+This is ideally suited for read-only updates, i.e., pulling from
+Git repositories.
+
+An `upload-archive` also exists to serve 'git archive'.
+
+OPTIONS
+-------
+--strict-paths::
+	Match paths exactly (i.e. don't allow "/foo/repo" when the real path is
+	"/foo/repo.git" or "/foo/repo/.git") and don't do user-relative paths.
+	'git daemon' will refuse to start when this option is enabled and no
+	whitelist is specified.
+
+--base-path=<path>::
+	Remap all the path requests as relative to the given path.
+	This is sort of "Git root" - if you run 'git daemon' with
+	'--base-path=/srv/git' on example.com, then if you later try to pull
+	'git://example.com/hello.git', 'git daemon' will interpret the path
+	as `/srv/git/hello.git`.
+
+--base-path-relaxed::
+	If --base-path is enabled and repo lookup fails, with this option
+	'git daemon' will attempt to lookup without prefixing the base path.
+	This is useful for switching to --base-path usage, while still
+	allowing the old paths.
+
+--interpolated-path=<pathtemplate>::
+	To support virtual hosting, an interpolated path template can be
+	used to dynamically construct alternate paths.  The template
+	supports %H for the target hostname as supplied by the client but
+	converted to all lowercase, %CH for the canonical hostname,
+	%IP for the server's IP address, %P for the port number,
+	and %D for the absolute path of the named repository.
+	After interpolation, the path is validated against the directory
+	whitelist.
+
+--export-all::
+	Allow pulling from all directories that look like Git repositories
+	(have the 'objects' and 'refs' subdirectories), even if they
+	do not have the 'git-daemon-export-ok' file.
+
+--inetd::
+	Have the server run as an inetd service. Implies --syslog (may be
+	overridden with `--log-destination=`).
+	Incompatible with --detach, --port, --listen, --user and --group
+	options.
+
+--listen=<host_or_ipaddr>::
+	Listen on a specific IP address or hostname.  IP addresses can
+	be either an IPv4 address or an IPv6 address if supported.  If IPv6
+	is not supported, then --listen=hostname is also not supported and
+	--listen must be given an IPv4 address.
+	Can be given more than once.
+	Incompatible with `--inetd` option.
+
+--port=<n>::
+	Listen on an alternative port.  Incompatible with `--inetd` option.
+
+--init-timeout=<n>::
+	Timeout (in seconds) between the moment the connection is established
+	and the client request is received (typically a rather low value, since
+	that should be basically immediate).
+
+--timeout=<n>::
+	Timeout (in seconds) for specific client sub-requests. This includes
+	the time it takes for the server to process the sub-request and the
+	time spent waiting for the next client's request.
+
+--max-connections=<n>::
+	Maximum number of concurrent clients, defaults to 32.  Set it to
+	zero for no limit.
+
+--syslog::
+	Short for `--log-destination=syslog`.
+
+--log-destination=<destination>::
+	Send log messages to the specified destination.
+	Note that this option does not imply --verbose,
+	thus by default only error conditions will be logged.
+	The <destination> must be one of:
++
+--
+stderr::
+	Write to standard error.
+	Note that if `--detach` is specified,
+	the process disconnects from the real standard error,
+	making this destination effectively equivalent to `none`.
+syslog::
+	Write to syslog, using the `git-daemon` identifier.
+none::
+	Disable all logging.
+--
++
+The default destination is `syslog` if `--inetd` or `--detach` is specified,
+otherwise `stderr`.
+
+--user-path::
+--user-path=<path>::
+	Allow {tilde}user notation to be used in requests.  When
+	specified with no parameter, requests to
+	git://host/{tilde}alice/foo is taken as a request to access
+	'foo' repository in the home directory of user `alice`.
+	If `--user-path=path` is specified, the same request is
+	taken as a request to access `path/foo` repository in
+	the home directory of user `alice`.
+
+--verbose::
+	Log details about the incoming connections and requested files.
+
+--reuseaddr::
+	Use SO_REUSEADDR when binding the listening socket.
+	This allows the server to restart without waiting for
+	old connections to time out.
+
+--detach::
+	Detach from the shell. Implies --syslog.
+
+--pid-file=<file>::
+	Save the process id in 'file'.  Ignored when the daemon
+	is run under `--inetd`.
+
+--user=<user>::
+--group=<group>::
+	Change daemon's uid and gid before entering the service loop.
+	When only `--user` is given without `--group`, the
+	primary group ID for the user is used.  The values of
+	the option are given to `getpwnam(3)` and `getgrnam(3)`
+	and numeric IDs are not supported.
++
+Giving these options is an error when used with `--inetd`; use
+the facility of inet daemon to achieve the same before spawning
+'git daemon' if needed.
++
+Like many programs that switch user id, the daemon does not reset
+environment variables such as `$HOME` when it runs git programs,
+e.g. `upload-pack` and `receive-pack`. When using this option, you
+may also want to set and export `HOME` to point at the home
+directory of `<user>` before starting the daemon, and make sure any
+Git configuration files in that directory are readable by `<user>`.
+
+--enable=<service>::
+--disable=<service>::
+	Enable/disable the service site-wide per default.  Note
+	that a service disabled site-wide can still be enabled
+	per repository if it is marked overridable and the
+	repository enables the service with a configuration
+	item.
+
+--allow-override=<service>::
+--forbid-override=<service>::
+	Allow/forbid overriding the site-wide default with per
+	repository configuration.  By default, all the services
+	may be overridden.
+
+--[no-]informative-errors::
+	When informative errors are turned on, git-daemon will report
+	more verbose errors to the client, differentiating conditions
+	like "no such repository" from "repository not exported". This
+	is more convenient for clients, but may leak information about
+	the existence of unexported repositories.  When informative
+	errors are not enabled, all errors report "access denied" to the
+	client. The default is --no-informative-errors.
+
+--access-hook=<path>::
+	Every time a client connects, first run an external command
+	specified by the <path> with service name (e.g. "upload-pack"),
+	path to the repository, hostname (%H), canonical hostname
+	(%CH), IP address (%IP), and TCP port (%P) as its command-line
+	arguments. The external command can decide to decline the
+	service by exiting with a non-zero status (or to allow it by
+	exiting with a zero status).  It can also look at the $REMOTE_ADDR
+	and `$REMOTE_PORT` environment variables to learn about the
+	requestor when making this decision.
++
+The external command can optionally write a single line to its
+standard output to be sent to the requestor as an error message when
+it declines the service.
+
+<directory>::
+	A directory to add to the whitelist of allowed directories. Unless
+	--strict-paths is specified this will also include subdirectories
+	of each named directory.
+
+SERVICES
+--------
+
+These services can be globally enabled/disabled using the
+command-line options of this command.  If finer-grained
+control is desired (e.g. to allow 'git archive' to be run
+against only in a few selected repositories the daemon serves),
+the per-repository configuration file can be used to enable or
+disable them.
+
+upload-pack::
+	This serves 'git fetch-pack' and 'git ls-remote'
+	clients.  It is enabled by default, but a repository can
+	disable it by setting `daemon.uploadpack` configuration
+	item to `false`.
+
+upload-archive::
+	This serves 'git archive --remote'.  It is disabled by
+	default, but a repository can enable it by setting
+	`daemon.uploadarch` configuration item to `true`.
+
+receive-pack::
+	This serves 'git send-pack' clients, allowing anonymous
+	push.  It is disabled by default, as there is _no_
+	authentication in the protocol (in other words, anybody
+	can push anything into the repository, including removal
+	of refs).  This is solely meant for a closed LAN setting
+	where everybody is friendly.  This service can be
+	enabled by setting `daemon.receivepack` configuration item to
+	`true`.
+
+EXAMPLES
+--------
+We assume the following in /etc/services::
++
+------------
+$ grep 9418 /etc/services
+git		9418/tcp		# Git Version Control System
+------------
+
+'git daemon' as inetd server::
+	To set up 'git daemon' as an inetd service that handles any
+	repository under the whitelisted set of directories, /pub/foo
+	and /pub/bar, place an entry like the following into
+	/etc/inetd all on one line:
++
+------------------------------------------------
+	git stream tcp nowait nobody  /usr/bin/git
+		git daemon --inetd --verbose --export-all
+		/pub/foo /pub/bar
+------------------------------------------------
+
+
+'git daemon' as inetd server for virtual hosts::
+	To set up 'git daemon' as an inetd service that handles
+	repositories for different virtual hosts, `www.example.com`
+	and `www.example.org`, place an entry like the following into
+	`/etc/inetd` all on one line:
++
+------------------------------------------------
+	git stream tcp nowait nobody /usr/bin/git
+		git daemon --inetd --verbose --export-all
+		--interpolated-path=/pub/%H%D
+		/pub/www.example.org/software
+		/pub/www.example.com/software
+		/software
+------------------------------------------------
++
+In this example, the root-level directory `/pub` will contain
+a subdirectory for each virtual host name supported.
+Further, both hosts advertise repositories simply as
+`git://www.example.com/software/repo.git`.  For pre-1.4.0
+clients, a symlink from `/software` into the appropriate
+default repository could be made as well.
+
+
+'git daemon' as regular daemon for virtual hosts::
+	To set up 'git daemon' as a regular, non-inetd service that
+	handles repositories for multiple virtual hosts based on
+	their IP addresses, start the daemon like this:
++
+------------------------------------------------
+	git daemon --verbose --export-all
+		--interpolated-path=/pub/%IP/%D
+		/pub/192.168.1.200/software
+		/pub/10.10.220.23/software
+------------------------------------------------
++
+In this example, the root-level directory `/pub` will contain
+a subdirectory for each virtual host IP address supported.
+Repositories can still be accessed by hostname though, assuming
+they correspond to these IP addresses.
+
+selectively enable/disable services per repository::
+	To enable 'git archive --remote' and disable 'git fetch' against
+	a repository, have the following in the configuration file in the
+	repository (that is the file 'config' next to `HEAD`, 'refs' and
+	'objects').
++
+----------------------------------------------------------------
+	[daemon]
+		uploadpack = false
+		uploadarch = true
+----------------------------------------------------------------
+
+
+ENVIRONMENT
+-----------
+'git daemon' will set REMOTE_ADDR to the IP address of the client
+that connected to it, if the IP address is available. REMOTE_ADDR will
+be available in the environment of hooks called when
+services are performed.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-describe.txt b/third_party/git/Documentation/git-describe.txt
new file mode 100644
index 0000000000..a88f6ae2c6
--- /dev/null
+++ b/third_party/git/Documentation/git-describe.txt
@@ -0,0 +1,207 @@
+git-describe(1)
+===============
+
+NAME
+----
+git-describe - Give an object a human readable name based on an available ref
+
+SYNOPSIS
+--------
+[verse]
+'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]
+'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
+'git describe' <blob>
+
+DESCRIPTION
+-----------
+The command finds the most recent tag that is reachable from a
+commit.  If the tag points to the commit, then only the tag is
+shown.  Otherwise, it suffixes the tag name with the number of
+additional commits on top of the tagged object and the
+abbreviated object name of the most recent commit. The result
+is a "human-readable" object name which can also be used to
+identify the commit to other git commands.
+
+By default (without --all or --tags) `git describe` only shows
+annotated tags.  For more information about creating annotated tags
+see the -a and -s options to linkgit:git-tag[1].
+
+If the given object refers to a blob, it will be described
+as `<commit-ish>:<path>`, such that the blob can be found
+at `<path>` in the `<commit-ish>`, which itself describes the
+first commit in which this blob occurs in a reverse revision walk
+from HEAD.
+
+OPTIONS
+-------
+<commit-ish>...::
+	Commit-ish object names to describe.  Defaults to HEAD if omitted.
+
+--dirty[=<mark>]::
+--broken[=<mark>]::
+	Describe the state of the working tree.  When the working
+	tree matches HEAD, the output is the same as "git describe
+	HEAD".  If the working tree has local modification "-dirty"
+	is appended to it.  If a repository is corrupt and Git
+	cannot determine if there is local modification, Git will
+	error out, unless `--broken' is given, which appends
+	the suffix "-broken" instead.
+
+--all::
+	Instead of using only the annotated tags, use any ref
+	found in `refs/` namespace.  This option enables matching
+	any known branch, remote-tracking branch, or lightweight tag.
+
+--tags::
+	Instead of using only the annotated tags, use any tag
+	found in `refs/tags` namespace.  This option enables matching
+	a lightweight (non-annotated) tag.
+
+--contains::
+	Instead of finding the tag that predates the commit, find
+	the tag that comes after the commit, and thus contains it.
+	Automatically implies --tags.
+
+--abbrev=<n>::
+	Instead of using the default 7 hexadecimal digits as the
+	abbreviated object name, use <n> digits, or as many digits
+	as needed to form a unique object name.  An <n> of 0
+	will suppress long format, only showing the closest tag.
+
+--candidates=<n>::
+	Instead of considering only the 10 most recent tags as
+	candidates to describe the input commit-ish consider
+	up to <n> candidates.  Increasing <n> above 10 will take
+	slightly longer but may produce a more accurate result.
+	An <n> of 0 will cause only exact matches to be output.
+
+--exact-match::
+	Only output exact matches (a tag directly references the
+	supplied commit).  This is a synonym for --candidates=0.
+
+--debug::
+	Verbosely display information about the searching strategy
+	being employed to standard error.  The tag name will still
+	be printed to standard out.
+
+--long::
+	Always output the long format (the tag, the number of commits
+	and the abbreviated commit name) even when it matches a tag.
+	This is useful when you want to see parts of the commit object name
+	in "describe" output, even when the commit in question happens to be
+	a tagged version.  Instead of just emitting the tag name, it will
+	describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2
+	that points at object deadbee....).
+
+--match <pattern>::
+	Only consider tags matching the given `glob(7)` pattern,
+	excluding the "refs/tags/" prefix. If used with `--all`, it also
+	considers local branches and remote-tracking references matching the
+	pattern, excluding respectively "refs/heads/" and "refs/remotes/"
+	prefix; references of other types are never considered. If given
+	multiple times, a list of patterns will be accumulated, and tags
+	matching any of the patterns will be considered.  Use `--no-match` to
+	clear and reset the list of patterns.
+
+--exclude <pattern>::
+	Do not consider tags matching the given `glob(7)` pattern, excluding
+	the "refs/tags/" prefix. If used with `--all`, it also does not consider
+	local branches and remote-tracking references matching the pattern,
+	excluding respectively "refs/heads/" and "refs/remotes/" prefix;
+	references of other types are never considered. If given multiple times,
+	a list of patterns will be accumulated and tags matching any of the
+	patterns will be excluded. When combined with --match a tag will be
+	considered when it matches at least one --match pattern and does not
+	match any of the --exclude patterns. Use `--no-exclude` to clear and
+	reset the list of patterns.
+
+--always::
+	Show uniquely abbreviated commit object as fallback.
+
+--first-parent::
+	Follow only the first parent commit upon seeing a merge commit.
+	This is useful when you wish to not match tags on branches merged
+	in the history of the target commit.
+
+EXAMPLES
+--------
+
+With something like git.git current tree, I get:
+
+	[torvalds@g5 git]$ git describe parent
+	v1.0.4-14-g2414721
+
+i.e. the current head of my "parent" branch is based on v1.0.4,
+but since it has a few commits on top of that,
+describe has added the number of additional commits ("14") and
+an abbreviated object name for the commit itself ("2414721")
+at the end.
+
+The number of additional commits is the number
+of commits which would be displayed by "git log v1.0.4..parent".
+The hash suffix is "-g" + unambiguous abbreviation for the tip commit
+of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
+The "g" prefix stands for "git" and is used to allow describing the version of
+a software depending on the SCM the software is managed with. This is useful
+in an environment where people may use different SCMs.
+
+Doing a 'git describe' on a tag-name will just show the tag name:
+
+	[torvalds@g5 git]$ git describe v1.0.4
+	v1.0.4
+
+With --all, the command can use branch heads as references, so
+the output shows the reference path as well:
+
+	[torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
+	tags/v1.0.0-21-g975b
+
+	[torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
+	heads/lt/describe-7-g975b
+
+With --abbrev set to 0, the command can be used to find the
+closest tagname without any suffix:
+
+	[torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
+	tags/v1.0.0
+
+Note that the suffix you get if you type these commands today may be
+longer than what Linus saw above when he ran these commands, as your
+Git repository may have new commits whose object names begin with
+975b that did not exist back then, and "-g975b" suffix alone may not
+be sufficient to disambiguate these commits.
+
+
+SEARCH STRATEGY
+---------------
+
+For each commit-ish supplied, 'git describe' will first look for
+a tag which tags exactly that commit.  Annotated tags will always
+be preferred over lightweight tags, and tags with newer dates will
+always be preferred over tags with older dates.  If an exact match
+is found, its name will be output and searching will stop.
+
+If an exact match was not found, 'git describe' will walk back
+through the commit history to locate an ancestor commit which
+has been tagged.  The ancestor's tag will be output along with an
+abbreviation of the input commit-ish's SHA-1. If `--first-parent` was
+specified then the walk will only consider the first parent of each
+commit.
+
+If multiple tags were found during the walk then the tag which
+has the fewest commits different from the input commit-ish will be
+selected and output.  Here fewest commits different is defined as
+the number of commits which would be shown by `git log tag..input`
+will be the smallest number of commits possible.
+
+BUGS
+----
+
+Tree objects as well as tag objects not pointing at commits, cannot be described.
+When describing blobs, the lightweight tags pointing at blobs are ignored,
+but the blob is still described as <committ-ish>:<path> despite the lightweight
+tag being favorable.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-diff-files.txt b/third_party/git/Documentation/git-diff-files.txt
new file mode 100644
index 0000000000..906774f0f7
--- /dev/null
+++ b/third_party/git/Documentation/git-diff-files.txt
@@ -0,0 +1,52 @@
+git-diff-files(1)
+=================
+
+NAME
+----
+git-diff-files - Compares files in the working tree and the index
+
+
+SYNOPSIS
+--------
+[verse]
+'git diff-files' [-q] [-0|-1|-2|-3|-c|--cc] [<common diff options>] [<path>...]
+
+DESCRIPTION
+-----------
+Compares the files in the working tree and the index.  When paths
+are specified, compares only those named paths.  Otherwise all
+entries in the index are compared.  The output format is the
+same as for 'git diff-index' and 'git diff-tree'.
+
+OPTIONS
+-------
+include::diff-options.txt[]
+
+-1 --base::
+-2 --ours::
+-3 --theirs::
+-0::
+	Diff against the "base" version, "our branch" or "their
+	branch" respectively.  With these options, diffs for
+	merged entries are not shown.
++
+The default is to diff against our branch (-2) and the
+cleanly resolved paths.  The option -0 can be given to
+omit diff output for unmerged entries and just show "Unmerged".
+
+-c::
+--cc::
+	This compares stage 2 (our branch), stage 3 (their
+	branch) and the working tree file and outputs a combined
+	diff, similar to the way 'diff-tree' shows a merge
+	commit with these flags.
+
+-q::
+	Remain silent even on nonexistent files
+
+
+include::diff-format.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-diff-index.txt b/third_party/git/Documentation/git-diff-index.txt
new file mode 100644
index 0000000000..f4bd8155c0
--- /dev/null
+++ b/third_party/git/Documentation/git-diff-index.txt
@@ -0,0 +1,122 @@
+git-diff-index(1)
+=================
+
+NAME
+----
+git-diff-index - Compare a tree to the working tree or index
+
+
+SYNOPSIS
+--------
+[verse]
+'git diff-index' [-m] [--cached] [<common diff options>] <tree-ish> [<path>...]
+
+DESCRIPTION
+-----------
+Compares the content and mode of the blobs found in a tree object
+with the corresponding tracked files in the working tree, or with the
+corresponding paths in the index.  When <path> arguments are present,
+compares only paths matching those patterns.  Otherwise all tracked
+files are compared.
+
+OPTIONS
+-------
+include::diff-options.txt[]
+
+<tree-ish>::
+	The id of a tree object to diff against.
+
+--cached::
+	do not consider the on-disk file at all
+
+-m::
+	By default, files recorded in the index but not checked
+	out are reported as deleted.  This flag makes
+	'git diff-index' say that all non-checked-out files are up
+	to date.
+
+include::diff-format.txt[]
+
+OPERATING MODES
+---------------
+You can choose whether you want to trust the index file entirely
+(using the `--cached` flag) or ask the diff logic to show any files
+that don't match the stat state as being "tentatively changed".  Both
+of these operations are very useful indeed.
+
+CACHED MODE
+-----------
+If `--cached` is specified, it allows you to ask:
+
+	show me the differences between HEAD and the current index
+	contents (the ones I'd write using 'git write-tree')
+
+For example, let's say that you have worked on your working directory, updated
+some files in the index and are ready to commit. You want to see exactly
+*what* you are going to commit, without having to write a new tree
+object and compare it that way, and to do that, you just do
+
+	git diff-index --cached HEAD
+
+Example: let's say I had renamed `commit.c` to `git-commit.c`, and I had
+done an `update-index` to make that effective in the index file.
+`git diff-files` wouldn't show anything at all, since the index file
+matches my working directory. But doing a 'git diff-index' does:
+
+  torvalds@ppc970:~/git> git diff-index --cached HEAD
+  -100644 blob    4161aecc6700a2eb579e842af0b7f22b98443f74        commit.c
+  +100644 blob    4161aecc6700a2eb579e842af0b7f22b98443f74        git-commit.c
+
+You can see easily that the above is a rename.
+
+In fact, `git diff-index --cached` *should* always be entirely equivalent to
+actually doing a 'git write-tree' and comparing that. Except this one is much
+nicer for the case where you just want to check where you are.
+
+So doing a `git diff-index --cached` is basically very useful when you are
+asking yourself "what have I already marked for being committed, and
+what's the difference to a previous tree".
+
+NON-CACHED MODE
+---------------
+The "non-cached" mode takes a different approach, and is potentially
+the more useful of the two in that what it does can't be emulated with
+a 'git write-tree' + 'git diff-tree'. Thus that's the default mode.
+The non-cached version asks the question:
+
+  show me the differences between HEAD and the currently checked out
+  tree - index contents _and_ files that aren't up to date
+
+which is obviously a very useful question too, since that tells you what
+you *could* commit. Again, the output matches the 'git diff-tree -r'
+output to a tee, but with a twist.
+
+The twist is that if some file doesn't match the index, we don't have
+a backing store thing for it, and we use the magic "all-zero" sha1 to
+show that. So let's say that you have edited `kernel/sched.c`, but
+have not actually done a 'git update-index' on it yet - there is no
+"object" associated with the new state, and you get:
+
+  torvalds@ppc970:~/v2.6/linux> git diff-index --abbrev HEAD
+  :100644 100664 7476bb... 000000...      kernel/sched.c
+
+i.e., it shows that the tree has changed, and that `kernel/sched.c` is
+not up to date and may contain new stuff. The all-zero sha1 means that to
+get the real diff, you need to look at the object in the working directory
+directly rather than do an object-to-object diff.
+
+NOTE: As with other commands of this type, 'git diff-index' does not
+actually look at the contents of the file at all. So maybe
+`kernel/sched.c` hasn't actually changed, and it's just that you
+touched it. In either case, it's a note that you need to
+'git update-index' it to make the index be in sync.
+
+NOTE: You can have a mixture of files show up as "has been updated"
+and "is still dirty in the working directory" together. You can always
+tell which file is in which state, since the "has been updated" ones
+show a valid sha1, and the "not in sync with the index" ones will
+always have the special all-zero sha1.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-diff-tree.txt b/third_party/git/Documentation/git-diff-tree.txt
new file mode 100644
index 0000000000..5c8a2a5e97
--- /dev/null
+++ b/third_party/git/Documentation/git-diff-tree.txt
@@ -0,0 +1,126 @@
+git-diff-tree(1)
+================
+
+NAME
+----
+git-diff-tree - Compares the content and mode of blobs found via two tree objects
+
+
+SYNOPSIS
+--------
+[verse]
+'git diff-tree' [--stdin] [-m] [-s] [-v] [--no-commit-id] [--pretty]
+	      [-t] [-r] [-c | --cc] [--combined-all-paths] [--root]
+	      [<common diff options>] <tree-ish> [<tree-ish>] [<path>...]
+
+DESCRIPTION
+-----------
+Compares the content and mode of the blobs found via two tree objects.
+
+If there is only one <tree-ish> given, the commit is compared with its parents
+(see --stdin below).
+
+Note that 'git diff-tree' can use the tree encapsulated in a commit object.
+
+OPTIONS
+-------
+include::diff-options.txt[]
+
+<tree-ish>::
+	The id of a tree object.
+
+<path>...::
+	If provided, the results are limited to a subset of files
+	matching one of the provided pathspecs.
+
+-r::
+        recurse into sub-trees
+
+-t::
+	show tree entry itself as well as subtrees.  Implies -r.
+
+--root::
+	When `--root` is specified the initial commit will be shown as a big
+	creation event. This is equivalent to a diff against the NULL tree.
+
+--stdin::
+	When `--stdin` is specified, the command does not take
+	<tree-ish> arguments from the command line.  Instead, it
+	reads lines containing either two <tree>, one <commit>, or a
+	list of <commit> from its standard input.  (Use a single space
+	as separator.)
++
+When two trees are given, it compares the first tree with the second.
+When a single commit is given, it compares the commit with its
+parents.  The remaining commits, when given, are used as if they are
+parents of the first commit.
++
+When comparing two trees, the ID of both trees (separated by a space
+and terminated by a newline) is printed before the difference.  When
+comparing commits, the ID of the first (or only) commit, followed by a
+newline, is printed.
++
+The following flags further affect the behavior when comparing
+commits (but not trees).
+
+-m::
+	By default, 'git diff-tree --stdin' does not show
+	differences for merge commits.  With this flag, it shows
+	differences to that commit from all of its parents. See
+	also `-c`.
+
+-s::
+	By default, 'git diff-tree --stdin' shows differences,
+	either in machine-readable form (without `-p`) or in patch
+	form (with `-p`).  This output can be suppressed.  It is
+	only useful with `-v` flag.
+
+-v::
+	This flag causes 'git diff-tree --stdin' to also show
+	the commit message before the differences.
+
+include::pretty-options.txt[]
+
+--no-commit-id::
+	'git diff-tree' outputs a line with the commit ID when
+	applicable.  This flag suppressed the commit ID output.
+
+-c::
+	This flag changes the way a merge commit is displayed
+	(which means it is useful only when the command is given
+	one <tree-ish>, or `--stdin`).  It shows the differences
+	from each of the parents to the merge result simultaneously
+	instead of showing pairwise diff between a parent and the
+	result one at a time (which is what the `-m` option does).
+	Furthermore, it lists only files which were modified
+	from all parents.
+
+--cc::
+	This flag changes the way a merge commit patch is displayed,
+	in a similar way to the `-c` option. It implies the `-c`
+	and `-p` options and further compresses the patch output
+	by omitting uninteresting hunks whose the contents in the parents
+	have only two variants and the merge result picks one of them
+	without modification.  When all hunks are uninteresting, the commit
+	itself and the commit log message is not shown, just like in any other
+	"empty diff" case.
+
+--combined-all-paths::
+	This flag causes combined diffs (used for merge commits) to
+	list the name of the file from all parents.  It thus only has
+	effect when -c or --cc are specified, and is likely only
+	useful if filename changes are detected (i.e. when either
+	rename or copy detection have been requested).
+
+--always::
+	Show the commit itself and the commit log message even
+	if the diff itself is empty.
+
+
+include::pretty-formats.txt[]
+
+include::diff-format.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-diff.txt b/third_party/git/Documentation/git-diff.txt
new file mode 100644
index 0000000000..72179d993c
--- /dev/null
+++ b/third_party/git/Documentation/git-diff.txt
@@ -0,0 +1,203 @@
+git-diff(1)
+===========
+
+NAME
+----
+git-diff - Show changes between commits, commit and working tree, etc
+
+
+SYNOPSIS
+--------
+[verse]
+'git diff' [<options>] [<commit>] [--] [<path>...]
+'git diff' [<options>] --cached [<commit>] [--] [<path>...]
+'git diff' [<options>] <commit> <commit> [--] [<path>...]
+'git diff' [<options>] <blob> <blob>
+'git diff' [<options>] --no-index [--] <path> <path>
+
+DESCRIPTION
+-----------
+Show changes between the working tree and the index or a tree, changes
+between the index and a tree, changes between two trees, changes between
+two blob objects, or changes between two files on disk.
+
+'git diff' [<options>] [--] [<path>...]::
+
+	This form is to view the changes you made relative to
+	the index (staging area for the next commit).  In other
+	words, the differences are what you _could_ tell Git to
+	further add to the index but you still haven't.  You can
+	stage these changes by using linkgit:git-add[1].
+
+'git diff' [<options>] --no-index [--] <path> <path>::
+
+	This form is to compare the given two paths on the
+	filesystem.  You can omit the `--no-index` option when
+	running the command in a working tree controlled by Git and
+	at least one of the paths points outside the working tree,
+	or when running the command outside a working tree
+	controlled by Git.
+
+'git diff' [<options>] --cached [<commit>] [--] [<path>...]::
+
+	This form is to view the changes you staged for the next
+	commit relative to the named <commit>.  Typically you
+	would want comparison with the latest commit, so if you
+	do not give <commit>, it defaults to HEAD.
+	If HEAD does not exist (e.g. unborn branches) and
+	<commit> is not given, it shows all staged changes.
+	--staged is a synonym of --cached.
+
+'git diff' [<options>] <commit> [--] [<path>...]::
+
+	This form is to view the changes you have in your
+	working tree relative to the named <commit>.  You can
+	use HEAD to compare it with the latest commit, or a
+	branch name to compare with the tip of a different
+	branch.
+
+'git diff' [<options>] <commit> <commit> [--] [<path>...]::
+
+	This is to view the changes between two arbitrary
+	<commit>.
+
+'git diff' [<options>] <commit>..<commit> [--] [<path>...]::
+
+	This is synonymous to the previous form.  If <commit> on
+	one side is omitted, it will have the same effect as
+	using HEAD instead.
+
+'git diff' [<options>] <commit>\...<commit> [--] [<path>...]::
+
+	This form is to view the changes on the branch containing
+	and up to the second <commit>, starting at a common ancestor
+	of both <commit>.  "git diff A\...B" is equivalent to
+	"git diff $(git merge-base A B) B".  You can omit any one
+	of <commit>, which has the same effect as using HEAD instead.
+
+Just in case you are doing something exotic, it should be
+noted that all of the <commit> in the above description, except
+in the last two forms that use ".." notations, can be any
+<tree>.
+
+For a more complete list of ways to spell <commit>, see
+"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
+However, "diff" is about comparing two _endpoints_, not ranges,
+and the range notations ("<commit>..<commit>" and
+"<commit>\...<commit>") do not mean a range as defined in the
+"SPECIFYING RANGES" section in linkgit:gitrevisions[7].
+
+'git diff' [<options>] <blob> <blob>::
+
+	This form is to view the differences between the raw
+	contents of two blob objects.
+
+OPTIONS
+-------
+:git-diff: 1
+include::diff-options.txt[]
+
+-1 --base::
+-2 --ours::
+-3 --theirs::
+	Compare the working tree with the "base" version (stage #1),
+	"our branch" (stage #2) or "their branch" (stage #3).  The
+	index contains these stages only for unmerged entries i.e.
+	while resolving conflicts.  See linkgit:git-read-tree[1]
+	section "3-Way Merge" for detailed information.
+
+-0::
+	Omit diff output for unmerged entries and just show
+	"Unmerged".  Can be used only when comparing the working tree
+	with the index.
+
+<path>...::
+	The <paths> parameters, when given, are used to limit
+	the diff to the named paths (you can give directory
+	names and get diff for all files under them).
+
+
+include::diff-format.txt[]
+
+EXAMPLES
+--------
+
+Various ways to check your working tree::
++
+------------
+$ git diff            <1>
+$ git diff --cached   <2>
+$ git diff HEAD       <3>
+------------
++
+<1> Changes in the working tree not yet staged for the next commit.
+<2> Changes between the index and your last commit; what you
+    would be committing if you run "git commit" without "-a" option.
+<3> Changes in the working tree since your last commit; what you
+    would be committing if you run "git commit -a"
+
+Comparing with arbitrary commits::
++
+------------
+$ git diff test            <1>
+$ git diff HEAD -- ./test  <2>
+$ git diff HEAD^ HEAD      <3>
+------------
++
+<1> Instead of using the tip of the current branch, compare with the
+    tip of "test" branch.
+<2> Instead of comparing with the tip of "test" branch, compare with
+    the tip of the current branch, but limit the comparison to the
+    file "test".
+<3> Compare the version before the last commit and the last commit.
+
+Comparing branches::
++
+------------
+$ git diff topic master    <1>
+$ git diff topic..master   <2>
+$ git diff topic...master  <3>
+------------
++
+<1> Changes between the tips of the topic and the master branches.
+<2> Same as above.
+<3> Changes that occurred on the master branch since when the topic
+    branch was started off it.
+
+Limiting the diff output::
++
+------------
+$ git diff --diff-filter=MRC            <1>
+$ git diff --name-status                <2>
+$ git diff arch/i386 include/asm-i386   <3>
+------------
++
+<1> Show only modification, rename, and copy, but not addition
+    or deletion.
+<2> Show only names and the nature of change, but not actual
+    diff output.
+<3> Limit diff output to named subtrees.
+
+Munging the diff output::
++
+------------
+$ git diff --find-copies-harder -B -C  <1>
+$ git diff -R                          <2>
+------------
++
+<1> Spend extra cycles to find renames, copies and complete
+    rewrites (very expensive).
+<2> Output diff in reverse.
+
+SEE ALSO
+--------
+diff(1),
+linkgit:git-difftool[1],
+linkgit:git-log[1],
+linkgit:gitdiffcore[7],
+linkgit:git-format-patch[1],
+linkgit:git-apply[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-difftool.txt b/third_party/git/Documentation/git-difftool.txt
new file mode 100644
index 0000000000..484c485fd0
--- /dev/null
+++ b/third_party/git/Documentation/git-difftool.txt
@@ -0,0 +1,149 @@
+git-difftool(1)
+===============
+
+NAME
+----
+git-difftool - Show changes using common diff tools
+
+SYNOPSIS
+--------
+[verse]
+'git difftool' [<options>] [<commit> [<commit>]] [--] [<path>...]
+
+DESCRIPTION
+-----------
+'git difftool' is a Git command that allows you to compare and edit files
+between revisions using common diff tools.  'git difftool' is a frontend
+to 'git diff' and accepts the same options and arguments. See
+linkgit:git-diff[1].
+
+OPTIONS
+-------
+-d::
+--dir-diff::
+	Copy the modified files to a temporary location and perform
+	a directory diff on them. This mode never prompts before
+	launching the diff tool.
+
+-y::
+--no-prompt::
+	Do not prompt before launching a diff tool.
+
+--prompt::
+	Prompt before each invocation of the diff tool.
+	This is the default behaviour; the option is provided to
+	override any configuration settings.
+
+-t <tool>::
+--tool=<tool>::
+	Use the diff tool specified by <tool>.  Valid values include
+	emerge, kompare, meld, and vimdiff. Run `git difftool --tool-help`
+	for the list of valid <tool> settings.
++
+If a diff tool is not specified, 'git difftool'
+will use the configuration variable `diff.tool`.  If the
+configuration variable `diff.tool` is not set, 'git difftool'
+will pick a suitable default.
++
+You can explicitly provide a full path to the tool by setting the
+configuration variable `difftool.<tool>.path`. For example, you
+can configure the absolute path to kdiff3 by setting
+`difftool.kdiff3.path`. Otherwise, 'git difftool' assumes the
+tool is available in PATH.
++
+Instead of running one of the known diff tools,
+'git difftool' can be customized to run an alternative program
+by specifying the command line to invoke in a configuration
+variable `difftool.<tool>.cmd`.
++
+When 'git difftool' is invoked with this tool (either through the
+`-t` or `--tool` option or the `diff.tool` configuration variable)
+the configured command line will be invoked with the following
+variables available: `$LOCAL` is set to the name of the temporary
+file containing the contents of the diff pre-image and `$REMOTE`
+is set to the name of the temporary file containing the contents
+of the diff post-image.  `$MERGED` is the name of the file which is
+being compared. `$BASE` is provided for compatibility
+with custom merge tool commands and has the same value as `$MERGED`.
+
+--tool-help::
+	Print a list of diff tools that may be used with `--tool`.
+
+--[no-]symlinks::
+	'git difftool''s default behavior is create symlinks to the
+	working tree when run in `--dir-diff` mode and the right-hand
+	side of the comparison yields the same content as the file in
+	the working tree.
++
+Specifying `--no-symlinks` instructs 'git difftool' to create copies
+instead.  `--no-symlinks` is the default on Windows.
+
+-x <command>::
+--extcmd=<command>::
+	Specify a custom command for viewing diffs.
+	'git-difftool' ignores the configured defaults and runs
+	`$command $LOCAL $REMOTE` when this option is specified.
+	Additionally, `$BASE` is set in the environment.
+
+-g::
+--[no-]gui::
+	When 'git-difftool' is invoked with the `-g` or `--gui` option
+	the default diff tool will be read from the configured
+	`diff.guitool` variable instead of `diff.tool`. The `--no-gui`
+	option can be used to override this setting. If `diff.guitool`
+	is not set, we will fallback in the order of `merge.guitool`,
+	`diff.tool`, `merge.tool` until a tool is found.
+
+--[no-]trust-exit-code::
+	'git-difftool' invokes a diff tool individually on each file.
+	Errors reported by the diff tool are ignored by default.
+	Use `--trust-exit-code` to make 'git-difftool' exit when an
+	invoked diff tool returns a non-zero exit code.
++
+'git-difftool' will forward the exit code of the invoked tool when
+`--trust-exit-code` is used.
+
+See linkgit:git-diff[1] for the full list of supported options.
+
+CONFIG VARIABLES
+----------------
+'git difftool' falls back to 'git mergetool' config variables when the
+difftool equivalents have not been defined.
+
+diff.tool::
+	The default diff tool to use.
+
+diff.guitool::
+	The default diff tool to use when `--gui` is specified.
+
+difftool.<tool>.path::
+	Override the path for the given tool.  This is useful in case
+	your tool is not in the PATH.
+
+difftool.<tool>.cmd::
+	Specify the command to invoke the specified diff tool.
++
+See the `--tool=<tool>` option above for more details.
+
+difftool.prompt::
+	Prompt before each invocation of the diff tool.
+
+difftool.trustExitCode::
+	Exit difftool if the invoked diff tool returns a non-zero exit status.
++
+See the `--trust-exit-code` option above for more details.
+
+SEE ALSO
+--------
+linkgit:git-diff[1]::
+	 Show changes between commits, commit and working tree, etc
+
+linkgit:git-mergetool[1]::
+	Run merge conflict resolution tools to resolve merge conflicts
+
+linkgit:git-config[1]::
+	 Get and set repository or global options
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fast-export.txt b/third_party/git/Documentation/git-fast-export.txt
new file mode 100644
index 0000000000..cc940eb9ad
--- /dev/null
+++ b/third_party/git/Documentation/git-fast-export.txt
@@ -0,0 +1,246 @@
+git-fast-export(1)
+==================
+
+NAME
+----
+git-fast-export - Git data exporter
+
+
+SYNOPSIS
+--------
+[verse]
+'git fast-export [<options>]' | 'git fast-import'
+
+DESCRIPTION
+-----------
+This program dumps the given revisions in a form suitable to be piped
+into 'git fast-import'.
+
+You can use it as a human-readable bundle replacement (see
+linkgit:git-bundle[1]), or as a kind of an interactive
+'git filter-branch'.
+
+
+OPTIONS
+-------
+--progress=<n>::
+	Insert 'progress' statements every <n> objects, to be shown by
+	'git fast-import' during import.
+
+--signed-tags=(verbatim|warn|warn-strip|strip|abort)::
+	Specify how to handle signed tags.  Since any transformation
+	after the export can change the tag names (which can also happen
+	when excluding revisions) the signatures will not match.
++
+When asking to 'abort' (which is the default), this program will die
+when encountering a signed tag.  With 'strip', the tags will silently
+be made unsigned, with 'warn-strip' they will be made unsigned but a
+warning will be displayed, with 'verbatim', they will be silently
+exported and with 'warn', they will be exported, but you will see a
+warning.
+
+--tag-of-filtered-object=(abort|drop|rewrite)::
+	Specify how to handle tags whose tagged object is filtered out.
+	Since revisions and files to export can be limited by path,
+	tagged objects may be filtered completely.
++
+When asking to 'abort' (which is the default), this program will die
+when encountering such a tag.  With 'drop' it will omit such tags from
+the output.  With 'rewrite', if the tagged object is a commit, it will
+rewrite the tag to tag an ancestor commit (via parent rewriting; see
+linkgit:git-rev-list[1])
+
+-M::
+-C::
+	Perform move and/or copy detection, as described in the
+	linkgit:git-diff[1] manual page, and use it to generate
+	rename and copy commands in the output dump.
++
+Note that earlier versions of this command did not complain and
+produced incorrect results if you gave these options.
+
+--export-marks=<file>::
+	Dumps the internal marks table to <file> when complete.
+	Marks are written one per line as `:markid SHA-1`. Only marks
+	for revisions are dumped; marks for blobs are ignored.
+	Backends can use this file to validate imports after they
+	have been completed, or to save the marks table across
+	incremental runs.  As <file> is only opened and truncated
+	at completion, the same path can also be safely given to
+	--import-marks.
+	The file will not be written if no new object has been
+	marked/exported.
+
+--import-marks=<file>::
+	Before processing any input, load the marks specified in
+	<file>.  The input file must exist, must be readable, and
+	must use the same format as produced by --export-marks.
++
+Any commits that have already been marked will not be exported again.
+If the backend uses a similar --import-marks file, this allows for
+incremental bidirectional exporting of the repository by keeping the
+marks the same across runs.
+
+--fake-missing-tagger::
+	Some old repositories have tags without a tagger.  The
+	fast-import protocol was pretty strict about that, and did not
+	allow that.  So fake a tagger to be able to fast-import the
+	output.
+
+--use-done-feature::
+	Start the stream with a 'feature done' stanza, and terminate
+	it with a 'done' command.
+
+--no-data::
+	Skip output of blob objects and instead refer to blobs via
+	their original SHA-1 hash.  This is useful when rewriting the
+	directory structure or history of a repository without
+	touching the contents of individual files.  Note that the
+	resulting stream can only be used by a repository which
+	already contains the necessary objects.
+
+--full-tree::
+	This option will cause fast-export to issue a "deleteall"
+	directive for each commit followed by a full list of all files
+	in the commit (as opposed to just listing the files which are
+	different from the commit's first parent).
+
+--anonymize::
+	Anonymize the contents of the repository while still retaining
+	the shape of the history and stored tree.  See the section on
+	`ANONYMIZING` below.
+
+--reference-excluded-parents::
+	By default, running a command such as `git fast-export
+	master~5..master` will not include the commit master{tilde}5
+	and will make master{tilde}4 no longer have master{tilde}5 as
+	a parent (though both the old master{tilde}4 and new
+	master{tilde}4 will have all the same files).  Use
+	--reference-excluded-parents to instead have the stream
+	refer to commits in the excluded range of history by their
+	sha1sum.  Note that the resulting stream can only be used by a
+	repository which already contains the necessary parent
+	commits.
+
+--show-original-ids::
+	Add an extra directive to the output for commits and blobs,
+	`original-oid <SHA1SUM>`.  While such directives will likely be
+	ignored by importers such as git-fast-import, it may be useful
+	for intermediary filters (e.g. for rewriting commit messages
+	which refer to older commits, or for stripping blobs by id).
+
+--reencode=(yes|no|abort)::
+	Specify how to handle `encoding` header in commit objects.  When
+	asking to 'abort' (which is the default), this program will die
+	when encountering such a commit object.  With 'yes', the commit
+	message will be reencoded into UTF-8.  With 'no', the original
+	encoding will be preserved.
+
+--refspec::
+	Apply the specified refspec to each ref exported. Multiple of them can
+	be specified.
+
+[<git-rev-list-args>...]::
+	A list of arguments, acceptable to 'git rev-parse' and
+	'git rev-list', that specifies the specific objects and references
+	to export.  For example, `master~10..master` causes the
+	current master reference to be exported along with all objects
+	added since its 10th ancestor commit and (unless the
+	--reference-excluded-parents option is specified) all files
+	common to master{tilde}9 and master{tilde}10.
+
+EXAMPLES
+--------
+
+-------------------------------------------------------------------
+$ git fast-export --all | (cd /empty/repository && git fast-import)
+-------------------------------------------------------------------
+
+This will export the whole repository and import it into the existing
+empty repository.  Except for reencoding commits that are not in
+UTF-8, it would be a one-to-one mirror.
+
+-----------------------------------------------------
+$ git fast-export master~5..master |
+	sed "s|refs/heads/master|refs/heads/other|" |
+	git fast-import
+-----------------------------------------------------
+
+This makes a new branch called 'other' from 'master~5..master'
+(i.e. if 'master' has linear history, it will take the last 5 commits).
+
+Note that this assumes that none of the blobs and commit messages
+referenced by that revision range contains the string
+'refs/heads/master'.
+
+
+ANONYMIZING
+-----------
+
+If the `--anonymize` option is given, git will attempt to remove all
+identifying information from the repository while still retaining enough
+of the original tree and history patterns to reproduce some bugs. The
+goal is that a git bug which is found on a private repository will
+persist in the anonymized repository, and the latter can be shared with
+git developers to help solve the bug.
+
+With this option, git will replace all refnames, paths, blob contents,
+commit and tag messages, names, and email addresses in the output with
+anonymized data.  Two instances of the same string will be replaced
+equivalently (e.g., two commits with the same author will have the same
+anonymized author in the output, but bear no resemblance to the original
+author string). The relationship between commits, branches, and tags is
+retained, as well as the commit timestamps (but the commit messages and
+refnames bear no resemblance to the originals). The relative makeup of
+the tree is retained (e.g., if you have a root tree with 10 files and 3
+trees, so will the output), but their names and the contents of the
+files will be replaced.
+
+If you think you have found a git bug, you can start by exporting an
+anonymized stream of the whole repository:
+
+---------------------------------------------------
+$ git fast-export --anonymize --all >anon-stream
+---------------------------------------------------
+
+Then confirm that the bug persists in a repository created from that
+stream (many bugs will not, as they really do depend on the exact
+repository contents):
+
+---------------------------------------------------
+$ git init anon-repo
+$ cd anon-repo
+$ git fast-import <../anon-stream
+$ ... test your bug ...
+---------------------------------------------------
+
+If the anonymized repository shows the bug, it may be worth sharing
+`anon-stream` along with a regular bug report. Note that the anonymized
+stream compresses very well, so gzipping it is encouraged. If you want
+to examine the stream to see that it does not contain any private data,
+you can peruse it directly before sending. You may also want to try:
+
+---------------------------------------------------
+$ perl -pe 's/\d+/X/g' <anon-stream | sort -u | less
+---------------------------------------------------
+
+which shows all of the unique lines (with numbers converted to "X", to
+collapse "User 0", "User 1", etc into "User X"). This produces a much
+smaller output, and it is usually easy to quickly confirm that there is
+no private data in the stream.
+
+
+LIMITATIONS
+-----------
+
+Since 'git fast-import' cannot tag trees, you will not be
+able to export the linux.git repository completely, as it contains
+a tag referencing a tree instead of a commit.
+
+SEE ALSO
+--------
+linkgit:git-fast-import[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fast-import.txt b/third_party/git/Documentation/git-fast-import.txt
new file mode 100644
index 0000000000..fad327aecc
--- /dev/null
+++ b/third_party/git/Documentation/git-fast-import.txt
@@ -0,0 +1,1508 @@
+git-fast-import(1)
+==================
+
+NAME
+----
+git-fast-import - Backend for fast Git data importers
+
+
+SYNOPSIS
+--------
+[verse]
+frontend | 'git fast-import' [<options>]
+
+DESCRIPTION
+-----------
+This program is usually not what the end user wants to run directly.
+Most end users want to use one of the existing frontend programs,
+which parses a specific type of foreign source and feeds the contents
+stored there to 'git fast-import'.
+
+fast-import reads a mixed command/data stream from standard input and
+writes one or more packfiles directly into the current repository.
+When EOF is received on standard input, fast import writes out
+updated branch and tag refs, fully updating the current repository
+with the newly imported data.
+
+The fast-import backend itself can import into an empty repository (one that
+has already been initialized by 'git init') or incrementally
+update an existing populated repository.  Whether or not incremental
+imports are supported from a particular foreign source depends on
+the frontend program in use.
+
+
+OPTIONS
+-------
+
+--force::
+	Force updating modified existing branches, even if doing
+	so would cause commits to be lost (as the new commit does
+	not contain the old commit).
+
+--quiet::
+	Disable the output shown by --stats, making fast-import usually
+	be silent when it is successful.  However, if the import stream
+	has directives intended to show user output (e.g. `progress`
+	directives), the corresponding messages will still be shown.
+
+--stats::
+	Display some basic statistics about the objects fast-import has
+	created, the packfiles they were stored into, and the
+	memory used by fast-import during this run.  Showing this output
+	is currently the default, but can be disabled with --quiet.
+
+Options for Frontends
+~~~~~~~~~~~~~~~~~~~~~
+
+--cat-blob-fd=<fd>::
+	Write responses to `get-mark`, `cat-blob`, and `ls` queries to the
+	file descriptor <fd> instead of `stdout`.  Allows `progress`
+	output intended for the end-user to be separated from other
+	output.
+
+--date-format=<fmt>::
+	Specify the type of dates the frontend will supply to
+	fast-import within `author`, `committer` and `tagger` commands.
+	See ``Date Formats'' below for details about which formats
+	are supported, and their syntax.
+
+--done::
+	Terminate with error if there is no `done` command at the end of
+	the stream.  This option might be useful for detecting errors
+	that cause the frontend to terminate before it has started to
+	write a stream.
+
+Locations of Marks Files
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+--export-marks=<file>::
+	Dumps the internal marks table to <file> when complete.
+	Marks are written one per line as `:markid SHA-1`.
+	Frontends can use this file to validate imports after they
+	have been completed, or to save the marks table across
+	incremental runs.  As <file> is only opened and truncated
+	at checkpoint (or completion) the same path can also be
+	safely given to --import-marks.
+
+--import-marks=<file>::
+	Before processing any input, load the marks specified in
+	<file>.  The input file must exist, must be readable, and
+	must use the same format as produced by --export-marks.
+	Multiple options may be supplied to import more than one
+	set of marks.  If a mark is defined to different values,
+	the last file wins.
+
+--import-marks-if-exists=<file>::
+	Like --import-marks but instead of erroring out, silently
+	skips the file if it does not exist.
+
+--[no-]relative-marks::
+	After specifying --relative-marks the paths specified
+	with --import-marks= and --export-marks= are relative
+	to an internal directory in the current repository.
+	In git-fast-import this means that the paths are relative
+	to the .git/info/fast-import directory. However, other
+	importers may use a different location.
++
+Relative and non-relative marks may be combined by interweaving
+--(no-)-relative-marks with the --(import|export)-marks= options.
+
+Performance and Compression Tuning
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+--active-branches=<n>::
+	Maximum number of branches to maintain active at once.
+	See ``Memory Utilization'' below for details.  Default is 5.
+
+--big-file-threshold=<n>::
+	Maximum size of a blob that fast-import will attempt to
+	create a delta for, expressed in bytes.  The default is 512m
+	(512 MiB).  Some importers may wish to lower this on systems
+	with constrained memory.
+
+--depth=<n>::
+	Maximum delta depth, for blob and tree deltification.
+	Default is 50.
+
+--export-pack-edges=<file>::
+	After creating a packfile, print a line of data to
+	<file> listing the filename of the packfile and the last
+	commit on each branch that was written to that packfile.
+	This information may be useful after importing projects
+	whose total object set exceeds the 4 GiB packfile limit,
+	as these commits can be used as edge points during calls
+	to 'git pack-objects'.
+
+--max-pack-size=<n>::
+	Maximum size of each output packfile.
+	The default is unlimited.
+
+fastimport.unpackLimit::
+	See linkgit:git-config[1]
+
+PERFORMANCE
+-----------
+The design of fast-import allows it to import large projects in a minimum
+amount of memory usage and processing time.  Assuming the frontend
+is able to keep up with fast-import and feed it a constant stream of data,
+import times for projects holding 10+ years of history and containing
+100,000+ individual commits are generally completed in just 1-2
+hours on quite modest (~$2,000 USD) hardware.
+
+Most bottlenecks appear to be in foreign source data access (the
+source just cannot extract revisions fast enough) or disk IO (fast-import
+writes as fast as the disk will take the data).  Imports will run
+faster if the source data is stored on a different drive than the
+destination Git repository (due to less IO contention).
+
+
+DEVELOPMENT COST
+----------------
+A typical frontend for fast-import tends to weigh in at approximately 200
+lines of Perl/Python/Ruby code.  Most developers have been able to
+create working importers in just a couple of hours, even though it
+is their first exposure to fast-import, and sometimes even to Git.  This is
+an ideal situation, given that most conversion tools are throw-away
+(use once, and never look back).
+
+
+PARALLEL OPERATION
+------------------
+Like 'git push' or 'git fetch', imports handled by fast-import are safe to
+run alongside parallel `git repack -a -d` or `git gc` invocations,
+or any other Git operation (including 'git prune', as loose objects
+are never used by fast-import).
+
+fast-import does not lock the branch or tag refs it is actively importing.
+After the import, during its ref update phase, fast-import tests each
+existing branch ref to verify the update will be a fast-forward
+update (the commit stored in the ref is contained in the new
+history of the commit to be written).  If the update is not a
+fast-forward update, fast-import will skip updating that ref and instead
+prints a warning message.  fast-import will always attempt to update all
+branch refs, and does not stop on the first failure.
+
+Branch updates can be forced with --force, but it's recommended that
+this only be used on an otherwise quiet repository.  Using --force
+is not necessary for an initial import into an empty repository.
+
+
+TECHNICAL DISCUSSION
+--------------------
+fast-import tracks a set of branches in memory.  Any branch can be created
+or modified at any point during the import process by sending a
+`commit` command on the input stream.  This design allows a frontend
+program to process an unlimited number of branches simultaneously,
+generating commits in the order they are available from the source
+data.  It also simplifies the frontend programs considerably.
+
+fast-import does not use or alter the current working directory, or any
+file within it.  (It does however update the current Git repository,
+as referenced by `GIT_DIR`.)  Therefore an import frontend may use
+the working directory for its own purposes, such as extracting file
+revisions from the foreign source.  This ignorance of the working
+directory also allows fast-import to run very quickly, as it does not
+need to perform any costly file update operations when switching
+between branches.
+
+INPUT FORMAT
+------------
+With the exception of raw file data (which Git does not interpret)
+the fast-import input format is text (ASCII) based.  This text based
+format simplifies development and debugging of frontend programs,
+especially when a higher level language such as Perl, Python or
+Ruby is being used.
+
+fast-import is very strict about its input.  Where we say SP below we mean
+*exactly* one space.  Likewise LF means one (and only one) linefeed
+and HT one (and only one) horizontal tab.
+Supplying additional whitespace characters will cause unexpected
+results, such as branch names or file names with leading or trailing
+spaces in their name, or early termination of fast-import when it encounters
+unexpected input.
+
+Stream Comments
+~~~~~~~~~~~~~~~
+To aid in debugging frontends fast-import ignores any line that
+begins with `#` (ASCII pound/hash) up to and including the line
+ending `LF`.  A comment line may contain any sequence of bytes
+that does not contain an LF and therefore may be used to include
+any detailed debugging information that might be specific to the
+frontend and useful when inspecting a fast-import data stream.
+
+Date Formats
+~~~~~~~~~~~~
+The following date formats are supported.  A frontend should select
+the format it will use for this import by passing the format name
+in the --date-format=<fmt> command-line option.
+
+`raw`::
+	This is the Git native format and is `<time> SP <offutc>`.
+	It is also fast-import's default format, if --date-format was
+	not specified.
++
+The time of the event is specified by `<time>` as the number of
+seconds since the UNIX epoch (midnight, Jan 1, 1970, UTC) and is
+written as an ASCII decimal integer.
++
+The local offset is specified by `<offutc>` as a positive or negative
+offset from UTC.  For example EST (which is 5 hours behind UTC)
+would be expressed in `<tz>` by ``-0500'' while UTC is ``+0000''.
+The local offset does not affect `<time>`; it is used only as an
+advisement to help formatting routines display the timestamp.
++
+If the local offset is not available in the source material, use
+``+0000'', or the most common local offset.  For example many
+organizations have a CVS repository which has only ever been accessed
+by users who are located in the same location and time zone.  In this
+case a reasonable offset from UTC could be assumed.
++
+Unlike the `rfc2822` format, this format is very strict.  Any
+variation in formatting will cause fast-import to reject the value.
+
+`rfc2822`::
+	This is the standard email format as described by RFC 2822.
++
+An example value is ``Tue Feb 6 11:22:18 2007 -0500''.  The Git
+parser is accurate, but a little on the lenient side.  It is the
+same parser used by 'git am' when applying patches
+received from email.
++
+Some malformed strings may be accepted as valid dates.  In some of
+these cases Git will still be able to obtain the correct date from
+the malformed string.  There are also some types of malformed
+strings which Git will parse wrong, and yet consider valid.
+Seriously malformed strings will be rejected.
++
+Unlike the `raw` format above, the time zone/UTC offset information
+contained in an RFC 2822 date string is used to adjust the date
+value to UTC prior to storage.  Therefore it is important that
+this information be as accurate as possible.
++
+If the source material uses RFC 2822 style dates,
+the frontend should let fast-import handle the parsing and conversion
+(rather than attempting to do it itself) as the Git parser has
+been well tested in the wild.
++
+Frontends should prefer the `raw` format if the source material
+already uses UNIX-epoch format, can be coaxed to give dates in that
+format, or its format is easily convertible to it, as there is no
+ambiguity in parsing.
+
+`now`::
+	Always use the current time and time zone.  The literal
+	`now` must always be supplied for `<when>`.
++
+This is a toy format.  The current time and time zone of this system
+is always copied into the identity string at the time it is being
+created by fast-import.  There is no way to specify a different time or
+time zone.
++
+This particular format is supplied as it's short to implement and
+may be useful to a process that wants to create a new commit
+right now, without needing to use a working directory or
+'git update-index'.
++
+If separate `author` and `committer` commands are used in a `commit`
+the timestamps may not match, as the system clock will be polled
+twice (once for each command).  The only way to ensure that both
+author and committer identity information has the same timestamp
+is to omit `author` (thus copying from `committer`) or to use a
+date format other than `now`.
+
+Commands
+~~~~~~~~
+fast-import accepts several commands to update the current repository
+and control the current import process.  More detailed discussion
+(with examples) of each command follows later.
+
+`commit`::
+	Creates a new branch or updates an existing branch by
+	creating a new commit and updating the branch to point at
+	the newly created commit.
+
+`tag`::
+	Creates an annotated tag object from an existing commit or
+	branch.  Lightweight tags are not supported by this command,
+	as they are not recommended for recording meaningful points
+	in time.
+
+`reset`::
+	Reset an existing branch (or a new branch) to a specific
+	revision.  This command must be used to change a branch to
+	a specific revision without making a commit on it.
+
+`blob`::
+	Convert raw file data into a blob, for future use in a
+	`commit` command.  This command is optional and is not
+	needed to perform an import.
+
+`checkpoint`::
+	Forces fast-import to close the current packfile, generate its
+	unique SHA-1 checksum and index, and start a new packfile.
+	This command is optional and is not needed to perform
+	an import.
+
+`progress`::
+	Causes fast-import to echo the entire line to its own
+	standard output.  This command is optional and is not needed
+	to perform an import.
+
+`done`::
+	Marks the end of the stream. This command is optional
+	unless the `done` feature was requested using the
+	`--done` command-line option or `feature done` command.
+
+`get-mark`::
+	Causes fast-import to print the SHA-1 corresponding to a mark
+	to the file descriptor set with `--cat-blob-fd`, or `stdout` if
+	unspecified.
+
+`cat-blob`::
+	Causes fast-import to print a blob in 'cat-file --batch'
+	format to the file descriptor set with `--cat-blob-fd` or
+	`stdout` if unspecified.
+
+`ls`::
+	Causes fast-import to print a line describing a directory
+	entry in 'ls-tree' format to the file descriptor set with
+	`--cat-blob-fd` or `stdout` if unspecified.
+
+`feature`::
+	Enable the specified feature. This requires that fast-import
+	supports the specified feature, and aborts if it does not.
+
+`option`::
+	Specify any of the options listed under OPTIONS that do not
+	change stream semantic to suit the frontend's needs. This
+	command is optional and is not needed to perform an import.
+
+`commit`
+~~~~~~~~
+Create or update a branch with a new commit, recording one logical
+change to the project.
+
+....
+	'commit' SP <ref> LF
+	mark?
+	original-oid?
+	('author' (SP <name>)? SP LT <email> GT SP <when> LF)?
+	'committer' (SP <name>)? SP LT <email> GT SP <when> LF
+	('encoding' SP <encoding>)?
+	data
+	('from' SP <commit-ish> LF)?
+	('merge' SP <commit-ish> LF)?
+	(filemodify | filedelete | filecopy | filerename | filedeleteall | notemodify)*
+	LF?
+....
+
+where `<ref>` is the name of the branch to make the commit on.
+Typically branch names are prefixed with `refs/heads/` in
+Git, so importing the CVS branch symbol `RELENG-1_0` would use
+`refs/heads/RELENG-1_0` for the value of `<ref>`.  The value of
+`<ref>` must be a valid refname in Git.  As `LF` is not valid in
+a Git refname, no quoting or escaping syntax is supported here.
+
+A `mark` command may optionally appear, requesting fast-import to save a
+reference to the newly created commit for future use by the frontend
+(see below for format).  It is very common for frontends to mark
+every commit they create, thereby allowing future branch creation
+from any imported commit.
+
+The `data` command following `committer` must supply the commit
+message (see below for `data` command syntax).  To import an empty
+commit message use a 0 length data.  Commit messages are free-form
+and are not interpreted by Git.  Currently they must be encoded in
+UTF-8, as fast-import does not permit other encodings to be specified.
+
+Zero or more `filemodify`, `filedelete`, `filecopy`, `filerename`,
+`filedeleteall` and `notemodify` commands
+may be included to update the contents of the branch prior to
+creating the commit.  These commands may be supplied in any order.
+However it is recommended that a `filedeleteall` command precede
+all `filemodify`, `filecopy`, `filerename` and `notemodify` commands in
+the same commit, as `filedeleteall` wipes the branch clean (see below).
+
+The `LF` after the command is optional (it used to be required).  Note
+that for reasons of backward compatibility, if the commit ends with a
+`data` command (i.e. it has no `from`, `merge`, `filemodify`,
+`filedelete`, `filecopy`, `filerename`, `filedeleteall` or
+`notemodify` commands) then two `LF` commands may appear at the end of
+the command instead of just one.
+
+`author`
+^^^^^^^^
+An `author` command may optionally appear, if the author information
+might differ from the committer information.  If `author` is omitted
+then fast-import will automatically use the committer's information for
+the author portion of the commit.  See below for a description of
+the fields in `author`, as they are identical to `committer`.
+
+`committer`
+^^^^^^^^^^^
+The `committer` command indicates who made this commit, and when
+they made it.
+
+Here `<name>` is the person's display name (for example
+``Com M Itter'') and `<email>` is the person's email address
+(``\cm@example.com'').  `LT` and `GT` are the literal less-than (\x3c)
+and greater-than (\x3e) symbols.  These are required to delimit
+the email address from the other fields in the line.  Note that
+`<name>` and `<email>` are free-form and may contain any sequence
+of bytes, except `LT`, `GT` and `LF`.  `<name>` is typically UTF-8 encoded.
+
+The time of the change is specified by `<when>` using the date format
+that was selected by the --date-format=<fmt> command-line option.
+See ``Date Formats'' above for the set of supported formats, and
+their syntax.
+
+`encoding`
+^^^^^^^^^^
+The optional `encoding` command indicates the encoding of the commit
+message.  Most commits are UTF-8 and the encoding is omitted, but this
+allows importing commit messages into git without first reencoding them.
+
+`from`
+^^^^^^
+The `from` command is used to specify the commit to initialize
+this branch from.  This revision will be the first ancestor of the
+new commit.  The state of the tree built at this commit will begin
+with the state at the `from` commit, and be altered by the content
+modifications in this commit.
+
+Omitting the `from` command in the first commit of a new branch
+will cause fast-import to create that commit with no ancestor. This
+tends to be desired only for the initial commit of a project.
+If the frontend creates all files from scratch when making a new
+branch, a `merge` command may be used instead of `from` to start
+the commit with an empty tree.
+Omitting the `from` command on existing branches is usually desired,
+as the current commit on that branch is automatically assumed to
+be the first ancestor of the new commit.
+
+As `LF` is not valid in a Git refname or SHA-1 expression, no
+quoting or escaping syntax is supported within `<commit-ish>`.
+
+Here `<commit-ish>` is any of the following:
+
+* The name of an existing branch already in fast-import's internal branch
+  table.  If fast-import doesn't know the name, it's treated as a SHA-1
+  expression.
+
+* A mark reference, `:<idnum>`, where `<idnum>` is the mark number.
++
+The reason fast-import uses `:` to denote a mark reference is this character
+is not legal in a Git branch name.  The leading `:` makes it easy
+to distinguish between the mark 42 (`:42`) and the branch 42 (`42`
+or `refs/heads/42`), or an abbreviated SHA-1 which happened to
+consist only of base-10 digits.
++
+Marks must be declared (via `mark`) before they can be used.
+
+* A complete 40 byte or abbreviated commit SHA-1 in hex.
+
+* Any valid Git SHA-1 expression that resolves to a commit.  See
+  ``SPECIFYING REVISIONS'' in linkgit:gitrevisions[7] for details.
+
+* The special null SHA-1 (40 zeros) specifies that the branch is to be
+  removed.
+
+The special case of restarting an incremental import from the
+current branch value should be written as:
+----
+	from refs/heads/branch^0
+----
+The `^0` suffix is necessary as fast-import does not permit a branch to
+start from itself, and the branch is created in memory before the
+`from` command is even read from the input.  Adding `^0` will force
+fast-import to resolve the commit through Git's revision parsing library,
+rather than its internal branch table, thereby loading in the
+existing value of the branch.
+
+`merge`
+^^^^^^^
+Includes one additional ancestor commit.  The additional ancestry
+link does not change the way the tree state is built at this commit.
+If the `from` command is
+omitted when creating a new branch, the first `merge` commit will be
+the first ancestor of the current commit, and the branch will start
+out with no files.  An unlimited number of `merge` commands per
+commit are permitted by fast-import, thereby establishing an n-way merge.
+
+Here `<commit-ish>` is any of the commit specification expressions
+also accepted by `from` (see above).
+
+`filemodify`
+^^^^^^^^^^^^
+Included in a `commit` command to add a new file or change the
+content of an existing file.  This command has two different means
+of specifying the content of the file.
+
+External data format::
+	The data content for the file was already supplied by a prior
+	`blob` command.  The frontend just needs to connect it.
++
+....
+	'M' SP <mode> SP <dataref> SP <path> LF
+....
++
+Here usually `<dataref>` must be either a mark reference (`:<idnum>`)
+set by a prior `blob` command, or a full 40-byte SHA-1 of an
+existing Git blob object.  If `<mode>` is `040000`` then
+`<dataref>` must be the full 40-byte SHA-1 of an existing
+Git tree object or a mark reference set with `--import-marks`.
+
+Inline data format::
+	The data content for the file has not been supplied yet.
+	The frontend wants to supply it as part of this modify
+	command.
++
+....
+	'M' SP <mode> SP 'inline' SP <path> LF
+	data
+....
++
+See below for a detailed description of the `data` command.
+
+In both formats `<mode>` is the type of file entry, specified
+in octal.  Git only supports the following modes:
+
+* `100644` or `644`: A normal (not-executable) file.  The majority
+  of files in most projects use this mode.  If in doubt, this is
+  what you want.
+* `100755` or `755`: A normal, but executable, file.
+* `120000`: A symlink, the content of the file will be the link target.
+* `160000`: A gitlink, SHA-1 of the object refers to a commit in
+  another repository. Git links can only be specified by SHA or through
+  a commit mark. They are used to implement submodules.
+* `040000`: A subdirectory.  Subdirectories can only be specified by
+  SHA or through a tree mark set with `--import-marks`.
+
+In both formats `<path>` is the complete path of the file to be added
+(if not already existing) or modified (if already existing).
+
+A `<path>` string must use UNIX-style directory separators (forward
+slash `/`), may contain any byte other than `LF`, and must not
+start with double quote (`"`).
+
+A path can use C-style string quoting; this is accepted in all cases
+and mandatory if the filename starts with double quote or contains
+`LF`. In C-style quoting, the complete name should be surrounded with
+double quotes, and any `LF`, backslash, or double quote characters
+must be escaped by preceding them with a backslash (e.g.,
+`"path/with\n, \\ and \" in it"`).
+
+The value of `<path>` must be in canonical form. That is it must not:
+
+* contain an empty directory component (e.g. `foo//bar` is invalid),
+* end with a directory separator (e.g. `foo/` is invalid),
+* start with a directory separator (e.g. `/foo` is invalid),
+* contain the special component `.` or `..` (e.g. `foo/./bar` and
+  `foo/../bar` are invalid).
+
+The root of the tree can be represented by an empty string as `<path>`.
+
+It is recommended that `<path>` always be encoded using UTF-8.
+
+`filedelete`
+^^^^^^^^^^^^
+Included in a `commit` command to remove a file or recursively
+delete an entire directory from the branch.  If the file or directory
+removal makes its parent directory empty, the parent directory will
+be automatically removed too.  This cascades up the tree until the
+first non-empty directory or the root is reached.
+
+....
+	'D' SP <path> LF
+....
+
+here `<path>` is the complete path of the file or subdirectory to
+be removed from the branch.
+See `filemodify` above for a detailed description of `<path>`.
+
+`filecopy`
+^^^^^^^^^^
+Recursively copies an existing file or subdirectory to a different
+location within the branch.  The existing file or directory must
+exist.  If the destination exists it will be completely replaced
+by the content copied from the source.
+
+....
+	'C' SP <path> SP <path> LF
+....
+
+here the first `<path>` is the source location and the second
+`<path>` is the destination.  See `filemodify` above for a detailed
+description of what `<path>` may look like.  To use a source path
+that contains SP the path must be quoted.
+
+A `filecopy` command takes effect immediately.  Once the source
+location has been copied to the destination any future commands
+applied to the source location will not impact the destination of
+the copy.
+
+`filerename`
+^^^^^^^^^^^^
+Renames an existing file or subdirectory to a different location
+within the branch.  The existing file or directory must exist. If
+the destination exists it will be replaced by the source directory.
+
+....
+	'R' SP <path> SP <path> LF
+....
+
+here the first `<path>` is the source location and the second
+`<path>` is the destination.  See `filemodify` above for a detailed
+description of what `<path>` may look like.  To use a source path
+that contains SP the path must be quoted.
+
+A `filerename` command takes effect immediately.  Once the source
+location has been renamed to the destination any future commands
+applied to the source location will create new files there and not
+impact the destination of the rename.
+
+Note that a `filerename` is the same as a `filecopy` followed by a
+`filedelete` of the source location.  There is a slight performance
+advantage to using `filerename`, but the advantage is so small
+that it is never worth trying to convert a delete/add pair in
+source material into a rename for fast-import.  This `filerename`
+command is provided just to simplify frontends that already have
+rename information and don't want bother with decomposing it into a
+`filecopy` followed by a `filedelete`.
+
+`filedeleteall`
+^^^^^^^^^^^^^^^
+Included in a `commit` command to remove all files (and also all
+directories) from the branch.  This command resets the internal
+branch structure to have no files in it, allowing the frontend
+to subsequently add all interesting files from scratch.
+
+....
+	'deleteall' LF
+....
+
+This command is extremely useful if the frontend does not know
+(or does not care to know) what files are currently on the branch,
+and therefore cannot generate the proper `filedelete` commands to
+update the content.
+
+Issuing a `filedeleteall` followed by the needed `filemodify`
+commands to set the correct content will produce the same results
+as sending only the needed `filemodify` and `filedelete` commands.
+The `filedeleteall` approach may however require fast-import to use slightly
+more memory per active branch (less than 1 MiB for even most large
+projects); so frontends that can easily obtain only the affected
+paths for a commit are encouraged to do so.
+
+`notemodify`
+^^^^^^^^^^^^
+Included in a `commit` `<notes_ref>` command to add a new note
+annotating a `<commit-ish>` or change this annotation contents.
+Internally it is similar to filemodify 100644 on `<commit-ish>`
+path (maybe split into subdirectories). It's not advised to
+use any other commands to write to the `<notes_ref>` tree except
+`filedeleteall` to delete all existing notes in this tree.
+This command has two different means of specifying the content
+of the note.
+
+External data format::
+	The data content for the note was already supplied by a prior
+	`blob` command.  The frontend just needs to connect it to the
+	commit that is to be annotated.
++
+....
+	'N' SP <dataref> SP <commit-ish> LF
+....
++
+Here `<dataref>` can be either a mark reference (`:<idnum>`)
+set by a prior `blob` command, or a full 40-byte SHA-1 of an
+existing Git blob object.
+
+Inline data format::
+	The data content for the note has not been supplied yet.
+	The frontend wants to supply it as part of this modify
+	command.
++
+....
+	'N' SP 'inline' SP <commit-ish> LF
+	data
+....
++
+See below for a detailed description of the `data` command.
+
+In both formats `<commit-ish>` is any of the commit specification
+expressions also accepted by `from` (see above).
+
+`mark`
+~~~~~~
+Arranges for fast-import to save a reference to the current object, allowing
+the frontend to recall this object at a future point in time, without
+knowing its SHA-1.  Here the current object is the object creation
+command the `mark` command appears within.  This can be `commit`,
+`tag`, and `blob`, but `commit` is the most common usage.
+
+....
+	'mark' SP ':' <idnum> LF
+....
+
+where `<idnum>` is the number assigned by the frontend to this mark.
+The value of `<idnum>` is expressed as an ASCII decimal integer.
+The value 0 is reserved and cannot be used as
+a mark.  Only values greater than or equal to 1 may be used as marks.
+
+New marks are created automatically.  Existing marks can be moved
+to another object simply by reusing the same `<idnum>` in another
+`mark` command.
+
+`original-oid`
+~~~~~~~~~~~~~~
+Provides the name of the object in the original source control system.
+fast-import will simply ignore this directive, but filter processes
+which operate on and modify the stream before feeding to fast-import
+may have uses for this information
+
+....
+	'original-oid' SP <object-identifier> LF
+....
+
+where `<object-identifer>` is any string not containing LF.
+
+`tag`
+~~~~~
+Creates an annotated tag referring to a specific commit.  To create
+lightweight (non-annotated) tags see the `reset` command below.
+
+....
+	'tag' SP <name> LF
+	'from' SP <commit-ish> LF
+	original-oid?
+	'tagger' (SP <name>)? SP LT <email> GT SP <when> LF
+	data
+....
+
+where `<name>` is the name of the tag to create.
+
+Tag names are automatically prefixed with `refs/tags/` when stored
+in Git, so importing the CVS branch symbol `RELENG-1_0-FINAL` would
+use just `RELENG-1_0-FINAL` for `<name>`, and fast-import will write the
+corresponding ref as `refs/tags/RELENG-1_0-FINAL`.
+
+The value of `<name>` must be a valid refname in Git and therefore
+may contain forward slashes.  As `LF` is not valid in a Git refname,
+no quoting or escaping syntax is supported here.
+
+The `from` command is the same as in the `commit` command; see
+above for details.
+
+The `tagger` command uses the same format as `committer` within
+`commit`; again see above for details.
+
+The `data` command following `tagger` must supply the annotated tag
+message (see below for `data` command syntax).  To import an empty
+tag message use a 0 length data.  Tag messages are free-form and are
+not interpreted by Git.  Currently they must be encoded in UTF-8,
+as fast-import does not permit other encodings to be specified.
+
+Signing annotated tags during import from within fast-import is not
+supported.  Trying to include your own PGP/GPG signature is not
+recommended, as the frontend does not (easily) have access to the
+complete set of bytes which normally goes into such a signature.
+If signing is required, create lightweight tags from within fast-import with
+`reset`, then create the annotated versions of those tags offline
+with the standard 'git tag' process.
+
+`reset`
+~~~~~~~
+Creates (or recreates) the named branch, optionally starting from
+a specific revision.  The reset command allows a frontend to issue
+a new `from` command for an existing branch, or to create a new
+branch from an existing commit without creating a new commit.
+
+....
+	'reset' SP <ref> LF
+	('from' SP <commit-ish> LF)?
+	LF?
+....
+
+For a detailed description of `<ref>` and `<commit-ish>` see above
+under `commit` and `from`.
+
+The `LF` after the command is optional (it used to be required).
+
+The `reset` command can also be used to create lightweight
+(non-annotated) tags.  For example:
+
+====
+	reset refs/tags/938
+	from :938
+====
+
+would create the lightweight tag `refs/tags/938` referring to
+whatever commit mark `:938` references.
+
+`blob`
+~~~~~~
+Requests writing one file revision to the packfile.  The revision
+is not connected to any commit; this connection must be formed in
+a subsequent `commit` command by referencing the blob through an
+assigned mark.
+
+....
+	'blob' LF
+	mark?
+	original-oid?
+	data
+....
+
+The mark command is optional here as some frontends have chosen
+to generate the Git SHA-1 for the blob on their own, and feed that
+directly to `commit`.  This is typically more work than it's worth
+however, as marks are inexpensive to store and easy to use.
+
+`data`
+~~~~~~
+Supplies raw data (for use as blob/file content, commit messages, or
+annotated tag messages) to fast-import.  Data can be supplied using an exact
+byte count or delimited with a terminating line.  Real frontends
+intended for production-quality conversions should always use the
+exact byte count format, as it is more robust and performs better.
+The delimited format is intended primarily for testing fast-import.
+
+Comment lines appearing within the `<raw>` part of `data` commands
+are always taken to be part of the body of the data and are therefore
+never ignored by fast-import.  This makes it safe to import any
+file/message content whose lines might start with `#`.
+
+Exact byte count format::
+	The frontend must specify the number of bytes of data.
++
+....
+	'data' SP <count> LF
+	<raw> LF?
+....
++
+where `<count>` is the exact number of bytes appearing within
+`<raw>`.  The value of `<count>` is expressed as an ASCII decimal
+integer.  The `LF` on either side of `<raw>` is not
+included in `<count>` and will not be included in the imported data.
++
+The `LF` after `<raw>` is optional (it used to be required) but
+recommended.  Always including it makes debugging a fast-import
+stream easier as the next command always starts in column 0
+of the next line, even if `<raw>` did not end with an `LF`.
+
+Delimited format::
+	A delimiter string is used to mark the end of the data.
+	fast-import will compute the length by searching for the delimiter.
+	This format is primarily useful for testing and is not
+	recommended for real data.
++
+....
+	'data' SP '<<' <delim> LF
+	<raw> LF
+	<delim> LF
+	LF?
+....
++
+where `<delim>` is the chosen delimiter string.  The string `<delim>`
+must not appear on a line by itself within `<raw>`, as otherwise
+fast-import will think the data ends earlier than it really does.  The `LF`
+immediately trailing `<raw>` is part of `<raw>`.  This is one of
+the limitations of the delimited format, it is impossible to supply
+a data chunk which does not have an LF as its last byte.
++
+The `LF` after `<delim> LF` is optional (it used to be required).
+
+`checkpoint`
+~~~~~~~~~~~~
+Forces fast-import to close the current packfile, start a new one, and to
+save out all current branch refs, tags and marks.
+
+....
+	'checkpoint' LF
+	LF?
+....
+
+Note that fast-import automatically switches packfiles when the current
+packfile reaches --max-pack-size, or 4 GiB, whichever limit is
+smaller.  During an automatic packfile switch fast-import does not update
+the branch refs, tags or marks.
+
+As a `checkpoint` can require a significant amount of CPU time and
+disk IO (to compute the overall pack SHA-1 checksum, generate the
+corresponding index file, and update the refs) it can easily take
+several minutes for a single `checkpoint` command to complete.
+
+Frontends may choose to issue checkpoints during extremely large
+and long running imports, or when they need to allow another Git
+process access to a branch.  However given that a 30 GiB Subversion
+repository can be loaded into Git through fast-import in about 3 hours,
+explicit checkpointing may not be necessary.
+
+The `LF` after the command is optional (it used to be required).
+
+`progress`
+~~~~~~~~~~
+Causes fast-import to print the entire `progress` line unmodified to
+its standard output channel (file descriptor 1) when the command is
+processed from the input stream.  The command otherwise has no impact
+on the current import, or on any of fast-import's internal state.
+
+....
+	'progress' SP <any> LF
+	LF?
+....
+
+The `<any>` part of the command may contain any sequence of bytes
+that does not contain `LF`.  The `LF` after the command is optional.
+Callers may wish to process the output through a tool such as sed to
+remove the leading part of the line, for example:
+
+====
+	frontend | git fast-import | sed 's/^progress //'
+====
+
+Placing a `progress` command immediately after a `checkpoint` will
+inform the reader when the `checkpoint` has been completed and it
+can safely access the refs that fast-import updated.
+
+`get-mark`
+~~~~~~~~~~
+Causes fast-import to print the SHA-1 corresponding to a mark to
+stdout or to the file descriptor previously arranged with the
+`--cat-blob-fd` argument. The command otherwise has no impact on the
+current import; its purpose is to retrieve SHA-1s that later commits
+might want to refer to in their commit messages.
+
+....
+	'get-mark' SP ':' <idnum> LF
+....
+
+See ``Responses To Commands'' below for details about how to read
+this output safely.
+
+`cat-blob`
+~~~~~~~~~~
+Causes fast-import to print a blob to a file descriptor previously
+arranged with the `--cat-blob-fd` argument.  The command otherwise
+has no impact on the current import; its main purpose is to
+retrieve blobs that may be in fast-import's memory but not
+accessible from the target repository.
+
+....
+	'cat-blob' SP <dataref> LF
+....
+
+The `<dataref>` can be either a mark reference (`:<idnum>`)
+set previously or a full 40-byte SHA-1 of a Git blob, preexisting or
+ready to be written.
+
+Output uses the same format as `git cat-file --batch`:
+
+====
+	<sha1> SP 'blob' SP <size> LF
+	<contents> LF
+====
+
+This command can be used where a `filemodify` directive can appear,
+allowing it to be used in the middle of a commit.  For a `filemodify`
+using an inline directive, it can also appear right before the `data`
+directive.
+
+See ``Responses To Commands'' below for details about how to read
+this output safely.
+
+`ls`
+~~~~
+Prints information about the object at a path to a file descriptor
+previously arranged with the `--cat-blob-fd` argument.  This allows
+printing a blob from the active commit (with `cat-blob`) or copying a
+blob or tree from a previous commit for use in the current one (with
+`filemodify`).
+
+The `ls` command can also be used where a `filemodify` directive can
+appear, allowing it to be used in the middle of a commit.
+
+Reading from the active commit::
+	This form can only be used in the middle of a `commit`.
+	The path names a directory entry within fast-import's
+	active commit.  The path must be quoted in this case.
++
+....
+	'ls' SP <path> LF
+....
+
+Reading from a named tree::
+	The `<dataref>` can be a mark reference (`:<idnum>`) or the
+	full 40-byte SHA-1 of a Git tag, commit, or tree object,
+	preexisting or waiting to be written.
+	The path is relative to the top level of the tree
+	named by `<dataref>`.
++
+....
+	'ls' SP <dataref> SP <path> LF
+....
+
+See `filemodify` above for a detailed description of `<path>`.
+
+Output uses the same format as `git ls-tree <tree> -- <path>`:
+
+====
+	<mode> SP ('blob' | 'tree' | 'commit') SP <dataref> HT <path> LF
+====
+
+The <dataref> represents the blob, tree, or commit object at <path>
+and can be used in later 'get-mark', 'cat-blob', 'filemodify', or
+'ls' commands.
+
+If there is no file or subtree at that path, 'git fast-import' will
+instead report
+
+====
+	missing SP <path> LF
+====
+
+See ``Responses To Commands'' below for details about how to read
+this output safely.
+
+`feature`
+~~~~~~~~~
+Require that fast-import supports the specified feature, or abort if
+it does not.
+
+....
+	'feature' SP <feature> ('=' <argument>)? LF
+....
+
+The <feature> part of the command may be any one of the following:
+
+date-format::
+export-marks::
+relative-marks::
+no-relative-marks::
+force::
+	Act as though the corresponding command-line option with
+	a leading `--` was passed on the command line
+	(see OPTIONS, above).
+
+import-marks::
+import-marks-if-exists::
+	Like --import-marks except in two respects: first, only one
+	"feature import-marks" or "feature import-marks-if-exists"
+	command is allowed per stream; second, an --import-marks=
+	or --import-marks-if-exists command-line option overrides
+	any of these "feature" commands in the stream; third,
+	"feature import-marks-if-exists" like a corresponding
+	command-line option silently skips a nonexistent file.
+
+get-mark::
+cat-blob::
+ls::
+	Require that the backend support the 'get-mark', 'cat-blob',
+	or 'ls' command respectively.
+	Versions of fast-import not supporting the specified command
+	will exit with a message indicating so.
+	This lets the import error out early with a clear message,
+	rather than wasting time on the early part of an import
+	before the unsupported command is detected.
+
+notes::
+	Require that the backend support the 'notemodify' (N)
+	subcommand to the 'commit' command.
+	Versions of fast-import not supporting notes will exit
+	with a message indicating so.
+
+done::
+	Error out if the stream ends without a 'done' command.
+	Without this feature, errors causing the frontend to end
+	abruptly at a convenient point in the stream can go
+	undetected.  This may occur, for example, if an import
+	front end dies in mid-operation without emitting SIGTERM
+	or SIGKILL at its subordinate git fast-import instance.
+
+`option`
+~~~~~~~~
+Processes the specified option so that git fast-import behaves in a
+way that suits the frontend's needs.
+Note that options specified by the frontend are overridden by any
+options the user may specify to git fast-import itself.
+
+....
+    'option' SP <option> LF
+....
+
+The `<option>` part of the command may contain any of the options
+listed in the OPTIONS section that do not change import semantics,
+without the leading `--` and is treated in the same way.
+
+Option commands must be the first commands on the input (not counting
+feature commands), to give an option command after any non-option
+command is an error.
+
+The following command-line options change import semantics and may therefore
+not be passed as option:
+
+* date-format
+* import-marks
+* export-marks
+* cat-blob-fd
+* force
+
+`done`
+~~~~~~
+If the `done` feature is not in use, treated as if EOF was read.
+This can be used to tell fast-import to finish early.
+
+If the `--done` command-line option or `feature done` command is
+in use, the `done` command is mandatory and marks the end of the
+stream.
+
+RESPONSES TO COMMANDS
+---------------------
+New objects written by fast-import are not available immediately.
+Most fast-import commands have no visible effect until the next
+checkpoint (or completion).  The frontend can send commands to
+fill fast-import's input pipe without worrying about how quickly
+they will take effect, which improves performance by simplifying
+scheduling.
+
+For some frontends, though, it is useful to be able to read back
+data from the current repository as it is being updated (for
+example when the source material describes objects in terms of
+patches to be applied to previously imported objects).  This can
+be accomplished by connecting the frontend and fast-import via
+bidirectional pipes:
+
+====
+	mkfifo fast-import-output
+	frontend <fast-import-output |
+	git fast-import >fast-import-output
+====
+
+A frontend set up this way can use `progress`, `get-mark`, `ls`, and
+`cat-blob` commands to read information from the import in progress.
+
+To avoid deadlock, such frontends must completely consume any
+pending output from `progress`, `ls`, `get-mark`, and `cat-blob` before
+performing writes to fast-import that might block.
+
+CRASH REPORTS
+-------------
+If fast-import is supplied invalid input it will terminate with a
+non-zero exit status and create a crash report in the top level of
+the Git repository it was importing into.  Crash reports contain
+a snapshot of the internal fast-import state as well as the most
+recent commands that lead up to the crash.
+
+All recent commands (including stream comments, file changes and
+progress commands) are shown in the command history within the crash
+report, but raw file data and commit messages are excluded from the
+crash report.  This exclusion saves space within the report file
+and reduces the amount of buffering that fast-import must perform
+during execution.
+
+After writing a crash report fast-import will close the current
+packfile and export the marks table.  This allows the frontend
+developer to inspect the repository state and resume the import from
+the point where it crashed.  The modified branches and tags are not
+updated during a crash, as the import did not complete successfully.
+Branch and tag information can be found in the crash report and
+must be applied manually if the update is needed.
+
+An example crash:
+
+====
+	$ cat >in <<END_OF_INPUT
+	# my very first test commit
+	commit refs/heads/master
+	committer Shawn O. Pearce <spearce> 19283 -0400
+	# who is that guy anyway?
+	data <<EOF
+	this is my commit
+	EOF
+	M 644 inline .gitignore
+	data <<EOF
+	.gitignore
+	EOF
+	M 777 inline bob
+	END_OF_INPUT
+
+	$ git fast-import <in
+	fatal: Corrupt mode: M 777 inline bob
+	fast-import: dumping crash report to .git/fast_import_crash_8434
+
+	$ cat .git/fast_import_crash_8434
+	fast-import crash report:
+	    fast-import process: 8434
+	    parent process     : 1391
+	    at Sat Sep 1 00:58:12 2007
+
+	fatal: Corrupt mode: M 777 inline bob
+
+	Most Recent Commands Before Crash
+	---------------------------------
+	  # my very first test commit
+	  commit refs/heads/master
+	  committer Shawn O. Pearce <spearce> 19283 -0400
+	  # who is that guy anyway?
+	  data <<EOF
+	  M 644 inline .gitignore
+	  data <<EOF
+	* M 777 inline bob
+
+	Active Branch LRU
+	-----------------
+	    active_branches = 1 cur, 5 max
+
+	  pos  clock name
+	  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+	   1)      0 refs/heads/master
+
+	Inactive Branches
+	-----------------
+	refs/heads/master:
+	  status      : active loaded dirty
+	  tip commit  : 0000000000000000000000000000000000000000
+	  old tree    : 0000000000000000000000000000000000000000
+	  cur tree    : 0000000000000000000000000000000000000000
+	  commit clock: 0
+	  last pack   :
+
+
+	-------------------
+	END OF CRASH REPORT
+====
+
+TIPS AND TRICKS
+---------------
+The following tips and tricks have been collected from various
+users of fast-import, and are offered here as suggestions.
+
+Use One Mark Per Commit
+~~~~~~~~~~~~~~~~~~~~~~~
+When doing a repository conversion, use a unique mark per commit
+(`mark :<n>`) and supply the --export-marks option on the command
+line.  fast-import will dump a file which lists every mark and the Git
+object SHA-1 that corresponds to it.  If the frontend can tie
+the marks back to the source repository, it is easy to verify the
+accuracy and completeness of the import by comparing each Git
+commit to the corresponding source revision.
+
+Coming from a system such as Perforce or Subversion this should be
+quite simple, as the fast-import mark can also be the Perforce changeset
+number or the Subversion revision number.
+
+Freely Skip Around Branches
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Don't bother trying to optimize the frontend to stick to one branch
+at a time during an import.  Although doing so might be slightly
+faster for fast-import, it tends to increase the complexity of the frontend
+code considerably.
+
+The branch LRU builtin to fast-import tends to behave very well, and the
+cost of activating an inactive branch is so low that bouncing around
+between branches has virtually no impact on import performance.
+
+Handling Renames
+~~~~~~~~~~~~~~~~
+When importing a renamed file or directory, simply delete the old
+name(s) and modify the new name(s) during the corresponding commit.
+Git performs rename detection after-the-fact, rather than explicitly
+during a commit.
+
+Use Tag Fixup Branches
+~~~~~~~~~~~~~~~~~~~~~~
+Some other SCM systems let the user create a tag from multiple
+files which are not from the same commit/changeset.  Or to create
+tags which are a subset of the files available in the repository.
+
+Importing these tags as-is in Git is impossible without making at
+least one commit which ``fixes up'' the files to match the content
+of the tag.  Use fast-import's `reset` command to reset a dummy branch
+outside of your normal branch space to the base commit for the tag,
+then commit one or more file fixup commits, and finally tag the
+dummy branch.
+
+For example since all normal branches are stored under `refs/heads/`
+name the tag fixup branch `TAG_FIXUP`.  This way it is impossible for
+the fixup branch used by the importer to have namespace conflicts
+with real branches imported from the source (the name `TAG_FIXUP`
+is not `refs/heads/TAG_FIXUP`).
+
+When committing fixups, consider using `merge` to connect the
+commit(s) which are supplying file revisions to the fixup branch.
+Doing so will allow tools such as 'git blame' to track
+through the real commit history and properly annotate the source
+files.
+
+After fast-import terminates the frontend will need to do `rm .git/TAG_FIXUP`
+to remove the dummy branch.
+
+Import Now, Repack Later
+~~~~~~~~~~~~~~~~~~~~~~~~
+As soon as fast-import completes the Git repository is completely valid
+and ready for use.  Typically this takes only a very short time,
+even for considerably large projects (100,000+ commits).
+
+However repacking the repository is necessary to improve data
+locality and access performance.  It can also take hours on extremely
+large projects (especially if -f and a large --window parameter is
+used).  Since repacking is safe to run alongside readers and writers,
+run the repack in the background and let it finish when it finishes.
+There is no reason to wait to explore your new Git project!
+
+If you choose to wait for the repack, don't try to run benchmarks
+or performance tests until repacking is completed.  fast-import outputs
+suboptimal packfiles that are simply never seen in real use
+situations.
+
+Repacking Historical Data
+~~~~~~~~~~~~~~~~~~~~~~~~~
+If you are repacking very old imported data (e.g. older than the
+last year), consider expending some extra CPU time and supplying
+--window=50 (or higher) when you run 'git repack'.
+This will take longer, but will also produce a smaller packfile.
+You only need to expend the effort once, and everyone using your
+project will benefit from the smaller repository.
+
+Include Some Progress Messages
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Every once in a while have your frontend emit a `progress` message
+to fast-import.  The contents of the messages are entirely free-form,
+so one suggestion would be to output the current month and year
+each time the current commit date moves into the next month.
+Your users will feel better knowing how much of the data stream
+has been processed.
+
+
+PACKFILE OPTIMIZATION
+---------------------
+When packing a blob fast-import always attempts to deltify against the last
+blob written.  Unless specifically arranged for by the frontend,
+this will probably not be a prior version of the same file, so the
+generated delta will not be the smallest possible.  The resulting
+packfile will be compressed, but will not be optimal.
+
+Frontends which have efficient access to all revisions of a
+single file (for example reading an RCS/CVS ,v file) can choose
+to supply all revisions of that file as a sequence of consecutive
+`blob` commands.  This allows fast-import to deltify the different file
+revisions against each other, saving space in the final packfile.
+Marks can be used to later identify individual file revisions during
+a sequence of `commit` commands.
+
+The packfile(s) created by fast-import do not encourage good disk access
+patterns.  This is caused by fast-import writing the data in the order
+it is received on standard input, while Git typically organizes
+data within packfiles to make the most recent (current tip) data
+appear before historical data.  Git also clusters commits together,
+speeding up revision traversal through better cache locality.
+
+For this reason it is strongly recommended that users repack the
+repository with `git repack -a -d` after fast-import completes, allowing
+Git to reorganize the packfiles for faster data access.  If blob
+deltas are suboptimal (see above) then also adding the `-f` option
+to force recomputation of all deltas can significantly reduce the
+final packfile size (30-50% smaller can be quite typical).
+
+Instead of running `git repack` you can also run `git gc
+--aggressive`, which will also optimize other things after an import
+(e.g. pack loose refs). As noted in the "AGGRESSIVE" section in
+linkgit:git-gc[1] the `--aggressive` option will find new deltas with
+the `-f` option to linkgit:git-repack[1]. For the reasons elaborated
+on above using `--aggressive` after a fast-import is one of the few
+cases where it's known to be worthwhile.
+
+MEMORY UTILIZATION
+------------------
+There are a number of factors which affect how much memory fast-import
+requires to perform an import.  Like critical sections of core
+Git, fast-import uses its own memory allocators to amortize any overheads
+associated with malloc.  In practice fast-import tends to amortize any
+malloc overheads to 0, due to its use of large block allocations.
+
+per object
+~~~~~~~~~~
+fast-import maintains an in-memory structure for every object written in
+this execution.  On a 32 bit system the structure is 32 bytes,
+on a 64 bit system the structure is 40 bytes (due to the larger
+pointer sizes).  Objects in the table are not deallocated until
+fast-import terminates.  Importing 2 million objects on a 32 bit system
+will require approximately 64 MiB of memory.
+
+The object table is actually a hashtable keyed on the object name
+(the unique SHA-1).  This storage configuration allows fast-import to reuse
+an existing or already written object and avoid writing duplicates
+to the output packfile.  Duplicate blobs are surprisingly common
+in an import, typically due to branch merges in the source.
+
+per mark
+~~~~~~~~
+Marks are stored in a sparse array, using 1 pointer (4 bytes or 8
+bytes, depending on pointer size) per mark.  Although the array
+is sparse, frontends are still strongly encouraged to use marks
+between 1 and n, where n is the total number of marks required for
+this import.
+
+per branch
+~~~~~~~~~~
+Branches are classified as active and inactive.  The memory usage
+of the two classes is significantly different.
+
+Inactive branches are stored in a structure which uses 96 or 120
+bytes (32 bit or 64 bit systems, respectively), plus the length of
+the branch name (typically under 200 bytes), per branch.  fast-import will
+easily handle as many as 10,000 inactive branches in under 2 MiB
+of memory.
+
+Active branches have the same overhead as inactive branches, but
+also contain copies of every tree that has been recently modified on
+that branch.  If subtree `include` has not been modified since the
+branch became active, its contents will not be loaded into memory,
+but if subtree `src` has been modified by a commit since the branch
+became active, then its contents will be loaded in memory.
+
+As active branches store metadata about the files contained on that
+branch, their in-memory storage size can grow to a considerable size
+(see below).
+
+fast-import automatically moves active branches to inactive status based on
+a simple least-recently-used algorithm.  The LRU chain is updated on
+each `commit` command.  The maximum number of active branches can be
+increased or decreased on the command line with --active-branches=.
+
+per active tree
+~~~~~~~~~~~~~~~
+Trees (aka directories) use just 12 bytes of memory on top of the
+memory required for their entries (see ``per active file'' below).
+The cost of a tree is virtually 0, as its overhead amortizes out
+over the individual file entries.
+
+per active file entry
+~~~~~~~~~~~~~~~~~~~~~
+Files (and pointers to subtrees) within active trees require 52 or 64
+bytes (32/64 bit platforms) per entry.  To conserve space, file and
+tree names are pooled in a common string table, allowing the filename
+``Makefile'' to use just 16 bytes (after including the string header
+overhead) no matter how many times it occurs within the project.
+
+The active branch LRU, when coupled with the filename string pool
+and lazy loading of subtrees, allows fast-import to efficiently import
+projects with 2,000+ branches and 45,114+ files in a very limited
+memory footprint (less than 2.7 MiB per active branch).
+
+SIGNALS
+-------
+Sending *SIGUSR1* to the 'git fast-import' process ends the current
+packfile early, simulating a `checkpoint` command.  The impatient
+operator can use this facility to peek at the objects and refs from an
+import in progress, at the cost of some added running time and worse
+compression.
+
+SEE ALSO
+--------
+linkgit:git-fast-export[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fetch-pack.txt b/third_party/git/Documentation/git-fetch-pack.txt
new file mode 100644
index 0000000000..c975884793
--- /dev/null
+++ b/third_party/git/Documentation/git-fetch-pack.txt
@@ -0,0 +1,132 @@
+git-fetch-pack(1)
+=================
+
+NAME
+----
+git-fetch-pack - Receive missing objects from another repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git fetch-pack' [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag]
+	[--upload-pack=<git-upload-pack>]
+	[--depth=<n>] [--no-progress]
+	[-v] <repository> [<refs>...]
+
+DESCRIPTION
+-----------
+Usually you would want to use 'git fetch', which is a
+higher level wrapper of this command, instead.
+
+Invokes 'git-upload-pack' on a possibly remote repository
+and asks it to send objects missing from this repository, to
+update the named heads.  The list of commits available locally
+is found out by scanning the local refs/ hierarchy and sent to
+'git-upload-pack' running on the other end.
+
+This command degenerates to download everything to complete the
+asked refs from the remote side when the local side does not
+have a common ancestor commit.
+
+
+OPTIONS
+-------
+--all::
+	Fetch all remote refs.
+
+--stdin::
+	Take the list of refs from stdin, one per line. If there
+	are refs specified on the command line in addition to this
+	option, then the refs from stdin are processed after those
+	on the command line.
++
+If `--stateless-rpc` is specified together with this option then
+the list of refs must be in packet format (pkt-line). Each ref must
+be in a separate packet, and the list must end with a flush packet.
+
+-q::
+--quiet::
+	Pass `-q` flag to 'git unpack-objects'; this makes the
+	cloning process less verbose.
+
+-k::
+--keep::
+	Do not invoke 'git unpack-objects' on received data, but
+	create a single packfile out of it instead, and store it
+	in the object database. If provided twice then the pack is
+	locked against repacking.
+
+--thin::
+	Fetch a "thin" pack, which records objects in deltified form based
+	on objects not included in the pack to reduce network traffic.
+
+--include-tag::
+	If the remote side supports it, annotated tags objects will
+	be downloaded on the same connection as the other objects if
+	the object the tag references is downloaded.  The caller must
+	otherwise determine the tags this option made available.
+
+--upload-pack=<git-upload-pack>::
+	Use this to specify the path to 'git-upload-pack' on the
+	remote side, if is not found on your $PATH.
+	Installations of sshd ignores the user's environment
+	setup scripts for login shells (e.g. .bash_profile) and
+	your privately installed git may not be found on the system
+	default $PATH.  Another workaround suggested is to set
+	up your $PATH in ".bashrc", but this flag is for people
+	who do not want to pay the overhead for non-interactive
+	shells by having a lean .bashrc file (they set most of
+	the things up in .bash_profile).
+
+--exec=<git-upload-pack>::
+	Same as --upload-pack=<git-upload-pack>.
+
+--depth=<n>::
+	Limit fetching to ancestor-chains not longer than n.
+	'git-upload-pack' treats the special depth 2147483647 as
+	infinite even if there is an ancestor-chain that long.
+
+--shallow-since=<date>::
+	Deepen or shorten the history of a shallow repository to
+	include all reachable commits after <date>.
+
+--shallow-exclude=<revision>::
+	Deepen or shorten the history of a shallow repository to
+	exclude commits reachable from a specified remote branch or tag.
+	This option can be specified multiple times.
+
+--deepen-relative::
+	Argument --depth specifies the number of commits from the
+	current shallow boundary instead of from the tip of each
+	remote branch history.
+
+--no-progress::
+	Do not show the progress.
+
+--check-self-contained-and-connected::
+	Output "connectivity-ok" if the received pack is
+	self-contained and connected.
+
+-v::
+	Run verbosely.
+
+<repository>::
+	The URL to the remote repository.
+
+<refs>...::
+	The remote heads to update from. This is relative to
+	$GIT_DIR (e.g. "HEAD", "refs/heads/master").  When
+	unspecified, update from all heads the remote side has.
++
+If the remote has enabled the options `uploadpack.allowTipSHA1InWant`,
+`uploadpack.allowReachableSHA1InWant`, or `uploadpack.allowAnySHA1InWant`,
+they may alternatively be 40-hex sha1s present on the remote.
+
+SEE ALSO
+--------
+linkgit:git-fetch[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fetch.txt b/third_party/git/Documentation/git-fetch.txt
new file mode 100644
index 0000000000..5b1909fdf4
--- /dev/null
+++ b/third_party/git/Documentation/git-fetch.txt
@@ -0,0 +1,299 @@
+git-fetch(1)
+============
+
+NAME
+----
+git-fetch - Download objects and refs from another repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git fetch' [<options>] [<repository> [<refspec>...]]
+'git fetch' [<options>] <group>
+'git fetch' --multiple [<options>] [(<repository> | <group>)...]
+'git fetch' --all [<options>]
+
+
+DESCRIPTION
+-----------
+Fetch branches and/or tags (collectively, "refs") from one or more
+other repositories, along with the objects necessary to complete their
+histories.  Remote-tracking branches are updated (see the description
+of <refspec> below for ways to control this behavior).
+
+By default, any tag that points into the histories being fetched is
+also fetched; the effect is to fetch tags that
+point at branches that you are interested in.  This default behavior
+can be changed by using the --tags or --no-tags options or by
+configuring remote.<name>.tagOpt.  By using a refspec that fetches tags
+explicitly, you can fetch tags that do not point into branches you
+are interested in as well.
+
+'git fetch' can fetch from either a single named repository or URL,
+or from several repositories at once if <group> is given and
+there is a remotes.<group> entry in the configuration file.
+(See linkgit:git-config[1]).
+
+When no remote is specified, by default the `origin` remote will be used,
+unless there's an upstream branch configured for the current branch.
+
+The names of refs that are fetched, together with the object names
+they point at, are written to `.git/FETCH_HEAD`.  This information
+may be used by scripts or other git commands, such as linkgit:git-pull[1].
+
+OPTIONS
+-------
+include::fetch-options.txt[]
+
+include::pull-fetch-param.txt[]
+
+include::urls-remotes.txt[]
+
+
+CONFIGURED REMOTE-TRACKING BRANCHES[[CRTB]]
+-------------------------------------------
+
+You often interact with the same remote repository by
+regularly and repeatedly fetching from it.  In order to keep track
+of the progress of such a remote repository, `git fetch` allows you
+to configure `remote.<repository>.fetch` configuration variables.
+
+Typically such a variable may look like this:
+
+------------------------------------------------
+[remote "origin"]
+	fetch = +refs/heads/*:refs/remotes/origin/*
+------------------------------------------------
+
+This configuration is used in two ways:
+
+* When `git fetch` is run without specifying what branches
+  and/or tags to fetch on the command line, e.g. `git fetch origin`
+  or `git fetch`, `remote.<repository>.fetch` values are used as
+  the refspecs--they specify which refs to fetch and which local refs
+  to update.  The example above will fetch
+  all branches that exist in the `origin` (i.e. any ref that matches
+  the left-hand side of the value, `refs/heads/*`) and update the
+  corresponding remote-tracking branches in the `refs/remotes/origin/*`
+  hierarchy.
+
+* When `git fetch` is run with explicit branches and/or tags
+  to fetch on the command line, e.g. `git fetch origin master`, the
+  <refspec>s given on the command line determine what are to be
+  fetched (e.g. `master` in the example,
+  which is a short-hand for `master:`, which in turn means
+  "fetch the 'master' branch but I do not explicitly say what
+  remote-tracking branch to update with it from the command line"),
+  and the example command will
+  fetch _only_ the 'master' branch.  The `remote.<repository>.fetch`
+  values determine which
+  remote-tracking branch, if any, is updated.  When used in this
+  way, the `remote.<repository>.fetch` values do not have any
+  effect in deciding _what_ gets fetched (i.e. the values are not
+  used as refspecs when the command-line lists refspecs); they are
+  only used to decide _where_ the refs that are fetched are stored
+  by acting as a mapping.
+
+The latter use of the `remote.<repository>.fetch` values can be
+overridden by giving the `--refmap=<refspec>` parameter(s) on the
+command line.
+
+PRUNING
+-------
+
+Git has a default disposition of keeping data unless it's explicitly
+thrown away; this extends to holding onto local references to branches
+on remotes that have themselves deleted those branches.
+
+If left to accumulate, these stale references might make performance
+worse on big and busy repos that have a lot of branch churn, and
+e.g. make the output of commands like `git branch -a --contains
+<commit>` needlessly verbose, as well as impacting anything else
+that'll work with the complete set of known references.
+
+These remote-tracking references can be deleted as a one-off with
+either of:
+
+------------------------------------------------
+# While fetching
+$ git fetch --prune <name>
+
+# Only prune, don't fetch
+$ git remote prune <name>
+------------------------------------------------
+
+To prune references as part of your normal workflow without needing to
+remember to run that, set `fetch.prune` globally, or
+`remote.<name>.prune` per-remote in the config. See
+linkgit:git-config[1].
+
+Here's where things get tricky and more specific. The pruning feature
+doesn't actually care about branches, instead it'll prune local <->
+remote-references as a function of the refspec of the remote (see
+`<refspec>` and <<CRTB,CONFIGURED REMOTE-TRACKING BRANCHES>> above).
+
+Therefore if the refspec for the remote includes
+e.g. `refs/tags/*:refs/tags/*`, or you manually run e.g. `git fetch
+--prune <name> "refs/tags/*:refs/tags/*"` it won't be stale remote
+tracking branches that are deleted, but any local tag that doesn't
+exist on the remote.
+
+This might not be what you expect, i.e. you want to prune remote
+`<name>`, but also explicitly fetch tags from it, so when you fetch
+from it you delete all your local tags, most of which may not have
+come from the `<name>` remote in the first place.
+
+So be careful when using this with a refspec like
+`refs/tags/*:refs/tags/*`, or any other refspec which might map
+references from multiple remotes to the same local namespace.
+
+Since keeping up-to-date with both branches and tags on the remote is
+a common use-case the `--prune-tags` option can be supplied along with
+`--prune` to prune local tags that don't exist on the remote, and
+force-update those tags that differ. Tag pruning can also be enabled
+with `fetch.pruneTags` or `remote.<name>.pruneTags` in the config. See
+linkgit:git-config[1].
+
+The `--prune-tags` option is equivalent to having
+`refs/tags/*:refs/tags/*` declared in the refspecs of the remote. This
+can lead to some seemingly strange interactions:
+
+------------------------------------------------
+# These both fetch tags
+$ git fetch --no-tags origin 'refs/tags/*:refs/tags/*'
+$ git fetch --no-tags --prune-tags origin
+------------------------------------------------
+
+The reason it doesn't error out when provided without `--prune` or its
+config versions is for flexibility of the configured versions, and to
+maintain a 1=1 mapping between what the command line flags do, and
+what the configuration versions do.
+
+It's reasonable to e.g. configure `fetch.pruneTags=true` in
+`~/.gitconfig` to have tags pruned whenever `git fetch --prune` is
+run, without making every invocation of `git fetch` without `--prune`
+an error.
+
+Pruning tags with `--prune-tags` also works when fetching a URL
+instead of a named remote. These will all prune tags not found on
+origin:
+
+------------------------------------------------
+$ git fetch origin --prune --prune-tags
+$ git fetch origin --prune 'refs/tags/*:refs/tags/*'
+$ git fetch <url of origin> --prune --prune-tags
+$ git fetch <url of origin> --prune 'refs/tags/*:refs/tags/*'
+------------------------------------------------
+
+OUTPUT
+------
+
+The output of "git fetch" depends on the transport method used; this
+section describes the output when fetching over the Git protocol
+(either locally or via ssh) and Smart HTTP protocol.
+
+The status of the fetch is output in tabular form, with each line
+representing the status of a single ref. Each line is of the form:
+
+-------------------------------
+ <flag> <summary> <from> -> <to> [<reason>]
+-------------------------------
+
+The status of up-to-date refs is shown only if the --verbose option is
+used.
+
+In compact output mode, specified with configuration variable
+fetch.output, if either entire `<from>` or `<to>` is found in the
+other string, it will be substituted with `*` in the other string. For
+example, `master -> origin/master` becomes `master -> origin/*`.
+
+flag::
+	A single character indicating the status of the ref:
+(space);; for a successfully fetched fast-forward;
+`+`;; for a successful forced update;
+`-`;; for a successfully pruned ref;
+`t`;; for a successful tag update;
+`*`;; for a successfully fetched new ref;
+`!`;; for a ref that was rejected or failed to update; and
+`=`;; for a ref that was up to date and did not need fetching.
+
+summary::
+	For a successfully fetched ref, the summary shows the old and new
+	values of the ref in a form suitable for using as an argument to
+	`git log` (this is `<old>..<new>` in most cases, and
+	`<old>...<new>` for forced non-fast-forward updates).
+
+from::
+	The name of the remote ref being fetched from, minus its
+	`refs/<type>/` prefix. In the case of deletion, the name of
+	the remote ref is "(none)".
+
+to::
+	The name of the local ref being updated, minus its
+	`refs/<type>/` prefix.
+
+reason::
+	A human-readable explanation. In the case of successfully fetched
+	refs, no explanation is needed. For a failed ref, the reason for
+	failure is described.
+
+EXAMPLES
+--------
+
+* Update the remote-tracking branches:
++
+------------------------------------------------
+$ git fetch origin
+------------------------------------------------
++
+The above command copies all branches from the remote refs/heads/
+namespace and stores them to the local refs/remotes/origin/ namespace,
+unless the branch.<name>.fetch option is used to specify a non-default
+refspec.
+
+* Using refspecs explicitly:
++
+------------------------------------------------
+$ git fetch origin +pu:pu maint:tmp
+------------------------------------------------
++
+This updates (or creates, as necessary) branches `pu` and `tmp` in
+the local repository by fetching from the branches (respectively)
+`pu` and `maint` from the remote repository.
++
+The `pu` branch will be updated even if it does not fast-forward,
+because it is prefixed with a plus sign; `tmp` will not be.
+
+* Peek at a remote's branch, without configuring the remote in your local
+  repository:
++
+------------------------------------------------
+$ git fetch git://git.kernel.org/pub/scm/git/git.git maint
+$ git log FETCH_HEAD
+------------------------------------------------
++
+The first command fetches the `maint` branch from the repository at
+`git://git.kernel.org/pub/scm/git/git.git` and the second command uses
+`FETCH_HEAD` to examine the branch with linkgit:git-log[1].  The fetched
+objects will eventually be removed by git's built-in housekeeping (see
+linkgit:git-gc[1]).
+
+include::transfer-data-leaks.txt[]
+
+BUGS
+----
+Using --recurse-submodules can only fetch new commits in already checked
+out submodules right now. When e.g. upstream added a new submodule in the
+just fetched commits of the superproject the submodule itself cannot be
+fetched, making it impossible to check out that submodule later without
+having to do a fetch again. This is expected to be fixed in a future Git
+version.
+
+SEE ALSO
+--------
+linkgit:git-pull[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-filter-branch.txt b/third_party/git/Documentation/git-filter-branch.txt
new file mode 100644
index 0000000000..6b53dd7e06
--- /dev/null
+++ b/third_party/git/Documentation/git-filter-branch.txt
@@ -0,0 +1,481 @@
+git-filter-branch(1)
+====================
+
+NAME
+----
+git-filter-branch - Rewrite branches
+
+SYNOPSIS
+--------
+[verse]
+'git filter-branch' [--setup <command>] [--subdirectory-filter <directory>]
+	[--env-filter <command>] [--tree-filter <command>]
+	[--index-filter <command>] [--parent-filter <command>]
+	[--msg-filter <command>] [--commit-filter <command>]
+	[--tag-name-filter <command>] [--prune-empty]
+	[--original <namespace>] [-d <directory>] [-f | --force]
+	[--state-branch <branch>] [--] [<rev-list options>...]
+
+DESCRIPTION
+-----------
+Lets you rewrite Git revision history by rewriting the branches mentioned
+in the <rev-list options>, applying custom filters on each revision.
+Those filters can modify each tree (e.g. removing a file or running
+a perl rewrite on all files) or information about each commit.
+Otherwise, all information (including original commit times or merge
+information) will be preserved.
+
+The command will only rewrite the _positive_ refs mentioned in the
+command line (e.g. if you pass 'a..b', only 'b' will be rewritten).
+If you specify no filters, the commits will be recommitted without any
+changes, which would normally have no effect.  Nevertheless, this may be
+useful in the future for compensating for some Git bugs or such,
+therefore such a usage is permitted.
+
+*NOTE*: This command honors `.git/info/grafts` file and refs in
+the `refs/replace/` namespace.
+If you have any grafts or replacement refs defined, running this command
+will make them permanent.
+
+*WARNING*! The rewritten history will have different object names for all
+the objects and will not converge with the original branch.  You will not
+be able to easily push and distribute the rewritten branch on top of the
+original branch.  Please do not use this command if you do not know the
+full implications, and avoid using it anyway, if a simple single commit
+would suffice to fix your problem.  (See the "RECOVERING FROM UPSTREAM
+REBASE" section in linkgit:git-rebase[1] for further information about
+rewriting published history.)
+
+Always verify that the rewritten version is correct: The original refs,
+if different from the rewritten ones, will be stored in the namespace
+'refs/original/'.
+
+Note that since this operation is very I/O expensive, it might
+be a good idea to redirect the temporary directory off-disk with the
+`-d` option, e.g. on tmpfs.  Reportedly the speedup is very noticeable.
+
+
+Filters
+~~~~~~~
+
+The filters are applied in the order as listed below.  The <command>
+argument is always evaluated in the shell context using the 'eval' command
+(with the notable exception of the commit filter, for technical reasons).
+Prior to that, the `$GIT_COMMIT` environment variable will be set to contain
+the id of the commit being rewritten.  Also, GIT_AUTHOR_NAME,
+GIT_AUTHOR_EMAIL, GIT_AUTHOR_DATE, GIT_COMMITTER_NAME, GIT_COMMITTER_EMAIL,
+and GIT_COMMITTER_DATE are taken from the current commit and exported to
+the environment, in order to affect the author and committer identities of
+the replacement commit created by linkgit:git-commit-tree[1] after the
+filters have run.
+
+If any evaluation of <command> returns a non-zero exit status, the whole
+operation will be aborted.
+
+A 'map' function is available that takes an "original sha1 id" argument
+and outputs a "rewritten sha1 id" if the commit has been already
+rewritten, and "original sha1 id" otherwise; the 'map' function can
+return several ids on separate lines if your commit filter emitted
+multiple commits.
+
+
+OPTIONS
+-------
+
+--setup <command>::
+	This is not a real filter executed for each commit but a one
+	time setup just before the loop. Therefore no commit-specific
+	variables are defined yet.  Functions or variables defined here
+	can be used or modified in the following filter steps except
+	the commit filter, for technical reasons.
+
+--subdirectory-filter <directory>::
+	Only look at the history which touches the given subdirectory.
+	The result will contain that directory (and only that) as its
+	project root. Implies <<Remap_to_ancestor>>.
+
+--env-filter <command>::
+	This filter may be used if you only need to modify the environment
+	in which the commit will be performed.  Specifically, you might
+	want to rewrite the author/committer name/email/time environment
+	variables (see linkgit:git-commit-tree[1] for details).
+
+--tree-filter <command>::
+	This is the filter for rewriting the tree and its contents.
+	The argument is evaluated in shell with the working
+	directory set to the root of the checked out tree.  The new tree
+	is then used as-is (new files are auto-added, disappeared files
+	are auto-removed - neither .gitignore files nor any other ignore
+	rules *HAVE ANY EFFECT*!).
+
+--index-filter <command>::
+	This is the filter for rewriting the index.  It is similar to the
+	tree filter but does not check out the tree, which makes it much
+	faster.  Frequently used with `git rm --cached
+	--ignore-unmatch ...`, see EXAMPLES below.  For hairy
+	cases, see linkgit:git-update-index[1].
+
+--parent-filter <command>::
+	This is the filter for rewriting the commit's parent list.
+	It will receive the parent string on stdin and shall output
+	the new parent string on stdout.  The parent string is in
+	the format described in linkgit:git-commit-tree[1]: empty for
+	the initial commit, "-p parent" for a normal commit and
+	"-p parent1 -p parent2 -p parent3 ..." for a merge commit.
+
+--msg-filter <command>::
+	This is the filter for rewriting the commit messages.
+	The argument is evaluated in the shell with the original
+	commit message on standard input; its standard output is
+	used as the new commit message.
+
+--commit-filter <command>::
+	This is the filter for performing the commit.
+	If this filter is specified, it will be called instead of the
+	'git commit-tree' command, with arguments of the form
+	"<TREE_ID> [(-p <PARENT_COMMIT_ID>)...]" and the log message on
+	stdin.  The commit id is expected on stdout.
++
+As a special extension, the commit filter may emit multiple
+commit ids; in that case, the rewritten children of the original commit will
+have all of them as parents.
++
+You can use the 'map' convenience function in this filter, and other
+convenience functions, too.  For example, calling 'skip_commit "$@"'
+will leave out the current commit (but not its changes! If you want
+that, use 'git rebase' instead).
++
+You can also use the `git_commit_non_empty_tree "$@"` instead of
+`git commit-tree "$@"` if you don't wish to keep commits with a single parent
+and that makes no change to the tree.
+
+--tag-name-filter <command>::
+	This is the filter for rewriting tag names. When passed,
+	it will be called for every tag ref that points to a rewritten
+	object (or to a tag object which points to a rewritten object).
+	The original tag name is passed via standard input, and the new
+	tag name is expected on standard output.
++
+The original tags are not deleted, but can be overwritten;
+use "--tag-name-filter cat" to simply update the tags.  In this
+case, be very careful and make sure you have the old tags
+backed up in case the conversion has run afoul.
++
+Nearly proper rewriting of tag objects is supported. If the tag has
+a message attached, a new tag object will be created with the same message,
+author, and timestamp. If the tag has a signature attached, the
+signature will be stripped. It is by definition impossible to preserve
+signatures. The reason this is "nearly" proper, is because ideally if
+the tag did not change (points to the same object, has the same name, etc.)
+it should retain any signature. That is not the case, signatures will always
+be removed, buyer beware. There is also no support for changing the
+author or timestamp (or the tag message for that matter). Tags which point
+to other tags will be rewritten to point to the underlying commit.
+
+--prune-empty::
+	Some filters will generate empty commits that leave the tree untouched.
+	This option instructs git-filter-branch to remove such commits if they
+	have exactly one or zero non-pruned parents; merge commits will
+	therefore remain intact.  This option cannot be used together with
+	`--commit-filter`, though the same effect can be achieved by using the
+	provided `git_commit_non_empty_tree` function in a commit filter.
+
+--original <namespace>::
+	Use this option to set the namespace where the original commits
+	will be stored. The default value is 'refs/original'.
+
+-d <directory>::
+	Use this option to set the path to the temporary directory used for
+	rewriting.  When applying a tree filter, the command needs to
+	temporarily check out the tree to some directory, which may consume
+	considerable space in case of large projects.  By default it
+	does this in the `.git-rewrite/` directory but you can override
+	that choice by this parameter.
+
+-f::
+--force::
+	'git filter-branch' refuses to start with an existing temporary
+	directory or when there are already refs starting with
+	'refs/original/', unless forced.
+
+--state-branch <branch>::
+	This option will cause the mapping from old to new objects to
+	be loaded from named branch upon startup and saved as a new
+	commit to that branch upon exit, enabling incremental of large
+	trees. If '<branch>' does not exist it will be created.
+
+<rev-list options>...::
+	Arguments for 'git rev-list'.  All positive refs included by
+	these options are rewritten.  You may also specify options
+	such as `--all`, but you must use `--` to separate them from
+	the 'git filter-branch' options. Implies <<Remap_to_ancestor>>.
+
+
+[[Remap_to_ancestor]]
+Remap to ancestor
+~~~~~~~~~~~~~~~~~
+
+By using linkgit:git-rev-list[1] arguments, e.g., path limiters, you can limit the
+set of revisions which get rewritten. However, positive refs on the command
+line are distinguished: we don't let them be excluded by such limiters. For
+this purpose, they are instead rewritten to point at the nearest ancestor that
+was not excluded.
+
+
+EXIT STATUS
+-----------
+
+On success, the exit status is `0`.  If the filter can't find any commits to
+rewrite, the exit status is `2`.  On any other error, the exit status may be
+any other non-zero value.
+
+
+EXAMPLES
+--------
+
+Suppose you want to remove a file (containing confidential information
+or copyright violation) from all commits:
+
+-------------------------------------------------------
+git filter-branch --tree-filter 'rm filename' HEAD
+-------------------------------------------------------
+
+However, if the file is absent from the tree of some commit,
+a simple `rm filename` will fail for that tree and commit.
+Thus you may instead want to use `rm -f filename` as the script.
+
+Using `--index-filter` with 'git rm' yields a significantly faster
+version.  Like with using `rm filename`, `git rm --cached filename`
+will fail if the file is absent from the tree of a commit.  If you
+want to "completely forget" a file, it does not matter when it entered
+history, so we also add `--ignore-unmatch`:
+
+--------------------------------------------------------------------------
+git filter-branch --index-filter 'git rm --cached --ignore-unmatch filename' HEAD
+--------------------------------------------------------------------------
+
+Now, you will get the rewritten history saved in HEAD.
+
+To rewrite the repository to look as if `foodir/` had been its project
+root, and discard all other history:
+
+-------------------------------------------------------
+git filter-branch --subdirectory-filter foodir -- --all
+-------------------------------------------------------
+
+Thus you can, e.g., turn a library subdirectory into a repository of
+its own.  Note the `--` that separates 'filter-branch' options from
+revision options, and the `--all` to rewrite all branches and tags.
+
+To set a commit (which typically is at the tip of another
+history) to be the parent of the current initial commit, in
+order to paste the other history behind the current history:
+
+-------------------------------------------------------------------
+git filter-branch --parent-filter 'sed "s/^\$/-p <graft-id>/"' HEAD
+-------------------------------------------------------------------
+
+(if the parent string is empty - which happens when we are dealing with
+the initial commit - add graftcommit as a parent).  Note that this assumes
+history with a single root (that is, no merge without common ancestors
+happened).  If this is not the case, use:
+
+--------------------------------------------------------------------------
+git filter-branch --parent-filter \
+	'test $GIT_COMMIT = <commit-id> && echo "-p <graft-id>" || cat' HEAD
+--------------------------------------------------------------------------
+
+or even simpler:
+
+-----------------------------------------------
+git replace --graft $commit-id $graft-id
+git filter-branch $graft-id..HEAD
+-----------------------------------------------
+
+To remove commits authored by "Darl McBribe" from the history:
+
+------------------------------------------------------------------------------
+git filter-branch --commit-filter '
+	if [ "$GIT_AUTHOR_NAME" = "Darl McBribe" ];
+	then
+		skip_commit "$@";
+	else
+		git commit-tree "$@";
+	fi' HEAD
+------------------------------------------------------------------------------
+
+The function 'skip_commit' is defined as follows:
+
+--------------------------
+skip_commit()
+{
+	shift;
+	while [ -n "$1" ];
+	do
+		shift;
+		map "$1";
+		shift;
+	done;
+}
+--------------------------
+
+The shift magic first throws away the tree id and then the -p
+parameters.  Note that this handles merges properly! In case Darl
+committed a merge between P1 and P2, it will be propagated properly
+and all children of the merge will become merge commits with P1,P2
+as their parents instead of the merge commit.
+
+*NOTE* the changes introduced by the commits, and which are not reverted
+by subsequent commits, will still be in the rewritten branch. If you want
+to throw out _changes_ together with the commits, you should use the
+interactive mode of 'git rebase'.
+
+You can rewrite the commit log messages using `--msg-filter`.  For
+example, 'git svn-id' strings in a repository created by 'git svn' can
+be removed this way:
+
+-------------------------------------------------------
+git filter-branch --msg-filter '
+	sed -e "/^git-svn-id:/d"
+'
+-------------------------------------------------------
+
+If you need to add 'Acked-by' lines to, say, the last 10 commits (none
+of which is a merge), use this command:
+
+--------------------------------------------------------
+git filter-branch --msg-filter '
+	cat &&
+	echo "Acked-by: Bugs Bunny <bunny@bugzilla.org>"
+' HEAD~10..HEAD
+--------------------------------------------------------
+
+The `--env-filter` option can be used to modify committer and/or author
+identity.  For example, if you found out that your commits have the wrong
+identity due to a misconfigured user.email, you can make a correction,
+before publishing the project, like this:
+
+--------------------------------------------------------
+git filter-branch --env-filter '
+	if test "$GIT_AUTHOR_EMAIL" = "root@localhost"
+	then
+		GIT_AUTHOR_EMAIL=john@example.com
+	fi
+	if test "$GIT_COMMITTER_EMAIL" = "root@localhost"
+	then
+		GIT_COMMITTER_EMAIL=john@example.com
+	fi
+' -- --all
+--------------------------------------------------------
+
+To restrict rewriting to only part of the history, specify a revision
+range in addition to the new branch name.  The new branch name will
+point to the top-most revision that a 'git rev-list' of this range
+will print.
+
+Consider this history:
+
+------------------
+     D--E--F--G--H
+    /     /
+A--B-----C
+------------------
+
+To rewrite only commits D,E,F,G,H, but leave A, B and C alone, use:
+
+--------------------------------
+git filter-branch ... C..H
+--------------------------------
+
+To rewrite commits E,F,G,H, use one of these:
+
+----------------------------------------
+git filter-branch ... C..H --not D
+git filter-branch ... D..H --not C
+----------------------------------------
+
+To move the whole tree into a subdirectory, or remove it from there:
+
+---------------------------------------------------------------
+git filter-branch --index-filter \
+	'git ls-files -s | sed "s-\t\"*-&newsubdir/-" |
+		GIT_INDEX_FILE=$GIT_INDEX_FILE.new \
+			git update-index --index-info &&
+	 mv "$GIT_INDEX_FILE.new" "$GIT_INDEX_FILE"' HEAD
+---------------------------------------------------------------
+
+
+
+CHECKLIST FOR SHRINKING A REPOSITORY
+------------------------------------
+
+git-filter-branch can be used to get rid of a subset of files,
+usually with some combination of `--index-filter` and
+`--subdirectory-filter`.  People expect the resulting repository to
+be smaller than the original, but you need a few more steps to
+actually make it smaller, because Git tries hard not to lose your
+objects until you tell it to.  First make sure that:
+
+* You really removed all variants of a filename, if a blob was moved
+  over its lifetime.  `git log --name-only --follow --all -- filename`
+  can help you find renames.
+
+* You really filtered all refs: use `--tag-name-filter cat -- --all`
+  when calling git-filter-branch.
+
+Then there are two ways to get a smaller repository.  A safer way is
+to clone, that keeps your original intact.
+
+* Clone it with `git clone file:///path/to/repo`.  The clone
+  will not have the removed objects.  See linkgit:git-clone[1].  (Note
+  that cloning with a plain path just hardlinks everything!)
+
+If you really don't want to clone it, for whatever reasons, check the
+following points instead (in this order).  This is a very destructive
+approach, so *make a backup* or go back to cloning it.  You have been
+warned.
+
+* Remove the original refs backed up by git-filter-branch: say `git
+  for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git
+  update-ref -d`.
+
+* Expire all reflogs with `git reflog expire --expire=now --all`.
+
+* Garbage collect all unreferenced objects with `git gc --prune=now`
+  (or if your git-gc is not new enough to support arguments to
+  `--prune`, use `git repack -ad; git prune` instead).
+
+NOTES
+-----
+
+git-filter-branch allows you to make complex shell-scripted rewrites
+of your Git history, but you probably don't need this flexibility if
+you're simply _removing unwanted data_ like large files or passwords.
+For those operations you may want to consider
+http://rtyley.github.io/bfg-repo-cleaner/[The BFG Repo-Cleaner],
+a JVM-based alternative to git-filter-branch, typically at least
+10-50x faster for those use-cases, and with quite different
+characteristics:
+
+* Any particular version of a file is cleaned exactly _once_. The BFG,
+  unlike git-filter-branch, does not give you the opportunity to
+  handle a file differently based on where or when it was committed
+  within your history. This constraint gives the core performance
+  benefit of The BFG, and is well-suited to the task of cleansing bad
+  data - you don't care _where_ the bad data is, you just want it
+  _gone_.
+
+* By default The BFG takes full advantage of multi-core machines,
+  cleansing commit file-trees in parallel. git-filter-branch cleans
+  commits sequentially (i.e. in a single-threaded manner), though it
+  _is_ possible to write filters that include their own parallelism,
+  in the scripts executed against each commit.
+
+* The http://rtyley.github.io/bfg-repo-cleaner/#examples[command options]
+  are much more restrictive than git-filter branch, and dedicated just
+  to the tasks of removing unwanted data- e.g:
+  `--strip-blobs-bigger-than 1M`.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fmt-merge-msg.txt b/third_party/git/Documentation/git-fmt-merge-msg.txt
new file mode 100644
index 0000000000..6793d8fc05
--- /dev/null
+++ b/third_party/git/Documentation/git-fmt-merge-msg.txt
@@ -0,0 +1,78 @@
+git-fmt-merge-msg(1)
+====================
+
+NAME
+----
+git-fmt-merge-msg - Produce a merge commit message
+
+
+SYNOPSIS
+--------
+[verse]
+'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log]
+'git fmt-merge-msg' [-m <message>] [--log[=<n>] | --no-log] -F <file>
+
+DESCRIPTION
+-----------
+Takes the list of merged objects on stdin and produces a suitable
+commit message to be used for the merge commit, usually to be
+passed as the '<merge-message>' argument of 'git merge'.
+
+This command is intended mostly for internal use by scripts
+automatically invoking 'git merge'.
+
+OPTIONS
+-------
+
+--log[=<n>]::
+	In addition to branch names, populate the log message with
+	one-line descriptions from the actual commits that are being
+	merged.  At most <n> commits from each merge parent will be
+	used (20 if <n> is omitted).  This overrides the `merge.log`
+	configuration variable.
+
+--no-log::
+	Do not list one-line descriptions from the actual commits being
+	merged.
+
+--[no-]summary::
+	Synonyms to --log and --no-log; these are deprecated and will be
+	removed in the future.
+
+-m <message>::
+--message <message>::
+	Use <message> instead of the branch names for the first line
+	of the log message.  For use with `--log`.
+
+-F <file>::
+--file <file>::
+	Take the list of merged objects from <file> instead of
+	stdin.
+
+CONFIGURATION
+-------------
+include::config/fmt-merge-msg.txt[]
+
+merge.summary::
+	Synonym to `merge.log`; this is deprecated and will be removed in
+	the future.
+
+EXAMPLES
+--------
+
+---------
+$ git fetch origin master
+$ git fmt-merge-msg --log <$GIT_DIR/FETCH_HEAD
+---------
+
+Print a log message describing a merge of the "master" branch from
+the "origin" remote.
+
+
+SEE ALSO
+--------
+linkgit:git-merge[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-for-each-ref.txt b/third_party/git/Documentation/git-for-each-ref.txt
new file mode 100644
index 0000000000..6dcd39f6f6
--- /dev/null
+++ b/third_party/git/Documentation/git-for-each-ref.txt
@@ -0,0 +1,394 @@
+git-for-each-ref(1)
+===================
+
+NAME
+----
+git-for-each-ref - Output information on each ref
+
+SYNOPSIS
+--------
+[verse]
+'git for-each-ref' [--count=<count>] [--shell|--perl|--python|--tcl]
+		   [(--sort=<key>)...] [--format=<format>] [<pattern>...]
+		   [--points-at=<object>]
+		   (--merged[=<object>] | --no-merged[=<object>])
+		   [--contains[=<object>]] [--no-contains[=<object>]]
+
+DESCRIPTION
+-----------
+
+Iterate over all refs that match `<pattern>` and show them
+according to the given `<format>`, after sorting them according
+to the given set of `<key>`.  If `<count>` is given, stop after
+showing that many refs.  The interpolated values in `<format>`
+can optionally be quoted as string literals in the specified
+host language allowing their direct evaluation in that language.
+
+OPTIONS
+-------
+<pattern>...::
+	If one or more patterns are given, only refs are shown that
+	match against at least one pattern, either using fnmatch(3) or
+	literally, in the latter case matching completely or from the
+	beginning up to a slash.
+
+--count=<count>::
+	By default the command shows all refs that match
+	`<pattern>`.  This option makes it stop after showing
+	that many refs.
+
+--sort=<key>::
+	A field name to sort on.  Prefix `-` to sort in
+	descending order of the value.  When unspecified,
+	`refname` is used.  You may use the --sort=<key> option
+	multiple times, in which case the last key becomes the primary
+	key.
+
+--format=<format>::
+	A string that interpolates `%(fieldname)` from a ref being shown
+	and the object it points at.  If `fieldname`
+	is prefixed with an asterisk (`*`) and the ref points
+	at a tag object, use the value for the field in the object
+	which the tag object refers to (instead of the field in the tag object).
+	When unspecified, `<format>` defaults to
+	`%(objectname) SPC %(objecttype) TAB %(refname)`.
+	It also interpolates `%%` to `%`, and `%xx` where `xx`
+	are hex digits interpolates to character with hex code
+	`xx`; for example `%00` interpolates to `\0` (NUL),
+	`%09` to `\t` (TAB) and `%0a` to `\n` (LF).
+
+--color[=<when>]::
+	Respect any colors specified in the `--format` option. The
+	`<when>` field must be one of `always`, `never`, or `auto` (if
+	`<when>` is absent, behave as if `always` was given).
+
+--shell::
+--perl::
+--python::
+--tcl::
+	If given, strings that substitute `%(fieldname)`
+	placeholders are quoted as string literals suitable for
+	the specified host language.  This is meant to produce
+	a scriptlet that can directly be `eval`ed.
+
+--points-at=<object>::
+	Only list refs which points at the given object.
+
+--merged[=<object>]::
+	Only list refs whose tips are reachable from the
+	specified commit (HEAD if not specified),
+	incompatible with `--no-merged`.
+
+--no-merged[=<object>]::
+	Only list refs whose tips are not reachable from the
+	specified commit (HEAD if not specified),
+	incompatible with `--merged`.
+
+--contains[=<object>]::
+	Only list refs which contain the specified commit (HEAD if not
+	specified).
+
+--no-contains[=<object>]::
+	Only list refs which don't contain the specified commit (HEAD
+	if not specified).
+
+--ignore-case::
+	Sorting and filtering refs are case insensitive.
+
+FIELD NAMES
+-----------
+
+Various values from structured fields in referenced objects can
+be used to interpolate into the resulting output, or as sort
+keys.
+
+For all objects, the following names can be used:
+
+refname::
+	The name of the ref (the part after $GIT_DIR/).
+	For a non-ambiguous short name of the ref append `:short`.
+	The option core.warnAmbiguousRefs is used to select the strict
+	abbreviation mode. If `lstrip=<N>` (`rstrip=<N>`) is appended, strips `<N>`
+	slash-separated path components from the front (back) of the refname
+	(e.g. `%(refname:lstrip=2)` turns `refs/tags/foo` into `foo` and
+	`%(refname:rstrip=2)` turns `refs/tags/foo` into `refs`).
+	If `<N>` is a negative number, strip as many path components as
+	necessary from the specified end to leave `-<N>` path components
+	(e.g. `%(refname:lstrip=-2)` turns
+	`refs/tags/foo` into `tags/foo` and `%(refname:rstrip=-1)`
+	turns `refs/tags/foo` into `refs`). When the ref does not have
+	enough components, the result becomes an empty string if
+	stripping with positive <N>, or it becomes the full refname if
+	stripping with negative <N>.  Neither is an error.
++
+`strip` can be used as a synonym to `lstrip`.
+
+objecttype::
+	The type of the object (`blob`, `tree`, `commit`, `tag`).
+
+objectsize::
+	The size of the object (the same as 'git cat-file -s' reports).
+	Append `:disk` to get the size, in bytes, that the object takes up on
+	disk. See the note about on-disk sizes in the `CAVEATS` section below.
+objectname::
+	The object name (aka SHA-1).
+	For a non-ambiguous abbreviation of the object name append `:short`.
+	For an abbreviation of the object name with desired length append
+	`:short=<length>`, where the minimum length is MINIMUM_ABBREV. The
+	length may be exceeded to ensure unique object names.
+deltabase::
+	This expands to the object name of the delta base for the
+	given object, if it is stored as a delta.  Otherwise it
+	expands to the null object name (all zeroes).
+
+upstream::
+	The name of a local ref which can be considered ``upstream''
+	from the displayed ref. Respects `:short`, `:lstrip` and
+	`:rstrip` in the same way as `refname` above.  Additionally
+	respects `:track` to show "[ahead N, behind M]" and
+	`:trackshort` to show the terse version: ">" (ahead), "<"
+	(behind), "<>" (ahead and behind), or "=" (in sync). `:track`
+	also prints "[gone]" whenever unknown upstream ref is
+	encountered. Append `:track,nobracket` to show tracking
+	information without brackets (i.e "ahead N, behind M").
++
+For any remote-tracking branch `%(upstream)`, `%(upstream:remotename)`
+and `%(upstream:remoteref)` refer to the name of the remote and the
+name of the tracked remote ref, respectively. In other words, the
+remote-tracking branch can be updated explicitly and individually by
+using the refspec `%(upstream:remoteref):%(upstream)` to fetch from
+`%(upstream:remotename)`.
++
+Has no effect if the ref does not have tracking information associated
+with it.  All the options apart from `nobracket` are mutually exclusive,
+but if used together the last option is selected.
+
+push::
+	The name of a local ref which represents the `@{push}`
+	location for the displayed ref. Respects `:short`, `:lstrip`,
+	`:rstrip`, `:track`, `:trackshort`, `:remotename`, and `:remoteref`
+	options as `upstream` does. Produces an empty string if no `@{push}`
+	ref is configured.
+
+HEAD::
+	'*' if HEAD matches current ref (the checked out branch), ' '
+	otherwise.
+
+color::
+	Change output color. Followed by `:<colorname>`, where color
+	names are described under Values in the "CONFIGURATION FILE"
+	section of linkgit:git-config[1].  For example,
+	`%(color:bold red)`.
+
+align::
+	Left-, middle-, or right-align the content between
+	%(align:...) and %(end). The "align:" is followed by
+	`width=<width>` and `position=<position>` in any order
+	separated by a comma, where the `<position>` is either left,
+	right or middle, default being left and `<width>` is the total
+	length of the content with alignment. For brevity, the
+	"width=" and/or "position=" prefixes may be omitted, and bare
+	<width> and <position> used instead.  For instance,
+	`%(align:<width>,<position>)`. If the contents length is more
+	than the width then no alignment is performed. If used with
+	`--quote` everything in between %(align:...) and %(end) is
+	quoted, but if nested then only the topmost level performs
+	quoting.
+
+if::
+	Used as %(if)...%(then)...%(end) or
+	%(if)...%(then)...%(else)...%(end).  If there is an atom with
+	value or string literal after the %(if) then everything after
+	the %(then) is printed, else if the %(else) atom is used, then
+	everything after %(else) is printed. We ignore space when
+	evaluating the string before %(then), this is useful when we
+	use the %(HEAD) atom which prints either "*" or " " and we
+	want to apply the 'if' condition only on the 'HEAD' ref.
+	Append ":equals=<string>" or ":notequals=<string>" to compare
+	the value between the %(if:...) and %(then) atoms with the
+	given string.
+
+symref::
+	The ref which the given symbolic ref refers to. If not a
+	symbolic ref, nothing is printed. Respects the `:short`,
+	`:lstrip` and `:rstrip` options in the same way as `refname`
+	above.
+
+worktreepath::
+	The absolute path to the worktree in which the ref is checked
+	out, if it is checked out in any linked worktree. Empty string
+	otherwise.
+
+In addition to the above, for commit and tag objects, the header
+field names (`tree`, `parent`, `object`, `type`, and `tag`) can
+be used to specify the value in the header field.
+
+For commit and tag objects, the special `creatordate` and `creator`
+fields will correspond to the appropriate date or name-email-date tuple
+from the `committer` or `tagger` fields depending on the object type.
+These are intended for working on a mix of annotated and lightweight tags.
+
+Fields that have name-email-date tuple as its value (`author`,
+`committer`, and `tagger`) can be suffixed with `name`, `email`,
+and `date` to extract the named component.
+
+The complete message in a commit and tag object is `contents`.
+Its first line is `contents:subject`, where subject is the concatenation
+of all lines of the commit message up to the first blank line.  The next
+line is `contents:body`, where body is all of the lines after the first
+blank line.  The optional GPG signature is `contents:signature`.  The
+first `N` lines of the message is obtained using `contents:lines=N`.
+Additionally, the trailers as interpreted by linkgit:git-interpret-trailers[1]
+are obtained as `trailers` (or by using the historical alias
+`contents:trailers`).  Non-trailer lines from the trailer block can be omitted
+with `trailers:only`. Whitespace-continuations can be removed from trailers so
+that each trailer appears on a line by itself with its full content with
+`trailers:unfold`. Both can be used together as `trailers:unfold,only`.
+
+For sorting purposes, fields with numeric values sort in numeric order
+(`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).
+All other fields are used to sort in their byte-value order.
+
+There is also an option to sort by versions, this can be done by using
+the fieldname `version:refname` or its alias `v:refname`.
+
+In any case, a field name that refers to a field inapplicable to
+the object referred by the ref does not cause an error.  It
+returns an empty string instead.
+
+As a special case for the date-type fields, you may specify a format for
+the date by adding `:` followed by date format name (see the
+values the `--date` option to linkgit:git-rev-list[1] takes).
+
+Some atoms like %(align) and %(if) always require a matching %(end).
+We call them "opening atoms" and sometimes denote them as %($open).
+
+When a scripting language specific quoting is in effect, everything
+between a top-level opening atom and its matching %(end) is evaluated
+according to the semantics of the opening atom and only its result
+from the top-level is quoted.
+
+
+EXAMPLES
+--------
+
+An example directly producing formatted text.  Show the most recent
+3 tagged commits:
+
+------------
+#!/bin/sh
+
+git for-each-ref --count=3 --sort='-*authordate' \
+--format='From: %(*authorname) %(*authoremail)
+Subject: %(*subject)
+Date: %(*authordate)
+Ref: %(*refname)
+
+%(*body)
+' 'refs/tags'
+------------
+
+
+A simple example showing the use of shell eval on the output,
+demonstrating the use of --shell.  List the prefixes of all heads:
+------------
+#!/bin/sh
+
+git for-each-ref --shell --format="ref=%(refname)" refs/heads | \
+while read entry
+do
+	eval "$entry"
+	echo `dirname $ref`
+done
+------------
+
+
+A bit more elaborate report on tags, demonstrating that the format
+may be an entire script:
+------------
+#!/bin/sh
+
+fmt='
+	r=%(refname)
+	t=%(*objecttype)
+	T=${r#refs/tags/}
+
+	o=%(*objectname)
+	n=%(*authorname)
+	e=%(*authoremail)
+	s=%(*subject)
+	d=%(*authordate)
+	b=%(*body)
+
+	kind=Tag
+	if test "z$t" = z
+	then
+		# could be a lightweight tag
+		t=%(objecttype)
+		kind="Lightweight tag"
+		o=%(objectname)
+		n=%(authorname)
+		e=%(authoremail)
+		s=%(subject)
+		d=%(authordate)
+		b=%(body)
+	fi
+	echo "$kind $T points at a $t object $o"
+	if test "z$t" = zcommit
+	then
+		echo "The commit was authored by $n $e
+at $d, and titled
+
+    $s
+
+Its message reads as:
+"
+		echo "$b" | sed -e "s/^/    /"
+		echo
+	fi
+'
+
+eval=`git for-each-ref --shell --format="$fmt" \
+	--sort='*objecttype' \
+	--sort=-taggerdate \
+	refs/tags`
+eval "$eval"
+------------
+
+
+An example to show the usage of %(if)...%(then)...%(else)...%(end).
+This prefixes the current branch with a star.
+
+------------
+git for-each-ref --format="%(if)%(HEAD)%(then)* %(else)  %(end)%(refname:short)" refs/heads/
+------------
+
+
+An example to show the usage of %(if)...%(then)...%(end).
+This prints the authorname, if present.
+
+------------
+git for-each-ref --format="%(refname)%(if)%(authorname)%(then) Authored by: %(authorname)%(end)"
+------------
+
+CAVEATS
+-------
+
+Note that the sizes of objects on disk are reported accurately, but care
+should be taken in drawing conclusions about which refs or objects are
+responsible for disk usage. The size of a packed non-delta object may be
+much larger than the size of objects which delta against it, but the
+choice of which object is the base and which is the delta is arbitrary
+and is subject to change during a repack.
+
+Note also that multiple copies of an object may be present in the object
+database; in this case, it is undefined which copy's size or delta base
+will be reported.
+
+SEE ALSO
+--------
+linkgit:git-show-ref[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-format-patch.txt b/third_party/git/Documentation/git-format-patch.txt
new file mode 100644
index 0000000000..b9b97e63ae
--- /dev/null
+++ b/third_party/git/Documentation/git-format-patch.txt
@@ -0,0 +1,684 @@
+git-format-patch(1)
+===================
+
+NAME
+----
+git-format-patch - Prepare patches for e-mail submission
+
+
+SYNOPSIS
+--------
+[verse]
+'git format-patch' [-k] [(-o|--output-directory) <dir> | --stdout]
+		   [--no-thread | --thread[=<style>]]
+		   [(--attach|--inline)[=<boundary>] | --no-attach]
+		   [-s | --signoff]
+		   [--signature=<signature> | --no-signature]
+		   [--signature-file=<file>]
+		   [-n | --numbered | -N | --no-numbered]
+		   [--start-number <n>] [--numbered-files]
+		   [--in-reply-to=Message-Id] [--suffix=.<sfx>]
+		   [--ignore-if-in-upstream]
+		   [--rfc] [--subject-prefix=Subject-Prefix]
+		   [(--reroll-count|-v) <n>]
+		   [--to=<email>] [--cc=<email>]
+		   [--[no-]cover-letter] [--quiet]
+		   [--no-notes | --notes[=<ref>]]
+		   [--interdiff=<previous>]
+		   [--range-diff=<previous> [--creation-factor=<percent>]]
+		   [--progress]
+		   [<common diff options>]
+		   [ <since> | <revision range> ]
+
+DESCRIPTION
+-----------
+
+Prepare each commit with its patch in
+one file per commit, formatted to resemble UNIX mailbox format.
+The output of this command is convenient for e-mail submission or
+for use with 'git am'.
+
+There are two ways to specify which commits to operate on.
+
+1. A single commit, <since>, specifies that the commits leading
+   to the tip of the current branch that are not in the history
+   that leads to the <since> to be output.
+
+2. Generic <revision range> expression (see "SPECIFYING
+   REVISIONS" section in linkgit:gitrevisions[7]) means the
+   commits in the specified range.
+
+The first rule takes precedence in the case of a single <commit>.  To
+apply the second rule, i.e., format everything since the beginning of
+history up until <commit>, use the `--root` option: `git format-patch
+--root <commit>`.  If you want to format only <commit> itself, you
+can do this with `git format-patch -1 <commit>`.
+
+By default, each output file is numbered sequentially from 1, and uses the
+first line of the commit message (massaged for pathname safety) as
+the filename. With the `--numbered-files` option, the output file names
+will only be numbers, without the first line of the commit appended.
+The names of the output files are printed to standard
+output, unless the `--stdout` option is specified.
+
+If `-o` is specified, output files are created in <dir>.  Otherwise
+they are created in the current working directory. The default path
+can be set with the `format.outputDirectory` configuration option.
+The `-o` option takes precedence over `format.outputDirectory`.
+To store patches in the current working directory even when
+`format.outputDirectory` points elsewhere, use `-o .`.
+
+By default, the subject of a single patch is "[PATCH] " followed by
+the concatenation of lines from the commit message up to the first blank
+line (see the DISCUSSION section of linkgit:git-commit[1]).
+
+When multiple patches are output, the subject prefix will instead be
+"[PATCH n/m] ".  To force 1/1 to be added for a single patch, use `-n`.
+To omit patch numbers from the subject, use `-N`.
+
+If given `--thread`, `git-format-patch` will generate `In-Reply-To` and
+`References` headers to make the second and subsequent patch mails appear
+as replies to the first mail; this also generates a `Message-Id` header to
+reference.
+
+OPTIONS
+-------
+:git-format-patch: 1
+include::diff-options.txt[]
+
+-<n>::
+	Prepare patches from the topmost <n> commits.
+
+-o <dir>::
+--output-directory <dir>::
+	Use <dir> to store the resulting files, instead of the
+	current working directory.
+
+-n::
+--numbered::
+	Name output in '[PATCH n/m]' format, even with a single patch.
+
+-N::
+--no-numbered::
+	Name output in '[PATCH]' format.
+
+--start-number <n>::
+	Start numbering the patches at <n> instead of 1.
+
+--numbered-files::
+	Output file names will be a simple number sequence
+	without the default first line of the commit appended.
+
+-k::
+--keep-subject::
+	Do not strip/add '[PATCH]' from the first line of the
+	commit log message.
+
+-s::
+--signoff::
+	Add `Signed-off-by:` line to the commit message, using
+	the committer identity of yourself.
+	See the signoff option in linkgit:git-commit[1] for more information.
+
+--stdout::
+	Print all commits to the standard output in mbox format,
+	instead of creating a file for each one.
+
+--attach[=<boundary>]::
+	Create multipart/mixed attachment, the first part of
+	which is the commit message and the patch itself in the
+	second part, with `Content-Disposition: attachment`.
+
+--no-attach::
+	Disable the creation of an attachment, overriding the
+	configuration setting.
+
+--inline[=<boundary>]::
+	Create multipart/mixed attachment, the first part of
+	which is the commit message and the patch itself in the
+	second part, with `Content-Disposition: inline`.
+
+--thread[=<style>]::
+--no-thread::
+	Controls addition of `In-Reply-To` and `References` headers to
+	make the second and subsequent mails appear as replies to the
+	first.  Also controls generation of the `Message-Id` header to
+	reference.
++
+The optional <style> argument can be either `shallow` or `deep`.
+'shallow' threading makes every mail a reply to the head of the
+series, where the head is chosen from the cover letter, the
+`--in-reply-to`, and the first patch mail, in this order.  'deep'
+threading makes every mail a reply to the previous one.
++
+The default is `--no-thread`, unless the `format.thread` configuration
+is set.  If `--thread` is specified without a style, it defaults to the
+style specified by `format.thread` if any, or else `shallow`.
++
+Beware that the default for 'git send-email' is to thread emails
+itself.  If you want `git format-patch` to take care of threading, you
+will want to ensure that threading is disabled for `git send-email`.
+
+--in-reply-to=Message-Id::
+	Make the first mail (or all the mails with `--no-thread`) appear as a
+	reply to the given Message-Id, which avoids breaking threads to
+	provide a new patch series.
+
+--ignore-if-in-upstream::
+	Do not include a patch that matches a commit in
+	<until>..<since>.  This will examine all patches reachable
+	from <since> but not from <until> and compare them with the
+	patches being generated, and any patch that matches is
+	ignored.
+
+--subject-prefix=<Subject-Prefix>::
+	Instead of the standard '[PATCH]' prefix in the subject
+	line, instead use '[<Subject-Prefix>]'. This
+	allows for useful naming of a patch series, and can be
+	combined with the `--numbered` option.
+
+--rfc::
+	Alias for `--subject-prefix="RFC PATCH"`. RFC means "Request For
+	Comments"; use this when sending an experimental patch for
+	discussion rather than application.
+
+-v <n>::
+--reroll-count=<n>::
+	Mark the series as the <n>-th iteration of the topic. The
+	output filenames have `v<n>` prepended to them, and the
+	subject prefix ("PATCH" by default, but configurable via the
+	`--subject-prefix` option) has ` v<n>` appended to it.  E.g.
+	`--reroll-count=4` may produce `v4-0001-add-makefile.patch`
+	file that has "Subject: [PATCH v4 1/20] Add makefile" in it.
+
+--to=<email>::
+	Add a `To:` header to the email headers. This is in addition
+	to any configured headers, and may be used multiple times.
+	The negated form `--no-to` discards all `To:` headers added so
+	far (from config or command line).
+
+--cc=<email>::
+	Add a `Cc:` header to the email headers. This is in addition
+	to any configured headers, and may be used multiple times.
+	The negated form `--no-cc` discards all `Cc:` headers added so
+	far (from config or command line).
+
+--from::
+--from=<ident>::
+	Use `ident` in the `From:` header of each commit email. If the
+	author ident of the commit is not textually identical to the
+	provided `ident`, place a `From:` header in the body of the
+	message with the original author. If no `ident` is given, use
+	the committer ident.
++
+Note that this option is only useful if you are actually sending the
+emails and want to identify yourself as the sender, but retain the
+original author (and `git am` will correctly pick up the in-body
+header). Note also that `git send-email` already handles this
+transformation for you, and this option should not be used if you are
+feeding the result to `git send-email`.
+
+--add-header=<header>::
+	Add an arbitrary header to the email headers.  This is in addition
+	to any configured headers, and may be used multiple times.
+	For example, `--add-header="Organization: git-foo"`.
+	The negated form `--no-add-header` discards *all* (`To:`,
+	`Cc:`, and custom) headers added so far from config or command
+	line.
+
+--[no-]cover-letter::
+	In addition to the patches, generate a cover letter file
+	containing the branch description, shortlog and the overall diffstat.  You can
+	fill in a description in the file before sending it out.
+
+--interdiff=<previous>::
+	As a reviewer aid, insert an interdiff into the cover letter,
+	or as commentary of the lone patch of a 1-patch series, showing
+	the differences between the previous version of the patch series and
+	the series currently being formatted. `previous` is a single revision
+	naming the tip of the previous series which shares a common base with
+	the series being formatted (for example `git format-patch
+	--cover-letter --interdiff=feature/v1 -3 feature/v2`).
+
+--range-diff=<previous>::
+	As a reviewer aid, insert a range-diff (see linkgit:git-range-diff[1])
+	into the cover letter, or as commentary of the lone patch of a
+	1-patch series, showing the differences between the previous
+	version of the patch series and the series currently being formatted.
+	`previous` can be a single revision naming the tip of the previous
+	series if it shares a common base with the series being formatted (for
+	example `git format-patch --cover-letter --range-diff=feature/v1 -3
+	feature/v2`), or a revision range if the two versions of the series are
+	disjoint (for example `git format-patch --cover-letter
+	--range-diff=feature/v1~3..feature/v1 -3 feature/v2`).
++
+Note that diff options passed to the command affect how the primary
+product of `format-patch` is generated, and they are not passed to
+the underlying `range-diff` machinery used to generate the cover-letter
+material (this may change in the future).
+
+--creation-factor=<percent>::
+	Used with `--range-diff`, tweak the heuristic which matches up commits
+	between the previous and current series of patches by adjusting the
+	creation/deletion cost fudge factor. See linkgit:git-range-diff[1])
+	for details.
+
+--notes[=<ref>]::
+--no-notes::
+	Append the notes (see linkgit:git-notes[1]) for the commit
+	after the three-dash line.
++
+The expected use case of this is to write supporting explanation for
+the commit that does not belong to the commit log message proper,
+and include it with the patch submission. While one can simply write
+these explanations after `format-patch` has run but before sending,
+keeping them as Git notes allows them to be maintained between versions
+of the patch series (but see the discussion of the `notes.rewrite`
+configuration options in linkgit:git-notes[1] to use this workflow).
++
+The default is `--no-notes`, unless the `format.notes` configuration is
+set.
+
+--[no-]signature=<signature>::
+	Add a signature to each message produced. Per RFC 3676 the signature
+	is separated from the body by a line with '-- ' on it. If the
+	signature option is omitted the signature defaults to the Git version
+	number.
+
+--signature-file=<file>::
+	Works just like --signature except the signature is read from a file.
+
+--suffix=.<sfx>::
+	Instead of using `.patch` as the suffix for generated
+	filenames, use specified suffix.  A common alternative is
+	`--suffix=.txt`.  Leaving this empty will remove the `.patch`
+	suffix.
++
+Note that the leading character does not have to be a dot; for example,
+you can use `--suffix=-patch` to get `0001-description-of-my-change-patch`.
+
+-q::
+--quiet::
+	Do not print the names of the generated files to standard output.
+
+--no-binary::
+	Do not output contents of changes in binary files, instead
+	display a notice that those files changed.  Patches generated
+	using this option cannot be applied properly, but they are
+	still useful for code review.
+
+--zero-commit::
+  Output an all-zero hash in each patch's From header instead
+  of the hash of the commit.
+
+--base=<commit>::
+	Record the base tree information to identify the state the
+	patch series applies to.  See the BASE TREE INFORMATION section
+	below for details.
+
+--root::
+	Treat the revision argument as a <revision range>, even if it
+	is just a single commit (that would normally be treated as a
+	<since>).  Note that root commits included in the specified
+	range are always formatted as creation patches, independently
+	of this flag.
+
+--progress::
+	Show progress reports on stderr as patches are generated.
+
+CONFIGURATION
+-------------
+You can specify extra mail header lines to be added to each message,
+defaults for the subject prefix and file suffix, number patches when
+outputting more than one patch, add "To" or "Cc:" headers, configure
+attachments, and sign off patches with configuration variables.
+
+------------
+[format]
+	headers = "Organization: git-foo\n"
+	subjectPrefix = CHANGE
+	suffix = .txt
+	numbered = auto
+	to = <email>
+	cc = <email>
+	attach [ = mime-boundary-string ]
+	signOff = true
+	coverletter = auto
+------------
+
+
+DISCUSSION
+----------
+
+The patch produced by 'git format-patch' is in UNIX mailbox format,
+with a fixed "magic" time stamp to indicate that the file is output
+from format-patch rather than a real mailbox, like so:
+
+------------
+From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
+From: Tony Luck <tony.luck@intel.com>
+Date: Tue, 13 Jul 2010 11:42:54 -0700
+Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
+ =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+arch/arm config files were slimmed down using a python script
+(See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)
+
+Do the same for ia64 so we can have sleek & trim looking
+...
+------------
+
+Typically it will be placed in a MUA's drafts folder, edited to add
+timely commentary that should not go in the changelog after the three
+dashes, and then sent as a message whose body, in our example, starts
+with "arch/arm config files were...".  On the receiving end, readers
+can save interesting patches in a UNIX mailbox and apply them with
+linkgit:git-am[1].
+
+When a patch is part of an ongoing discussion, the patch generated by
+'git format-patch' can be tweaked to take advantage of the 'git am
+--scissors' feature.  After your response to the discussion comes a
+line that consists solely of "`-- >8 --`" (scissors and perforation),
+followed by the patch with unnecessary header fields removed:
+
+------------
+...
+> So we should do such-and-such.
+
+Makes sense to me.  How about this patch?
+
+-- >8 --
+Subject: [IA64] Put ia64 config files on the Uwe Kleine-König diet
+
+arch/arm config files were slimmed down using a python script
+...
+------------
+
+When sending a patch this way, most often you are sending your own
+patch, so in addition to the "`From $SHA1 $magic_timestamp`" marker you
+should omit `From:` and `Date:` lines from the patch file.  The patch
+title is likely to be different from the subject of the discussion the
+patch is in response to, so it is likely that you would want to keep
+the Subject: line, like the example above.
+
+Checking for patch corruption
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Many mailers if not set up properly will corrupt whitespace.  Here are
+two common types of corruption:
+
+* Empty context lines that do not have _any_ whitespace.
+
+* Non-empty context lines that have one extra whitespace at the
+  beginning.
+
+One way to test if your MUA is set up correctly is:
+
+* Send the patch to yourself, exactly the way you would, except
+  with To: and Cc: lines that do not contain the list and
+  maintainer address.
+
+* Save that patch to a file in UNIX mailbox format.  Call it a.patch,
+  say.
+
+* Apply it:
+
+    $ git fetch <project> master:test-apply
+    $ git switch test-apply
+    $ git restore --source=HEAD --staged --worktree :/
+    $ git am a.patch
+
+If it does not apply correctly, there can be various reasons.
+
+* The patch itself does not apply cleanly.  That is _bad_ but
+  does not have much to do with your MUA.  You might want to rebase
+  the patch with linkgit:git-rebase[1] before regenerating it in
+  this case.
+
+* The MUA corrupted your patch; "am" would complain that
+  the patch does not apply.  Look in the .git/rebase-apply/ subdirectory and
+  see what 'patch' file contains and check for the common
+  corruption patterns mentioned above.
+
+* While at it, check the 'info' and 'final-commit' files as well.
+  If what is in 'final-commit' is not exactly what you would want to
+  see in the commit log message, it is very likely that the
+  receiver would end up hand editing the log message when applying
+  your patch.  Things like "Hi, this is my first patch.\n" in the
+  patch e-mail should come after the three-dash line that signals
+  the end of the commit message.
+
+MUA-SPECIFIC HINTS
+------------------
+Here are some hints on how to successfully submit patches inline using
+various mailers.
+
+GMail
+~~~~~
+GMail does not have any way to turn off line wrapping in the web
+interface, so it will mangle any emails that you send.  You can however
+use "git send-email" and send your patches through the GMail SMTP server, or
+use any IMAP email client to connect to the google IMAP server and forward
+the emails through that.
+
+For hints on using 'git send-email' to send your patches through the
+GMail SMTP server, see the EXAMPLE section of linkgit:git-send-email[1].
+
+For hints on submission using the IMAP interface, see the EXAMPLE
+section of linkgit:git-imap-send[1].
+
+Thunderbird
+~~~~~~~~~~~
+By default, Thunderbird will both wrap emails as well as flag
+them as being 'format=flowed', both of which will make the
+resulting email unusable by Git.
+
+There are three different approaches: use an add-on to turn off line wraps,
+configure Thunderbird to not mangle patches, or use
+an external editor to keep Thunderbird from mangling the patches.
+
+Approach #1 (add-on)
+^^^^^^^^^^^^^^^^^^^^
+
+Install the Toggle Word Wrap add-on that is available from
+https://addons.mozilla.org/thunderbird/addon/toggle-word-wrap/
+It adds a menu entry "Enable Word Wrap" in the composer's "Options" menu
+that you can tick off. Now you can compose the message as you otherwise do
+(cut + paste, 'git format-patch' | 'git imap-send', etc), but you have to
+insert line breaks manually in any text that you type.
+
+Approach #2 (configuration)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Three steps:
+
+1. Configure your mail server composition as plain text:
+   Edit...Account Settings...Composition & Addressing,
+   uncheck "Compose Messages in HTML".
+
+2. Configure your general composition window to not wrap.
++
+In Thunderbird 2:
+Edit..Preferences..Composition, wrap plain text messages at 0
++
+In Thunderbird 3:
+Edit..Preferences..Advanced..Config Editor.  Search for
+"mail.wrap_long_lines".
+Toggle it to make sure it is set to `false`. Also, search for
+"mailnews.wraplength" and set the value to 0.
+
+3. Disable the use of format=flowed:
+   Edit..Preferences..Advanced..Config Editor.  Search for
+   "mailnews.send_plaintext_flowed".
+   Toggle it to make sure it is set to `false`.
+
+After that is done, you should be able to compose email as you
+otherwise would (cut + paste, 'git format-patch' | 'git imap-send', etc),
+and the patches will not be mangled.
+
+Approach #3 (external editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following Thunderbird extensions are needed:
+AboutConfig from http://aboutconfig.mozdev.org/ and
+External Editor from http://globs.org/articles.php?lng=en&pg=8
+
+1. Prepare the patch as a text file using your method of choice.
+
+2. Before opening a compose window, use Edit->Account Settings to
+   uncheck the "Compose messages in HTML format" setting in the
+   "Composition & Addressing" panel of the account to be used to
+   send the patch.
+
+3. In the main Thunderbird window, 'before' you open the compose
+   window for the patch, use Tools->about:config to set the
+   following to the indicated values:
++
+----------
+	mailnews.send_plaintext_flowed  => false
+	mailnews.wraplength             => 0
+----------
+
+4. Open a compose window and click the external editor icon.
+
+5. In the external editor window, read in the patch file and exit
+   the editor normally.
+
+Side note: it may be possible to do step 2 with
+about:config and the following settings but no one's tried yet.
+
+----------
+	mail.html_compose                       => false
+	mail.identity.default.compose_html      => false
+	mail.identity.id?.compose_html          => false
+----------
+
+There is a script in contrib/thunderbird-patch-inline which can help
+you include patches with Thunderbird in an easy way. To use it, do the
+steps above and then use the script as the external editor.
+
+KMail
+~~~~~
+This should help you to submit patches inline using KMail.
+
+1. Prepare the patch as a text file.
+
+2. Click on New Mail.
+
+3. Go under "Options" in the Composer window and be sure that
+   "Word wrap" is not set.
+
+4. Use Message -> Insert file... and insert the patch.
+
+5. Back in the compose window: add whatever other text you wish to the
+   message, complete the addressing and subject fields, and press send.
+
+BASE TREE INFORMATION
+---------------------
+
+The base tree information block is used for maintainers or third party
+testers to know the exact state the patch series applies to. It consists
+of the 'base commit', which is a well-known commit that is part of the
+stable part of the project history everybody else works off of, and zero
+or more 'prerequisite patches', which are well-known patches in flight
+that is not yet part of the 'base commit' that need to be applied on top
+of 'base commit' in topological order before the patches can be applied.
+
+The 'base commit' is shown as "base-commit: " followed by the 40-hex of
+the commit object name.  A 'prerequisite patch' is shown as
+"prerequisite-patch-id: " followed by the 40-hex 'patch id', which can
+be obtained by passing the patch through the `git patch-id --stable`
+command.
+
+Imagine that on top of the public commit P, you applied well-known
+patches X, Y and Z from somebody else, and then built your three-patch
+series A, B, C, the history would be like:
+
+................................................
+---P---X---Y---Z---A---B---C
+................................................
+
+With `git format-patch --base=P -3 C` (or variants thereof, e.g. with
+`--cover-letter` or using `Z..C` instead of `-3 C` to specify the
+range), the base tree information block is shown at the end of the
+first message the command outputs (either the first patch, or the
+cover letter), like this:
+
+------------
+base-commit: P
+prerequisite-patch-id: X
+prerequisite-patch-id: Y
+prerequisite-patch-id: Z
+------------
+
+For non-linear topology, such as
+
+................................................
+---P---X---A---M---C
+    \         /
+     Y---Z---B
+................................................
+
+You can also use `git format-patch --base=P -3 C` to generate patches
+for A, B and C, and the identifiers for P, X, Y, Z are appended at the
+end of the first message.
+
+If set `--base=auto` in cmdline, it will track base commit automatically,
+the base commit will be the merge base of tip commit of the remote-tracking
+branch and revision-range specified in cmdline.
+For a local branch, you need to track a remote branch by `git branch
+--set-upstream-to` before using this option.
+
+EXAMPLES
+--------
+
+* Extract commits between revisions R1 and R2, and apply them on top of
+  the current branch using 'git am' to cherry-pick them:
++
+------------
+$ git format-patch -k --stdout R1..R2 | git am -3 -k
+------------
+
+* Extract all commits which are in the current branch but not in the
+  origin branch:
++
+------------
+$ git format-patch origin
+------------
++
+For each commit a separate file is created in the current directory.
+
+* Extract all commits that lead to 'origin' since the inception of the
+  project:
++
+------------
+$ git format-patch --root origin
+------------
+
+* The same as the previous one:
++
+------------
+$ git format-patch -M -B origin
+------------
++
+Additionally, it detects and handles renames and complete rewrites
+intelligently to produce a renaming patch.  A renaming patch reduces
+the amount of text output, and generally makes it easier to review.
+Note that non-Git "patch" programs won't understand renaming patches, so
+use it only when you know the recipient uses Git to apply your patch.
+
+* Extract three topmost commits from the current branch and format them
+  as e-mailable patches:
++
+------------
+$ git format-patch -3
+------------
+
+SEE ALSO
+--------
+linkgit:git-am[1], linkgit:git-send-email[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fsck-objects.txt b/third_party/git/Documentation/git-fsck-objects.txt
new file mode 100644
index 0000000000..eec4bdb600
--- /dev/null
+++ b/third_party/git/Documentation/git-fsck-objects.txt
@@ -0,0 +1,22 @@
+git-fsck-objects(1)
+===================
+
+NAME
+----
+git-fsck-objects - Verifies the connectivity and validity of the objects in the database
+
+
+SYNOPSIS
+--------
+[verse]
+'git fsck-objects' ...
+
+DESCRIPTION
+-----------
+
+This is a synonym for linkgit:git-fsck[1].  Please refer to the
+documentation of that command.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-fsck.txt b/third_party/git/Documentation/git-fsck.txt
new file mode 100644
index 0000000000..d72d15be5b
--- /dev/null
+++ b/third_party/git/Documentation/git-fsck.txt
@@ -0,0 +1,175 @@
+git-fsck(1)
+===========
+
+NAME
+----
+git-fsck - Verifies the connectivity and validity of the objects in the database
+
+
+SYNOPSIS
+--------
+[verse]
+'git fsck' [--tags] [--root] [--unreachable] [--cache] [--no-reflogs]
+	 [--[no-]full] [--strict] [--verbose] [--lost-found]
+	 [--[no-]dangling] [--[no-]progress] [--connectivity-only]
+	 [--[no-]name-objects] [<object>*]
+
+DESCRIPTION
+-----------
+Verifies the connectivity and validity of the objects in the database.
+
+OPTIONS
+-------
+<object>::
+	An object to treat as the head of an unreachability trace.
++
+If no objects are given, 'git fsck' defaults to using the
+index file, all SHA-1 references in `refs` namespace, and all reflogs
+(unless --no-reflogs is given) as heads.
+
+--unreachable::
+	Print out objects that exist but that aren't reachable from any
+	of the reference nodes.
+
+--[no-]dangling::
+	Print objects that exist but that are never 'directly' used (default).
+	`--no-dangling` can be used to omit this information from the output.
+
+--root::
+	Report root nodes.
+
+--tags::
+	Report tags.
+
+--cache::
+	Consider any object recorded in the index also as a head node for
+	an unreachability trace.
+
+--no-reflogs::
+	Do not consider commits that are referenced only by an
+	entry in a reflog to be reachable.  This option is meant
+	only to search for commits that used to be in a ref, but
+	now aren't, but are still in that corresponding reflog.
+
+--full::
+	Check not just objects in GIT_OBJECT_DIRECTORY
+	($GIT_DIR/objects), but also the ones found in alternate
+	object pools listed in GIT_ALTERNATE_OBJECT_DIRECTORIES
+	or $GIT_DIR/objects/info/alternates,
+	and in packed Git archives found in $GIT_DIR/objects/pack
+	and corresponding pack subdirectories in alternate
+	object pools.  This is now default; you can turn it off
+	with --no-full.
+
+--connectivity-only::
+	Check only the connectivity of reachable objects, making sure
+	that any objects referenced by a reachable tag, commit, or tree
+	is present. This speeds up the operation by avoiding reading
+	blobs entirely (though it does still check that referenced blobs
+	exist). This will detect corruption in commits and trees, but
+	not do any semantic checks (e.g., for format errors). Corruption
+	in blob objects will not be detected at all.
++
+Unreachable tags, commits, and trees will also be accessed to find the
+tips of dangling segments of history. Use `--no-dangling` if you don't
+care about this output and want to speed it up further.
+
+--strict::
+	Enable more strict checking, namely to catch a file mode
+	recorded with g+w bit set, which was created by older
+	versions of Git.  Existing repositories, including the
+	Linux kernel, Git itself, and sparse repository have old
+	objects that triggers this check, but it is recommended
+	to check new projects with this flag.
+
+--verbose::
+	Be chatty.
+
+--lost-found::
+	Write dangling objects into .git/lost-found/commit/ or
+	.git/lost-found/other/, depending on type.  If the object is
+	a blob, the contents are written into the file, rather than
+	its object name.
+
+--name-objects::
+	When displaying names of reachable objects, in addition to the
+	SHA-1 also display a name that describes *how* they are reachable,
+	compatible with linkgit:git-rev-parse[1], e.g.
+	`HEAD@{1234567890}~25^2:src/`.
+
+--[no-]progress::
+	Progress status is reported on the standard error stream by
+	default when it is attached to a terminal, unless
+	--no-progress or --verbose is specified. --progress forces
+	progress status even if the standard error stream is not
+	directed to a terminal.
+
+CONFIGURATION
+-------------
+
+include::config/fsck.txt[]
+
+DISCUSSION
+----------
+
+git-fsck tests SHA-1 and general object sanity, and it does full tracking
+of the resulting reachability and everything else. It prints out any
+corruption it finds (missing or bad objects), and if you use the
+`--unreachable` flag it will also print out objects that exist but that
+aren't reachable from any of the specified head nodes (or the default
+set, as mentioned above).
+
+Any corrupt objects you will have to find in backups or other archives
+(i.e., you can just remove them and do an 'rsync' with some other site in
+the hopes that somebody else has the object you have corrupted).
+
+If core.commitGraph is true, the commit-graph file will also be inspected
+using 'git commit-graph verify'. See linkgit:git-commit-graph[1].
+
+Extracted Diagnostics
+---------------------
+
+expect dangling commits - potential heads - due to lack of head information::
+	You haven't specified any nodes as heads so it won't be
+	possible to differentiate between un-parented commits and
+	root nodes.
+
+missing sha1 directory '<dir>'::
+	The directory holding the sha1 objects is missing.
+
+unreachable <type> <object>::
+	The <type> object <object>, isn't actually referred to directly
+	or indirectly in any of the trees or commits seen. This can
+	mean that there's another root node that you're not specifying
+	or that the tree is corrupt. If you haven't missed a root node
+	then you might as well delete unreachable nodes since they
+	can't be used.
+
+missing <type> <object>::
+	The <type> object <object>, is referred to but isn't present in
+	the database.
+
+dangling <type> <object>::
+	The <type> object <object>, is present in the database but never
+	'directly' used. A dangling commit could be a root node.
+
+hash mismatch <object>::
+	The database has an object whose hash doesn't match the
+	object database value.
+	This indicates a serious data integrity problem.
+
+Environment Variables
+---------------------
+
+GIT_OBJECT_DIRECTORY::
+	used to specify the object database root (usually $GIT_DIR/objects)
+
+GIT_INDEX_FILE::
+	used to specify the index file of the index
+
+GIT_ALTERNATE_OBJECT_DIRECTORIES::
+	used to specify additional object database roots (usually unset)
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-gc.txt b/third_party/git/Documentation/git-gc.txt
new file mode 100644
index 0000000000..247f765604
--- /dev/null
+++ b/third_party/git/Documentation/git-gc.txt
@@ -0,0 +1,162 @@
+git-gc(1)
+=========
+
+NAME
+----
+git-gc - Cleanup unnecessary files and optimize the local repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git gc' [--aggressive] [--auto] [--quiet] [--prune=<date> | --no-prune] [--force] [--keep-largest-pack]
+
+DESCRIPTION
+-----------
+Runs a number of housekeeping tasks within the current repository,
+such as compressing file revisions (to reduce disk space and increase
+performance), removing unreachable objects which may have been
+created from prior invocations of 'git add', packing refs, pruning
+reflog, rerere metadata or stale working trees. May also update ancillary
+indexes such as the commit-graph.
+
+When common porcelain operations that create objects are run, they
+will check whether the repository has grown substantially since the
+last maintenance, and if so run `git gc` automatically. See `gc.auto`
+below for how to disable this behavior.
+
+Running `git gc` manually should only be needed when adding objects to
+a repository without regularly running such porcelain commands, to do
+a one-off repository optimization, or e.g. to clean up a suboptimal
+mass-import. See the "PACKFILE OPTIMIZATION" section in
+linkgit:git-fast-import[1] for more details on the import case.
+
+OPTIONS
+-------
+
+--aggressive::
+	Usually 'git gc' runs very quickly while providing good disk
+	space utilization and performance.  This option will cause
+	'git gc' to more aggressively optimize the repository at the expense
+	of taking much more time.  The effects of this optimization are
+	mostly persistent. See the "AGGRESSIVE" section below for details.
+
+--auto::
+	With this option, 'git gc' checks whether any housekeeping is
+	required; if not, it exits without performing any work.
++
+See the `gc.auto` option in the "CONFIGURATION" section below for how
+this heuristic works.
++
+Once housekeeping is triggered by exceeding the limits of
+configuration options such as `gc.auto` and `gc.autoPackLimit`, all
+other housekeeping tasks (e.g. rerere, working trees, reflog...) will
+be performed as well.
+
+
+--prune=<date>::
+	Prune loose objects older than date (default is 2 weeks ago,
+	overridable by the config variable `gc.pruneExpire`).
+	--prune=now prunes loose objects regardless of their age and
+	increases the risk of corruption if another process is writing to
+	the repository concurrently; see "NOTES" below. --prune is on by
+	default.
+
+--no-prune::
+	Do not prune any loose objects.
+
+--quiet::
+	Suppress all progress reports.
+
+--force::
+	Force `git gc` to run even if there may be another `git gc`
+	instance running on this repository.
+
+--keep-largest-pack::
+	All packs except the largest pack and those marked with a
+	`.keep` files are consolidated into a single pack. When this
+	option is used, `gc.bigPackThreshold` is ignored.
+
+AGGRESSIVE
+----------
+
+When the `--aggressive` option is supplied, linkgit:git-repack[1] will
+be invoked with the `-f` flag, which in turn will pass
+`--no-reuse-delta` to linkgit:git-pack-objects[1]. This will throw
+away any existing deltas and re-compute them, at the expense of
+spending much more time on the repacking.
+
+The effects of this are mostly persistent, e.g. when packs and loose
+objects are coalesced into one another pack the existing deltas in
+that pack might get re-used, but there are also various cases where we
+might pick a sub-optimal delta from a newer pack instead.
+
+Furthermore, supplying `--aggressive` will tweak the `--depth` and
+`--window` options passed to linkgit:git-repack[1]. See the
+`gc.aggressiveDepth` and `gc.aggressiveWindow` settings below. By
+using a larger window size we're more likely to find more optimal
+deltas.
+
+It's probably not worth it to use this option on a given repository
+without running tailored performance benchmarks on it. It takes a lot
+more time, and the resulting space/delta optimization may or may not
+be worth it. Not using this at all is the right trade-off for most
+users and their repositories.
+
+CONFIGURATION
+-------------
+
+The below documentation is the same as what's found in
+linkgit:git-config[1]:
+
+include::config/gc.txt[]
+
+NOTES
+-----
+
+'git gc' tries very hard not to delete objects that are referenced
+anywhere in your repository. In
+particular, it will keep not only objects referenced by your current set
+of branches and tags, but also objects referenced by the index,
+remote-tracking branches, refs saved by 'git filter-branch' in
+refs/original/, reflogs (which may reference commits in branches
+that were later amended or rewound), and anything else in the refs/* namespace.
+If you are expecting some objects to be deleted and they aren't, check
+all of those locations and decide whether it makes sense in your case to
+remove those references.
+
+On the other hand, when 'git gc' runs concurrently with another process,
+there is a risk of it deleting an object that the other process is using
+but hasn't created a reference to. This may just cause the other process
+to fail or may corrupt the repository if the other process later adds a
+reference to the deleted object. Git has two features that significantly
+mitigate this problem:
+
+. Any object with modification time newer than the `--prune` date is kept,
+  along with everything reachable from it.
+
+. Most operations that add an object to the database update the
+  modification time of the object if it is already present so that #1
+  applies.
+
+However, these features fall short of a complete solution, so users who
+run commands concurrently have to live with some risk of corruption (which
+seems to be low in practice).
+
+HOOKS
+-----
+
+The 'git gc --auto' command will run the 'pre-auto-gc' hook.  See
+linkgit:githooks[5] for more information.
+
+
+SEE ALSO
+--------
+linkgit:git-prune[1]
+linkgit:git-reflog[1]
+linkgit:git-repack[1]
+linkgit:git-rerere[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-get-tar-commit-id.txt b/third_party/git/Documentation/git-get-tar-commit-id.txt
new file mode 100644
index 0000000000..ac44d85b0b
--- /dev/null
+++ b/third_party/git/Documentation/git-get-tar-commit-id.txt
@@ -0,0 +1,30 @@
+git-get-tar-commit-id(1)
+========================
+
+NAME
+----
+git-get-tar-commit-id - Extract commit ID from an archive created using git-archive
+
+
+SYNOPSIS
+--------
+[verse]
+'git get-tar-commit-id'
+
+
+DESCRIPTION
+-----------
+
+Read a tar archive created by 'git archive' from the standard input
+and extract the commit ID stored in it.  It reads only the first
+1024 bytes of input, thus its runtime is not influenced by the size
+of the tar archive very much.
+
+If no commit ID is found, 'git get-tar-commit-id' quietly exists with a
+return code of 1.  This can happen if the archive had not been created
+using 'git archive' or if the first parameter of 'git archive' had been
+a tree ID instead of a commit ID or tag.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-grep.txt b/third_party/git/Documentation/git-grep.txt
new file mode 100644
index 0000000000..2d27969057
--- /dev/null
+++ b/third_party/git/Documentation/git-grep.txt
@@ -0,0 +1,335 @@
+git-grep(1)
+===========
+
+NAME
+----
+git-grep - Print lines matching a pattern
+
+
+SYNOPSIS
+--------
+[verse]
+'git grep' [-a | --text] [-I] [--textconv] [-i | --ignore-case] [-w | --word-regexp]
+	   [-v | --invert-match] [-h|-H] [--full-name]
+	   [-E | --extended-regexp] [-G | --basic-regexp]
+	   [-P | --perl-regexp]
+	   [-F | --fixed-strings] [-n | --line-number] [--column]
+	   [-l | --files-with-matches] [-L | --files-without-match]
+	   [(-O | --open-files-in-pager) [<pager>]]
+	   [-z | --null]
+	   [ -o | --only-matching ] [-c | --count] [--all-match] [-q | --quiet]
+	   [--max-depth <depth>] [--[no-]recursive]
+	   [--color[=<when>] | --no-color]
+	   [--break] [--heading] [-p | --show-function]
+	   [-A <post-context>] [-B <pre-context>] [-C <context>]
+	   [-W | --function-context]
+	   [--threads <num>]
+	   [-f <file>] [-e] <pattern>
+	   [--and|--or|--not|(|)|-e <pattern>...]
+	   [--recurse-submodules] [--parent-basename <basename>]
+	   [ [--[no-]exclude-standard] [--cached | --no-index | --untracked] | <tree>...]
+	   [--] [<pathspec>...]
+
+DESCRIPTION
+-----------
+Look for specified patterns in the tracked files in the work tree, blobs
+registered in the index file, or blobs in given tree objects.  Patterns
+are lists of one or more search expressions separated by newline
+characters.  An empty string as search expression matches all lines.
+
+
+CONFIGURATION
+-------------
+
+grep.lineNumber::
+	If set to true, enable `-n` option by default.
+
+grep.column::
+	If set to true, enable the `--column` option by default.
+
+grep.patternType::
+	Set the default matching behavior. Using a value of 'basic', 'extended',
+	'fixed', or 'perl' will enable the `--basic-regexp`, `--extended-regexp`,
+	`--fixed-strings`, or `--perl-regexp` option accordingly, while the
+	value 'default' will return to the default matching behavior.
+
+grep.extendedRegexp::
+	If set to true, enable `--extended-regexp` option by default. This
+	option is ignored when the `grep.patternType` option is set to a value
+	other than 'default'.
+
+grep.threads::
+	Number of grep worker threads to use.  If unset (or set to 0),
+	8 threads are used by default (for now).
+
+grep.fullName::
+	If set to true, enable `--full-name` option by default.
+
+grep.fallbackToNoIndex::
+	If set to true, fall back to git grep --no-index if git grep
+	is executed outside of a git repository.  Defaults to false.
+
+
+OPTIONS
+-------
+--cached::
+	Instead of searching tracked files in the working tree, search
+	blobs registered in the index file.
+
+--no-index::
+	Search files in the current directory that is not managed by Git.
+
+--untracked::
+	In addition to searching in the tracked files in the working
+	tree, search also in untracked files.
+
+--no-exclude-standard::
+	Also search in ignored files by not honoring the `.gitignore`
+	mechanism. Only useful with `--untracked`.
+
+--exclude-standard::
+	Do not pay attention to ignored files specified via the `.gitignore`
+	mechanism.  Only useful when searching files in the current directory
+	with `--no-index`.
+
+--recurse-submodules::
+	Recursively search in each submodule that has been initialized and
+	checked out in the repository.  When used in combination with the
+	<tree> option the prefix of all submodule output will be the name of
+	the parent project's <tree> object.
+
+-a::
+--text::
+	Process binary files as if they were text.
+
+--textconv::
+	Honor textconv filter settings.
+
+--no-textconv::
+	Do not honor textconv filter settings.
+	This is the default.
+
+-i::
+--ignore-case::
+	Ignore case differences between the patterns and the
+	files.
+
+-I::
+	Don't match the pattern in binary files.
+
+--max-depth <depth>::
+	For each <pathspec> given on command line, descend at most <depth>
+	levels of directories. A value of -1 means no limit.
+	This option is ignored if <pathspec> contains active wildcards.
+	In other words if "a*" matches a directory named "a*",
+	"*" is matched literally so --max-depth is still effective.
+
+-r::
+--recursive::
+	Same as `--max-depth=-1`; this is the default.
+
+--no-recursive::
+	Same as `--max-depth=0`.
+
+-w::
+--word-regexp::
+	Match the pattern only at word boundary (either begin at the
+	beginning of a line, or preceded by a non-word character; end at
+	the end of a line or followed by a non-word character).
+
+-v::
+--invert-match::
+	Select non-matching lines.
+
+-h::
+-H::
+	By default, the command shows the filename for each
+	match.  `-h` option is used to suppress this output.
+	`-H` is there for completeness and does not do anything
+	except it overrides `-h` given earlier on the command
+	line.
+
+--full-name::
+	When run from a subdirectory, the command usually
+	outputs paths relative to the current directory.  This
+	option forces paths to be output relative to the project
+	top directory.
+
+-E::
+--extended-regexp::
+-G::
+--basic-regexp::
+	Use POSIX extended/basic regexp for patterns.  Default
+	is to use basic regexp.
+
+-P::
+--perl-regexp::
+	Use Perl-compatible regular expressions for patterns.
++
+Support for these types of regular expressions is an optional
+compile-time dependency. If Git wasn't compiled with support for them
+providing this option will cause it to die.
+
+-F::
+--fixed-strings::
+	Use fixed strings for patterns (don't interpret pattern
+	as a regex).
+
+-n::
+--line-number::
+	Prefix the line number to matching lines.
+
+--column::
+	Prefix the 1-indexed byte-offset of the first match from the start of the
+	matching line.
+
+-l::
+--files-with-matches::
+--name-only::
+-L::
+--files-without-match::
+	Instead of showing every matched line, show only the
+	names of files that contain (or do not contain) matches.
+	For better compatibility with 'git diff', `--name-only` is a
+	synonym for `--files-with-matches`.
+
+-O[<pager>]::
+--open-files-in-pager[=<pager>]::
+	Open the matching files in the pager (not the output of 'grep').
+	If the pager happens to be "less" or "vi", and the user
+	specified only one pattern, the first file is positioned at
+	the first match automatically. The `pager` argument is
+	optional; if specified, it must be stuck to the option
+	without a space. If `pager` is unspecified, the default pager
+	will be used (see `core.pager` in linkgit:git-config[1]).
+
+-z::
+--null::
+	Output \0 instead of the character that normally follows a
+	file name.
+
+-o::
+--only-matching::
+	Print only the matched (non-empty) parts of a matching line, with each such
+	part on a separate output line.
+
+-c::
+--count::
+	Instead of showing every matched line, show the number of
+	lines that match.
+
+--color[=<when>]::
+	Show colored matches.
+	The value must be always (the default), never, or auto.
+
+--no-color::
+	Turn off match highlighting, even when the configuration file
+	gives the default to color output.
+	Same as `--color=never`.
+
+--break::
+	Print an empty line between matches from different files.
+
+--heading::
+	Show the filename above the matches in that file instead of
+	at the start of each shown line.
+
+-p::
+--show-function::
+	Show the preceding line that contains the function name of
+	the match, unless the matching line is a function name itself.
+	The name is determined in the same way as 'git diff' works out
+	patch hunk headers (see 'Defining a custom hunk-header' in
+	linkgit:gitattributes[5]).
+
+-<num>::
+-C <num>::
+--context <num>::
+	Show <num> leading and trailing lines, and place a line
+	containing `--` between contiguous groups of matches.
+
+-A <num>::
+--after-context <num>::
+	Show <num> trailing lines, and place a line containing
+	`--` between contiguous groups of matches.
+
+-B <num>::
+--before-context <num>::
+	Show <num> leading lines, and place a line containing
+	`--` between contiguous groups of matches.
+
+-W::
+--function-context::
+	Show the surrounding text from the previous line containing a
+	function name up to the one before the next function name,
+	effectively showing the whole function in which the match was
+	found.
+
+--threads <num>::
+	Number of grep worker threads to use.
+	See `grep.threads` in 'CONFIGURATION' for more information.
+
+-f <file>::
+	Read patterns from <file>, one per line.
+
+-e::
+	The next parameter is the pattern. This option has to be
+	used for patterns starting with `-` and should be used in
+	scripts passing user input to grep.  Multiple patterns are
+	combined by 'or'.
+
+--and::
+--or::
+--not::
+( ... )::
+	Specify how multiple patterns are combined using Boolean
+	expressions.  `--or` is the default operator.  `--and` has
+	higher precedence than `--or`.  `-e` has to be used for all
+	patterns.
+
+--all-match::
+	When giving multiple pattern expressions combined with `--or`,
+	this flag is specified to limit the match to files that
+	have lines to match all of them.
+
+-q::
+--quiet::
+	Do not output matched lines; instead, exit with status 0 when
+	there is a match and with non-zero status when there isn't.
+
+<tree>...::
+	Instead of searching tracked files in the working tree, search
+	blobs in the given trees.
+
+\--::
+	Signals the end of options; the rest of the parameters
+	are <pathspec> limiters.
+
+<pathspec>...::
+	If given, limit the search to paths matching at least one pattern.
+	Both leading paths match and glob(7) patterns are supported.
++
+For more details about the <pathspec> syntax, see the 'pathspec' entry
+in linkgit:gitglossary[7].
+
+EXAMPLES
+--------
+
+`git grep 'time_t' -- '*.[ch]'`::
+	Looks for `time_t` in all tracked .c and .h files in the working
+	directory and its subdirectories.
+
+`git grep -e '#define' --and \( -e MAX_PATH -e PATH_MAX \)`::
+	Looks for a line that has `#define` and either `MAX_PATH` or
+	`PATH_MAX`.
+
+`git grep --all-match -e NODE -e Unexpected`::
+	Looks for a line that has `NODE` or `Unexpected` in
+	files that have lines that match both.
+
+`git grep solution -- :^Documentation`::
+	Looks for `solution`, excluding files in `Documentation`.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-gui.txt b/third_party/git/Documentation/git-gui.txt
new file mode 100644
index 0000000000..5f93f8003d
--- /dev/null
+++ b/third_party/git/Documentation/git-gui.txt
@@ -0,0 +1,127 @@
+git-gui(1)
+==========
+
+NAME
+----
+git-gui - A portable graphical interface to Git
+
+SYNOPSIS
+--------
+[verse]
+'git gui' [<command>] [arguments]
+
+DESCRIPTION
+-----------
+A Tcl/Tk based graphical user interface to Git.  'git gui' focuses
+on allowing users to make changes to their repository by making
+new commits, amending existing ones, creating branches, performing
+local merges, and fetching/pushing to remote repositories.
+
+Unlike 'gitk', 'git gui' focuses on commit generation
+and single file annotation and does not show project history.
+It does however supply menu actions to start a 'gitk' session from
+within 'git gui'.
+
+'git gui' is known to work on all popular UNIX systems, Mac OS X,
+and Windows (under both Cygwin and MSYS).  To the extent possible
+OS specific user interface guidelines are followed, making 'git gui'
+a fairly native interface for users.
+
+COMMANDS
+--------
+blame::
+	Start a blame viewer on the specified file on the given
+	version (or working directory if not specified).
+
+browser::
+	Start a tree browser showing all files in the specified
+	commit.  Files selected through the
+	browser are opened in the blame viewer.
+
+citool::
+	Start 'git gui' and arrange to make exactly one commit before
+	exiting and returning to the shell.  The interface is limited
+	to only commit actions, slightly reducing the application's
+	startup time and simplifying the menubar.
+
+version::
+	Display the currently running version of 'git gui'.
+
+
+Examples
+--------
+`git gui blame Makefile`::
+
+	Show the contents of the file 'Makefile' in the current
+	working directory, and provide annotations for both the
+	original author of each line, and who moved the line to its
+	current location.  The uncommitted file is annotated, and
+	uncommitted changes (if any) are explicitly attributed to
+	'Not Yet Committed'.
+
+`git gui blame v0.99.8 Makefile`::
+
+	Show the contents of 'Makefile' in revision 'v0.99.8'
+	and provide annotations for each line.  Unlike the above
+	example the file is read from the object database and not
+	the working directory.
+
+`git gui blame --line=100 Makefile`::
+
+	Loads annotations as described above and automatically
+	scrolls the view to center on line '100'.
+
+`git gui citool`::
+
+	Make one commit and return to the shell when it is complete.
+	This command returns a non-zero exit code if the window was
+	closed in any way other than by making a commit.
+
+`git gui citool --amend`::
+
+	Automatically enter the 'Amend Last Commit' mode of
+	the interface.
+
+`git gui citool --nocommit`::
+
+	Behave as normal citool, but instead of making a commit
+	simply terminate with a zero exit code. It still checks
+	that the index does not contain any unmerged entries, so
+	you can use it as a GUI version of linkgit:git-mergetool[1]
+
+`git citool`::
+
+	Same as `git gui citool` (above).
+
+`git gui browser maint`::
+
+	Show a browser for the tree of the 'maint' branch.  Files
+	selected in the browser can be viewed with the internal
+	blame viewer.
+
+SEE ALSO
+--------
+linkgit:gitk[1]::
+	The Git repository browser.  Shows branches, commit history
+	and file differences.  gitk is the utility started by
+	'git gui''s Repository Visualize actions.
+
+Other
+-----
+'git gui' is actually maintained as an independent project, but stable
+versions are distributed as part of the Git suite for the convenience
+of end users.
+
+A 'git gui' development repository can be obtained from:
+
+  git clone git://repo.or.cz/git-gui.git
+
+or
+
+  git clone http://repo.or.cz/r/git-gui.git
+
+or browsed online at http://repo.or.cz/w/git-gui.git/[].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-hash-object.txt b/third_party/git/Documentation/git-hash-object.txt
new file mode 100644
index 0000000000..df9e2c58bd
--- /dev/null
+++ b/third_party/git/Documentation/git-hash-object.txt
@@ -0,0 +1,63 @@
+git-hash-object(1)
+==================
+
+NAME
+----
+git-hash-object - Compute object ID and optionally creates a blob from a file
+
+
+SYNOPSIS
+--------
+[verse]
+'git hash-object' [-t <type>] [-w] [--path=<file>|--no-filters] [--stdin [--literally]] [--] <file>...
+'git hash-object' [-t <type>] [-w] --stdin-paths [--no-filters]
+
+DESCRIPTION
+-----------
+Computes the object ID value for an object with specified type
+with the contents of the named file (which can be outside of the
+work tree), and optionally writes the resulting object into the
+object database.  Reports its object ID to its standard output.
+When <type> is not specified, it defaults to "blob".
+
+OPTIONS
+-------
+
+-t <type>::
+	Specify the type (default: "blob").
+
+-w::
+	Actually write the object into the object database.
+
+--stdin::
+	Read the object from standard input instead of from a file.
+
+--stdin-paths::
+	Read file names from the standard input, one per line, instead
+	of from the command-line.
+
+--path::
+	Hash object as it were located at the given path. The location of
+	file does not directly influence on the hash value, but path is
+	used to determine what Git filters should be applied to the object
+	before it can be placed to the object database, and, as result of
+	applying filters, the actual blob put into the object database may
+	differ from the given file. This option is mainly useful for hashing
+	temporary files located outside of the working directory or files
+	read from stdin.
+
+--no-filters::
+	Hash the contents as is, ignoring any input filter that would
+	have been chosen by the attributes mechanism, including the end-of-line
+	conversion. If the file is read from standard input then this
+	is always implied, unless the `--path` option is given.
+
+--literally::
+	Allow `--stdin` to hash any garbage into a loose object which might not
+	otherwise pass standard object parsing or git-fsck checks. Useful for
+	stress-testing Git itself or reproducing characteristics of corrupt or
+	bogus objects encountered in the wild.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-help.txt b/third_party/git/Documentation/git-help.txt
new file mode 100644
index 0000000000..f71db0daa2
--- /dev/null
+++ b/third_party/git/Documentation/git-help.txt
@@ -0,0 +1,204 @@
+git-help(1)
+===========
+
+NAME
+----
+git-help - Display help information about Git
+
+SYNOPSIS
+--------
+[verse]
+'git help' [-a|--all [--[no-]verbose]] [-g|--guide]
+	   [-i|--info|-m|--man|-w|--web] [COMMAND|GUIDE]
+
+DESCRIPTION
+-----------
+
+With no options and no COMMAND or GUIDE given, the synopsis of the 'git'
+command and a list of the most commonly used Git commands are printed
+on the standard output.
+
+If the option `--all` or `-a` is given, all available commands are
+printed on the standard output.
+
+If the option `--guide` or `-g` is given, a list of the useful
+Git guides is also printed on the standard output.
+
+If a command, or a guide, is given, a manual page for that command or
+guide is brought up. The 'man' program is used by default for this
+purpose, but this can be overridden by other options or configuration
+variables.
+
+If an alias is given, git shows the definition of the alias on
+standard output. To get the manual page for the aliased command, use
+`git COMMAND --help`.
+
+Note that `git --help ...` is identical to `git help ...` because the
+former is internally converted into the latter.
+
+To display the linkgit:git[1] man page, use `git help git`.
+
+This page can be displayed with 'git help help' or `git help --help`
+
+OPTIONS
+-------
+-a::
+--all::
+	Prints all the available commands on the standard output. This
+	option overrides any given command or guide name.
+
+--verbose::
+	When used with `--all` print description for all recognized
+	commands. This is the default.
+
+-c::
+--config::
+	List all available configuration variables. This is a short
+	summary of the list in linkgit:git-config[1].
+
+-g::
+--guides::
+	Prints a list of useful guides on the standard output. This
+	option overrides any given command or guide name.
+
+-i::
+--info::
+	Display manual page for the command in the 'info' format. The
+	'info' program will be used for that purpose.
+
+-m::
+--man::
+	Display manual page for the command in the 'man' format. This
+	option may be used to override a value set in the
+	`help.format` configuration variable.
++
+By default the 'man' program will be used to display the manual page,
+but the `man.viewer` configuration variable may be used to choose
+other display programs (see below).
+
+-w::
+--web::
+	Display manual page for the command in the 'web' (HTML)
+	format. A web browser will be used for that purpose.
++
+The web browser can be specified using the configuration variable
+`help.browser`, or `web.browser` if the former is not set. If none of
+these config variables is set, the 'git web{litdd}browse' helper script
+(called by 'git help') will pick a suitable default. See
+linkgit:git-web{litdd}browse[1] for more information about this.
+
+CONFIGURATION VARIABLES
+-----------------------
+
+help.format
+~~~~~~~~~~~
+
+If no command-line option is passed, the `help.format` configuration
+variable will be checked. The following values are supported for this
+variable; they make 'git help' behave as their corresponding command-
+line option:
+
+* "man" corresponds to '-m|--man',
+* "info" corresponds to '-i|--info',
+* "web" or "html" correspond to '-w|--web'.
+
+help.browser, web.browser and browser.<tool>.path
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The `help.browser`, `web.browser` and `browser.<tool>.path` will also
+be checked if the 'web' format is chosen (either by command-line
+option or configuration variable). See '-w|--web' in the OPTIONS
+section above and linkgit:git-web{litdd}browse[1].
+
+man.viewer
+~~~~~~~~~~
+
+The `man.viewer` configuration variable will be checked if the 'man'
+format is chosen. The following values are currently supported:
+
+* "man": use the 'man' program as usual,
+* "woman": use 'emacsclient' to launch the "woman" mode in emacs
+  (this only works starting with emacsclient versions 22),
+* "konqueror": use 'kfmclient' to open the man page in a new konqueror
+  tab (see 'Note about konqueror' below).
+
+Values for other tools can be used if there is a corresponding
+`man.<tool>.cmd` configuration entry (see below).
+
+Multiple values may be given to the `man.viewer` configuration
+variable. Their corresponding programs will be tried in the order
+listed in the configuration file.
+
+For example, this configuration:
+
+------------------------------------------------
+	[man]
+		viewer = konqueror
+		viewer = woman
+------------------------------------------------
+
+will try to use konqueror first. But this may fail (for example, if
+DISPLAY is not set) and in that case emacs' woman mode will be tried.
+
+If everything fails, or if no viewer is configured, the viewer specified
+in the `GIT_MAN_VIEWER` environment variable will be tried.  If that
+fails too, the 'man' program will be tried anyway.
+
+man.<tool>.path
+~~~~~~~~~~~~~~~
+
+You can explicitly provide a full path to your preferred man viewer by
+setting the configuration variable `man.<tool>.path`. For example, you
+can configure the absolute path to konqueror by setting
+'man.konqueror.path'. Otherwise, 'git help' assumes the tool is
+available in PATH.
+
+man.<tool>.cmd
+~~~~~~~~~~~~~~
+
+When the man viewer, specified by the `man.viewer` configuration
+variables, is not among the supported ones, then the corresponding
+`man.<tool>.cmd` configuration variable will be looked up. If this
+variable exists then the specified tool will be treated as a custom
+command and a shell eval will be used to run the command with the man
+page passed as arguments.
+
+Note about konqueror
+~~~~~~~~~~~~~~~~~~~~
+
+When 'konqueror' is specified in the `man.viewer` configuration
+variable, we launch 'kfmclient' to try to open the man page on an
+already opened konqueror in a new tab if possible.
+
+For consistency, we also try such a trick if 'man.konqueror.path' is
+set to something like `A_PATH_TO/konqueror`. That means we will try to
+launch `A_PATH_TO/kfmclient` instead.
+
+If you really want to use 'konqueror', then you can use something like
+the following:
+
+------------------------------------------------
+	[man]
+		viewer = konq
+
+	[man "konq"]
+		cmd = A_PATH_TO/konqueror
+------------------------------------------------
+
+Note about git config --global
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Note that all these configuration variables should probably be set
+using the `--global` flag, for example like this:
+
+------------------------------------------------
+$ git config --global help.format web
+$ git config --global web.browser firefox
+------------------------------------------------
+
+as they are probably more user specific than repository specific.
+See linkgit:git-config[1] for more information about this.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-http-backend.txt b/third_party/git/Documentation/git-http-backend.txt
new file mode 100644
index 0000000000..558966aa83
--- /dev/null
+++ b/third_party/git/Documentation/git-http-backend.txt
@@ -0,0 +1,277 @@
+git-http-backend(1)
+===================
+
+NAME
+----
+git-http-backend - Server side implementation of Git over HTTP
+
+SYNOPSIS
+--------
+[verse]
+'git http-backend'
+
+DESCRIPTION
+-----------
+A simple CGI program to serve the contents of a Git repository to Git
+clients accessing the repository over http:// and https:// protocols.
+The program supports clients fetching using both the smart HTTP protocol
+and the backwards-compatible dumb HTTP protocol, as well as clients
+pushing using the smart HTTP protocol.
+
+It verifies that the directory has the magic file
+"git-daemon-export-ok", and it will refuse to export any Git directory
+that hasn't explicitly been marked for export this way (unless the
+`GIT_HTTP_EXPORT_ALL` environmental variable is set).
+
+By default, only the `upload-pack` service is enabled, which serves
+'git fetch-pack' and 'git ls-remote' clients, which are invoked from
+'git fetch', 'git pull', and 'git clone'.  If the client is authenticated,
+the `receive-pack` service is enabled, which serves 'git send-pack'
+clients, which is invoked from 'git push'.
+
+SERVICES
+--------
+These services can be enabled/disabled using the per-repository
+configuration file:
+
+http.getanyfile::
+	This serves Git clients older than version 1.6.6 that are unable to use the
+	upload pack service.  When enabled, clients are able to read
+	any file within the repository, including objects that are
+	no longer reachable from a branch but are still present.
+	It is enabled by default, but a repository can disable it
+	by setting this configuration item to `false`.
+
+http.uploadpack::
+	This serves 'git fetch-pack' and 'git ls-remote' clients.
+	It is enabled by default, but a repository can disable it
+	by setting this configuration item to `false`.
+
+http.receivepack::
+	This serves 'git send-pack' clients, allowing push.  It is
+	disabled by default for anonymous users, and enabled by
+	default for users authenticated by the web server.  It can be
+	disabled by setting this item to `false`, or enabled for all
+	users, including anonymous users, by setting it to `true`.
+
+URL TRANSLATION
+---------------
+To determine the location of the repository on disk, 'git http-backend'
+concatenates the environment variables PATH_INFO, which is set
+automatically by the web server, and GIT_PROJECT_ROOT, which must be set
+manually in the web server configuration.  If GIT_PROJECT_ROOT is not
+set, 'git http-backend' reads PATH_TRANSLATED, which is also set
+automatically by the web server.
+
+EXAMPLES
+--------
+All of the following examples map `http://$hostname/git/foo/bar.git`
+to `/var/www/git/foo/bar.git`.
+
+Apache 2.x::
+	Ensure mod_cgi, mod_alias, and mod_env are enabled, set
+	GIT_PROJECT_ROOT (or DocumentRoot) appropriately, and
+	create a ScriptAlias to the CGI:
++
+----------------------------------------------------------------
+SetEnv GIT_PROJECT_ROOT /var/www/git
+SetEnv GIT_HTTP_EXPORT_ALL
+ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
+----------------------------------------------------------------
++
+To enable anonymous read access but authenticated write access,
+require authorization for both the initial ref advertisement (which we
+detect as a push via the service parameter in the query string), and the
+receive-pack invocation itself:
++
+----------------------------------------------------------------
+RewriteCond %{QUERY_STRING} service=git-receive-pack [OR]
+RewriteCond %{REQUEST_URI} /git-receive-pack$
+RewriteRule ^/git/ - [E=AUTHREQUIRED:yes]
+
+<LocationMatch "^/git/">
+	Order Deny,Allow
+	Deny from env=AUTHREQUIRED
+
+	AuthType Basic
+	AuthName "Git Access"
+	Require group committers
+	Satisfy Any
+	...
+</LocationMatch>
+----------------------------------------------------------------
++
+If you do not have `mod_rewrite` available to match against the query
+string, it is sufficient to just protect `git-receive-pack` itself,
+like:
++
+----------------------------------------------------------------
+<LocationMatch "^/git/.*/git-receive-pack$">
+	AuthType Basic
+	AuthName "Git Access"
+	Require group committers
+	...
+</LocationMatch>
+----------------------------------------------------------------
++
+In this mode, the server will not request authentication until the
+client actually starts the object negotiation phase of the push, rather
+than during the initial contact.  For this reason, you must also enable
+the `http.receivepack` config option in any repositories that should
+accept a push. The default behavior, if `http.receivepack` is not set,
+is to reject any pushes by unauthenticated users; the initial request
+will therefore report `403 Forbidden` to the client, without even giving
+an opportunity for authentication.
++
+To require authentication for both reads and writes, use a Location
+directive around the repository, or one of its parent directories:
++
+----------------------------------------------------------------
+<Location /git/private>
+	AuthType Basic
+	AuthName "Private Git Access"
+	Require group committers
+	...
+</Location>
+----------------------------------------------------------------
++
+To serve gitweb at the same url, use a ScriptAliasMatch to only
+those URLs that 'git http-backend' can handle, and forward the
+rest to gitweb:
++
+----------------------------------------------------------------
+ScriptAliasMatch \
+	"(?x)^/git/(.*/(HEAD | \
+			info/refs | \
+			objects/(info/[^/]+ | \
+				 [0-9a-f]{2}/[0-9a-f]{38} | \
+				 pack/pack-[0-9a-f]{40}\.(pack|idx)) | \
+			git-(upload|receive)-pack))$" \
+	/usr/libexec/git-core/git-http-backend/$1
+
+ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
+----------------------------------------------------------------
++
+To serve multiple repositories from different linkgit:gitnamespaces[7] in a
+single repository:
++
+----------------------------------------------------------------
+SetEnvIf Request_URI "^/git/([^/]*)" GIT_NAMESPACE=$1
+ScriptAliasMatch ^/git/[^/]*(.*) /usr/libexec/git-core/git-http-backend/storage.git$1
+----------------------------------------------------------------
+
+Accelerated static Apache 2.x::
+	Similar to the above, but Apache can be used to return static
+	files that are stored on disk.  On many systems this may
+	be more efficient as Apache can ask the kernel to copy the
+	file contents from the file system directly to the network:
++
+----------------------------------------------------------------
+SetEnv GIT_PROJECT_ROOT /var/www/git
+
+AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
+AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
+ScriptAlias /git/ /usr/libexec/git-core/git-http-backend/
+----------------------------------------------------------------
++
+This can be combined with the gitweb configuration:
++
+----------------------------------------------------------------
+SetEnv GIT_PROJECT_ROOT /var/www/git
+
+AliasMatch ^/git/(.*/objects/[0-9a-f]{2}/[0-9a-f]{38})$          /var/www/git/$1
+AliasMatch ^/git/(.*/objects/pack/pack-[0-9a-f]{40}.(pack|idx))$ /var/www/git/$1
+ScriptAliasMatch \
+	"(?x)^/git/(.*/(HEAD | \
+			info/refs | \
+			objects/info/[^/]+ | \
+			git-(upload|receive)-pack))$" \
+	/usr/libexec/git-core/git-http-backend/$1
+ScriptAlias /git/ /var/www/cgi-bin/gitweb.cgi/
+----------------------------------------------------------------
+
+Lighttpd::
+	Ensure that `mod_cgi`, `mod_alias`, `mod_auth`, `mod_setenv` are
+	loaded, then set `GIT_PROJECT_ROOT` appropriately and redirect
+	all requests to the CGI:
++
+----------------------------------------------------------------
+alias.url += ( "/git" => "/usr/lib/git-core/git-http-backend" )
+$HTTP["url"] =~ "^/git" {
+	cgi.assign = ("" => "")
+	setenv.add-environment = (
+		"GIT_PROJECT_ROOT" => "/var/www/git",
+		"GIT_HTTP_EXPORT_ALL" => ""
+	)
+}
+----------------------------------------------------------------
++
+To enable anonymous read access but authenticated write access:
++
+----------------------------------------------------------------
+$HTTP["querystring"] =~ "service=git-receive-pack" {
+	include "git-auth.conf"
+}
+$HTTP["url"] =~ "^/git/.*/git-receive-pack$" {
+	include "git-auth.conf"
+}
+----------------------------------------------------------------
++
+where `git-auth.conf` looks something like:
++
+----------------------------------------------------------------
+auth.require = (
+	"/" => (
+		"method" => "basic",
+		"realm" => "Git Access",
+		"require" => "valid-user"
+	       )
+)
+# ...and set up auth.backend here
+----------------------------------------------------------------
++
+To require authentication for both reads and writes:
++
+----------------------------------------------------------------
+$HTTP["url"] =~ "^/git/private" {
+	include "git-auth.conf"
+}
+----------------------------------------------------------------
+
+
+ENVIRONMENT
+-----------
+'git http-backend' relies upon the `CGI` environment variables set
+by the invoking web server, including:
+
+* PATH_INFO (if GIT_PROJECT_ROOT is set, otherwise PATH_TRANSLATED)
+* REMOTE_USER
+* REMOTE_ADDR
+* CONTENT_TYPE
+* QUERY_STRING
+* REQUEST_METHOD
+
+The `GIT_HTTP_EXPORT_ALL` environmental variable may be passed to
+'git-http-backend' to bypass the check for the "git-daemon-export-ok"
+file in each repository before allowing export of that repository.
+
+The `GIT_HTTP_MAX_REQUEST_BUFFER` environment variable (or the
+`http.maxRequestBuffer` config variable) may be set to change the
+largest ref negotiation request that git will handle during a fetch; any
+fetch requiring a larger buffer will not succeed.  This value should not
+normally need to be changed, but may be helpful if you are fetching from
+a repository with an extremely large number of refs.  The value can be
+specified with a unit (e.g., `100M` for 100 megabytes). The default is
+10 megabytes.
+
+The backend process sets GIT_COMMITTER_NAME to '$REMOTE_USER' and
+GIT_COMMITTER_EMAIL to '$\{REMOTE_USER}@http.$\{REMOTE_ADDR\}',
+ensuring that any reflogs created by 'git-receive-pack' contain some
+identifying information of the remote user who performed the push.
+
+All `CGI` environment variables are available to each of the hooks
+invoked by the 'git-receive-pack'.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-http-fetch.txt b/third_party/git/Documentation/git-http-fetch.txt
new file mode 100644
index 0000000000..666b042679
--- /dev/null
+++ b/third_party/git/Documentation/git-http-fetch.txt
@@ -0,0 +1,49 @@
+git-http-fetch(1)
+=================
+
+NAME
+----
+git-http-fetch - Download from a remote Git repository via HTTP
+
+
+SYNOPSIS
+--------
+[verse]
+'git http-fetch' [-c] [-t] [-a] [-d] [-v] [-w filename] [--recover] [--stdin] <commit> <url>
+
+DESCRIPTION
+-----------
+Downloads a remote Git repository via HTTP.
+
+This command always gets all objects. Historically, there were three options
+`-a`, `-c` and `-t` for choosing which objects to download. They are now
+silently ignored.
+
+OPTIONS
+-------
+commit-id::
+        Either the hash or the filename under [URL]/refs/ to
+        pull.
+
+-a, -c, -t::
+	These options are ignored for historical reasons.
+-v::
+	Report what is downloaded.
+
+-w <filename>::
+        Writes the commit-id into the filename under $GIT_DIR/refs/<filename> on
+        the local end after the transfer is complete.
+
+--stdin::
+	Instead of a commit id on the command line (which is not expected in this
+	case), 'git http-fetch' expects lines on stdin in the format
+
+		<commit-id>['\t'<filename-as-in--w>]
+
+--recover::
+	Verify that everything reachable from target is fetched.  Used after
+	an earlier fetch is interrupted.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-http-push.txt b/third_party/git/Documentation/git-http-push.txt
new file mode 100644
index 0000000000..ea03a4eeb0
--- /dev/null
+++ b/third_party/git/Documentation/git-http-push.txt
@@ -0,0 +1,97 @@
+git-http-push(1)
+================
+
+NAME
+----
+git-http-push - Push objects over HTTP/DAV to another repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git http-push' [--all] [--dry-run] [--force] [--verbose] <url> <ref> [<ref>...]
+
+DESCRIPTION
+-----------
+Sends missing objects to remote repository, and updates the
+remote branch.
+
+*NOTE*: This command is temporarily disabled if your libcurl
+is older than 7.16, as the combination has been reported
+not to work and sometimes corrupts repository.
+
+OPTIONS
+-------
+--all::
+	Do not assume that the remote repository is complete in its
+	current state, and verify all objects in the entire local
+	ref's history exist in the remote repository.
+
+--force::
+	Usually, the command refuses to update a remote ref that
+	is not an ancestor of the local ref used to overwrite it.
+	This flag disables the check.  What this means is that
+	the remote repository can lose commits; use it with
+	care.
+
+--dry-run::
+	Do everything except actually send the updates.
+
+--verbose::
+	Report the list of objects being walked locally and the
+	list of objects successfully sent to the remote repository.
+
+-d::
+-D::
+	Remove <ref> from remote repository.  The specified branch
+	cannot be the remote HEAD.  If -d is specified the following
+	other conditions must also be met:
+
+	- Remote HEAD must resolve to an object that exists locally
+	- Specified branch resolves to an object that exists locally
+	- Specified branch is an ancestor of the remote HEAD
+
+<ref>...::
+	The remote refs to update.
+
+
+SPECIFYING THE REFS
+-------------------
+
+A '<ref>' specification can be either a single pattern, or a pair
+of such patterns separated by a colon ":" (this means that a ref name
+cannot have a colon in it).  A single pattern '<name>' is just a
+shorthand for '<name>:<name>'.
+
+Each pattern pair consists of the source side (before the colon)
+and the destination side (after the colon).  The ref to be
+pushed is determined by finding a match that matches the source
+side, and where it is pushed is determined by using the
+destination side.
+
+ - It is an error if <src> does not match exactly one of the
+   local refs.
+
+ - If <dst> does not match any remote ref, either
+
+   * it has to start with "refs/"; <dst> is used as the
+     destination literally in this case.
+
+   * <src> == <dst> and the ref that matched the <src> must not
+     exist in the set of remote refs; the ref matched <src>
+     locally is used as the name of the destination.
+
+Without `--force`, the <src> ref is stored at the remote only if
+<dst> does not exist, or <dst> is a proper subset (i.e. an
+ancestor) of <src>.  This check, known as "fast-forward check",
+is performed in order to avoid accidentally overwriting the
+remote ref and lose other peoples' commits from there.
+
+With `--force`, the fast-forward check is disabled for all refs.
+
+Optionally, a <ref> parameter can be prefixed with a plus '+' sign
+to disable the fast-forward check only on that ref.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-imap-send.txt b/third_party/git/Documentation/git-imap-send.txt
new file mode 100644
index 0000000000..65b53fcc47
--- /dev/null
+++ b/third_party/git/Documentation/git-imap-send.txt
@@ -0,0 +1,140 @@
+git-imap-send(1)
+================
+
+NAME
+----
+git-imap-send - Send a collection of patches from stdin to an IMAP folder
+
+
+SYNOPSIS
+--------
+[verse]
+'git imap-send' [-v] [-q] [--[no-]curl]
+
+
+DESCRIPTION
+-----------
+This command uploads a mailbox generated with 'git format-patch'
+into an IMAP drafts folder.  This allows patches to be sent as
+other email is when using mail clients that cannot read mailbox
+files directly. The command also works with any general mailbox
+in which emails have the fields "From", "Date", and "Subject" in
+that order.
+
+Typical usage is something like:
+
+git format-patch --signoff --stdout --attach origin | git imap-send
+
+
+OPTIONS
+-------
+
+-v::
+--verbose::
+	Be verbose.
+
+-q::
+--quiet::
+	Be quiet.
+
+--curl::
+	Use libcurl to communicate with the IMAP server, unless tunneling
+	into it.  Ignored if Git was built without the USE_CURL_FOR_IMAP_SEND
+	option set.
+
+--no-curl::
+	Talk to the IMAP server using git's own IMAP routines instead of
+	using libcurl.  Ignored if Git was built with the NO_OPENSSL option
+	set.
+
+
+CONFIGURATION
+-------------
+
+To use the tool, imap.folder and either imap.tunnel or imap.host must be set
+to appropriate values.
+
+Variables
+~~~~~~~~~
+
+include::config/imap.txt[]
+
+Examples
+~~~~~~~~
+
+Using tunnel mode:
+
+..........................
+[imap]
+    folder = "INBOX.Drafts"
+    tunnel = "ssh -q -C user@example.com /usr/bin/imapd ./Maildir 2> /dev/null"
+..........................
+
+Using direct mode:
+
+.........................
+[imap]
+    folder = "INBOX.Drafts"
+    host = imap://imap.example.com
+    user = bob
+    pass = p4ssw0rd
+.........................
+
+Using direct mode with SSL:
+
+.........................
+[imap]
+    folder = "INBOX.Drafts"
+    host = imaps://imap.example.com
+    user = bob
+    pass = p4ssw0rd
+    port = 123
+    sslverify = false
+.........................
+
+
+EXAMPLES
+--------
+To submit patches using GMail's IMAP interface, first, edit your ~/.gitconfig
+to specify your account settings:
+
+---------
+[imap]
+	folder = "[Gmail]/Drafts"
+	host = imaps://imap.gmail.com
+	user = user@gmail.com
+	port = 993
+	sslverify = false
+---------
+
+You might need to instead use: folder = "[Google Mail]/Drafts" if you get an error
+that the "Folder doesn't exist".
+
+Once the commits are ready to be sent, run the following command:
+
+  $ git format-patch --cover-letter -M --stdout origin/master | git imap-send
+
+Just make sure to disable line wrapping in the email client (GMail's web
+interface will wrap lines no matter what, so you need to use a real
+IMAP client).
+
+CAUTION
+-------
+It is still your responsibility to make sure that the email message
+sent by your email program meets the standards of your project.
+Many projects do not like patches to be attached.  Some mail
+agents will transform patches (e.g. wrap lines, send them as
+format=flowed) in ways that make them fail.  You will get angry
+flames ridiculing you if you don't check this.
+
+Thunderbird in particular is known to be problematic.  Thunderbird
+users may wish to visit this web page for more information:
+  http://kb.mozillazine.org/Plain_text_e-mail_-_Thunderbird#Completely_plain_email
+
+SEE ALSO
+--------
+linkgit:git-format-patch[1], linkgit:git-send-email[1], mbox(5)
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-index-pack.txt b/third_party/git/Documentation/git-index-pack.txt
new file mode 100644
index 0000000000..d5b7560bfe
--- /dev/null
+++ b/third_party/git/Documentation/git-index-pack.txt
@@ -0,0 +1,108 @@
+git-index-pack(1)
+=================
+
+NAME
+----
+git-index-pack - Build pack index file for an existing packed archive
+
+
+SYNOPSIS
+--------
+[verse]
+'git index-pack' [-v] [-o <index-file>] <pack-file>
+'git index-pack' --stdin [--fix-thin] [--keep] [-v] [-o <index-file>]
+                 [<pack-file>]
+
+
+DESCRIPTION
+-----------
+Reads a packed archive (.pack) from the specified file, and
+builds a pack index file (.idx) for it.  The packed archive
+together with the pack index can then be placed in the
+objects/pack/ directory of a Git repository.
+
+
+OPTIONS
+-------
+-v::
+	Be verbose about what is going on, including progress status.
+
+-o <index-file>::
+	Write the generated pack index into the specified
+	file.  Without this option the name of pack index
+	file is constructed from the name of packed archive
+	file by replacing .pack with .idx (and the program
+	fails if the name of packed archive does not end
+	with .pack).
+
+--stdin::
+	When this flag is provided, the pack is read from stdin
+	instead and a copy is then written to <pack-file>. If
+	<pack-file> is not specified, the pack is written to
+	objects/pack/ directory of the current Git repository with
+	a default name determined from the pack content.  If
+	<pack-file> is not specified consider using --keep to
+	prevent a race condition between this process and
+	'git repack'.
+
+--fix-thin::
+	Fix a "thin" pack produced by `git pack-objects --thin` (see
+	linkgit:git-pack-objects[1] for details) by adding the
+	excluded objects the deltified objects are based on to the
+	pack. This option only makes sense in conjunction with --stdin.
+
+--keep::
+	Before moving the index into its final destination
+	create an empty .keep file for the associated pack file.
+	This option is usually necessary with --stdin to prevent a
+	simultaneous 'git repack' process from deleting
+	the newly constructed pack and index before refs can be
+	updated to use objects contained in the pack.
+
+--keep=<msg>::
+	Like --keep create a .keep file before moving the index into
+	its final destination, but rather than creating an empty file
+	place '<msg>' followed by an LF into the .keep file.  The '<msg>'
+	message can later be searched for within all .keep files to
+	locate any which have outlived their usefulness.
+
+--index-version=<version>[,<offset>]::
+	This is intended to be used by the test suite only. It allows
+	to force the version for the generated pack index, and to force
+	64-bit index entries on objects located above the given offset.
+
+--strict::
+	Die, if the pack contains broken objects or links.
+
+--check-self-contained-and-connected::
+	Die if the pack contains broken links. For internal use only.
+
+--fsck-objects::
+	Die if the pack contains broken objects. For internal use only.
+
+--threads=<n>::
+	Specifies the number of threads to spawn when resolving
+	deltas. This requires that index-pack be compiled with
+	pthreads otherwise this option is ignored with a warning.
+	This is meant to reduce packing time on multiprocessor
+	machines. The required amount of memory for the delta search
+	window is however multiplied by the number of threads.
+	Specifying 0 will cause Git to auto-detect the number of CPU's
+	and use maximum 3 threads.
+
+--max-input-size=<size>::
+	Die, if the pack is larger than <size>.
+
+NOTES
+-----
+
+Once the index has been created, the list of object names is sorted
+and the SHA-1 hash of that list is printed to stdout. If --stdin was
+also used then this is prefixed by either "pack\t", or "keep\t" if a
+new .keep file was successfully created. This is useful to remove a
+.keep file used as a lock to prevent the race with 'git repack'
+mentioned above.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-init-db.txt b/third_party/git/Documentation/git-init-db.txt
new file mode 100644
index 0000000000..648a6cd78a
--- /dev/null
+++ b/third_party/git/Documentation/git-init-db.txt
@@ -0,0 +1,23 @@
+git-init-db(1)
+==============
+
+NAME
+----
+git-init-db - Creates an empty Git repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git init-db' [-q | --quiet] [--bare] [--template=<template_directory>] [--separate-git-dir <git dir>] [--shared[=<permissions>]]
+
+
+DESCRIPTION
+-----------
+
+This is a synonym for linkgit:git-init[1].  Please refer to the
+documentation of that command.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-init.txt b/third_party/git/Documentation/git-init.txt
new file mode 100644
index 0000000000..32880aafb0
--- /dev/null
+++ b/third_party/git/Documentation/git-init.txt
@@ -0,0 +1,154 @@
+git-init(1)
+===========
+
+NAME
+----
+git-init - Create an empty Git repository or reinitialize an existing one
+
+
+SYNOPSIS
+--------
+[verse]
+'git init' [-q | --quiet] [--bare] [--template=<template_directory>]
+	  [--separate-git-dir <git dir>]
+	  [--shared[=<permissions>]] [directory]
+
+
+DESCRIPTION
+-----------
+
+This command creates an empty Git repository - basically a `.git`
+directory with subdirectories for `objects`, `refs/heads`,
+`refs/tags`, and template files.  An initial `HEAD` file that
+references the HEAD of the master branch is also created.
+
+If the `$GIT_DIR` environment variable is set then it specifies a path
+to use instead of `./.git` for the base of the repository.
+
+If the object storage directory is specified via the
+`$GIT_OBJECT_DIRECTORY` environment variable then the sha1 directories
+are created underneath - otherwise the default `$GIT_DIR/objects`
+directory is used.
+
+Running 'git init' in an existing repository is safe. It will not
+overwrite things that are already there. The primary reason for
+rerunning 'git init' is to pick up newly added templates (or to move
+the repository to another place if --separate-git-dir is given).
+
+OPTIONS
+-------
+
+-q::
+--quiet::
+
+Only print error and warning messages; all other output will be suppressed.
+
+--bare::
+
+Create a bare repository. If `GIT_DIR` environment is not set, it is set to the
+current working directory.
+
+--template=<template_directory>::
+
+Specify the directory from which templates will be used.  (See the "TEMPLATE
+DIRECTORY" section below.)
+
+--separate-git-dir=<git dir>::
+
+Instead of initializing the repository as a directory to either `$GIT_DIR` or
+`./.git/`, create a text file there containing the path to the actual
+repository.  This file acts as filesystem-agnostic Git symbolic link to the
+repository.
++
+If this is reinitialization, the repository will be moved to the specified path.
+
+--shared[=(false|true|umask|group|all|world|everybody|0xxx)]::
+
+Specify that the Git repository is to be shared amongst several users.  This
+allows users belonging to the same group to push into that
+repository.  When specified, the config variable "core.sharedRepository" is
+set so that files and directories under `$GIT_DIR` are created with the
+requested permissions.  When not specified, Git will use permissions reported
+by umask(2).
++
+The option can have the following values, defaulting to 'group' if no value
+is given:
++
+--
+'umask' (or 'false')::
+
+Use permissions reported by umask(2). The default, when `--shared` is not
+specified.
+
+'group' (or 'true')::
+
+Make the repository group-writable, (and g+sx, since the git group may be not
+the primary group of all users). This is used to loosen the permissions of an
+otherwise safe umask(2) value. Note that the umask still applies to the other
+permission bits (e.g. if umask is '0022', using 'group' will not remove read
+privileges from other (non-group) users). See '0xxx' for how to exactly specify
+the repository permissions.
+
+'all' (or 'world' or 'everybody')::
+
+Same as 'group', but make the repository readable by all users.
+
+'0xxx'::
+
+'0xxx' is an octal number and each file will have mode '0xxx'. '0xxx' will
+override users' umask(2) value (and not only loosen permissions as 'group' and
+'all' does). '0640' will create a repository which is group-readable, but not
+group-writable or accessible to others. '0660' will create a repo that is
+readable and writable to the current user and group, but inaccessible to others.
+--
+
+By default, the configuration flag `receive.denyNonFastForwards` is enabled
+in shared repositories, so that you cannot force a non fast-forwarding push
+into it.
+
+If you provide a 'directory', the command is run inside it. If this directory
+does not exist, it will be created.
+
+TEMPLATE DIRECTORY
+------------------
+
+Files and directories in the template directory whose name do not start with a
+dot will be copied to the `$GIT_DIR` after it is created.
+
+The template directory will be one of the following (in order):
+
+ - the argument given with the `--template` option;
+
+ - the contents of the `$GIT_TEMPLATE_DIR` environment variable;
+
+ - the `init.templateDir` configuration variable; or
+
+ - the default template directory: `/usr/share/git-core/templates`.
+
+The default template directory includes some directory structure, suggested
+"exclude patterns" (see linkgit:gitignore[5]), and sample hook files.
+
+The sample hooks are all disabled by default. To enable one of the
+sample hooks rename it by removing its `.sample` suffix.
+
+See linkgit:githooks[5] for more general info on hook execution.
+
+EXAMPLES
+--------
+
+Start a new Git repository for an existing code base::
++
+----------------
+$ cd /path/to/my/codebase
+$ git init      <1>
+$ git add .     <2>
+$ git commit    <3>
+----------------
++
+<1> Create a /path/to/my/codebase/.git directory.
+<2> Add all existing files to the index.
+<3> Record the pristine state as the first commit in the history.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-instaweb.txt b/third_party/git/Documentation/git-instaweb.txt
new file mode 100644
index 0000000000..a54fe4401b
--- /dev/null
+++ b/third_party/git/Documentation/git-instaweb.txt
@@ -0,0 +1,94 @@
+git-instaweb(1)
+===============
+
+NAME
+----
+git-instaweb - Instantly browse your working repository in gitweb
+
+SYNOPSIS
+--------
+[verse]
+'git instaweb' [--local] [--httpd=<httpd>] [--port=<port>]
+               [--browser=<browser>]
+'git instaweb' [--start] [--stop] [--restart]
+
+DESCRIPTION
+-----------
+A simple script to set up `gitweb` and a web server for browsing the local
+repository.
+
+OPTIONS
+-------
+
+-l::
+--local::
+	Only bind the web server to the local IP (127.0.0.1).
+
+-d::
+--httpd::
+	The HTTP daemon command-line that will be executed.
+	Command-line options may be specified here, and the
+	configuration file will be added at the end of the command-line.
+	Currently apache2, lighttpd, mongoose, plackup, python and
+	webrick are supported.
+	(Default: lighttpd)
+
+-m::
+--module-path::
+	The module path (only needed if httpd is Apache).
+	(Default: /usr/lib/apache2/modules)
+
+-p::
+--port::
+	The port number to bind the httpd to.  (Default: 1234)
+
+-b::
+--browser::
+	The web browser that should be used to view the gitweb
+	page. This will be passed to the 'git web{litdd}browse' helper
+	script along with the URL of the gitweb instance. See
+	linkgit:git-web{litdd}browse[1] for more information about this. If
+	the script fails, the URL will be printed to stdout.
+
+start::
+--start::
+	Start the httpd instance and exit.  Regenerate configuration files
+	as necessary for spawning a new instance.
+
+stop::
+--stop::
+	Stop the httpd instance and exit.  This does not generate
+	any of the configuration files for spawning a new instance,
+	nor does it close the browser.
+
+restart::
+--restart::
+	Restart the httpd instance and exit.  Regenerate configuration files
+	as necessary for spawning a new instance.
+
+CONFIGURATION
+-------------
+
+You may specify configuration in your .git/config
+
+-----------------------------------------------------------------------
+[instaweb]
+	local = true
+	httpd = apache2 -f
+	port = 4321
+	browser = konqueror
+	modulePath = /usr/lib/apache2/modules
+
+-----------------------------------------------------------------------
+
+If the configuration variable `instaweb.browser` is not set,
+`web.browser` will be used instead if it is defined. See
+linkgit:git-web{litdd}browse[1] for more information about this.
+
+SEE ALSO
+--------
+linkgit:gitweb[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-interpret-trailers.txt b/third_party/git/Documentation/git-interpret-trailers.txt
new file mode 100644
index 0000000000..96ec6499f0
--- /dev/null
+++ b/third_party/git/Documentation/git-interpret-trailers.txt
@@ -0,0 +1,390 @@
+git-interpret-trailers(1)
+=========================
+
+NAME
+----
+git-interpret-trailers - Add or parse structured information in commit messages
+
+SYNOPSIS
+--------
+[verse]
+'git interpret-trailers' [<options>] [(--trailer <token>[(=|:)<value>])...] [<file>...]
+'git interpret-trailers' [<options>] [--parse] [<file>...]
+
+DESCRIPTION
+-----------
+Help parsing or adding 'trailers' lines, that look similar to RFC 822 e-mail
+headers, at the end of the otherwise free-form part of a commit
+message.
+
+This command reads some patches or commit messages from either the
+<file> arguments or the standard input if no <file> is specified. If
+`--parse` is specified, the output consists of the parsed trailers.
+
+Otherwise, this command applies the arguments passed using the
+`--trailer` option, if any, to the commit message part of each input
+file. The result is emitted on the standard output.
+
+Some configuration variables control the way the `--trailer` arguments
+are applied to each commit message and the way any existing trailer in
+the commit message is changed. They also make it possible to
+automatically add some trailers.
+
+By default, a '<token>=<value>' or '<token>:<value>' argument given
+using `--trailer` will be appended after the existing trailers only if
+the last trailer has a different (<token>, <value>) pair (or if there
+is no existing trailer). The <token> and <value> parts will be trimmed
+to remove starting and trailing whitespace, and the resulting trimmed
+<token> and <value> will appear in the message like this:
+
+------------------------------------------------
+token: value
+------------------------------------------------
+
+This means that the trimmed <token> and <value> will be separated by
+`': '` (one colon followed by one space).
+
+By default the new trailer will appear at the end of all the existing
+trailers. If there is no existing trailer, the new trailer will appear
+after the commit message part of the output, and, if there is no line
+with only spaces at the end of the commit message part, one blank line
+will be added before the new trailer.
+
+Existing trailers are extracted from the input message by looking for
+a group of one or more lines that (i) is all trailers, or (ii) contains at
+least one Git-generated or user-configured trailer and consists of at
+least 25% trailers.
+The group must be preceded by one or more empty (or whitespace-only) lines.
+The group must either be at the end of the message or be the last
+non-whitespace lines before a line that starts with '---' (followed by a
+space or the end of the line). Such three minus signs start the patch
+part of the message. See also `--no-divider` below.
+
+When reading trailers, there can be whitespaces after the
+token, the separator and the value. There can also be whitespaces
+inside the token and the value. The value may be split over multiple lines with
+each subsequent line starting with whitespace, like the "folding" in RFC 822.
+
+Note that 'trailers' do not follow and are not intended to follow many
+rules for RFC 822 headers. For example they do not follow
+the encoding rules and probably many other rules.
+
+OPTIONS
+-------
+--in-place::
+	Edit the files in place.
+
+--trim-empty::
+	If the <value> part of any trailer contains only whitespace,
+	the whole trailer will be removed from the resulting message.
+	This applies to existing trailers as well as new trailers.
+
+--trailer <token>[(=|:)<value>]::
+	Specify a (<token>, <value>) pair that should be applied as a
+	trailer to the input messages. See the description of this
+	command.
+
+--where <placement>::
+--no-where::
+	Specify where all new trailers will be added.  A setting
+	provided with '--where' overrides all configuration variables
+	and applies to all '--trailer' options until the next occurrence of
+	'--where' or '--no-where'. Possible values are `after`, `before`,
+	`end` or `start`.
+
+--if-exists <action>::
+--no-if-exists::
+	Specify what action will be performed when there is already at
+	least one trailer with the same <token> in the message.  A setting
+	provided with '--if-exists' overrides all configuration variables
+	and applies to all '--trailer' options until the next occurrence of
+	'--if-exists' or '--no-if-exists'. Possible actions are `addIfDifferent`,
+	`addIfDifferentNeighbor`, `add`, `replace` and `doNothing`.
+
+--if-missing <action>::
+--no-if-missing::
+	Specify what action will be performed when there is no other
+	trailer with the same <token> in the message.  A setting
+	provided with '--if-missing' overrides all configuration variables
+	and applies to all '--trailer' options until the next occurrence of
+	'--if-missing' or '--no-if-missing'. Possible actions are `doNothing`
+	or `add`.
+
+--only-trailers::
+	Output only the trailers, not any other parts of the input.
+
+--only-input::
+	Output only trailers that exist in the input; do not add any
+	from the command-line or by following configured `trailer.*`
+	rules.
+
+--unfold::
+	Remove any whitespace-continuation in trailers, so that each
+	trailer appears on a line by itself with its full content.
+
+--parse::
+	A convenience alias for `--only-trailers --only-input
+	--unfold`.
+
+--no-divider::
+	Do not treat `---` as the end of the commit message. Use this
+	when you know your input contains just the commit message itself
+	(and not an email or the output of `git format-patch`).
+
+CONFIGURATION VARIABLES
+-----------------------
+
+trailer.separators::
+	This option tells which characters are recognized as trailer
+	separators. By default only ':' is recognized as a trailer
+	separator, except that '=' is always accepted on the command
+	line for compatibility with other git commands.
++
+The first character given by this option will be the default character
+used when another separator is not specified in the config for this
+trailer.
++
+For example, if the value for this option is "%=$", then only lines
+using the format '<token><sep><value>' with <sep> containing '%', '='
+or '$' and then spaces will be considered trailers. And '%' will be
+the default separator used, so by default trailers will appear like:
+'<token>% <value>' (one percent sign and one space will appear between
+the token and the value).
+
+trailer.where::
+	This option tells where a new trailer will be added.
++
+This can be `end`, which is the default, `start`, `after` or `before`.
++
+If it is `end`, then each new trailer will appear at the end of the
+existing trailers.
++
+If it is `start`, then each new trailer will appear at the start,
+instead of the end, of the existing trailers.
++
+If it is `after`, then each new trailer will appear just after the
+last trailer with the same <token>.
++
+If it is `before`, then each new trailer will appear just before the
+first trailer with the same <token>.
+
+trailer.ifexists::
+	This option makes it possible to choose what action will be
+	performed when there is already at least one trailer with the
+	same <token> in the message.
++
+The valid values for this option are: `addIfDifferentNeighbor` (this
+is the default), `addIfDifferent`, `add`, `replace` or `doNothing`.
++
+With `addIfDifferentNeighbor`, a new trailer will be added only if no
+trailer with the same (<token>, <value>) pair is above or below the line
+where the new trailer will be added.
++
+With `addIfDifferent`, a new trailer will be added only if no trailer
+with the same (<token>, <value>) pair is already in the message.
++
+With `add`, a new trailer will be added, even if some trailers with
+the same (<token>, <value>) pair are already in the message.
++
+With `replace`, an existing trailer with the same <token> will be
+deleted and the new trailer will be added. The deleted trailer will be
+the closest one (with the same <token>) to the place where the new one
+will be added.
++
+With `doNothing`, nothing will be done; that is no new trailer will be
+added if there is already one with the same <token> in the message.
+
+trailer.ifmissing::
+	This option makes it possible to choose what action will be
+	performed when there is not yet any trailer with the same
+	<token> in the message.
++
+The valid values for this option are: `add` (this is the default) and
+`doNothing`.
++
+With `add`, a new trailer will be added.
++
+With `doNothing`, nothing will be done.
+
+trailer.<token>.key::
+	This `key` will be used instead of <token> in the trailer. At
+	the end of this key, a separator can appear and then some
+	space characters. By default the only valid separator is ':',
+	but this can be changed using the `trailer.separators` config
+	variable.
++
+If there is a separator, then the key will be used instead of both the
+<token> and the default separator when adding the trailer.
+
+trailer.<token>.where::
+	This option takes the same values as the 'trailer.where'
+	configuration variable and it overrides what is specified by
+	that option for trailers with the specified <token>.
+
+trailer.<token>.ifexists::
+	This option takes the same values as the 'trailer.ifexists'
+	configuration variable and it overrides what is specified by
+	that option for trailers with the specified <token>.
+
+trailer.<token>.ifmissing::
+	This option takes the same values as the 'trailer.ifmissing'
+	configuration variable and it overrides what is specified by
+	that option for trailers with the specified <token>.
+
+trailer.<token>.command::
+	This option can be used to specify a shell command that will
+	be called to automatically add or modify a trailer with the
+	specified <token>.
++
+When this option is specified, the behavior is as if a special
+'<token>=<value>' argument were added at the beginning of the command
+line, where <value> is taken to be the standard output of the
+specified command with any leading and trailing whitespace trimmed
+off.
++
+If the command contains the `$ARG` string, this string will be
+replaced with the <value> part of an existing trailer with the same
+<token>, if any, before the command is launched.
++
+If some '<token>=<value>' arguments are also passed on the command
+line, when a 'trailer.<token>.command' is configured, the command will
+also be executed for each of these arguments. And the <value> part of
+these arguments, if any, will be used to replace the `$ARG` string in
+the command.
+
+EXAMPLES
+--------
+
+* Configure a 'sign' trailer with a 'Signed-off-by' key, and then
+  add two of these trailers to a message:
++
+------------
+$ git config trailer.sign.key "Signed-off-by"
+$ cat msg.txt
+subject
+
+message
+$ cat msg.txt | git interpret-trailers --trailer 'sign: Alice <alice@example.com>' --trailer 'sign: Bob <bob@example.com>'
+subject
+
+message
+
+Signed-off-by: Alice <alice@example.com>
+Signed-off-by: Bob <bob@example.com>
+------------
+
+* Use the `--in-place` option to edit a message file in place:
++
+------------
+$ cat msg.txt
+subject
+
+message
+
+Signed-off-by: Bob <bob@example.com>
+$ git interpret-trailers --trailer 'Acked-by: Alice <alice@example.com>' --in-place msg.txt
+$ cat msg.txt
+subject
+
+message
+
+Signed-off-by: Bob <bob@example.com>
+Acked-by: Alice <alice@example.com>
+------------
+
+* Extract the last commit as a patch, and add a 'Cc' and a
+  'Reviewed-by' trailer to it:
++
+------------
+$ git format-patch -1
+0001-foo.patch
+$ git interpret-trailers --trailer 'Cc: Alice <alice@example.com>' --trailer 'Reviewed-by: Bob <bob@example.com>' 0001-foo.patch >0001-bar.patch
+------------
+
+* Configure a 'sign' trailer with a command to automatically add a
+  'Signed-off-by: ' with the author information only if there is no
+  'Signed-off-by: ' already, and show how it works:
++
+------------
+$ git config trailer.sign.key "Signed-off-by: "
+$ git config trailer.sign.ifmissing add
+$ git config trailer.sign.ifexists doNothing
+$ git config trailer.sign.command 'echo "$(git config user.name) <$(git config user.email)>"'
+$ git interpret-trailers <<EOF
+> EOF
+
+Signed-off-by: Bob <bob@example.com>
+$ git interpret-trailers <<EOF
+> Signed-off-by: Alice <alice@example.com>
+> EOF
+
+Signed-off-by: Alice <alice@example.com>
+------------
+
+* Configure a 'fix' trailer with a key that contains a '#' and no
+  space after this character, and show how it works:
++
+------------
+$ git config trailer.separators ":#"
+$ git config trailer.fix.key "Fix #"
+$ echo "subject" | git interpret-trailers --trailer fix=42
+subject
+
+Fix #42
+------------
+
+* Configure a 'see' trailer with a command to show the subject of a
+  commit that is related, and show how it works:
++
+------------
+$ git config trailer.see.key "See-also: "
+$ git config trailer.see.ifExists "replace"
+$ git config trailer.see.ifMissing "doNothing"
+$ git config trailer.see.command "git log -1 --oneline --format=\"%h (%s)\" --abbrev-commit --abbrev=14 \$ARG"
+$ git interpret-trailers <<EOF
+> subject
+> 
+> message
+> 
+> see: HEAD~2
+> EOF
+subject
+
+message
+
+See-also: fe3187489d69c4 (subject of related commit)
+------------
+
+* Configure a commit template with some trailers with empty values
+  (using sed to show and keep the trailing spaces at the end of the
+  trailers), then configure a commit-msg hook that uses
+  'git interpret-trailers' to remove trailers with empty values and
+  to add a 'git-version' trailer:
++
+------------
+$ sed -e 's/ Z$/ /' >commit_template.txt <<EOF
+> ***subject***
+> 
+> ***message***
+> 
+> Fixes: Z
+> Cc: Z
+> Reviewed-by: Z
+> Signed-off-by: Z
+> EOF
+$ git config commit.template commit_template.txt
+$ cat >.git/hooks/commit-msg <<EOF
+> #!/bin/sh
+> git interpret-trailers --trim-empty --trailer "git-version: \$(git describe)" "\$1" > "\$1.new"
+> mv "\$1.new" "\$1"
+> EOF
+$ chmod +x .git/hooks/commit-msg
+------------
+
+SEE ALSO
+--------
+linkgit:git-commit[1], linkgit:git-format-patch[1], linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-log.txt b/third_party/git/Documentation/git-log.txt
new file mode 100644
index 0000000000..b406bc4c48
--- /dev/null
+++ b/third_party/git/Documentation/git-log.txt
@@ -0,0 +1,235 @@
+git-log(1)
+==========
+
+NAME
+----
+git-log - Show commit logs
+
+
+SYNOPSIS
+--------
+[verse]
+'git log' [<options>] [<revision range>] [[--] <path>...]
+
+DESCRIPTION
+-----------
+Shows the commit logs.
+
+The command takes options applicable to the `git rev-list`
+command to control what is shown and how, and options applicable to
+the `git diff-*` commands to control how the changes
+each commit introduces are shown.
+
+
+OPTIONS
+-------
+
+--follow::
+	Continue listing the history of a file beyond renames
+	(works only for a single file).
+
+--no-decorate::
+--decorate[=short|full|auto|no]::
+	Print out the ref names of any commits that are shown. If 'short' is
+	specified, the ref name prefixes 'refs/heads/', 'refs/tags/' and
+	'refs/remotes/' will not be printed. If 'full' is specified, the
+	full ref name (including prefix) will be printed. If 'auto' is
+	specified, then if the output is going to a terminal, the ref names
+	are shown as if 'short' were given, otherwise no ref names are
+	shown. The default option is 'short'.
+
+--decorate-refs=<pattern>::
+--decorate-refs-exclude=<pattern>::
+	If no `--decorate-refs` is given, pretend as if all refs were
+	included.  For each candidate, do not use it for decoration if it
+	matches any patterns given to `--decorate-refs-exclude` or if it
+	doesn't match any of the patterns given to `--decorate-refs`.
+
+--source::
+	Print out the ref name given on the command line by which each
+	commit was reached.
+
+--[no-]use-mailmap::
+	Use mailmap file to map author and committer names and email
+	addresses to canonical real names and email addresses. See
+	linkgit:git-shortlog[1].
+
+--full-diff::
+	Without this flag, `git log -p <path>...` shows commits that
+	touch the specified paths, and diffs about the same specified
+	paths.  With this, the full diff is shown for commits that touch
+	the specified paths; this means that "<path>..." limits only
+	commits, and doesn't limit diff for those commits.
++
+Note that this affects all diff-based output types, e.g. those
+produced by `--stat`, etc.
+
+--log-size::
+	Include a line ``log size <number>'' in the output for each commit,
+	where <number> is the length of that commit's message in bytes.
+	Intended to speed up tools that read log messages from `git log`
+	output by allowing them to allocate space in advance.
+
+-L <start>,<end>:<file>::
+-L :<funcname>:<file>::
+	Trace the evolution of the line range given by "<start>,<end>"
+	(or the function name regex <funcname>) within the <file>.  You may
+	not give any pathspec limiters.  This is currently limited to
+	a walk starting from a single revision, i.e., you may only
+	give zero or one positive revision arguments.
+	You can specify this option more than once.
++
+include::line-range-format.txt[]
+
+<revision range>::
+	Show only commits in the specified revision range.  When no
+	<revision range> is specified, it defaults to `HEAD` (i.e. the
+	whole history leading to the current commit).  `origin..HEAD`
+	specifies all the commits reachable from the current commit
+	(i.e. `HEAD`), but not from `origin`. For a complete list of
+	ways to spell <revision range>, see the 'Specifying Ranges'
+	section of linkgit:gitrevisions[7].
+
+[--] <path>...::
+	Show only commits that are enough to explain how the files
+	that match the specified paths came to be.  See 'History
+	Simplification' below for details and other simplification
+	modes.
++
+Paths may need to be prefixed with `--` to separate them from
+options or the revision range, when confusion arises.
+
+include::rev-list-options.txt[]
+
+include::pretty-formats.txt[]
+
+COMMON DIFF OPTIONS
+-------------------
+
+:git-log: 1
+include::diff-options.txt[]
+
+include::diff-generate-patch.txt[]
+
+EXAMPLES
+--------
+`git log --no-merges`::
+
+	Show the whole commit history, but skip any merges
+
+`git log v2.6.12.. include/scsi drivers/scsi`::
+
+	Show all commits since version 'v2.6.12' that changed any file
+	in the `include/scsi` or `drivers/scsi` subdirectories
+
+`git log --since="2 weeks ago" -- gitk`::
+
+	Show the changes during the last two weeks to the file 'gitk'.
+	The `--` is necessary to avoid confusion with the *branch* named
+	'gitk'
+
+`git log --name-status release..test`::
+
+	Show the commits that are in the "test" branch but not yet
+	in the "release" branch, along with the list of paths
+	each commit modifies.
+
+`git log --follow builtin/rev-list.c`::
+
+	Shows the commits that changed `builtin/rev-list.c`, including
+	those commits that occurred before the file was given its
+	present name.
+
+`git log --branches --not --remotes=origin`::
+
+	Shows all commits that are in any of local branches but not in
+	any of remote-tracking branches for 'origin' (what you have that
+	origin doesn't).
+
+`git log master --not --remotes=*/master`::
+
+	Shows all commits that are in local master but not in any remote
+	repository master branches.
+
+`git log -p -m --first-parent`::
+
+	Shows the history including change diffs, but only from the
+	``main branch'' perspective, skipping commits that come from merged
+	branches, and showing full diffs of changes introduced by the merges.
+	This makes sense only when following a strict policy of merging all
+	topic branches when staying on a single integration branch.
+
+`git log -L '/int main/',/^}/:main.c`::
+
+	Shows how the function `main()` in the file `main.c` evolved
+	over time.
+
+`git log -3`::
+
+	Limits the number of commits to show to 3.
+
+DISCUSSION
+----------
+
+include::i18n.txt[]
+
+CONFIGURATION
+-------------
+
+See linkgit:git-config[1] for core variables and linkgit:git-diff[1]
+for settings related to diff generation.
+
+format.pretty::
+	Default for the `--format` option.  (See 'Pretty Formats' above.)
+	Defaults to `medium`.
+
+i18n.logOutputEncoding::
+	Encoding to use when displaying logs.  (See 'Discussion' above.)
+	Defaults to the value of `i18n.commitEncoding` if set, and UTF-8
+	otherwise.
+
+log.date::
+	Default format for human-readable dates.  (Compare the
+	`--date` option.)  Defaults to "default", which means to write
+	dates like `Sat May 8 19:35:34 2010 -0500`.
++
+If the format is set to "auto:foo" and the pager is in use, format
+"foo" will be the used for the date format. Otherwise "default" will
+be used.
+
+log.follow::
+	If `true`, `git log` will act as if the `--follow` option was used when
+	a single <path> is given.  This has the same limitations as `--follow`,
+	i.e. it cannot be used to follow multiple files and does not work well
+	on non-linear history.
+
+log.showRoot::
+	If `false`, `git log` and related commands will not treat the
+	initial commit as a big creation event.  Any root commits in
+	`git log -p` output would be shown without a diff attached.
+	The default is `true`.
+
+log.showSignature::
+	If `true`, `git log` and related commands will act as if the
+	`--show-signature` option was passed to them.
+
+mailmap.*::
+	See linkgit:git-shortlog[1].
+
+notes.displayRef::
+	Which refs, in addition to the default set by `core.notesRef`
+	or `GIT_NOTES_REF`, to read notes from when showing commit
+	messages with the `log` family of commands.  See
+	linkgit:git-notes[1].
++
+May be an unabbreviated ref name or a glob and may be specified
+multiple times.  A warning will be issued for refs that do not exist,
+but a glob that does not match any refs is silently ignored.
++
+This setting can be disabled by the `--no-notes` option,
+overridden by the `GIT_NOTES_DISPLAY_REF` environment variable,
+and overridden by the `--notes=<ref>` option.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-ls-files.txt b/third_party/git/Documentation/git-ls-files.txt
new file mode 100644
index 0000000000..8461c0e83e
--- /dev/null
+++ b/third_party/git/Documentation/git-ls-files.txt
@@ -0,0 +1,250 @@
+git-ls-files(1)
+===============
+
+NAME
+----
+git-ls-files - Show information about files in the index and the working tree
+
+
+SYNOPSIS
+--------
+[verse]
+'git ls-files' [-z] [-t] [-v] [-f]
+		(--[cached|deleted|others|ignored|stage|unmerged|killed|modified])*
+		(-[c|d|o|i|s|u|k|m])*
+		[--eol]
+		[-x <pattern>|--exclude=<pattern>]
+		[-X <file>|--exclude-from=<file>]
+		[--exclude-per-directory=<file>]
+		[--exclude-standard]
+		[--error-unmatch] [--with-tree=<tree-ish>]
+		[--full-name] [--recurse-submodules]
+		[--abbrev] [--] [<file>...]
+
+DESCRIPTION
+-----------
+This merges the file listing in the directory cache index with the
+actual working directory list, and shows different combinations of the
+two.
+
+One or more of the options below may be used to determine the files
+shown:
+
+OPTIONS
+-------
+-c::
+--cached::
+	Show cached files in the output (default)
+
+-d::
+--deleted::
+	Show deleted files in the output
+
+-m::
+--modified::
+	Show modified files in the output
+
+-o::
+--others::
+	Show other (i.e. untracked) files in the output
+
+-i::
+--ignored::
+	Show only ignored files in the output. When showing files in the
+	index, print only those matched by an exclude pattern. When
+	showing "other" files, show only those matched by an exclude
+	pattern. Standard ignore rules are not automatically activated,
+	therefore at least one of the `--exclude*` options is required.
+
+-s::
+--stage::
+	Show staged contents' mode bits, object name and stage number in the output.
+
+--directory::
+	If a whole directory is classified as "other", show just its
+	name (with a trailing slash) and not its whole contents.
+
+--no-empty-directory::
+	Do not list empty directories. Has no effect without --directory.
+
+-u::
+--unmerged::
+	Show unmerged files in the output (forces --stage)
+
+-k::
+--killed::
+	Show files on the filesystem that need to be removed due
+	to file/directory conflicts for checkout-index to
+	succeed.
+
+-z::
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT below for more information.
+
+-x <pattern>::
+--exclude=<pattern>::
+	Skip untracked files matching pattern.
+	Note that pattern is a shell wildcard pattern. See EXCLUDE PATTERNS
+	below for more information.
+
+-X <file>::
+--exclude-from=<file>::
+	Read exclude patterns from <file>; 1 per line.
+
+--exclude-per-directory=<file>::
+	Read additional exclude patterns that apply only to the
+	directory and its subdirectories in <file>.
+
+--exclude-standard::
+	Add the standard Git exclusions: .git/info/exclude, .gitignore
+	in each directory, and the user's global exclusion file.
+
+--error-unmatch::
+	If any <file> does not appear in the index, treat this as an
+	error (return 1).
+
+--with-tree=<tree-ish>::
+	When using --error-unmatch to expand the user supplied
+	<file> (i.e. path pattern) arguments to paths, pretend
+	that paths which were removed in the index since the
+	named <tree-ish> are still present.  Using this option
+	with `-s` or `-u` options does not make any sense.
+
+-t::
+	This feature is semi-deprecated. For scripting purpose,
+	linkgit:git-status[1] `--porcelain` and
+	linkgit:git-diff-files[1] `--name-status` are almost always
+	superior alternatives, and users should look at
+	linkgit:git-status[1] `--short` or linkgit:git-diff[1]
+	`--name-status` for more user-friendly alternatives.
++
+--
+This option identifies the file status with the following tags (followed by
+a space) at the start of each line:
+
+	H::	cached
+	S::	skip-worktree
+	M::	unmerged
+	R::	removed/deleted
+	C::	modified/changed
+	K::	to be killed
+	?::	other
+--
+
+-v::
+	Similar to `-t`, but use lowercase letters for files
+	that are marked as 'assume unchanged' (see
+	linkgit:git-update-index[1]).
+
+-f::
+	Similar to `-t`, but use lowercase letters for files
+	that are marked as 'fsmonitor valid' (see
+	linkgit:git-update-index[1]).
+
+--full-name::
+	When run from a subdirectory, the command usually
+	outputs paths relative to the current directory.  This
+	option forces paths to be output relative to the project
+	top directory.
+
+--recurse-submodules::
+	Recursively calls ls-files on each submodule in the repository.
+	Currently there is only support for the --cached mode.
+
+--abbrev[=<n>]::
+	Instead of showing the full 40-byte hexadecimal object
+	lines, show only a partial prefix.
+	Non default number of digits can be specified with --abbrev=<n>.
+
+--debug::
+	After each line that describes a file, add more data about its
+	cache entry.  This is intended to show as much information as
+	possible for manual inspection; the exact format may change at
+	any time.
+
+--eol::
+	Show <eolinfo> and <eolattr> of files.
+	<eolinfo> is the file content identification used by Git when
+	the "text" attribute is "auto" (or not set and core.autocrlf is not false).
+	<eolinfo> is either "-text", "none", "lf", "crlf", "mixed" or "".
++
+"" means the file is not a regular file, it is not in the index or
+not accessible in the working tree.
++
+<eolattr> is the attribute that is used when checking out or committing,
+it is either "", "-text", "text", "text=auto", "text eol=lf", "text eol=crlf".
+Since Git 2.10 "text=auto eol=lf" and "text=auto eol=crlf" are supported.
++
+Both the <eolinfo> in the index ("i/<eolinfo>")
+and in the working tree ("w/<eolinfo>") are shown for regular files,
+followed by the  ("attr/<eolattr>").
+
+\--::
+	Do not interpret any more arguments as options.
+
+<file>::
+	Files to show. If no files are given all files which match the other
+	specified criteria are shown.
+
+OUTPUT
+------
+'git ls-files' just outputs the filenames unless `--stage` is specified in
+which case it outputs:
+
+        [<tag> ]<mode> <object> <stage> <file>
+
+'git ls-files --eol' will show
+	i/<eolinfo><SPACES>w/<eolinfo><SPACES>attr/<eolattr><SPACE*><TAB><file>
+
+'git ls-files --unmerged' and 'git ls-files --stage' can be used to examine
+detailed information on unmerged paths.
+
+For an unmerged path, instead of recording a single mode/SHA-1 pair,
+the index records up to three such pairs; one from tree O in stage
+1, A in stage 2, and B in stage 3.  This information can be used by
+the user (or the porcelain) to see what should eventually be recorded at the
+path. (see linkgit:git-read-tree[1] for more information on state)
+
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
+
+
+EXCLUDE PATTERNS
+----------------
+
+'git ls-files' can use a list of "exclude patterns" when
+traversing the directory tree and finding files to show when the
+flags --others or --ignored are specified.  linkgit:gitignore[5]
+specifies the format of exclude patterns.
+
+These exclude patterns come from these places, in order:
+
+  1. The command-line flag --exclude=<pattern> specifies a
+     single pattern.  Patterns are ordered in the same order
+     they appear in the command line.
+
+  2. The command-line flag --exclude-from=<file> specifies a
+     file containing a list of patterns.  Patterns are ordered
+     in the same order they appear in the file.
+
+  3. The command-line flag --exclude-per-directory=<name> specifies
+     a name of the file in each directory 'git ls-files'
+     examines, normally `.gitignore`.  Files in deeper
+     directories take precedence.  Patterns are ordered in the
+     same order they appear in the files.
+
+A pattern specified on the command line with --exclude or read
+from the file specified with --exclude-from is relative to the
+top of the directory tree.  A pattern read from a file specified
+by --exclude-per-directory is relative to the directory that the
+pattern file appears in.
+
+SEE ALSO
+--------
+linkgit:git-read-tree[1], linkgit:gitignore[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-ls-remote.txt b/third_party/git/Documentation/git-ls-remote.txt
new file mode 100644
index 0000000000..0b057cbb10
--- /dev/null
+++ b/third_party/git/Documentation/git-ls-remote.txt
@@ -0,0 +1,117 @@
+git-ls-remote(1)
+================
+
+NAME
+----
+git-ls-remote - List references in a remote repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git ls-remote' [--heads] [--tags] [--refs] [--upload-pack=<exec>]
+	      [-q | --quiet] [--exit-code] [--get-url] [--sort=<key>]
+	      [--symref] [<repository> [<refs>...]]
+
+DESCRIPTION
+-----------
+Displays references available in a remote repository along with the associated
+commit IDs.
+
+
+OPTIONS
+-------
+-h::
+--heads::
+-t::
+--tags::
+	Limit to only refs/heads and refs/tags, respectively.
+	These options are _not_ mutually exclusive; when given
+	both, references stored in refs/heads and refs/tags are
+	displayed.
+
+--refs::
+	Do not show peeled tags or pseudorefs like `HEAD` in the output.
+
+-q::
+--quiet::
+	Do not print remote URL to stderr.
+
+--upload-pack=<exec>::
+	Specify the full path of 'git-upload-pack' on the remote
+	host. This allows listing references from repositories accessed via
+	SSH and where the SSH daemon does not use the PATH configured by the
+	user.
+
+--exit-code::
+	Exit with status "2" when no matching refs are found in the remote
+	repository. Usually the command exits with status "0" to indicate
+	it successfully talked with the remote repository, whether it
+	found any matching refs.
+
+--get-url::
+	Expand the URL of the given remote repository taking into account any
+	"url.<base>.insteadOf" config setting (See linkgit:git-config[1]) and
+	exit without talking to the remote.
+
+--symref::
+	In addition to the object pointed by it, show the underlying
+	ref pointed by it when showing a symbolic ref.  Currently,
+	upload-pack only shows the symref HEAD, so it will be the only
+	one shown by ls-remote.
+
+--sort=<key>::
+	Sort based on the key given. Prefix `-` to sort in descending order
+	of the value. Supports "version:refname" or "v:refname" (tag names
+	are treated as versions). The "version:refname" sort order can also
+	be affected by the "versionsort.suffix" configuration variable.
+	See linkgit:git-for-each-ref[1] for more sort options, but be aware
+	keys like `committerdate` that require access to the objects
+	themselves will not work for refs whose objects have not yet been
+	fetched from the remote, and will give a `missing object` error.
+
+-o <option>::
+--server-option=<option>::
+	Transmit the given string to the server when communicating using
+	protocol version 2.  The given string must not contain a NUL or LF
+	character.
+	When multiple `--server-option=<option>` are given, they are all
+	sent to the other side in the order listed on the command line.
+
+<repository>::
+	The "remote" repository to query.  This parameter can be
+	either a URL or the name of a remote (see the GIT URLS and
+	REMOTES sections of linkgit:git-fetch[1]).
+
+<refs>...::
+	When unspecified, all references, after filtering done
+	with --heads and --tags, are shown.  When <refs>... are
+	specified, only references matching the given patterns
+	are displayed.
+
+EXAMPLES
+--------
+
+	$ git ls-remote --tags ./.
+	d6602ec5194c87b0fc87103ca4d67251c76f233a	refs/tags/v0.99
+	f25a265a342aed6041ab0cc484224d9ca54b6f41	refs/tags/v0.99.1
+	7ceca275d047c90c0c7d5afb13ab97efdf51bd6e	refs/tags/v0.99.3
+	c5db5456ae3b0873fc659c19fafdde22313cc441	refs/tags/v0.99.2
+	0918385dbd9656cab0d1d81ba7453d49bbc16250	refs/tags/junio-gpg-pub
+	$ git ls-remote http://www.kernel.org/pub/scm/git/git.git master pu rc
+	5fe978a5381f1fbad26a80e682ddd2a401966740	refs/heads/master
+	c781a84b5204fb294c9ccc79f8b3baceeb32c061	refs/heads/pu
+	$ git remote add korg http://www.kernel.org/pub/scm/git/git.git
+	$ git ls-remote --tags korg v\*
+	d6602ec5194c87b0fc87103ca4d67251c76f233a	refs/tags/v0.99
+	f25a265a342aed6041ab0cc484224d9ca54b6f41	refs/tags/v0.99.1
+	c5db5456ae3b0873fc659c19fafdde22313cc441	refs/tags/v0.99.2
+	7ceca275d047c90c0c7d5afb13ab97efdf51bd6e	refs/tags/v0.99.3
+
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-ls-tree.txt b/third_party/git/Documentation/git-ls-tree.txt
new file mode 100644
index 0000000000..a7515714da
--- /dev/null
+++ b/third_party/git/Documentation/git-ls-tree.txt
@@ -0,0 +1,104 @@
+git-ls-tree(1)
+==============
+
+NAME
+----
+git-ls-tree - List the contents of a tree object
+
+
+SYNOPSIS
+--------
+[verse]
+'git ls-tree' [-d] [-r] [-t] [-l] [-z]
+	    [--name-only] [--name-status] [--full-name] [--full-tree] [--abbrev[=<n>]]
+	    <tree-ish> [<path>...]
+
+DESCRIPTION
+-----------
+Lists the contents of a given tree object, like what "/bin/ls -a" does
+in the current working directory.  Note that:
+
+ - the behaviour is slightly different from that of "/bin/ls" in that the
+   '<path>' denotes just a list of patterns to match, e.g. so specifying
+   directory name (without `-r`) will behave differently, and order of the
+   arguments does not matter.
+
+ - the behaviour is similar to that of "/bin/ls" in that the '<path>' is
+   taken as relative to the current working directory.  E.g. when you are
+   in a directory 'sub' that has a directory 'dir', you can run 'git
+   ls-tree -r HEAD dir' to list the contents of the tree (that is
+   `sub/dir` in `HEAD`).  You don't want to give a tree that is not at the
+   root level (e.g. `git ls-tree -r HEAD:sub dir`) in this case, as that
+   would result in asking for `sub/sub/dir` in the `HEAD` commit.
+   However, the current working directory can be ignored by passing
+   --full-tree option.
+
+OPTIONS
+-------
+<tree-ish>::
+	Id of a tree-ish.
+
+-d::
+	Show only the named tree entry itself, not its children.
+
+-r::
+	Recurse into sub-trees.
+
+-t::
+	Show tree entries even when going to recurse them. Has no effect
+	if `-r` was not passed. `-d` implies `-t`.
+
+-l::
+--long::
+	Show object size of blob (file) entries.
+
+-z::
+	\0 line termination on output and do not quote filenames.
+	See OUTPUT FORMAT below for more information.
+
+--name-only::
+--name-status::
+	List only filenames (instead of the "long" output), one per line.
+
+--abbrev[=<n>]::
+	Instead of showing the full 40-byte hexadecimal object
+	lines, show only a partial prefix.
+	Non default number of digits can be specified with --abbrev=<n>.
+
+--full-name::
+	Instead of showing the path names relative to the current working
+	directory, show the full path names.
+
+--full-tree::
+	Do not limit the listing to the current working directory.
+	Implies --full-name.
+
+[<path>...]::
+	When paths are given, show them (note that this isn't really raw
+	pathnames, but rather a list of patterns to match).  Otherwise
+	implicitly uses the root level of the tree as the sole path argument.
+
+
+Output Format
+-------------
+        <mode> SP <type> SP <object> TAB <file>
+
+This output format is compatible with what `--index-info --stdin` of
+'git update-index' expects.
+
+When the `-l` option is used, format changes to
+
+        <mode> SP <type> SP <object> SP <object size> TAB <file>
+
+Object size identified by <object> is given in bytes, and right-justified
+with minimum width of 7 characters.  Object size is given only for blobs
+(file) entries; for other entries `-` character is used in place of size.
+
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).  Using `-z` the filename is output
+verbatim and the line is terminated by a NUL byte.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mailinfo.txt b/third_party/git/Documentation/git-mailinfo.txt
new file mode 100644
index 0000000000..3bbc731f67
--- /dev/null
+++ b/third_party/git/Documentation/git-mailinfo.txt
@@ -0,0 +1,102 @@
+git-mailinfo(1)
+===============
+
+NAME
+----
+git-mailinfo - Extracts patch and authorship from a single e-mail message
+
+
+SYNOPSIS
+--------
+[verse]
+'git mailinfo' [-k|-b] [-u | --encoding=<encoding> | -n] [--[no-]scissors] <msg> <patch>
+
+
+DESCRIPTION
+-----------
+Reads a single e-mail message from the standard input, and
+writes the commit log message in <msg> file, and the patches in
+<patch> file.  The author name, e-mail and e-mail subject are
+written out to the standard output to be used by 'git am'
+to create a commit.  It is usually not necessary to use this
+command directly.  See linkgit:git-am[1] instead.
+
+
+OPTIONS
+-------
+-k::
+	Usually the program removes email cruft from the Subject:
+	header line to extract the title line for the commit log
+	message.  This option prevents this munging, and is most
+	useful when used to read back 'git format-patch -k' output.
++
+Specifically, the following are removed until none of them remain:
++
+--
+*	Leading and trailing whitespace.
+
+*	Leading `Re:`, `re:`, and `:`.
+
+*	Leading bracketed strings (between `[` and `]`, usually
+	`[PATCH]`).
+--
++
+Finally, runs of whitespace are normalized to a single ASCII space
+character.
+
+-b::
+	When -k is not in effect, all leading strings bracketed with '['
+	and ']' pairs are stripped.  This option limits the stripping to
+	only the pairs whose bracketed string contains the word "PATCH".
+
+-u::
+	The commit log message, author name and author email are
+	taken from the e-mail, and after minimally decoding MIME
+	transfer encoding, re-coded in the charset specified by
+	i18n.commitencoding (defaulting to UTF-8) by transliterating
+	them.  This used to be optional but now it is the default.
++
+Note that the patch is always used as-is without charset
+conversion, even with this flag.
+
+--encoding=<encoding>::
+	Similar to -u.  But when re-coding, the charset specified here is
+	used instead of the one specified by i18n.commitencoding or UTF-8.
+
+-n::
+	Disable all charset re-coding of the metadata.
+
+-m::
+--message-id::
+	Copy the Message-ID header at the end of the commit message.  This
+	is useful in order to associate commits with mailing list discussions.
+
+--scissors::
+	Remove everything in body before a scissors line.  A line that
+	mainly consists of scissors (either ">8" or "8<") and perforation
+	(dash "-") marks is called a scissors line, and is used to request
+	the reader to cut the message at that line.  If such a line
+	appears in the body of the message before the patch, everything
+	before it (including the scissors line itself) is ignored when
+	this option is used.
++
+This is useful if you want to begin your message in a discussion thread
+with comments and suggestions on the message you are responding to, and to
+conclude it with a patch submission, separating the discussion and the
+beginning of the proposed commit log message with a scissors line.
++
+This can be enabled by default with the configuration option mailinfo.scissors.
+
+--no-scissors::
+	Ignore scissors lines. Useful for overriding mailinfo.scissors settings.
+
+<msg>::
+	The commit log message extracted from e-mail, usually
+	except the title line which comes from e-mail Subject.
+
+<patch>::
+	The patch extracted from e-mail.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mailsplit.txt b/third_party/git/Documentation/git-mailsplit.txt
new file mode 100644
index 0000000000..e3b2a88c4b
--- /dev/null
+++ b/third_party/git/Documentation/git-mailsplit.txt
@@ -0,0 +1,57 @@
+git-mailsplit(1)
+================
+
+NAME
+----
+git-mailsplit - Simple UNIX mbox splitter program
+
+SYNOPSIS
+--------
+[verse]
+'git mailsplit' [-b] [-f<nn>] [-d<prec>] [--keep-cr] [--mboxrd]
+		-o<directory> [--] [(<mbox>|<Maildir>)...]
+
+DESCRIPTION
+-----------
+Splits a mbox file or a Maildir into a list of files: "0001" "0002" ..  in the
+specified directory so you can process them further from there.
+
+IMPORTANT: Maildir splitting relies upon filenames being sorted to output
+patches in the correct order.
+
+OPTIONS
+-------
+<mbox>::
+	Mbox file to split.  If not given, the mbox is read from
+	the standard input.
+
+<Maildir>::
+	Root of the Maildir to split. This directory should contain the cur, tmp
+	and new subdirectories.
+
+-o<directory>::
+	Directory in which to place the individual messages.
+
+-b::
+	If any file doesn't begin with a From line, assume it is a
+	single mail message instead of signaling error.
+
+-d<prec>::
+	Instead of the default 4 digits with leading zeros,
+	different precision can be specified for the generated
+	filenames.
+
+-f<nn>::
+	Skip the first <nn> numbers, for example if -f3 is specified,
+	start the numbering with 0004.
+
+--keep-cr::
+	Do not remove `\r` from lines ending with `\r\n`.
+
+--mboxrd::
+	Input is of the "mboxrd" format and "^>+From " line escaping is
+	reversed.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge-base.txt b/third_party/git/Documentation/git-merge-base.txt
new file mode 100644
index 0000000000..261d5c1164
--- /dev/null
+++ b/third_party/git/Documentation/git-merge-base.txt
@@ -0,0 +1,231 @@
+git-merge-base(1)
+=================
+
+NAME
+----
+git-merge-base - Find as good common ancestors as possible for a merge
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge-base' [-a|--all] <commit> <commit>...
+'git merge-base' [-a|--all] --octopus <commit>...
+'git merge-base' --is-ancestor <commit> <commit>
+'git merge-base' --independent <commit>...
+'git merge-base' --fork-point <ref> [<commit>]
+
+DESCRIPTION
+-----------
+
+'git merge-base' finds best common ancestor(s) between two commits to use
+in a three-way merge.  One common ancestor is 'better' than another common
+ancestor if the latter is an ancestor of the former.  A common ancestor
+that does not have any better common ancestor is a 'best common
+ancestor', i.e. a 'merge base'.  Note that there can be more than one
+merge base for a pair of commits.
+
+OPERATION MODES
+---------------
+
+As the most common special case, specifying only two commits on the
+command line means computing the merge base between the given two commits.
+
+More generally, among the two commits to compute the merge base from,
+one is specified by the first commit argument on the command line;
+the other commit is a (possibly hypothetical) commit that is a merge
+across all the remaining commits on the command line.
+
+As a consequence, the 'merge base' is not necessarily contained in each of the
+commit arguments if more than two commits are specified. This is different
+from linkgit:git-show-branch[1] when used with the `--merge-base` option.
+
+--octopus::
+	Compute the best common ancestors of all supplied commits,
+	in preparation for an n-way merge.  This mimics the behavior
+	of 'git show-branch --merge-base'.
+
+--independent::
+	Instead of printing merge bases, print a minimal subset of
+	the supplied commits with the same ancestors.  In other words,
+	among the commits given, list those which cannot be reached
+	from any other.  This mimics the behavior of 'git show-branch
+	--independent'.
+
+--is-ancestor::
+	Check if the first <commit> is an ancestor of the second <commit>,
+	and exit with status 0 if true, or with status 1 if not.
+	Errors are signaled by a non-zero status that is not 1.
+
+--fork-point::
+	Find the point at which a branch (or any history that leads
+	to <commit>) forked from another branch (or any reference)
+	<ref>. This does not just look for the common ancestor of
+	the two commits, but also takes into account the reflog of
+	<ref> to see if the history leading to <commit> forked from
+	an earlier incarnation of the branch <ref> (see discussion
+	on this mode below).
+
+OPTIONS
+-------
+-a::
+--all::
+	Output all merge bases for the commits, instead of just one.
+
+DISCUSSION
+----------
+
+Given two commits 'A' and 'B', `git merge-base A B` will output a commit
+which is reachable from both 'A' and 'B' through the parent relationship.
+
+For example, with this topology:
+
+	         o---o---o---B
+	        /
+	---o---1---o---o---o---A
+
+the merge base between 'A' and 'B' is '1'.
+
+Given three commits 'A', 'B' and 'C', `git merge-base A B C` will compute the
+merge base between 'A' and a hypothetical commit 'M', which is a merge
+between 'B' and 'C'.  For example, with this topology:
+
+	       o---o---o---o---C
+	      /
+	     /   o---o---o---B
+	    /   /
+	---2---1---o---o---o---A
+
+the result of `git merge-base A B C` is '1'.  This is because the
+equivalent topology with a merge commit 'M' between 'B' and 'C' is:
+
+
+	       o---o---o---o---o
+	      /                 \
+	     /   o---o---o---o---M
+	    /   /
+	---2---1---o---o---o---A
+
+and the result of `git merge-base A M` is '1'.  Commit '2' is also a
+common ancestor between 'A' and 'M', but '1' is a better common ancestor,
+because '2' is an ancestor of '1'.  Hence, '2' is not a merge base.
+
+The result of `git merge-base --octopus A B C` is '2', because '2' is
+the best common ancestor of all commits.
+
+When the history involves criss-cross merges, there can be more than one
+'best' common ancestor for two commits.  For example, with this topology:
+
+	---1---o---A
+	    \ /
+	     X
+	    / \
+	---2---o---o---B
+
+both '1' and '2' are merge-bases of A and B.  Neither one is better than
+the other (both are 'best' merge bases).  When the `--all` option is not given,
+it is unspecified which best one is output.
+
+A common idiom to check "fast-forward-ness" between two commits A
+and B is (or at least used to be) to compute the merge base between
+A and B, and check if it is the same as A, in which case, A is an
+ancestor of B.  You will see this idiom used often in older scripts.
+
+	A=$(git rev-parse --verify A)
+	if test "$A" = "$(git merge-base A B)"
+	then
+		... A is an ancestor of B ...
+	fi
+
+In modern git, you can say this in a more direct way:
+
+	if git merge-base --is-ancestor A B
+	then
+		... A is an ancestor of B ...
+	fi
+
+instead.
+
+Discussion on fork-point mode
+-----------------------------
+
+After working on the `topic` branch created with `git switch -c
+topic origin/master`, the history of remote-tracking branch
+`origin/master` may have been rewound and rebuilt, leading to a
+history of this shape:
+
+	                 o---B2
+	                /
+	---o---o---B1--o---o---o---B (origin/master)
+	        \
+	         B0
+	          \
+	           D0---D1---D (topic)
+
+where `origin/master` used to point at commits B0, B1, B2 and now it
+points at B, and your `topic` branch was started on top of it back
+when `origin/master` was at B0, and you built three commits, D0, D1,
+and D, on top of it.  Imagine that you now want to rebase the work
+you did on the topic on top of the updated origin/master.
+
+In such a case, `git merge-base origin/master topic` would return the
+parent of B0 in the above picture, but B0^..D is *not* the range of
+commits you would want to replay on top of B (it includes B0, which
+is not what you wrote; it is a commit the other side discarded when
+it moved its tip from B0 to B1).
+
+`git merge-base --fork-point origin/master topic` is designed to
+help in such a case.  It takes not only B but also B0, B1, and B2
+(i.e. old tips of the remote-tracking branches your repository's
+reflog knows about) into account to see on which commit your topic
+branch was built and finds B0, allowing you to replay only the
+commits on your topic, excluding the commits the other side later
+discarded.
+
+Hence
+
+    $ fork_point=$(git merge-base --fork-point origin/master topic)
+
+will find B0, and
+
+    $ git rebase --onto origin/master $fork_point topic
+
+will replay D0, D1 and D on top of B to create a new history of this
+shape:
+
+			 o---B2
+			/
+	---o---o---B1--o---o---o---B (origin/master)
+		\                   \
+		 B0                  D0'--D1'--D' (topic - updated)
+		  \
+		   D0---D1---D (topic - old)
+
+A caveat is that older reflog entries in your repository may be
+expired by `git gc`.  If B0 no longer appears in the reflog of the
+remote-tracking branch `origin/master`, the `--fork-point` mode
+obviously cannot find it and fails, avoiding to give a random and
+useless result (such as the parent of B0, like the same command
+without the `--fork-point` option gives).
+
+Also, the remote-tracking branch you use the `--fork-point` mode
+with must be the one your topic forked from its tip.  If you forked
+from an older commit than the tip, this mode would not find the fork
+point (imagine in the above sample history B0 did not exist,
+origin/master started at B1, moved to B2 and then B, and you forked
+your topic at origin/master^ when origin/master was B1; the shape of
+the history would be the same as above, without B0, and the parent
+of B1 is what `git merge-base origin/master topic` correctly finds,
+but the `--fork-point` mode will not, because it is not one of the
+commits that used to be at the tip of origin/master).
+
+
+See also
+--------
+linkgit:git-rev-list[1],
+linkgit:git-show-branch[1],
+linkgit:git-merge[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge-file.txt b/third_party/git/Documentation/git-merge-file.txt
new file mode 100644
index 0000000000..f856032613
--- /dev/null
+++ b/third_party/git/Documentation/git-merge-file.txt
@@ -0,0 +1,95 @@
+git-merge-file(1)
+=================
+
+NAME
+----
+git-merge-file - Run a three-way file merge
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge-file' [-L <current-name> [-L <base-name> [-L <other-name>]]]
+	[--ours|--theirs|--union] [-p|--stdout] [-q|--quiet] [--marker-size=<n>]
+	[--[no-]diff3] <current-file> <base-file> <other-file>
+
+
+DESCRIPTION
+-----------
+'git merge-file' incorporates all changes that lead from the `<base-file>`
+to `<other-file>` into `<current-file>`. The result ordinarily goes into
+`<current-file>`. 'git merge-file' is useful for combining separate changes
+to an original. Suppose `<base-file>` is the original, and both
+`<current-file>` and `<other-file>` are modifications of `<base-file>`,
+then 'git merge-file' combines both changes.
+
+A conflict occurs if both `<current-file>` and `<other-file>` have changes
+in a common segment of lines. If a conflict is found, 'git merge-file'
+normally outputs a warning and brackets the conflict with lines containing
+<<<<<<< and >>>>>>> markers. A typical conflict will look like this:
+
+	<<<<<<< A
+	lines in file A
+	=======
+	lines in file B
+	>>>>>>> B
+
+If there are conflicts, the user should edit the result and delete one of
+the alternatives.  When `--ours`, `--theirs`, or `--union` option is in effect,
+however, these conflicts are resolved favouring lines from `<current-file>`,
+lines from `<other-file>`, or lines from both respectively.  The length of the
+conflict markers can be given with the `--marker-size` option.
+
+The exit value of this program is negative on error, and the number of
+conflicts otherwise (truncated to 127 if there are more than that many
+conflicts). If the merge was clean, the exit value is 0.
+
+'git merge-file' is designed to be a minimal clone of RCS 'merge'; that is, it
+implements all of RCS 'merge''s functionality which is needed by
+linkgit:git[1].
+
+
+OPTIONS
+-------
+
+-L <label>::
+	This option may be given up to three times, and
+	specifies labels to be used in place of the
+	corresponding file names in conflict reports. That is,
+	`git merge-file -L x -L y -L z a b c` generates output that
+	looks like it came from files x, y and z instead of
+	from files a, b and c.
+
+-p::
+	Send results to standard output instead of overwriting
+	`<current-file>`.
+
+-q::
+	Quiet; do not warn about conflicts.
+
+--diff3::
+	Show conflicts in "diff3" style.
+
+--ours::
+--theirs::
+--union::
+	Instead of leaving conflicts in the file, resolve conflicts
+	favouring our (or their or both) side of the lines.
+
+
+EXAMPLES
+--------
+
+`git merge-file README.my README README.upstream`::
+
+	combines the changes of README.my and README.upstream since README,
+	tries to merge them and writes the result into README.my.
+
+`git merge-file -L a -L b -L c tmp/a123 tmp/b234 tmp/c345`::
+
+	merges tmp/a123 and tmp/c345 with the base tmp/b234, but uses labels
+	`a` and `c` instead of `tmp/a123` and `tmp/c345`.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge-index.txt b/third_party/git/Documentation/git-merge-index.txt
new file mode 100644
index 0000000000..02676fb391
--- /dev/null
+++ b/third_party/git/Documentation/git-merge-index.txt
@@ -0,0 +1,79 @@
+git-merge-index(1)
+==================
+
+NAME
+----
+git-merge-index - Run a merge for files needing merging
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge-index' [-o] [-q] <merge-program> (-a | [--] <file>*)
+
+DESCRIPTION
+-----------
+This looks up the <file>(s) in the index and, if there are any merge
+entries, passes the SHA-1 hash for those files as arguments 1, 2, 3 (empty
+argument if no file), and <file> as argument 4.  File modes for the three
+files are passed as arguments 5, 6 and 7.
+
+OPTIONS
+-------
+\--::
+	Do not interpret any more arguments as options.
+
+-a::
+	Run merge against all files in the index that need merging.
+
+-o::
+	Instead of stopping at the first failed merge, do all of them
+	in one shot - continue with merging even when previous merges
+	returned errors, and only return the error code after all the
+	merges.
+
+-q::
+	Do not complain about a failed merge program (a merge program
+	failure usually indicates conflicts during the merge). This is for
+	porcelains which might want to emit custom messages.
+
+If 'git merge-index' is called with multiple <file>s (or -a) then it
+processes them in turn only stopping if merge returns a non-zero exit
+code.
+
+Typically this is run with a script calling Git's imitation of
+the 'merge' command from the RCS package.
+
+A sample script called 'git merge-one-file' is included in the
+distribution.
+
+ALERT ALERT ALERT! The Git "merge object order" is different from the
+RCS 'merge' program merge object order. In the above ordering, the
+original is first. But the argument order to the 3-way merge program
+'merge' is to have the original in the middle. Don't ask me why.
+
+Examples:
+
+  torvalds@ppc970:~/merge-test> git merge-index cat MM
+  This is MM from the original tree.			# original
+  This is modified MM in the branch A.			# merge1
+  This is modified MM in the branch B.			# merge2
+  This is modified MM in the branch B.			# current contents
+
+or
+
+  torvalds@ppc970:~/merge-test> git merge-index cat AA MM
+  cat: : No such file or directory
+  This is added AA in the branch A.
+  This is added AA in the branch B.
+  This is added AA in the branch B.
+  fatal: merge program failed
+
+where the latter example shows how 'git merge-index' will stop trying to
+merge once anything has returned an error (i.e., `cat` returned an error
+for the AA file, because it didn't exist in the original, and thus
+'git merge-index' didn't even try to merge the MM thing).
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge-one-file.txt b/third_party/git/Documentation/git-merge-one-file.txt
new file mode 100644
index 0000000000..04e803d5d3
--- /dev/null
+++ b/third_party/git/Documentation/git-merge-one-file.txt
@@ -0,0 +1,21 @@
+git-merge-one-file(1)
+=====================
+
+NAME
+----
+git-merge-one-file - The standard helper program to use with git-merge-index
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge-one-file'
+
+DESCRIPTION
+-----------
+This is the standard helper program to use with 'git merge-index'
+to resolve a merge after the trivial merge done with 'git read-tree -m'.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge-tree.txt b/third_party/git/Documentation/git-merge-tree.txt
new file mode 100644
index 0000000000..58731c1942
--- /dev/null
+++ b/third_party/git/Documentation/git-merge-tree.txt
@@ -0,0 +1,29 @@
+git-merge-tree(1)
+=================
+
+NAME
+----
+git-merge-tree - Show three-way merge without touching index
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge-tree' <base-tree> <branch1> <branch2>
+
+DESCRIPTION
+-----------
+Reads three tree-ish, and output trivial merge results and
+conflicting stages to the standard output.  This is similar to
+what three-way 'git read-tree -m' does, but instead of storing the
+results in the index, the command outputs the entries to the
+standard output.
+
+This is meant to be used by higher level scripts to compute
+merge results outside of the index, and stuff the results back into the
+index.  For this reason, the output from the command omits
+entries that match the <branch1> tree.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-merge.txt b/third_party/git/Documentation/git-merge.txt
new file mode 100644
index 0000000000..01fd52dc70
--- /dev/null
+++ b/third_party/git/Documentation/git-merge.txt
@@ -0,0 +1,372 @@
+git-merge(1)
+============
+
+NAME
+----
+git-merge - Join two or more development histories together
+
+
+SYNOPSIS
+--------
+[verse]
+'git merge' [-n] [--stat] [--no-commit] [--squash] [--[no-]edit]
+	[-s <strategy>] [-X <strategy-option>] [-S[<keyid>]]
+	[--[no-]allow-unrelated-histories]
+	[--[no-]rerere-autoupdate] [-m <msg>] [-F <file>] [<commit>...]
+'git merge' (--continue | --abort | --quit)
+
+DESCRIPTION
+-----------
+Incorporates changes from the named commits (since the time their
+histories diverged from the current branch) into the current
+branch.  This command is used by 'git pull' to incorporate changes
+from another repository and can be used by hand to merge changes
+from one branch into another.
+
+Assume the following history exists and the current branch is
+"`master`":
+
+------------
+	  A---B---C topic
+	 /
+    D---E---F---G master
+------------
+
+Then "`git merge topic`" will replay the changes made on the
+`topic` branch since it diverged from `master` (i.e., `E`) until
+its current commit (`C`) on top of `master`, and record the result
+in a new commit along with the names of the two parent commits and
+a log message from the user describing the changes.
+
+------------
+	  A---B---C topic
+	 /         \
+    D---E---F---G---H master
+------------
+
+The second syntax ("`git merge --abort`") can only be run after the
+merge has resulted in conflicts. 'git merge --abort' will abort the
+merge process and try to reconstruct the pre-merge state. However,
+if there were uncommitted changes when the merge started (and
+especially if those changes were further modified after the merge
+was started), 'git merge --abort' will in some cases be unable to
+reconstruct the original (pre-merge) changes. Therefore:
+
+*Warning*: Running 'git merge' with non-trivial uncommitted changes is
+discouraged: while possible, it may leave you in a state that is hard to
+back out of in the case of a conflict.
+
+The third syntax ("`git merge --continue`") can only be run after the
+merge has resulted in conflicts.
+
+OPTIONS
+-------
+include::merge-options.txt[]
+
+-m <msg>::
+	Set the commit message to be used for the merge commit (in
+	case one is created).
++
+If `--log` is specified, a shortlog of the commits being merged
+will be appended to the specified message.
++
+The 'git fmt-merge-msg' command can be
+used to give a good default for automated 'git merge'
+invocations. The automated message can include the branch description.
+
+-F <file>::
+--file=<file>::
+	Read the commit message to be used for the merge commit (in
+	case one is created).
++
+If `--log` is specified, a shortlog of the commits being merged
+will be appended to the specified message.
+
+--rerere-autoupdate::
+--no-rerere-autoupdate::
+	Allow the rerere mechanism to update the index with the
+	result of auto-conflict resolution if possible.
+
+--overwrite-ignore::
+--no-overwrite-ignore::
+	Silently overwrite ignored files from the merge result. This
+	is the default behavior. Use `--no-overwrite-ignore` to abort.
+
+--abort::
+	Abort the current conflict resolution process, and
+	try to reconstruct the pre-merge state.
++
+If there were uncommitted worktree changes present when the merge
+started, 'git merge --abort' will in some cases be unable to
+reconstruct these changes. It is therefore recommended to always
+commit or stash your changes before running 'git merge'.
++
+'git merge --abort' is equivalent to 'git reset --merge' when
+`MERGE_HEAD` is present.
+
+--quit::
+	Forget about the current merge in progress. Leave the index
+	and the working tree as-is.
+
+--continue::
+	After a 'git merge' stops due to conflicts you can conclude the
+	merge by running 'git merge --continue' (see "HOW TO RESOLVE
+	CONFLICTS" section below).
+
+<commit>...::
+	Commits, usually other branch heads, to merge into our branch.
+	Specifying more than one commit will create a merge with
+	more than two parents (affectionately called an Octopus merge).
++
+If no commit is given from the command line, merge the remote-tracking
+branches that the current branch is configured to use as its upstream.
+See also the configuration section of this manual page.
++
+When `FETCH_HEAD` (and no other commit) is specified, the branches
+recorded in the `.git/FETCH_HEAD` file by the previous invocation
+of `git fetch` for merging are merged to the current branch.
+
+
+PRE-MERGE CHECKS
+----------------
+
+Before applying outside changes, you should get your own work in
+good shape and committed locally, so it will not be clobbered if
+there are conflicts.  See also linkgit:git-stash[1].
+'git pull' and 'git merge' will stop without doing anything when
+local uncommitted changes overlap with files that 'git pull'/'git
+merge' may need to update.
+
+To avoid recording unrelated changes in the merge commit,
+'git pull' and 'git merge' will also abort if there are any changes
+registered in the index relative to the `HEAD` commit.  (Special
+narrow exceptions to this rule may exist depending on which merge
+strategy is in use, but generally, the index must match HEAD.)
+
+If all named commits are already ancestors of `HEAD`, 'git merge'
+will exit early with the message "Already up to date."
+
+FAST-FORWARD MERGE
+------------------
+
+Often the current branch head is an ancestor of the named commit.
+This is the most common case especially when invoked from 'git
+pull': you are tracking an upstream repository, you have committed
+no local changes, and now you want to update to a newer upstream
+revision.  In this case, a new commit is not needed to store the
+combined history; instead, the `HEAD` (along with the index) is
+updated to point at the named commit, without creating an extra
+merge commit.
+
+This behavior can be suppressed with the `--no-ff` option.
+
+TRUE MERGE
+----------
+
+Except in a fast-forward merge (see above), the branches to be
+merged must be tied together by a merge commit that has both of them
+as its parents.
+
+A merged version reconciling the changes from all branches to be
+merged is committed, and your `HEAD`, index, and working tree are
+updated to it.  It is possible to have modifications in the working
+tree as long as they do not overlap; the update will preserve them.
+
+When it is not obvious how to reconcile the changes, the following
+happens:
+
+1. The `HEAD` pointer stays the same.
+2. The `MERGE_HEAD` ref is set to point to the other branch head.
+3. Paths that merged cleanly are updated both in the index file and
+   in your working tree.
+4. For conflicting paths, the index file records up to three
+   versions: stage 1 stores the version from the common ancestor,
+   stage 2 from `HEAD`, and stage 3 from `MERGE_HEAD` (you
+   can inspect the stages with `git ls-files -u`).  The working
+   tree files contain the result of the "merge" program; i.e. 3-way
+   merge results with familiar conflict markers `<<<` `===` `>>>`.
+5. No other changes are made.  In particular, the local
+   modifications you had before you started merge will stay the
+   same and the index entries for them stay as they were,
+   i.e. matching `HEAD`.
+
+If you tried a merge which resulted in complex conflicts and
+want to start over, you can recover with `git merge --abort`.
+
+MERGING TAG
+-----------
+
+When merging an annotated (and possibly signed) tag, Git always
+creates a merge commit even if a fast-forward merge is possible, and
+the commit message template is prepared with the tag message.
+Additionally, if the tag is signed, the signature check is reported
+as a comment in the message template. See also linkgit:git-tag[1].
+
+When you want to just integrate with the work leading to the commit
+that happens to be tagged, e.g. synchronizing with an upstream
+release point, you may not want to make an unnecessary merge commit.
+
+In such a case, you can "unwrap" the tag yourself before feeding it
+to `git merge`, or pass `--ff-only` when you do not have any work on
+your own. e.g.
+
+----
+git fetch origin
+git merge v1.2.3^0
+git merge --ff-only v1.2.3
+----
+
+
+HOW CONFLICTS ARE PRESENTED
+---------------------------
+
+During a merge, the working tree files are updated to reflect the result
+of the merge.  Among the changes made to the common ancestor's version,
+non-overlapping ones (that is, you changed an area of the file while the
+other side left that area intact, or vice versa) are incorporated in the
+final result verbatim.  When both sides made changes to the same area,
+however, Git cannot randomly pick one side over the other, and asks you to
+resolve it by leaving what both sides did to that area.
+
+By default, Git uses the same style as the one used by the "merge" program
+from the RCS suite to present such a conflicted hunk, like this:
+
+------------
+Here are lines that are either unchanged from the common
+ancestor, or cleanly resolved because only one side changed.
+<<<<<<< yours:sample.txt
+Conflict resolution is hard;
+let's go shopping.
+=======
+Git makes conflict resolution easy.
+>>>>>>> theirs:sample.txt
+And here is another line that is cleanly resolved or unmodified.
+------------
+
+The area where a pair of conflicting changes happened is marked with markers
+`<<<<<<<`, `=======`, and `>>>>>>>`.  The part before the `=======`
+is typically your side, and the part afterwards is typically their side.
+
+The default format does not show what the original said in the conflicting
+area.  You cannot tell how many lines are deleted and replaced with
+Barbie's remark on your side.  The only thing you can tell is that your
+side wants to say it is hard and you'd prefer to go shopping, while the
+other side wants to claim it is easy.
+
+An alternative style can be used by setting the "merge.conflictStyle"
+configuration variable to "diff3".  In "diff3" style, the above conflict
+may look like this:
+
+------------
+Here are lines that are either unchanged from the common
+ancestor, or cleanly resolved because only one side changed.
+<<<<<<< yours:sample.txt
+Conflict resolution is hard;
+let's go shopping.
+|||||||
+Conflict resolution is hard.
+=======
+Git makes conflict resolution easy.
+>>>>>>> theirs:sample.txt
+And here is another line that is cleanly resolved or unmodified.
+------------
+
+In addition to the `<<<<<<<`, `=======`, and `>>>>>>>` markers, it uses
+another `|||||||` marker that is followed by the original text.  You can
+tell that the original just stated a fact, and your side simply gave in to
+that statement and gave up, while the other side tried to have a more
+positive attitude.  You can sometimes come up with a better resolution by
+viewing the original.
+
+
+HOW TO RESOLVE CONFLICTS
+------------------------
+
+After seeing a conflict, you can do two things:
+
+ * Decide not to merge.  The only clean-ups you need are to reset
+   the index file to the `HEAD` commit to reverse 2. and to clean
+   up working tree changes made by 2. and 3.; `git merge --abort`
+   can be used for this.
+
+ * Resolve the conflicts.  Git will mark the conflicts in
+   the working tree.  Edit the files into shape and
+   'git add' them to the index.  Use 'git commit' or
+   'git merge --continue' to seal the deal. The latter command
+   checks whether there is a (interrupted) merge in progress
+   before calling 'git commit'.
+
+You can work through the conflict with a number of tools:
+
+ * Use a mergetool.  `git mergetool` to launch a graphical
+   mergetool which will work you through the merge.
+
+ * Look at the diffs.  `git diff` will show a three-way diff,
+   highlighting changes from both the `HEAD` and `MERGE_HEAD`
+   versions.
+
+ * Look at the diffs from each branch. `git log --merge -p <path>`
+   will show diffs first for the `HEAD` version and then the
+   `MERGE_HEAD` version.
+
+ * Look at the originals.  `git show :1:filename` shows the
+   common ancestor, `git show :2:filename` shows the `HEAD`
+   version, and `git show :3:filename` shows the `MERGE_HEAD`
+   version.
+
+
+EXAMPLES
+--------
+
+* Merge branches `fixes` and `enhancements` on top of
+  the current branch, making an octopus merge:
++
+------------------------------------------------
+$ git merge fixes enhancements
+------------------------------------------------
+
+* Merge branch `obsolete` into the current branch, using `ours`
+  merge strategy:
++
+------------------------------------------------
+$ git merge -s ours obsolete
+------------------------------------------------
+
+* Merge branch `maint` into the current branch, but do not make
+  a new commit automatically:
++
+------------------------------------------------
+$ git merge --no-commit maint
+------------------------------------------------
++
+This can be used when you want to include further changes to the
+merge, or want to write your own merge commit message.
++
+You should refrain from abusing this option to sneak substantial
+changes into a merge commit.  Small fixups like bumping
+release/version name would be acceptable.
+
+
+include::merge-strategies.txt[]
+
+CONFIGURATION
+-------------
+include::config/merge.txt[]
+
+branch.<name>.mergeOptions::
+	Sets default options for merging into branch <name>. The syntax and
+	supported options are the same as those of 'git merge', but option
+	values containing whitespace characters are currently not supported.
+
+SEE ALSO
+--------
+linkgit:git-fmt-merge-msg[1], linkgit:git-pull[1],
+linkgit:gitattributes[5],
+linkgit:git-reset[1],
+linkgit:git-diff[1], linkgit:git-ls-files[1],
+linkgit:git-add[1], linkgit:git-rm[1],
+linkgit:git-mergetool[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mergetool--lib.txt b/third_party/git/Documentation/git-mergetool--lib.txt
new file mode 100644
index 0000000000..4da9d24096
--- /dev/null
+++ b/third_party/git/Documentation/git-mergetool--lib.txt
@@ -0,0 +1,49 @@
+git-mergetool{litdd}lib(1)
+==========================
+
+NAME
+----
+git-mergetool--lib - Common Git merge tool shell scriptlets
+
+SYNOPSIS
+--------
+[verse]
+'TOOL_MODE=(diff|merge) . "$(git --exec-path)/git-mergetool{litdd}lib"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git-mergetool{litdd}lib' scriptlet is designed to be sourced (using
+`.`) by other shell scripts to set up functions for working
+with Git merge tools.
+
+Before sourcing 'git-mergetool{litdd}lib', your script must set `TOOL_MODE`
+to define the operation mode for the functions listed below.
+'diff' and 'merge' are valid values.
+
+FUNCTIONS
+---------
+get_merge_tool::
+	returns a merge tool. the return code is 1 if we returned a guessed
+	merge tool, else 0. '$GIT_MERGETOOL_GUI' may be set to 'true' to
+	search for the appropriate guitool.
+
+get_merge_tool_cmd::
+	returns the custom command for a merge tool.
+
+get_merge_tool_path::
+	returns the custom path for a merge tool.
+
+run_merge_tool::
+	launches a merge tool given the tool name and a true/false
+	flag to indicate whether a merge base is present.
+	'$MERGED', '$LOCAL', '$REMOTE', and '$BASE' must be defined
+	for use by the merge tool.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mergetool.txt b/third_party/git/Documentation/git-mergetool.txt
new file mode 100644
index 0000000000..6b14702e78
--- /dev/null
+++ b/third_party/git/Documentation/git-mergetool.txt
@@ -0,0 +1,114 @@
+git-mergetool(1)
+================
+
+NAME
+----
+git-mergetool - Run merge conflict resolution tools to resolve merge conflicts
+
+SYNOPSIS
+--------
+[verse]
+'git mergetool' [--tool=<tool>] [-y | --[no-]prompt] [<file>...]
+
+DESCRIPTION
+-----------
+
+Use `git mergetool` to run one of several merge utilities to resolve
+merge conflicts.  It is typically run after 'git merge'.
+
+If one or more <file> parameters are given, the merge tool program will
+be run to resolve differences on each file (skipping those without
+conflicts).  Specifying a directory will include all unresolved files in
+that path.  If no <file> names are specified, 'git mergetool' will run
+the merge tool program on every file with merge conflicts.
+
+OPTIONS
+-------
+-t <tool>::
+--tool=<tool>::
+	Use the merge resolution program specified by <tool>.
+	Valid values include emerge, gvimdiff, kdiff3,
+	meld, vimdiff, and tortoisemerge. Run `git mergetool --tool-help`
+	for the list of valid <tool> settings.
++
+If a merge resolution program is not specified, 'git mergetool'
+will use the configuration variable `merge.tool`.  If the
+configuration variable `merge.tool` is not set, 'git mergetool'
+will pick a suitable default.
++
+You can explicitly provide a full path to the tool by setting the
+configuration variable `mergetool.<tool>.path`. For example, you
+can configure the absolute path to kdiff3 by setting
+`mergetool.kdiff3.path`. Otherwise, 'git mergetool' assumes the
+tool is available in PATH.
++
+Instead of running one of the known merge tool programs,
+'git mergetool' can be customized to run an alternative program
+by specifying the command line to invoke in a configuration
+variable `mergetool.<tool>.cmd`.
++
+When 'git mergetool' is invoked with this tool (either through the
+`-t` or `--tool` option or the `merge.tool` configuration
+variable) the configured command line will be invoked with `$BASE`
+set to the name of a temporary file containing the common base for
+the merge, if available; `$LOCAL` set to the name of a temporary
+file containing the contents of the file on the current branch;
+`$REMOTE` set to the name of a temporary file containing the
+contents of the file to be merged, and `$MERGED` set to the name
+of the file to which the merge tool should write the result of the
+merge resolution.
++
+If the custom merge tool correctly indicates the success of a
+merge resolution with its exit code, then the configuration
+variable `mergetool.<tool>.trustExitCode` can be set to `true`.
+Otherwise, 'git mergetool' will prompt the user to indicate the
+success of the resolution after the custom tool has exited.
+
+--tool-help::
+	Print a list of merge tools that may be used with `--tool`.
+
+-y::
+--no-prompt::
+	Don't prompt before each invocation of the merge resolution
+	program.
+	This is the default if the merge resolution program is
+	explicitly specified with the `--tool` option or with the
+	`merge.tool` configuration variable.
+
+--prompt::
+	Prompt before each invocation of the merge resolution program
+	to give the user a chance to skip the path.
+
+-g::
+--gui::
+	When 'git-mergetool' is invoked with the `-g` or `--gui` option
+	the default merge tool will be read from the configured
+	`merge.guitool` variable instead of `merge.tool`. If
+	`merge.guitool` is not set, we will fallback to the tool
+	configured under `merge.tool`.
+
+--no-gui::
+	This overrides a previous `-g` or `--gui` setting and reads the
+	default merge tool will be read from the configured `merge.tool`
+	variable.
+
+-O<orderfile>::
+	Process files in the order specified in the
+	<orderfile>, which has one shell glob pattern per line.
+	This overrides the `diff.orderFile` configuration variable
+	(see linkgit:git-config[1]).  To cancel `diff.orderFile`,
+	use `-O/dev/null`.
+
+TEMPORARY FILES
+---------------
+`git mergetool` creates `*.orig` backup files while resolving merges.
+These are safe to remove once a file has been merged and its
+`git mergetool` session has completed.
+
+Setting the `mergetool.keepBackup` configuration variable to `false`
+causes `git mergetool` to automatically remove the backup as files
+are successfully merged.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mktag.txt b/third_party/git/Documentation/git-mktag.txt
new file mode 100644
index 0000000000..fa6a756123
--- /dev/null
+++ b/third_party/git/Documentation/git-mktag.txt
@@ -0,0 +1,39 @@
+git-mktag(1)
+============
+
+NAME
+----
+git-mktag - Creates a tag object
+
+
+SYNOPSIS
+--------
+[verse]
+'git mktag'
+
+DESCRIPTION
+-----------
+Reads a tag contents on standard input and creates a tag object
+that can also be used to sign other objects.
+
+The output is the new tag's <object> identifier.
+
+Tag Format
+----------
+A tag signature file, to be fed to this command's standard input,
+has a very simple fixed format: four lines of
+
+  object <sha1>
+  type <typename>
+  tag <tagname>
+  tagger <tagger>
+
+followed by some 'optional' free-form message (some tags created
+by older Git may not have `tagger` line).  The message, when
+exists, is separated by a blank line from the header.  The
+message part may contain a signature that Git itself doesn't
+care about, but that can be verified with gpg.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mktree.txt b/third_party/git/Documentation/git-mktree.txt
new file mode 100644
index 0000000000..27fe2b32e1
--- /dev/null
+++ b/third_party/git/Documentation/git-mktree.txt
@@ -0,0 +1,40 @@
+git-mktree(1)
+=============
+
+NAME
+----
+git-mktree - Build a tree-object from ls-tree formatted text
+
+
+SYNOPSIS
+--------
+[verse]
+'git mktree' [-z] [--missing] [--batch]
+
+DESCRIPTION
+-----------
+Reads standard input in non-recursive `ls-tree` output format, and creates
+a tree object.  The order of the tree entries is normalized by mktree so
+pre-sorting the input is not required.  The object name of the tree object
+built is written to the standard output.
+
+OPTIONS
+-------
+-z::
+	Read the NUL-terminated `ls-tree -z` output instead.
+
+--missing::
+	Allow missing objects.  The default behaviour (without this option)
+	is to verify that each tree entry's sha1 identifies an existing
+	object.  This option has no effect on the treatment of gitlink entries
+	(aka "submodules") which are always allowed to be missing.
+
+--batch::
+	Allow building of more than one tree object before exiting.  Each
+	tree is separated by as single blank line. The final new-line is
+	optional.  Note - if the `-z` option is used, lines are terminated
+	with NUL.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-multi-pack-index.txt b/third_party/git/Documentation/git-multi-pack-index.txt
new file mode 100644
index 0000000000..233b2b7862
--- /dev/null
+++ b/third_party/git/Documentation/git-multi-pack-index.txt
@@ -0,0 +1,88 @@
+git-multi-pack-index(1)
+=======================
+
+NAME
+----
+git-multi-pack-index - Write and verify multi-pack-indexes
+
+
+SYNOPSIS
+--------
+[verse]
+'git multi-pack-index' [--object-dir=<dir>] <subcommand>
+
+DESCRIPTION
+-----------
+Write or verify a multi-pack-index (MIDX) file.
+
+OPTIONS
+-------
+
+--object-dir=<dir>::
+	Use given directory for the location of Git objects. We check
+	`<dir>/packs/multi-pack-index` for the current MIDX file, and
+	`<dir>/packs` for the pack-files to index.
+
+The following subcommands are available:
+
+write::
+	Write a new MIDX file.
+
+verify::
+	Verify the contents of the MIDX file.
+
+expire::
+	Delete the pack-files that are tracked 	by the MIDX file, but
+	have no objects referenced by the MIDX. Rewrite the MIDX file
+	afterward to remove all references to these pack-files.
+
+repack::
+	Create a new pack-file containing objects in small pack-files
+	referenced by the multi-pack-index. If the size given by the
+	`--batch-size=<size>` argument is zero, then create a pack
+	containing all objects referenced by the multi-pack-index. For
+	a non-zero batch size, Select the pack-files by examining packs
+	from oldest-to-newest, computing the "expected size" by counting
+	the number of objects in the pack referenced by the
+	multi-pack-index, then divide by the total number of objects in
+	the pack and multiply by the pack size. We select packs with
+	expected size below the batch size until the set of packs have
+	total expected size at least the batch size. If the total size
+	does not reach the batch size, then do nothing. If a new pack-
+	file is created, rewrite the multi-pack-index to reference the
+	new pack-file. A later run of 'git multi-pack-index expire' will
+	delete the pack-files that were part of this batch.
+
+
+EXAMPLES
+--------
+
+* Write a MIDX file for the packfiles in the current .git folder.
++
+-----------------------------------------------
+$ git multi-pack-index write
+-----------------------------------------------
+
+* Write a MIDX file for the packfiles in an alternate object store.
++
+-----------------------------------------------
+$ git multi-pack-index --object-dir <alt> write
+-----------------------------------------------
+
+* Verify the MIDX file for the packfiles in the current .git folder.
++
+-----------------------------------------------
+$ git multi-pack-index verify
+-----------------------------------------------
+
+
+SEE ALSO
+--------
+See link:technical/multi-pack-index.html[The Multi-Pack-Index Design
+Document] and link:technical/pack-format.html[The Multi-Pack-Index
+Format] for more information on the multi-pack-index feature.
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-mv.txt b/third_party/git/Documentation/git-mv.txt
new file mode 100644
index 0000000000..79449bf98f
--- /dev/null
+++ b/third_party/git/Documentation/git-mv.txt
@@ -0,0 +1,69 @@
+git-mv(1)
+=========
+
+NAME
+----
+git-mv - Move or rename a file, a directory, or a symlink
+
+
+SYNOPSIS
+--------
+[verse]
+'git mv' <options>... <args>...
+
+DESCRIPTION
+-----------
+Move or rename a file, directory or symlink.
+
+ git mv [-v] [-f] [-n] [-k] <source> <destination>
+ git mv [-v] [-f] [-n] [-k] <source> ... <destination directory>
+
+In the first form, it renames <source>, which must exist and be either
+a file, symlink or directory, to <destination>.
+In the second form, the last argument has to be an existing
+directory; the given sources will be moved into this directory.
+
+The index is updated after successful completion, but the change must still be
+committed.
+
+OPTIONS
+-------
+-f::
+--force::
+	Force renaming or moving of a file even if the target exists
+-k::
+	Skip move or rename actions which would lead to an error
+	condition. An error happens when a source is neither existing nor
+	controlled by Git, or when it would overwrite an existing
+	file unless `-f` is given.
+-n::
+--dry-run::
+	Do nothing; only show what would happen
+
+-v::
+--verbose::
+	Report the names of files as they are moved.
+
+SUBMODULES
+----------
+Moving a submodule using a gitfile (which means they were cloned
+with a Git version 1.7.8 or newer) will update the gitfile and
+core.worktree setting to make the submodule work in the new location.
+It also will attempt to update the submodule.<name>.path setting in
+the linkgit:gitmodules[5] file and stage that file (unless -n is used).
+
+BUGS
+----
+Each time a superproject update moves a populated submodule (e.g. when
+switching between commits before and after the move) a stale submodule
+checkout will remain in the old location and an empty directory will
+appear in the new location. To populate the submodule again in the new
+location the user will have to run "git submodule update"
+afterwards. Removing the old directory is only safe when it uses a
+gitfile, as otherwise the history of the submodule will be deleted
+too. Both steps will be obsolete when recursive submodule update has
+been implemented.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-name-rev.txt b/third_party/git/Documentation/git-name-rev.txt
new file mode 100644
index 0000000000..5cb0eb0855
--- /dev/null
+++ b/third_party/git/Documentation/git-name-rev.txt
@@ -0,0 +1,89 @@
+git-name-rev(1)
+===============
+
+NAME
+----
+git-name-rev - Find symbolic names for given revs
+
+
+SYNOPSIS
+--------
+[verse]
+'git name-rev' [--tags] [--refs=<pattern>]
+	       ( --all | --stdin | <commit-ish>... )
+
+DESCRIPTION
+-----------
+Finds symbolic names suitable for human digestion for revisions given in any
+format parsable by 'git rev-parse'.
+
+
+OPTIONS
+-------
+
+--tags::
+	Do not use branch names, but only tags to name the commits
+
+--refs=<pattern>::
+	Only use refs whose names match a given shell pattern.  The pattern
+	can be one of branch name, tag name or fully qualified ref name. If
+	given multiple times, use refs whose names match any of the given shell
+	patterns. Use `--no-refs` to clear any previous ref patterns given.
+
+--exclude=<pattern>::
+	Do not use any ref whose name matches a given shell pattern. The
+	pattern can be one of branch name, tag name or fully qualified ref
+	name. If given multiple times, a ref will be excluded when it matches
+	any of the given patterns. When used together with --refs, a ref will
+	be used as a match only when it matches at least one --refs pattern and
+	does not match any --exclude patterns. Use `--no-exclude` to clear the
+	list of exclude patterns.
+
+--all::
+	List all commits reachable from all refs
+
+--stdin::
+	Transform stdin by substituting all the 40-character SHA-1
+	hexes (say $hex) with "$hex ($rev_name)".  When used with
+	--name-only, substitute with "$rev_name", omitting $hex
+	altogether.  Intended for the scripter's use.
+
+--name-only::
+	Instead of printing both the SHA-1 and the name, print only
+	the name.  If given with --tags the usual tag prefix of
+	"tags/" is also omitted from the name, matching the output
+	of `git-describe` more closely.
+
+--no-undefined::
+	Die with error code != 0 when a reference is undefined,
+	instead of printing `undefined`.
+
+--always::
+	Show uniquely abbreviated commit object as fallback.
+
+EXAMPLES
+--------
+
+Given a commit, find out where it is relative to the local refs. Say somebody
+wrote you about that fantastic commit 33db5f4d9027a10e477ccf054b2c1ab94f74c85a.
+Of course, you look into the commit, but that only tells you what happened, but
+not the context.
+
+Enter 'git name-rev':
+
+------------
+% git name-rev 33db5f4d9027a10e477ccf054b2c1ab94f74c85a
+33db5f4d9027a10e477ccf054b2c1ab94f74c85a tags/v0.99~940
+------------
+
+Now you are wiser, because you know that it happened 940 revisions before v0.99.
+
+Another nice thing you can do is:
+
+------------
+% git log | git name-rev --stdin
+------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-notes.txt b/third_party/git/Documentation/git-notes.txt
new file mode 100644
index 0000000000..f56a5a9197
--- /dev/null
+++ b/third_party/git/Documentation/git-notes.txt
@@ -0,0 +1,405 @@
+git-notes(1)
+============
+
+NAME
+----
+git-notes - Add or inspect object notes
+
+SYNOPSIS
+--------
+[verse]
+'git notes' [list [<object>]]
+'git notes' add [-f] [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
+'git notes' copy [-f] ( --stdin | <from-object> <to-object> )
+'git notes' append [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
+'git notes' edit [--allow-empty] [<object>]
+'git notes' show [<object>]
+'git notes' merge [-v | -q] [-s <strategy> ] <notes-ref>
+'git notes' merge --commit [-v | -q]
+'git notes' merge --abort [-v | -q]
+'git notes' remove [--ignore-missing] [--stdin] [<object>...]
+'git notes' prune [-n] [-v]
+'git notes' get-ref
+
+
+DESCRIPTION
+-----------
+Adds, removes, or reads notes attached to objects, without touching
+the objects themselves.
+
+By default, notes are saved to and read from `refs/notes/commits`, but
+this default can be overridden.  See the OPTIONS, CONFIGURATION, and
+ENVIRONMENT sections below.  If this ref does not exist, it will be
+quietly created when it is first needed to store a note.
+
+A typical use of notes is to supplement a commit message without
+changing the commit itself. Notes can be shown by 'git log' along with
+the original commit message. To distinguish these notes from the
+message stored in the commit object, the notes are indented like the
+message, after an unindented line saying "Notes (<refname>):" (or
+"Notes:" for `refs/notes/commits`).
+
+Notes can also be added to patches prepared with `git format-patch` by
+using the `--notes` option. Such notes are added as a patch commentary
+after a three dash separator line.
+
+To change which notes are shown by 'git log', see the
+"notes.displayRef" configuration in linkgit:git-log[1].
+
+See the "notes.rewrite.<command>" configuration for a way to carry
+notes across commands that rewrite commits.
+
+
+SUBCOMMANDS
+-----------
+
+list::
+	List the notes object for a given object. If no object is
+	given, show a list of all note objects and the objects they
+	annotate (in the format "<note object> <annotated object>").
+	This is the default subcommand if no subcommand is given.
+
+add::
+	Add notes for a given object (defaults to HEAD). Abort if the
+	object already has notes (use `-f` to overwrite existing notes).
+	However, if you're using `add` interactively (using an editor
+	to supply the notes contents), then - instead of aborting -
+	the existing notes will be opened in the editor (like the `edit`
+	subcommand).
+
+copy::
+	Copy the notes for the first object onto the second object.
+	Abort if the second object already has notes, or if the first
+	object has none (use -f to overwrite existing notes to the
+	second object). This subcommand is equivalent to:
+	`git notes add [-f] -C $(git notes list <from-object>) <to-object>`
++
+In `--stdin` mode, take lines in the format
++
+----------
+<from-object> SP <to-object> [ SP <rest> ] LF
+----------
++
+on standard input, and copy the notes from each <from-object> to its
+corresponding <to-object>.  (The optional `<rest>` is ignored so that
+the command can read the input given to the `post-rewrite` hook.)
+
+append::
+	Append to the notes of an existing object (defaults to HEAD).
+	Creates a new notes object if needed.
+
+edit::
+	Edit the notes for a given object (defaults to HEAD).
+
+show::
+	Show the notes for a given object (defaults to HEAD).
+
+merge::
+	Merge the given notes ref into the current notes ref.
+	This will try to merge the changes made by the given
+	notes ref (called "remote") since the merge-base (if
+	any) into the current notes ref (called "local").
++
+If conflicts arise and a strategy for automatically resolving
+conflicting notes (see the "NOTES MERGE STRATEGIES" section) is not given,
+the "manual" resolver is used. This resolver checks out the
+conflicting notes in a special worktree (`.git/NOTES_MERGE_WORKTREE`),
+and instructs the user to manually resolve the conflicts there.
+When done, the user can either finalize the merge with
+'git notes merge --commit', or abort the merge with
+'git notes merge --abort'.
+
+remove::
+	Remove the notes for given objects (defaults to HEAD). When
+	giving zero or one object from the command line, this is
+	equivalent to specifying an empty note message to
+	the `edit` subcommand.
+
+prune::
+	Remove all notes for non-existing/unreachable objects.
+
+get-ref::
+	Print the current notes ref. This provides an easy way to
+	retrieve the current notes ref (e.g. from scripts).
+
+OPTIONS
+-------
+-f::
+--force::
+	When adding notes to an object that already has notes,
+	overwrite the existing notes (instead of aborting).
+
+-m <msg>::
+--message=<msg>::
+	Use the given note message (instead of prompting).
+	If multiple `-m` options are given, their values
+	are concatenated as separate paragraphs.
+	Lines starting with `#` and empty lines other than a
+	single line between paragraphs will be stripped out.
+
+-F <file>::
+--file=<file>::
+	Take the note message from the given file.  Use '-' to
+	read the note message from the standard input.
+	Lines starting with `#` and empty lines other than a
+	single line between paragraphs will be stripped out.
+
+-C <object>::
+--reuse-message=<object>::
+	Take the given blob object (for example, another note) as the
+	note message. (Use `git notes copy <object>` instead to
+	copy notes between objects.)
+
+-c <object>::
+--reedit-message=<object>::
+	Like '-C', but with `-c` the editor is invoked, so that
+	the user can further edit the note message.
+
+--allow-empty::
+	Allow an empty note object to be stored. The default behavior is
+	to automatically remove empty notes.
+
+--ref <ref>::
+	Manipulate the notes tree in <ref>.  This overrides
+	`GIT_NOTES_REF` and the "core.notesRef" configuration.  The ref
+	specifies the full refname when it begins with `refs/notes/`; when it
+	begins with `notes/`, `refs/` and otherwise `refs/notes/` is prefixed
+	to form a full name of the ref.
+
+--ignore-missing::
+	Do not consider it an error to request removing notes from an
+	object that does not have notes attached to it.
+
+--stdin::
+	Also read the object names to remove notes from the standard
+	input (there is no reason you cannot combine this with object
+	names from the command line).
+
+-n::
+--dry-run::
+	Do not remove anything; just report the object names whose notes
+	would be removed.
+
+-s <strategy>::
+--strategy=<strategy>::
+	When merging notes, resolve notes conflicts using the given
+	strategy. The following strategies are recognized: "manual"
+	(default), "ours", "theirs", "union" and "cat_sort_uniq".
+	This option overrides the "notes.mergeStrategy" configuration setting.
+	See the "NOTES MERGE STRATEGIES" section below for more
+	information on each notes merge strategy.
+
+--commit::
+	Finalize an in-progress 'git notes merge'. Use this option
+	when you have resolved the conflicts that 'git notes merge'
+	stored in .git/NOTES_MERGE_WORKTREE. This amends the partial
+	merge commit created by 'git notes merge' (stored in
+	.git/NOTES_MERGE_PARTIAL) by adding the notes in
+	.git/NOTES_MERGE_WORKTREE. The notes ref stored in the
+	.git/NOTES_MERGE_REF symref is updated to the resulting commit.
+
+--abort::
+	Abort/reset an in-progress 'git notes merge', i.e. a notes merge
+	with conflicts. This simply removes all files related to the
+	notes merge.
+
+-q::
+--quiet::
+	When merging notes, operate quietly.
+
+-v::
+--verbose::
+	When merging notes, be more verbose.
+	When pruning notes, report all object names whose notes are
+	removed.
+
+
+DISCUSSION
+----------
+
+Commit notes are blobs containing extra information about an object
+(usually information to supplement a commit's message).  These blobs
+are taken from notes refs.  A notes ref is usually a branch which
+contains "files" whose paths are the object names for the objects
+they describe, with some directory separators included for performance
+reasons footnote:[Permitted pathnames have the form
+'ab'`/`'cd'`/`'ef'`/`'...'`/`'abcdef...': a sequence of directory
+names of two hexadecimal digits each followed by a filename with the
+rest of the object ID.].
+
+Every notes change creates a new commit at the specified notes ref.
+You can therefore inspect the history of the notes by invoking, e.g.,
+`git log -p notes/commits`.  Currently the commit message only records
+which operation triggered the update, and the commit authorship is
+determined according to the usual rules (see linkgit:git-commit[1]).
+These details may change in the future.
+
+It is also permitted for a notes ref to point directly to a tree
+object, in which case the history of the notes can be read with
+`git log -p -g <refname>`.
+
+
+NOTES MERGE STRATEGIES
+----------------------
+
+The default notes merge strategy is "manual", which checks out
+conflicting notes in a special work tree for resolving notes conflicts
+(`.git/NOTES_MERGE_WORKTREE`), and instructs the user to resolve the
+conflicts in that work tree.
+When done, the user can either finalize the merge with
+'git notes merge --commit', or abort the merge with
+'git notes merge --abort'.
+
+Users may select an automated merge strategy from among the following using
+either -s/--strategy option or configuring notes.mergeStrategy accordingly:
+
+"ours" automatically resolves conflicting notes in favor of the local
+version (i.e. the current notes ref).
+
+"theirs" automatically resolves notes conflicts in favor of the remote
+version (i.e. the given notes ref being merged into the current notes
+ref).
+
+"union" automatically resolves notes conflicts by concatenating the
+local and remote versions.
+
+"cat_sort_uniq" is similar to "union", but in addition to concatenating
+the local and remote versions, this strategy also sorts the resulting
+lines, and removes duplicate lines from the result. This is equivalent
+to applying the "cat | sort | uniq" shell pipeline to the local and
+remote versions. This strategy is useful if the notes follow a line-based
+format where one wants to avoid duplicated lines in the merge result.
+Note that if either the local or remote version contain duplicate lines
+prior to the merge, these will also be removed by this notes merge
+strategy.
+
+
+EXAMPLES
+--------
+
+You can use notes to add annotations with information that was not
+available at the time a commit was written.
+
+------------
+$ git notes add -m 'Tested-by: Johannes Sixt <j6t@kdbg.org>' 72a144e2
+$ git show -s 72a144e
+[...]
+    Signed-off-by: Junio C Hamano <gitster@pobox.com>
+
+Notes:
+    Tested-by: Johannes Sixt <j6t@kdbg.org>
+------------
+
+In principle, a note is a regular Git blob, and any kind of
+(non-)format is accepted.  You can binary-safely create notes from
+arbitrary files using 'git hash-object':
+
+------------
+$ cc *.c
+$ blob=$(git hash-object -w a.out)
+$ git notes --ref=built add --allow-empty -C "$blob" HEAD
+------------
+
+(You cannot simply use `git notes --ref=built add -F a.out HEAD`
+because that is not binary-safe.)
+Of course, it doesn't make much sense to display non-text-format notes
+with 'git log', so if you use such notes, you'll probably need to write
+some special-purpose tools to do something useful with them.
+
+
+CONFIGURATION
+-------------
+
+core.notesRef::
+	Notes ref to read and manipulate instead of
+	`refs/notes/commits`.  Must be an unabbreviated ref name.
+	This setting can be overridden through the environment and
+	command line.
+
+notes.mergeStrategy::
+	Which merge strategy to choose by default when resolving notes
+	conflicts.  Must be one of `manual`, `ours`, `theirs`, `union`, or
+	`cat_sort_uniq`.  Defaults to `manual`.  See "NOTES MERGE STRATEGIES"
+	section above for more information on each strategy.
++
+This setting can be overridden by passing the `--strategy` option.
+
+notes.<name>.mergeStrategy::
+	Which merge strategy to choose when doing a notes merge into
+	refs/notes/<name>.  This overrides the more general
+	"notes.mergeStrategy".  See the "NOTES MERGE STRATEGIES" section above
+	for more information on each available strategy.
+
+notes.displayRef::
+	Which ref (or refs, if a glob or specified more than once), in
+	addition to the default set by `core.notesRef` or
+	`GIT_NOTES_REF`, to read notes from when showing commit
+	messages with the 'git log' family of commands.
+	This setting can be overridden on the command line or by the
+	`GIT_NOTES_DISPLAY_REF` environment variable.
+	See linkgit:git-log[1].
+
+notes.rewrite.<command>::
+	When rewriting commits with <command> (currently `amend` or
+	`rebase`), if this variable is `false`, git will not copy
+	notes from the original to the rewritten commit.  Defaults to
+	`true`.  See also "`notes.rewriteRef`" below.
++
+This setting can be overridden by the `GIT_NOTES_REWRITE_REF`
+environment variable.
+
+notes.rewriteMode::
+	When copying notes during a rewrite, what to do if the target
+	commit already has a note.  Must be one of `overwrite`,
+	`concatenate`, `cat_sort_uniq`, or `ignore`.  Defaults to
+	`concatenate`.
++
+This setting can be overridden with the `GIT_NOTES_REWRITE_MODE`
+environment variable.
+
+notes.rewriteRef::
+	When copying notes during a rewrite, specifies the (fully
+	qualified) ref whose notes should be copied.  May be a glob,
+	in which case notes in all matching refs will be copied.  You
+	may also specify this configuration several times.
++
+Does not have a default value; you must configure this variable to
+enable note rewriting.
++
+Can be overridden with the `GIT_NOTES_REWRITE_REF` environment variable.
+
+
+ENVIRONMENT
+-----------
+
+`GIT_NOTES_REF`::
+	Which ref to manipulate notes from, instead of `refs/notes/commits`.
+	This overrides the `core.notesRef` setting.
+
+`GIT_NOTES_DISPLAY_REF`::
+	Colon-delimited list of refs or globs indicating which refs,
+	in addition to the default from `core.notesRef` or
+	`GIT_NOTES_REF`, to read notes from when showing commit
+	messages.
+	This overrides the `notes.displayRef` setting.
++
+A warning will be issued for refs that do not exist, but a glob that
+does not match any refs is silently ignored.
+
+`GIT_NOTES_REWRITE_MODE`::
+	When copying notes during a rewrite, what to do if the target
+	commit already has a note.
+	Must be one of `overwrite`, `concatenate`, `cat_sort_uniq`, or `ignore`.
+	This overrides the `core.rewriteMode` setting.
+
+`GIT_NOTES_REWRITE_REF`::
+	When rewriting commits, which notes to copy from the original
+	to the rewritten commit.  Must be a colon-delimited list of
+	refs or globs.
++
+If not set in the environment, the list of notes to copy depends
+on the `notes.rewrite.<command>` and `notes.rewriteRef` settings.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-p4.txt b/third_party/git/Documentation/git-p4.txt
new file mode 100644
index 0000000000..3494a1db3e
--- /dev/null
+++ b/third_party/git/Documentation/git-p4.txt
@@ -0,0 +1,723 @@
+git-p4(1)
+=========
+
+NAME
+----
+git-p4 - Import from and submit to Perforce repositories
+
+
+SYNOPSIS
+--------
+[verse]
+'git p4 clone' [<sync options>] [<clone options>] <p4 depot path>...
+'git p4 sync' [<sync options>] [<p4 depot path>...]
+'git p4 rebase'
+'git p4 submit' [<submit options>] [<master branch name>]
+
+
+DESCRIPTION
+-----------
+This command provides a way to interact with p4 repositories
+using Git.
+
+Create a new Git repository from an existing p4 repository using
+'git p4 clone', giving it one or more p4 depot paths.  Incorporate
+new commits from p4 changes with 'git p4 sync'.  The 'sync' command
+is also used to include new branches from other p4 depot paths.
+Submit Git changes back to p4 using 'git p4 submit'.  The command
+'git p4 rebase' does a sync plus rebases the current branch onto
+the updated p4 remote branch.
+
+
+EXAMPLES
+--------
+* Clone a repository:
++
+------------
+$ git p4 clone //depot/path/project
+------------
+
+* Do some work in the newly created Git repository:
++
+------------
+$ cd project
+$ vi foo.h
+$ git commit -a -m "edited foo.h"
+------------
+
+* Update the Git repository with recent changes from p4, rebasing your
+  work on top:
++
+------------
+$ git p4 rebase
+------------
+
+* Submit your commits back to p4:
++
+------------
+$ git p4 submit
+------------
+
+
+COMMANDS
+--------
+
+Clone
+~~~~~
+Generally, 'git p4 clone' is used to create a new Git directory
+from an existing p4 repository:
+------------
+$ git p4 clone //depot/path/project
+------------
+This:
+
+1. Creates an empty Git repository in a subdirectory called 'project'.
++
+2. Imports the full contents of the head revision from the given p4
+   depot path into a single commit in the Git branch 'refs/remotes/p4/master'.
++
+3. Creates a local branch, 'master' from this remote and checks it out.
+
+To reproduce the entire p4 history in Git, use the '@all' modifier on
+the depot path:
+------------
+$ git p4 clone //depot/path/project@all
+------------
+
+
+Sync
+~~~~
+As development continues in the p4 repository, those changes can
+be included in the Git repository using:
+------------
+$ git p4 sync
+------------
+This command finds new changes in p4 and imports them as Git commits.
+
+P4 repositories can be added to an existing Git repository using
+'git p4 sync' too:
+------------
+$ mkdir repo-git
+$ cd repo-git
+$ git init
+$ git p4 sync //path/in/your/perforce/depot
+------------
+This imports the specified depot into
+'refs/remotes/p4/master' in an existing Git repository.  The
+`--branch` option can be used to specify a different branch to
+be used for the p4 content.
+
+If a Git repository includes branches 'refs/remotes/origin/p4', these
+will be fetched and consulted first during a 'git p4 sync'.  Since
+importing directly from p4 is considerably slower than pulling changes
+from a Git remote, this can be useful in a multi-developer environment.
+
+If there are multiple branches, doing 'git p4 sync' will automatically
+use the "BRANCH DETECTION" algorithm to try to partition new changes
+into the right branch.  This can be overridden with the `--branch`
+option to specify just a single branch to update.
+
+
+Rebase
+~~~~~~
+A common working pattern is to fetch the latest changes from the p4 depot
+and merge them with local uncommitted changes.  Often, the p4 repository
+is the ultimate location for all code, thus a rebase workflow makes
+sense.  This command does 'git p4 sync' followed by 'git rebase' to move
+local commits on top of updated p4 changes.
+------------
+$ git p4 rebase
+------------
+
+
+Submit
+~~~~~~
+Submitting changes from a Git repository back to the p4 repository
+requires a separate p4 client workspace.  This should be specified
+using the `P4CLIENT` environment variable or the Git configuration
+variable 'git-p4.client'.  The p4 client must exist, but the client root
+will be created and populated if it does not already exist.
+
+To submit all changes that are in the current Git branch but not in
+the 'p4/master' branch, use:
+------------
+$ git p4 submit
+------------
+
+To specify a branch other than the current one, use:
+------------
+$ git p4 submit topicbranch
+------------
+
+To specify a single commit or a range of commits, use:
+------------
+$ git p4 submit --commit <sha1>
+$ git p4 submit --commit <sha1..sha1>
+------------
+
+The upstream reference is generally 'refs/remotes/p4/master', but can
+be overridden using the `--origin=` command-line option.
+
+The p4 changes will be created as the user invoking 'git p4 submit'. The
+`--preserve-user` option will cause ownership to be modified
+according to the author of the Git commit.  This option requires admin
+privileges in p4, which can be granted using 'p4 protect'.
+
+To shelve changes instead of submitting, use `--shelve` and `--update-shelve`:
+
+----
+$ git p4 submit --shelve
+$ git p4 submit --update-shelve 1234 --update-shelve 2345
+----
+
+
+Unshelve
+~~~~~~~~
+Unshelving will take a shelved P4 changelist, and produce the equivalent git commit
+in the branch refs/remotes/p4-unshelved/<changelist>.
+
+The git commit is created relative to the current origin revision (HEAD by default).
+A parent commit is created based on the origin, and then the unshelve commit is
+created based on that.
+
+The origin revision can be changed with the "--origin" option.
+
+If the target branch in refs/remotes/p4-unshelved already exists, the old one will
+be renamed.
+
+----
+$ git p4 sync
+$ git p4 unshelve 12345
+$ git show p4-unshelved/12345
+<submit more changes via p4 to the same files>
+$ git p4 unshelve 12345
+<refuses to unshelve until git is in sync with p4 again>
+
+----
+
+OPTIONS
+-------
+
+General options
+~~~~~~~~~~~~~~~
+All commands except clone accept these options.
+
+--git-dir <dir>::
+	Set the `GIT_DIR` environment variable.  See linkgit:git[1].
+
+-v::
+--verbose::
+	Provide more progress information.
+
+Sync options
+~~~~~~~~~~~~
+These options can be used in the initial 'clone' as well as in
+subsequent 'sync' operations.
+
+--branch <ref>::
+	Import changes into <ref> instead of refs/remotes/p4/master.
+	If <ref> starts with refs/, it is used as is.  Otherwise, if
+	it does not start with p4/, that prefix is added.
++
+By default a <ref> not starting with refs/ is treated as the
+name of a remote-tracking branch (under refs/remotes/).  This
+behavior can be modified using the --import-local option.
++
+The default <ref> is "master".
++
+This example imports a new remote "p4/proj2" into an existing
+Git repository:
++
+----
+    $ git init
+    $ git p4 sync --branch=refs/remotes/p4/proj2 //depot/proj2
+----
+
+--detect-branches::
+	Use the branch detection algorithm to find new paths in p4.  It is
+	documented below in "BRANCH DETECTION".
+
+--changesfile <file>::
+	Import exactly the p4 change numbers listed in 'file', one per
+	line.  Normally, 'git p4' inspects the current p4 repository
+	state and detects the changes it should import.
+
+--silent::
+	Do not print any progress information.
+
+--detect-labels::
+	Query p4 for labels associated with the depot paths, and add
+	them as tags in Git. Limited usefulness as only imports labels
+	associated with new changelists. Deprecated.
+
+--import-labels::
+	Import labels from p4 into Git.
+
+--import-local::
+	By default, p4 branches are stored in 'refs/remotes/p4/',
+	where they will be treated as remote-tracking branches by
+	linkgit:git-branch[1] and other commands.  This option instead
+	puts p4 branches in 'refs/heads/p4/'.  Note that future
+	sync operations must specify `--import-local` as well so that
+	they can find the p4 branches in refs/heads.
+
+--max-changes <n>::
+	Import at most 'n' changes, rather than the entire range of
+	changes included in the given revision specifier. A typical
+	usage would be use '@all' as the revision specifier, but then
+	to use '--max-changes 1000' to import only the last 1000
+	revisions rather than the entire revision history.
+
+--changes-block-size <n>::
+	The internal block size to use when converting a revision
+	specifier such as '@all' into a list of specific change
+	numbers. Instead of using a single call to 'p4 changes' to
+	find the full list of changes for the conversion, there are a
+	sequence of calls to 'p4 changes -m', each of which requests
+	one block of changes of the given size. The default block size
+	is 500, which should usually be suitable.
+
+--keep-path::
+	The mapping of file names from the p4 depot path to Git, by
+	default, involves removing the entire depot path.  With this
+	option, the full p4 depot path is retained in Git.  For example,
+	path '//depot/main/foo/bar.c', when imported from
+	'//depot/main/', becomes 'foo/bar.c'.  With `--keep-path`, the
+	Git path is instead 'depot/main/foo/bar.c'.
+
+--use-client-spec::
+	Use a client spec to find the list of interesting files in p4.
+	See the "CLIENT SPEC" section below.
+
+-/ <path>::
+	Exclude selected depot paths when cloning or syncing.
+
+Clone options
+~~~~~~~~~~~~~
+These options can be used in an initial 'clone', along with the 'sync'
+options described above.
+
+--destination <directory>::
+	Where to create the Git repository.  If not provided, the last
+	component in the p4 depot path is used to create a new
+	directory.
+
+--bare::
+	Perform a bare clone.  See linkgit:git-clone[1].
+
+Submit options
+~~~~~~~~~~~~~~
+These options can be used to modify 'git p4 submit' behavior.
+
+--origin <commit>::
+	Upstream location from which commits are identified to submit to
+	p4.  By default, this is the most recent p4 commit reachable
+	from `HEAD`.
+
+-M::
+	Detect renames.  See linkgit:git-diff[1].  Renames will be
+	represented in p4 using explicit 'move' operations.  There
+	is no corresponding option to detect copies, but there are
+	variables for both moves and copies.
+
+--preserve-user::
+	Re-author p4 changes before submitting to p4.  This option
+	requires p4 admin privileges.
+
+--export-labels::
+	Export tags from Git as p4 labels. Tags found in Git are applied
+	to the perforce working directory.
+
+-n::
+--dry-run::
+	Show just what commits would be submitted to p4; do not change
+	state in Git or p4.
+
+--prepare-p4-only::
+	Apply a commit to the p4 workspace, opening, adding and deleting
+	files in p4 as for a normal submit operation.  Do not issue the
+	final "p4 submit", but instead print a message about how to
+	submit manually or revert.  This option always stops after the
+	first (oldest) commit.  Git tags are not exported to p4.
+
+--shelve::
+	Instead of submitting create a series of shelved changelists.
+	After creating each shelve, the relevant files are reverted/deleted.
+	If you have multiple commits pending multiple shelves will be created.
+
+--update-shelve CHANGELIST::
+	Update an existing shelved changelist with this commit. Implies
+	--shelve. Repeat for multiple shelved changelists.
+
+--conflict=(ask|skip|quit)::
+	Conflicts can occur when applying a commit to p4.  When this
+	happens, the default behavior ("ask") is to prompt whether to
+	skip this commit and continue, or quit.  This option can be used
+	to bypass the prompt, causing conflicting commits to be automatically
+	skipped, or to quit trying to apply commits, without prompting.
+
+--branch <branch>::
+	After submitting, sync this named branch instead of the default
+	p4/master.  See the "Sync options" section above for more
+	information.
+
+--commit <sha1>|<sha1..sha1>::
+    Submit only the specified commit or range of commits, instead of the full
+    list of changes that are in the current Git branch.
+
+--disable-rebase::
+    Disable the automatic rebase after all commits have been successfully
+    submitted. Can also be set with git-p4.disableRebase.
+
+--disable-p4sync::
+    Disable the automatic sync of p4/master from Perforce after commits have
+    been submitted. Implies --disable-rebase. Can also be set with
+    git-p4.disableP4Sync. Sync with origin/master still goes ahead if possible.
+
+Hook for submit
+~~~~~~~~~~~~~~~
+The `p4-pre-submit` hook is executed if it exists and is executable.
+The hook takes no parameters and nothing from standard input. Exiting with
+non-zero status from this script prevents `git-p4 submit` from launching.
+
+One usage scenario is to run unit tests in the hook.
+
+Rebase options
+~~~~~~~~~~~~~~
+These options can be used to modify 'git p4 rebase' behavior.
+
+--import-labels::
+	Import p4 labels.
+
+Unshelve options
+~~~~~~~~~~~~~~~~
+
+--origin::
+    Sets the git refspec against which the shelved P4 changelist is compared.
+    Defaults to p4/master.
+
+DEPOT PATH SYNTAX
+-----------------
+The p4 depot path argument to 'git p4 sync' and 'git p4 clone' can
+be one or more space-separated p4 depot paths, with an optional
+p4 revision specifier on the end:
+
+"//depot/my/project"::
+    Import one commit with all files in the '#head' change under that tree.
+
+"//depot/my/project@all"::
+    Import one commit for each change in the history of that depot path.
+
+"//depot/my/project@1,6"::
+    Import only changes 1 through 6.
+
+"//depot/proj1@all //depot/proj2@all"::
+    Import all changes from both named depot paths into a single
+    repository.  Only files below these directories are included.
+    There is not a subdirectory in Git for each "proj1" and "proj2".
+    You must use the `--destination` option when specifying more
+    than one depot path.  The revision specifier must be specified
+    identically on each depot path.  If there are files in the
+    depot paths with the same name, the path with the most recently
+    updated version of the file is the one that appears in Git.
+
+See 'p4 help revisions' for the full syntax of p4 revision specifiers.
+
+
+CLIENT SPEC
+-----------
+The p4 client specification is maintained with the 'p4 client' command
+and contains among other fields, a View that specifies how the depot
+is mapped into the client repository.  The 'clone' and 'sync' commands
+can consult the client spec when given the `--use-client-spec` option or
+when the useClientSpec variable is true.  After 'git p4 clone', the
+useClientSpec variable is automatically set in the repository
+configuration file.  This allows future 'git p4 submit' commands to
+work properly; the submit command looks only at the variable and does
+not have a command-line option.
+
+The full syntax for a p4 view is documented in 'p4 help views'.  'git p4'
+knows only a subset of the view syntax.  It understands multi-line
+mappings, overlays with '+', exclusions with '-' and double-quotes
+around whitespace.  Of the possible wildcards, 'git p4' only handles
+'...', and only when it is at the end of the path.  'git p4' will complain
+if it encounters an unhandled wildcard.
+
+Bugs in the implementation of overlap mappings exist.  If multiple depot
+paths map through overlays to the same location in the repository,
+'git p4' can choose the wrong one.  This is hard to solve without
+dedicating a client spec just for 'git p4'.
+
+The name of the client can be given to 'git p4' in multiple ways.  The
+variable 'git-p4.client' takes precedence if it exists.  Otherwise,
+normal p4 mechanisms of determining the client are used:  environment
+variable `P4CLIENT`, a file referenced by `P4CONFIG`, or the local host name.
+
+
+BRANCH DETECTION
+----------------
+P4 does not have the same concept of a branch as Git.  Instead,
+p4 organizes its content as a directory tree, where by convention
+different logical branches are in different locations in the tree.
+The 'p4 branch' command is used to maintain mappings between
+different areas in the tree, and indicate related content.  'git p4'
+can use these mappings to determine branch relationships.
+
+If you have a repository where all the branches of interest exist as
+subdirectories of a single depot path, you can use `--detect-branches`
+when cloning or syncing to have 'git p4' automatically find
+subdirectories in p4, and to generate these as branches in Git.
+
+For example, if the P4 repository structure is:
+----
+//depot/main/...
+//depot/branch1/...
+----
+
+And "p4 branch -o branch1" shows a View line that looks like:
+----
+//depot/main/... //depot/branch1/...
+----
+
+Then this 'git p4 clone' command:
+----
+git p4 clone --detect-branches //depot@all
+----
+produces a separate branch in 'refs/remotes/p4/' for //depot/main,
+called 'master', and one for //depot/branch1 called 'depot/branch1'.
+
+However, it is not necessary to create branches in p4 to be able to use
+them like branches.  Because it is difficult to infer branch
+relationships automatically, a Git configuration setting
+'git-p4.branchList' can be used to explicitly identify branch
+relationships.  It is a list of "source:destination" pairs, like a
+simple p4 branch specification, where the "source" and "destination" are
+the path elements in the p4 repository.  The example above relied on the
+presence of the p4 branch.  Without p4 branches, the same result will
+occur with:
+----
+git init depot
+cd depot
+git config git-p4.branchList main:branch1
+git p4 clone --detect-branches //depot@all .
+----
+
+
+PERFORMANCE
+-----------
+The fast-import mechanism used by 'git p4' creates one pack file for
+each invocation of 'git p4 sync'.  Normally, Git garbage compression
+(linkgit:git-gc[1]) automatically compresses these to fewer pack files,
+but explicit invocation of 'git repack -adf' may improve performance.
+
+
+CONFIGURATION VARIABLES
+-----------------------
+The following config settings can be used to modify 'git p4' behavior.
+They all are in the 'git-p4' section.
+
+General variables
+~~~~~~~~~~~~~~~~~
+git-p4.user::
+	User specified as an option to all p4 commands, with '-u <user>'.
+	The environment variable `P4USER` can be used instead.
+
+git-p4.password::
+	Password specified as an option to all p4 commands, with
+	'-P <password>'.
+	The environment variable `P4PASS` can be used instead.
+
+git-p4.port::
+	Port specified as an option to all p4 commands, with
+	'-p <port>'.
+	The environment variable `P4PORT` can be used instead.
+
+git-p4.host::
+	Host specified as an option to all p4 commands, with
+	'-h <host>'.
+	The environment variable `P4HOST` can be used instead.
+
+git-p4.client::
+	Client specified as an option to all p4 commands, with
+	'-c <client>', including the client spec.
+
+git-p4.retries::
+	Specifies the number of times to retry a p4 command (notably,
+	'p4 sync') if the network times out. The default value is 3.
+	Set the value to 0 to disable retries or if your p4 version
+	does not support retries (pre 2012.2).
+
+Clone and sync variables
+~~~~~~~~~~~~~~~~~~~~~~~~
+git-p4.syncFromOrigin::
+	Because importing commits from other Git repositories is much faster
+	than importing them from p4, a mechanism exists to find p4 changes
+	first in Git remotes.  If branches exist under 'refs/remote/origin/p4',
+	those will be fetched and used when syncing from p4.  This
+	variable can be set to 'false' to disable this behavior.
+
+git-p4.branchUser::
+	One phase in branch detection involves looking at p4 branches
+	to find new ones to import.  By default, all branches are
+	inspected.  This option limits the search to just those owned
+	by the single user named in the variable.
+
+git-p4.branchList::
+	List of branches to be imported when branch detection is
+	enabled.  Each entry should be a pair of branch names separated
+	by a colon (:).  This example declares that both branchA and
+	branchB were created from main:
++
+-------------
+git config       git-p4.branchList main:branchA
+git config --add git-p4.branchList main:branchB
+-------------
+
+git-p4.ignoredP4Labels::
+	List of p4 labels to ignore. This is built automatically as
+	unimportable labels are discovered.
+
+git-p4.importLabels::
+	Import p4 labels into git, as per --import-labels.
+
+git-p4.labelImportRegexp::
+	Only p4 labels matching this regular expression will be imported. The
+	default value is '[a-zA-Z0-9_\-.]+$'.
+
+git-p4.useClientSpec::
+	Specify that the p4 client spec should be used to identify p4
+	depot paths of interest.  This is equivalent to specifying the
+	option `--use-client-spec`.  See the "CLIENT SPEC" section above.
+	This variable is a boolean, not the name of a p4 client.
+
+git-p4.pathEncoding::
+	Perforce keeps the encoding of a path as given by the originating OS.
+	Git expects paths encoded as UTF-8. Use this config to tell git-p4
+	what encoding Perforce had used for the paths. This encoding is used
+	to transcode the paths to UTF-8. As an example, Perforce on Windows
+	often uses "cp1252" to encode path names.
+
+git-p4.largeFileSystem::
+	Specify the system that is used for large (binary) files. Please note
+	that large file systems do not support the 'git p4 submit' command.
+	Only Git LFS is implemented right now (see https://git-lfs.github.com/
+	for more information). Download and install the Git LFS command line
+	extension to use this option and configure it like this:
++
+-------------
+git config       git-p4.largeFileSystem GitLFS
+-------------
+
+git-p4.largeFileExtensions::
+	All files matching a file extension in the list will be processed
+	by the large file system. Do not prefix the extensions with '.'.
+
+git-p4.largeFileThreshold::
+	All files with an uncompressed size exceeding the threshold will be
+	processed by the large file system. By default the threshold is
+	defined in bytes. Add the suffix k, m, or g to change the unit.
+
+git-p4.largeFileCompressedThreshold::
+	All files with a compressed size exceeding the threshold will be
+	processed by the large file system. This option might slow down
+	your clone/sync process. By default the threshold is defined in
+	bytes. Add the suffix k, m, or g to change the unit.
+
+git-p4.largeFilePush::
+	Boolean variable which defines if large files are automatically
+	pushed to a server.
+
+git-p4.keepEmptyCommits::
+	A changelist that contains only excluded files will be imported
+	as an empty commit if this boolean option is set to true.
+
+git-p4.mapUser::
+	Map a P4 user to a name and email address in Git. Use a string
+	with the following format to create a mapping:
++
+-------------
+git config --add git-p4.mapUser "p4user = First Last <mail@address.com>"
+-------------
++
+A mapping will override any user information from P4. Mappings for
+multiple P4 user can be defined.
+
+Submit variables
+~~~~~~~~~~~~~~~~
+git-p4.detectRenames::
+	Detect renames.  See linkgit:git-diff[1].  This can be true,
+	false, or a score as expected by 'git diff -M'.
+
+git-p4.detectCopies::
+	Detect copies.  See linkgit:git-diff[1].  This can be true,
+	false, or a score as expected by 'git diff -C'.
+
+git-p4.detectCopiesHarder::
+	Detect copies harder.  See linkgit:git-diff[1].  A boolean.
+
+git-p4.preserveUser::
+	On submit, re-author changes to reflect the Git author,
+	regardless of who invokes 'git p4 submit'.
+
+git-p4.allowMissingP4Users::
+	When 'preserveUser' is true, 'git p4' normally dies if it
+	cannot find an author in the p4 user map.  This setting
+	submits the change regardless.
+
+git-p4.skipSubmitEdit::
+	The submit process invokes the editor before each p4 change
+	is submitted.  If this setting is true, though, the editing
+	step is skipped.
+
+git-p4.skipSubmitEditCheck::
+	After editing the p4 change message, 'git p4' makes sure that
+	the description really was changed by looking at the file
+	modification time.  This option disables that test.
+
+git-p4.allowSubmit::
+	By default, any branch can be used as the source for a 'git p4
+	submit' operation.  This configuration variable, if set, permits only
+	the named branches to be used as submit sources.  Branch names
+	must be the short names (no "refs/heads/"), and should be
+	separated by commas (","), with no spaces.
+
+git-p4.skipUserNameCheck::
+	If the user running 'git p4 submit' does not exist in the p4
+	user map, 'git p4' exits.  This option can be used to force
+	submission regardless.
+
+git-p4.attemptRCSCleanup::
+	If enabled, 'git p4 submit' will attempt to cleanup RCS keywords
+	($Header$, etc). These would otherwise cause merge conflicts and prevent
+	the submit going ahead. This option should be considered experimental at
+	present.
+
+git-p4.exportLabels::
+	Export Git tags to p4 labels, as per --export-labels.
+
+git-p4.labelExportRegexp::
+	Only p4 labels matching this regular expression will be exported. The
+	default value is '[a-zA-Z0-9_\-.]+$'.
+
+git-p4.conflict::
+	Specify submit behavior when a conflict with p4 is found, as per
+	--conflict.  The default behavior is 'ask'.
+
+git-p4.disableRebase::
+    Do not rebase the tree against p4/master following a submit.
+
+git-p4.disableP4Sync::
+    Do not sync p4/master with Perforce following a submit. Implies git-p4.disableRebase.
+
+IMPLEMENTATION DETAILS
+----------------------
+* Changesets from p4 are imported using Git fast-import.
+* Cloning or syncing does not require a p4 client; file contents are
+  collected using 'p4 print'.
+* Submitting requires a p4 client, which is not in the same location
+  as the Git repository.  Patches are applied, one at a time, to
+  this p4 client and submitted from there.
+* Each commit imported by 'git p4' has a line at the end of the log
+  message indicating the p4 depot location and change number.  This
+  line is used by later 'git p4 sync' operations to know which p4
+  changes are new.
diff --git a/third_party/git/Documentation/git-pack-objects.txt b/third_party/git/Documentation/git-pack-objects.txt
new file mode 100644
index 0000000000..fecdf2600c
--- /dev/null
+++ b/third_party/git/Documentation/git-pack-objects.txt
@@ -0,0 +1,406 @@
+git-pack-objects(1)
+===================
+
+NAME
+----
+git-pack-objects - Create a packed archive of objects
+
+
+SYNOPSIS
+--------
+[verse]
+'git pack-objects' [-q | --progress | --all-progress] [--all-progress-implied]
+	[--no-reuse-delta] [--delta-base-offset] [--non-empty]
+	[--local] [--incremental] [--window=<n>] [--depth=<n>]
+	[--revs [--unpacked | --all]] [--keep-pack=<pack-name>]
+	[--stdout [--filter=<filter-spec>] | base-name]
+	[--shallow] [--keep-true-parents] [--sparse] < object-list
+
+
+DESCRIPTION
+-----------
+Reads list of objects from the standard input, and writes either one or
+more packed archives with the specified base-name to disk, or a packed
+archive to the standard output.
+
+A packed archive is an efficient way to transfer a set of objects
+between two repositories as well as an access efficient archival
+format.  In a packed archive, an object is either stored as a
+compressed whole or as a difference from some other object.
+The latter is often called a delta.
+
+The packed archive format (.pack) is designed to be self-contained
+so that it can be unpacked without any further information. Therefore,
+each object that a delta depends upon must be present within the pack.
+
+A pack index file (.idx) is generated for fast, random access to the
+objects in the pack. Placing both the index file (.idx) and the packed
+archive (.pack) in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or
+any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)
+enables Git to read from the pack archive.
+
+The 'git unpack-objects' command can read the packed archive and
+expand the objects contained in the pack into "one-file
+one-object" format; this is typically done by the smart-pull
+commands when a pack is created on-the-fly for efficient network
+transport by their peers.
+
+
+OPTIONS
+-------
+base-name::
+	Write into pairs of files (.pack and .idx), using
+	<base-name> to determine the name of the created file.
+	When this option is used, the two files in a pair are written in
+	<base-name>-<SHA-1>.{pack,idx} files.  <SHA-1> is a hash
+	based on the pack content and is written to the standard
+	output of the command.
+
+--stdout::
+	Write the pack contents (what would have been written to
+	.pack file) out to the standard output.
+
+--revs::
+	Read the revision arguments from the standard input, instead of
+	individual object names.  The revision arguments are processed
+	the same way as 'git rev-list' with the `--objects` flag
+	uses its `commit` arguments to build the list of objects it
+	outputs.  The objects on the resulting list are packed.
+	Besides revisions, `--not` or `--shallow <SHA-1>` lines are
+	also accepted.
+
+--unpacked::
+	This implies `--revs`.  When processing the list of
+	revision arguments read from the standard input, limit
+	the objects packed to those that are not already packed.
+
+--all::
+	This implies `--revs`.  In addition to the list of
+	revision arguments read from the standard input, pretend
+	as if all refs under `refs/` are specified to be
+	included.
+
+--include-tag::
+	Include unasked-for annotated tags if the object they
+	reference was included in the resulting packfile.  This
+	can be useful to send new tags to native Git clients.
+
+--window=<n>::
+--depth=<n>::
+	These two options affect how the objects contained in
+	the pack are stored using delta compression.  The
+	objects are first internally sorted by type, size and
+	optionally names and compared against the other objects
+	within --window to see if using delta compression saves
+	space.  --depth limits the maximum delta depth; making
+	it too deep affects the performance on the unpacker
+	side, because delta data needs to be applied that many
+	times to get to the necessary object.
++
+The default value for --window is 10 and --depth is 50. The maximum
+depth is 4095.
+
+--window-memory=<n>::
+	This option provides an additional limit on top of `--window`;
+	the window size will dynamically scale down so as to not take
+	up more than '<n>' bytes in memory.  This is useful in
+	repositories with a mix of large and small objects to not run
+	out of memory with a large window, but still be able to take
+	advantage of the large window for the smaller objects.  The
+	size can be suffixed with "k", "m", or "g".
+	`--window-memory=0` makes memory usage unlimited.  The default
+	is taken from the `pack.windowMemory` configuration variable.
+
+--max-pack-size=<n>::
+	In unusual scenarios, you may not be able to create files
+	larger than a certain size on your filesystem, and this option
+	can be used to tell the command to split the output packfile
+	into multiple independent packfiles, each not larger than the
+	given size. The size can be suffixed with
+	"k", "m", or "g". The minimum size allowed is limited to 1 MiB.
+	This option
+	prevents the creation of a bitmap index.
+	The default is unlimited, unless the config variable
+	`pack.packSizeLimit` is set.
+
+--honor-pack-keep::
+	This flag causes an object already in a local pack that
+	has a .keep file to be ignored, even if it would have
+	otherwise been packed.
+
+--keep-pack=<pack-name>::
+	This flag causes an object already in the given pack to be
+	ignored, even if it would have otherwise been
+	packed. `<pack-name>` is the pack file name without
+	leading directory (e.g. `pack-123.pack`). The option could be
+	specified multiple times to keep multiple packs.
+
+--incremental::
+	This flag causes an object already in a pack to be ignored
+	even if it would have otherwise been packed.
+
+--local::
+	This flag causes an object that is borrowed from an alternate
+	object store to be ignored even if it would have otherwise been
+	packed.
+
+--non-empty::
+        Only create a packed archive if it would contain at
+        least one object.
+
+--progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless -q
+	is specified. This flag forces progress status even if
+	the standard error stream is not directed to a terminal.
+
+--all-progress::
+	When --stdout is specified then progress report is
+	displayed during the object count and compression phases
+	but inhibited during the write-out phase. The reason is
+	that in some cases the output stream is directly linked
+	to another command which may wish to display progress
+	status of its own as it processes incoming pack data.
+	This flag is like --progress except that it forces progress
+	report for the write-out phase as well even if --stdout is
+	used.
+
+--all-progress-implied::
+	This is used to imply --all-progress whenever progress display
+	is activated.  Unlike --all-progress this flag doesn't actually
+	force any progress display by itself.
+
+-q::
+	This flag makes the command not to report its progress
+	on the standard error stream.
+
+--no-reuse-delta::
+	When creating a packed archive in a repository that
+	has existing packs, the command reuses existing deltas.
+	This sometimes results in a slightly suboptimal pack.
+	This flag tells the command not to reuse existing deltas
+	but compute them from scratch.
+
+--no-reuse-object::
+	This flag tells the command not to reuse existing object data at all,
+	including non deltified object, forcing recompression of everything.
+	This implies --no-reuse-delta. Useful only in the obscure case where
+	wholesale enforcement of a different compression level on the
+	packed data is desired.
+
+--compression=<n>::
+	Specifies compression level for newly-compressed data in the
+	generated pack.  If not specified,  pack compression level is
+	determined first by pack.compression,  then by core.compression,
+	and defaults to -1,  the zlib default,  if neither is set.
+	Add --no-reuse-object if you want to force a uniform compression
+	level on all data no matter the source.
+
+--sparse::
+	Use the "sparse" algorithm to determine which objects to include in
+	the pack, when combined with the "--revs" option. This algorithm
+	only walks trees that appear in paths that introduce new objects.
+	This can have significant performance benefits when computing
+	a pack to send a small change. However, it is possible that extra
+	objects are added to the pack-file if the included commits contain
+	certain types of direct renames.
+
+--thin::
+	Create a "thin" pack by omitting the common objects between a
+	sender and a receiver in order to reduce network transfer. This
+	option only makes sense in conjunction with --stdout.
++
+Note: A thin pack violates the packed archive format by omitting
+required objects and is thus unusable by Git without making it
+self-contained. Use `git index-pack --fix-thin`
+(see linkgit:git-index-pack[1]) to restore the self-contained property.
+
+--shallow::
+	Optimize a pack that will be provided to a client with a shallow
+	repository.  This option, combined with --thin, can result in a
+	smaller pack at the cost of speed.
+
+--delta-base-offset::
+	A packed archive can express the base object of a delta as
+	either a 20-byte object name or as an offset in the
+	stream, but ancient versions of Git don't understand the
+	latter.  By default, 'git pack-objects' only uses the
+	former format for better compatibility.  This option
+	allows the command to use the latter format for
+	compactness.  Depending on the average delta chain
+	length, this option typically shrinks the resulting
+	packfile by 3-5 per-cent.
++
+Note: Porcelain commands such as `git gc` (see linkgit:git-gc[1]),
+`git repack` (see linkgit:git-repack[1]) pass this option by default
+in modern Git when they put objects in your repository into pack files.
+So does `git bundle` (see linkgit:git-bundle[1]) when it creates a bundle.
+
+--threads=<n>::
+	Specifies the number of threads to spawn when searching for best
+	delta matches.  This requires that pack-objects be compiled with
+	pthreads otherwise this option is ignored with a warning.
+	This is meant to reduce packing time on multiprocessor machines.
+	The required amount of memory for the delta search window is
+	however multiplied by the number of threads.
+	Specifying 0 will cause Git to auto-detect the number of CPU's
+	and set the number of threads accordingly.
+
+--index-version=<version>[,<offset>]::
+	This is intended to be used by the test suite only. It allows
+	to force the version for the generated pack index, and to force
+	64-bit index entries on objects located above the given offset.
+
+--keep-true-parents::
+	With this option, parents that are hidden by grafts are packed
+	nevertheless.
+
+--filter=<filter-spec>::
+	Requires `--stdout`.  Omits certain objects (usually blobs) from
+	the resulting packfile.  See linkgit:git-rev-list[1] for valid
+	`<filter-spec>` forms.
+
+--no-filter::
+	Turns off any previous `--filter=` argument.
+
+--missing=<missing-action>::
+	A debug option to help with future "partial clone" development.
+	This option specifies how missing objects are handled.
++
+The form '--missing=error' requests that pack-objects stop with an error if
+a missing object is encountered.  This is the default action.
++
+The form '--missing=allow-any' will allow object traversal to continue
+if a missing object is encountered.  Missing objects will silently be
+omitted from the results.
++
+The form '--missing=allow-promisor' is like 'allow-any', but will only
+allow object traversal to continue for EXPECTED promisor missing objects.
+Unexpected missing object will raise an error.
+
+--exclude-promisor-objects::
+	Omit objects that are known to be in the promisor remote.  (This
+	option has the purpose of operating only on locally created objects,
+	so that when we repack, we still maintain a distinction between
+	locally created objects [without .promisor] and objects from the
+	promisor remote [with .promisor].)  This is used with partial clone.
+
+--keep-unreachable::
+	Objects unreachable from the refs in packs named with
+	--unpacked= option are added to the resulting pack, in
+	addition to the reachable objects that are not in packs marked
+	with *.keep files. This implies `--revs`.
+
+--pack-loose-unreachable::
+	Pack unreachable loose objects (and their loose counterparts
+	removed). This implies `--revs`.
+
+--unpack-unreachable::
+	Keep unreachable objects in loose form. This implies `--revs`.
+
+--delta-islands::
+	Restrict delta matches based on "islands". See DELTA ISLANDS
+	below.
+
+
+DELTA ISLANDS
+-------------
+
+When possible, `pack-objects` tries to reuse existing on-disk deltas to
+avoid having to search for new ones on the fly. This is an important
+optimization for serving fetches, because it means the server can avoid
+inflating most objects at all and just send the bytes directly from
+disk. This optimization can't work when an object is stored as a delta
+against a base which the receiver does not have (and which we are not
+already sending). In that case the server "breaks" the delta and has to
+find a new one, which has a high CPU cost. Therefore it's important for
+performance that the set of objects in on-disk delta relationships match
+what a client would fetch.
+
+In a normal repository, this tends to work automatically. The objects
+are mostly reachable from the branches and tags, and that's what clients
+fetch. Any deltas we find on the server are likely to be between objects
+the client has or will have.
+
+But in some repository setups, you may have several related but separate
+groups of ref tips, with clients tending to fetch those groups
+independently. For example, imagine that you are hosting several "forks"
+of a repository in a single shared object store, and letting clients
+view them as separate repositories through `GIT_NAMESPACE` or separate
+repos using the alternates mechanism. A naive repack may find that the
+optimal delta for an object is against a base that is only found in
+another fork. But when a client fetches, they will not have the base
+object, and we'll have to find a new delta on the fly.
+
+A similar situation may exist if you have many refs outside of
+`refs/heads/` and `refs/tags/` that point to related objects (e.g.,
+`refs/pull` or `refs/changes` used by some hosting providers). By
+default, clients fetch only heads and tags, and deltas against objects
+found only in those other groups cannot be sent as-is.
+
+Delta islands solve this problem by allowing you to group your refs into
+distinct "islands". Pack-objects computes which objects are reachable
+from which islands, and refuses to make a delta from an object `A`
+against a base which is not present in all of `A`'s islands. This
+results in slightly larger packs (because we miss some delta
+opportunities), but guarantees that a fetch of one island will not have
+to recompute deltas on the fly due to crossing island boundaries.
+
+When repacking with delta islands the delta window tends to get
+clogged with candidates that are forbidden by the config. Repacking
+with a big --window helps (and doesn't take as long as it otherwise
+might because we can reject some object pairs based on islands before
+doing any computation on the content).
+
+Islands are configured via the `pack.island` option, which can be
+specified multiple times. Each value is a left-anchored regular
+expressions matching refnames. For example:
+
+-------------------------------------------
+[pack]
+island = refs/heads/
+island = refs/tags/
+-------------------------------------------
+
+puts heads and tags into an island (whose name is the empty string; see
+below for more on naming). Any refs which do not match those regular
+expressions (e.g., `refs/pull/123`) is not in any island. Any object
+which is reachable only from `refs/pull/` (but not heads or tags) is
+therefore not a candidate to be used as a base for `refs/heads/`.
+
+Refs are grouped into islands based on their "names", and two regexes
+that produce the same name are considered to be in the same
+island. The names are computed from the regexes by concatenating any
+capture groups from the regex, with a '-' dash in between. (And if
+there are no capture groups, then the name is the empty string, as in
+the above example.) This allows you to create arbitrary numbers of
+islands. Only up to 14 such capture groups are supported though.
+
+For example, imagine you store the refs for each fork in
+`refs/virtual/ID`, where `ID` is a numeric identifier. You might then
+configure:
+
+-------------------------------------------
+[pack]
+island = refs/virtual/([0-9]+)/heads/
+island = refs/virtual/([0-9]+)/tags/
+island = refs/virtual/([0-9]+)/(pull)/
+-------------------------------------------
+
+That puts the heads and tags for each fork in their own island (named
+"1234" or similar), and the pull refs for each go into their own
+"1234-pull".
+
+Note that we pick a single island for each regex to go into, using "last
+one wins" ordering (which allows repo-specific config to take precedence
+over user-wide config, and so forth).
+
+SEE ALSO
+--------
+linkgit:git-rev-list[1]
+linkgit:git-repack[1]
+linkgit:git-prune-packed[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-pack-redundant.txt b/third_party/git/Documentation/git-pack-redundant.txt
new file mode 100644
index 0000000000..f2869da572
--- /dev/null
+++ b/third_party/git/Documentation/git-pack-redundant.txt
@@ -0,0 +1,50 @@
+git-pack-redundant(1)
+=====================
+
+NAME
+----
+git-pack-redundant - Find redundant pack files
+
+
+SYNOPSIS
+--------
+[verse]
+'git pack-redundant' [ --verbose ] [ --alt-odb ] < --all | .pack filename ... >
+
+DESCRIPTION
+-----------
+This program computes which packs in your repository
+are redundant. The output is suitable for piping to
+`xargs rm` if you are in the root of the repository.
+
+'git pack-redundant' accepts a list of objects on standard input. Any objects
+given will be ignored when checking which packs are required. This makes the
+following command useful when wanting to remove packs which contain unreachable
+objects.
+
+git fsck --full --unreachable | cut -d ' ' -f3 | \
+git pack-redundant --all | xargs rm
+
+OPTIONS
+-------
+
+
+--all::
+	Processes all packs. Any filenames on the command line are ignored.
+
+--alt-odb::
+	Don't require objects present in packs from alternate object
+	directories to be present in local packs.
+
+--verbose::
+	Outputs some statistics to stderr. Has a small performance penalty.
+
+SEE ALSO
+--------
+linkgit:git-pack-objects[1]
+linkgit:git-repack[1]
+linkgit:git-prune-packed[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-pack-refs.txt b/third_party/git/Documentation/git-pack-refs.txt
new file mode 100644
index 0000000000..154081f2de
--- /dev/null
+++ b/third_party/git/Documentation/git-pack-refs.txt
@@ -0,0 +1,73 @@
+git-pack-refs(1)
+================
+
+NAME
+----
+git-pack-refs - Pack heads and tags for efficient repository access
+
+SYNOPSIS
+--------
+[verse]
+'git pack-refs' [--all] [--no-prune]
+
+DESCRIPTION
+-----------
+
+Traditionally, tips of branches and tags (collectively known as
+'refs') were stored one file per ref in a (sub)directory
+under `$GIT_DIR/refs`
+directory.  While many branch tips tend to be updated often,
+most tags and some branch tips are never updated.  When a
+repository has hundreds or thousands of tags, this
+one-file-per-ref format both wastes storage and hurts
+performance.
+
+This command is used to solve the storage and performance
+problem by storing the refs in a single file,
+`$GIT_DIR/packed-refs`.  When a ref is missing from the
+traditional `$GIT_DIR/refs` directory hierarchy, it is looked
+up in this
+file and used if found.
+
+Subsequent updates to branches always create new files under
+`$GIT_DIR/refs` directory hierarchy.
+
+A recommended practice to deal with a repository with too many
+refs is to pack its refs with `--all` once, and
+occasionally run `git pack-refs`.  Tags are by
+definition stationary and are not expected to change.  Branch
+heads will be packed with the initial `pack-refs --all`, but
+only the currently active branch heads will become unpacked,
+and the next `pack-refs` (without `--all`) will leave them
+unpacked.
+
+
+OPTIONS
+-------
+
+--all::
+
+The command by default packs all tags and refs that are already
+packed, and leaves other refs
+alone.  This is because branches are expected to be actively
+developed and packing their tips does not help performance.
+This option causes branch tips to be packed as well.  Useful for
+a repository with many branches of historical interests.
+
+--no-prune::
+
+The command usually removes loose refs under `$GIT_DIR/refs`
+hierarchy after packing them.  This option tells it not to.
+
+
+BUGS
+----
+
+Older documentation written before the packed-refs mechanism was
+introduced may still say things like ".git/refs/heads/<branch> file
+exists" when it means "branch <branch> exists".
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-parse-remote.txt b/third_party/git/Documentation/git-parse-remote.txt
new file mode 100644
index 0000000000..a45ea1ece8
--- /dev/null
+++ b/third_party/git/Documentation/git-parse-remote.txt
@@ -0,0 +1,23 @@
+git-parse-remote(1)
+===================
+
+NAME
+----
+git-parse-remote - Routines to help parsing remote repository access parameters
+
+
+SYNOPSIS
+--------
+[verse]
+'. "$(git --exec-path)/git-parse-remote"'
+
+DESCRIPTION
+-----------
+This script is included in various scripts to supply
+routines to parse files under $GIT_DIR/remotes/ and
+$GIT_DIR/branches/ and configuration variables that are related
+to fetching, pulling and pushing.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-patch-id.txt b/third_party/git/Documentation/git-patch-id.txt
new file mode 100644
index 0000000000..442caff8a9
--- /dev/null
+++ b/third_party/git/Documentation/git-patch-id.txt
@@ -0,0 +1,61 @@
+git-patch-id(1)
+===============
+
+NAME
+----
+git-patch-id - Compute unique ID for a patch
+
+SYNOPSIS
+--------
+[verse]
+'git patch-id' [--stable | --unstable]
+
+DESCRIPTION
+-----------
+Read a patch from the standard input and compute the patch ID for it.
+
+A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a
+patch, with whitespace and line numbers ignored.  As such, it's "reasonably
+stable", but at the same time also reasonably unique, i.e., two patches that
+have the same "patch ID" are almost guaranteed to be the same thing.
+
+IOW, you can use this thing to look for likely duplicate commits.
+
+When dealing with 'git diff-tree' output, it takes advantage of
+the fact that the patch is prefixed with the object name of the
+commit, and outputs two 40-byte hexadecimal strings.  The first
+string is the patch ID, and the second string is the commit ID.
+This can be used to make a mapping from patch ID to commit ID.
+
+OPTIONS
+-------
+
+--stable::
+	Use a "stable" sum of hashes as the patch ID. With this option:
+	 - Reordering file diffs that make up a patch does not affect the ID.
+	   In particular, two patches produced by comparing the same two trees
+	   with two different settings for "-O<orderfile>" result in the same
+	   patch ID signature, thereby allowing the computed result to be used
+	   as a key to index some meta-information about the change between
+	   the two trees;
+
+	 - Result is different from the value produced by git 1.9 and older
+	   or produced when an "unstable" hash (see --unstable below) is
+	   configured - even when used on a diff output taken without any use
+	   of "-O<orderfile>", thereby making existing databases storing such
+	   "unstable" or historical patch-ids unusable.
+
+	This is the default if patchid.stable is set to true.
+
+--unstable::
+	Use an "unstable" hash as the patch ID. With this option,
+	the result produced is compatible with the patch-id value produced
+	by git 1.9 and older.  Users with pre-existing databases storing
+	patch-ids produced by git 1.9 and older (who do not deal with reordered
+	patches) may want to use this option.
+
+	This is the default.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-prune-packed.txt b/third_party/git/Documentation/git-prune-packed.txt
new file mode 100644
index 0000000000..9fed59a317
--- /dev/null
+++ b/third_party/git/Documentation/git-prune-packed.txt
@@ -0,0 +1,47 @@
+git-prune-packed(1)
+===================
+
+NAME
+----
+git-prune-packed - Remove extra objects that are already in pack files
+
+
+SYNOPSIS
+--------
+[verse]
+'git prune-packed' [-n|--dry-run] [-q|--quiet]
+
+
+DESCRIPTION
+-----------
+This program searches the `$GIT_OBJECT_DIRECTORY` for all objects that currently
+exist in a pack file as well as the independent object directories.
+
+All such extra objects are removed.
+
+A pack is a collection of objects, individually compressed, with delta
+compression applied, stored in a single file, with an associated index file.
+
+Packs are used to reduce the load on mirror systems, backup engines,
+disk storage, etc.
+
+
+OPTIONS
+-------
+-n::
+--dry-run::
+        Don't actually remove any objects, only show those that would have been
+        removed.
+
+-q::
+--quiet::
+	Squelch the progress indicator.
+
+SEE ALSO
+--------
+linkgit:git-pack-objects[1]
+linkgit:git-repack[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-prune.txt b/third_party/git/Documentation/git-prune.txt
new file mode 100644
index 0000000000..03552dd86f
--- /dev/null
+++ b/third_party/git/Documentation/git-prune.txt
@@ -0,0 +1,89 @@
+git-prune(1)
+============
+
+NAME
+----
+git-prune - Prune all unreachable objects from the object database
+
+
+SYNOPSIS
+--------
+[verse]
+'git prune' [-n] [-v] [--progress] [--expire <time>] [--] [<head>...]
+
+DESCRIPTION
+-----------
+
+NOTE: In most cases, users should run 'git gc', which calls
+'git prune'. See the section "NOTES", below.
+
+This runs 'git fsck --unreachable' using all the refs
+available in `refs/`, optionally with additional set of
+objects specified on the command line, and prunes all unpacked
+objects unreachable from any of these head objects from the object database.
+In addition, it
+prunes the unpacked objects that are also found in packs by
+running 'git prune-packed'.
+It also removes entries from .git/shallow that are not reachable by
+any ref.
+
+Note that unreachable, packed objects will remain.  If this is
+not desired, see linkgit:git-repack[1].
+
+OPTIONS
+-------
+
+-n::
+--dry-run::
+	Do not remove anything; just report what it would
+	remove.
+
+-v::
+--verbose::
+	Report all removed objects.
+
+--progress::
+	Show progress.
+
+--expire <time>::
+	Only expire loose objects older than <time>.
+
+\--::
+	Do not interpret any more arguments as options.
+
+<head>...::
+	In addition to objects
+	reachable from any of our references, keep objects
+	reachable from listed <head>s.
+
+EXAMPLES
+--------
+
+To prune objects not used by your repository or another that
+borrows from your repository via its
+`.git/objects/info/alternates`:
+
+------------
+$ git prune $(cd ../another && git rev-parse --all)
+------------
+
+NOTES
+-----
+
+In most cases, users will not need to call 'git prune' directly, but
+should instead call 'git gc', which handles pruning along with
+many other housekeeping tasks.
+
+For a description of which objects are considered for pruning, see
+'git fsck''s --unreachable option.
+
+SEE ALSO
+--------
+
+linkgit:git-fsck[1],
+linkgit:git-gc[1],
+linkgit:git-reflog[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-pull.txt b/third_party/git/Documentation/git-pull.txt
new file mode 100644
index 0000000000..dfb901f8b8
--- /dev/null
+++ b/third_party/git/Documentation/git-pull.txt
@@ -0,0 +1,263 @@
+git-pull(1)
+===========
+
+NAME
+----
+git-pull - Fetch from and integrate with another repository or a local branch
+
+
+SYNOPSIS
+--------
+[verse]
+'git pull' [<options>] [<repository> [<refspec>...]]
+
+
+DESCRIPTION
+-----------
+
+Incorporates changes from a remote repository into the current
+branch.  In its default mode, `git pull` is shorthand for
+`git fetch` followed by `git merge FETCH_HEAD`.
+
+More precisely, 'git pull' runs 'git fetch' with the given
+parameters and calls 'git merge' to merge the retrieved branch
+heads into the current branch.
+With `--rebase`, it runs 'git rebase' instead of 'git merge'.
+
+<repository> should be the name of a remote repository as
+passed to linkgit:git-fetch[1].  <refspec> can name an
+arbitrary remote ref (for example, the name of a tag) or even
+a collection of refs with corresponding remote-tracking branches
+(e.g., refs/heads/{asterisk}:refs/remotes/origin/{asterisk}),
+but usually it is the name of a branch in the remote repository.
+
+Default values for <repository> and <branch> are read from the
+"remote" and "merge" configuration for the current branch
+as set by linkgit:git-branch[1] `--track`.
+
+Assume the following history exists and the current branch is
+"`master`":
+
+------------
+	  A---B---C master on origin
+	 /
+    D---E---F---G master
+	^
+	origin/master in your repository
+------------
+
+Then "`git pull`" will fetch and replay the changes from the remote
+`master` branch since it diverged from the local `master` (i.e., `E`)
+until its current commit (`C`) on top of `master` and record the
+result in a new commit along with the names of the two parent commits
+and a log message from the user describing the changes.
+
+------------
+	  A---B---C origin/master
+	 /         \
+    D---E---F---G---H master
+------------
+
+See linkgit:git-merge[1] for details, including how conflicts
+are presented and handled.
+
+In Git 1.7.0 or later, to cancel a conflicting merge, use
+`git reset --merge`.  *Warning*: In older versions of Git, running 'git pull'
+with uncommitted changes is discouraged: while possible, it leaves you
+in a state that may be hard to back out of in the case of a conflict.
+
+If any of the remote changes overlap with local uncommitted changes,
+the merge will be automatically canceled and the work tree untouched.
+It is generally best to get any local changes in working order before
+pulling or stash them away with linkgit:git-stash[1].
+
+OPTIONS
+-------
+
+-q::
+--quiet::
+	This is passed to both underlying git-fetch to squelch reporting of
+	during transfer, and underlying git-merge to squelch output during
+	merging.
+
+-v::
+--verbose::
+	Pass --verbose to git-fetch and git-merge.
+
+--[no-]recurse-submodules[=yes|on-demand|no]::
+	This option controls if new commits of all populated submodules should
+	be fetched and updated, too (see linkgit:git-config[1] and
+	linkgit:gitmodules[5]).
++
+If the checkout is done via rebase, local submodule commits are rebased as well.
++
+If the update is done via merge, the submodule conflicts are resolved and checked out.
+
+Options related to merging
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+:git-pull: 1
+
+include::merge-options.txt[]
+
+-r::
+--rebase[=false|true|merges|preserve|interactive]::
+	When true, rebase the current branch on top of the upstream
+	branch after fetching. If there is a remote-tracking branch
+	corresponding to the upstream branch and the upstream branch
+	was rebased since last fetched, the rebase uses that information
+	to avoid rebasing non-local changes.
++
+When set to `merges`, rebase using `git rebase --rebase-merges` so that
+the local merge commits are included in the rebase (see
+linkgit:git-rebase[1] for details).
++
+When set to `preserve` (deprecated in favor of `merges`), rebase with the
+`--preserve-merges` option passed to `git rebase` so that locally created
+merge commits will not be flattened.
++
+When false, merge the current branch into the upstream branch.
++
+When `interactive`, enable the interactive mode of rebase.
++
+See `pull.rebase`, `branch.<name>.rebase` and `branch.autoSetupRebase` in
+linkgit:git-config[1] if you want to make `git pull` always use
+`--rebase` instead of merging.
++
+[NOTE]
+This is a potentially _dangerous_ mode of operation.
+It rewrites history, which does not bode well when you
+published that history already.  Do *not* use this option
+unless you have read linkgit:git-rebase[1] carefully.
+
+--no-rebase::
+	Override earlier --rebase.
+
+--autostash::
+--no-autostash::
+	Before starting rebase, stash local modifications away (see
+	linkgit:git-stash[1]) if needed, and apply the stash entry when
+	done. `--no-autostash` is useful to override the `rebase.autoStash`
+	configuration variable (see linkgit:git-config[1]).
++
+This option is only valid when "--rebase" is used.
+
+Options related to fetching
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+include::fetch-options.txt[]
+
+include::pull-fetch-param.txt[]
+
+include::urls-remotes.txt[]
+
+include::merge-strategies.txt[]
+
+DEFAULT BEHAVIOUR
+-----------------
+
+Often people use `git pull` without giving any parameter.
+Traditionally, this has been equivalent to saying `git pull
+origin`.  However, when configuration `branch.<name>.remote` is
+present while on branch `<name>`, that value is used instead of
+`origin`.
+
+In order to determine what URL to use to fetch from, the value
+of the configuration `remote.<origin>.url` is consulted
+and if there is not any such variable, the value on the `URL:` line
+in `$GIT_DIR/remotes/<origin>` is used.
+
+In order to determine what remote branches to fetch (and
+optionally store in the remote-tracking branches) when the command is
+run without any refspec parameters on the command line, values
+of the configuration variable `remote.<origin>.fetch` are
+consulted, and if there aren't any, `$GIT_DIR/remotes/<origin>`
+is consulted and its `Pull:` lines are used.
+In addition to the refspec formats described in the OPTIONS
+section, you can have a globbing refspec that looks like this:
+
+------------
+refs/heads/*:refs/remotes/origin/*
+------------
+
+A globbing refspec must have a non-empty RHS (i.e. must store
+what were fetched in remote-tracking branches), and its LHS and RHS
+must end with `/*`.  The above specifies that all remote
+branches are tracked using remote-tracking branches in
+`refs/remotes/origin/` hierarchy under the same name.
+
+The rule to determine which remote branch to merge after
+fetching is a bit involved, in order not to break backward
+compatibility.
+
+If explicit refspecs were given on the command
+line of `git pull`, they are all merged.
+
+When no refspec was given on the command line, then `git pull`
+uses the refspec from the configuration or
+`$GIT_DIR/remotes/<origin>`.  In such cases, the following
+rules apply:
+
+. If `branch.<name>.merge` configuration for the current
+  branch `<name>` exists, that is the name of the branch at the
+  remote site that is merged.
+
+. If the refspec is a globbing one, nothing is merged.
+
+. Otherwise the remote branch of the first refspec is merged.
+
+
+EXAMPLES
+--------
+
+* Update the remote-tracking branches for the repository
+  you cloned from, then merge one of them into your
+  current branch:
++
+------------------------------------------------
+$ git pull
+$ git pull origin
+------------------------------------------------
++
+Normally the branch merged in is the HEAD of the remote repository,
+but the choice is determined by the branch.<name>.remote and
+branch.<name>.merge options; see linkgit:git-config[1] for details.
+
+* Merge into the current branch the remote branch `next`:
++
+------------------------------------------------
+$ git pull origin next
+------------------------------------------------
++
+This leaves a copy of `next` temporarily in FETCH_HEAD, but
+does not update any remote-tracking branches. Using remote-tracking
+branches, the same can be done by invoking fetch and merge:
++
+------------------------------------------------
+$ git fetch origin
+$ git merge origin/next
+------------------------------------------------
+
+
+If you tried a pull which resulted in complex conflicts and
+would want to start over, you can recover with 'git reset'.
+
+
+include::transfer-data-leaks.txt[]
+
+BUGS
+----
+Using --recurse-submodules can only fetch new commits in already checked
+out submodules right now. When e.g. upstream added a new submodule in the
+just fetched commits of the superproject the submodule itself cannot be
+fetched, making it impossible to check out that submodule later without
+having to do a fetch again. This is expected to be fixed in a future Git
+version.
+
+SEE ALSO
+--------
+linkgit:git-fetch[1], linkgit:git-merge[1], linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-push.txt b/third_party/git/Documentation/git-push.txt
new file mode 100644
index 0000000000..3b8053447e
--- /dev/null
+++ b/third_party/git/Documentation/git-push.txt
@@ -0,0 +1,673 @@
+git-push(1)
+===========
+
+NAME
+----
+git-push - Update remote refs along with associated objects
+
+
+SYNOPSIS
+--------
+[verse]
+'git push' [--all | --mirror | --tags] [--follow-tags] [--atomic] [-n | --dry-run] [--receive-pack=<git-receive-pack>]
+	   [--repo=<repository>] [-f | --force] [-d | --delete] [--prune] [-v | --verbose]
+	   [-u | --set-upstream] [-o <string> | --push-option=<string>]
+	   [--[no-]signed|--signed=(true|false|if-asked)]
+	   [--force-with-lease[=<refname>[:<expect>]]]
+	   [--no-verify] [<repository> [<refspec>...]]
+
+DESCRIPTION
+-----------
+
+Updates remote refs using local refs, while sending objects
+necessary to complete the given refs.
+
+You can make interesting things happen to a repository
+every time you push into it, by setting up 'hooks' there.  See
+documentation for linkgit:git-receive-pack[1].
+
+When the command line does not specify where to push with the
+`<repository>` argument, `branch.*.remote` configuration for the
+current branch is consulted to determine where to push.  If the
+configuration is missing, it defaults to 'origin'.
+
+When the command line does not specify what to push with `<refspec>...`
+arguments or `--all`, `--mirror`, `--tags` options, the command finds
+the default `<refspec>` by consulting `remote.*.push` configuration,
+and if it is not found, honors `push.default` configuration to decide
+what to push (See linkgit:git-config[1] for the meaning of `push.default`).
+
+When neither the command-line nor the configuration specify what to
+push, the default behavior is used, which corresponds to the `simple`
+value for `push.default`: the current branch is pushed to the
+corresponding upstream branch, but as a safety measure, the push is
+aborted if the upstream branch does not have the same name as the
+local one.
+
+
+OPTIONS[[OPTIONS]]
+------------------
+<repository>::
+	The "remote" repository that is destination of a push
+	operation.  This parameter can be either a URL
+	(see the section <<URLS,GIT URLS>> below) or the name
+	of a remote (see the section <<REMOTES,REMOTES>> below).
+
+<refspec>...::
+	Specify what destination ref to update with what source object.
+	The format of a <refspec> parameter is an optional plus
+	`+`, followed by the source object <src>, followed
+	by a colon `:`, followed by the destination ref <dst>.
++
+The <src> is often the name of the branch you would want to push, but
+it can be any arbitrary "SHA-1 expression", such as `master~4` or
+`HEAD` (see linkgit:gitrevisions[7]).
++
+The <dst> tells which ref on the remote side is updated with this
+push. Arbitrary expressions cannot be used here, an actual ref must
+be named.
+If `git push [<repository>]` without any `<refspec>` argument is set to
+update some ref at the destination with `<src>` with
+`remote.<repository>.push` configuration variable, `:<dst>` part can
+be omitted--such a push will update a ref that `<src>` normally updates
+without any `<refspec>` on the command line.  Otherwise, missing
+`:<dst>` means to update the same ref as the `<src>`.
++
+If <dst> doesn't start with `refs/` (e.g. `refs/heads/master`) we will
+try to infer where in `refs/*` on the destination <repository> it
+belongs based on the type of <src> being pushed and whether <dst>
+is ambiguous.
++
+--
+* If <dst> unambiguously refers to a ref on the <repository> remote,
+  then push to that ref.
+
+* If <src> resolves to a ref starting with refs/heads/ or refs/tags/,
+  then prepend that to <dst>.
+
+* Other ambiguity resolutions might be added in the future, but for
+  now any other cases will error out with an error indicating what we
+  tried, and depending on the `advice.pushUnqualifiedRefname`
+  configuration (see linkgit:git-config[1]) suggest what refs/
+  namespace you may have wanted to push to.
+
+--
++
+The object referenced by <src> is used to update the <dst> reference
+on the remote side. Whether this is allowed depends on where in
+`refs/*` the <dst> reference lives as described in detail below, in
+those sections "update" means any modifications except deletes, which
+as noted after the next few sections are treated differently.
++
+The `refs/heads/*` namespace will only accept commit objects, and
+updates only if they can be fast-forwarded.
++
+The `refs/tags/*` namespace will accept any kind of object (as
+commits, trees and blobs can be tagged), and any updates to them will
+be rejected.
++
+It's possible to push any type of object to any namespace outside of
+`refs/{tags,heads}/*`. In the case of tags and commits, these will be
+treated as if they were the commits inside `refs/heads/*` for the
+purposes of whether the update is allowed.
++
+I.e. a fast-forward of commits and tags outside `refs/{tags,heads}/*`
+is allowed, even in cases where what's being fast-forwarded is not a
+commit, but a tag object which happens to point to a new commit which
+is a fast-forward of the commit the last tag (or commit) it's
+replacing. Replacing a tag with an entirely different tag is also
+allowed, if it points to the same commit, as well as pushing a peeled
+tag, i.e. pushing the commit that existing tag object points to, or a
+new tag object which an existing commit points to.
++
+Tree and blob objects outside of `refs/{tags,heads}/*` will be treated
+the same way as if they were inside `refs/tags/*`, any update of them
+will be rejected.
++
+All of the rules described above about what's not allowed as an update
+can be overridden by adding an the optional leading `+` to a refspec
+(or using `--force` command line option). The only exception to this
+is that no amount of forcing will make the `refs/heads/*` namespace
+accept a non-commit object. Hooks and configuration can also override
+or amend these rules, see e.g. `receive.denyNonFastForwards` in
+linkgit:git-config[1] and `pre-receive` and `update` in
+linkgit:githooks[5].
++
+Pushing an empty <src> allows you to delete the <dst> ref from the
+remote repository. Deletions are always accepted without a leading `+`
+in the refspec (or `--force`), except when forbidden by configuration
+or hooks. See `receive.denyDeletes` in linkgit:git-config[1] and
+`pre-receive` and `update` in linkgit:githooks[5].
++
+The special refspec `:` (or `+:` to allow non-fast-forward updates)
+directs Git to push "matching" branches: for every branch that exists on
+the local side, the remote side is updated if a branch of the same name
+already exists on the remote side.
++
+`tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`.
+
+--all::
+	Push all branches (i.e. refs under `refs/heads/`); cannot be
+	used with other <refspec>.
+
+--prune::
+	Remove remote branches that don't have a local counterpart. For example
+	a remote branch `tmp` will be removed if a local branch with the same
+	name doesn't exist any more. This also respects refspecs, e.g.
+	`git push --prune remote refs/heads/*:refs/tmp/*` would
+	make sure that remote `refs/tmp/foo` will be removed if `refs/heads/foo`
+	doesn't exist.
+
+--mirror::
+	Instead of naming each ref to push, specifies that all
+	refs under `refs/` (which includes but is not
+	limited to `refs/heads/`, `refs/remotes/`, and `refs/tags/`)
+	be mirrored to the remote repository.  Newly created local
+	refs will be pushed to the remote end, locally updated refs
+	will be force updated on the remote end, and deleted refs
+	will be removed from the remote end.  This is the default
+	if the configuration option `remote.<remote>.mirror` is
+	set.
+
+-n::
+--dry-run::
+	Do everything except actually send the updates.
+
+--porcelain::
+	Produce machine-readable output.  The output status line for each ref
+	will be tab-separated and sent to stdout instead of stderr.  The full
+	symbolic names of the refs will be given.
+
+-d::
+--delete::
+	All listed refs are deleted from the remote repository. This is
+	the same as prefixing all refs with a colon.
+
+--tags::
+	All refs under `refs/tags` are pushed, in
+	addition to refspecs explicitly listed on the command
+	line.
+
+--follow-tags::
+	Push all the refs that would be pushed without this option,
+	and also push annotated tags in `refs/tags` that are missing
+	from the remote but are pointing at commit-ish that are
+	reachable from the refs being pushed.  This can also be specified
+	with configuration variable `push.followTags`.  For more
+	information, see `push.followTags` in linkgit:git-config[1].
+
+--[no-]signed::
+--signed=(true|false|if-asked)::
+	GPG-sign the push request to update refs on the receiving
+	side, to allow it to be checked by the hooks and/or be
+	logged.  If `false` or `--no-signed`, no signing will be
+	attempted.  If `true` or `--signed`, the push will fail if the
+	server does not support signed pushes.  If set to `if-asked`,
+	sign if and only if the server supports signed pushes.  The push
+	will also fail if the actual call to `gpg --sign` fails.  See
+	linkgit:git-receive-pack[1] for the details on the receiving end.
+
+--[no-]atomic::
+	Use an atomic transaction on the remote side if available.
+	Either all refs are updated, or on error, no refs are updated.
+	If the server does not support atomic pushes the push will fail.
+
+-o <option>::
+--push-option=<option>::
+	Transmit the given string to the server, which passes them to
+	the pre-receive as well as the post-receive hook. The given string
+	must not contain a NUL or LF character.
+	When multiple `--push-option=<option>` are given, they are
+	all sent to the other side in the order listed on the
+	command line.
+	When no `--push-option=<option>` is given from the command
+	line, the values of configuration variable `push.pushOption`
+	are used instead.
+
+--receive-pack=<git-receive-pack>::
+--exec=<git-receive-pack>::
+	Path to the 'git-receive-pack' program on the remote
+	end.  Sometimes useful when pushing to a remote
+	repository over ssh, and you do not have the program in
+	a directory on the default $PATH.
+
+--[no-]force-with-lease::
+--force-with-lease=<refname>::
+--force-with-lease=<refname>:<expect>::
+	Usually, "git push" refuses to update a remote ref that is
+	not an ancestor of the local ref used to overwrite it.
++
+This option overrides this restriction if the current value of the
+remote ref is the expected value.  "git push" fails otherwise.
++
+Imagine that you have to rebase what you have already published.
+You will have to bypass the "must fast-forward" rule in order to
+replace the history you originally published with the rebased history.
+If somebody else built on top of your original history while you are
+rebasing, the tip of the branch at the remote may advance with her
+commit, and blindly pushing with `--force` will lose her work.
++
+This option allows you to say that you expect the history you are
+updating is what you rebased and want to replace. If the remote ref
+still points at the commit you specified, you can be sure that no
+other people did anything to the ref. It is like taking a "lease" on
+the ref without explicitly locking it, and the remote ref is updated
+only if the "lease" is still valid.
++
+`--force-with-lease` alone, without specifying the details, will protect
+all remote refs that are going to be updated by requiring their
+current value to be the same as the remote-tracking branch we have
+for them.
++
+`--force-with-lease=<refname>`, without specifying the expected value, will
+protect the named ref (alone), if it is going to be updated, by
+requiring its current value to be the same as the remote-tracking
+branch we have for it.
++
+`--force-with-lease=<refname>:<expect>` will protect the named ref (alone),
+if it is going to be updated, by requiring its current value to be
+the same as the specified value `<expect>` (which is allowed to be
+different from the remote-tracking branch we have for the refname,
+or we do not even have to have such a remote-tracking branch when
+this form is used).  If `<expect>` is the empty string, then the named ref
+must not already exist.
++
+Note that all forms other than `--force-with-lease=<refname>:<expect>`
+that specifies the expected current value of the ref explicitly are
+still experimental and their semantics may change as we gain experience
+with this feature.
++
+"--no-force-with-lease" will cancel all the previous --force-with-lease on the
+command line.
++
+A general note on safety: supplying this option without an expected
+value, i.e. as `--force-with-lease` or `--force-with-lease=<refname>`
+interacts very badly with anything that implicitly runs `git fetch` on
+the remote to be pushed to in the background, e.g. `git fetch origin`
+on your repository in a cronjob.
++
+The protection it offers over `--force` is ensuring that subsequent
+changes your work wasn't based on aren't clobbered, but this is
+trivially defeated if some background process is updating refs in the
+background. We don't have anything except the remote tracking info to
+go by as a heuristic for refs you're expected to have seen & are
+willing to clobber.
++
+If your editor or some other system is running `git fetch` in the
+background for you a way to mitigate this is to simply set up another
+remote:
++
+	git remote add origin-push $(git config remote.origin.url)
+	git fetch origin-push
++
+Now when the background process runs `git fetch origin` the references
+on `origin-push` won't be updated, and thus commands like:
++
+	git push --force-with-lease origin-push
++
+Will fail unless you manually run `git fetch origin-push`. This method
+is of course entirely defeated by something that runs `git fetch
+--all`, in that case you'd need to either disable it or do something
+more tedious like:
++
+	git fetch              # update 'master' from remote
+	git tag base master    # mark our base point
+	git rebase -i master   # rewrite some commits
+	git push --force-with-lease=master:base master:master
++
+I.e. create a `base` tag for versions of the upstream code that you've
+seen and are willing to overwrite, then rewrite history, and finally
+force push changes to `master` if the remote version is still at
+`base`, regardless of what your local `remotes/origin/master` has been
+updated to in the background.
+
+-f::
+--force::
+	Usually, the command refuses to update a remote ref that is
+	not an ancestor of the local ref used to overwrite it.
+	Also, when `--force-with-lease` option is used, the command refuses
+	to update a remote ref whose current value does not match
+	what is expected.
++
+This flag disables these checks, and can cause the remote repository
+to lose commits; use it with care.
++
+Note that `--force` applies to all the refs that are pushed, hence
+using it with `push.default` set to `matching` or with multiple push
+destinations configured with `remote.*.push` may overwrite refs
+other than the current branch (including local refs that are
+strictly behind their remote counterpart).  To force a push to only
+one branch, use a `+` in front of the refspec to push (e.g `git push
+origin +master` to force a push to the `master` branch). See the
+`<refspec>...` section above for details.
+
+--repo=<repository>::
+	This option is equivalent to the <repository> argument. If both
+	are specified, the command-line argument takes precedence.
+
+-u::
+--set-upstream::
+	For every branch that is up to date or successfully pushed, add
+	upstream (tracking) reference, used by argument-less
+	linkgit:git-pull[1] and other commands. For more information,
+	see `branch.<name>.merge` in linkgit:git-config[1].
+
+--[no-]thin::
+	These options are passed to linkgit:git-send-pack[1]. A thin transfer
+	significantly reduces the amount of sent data when the sender and
+	receiver share many of the same objects in common. The default is
+	`--thin`.
+
+-q::
+--quiet::
+	Suppress all output, including the listing of updated refs,
+	unless an error occurs. Progress is not reported to the standard
+	error stream.
+
+-v::
+--verbose::
+	Run verbosely.
+
+--progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless -q
+	is specified. This flag forces progress status even if the
+	standard error stream is not directed to a terminal.
+
+--no-recurse-submodules::
+--recurse-submodules=check|on-demand|only|no::
+	May be used to make sure all submodule commits used by the
+	revisions to be pushed are available on a remote-tracking branch.
+	If 'check' is used Git will verify that all submodule commits that
+	changed in the revisions to be pushed are available on at least one
+	remote of the submodule. If any commits are missing the push will
+	be aborted and exit with non-zero status. If 'on-demand' is used
+	all submodules that changed in the revisions to be pushed will be
+	pushed. If on-demand was not able to push all necessary revisions it will
+	also be aborted and exit with non-zero status. If 'only' is used all
+	submodules will be recursively pushed while the superproject is left
+	unpushed. A value of 'no' or using `--no-recurse-submodules` can be used
+	to override the push.recurseSubmodules configuration variable when no
+	submodule recursion is required.
+
+--[no-]verify::
+	Toggle the pre-push hook (see linkgit:githooks[5]).  The
+	default is --verify, giving the hook a chance to prevent the
+	push.  With --no-verify, the hook is bypassed completely.
+
+-4::
+--ipv4::
+	Use IPv4 addresses only, ignoring IPv6 addresses.
+
+-6::
+--ipv6::
+	Use IPv6 addresses only, ignoring IPv4 addresses.
+
+include::urls-remotes.txt[]
+
+OUTPUT
+------
+
+The output of "git push" depends on the transport method used; this
+section describes the output when pushing over the Git protocol (either
+locally or via ssh).
+
+The status of the push is output in tabular form, with each line
+representing the status of a single ref. Each line is of the form:
+
+-------------------------------
+ <flag> <summary> <from> -> <to> (<reason>)
+-------------------------------
+
+If --porcelain is used, then each line of the output is of the form:
+
+-------------------------------
+ <flag> \t <from>:<to> \t <summary> (<reason>)
+-------------------------------
+
+The status of up-to-date refs is shown only if --porcelain or --verbose
+option is used.
+
+flag::
+	A single character indicating the status of the ref:
+(space);; for a successfully pushed fast-forward;
+`+`;; for a successful forced update;
+`-`;; for a successfully deleted ref;
+`*`;; for a successfully pushed new ref;
+`!`;; for a ref that was rejected or failed to push; and
+`=`;; for a ref that was up to date and did not need pushing.
+
+summary::
+	For a successfully pushed ref, the summary shows the old and new
+	values of the ref in a form suitable for using as an argument to
+	`git log` (this is `<old>..<new>` in most cases, and
+	`<old>...<new>` for forced non-fast-forward updates).
++
+For a failed update, more details are given:
++
+--
+rejected::
+	Git did not try to send the ref at all, typically because it
+	is not a fast-forward and you did not force the update.
+
+remote rejected::
+	The remote end refused the update.  Usually caused by a hook
+	on the remote side, or because the remote repository has one
+	of the following safety options in effect:
+	`receive.denyCurrentBranch` (for pushes to the checked out
+	branch), `receive.denyNonFastForwards` (for forced
+	non-fast-forward updates), `receive.denyDeletes` or
+	`receive.denyDeleteCurrent`.  See linkgit:git-config[1].
+
+remote failure::
+	The remote end did not report the successful update of the ref,
+	perhaps because of a temporary error on the remote side, a
+	break in the network connection, or other transient error.
+--
+
+from::
+	The name of the local ref being pushed, minus its
+	`refs/<type>/` prefix. In the case of deletion, the
+	name of the local ref is omitted.
+
+to::
+	The name of the remote ref being updated, minus its
+	`refs/<type>/` prefix.
+
+reason::
+	A human-readable explanation. In the case of successfully pushed
+	refs, no explanation is needed. For a failed ref, the reason for
+	failure is described.
+
+NOTE ABOUT FAST-FORWARDS
+------------------------
+
+When an update changes a branch (or more in general, a ref) that used to
+point at commit A to point at another commit B, it is called a
+fast-forward update if and only if B is a descendant of A.
+
+In a fast-forward update from A to B, the set of commits that the original
+commit A built on top of is a subset of the commits the new commit B
+builds on top of.  Hence, it does not lose any history.
+
+In contrast, a non-fast-forward update will lose history.  For example,
+suppose you and somebody else started at the same commit X, and you built
+a history leading to commit B while the other person built a history
+leading to commit A.  The history looks like this:
+
+----------------
+
+      B
+     /
+ ---X---A
+
+----------------
+
+Further suppose that the other person already pushed changes leading to A
+back to the original repository from which you two obtained the original
+commit X.
+
+The push done by the other person updated the branch that used to point at
+commit X to point at commit A.  It is a fast-forward.
+
+But if you try to push, you will attempt to update the branch (that
+now points at A) with commit B.  This does _not_ fast-forward.  If you did
+so, the changes introduced by commit A will be lost, because everybody
+will now start building on top of B.
+
+The command by default does not allow an update that is not a fast-forward
+to prevent such loss of history.
+
+If you do not want to lose your work (history from X to B) or the work by
+the other person (history from X to A), you would need to first fetch the
+history from the repository, create a history that contains changes done
+by both parties, and push the result back.
+
+You can perform "git pull", resolve potential conflicts, and "git push"
+the result.  A "git pull" will create a merge commit C between commits A
+and B.
+
+----------------
+
+      B---C
+     /   /
+ ---X---A
+
+----------------
+
+Updating A with the resulting merge commit will fast-forward and your
+push will be accepted.
+
+Alternatively, you can rebase your change between X and B on top of A,
+with "git pull --rebase", and push the result back.  The rebase will
+create a new commit D that builds the change between X and B on top of
+A.
+
+----------------
+
+      B   D
+     /   /
+ ---X---A
+
+----------------
+
+Again, updating A with this commit will fast-forward and your push will be
+accepted.
+
+There is another common situation where you may encounter non-fast-forward
+rejection when you try to push, and it is possible even when you are
+pushing into a repository nobody else pushes into. After you push commit
+A yourself (in the first picture in this section), replace it with "git
+commit --amend" to produce commit B, and you try to push it out, because
+forgot that you have pushed A out already. In such a case, and only if
+you are certain that nobody in the meantime fetched your earlier commit A
+(and started building on top of it), you can run "git push --force" to
+overwrite it. In other words, "git push --force" is a method reserved for
+a case where you do mean to lose history.
+
+
+EXAMPLES
+--------
+
+`git push`::
+	Works like `git push <remote>`, where <remote> is the
+	current branch's remote (or `origin`, if no remote is
+	configured for the current branch).
+
+`git push origin`::
+	Without additional configuration, pushes the current branch to
+	the configured upstream (`remote.origin.merge` configuration
+	variable) if it has the same name as the current branch, and
+	errors out without pushing otherwise.
++
+The default behavior of this command when no <refspec> is given can be
+configured by setting the `push` option of the remote, or the `push.default`
+configuration variable.
++
+For example, to default to pushing only the current branch to `origin`
+use `git config remote.origin.push HEAD`.  Any valid <refspec> (like
+the ones in the examples below) can be configured as the default for
+`git push origin`.
+
+`git push origin :`::
+	Push "matching" branches to `origin`. See
+	<refspec> in the <<OPTIONS,OPTIONS>> section above for a
+	description of "matching" branches.
+
+`git push origin master`::
+	Find a ref that matches `master` in the source repository
+	(most likely, it would find `refs/heads/master`), and update
+	the same ref (e.g. `refs/heads/master`) in `origin` repository
+	with it.  If `master` did not exist remotely, it would be
+	created.
+
+`git push origin HEAD`::
+	A handy way to push the current branch to the same name on the
+	remote.
+
+`git push mothership master:satellite/master dev:satellite/dev`::
+	Use the source ref that matches `master` (e.g. `refs/heads/master`)
+	to update the ref that matches `satellite/master` (most probably
+	`refs/remotes/satellite/master`) in the `mothership` repository;
+	do the same for `dev` and `satellite/dev`.
++
+See the section describing `<refspec>...` above for a discussion of
+the matching semantics.
++
+This is to emulate `git fetch` run on the `mothership` using `git
+push` that is run in the opposite direction in order to integrate
+the work done on `satellite`, and is often necessary when you can
+only make connection in one way (i.e. satellite can ssh into
+mothership but mothership cannot initiate connection to satellite
+because the latter is behind a firewall or does not run sshd).
++
+After running this `git push` on the `satellite` machine, you would
+ssh into the `mothership` and run `git merge` there to complete the
+emulation of `git pull` that were run on `mothership` to pull changes
+made on `satellite`.
+
+`git push origin HEAD:master`::
+	Push the current branch to the remote ref matching `master` in the
+	`origin` repository. This form is convenient to push the current
+	branch without thinking about its local name.
+
+`git push origin master:refs/heads/experimental`::
+	Create the branch `experimental` in the `origin` repository
+	by copying the current `master` branch.  This form is only
+	needed to create a new branch or tag in the remote repository when
+	the local name and the remote name are different; otherwise,
+	the ref name on its own will work.
+
+`git push origin :experimental`::
+	Find a ref that matches `experimental` in the `origin` repository
+	(e.g. `refs/heads/experimental`), and delete it.
+
+`git push origin +dev:master`::
+	Update the origin repository's master branch with the dev branch,
+	allowing non-fast-forward updates.  *This can leave unreferenced
+	commits dangling in the origin repository.*  Consider the
+	following situation, where a fast-forward is not possible:
++
+----
+	    o---o---o---A---B  origin/master
+		     \
+		      X---Y---Z  dev
+----
++
+The above command would change the origin repository to
++
+----
+		      A---B  (unnamed branch)
+		     /
+	    o---o---o---X---Y---Z  master
+----
++
+Commits A and B would no longer belong to a branch with a symbolic name,
+and so would be unreachable.  As such, these commits would be removed by
+a `git gc` command on the origin repository.
+
+include::transfer-data-leaks.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-quiltimport.txt b/third_party/git/Documentation/git-quiltimport.txt
new file mode 100644
index 0000000000..70562dc4c0
--- /dev/null
+++ b/third_party/git/Documentation/git-quiltimport.txt
@@ -0,0 +1,64 @@
+git-quiltimport(1)
+==================
+
+NAME
+----
+git-quiltimport - Applies a quilt patchset onto the current branch
+
+
+SYNOPSIS
+--------
+[verse]
+'git quiltimport' [--dry-run | -n] [--author <author>] [--patches <dir>]
+		[--series <file>] [--keep-non-patch]
+
+
+DESCRIPTION
+-----------
+Applies a quilt patchset onto the current Git branch, preserving
+the patch boundaries, patch order, and patch descriptions present
+in the quilt patchset.
+
+For each patch the code attempts to extract the author from the
+patch description.  If that fails it falls back to the author
+specified with --author.  If the --author flag was not given
+the patch description is displayed and the user is asked to
+interactively enter the author of the patch.
+
+If a subject is not found in the patch description the patch name is
+preserved as the 1 line subject in the Git description.
+
+OPTIONS
+-------
+
+-n::
+--dry-run::
+	Walk through the patches in the series and warn
+	if we cannot find all of the necessary information to commit
+	a patch.  At the time of this writing only missing author
+	information is warned about.
+
+--author Author Name <Author Email>::
+	The author name and email address to use when no author
+	information can be found in the patch description.
+
+--patches <dir>::
+	The directory to find the quilt patches.
++
+The default for the patch directory is patches
+or the value of the `$QUILT_PATCHES` environment
+variable.
+
+--series <file>::
+	The quilt series file.
++
+The default for the series file is <patches>/series
+or the value of the `$QUILT_SERIES` environment
+variable.
+
+--keep-non-patch::
+	Pass `-b` flag to 'git mailinfo' (see linkgit:git-mailinfo[1]).
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-range-diff.txt b/third_party/git/Documentation/git-range-diff.txt
new file mode 100644
index 0000000000..8a6ea2c6c5
--- /dev/null
+++ b/third_party/git/Documentation/git-range-diff.txt
@@ -0,0 +1,269 @@
+git-range-diff(1)
+=================
+
+NAME
+----
+git-range-diff - Compare two commit ranges (e.g. two versions of a branch)
+
+SYNOPSIS
+--------
+[verse]
+'git range-diff' [--color=[<when>]] [--no-color] [<diff-options>]
+	[--no-dual-color] [--creation-factor=<factor>]
+	( <range1> <range2> | <rev1>...<rev2> | <base> <rev1> <rev2> )
+
+DESCRIPTION
+-----------
+
+This command shows the differences between two versions of a patch
+series, or more generally, two commit ranges (ignoring merge commits).
+
+To that end, it first finds pairs of commits from both commit ranges
+that correspond with each other. Two commits are said to correspond when
+the diff between their patches (i.e. the author information, the commit
+message and the commit diff) is reasonably small compared to the
+patches' size. See ``Algorithm`` below for details.
+
+Finally, the list of matching commits is shown in the order of the
+second commit range, with unmatched commits being inserted just after
+all of their ancestors have been shown.
+
+
+OPTIONS
+-------
+--no-dual-color::
+	When the commit diffs differ, `git range-diff` recreates the
+	original diffs' coloring, and adds outer -/+ diff markers with
+	the *background* being red/green to make it easier to see e.g.
+	when there was a change in what exact lines were added.
++
+Additionally, the commit diff lines that are only present in the first commit
+range are shown "dimmed" (this can be overridden using the `color.diff.<slot>`
+config setting where `<slot>` is one of `contextDimmed`, `oldDimmed` and
+`newDimmed`), and the commit diff lines that are only present in the second
+commit range are shown in bold (which can be overridden using the config
+settings `color.diff.<slot>` with `<slot>` being one of `contextBold`,
+`oldBold` or `newBold`).
++
+This is known to `range-diff` as "dual coloring". Use `--no-dual-color`
+to revert to color all lines according to the outer diff markers
+(and completely ignore the inner diff when it comes to color).
+
+--creation-factor=<percent>::
+	Set the creation/deletion cost fudge factor to `<percent>`.
+	Defaults to 60. Try a larger value if `git range-diff` erroneously
+	considers a large change a total rewrite (deletion of one commit
+	and addition of another), and a smaller one in the reverse case.
+	See the ``Algorithm`` section below for an explanation why this is
+	needed.
+
+<range1> <range2>::
+	Compare the commits specified by the two ranges, where
+	`<range1>` is considered an older version of `<range2>`.
+
+<rev1>...<rev2>::
+	Equivalent to passing `<rev2>..<rev1>` and `<rev1>..<rev2>`.
+
+<base> <rev1> <rev2>::
+	Equivalent to passing `<base>..<rev1>` and `<base>..<rev2>`.
+	Note that `<base>` does not need to be the exact branch point
+	of the branches. Example: after rebasing a branch `my-topic`,
+	`git range-diff my-topic@{u} my-topic@{1} my-topic` would
+	show the differences introduced by the rebase.
+
+`git range-diff` also accepts the regular diff options (see
+linkgit:git-diff[1]), most notably the `--color=[<when>]` and
+`--no-color` options. These options are used when generating the "diff
+between patches", i.e. to compare the author, commit message and diff of
+corresponding old/new commits. There is currently no means to tweak the
+diff options passed to `git log` when generating those patches.
+
+OUTPUT STABILITY
+----------------
+
+The output of the `range-diff` command is subject to change. It is
+intended to be human-readable porcelain output, not something that can
+be used across versions of Git to get a textually stable `range-diff`
+(as opposed to something like the `--stable` option to
+linkgit:git-patch-id[1]). There's also no equivalent of
+linkgit:git-apply[1] for `range-diff`, the output is not intended to
+be machine-readable.
+
+This is particularly true when passing in diff options. Currently some
+options like `--stat` can, as an emergent effect, produce output
+that's quite useless in the context of `range-diff`. Future versions
+of `range-diff` may learn to interpret such options in a manner
+specific to `range-diff` (e.g. for `--stat` producing human-readable
+output which summarizes how the diffstat changed).
+
+CONFIGURATION
+-------------
+This command uses the `diff.color.*` and `pager.range-diff` settings
+(the latter is on by default).
+See linkgit:git-config[1].
+
+
+EXAMPLES
+--------
+
+When a rebase required merge conflicts to be resolved, compare the changes
+introduced by the rebase directly afterwards using:
+
+------------
+$ git range-diff @{u} @{1} @
+------------
+
+
+A typical output of `git range-diff` would look like this:
+
+------------
+-:  ------- > 1:  0ddba11 Prepare for the inevitable!
+1:  c0debee = 2:  cab005e Add a helpful message at the start
+2:  f00dbal ! 3:  decafe1 Describe a bug
+    @@ -1,3 +1,3 @@
+     Author: A U Thor <author@example.com>
+
+    -TODO: Describe a bug
+    +Describe a bug
+    @@ -324,5 +324,6
+      This is expected.
+
+    -+What is unexpected is that it will also crash.
+    ++Unexpectedly, it also crashes. This is a bug, and the jury is
+    ++still out there how to fix it best. See ticket #314 for details.
+
+      Contact
+3:  bedead < -:  ------- TO-UNDO
+------------
+
+In this example, there are 3 old and 3 new commits, where the developer
+removed the 3rd, added a new one before the first two, and modified the
+commit message of the 2nd commit as well its diff.
+
+When the output goes to a terminal, it is color-coded by default, just
+like regular `git diff`'s output. In addition, the first line (adding a
+commit) is green, the last line (deleting a commit) is red, the second
+line (with a perfect match) is yellow like the commit header of `git
+show`'s output, and the third line colors the old commit red, the new
+one green and the rest like `git show`'s commit header.
+
+A naive color-coded diff of diffs is actually a bit hard to read,
+though, as it colors the entire lines red or green. The line that added
+"What is unexpected" in the old commit, for example, is completely red,
+even if the intent of the old commit was to add something.
+
+To help with that, `range` uses the `--dual-color` mode by default. In
+this mode, the diff of diffs will retain the original diff colors, and
+prefix the lines with -/+ markers that have their *background* red or
+green, to make it more obvious that they describe how the diff itself
+changed.
+
+
+Algorithm
+---------
+
+The general idea is this: we generate a cost matrix between the commits
+in both commit ranges, then solve the least-cost assignment.
+
+The cost matrix is populated thusly: for each pair of commits, both
+diffs are generated and the "diff of diffs" is generated, with 3 context
+lines, then the number of lines in that diff is used as cost.
+
+To avoid false positives (e.g. when a patch has been removed, and an
+unrelated patch has been added between two iterations of the same patch
+series), the cost matrix is extended to allow for that, by adding
+fixed-cost entries for wholesale deletes/adds.
+
+Example: Let commits `1--2` be the first iteration of a patch series and
+`A--C` the second iteration. Let's assume that `A` is a cherry-pick of
+`2,` and `C` is a cherry-pick of `1` but with a small modification (say,
+a fixed typo). Visualize the commits as a bipartite graph:
+
+------------
+    1            A
+
+    2            B
+
+		 C
+------------
+
+We are looking for a "best" explanation of the new series in terms of
+the old one. We can represent an "explanation" as an edge in the graph:
+
+
+------------
+    1            A
+	       /
+    2 --------'  B
+
+		 C
+------------
+
+This explanation comes for "free" because there was no change. Similarly
+`C` could be explained using `1`, but that comes at some cost c>0
+because of the modification:
+
+------------
+    1 ----.      A
+	  |    /
+    2 ----+---'  B
+	  |
+	  `----- C
+	  c>0
+------------
+
+In mathematical terms, what we are looking for is some sort of a minimum
+cost bipartite matching; `1` is matched to `C` at some cost, etc. The
+underlying graph is in fact a complete bipartite graph; the cost we
+associate with every edge is the size of the diff between the two
+commits' patches. To explain also new commits, we introduce dummy nodes
+on both sides:
+
+------------
+    1 ----.      A
+	  |    /
+    2 ----+---'  B
+	  |
+    o     `----- C
+	  c>0
+    o            o
+
+    o            o
+------------
+
+The cost of an edge `o--C` is the size of `C`'s diff, modified by a
+fudge factor that should be smaller than 100%. The cost of an edge
+`o--o` is free. The fudge factor is necessary because even if `1` and
+`C` have nothing in common, they may still share a few empty lines and
+such, possibly making the assignment `1--C`, `o--o` slightly cheaper
+than `1--o`, `o--C` even if `1` and `C` have nothing in common. With the
+fudge factor we require a much larger common part to consider patches as
+corresponding.
+
+The overall time needed to compute this algorithm is the time needed to
+compute n+m commit diffs and then n*m diffs of patches, plus the time
+needed to compute the least-cost assigment between n and m diffs. Git
+uses an implementation of the Jonker-Volgenant algorithm to solve the
+assignment problem, which has cubic runtime complexity. The matching
+found in this case will look like this:
+
+------------
+    1 ----.      A
+	  |    /
+    2 ----+---'  B
+       .--+-----'
+    o -'  `----- C
+	  c>0
+    o ---------- o
+
+    o ---------- o
+------------
+
+
+SEE ALSO
+--------
+linkgit:git-log[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-read-tree.txt b/third_party/git/Documentation/git-read-tree.txt
new file mode 100644
index 0000000000..d271842608
--- /dev/null
+++ b/third_party/git/Documentation/git-read-tree.txt
@@ -0,0 +1,443 @@
+git-read-tree(1)
+================
+
+NAME
+----
+git-read-tree - Reads tree information into the index
+
+
+SYNOPSIS
+--------
+[verse]
+'git read-tree' [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>]
+		[-u [--exclude-per-directory=<gitignore>] | -i]]
+		[--index-output=<file>] [--no-sparse-checkout]
+		(--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])
+
+
+DESCRIPTION
+-----------
+Reads the tree information given by <tree-ish> into the index,
+but does not actually *update* any of the files it "caches". (see:
+linkgit:git-checkout-index[1])
+
+Optionally, it can merge a tree into the index, perform a
+fast-forward (i.e. 2-way) merge, or a 3-way merge, with the `-m`
+flag.  When used with `-m`, the `-u` flag causes it to also update
+the files in the work tree with the result of the merge.
+
+Trivial merges are done by 'git read-tree' itself.  Only conflicting paths
+will be in unmerged state when 'git read-tree' returns.
+
+OPTIONS
+-------
+-m::
+	Perform a merge, not just a read.  The command will
+	refuse to run if your index file has unmerged entries,
+	indicating that you have not finished previous merge you
+	started.
+
+--reset::
+	Same as -m, except that unmerged entries are discarded instead
+	of failing. When used with `-u`, updates leading to loss of
+	working tree changes will not abort the operation.
+
+-u::
+	After a successful merge, update the files in the work
+	tree with the result of the merge.
+
+-i::
+	Usually a merge requires the index file as well as the
+	files in the working tree to be up to date with the
+	current head commit, in order not to lose local
+	changes.  This flag disables the check with the working
+	tree and is meant to be used when creating a merge of
+	trees that are not directly related to the current
+	working tree status into a temporary index file.
+
+-n::
+--dry-run::
+	Check if the command would error out, without updating the index
+	or the files in the working tree for real.
+
+-v::
+	Show the progress of checking files out.
+
+--trivial::
+	Restrict three-way merge by 'git read-tree' to happen
+	only if there is no file-level merging required, instead
+	of resolving merge for trivial cases and leaving
+	conflicting files unresolved in the index.
+
+--aggressive::
+	Usually a three-way merge by 'git read-tree' resolves
+	the merge for really trivial cases and leaves other
+	cases unresolved in the index, so that porcelains can
+	implement different merge policies.  This flag makes the
+	command resolve a few more cases internally:
++
+* when one side removes a path and the other side leaves the path
+  unmodified.  The resolution is to remove that path.
+* when both sides remove a path.  The resolution is to remove that path.
+* when both sides add a path identically.  The resolution
+  is to add that path.
+
+--prefix=<prefix>::
+	Keep the current index contents, and read the contents
+	of the named tree-ish under the directory at `<prefix>`.
+	The command will refuse to overwrite entries that already
+	existed in the original index file.
+
+--exclude-per-directory=<gitignore>::
+	When running the command with `-u` and `-m` options, the
+	merge result may need to overwrite paths that are not
+	tracked in the current branch.  The command usually
+	refuses to proceed with the merge to avoid losing such a
+	path.  However this safety valve sometimes gets in the
+	way.  For example, it often happens that the other
+	branch added a file that used to be a generated file in
+	your branch, and the safety valve triggers when you try
+	to switch to that branch after you ran `make` but before
+	running `make clean` to remove the generated file.  This
+	option tells the command to read per-directory exclude
+	file (usually '.gitignore') and allows such an untracked
+	but explicitly ignored file to be overwritten.
+
+--index-output=<file>::
+	Instead of writing the results out to `$GIT_INDEX_FILE`,
+	write the resulting index in the named file.  While the
+	command is operating, the original index file is locked
+	with the same mechanism as usual.  The file must allow
+	to be rename(2)ed into from a temporary file that is
+	created next to the usual index file; typically this
+	means it needs to be on the same filesystem as the index
+	file itself, and you need write permission to the
+	directories the index file and index output file are
+	located in.
+
+--[no-]recurse-submodules::
+	Using --recurse-submodules will update the content of all initialized
+	submodules according to the commit recorded in the superproject by
+	calling read-tree recursively, also setting the submodules HEAD to be
+	detached at that commit.
+
+--no-sparse-checkout::
+	Disable sparse checkout support even if `core.sparseCheckout`
+	is true.
+
+--empty::
+	Instead of reading tree object(s) into the index, just empty
+	it.
+
+-q::
+--quiet::
+	Quiet, suppress feedback messages.
+
+<tree-ish#>::
+	The id of the tree object(s) to be read/merged.
+
+
+MERGING
+-------
+If `-m` is specified, 'git read-tree' can perform 3 kinds of
+merge, a single tree merge if only 1 tree is given, a
+fast-forward merge with 2 trees, or a 3-way merge if 3 or more trees are
+provided.
+
+
+Single Tree Merge
+~~~~~~~~~~~~~~~~~
+If only 1 tree is specified, 'git read-tree' operates as if the user did not
+specify `-m`, except that if the original index has an entry for a
+given pathname, and the contents of the path match with the tree
+being read, the stat info from the index is used. (In other words, the
+index's stat()s take precedence over the merged tree's).
+
+That means that if you do a `git read-tree -m <newtree>` followed by a
+`git checkout-index -f -u -a`, the 'git checkout-index' only checks out
+the stuff that really changed.
+
+This is used to avoid unnecessary false hits when 'git diff-files' is
+run after 'git read-tree'.
+
+
+Two Tree Merge
+~~~~~~~~~~~~~~
+
+Typically, this is invoked as `git read-tree -m $H $M`, where $H
+is the head commit of the current repository, and $M is the head
+of a foreign tree, which is simply ahead of $H (i.e. we are in a
+fast-forward situation).
+
+When two trees are specified, the user is telling 'git read-tree'
+the following:
+
+     1. The current index and work tree is derived from $H, but
+	the user may have local changes in them since $H.
+
+     2. The user wants to fast-forward to $M.
+
+In this case, the `git read-tree -m $H $M` command makes sure
+that no local change is lost as the result of this "merge".
+Here are the "carry forward" rules, where "I" denotes the index,
+"clean" means that index and work tree coincide, and "exists"/"nothing"
+refer to the presence of a path in the specified commit:
+
+....
+	I                   H        M        Result
+       -------------------------------------------------------
+     0  nothing             nothing  nothing  (does not happen)
+     1  nothing             nothing  exists   use M
+     2  nothing             exists   nothing  remove path from index
+     3  nothing             exists   exists,  use M if "initial checkout",
+				     H == M   keep index otherwise
+				     exists,  fail
+				     H != M
+
+        clean I==H  I==M
+       ------------------
+     4  yes   N/A   N/A     nothing  nothing  keep index
+     5  no    N/A   N/A     nothing  nothing  keep index
+
+     6  yes   N/A   yes     nothing  exists   keep index
+     7  no    N/A   yes     nothing  exists   keep index
+     8  yes   N/A   no      nothing  exists   fail
+     9  no    N/A   no      nothing  exists   fail
+
+     10 yes   yes   N/A     exists   nothing  remove path from index
+     11 no    yes   N/A     exists   nothing  fail
+     12 yes   no    N/A     exists   nothing  fail
+     13 no    no    N/A     exists   nothing  fail
+
+	clean (H==M)
+       ------
+     14 yes                 exists   exists   keep index
+     15 no                  exists   exists   keep index
+
+        clean I==H  I==M (H!=M)
+       ------------------
+     16 yes   no    no      exists   exists   fail
+     17 no    no    no      exists   exists   fail
+     18 yes   no    yes     exists   exists   keep index
+     19 no    no    yes     exists   exists   keep index
+     20 yes   yes   no      exists   exists   use M
+     21 no    yes   no      exists   exists   fail
+....
+
+In all "keep index" cases, the index entry stays as in the
+original index file.  If the entry is not up to date,
+'git read-tree' keeps the copy in the work tree intact when
+operating under the -u flag.
+
+When this form of 'git read-tree' returns successfully, you can
+see which of the "local changes" that you made were carried forward by running
+`git diff-index --cached $M`.  Note that this does not
+necessarily match what `git diff-index --cached $H` would have
+produced before such a two tree merge.  This is because of cases
+18 and 19 --- if you already had the changes in $M (e.g. maybe
+you picked it up via e-mail in a patch form), `git diff-index
+--cached $H` would have told you about the change before this
+merge, but it would not show in `git diff-index --cached $M`
+output after the two-tree merge.
+
+Case 3 is slightly tricky and needs explanation.  The result from this
+rule logically should be to remove the path if the user staged the removal
+of the path and then switching to a new branch.  That however will prevent
+the initial checkout from happening, so the rule is modified to use M (new
+tree) only when the content of the index is empty.  Otherwise the removal
+of the path is kept as long as $H and $M are the same.
+
+3-Way Merge
+~~~~~~~~~~~
+Each "index" entry has two bits worth of "stage" state. stage 0 is the
+normal one, and is the only one you'd see in any kind of normal use.
+
+However, when you do 'git read-tree' with three trees, the "stage"
+starts out at 1.
+
+This means that you can do
+
+----------------
+$ git read-tree -m <tree1> <tree2> <tree3>
+----------------
+
+and you will end up with an index with all of the <tree1> entries in
+"stage1", all of the <tree2> entries in "stage2" and all of the
+<tree3> entries in "stage3".  When performing a merge of another
+branch into the current branch, we use the common ancestor tree
+as <tree1>, the current branch head as <tree2>, and the other
+branch head as <tree3>.
+
+Furthermore, 'git read-tree' has special-case logic that says: if you see
+a file that matches in all respects in the following states, it
+"collapses" back to "stage0":
+
+   - stage 2 and 3 are the same; take one or the other (it makes no
+     difference - the same work has been done on our branch in
+     stage 2 and their branch in stage 3)
+
+   - stage 1 and stage 2 are the same and stage 3 is different; take
+     stage 3 (our branch in stage 2 did not do anything since the
+     ancestor in stage 1 while their branch in stage 3 worked on
+     it)
+
+   - stage 1 and stage 3 are the same and stage 2 is different take
+     stage 2 (we did something while they did nothing)
+
+The 'git write-tree' command refuses to write a nonsensical tree, and it
+will complain about unmerged entries if it sees a single entry that is not
+stage 0.
+
+OK, this all sounds like a collection of totally nonsensical rules,
+but it's actually exactly what you want in order to do a fast
+merge. The different stages represent the "result tree" (stage 0, aka
+"merged"), the original tree (stage 1, aka "orig"), and the two trees
+you are trying to merge (stage 2 and 3 respectively).
+
+The order of stages 1, 2 and 3 (hence the order of three
+<tree-ish> command-line arguments) are significant when you
+start a 3-way merge with an index file that is already
+populated.  Here is an outline of how the algorithm works:
+
+- if a file exists in identical format in all three trees, it will
+  automatically collapse to "merged" state by 'git read-tree'.
+
+- a file that has _any_ difference what-so-ever in the three trees
+  will stay as separate entries in the index. It's up to "porcelain
+  policy" to determine how to remove the non-0 stages, and insert a
+  merged version.
+
+- the index file saves and restores with all this information, so you
+  can merge things incrementally, but as long as it has entries in
+  stages 1/2/3 (i.e., "unmerged entries") you can't write the result. So
+  now the merge algorithm ends up being really simple:
+
+  * you walk the index in order, and ignore all entries of stage 0,
+    since they've already been done.
+
+  * if you find a "stage1", but no matching "stage2" or "stage3", you
+    know it's been removed from both trees (it only existed in the
+    original tree), and you remove that entry.
+
+  * if you find a matching "stage2" and "stage3" tree, you remove one
+    of them, and turn the other into a "stage0" entry. Remove any
+    matching "stage1" entry if it exists too.  .. all the normal
+    trivial rules ..
+
+You would normally use 'git merge-index' with supplied
+'git merge-one-file' to do this last step.  The script updates
+the files in the working tree as it merges each path and at the
+end of a successful merge.
+
+When you start a 3-way merge with an index file that is already
+populated, it is assumed that it represents the state of the
+files in your work tree, and you can even have files with
+changes unrecorded in the index file.  It is further assumed
+that this state is "derived" from the stage 2 tree.  The 3-way
+merge refuses to run if it finds an entry in the original index
+file that does not match stage 2.
+
+This is done to prevent you from losing your work-in-progress
+changes, and mixing your random changes in an unrelated merge
+commit.  To illustrate, suppose you start from what has been
+committed last to your repository:
+
+----------------
+$ JC=`git rev-parse --verify "HEAD^0"`
+$ git checkout-index -f -u -a $JC
+----------------
+
+You do random edits, without running 'git update-index'.  And then
+you notice that the tip of your "upstream" tree has advanced
+since you pulled from him:
+
+----------------
+$ git fetch git://.... linus
+$ LT=`git rev-parse FETCH_HEAD`
+----------------
+
+Your work tree is still based on your HEAD ($JC), but you have
+some edits since.  Three-way merge makes sure that you have not
+added or modified index entries since $JC, and if you haven't,
+then does the right thing.  So with the following sequence:
+
+----------------
+$ git read-tree -m -u `git merge-base $JC $LT` $JC $LT
+$ git merge-index git-merge-one-file -a
+$ echo "Merge with Linus" | \
+  git commit-tree `git write-tree` -p $JC -p $LT
+----------------
+
+what you would commit is a pure merge between $JC and $LT without
+your work-in-progress changes, and your work tree would be
+updated to the result of the merge.
+
+However, if you have local changes in the working tree that
+would be overwritten by this merge, 'git read-tree' will refuse
+to run to prevent your changes from being lost.
+
+In other words, there is no need to worry about what exists only
+in the working tree.  When you have local changes in a part of
+the project that is not involved in the merge, your changes do
+not interfere with the merge, and are kept intact.  When they
+*do* interfere, the merge does not even start ('git read-tree'
+complains loudly and fails without modifying anything).  In such
+a case, you can simply continue doing what you were in the
+middle of doing, and when your working tree is ready (i.e. you
+have finished your work-in-progress), attempt the merge again.
+
+
+SPARSE CHECKOUT
+---------------
+
+"Sparse checkout" allows populating the working directory sparsely.
+It uses the skip-worktree bit (see linkgit:git-update-index[1]) to tell
+Git whether a file in the working directory is worth looking at.
+
+'git read-tree' and other merge-based commands ('git merge', 'git
+checkout'...) can help maintaining the skip-worktree bitmap and working
+directory update. `$GIT_DIR/info/sparse-checkout` is used to
+define the skip-worktree reference bitmap. When 'git read-tree' needs
+to update the working directory, it resets the skip-worktree bit in the index
+based on this file, which uses the same syntax as .gitignore files.
+If an entry matches a pattern in this file, skip-worktree will not be
+set on that entry. Otherwise, skip-worktree will be set.
+
+Then it compares the new skip-worktree value with the previous one. If
+skip-worktree turns from set to unset, it will add the corresponding
+file back. If it turns from unset to set, that file will be removed.
+
+While `$GIT_DIR/info/sparse-checkout` is usually used to specify what
+files are in, you can also specify what files are _not_ in, using
+negate patterns. For example, to remove the file `unwanted`:
+
+----------------
+/*
+!unwanted
+----------------
+
+Another tricky thing is fully repopulating the working directory when you
+no longer want sparse checkout. You cannot just disable "sparse
+checkout" because skip-worktree bits are still in the index and your working
+directory is still sparsely populated. You should re-populate the working
+directory with the `$GIT_DIR/info/sparse-checkout` file content as
+follows:
+
+----------------
+/*
+----------------
+
+Then you can disable sparse checkout. Sparse checkout support in 'git
+read-tree' and similar commands is disabled by default. You need to
+turn `core.sparseCheckout` on in order to have sparse checkout
+support.
+
+
+SEE ALSO
+--------
+linkgit:git-write-tree[1]; linkgit:git-ls-files[1];
+linkgit:gitignore[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-rebase.txt b/third_party/git/Documentation/git-rebase.txt
new file mode 100644
index 0000000000..6156609cf7
--- /dev/null
+++ b/third_party/git/Documentation/git-rebase.txt
@@ -0,0 +1,1053 @@
+git-rebase(1)
+=============
+
+NAME
+----
+git-rebase - Reapply commits on top of another base tip
+
+SYNOPSIS
+--------
+[verse]
+'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>]
+	[<upstream> [<branch>]]
+'git rebase' [-i | --interactive] [<options>] [--exec <cmd>] [--onto <newbase>]
+	--root [<branch>]
+'git rebase' (--continue | --skip | --abort | --quit | --edit-todo | --show-current-patch)
+
+DESCRIPTION
+-----------
+If <branch> is specified, 'git rebase' will perform an automatic
+`git switch <branch>` before doing anything else.  Otherwise
+it remains on the current branch.
+
+If <upstream> is not specified, the upstream configured in
+branch.<name>.remote and branch.<name>.merge options will be used (see
+linkgit:git-config[1] for details) and the `--fork-point` option is
+assumed.  If you are currently not on any branch or if the current
+branch does not have a configured upstream, the rebase will abort.
+
+All changes made by commits in the current branch but that are not
+in <upstream> are saved to a temporary area.  This is the same set
+of commits that would be shown by `git log <upstream>..HEAD`; or by
+`git log 'fork_point'..HEAD`, if `--fork-point` is active (see the
+description on `--fork-point` below); or by `git log HEAD`, if the
+`--root` option is specified.
+
+The current branch is reset to <upstream>, or <newbase> if the
+--onto option was supplied.  This has the exact same effect as
+`git reset --hard <upstream>` (or <newbase>).  ORIG_HEAD is set
+to point at the tip of the branch before the reset.
+
+The commits that were previously saved into the temporary area are
+then reapplied to the current branch, one by one, in order. Note that
+any commits in HEAD which introduce the same textual changes as a commit
+in HEAD..<upstream> are omitted (i.e., a patch already accepted upstream
+with a different commit message or timestamp will be skipped).
+
+It is possible that a merge failure will prevent this process from being
+completely automatic.  You will have to resolve any such merge failure
+and run `git rebase --continue`.  Another option is to bypass the commit
+that caused the merge failure with `git rebase --skip`.  To check out the
+original <branch> and remove the .git/rebase-apply working files, use the
+command `git rebase --abort` instead.
+
+Assume the following history exists and the current branch is "topic":
+
+------------
+          A---B---C topic
+         /
+    D---E---F---G master
+------------
+
+From this point, the result of either of the following commands:
+
+
+    git rebase master
+    git rebase master topic
+
+would be:
+
+------------
+                  A'--B'--C' topic
+                 /
+    D---E---F---G master
+------------
+
+*NOTE:* The latter form is just a short-hand of `git checkout topic`
+followed by `git rebase master`. When rebase exits `topic` will
+remain the checked-out branch.
+
+If the upstream branch already contains a change you have made (e.g.,
+because you mailed a patch which was applied upstream), then that commit
+will be skipped. For example, running `git rebase master` on the
+following history (in which `A'` and `A` introduce the same set of changes,
+but have different committer information):
+
+------------
+          A---B---C topic
+         /
+    D---E---A'---F master
+------------
+
+will result in:
+
+------------
+                   B'---C' topic
+                  /
+    D---E---A'---F master
+------------
+
+Here is how you would transplant a topic branch based on one
+branch to another, to pretend that you forked the topic branch
+from the latter branch, using `rebase --onto`.
+
+First let's assume your 'topic' is based on branch 'next'.
+For example, a feature developed in 'topic' depends on some
+functionality which is found in 'next'.
+
+------------
+    o---o---o---o---o  master
+         \
+          o---o---o---o---o  next
+                           \
+                            o---o---o  topic
+------------
+
+We want to make 'topic' forked from branch 'master'; for example,
+because the functionality on which 'topic' depends was merged into the
+more stable 'master' branch. We want our tree to look like this:
+
+------------
+    o---o---o---o---o  master
+        |            \
+        |             o'--o'--o'  topic
+         \
+          o---o---o---o---o  next
+------------
+
+We can get this using the following command:
+
+    git rebase --onto master next topic
+
+
+Another example of --onto option is to rebase part of a
+branch.  If we have the following situation:
+
+------------
+                            H---I---J topicB
+                           /
+                  E---F---G  topicA
+                 /
+    A---B---C---D  master
+------------
+
+then the command
+
+    git rebase --onto master topicA topicB
+
+would result in:
+
+------------
+                 H'--I'--J'  topicB
+                /
+                | E---F---G  topicA
+                |/
+    A---B---C---D  master
+------------
+
+This is useful when topicB does not depend on topicA.
+
+A range of commits could also be removed with rebase.  If we have
+the following situation:
+
+------------
+    E---F---G---H---I---J  topicA
+------------
+
+then the command
+
+    git rebase --onto topicA~5 topicA~3 topicA
+
+would result in the removal of commits F and G:
+
+------------
+    E---H'---I'---J'  topicA
+------------
+
+This is useful if F and G were flawed in some way, or should not be
+part of topicA.  Note that the argument to --onto and the <upstream>
+parameter can be any valid commit-ish.
+
+In case of conflict, 'git rebase' will stop at the first problematic commit
+and leave conflict markers in the tree.  You can use 'git diff' to locate
+the markers (<<<<<<) and make edits to resolve the conflict.  For each
+file you edit, you need to tell Git that the conflict has been resolved,
+typically this would be done with
+
+
+    git add <filename>
+
+
+After resolving the conflict manually and updating the index with the
+desired resolution, you can continue the rebasing process with
+
+
+    git rebase --continue
+
+
+Alternatively, you can undo the 'git rebase' with
+
+
+    git rebase --abort
+
+CONFIGURATION
+-------------
+
+include::config/rebase.txt[]
+
+OPTIONS
+-------
+--onto <newbase>::
+	Starting point at which to create the new commits. If the
+	--onto option is not specified, the starting point is
+	<upstream>.  May be any valid commit, and not just an
+	existing branch name.
++
+As a special case, you may use "A\...B" as a shortcut for the
+merge base of A and B if there is exactly one merge base. You can
+leave out at most one of A and B, in which case it defaults to HEAD.
+
+<upstream>::
+	Upstream branch to compare against.  May be any valid commit,
+	not just an existing branch name. Defaults to the configured
+	upstream for the current branch.
+
+<branch>::
+	Working branch; defaults to HEAD.
+
+--continue::
+	Restart the rebasing process after having resolved a merge conflict.
+
+--abort::
+	Abort the rebase operation and reset HEAD to the original
+	branch. If <branch> was provided when the rebase operation was
+	started, then HEAD will be reset to <branch>. Otherwise HEAD
+	will be reset to where it was when the rebase operation was
+	started.
+
+--quit::
+	Abort the rebase operation but HEAD is not reset back to the
+	original branch. The index and working tree are also left
+	unchanged as a result.
+
+--keep-empty::
+	Keep the commits that do not change anything from its
+	parents in the result.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--allow-empty-message::
+	By default, rebasing commits with an empty message will fail.
+	This option overrides that behavior, allowing commits with empty
+	messages to be rebased.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--skip::
+	Restart the rebasing process by skipping the current patch.
+
+--edit-todo::
+	Edit the todo list during an interactive rebase.
+
+--show-current-patch::
+	Show the current patch in an interactive rebase or when rebase
+	is stopped because of conflicts. This is the equivalent of
+	`git show REBASE_HEAD`.
+
+-m::
+--merge::
+	Use merging strategies to rebase.  When the recursive (default) merge
+	strategy is used, this allows rebase to be aware of renames on the
+	upstream side.
++
+Note that a rebase merge works by replaying each commit from the working
+branch on top of the <upstream> branch.  Because of this, when a merge
+conflict happens, the side reported as 'ours' is the so-far rebased
+series, starting with <upstream>, and 'theirs' is the working branch.  In
+other words, the sides are swapped.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-s <strategy>::
+--strategy=<strategy>::
+	Use the given merge strategy.
+	If there is no `-s` option 'git merge-recursive' is used
+	instead.  This implies --merge.
++
+Because 'git rebase' replays each commit from the working branch
+on top of the <upstream> branch using the given strategy, using
+the 'ours' strategy simply empties all patches from the <branch>,
+which makes little sense.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-X <strategy-option>::
+--strategy-option=<strategy-option>::
+	Pass the <strategy-option> through to the merge strategy.
+	This implies `--merge` and, if no strategy has been
+	specified, `-s recursive`.  Note the reversal of 'ours' and
+	'theirs' as noted above for the `-m` option.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--rerere-autoupdate::
+--no-rerere-autoupdate::
+	Allow the rerere mechanism to update the index with the
+	result of auto-conflict resolution if possible.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+-q::
+--quiet::
+	Be quiet. Implies --no-stat.
+
+-v::
+--verbose::
+	Be verbose. Implies --stat.
+
+--stat::
+	Show a diffstat of what changed upstream since the last rebase. The
+	diffstat is also controlled by the configuration option rebase.stat.
+
+-n::
+--no-stat::
+	Do not show a diffstat as part of the rebase process.
+
+--no-verify::
+	This option bypasses the pre-rebase hook.  See also linkgit:githooks[5].
+
+--verify::
+	Allows the pre-rebase hook to run, which is the default.  This option can
+	be used to override --no-verify.  See also linkgit:githooks[5].
+
+-C<n>::
+	Ensure at least <n> lines of surrounding context match before
+	and after each change.  When fewer lines of surrounding
+	context exist they all must match.  By default no context is
+	ever ignored.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--no-ff::
+--force-rebase::
+-f::
+	Individually replay all rebased commits instead of fast-forwarding
+	over the unchanged ones.  This ensures that the entire history of
+	the rebased branch is composed of new commits.
++
+You may find this helpful after reverting a topic branch merge, as this option
+recreates the topic branch with fresh commits so it can be remerged
+successfully without needing to "revert the reversion" (see the
+link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for
+details).
+
+--fork-point::
+--no-fork-point::
+	Use reflog to find a better common ancestor between <upstream>
+	and <branch> when calculating which commits have been
+	introduced by <branch>.
++
+When --fork-point is active, 'fork_point' will be used instead of
+<upstream> to calculate the set of commits to rebase, where
+'fork_point' is the result of `git merge-base --fork-point <upstream>
+<branch>` command (see linkgit:git-merge-base[1]).  If 'fork_point'
+ends up being empty, the <upstream> will be used as a fallback.
++
+If either <upstream> or --root is given on the command line, then the
+default is `--no-fork-point`, otherwise the default is `--fork-point`.
+
+--ignore-whitespace::
+--whitespace=<option>::
+	These flag are passed to the 'git apply' program
+	(see linkgit:git-apply[1]) that applies the patch.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--committer-date-is-author-date::
+--ignore-date::
+	These flags are passed to 'git am' to easily change the dates
+	of the rebased commits (see linkgit:git-am[1]).
++
+See also INCOMPATIBLE OPTIONS below.
+
+--signoff::
+	Add a Signed-off-by: trailer to all the rebased commits. Note
+	that if `--interactive` is given then only commits marked to be
+	picked, edited or reworded will have the trailer added.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-i::
+--interactive::
+	Make a list of the commits which are about to be rebased.  Let the
+	user edit that list before rebasing.  This mode can also be used to
+	split commits (see SPLITTING COMMITS below).
++
+The commit list format can be changed by setting the configuration option
+rebase.instructionFormat.  A customized instruction format will automatically
+have the long commit hash prepended to the format.
++
+See also INCOMPATIBLE OPTIONS below.
+
+-r::
+--rebase-merges[=(rebase-cousins|no-rebase-cousins)]::
+	By default, a rebase will simply drop merge commits from the todo
+	list, and put the rebased commits into a single, linear branch.
+	With `--rebase-merges`, the rebase will instead try to preserve
+	the branching structure within the commits that are to be rebased,
+	by recreating the merge commits. Any resolved merge conflicts or
+	manual amendments in these merge commits will have to be
+	resolved/re-applied manually.
++
+By default, or when `no-rebase-cousins` was specified, commits which do not
+have `<upstream>` as direct ancestor will keep their original branch point,
+i.e. commits that would be excluded by linkgit:git-log[1]'s
+`--ancestry-path` option will keep their original ancestry by default. If
+the `rebase-cousins` mode is turned on, such commits are instead rebased
+onto `<upstream>` (or `<onto>`, if specified).
++
+The `--rebase-merges` mode is similar in spirit to the deprecated
+`--preserve-merges`, but in contrast to that option works well in interactive
+rebases: commits can be reordered, inserted and dropped at will.
++
+It is currently only possible to recreate the merge commits using the
+`recursive` merge strategy; Different merge strategies can be used only via
+explicit `exec git merge -s <strategy> [...]` commands.
++
+See also REBASING MERGES and INCOMPATIBLE OPTIONS below.
+
+-p::
+--preserve-merges::
+	[DEPRECATED: use `--rebase-merges` instead] Recreate merge commits
+	instead of flattening the history by replaying commits a merge commit
+	introduces. Merge conflict resolutions or manual amendments to merge
+	commits are not preserved.
++
+This uses the `--interactive` machinery internally, but combining it
+with the `--interactive` option explicitly is generally not a good
+idea unless you know what you are doing (see BUGS below).
++
+See also INCOMPATIBLE OPTIONS below.
+
+-x <cmd>::
+--exec <cmd>::
+	Append "exec <cmd>" after each line creating a commit in the
+	final history. <cmd> will be interpreted as one or more shell
+	commands. Any command that fails will interrupt the rebase,
+	with exit code 1.
++
+You may execute several commands by either using one instance of `--exec`
+with several commands:
++
+	git rebase -i --exec "cmd1 && cmd2 && ..."
++
+or by giving more than one `--exec`:
++
+	git rebase -i --exec "cmd1" --exec "cmd2" --exec ...
++
+If `--autosquash` is used, "exec" lines will not be appended for
+the intermediate commits, and will only appear at the end of each
+squash/fixup series.
++
+This uses the `--interactive` machinery internally, but it can be run
+without an explicit `--interactive`.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--root::
+	Rebase all commits reachable from <branch>, instead of
+	limiting them with an <upstream>.  This allows you to rebase
+	the root commit(s) on a branch.  When used with --onto, it
+	will skip changes already contained in <newbase> (instead of
+	<upstream>) whereas without --onto it will operate on every change.
+	When used together with both --onto and --preserve-merges,
+	'all' root commits will be rewritten to have <newbase> as parent
+	instead.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--autosquash::
+--no-autosquash::
+	When the commit log message begins with "squash! ..." (or
+	"fixup! ..."), and there is already a commit in the todo list that
+	matches the same `...`, automatically modify the todo list of rebase
+	-i so that the commit marked for squashing comes right after the
+	commit to be modified, and change the action of the moved commit
+	from `pick` to `squash` (or `fixup`).  A commit matches the `...` if
+	the commit subject matches, or if the `...` refers to the commit's
+	hash. As a fall-back, partial matches of the commit subject work,
+	too.  The recommended way to create fixup/squash commits is by using
+	the `--fixup`/`--squash` options of linkgit:git-commit[1].
++
+If the `--autosquash` option is enabled by default using the
+configuration variable `rebase.autoSquash`, this option can be
+used to override and disable this setting.
++
+See also INCOMPATIBLE OPTIONS below.
+
+--autostash::
+--no-autostash::
+	Automatically create a temporary stash entry before the operation
+	begins, and apply it after the operation ends.  This means
+	that you can run rebase on a dirty worktree.  However, use
+	with care: the final stash application after a successful
+	rebase might result in non-trivial conflicts.
+
+--reschedule-failed-exec::
+--no-reschedule-failed-exec::
+	Automatically reschedule `exec` commands that failed. This only makes
+	sense in interactive mode (or when an `--exec` option was provided).
+
+INCOMPATIBLE OPTIONS
+--------------------
+
+The following options:
+
+ * --committer-date-is-author-date
+ * --ignore-date
+ * --whitespace
+ * --ignore-whitespace
+ * -C
+
+are incompatible with the following options:
+
+ * --merge
+ * --strategy
+ * --strategy-option
+ * --allow-empty-message
+ * --[no-]autosquash
+ * --rebase-merges
+ * --preserve-merges
+ * --interactive
+ * --exec
+ * --keep-empty
+ * --edit-todo
+ * --root when used in combination with --onto
+
+In addition, the following pairs of options are incompatible:
+
+ * --preserve-merges and --interactive
+ * --preserve-merges and --signoff
+ * --preserve-merges and --rebase-merges
+ * --rebase-merges and --strategy
+ * --rebase-merges and --strategy-option
+
+BEHAVIORAL DIFFERENCES
+-----------------------
+
+There are some subtle differences how the backends behave.
+
+Empty commits
+~~~~~~~~~~~~~
+
+The am backend drops any "empty" commits, regardless of whether the
+commit started empty (had no changes relative to its parent to
+start with) or ended empty (all changes were already applied
+upstream in other commits).
+
+The interactive backend drops commits by default that
+started empty and halts if it hits a commit that ended up empty.
+The `--keep-empty` option exists for the interactive backend to allow
+it to keep commits that started empty.
+
+Directory rename detection
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Directory rename heuristics are enabled in the merge and interactive
+backends.  Due to the lack of accurate tree information, directory
+rename detection is disabled in the am backend.
+
+include::merge-strategies.txt[]
+
+NOTES
+-----
+
+You should understand the implications of using 'git rebase' on a
+repository that you share.  See also RECOVERING FROM UPSTREAM REBASE
+below.
+
+When the git-rebase command is run, it will first execute a "pre-rebase"
+hook if one exists.  You can use this hook to do sanity checks and
+reject the rebase if it isn't appropriate.  Please see the template
+pre-rebase hook script for an example.
+
+Upon completion, <branch> will be the current branch.
+
+INTERACTIVE MODE
+----------------
+
+Rebasing interactively means that you have a chance to edit the commits
+which are rebased.  You can reorder the commits, and you can
+remove them (weeding out bad or otherwise unwanted patches).
+
+The interactive mode is meant for this type of workflow:
+
+1. have a wonderful idea
+2. hack on the code
+3. prepare a series for submission
+4. submit
+
+where point 2. consists of several instances of
+
+a) regular use
+
+ 1. finish something worthy of a commit
+ 2. commit
+
+b) independent fixup
+
+ 1. realize that something does not work
+ 2. fix that
+ 3. commit it
+
+Sometimes the thing fixed in b.2. cannot be amended to the not-quite
+perfect commit it fixes, because that commit is buried deeply in a
+patch series.  That is exactly what interactive rebase is for: use it
+after plenty of "a"s and "b"s, by rearranging and editing
+commits, and squashing multiple commits into one.
+
+Start it with the last commit you want to retain as-is:
+
+	git rebase -i <after-this-commit>
+
+An editor will be fired up with all the commits in your current branch
+(ignoring merge commits), which come after the given commit.  You can
+reorder the commits in this list to your heart's content, and you can
+remove them.  The list looks more or less like this:
+
+-------------------------------------------
+pick deadbee The oneline of this commit
+pick fa1afe1 The oneline of the next commit
+...
+-------------------------------------------
+
+The oneline descriptions are purely for your pleasure; 'git rebase' will
+not look at them but at the commit names ("deadbee" and "fa1afe1" in this
+example), so do not delete or edit the names.
+
+By replacing the command "pick" with the command "edit", you can tell
+'git rebase' to stop after applying that commit, so that you can edit
+the files and/or the commit message, amend the commit, and continue
+rebasing.
+
+To interrupt the rebase (just like an "edit" command would do, but without
+cherry-picking any commit first), use the "break" command.
+
+If you just want to edit the commit message for a commit, replace the
+command "pick" with the command "reword".
+
+To drop a commit, replace the command "pick" with "drop", or just
+delete the matching line.
+
+If you want to fold two or more commits into one, replace the command
+"pick" for the second and subsequent commits with "squash" or "fixup".
+If the commits had different authors, the folded commit will be
+attributed to the author of the first commit.  The suggested commit
+message for the folded commit is the concatenation of the commit
+messages of the first commit and of those with the "squash" command,
+but omits the commit messages of commits with the "fixup" command.
+
+'git rebase' will stop when "pick" has been replaced with "edit" or
+when a command fails due to merge errors. When you are done editing
+and/or resolving conflicts you can continue with `git rebase --continue`.
+
+For example, if you want to reorder the last 5 commits, such that what
+was HEAD~4 becomes the new HEAD. To achieve that, you would call
+'git rebase' like this:
+
+----------------------
+$ git rebase -i HEAD~5
+----------------------
+
+And move the first patch to the end of the list.
+
+You might want to recreate merge commits, e.g. if you have a history
+like this:
+
+------------------
+           X
+            \
+         A---M---B
+        /
+---o---O---P---Q
+------------------
+
+Suppose you want to rebase the side branch starting at "A" to "Q". Make
+sure that the current HEAD is "B", and call
+
+-----------------------------
+$ git rebase -i -r --onto Q O
+-----------------------------
+
+Reordering and editing commits usually creates untested intermediate
+steps.  You may want to check that your history editing did not break
+anything by running a test, or at least recompiling at intermediate
+points in history by using the "exec" command (shortcut "x").  You may
+do so by creating a todo list like this one:
+
+-------------------------------------------
+pick deadbee Implement feature XXX
+fixup f1a5c00 Fix to feature XXX
+exec make
+pick c0ffeee The oneline of the next commit
+edit deadbab The oneline of the commit after
+exec cd subdir; make test
+...
+-------------------------------------------
+
+The interactive rebase will stop when a command fails (i.e. exits with
+non-0 status) to give you an opportunity to fix the problem. You can
+continue with `git rebase --continue`.
+
+The "exec" command launches the command in a shell (the one specified
+in `$SHELL`, or the default shell if `$SHELL` is not set), so you can
+use shell features (like "cd", ">", ";" ...). The command is run from
+the root of the working tree.
+
+----------------------------------
+$ git rebase -i --exec "make test"
+----------------------------------
+
+This command lets you check that intermediate commits are compilable.
+The todo list becomes like that:
+
+--------------------
+pick 5928aea one
+exec make test
+pick 04d0fda two
+exec make test
+pick ba46169 three
+exec make test
+pick f4593f9 four
+exec make test
+--------------------
+
+SPLITTING COMMITS
+-----------------
+
+In interactive mode, you can mark commits with the action "edit".  However,
+this does not necessarily mean that 'git rebase' expects the result of this
+edit to be exactly one commit.  Indeed, you can undo the commit, or you can
+add other commits.  This can be used to split a commit into two:
+
+- Start an interactive rebase with `git rebase -i <commit>^`, where
+  <commit> is the commit you want to split.  In fact, any commit range
+  will do, as long as it contains that commit.
+
+- Mark the commit you want to split with the action "edit".
+
+- When it comes to editing that commit, execute `git reset HEAD^`.  The
+  effect is that the HEAD is rewound by one, and the index follows suit.
+  However, the working tree stays the same.
+
+- Now add the changes to the index that you want to have in the first
+  commit.  You can use `git add` (possibly interactively) or
+  'git gui' (or both) to do that.
+
+- Commit the now-current index with whatever commit message is appropriate
+  now.
+
+- Repeat the last two steps until your working tree is clean.
+
+- Continue the rebase with `git rebase --continue`.
+
+If you are not absolutely sure that the intermediate revisions are
+consistent (they compile, pass the testsuite, etc.) you should use
+'git stash' to stash away the not-yet-committed changes
+after each commit, test, and amend the commit if fixes are necessary.
+
+
+RECOVERING FROM UPSTREAM REBASE
+-------------------------------
+
+Rebasing (or any other form of rewriting) a branch that others have
+based work on is a bad idea: anyone downstream of it is forced to
+manually fix their history.  This section explains how to do the fix
+from the downstream's point of view.  The real fix, however, would be
+to avoid rebasing the upstream in the first place.
+
+To illustrate, suppose you are in a situation where someone develops a
+'subsystem' branch, and you are working on a 'topic' that is dependent
+on this 'subsystem'.  You might end up with a history like the
+following:
+
+------------
+    o---o---o---o---o---o---o---o  master
+	 \
+	  o---o---o---o---o  subsystem
+			   \
+			    *---*---*  topic
+------------
+
+If 'subsystem' is rebased against 'master', the following happens:
+
+------------
+    o---o---o---o---o---o---o---o  master
+	 \			 \
+	  o---o---o---o---o	  o'--o'--o'--o'--o'  subsystem
+			   \
+			    *---*---*  topic
+------------
+
+If you now continue development as usual, and eventually merge 'topic'
+to 'subsystem', the commits from 'subsystem' will remain duplicated forever:
+
+------------
+    o---o---o---o---o---o---o---o  master
+	 \			 \
+	  o---o---o---o---o	  o'--o'--o'--o'--o'--M	 subsystem
+			   \			     /
+			    *---*---*-..........-*--*  topic
+------------
+
+Such duplicates are generally frowned upon because they clutter up
+history, making it harder to follow.  To clean things up, you need to
+transplant the commits on 'topic' to the new 'subsystem' tip, i.e.,
+rebase 'topic'.  This becomes a ripple effect: anyone downstream from
+'topic' is forced to rebase too, and so on!
+
+There are two kinds of fixes, discussed in the following subsections:
+
+Easy case: The changes are literally the same.::
+
+	This happens if the 'subsystem' rebase was a simple rebase and
+	had no conflicts.
+
+Hard case: The changes are not the same.::
+
+	This happens if the 'subsystem' rebase had conflicts, or used
+	`--interactive` to omit, edit, squash, or fixup commits; or
+	if the upstream used one of `commit --amend`, `reset`, or
+	`filter-branch`.
+
+
+The easy case
+~~~~~~~~~~~~~
+
+Only works if the changes (patch IDs based on the diff contents) on
+'subsystem' are literally the same before and after the rebase
+'subsystem' did.
+
+In that case, the fix is easy because 'git rebase' knows to skip
+changes that are already present in the new upstream.  So if you say
+(assuming you're on 'topic')
+------------
+    $ git rebase subsystem
+------------
+you will end up with the fixed history
+------------
+    o---o---o---o---o---o---o---o  master
+				 \
+				  o'--o'--o'--o'--o'  subsystem
+						   \
+						    *---*---*  topic
+------------
+
+
+The hard case
+~~~~~~~~~~~~~
+
+Things get more complicated if the 'subsystem' changes do not exactly
+correspond to the ones before the rebase.
+
+NOTE: While an "easy case recovery" sometimes appears to be successful
+      even in the hard case, it may have unintended consequences.  For
+      example, a commit that was removed via `git rebase
+      --interactive` will be **resurrected**!
+
+The idea is to manually tell 'git rebase' "where the old 'subsystem'
+ended and your 'topic' began", that is, what the old merge-base
+between them was.  You will have to find a way to name the last commit
+of the old 'subsystem', for example:
+
+* With the 'subsystem' reflog: after 'git fetch', the old tip of
+  'subsystem' is at `subsystem@{1}`.  Subsequent fetches will
+  increase the number.  (See linkgit:git-reflog[1].)
+
+* Relative to the tip of 'topic': knowing that your 'topic' has three
+  commits, the old tip of 'subsystem' must be `topic~3`.
+
+You can then transplant the old `subsystem..topic` to the new tip by
+saying (for the reflog case, and assuming you are on 'topic' already):
+------------
+    $ git rebase --onto subsystem subsystem@{1}
+------------
+
+The ripple effect of a "hard case" recovery is especially bad:
+'everyone' downstream from 'topic' will now have to perform a "hard
+case" recovery too!
+
+REBASING MERGES
+---------------
+
+The interactive rebase command was originally designed to handle
+individual patch series. As such, it makes sense to exclude merge
+commits from the todo list, as the developer may have merged the
+then-current `master` while working on the branch, only to rebase
+all the commits onto `master` eventually (skipping the merge
+commits).
+
+However, there are legitimate reasons why a developer may want to
+recreate merge commits: to keep the branch structure (or "commit
+topology") when working on multiple, inter-related branches.
+
+In the following example, the developer works on a topic branch that
+refactors the way buttons are defined, and on another topic branch
+that uses that refactoring to implement a "Report a bug" button. The
+output of `git log --graph --format=%s -5` may look like this:
+
+------------
+*   Merge branch 'report-a-bug'
+|\
+| * Add the feedback button
+* | Merge branch 'refactor-button'
+|\ \
+| |/
+| * Use the Button class for all buttons
+| * Extract a generic Button class from the DownloadButton one
+------------
+
+The developer might want to rebase those commits to a newer `master`
+while keeping the branch topology, for example when the first topic
+branch is expected to be integrated into `master` much earlier than the
+second one, say, to resolve merge conflicts with changes to the
+DownloadButton class that made it into `master`.
+
+This rebase can be performed using the `--rebase-merges` option.
+It will generate a todo list looking like this:
+
+------------
+label onto
+
+# Branch: refactor-button
+reset onto
+pick 123456 Extract a generic Button class from the DownloadButton one
+pick 654321 Use the Button class for all buttons
+label refactor-button
+
+# Branch: report-a-bug
+reset refactor-button # Use the Button class for all buttons
+pick abcdef Add the feedback button
+label report-a-bug
+
+reset onto
+merge -C a1b2c3 refactor-button # Merge 'refactor-button'
+merge -C 6f5e4d report-a-bug # Merge 'report-a-bug'
+------------
+
+In contrast to a regular interactive rebase, there are `label`, `reset`
+and `merge` commands in addition to `pick` ones.
+
+The `label` command associates a label with the current HEAD when that
+command is executed. These labels are created as worktree-local refs
+(`refs/rewritten/<label>`) that will be deleted when the rebase
+finishes. That way, rebase operations in multiple worktrees linked to
+the same repository do not interfere with one another. If the `label`
+command fails, it is rescheduled immediately, with a helpful message how
+to proceed.
+
+The `reset` command resets the HEAD, index and worktree to the specified
+revision. It is similar to an `exec git reset --hard <label>`, but
+refuses to overwrite untracked files. If the `reset` command fails, it is
+rescheduled immediately, with a helpful message how to edit the todo list
+(this typically happens when a `reset` command was inserted into the todo
+list manually and contains a typo).
+
+The `merge` command will merge the specified revision(s) into whatever
+is HEAD at that time. With `-C <original-commit>`, the commit message of
+the specified merge commit will be used. When the `-C` is changed to
+a lower-case `-c`, the message will be opened in an editor after a
+successful merge so that the user can edit the message.
+
+If a `merge` command fails for any reason other than merge conflicts (i.e.
+when the merge operation did not even start), it is rescheduled immediately.
+
+At this time, the `merge` command will *always* use the `recursive`
+merge strategy for regular merges, and `octopus` for octopus merges,
+with no way to choose a different one. To work around
+this, an `exec` command can be used to call `git merge` explicitly,
+using the fact that the labels are worktree-local refs (the ref
+`refs/rewritten/onto` would correspond to the label `onto`, for example).
+
+Note: the first command (`label onto`) labels the revision onto which
+the commits are rebased; The name `onto` is just a convention, as a nod
+to the `--onto` option.
+
+It is also possible to introduce completely new merge commits from scratch
+by adding a command of the form `merge <merge-head>`. This form will
+generate a tentative commit message and always open an editor to let the
+user edit it. This can be useful e.g. when a topic branch turns out to
+address more than a single concern and wants to be split into two or
+even more topic branches. Consider this todo list:
+
+------------
+pick 192837 Switch from GNU Makefiles to CMake
+pick 5a6c7e Document the switch to CMake
+pick 918273 Fix detection of OpenSSL in CMake
+pick afbecd http: add support for TLS v1.3
+pick fdbaec Fix detection of cURL in CMake on Windows
+------------
+
+The one commit in this list that is not related to CMake may very well
+have been motivated by working on fixing all those bugs introduced by
+switching to CMake, but it addresses a different concern. To split this
+branch into two topic branches, the todo list could be edited like this:
+
+------------
+label onto
+
+pick afbecd http: add support for TLS v1.3
+label tlsv1.3
+
+reset onto
+pick 192837 Switch from GNU Makefiles to CMake
+pick 918273 Fix detection of OpenSSL in CMake
+pick fdbaec Fix detection of cURL in CMake on Windows
+pick 5a6c7e Document the switch to CMake
+label cmake
+
+reset onto
+merge tlsv1.3
+merge cmake
+------------
+
+BUGS
+----
+The todo list presented by the deprecated `--preserve-merges --interactive`
+does not represent the topology of the revision graph (use `--rebase-merges`
+instead).  Editing commits and rewording their commit messages should work
+fine, but attempts to reorder commits tend to produce counterintuitive results.
+Use `--rebase-merges` in such scenarios instead.
+
+For example, an attempt to rearrange
+------------
+1 --- 2 --- 3 --- 4 --- 5
+------------
+to
+------------
+1 --- 2 --- 4 --- 3 --- 5
+------------
+by moving the "pick 4" line will result in the following history:
+------------
+	3
+       /
+1 --- 2 --- 4 --- 5
+------------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-receive-pack.txt b/third_party/git/Documentation/git-receive-pack.txt
new file mode 100644
index 0000000000..dedf97efbb
--- /dev/null
+++ b/third_party/git/Documentation/git-receive-pack.txt
@@ -0,0 +1,252 @@
+git-receive-pack(1)
+===================
+
+NAME
+----
+git-receive-pack - Receive what is pushed into the repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git-receive-pack' <directory>
+
+DESCRIPTION
+-----------
+Invoked by 'git send-pack' and updates the repository with the
+information fed from the remote end.
+
+This command is usually not invoked directly by the end user.
+The UI for the protocol is on the 'git send-pack' side, and the
+program pair is meant to be used to push updates to remote
+repository.  For pull operations, see linkgit:git-fetch-pack[1].
+
+The command allows for creation and fast-forwarding of sha1 refs
+(heads/tags) on the remote end (strictly speaking, it is the
+local end 'git-receive-pack' runs, but to the user who is sitting at
+the send-pack end, it is updating the remote.  Confused?)
+
+There are other real-world examples of using update and
+post-update hooks found in the Documentation/howto directory.
+
+'git-receive-pack' honours the receive.denyNonFastForwards config
+option, which tells it if updates to a ref should be denied if they
+are not fast-forwards.
+
+A number of other receive.* config options are available to tweak
+its behavior, see linkgit:git-config[1].
+
+OPTIONS
+-------
+<directory>::
+	The repository to sync into.
+
+PRE-RECEIVE HOOK
+----------------
+Before any ref is updated, if $GIT_DIR/hooks/pre-receive file exists
+and is executable, it will be invoked once with no parameters.  The
+standard input of the hook will be one line per ref to be updated:
+
+       sha1-old SP sha1-new SP refname LF
+
+The refname value is relative to $GIT_DIR; e.g. for the master
+head this is "refs/heads/master".  The two sha1 values before
+each refname are the object names for the refname before and after
+the update.  Refs to be created will have sha1-old equal to 0\{40},
+while refs to be deleted will have sha1-new equal to 0\{40}, otherwise
+sha1-old and sha1-new should be valid objects in the repository.
+
+When accepting a signed push (see linkgit:git-push[1]), the signed
+push certificate is stored in a blob and an environment variable
+`GIT_PUSH_CERT` can be consulted for its object name.  See the
+description of `post-receive` hook for an example.  In addition, the
+certificate is verified using GPG and the result is exported with
+the following environment variables:
+
+`GIT_PUSH_CERT_SIGNER`::
+	The name and the e-mail address of the owner of the key that
+	signed the push certificate.
+
+`GIT_PUSH_CERT_KEY`::
+	The GPG key ID of the key that signed the push certificate.
+
+`GIT_PUSH_CERT_STATUS`::
+	The status of GPG verification of the push certificate,
+	using the same mnemonic as used in `%G?` format of `git log`
+	family of commands (see linkgit:git-log[1]).
+
+`GIT_PUSH_CERT_NONCE`::
+	The nonce string the process asked the signer to include
+	in the push certificate.  If this does not match the value
+	recorded on the "nonce" header in the push certificate, it
+	may indicate that the certificate is a valid one that is
+	being replayed from a separate "git push" session.
+
+`GIT_PUSH_CERT_NONCE_STATUS`::
+`UNSOLICITED`;;
+	"git push --signed" sent a nonce when we did not ask it to
+	send one.
+`MISSING`;;
+	"git push --signed" did not send any nonce header.
+`BAD`;;
+	"git push --signed" sent a bogus nonce.
+`OK`;;
+	"git push --signed" sent the nonce we asked it to send.
+`SLOP`;;
+	"git push --signed" sent a nonce different from what we
+	asked it to send now, but in a previous session.  See
+	`GIT_PUSH_CERT_NONCE_SLOP` environment variable.
+
+`GIT_PUSH_CERT_NONCE_SLOP`::
+	"git push --signed" sent a nonce different from what we
+	asked it to send now, but in a different session whose
+	starting time is different by this many seconds from the
+	current session.  Only meaningful when
+	`GIT_PUSH_CERT_NONCE_STATUS` says `SLOP`.
+	Also read about `receive.certNonceSlop` variable in
+	linkgit:git-config[1].
+
+This hook is called before any refname is updated and before any
+fast-forward checks are performed.
+
+If the pre-receive hook exits with a non-zero exit status no updates
+will be performed, and the update, post-receive and post-update
+hooks will not be invoked either.  This can be useful to quickly
+bail out if the update is not to be supported.
+
+See the notes on the quarantine environment below.
+
+UPDATE HOOK
+-----------
+Before each ref is updated, if $GIT_DIR/hooks/update file exists
+and is executable, it is invoked once per ref, with three parameters:
+
+       $GIT_DIR/hooks/update refname sha1-old sha1-new
+
+The refname parameter is relative to $GIT_DIR; e.g. for the master
+head this is "refs/heads/master".  The two sha1 arguments are
+the object names for the refname before and after the update.
+Note that the hook is called before the refname is updated,
+so either sha1-old is 0\{40} (meaning there is no such ref yet),
+or it should match what is recorded in refname.
+
+The hook should exit with non-zero status if it wants to disallow
+updating the named ref.  Otherwise it should exit with zero.
+
+Successful execution (a zero exit status) of this hook does not
+ensure the ref will actually be updated, it is only a prerequisite.
+As such it is not a good idea to send notices (e.g. email) from
+this hook.  Consider using the post-receive hook instead.
+
+POST-RECEIVE HOOK
+-----------------
+After all refs were updated (or attempted to be updated), if any
+ref update was successful, and if $GIT_DIR/hooks/post-receive
+file exists and is executable, it will be invoked once with no
+parameters.  The standard input of the hook will be one line
+for each successfully updated ref:
+
+       sha1-old SP sha1-new SP refname LF
+
+The refname value is relative to $GIT_DIR; e.g. for the master
+head this is "refs/heads/master".  The two sha1 values before
+each refname are the object names for the refname before and after
+the update.  Refs that were created will have sha1-old equal to
+0\{40}, while refs that were deleted will have sha1-new equal to
+0\{40}, otherwise sha1-old and sha1-new should be valid objects in
+the repository.
+
+The `GIT_PUSH_CERT*` environment variables can be inspected, just as
+in `pre-receive` hook, after accepting a signed push.
+
+Using this hook, it is easy to generate mails describing the updates
+to the repository.  This example script sends one mail message per
+ref listing the commits pushed to the repository, and logs the push
+certificates of signed pushes with good signatures to a logger
+service:
+
+	#!/bin/sh
+	# mail out commit update information.
+	while read oval nval ref
+	do
+		if expr "$oval" : '0*$' >/dev/null
+		then
+			echo "Created a new ref, with the following commits:"
+			git rev-list --pretty "$nval"
+		else
+			echo "New commits:"
+			git rev-list --pretty "$nval" "^$oval"
+		fi |
+		mail -s "Changes to ref $ref" commit-list@mydomain
+	done
+	# log signed push certificate, if any
+	if test -n "${GIT_PUSH_CERT-}" && test ${GIT_PUSH_CERT_STATUS} = G
+	then
+		(
+			echo expected nonce is ${GIT_PUSH_NONCE}
+			git cat-file blob ${GIT_PUSH_CERT}
+		) | mail -s "push certificate from $GIT_PUSH_CERT_SIGNER" push-log@mydomain
+	fi
+	exit 0
+
+The exit code from this hook invocation is ignored, however a
+non-zero exit code will generate an error message.
+
+Note that it is possible for refname to not have sha1-new when this
+hook runs.  This can easily occur if another user modifies the ref
+after it was updated by 'git-receive-pack', but before the hook was able
+to evaluate it.  It is recommended that hooks rely on sha1-new
+rather than the current value of refname.
+
+POST-UPDATE HOOK
+----------------
+After all other processing, if at least one ref was updated, and
+if $GIT_DIR/hooks/post-update file exists and is executable, then
+post-update will be called with the list of refs that have been updated.
+This can be used to implement any repository wide cleanup tasks.
+
+The exit code from this hook invocation is ignored; the only thing
+left for 'git-receive-pack' to do at that point is to exit itself
+anyway.
+
+This hook can be used, for example, to run `git update-server-info`
+if the repository is packed and is served via a dumb transport.
+
+	#!/bin/sh
+	exec git update-server-info
+
+
+QUARANTINE ENVIRONMENT
+----------------------
+
+When `receive-pack` takes in objects, they are placed into a temporary
+"quarantine" directory within the `$GIT_DIR/objects` directory and
+migrated into the main object store only after the `pre-receive` hook
+has completed. If the push fails before then, the temporary directory is
+removed entirely.
+
+This has a few user-visible effects and caveats:
+
+  1. Pushes which fail due to problems with the incoming pack, missing
+     objects, or due to the `pre-receive` hook will not leave any
+     on-disk data. This is usually helpful to prevent repeated failed
+     pushes from filling up your disk, but can make debugging more
+     challenging.
+
+  2. Any objects created by the `pre-receive` hook will be created in
+     the quarantine directory (and migrated only if it succeeds).
+
+  3. The `pre-receive` hook MUST NOT update any refs to point to
+     quarantined objects. Other programs accessing the repository will
+     not be able to see the objects (and if the pre-receive hook fails,
+     those refs would become corrupted). For safety, any ref updates
+     from within `pre-receive` are automatically rejected.
+
+
+SEE ALSO
+--------
+linkgit:git-send-pack[1], linkgit:gitnamespaces[7]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-reflog.txt b/third_party/git/Documentation/git-reflog.txt
new file mode 100644
index 0000000000..ff487ff77d
--- /dev/null
+++ b/third_party/git/Documentation/git-reflog.txt
@@ -0,0 +1,138 @@
+git-reflog(1)
+=============
+
+NAME
+----
+git-reflog - Manage reflog information
+
+
+SYNOPSIS
+--------
+[verse]
+'git reflog' <subcommand> <options>
+
+DESCRIPTION
+-----------
+The command takes various subcommands, and different options
+depending on the subcommand:
+
+[verse]
+'git reflog' ['show'] [log-options] [<ref>]
+'git reflog expire' [--expire=<time>] [--expire-unreachable=<time>]
+	[--rewrite] [--updateref] [--stale-fix]
+	[--dry-run | -n] [--verbose] [--all [--single-worktree] | <refs>...]
+'git reflog delete' [--rewrite] [--updateref]
+	[--dry-run | -n] [--verbose] ref@\{specifier\}...
+'git reflog exists' <ref>
+
+Reference logs, or "reflogs", record when the tips of branches and
+other references were updated in the local repository. Reflogs are
+useful in various Git commands, to specify the old value of a
+reference. For example, `HEAD@{2}` means "where HEAD used to be two
+moves ago", `master@{one.week.ago}` means "where master used to point
+to one week ago in this local repository", and so on. See
+linkgit:gitrevisions[7] for more details.
+
+This command manages the information recorded in the reflogs.
+
+The "show" subcommand (which is also the default, in the absence of
+any subcommands) shows the log of the reference provided in the
+command-line (or `HEAD`, by default). The reflog covers all recent
+actions, and in addition the `HEAD` reflog records branch switching.
+`git reflog show` is an alias for `git log -g --abbrev-commit
+--pretty=oneline`; see linkgit:git-log[1] for more information.
+
+The "expire" subcommand prunes older reflog entries. Entries older
+than `expire` time, or entries older than `expire-unreachable` time
+and not reachable from the current tip, are removed from the reflog.
+This is typically not used directly by end users -- instead, see
+linkgit:git-gc[1].
+
+The "delete" subcommand deletes single entries from the reflog. Its
+argument must be an _exact_ entry (e.g. "`git reflog delete
+master@{2}`"). This subcommand is also typically not used directly by
+end users.
+
+The "exists" subcommand checks whether a ref has a reflog.  It exits
+with zero status if the reflog exists, and non-zero status if it does
+not.
+
+OPTIONS
+-------
+
+Options for `show`
+~~~~~~~~~~~~~~~~~~
+
+`git reflog show` accepts any of the options accepted by `git log`.
+
+
+Options for `expire`
+~~~~~~~~~~~~~~~~~~~~
+
+--all::
+	Process the reflogs of all references.
+
+--single-worktree::
+	By default when `--all` is specified, reflogs from all working
+	trees are processed. This option limits the processing to reflogs
+	from the current working tree only.
+
+--expire=<time>::
+	Prune entries older than the specified time. If this option is
+	not specified, the expiration time is taken from the
+	configuration setting `gc.reflogExpire`, which in turn
+	defaults to 90 days. `--expire=all` prunes entries regardless
+	of their age; `--expire=never` turns off pruning of reachable
+	entries (but see `--expire-unreachable`).
+
+--expire-unreachable=<time>::
+	Prune entries older than `<time>` that are not reachable from
+	the current tip of the branch. If this option is not
+	specified, the expiration time is taken from the configuration
+	setting `gc.reflogExpireUnreachable`, which in turn defaults
+	to 30 days. `--expire-unreachable=all` prunes unreachable
+	entries regardless of their age; `--expire-unreachable=never`
+	turns off early pruning of unreachable entries (but see
+	`--expire`).
+
+--updateref::
+	Update the reference to the value of the top reflog entry (i.e.
+	<ref>@\{0\}) if the previous top entry was pruned.  (This
+	option is ignored for symbolic references.)
+
+--rewrite::
+	If a reflog entry's predecessor is pruned, adjust its "old"
+	SHA-1 to be equal to the "new" SHA-1 field of the entry that
+	now precedes it.
+
+--stale-fix::
+	Prune any reflog entries that point to "broken commits". A
+	broken commit is a commit that is not reachable from any of
+	the reference tips and that refers, directly or indirectly, to
+	a missing commit, tree, or blob object.
++
+This computation involves traversing all the reachable objects, i.e. it
+has the same cost as 'git prune'.  It is primarily intended to fix
+corruption caused by garbage collecting using older versions of Git,
+which didn't protect objects referred to by reflogs.
+
+-n::
+--dry-run::
+	Do not actually prune any entries; just show what would have
+	been pruned.
+
+--verbose::
+	Print extra information on screen.
+
+
+Options for `delete`
+~~~~~~~~~~~~~~~~~~~~
+
+`git reflog delete` accepts options `--updateref`, `--rewrite`, `-n`,
+`--dry-run`, and `--verbose`, with the same meanings as when they are
+used with `expire`.
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-remote-ext.txt b/third_party/git/Documentation/git-remote-ext.txt
new file mode 100644
index 0000000000..88ea7e1cc0
--- /dev/null
+++ b/third_party/git/Documentation/git-remote-ext.txt
@@ -0,0 +1,125 @@
+git-remote-ext(1)
+=================
+
+NAME
+----
+git-remote-ext - Bridge smart transport to external command.
+
+SYNOPSIS
+--------
+[verse]
+git remote add <nick> "ext::<command>[ <arguments>...]"
+
+DESCRIPTION
+-----------
+This remote helper uses the specified '<command>' to connect
+to a remote Git server.
+
+Data written to stdin of the specified '<command>' is assumed
+to be sent to a git:// server, git-upload-pack, git-receive-pack
+or git-upload-archive (depending on situation), and data read
+from stdout of <command> is assumed to be received from
+the same service.
+
+Command and arguments are separated by an unescaped space.
+
+The following sequences have a special meaning:
+
+'% '::
+	Literal space in command or argument.
+
+'%%'::
+	Literal percent sign.
+
+'%s'::
+	Replaced with name (receive-pack, upload-pack, or
+	upload-archive) of the service Git wants to invoke.
+
+'%S'::
+	Replaced with long name (git-receive-pack,
+	git-upload-pack, or git-upload-archive) of the service
+	Git wants to invoke.
+
+'%G' (must be the first characters in an argument)::
+	This argument will not be passed to '<command>'. Instead, it
+	will cause the helper to start by sending git:// service requests to
+	the remote side with the service field set to an appropriate value and
+	the repository field set to rest of the argument. Default is not to send
+	such a request.
++
+This is useful if remote side is git:// server accessed over
+some tunnel.
+
+'%V' (must be first characters in argument)::
+	This argument will not be passed to '<command>'. Instead it sets
+	the vhost field in the git:// service request (to rest of the argument).
+	Default is not to send vhost in such request (if sent).
+
+ENVIRONMENT VARIABLES
+---------------------
+
+GIT_TRANSLOOP_DEBUG::
+	If set, prints debugging information about various reads/writes.
+
+ENVIRONMENT VARIABLES PASSED TO COMMAND
+---------------------------------------
+
+GIT_EXT_SERVICE::
+	Set to long name (git-upload-pack, etc...) of service helper needs
+	to invoke.
+
+GIT_EXT_SERVICE_NOPREFIX::
+	Set to long name (upload-pack, etc...) of service helper needs
+	to invoke.
+
+
+EXAMPLES
+--------
+This remote helper is transparently used by Git when
+you use commands such as "git fetch <URL>", "git clone <URL>",
+, "git push <URL>" or "git remote add <nick> <URL>", where <URL>
+begins with `ext::`.  Examples:
+
+"ext::ssh -i /home/foo/.ssh/somekey user&#64;host.example %S 'foo/repo'"::
+	Like host.example:foo/repo, but use /home/foo/.ssh/somekey as
+	keypair and user as user on remote side. This avoids needing to
+	edit .ssh/config.
+
+"ext::socat -t3600 - ABSTRACT-CONNECT:/git-server %G/somerepo"::
+	Represents repository with path /somerepo accessible over
+	git protocol at abstract namespace address /git-server.
+
+"ext::git-server-alias foo %G/repo"::
+	Represents a repository with path /repo accessed using the
+	helper program "git-server-alias foo".  The path to the
+	repository and type of request are not passed on the command
+	line but as part of the protocol stream, as usual with git://
+	protocol.
+
+"ext::git-server-alias foo %G/repo %Vfoo"::
+	Represents a repository with path /repo accessed using the
+	helper program "git-server-alias foo".  The hostname for the
+	remote server passed in the protocol stream will be "foo"
+	(this allows multiple virtual Git servers to share a
+	link-level address).
+
+"ext::git-server-alias foo %G/repo% with% spaces %Vfoo"::
+	Represents a repository with path `/repo with spaces` accessed
+	using the helper program "git-server-alias foo".  The hostname for
+	the remote server passed in the protocol stream will be "foo"
+	(this allows multiple virtual Git servers to share a
+	link-level address).
+
+"ext::git-ssl foo.example /bar"::
+	Represents a repository accessed using the helper program
+	"git-ssl foo.example /bar".  The type of request can be
+	determined by the helper using environment variables (see
+	above).
+
+SEE ALSO
+--------
+linkgit:gitremote-helpers[7]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-remote-fd.txt b/third_party/git/Documentation/git-remote-fd.txt
new file mode 100644
index 0000000000..0451ceb8a2
--- /dev/null
+++ b/third_party/git/Documentation/git-remote-fd.txt
@@ -0,0 +1,59 @@
+git-remote-fd(1)
+================
+
+NAME
+----
+git-remote-fd - Reflect smart transport stream back to caller
+
+SYNOPSIS
+--------
+"fd::<infd>[,<outfd>][/<anything>]" (as URL)
+
+DESCRIPTION
+-----------
+This helper uses specified file descriptors to connect to a remote Git server.
+This is not meant for end users but for programs and scripts calling git
+fetch, push or archive.
+
+If only <infd> is given, it is assumed to be a bidirectional socket connected
+to remote Git server (git-upload-pack, git-receive-pack or
+git-upload-archive). If both <infd> and <outfd> are given, they are assumed
+to be pipes connected to a remote Git server (<infd> being the inbound pipe
+and <outfd> being the outbound pipe.
+
+It is assumed that any handshaking procedures have already been completed
+(such as sending service request for git://) before this helper is started.
+
+<anything> can be any string. It is ignored. It is meant for providing
+information to user in the URL in case that URL is displayed in some
+context.
+
+ENVIRONMENT VARIABLES
+---------------------
+GIT_TRANSLOOP_DEBUG::
+	If set, prints debugging information about various reads/writes.
+
+EXAMPLES
+--------
+`git fetch fd::17 master`::
+	Fetch master, using file descriptor #17 to communicate with
+	git-upload-pack.
+
+`git fetch fd::17/foo master`::
+	Same as above.
+
+`git push fd::7,8 master (as URL)`::
+	Push master, using file descriptor #7 to read data from
+	git-receive-pack and file descriptor #8 to write data to
+	same service.
+
+`git push fd::7,8/bar master`::
+	Same as above.
+
+SEE ALSO
+--------
+linkgit:gitremote-helpers[7]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-remote-helpers.txto b/third_party/git/Documentation/git-remote-helpers.txto
new file mode 100644
index 0000000000..6f353ebfd3
--- /dev/null
+++ b/third_party/git/Documentation/git-remote-helpers.txto
@@ -0,0 +1,9 @@
+git-remote-helpers
+==================
+
+This document has been moved to linkgit:gitremote-helpers[7].
+
+Please let the owners of the referring site know so that they can update the
+link you clicked to get here.
+
+Thanks.
diff --git a/third_party/git/Documentation/git-remote.txt b/third_party/git/Documentation/git-remote.txt
new file mode 100644
index 0000000000..9659abbf8e
--- /dev/null
+++ b/third_party/git/Documentation/git-remote.txt
@@ -0,0 +1,256 @@
+git-remote(1)
+=============
+
+NAME
+----
+git-remote - Manage set of tracked repositories
+
+
+SYNOPSIS
+--------
+[verse]
+'git remote' [-v | --verbose]
+'git remote add' [-t <branch>] [-m <master>] [-f] [--[no-]tags] [--mirror=<fetch|push>] <name> <url>
+'git remote rename' <old> <new>
+'git remote remove' <name>
+'git remote set-head' <name> (-a | --auto | -d | --delete | <branch>)
+'git remote set-branches' [--add] <name> <branch>...
+'git remote get-url' [--push] [--all] <name>
+'git remote set-url' [--push] <name> <newurl> [<oldurl>]
+'git remote set-url --add' [--push] <name> <newurl>
+'git remote set-url --delete' [--push] <name> <url>
+'git remote' [-v | --verbose] 'show' [-n] <name>...
+'git remote prune' [-n | --dry-run] <name>...
+'git remote' [-v | --verbose] 'update' [-p | --prune] [(<group> | <remote>)...]
+
+DESCRIPTION
+-----------
+
+Manage the set of repositories ("remotes") whose branches you track.
+
+
+OPTIONS
+-------
+
+-v::
+--verbose::
+	Be a little more verbose and show remote url after name.
+	NOTE: This must be placed between `remote` and `subcommand`.
+
+
+COMMANDS
+--------
+
+With no arguments, shows a list of existing remotes.  Several
+subcommands are available to perform operations on the remotes.
+
+'add'::
+
+Adds a remote named <name> for the repository at
+<url>.  The command `git fetch <name>` can then be used to create and
+update remote-tracking branches <name>/<branch>.
++
+With `-f` option, `git fetch <name>` is run immediately after
+the remote information is set up.
++
+With `--tags` option, `git fetch <name>` imports every tag from the
+remote repository.
++
+With `--no-tags` option, `git fetch <name>` does not import tags from
+the remote repository.
++
+By default, only tags on fetched branches are imported
+(see linkgit:git-fetch[1]).
++
+With `-t <branch>` option, instead of the default glob
+refspec for the remote to track all branches under
+the `refs/remotes/<name>/` namespace, a refspec to track only `<branch>`
+is created.  You can give more than one `-t <branch>` to track
+multiple branches without grabbing all branches.
++
+With `-m <master>` option, a symbolic-ref `refs/remotes/<name>/HEAD` is set
+up to point at remote's `<master>` branch. See also the set-head command.
++
+When a fetch mirror is created with `--mirror=fetch`, the refs will not
+be stored in the 'refs/remotes/' namespace, but rather everything in
+'refs/' on the remote will be directly mirrored into 'refs/' in the
+local repository. This option only makes sense in bare repositories,
+because a fetch would overwrite any local commits.
++
+When a push mirror is created with `--mirror=push`, then `git push`
+will always behave as if `--mirror` was passed.
+
+'rename'::
+
+Rename the remote named <old> to <new>. All remote-tracking branches and
+configuration settings for the remote are updated.
++
+In case <old> and <new> are the same, and <old> is a file under
+`$GIT_DIR/remotes` or `$GIT_DIR/branches`, the remote is converted to
+the configuration file format.
+
+'remove'::
+'rm'::
+
+Remove the remote named <name>. All remote-tracking branches and
+configuration settings for the remote are removed.
+
+'set-head'::
+
+Sets or deletes the default branch (i.e. the target of the
+symbolic-ref `refs/remotes/<name>/HEAD`) for
+the named remote. Having a default branch for a remote is not required,
+but allows the name of the remote to be specified in lieu of a specific
+branch. For example, if the default branch for `origin` is set to
+`master`, then `origin` may be specified wherever you would normally
+specify `origin/master`.
++
+With `-d` or `--delete`, the symbolic ref `refs/remotes/<name>/HEAD` is deleted.
++
+With `-a` or `--auto`, the remote is queried to determine its `HEAD`, then the
+symbolic-ref `refs/remotes/<name>/HEAD` is set to the same branch. e.g., if the remote
+`HEAD` is pointed at `next`, "`git remote set-head origin -a`" will set
+the symbolic-ref `refs/remotes/origin/HEAD` to `refs/remotes/origin/next`. This will
+only work if `refs/remotes/origin/next` already exists; if not it must be
+fetched first.
++
+Use `<branch>` to set the symbolic-ref `refs/remotes/<name>/HEAD` explicitly. e.g., "git
+remote set-head origin master" will set the symbolic-ref `refs/remotes/origin/HEAD` to
+`refs/remotes/origin/master`. This will only work if
+`refs/remotes/origin/master` already exists; if not it must be fetched first.
++
+
+'set-branches'::
+
+Changes the list of branches tracked by the named remote.
+This can be used to track a subset of the available remote branches
+after the initial setup for a remote.
++
+The named branches will be interpreted as if specified with the
+`-t` option on the 'git remote add' command line.
++
+With `--add`, instead of replacing the list of currently tracked
+branches, adds to that list.
+
+'get-url'::
+
+Retrieves the URLs for a remote. Configurations for `insteadOf` and
+`pushInsteadOf` are expanded here. By default, only the first URL is listed.
++
+With `--push`, push URLs are queried rather than fetch URLs.
++
+With `--all`, all URLs for the remote will be listed.
+
+'set-url'::
+
+Changes URLs for the remote. Sets first URL for remote <name> that matches
+regex <oldurl> (first URL if no <oldurl> is given) to <newurl>. If
+<oldurl> doesn't match any URL, an error occurs and nothing is changed.
++
+With `--push`, push URLs are manipulated instead of fetch URLs.
++
+With `--add`, instead of changing existing URLs, new URL is added.
++
+With `--delete`, instead of changing existing URLs, all URLs matching
+regex <url> are deleted for remote <name>.  Trying to delete all
+non-push URLs is an error.
++
+Note that the push URL and the fetch URL, even though they can
+be set differently, must still refer to the same place.  What you
+pushed to the push URL should be what you would see if you
+immediately fetched from the fetch URL.  If you are trying to
+fetch from one place (e.g. your upstream) and push to another (e.g.
+your publishing repository), use two separate remotes.
+
+
+'show'::
+
+Gives some information about the remote <name>.
++
+With `-n` option, the remote heads are not queried first with
+`git ls-remote <name>`; cached information is used instead.
+
+'prune'::
+
+Deletes stale references associated with <name>. By default, stale
+remote-tracking branches under <name> are deleted, but depending on
+global configuration and the configuration of the remote we might even
+prune local tags that haven't been pushed there. Equivalent to `git
+fetch --prune <name>`, except that no new references will be fetched.
++
+See the PRUNING section of linkgit:git-fetch[1] for what it'll prune
+depending on various configuration.
++
+With `--dry-run` option, report what branches will be pruned, but do not
+actually prune them.
+
+'update'::
+
+Fetch updates for remotes or remote groups in the repository as defined by
+remotes.<group>.  If neither group nor remote is specified on the command line,
+the configuration parameter remotes.default will be used; if
+remotes.default is not defined, all remotes which do not have the
+configuration parameter remote.<name>.skipDefaultUpdate set to true will
+be updated.  (See linkgit:git-config[1]).
++
+With `--prune` option, run pruning against all the remotes that are updated.
+
+
+DISCUSSION
+----------
+
+The remote configuration is achieved using the `remote.origin.url` and
+`remote.origin.fetch` configuration variables.  (See
+linkgit:git-config[1]).
+
+EXAMPLES
+--------
+
+* Add a new remote, fetch, and check out a branch from it
++
+------------
+$ git remote
+origin
+$ git branch -r
+  origin/HEAD -> origin/master
+  origin/master
+$ git remote add staging git://git.kernel.org/.../gregkh/staging.git
+$ git remote
+origin
+staging
+$ git fetch staging
+...
+From git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
+ * [new branch]      master     -> staging/master
+ * [new branch]      staging-linus -> staging/staging-linus
+ * [new branch]      staging-next -> staging/staging-next
+$ git branch -r
+  origin/HEAD -> origin/master
+  origin/master
+  staging/master
+  staging/staging-linus
+  staging/staging-next
+$ git switch -c staging staging/master
+...
+------------
+
+* Imitate 'git clone' but track only selected branches
++
+------------
+$ mkdir project.git
+$ cd project.git
+$ git init
+$ git remote add -f -t master -m master origin git://example.com/git.git/
+$ git merge origin
+------------
+
+
+SEE ALSO
+--------
+linkgit:git-fetch[1]
+linkgit:git-branch[1]
+linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-repack.txt b/third_party/git/Documentation/git-repack.txt
new file mode 100644
index 0000000000..92f146d27d
--- /dev/null
+++ b/third_party/git/Documentation/git-repack.txt
@@ -0,0 +1,188 @@
+git-repack(1)
+=============
+
+NAME
+----
+git-repack - Pack unpacked objects in a repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git repack' [-a] [-A] [-d] [-f] [-F] [-l] [-n] [-q] [-b] [--window=<n>] [--depth=<n>] [--threads=<n>] [--keep-pack=<pack-name>]
+
+DESCRIPTION
+-----------
+
+This command is used to combine all objects that do not currently
+reside in a "pack", into a pack.  It can also be used to re-organize
+existing packs into a single, more efficient pack.
+
+A pack is a collection of objects, individually compressed, with
+delta compression applied, stored in a single file, with an
+associated index file.
+
+Packs are used to reduce the load on mirror systems, backup
+engines, disk storage, etc.
+
+OPTIONS
+-------
+
+-a::
+	Instead of incrementally packing the unpacked objects,
+	pack everything referenced into a single pack.
+	Especially useful when packing a repository that is used
+	for private development. Use
+	with `-d`.  This will clean up the objects that `git prune`
+	leaves behind, but `git fsck --full --dangling` shows as
+	dangling.
++
+Note that users fetching over dumb protocols will have to fetch the
+whole new pack in order to get any contained object, no matter how many
+other objects in that pack they already have locally.
++
+Promisor packfiles are repacked separately: if there are packfiles that
+have an associated ".promisor" file, these packfiles will be repacked
+into another separate pack, and an empty ".promisor" file corresponding
+to the new separate pack will be written.
+
+-A::
+	Same as `-a`, unless `-d` is used.  Then any unreachable
+	objects in a previous pack become loose, unpacked objects,
+	instead of being left in the old pack.  Unreachable objects
+	are never intentionally added to a pack, even when repacking.
+	This option prevents unreachable objects from being immediately
+	deleted by way of being left in the old pack and then
+	removed.  Instead, the loose unreachable objects
+	will be pruned according to normal expiry rules
+	with the next 'git gc' invocation. See linkgit:git-gc[1].
+
+-d::
+	After packing, if the newly created packs make some
+	existing packs redundant, remove the redundant packs.
+	Also run  'git prune-packed' to remove redundant
+	loose object files.
+
+-l::
+	Pass the `--local` option to 'git pack-objects'. See
+	linkgit:git-pack-objects[1].
+
+-f::
+	Pass the `--no-reuse-delta` option to `git-pack-objects`, see
+	linkgit:git-pack-objects[1].
+
+-F::
+	Pass the `--no-reuse-object` option to `git-pack-objects`, see
+	linkgit:git-pack-objects[1].
+
+-q::
+	Pass the `-q` option to 'git pack-objects'. See
+	linkgit:git-pack-objects[1].
+
+-n::
+	Do not update the server information with
+	'git update-server-info'.  This option skips
+	updating local catalog files needed to publish
+	this repository (or a direct copy of it)
+	over HTTP or FTP.  See linkgit:git-update-server-info[1].
+
+--window=<n>::
+--depth=<n>::
+	These two options affect how the objects contained in the pack are
+	stored using delta compression. The objects are first internally
+	sorted by type, size and optionally names and compared against the
+	other objects within `--window` to see if using delta compression saves
+	space. `--depth` limits the maximum delta depth; making it too deep
+	affects the performance on the unpacker side, because delta data needs
+	to be applied that many times to get to the necessary object.
++
+The default value for --window is 10 and --depth is 50. The maximum
+depth is 4095.
+
+--threads=<n>::
+	This option is passed through to `git pack-objects`.
+
+--window-memory=<n>::
+	This option provides an additional limit on top of `--window`;
+	the window size will dynamically scale down so as to not take
+	up more than '<n>' bytes in memory.  This is useful in
+	repositories with a mix of large and small objects to not run
+	out of memory with a large window, but still be able to take
+	advantage of the large window for the smaller objects.  The
+	size can be suffixed with "k", "m", or "g".
+	`--window-memory=0` makes memory usage unlimited.  The default
+	is taken from the `pack.windowMemory` configuration variable.
+	Note that the actual memory usage will be the limit multiplied
+	by the number of threads used by linkgit:git-pack-objects[1].
+
+--max-pack-size=<n>::
+	Maximum size of each output pack file. The size can be suffixed with
+	"k", "m", or "g". The minimum size allowed is limited to 1 MiB.
+	If specified, multiple packfiles may be created, which also
+	prevents the creation of a bitmap index.
+	The default is unlimited, unless the config variable
+	`pack.packSizeLimit` is set.
+
+-b::
+--write-bitmap-index::
+	Write a reachability bitmap index as part of the repack. This
+	only makes sense when used with `-a` or `-A`, as the bitmaps
+	must be able to refer to all reachable objects. This option
+	overrides the setting of `repack.writeBitmaps`.  This option
+	has no effect if multiple packfiles are created.
+
+--pack-kept-objects::
+	Include objects in `.keep` files when repacking.  Note that we
+	still do not delete `.keep` packs after `pack-objects` finishes.
+	This means that we may duplicate objects, but this makes the
+	option safe to use when there are concurrent pushes or fetches.
+	This option is generally only useful if you are writing bitmaps
+	with `-b` or `repack.writeBitmaps`, as it ensures that the
+	bitmapped packfile has the necessary objects.
+
+--keep-pack=<pack-name>::
+	Exclude the given pack from repacking. This is the equivalent
+	of having `.keep` file on the pack. `<pack-name>` is the
+	pack file name without leading directory (e.g. `pack-123.pack`).
+	The option could be specified multiple times to keep multiple
+	packs.
+
+--unpack-unreachable=<when>::
+	When loosening unreachable objects, do not bother loosening any
+	objects older than `<when>`. This can be used to optimize out
+	the write of any objects that would be immediately pruned by
+	a follow-up `git prune`.
+
+-k::
+--keep-unreachable::
+	When used with `-ad`, any unreachable objects from existing
+	packs will be appended to the end of the packfile instead of
+	being removed. In addition, any unreachable loose objects will
+	be packed (and their loose counterparts removed).
+
+-i::
+--delta-islands::
+	Pass the `--delta-islands` option to `git-pack-objects`, see
+	linkgit:git-pack-objects[1].
+
+Configuration
+-------------
+
+By default, the command passes `--delta-base-offset` option to
+'git pack-objects'; this typically results in slightly smaller packs,
+but the generated packs are incompatible with versions of Git older than
+version 1.4.4. If you need to share your repository with such ancient Git
+versions, either directly or via the dumb http protocol, then you
+need to set the configuration variable `repack.UseDeltaBaseOffset` to
+"false" and repack. Access from old Git versions over the native protocol
+is unaffected by this option as the conversion is performed on the fly
+as needed in that case.
+
+SEE ALSO
+--------
+linkgit:git-pack-objects[1]
+linkgit:git-prune-packed[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-replace.txt b/third_party/git/Documentation/git-replace.txt
new file mode 100644
index 0000000000..246dc9943c
--- /dev/null
+++ b/third_party/git/Documentation/git-replace.txt
@@ -0,0 +1,161 @@
+git-replace(1)
+==============
+
+NAME
+----
+git-replace - Create, list, delete refs to replace objects
+
+SYNOPSIS
+--------
+[verse]
+'git replace' [-f] <object> <replacement>
+'git replace' [-f] --edit <object>
+'git replace' [-f] --graft <commit> [<parent>...]
+'git replace' [-f] --convert-graft-file
+'git replace' -d <object>...
+'git replace' [--format=<format>] [-l [<pattern>]]
+
+DESCRIPTION
+-----------
+Adds a 'replace' reference in `refs/replace/` namespace.
+
+The name of the 'replace' reference is the SHA-1 of the object that is
+replaced. The content of the 'replace' reference is the SHA-1 of the
+replacement object.
+
+The replaced object and the replacement object must be of the same type.
+This restriction can be bypassed using `-f`.
+
+Unless `-f` is given, the 'replace' reference must not yet exist.
+
+There is no other restriction on the replaced and replacement objects.
+Merge commits can be replaced by non-merge commits and vice versa.
+
+Replacement references will be used by default by all Git commands
+except those doing reachability traversal (prune, pack transfer and
+fsck).
+
+It is possible to disable use of replacement references for any
+command using the `--no-replace-objects` option just after 'git'.
+
+For example if commit 'foo' has been replaced by commit 'bar':
+
+------------------------------------------------
+$ git --no-replace-objects cat-file commit foo
+------------------------------------------------
+
+shows information about commit 'foo', while:
+
+------------------------------------------------
+$ git cat-file commit foo
+------------------------------------------------
+
+shows information about commit 'bar'.
+
+The `GIT_NO_REPLACE_OBJECTS` environment variable can be set to
+achieve the same effect as the `--no-replace-objects` option.
+
+OPTIONS
+-------
+-f::
+--force::
+	If an existing replace ref for the same object exists, it will
+	be overwritten (instead of failing).
+
+-d::
+--delete::
+	Delete existing replace refs for the given objects.
+
+--edit <object>::
+	Edit an object's content interactively. The existing content
+	for <object> is pretty-printed into a temporary file, an
+	editor is launched on the file, and the result is parsed to
+	create a new object of the same type as <object>. A
+	replacement ref is then created to replace <object> with the
+	newly created object. See linkgit:git-var[1] for details about
+	how the editor will be chosen.
+
+--raw::
+	When editing, provide the raw object contents rather than
+	pretty-printed ones. Currently this only affects trees, which
+	will be shown in their binary form. This is harder to work with,
+	but can help when repairing a tree that is so corrupted it
+	cannot be pretty-printed. Note that you may need to configure
+	your editor to cleanly read and write binary data.
+
+--graft <commit> [<parent>...]::
+	Create a graft commit. A new commit is created with the same
+	content as <commit> except that its parents will be
+	[<parent>...] instead of <commit>'s parents. A replacement ref
+	is then created to replace <commit> with the newly created
+	commit. Use `--convert-graft-file` to convert a
+	`$GIT_DIR/info/grafts` file and use replace refs instead.
+
+--convert-graft-file::
+	Creates graft commits for all entries in `$GIT_DIR/info/grafts`
+	and deletes that file upon success. The purpose is to help users
+	with transitioning off of the now-deprecated graft file.
+
+-l <pattern>::
+--list <pattern>::
+	List replace refs for objects that match the given pattern (or
+	all if no pattern is given).
+	Typing "git replace" without arguments, also lists all replace
+	refs.
+
+--format=<format>::
+	When listing, use the specified <format>, which can be one of
+	'short', 'medium' and 'long'. When omitted, the format
+	defaults to 'short'.
+
+FORMATS
+-------
+
+The following format are available:
+
+* 'short':
+	<replaced sha1>
+* 'medium':
+	<replaced sha1> -> <replacement sha1>
+* 'long':
+	<replaced sha1> (<replaced type>) -> <replacement sha1> (<replacement type>)
+
+CREATING REPLACEMENT OBJECTS
+----------------------------
+
+linkgit:git-filter-branch[1], linkgit:git-hash-object[1] and
+linkgit:git-rebase[1], among other git commands, can be used to create
+replacement objects from existing objects. The `--edit` option can
+also be used with 'git replace' to create a replacement object by
+editing an existing object.
+
+If you want to replace many blobs, trees or commits that are part of a
+string of commits, you may just want to create a replacement string of
+commits and then only replace the commit at the tip of the target
+string of commits with the commit at the tip of the replacement string
+of commits.
+
+BUGS
+----
+Comparing blobs or trees that have been replaced with those that
+replace them will not work properly. And using `git reset --hard` to
+go back to a replaced commit will move the branch to the replacement
+commit instead of the replaced commit.
+
+There may be other problems when using 'git rev-list' related to
+pending objects.
+
+SEE ALSO
+--------
+linkgit:git-hash-object[1]
+linkgit:git-filter-branch[1]
+linkgit:git-rebase[1]
+linkgit:git-tag[1]
+linkgit:git-branch[1]
+linkgit:git-commit[1]
+linkgit:git-var[1]
+linkgit:git[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-request-pull.txt b/third_party/git/Documentation/git-request-pull.txt
new file mode 100644
index 0000000000..4d4392d0f8
--- /dev/null
+++ b/third_party/git/Documentation/git-request-pull.txt
@@ -0,0 +1,79 @@
+git-request-pull(1)
+===================
+
+NAME
+----
+git-request-pull - Generates a summary of pending changes
+
+SYNOPSIS
+--------
+[verse]
+'git request-pull' [-p] <start> <url> [<end>]
+
+DESCRIPTION
+-----------
+
+Generate a request asking your upstream project to pull changes into
+their tree.  The request, printed to the standard output,
+begins with the branch description, summarizes
+the changes and indicates from where they can be pulled.
+
+The upstream project is expected to have the commit named by
+`<start>` and the output asks it to integrate the changes you made
+since that commit, up to the commit named by `<end>`, by visiting
+the repository named by `<url>`.
+
+
+OPTIONS
+-------
+-p::
+	Include patch text in the output.
+
+<start>::
+	Commit to start at.  This names a commit that is already in
+	the upstream history.
+
+<url>::
+	The repository URL to be pulled from.
+
+<end>::
+	Commit to end at (defaults to HEAD).  This names the commit
+	at the tip of the history you are asking to be pulled.
++
+When the repository named by `<url>` has the commit at a tip of a
+ref that is different from the ref you have locally, you can use the
+`<local>:<remote>` syntax, to have its local name, a colon `:`, and
+its remote name.
+
+
+EXAMPLES
+--------
+
+Imagine that you built your work on your `master` branch on top of
+the `v1.0` release, and want it to be integrated to the project.
+First you push that change to your public repository for others to
+see:
+
+	git push https://git.ko.xz/project master
+
+Then, you run this command:
+
+	git request-pull v1.0 https://git.ko.xz/project master
+
+which will produce a request to the upstream, summarizing the
+changes between the `v1.0` release and your `master`, to pull it
+from your public repository.
+
+If you pushed your change to a branch whose name is different from
+the one you have locally, e.g.
+
+	git push https://git.ko.xz/project master:for-linus
+
+then you can ask that to be pulled with
+
+	git request-pull v1.0 https://git.ko.xz/project master:for-linus
+
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-rerere.txt b/third_party/git/Documentation/git-rerere.txt
new file mode 100644
index 0000000000..4cfc883378
--- /dev/null
+++ b/third_party/git/Documentation/git-rerere.txt
@@ -0,0 +1,222 @@
+git-rerere(1)
+=============
+
+NAME
+----
+git-rerere - Reuse recorded resolution of conflicted merges
+
+SYNOPSIS
+--------
+[verse]
+'git rerere' ['clear'|'forget' <pathspec>|'diff'|'remaining'|'status'|'gc']
+
+DESCRIPTION
+-----------
+
+In a workflow employing relatively long lived topic branches,
+the developer sometimes needs to resolve the same conflicts over
+and over again until the topic branches are done (either merged
+to the "release" branch, or sent out and accepted upstream).
+
+This command assists the developer in this process by recording
+conflicted automerge results and corresponding hand resolve results
+on the initial manual merge, and applying previously recorded
+hand resolutions to their corresponding automerge results.
+
+[NOTE]
+You need to set the configuration variable `rerere.enabled` in order to
+enable this command.
+
+
+COMMANDS
+--------
+
+Normally, 'git rerere' is run without arguments or user-intervention.
+However, it has several commands that allow it to interact with
+its working state.
+
+'clear'::
+
+Reset the metadata used by rerere if a merge resolution is to be
+aborted.  Calling 'git am [--skip|--abort]' or 'git rebase [--skip|--abort]'
+will automatically invoke this command.
+
+'forget' <pathspec>::
+
+Reset the conflict resolutions which rerere has recorded for the current
+conflict in <pathspec>.
+
+'diff'::
+
+Display diffs for the current state of the resolution.  It is
+useful for tracking what has changed while the user is resolving
+conflicts.  Additional arguments are passed directly to the system
+'diff' command installed in PATH.
+
+'status'::
+
+Print paths with conflicts whose merge resolution rerere will record.
+
+'remaining'::
+
+Print paths with conflicts that have not been autoresolved by rerere.
+This includes paths whose resolutions cannot be tracked by rerere,
+such as conflicting submodules.
+
+'gc'::
+
+Prune records of conflicted merges that
+occurred a long time ago.  By default, unresolved conflicts older
+than 15 days and resolved conflicts older than 60
+days are pruned.  These defaults are controlled via the
+`gc.rerereUnresolved` and `gc.rerereResolved` configuration
+variables respectively.
+
+
+DISCUSSION
+----------
+
+When your topic branch modifies an overlapping area that your
+master branch (or upstream) touched since your topic branch
+forked from it, you may want to test it with the latest master,
+even before your topic branch is ready to be pushed upstream:
+
+------------
+              o---*---o topic
+             /
+    o---o---o---*---o---o master
+------------
+
+For such a test, you need to merge master and topic somehow.
+One way to do it is to pull master into the topic branch:
+
+------------
+	$ git switch topic
+	$ git merge master
+
+              o---*---o---+ topic
+             /           /
+    o---o---o---*---o---o master
+------------
+
+The commits marked with `*` touch the same area in the same
+file; you need to resolve the conflicts when creating the commit
+marked with `+`.  Then you can test the result to make sure your
+work-in-progress still works with what is in the latest master.
+
+After this test merge, there are two ways to continue your work
+on the topic.  The easiest is to build on top of the test merge
+commit `+`, and when your work in the topic branch is finally
+ready, pull the topic branch into master, and/or ask the
+upstream to pull from you.  By that time, however, the master or
+the upstream might have been advanced since the test merge `+`,
+in which case the final commit graph would look like this:
+
+------------
+	$ git switch topic
+	$ git merge master
+	$ ... work on both topic and master branches
+	$ git switch master
+	$ git merge topic
+
+              o---*---o---+---o---o topic
+             /           /         \
+    o---o---o---*---o---o---o---o---+ master
+------------
+
+When your topic branch is long-lived, however, your topic branch
+would end up having many such "Merge from master" commits on it,
+which would unnecessarily clutter the development history.
+Readers of the Linux kernel mailing list may remember that Linus
+complained about such too frequent test merges when a subsystem
+maintainer asked to pull from a branch full of "useless merges".
+
+As an alternative, to keep the topic branch clean of test
+merges, you could blow away the test merge, and keep building on
+top of the tip before the test merge:
+
+------------
+	$ git switch topic
+	$ git merge master
+	$ git reset --hard HEAD^ ;# rewind the test merge
+	$ ... work on both topic and master branches
+	$ git switch master
+	$ git merge topic
+
+              o---*---o-------o---o topic
+             /                     \
+    o---o---o---*---o---o---o---o---+ master
+------------
+
+This would leave only one merge commit when your topic branch is
+finally ready and merged into the master branch.  This merge
+would require you to resolve the conflict, introduced by the
+commits marked with `*`.  However, this conflict is often the
+same conflict you resolved when you created the test merge you
+blew away.  'git rerere' helps you resolve this final
+conflicted merge using the information from your earlier hand
+resolve.
+
+Running the 'git rerere' command immediately after a conflicted
+automerge records the conflicted working tree files, with the
+usual conflict markers `<<<<<<<`, `=======`, and `>>>>>>>` in
+them.  Later, after you are done resolving the conflicts,
+running 'git rerere' again will record the resolved state of these
+files.  Suppose you did this when you created the test merge of
+master into the topic branch.
+
+Next time, after seeing the same conflicted automerge,
+running 'git rerere' will perform a three-way merge between the
+earlier conflicted automerge, the earlier manual resolution, and
+the current conflicted automerge.
+If this three-way merge resolves cleanly, the result is written
+out to your working tree file, so you do not have to manually
+resolve it.  Note that 'git rerere' leaves the index file alone,
+so you still need to do the final sanity checks with `git diff`
+(or `git diff -c`) and 'git add' when you are satisfied.
+
+As a convenience measure, 'git merge' automatically invokes
+'git rerere' upon exiting with a failed automerge and 'git rerere'
+records the hand resolve when it is a new conflict, or reuses the earlier hand
+resolve when it is not.  'git commit' also invokes 'git rerere'
+when committing a merge result.  What this means is that you do
+not have to do anything special yourself (besides enabling
+the rerere.enabled config variable).
+
+In our example, when you do the test merge, the manual
+resolution is recorded, and it will be reused when you do the
+actual merge later with the updated master and topic branch, as long
+as the recorded resolution is still applicable.
+
+The information 'git rerere' records is also used when running
+'git rebase'.  After blowing away the test merge and continuing
+development on the topic branch:
+
+------------
+              o---*---o-------o---o topic
+             /
+    o---o---o---*---o---o---o---o   master
+
+	$ git rebase master topic
+
+				  o---*---o-------o---o topic
+				 /
+    o---o---o---*---o---o---o---o   master
+------------
+
+you could run `git rebase master topic`, to bring yourself
+up to date before your topic is ready to be sent upstream.
+This would result in falling back to a three-way merge, and it
+would conflict the same way as the test merge you resolved earlier.
+'git rerere' will be run by 'git rebase' to help you resolve this
+conflict.
+
+[NOTE] 'git rerere' relies on the conflict markers in the file to
+detect the conflict.  If the file already contains lines that look the
+same as lines with conflict markers, 'git rerere' may fail to record a
+conflict resolution.  To work around this, the `conflict-marker-size`
+setting in linkgit:gitattributes[5] can be used.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-reset.txt b/third_party/git/Documentation/git-reset.txt
new file mode 100644
index 0000000000..97e0544d9e
--- /dev/null
+++ b/third_party/git/Documentation/git-reset.txt
@@ -0,0 +1,475 @@
+git-reset(1)
+============
+
+NAME
+----
+git-reset - Reset current HEAD to the specified state
+
+SYNOPSIS
+--------
+[verse]
+'git reset' [-q] [<tree-ish>] [--] <paths>...
+'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]
+'git reset' [--soft | --mixed [-N] | --hard | --merge | --keep] [-q] [<commit>]
+
+DESCRIPTION
+-----------
+In the first and second form, copy entries from `<tree-ish>` to the index.
+In the third form, set the current branch head (`HEAD`) to `<commit>`,
+optionally modifying index and working tree to match.
+The `<tree-ish>`/`<commit>` defaults to `HEAD` in all forms.
+
+'git reset' [-q] [<tree-ish>] [--] <paths>...::
+	This form resets the index entries for all `<paths>` to their
+	state at `<tree-ish>`.  (It does not affect the working tree or
+	the current branch.)
++
+This means that `git reset <paths>` is the opposite of `git add
+<paths>`. This command is equivalent to
+`git restore [--source=<tree-ish>] --staged <paths>...`.
++
+After running `git reset <paths>` to update the index entry, you can
+use linkgit:git-restore[1] to check the contents out of the index to
+the working tree. Alternatively, using linkgit:git-restore[1]
+and specifying a commit with `--source`, you
+can copy the contents of a path out of a commit to the index and to the
+working tree in one go.
+
+'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]::
+	Interactively select hunks in the difference between the index
+	and `<tree-ish>` (defaults to `HEAD`).  The chosen hunks are applied
+	in reverse to the index.
++
+This means that `git reset -p` is the opposite of `git add -p`, i.e.
+you can use it to selectively reset hunks. See the ``Interactive Mode''
+section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
+
+'git reset' [<mode>] [<commit>]::
+	This form resets the current branch head to `<commit>` and
+	possibly updates the index (resetting it to the tree of `<commit>`) and
+	the working tree depending on `<mode>`. If `<mode>` is omitted,
+	defaults to `--mixed`. The `<mode>` must be one of the following:
++
+--
+--soft::
+	Does not touch the index file or the working tree at all (but
+	resets the head to `<commit>`, just like all modes do). This leaves
+	all your changed files "Changes to be committed", as `git status`
+	would put it.
+
+--mixed::
+	Resets the index but not the working tree (i.e., the changed files
+	are preserved but not marked for commit) and reports what has not
+	been updated. This is the default action.
++
+If `-N` is specified, removed paths are marked as intent-to-add (see
+linkgit:git-add[1]).
+
+--hard::
+	Resets the index and working tree. Any changes to tracked files in the
+	working tree since `<commit>` are discarded.
+
+--merge::
+	Resets the index and updates the files in the working tree that are
+	different between `<commit>` and `HEAD`, but keeps those which are
+	different between the index and working tree (i.e. which have changes
+	which have not been added).
+	If a file that is different between `<commit>` and the index has
+	unstaged changes, reset is aborted.
++
+In other words, `--merge` does something like a `git read-tree -u -m <commit>`,
+but carries forward unmerged index entries.
+
+--keep::
+	Resets index entries and updates files in the working tree that are
+	different between `<commit>` and `HEAD`.
+	If a file that is different between `<commit>` and `HEAD` has local
+	changes, reset is aborted.
+--
+
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
+
+
+OPTIONS
+-------
+
+-q::
+--quiet::
+--no-quiet::
+	Be quiet, only report errors. The default behavior is set by the
+	`reset.quiet` config option. `--quiet` and `--no-quiet` will
+	override the default behavior.
+
+
+EXAMPLES
+--------
+
+Undo add::
++
+------------
+$ edit                                     <1>
+$ git add frotz.c filfre.c
+$ mailx                                    <2>
+$ git reset                                <3>
+$ git pull git://info.example.com/ nitfol  <4>
+------------
++
+<1> You are happily working on something, and find the changes
+    in these files are in good order.  You do not want to see them
+    when you run `git diff`, because you plan to work on other files
+    and changes with these files are distracting.
+<2> Somebody asks you to pull, and the changes sound worthy of merging.
+<3> However, you already dirtied the index (i.e. your index does
+    not match the `HEAD` commit).  But you know the pull you are going
+    to make does not affect `frotz.c` or `filfre.c`, so you revert the
+    index changes for these two files.  Your changes in working tree
+    remain there.
+<4> Then you can pull and merge, leaving `frotz.c` and `filfre.c`
+    changes still in the working tree.
+
+Undo a commit and redo::
++
+------------
+$ git commit ...
+$ git reset --soft HEAD^      <1>
+$ edit                        <2>
+$ git commit -a -c ORIG_HEAD  <3>
+------------
++
+<1> This is most often done when you remembered what you
+    just committed is incomplete, or you misspelled your commit
+    message, or both.  Leaves working tree as it was before "reset".
+<2> Make corrections to working tree files.
+<3> "reset" copies the old head to `.git/ORIG_HEAD`; redo the
+    commit by starting with its log message.  If you do not need to
+    edit the message further, you can give `-C` option instead.
++
+See also the `--amend` option to linkgit:git-commit[1].
+
+Undo a commit, making it a topic branch::
++
+------------
+$ git branch topic/wip          <1>
+$ git reset --hard HEAD~3       <2>
+$ git switch topic/wip          <3>
+------------
++
+<1> You have made some commits, but realize they were premature
+    to be in the `master` branch.  You want to continue polishing
+    them in a topic branch, so create `topic/wip` branch off of the
+    current `HEAD`.
+<2> Rewind the master branch to get rid of those three commits.
+<3> Switch to `topic/wip` branch and keep working.
+
+Undo commits permanently::
++
+------------
+$ git commit ...
+$ git reset --hard HEAD~3   <1>
+------------
++
+<1> The last three commits (`HEAD`, `HEAD^`, and `HEAD~2`) were bad
+    and you do not want to ever see them again.  Do *not* do this if
+    you have already given these commits to somebody else.  (See the
+    "RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1]
+    for the implications of doing so.)
+
+Undo a merge or pull::
++
+------------
+$ git pull                         <1>
+Auto-merging nitfol
+CONFLICT (content): Merge conflict in nitfol
+Automatic merge failed; fix conflicts and then commit the result.
+$ git reset --hard                 <2>
+$ git pull . topic/branch          <3>
+Updating from 41223... to 13134...
+Fast-forward
+$ git reset --hard ORIG_HEAD       <4>
+------------
++
+<1> Try to update from the upstream resulted in a lot of
+    conflicts; you were not ready to spend a lot of time merging
+    right now, so you decide to do that later.
+<2> "pull" has not made merge commit, so `git reset --hard`
+    which is a synonym for `git reset --hard HEAD` clears the mess
+    from the index file and the working tree.
+<3> Merge a topic branch into the current branch, which resulted
+    in a fast-forward.
+<4> But you decided that the topic branch is not ready for public
+    consumption yet.  "pull" or "merge" always leaves the original
+    tip of the current branch in `ORIG_HEAD`, so resetting hard to it
+    brings your index file and the working tree back to that state,
+    and resets the tip of the branch to that commit.
+
+Undo a merge or pull inside a dirty working tree::
++
+------------
+$ git pull                         <1>
+Auto-merging nitfol
+Merge made by recursive.
+ nitfol                |   20 +++++----
+ ...
+$ git reset --merge ORIG_HEAD      <2>
+------------
++
+<1> Even if you may have local modifications in your
+    working tree, you can safely say `git pull` when you know
+    that the change in the other branch does not overlap with
+    them.
+<2> After inspecting the result of the merge, you may find
+    that the change in the other branch is unsatisfactory.  Running
+    `git reset --hard ORIG_HEAD` will let you go back to where you
+    were, but it will discard your local changes, which you do not
+    want.  `git reset --merge` keeps your local changes.
+
+
+Interrupted workflow::
++
+Suppose you are interrupted by an urgent fix request while you
+are in the middle of a large change.  The files in your
+working tree are not in any shape to be committed yet, but you
+need to get to the other branch for a quick bugfix.
++
+------------
+$ git switch feature  ;# you were working in "feature" branch and
+$ work work work      ;# got interrupted
+$ git commit -a -m "snapshot WIP"                 <1>
+$ git switch master
+$ fix fix fix
+$ git commit ;# commit with real log
+$ git switch feature
+$ git reset --soft HEAD^ ;# go back to WIP state  <2>
+$ git reset                                       <3>
+------------
++
+<1> This commit will get blown away so a throw-away log message is OK.
+<2> This removes the 'WIP' commit from the commit history, and sets
+    your working tree to the state just before you made that snapshot.
+<3> At this point the index file still has all the WIP changes you
+    committed as 'snapshot WIP'.  This updates the index to show your
+    WIP files as uncommitted.
++
+See also linkgit:git-stash[1].
+
+Reset a single file in the index::
++
+Suppose you have added a file to your index, but later decide you do not
+want to add it to your commit. You can remove the file from the index
+while keeping your changes with git reset.
++
+------------
+$ git reset -- frotz.c                      <1>
+$ git commit -m "Commit files in index"     <2>
+$ git add frotz.c                           <3>
+------------
++
+<1> This removes the file from the index while keeping it in the working
+    directory.
+<2> This commits all other changes in the index.
+<3> Adds the file to the index again.
+
+Keep changes in working tree while discarding some previous commits::
++
+Suppose you are working on something and you commit it, and then you
+continue working a bit more, but now you think that what you have in
+your working tree should be in another branch that has nothing to do
+with what you committed previously. You can start a new branch and
+reset it while keeping the changes in your working tree.
++
+------------
+$ git tag start
+$ git switch -c branch1
+$ edit
+$ git commit ...                            <1>
+$ edit
+$ git switch -c branch2                     <2>
+$ git reset --keep start                    <3>
+------------
++
+<1> This commits your first edits in `branch1`.
+<2> In the ideal world, you could have realized that the earlier
+    commit did not belong to the new topic when you created and switched
+    to `branch2` (i.e. `git switch -c branch2 start`), but nobody is
+    perfect.
+<3> But you can use `reset --keep` to remove the unwanted commit after
+    you switched to `branch2`.
+
+Split a commit apart into a sequence of commits::
++
+Suppose that you have created lots of logically separate changes and committed
+them together. Then, later you decide that it might be better to have each
+logical chunk associated with its own commit. You can use git reset to rewind
+history without changing the contents of your local files, and then successively
+use `git add -p` to interactively select which hunks to include into each commit,
+using `git commit -c` to pre-populate the commit message.
++
+------------
+$ git reset -N HEAD^                        <1>
+$ git add -p                                <2>
+$ git diff --cached                         <3>
+$ git commit -c HEAD@{1}                    <4>
+...                                         <5>
+$ git add ...                               <6>
+$ git diff --cached                         <7>
+$ git commit ...                            <8>
+------------
++
+<1> First, reset the history back one commit so that we remove the original
+    commit, but leave the working tree with all the changes. The -N ensures
+    that any new files added with `HEAD` are still marked so that `git add -p`
+    will find them.
+<2> Next, we interactively select diff hunks to add using the `git add -p`
+    facility. This will ask you about each diff hunk in sequence and you can
+    use simple commands such as "yes, include this", "No don't include this"
+    or even the very powerful "edit" facility.
+<3> Once satisfied with the hunks you want to include, you should verify what
+    has been prepared for the first commit by using `git diff --cached`. This
+    shows all the changes that have been moved into the index and are about
+    to be committed.
+<4> Next, commit the changes stored in the index. The `-c` option specifies to
+    pre-populate the commit message from the original message that you started
+    with in the first commit. This is helpful to avoid retyping it. The
+    `HEAD@{1}` is a special notation for the commit that `HEAD` used to be at
+    prior to the original reset commit (1 change ago).
+    See linkgit:git-reflog[1] for more details. You may also use any other
+    valid commit reference.
+<5> You can repeat steps 2-4 multiple times to break the original code into
+    any number of commits.
+<6> Now you've split out many of the changes into their own commits, and might
+    no longer use the patch mode of `git add`, in order to select all remaining
+    uncommitted changes.
+<7> Once again, check to verify that you've included what you want to. You may
+    also wish to verify that git diff doesn't show any remaining changes to be
+    committed later.
+<8> And finally create the final commit.
+
+
+DISCUSSION
+----------
+
+The tables below show what happens when running:
+
+----------
+git reset --option target
+----------
+
+to reset the `HEAD` to another commit (`target`) with the different
+reset options depending on the state of the files.
+
+In these tables, `A`, `B`, `C` and `D` are some different states of a
+file. For example, the first line of the first table means that if a
+file is in state `A` in the working tree, in state `B` in the index, in
+state `C` in `HEAD` and in state `D` in the target, then `git reset --soft
+target` will leave the file in the working tree in state `A` and in the
+index in state `B`.  It resets (i.e. moves) the `HEAD` (i.e. the tip of
+the current branch, if you are on one) to `target` (which has the file
+in state `D`).
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ A       B     C    D     --soft   A       B     D
+			  --mixed  A       D     D
+			  --hard   D       D     D
+			  --merge (disallowed)
+			  --keep  (disallowed)
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ A       B     C    C     --soft   A       B     C
+			  --mixed  A       C     C
+			  --hard   C       C     C
+			  --merge (disallowed)
+			  --keep   A       C     C
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       B     C    D     --soft   B       B     D
+			  --mixed  B       D     D
+			  --hard   D       D     D
+			  --merge  D       D     D
+			  --keep  (disallowed)
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       B     C    C     --soft   B       B     C
+			  --mixed  B       C     C
+			  --hard   C       C     C
+			  --merge  C       C     C
+			  --keep   B       C     C
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       C     C    D     --soft   B       C     D
+			  --mixed  B       D     D
+			  --hard   D       D     D
+			  --merge (disallowed)
+			  --keep  (disallowed)
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ B       C     C    C     --soft   B       C     C
+			  --mixed  B       C     C
+			  --hard   C       C     C
+			  --merge  B       C     C
+			  --keep   B       C     C
+....
+
+`reset --merge` is meant to be used when resetting out of a conflicted
+merge. Any mergy operation guarantees that the working tree file that is
+involved in the merge does not have a local change with respect to the index
+before it starts, and that it writes the result out to the working tree. So if
+we see some difference between the index and the target and also
+between the index and the working tree, then it means that we are not
+resetting out from a state that a mergy operation left after failing
+with a conflict. That is why we disallow `--merge` option in this case.
+
+`reset --keep` is meant to be used when removing some of the last
+commits in the current branch while keeping changes in the working
+tree. If there could be conflicts between the changes in the commit we
+want to remove and the changes in the working tree we want to keep,
+the reset is disallowed. That's why it is disallowed if there are both
+changes between the working tree and `HEAD`, and between `HEAD` and the
+target. To be safe, it is also disallowed when there are unmerged
+entries.
+
+The following tables show what happens when there are unmerged
+entries:
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ X       U     A    B     --soft  (disallowed)
+			  --mixed  X       B     B
+			  --hard   B       B     B
+			  --merge  B       B     B
+			  --keep  (disallowed)
+....
+
+....
+working index HEAD target         working index HEAD
+----------------------------------------------------
+ X       U     A    A     --soft  (disallowed)
+			  --mixed  X       A     A
+			  --hard   A       A     A
+			  --merge  A       A     A
+			  --keep  (disallowed)
+....
+
+`X` means any state and `U` means an unmerged index.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-restore.txt b/third_party/git/Documentation/git-restore.txt
new file mode 100644
index 0000000000..1ab2e40ea9
--- /dev/null
+++ b/third_party/git/Documentation/git-restore.txt
@@ -0,0 +1,185 @@
+git-restore(1)
+==============
+
+NAME
+----
+git-restore - Restore working tree files
+
+SYNOPSIS
+--------
+[verse]
+'git restore' [<options>] [--source=<tree>] [--staged] [--worktree] <pathspec>...
+'git restore' (-p|--patch) [<options>] [--source=<tree>] [--staged] [--worktree] [<pathspec>...]
+
+DESCRIPTION
+-----------
+Restore specified paths in the working tree with some contents from a
+restore source. If a path is tracked but does not exist in the restore
+source, it will be removed to match the source.
+
+The command can also be used to restore the content in the index with
+`--staged`, or restore both the working tree and the index with
+`--staged --worktree`.
+
+By default, the restore sources for working tree and the index are the
+index and `HEAD` respectively. `--source` could be used to specify a
+commit as the restore source.
+
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
+
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
+OPTIONS
+-------
+-s <tree>::
+--source=<tree>::
+	Restore the working tree files with the content from the given
+	tree. It is common to specify the source tree by naming a
+	commit, branch or tag associated with it.
++
+If not specified, the default restore source for the working tree is
+the index, and the default restore source for the index is
+`HEAD`. When both `--staged` and `--worktree` are specified,
+`--source` must also be specified.
+
+-p::
+--patch::
+	Interactively select hunks in the difference between the
+	restore source and the restore location. See the ``Interactive
+	Mode'' section of linkgit:git-add[1] to learn how to operate
+	the `--patch` mode.
++
+Note that `--patch` can accept no pathspec and will prompt to restore
+all modified paths.
+
+-W::
+--worktree::
+-S::
+--staged::
+	Specify the restore location. If neither option is specified,
+	by default the working tree is restored. Specifying `--staged`
+	will only restore the index. Specifying both restores both.
+
+-q::
+--quiet::
+	Quiet, suppress feedback messages. Implies `--no-progress`.
+
+--progress::
+--no-progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
+--ours::
+--theirs::
+	When restoring files in the working tree from the index, use
+	stage #2 ('ours') or #3 ('theirs') for unmerged paths.
++
+Note that during `git rebase` and `git pull --rebase`, 'ours' and
+'theirs' may appear swapped. See the explanation of the same options
+in linkgit:git-checkout[1] for details.
+
+-m::
+--merge::
+	When restoring files on the working tree from the index,
+	recreate the conflicted merge in the unmerged paths.
+
+--conflict=<style>::
+	The same as `--merge` option above, but changes the way the
+	conflicting hunks are presented, overriding the
+	`merge.conflictStyle` configuration variable.  Possible values
+	are "merge" (default) and "diff3" (in addition to what is
+	shown by "merge" style, shows the original contents).
+
+--ignore-unmerged::
+	When restoring files on the working tree from the index, do
+	not abort the operation if there are unmerged entries and
+	neither `--ours`, `--theirs`, `--merge` or `--conflict` is
+	specified. Unmerged paths on the working tree are left alone.
+
+--ignore-skip-worktree-bits::
+	In sparse checkout mode, by default is to only update entries
+	matched by `<pathspec>` and sparse patterns in
+	$GIT_DIR/info/sparse-checkout. This option ignores the sparse
+	patterns and unconditionally restores any files in
+	`<pathspec>`.
+
+--overlay::
+--no-overlay::
+	In overlay mode, the command never removes files when
+	restoring. In no-overlay mode, tracked files that do not
+	appear in the `--source` tree are removed, to make them match
+	`<tree>` exactly. The default is no-overlay mode.
+
+EXAMPLES
+--------
+
+The following sequence switches to the `master` branch, reverts the
+`Makefile` to two revisions back, deletes hello.c by mistake, and gets
+it back from the index.
+
+------------
+$ git switch master
+$ git restore --source master~2 Makefile  <1>
+$ rm -f hello.c
+$ git restore hello.c                     <2>
+------------
+
+<1> take a file out of another commit
+<2> restore hello.c from the index
+
+If you want to restore _all_ C source files to match the version in
+the index, you can say
+
+------------
+$ git restore '*.c'
+------------
+
+Note the quotes around `*.c`.  The file `hello.c` will also be
+restored, even though it is no longer in the working tree, because the
+file globbing is used to match entries in the index (not in the
+working tree by the shell).
+
+To restore all files in the current directory
+
+------------
+$ git restore .
+------------
+
+or to restore all working tree files with 'top' pathspec magic (see
+linkgit:gitglossary[7])
+
+------------
+$ git restore :/
+------------
+
+To restore a file in the index to match the version in `HEAD` (this is
+the same as using linkgit:git-reset[1])
+
+------------
+$ git restore --staged hello.c
+------------
+
+or you can restore both the index and the working tree (this the same
+as using linkgit:git-checkout[1])
+
+------------
+$ git restore --source=HEAD --staged --worktree hello.c
+------------
+
+or the short form which is more practical but less readable:
+
+------------
+$ git restore -s@ -SW hello.c
+------------
+
+SEE ALSO
+--------
+linkgit:git-checkout[1],
+linkgit:git-reset[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-rev-list.txt b/third_party/git/Documentation/git-rev-list.txt
new file mode 100644
index 0000000000..9392760b25
--- /dev/null
+++ b/third_party/git/Documentation/git-rev-list.txt
@@ -0,0 +1,124 @@
+git-rev-list(1)
+===============
+
+NAME
+----
+git-rev-list - Lists commit objects in reverse chronological order
+
+
+SYNOPSIS
+--------
+[verse]
+'git rev-list' [ --max-count=<number> ]
+	     [ --skip=<number> ]
+	     [ --max-age=<timestamp> ]
+	     [ --min-age=<timestamp> ]
+	     [ --sparse ]
+	     [ --merges ]
+	     [ --no-merges ]
+	     [ --min-parents=<number> ]
+	     [ --no-min-parents ]
+	     [ --max-parents=<number> ]
+	     [ --no-max-parents ]
+	     [ --first-parent ]
+	     [ --remove-empty ]
+	     [ --full-history ]
+	     [ --not ]
+	     [ --all ]
+	     [ --branches[=<pattern>] ]
+	     [ --tags[=<pattern>] ]
+	     [ --remotes[=<pattern>] ]
+	     [ --glob=<glob-pattern> ]
+	     [ --ignore-missing ]
+	     [ --stdin ]
+	     [ --quiet ]
+	     [ --topo-order ]
+	     [ --parents ]
+	     [ --timestamp ]
+	     [ --left-right ]
+	     [ --left-only ]
+	     [ --right-only ]
+	     [ --cherry-mark ]
+	     [ --cherry-pick ]
+	     [ --encoding=<encoding> ]
+	     [ --(author|committer|grep)=<pattern> ]
+	     [ --regexp-ignore-case | -i ]
+	     [ --extended-regexp | -E ]
+	     [ --fixed-strings | -F ]
+	     [ --date=<format>]
+	     [ [ --objects | --objects-edge | --objects-edge-aggressive ]
+	       [ --unpacked ]
+	       [ --object-names | --no-object-names ]
+	       [ --filter=<filter-spec> [ --filter-print-omitted ] ] ]
+	     [ --missing=<missing-action> ]
+	     [ --pretty | --header ]
+	     [ --bisect ]
+	     [ --bisect-vars ]
+	     [ --bisect-all ]
+	     [ --merge ]
+	     [ --reverse ]
+	     [ --walk-reflogs ]
+	     [ --no-walk ] [ --do-walk ]
+	     [ --count ]
+	     [ --use-bitmap-index ]
+	     <commit>... [ \-- <paths>... ]
+
+DESCRIPTION
+-----------
+
+List commits that are reachable by following the `parent` links from the
+given commit(s), but exclude commits that are reachable from the one(s)
+given with a '{caret}' in front of them.  The output is given in reverse
+chronological order by default.
+
+You can think of this as a set operation.  Commits given on the command
+line form a set of commits that are reachable from any of them, and then
+commits reachable from any of the ones given with '{caret}' in front are
+subtracted from that set.  The remaining commits are what comes out in the
+command's output.  Various other options and paths parameters can be used
+to further limit the result.
+
+Thus, the following command:
+
+-----------------------------------------------------------------------
+	$ git rev-list foo bar ^baz
+-----------------------------------------------------------------------
+
+means "list all the commits which are reachable from 'foo' or 'bar', but
+not from 'baz'".
+
+A special notation "'<commit1>'..'<commit2>'" can be used as a
+short-hand for "{caret}'<commit1>' '<commit2>'". For example, either of
+the following may be used interchangeably:
+
+-----------------------------------------------------------------------
+	$ git rev-list origin..HEAD
+	$ git rev-list HEAD ^origin
+-----------------------------------------------------------------------
+
+Another special notation is "'<commit1>'...'<commit2>'" which is useful
+for merges.  The resulting set of commits is the symmetric difference
+between the two operands.  The following two commands are equivalent:
+
+-----------------------------------------------------------------------
+	$ git rev-list A B --not $(git merge-base --all A B)
+	$ git rev-list A...B
+-----------------------------------------------------------------------
+
+'rev-list' is a very essential Git command, since it
+provides the ability to build and traverse commit ancestry graphs. For
+this reason, it has a lot of different options that enables it to be
+used by commands as different as 'git bisect' and
+'git repack'.
+
+OPTIONS
+-------
+
+:git-rev-list: 1
+include::rev-list-options.txt[]
+
+include::pretty-formats.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-rev-parse.txt b/third_party/git/Documentation/git-rev-parse.txt
new file mode 100644
index 0000000000..e72d332b83
--- /dev/null
+++ b/third_party/git/Documentation/git-rev-parse.txt
@@ -0,0 +1,456 @@
+git-rev-parse(1)
+================
+
+NAME
+----
+git-rev-parse - Pick out and massage parameters
+
+
+SYNOPSIS
+--------
+[verse]
+'git rev-parse' [<options>] <args>...
+
+DESCRIPTION
+-----------
+
+Many Git porcelainish commands take mixture of flags
+(i.e. parameters that begin with a dash '-') and parameters
+meant for the underlying 'git rev-list' command they use internally
+and flags and parameters for the other commands they use
+downstream of 'git rev-list'.  This command is used to
+distinguish between them.
+
+
+OPTIONS
+-------
+
+Operation Modes
+~~~~~~~~~~~~~~~
+
+Each of these options must appear first on the command line.
+
+--parseopt::
+	Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
+
+--sq-quote::
+	Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
+	section below). In contrast to the `--sq` option below, this
+	mode does only quoting. Nothing else is done to command input.
+
+Options for --parseopt
+~~~~~~~~~~~~~~~~~~~~~~
+
+--keep-dashdash::
+	Only meaningful in `--parseopt` mode. Tells the option parser to echo
+	out the first `--` met instead of skipping it.
+
+--stop-at-non-option::
+	Only meaningful in `--parseopt` mode.  Lets the option parser stop at
+	the first non-option argument.  This can be used to parse sub-commands
+	that take options themselves.
+
+--stuck-long::
+	Only meaningful in `--parseopt` mode. Output the options in their
+	long form if available, and with their arguments stuck.
+
+Options for Filtering
+~~~~~~~~~~~~~~~~~~~~~
+
+--revs-only::
+	Do not output flags and parameters not meant for
+	'git rev-list' command.
+
+--no-revs::
+	Do not output flags and parameters meant for
+	'git rev-list' command.
+
+--flags::
+	Do not output non-flag parameters.
+
+--no-flags::
+	Do not output flag parameters.
+
+Options for Output
+~~~~~~~~~~~~~~~~~~
+
+--default <arg>::
+	If there is no parameter given by the user, use `<arg>`
+	instead.
+
+--prefix <arg>::
+	Behave as if 'git rev-parse' was invoked from the `<arg>`
+	subdirectory of the working tree.  Any relative filenames are
+	resolved as if they are prefixed by `<arg>` and will be printed
+	in that form.
++
+This can be used to convert arguments to a command run in a subdirectory
+so that they can still be used after moving to the top-level of the
+repository.  For example:
++
+----
+prefix=$(git rev-parse --show-prefix)
+cd "$(git rev-parse --show-toplevel)"
+# rev-parse provides the -- needed for 'set'
+eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
+----
+
+--verify::
+	Verify that exactly one parameter is provided, and that it
+	can be turned into a raw 20-byte SHA-1 that can be used to
+	access the object database. If so, emit it to the standard
+	output; otherwise, error out.
++
+If you want to make sure that the output actually names an object in
+your object database and/or can be used as a specific type of object
+you require, you can add the `^{type}` peeling operator to the parameter.
+For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
+names an existing object that is a commit-ish (i.e. a commit, or an
+annotated tag that points at a commit).  To make sure that `$VAR`
+names an existing object of any type, `git rev-parse "$VAR^{object}"`
+can be used.
+
+-q::
+--quiet::
+	Only meaningful in `--verify` mode. Do not output an error
+	message if the first argument is not a valid object name;
+	instead exit with non-zero status silently.
+	SHA-1s for valid object names are printed to stdout on success.
+
+--sq::
+	Usually the output is made one line per flag and
+	parameter.  This option makes output a single line,
+	properly quoted for consumption by shell.  Useful when
+	you expect your parameter to contain whitespaces and
+	newlines (e.g. when using pickaxe `-S` with
+	'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
+	the command input is still interpreted as usual.
+
+--short[=length]::
+	Same as `--verify` but shortens the object name to a unique
+	prefix with at least `length` characters. The minimum length
+	is 4, the default is the effective value of the `core.abbrev`
+	configuration variable (see linkgit:git-config[1]).
+
+--not::
+	When showing object names, prefix them with '{caret}' and
+	strip '{caret}' prefix from the object names that already have
+	one.
+
+--abbrev-ref[=(strict|loose)]::
+	A non-ambiguous short name of the objects name.
+	The option core.warnAmbiguousRefs is used to select the strict
+	abbreviation mode.
+
+--symbolic::
+	Usually the object names are output in SHA-1 form (with
+	possible '{caret}' prefix); this option makes them output in a
+	form as close to the original input as possible.
+
+--symbolic-full-name::
+	This is similar to --symbolic, but it omits input that
+	are not refs (i.e. branch or tag names; or more
+	explicitly disambiguating "heads/master" form, when you
+	want to name the "master" branch when there is an
+	unfortunately named tag "master"), and show them as full
+	refnames (e.g. "refs/heads/master").
+
+Options for Objects
+~~~~~~~~~~~~~~~~~~~
+
+--all::
+	Show all refs found in `refs/`.
+
+--branches[=pattern]::
+--tags[=pattern]::
+--remotes[=pattern]::
+	Show all branches, tags, or remote-tracking branches,
+	respectively (i.e., refs found in `refs/heads`,
+	`refs/tags`, or `refs/remotes`, respectively).
++
+If a `pattern` is given, only refs matching the given shell glob are
+shown.  If the pattern does not contain a globbing character (`?`,
+`*`, or `[`), it is turned into a prefix match by appending `/*`.
+
+--glob=pattern::
+	Show all refs matching the shell glob pattern `pattern`. If
+	the pattern does not start with `refs/`, this is automatically
+	prepended.  If the pattern does not contain a globbing
+	character (`?`, `*`, or `[`), it is turned into a prefix
+	match by appending `/*`.
+
+--exclude=<glob-pattern>::
+	Do not include refs matching '<glob-pattern>' that the next `--all`,
+	`--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
+	consider. Repetitions of this option accumulate exclusion patterns
+	up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
+	`--glob` option (other options or arguments do not clear
+	accumulated patterns).
++
+The patterns given should not begin with `refs/heads`, `refs/tags`, or
+`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
+respectively, and they must begin with `refs/` when applied to `--glob`
+or `--all`. If a trailing '/{asterisk}' is intended, it must be given
+explicitly.
+
+--disambiguate=<prefix>::
+	Show every object whose name begins with the given prefix.
+	The <prefix> must be at least 4 hexadecimal digits long to
+	avoid listing each and every object in the repository by
+	mistake.
+
+Options for Files
+~~~~~~~~~~~~~~~~~
+
+--local-env-vars::
+	List the GIT_* environment variables that are local to the
+	repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
+	Only the names of the variables are listed, not their value,
+	even if they are set.
+
+--git-dir::
+	Show `$GIT_DIR` if defined. Otherwise show the path to
+	the .git directory. The path shown, when relative, is
+	relative to the current working directory.
++
+If `$GIT_DIR` is not defined and the current directory
+is not detected to lie in a Git repository or work tree
+print a message to stderr and exit with nonzero status.
+
+--absolute-git-dir::
+	Like `--git-dir`, but its output is always the canonicalized
+	absolute path.
+
+--git-common-dir::
+	Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
+
+--is-inside-git-dir::
+	When the current working directory is below the repository
+	directory print "true", otherwise "false".
+
+--is-inside-work-tree::
+	When the current working directory is inside the work tree of the
+	repository print "true", otherwise "false".
+
+--is-bare-repository::
+	When the repository is bare print "true", otherwise "false".
+
+--is-shallow-repository::
+	When the repository is shallow print "true", otherwise "false".
+
+--resolve-git-dir <path>::
+	Check if <path> is a valid repository or a gitfile that
+	points at a valid repository, and print the location of the
+	repository.  If <path> is a gitfile then the resolved path
+	to the real repository is printed.
+
+--git-path <path>::
+	Resolve "$GIT_DIR/<path>" and takes other path relocation
+	variables such as $GIT_OBJECT_DIRECTORY,
+	$GIT_INDEX_FILE... into account. For example, if
+	$GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
+	--git-path objects/abc" returns /foo/bar/abc.
+
+--show-cdup::
+	When the command is invoked from a subdirectory, show the
+	path of the top-level directory relative to the current
+	directory (typically a sequence of "../", or an empty string).
+
+--show-prefix::
+	When the command is invoked from a subdirectory, show the
+	path of the current directory relative to the top-level
+	directory.
+
+--show-toplevel::
+	Show the absolute path of the top-level directory.
+
+--show-superproject-working-tree::
+	Show the absolute path of the root of the superproject's
+	working tree (if exists) that uses the current repository as
+	its submodule.  Outputs nothing if the current repository is
+	not used as a submodule by any project.
+
+--shared-index-path::
+	Show the path to the shared index file in split index mode, or
+	empty if not in split-index mode.
+
+Other Options
+~~~~~~~~~~~~~
+
+--since=datestring::
+--after=datestring::
+	Parse the date string, and output the corresponding
+	--max-age= parameter for 'git rev-list'.
+
+--until=datestring::
+--before=datestring::
+	Parse the date string, and output the corresponding
+	--min-age= parameter for 'git rev-list'.
+
+<args>...::
+	Flags and parameters to be parsed.
+
+
+include::revisions.txt[]
+
+PARSEOPT
+--------
+
+In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
+scripts the same facilities C builtins have. It works as an option normalizer
+(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
+
+It takes on the standard input the specification of the options to parse and
+understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
+to replace the arguments with normalized ones.  In case of error, it outputs
+usage on the standard error stream, and exits with code 129.
+
+Note: Make sure you quote the result when passing it to `eval`.  See
+below for an example.
+
+Input Format
+~~~~~~~~~~~~
+
+'git rev-parse --parseopt' input format is fully text based. It has two parts,
+separated by a line that contains only `--`. The lines before the separator
+(should be one or more) are used for the usage.
+The lines after the separator describe the options.
+
+Each line of options has this format:
+
+------------
+<opt-spec><flags>*<arg-hint>? SP+ help LF
+------------
+
+`<opt-spec>`::
+	its format is the short option character, then the long option name
+	separated by a comma. Both parts are not required, though at least one
+	is necessary. May not contain any of the `<flags>` characters.
+	`h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
+
+`<flags>`::
+	`<flags>` are of `*`, `=`, `?` or `!`.
+	* Use `=` if the option takes an argument.
+
+	* Use `?` to mean that the option takes an optional argument. You
+	  probably want to use the `--stuck-long` mode to be able to
+	  unambiguously parse the optional argument.
+
+	* Use `*` to mean that this option should not be listed in the usage
+	  generated for the `-h` argument. It's shown for `--help-all` as
+	  documented in linkgit:gitcli[7].
+
+	* Use `!` to not make the corresponding negated long option available.
+
+`<arg-hint>`::
+	`<arg-hint>`, if specified, is used as a name of the argument in the
+	help output, for options that take arguments. `<arg-hint>` is
+	terminated by the first whitespace.  It is customary to use a
+	dash to separate words in a multi-word argument hint.
+
+The remainder of the line, after stripping the spaces, is used
+as the help associated to the option.
+
+Blank lines are ignored, and lines that don't match this specification are used
+as option group headers (start the line with a space to create such
+lines on purpose).
+
+Example
+~~~~~~~
+
+------------
+OPTS_SPEC="\
+some-command [<options>] <args>...
+
+some-command does foo and bar!
+--
+h,help    show the help
+
+foo       some nifty option --foo
+bar=      some cool option --bar with an argument
+baz=arg   another cool option --baz with a named argument
+qux?path  qux may take a path argument but has meaning by itself
+
+  An option group Header
+C?        option C with an optional argument"
+
+eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
+------------
+
+
+Usage text
+~~~~~~~~~~
+
+When `"$@"` is `-h` or `--help` in the above example, the following
+usage text would be shown:
+
+------------
+usage: some-command [<options>] <args>...
+
+    some-command does foo and bar!
+
+    -h, --help            show the help
+    --foo                 some nifty option --foo
+    --bar ...             some cool option --bar with an argument
+    --baz <arg>           another cool option --baz with a named argument
+    --qux[=<path>]        qux may take a path argument but has meaning by itself
+
+An option group Header
+    -C[...]               option C with an optional argument
+------------
+
+SQ-QUOTE
+--------
+
+In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
+single line suitable for `sh(1)` `eval`. This line is made by
+normalizing the arguments following `--sq-quote`. Nothing other than
+quoting the arguments is done.
+
+If you want command input to still be interpreted as usual by
+'git rev-parse' before the output is shell quoted, see the `--sq`
+option.
+
+Example
+~~~~~~~
+
+------------
+$ cat >your-git-script.sh <<\EOF
+#!/bin/sh
+args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
+command="git frotz -n24 $args"          # and use it inside a handcrafted
+					# command line
+eval "$command"
+EOF
+
+$ sh your-git-script.sh "a b'c"
+------------
+
+EXAMPLES
+--------
+
+* Print the object name of the current commit:
++
+------------
+$ git rev-parse --verify HEAD
+------------
+
+* Print the commit object name from the revision in the $REV shell variable:
++
+------------
+$ git rev-parse --verify $REV^{commit}
+------------
++
+This will error out if $REV is empty or not a valid revision.
+
+* Similar to above:
++
+------------
+$ git rev-parse --default master --verify $REV
+------------
++
+but if $REV is empty, the commit object name from master will be printed.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-revert.txt b/third_party/git/Documentation/git-revert.txt
new file mode 100644
index 0000000000..9d22270757
--- /dev/null
+++ b/third_party/git/Documentation/git-revert.txt
@@ -0,0 +1,142 @@
+git-revert(1)
+=============
+
+NAME
+----
+git-revert - Revert some existing commits
+
+SYNOPSIS
+--------
+[verse]
+'git revert' [--[no-]edit] [-n] [-m parent-number] [-s] [-S[<keyid>]] <commit>...
+'git revert' (--continue | --skip | --abort | --quit)
+
+DESCRIPTION
+-----------
+
+Given one or more existing commits, revert the changes that the
+related patches introduce, and record some new commits that record
+them.  This requires your working tree to be clean (no modifications
+from the HEAD commit).
+
+Note: 'git revert' is used to record some new commits to reverse the
+effect of some earlier commits (often only a faulty one).  If you want to
+throw away all uncommitted changes in your working directory, you
+should see linkgit:git-reset[1], particularly the `--hard` option.  If
+you want to extract specific files as they were in another commit, you
+should see linkgit:git-restore[1], specifically the `--source`
+option. Take care with these alternatives as
+both will discard uncommitted changes in your working directory.
+
+See "Reset, restore and revert" in linkgit:git[1] for the differences
+between the three commands.
+
+OPTIONS
+-------
+<commit>...::
+	Commits to revert.
+	For a more complete list of ways to spell commit names, see
+	linkgit:gitrevisions[7].
+	Sets of commits can also be given but no traversal is done by
+	default, see linkgit:git-rev-list[1] and its `--no-walk`
+	option.
+
+-e::
+--edit::
+	With this option, 'git revert' will let you edit the commit
+	message prior to committing the revert. This is the default if
+	you run the command from a terminal.
+
+-m parent-number::
+--mainline parent-number::
+	Usually you cannot revert a merge because you do not know which
+	side of the merge should be considered the mainline.  This
+	option specifies the parent number (starting from 1) of
+	the mainline and allows revert to reverse the change
+	relative to the specified parent.
++
+Reverting a merge commit declares that you will never want the tree changes
+brought in by the merge.  As a result, later merges will only bring in tree
+changes introduced by commits that are not ancestors of the previously
+reverted merge.  This may or may not be what you want.
++
+See the link:howto/revert-a-faulty-merge.html[revert-a-faulty-merge How-To] for
+more details.
+
+--no-edit::
+	With this option, 'git revert' will not start the commit
+	message editor.
+
+--cleanup=<mode>::
+	This option determines how the commit message will be cleaned up before
+	being passed on to the commit machinery. See linkgit:git-commit[1] for more
+	details. In particular, if the '<mode>' is given a value of `scissors`,
+	scissors will be appended to `MERGE_MSG` before being passed on in the case
+	of a conflict.
+
+-n::
+--no-commit::
+	Usually the command automatically creates some commits with
+	commit log messages stating which commits were
+	reverted.  This flag applies the changes necessary
+	to revert the named commits to your working tree
+	and the index, but does not make the commits.  In addition,
+	when this option is used, your index does not have to match
+	the HEAD commit.  The revert is done against the
+	beginning state of your index.
++
+This is useful when reverting more than one commits'
+effect to your index in a row.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign commits. The `keyid` argument is optional and
+	defaults to the committer identity; if specified, it must be
+	stuck to the option without a space.
+
+-s::
+--signoff::
+	Add Signed-off-by line at the end of the commit message.
+	See the signoff option in linkgit:git-commit[1] for more information.
+
+--strategy=<strategy>::
+	Use the given merge strategy.  Should only be used once.
+	See the MERGE STRATEGIES section in linkgit:git-merge[1]
+	for details.
+
+-X<option>::
+--strategy-option=<option>::
+	Pass the merge strategy-specific option through to the
+	merge strategy.  See linkgit:git-merge[1] for details.
+
+--rerere-autoupdate::
+--no-rerere-autoupdate::
+	Allow the rerere mechanism to update the index with the
+	result of auto-conflict resolution if possible.
+
+SEQUENCER SUBCOMMANDS
+---------------------
+include::sequencer.txt[]
+
+EXAMPLES
+--------
+`git revert HEAD~3`::
+
+	Revert the changes specified by the fourth last commit in HEAD
+	and create a new commit with the reverted changes.
+
+`git revert -n master~5..master~2`::
+
+	Revert the changes done by commits from the fifth last commit
+	in master (included) to the third last commit in master
+	(included), but do not create any commit with the reverted
+	changes. The revert only modifies the working tree and the
+	index.
+
+SEE ALSO
+--------
+linkgit:git-cherry-pick[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-rm.txt b/third_party/git/Documentation/git-rm.txt
new file mode 100644
index 0000000000..b5c46223c4
--- /dev/null
+++ b/third_party/git/Documentation/git-rm.txt
@@ -0,0 +1,189 @@
+git-rm(1)
+=========
+
+NAME
+----
+git-rm - Remove files from the working tree and from the index
+
+SYNOPSIS
+--------
+[verse]
+'git rm' [-f | --force] [-n] [-r] [--cached] [--ignore-unmatch] [--quiet] [--] <file>...
+
+DESCRIPTION
+-----------
+Remove files from the index, or from the working tree and the index.
+`git rm` will not remove a file from just your working directory.
+(There is no option to remove a file only from the working tree
+and yet keep it in the index; use `/bin/rm` if you want to do that.)
+The files being removed have to be identical to the tip of the branch,
+and no updates to their contents can be staged in the index,
+though that default behavior can be overridden with the `-f` option.
+When `--cached` is given, the staged content has to
+match either the tip of the branch or the file on disk,
+allowing the file to be removed from just the index.
+
+
+OPTIONS
+-------
+<file>...::
+	Files to remove.  Fileglobs (e.g. `*.c`) can be given to
+	remove all matching files.  If you want Git to expand
+	file glob characters, you may need to shell-escape them.
+	A leading directory name
+	(e.g. `dir` to remove `dir/file1` and `dir/file2`) can be
+	given to remove all files in the directory, and recursively
+	all sub-directories,
+	but this requires the `-r` option to be explicitly given.
+
+-f::
+--force::
+	Override the up-to-date check.
+
+-n::
+--dry-run::
+	Don't actually remove any file(s).  Instead, just show
+	if they exist in the index and would otherwise be removed
+	by the command.
+
+-r::
+        Allow recursive removal when a leading directory name is
+        given.
+
+\--::
+	This option can be used to separate command-line options from
+	the list of files, (useful when filenames might be mistaken
+	for command-line options).
+
+--cached::
+	Use this option to unstage and remove paths only from the index.
+	Working tree files, whether modified or not, will be
+	left alone.
+
+--ignore-unmatch::
+	Exit with a zero status even if no files matched.
+
+-q::
+--quiet::
+	`git rm` normally outputs one line (in the form of an `rm` command)
+	for each file removed. This option suppresses that output.
+
+
+DISCUSSION
+----------
+
+The <file> list given to the command can be exact pathnames,
+file glob patterns, or leading directory names.  The command
+removes only the paths that are known to Git.  Giving the name of
+a file that you have not told Git about does not remove that file.
+
+File globbing matches across directory boundaries.  Thus, given
+two directories `d` and `d2`, there is a difference between
+using `git rm 'd*'` and `git rm 'd/*'`, as the former will
+also remove all of directory `d2`.
+
+REMOVING FILES THAT HAVE DISAPPEARED FROM THE FILESYSTEM
+--------------------------------------------------------
+There is no option for `git rm` to remove from the index only
+the paths that have disappeared from the filesystem. However,
+depending on the use case, there are several ways that can be
+done.
+
+Using ``git commit -a''
+~~~~~~~~~~~~~~~~~~~~~~~
+If you intend that your next commit should record all modifications
+of tracked files in the working tree and record all removals of
+files that have been removed from the working tree with `rm`
+(as opposed to `git rm`), use `git commit -a`, as it will
+automatically notice and record all removals.  You can also have a
+similar effect without committing by using `git add -u`.
+
+Using ``git add -A''
+~~~~~~~~~~~~~~~~~~~~
+When accepting a new code drop for a vendor branch, you probably
+want to record both the removal of paths and additions of new paths
+as well as modifications of existing paths.
+
+Typically you would first remove all tracked files from the working
+tree using this command:
+
+----------------
+git ls-files -z | xargs -0 rm -f
+----------------
+
+and then untar the new code in the working tree. Alternately
+you could 'rsync' the changes into the working tree.
+
+After that, the easiest way to record all removals, additions, and
+modifications in the working tree is:
+
+----------------
+git add -A
+----------------
+
+See linkgit:git-add[1].
+
+Other ways
+~~~~~~~~~~
+If all you really want to do is to remove from the index the files
+that are no longer present in the working tree (perhaps because
+your working tree is dirty so that you cannot use `git commit -a`),
+use the following command:
+
+----------------
+git diff --name-only --diff-filter=D -z | xargs -0 git rm --cached
+----------------
+
+SUBMODULES
+----------
+Only submodules using a gitfile (which means they were cloned
+with a Git version 1.7.8 or newer) will be removed from the work
+tree, as their repository lives inside the .git directory of the
+superproject. If a submodule (or one of those nested inside it)
+still uses a .git directory, `git rm` will move the submodules
+git directory into the superprojects git directory to protect
+the submodule's history. If it exists the submodule.<name> section
+in the linkgit:gitmodules[5] file will also be removed and that file
+will be staged (unless --cached or -n are used).
+
+A submodule is considered up to date when the HEAD is the same as
+recorded in the index, no tracked files are modified and no untracked
+files that aren't ignored are present in the submodules work tree.
+Ignored files are deemed expendable and won't stop a submodule's work
+tree from being removed.
+
+If you only want to remove the local checkout of a submodule from your
+work tree without committing the removal, use linkgit:git-submodule[1] `deinit`
+instead. Also see linkgit:gitsubmodules[7] for details on submodule removal.
+
+EXAMPLES
+--------
+`git rm Documentation/\*.txt`::
+	Removes all `*.txt` files from the index that are under the
+	`Documentation` directory and any of its subdirectories.
++
+Note that the asterisk `*` is quoted from the shell in this
+example; this lets Git, and not the shell, expand the pathnames
+of files and subdirectories under the `Documentation/` directory.
+
+`git rm -f git-*.sh`::
+	Because this example lets the shell expand the asterisk
+	(i.e. you are listing the files explicitly), it
+	does not remove `subdir/git-foo.sh`.
+
+BUGS
+----
+Each time a superproject update removes a populated submodule
+(e.g. when switching between commits before and after the removal) a
+stale submodule checkout will remain in the old location. Removing the
+old directory is only safe when it uses a gitfile, as otherwise the
+history of the submodule will be deleted too. This step will be
+obsolete when recursive submodule update has been implemented.
+
+SEE ALSO
+--------
+linkgit:git-add[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-send-email.txt b/third_party/git/Documentation/git-send-email.txt
new file mode 100644
index 0000000000..d93e5d0f58
--- /dev/null
+++ b/third_party/git/Documentation/git-send-email.txt
@@ -0,0 +1,524 @@
+git-send-email(1)
+=================
+
+NAME
+----
+git-send-email - Send a collection of patches as emails
+
+
+SYNOPSIS
+--------
+[verse]
+'git send-email' [<options>] <file|directory|rev-list options>...
+'git send-email' --dump-aliases
+
+
+DESCRIPTION
+-----------
+Takes the patches given on the command line and emails them out.
+Patches can be specified as files, directories (which will send all
+files in the directory), or directly as a revision list.  In the
+last case, any format accepted by linkgit:git-format-patch[1] can
+be passed to git send-email.
+
+The header of the email is configurable via command-line options.  If not
+specified on the command line, the user will be prompted with a ReadLine
+enabled interface to provide the necessary information.
+
+There are two formats accepted for patch files:
+
+1. mbox format files
++
+This is what linkgit:git-format-patch[1] generates.  Most headers and MIME
+formatting are ignored.
+
+2. The original format used by Greg Kroah-Hartman's 'send_lots_of_email.pl'
+   script
++
+This format expects the first line of the file to contain the "Cc:" value
+and the "Subject:" of the message as the second line.
+
+
+OPTIONS
+-------
+
+Composing
+~~~~~~~~~
+
+--annotate::
+	Review and edit each patch you're about to send. Default is the value
+	of `sendemail.annotate`. See the CONFIGURATION section for
+	`sendemail.multiEdit`.
+
+--bcc=<address>,...::
+	Specify a "Bcc:" value for each email. Default is the value of
+	`sendemail.bcc`.
++
+This option may be specified multiple times.
+
+--cc=<address>,...::
+	Specify a starting "Cc:" value for each email.
+	Default is the value of `sendemail.cc`.
++
+This option may be specified multiple times.
+
+--compose::
+	Invoke a text editor (see GIT_EDITOR in linkgit:git-var[1])
+	to edit an introductory message for the patch series.
++
+When `--compose` is used, git send-email will use the From, Subject, and
+In-Reply-To headers specified in the message. If the body of the message
+(what you type after the headers and a blank line) only contains blank
+(or Git: prefixed) lines, the summary won't be sent, but From, Subject,
+and In-Reply-To headers will be used unless they are removed.
++
+Missing From or In-Reply-To headers will be prompted for.
++
+See the CONFIGURATION section for `sendemail.multiEdit`.
+
+--from=<address>::
+	Specify the sender of the emails.  If not specified on the command line,
+	the value of the `sendemail.from` configuration option is used.  If
+	neither the command-line option nor `sendemail.from` are set, then the
+	user will be prompted for the value.  The default for the prompt will be
+	the value of GIT_AUTHOR_IDENT, or GIT_COMMITTER_IDENT if that is not
+	set, as returned by "git var -l".
+
+--reply-to=<address>::
+	Specify the address where replies from recipients should go to.
+	Use this if replies to messages should go to another address than what
+	is specified with the --from parameter.
+
+--in-reply-to=<identifier>::
+	Make the first mail (or all the mails with `--no-thread`) appear as a
+	reply to the given Message-Id, which avoids breaking threads to
+	provide a new patch series.
+	The second and subsequent emails will be sent as replies according to
+	the `--[no-]chain-reply-to` setting.
++
+So for example when `--thread` and `--no-chain-reply-to` are specified, the
+second and subsequent patches will be replies to the first one like in the
+illustration below where `[PATCH v2 0/3]` is in reply to `[PATCH 0/2]`:
++
+  [PATCH 0/2] Here is what I did...
+    [PATCH 1/2] Clean up and tests
+    [PATCH 2/2] Implementation
+    [PATCH v2 0/3] Here is a reroll
+      [PATCH v2 1/3] Clean up
+      [PATCH v2 2/3] New tests
+      [PATCH v2 3/3] Implementation
++
+Only necessary if --compose is also set.  If --compose
+is not set, this will be prompted for.
+
+--subject=<string>::
+	Specify the initial subject of the email thread.
+	Only necessary if --compose is also set.  If --compose
+	is not set, this will be prompted for.
+
+--to=<address>,...::
+	Specify the primary recipient of the emails generated. Generally, this
+	will be the upstream maintainer of the project involved. Default is the
+	value of the `sendemail.to` configuration value; if that is unspecified,
+	and --to-cmd is not specified, this will be prompted for.
++
+This option may be specified multiple times.
+
+--8bit-encoding=<encoding>::
+	When encountering a non-ASCII message or subject that does not
+	declare its encoding, add headers/quoting to indicate it is
+	encoded in <encoding>.  Default is the value of the
+	'sendemail.assume8bitEncoding'; if that is unspecified, this
+	will be prompted for if any non-ASCII files are encountered.
++
+Note that no attempts whatsoever are made to validate the encoding.
+
+--compose-encoding=<encoding>::
+	Specify encoding of compose message. Default is the value of the
+	'sendemail.composeencoding'; if that is unspecified, UTF-8 is assumed.
+
+--transfer-encoding=(7bit|8bit|quoted-printable|base64|auto)::
+	Specify the transfer encoding to be used to send the message over SMTP.
+	7bit will fail upon encountering a non-ASCII message.  quoted-printable
+	can be useful when the repository contains files that contain carriage
+	returns, but makes the raw patch email file (as saved from a MUA) much
+	harder to inspect manually.  base64 is even more fool proof, but also
+	even more opaque.  auto will use 8bit when possible, and quoted-printable
+	otherwise.
++
+Default is the value of the `sendemail.transferEncoding` configuration
+value; if that is unspecified, default to `auto`.
+
+--xmailer::
+--no-xmailer::
+	Add (or prevent adding) the "X-Mailer:" header.  By default,
+	the header is added, but it can be turned off by setting the
+	`sendemail.xmailer` configuration variable to `false`.
+
+Sending
+~~~~~~~
+
+--envelope-sender=<address>::
+	Specify the envelope sender used to send the emails.
+	This is useful if your default address is not the address that is
+	subscribed to a list. In order to use the 'From' address, set the
+	value to "auto". If you use the sendmail binary, you must have
+	suitable privileges for the -f parameter.  Default is the value of the
+	`sendemail.envelopeSender` configuration variable; if that is
+	unspecified, choosing the envelope sender is left to your MTA.
+
+--smtp-encryption=<encryption>::
+	Specify the encryption to use, either 'ssl' or 'tls'.  Any other
+	value reverts to plain SMTP.  Default is the value of
+	`sendemail.smtpEncryption`.
+
+--smtp-domain=<FQDN>::
+	Specifies the Fully Qualified Domain Name (FQDN) used in the
+	HELO/EHLO command to the SMTP server.  Some servers require the
+	FQDN to match your IP address.  If not set, git send-email attempts
+	to determine your FQDN automatically.  Default is the value of
+	`sendemail.smtpDomain`.
+
+--smtp-auth=<mechanisms>::
+	Whitespace-separated list of allowed SMTP-AUTH mechanisms. This setting
+	forces using only the listed mechanisms. Example:
++
+------
+$ git send-email --smtp-auth="PLAIN LOGIN GSSAPI" ...
+------
++
+If at least one of the specified mechanisms matches the ones advertised by the
+SMTP server and if it is supported by the utilized SASL library, the mechanism
+is used for authentication. If neither 'sendemail.smtpAuth' nor `--smtp-auth`
+is specified, all mechanisms supported by the SASL library can be used. The
+special value 'none' maybe specified to completely disable authentication
+independently of `--smtp-user`
+
+--smtp-pass[=<password>]::
+	Password for SMTP-AUTH. The argument is optional: If no
+	argument is specified, then the empty string is used as
+	the password. Default is the value of `sendemail.smtpPass`,
+	however `--smtp-pass` always overrides this value.
++
+Furthermore, passwords need not be specified in configuration files
+or on the command line. If a username has been specified (with
+`--smtp-user` or a `sendemail.smtpUser`), but no password has been
+specified (with `--smtp-pass` or `sendemail.smtpPass`), then
+a password is obtained using 'git-credential'.
+
+--no-smtp-auth::
+	Disable SMTP authentication. Short hand for `--smtp-auth=none`
+
+--smtp-server=<host>::
+	If set, specifies the outgoing SMTP server to use (e.g.
+	`smtp.example.com` or a raw IP address).  Alternatively it can
+	specify a full pathname of a sendmail-like program instead;
+	the program must support the `-i` option.  Default value can
+	be specified by the `sendemail.smtpServer` configuration
+	option; the built-in default is to search for `sendmail` in
+	`/usr/sbin`, `/usr/lib` and $PATH if such program is
+	available, falling back to `localhost` otherwise.
+
+--smtp-server-port=<port>::
+	Specifies a port different from the default port (SMTP
+	servers typically listen to smtp port 25, but may also listen to
+	submission port 587, or the common SSL smtp port 465);
+	symbolic port names (e.g. "submission" instead of 587)
+	are also accepted. The port can also be set with the
+	`sendemail.smtpServerPort` configuration variable.
+
+--smtp-server-option=<option>::
+	If set, specifies the outgoing SMTP server option to use.
+	Default value can be specified by the `sendemail.smtpServerOption`
+	configuration option.
++
+The --smtp-server-option option must be repeated for each option you want
+to pass to the server. Likewise, different lines in the configuration files
+must be used for each option.
+
+--smtp-ssl::
+	Legacy alias for '--smtp-encryption ssl'.
+
+--smtp-ssl-cert-path::
+	Path to a store of trusted CA certificates for SMTP SSL/TLS
+	certificate validation (either a directory that has been processed
+	by 'c_rehash', or a single file containing one or more PEM format
+	certificates concatenated together: see verify(1) -CAfile and
+	-CApath for more information on these). Set it to an empty string
+	to disable certificate verification. Defaults to the value of the
+	`sendemail.smtpsslcertpath` configuration variable, if set, or the
+	backing SSL library's compiled-in default otherwise (which should
+	be the best choice on most platforms).
+
+--smtp-user=<user>::
+	Username for SMTP-AUTH. Default is the value of `sendemail.smtpUser`;
+	if a username is not specified (with `--smtp-user` or `sendemail.smtpUser`),
+	then authentication is not attempted.
+
+--smtp-debug=0|1::
+	Enable (1) or disable (0) debug output. If enabled, SMTP
+	commands and replies will be printed. Useful to debug TLS
+	connection and authentication problems.
+
+--batch-size=<num>::
+	Some email servers (e.g. smtp.163.com) limit the number emails to be
+	sent per session (connection) and this will lead to a failure when
+	sending many messages.  With this option, send-email will disconnect after
+	sending $<num> messages and wait for a few seconds (see --relogin-delay)
+	and reconnect, to work around such a limit.  You may want to
+	use some form of credential helper to avoid having to retype
+	your password every time this happens.  Defaults to the
+	`sendemail.smtpBatchSize` configuration variable.
+
+--relogin-delay=<int>::
+	Waiting $<int> seconds before reconnecting to SMTP server. Used together
+	with --batch-size option.  Defaults to the `sendemail.smtpReloginDelay`
+	configuration variable.
+
+Automating
+~~~~~~~~~~
+
+--no-[to|cc|bcc]::
+	Clears any list of "To:", "Cc:", "Bcc:" addresses previously
+	set via config.
+
+--no-identity::
+	Clears the previously read value of `sendemail.identity` set
+	via config, if any.
+
+--to-cmd=<command>::
+	Specify a command to execute once per patch file which
+	should generate patch file specific "To:" entries.
+	Output of this command must be single email address per line.
+	Default is the value of 'sendemail.tocmd' configuration value.
+
+--cc-cmd=<command>::
+	Specify a command to execute once per patch file which
+	should generate patch file specific "Cc:" entries.
+	Output of this command must be single email address per line.
+	Default is the value of `sendemail.ccCmd` configuration value.
+
+--[no-]chain-reply-to::
+	If this is set, each email will be sent as a reply to the previous
+	email sent.  If disabled with "--no-chain-reply-to", all emails after
+	the first will be sent as replies to the first email sent.  When using
+	this, it is recommended that the first file given be an overview of the
+	entire patch series. Disabled by default, but the `sendemail.chainReplyTo`
+	configuration variable can be used to enable it.
+
+--identity=<identity>::
+	A configuration identity. When given, causes values in the
+	'sendemail.<identity>' subsection to take precedence over
+	values in the 'sendemail' section. The default identity is
+	the value of `sendemail.identity`.
+
+--[no-]signed-off-by-cc::
+	If this is set, add emails found in Signed-off-by: or Cc: lines to the
+	cc list. Default is the value of `sendemail.signedoffbycc` configuration
+	value; if that is unspecified, default to --signed-off-by-cc.
+
+--[no-]cc-cover::
+	If this is set, emails found in Cc: headers in the first patch of
+	the series (typically the cover letter) are added to the cc list
+	for each email set. Default is the value of 'sendemail.cccover'
+	configuration value; if that is unspecified, default to --no-cc-cover.
+
+--[no-]to-cover::
+	If this is set, emails found in To: headers in the first patch of
+	the series (typically the cover letter) are added to the to list
+	for each email set. Default is the value of 'sendemail.tocover'
+	configuration value; if that is unspecified, default to --no-to-cover.
+
+--suppress-cc=<category>::
+	Specify an additional category of recipients to suppress the
+	auto-cc of:
++
+--
+- 'author' will avoid including the patch author.
+- 'self' will avoid including the sender.
+- 'cc' will avoid including anyone mentioned in Cc lines in the patch header
+  except for self (use 'self' for that).
+- 'bodycc' will avoid including anyone mentioned in Cc lines in the
+  patch body (commit message) except for self (use 'self' for that).
+- 'sob' will avoid including anyone mentioned in Signed-off-by lines except
+  for self (use 'self' for that).
+- 'misc-by' will avoid including anyone mentioned in Acked-by,
+  Reviewed-by, Tested-by and other "-by" lines in the patch body,
+  except Signed-off-by (use 'sob' for that).
+- 'cccmd' will avoid running the --cc-cmd.
+- 'body' is equivalent to 'sob' + 'bodycc' + 'misc-by'.
+- 'all' will suppress all auto cc values.
+--
++
+Default is the value of `sendemail.suppresscc` configuration value; if
+that is unspecified, default to 'self' if --suppress-from is
+specified, as well as 'body' if --no-signed-off-cc is specified.
+
+--[no-]suppress-from::
+	If this is set, do not add the From: address to the cc: list.
+	Default is the value of `sendemail.suppressFrom` configuration
+	value; if that is unspecified, default to --no-suppress-from.
+
+--[no-]thread::
+	If this is set, the In-Reply-To and References headers will be
+	added to each email sent.  Whether each mail refers to the
+	previous email (`deep` threading per 'git format-patch'
+	wording) or to the first email (`shallow` threading) is
+	governed by "--[no-]chain-reply-to".
++
+If disabled with "--no-thread", those headers will not be added
+(unless specified with --in-reply-to).  Default is the value of the
+`sendemail.thread` configuration value; if that is unspecified,
+default to --thread.
++
+It is up to the user to ensure that no In-Reply-To header already
+exists when 'git send-email' is asked to add it (especially note that
+'git format-patch' can be configured to do the threading itself).
+Failure to do so may not produce the expected result in the
+recipient's MUA.
+
+
+Administering
+~~~~~~~~~~~~~
+
+--confirm=<mode>::
+	Confirm just before sending:
++
+--
+- 'always' will always confirm before sending
+- 'never' will never confirm before sending
+- 'cc' will confirm before sending when send-email has automatically
+  added addresses from the patch to the Cc list
+- 'compose' will confirm before sending the first message when using --compose.
+- 'auto' is equivalent to 'cc' + 'compose'
+--
++
+Default is the value of `sendemail.confirm` configuration value; if that
+is unspecified, default to 'auto' unless any of the suppress options
+have been specified, in which case default to 'compose'.
+
+--dry-run::
+	Do everything except actually send the emails.
+
+--[no-]format-patch::
+	When an argument may be understood either as a reference or as a file name,
+	choose to understand it as a format-patch argument (`--format-patch`)
+	or as a file name (`--no-format-patch`). By default, when such a conflict
+	occurs, git send-email will fail.
+
+--quiet::
+	Make git-send-email less verbose.  One line per email should be
+	all that is output.
+
+--[no-]validate::
+	Perform sanity checks on patches.
+	Currently, validation means the following:
++
+--
+		*	Invoke the sendemail-validate hook if present (see linkgit:githooks[5]).
+		*	Warn of patches that contain lines longer than
+			998 characters unless a suitable transfer encoding
+			('auto', 'base64', or 'quoted-printable') is used;
+			this is due to SMTP limits as described by
+			http://www.ietf.org/rfc/rfc5322.txt.
+--
++
+Default is the value of `sendemail.validate`; if this is not set,
+default to `--validate`.
+
+--force::
+	Send emails even if safety checks would prevent it.
+
+
+Information
+~~~~~~~~~~~
+
+--dump-aliases::
+	Instead of the normal operation, dump the shorthand alias names from
+	the configured alias file(s), one per line in alphabetical order. Note,
+	this only includes the alias name and not its expanded email addresses.
+	See 'sendemail.aliasesfile' for more information about aliases.
+
+
+CONFIGURATION
+-------------
+
+sendemail.aliasesFile::
+	To avoid typing long email addresses, point this to one or more
+	email aliases files.  You must also supply `sendemail.aliasFileType`.
+
+sendemail.aliasFileType::
+	Format of the file(s) specified in sendemail.aliasesFile. Must be
+	one of 'mutt', 'mailrc', 'pine', 'elm', or 'gnus', or 'sendmail'.
++
+What an alias file in each format looks like can be found in
+the documentation of the email program of the same name. The
+differences and limitations from the standard formats are
+described below:
++
+--
+sendmail;;
+*	Quoted aliases and quoted addresses are not supported: lines that
+	contain a `"` symbol are ignored.
+*	Redirection to a file (`/path/name`) or pipe (`|command`) is not
+	supported.
+*	File inclusion (`:include: /path/name`) is not supported.
+*	Warnings are printed on the standard error output for any
+	explicitly unsupported constructs, and any other lines that are not
+	recognized by the parser.
+--
+
+sendemail.multiEdit::
+	If true (default), a single editor instance will be spawned to edit
+	files you have to edit (patches when `--annotate` is used, and the
+	summary when `--compose` is used). If false, files will be edited one
+	after the other, spawning a new editor each time.
+
+sendemail.confirm::
+	Sets the default for whether to confirm before sending. Must be
+	one of 'always', 'never', 'cc', 'compose', or 'auto'. See `--confirm`
+	in the previous section for the meaning of these values.
+
+EXAMPLES
+--------
+Use gmail as the smtp server
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+To use 'git send-email' to send your patches through the GMail SMTP server,
+edit ~/.gitconfig to specify your account settings:
+
+	[sendemail]
+		smtpEncryption = tls
+		smtpServer = smtp.gmail.com
+		smtpUser = yourname@gmail.com
+		smtpServerPort = 587
+
+If you have multifactor authentication setup on your gmail account, you will
+need to generate an app-specific password for use with 'git send-email'. Visit
+https://security.google.com/settings/security/apppasswords to create it.
+
+Once your commits are ready to be sent to the mailing list, run the
+following commands:
+
+	$ git format-patch --cover-letter -M origin/master -o outgoing/
+	$ edit outgoing/0000-*
+	$ git send-email outgoing/*
+
+The first time you run it, you will be prompted for your credentials.  Enter the
+app-specific or your regular password as appropriate.  If you have credential
+helper configured (see linkgit:git-credential[1]), the password will be saved in
+the credential store so you won't have to type it the next time.
+
+Note: the following core Perl modules that may be installed with your
+distribution of Perl are required:
+MIME::Base64, MIME::QuotedPrint, Net::Domain and Net::SMTP.
+These additional Perl modules are also required:
+Authen::SASL and Mail::Address.
+
+
+SEE ALSO
+--------
+linkgit:git-format-patch[1], linkgit:git-imap-send[1], mbox(5)
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-send-pack.txt b/third_party/git/Documentation/git-send-pack.txt
new file mode 100644
index 0000000000..44fd146b91
--- /dev/null
+++ b/third_party/git/Documentation/git-send-pack.txt
@@ -0,0 +1,156 @@
+git-send-pack(1)
+================
+
+NAME
+----
+git-send-pack - Push objects over Git protocol to another repository
+
+
+SYNOPSIS
+--------
+[verse]
+'git send-pack' [--all] [--dry-run] [--force] [--receive-pack=<git-receive-pack>]
+		[--verbose] [--thin] [--atomic]
+		[--[no-]signed|--signed=(true|false|if-asked)]
+		[<host>:]<directory> [<ref>...]
+
+DESCRIPTION
+-----------
+Usually you would want to use 'git push', which is a
+higher-level wrapper of this command, instead. See linkgit:git-push[1].
+
+Invokes 'git-receive-pack' on a possibly remote repository, and
+updates it from the current repository, sending named refs.
+
+
+OPTIONS
+-------
+--receive-pack=<git-receive-pack>::
+	Path to the 'git-receive-pack' program on the remote
+	end.  Sometimes useful when pushing to a remote
+	repository over ssh, and you do not have the program in
+	a directory on the default $PATH.
+
+--exec=<git-receive-pack>::
+	Same as --receive-pack=<git-receive-pack>.
+
+--all::
+	Instead of explicitly specifying which refs to update,
+	update all heads that locally exist.
+
+--stdin::
+	Take the list of refs from stdin, one per line. If there
+	are refs specified on the command line in addition to this
+	option, then the refs from stdin are processed after those
+	on the command line.
++
+If `--stateless-rpc` is specified together with this option then
+the list of refs must be in packet format (pkt-line). Each ref must
+be in a separate packet, and the list must end with a flush packet.
+
+--dry-run::
+	Do everything except actually send the updates.
+
+--force::
+	Usually, the command refuses to update a remote ref that
+	is not an ancestor of the local ref used to overwrite it.
+	This flag disables the check.  What this means is that
+	the remote repository can lose commits; use it with
+	care.
+
+--verbose::
+	Run verbosely.
+
+--thin::
+	Send a "thin" pack, which records objects in deltified form based
+	on objects not included in the pack to reduce network traffic.
+
+--atomic::
+	Use an atomic transaction for updating the refs. If any of the refs
+	fails to update then the entire push will fail without changing any
+	refs.
+
+--[no-]signed::
+--signed=(true|false|if-asked)::
+	GPG-sign the push request to update refs on the receiving
+	side, to allow it to be checked by the hooks and/or be
+	logged.  If `false` or `--no-signed`, no signing will be
+	attempted.  If `true` or `--signed`, the push will fail if the
+	server does not support signed pushes.  If set to `if-asked`,
+	sign if and only if the server supports signed pushes.  The push
+	will also fail if the actual call to `gpg --sign` fails.  See
+	linkgit:git-receive-pack[1] for the details on the receiving end.
+
+--push-option=<string>::
+	Pass the specified string as a push option for consumption by
+	hooks on the server side.  If the server doesn't support push
+	options, error out.  See linkgit:git-push[1] and
+	linkgit:githooks[5] for details.
+
+<host>::
+	A remote host to house the repository.  When this
+	part is specified, 'git-receive-pack' is invoked via
+	ssh.
+
+<directory>::
+	The repository to update.
+
+<ref>...::
+	The remote refs to update.
+
+
+SPECIFYING THE REFS
+-------------------
+
+There are three ways to specify which refs to update on the
+remote end.
+
+With `--all` flag, all refs that exist locally are transferred to
+the remote side.  You cannot specify any '<ref>' if you use
+this flag.
+
+Without `--all` and without any '<ref>', the heads that exist
+both on the local side and on the remote side are updated.
+
+When one or more '<ref>' are specified explicitly (whether on the
+command line or via `--stdin`), it can be either a
+single pattern, or a pair of such pattern separated by a colon
+":" (this means that a ref name cannot have a colon in it).  A
+single pattern '<name>' is just a shorthand for '<name>:<name>'.
+
+Each pattern pair consists of the source side (before the colon)
+and the destination side (after the colon).  The ref to be
+pushed is determined by finding a match that matches the source
+side, and where it is pushed is determined by using the
+destination side. The rules used to match a ref are the same
+rules used by 'git rev-parse' to resolve a symbolic ref
+name. See linkgit:git-rev-parse[1].
+
+ - It is an error if <src> does not match exactly one of the
+   local refs.
+
+ - It is an error if <dst> matches more than one remote refs.
+
+ - If <dst> does not match any remote ref, either
+
+   * it has to start with "refs/"; <dst> is used as the
+     destination literally in this case.
+
+   * <src> == <dst> and the ref that matched the <src> must not
+     exist in the set of remote refs; the ref matched <src>
+     locally is used as the name of the destination.
+
+Without `--force`, the <src> ref is stored at the remote only if
+<dst> does not exist, or <dst> is a proper subset (i.e. an
+ancestor) of <src>.  This check, known as "fast-forward check",
+is performed in order to avoid accidentally overwriting the
+remote ref and lose other peoples' commits from there.
+
+With `--force`, the fast-forward check is disabled for all refs.
+
+Optionally, a <ref> parameter can be prefixed with a plus '+' sign
+to disable the fast-forward check only on that ref.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-sh-i18n--envsubst.txt b/third_party/git/Documentation/git-sh-i18n--envsubst.txt
new file mode 100644
index 0000000000..2ffaf9392e
--- /dev/null
+++ b/third_party/git/Documentation/git-sh-i18n--envsubst.txt
@@ -0,0 +1,36 @@
+git-sh-i18n{litdd}envsubst(1)
+=============================
+
+NAME
+----
+git-sh-i18n--envsubst - Git's own envsubst(1) for i18n fallbacks
+
+SYNOPSIS
+--------
+[verse]
+eval_gettext () {
+	printf "%s" "$1" | (
+		export PATH $('git sh-i18n{litdd}envsubst' --variables "$1");
+		'git sh-i18n{litdd}envsubst' "$1"
+	)
+}
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+plumbing scripts and/or are writing new ones.
+
+'git sh-i18n{litdd}envsubst' is Git's stripped-down copy of the GNU
+`envsubst(1)` program that comes with the GNU gettext package. It's
+used internally by linkgit:git-sh-i18n[1] to interpolate the variables
+passed to the `eval_gettext` function.
+
+No promises are made about the interface, or that this
+program won't disappear without warning in the next version
+of Git. Don't use it.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-sh-i18n.txt b/third_party/git/Documentation/git-sh-i18n.txt
new file mode 100644
index 0000000000..60cf49cb2a
--- /dev/null
+++ b/third_party/git/Documentation/git-sh-i18n.txt
@@ -0,0 +1,43 @@
+git-sh-i18n(1)
+==============
+
+NAME
+----
+git-sh-i18n - Git's i18n setup code for shell scripts
+
+SYNOPSIS
+--------
+[verse]
+'. "$(git --exec-path)/git-sh-i18n"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git sh-i18n scriptlet is designed to be sourced (using
+`.`) by Git's porcelain programs implemented in shell
+script. It provides wrappers for the GNU `gettext` and
+`eval_gettext` functions accessible through the `gettext.sh`
+script, and provides pass-through fallbacks on systems
+without GNU gettext.
+
+FUNCTIONS
+---------
+
+gettext::
+	Currently a dummy fall-through function implemented as a wrapper
+	around `printf(1)`. Will be replaced by a real gettext
+	implementation in a later version.
+
+eval_gettext::
+	Currently a dummy fall-through function implemented as a wrapper
+	around `printf(1)` with variables expanded by the
+	linkgit:git-sh-i18n{litdd}envsubst[1] helper. Will be replaced by a
+	real gettext implementation in a later version.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-sh-setup.txt b/third_party/git/Documentation/git-sh-setup.txt
new file mode 100644
index 0000000000..8632612c31
--- /dev/null
+++ b/third_party/git/Documentation/git-sh-setup.txt
@@ -0,0 +1,95 @@
+git-sh-setup(1)
+===============
+
+NAME
+----
+git-sh-setup - Common Git shell script setup code
+
+SYNOPSIS
+--------
+[verse]
+'. "$(git --exec-path)/git-sh-setup"'
+
+DESCRIPTION
+-----------
+
+This is not a command the end user would want to run.  Ever.
+This documentation is meant for people who are studying the
+Porcelain-ish scripts and/or are writing new ones.
+
+The 'git sh-setup' scriptlet is designed to be sourced (using
+`.`) by other shell scripts to set up some variables pointing at
+the normal Git directories and a few helper shell functions.
+
+Before sourcing it, your script should set up a few variables;
+`USAGE` (and `LONG_USAGE`, if any) is used to define message
+given by `usage()` shell function.  `SUBDIRECTORY_OK` can be set
+if the script can run from a subdirectory of the working tree
+(some commands do not).
+
+The scriptlet sets `GIT_DIR` and `GIT_OBJECT_DIRECTORY` shell
+variables, but does *not* export them to the environment.
+
+FUNCTIONS
+---------
+
+die::
+	exit after emitting the supplied error message to the
+	standard error stream.
+
+usage::
+	die with the usage message.
+
+set_reflog_action::
+	Set `GIT_REFLOG_ACTION` environment to a given string (typically
+	the name of the program) unless it is already set.  Whenever
+	the script runs a `git` command that updates refs, a reflog
+	entry is created using the value of this string to leave the
+	record of what command updated the ref.
+
+git_editor::
+	runs an editor of user's choice (GIT_EDITOR, core.editor, VISUAL or
+	EDITOR) on a given file, but error out if no editor is specified
+	and the terminal is dumb.
+
+is_bare_repository::
+	outputs `true` or `false` to the standard output stream
+	to indicate if the repository is a bare repository
+	(i.e. without an associated working tree).
+
+cd_to_toplevel::
+	runs chdir to the toplevel of the working tree.
+
+require_work_tree::
+	checks if the current directory is within the working tree
+	of the repository, and otherwise dies.
+
+require_work_tree_exists::
+	checks if the working tree associated with the repository
+	exists, and otherwise dies.  Often done before calling
+	cd_to_toplevel, which is impossible to do if there is no
+	working tree.
+
+require_clean_work_tree <action> [<hint>]::
+	checks that the working tree and index associated with the
+	repository have no uncommitted changes to tracked files.
+	Otherwise it emits an error message of the form `Cannot
+	<action>: <reason>. <hint>`, and dies.  Example:
++
+----------------
+require_clean_work_tree rebase "Please commit or stash them."
+----------------
+
+get_author_ident_from_commit::
+	outputs code for use with eval to set the GIT_AUTHOR_NAME,
+	GIT_AUTHOR_EMAIL and GIT_AUTHOR_DATE variables for a given commit.
+
+create_virtual_base::
+	modifies the first file so only lines in common with the
+	second file remain. If there is insufficient common material,
+	then the first file is left empty. The result is suitable
+	as a virtual base input for a 3-way merge.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-shell.txt b/third_party/git/Documentation/git-shell.txt
new file mode 100644
index 0000000000..11361f33e9
--- /dev/null
+++ b/third_party/git/Documentation/git-shell.txt
@@ -0,0 +1,106 @@
+git-shell(1)
+============
+
+NAME
+----
+git-shell - Restricted login shell for Git-only SSH access
+
+
+SYNOPSIS
+--------
+[verse]
+'chsh' -s $(command -v git-shell) <user>
+'git clone' <user>`@localhost:/path/to/repo.git`
+'ssh' <user>`@localhost`
+
+DESCRIPTION
+-----------
+
+This is a login shell for SSH accounts to provide restricted Git access.
+It permits execution only of server-side Git commands implementing the
+pull/push functionality, plus custom commands present in a subdirectory
+named `git-shell-commands` in the user's home directory.
+
+COMMANDS
+--------
+
+'git shell' accepts the following commands after the `-c` option:
+
+'git receive-pack <argument>'::
+'git upload-pack <argument>'::
+'git upload-archive <argument>'::
+	Call the corresponding server-side command to support
+	the client's 'git push', 'git fetch', or 'git archive --remote'
+	request.
+'cvs server'::
+	Imitate a CVS server.  See linkgit:git-cvsserver[1].
+
+If a `~/git-shell-commands` directory is present, 'git shell' will
+also handle other, custom commands by running
+"`git-shell-commands/<command> <arguments>`" from the user's home
+directory.
+
+INTERACTIVE USE
+---------------
+
+By default, the commands above can be executed only with the `-c`
+option; the shell is not interactive.
+
+If a `~/git-shell-commands` directory is present, 'git shell'
+can also be run interactively (with no arguments).  If a `help`
+command is present in the `git-shell-commands` directory, it is
+run to provide the user with an overview of allowed actions.  Then a
+"git> " prompt is presented at which one can enter any of the
+commands from the `git-shell-commands` directory, or `exit` to close
+the connection.
+
+Generally this mode is used as an administrative interface to allow
+users to list repositories they have access to, create, delete, or
+rename repositories, or change repository descriptions and
+permissions.
+
+If a `no-interactive-login` command exists, then it is run and the
+interactive shell is aborted.
+
+EXAMPLES
+--------
+
+To disable interactive logins, displaying a greeting instead:
+
+----------------
+$ chsh -s /usr/bin/git-shell
+$ mkdir $HOME/git-shell-commands
+$ cat >$HOME/git-shell-commands/no-interactive-login <<\EOF
+#!/bin/sh
+printf '%s\n' "Hi $USER! You've successfully authenticated, but I do not"
+printf '%s\n' "provide interactive shell access."
+exit 128
+EOF
+$ chmod +x $HOME/git-shell-commands/no-interactive-login
+----------------
+
+To enable git-cvsserver access (which should generally have the
+`no-interactive-login` example above as a prerequisite, as creating
+the git-shell-commands directory allows interactive logins):
+
+----------------
+$ cat >$HOME/git-shell-commands/cvs <<\EOF
+if ! test $# = 1 && test "$1" = "server"
+then
+	echo >&2 "git-cvsserver only handles \"server\""
+	exit 1
+fi
+exec git cvsserver server
+EOF
+$ chmod +x $HOME/git-shell-commands/cvs
+----------------
+
+SEE ALSO
+--------
+ssh(1),
+linkgit:git-daemon[1],
+contrib/git-shell-commands/README
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-shortlog.txt b/third_party/git/Documentation/git-shortlog.txt
new file mode 100644
index 0000000000..bc80905a8a
--- /dev/null
+++ b/third_party/git/Documentation/git-shortlog.txt
@@ -0,0 +1,90 @@
+git-shortlog(1)
+===============
+
+NAME
+----
+git-shortlog - Summarize 'git log' output
+
+SYNOPSIS
+--------
+[verse]
+'git shortlog' [<options>] [<revision range>] [[--] <path>...]
+git log --pretty=short | 'git shortlog' [<options>]
+
+DESCRIPTION
+-----------
+Summarizes 'git log' output in a format suitable for inclusion
+in release announcements. Each commit will be grouped by author and title.
+
+Additionally, "[PATCH]" will be stripped from the commit description.
+
+If no revisions are passed on the command line and either standard input
+is not a terminal or there is no current branch, 'git shortlog' will
+output a summary of the log read from standard input, without
+reference to the current repository.
+
+OPTIONS
+-------
+
+-n::
+--numbered::
+	Sort output according to the number of commits per author instead
+	of author alphabetic order.
+
+-s::
+--summary::
+	Suppress commit description and provide a commit count summary only.
+
+-e::
+--email::
+	Show the email address of each author.
+
+--format[=<format>]::
+	Instead of the commit subject, use some other information to
+	describe each commit.  '<format>' can be any string accepted
+	by the `--format` option of 'git log', such as '* [%h] %s'.
+	(See the "PRETTY FORMATS" section of linkgit:git-log[1].)
+
+	Each pretty-printed commit will be rewrapped before it is shown.
+
+-c::
+--committer::
+	Collect and show committer identities instead of authors.
+
+-w[<width>[,<indent1>[,<indent2>]]]::
+	Linewrap the output by wrapping each line at `width`.  The first
+	line of each entry is indented by `indent1` spaces, and the second
+	and subsequent lines are indented by `indent2` spaces. `width`,
+	`indent1`, and `indent2` default to 76, 6 and 9 respectively.
++
+If width is `0` (zero) then indent the lines of the output without wrapping
+them.
+
+<revision range>::
+	Show only commits in the specified revision range.  When no
+	<revision range> is specified, it defaults to `HEAD` (i.e. the
+	whole history leading to the current commit).  `origin..HEAD`
+	specifies all the commits reachable from the current commit
+	(i.e. `HEAD`), but not from `origin`. For a complete list of
+	ways to spell <revision range>, see the "Specifying Ranges"
+	section of linkgit:gitrevisions[7].
+
+[--] <path>...::
+	Consider only commits that are enough to explain how the files
+	that match the specified paths came to be.
++
+Paths may need to be prefixed with `--` to separate them from
+options or the revision range, when confusion arises.
+
+MAPPING AUTHORS
+---------------
+
+The `.mailmap` feature is used to coalesce together commits by the same
+person in the shortlog, where their name and/or email address was
+spelled differently.
+
+include::mailmap.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-show-branch.txt b/third_party/git/Documentation/git-show-branch.txt
new file mode 100644
index 0000000000..5cc2fcefba
--- /dev/null
+++ b/third_party/git/Documentation/git-show-branch.txt
@@ -0,0 +1,204 @@
+git-show-branch(1)
+==================
+
+NAME
+----
+git-show-branch - Show branches and their commits
+
+SYNOPSIS
+--------
+[verse]
+'git show-branch' [-a|--all] [-r|--remotes] [--topo-order | --date-order]
+		[--current] [--color[=<when>] | --no-color] [--sparse]
+		[--more=<n> | --list | --independent | --merge-base]
+		[--no-name | --sha1-name] [--topics]
+		[(<rev> | <glob>)...]
+'git show-branch' (-g|--reflog)[=<n>[,<base>]] [--list] [<ref>]
+
+DESCRIPTION
+-----------
+
+Shows the commit ancestry graph starting from the commits named
+with <rev>s or <glob>s (or all refs under refs/heads
+and/or refs/tags) semi-visually.
+
+It cannot show more than 29 branches and commits at a time.
+
+It uses `showbranch.default` multi-valued configuration items if
+no <rev> or <glob> is given on the command line.
+
+
+OPTIONS
+-------
+<rev>::
+	Arbitrary extended SHA-1 expression (see linkgit:gitrevisions[7])
+	that typically names a branch head or a tag.
+
+<glob>::
+	A glob pattern that matches branch or tag names under
+	refs/.  For example, if you have many topic
+	branches under refs/heads/topic, giving
+	`topic/*` would show all of them.
+
+-r::
+--remotes::
+	Show the remote-tracking branches.
+
+-a::
+--all::
+	Show both remote-tracking branches and local branches.
+
+--current::
+	With this option, the command includes the current
+	branch to the list of revs to be shown when it is not
+	given on the command line.
+
+--topo-order::
+        By default, the branches and their commits are shown in
+        reverse chronological order.  This option makes them
+        appear in topological order (i.e., descendant commits
+        are shown before their parents).
+
+--date-order::
+	This option is similar to `--topo-order` in the sense that no
+	parent comes before all of its children, but otherwise commits
+	are ordered according to their commit date.
+
+--sparse::
+	By default, the output omits merges that are reachable
+	from only one tip being shown.  This option makes them
+	visible.
+
+--more=<n>::
+	Usually the command stops output upon showing the commit
+	that is the common ancestor of all the branches.  This
+	flag tells the command to go <n> more common commits
+	beyond that.  When <n> is negative, display only the
+	<reference>s given, without showing the commit ancestry
+	tree.
+
+--list::
+	Synonym to `--more=-1`
+
+--merge-base::
+	Instead of showing the commit list, determine possible
+	merge bases for the specified commits. All merge bases
+	will be contained in all specified commits. This is
+	different from how linkgit:git-merge-base[1] handles
+	the case of three or more commits.
+
+--independent::
+	Among the <reference>s given, display only the ones that
+	cannot be reached from any other <reference>.
+
+--no-name::
+	Do not show naming strings for each commit.
+
+--sha1-name::
+	Instead of naming the commits using the path to reach
+	them from heads (e.g. "master~2" to mean the grandparent
+	of "master"), name them with the unique prefix of their
+	object names.
+
+--topics::
+	Shows only commits that are NOT on the first branch given.
+	This helps track topic branches by hiding any commit that
+	is already in the main line of development.  When given
+	"git show-branch --topics master topic1 topic2", this
+	will show the revisions given by "git rev-list {caret}master
+	topic1 topic2"
+
+-g::
+--reflog[=<n>[,<base>]] [<ref>]::
+	Shows <n> most recent ref-log entries for the given
+	ref.  If <base> is given, <n> entries going back from
+	that entry.  <base> can be specified as count or date.
+	When no explicit <ref> parameter is given, it defaults to the
+	current branch (or `HEAD` if it is detached).
+
+--color[=<when>]::
+	Color the status sign (one of these: `*` `!` `+` `-`) of each commit
+	corresponding to the branch it's in.
+	The value must be always (the default), never, or auto.
+
+--no-color::
+	Turn off colored output, even when the configuration file gives the
+	default to color output.
+	Same as `--color=never`.
+
+Note that --more, --list, --independent and --merge-base options
+are mutually exclusive.
+
+
+OUTPUT
+------
+Given N <references>, the first N lines are the one-line
+description from their commit message.  The branch head that is
+pointed at by $GIT_DIR/HEAD is prefixed with an asterisk `*`
+character while other heads are prefixed with a `!` character.
+
+Following these N lines, one-line log for each commit is
+displayed, indented N places.  If a commit is on the I-th
+branch, the I-th indentation character shows a `+` sign;
+otherwise it shows a space.  Merge commits are denoted by
+a `-` sign.  Each commit shows a short name that
+can be used as an extended SHA-1 to name that commit.
+
+The following example shows three branches, "master", "fixes"
+and "mhf":
+
+------------------------------------------------
+$ git show-branch master fixes mhf
+* [master] Add 'git show-branch'.
+ ! [fixes] Introduce "reset type" flag to "git reset"
+  ! [mhf] Allow "+remote:local" refspec to cause --force when fetching.
+---
+  + [mhf] Allow "+remote:local" refspec to cause --force when fetching.
+  + [mhf~1] Use git-octopus when pulling more than one heads.
+ +  [fixes] Introduce "reset type" flag to "git reset"
+  + [mhf~2] "git fetch --force".
+  + [mhf~3] Use .git/remote/origin, not .git/branches/origin.
+  + [mhf~4] Make "git pull" and "git fetch" default to origin
+  + [mhf~5] Infamous 'octopus merge'
+  + [mhf~6] Retire git-parse-remote.
+  + [mhf~7] Multi-head fetch.
+  + [mhf~8] Start adding the $GIT_DIR/remotes/ support.
+*++ [master] Add 'git show-branch'.
+------------------------------------------------
+
+These three branches all forked from a common commit, [master],
+whose commit message is "Add \'git show-branch'".
+The "fixes" branch adds one commit "Introduce "reset type" flag to
+"git reset"". The "mhf" branch adds many other commits.
+The current branch is "master".
+
+
+EXAMPLES
+--------
+
+If you keep your primary branches immediately under
+`refs/heads`, and topic branches in subdirectories of
+it, having the following in the configuration file may help:
+
+------------
+[showbranch]
+	default = --topo-order
+	default = heads/*
+
+------------
+
+With this, `git show-branch` without extra parameters would show
+only the primary branches.  In addition, if you happen to be on
+your topic branch, it is shown as well.
+
+------------
+$ git show-branch --reflog="10,1 hour ago" --list master
+------------
+
+shows 10 reflog entries going back from the tip as of 1 hour ago.
+Without `--list`, the output also shows how these tips are
+topologically related with each other.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-show-index.txt b/third_party/git/Documentation/git-show-index.txt
new file mode 100644
index 0000000000..424e4ba84c
--- /dev/null
+++ b/third_party/git/Documentation/git-show-index.txt
@@ -0,0 +1,41 @@
+git-show-index(1)
+=================
+
+NAME
+----
+git-show-index - Show packed archive index
+
+
+SYNOPSIS
+--------
+[verse]
+'git show-index'
+
+
+DESCRIPTION
+-----------
+Read the `.idx` file for a Git packfile (created with
+linkgit:git-pack-objects[1] or linkgit:git-index-pack[1]) from the
+standard input, and dump its contents. The output consists of one object
+per line, with each line containing two or three space-separated
+columns:
+
+  - the first column is the offset in bytes of the object within the
+    corresponding packfile
+
+  - the second column is the object id of the object
+
+  - if the index version is 2 or higher, the third column contains the
+    CRC32 of the object data
+
+The objects are output in the order in which they are found in the index
+file, which should be (in a correctly constructed file) sorted by object
+id.
+
+Note that you can get more information on a packfile by calling
+linkgit:git-verify-pack[1]. However, as this command considers only the
+index file itself, it's both faster and more flexible.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-show-ref.txt b/third_party/git/Documentation/git-show-ref.txt
new file mode 100644
index 0000000000..ab4d271925
--- /dev/null
+++ b/third_party/git/Documentation/git-show-ref.txt
@@ -0,0 +1,186 @@
+git-show-ref(1)
+===============
+
+NAME
+----
+git-show-ref - List references in a local repository
+
+SYNOPSIS
+--------
+[verse]
+'git show-ref' [-q|--quiet] [--verify] [--head] [-d|--dereference]
+	     [-s|--hash[=<n>]] [--abbrev[=<n>]] [--tags]
+	     [--heads] [--] [<pattern>...]
+'git show-ref' --exclude-existing[=<pattern>]
+
+DESCRIPTION
+-----------
+
+Displays references available in a local repository along with the associated
+commit IDs. Results can be filtered using a pattern and tags can be
+dereferenced into object IDs. Additionally, it can be used to test whether a
+particular ref exists.
+
+By default, shows the tags, heads, and remote refs.
+
+The --exclude-existing form is a filter that does the inverse. It reads
+refs from stdin, one ref per line, and shows those that don't exist in
+the local repository.
+
+Use of this utility is encouraged in favor of directly accessing files under
+the `.git` directory.
+
+OPTIONS
+-------
+
+--head::
+
+	Show the HEAD reference, even if it would normally be filtered out.
+
+--heads::
+--tags::
+
+	Limit to "refs/heads" and "refs/tags", respectively.  These options
+	are not mutually exclusive; when given both, references stored in
+	"refs/heads" and "refs/tags" are displayed.
+
+-d::
+--dereference::
+
+	Dereference tags into object IDs as well. They will be shown with "{caret}{}"
+	appended.
+
+-s::
+--hash[=<n>]::
+
+	Only show the SHA-1 hash, not the reference name. When combined with
+	--dereference the dereferenced tag will still be shown after the SHA-1.
+
+--verify::
+
+	Enable stricter reference checking by requiring an exact ref path.
+	Aside from returning an error code of 1, it will also print an error
+	message if `--quiet` was not specified.
+
+--abbrev[=<n>]::
+
+	Abbreviate the object name.  When using `--hash`, you do
+	not have to say `--hash --abbrev`; `--hash=n` would do.
+
+-q::
+--quiet::
+
+	Do not print any results to stdout. When combined with `--verify` this
+	can be used to silently check if a reference exists.
+
+--exclude-existing[=<pattern>]::
+
+	Make 'git show-ref' act as a filter that reads refs from stdin of the
+	form "`^(?:<anything>\s)?<refname>(?:\^{})?$`"
+	and performs the following actions on each:
+	(1) strip "{caret}{}" at the end of line if any;
+	(2) ignore if pattern is provided and does not head-match refname;
+	(3) warn if refname is not a well-formed refname and skip;
+	(4) ignore if refname is a ref that exists in the local repository;
+	(5) otherwise output the line.
+
+
+<pattern>...::
+
+	Show references matching one or more patterns. Patterns are matched from
+	the end of the full name, and only complete parts are matched, e.g.
+	'master' matches 'refs/heads/master', 'refs/remotes/origin/master',
+	'refs/tags/jedi/master' but not 'refs/heads/mymaster' or
+	'refs/remotes/master/jedi'.
+
+OUTPUT
+------
+
+The output is in the format: '<SHA-1 ID>' '<space>' '<reference name>'.
+
+-----------------------------------------------------------------------------
+$ git show-ref --head --dereference
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 HEAD
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/master
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/origin
+3521017556c5de4159da4615a39fa4d5d2c279b5 refs/tags/v0.99.9c
+6ddc0964034342519a87fe013781abf31c6db6ad refs/tags/v0.99.9c^{}
+055e4ae3ae6eb344cbabf2a5256a49ea66040131 refs/tags/v1.0rc4
+423325a2d24638ddcc82ce47be5e40be550f4507 refs/tags/v1.0rc4^{}
+...
+-----------------------------------------------------------------------------
+
+When using --hash (and not --dereference) the output format is: '<SHA-1 ID>'
+
+-----------------------------------------------------------------------------
+$ git show-ref --heads --hash
+2e3ba0114a1f52b47df29743d6915d056be13278
+185008ae97960c8d551adcd9e23565194651b5d1
+03adf42c988195b50e1a1935ba5fcbc39b2b029b
+...
+-----------------------------------------------------------------------------
+
+EXAMPLES
+--------
+
+To show all references called "master", whether tags or heads or anything
+else, and regardless of how deep in the reference naming hierarchy they are,
+use:
+
+-----------------------------------------------------------------------------
+	git show-ref master
+-----------------------------------------------------------------------------
+
+This will show "refs/heads/master" but also "refs/remote/other-repo/master",
+if such references exists.
+
+When using the `--verify` flag, the command requires an exact path:
+
+-----------------------------------------------------------------------------
+	git show-ref --verify refs/heads/master
+-----------------------------------------------------------------------------
+
+will only match the exact branch called "master".
+
+If nothing matches, 'git show-ref' will return an error code of 1,
+and in the case of verification, it will show an error message.
+
+For scripting, you can ask it to be quiet with the "--quiet" flag, which
+allows you to do things like
+
+-----------------------------------------------------------------------------
+	git show-ref --quiet --verify -- "refs/heads/$headname" ||
+		echo "$headname is not a valid branch"
+-----------------------------------------------------------------------------
+
+to check whether a particular branch exists or not (notice how we don't
+actually want to show any results, and we want to use the full refname for it
+in order to not trigger the problem with ambiguous partial matches).
+
+To show only tags, or only proper branch heads, use "--tags" and/or "--heads"
+respectively (using both means that it shows tags and heads, but not other
+random references under the refs/ subdirectory).
+
+To do automatic tag object dereferencing, use the "-d" or "--dereference"
+flag, so you can do
+
+-----------------------------------------------------------------------------
+	git show-ref --tags --dereference
+-----------------------------------------------------------------------------
+
+to get a listing of all tags together with what they dereference.
+
+FILES
+-----
+`.git/refs/*`, `.git/packed-refs`
+
+SEE ALSO
+--------
+linkgit:git-for-each-ref[1],
+linkgit:git-ls-remote[1],
+linkgit:git-update-ref[1],
+linkgit:gitrepository-layout[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-show.txt b/third_party/git/Documentation/git-show.txt
new file mode 100644
index 0000000000..fcf528c1b3
--- /dev/null
+++ b/third_party/git/Documentation/git-show.txt
@@ -0,0 +1,87 @@
+git-show(1)
+===========
+
+NAME
+----
+git-show - Show various types of objects
+
+
+SYNOPSIS
+--------
+[verse]
+'git show' [<options>] [<object>...]
+
+DESCRIPTION
+-----------
+Shows one or more objects (blobs, trees, tags and commits).
+
+For commits it shows the log message and textual diff. It also
+presents the merge commit in a special format as produced by
+'git diff-tree --cc'.
+
+For tags, it shows the tag message and the referenced objects.
+
+For trees, it shows the names (equivalent to 'git ls-tree'
+with --name-only).
+
+For plain blobs, it shows the plain contents.
+
+The command takes options applicable to the 'git diff-tree' command to
+control how the changes the commit introduces are shown.
+
+This manual page describes only the most frequently used options.
+
+
+OPTIONS
+-------
+<object>...::
+	The names of objects to show (defaults to 'HEAD').
+	For a more complete list of ways to spell object names, see
+	"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
+
+include::pretty-options.txt[]
+
+
+include::pretty-formats.txt[]
+
+
+COMMON DIFF OPTIONS
+-------------------
+
+:git-log: 1
+include::diff-options.txt[]
+
+include::diff-generate-patch.txt[]
+
+
+EXAMPLES
+--------
+
+`git show v1.0.0`::
+	Shows the tag `v1.0.0`, along with the object the tags
+	points at.
+
+`git show v1.0.0^{tree}`::
+	Shows the tree pointed to by the tag `v1.0.0`.
+
+`git show -s --format=%s v1.0.0^{commit}`::
+	Shows the subject of the commit pointed to by the
+	tag `v1.0.0`.
+
+`git show next~10:Documentation/README`::
+	Shows the contents of the file `Documentation/README` as
+	they were current in the 10th last commit of the branch
+	`next`.
+
+`git show master:Makefile master:t/Makefile`::
+	Concatenates the contents of said Makefiles in the head
+	of the branch `master`.
+
+DISCUSSION
+----------
+
+include::i18n.txt[]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-stage.txt b/third_party/git/Documentation/git-stage.txt
new file mode 100644
index 0000000000..25bcda936d
--- /dev/null
+++ b/third_party/git/Documentation/git-stage.txt
@@ -0,0 +1,23 @@
+git-stage(1)
+============
+
+NAME
+----
+git-stage - Add file contents to the staging area
+
+
+SYNOPSIS
+--------
+[verse]
+'git stage' args...
+
+
+DESCRIPTION
+-----------
+
+This is a synonym for linkgit:git-add[1].  Please refer to the
+documentation of that command.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-stash.txt b/third_party/git/Documentation/git-stash.txt
new file mode 100644
index 0000000000..8fbe12c66c
--- /dev/null
+++ b/third_party/git/Documentation/git-stash.txt
@@ -0,0 +1,301 @@
+git-stash(1)
+============
+
+NAME
+----
+git-stash - Stash the changes in a dirty working directory away
+
+SYNOPSIS
+--------
+[verse]
+'git stash' list [<options>]
+'git stash' show [<options>] [<stash>]
+'git stash' drop [-q|--quiet] [<stash>]
+'git stash' ( pop | apply ) [--index] [-q|--quiet] [<stash>]
+'git stash' branch <branchname> [<stash>]
+'git stash' [push [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]
+	     [-u|--include-untracked] [-a|--all] [-m|--message <message>]
+	     [--] [<pathspec>...]]
+'git stash' clear
+'git stash' create [<message>]
+'git stash' store [-m|--message <message>] [-q|--quiet] <commit>
+
+DESCRIPTION
+-----------
+
+Use `git stash` when you want to record the current state of the
+working directory and the index, but want to go back to a clean
+working directory.  The command saves your local modifications away
+and reverts the working directory to match the `HEAD` commit.
+
+The modifications stashed away by this command can be listed with
+`git stash list`, inspected with `git stash show`, and restored
+(potentially on top of a different commit) with `git stash apply`.
+Calling `git stash` without any arguments is equivalent to `git stash push`.
+A stash is by default listed as "WIP on 'branchname' ...", but
+you can give a more descriptive message on the command line when
+you create one.
+
+The latest stash you created is stored in `refs/stash`; older
+stashes are found in the reflog of this reference and can be named using
+the usual reflog syntax (e.g. `stash@{0}` is the most recently
+created stash, `stash@{1}` is the one before it, `stash@{2.hours.ago}`
+is also possible). Stashes may also be referenced by specifying just the
+stash index (e.g. the integer `n` is equivalent to `stash@{n}`).
+
+OPTIONS
+-------
+
+push [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [-m|--message <message>] [--] [<pathspec>...]::
+
+	Save your local modifications to a new 'stash entry' and roll them
+	back to HEAD (in the working tree and in the index).
+	The <message> part is optional and gives
+	the description along with the stashed state.
++
+For quickly making a snapshot, you can omit "push".  In this mode,
+non-option arguments are not allowed to prevent a misspelled
+subcommand from making an unwanted stash entry.  The two exceptions to this
+are `stash -p` which acts as alias for `stash push -p` and pathspecs,
+which are allowed after a double hyphen `--` for disambiguation.
++
+When pathspec is given to 'git stash push', the new stash entry records the
+modified states only for the files that match the pathspec.  The index
+entries and working tree files are then rolled back to the state in
+HEAD only for these files, too, leaving files that do not match the
+pathspec intact.
++
+If the `--keep-index` option is used, all changes already added to the
+index are left intact.
++
+If the `--include-untracked` option is used, all untracked files are also
+stashed and then cleaned up with `git clean`, leaving the working directory
+in a very clean state. If the `--all` option is used instead then the
+ignored files are stashed and cleaned in addition to the untracked files.
++
+With `--patch`, you can interactively select hunks from the diff
+between HEAD and the working tree to be stashed.  The stash entry is
+constructed such that its index state is the same as the index state
+of your repository, and its worktree contains only the changes you
+selected interactively.  The selected changes are then rolled back
+from your worktree. See the ``Interactive Mode'' section of
+linkgit:git-add[1] to learn how to operate the `--patch` mode.
++
+The `--patch` option implies `--keep-index`.  You can use
+`--no-keep-index` to override this.
+
+save [-p|--patch] [-k|--[no-]keep-index] [-u|--include-untracked] [-a|--all] [-q|--quiet] [<message>]::
+
+	This option is deprecated in favour of 'git stash push'.  It
+	differs from "stash push" in that it cannot take pathspecs,
+	and any non-option arguments form the message.
+
+list [<options>]::
+
+	List the stash entries that you currently have.  Each 'stash entry' is
+	listed with its name (e.g. `stash@{0}` is the latest entry, `stash@{1}` is
+	the one before, etc.), the name of the branch that was current when the
+	entry was made, and a short description of the commit the entry was
+	based on.
++
+----------------------------------------------------------------
+stash@{0}: WIP on submit: 6ebd0e2... Update git-stash documentation
+stash@{1}: On master: 9cc0589... Add git-stash
+----------------------------------------------------------------
++
+The command takes options applicable to the 'git log'
+command to control what is shown and how. See linkgit:git-log[1].
+
+show [<options>] [<stash>]::
+
+	Show the changes recorded in the stash entry as a diff between the
+	stashed contents and the commit back when the stash entry was first
+	created. When no `<stash>` is given, it shows the latest one.
+	By default, the command shows the diffstat, but it will accept any
+	format known to 'git diff' (e.g., `git stash show -p stash@{1}`
+	to view the second most recent entry in patch form).
+	You can use stash.showStat and/or stash.showPatch config variables
+	to change the default behavior.
+
+pop [--index] [-q|--quiet] [<stash>]::
+
+	Remove a single stashed state from the stash list and apply it
+	on top of the current working tree state, i.e., do the inverse
+	operation of `git stash push`. The working directory must
+	match the index.
++
+Applying the state can fail with conflicts; in this case, it is not
+removed from the stash list. You need to resolve the conflicts by hand
+and call `git stash drop` manually afterwards.
++
+If the `--index` option is used, then tries to reinstate not only the working
+tree's changes, but also the index's ones. However, this can fail, when you
+have conflicts (which are stored in the index, where you therefore can no
+longer apply the changes as they were originally).
++
+When no `<stash>` is given, `stash@{0}` is assumed, otherwise `<stash>` must
+be a reference of the form `stash@{<revision>}`.
+
+apply [--index] [-q|--quiet] [<stash>]::
+
+	Like `pop`, but do not remove the state from the stash list. Unlike `pop`,
+	`<stash>` may be any commit that looks like a commit created by
+	`stash push` or `stash create`.
+
+branch <branchname> [<stash>]::
+
+	Creates and checks out a new branch named `<branchname>` starting from
+	the commit at which the `<stash>` was originally created, applies the
+	changes recorded in `<stash>` to the new working tree and index.
+	If that succeeds, and `<stash>` is a reference of the form
+	`stash@{<revision>}`, it then drops the `<stash>`. When no `<stash>`
+	is given, applies the latest one.
++
+This is useful if the branch on which you ran `git stash push` has
+changed enough that `git stash apply` fails due to conflicts. Since
+the stash entry is applied on top of the commit that was HEAD at the
+time `git stash` was run, it restores the originally stashed state
+with no conflicts.
+
+clear::
+	Remove all the stash entries. Note that those entries will then
+	be subject to pruning, and may be impossible to recover (see
+	'Examples' below for a possible strategy).
+
+drop [-q|--quiet] [<stash>]::
+
+	Remove a single stash entry from the list of stash entries.
+	When no `<stash>` is given, it removes the latest one.
+	i.e. `stash@{0}`, otherwise `<stash>` must be a valid stash
+	log reference of the form `stash@{<revision>}`.
+
+create::
+
+	Create a stash entry (which is a regular commit object) and
+	return its object name, without storing it anywhere in the ref
+	namespace.
+	This is intended to be useful for scripts.  It is probably not
+	the command you want to use; see "push" above.
+
+store::
+
+	Store a given stash created via 'git stash create' (which is a
+	dangling merge commit) in the stash ref, updating the stash
+	reflog.  This is intended to be useful for scripts.  It is
+	probably not the command you want to use; see "push" above.
+
+DISCUSSION
+----------
+
+A stash entry is represented as a commit whose tree records the state
+of the working directory, and its first parent is the commit at `HEAD`
+when the entry was created.  The tree of the second parent records the
+state of the index when the entry is made, and it is made a child of
+the `HEAD` commit.  The ancestry graph looks like this:
+
+            .----W
+           /    /
+     -----H----I
+
+where `H` is the `HEAD` commit, `I` is a commit that records the state
+of the index, and `W` is a commit that records the state of the working
+tree.
+
+
+EXAMPLES
+--------
+
+Pulling into a dirty tree::
+
+When you are in the middle of something, you learn that there are
+upstream changes that are possibly relevant to what you are
+doing.  When your local changes do not conflict with the changes in
+the upstream, a simple `git pull` will let you move forward.
++
+However, there are cases in which your local changes do conflict with
+the upstream changes, and `git pull` refuses to overwrite your
+changes.  In such a case, you can stash your changes away,
+perform a pull, and then unstash, like this:
++
+----------------------------------------------------------------
+$ git pull
+ ...
+file foobar not up to date, cannot merge.
+$ git stash
+$ git pull
+$ git stash pop
+----------------------------------------------------------------
+
+Interrupted workflow::
+
+When you are in the middle of something, your boss comes in and
+demands that you fix something immediately.  Traditionally, you would
+make a commit to a temporary branch to store your changes away, and
+return to your original branch to make the emergency fix, like this:
++
+----------------------------------------------------------------
+# ... hack hack hack ...
+$ git switch -c my_wip
+$ git commit -a -m "WIP"
+$ git switch master
+$ edit emergency fix
+$ git commit -a -m "Fix in a hurry"
+$ git switch my_wip
+$ git reset --soft HEAD^
+# ... continue hacking ...
+----------------------------------------------------------------
++
+You can use 'git stash' to simplify the above, like this:
++
+----------------------------------------------------------------
+# ... hack hack hack ...
+$ git stash
+$ edit emergency fix
+$ git commit -a -m "Fix in a hurry"
+$ git stash pop
+# ... continue hacking ...
+----------------------------------------------------------------
+
+Testing partial commits::
+
+You can use `git stash push --keep-index` when you want to make two or
+more commits out of the changes in the work tree, and you want to test
+each change before committing:
++
+----------------------------------------------------------------
+# ... hack hack hack ...
+$ git add --patch foo            # add just first part to the index
+$ git stash push --keep-index    # save all other changes to the stash
+$ edit/build/test first part
+$ git commit -m 'First part'     # commit fully tested change
+$ git stash pop                  # prepare to work on all other changes
+# ... repeat above five steps until one commit remains ...
+$ edit/build/test remaining parts
+$ git commit foo -m 'Remaining parts'
+----------------------------------------------------------------
+
+Recovering stash entries that were cleared/dropped erroneously::
+
+If you mistakenly drop or clear stash entries, they cannot be recovered
+through the normal safety mechanisms.  However, you can try the
+following incantation to get a list of stash entries that are still in
+your repository, but not reachable any more:
++
+----------------------------------------------------------------
+git fsck --unreachable |
+grep commit | cut -d\  -f3 |
+xargs git log --merges --no-walk --grep=WIP
+----------------------------------------------------------------
+
+
+SEE ALSO
+--------
+linkgit:git-checkout[1],
+linkgit:git-commit[1],
+linkgit:git-reflog[1],
+linkgit:git-reset[1],
+linkgit:git-switch[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-status.txt b/third_party/git/Documentation/git-status.txt
new file mode 100644
index 0000000000..d4e8f24f0c
--- /dev/null
+++ b/third_party/git/Documentation/git-status.txt
@@ -0,0 +1,439 @@
+git-status(1)
+=============
+
+NAME
+----
+git-status - Show the working tree status
+
+
+SYNOPSIS
+--------
+[verse]
+'git status' [<options>...] [--] [<pathspec>...]
+
+DESCRIPTION
+-----------
+Displays paths that have differences between the index file and the
+current HEAD commit, paths that have differences between the working
+tree and the index file, and paths in the working tree that are not
+tracked by Git (and are not ignored by linkgit:gitignore[5]). The first
+are what you _would_ commit by running `git commit`; the second and
+third are what you _could_ commit by running 'git add' before running
+`git commit`.
+
+OPTIONS
+-------
+
+-s::
+--short::
+	Give the output in the short-format.
+
+-b::
+--branch::
+	Show the branch and tracking info even in short-format.
+
+--show-stash::
+	Show the number of entries currently stashed away.
+
+--porcelain[=<version>]::
+	Give the output in an easy-to-parse format for scripts.
+	This is similar to the short output, but will remain stable
+	across Git versions and regardless of user configuration. See
+	below for details.
++
+The version parameter is used to specify the format version.
+This is optional and defaults to the original version 'v1' format.
+
+--long::
+	Give the output in the long-format. This is the default.
+
+-v::
+--verbose::
+	In addition to the names of files that have been changed, also
+	show the textual changes that are staged to be committed
+	(i.e., like the output of `git diff --cached`). If `-v` is specified
+	twice, then also show the changes in the working tree that
+	have not yet been staged (i.e., like the output of `git diff`).
+
+-u[<mode>]::
+--untracked-files[=<mode>]::
+	Show untracked files.
++
+The mode parameter is used to specify the handling of untracked files.
+It is optional: it defaults to 'all', and if specified, it must be
+stuck to the option (e.g. `-uno`, but not `-u no`).
++
+The possible options are:
++
+	- 'no'     - Show no untracked files.
+	- 'normal' - Shows untracked files and directories.
+	- 'all'    - Also shows individual files in untracked directories.
++
+When `-u` option is not used, untracked files and directories are
+shown (i.e. the same as specifying `normal`), to help you avoid
+forgetting to add newly created files.  Because it takes extra work
+to find untracked files in the filesystem, this mode may take some
+time in a large working tree.
+Consider enabling untracked cache and split index if supported (see
+`git update-index --untracked-cache` and `git update-index
+--split-index`), Otherwise you can use `no` to have `git status`
+return more quickly without showing untracked files.
++
+The default can be changed using the status.showUntrackedFiles
+configuration variable documented in linkgit:git-config[1].
+
+--ignore-submodules[=<when>]::
+	Ignore changes to submodules when looking for changes. <when> can be
+	either "none", "untracked", "dirty" or "all", which is the default.
+	Using "none" will consider the submodule modified when it either contains
+	untracked or modified files or its HEAD differs from the commit recorded
+	in the superproject and can be used to override any settings of the
+	'ignore' option in linkgit:git-config[1] or linkgit:gitmodules[5]. When
+	"untracked" is used submodules are not considered dirty when they only
+	contain untracked content (but they are still scanned for modified
+	content). Using "dirty" ignores all changes to the work tree of submodules,
+	only changes to the commits stored in the superproject are shown (this was
+	the behavior before 1.7.0). Using "all" hides all changes to submodules
+	(and suppresses the output of submodule summaries when the config option
+	`status.submoduleSummary` is set).
+
+--ignored[=<mode>]::
+	Show ignored files as well.
++
+The mode parameter is used to specify the handling of ignored files.
+It is optional: it defaults to 'traditional'.
++
+The possible options are:
++
+	- 'traditional' - Shows ignored files and directories, unless
+			  --untracked-files=all is specified, in which case
+			  individual files in ignored directories are
+			  displayed.
+	- 'no'	        - Show no ignored files.
+	- 'matching'    - Shows ignored files and directories matching an
+			  ignore pattern.
++
+When 'matching' mode is specified, paths that explicitly match an
+ignored pattern are shown. If a directory matches an ignore pattern,
+then it is shown, but not paths contained in the ignored directory. If
+a directory does not match an ignore pattern, but all contents are
+ignored, then the directory is not shown, but all contents are shown.
+
+-z::
+	Terminate entries with NUL, instead of LF.  This implies
+	the `--porcelain=v1` output format if no other format is given.
+
+--column[=<options>]::
+--no-column::
+	Display untracked files in columns. See configuration variable
+	column.status for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never'
+	respectively.
+
+--ahead-behind::
+--no-ahead-behind::
+	Display or do not display detailed ahead/behind counts for the
+	branch relative to its upstream branch.  Defaults to true.
+
+--renames::
+--no-renames::
+	Turn on/off rename detection regardless of user configuration.
+	See also linkgit:git-diff[1] `--no-renames`.
+
+--find-renames[=<n>]::
+	Turn on rename detection, optionally setting the similarity
+	threshold.
+	See also linkgit:git-diff[1] `--find-renames`.
+
+<pathspec>...::
+	See the 'pathspec' entry in linkgit:gitglossary[7].
+
+OUTPUT
+------
+The output from this command is designed to be used as a commit
+template comment.
+The default, long format, is designed to be human readable,
+verbose and descriptive.  Its contents and format are subject to change
+at any time.
+
+The paths mentioned in the output, unlike many other Git commands, are
+made relative to the current directory if you are working in a
+subdirectory (this is on purpose, to help cutting and pasting). See
+the status.relativePaths config option below.
+
+Short Format
+~~~~~~~~~~~~
+
+In the short-format, the status of each path is shown as one of these
+forms
+
+	XY PATH
+	XY ORIG_PATH -> PATH
+
+where `ORIG_PATH` is where the renamed/copied contents came
+from. `ORIG_PATH` is only shown when the entry is renamed or
+copied. The `XY` is a two-letter status code.
+
+The fields (including the `->`) are separated from each other by a
+single space. If a filename contains whitespace or other nonprintable
+characters, that field will be quoted in the manner of a C string
+literal: surrounded by ASCII double quote (34) characters, and with
+interior special characters backslash-escaped.
+
+For paths with merge conflicts, `X` and `Y` show the modification
+states of each side of the merge. For paths that do not have merge
+conflicts, `X` shows the status of the index, and `Y` shows the status
+of the work tree.  For untracked paths, `XY` are `??`.  Other status
+codes can be interpreted as follows:
+
+* ' ' = unmodified
+* 'M' = modified
+* 'A' = added
+* 'D' = deleted
+* 'R' = renamed
+* 'C' = copied
+* 'U' = updated but unmerged
+
+Ignored files are not listed, unless `--ignored` option is in effect,
+in which case `XY` are `!!`.
+
+....
+X          Y     Meaning
+-------------------------------------------------
+	 [AMD]   not updated
+M        [ MD]   updated in index
+A        [ MD]   added to index
+D                deleted from index
+R        [ MD]   renamed in index
+C        [ MD]   copied in index
+[MARC]           index and work tree matches
+[ MARC]     M    work tree changed since index
+[ MARC]     D    deleted in work tree
+[ D]        R    renamed in work tree
+[ D]        C    copied in work tree
+-------------------------------------------------
+D           D    unmerged, both deleted
+A           U    unmerged, added by us
+U           D    unmerged, deleted by them
+U           A    unmerged, added by them
+D           U    unmerged, deleted by us
+A           A    unmerged, both added
+U           U    unmerged, both modified
+-------------------------------------------------
+?           ?    untracked
+!           !    ignored
+-------------------------------------------------
+....
+
+Submodules have more state and instead report
+		M    the submodule has a different HEAD than
+		     recorded in the index
+		m    the submodule has modified content
+		?    the submodule has untracked files
+since modified content or untracked files in a submodule cannot be added
+via `git add` in the superproject to prepare a commit.
+
+'m' and '?' are applied recursively. For example if a nested submodule
+in a submodule contains an untracked file, this is reported as '?' as well.
+
+If -b is used the short-format status is preceded by a line
+
+    ## branchname tracking info
+
+Porcelain Format Version 1
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Version 1 porcelain format is similar to the short format, but is guaranteed
+not to change in a backwards-incompatible way between Git versions or
+based on user configuration. This makes it ideal for parsing by scripts.
+The description of the short format above also describes the porcelain
+format, with a few exceptions:
+
+1. The user's color.status configuration is not respected; color will
+   always be off.
+
+2. The user's status.relativePaths configuration is not respected; paths
+   shown will always be relative to the repository root.
+
+There is also an alternate -z format recommended for machine parsing. In
+that format, the status field is the same, but some other things
+change.  First, the '\->' is omitted from rename entries and the field
+order is reversed (e.g 'from \-> to' becomes 'to from'). Second, a NUL
+(ASCII 0) follows each filename, replacing space as a field separator
+and the terminating newline (but a space still separates the status
+field from the first filename).  Third, filenames containing special
+characters are not specially formatted; no quoting or
+backslash-escaping is performed.
+
+Any submodule changes are reported as modified `M` instead of `m` or single `?`.
+
+Porcelain Format Version 2
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Version 2 format adds more detailed information about the state of
+the worktree and changed items.  Version 2 also defines an extensible
+set of easy to parse optional headers.
+
+Header lines start with "#" and are added in response to specific
+command line arguments.  Parsers should ignore headers they
+don't recognize.
+
+Branch Headers
+^^^^^^^^^^^^^^
+
+If `--branch` is given, a series of header lines are printed with
+information about the current branch.
+
+....
+Line                                     Notes
+------------------------------------------------------------
+# branch.oid <commit> | (initial)        Current commit.
+# branch.head <branch> | (detached)      Current branch.
+# branch.upstream <upstream_branch>      If upstream is set.
+# branch.ab +<ahead> -<behind>           If upstream is set and
+					 the commit is present.
+------------------------------------------------------------
+....
+
+Changed Tracked Entries
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Following the headers, a series of lines are printed for tracked
+entries.  One of three different line formats may be used to describe
+an entry depending on the type of change.  Tracked entries are printed
+in an undefined order; parsers should allow for a mixture of the 3
+line types in any order.
+
+Ordinary changed entries have the following format:
+
+    1 <XY> <sub> <mH> <mI> <mW> <hH> <hI> <path>
+
+Renamed or copied entries have the following format:
+
+    2 <XY> <sub> <mH> <mI> <mW> <hH> <hI> <X><score> <path><sep><origPath>
+
+....
+Field       Meaning
+--------------------------------------------------------
+<XY>        A 2 character field containing the staged and
+	    unstaged XY values described in the short format,
+	    with unchanged indicated by a "." rather than
+	    a space.
+<sub>       A 4 character field describing the submodule state.
+	    "N..." when the entry is not a submodule.
+	    "S<c><m><u>" when the entry is a submodule.
+	    <c> is "C" if the commit changed; otherwise ".".
+	    <m> is "M" if it has tracked changes; otherwise ".".
+	    <u> is "U" if there are untracked changes; otherwise ".".
+<mH>        The octal file mode in HEAD.
+<mI>        The octal file mode in the index.
+<mW>        The octal file mode in the worktree.
+<hH>        The object name in HEAD.
+<hI>        The object name in the index.
+<X><score>  The rename or copy score (denoting the percentage
+	    of similarity between the source and target of the
+	    move or copy). For example "R100" or "C75".
+<path>      The pathname.  In a renamed/copied entry, this
+	    is the target path.
+<sep>       When the `-z` option is used, the 2 pathnames are separated
+	    with a NUL (ASCII 0x00) byte; otherwise, a tab (ASCII 0x09)
+	    byte separates them.
+<origPath>  The pathname in the commit at HEAD or in the index.
+	    This is only present in a renamed/copied entry, and
+	    tells where the renamed/copied contents came from.
+--------------------------------------------------------
+....
+
+Unmerged entries have the following format; the first character is
+a "u" to distinguish from ordinary changed entries.
+
+    u <xy> <sub> <m1> <m2> <m3> <mW> <h1> <h2> <h3> <path>
+
+....
+Field       Meaning
+--------------------------------------------------------
+<XY>        A 2 character field describing the conflict type
+	    as described in the short format.
+<sub>       A 4 character field describing the submodule state
+	    as described above.
+<m1>        The octal file mode in stage 1.
+<m2>        The octal file mode in stage 2.
+<m3>        The octal file mode in stage 3.
+<mW>        The octal file mode in the worktree.
+<h1>        The object name in stage 1.
+<h2>        The object name in stage 2.
+<h3>        The object name in stage 3.
+<path>      The pathname.
+--------------------------------------------------------
+....
+
+Other Items
+^^^^^^^^^^^
+
+Following the tracked entries (and if requested), a series of
+lines will be printed for untracked and then ignored items
+found in the worktree.
+
+Untracked items have the following format:
+
+    ? <path>
+
+Ignored items have the following format:
+
+    ! <path>
+
+Pathname Format Notes and -z
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When the `-z` option is given, pathnames are printed as is and
+without any quoting and lines are terminated with a NUL (ASCII 0x00)
+byte.
+
+Without the `-z` option, pathnames with "unusual" characters are
+quoted as explained for the configuration variable `core.quotePath`
+(see linkgit:git-config[1]).
+
+
+CONFIGURATION
+-------------
+
+The command honors `color.status` (or `status.color` -- they
+mean the same thing and the latter is kept for backward
+compatibility) and `color.status.<slot>` configuration variables
+to colorize its output.
+
+If the config variable `status.relativePaths` is set to false, then all
+paths shown are relative to the repository root, not to the current
+directory.
+
+If `status.submoduleSummary` is set to a non zero number or true (identical
+to -1 or an unlimited number), the submodule summary will be enabled for
+the long format and a summary of commits for modified submodules will be
+shown (see --summary-limit option of linkgit:git-submodule[1]). Please note
+that the summary output from the status command will be suppressed for all
+submodules when `diff.ignoreSubmodules` is set to 'all' or only for those
+submodules where `submodule.<name>.ignore=all`. To also view the summary for
+ignored submodules you can either use the --ignore-submodules=dirty command
+line option or the 'git submodule summary' command, which shows a similar
+output but does not honor these settings.
+
+BACKGROUND REFRESH
+------------------
+
+By default, `git status` will automatically refresh the index, updating
+the cached stat information from the working tree and writing out the
+result. Writing out the updated index is an optimization that isn't
+strictly necessary (`status` computes the values for itself, but writing
+them out is just to save subsequent programs from repeating our
+computation). When `status` is run in the background, the lock held
+during the write may conflict with other simultaneous processes, causing
+them to fail. Scripts running `status` in the background should consider
+using `git --no-optional-locks status` (see linkgit:git[1] for details).
+
+SEE ALSO
+--------
+linkgit:gitignore[5]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-stripspace.txt b/third_party/git/Documentation/git-stripspace.txt
new file mode 100644
index 0000000000..2438f76da0
--- /dev/null
+++ b/third_party/git/Documentation/git-stripspace.txt
@@ -0,0 +1,94 @@
+git-stripspace(1)
+=================
+
+NAME
+----
+git-stripspace - Remove unnecessary whitespace
+
+
+SYNOPSIS
+--------
+[verse]
+'git stripspace' [-s | --strip-comments]
+'git stripspace' [-c | --comment-lines]
+
+DESCRIPTION
+-----------
+
+Read text, such as commit messages, notes, tags and branch
+descriptions, from the standard input and clean it in the manner
+used by Git.
+
+With no arguments, this will:
+
+- remove trailing whitespace from all lines
+- collapse multiple consecutive empty lines into one empty line
+- remove empty lines from the beginning and end of the input
+- add a missing '\n' to the last line if necessary.
+
+In the case where the input consists entirely of whitespace characters, no
+output will be produced.
+
+*NOTE*: This is intended for cleaning metadata, prefer the `--whitespace=fix`
+mode of linkgit:git-apply[1] for correcting whitespace of patches or files in
+the repository.
+
+OPTIONS
+-------
+-s::
+--strip-comments::
+	Skip and remove all lines starting with comment character (default '#').
+
+-c::
+--comment-lines::
+	Prepend comment character and blank to each line. Lines will automatically
+	be terminated with a newline. On empty lines, only the comment character
+	will be prepended.
+
+EXAMPLES
+--------
+
+Given the following noisy input with '$' indicating the end of a line:
+
+---------
+|A brief introduction   $
+|   $
+|$
+|A new paragraph$
+|# with a commented-out line    $
+|explaining lots of stuff.$
+|$
+|# An old paragraph, also commented-out. $
+|      $
+|The end.$
+|  $
+---------
+
+Use 'git stripspace' with no arguments to obtain:
+
+---------
+|A brief introduction$
+|$
+|A new paragraph$
+|# with a commented-out line$
+|explaining lots of stuff.$
+|$
+|# An old paragraph, also commented-out.$
+|$
+|The end.$
+---------
+
+Use 'git stripspace --strip-comments' to obtain:
+
+---------
+|A brief introduction$
+|$
+|A new paragraph$
+|explaining lots of stuff.$
+|$
+|The end.$
+---------
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-submodule.txt b/third_party/git/Documentation/git-submodule.txt
new file mode 100644
index 0000000000..0ed5c24dc1
--- /dev/null
+++ b/third_party/git/Documentation/git-submodule.txt
@@ -0,0 +1,441 @@
+git-submodule(1)
+================
+
+NAME
+----
+git-submodule - Initialize, update or inspect submodules
+
+
+SYNOPSIS
+--------
+[verse]
+'git submodule' [--quiet] [--cached]
+'git submodule' [--quiet] add [<options>] [--] <repository> [<path>]
+'git submodule' [--quiet] status [--cached] [--recursive] [--] [<path>...]
+'git submodule' [--quiet] init [--] [<path>...]
+'git submodule' [--quiet] deinit [-f|--force] (--all|[--] <path>...)
+'git submodule' [--quiet] update [<options>] [--] [<path>...]
+'git submodule' [--quiet] set-branch [<options>] [--] <path>
+'git submodule' [--quiet] summary [<options>] [--] [<path>...]
+'git submodule' [--quiet] foreach [--recursive] <command>
+'git submodule' [--quiet] sync [--recursive] [--] [<path>...]
+'git submodule' [--quiet] absorbgitdirs [--] [<path>...]
+
+
+DESCRIPTION
+-----------
+Inspects, updates and manages submodules.
+
+For more information about submodules, see linkgit:gitsubmodules[7].
+
+COMMANDS
+--------
+With no arguments, shows the status of existing submodules.  Several
+subcommands are available to perform operations on the submodules.
+
+add [-b <branch>] [-f|--force] [--name <name>] [--reference <repository>] [--depth <depth>] [--] <repository> [<path>]::
+	Add the given repository as a submodule at the given path
+	to the changeset to be committed next to the current
+	project: the current project is termed the "superproject".
++
+<repository> is the URL of the new submodule's origin repository.
+This may be either an absolute URL, or (if it begins with ./
+or ../), the location relative to the superproject's default remote
+repository (Please note that to specify a repository 'foo.git'
+which is located right next to a superproject 'bar.git', you'll
+have to use `../foo.git` instead of `./foo.git` - as one might expect
+when following the rules for relative URLs - because the evaluation
+of relative URLs in Git is identical to that of relative directories).
++
+The default remote is the remote of the remote-tracking branch
+of the current branch. If no such remote-tracking branch exists or
+the HEAD is detached, "origin" is assumed to be the default remote.
+If the superproject doesn't have a default remote configured
+the superproject is its own authoritative upstream and the current
+working directory is used instead.
++
+The optional argument <path> is the relative location for the cloned
+submodule to exist in the superproject. If <path> is not given, the
+canonical part of the source repository is used ("repo" for
+"/path/to/repo.git" and "foo" for "host.xz:foo/.git"). If <path>
+exists and is already a valid Git repository, then it is staged
+for commit without cloning. The <path> is also used as the submodule's
+logical name in its configuration entries unless `--name` is used
+to specify a logical name.
++
+The given URL is recorded into `.gitmodules` for use by subsequent users
+cloning the superproject. If the URL is given relative to the
+superproject's repository, the presumption is the superproject and
+submodule repositories will be kept together in the same relative
+location, and only the superproject's URL needs to be provided.
+git-submodule will correctly locate the submodule using the relative
+URL in `.gitmodules`.
+
+status [--cached] [--recursive] [--] [<path>...]::
+	Show the status of the submodules. This will print the SHA-1 of the
+	currently checked out commit for each submodule, along with the
+	submodule path and the output of 'git describe' for the
+	SHA-1. Each SHA-1 will possibly be prefixed with `-` if the submodule is
+	not initialized, `+` if the currently checked out submodule commit
+	does not match the SHA-1 found in the index of the containing
+	repository and `U` if the submodule has merge conflicts.
++
+If `--recursive` is specified, this command will recurse into nested
+submodules, and show their status as well.
++
+If you are only interested in changes of the currently initialized
+submodules with respect to the commit recorded in the index or the HEAD,
+linkgit:git-status[1] and linkgit:git-diff[1] will provide that information
+too (and can also report changes to a submodule's work tree).
+
+init [--] [<path>...]::
+	Initialize the submodules recorded in the index (which were
+	added and committed elsewhere) by setting `submodule.$name.url`
+	in .git/config. It uses the same setting from `.gitmodules` as
+	a template. If the URL is relative, it will be resolved using
+	the default remote. If there is no default remote, the current
+	repository will be assumed to be upstream.
++
+Optional <path> arguments limit which submodules will be initialized.
+If no path is specified and submodule.active has been configured, submodules
+configured to be active will be initialized, otherwise all submodules are
+initialized.
++
+When present, it will also copy the value of `submodule.$name.update`.
+This command does not alter existing information in .git/config.
+You can then customize the submodule clone URLs in .git/config
+for your local setup and proceed to `git submodule update`;
+you can also just use `git submodule update --init` without
+the explicit 'init' step if you do not intend to customize
+any submodule locations.
++
+See the add subcommand for the definition of default remote.
+
+deinit [-f|--force] (--all|[--] <path>...)::
+	Unregister the given submodules, i.e. remove the whole
+	`submodule.$name` section from .git/config together with their work
+	tree. Further calls to `git submodule update`, `git submodule foreach`
+	and `git submodule sync` will skip any unregistered submodules until
+	they are initialized again, so use this command if you don't want to
+	have a local checkout of the submodule in your working tree anymore.
++
+When the command is run without pathspec, it errors out,
+instead of deinit-ing everything, to prevent mistakes.
++
+If `--force` is specified, the submodule's working tree will
+be removed even if it contains local modifications.
++
+If you really want to remove a submodule from the repository and commit
+that use linkgit:git-rm[1] instead. See linkgit:gitsubmodules[7] for removal
+options.
+
+update [--init] [--remote] [-N|--no-fetch] [--[no-]recommend-shallow] [-f|--force] [--checkout|--rebase|--merge] [--reference <repository>] [--depth <depth>] [--recursive] [--jobs <n>] [--] [<path>...]::
++
+--
+Update the registered submodules to match what the superproject
+expects by cloning missing submodules and updating the working tree of
+the submodules. The "updating" can be done in several ways depending
+on command line options and the value of `submodule.<name>.update`
+configuration variable. The command line option takes precedence over
+the configuration variable. If neither is given, a 'checkout' is performed.
+The 'update' procedures supported both from the command line as well as
+through the `submodule.<name>.update` configuration are:
+
+	checkout;; the commit recorded in the superproject will be
+	    checked out in the submodule on a detached HEAD.
++
+If `--force` is specified, the submodule will be checked out (using
+`git checkout --force`), even if the commit specified
+in the index of the containing repository already matches the commit
+checked out in the submodule.
+
+	rebase;; the current branch of the submodule will be rebased
+	    onto the commit recorded in the superproject.
+
+	merge;; the commit recorded in the superproject will be merged
+	    into the current branch in the submodule.
+
+The following 'update' procedures are only available via the
+`submodule.<name>.update` configuration variable:
+
+	custom command;; arbitrary shell command that takes a single
+	    argument (the sha1 of the commit recorded in the
+	    superproject) is executed. When `submodule.<name>.update`
+	    is set to '!command', the remainder after the exclamation mark
+	    is the custom command.
+
+	none;; the submodule is not updated.
+
+If the submodule is not yet initialized, and you just want to use the
+setting as stored in `.gitmodules`, you can automatically initialize the
+submodule with the `--init` option.
+
+If `--recursive` is specified, this command will recurse into the
+registered submodules, and update any nested submodules within.
+--
+set-branch ((-d|--default)|(-b|--branch <branch>)) [--] <path>::
+	Sets the default remote tracking branch for the submodule. The
+	`--branch` option allows the remote branch to be specified. The
+	`--default` option removes the submodule.<name>.branch configuration
+	key, which causes the tracking branch to default to 'master'.
+
+summary [--cached|--files] [(-n|--summary-limit) <n>] [commit] [--] [<path>...]::
+	Show commit summary between the given commit (defaults to HEAD) and
+	working tree/index. For a submodule in question, a series of commits
+	in the submodule between the given super project commit and the
+	index or working tree (switched by `--cached`) are shown. If the option
+	`--files` is given, show the series of commits in the submodule between
+	the index of the super project and the working tree of the submodule
+	(this option doesn't allow to use the `--cached` option or to provide an
+	explicit commit).
++
+Using the `--submodule=log` option with linkgit:git-diff[1] will provide that
+information too.
+
+foreach [--recursive] <command>::
+	Evaluates an arbitrary shell command in each checked out submodule.
+	The command has access to the variables $name, $sm_path, $displaypath,
+	$sha1 and $toplevel:
+	$name is the name of the relevant submodule section in `.gitmodules`,
+	$sm_path is the path of the submodule as recorded in the immediate
+	superproject, $displaypath contains the relative path from the
+	current working directory to the submodules root directory,
+	$sha1 is the commit as recorded in the immediate
+	superproject, and $toplevel is the absolute path to the top-level
+	of the immediate superproject.
+	Note that to avoid conflicts with '$PATH' on Windows, the '$path'
+	variable is now a deprecated synonym of '$sm_path' variable.
+	Any submodules defined in the superproject but not checked out are
+	ignored by this command. Unless given `--quiet`, foreach prints the name
+	of each submodule before evaluating the command.
+	If `--recursive` is given, submodules are traversed recursively (i.e.
+	the given shell command is evaluated in nested submodules as well).
+	A non-zero return from the command in any submodule causes
+	the processing to terminate. This can be overridden by adding '|| :'
+	to the end of the command.
++
+As an example, the command below will show the path and currently
+checked out commit for each submodule:
++
+--------------
+git submodule foreach 'echo $path `git rev-parse HEAD`'
+--------------
+
+sync [--recursive] [--] [<path>...]::
+	Synchronizes submodules' remote URL configuration setting
+	to the value specified in `.gitmodules`. It will only affect those
+	submodules which already have a URL entry in .git/config (that is the
+	case when they are initialized or freshly added). This is useful when
+	submodule URLs change upstream and you need to update your local
+	repositories accordingly.
++
+`git submodule sync` synchronizes all submodules while
+`git submodule sync -- A` synchronizes submodule "A" only.
++
+If `--recursive` is specified, this command will recurse into the
+registered submodules, and sync any nested submodules within.
+
+absorbgitdirs::
+	If a git directory of a submodule is inside the submodule,
+	move the git directory of the submodule into its superprojects
+	`$GIT_DIR/modules` path and then connect the git directory and
+	its working directory by setting the `core.worktree` and adding
+	a .git file pointing to the git directory embedded in the
+	superprojects git directory.
++
+A repository that was cloned independently and later added as a submodule or
+old setups have the submodules git directory inside the submodule instead of
+embedded into the superprojects git directory.
++
+This command is recursive by default.
+
+OPTIONS
+-------
+-q::
+--quiet::
+	Only print error messages.
+
+--progress::
+	This option is only valid for add and update commands.
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless -q
+	is specified. This flag forces progress status even if the
+	standard error stream is not directed to a terminal.
+
+--all::
+	This option is only valid for the deinit command. Unregister all
+	submodules in the working tree.
+
+-b <branch>::
+--branch <branch>::
+	Branch of repository to add as submodule.
+	The name of the branch is recorded as `submodule.<name>.branch` in
+	`.gitmodules` for `update --remote`.  A special value of `.` is used to
+	indicate that the name of the branch in the submodule should be the
+	same name as the current branch in the current repository.  If the
+	option is not specified, it defaults to 'master'.
+
+-f::
+--force::
+	This option is only valid for add, deinit and update commands.
+	When running add, allow adding an otherwise ignored submodule path.
+	When running deinit the submodule working trees will be removed even
+	if they contain local changes.
+	When running update (only effective with the checkout procedure),
+	throw away local changes in submodules when switching to a
+	different commit; and always run a checkout operation in the
+	submodule, even if the commit listed in the index of the
+	containing repository matches the commit checked out in the
+	submodule.
+
+--cached::
+	This option is only valid for status and summary commands.  These
+	commands typically use the commit found in the submodule HEAD, but
+	with this option, the commit stored in the index is used instead.
+
+--files::
+	This option is only valid for the summary command. This command
+	compares the commit in the index with that in the submodule HEAD
+	when this option is used.
+
+-n::
+--summary-limit::
+	This option is only valid for the summary command.
+	Limit the summary size (number of commits shown in total).
+	Giving 0 will disable the summary; a negative number means unlimited
+	(the default). This limit only applies to modified submodules. The
+	size is always limited to 1 for added/deleted/typechanged submodules.
+
+--remote::
+	This option is only valid for the update command.  Instead of using
+	the superproject's recorded SHA-1 to update the submodule, use the
+	status of the submodule's remote-tracking branch.  The remote used
+	is branch's remote (`branch.<name>.remote`), defaulting to `origin`.
+	The remote branch used defaults to `master`, but the branch name may
+	be overridden by setting the `submodule.<name>.branch` option in
+	either `.gitmodules` or `.git/config` (with `.git/config` taking
+	precedence).
++
+This works for any of the supported update procedures (`--checkout`,
+`--rebase`, etc.).  The only change is the source of the target SHA-1.
+For example, `submodule update --remote --merge` will merge upstream
+submodule changes into the submodules, while `submodule update
+--merge` will merge superproject gitlink changes into the submodules.
++
+In order to ensure a current tracking branch state, `update --remote`
+fetches the submodule's remote repository before calculating the
+SHA-1.  If you don't want to fetch, you should use `submodule update
+--remote --no-fetch`.
++
+Use this option to integrate changes from the upstream subproject with
+your submodule's current HEAD.  Alternatively, you can run `git pull`
+from the submodule, which is equivalent except for the remote branch
+name: `update --remote` uses the default upstream repository and
+`submodule.<name>.branch`, while `git pull` uses the submodule's
+`branch.<name>.merge`.  Prefer `submodule.<name>.branch` if you want
+to distribute the default upstream branch with the superproject and
+`branch.<name>.merge` if you want a more native feel while working in
+the submodule itself.
+
+-N::
+--no-fetch::
+	This option is only valid for the update command.
+	Don't fetch new objects from the remote site.
+
+--checkout::
+	This option is only valid for the update command.
+	Checkout the commit recorded in the superproject on a detached HEAD
+	in the submodule. This is the default behavior, the main use of
+	this option is to override `submodule.$name.update` when set to
+	a value other than `checkout`.
+	If the key `submodule.$name.update` is either not explicitly set or
+	set to `checkout`, this option is implicit.
+
+--merge::
+	This option is only valid for the update command.
+	Merge the commit recorded in the superproject into the current branch
+	of the submodule. If this option is given, the submodule's HEAD will
+	not be detached. If a merge failure prevents this process, you will
+	have to resolve the resulting conflicts within the submodule with the
+	usual conflict resolution tools.
+	If the key `submodule.$name.update` is set to `merge`, this option is
+	implicit.
+
+--rebase::
+	This option is only valid for the update command.
+	Rebase the current branch onto the commit recorded in the
+	superproject. If this option is given, the submodule's HEAD will not
+	be detached. If a merge failure prevents this process, you will have
+	to resolve these failures with linkgit:git-rebase[1].
+	If the key `submodule.$name.update` is set to `rebase`, this option is
+	implicit.
+
+--init::
+	This option is only valid for the update command.
+	Initialize all submodules for which "git submodule init" has not been
+	called so far before updating.
+
+--name::
+	This option is only valid for the add command. It sets the submodule's
+	name to the given string instead of defaulting to its path. The name
+	must be valid as a directory name and may not end with a '/'.
+
+--reference <repository>::
+	This option is only valid for add and update commands.  These
+	commands sometimes need to clone a remote repository. In this case,
+	this option will be passed to the linkgit:git-clone[1] command.
++
+*NOTE*: Do *not* use this option unless you have read the note
+for linkgit:git-clone[1]'s `--reference`, `--shared`, and `--dissociate`
+options carefully.
+
+--dissociate::
+	This option is only valid for add and update commands.  These
+	commands sometimes need to clone a remote repository. In this case,
+	this option will be passed to the linkgit:git-clone[1] command.
++
+*NOTE*: see the NOTE for the `--reference` option.
+
+--recursive::
+	This option is only valid for foreach, update, status and sync commands.
+	Traverse submodules recursively. The operation is performed not
+	only in the submodules of the current repo, but also
+	in any nested submodules inside those submodules (and so on).
+
+--depth::
+	This option is valid for add and update commands. Create a 'shallow'
+	clone with a history truncated to the specified number of revisions.
+	See linkgit:git-clone[1]
+
+--[no-]recommend-shallow::
+	This option is only valid for the update command.
+	The initial clone of a submodule will use the recommended
+	`submodule.<name>.shallow` as provided by the `.gitmodules` file
+	by default. To ignore the suggestions use `--no-recommend-shallow`.
+
+-j <n>::
+--jobs <n>::
+	This option is only valid for the update command.
+	Clone new submodules in parallel with as many jobs.
+	Defaults to the `submodule.fetchJobs` option.
+
+<path>...::
+	Paths to submodule(s). When specified this will restrict the command
+	to only operate on the submodules found at the specified paths.
+	(This argument is required with add).
+
+FILES
+-----
+When initializing submodules, a `.gitmodules` file in the top-level directory
+of the containing repository is used to find the url of each submodule.
+This file should be formatted in the same way as `$GIT_DIR/config`. The key
+to each submodule url is "submodule.$name.url".  See linkgit:gitmodules[5]
+for details.
+
+SEE ALSO
+--------
+linkgit:gitsubmodules[7], linkgit:gitmodules[5].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-svn.txt b/third_party/git/Documentation/git-svn.txt
new file mode 100644
index 0000000000..30711625fd
--- /dev/null
+++ b/third_party/git/Documentation/git-svn.txt
@@ -0,0 +1,1174 @@
+git-svn(1)
+==========
+
+NAME
+----
+git-svn - Bidirectional operation between a Subversion repository and Git
+
+SYNOPSIS
+--------
+[verse]
+'git svn' <command> [<options>] [<arguments>]
+
+DESCRIPTION
+-----------
+'git svn' is a simple conduit for changesets between Subversion and Git.
+It provides a bidirectional flow of changes between a Subversion and a Git
+repository.
+
+'git svn' can track a standard Subversion repository,
+following the common "trunk/branches/tags" layout, with the --stdlayout option.
+It can also follow branches and tags in any layout with the -T/-t/-b options
+(see options to 'init' below, and also the 'clone' command).
+
+Once tracking a Subversion repository (with any of the above methods), the Git
+repository can be updated from Subversion by the 'fetch' command and
+Subversion updated from Git by the 'dcommit' command.
+
+COMMANDS
+--------
+
+'init'::
+	Initializes an empty Git repository with additional
+	metadata directories for 'git svn'.  The Subversion URL
+	may be specified as a command-line argument, or as full
+	URL arguments to -T/-t/-b.  Optionally, the target
+	directory to operate on can be specified as a second
+	argument.  Normally this command initializes the current
+	directory.
+
+-T<trunk_subdir>;;
+--trunk=<trunk_subdir>;;
+-t<tags_subdir>;;
+--tags=<tags_subdir>;;
+-b<branches_subdir>;;
+--branches=<branches_subdir>;;
+-s;;
+--stdlayout;;
+	These are optional command-line options for init.  Each of
+	these flags can point to a relative repository path
+	(--tags=project/tags) or a full url
+	(--tags=https://foo.org/project/tags).
+	You can specify more than one --tags and/or --branches options, in case
+	your Subversion repository places tags or branches under multiple paths.
+	The option --stdlayout is
+	a shorthand way of setting trunk,tags,branches as the relative paths,
+	which is the Subversion default. If any of the other options are given
+	as well, they take precedence.
+--no-metadata;;
+	Set the 'noMetadata' option in the [svn-remote] config.
+	This option is not recommended, please read the 'svn.noMetadata'
+	section of this manpage before using this option.
+--use-svm-props;;
+	Set the 'useSvmProps' option in the [svn-remote] config.
+--use-svnsync-props;;
+	Set the 'useSvnsyncProps' option in the [svn-remote] config.
+--rewrite-root=<URL>;;
+	Set the 'rewriteRoot' option in the [svn-remote] config.
+--rewrite-uuid=<UUID>;;
+	Set the 'rewriteUUID' option in the [svn-remote] config.
+--username=<user>;;
+	For transports that SVN handles authentication for (http,
+	https, and plain svn), specify the username.  For other
+	transports (e.g. `svn+ssh://`), you must include the username in
+	the URL, e.g. `svn+ssh://foo@svn.bar.com/project`
+--prefix=<prefix>;;
+	This allows one to specify a prefix which is prepended
+	to the names of remotes if trunk/branches/tags are
+	specified.  The prefix does not automatically include a
+	trailing slash, so be sure you include one in the
+	argument if that is what you want.  If --branches/-b is
+	specified, the prefix must include a trailing slash.
+	Setting a prefix (with a trailing slash) is strongly
+	encouraged in any case, as your SVN-tracking refs will
+	then be located at "refs/remotes/$prefix/*", which is
+	compatible with Git's own remote-tracking ref layout
+	(refs/remotes/$remote/*). Setting a prefix is also useful
+	if you wish to track multiple projects that share a common
+	repository.
+	By default, the prefix is set to 'origin/'.
++
+NOTE: Before Git v2.0, the default prefix was "" (no prefix). This
+meant that SVN-tracking refs were put at "refs/remotes/*", which is
+incompatible with how Git's own remote-tracking refs are organized.
+If you still want the old default, you can get it by passing
+`--prefix ""` on the command line (`--prefix=""` may not work if
+your Perl's Getopt::Long is < v2.37).
+
+--ignore-refs=<regex>;;
+	When passed to 'init' or 'clone' this regular expression will
+	be preserved as a config key.  See 'fetch' for a description
+	of `--ignore-refs`.
+--ignore-paths=<regex>;;
+	When passed to 'init' or 'clone' this regular expression will
+	be preserved as a config key.  See 'fetch' for a description
+	of `--ignore-paths`.
+--include-paths=<regex>;;
+	When passed to 'init' or 'clone' this regular expression will
+	be preserved as a config key.  See 'fetch' for a description
+	of `--include-paths`.
+--no-minimize-url;;
+	When tracking multiple directories (using --stdlayout,
+	--branches, or --tags options), git svn will attempt to connect
+	to the root (or highest allowed level) of the Subversion
+	repository.  This default allows better tracking of history if
+	entire projects are moved within a repository, but may cause
+	issues on repositories where read access restrictions are in
+	place.  Passing `--no-minimize-url` will allow git svn to
+	accept URLs as-is without attempting to connect to a higher
+	level directory.  This option is off by default when only
+	one URL/branch is tracked (it would do little good).
+
+'fetch'::
+	Fetch unfetched revisions from the Subversion remote we are
+	tracking.  The name of the [svn-remote "..."] section in the
+	$GIT_DIR/config file may be specified as an optional
+	command-line argument.
++
+This automatically updates the rev_map if needed (see
+'$GIT_DIR/svn/\**/.rev_map.*' in the FILES section below for details).
+
+--localtime;;
+	Store Git commit times in the local time zone instead of UTC.  This
+	makes 'git log' (even without --date=local) show the same times
+	that `svn log` would in the local time zone.
++
+This doesn't interfere with interoperating with the Subversion
+repository you cloned from, but if you wish for your local Git
+repository to be able to interoperate with someone else's local Git
+repository, either don't use this option or you should both use it in
+the same local time zone.
+
+--parent;;
+	Fetch only from the SVN parent of the current HEAD.
+
+--ignore-refs=<regex>;;
+	Ignore refs for branches or tags matching the Perl regular
+	expression. A "negative look-ahead assertion" like
+	`^refs/remotes/origin/(?!tags/wanted-tag|wanted-branch).*$`
+	can be used to allow only certain refs.
++
+[verse]
+config key: svn-remote.<name>.ignore-refs
++
+If the ignore-refs configuration key is set, and the command-line
+option is also given, both regular expressions will be used.
+
+--ignore-paths=<regex>;;
+	This allows one to specify a Perl regular expression that will
+	cause skipping of all matching paths from checkout from SVN.
+	The `--ignore-paths` option should match for every 'fetch'
+	(including automatic fetches due to 'clone', 'dcommit',
+	'rebase', etc) on a given repository.
++
+[verse]
+config key: svn-remote.<name>.ignore-paths
++
+If the ignore-paths configuration key is set, and the command-line
+option is also given, both regular expressions will be used.
++
+Examples:
++
+--
+Skip "doc*" directory for every fetch;;
++
+------------------------------------------------------------------------
+--ignore-paths="^doc"
+------------------------------------------------------------------------
+
+Skip "branches" and "tags" of first level directories;;
++
+------------------------------------------------------------------------
+--ignore-paths="^[^/]+/(?:branches|tags)"
+------------------------------------------------------------------------
+--
+
+--include-paths=<regex>;;
+	This allows one to specify a Perl regular expression that will
+	cause the inclusion of only matching paths from checkout from SVN.
+	The `--include-paths` option should match for every 'fetch'
+	(including automatic fetches due to 'clone', 'dcommit',
+	'rebase', etc) on a given repository. `--ignore-paths` takes
+	precedence over `--include-paths`.
++
+[verse]
+config key: svn-remote.<name>.include-paths
+
+--log-window-size=<n>;;
+	Fetch <n> log entries per request when scanning Subversion history.
+	The default is 100. For very large Subversion repositories, larger
+	values may be needed for 'clone'/'fetch' to complete in reasonable
+	time. But overly large values may lead to higher memory usage and
+	request timeouts.
+
+'clone'::
+	Runs 'init' and 'fetch'.  It will automatically create a
+	directory based on the basename of the URL passed to it;
+	or if a second argument is passed; it will create a directory
+	and work within that.  It accepts all arguments that the
+	'init' and 'fetch' commands accept; with the exception of
+	`--fetch-all` and `--parent`.  After a repository is cloned,
+	the 'fetch' command will be able to update revisions without
+	affecting the working tree; and the 'rebase' command will be
+	able to update the working tree with the latest changes.
+
+--preserve-empty-dirs;;
+	Create a placeholder file in the local Git repository for each
+	empty directory fetched from Subversion.  This includes directories
+	that become empty by removing all entries in the Subversion
+	repository (but not the directory itself).  The placeholder files
+	are also tracked and removed when no longer necessary.
+
+--placeholder-filename=<filename>;;
+	Set the name of placeholder files created by --preserve-empty-dirs.
+	Default: ".gitignore"
+
+'rebase'::
+	This fetches revisions from the SVN parent of the current HEAD
+	and rebases the current (uncommitted to SVN) work against it.
++
+This works similarly to `svn update` or 'git pull' except that
+it preserves linear history with 'git rebase' instead of
+'git merge' for ease of dcommitting with 'git svn'.
++
+This accepts all options that 'git svn fetch' and 'git rebase'
+accept.  However, `--fetch-all` only fetches from the current
+[svn-remote], and not all [svn-remote] definitions.
++
+Like 'git rebase'; this requires that the working tree be clean
+and have no uncommitted changes.
++
+This automatically updates the rev_map if needed (see
+'$GIT_DIR/svn/\**/.rev_map.*' in the FILES section below for details).
+
+-l;;
+--local;;
+	Do not fetch remotely; only run 'git rebase' against the
+	last fetched commit from the upstream SVN.
+
+'dcommit'::
+	Commit each diff from the current branch directly to the SVN
+	repository, and then rebase or reset (depending on whether or
+	not there is a diff between SVN and head).  This will create
+	a revision in SVN for each commit in Git.
++
+When an optional Git branch name (or a Git commit object name)
+is specified as an argument, the subcommand works on the specified
+branch, not on the current branch.
++
+Use of 'dcommit' is preferred to 'set-tree' (below).
++
+--no-rebase;;
+	After committing, do not rebase or reset.
+--commit-url <URL>;;
+	Commit to this SVN URL (the full path).  This is intended to
+	allow existing 'git svn' repositories created with one transport
+	method (e.g. `svn://` or `http://` for anonymous read) to be
+	reused if a user is later given access to an alternate transport
+	method (e.g. `svn+ssh://` or `https://`) for commit.
++
+[verse]
+config key: svn-remote.<name>.commiturl
+config key: svn.commiturl (overwrites all svn-remote.<name>.commiturl options)
++
+Note that the SVN URL of the commiturl config key includes the SVN branch.
+If you rather want to set the commit URL for an entire SVN repository use
+svn-remote.<name>.pushurl instead.
++
+Using this option for any other purpose (don't ask) is very strongly
+discouraged.
+
+--mergeinfo=<mergeinfo>;;
+	Add the given merge information during the dcommit
+	(e.g. `--mergeinfo="/branches/foo:1-10"`). All svn server versions can
+	store this information (as a property), and svn clients starting from
+	version 1.5 can make use of it. To specify merge information from multiple
+	branches, use a single space character between the branches
+	(`--mergeinfo="/branches/foo:1-10 /branches/bar:3,5-6,8"`)
++
+[verse]
+config key: svn.pushmergeinfo
++
+This option will cause git-svn to attempt to automatically populate the
+svn:mergeinfo property in the SVN repository when possible. Currently, this can
+only be done when dcommitting non-fast-forward merges where all parents but the
+first have already been pushed into SVN.
+
+--interactive;;
+	Ask the user to confirm that a patch set should actually be sent to SVN.
+	For each patch, one may answer "yes" (accept this patch), "no" (discard this
+	patch), "all" (accept all patches), or "quit".
++
+'git svn dcommit' returns immediately if answer is "no" or "quit", without
+committing anything to SVN.
+
+'branch'::
+	Create a branch in the SVN repository.
+
+-m;;
+--message;;
+	Allows to specify the commit message.
+
+-t;;
+--tag;;
+	Create a tag by using the tags_subdir instead of the branches_subdir
+	specified during git svn init.
+
+-d<path>;;
+--destination=<path>;;
+
+	If more than one --branches (or --tags) option was given to the 'init'
+	or 'clone' command, you must provide the location of the branch (or
+	tag) you wish to create in the SVN repository.  <path> specifies which
+	path to use to create the branch or tag and should match the pattern
+	on the left-hand side of one of the configured branches or tags
+	refspecs.  You can see these refspecs with the commands
++
+	git config --get-all svn-remote.<name>.branches
+	git config --get-all svn-remote.<name>.tags
++
+where <name> is the name of the SVN repository as specified by the -R option to
+'init' (or "svn" by default).
+
+--username;;
+	Specify the SVN username to perform the commit as.  This option overrides
+	the 'username' configuration property.
+
+--commit-url;;
+	Use the specified URL to connect to the destination Subversion
+	repository.  This is useful in cases where the source SVN
+	repository is read-only.  This option overrides configuration
+	property 'commiturl'.
++
+	git config --get-all svn-remote.<name>.commiturl
++
+
+--parents;;
+	Create parent folders. This parameter is equivalent to the parameter
+	--parents on svn cp commands and is useful for non-standard repository
+	layouts.
+
+'tag'::
+	Create a tag in the SVN repository. This is a shorthand for
+	'branch -t'.
+
+'log'::
+	This should make it easy to look up svn log messages when svn
+	users refer to -r/--revision numbers.
++
+The following features from `svn log' are supported:
++
+--
+-r <n>[:<n>];;
+--revision=<n>[:<n>];;
+	is supported, non-numeric args are not:
+	HEAD, NEXT, BASE, PREV, etc ...
+-v;;
+--verbose;;
+	it's not completely compatible with the --verbose
+	output in svn log, but reasonably close.
+--limit=<n>;;
+	is NOT the same as --max-count, doesn't count
+	merged/excluded commits
+--incremental;;
+	supported
+--
++
+New features:
++
+--
+--show-commit;;
+	shows the Git commit sha1, as well
+--oneline;;
+	our version of --pretty=oneline
+--
++
+NOTE: SVN itself only stores times in UTC and nothing else. The regular svn
+client converts the UTC time to the local time (or based on the TZ=
+environment). This command has the same behaviour.
++
+Any other arguments are passed directly to 'git log'
+
+'blame'::
+	Show what revision and author last modified each line of a file. The
+	output of this mode is format-compatible with the output of
+	`svn blame' by default. Like the SVN blame command,
+	local uncommitted changes in the working tree are ignored;
+	the version of the file in the HEAD revision is annotated. Unknown
+	arguments are passed directly to 'git blame'.
++
+--git-format;;
+	Produce output in the same format as 'git blame', but with
+	SVN revision numbers instead of Git commit hashes. In this mode,
+	changes that haven't been committed to SVN (including local
+	working-copy edits) are shown as revision 0.
+
+'find-rev'::
+	When given an SVN revision number of the form 'rN', returns the
+	corresponding Git commit hash (this can optionally be followed by a
+	tree-ish to specify which branch should be searched).  When given a
+	tree-ish, returns the corresponding SVN revision number.
++
+-B;;
+--before;;
+	Don't require an exact match if given an SVN revision, instead find
+	the commit corresponding to the state of the SVN repository (on the
+	current branch) at the specified revision.
++
+-A;;
+--after;;
+	Don't require an exact match if given an SVN revision; if there is
+	not an exact match return the closest match searching forward in the
+	history.
+
+'set-tree'::
+	You should consider using 'dcommit' instead of this command.
+	Commit specified commit or tree objects to SVN.  This relies on
+	your imported fetch data being up to date.  This makes
+	absolutely no attempts to do patching when committing to SVN, it
+	simply overwrites files with those specified in the tree or
+	commit.  All merging is assumed to have taken place
+	independently of 'git svn' functions.
+
+'create-ignore'::
+	Recursively finds the svn:ignore property on directories and
+	creates matching .gitignore files. The resulting files are staged to
+	be committed, but are not committed. Use -r/--revision to refer to a
+	specific revision.
+
+'show-ignore'::
+	Recursively finds and lists the svn:ignore property on
+	directories.  The output is suitable for appending to
+	the $GIT_DIR/info/exclude file.
+
+'mkdirs'::
+	Attempts to recreate empty directories that core Git cannot track
+	based on information in $GIT_DIR/svn/<refname>/unhandled.log files.
+	Empty directories are automatically recreated when using
+	"git svn clone" and "git svn rebase", so "mkdirs" is intended
+	for use after commands like "git checkout" or "git reset".
+	(See the svn-remote.<name>.automkdirs config file option for
+	more information.)
+
+'commit-diff'::
+	Commits the diff of two tree-ish arguments from the
+	command-line.  This command does not rely on being inside a `git svn
+	init`-ed repository.  This command takes three arguments, (a) the
+	original tree to diff against, (b) the new tree result, (c) the
+	URL of the target Subversion repository.  The final argument
+	(URL) may be omitted if you are working from a 'git svn'-aware
+	repository (that has been `init`-ed with 'git svn').
+	The -r<revision> option is required for this.
++
+The commit message is supplied either directly with the `-m` or `-F`
+option, or indirectly from the tag or commit when the second tree-ish
+denotes such an object, or it is requested by invoking an editor (see
+`--edit` option below).
+
+-m <msg>;;
+--message=<msg>;;
+	Use the given `msg` as the commit message. This option
+	disables the `--edit` option.
+
+-F <filename>;;
+--file=<filename>;;
+	Take the commit message from the given file. This option
+	disables the `--edit` option.
+
+'info'::
+	Shows information about a file or directory similar to what
+	`svn info' provides.  Does not currently support a -r/--revision
+	argument.  Use the --url option to output only the value of the
+	'URL:' field.
+
+'proplist'::
+	Lists the properties stored in the Subversion repository about a
+	given file or directory.  Use -r/--revision to refer to a specific
+	Subversion revision.
+
+'propget'::
+	Gets the Subversion property given as the first argument, for a
+	file.  A specific revision can be specified with -r/--revision.
+
+'propset'::
+	Sets the Subversion property given as the first argument, to the
+	value given as the second argument for the file given as the
+	third argument.
++
+Example:
++
+------------------------------------------------------------------------
+git svn propset svn:keywords "FreeBSD=%H" devel/py-tipper/Makefile
+------------------------------------------------------------------------
++
+This will set the property 'svn:keywords' to 'FreeBSD=%H' for the file
+'devel/py-tipper/Makefile'.
+
+'show-externals'::
+	Shows the Subversion externals.  Use -r/--revision to specify a
+	specific revision.
+
+'gc'::
+	Compress $GIT_DIR/svn/<refname>/unhandled.log files and remove
+	$GIT_DIR/svn/<refname>/index files.
+
+'reset'::
+	Undoes the effects of 'fetch' back to the specified revision.
+	This allows you to re-'fetch' an SVN revision.  Normally the
+	contents of an SVN revision should never change and 'reset'
+	should not be necessary.  However, if SVN permissions change,
+	or if you alter your --ignore-paths option, a 'fetch' may fail
+	with "not found in commit" (file not previously visible) or
+	"checksum mismatch" (missed a modification).  If the problem
+	file cannot be ignored forever (with --ignore-paths) the only
+	way to repair the repo is to use 'reset'.
++
+Only the rev_map and refs/remotes/git-svn are changed (see
+'$GIT_DIR/svn/\**/.rev_map.*' in the FILES section below for details).
+Follow 'reset' with a 'fetch' and then 'git reset' or 'git rebase' to
+move local branches onto the new tree.
+
+-r <n>;;
+--revision=<n>;;
+	Specify the most recent revision to keep.  All later revisions
+	are discarded.
+-p;;
+--parent;;
+	Discard the specified revision as well, keeping the nearest
+	parent instead.
+Example:;;
+Assume you have local changes in "master", but you need to refetch "r2".
++
+------------
+    r1---r2---r3 remotes/git-svn
+                \
+                 A---B master
+------------
++
+Fix the ignore-paths or SVN permissions problem that caused "r2" to
+be incomplete in the first place.  Then:
++
+[verse]
+git svn reset -r2 -p
+git svn fetch
++
+------------
+    r1---r2'--r3' remotes/git-svn
+      \
+       r2---r3---A---B master
+------------
++
+Then fixup "master" with 'git rebase'.
+Do NOT use 'git merge' or your history will not be compatible with a
+future 'dcommit'!
++
+[verse]
+git rebase --onto remotes/git-svn A^ master
++
+------------
+    r1---r2'--r3' remotes/git-svn
+                \
+                 A'--B' master
+------------
+
+OPTIONS
+-------
+
+--shared[=(false|true|umask|group|all|world|everybody)]::
+--template=<template_directory>::
+	Only used with the 'init' command.
+	These are passed directly to 'git init'.
+
+-r <arg>::
+--revision <arg>::
+	   Used with the 'fetch' command.
++
+This allows revision ranges for partial/cauterized history
+to be supported.  $NUMBER, $NUMBER1:$NUMBER2 (numeric ranges),
+$NUMBER:HEAD, and BASE:$NUMBER are all supported.
++
+This can allow you to make partial mirrors when running fetch;
+but is generally not recommended because history will be skipped
+and lost.
+
+-::
+--stdin::
+	Only used with the 'set-tree' command.
++
+Read a list of commits from stdin and commit them in reverse
+order.  Only the leading sha1 is read from each line, so
+'git rev-list --pretty=oneline' output can be used.
+
+--rmdir::
+	Only used with the 'dcommit', 'set-tree' and 'commit-diff' commands.
++
+Remove directories from the SVN tree if there are no files left
+behind.  SVN can version empty directories, and they are not
+removed by default if there are no files left in them.  Git
+cannot version empty directories.  Enabling this flag will make
+the commit to SVN act like Git.
++
+[verse]
+config key: svn.rmdir
+
+-e::
+--edit::
+	Only used with the 'dcommit', 'set-tree' and 'commit-diff' commands.
++
+Edit the commit message before committing to SVN.  This is off by
+default for objects that are commits, and forced on when committing
+tree objects.
++
+[verse]
+config key: svn.edit
+
+-l<num>::
+--find-copies-harder::
+	Only used with the 'dcommit', 'set-tree' and 'commit-diff' commands.
++
+They are both passed directly to 'git diff-tree'; see
+linkgit:git-diff-tree[1] for more information.
++
+[verse]
+config key: svn.l
+config key: svn.findcopiesharder
+
+-A<filename>::
+--authors-file=<filename>::
+	Syntax is compatible with the file used by 'git cvsimport' but
+	an empty email address can be supplied with '<>':
++
+------------------------------------------------------------------------
+	loginname = Joe User <user@example.com>
+------------------------------------------------------------------------
++
+If this option is specified and 'git svn' encounters an SVN
+committer name that does not exist in the authors-file, 'git svn'
+will abort operation. The user will then have to add the
+appropriate entry.  Re-running the previous 'git svn' command
+after the authors-file is modified should continue operation.
++
+[verse]
+config key: svn.authorsfile
+
+--authors-prog=<filename>::
+	If this option is specified, for each SVN committer name that
+	does not exist in the authors file, the given file is executed
+	with the committer name as the first argument.  The program is
+	expected to return a single line of the form "Name <email>" or
+	"Name <>", which will be treated as if included in the authors
+	file.
++
+Due to historical reasons a relative 'filename' is first searched
+relative to the current directory for 'init' and 'clone' and relative
+to the root of the working tree for 'fetch'. If 'filename' is
+not found, it is searched like any other command in '$PATH'.
++
+[verse]
+config key: svn.authorsProg
+
+-q::
+--quiet::
+	Make 'git svn' less verbose. Specify a second time to make it
+	even less verbose.
+
+-m::
+--merge::
+-s<strategy>::
+--strategy=<strategy>::
+-p::
+--preserve-merges::
+	These are only used with the 'dcommit' and 'rebase' commands.
++
+Passed directly to 'git rebase' when using 'dcommit' if a
+'git reset' cannot be used (see 'dcommit').
+
+-n::
+--dry-run::
+	This can be used with the 'dcommit', 'rebase', 'branch' and
+	'tag' commands.
++
+For 'dcommit', print out the series of Git arguments that would show
+which diffs would be committed to SVN.
++
+For 'rebase', display the local branch associated with the upstream svn
+repository associated with the current branch and the URL of svn
+repository that will be fetched from.
++
+For 'branch' and 'tag', display the urls that will be used for copying when
+creating the branch or tag.
+
+--use-log-author::
+	When retrieving svn commits into Git (as part of 'fetch', 'rebase', or
+	'dcommit' operations), look for the first `From:` or `Signed-off-by:` line
+	in the log message and use that as the author string.
++
+[verse]
+config key: svn.useLogAuthor
+
+--add-author-from::
+	When committing to svn from Git (as part of 'set-tree' or 'dcommit'
+	operations), if the existing log message doesn't already have a
+	`From:` or `Signed-off-by:` line, append a `From:` line based on the
+	Git commit's author string.  If you use this, then `--use-log-author`
+	will retrieve a valid author string for all commits.
++
+[verse]
+config key: svn.addAuthorFrom
+
+ADVANCED OPTIONS
+----------------
+
+-i<GIT_SVN_ID>::
+--id <GIT_SVN_ID>::
+	This sets GIT_SVN_ID (instead of using the environment).  This
+	allows the user to override the default refname to fetch from
+	when tracking a single URL.  The 'log' and 'dcommit' commands
+	no longer require this switch as an argument.
+
+-R<remote name>::
+--svn-remote <remote name>::
+	Specify the [svn-remote "<remote name>"] section to use,
+	this allows SVN multiple repositories to be tracked.
+	Default: "svn"
+
+--follow-parent::
+	This option is only relevant if we are tracking branches (using
+	one of the repository layout options --trunk, --tags,
+	--branches, --stdlayout). For each tracked branch, try to find
+	out where its revision was copied from, and set
+	a suitable parent in the first Git commit for the branch.
+	This is especially helpful when we're tracking a directory
+	that has been moved around within the repository.  If this
+	feature is disabled, the branches created by 'git svn' will all
+	be linear and not share any history, meaning that there will be
+	no information on where branches were branched off or merged.
+	However, following long/convoluted histories can take a long
+	time, so disabling this feature may speed up the cloning
+	process. This feature is enabled by default, use
+	--no-follow-parent to disable it.
++
+[verse]
+config key: svn.followparent
+
+CONFIG FILE-ONLY OPTIONS
+------------------------
+
+svn.noMetadata::
+svn-remote.<name>.noMetadata::
+	This gets rid of the 'git-svn-id:' lines at the end of every commit.
++
+This option can only be used for one-shot imports as 'git svn'
+will not be able to fetch again without metadata. Additionally,
+if you lose your '$GIT_DIR/svn/\**/.rev_map.*' files, 'git svn' will not
+be able to rebuild them.
++
+The 'git svn log' command will not work on repositories using
+this, either.  Using this conflicts with the 'useSvmProps'
+option for (hopefully) obvious reasons.
++
+This option is NOT recommended as it makes it difficult to track down
+old references to SVN revision numbers in existing documentation, bug
+reports and archives.  If you plan to eventually migrate from SVN to Git
+and are certain about dropping SVN history, consider
+linkgit:git-filter-branch[1] instead.  filter-branch also allows
+reformatting of metadata for ease-of-reading and rewriting authorship
+info for non-"svn.authorsFile" users.
+
+svn.useSvmProps::
+svn-remote.<name>.useSvmProps::
+	This allows 'git svn' to re-map repository URLs and UUIDs from
+	mirrors created using SVN::Mirror (or svk) for metadata.
++
+If an SVN revision has a property, "svm:headrev", it is likely
+that the revision was created by SVN::Mirror (also used by SVK).
+The property contains a repository UUID and a revision.  We want
+to make it look like we are mirroring the original URL, so
+introduce a helper function that returns the original identity
+URL and UUID, and use it when generating metadata in commit
+messages.
+
+svn.useSvnsyncProps::
+svn-remote.<name>.useSvnsyncprops::
+	Similar to the useSvmProps option; this is for users
+	of the svnsync(1) command distributed with SVN 1.4.x and
+	later.
+
+svn-remote.<name>.rewriteRoot::
+	This allows users to create repositories from alternate
+	URLs.  For example, an administrator could run 'git svn' on the
+	server locally (accessing via file://) but wish to distribute
+	the repository with a public http:// or svn:// URL in the
+	metadata so users of it will see the public URL.
+
+svn-remote.<name>.rewriteUUID::
+	Similar to the useSvmProps option; this is for users who need
+	to remap the UUID manually. This may be useful in situations
+	where the original UUID is not available via either useSvmProps
+	or useSvnsyncProps.
+
+svn-remote.<name>.pushurl::
+
+	Similar to Git's `remote.<name>.pushurl`, this key is designed
+	to be used in cases where 'url' points to an SVN repository
+	via a read-only transport, to provide an alternate read/write
+	transport. It is assumed that both keys point to the same
+	repository. Unlike 'commiturl', 'pushurl' is a base path. If
+	either 'commiturl' or 'pushurl' could be used, 'commiturl'
+	takes precedence.
+
+svn.brokenSymlinkWorkaround::
+	This disables potentially expensive checks to workaround
+	broken symlinks checked into SVN by broken clients.  Set this
+	option to "false" if you track a SVN repository with many
+	empty blobs that are not symlinks.  This option may be changed
+	while 'git svn' is running and take effect on the next
+	revision fetched.  If unset, 'git svn' assumes this option to
+	be "true".
+
+svn.pathnameencoding::
+	This instructs git svn to recode pathnames to a given encoding.
+	It can be used by windows users and by those who work in non-utf8
+	locales to avoid corrupted file names with non-ASCII characters.
+	Valid encodings are the ones supported by Perl's Encode module.
+
+svn-remote.<name>.automkdirs::
+	Normally, the "git svn clone" and "git svn rebase" commands
+	attempt to recreate empty directories that are in the
+	Subversion repository.  If this option is set to "false", then
+	empty directories will only be created if the "git svn mkdirs"
+	command is run explicitly.  If unset, 'git svn' assumes this
+	option to be "true".
+
+Since the noMetadata, rewriteRoot, rewriteUUID, useSvnsyncProps and useSvmProps
+options all affect the metadata generated and used by 'git svn'; they
+*must* be set in the configuration file before any history is imported
+and these settings should never be changed once they are set.
+
+Additionally, only one of these options can be used per svn-remote
+section because they affect the 'git-svn-id:' metadata line, except
+for rewriteRoot and rewriteUUID which can be used together.
+
+
+BASIC EXAMPLES
+--------------
+
+Tracking and contributing to the trunk of a Subversion-managed project
+(ignoring tags and branches):
+
+------------------------------------------------------------------------
+# Clone a repo (like git clone):
+	git svn clone http://svn.example.com/project/trunk
+# Enter the newly cloned directory:
+	cd trunk
+# You should be on master branch, double-check with 'git branch'
+	git branch
+# Do some work and commit locally to Git:
+	git commit ...
+# Something is committed to SVN, rebase your local changes against the
+# latest changes in SVN:
+	git svn rebase
+# Now commit your changes (that were committed previously using Git) to SVN,
+# as well as automatically updating your working HEAD:
+	git svn dcommit
+# Append svn:ignore settings to the default Git exclude file:
+	git svn show-ignore >> .git/info/exclude
+------------------------------------------------------------------------
+
+Tracking and contributing to an entire Subversion-managed project
+(complete with a trunk, tags and branches):
+
+------------------------------------------------------------------------
+# Clone a repo with standard SVN directory layout (like git clone):
+	git svn clone http://svn.example.com/project --stdlayout --prefix svn/
+# Or, if the repo uses a non-standard directory layout:
+	git svn clone http://svn.example.com/project -T tr -b branch -t tag --prefix svn/
+# View all branches and tags you have cloned:
+	git branch -r
+# Create a new branch in SVN
+	git svn branch waldo
+# Reset your master to trunk (or any other branch, replacing 'trunk'
+# with the appropriate name):
+	git reset --hard svn/trunk
+# You may only dcommit to one branch/tag/trunk at a time.  The usage
+# of dcommit/rebase/show-ignore should be the same as above.
+------------------------------------------------------------------------
+
+The initial 'git svn clone' can be quite time-consuming
+(especially for large Subversion repositories). If multiple
+people (or one person with multiple machines) want to use
+'git svn' to interact with the same Subversion repository, you can
+do the initial 'git svn clone' to a repository on a server and
+have each person clone that repository with 'git clone':
+
+------------------------------------------------------------------------
+# Do the initial import on a server
+	ssh server "cd /pub && git svn clone http://svn.example.com/project [options...]"
+# Clone locally - make sure the refs/remotes/ space matches the server
+	mkdir project
+	cd project
+	git init
+	git remote add origin server:/pub/project
+	git config --replace-all remote.origin.fetch '+refs/remotes/*:refs/remotes/*'
+	git fetch
+# Prevent fetch/pull from remote Git server in the future,
+# we only want to use git svn for future updates
+	git config --remove-section remote.origin
+# Create a local branch from one of the branches just fetched
+	git checkout -b master FETCH_HEAD
+# Initialize 'git svn' locally (be sure to use the same URL and
+# --stdlayout/-T/-b/-t/--prefix options as were used on server)
+	git svn init http://svn.example.com/project [options...]
+# Pull the latest changes from Subversion
+	git svn rebase
+------------------------------------------------------------------------
+
+REBASE VS. PULL/MERGE
+---------------------
+Prefer to use 'git svn rebase' or 'git rebase', rather than
+'git pull' or 'git merge' to synchronize unintegrated commits with a 'git svn'
+branch. Doing so will keep the history of unintegrated commits linear with
+respect to the upstream SVN repository and allow the use of the preferred
+'git svn dcommit' subcommand to push unintegrated commits back into SVN.
+
+Originally, 'git svn' recommended that developers pulled or merged from
+the 'git svn' branch.  This was because the author favored
+`git svn set-tree B` to commit a single head rather than the
+`git svn set-tree A..B` notation to commit multiple commits. Use of
+'git pull' or 'git merge' with `git svn set-tree A..B` will cause non-linear
+history to be flattened when committing into SVN and this can lead to merge
+commits unexpectedly reversing previous commits in SVN.
+
+MERGE TRACKING
+--------------
+While 'git svn' can track
+copy history (including branches and tags) for repositories adopting a
+standard layout, it cannot yet represent merge history that happened
+inside git back upstream to SVN users.  Therefore it is advised that
+users keep history as linear as possible inside Git to ease
+compatibility with SVN (see the CAVEATS section below).
+
+HANDLING OF SVN BRANCHES
+------------------------
+If 'git svn' is configured to fetch branches (and --follow-branches
+is in effect), it sometimes creates multiple Git branches for one
+SVN branch, where the additional branches have names of the form
+'branchname@nnn' (with nnn an SVN revision number).  These additional
+branches are created if 'git svn' cannot find a parent commit for the
+first commit in an SVN branch, to connect the branch to the history of
+the other branches.
+
+Normally, the first commit in an SVN branch consists
+of a copy operation. 'git svn' will read this commit to get the SVN
+revision the branch was created from. It will then try to find the
+Git commit that corresponds to this SVN revision, and use that as the
+parent of the branch. However, it is possible that there is no suitable
+Git commit to serve as parent.  This will happen, among other reasons,
+if the SVN branch is a copy of a revision that was not fetched by 'git
+svn' (e.g. because it is an old revision that was skipped with
+`--revision`), or if in SVN a directory was copied that is not tracked
+by 'git svn' (such as a branch that is not tracked at all, or a
+subdirectory of a tracked branch). In these cases, 'git svn' will still
+create a Git branch, but instead of using an existing Git commit as the
+parent of the branch, it will read the SVN history of the directory the
+branch was copied from and create appropriate Git commits.  This is
+indicated by the message "Initializing parent: <branchname>".
+
+Additionally, it will create a special branch named
+'<branchname>@<SVN-Revision>', where <SVN-Revision> is the SVN revision
+number the branch was copied from.  This branch will point to the newly
+created parent commit of the branch.  If in SVN the branch was deleted
+and later recreated from a different version, there will be multiple
+such branches with an '@'.
+
+Note that this may mean that multiple Git commits are created for a
+single SVN revision.
+
+An example: in an SVN repository with a standard
+trunk/tags/branches layout, a directory trunk/sub is created in r.100.
+In r.200, trunk/sub is branched by copying it to branches/. 'git svn
+clone -s' will then create a branch 'sub'. It will also create new Git
+commits for r.100 through r.199 and use these as the history of branch
+'sub'. Thus there will be two Git commits for each revision from r.100
+to r.199 (one containing trunk/, one containing trunk/sub/). Finally,
+it will create a branch 'sub@200' pointing to the new parent commit of
+branch 'sub' (i.e. the commit for r.200 and trunk/sub/).
+
+CAVEATS
+-------
+
+For the sake of simplicity and interoperating with Subversion,
+it is recommended that all 'git svn' users clone, fetch and dcommit
+directly from the SVN server, and avoid all 'git clone'/'pull'/'merge'/'push'
+operations between Git repositories and branches.  The recommended
+method of exchanging code between Git branches and users is
+'git format-patch' and 'git am', or just 'dcommit'ing to the SVN repository.
+
+Running 'git merge' or 'git pull' is NOT recommended on a branch you
+plan to 'dcommit' from because Subversion users cannot see any
+merges you've made.  Furthermore, if you merge or pull from a Git branch
+that is a mirror of an SVN branch, 'dcommit' may commit to the wrong
+branch.
+
+If you do merge, note the following rule: 'git svn dcommit' will
+attempt to commit on top of the SVN commit named in
+------------------------------------------------------------------------
+git log --grep=^git-svn-id: --first-parent -1
+------------------------------------------------------------------------
+You 'must' therefore ensure that the most recent commit of the branch
+you want to dcommit to is the 'first' parent of the merge.  Chaos will
+ensue otherwise, especially if the first parent is an older commit on
+the same SVN branch.
+
+'git clone' does not clone branches under the refs/remotes/ hierarchy or
+any 'git svn' metadata, or config.  So repositories created and managed with
+using 'git svn' should use 'rsync' for cloning, if cloning is to be done
+at all.
+
+Since 'dcommit' uses rebase internally, any Git branches you 'git push' to
+before 'dcommit' on will require forcing an overwrite of the existing ref
+on the remote repository.  This is generally considered bad practice,
+see the linkgit:git-push[1] documentation for details.
+
+Do not use the --amend option of linkgit:git-commit[1] on a change you've
+already dcommitted.  It is considered bad practice to --amend commits
+you've already pushed to a remote repository for other users, and
+dcommit with SVN is analogous to that.
+
+When cloning an SVN repository, if none of the options for describing
+the repository layout is used (--trunk, --tags, --branches,
+--stdlayout), 'git svn clone' will create a Git repository with
+completely linear history, where branches and tags appear as separate
+directories in the working copy.  While this is the easiest way to get a
+copy of a complete repository, for projects with many branches it will
+lead to a working copy many times larger than just the trunk. Thus for
+projects using the standard directory structure (trunk/branches/tags),
+it is recommended to clone with option `--stdlayout`. If the project
+uses a non-standard structure, and/or if branches and tags are not
+required, it is easiest to only clone one directory (typically trunk),
+without giving any repository layout options.  If the full history with
+branches and tags is required, the options `--trunk` / `--branches` /
+`--tags` must be used.
+
+When using multiple --branches or --tags, 'git svn' does not automatically
+handle name collisions (for example, if two branches from different paths have
+the same name, or if a branch and a tag have the same name).  In these cases,
+use 'init' to set up your Git repository then, before your first 'fetch', edit
+the $GIT_DIR/config file so that the branches and tags are associated
+with different name spaces.  For example:
+
+	branches = stable/*:refs/remotes/svn/stable/*
+	branches = debug/*:refs/remotes/svn/debug/*
+
+BUGS
+----
+
+We ignore all SVN properties except svn:executable.  Any unhandled
+properties are logged to $GIT_DIR/svn/<refname>/unhandled.log
+
+Renamed and copied directories are not detected by Git and hence not
+tracked when committing to SVN.  I do not plan on adding support for
+this as it's quite difficult and time-consuming to get working for all
+the possible corner cases (Git doesn't do it, either).  Committing
+renamed and copied files is fully supported if they're similar enough
+for Git to detect them.
+
+In SVN, it is possible (though discouraged) to commit changes to a tag
+(because a tag is just a directory copy, thus technically the same as a
+branch). When cloning an SVN repository, 'git svn' cannot know if such a
+commit to a tag will happen in the future. Thus it acts conservatively
+and imports all SVN tags as branches, prefixing the tag name with 'tags/'.
+
+CONFIGURATION
+-------------
+
+'git svn' stores [svn-remote] configuration information in the
+repository $GIT_DIR/config file.  It is similar the core Git
+[remote] sections except 'fetch' keys do not accept glob
+arguments; but they are instead handled by the 'branches'
+and 'tags' keys.  Since some SVN repositories are oddly
+configured with multiple projects glob expansions such those
+listed below are allowed:
+
+------------------------------------------------------------------------
+[svn-remote "project-a"]
+	url = http://server.org/svn
+	fetch = trunk/project-a:refs/remotes/project-a/trunk
+	branches = branches/*/project-a:refs/remotes/project-a/branches/*
+	branches = branches/release_*:refs/remotes/project-a/branches/release_*
+	branches = branches/re*se:refs/remotes/project-a/branches/*
+	tags = tags/*/project-a:refs/remotes/project-a/tags/*
+------------------------------------------------------------------------
+
+Keep in mind that the `*` (asterisk) wildcard of the local ref
+(right of the `:`) *must* be the farthest right path component;
+however the remote wildcard may be anywhere as long as it's an
+independent path component (surrounded by `/` or EOL).   This
+type of configuration is not automatically created by 'init' and
+should be manually entered with a text-editor or using 'git config'.
+
+Also note that only one asterisk is allowed per word. For example:
+
+	branches = branches/re*se:refs/remotes/project-a/branches/*
+
+will match branches 'release', 'rese', 're123se', however
+
+	branches = branches/re*s*e:refs/remotes/project-a/branches/*
+
+will produce an error.
+
+It is also possible to fetch a subset of branches or tags by using a
+comma-separated list of names within braces. For example:
+
+------------------------------------------------------------------------
+[svn-remote "huge-project"]
+	url = http://server.org/svn
+	fetch = trunk/src:refs/remotes/trunk
+	branches = branches/{red,green}/src:refs/remotes/project-a/branches/*
+	tags = tags/{1.0,2.0}/src:refs/remotes/project-a/tags/*
+------------------------------------------------------------------------
+
+Multiple fetch, branches, and tags keys are supported:
+
+------------------------------------------------------------------------
+[svn-remote "messy-repo"]
+	url = http://server.org/svn
+	fetch = trunk/project-a:refs/remotes/project-a/trunk
+	fetch = branches/demos/june-project-a-demo:refs/remotes/project-a/demos/june-demo
+	branches = branches/server/*:refs/remotes/project-a/branches/*
+	branches = branches/demos/2011/*:refs/remotes/project-a/2011-demos/*
+	tags = tags/server/*:refs/remotes/project-a/tags/*
+------------------------------------------------------------------------
+
+Creating a branch in such a configuration requires disambiguating which
+location to use using the -d or --destination flag:
+
+------------------------------------------------------------------------
+$ git svn branch -d branches/server release-2-3-0
+------------------------------------------------------------------------
+
+Note that git-svn keeps track of the highest revision in which a branch
+or tag has appeared. If the subset of branches or tags is changed after
+fetching, then $GIT_DIR/svn/.metadata must be manually edited to remove
+(or reset) branches-maxRev and/or tags-maxRev as appropriate.
+
+FILES
+-----
+$GIT_DIR/svn/\**/.rev_map.*::
+	Mapping between Subversion revision numbers and Git commit
+	names.  In a repository where the noMetadata option is not set,
+	this can be rebuilt from the git-svn-id: lines that are at the
+	end of every commit (see the 'svn.noMetadata' section above for
+	details).
++
+'git svn fetch' and 'git svn rebase' automatically update the rev_map
+if it is missing or not up to date.  'git svn reset' automatically
+rewinds it.
+
+SEE ALSO
+--------
+linkgit:git-rebase[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-switch.txt b/third_party/git/Documentation/git-switch.txt
new file mode 100644
index 0000000000..197900363b
--- /dev/null
+++ b/third_party/git/Documentation/git-switch.txt
@@ -0,0 +1,273 @@
+git-switch(1)
+=============
+
+NAME
+----
+git-switch - Switch branches
+
+SYNOPSIS
+--------
+[verse]
+'git switch' [<options>] [--no-guess] <branch>
+'git switch' [<options>] --detach [<start-point>]
+'git switch' [<options>] (-c|-C) <new-branch> [<start-point>]
+'git switch' [<options>] --orphan <new-branch>
+
+DESCRIPTION
+-----------
+Switch to a specified branch. The working tree and the index are
+updated to match the branch. All new commits will be added to the tip
+of this branch.
+
+Optionally a new branch could be created with either `-c`, `-C`,
+automatically from a remote branch of same name (see `--guess`), or
+detach the working tree from any branch with `--detach`, along with
+switching.
+
+Switching branches does not require a clean index and working tree
+(i.e. no differences compared to `HEAD`). The operation is aborted
+however if the operation leads to loss of local changes, unless told
+otherwise with `--discard-changes` or `--merge`.
+
+THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.
+
+OPTIONS
+-------
+<branch>::
+	Branch to switch to.
+
+<new-branch>::
+	Name for the new branch.
+
+<start-point>::
+	The starting point for the new branch. Specifying a
+	`<start-point>` allows you to create a branch based on some
+	other point in history than where HEAD currently points. (Or,
+	in the case of `--detach`, allows you to inspect and detach
+	from some other point.)
++
+You can use the `@{-N}` syntax to refer to the N-th last
+branch/commit switched to using "git switch" or "git checkout"
+operation. You may also specify `-` which is synonymous to `@{-1}`.
+This is often used to switch quickly between two branches, or to undo
+a branch switch by mistake.
++
+As a special case, you may use `A...B` as a shortcut for the merge
+base of `A` and `B` if there is exactly one merge base. You can leave
+out at most one of `A` and `B`, in which case it defaults to `HEAD`.
+
+-c <new-branch>::
+--create <new-branch>::
+	Create a new branch named `<new-branch>` starting at
+	`<start-point>` before switching to the branch. This is a
+	convenient shortcut for:
++
+------------
+$ git branch <new-branch>
+$ git switch <new-branch>
+------------
+
+-C <new-branch>::
+--force-create <new-branch>::
+	Similar to `--create` except that if `<new-branch>` already
+	exists, it will be reset to `<start-point>`. This is a
+	convenient shortcut for:
++
+------------
+$ git branch -f <new-branch>
+$ git switch <new-branch>
+------------
+
+-d::
+--detach::
+	Switch to a commit for inspection and discardable
+	experiments. See the "DETACHED HEAD" section in
+	linkgit:git-checkout[1] for details.
+
+--guess::
+--no-guess::
+	If `<branch>` is not found but there does exist a tracking
+	branch in exactly one remote (call it `<remote>`) with a
+	matching name, treat as equivalent to
++
+------------
+$ git switch -c <branch> --track <remote>/<branch>
+------------
++
+If the branch exists in multiple remotes and one of them is named by
+the `checkout.defaultRemote` configuration variable, we'll use that
+one for the purposes of disambiguation, even if the `<branch>` isn't
+unique across all remotes. Set it to e.g. `checkout.defaultRemote=origin`
+to always checkout remote branches from there if `<branch>` is
+ambiguous but exists on the 'origin' remote. See also
+`checkout.defaultRemote` in linkgit:git-config[1].
++
+`--guess` is the default behavior. Use `--no-guess` to disable it.
+
+-f::
+--force::
+	An alias for `--discard-changes`.
+
+--discard-changes::
+	Proceed even if the index or the working tree differs from
+	`HEAD`. Both the index and working tree are restored to match
+	the switching target. If `--recurse-submodules` is specified,
+	submodule content is also restored to match the switching
+	target. This is used to throw away local changes.
+
+-m::
+--merge::
+	If you have local modifications to one or more files that are
+	different between the current branch and the branch to which
+	you are switching, the command refuses to switch branches in
+	order to preserve your modifications in context.  However,
+	with this option, a three-way merge between the current
+	branch, your working tree contents, and the new branch is
+	done, and you will be on the new branch.
++
+When a merge conflict happens, the index entries for conflicting
+paths are left unmerged, and you need to resolve the conflicts
+and mark the resolved paths with `git add` (or `git rm` if the merge
+should result in deletion of the path).
+
+--conflict=<style>::
+	The same as `--merge` option above, but changes the way the
+	conflicting hunks are presented, overriding the
+	`merge.conflictStyle` configuration variable.  Possible values are
+	"merge" (default) and "diff3" (in addition to what is shown by
+	"merge" style, shows the original contents).
+
+-q::
+--quiet::
+	Quiet, suppress feedback messages.
+
+--progress::
+--no-progress::
+	Progress status is reported on the standard error stream
+	by default when it is attached to a terminal, unless `--quiet`
+	is specified. This flag enables progress reporting even if not
+	attached to a terminal, regardless of `--quiet`.
+
+-t::
+--track::
+	When creating a new branch, set up "upstream" configuration.
+	`-c` is implied. See `--track` in linkgit:git-branch[1] for
+	details.
++
+If no `-c` option is given, the name of the new branch will be derived
+from the remote-tracking branch, by looking at the local part of the
+refspec configured for the corresponding remote, and then stripping
+the initial part up to the "*".  This would tell us to use `hack` as
+the local branch when branching off of `origin/hack` (or
+`remotes/origin/hack`, or even `refs/remotes/origin/hack`).  If the
+given name has no slash, or the above guessing results in an empty
+name, the guessing is aborted.  You can explicitly give a name with
+`-c` in such a case.
+
+--no-track::
+	Do not set up "upstream" configuration, even if the
+	`branch.autoSetupMerge` configuration variable is true.
+
+--orphan <new-branch>::
+	Create a new 'orphan' branch, named `<new-branch>`. All
+	tracked files are removed.
+
+--ignore-other-worktrees::
+	`git switch` refuses when the wanted ref is already
+	checked out by another worktree. This option makes it check
+	the ref out anyway. In other words, the ref can be held by
+	more than one worktree.
+
+--recurse-submodules::
+--no-recurse-submodules::
+	Using `--recurse-submodules` will update the content of all
+	initialized submodules according to the commit recorded in the
+	superproject. If nothing (or `--no-recurse-submodules`) is
+	used, the work trees of submodules will not be updated. Just
+	like linkgit:git-submodule[1], this will detach `HEAD` of the
+	submodules.
+
+EXAMPLES
+--------
+
+The following command switches to the "master" branch:
+
+------------
+$ git switch master
+------------
+
+After working in the wrong branch, switching to the correct branch
+would be done using:
+
+------------
+$ git switch mytopic
+------------
+
+However, your "wrong" branch and correct "mytopic" branch may differ
+in files that you have modified locally, in which case the above
+switch would fail like this:
+
+------------
+$ git switch mytopic
+error: You have local changes to 'frotz'; not switching branches.
+------------
+
+You can give the `-m` flag to the command, which would try a three-way
+merge:
+
+------------
+$ git switch -m mytopic
+Auto-merging frotz
+------------
+
+After this three-way merge, the local modifications are _not_
+registered in your index file, so `git diff` would show you what
+changes you made since the tip of the new branch.
+
+To switch back to the previous branch before we switched to mytopic
+(i.e. "master" branch):
+
+------------
+$ git switch -
+------------
+
+You can grow a new branch from any commit. For example, switch to
+"HEAD~3" and create branch "fixup":
+
+------------
+$ git switch -c fixup HEAD~3
+Switched to a new branch 'fixup'
+------------
+
+If you want to start a new branch from a remote branch of the same
+name:
+
+------------
+$ git switch new-topic
+Branch 'new-topic' set up to track remote branch 'new-topic' from 'origin'
+Switched to a new branch 'new-topic'
+------------
+
+To check out commit `HEAD~3` for temporary inspection or experiment
+without creating a new branch:
+
+------------
+$ git switch --detach HEAD~3
+HEAD is now at 9fc9555312 Merge branch 'cc/shared-index-permbits'
+------------
+
+If it turns out whatever you have done is worth keeping, you can
+always create a new name for it (without switching away):
+
+------------
+$ git switch -c good-surprises
+------------
+
+SEE ALSO
+--------
+linkgit:git-checkout[1],
+linkgit:git-branch[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-symbolic-ref.txt b/third_party/git/Documentation/git-symbolic-ref.txt
new file mode 100644
index 0000000000..ef68ad2b71
--- /dev/null
+++ b/third_party/git/Documentation/git-symbolic-ref.txt
@@ -0,0 +1,69 @@
+git-symbolic-ref(1)
+===================
+
+NAME
+----
+git-symbolic-ref - Read, modify and delete symbolic refs
+
+SYNOPSIS
+--------
+[verse]
+'git symbolic-ref' [-m <reason>] <name> <ref>
+'git symbolic-ref' [-q] [--short] <name>
+'git symbolic-ref' --delete [-q] <name>
+
+DESCRIPTION
+-----------
+Given one argument, reads which branch head the given symbolic
+ref refers to and outputs its path, relative to the `.git/`
+directory.  Typically you would give `HEAD` as the <name>
+argument to see which branch your working tree is on.
+
+Given two arguments, creates or updates a symbolic ref <name> to
+point at the given branch <ref>.
+
+Given `--delete` and an additional argument, deletes the given
+symbolic ref.
+
+A symbolic ref is a regular file that stores a string that
+begins with `ref: refs/`.  For example, your `.git/HEAD` is
+a regular file whose contents is `ref: refs/heads/master`.
+
+OPTIONS
+-------
+
+-d::
+--delete::
+	Delete the symbolic ref <name>.
+
+-q::
+--quiet::
+	Do not issue an error message if the <name> is not a
+	symbolic ref but a detached HEAD; instead exit with
+	non-zero status silently.
+
+--short::
+	When showing the value of <name> as a symbolic ref, try to shorten the
+	value, e.g. from `refs/heads/master` to `master`.
+
+-m::
+	Update the reflog for <name> with <reason>.  This is valid only
+	when creating or updating a symbolic ref.
+
+NOTES
+-----
+In the past, `.git/HEAD` was a symbolic link pointing at
+`refs/heads/master`.  When we wanted to switch to another branch,
+we did `ln -sf refs/heads/newbranch .git/HEAD`, and when we wanted
+to find out which branch we are on, we did `readlink .git/HEAD`.
+But symbolic links are not entirely portable, so they are now
+deprecated and symbolic refs (as described above) are used by
+default.
+
+'git symbolic-ref' will exit with status 0 if the contents of the
+symbolic ref were printed correctly, with status 1 if the requested
+name is not a symbolic ref, or 128 if another error occurs.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-tag.txt b/third_party/git/Documentation/git-tag.txt
new file mode 100644
index 0000000000..2e5599a67f
--- /dev/null
+++ b/third_party/git/Documentation/git-tag.txt
@@ -0,0 +1,387 @@
+git-tag(1)
+==========
+
+NAME
+----
+git-tag - Create, list, delete or verify a tag object signed with GPG
+
+
+SYNOPSIS
+--------
+[verse]
+'git tag' [-a | -s | -u <keyid>] [-f] [-m <msg> | -F <file>] [-e]
+	<tagname> [<commit> | <object>]
+'git tag' -d <tagname>...
+'git tag' [-n[<num>]] -l [--contains <commit>] [--no-contains <commit>]
+	[--points-at <object>] [--column[=<options>] | --no-column]
+	[--create-reflog] [--sort=<key>] [--format=<format>]
+	[--[no-]merged [<commit>]] [<pattern>...]
+'git tag' -v [--format=<format>] <tagname>...
+
+DESCRIPTION
+-----------
+
+Add a tag reference in `refs/tags/`, unless `-d/-l/-v` is given
+to delete, list or verify tags.
+
+Unless `-f` is given, the named tag must not yet exist.
+
+If one of `-a`, `-s`, or `-u <keyid>` is passed, the command
+creates a 'tag' object, and requires a tag message.  Unless
+`-m <msg>` or `-F <file>` is given, an editor is started for the user to type
+in the tag message.
+
+If `-m <msg>` or `-F <file>` is given and `-a`, `-s`, and `-u <keyid>`
+are absent, `-a` is implied.
+
+Otherwise, a tag reference that points directly at the given object
+(i.e., a lightweight tag) is created.
+
+A GnuPG signed tag object will be created when `-s` or `-u
+<keyid>` is used.  When `-u <keyid>` is not used, the
+committer identity for the current user is used to find the
+GnuPG key for signing. 	The configuration variable `gpg.program`
+is used to specify custom GnuPG binary.
+
+Tag objects (created with `-a`, `-s`, or `-u`) are called "annotated"
+tags; they contain a creation date, the tagger name and e-mail, a
+tagging message, and an optional GnuPG signature. Whereas a
+"lightweight" tag is simply a name for an object (usually a commit
+object).
+
+Annotated tags are meant for release while lightweight tags are meant
+for private or temporary object labels. For this reason, some git
+commands for naming objects (like `git describe`) will ignore
+lightweight tags by default.
+
+
+OPTIONS
+-------
+-a::
+--annotate::
+	Make an unsigned, annotated tag object
+
+-s::
+--sign::
+	Make a GPG-signed tag, using the default e-mail address's key.
+	The default behavior of tag GPG-signing is controlled by `tag.gpgSign`
+	configuration variable if it exists, or disabled oder otherwise.
+	See linkgit:git-config[1].
+
+--no-sign::
+	Override `tag.gpgSign` configuration variable that is
+	set to force each and every tag to be signed.
+
+-u <keyid>::
+--local-user=<keyid>::
+	Make a GPG-signed tag, using the given key.
+
+-f::
+--force::
+	Replace an existing tag with the given name (instead of failing)
+
+-d::
+--delete::
+	Delete existing tags with the given names.
+
+-v::
+--verify::
+	Verify the GPG signature of the given tag names.
+
+-n<num>::
+	<num> specifies how many lines from the annotation, if any,
+	are printed when using -l. Implies `--list`.
++
+The default is not to print any annotation lines.
+If no number is given to `-n`, only the first line is printed.
+If the tag is not annotated, the commit message is displayed instead.
+
+-l::
+--list::
+	List tags. With optional `<pattern>...`, e.g. `git tag --list
+	'v-*'`, list only the tags that match the pattern(s).
++
+Running "git tag" without arguments also lists all tags. The pattern
+is a shell wildcard (i.e., matched using fnmatch(3)). Multiple
+patterns may be given; if any of them matches, the tag is shown.
++
+This option is implicitly supplied if any other list-like option such
+as `--contains` is provided. See the documentation for each of those
+options for details.
+
+--sort=<key>::
+	Sort based on the key given.  Prefix `-` to sort in
+	descending order of the value. You may use the --sort=<key> option
+	multiple times, in which case the last key becomes the primary
+	key. Also supports "version:refname" or "v:refname" (tag
+	names are treated as versions). The "version:refname" sort
+	order can also be affected by the "versionsort.suffix"
+	configuration variable.
+	The keys supported are the same as those in `git for-each-ref`.
+	Sort order defaults to the value configured for the `tag.sort`
+	variable if it exists, or lexicographic order otherwise. See
+	linkgit:git-config[1].
+
+--color[=<when>]::
+	Respect any colors specified in the `--format` option. The
+	`<when>` field must be one of `always`, `never`, or `auto` (if
+	`<when>` is absent, behave as if `always` was given).
+
+-i::
+--ignore-case::
+	Sorting and filtering tags are case insensitive.
+
+--column[=<options>]::
+--no-column::
+	Display tag listing in columns. See configuration variable
+	column.tag for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never' respectively.
++
+This option is only applicable when listing tags without annotation lines.
+
+--contains [<commit>]::
+	Only list tags which contain the specified commit (HEAD if not
+	specified). Implies `--list`.
+
+--no-contains [<commit>]::
+	Only list tags which don't contain the specified commit (HEAD if
+	not specified). Implies `--list`.
+
+--merged [<commit>]::
+	Only list tags whose commits are reachable from the specified
+	commit (`HEAD` if not specified), incompatible with `--no-merged`.
+
+--no-merged [<commit>]::
+	Only list tags whose commits are not reachable from the specified
+	commit (`HEAD` if not specified), incompatible with `--merged`.
+
+--points-at <object>::
+	Only list tags of the given object (HEAD if not
+	specified). Implies `--list`.
+
+-m <msg>::
+--message=<msg>::
+	Use the given tag message (instead of prompting).
+	If multiple `-m` options are given, their values are
+	concatenated as separate paragraphs.
+	Implies `-a` if none of `-a`, `-s`, or `-u <keyid>`
+	is given.
+
+-F <file>::
+--file=<file>::
+	Take the tag message from the given file.  Use '-' to
+	read the message from the standard input.
+	Implies `-a` if none of `-a`, `-s`, or `-u <keyid>`
+	is given.
+
+-e::
+--edit::
+	The message taken from file with `-F` and command line with
+	`-m` are usually used as the tag message unmodified.
+	This option lets you further edit the message taken from these sources.
+
+--cleanup=<mode>::
+	This option sets how the tag message is cleaned up.
+	The  '<mode>' can be one of 'verbatim', 'whitespace' and 'strip'.  The
+	'strip' mode is default. The 'verbatim' mode does not change message at
+	all, 'whitespace' removes just leading/trailing whitespace lines and
+	'strip' removes both whitespace and commentary.
+
+--create-reflog::
+	Create a reflog for the tag. To globally enable reflogs for tags, see
+	`core.logAllRefUpdates` in linkgit:git-config[1].
+	The negated form `--no-create-reflog` only overrides an earlier
+	`--create-reflog`, but currently does not negate the setting of
+	`core.logAllRefUpdates`.
+
+--format=<format>::
+	A string that interpolates `%(fieldname)` from a tag ref being shown
+	and the object it points at.  The format is the same as
+	that of linkgit:git-for-each-ref[1].  When unspecified,
+	defaults to `%(refname:strip=2)`.
+
+<tagname>::
+	The name of the tag to create, delete, or describe.
+	The new tag name must pass all checks defined by
+	linkgit:git-check-ref-format[1].  Some of these checks
+	may restrict the characters allowed in a tag name.
+
+<commit>::
+<object>::
+	The object that the new tag will refer to, usually a commit.
+	Defaults to HEAD.
+
+CONFIGURATION
+-------------
+By default, 'git tag' in sign-with-default mode (-s) will use your
+committer identity (of the form `Your Name <your@email.address>`) to
+find a key.  If you want to use a different default key, you can specify
+it in the repository configuration as follows:
+
+-------------------------------------
+[user]
+    signingKey = <gpg-keyid>
+-------------------------------------
+
+`pager.tag` is only respected when listing tags, i.e., when `-l` is
+used or implied. The default is to use a pager.
+See linkgit:git-config[1].
+
+DISCUSSION
+----------
+
+On Re-tagging
+~~~~~~~~~~~~~
+
+What should you do when you tag a wrong commit and you would
+want to re-tag?
+
+If you never pushed anything out, just re-tag it. Use "-f" to
+replace the old one. And you're done.
+
+But if you have pushed things out (or others could just read
+your repository directly), then others will have already seen
+the old tag. In that case you can do one of two things:
+
+. The sane thing.
+  Just admit you screwed up, and use a different name. Others have
+  already seen one tag-name, and if you keep the same name, you
+  may be in the situation that two people both have "version X",
+  but they actually have 'different' "X"'s.  So just call it "X.1"
+  and be done with it.
+
+. The insane thing.
+  You really want to call the new version "X" too, 'even though'
+  others have already seen the old one. So just use 'git tag -f'
+  again, as if you hadn't already published the old one.
+
+However, Git does *not* (and it should not) change tags behind
+users back. So if somebody already got the old tag, doing a
+'git pull' on your tree shouldn't just make them overwrite the old
+one.
+
+If somebody got a release tag from you, you cannot just change
+the tag for them by updating your own one. This is a big
+security issue, in that people MUST be able to trust their
+tag-names.  If you really want to do the insane thing, you need
+to just fess up to it, and tell people that you messed up. You
+can do that by making a very public announcement saying:
+
+------------
+Ok, I messed up, and I pushed out an earlier version tagged as X. I
+then fixed something, and retagged the *fixed* tree as X again.
+
+If you got the wrong tag, and want the new one, please delete
+the old one and fetch the new one by doing:
+
+	git tag -d X
+	git fetch origin tag X
+
+to get my updated tag.
+
+You can test which tag you have by doing
+
+	git rev-parse X
+
+which should return 0123456789abcdef.. if you have the new version.
+
+Sorry for the inconvenience.
+------------
+
+Does this seem a bit complicated?  It *should* be. There is no
+way that it would be correct to just "fix" it automatically.
+People need to know that their tags might have been changed.
+
+
+On Automatic following
+~~~~~~~~~~~~~~~~~~~~~~
+
+If you are following somebody else's tree, you are most likely
+using remote-tracking branches (eg. `refs/remotes/origin/master`).
+You usually want the tags from the other end.
+
+On the other hand, if you are fetching because you would want a
+one-shot merge from somebody else, you typically do not want to
+get tags from there.  This happens more often for people near
+the toplevel but not limited to them.  Mere mortals when pulling
+from each other do not necessarily want to automatically get
+private anchor point tags from the other person.
+
+Often, "please pull" messages on the mailing list just provide
+two pieces of information: a repo URL and a branch name; this
+is designed to be easily cut&pasted at the end of a 'git fetch'
+command line:
+
+------------
+Linus, please pull from
+
+	git://git..../proj.git master
+
+to get the following updates...
+------------
+
+becomes:
+
+------------
+$ git pull git://git..../proj.git master
+------------
+
+In such a case, you do not want to automatically follow the other
+person's tags.
+
+One important aspect of Git is its distributed nature, which
+largely means there is no inherent "upstream" or
+"downstream" in the system.  On the face of it, the above
+example might seem to indicate that the tag namespace is owned
+by the upper echelon of people and that tags only flow downwards, but
+that is not the case.  It only shows that the usage pattern
+determines who are interested in whose tags.
+
+A one-shot pull is a sign that a commit history is now crossing
+the boundary between one circle of people (e.g. "people who are
+primarily interested in the networking part of the kernel") who may
+have their own set of tags (e.g. "this is the third release
+candidate from the networking group to be proposed for general
+consumption with 2.6.21 release") to another circle of people
+(e.g. "people who integrate various subsystem improvements").
+The latter are usually not interested in the detailed tags used
+internally in the former group (that is what "internal" means).
+That is why it is desirable not to follow tags automatically in
+this case.
+
+It may well be that among networking people, they may want to
+exchange the tags internal to their group, but in that workflow
+they are most likely tracking each other's progress by
+having remote-tracking branches.  Again, the heuristic to automatically
+follow such tags is a good thing.
+
+
+On Backdating Tags
+~~~~~~~~~~~~~~~~~~
+
+If you have imported some changes from another VCS and would like
+to add tags for major releases of your work, it is useful to be able
+to specify the date to embed inside of the tag object; such data in
+the tag object affects, for example, the ordering of tags in the
+gitweb interface.
+
+To set the date used in future tag objects, set the environment
+variable GIT_COMMITTER_DATE (see the later discussion of possible
+values; the most common form is "YYYY-MM-DD HH:MM").
+
+For example:
+
+------------
+$ GIT_COMMITTER_DATE="2006-10-02 10:31" git tag -s v1.0.1
+------------
+
+include::date-formats.txt[]
+
+SEE ALSO
+--------
+linkgit:git-check-ref-format[1].
+linkgit:git-config[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-tools.txt b/third_party/git/Documentation/git-tools.txt
new file mode 100644
index 0000000000..d0fec4cddd
--- /dev/null
+++ b/third_party/git/Documentation/git-tools.txt
@@ -0,0 +1,10 @@
+Git Tools
+=========
+
+When Git was young, people looking for third-party Git-related tools came
+to the Git project itself to find them, thus a list of such tools was
+maintained here. These days, however, search engines fill that role much
+more efficiently, so this manually-maintained list has been retired.
+
+See also the `contrib/` area, and the Git wiki:
+https://git.wiki.kernel.org/index.php/InterfacesFrontendsAndTools
diff --git a/third_party/git/Documentation/git-unpack-file.txt b/third_party/git/Documentation/git-unpack-file.txt
new file mode 100644
index 0000000000..e9f148a00d
--- /dev/null
+++ b/third_party/git/Documentation/git-unpack-file.txt
@@ -0,0 +1,28 @@
+git-unpack-file(1)
+==================
+
+NAME
+----
+git-unpack-file - Creates a temporary file with a blob's contents
+
+
+
+SYNOPSIS
+--------
+[verse]
+'git unpack-file' <blob>
+
+DESCRIPTION
+-----------
+Creates a file holding the contents of the blob specified by sha1. It
+returns the name of the temporary file in the following format:
+	.merge_file_XXXXX
+
+OPTIONS
+-------
+<blob>::
+	Must be a blob id
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-unpack-objects.txt b/third_party/git/Documentation/git-unpack-objects.txt
new file mode 100644
index 0000000000..b3de50d710
--- /dev/null
+++ b/third_party/git/Documentation/git-unpack-objects.txt
@@ -0,0 +1,52 @@
+git-unpack-objects(1)
+=====================
+
+NAME
+----
+git-unpack-objects - Unpack objects from a packed archive
+
+
+SYNOPSIS
+--------
+[verse]
+'git unpack-objects' [-n] [-q] [-r] [--strict]
+
+
+DESCRIPTION
+-----------
+Read a packed archive (.pack) from the standard input, expanding
+the objects contained within and writing them into the repository in
+"loose" (one object per file) format.
+
+Objects that already exist in the repository will *not* be unpacked
+from the packfile.  Therefore, nothing will be unpacked if you use
+this command on a packfile that exists within the target repository.
+
+See linkgit:git-repack[1] for options to generate
+new packs and replace existing ones.
+
+OPTIONS
+-------
+-n::
+        Dry run.  Check the pack file without actually unpacking
+	the objects.
+
+-q::
+	The command usually shows percentage progress.  This
+	flag suppresses it.
+
+-r::
+	When unpacking a corrupt packfile, the command dies at
+	the first corruption.  This flag tells it to keep going
+	and make the best effort to recover as many objects as
+	possible.
+
+--strict::
+	Don't write objects with broken content or links.
+
+--max-input-size=<size>::
+	Die, if the pack is larger than <size>.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-update-index.txt b/third_party/git/Documentation/git-update-index.txt
new file mode 100644
index 0000000000..1c4d146a41
--- /dev/null
+++ b/third_party/git/Documentation/git-update-index.txt
@@ -0,0 +1,554 @@
+git-update-index(1)
+===================
+
+NAME
+----
+git-update-index - Register file contents in the working tree to the index
+
+
+SYNOPSIS
+--------
+[verse]
+'git update-index'
+	     [--add] [--remove | --force-remove] [--replace]
+	     [--refresh] [-q] [--unmerged] [--ignore-missing]
+	     [(--cacheinfo <mode>,<object>,<file>)...]
+	     [--chmod=(+|-)x]
+	     [--[no-]assume-unchanged]
+	     [--[no-]skip-worktree]
+	     [--[no-]fsmonitor-valid]
+	     [--ignore-submodules]
+	     [--[no-]split-index]
+	     [--[no-|test-|force-]untracked-cache]
+	     [--[no-]fsmonitor]
+	     [--really-refresh] [--unresolve] [--again | -g]
+	     [--info-only] [--index-info]
+	     [-z] [--stdin] [--index-version <n>]
+	     [--verbose]
+	     [--] [<file>...]
+
+DESCRIPTION
+-----------
+Modifies the index or directory cache. Each file mentioned is updated
+into the index and any 'unmerged' or 'needs updating' state is
+cleared.
+
+See also linkgit:git-add[1] for a more user-friendly way to do some of
+the most common operations on the index.
+
+The way 'git update-index' handles files it is told about can be modified
+using the various options:
+
+OPTIONS
+-------
+--add::
+	If a specified file isn't in the index already then it's
+	added.
+	Default behaviour is to ignore new files.
+
+--remove::
+	If a specified file is in the index but is missing then it's
+	removed.
+	Default behavior is to ignore removed file.
+
+--refresh::
+	Looks at the current index and checks to see if merges or
+	updates are needed by checking stat() information.
+
+-q::
+        Quiet.  If --refresh finds that the index needs an update, the
+        default behavior is to error out.  This option makes
+	'git update-index' continue anyway.
+
+--ignore-submodules::
+	Do not try to update submodules.  This option is only respected
+	when passed before --refresh.
+
+--unmerged::
+        If --refresh finds unmerged changes in the index, the default
+	behavior is to error out.  This option makes 'git update-index'
+        continue anyway.
+
+--ignore-missing::
+	Ignores missing files during a --refresh
+
+--cacheinfo <mode>,<object>,<path>::
+--cacheinfo <mode> <object> <path>::
+	Directly insert the specified info into the index.  For
+	backward compatibility, you can also give these three
+	arguments as three separate parameters, but new users are
+	encouraged to use a single-parameter form.
+
+--index-info::
+        Read index information from stdin.
+
+--chmod=(+|-)x::
+        Set the execute permissions on the updated files.
+
+--[no-]assume-unchanged::
+	When this flag is specified, the object names recorded
+	for the paths are not updated.  Instead, this option
+	sets/unsets the "assume unchanged" bit for the
+	paths.  When the "assume unchanged" bit is on, the user
+	promises not to change the file and allows Git to assume
+	that the working tree file matches what is recorded in
+	the index.  If you want to change the working tree file,
+	you need to unset the bit to tell Git.  This is
+	sometimes helpful when working with a big project on a
+	filesystem that has very slow lstat(2) system call
+	(e.g. cifs).
++
+Git will fail (gracefully) in case it needs to modify this file
+in the index e.g. when merging in a commit;
+thus, in case the assumed-untracked file is changed upstream,
+you will need to handle the situation manually.
+
+--really-refresh::
+	Like `--refresh`, but checks stat information unconditionally,
+	without regard to the "assume unchanged" setting.
+
+--[no-]skip-worktree::
+	When one of these flags is specified, the object name recorded
+	for the paths are not updated. Instead, these options
+	set and unset the "skip-worktree" bit for the paths. See
+	section "Skip-worktree bit" below for more information.
+
+--[no-]fsmonitor-valid::
+	When one of these flags is specified, the object name recorded
+	for the paths are not updated. Instead, these options
+	set and unset the "fsmonitor valid" bit for the paths. See
+	section "File System Monitor" below for more information.
+
+-g::
+--again::
+	Runs 'git update-index' itself on the paths whose index
+	entries are different from those from the `HEAD` commit.
+
+--unresolve::
+	Restores the 'unmerged' or 'needs updating' state of a
+	file during a merge if it was cleared by accident.
+
+--info-only::
+	Do not create objects in the object database for all
+	<file> arguments that follow this flag; just insert
+	their object IDs into the index.
+
+--force-remove::
+	Remove the file from the index even when the working directory
+	still has such a file. (Implies --remove.)
+
+--replace::
+	By default, when a file `path` exists in the index,
+	'git update-index' refuses an attempt to add `path/file`.
+	Similarly if a file `path/file` exists, a file `path`
+	cannot be added.  With --replace flag, existing entries
+	that conflict with the entry being added are
+	automatically removed with warning messages.
+
+--stdin::
+	Instead of taking list of paths from the command line,
+	read list of paths from the standard input.  Paths are
+	separated by LF (i.e. one path per line) by default.
+
+--verbose::
+        Report what is being added and removed from index.
+
+--index-version <n>::
+	Write the resulting index out in the named on-disk format version.
+	Supported versions are 2, 3 and 4. The current default version is 2
+	or 3, depending on whether extra features are used, such as
+	`git add -N`.
++
+Version 4 performs a simple pathname compression that reduces index
+size by 30%-50% on large repositories, which results in faster load
+time. Version 4 is relatively young (first released in 1.8.0 in
+October 2012). Other Git implementations such as JGit and libgit2
+may not support it yet.
+
+-z::
+	Only meaningful with `--stdin` or `--index-info`; paths are
+	separated with NUL character instead of LF.
+
+--split-index::
+--no-split-index::
+	Enable or disable split index mode. If split-index mode is
+	already enabled and `--split-index` is given again, all
+	changes in $GIT_DIR/index are pushed back to the shared index
+	file.
++
+These options take effect whatever the value of the `core.splitIndex`
+configuration variable (see linkgit:git-config[1]). But a warning is
+emitted when the change goes against the configured value, as the
+configured value will take effect next time the index is read and this
+will remove the intended effect of the option.
+
+--untracked-cache::
+--no-untracked-cache::
+	Enable or disable untracked cache feature. Please use
+	`--test-untracked-cache` before enabling it.
++
+These options take effect whatever the value of the `core.untrackedCache`
+configuration variable (see linkgit:git-config[1]). But a warning is
+emitted when the change goes against the configured value, as the
+configured value will take effect next time the index is read and this
+will remove the intended effect of the option.
+
+--test-untracked-cache::
+	Only perform tests on the working directory to make sure
+	untracked cache can be used. You have to manually enable
+	untracked cache using `--untracked-cache` or
+	`--force-untracked-cache` or the `core.untrackedCache`
+	configuration variable afterwards if you really want to use
+	it. If a test fails the exit code is 1 and a message
+	explains what is not working as needed, otherwise the exit
+	code is 0 and OK is printed.
+
+--force-untracked-cache::
+	Same as `--untracked-cache`. Provided for backwards
+	compatibility with older versions of Git where
+	`--untracked-cache` used to imply `--test-untracked-cache` but
+	this option would enable the extension unconditionally.
+
+--fsmonitor::
+--no-fsmonitor::
+	Enable or disable files system monitor feature. These options
+	take effect whatever the value of the `core.fsmonitor`
+	configuration variable (see linkgit:git-config[1]). But a warning
+	is emitted when the change goes against the configured value, as
+	the configured value will take effect next time the index is
+	read and this will remove the intended effect of the option.
+
+\--::
+	Do not interpret any more arguments as options.
+
+<file>::
+	Files to act on.
+	Note that files beginning with '.' are discarded. This includes
+	`./file` and `dir/./file`. If you don't want this, then use
+	cleaner names.
+	The same applies to directories ending '/' and paths with '//'
+
+USING --REFRESH
+---------------
+`--refresh` does not calculate a new sha1 file or bring the index
+up to date for mode/content changes. But what it *does* do is to
+"re-match" the stat information of a file with the index, so that you
+can refresh the index for a file that hasn't been changed but where
+the stat entry is out of date.
+
+For example, you'd want to do this after doing a 'git read-tree', to link
+up the stat index details with the proper files.
+
+USING --CACHEINFO OR --INFO-ONLY
+--------------------------------
+`--cacheinfo` is used to register a file that is not in the
+current working directory.  This is useful for minimum-checkout
+merging.
+
+To pretend you have a file at path with mode and sha1, say:
+
+----------------
+$ git update-index --add --cacheinfo <mode>,<sha1>,<path>
+----------------
+
+`--info-only` is used to register files without placing them in the object
+database.  This is useful for status-only repositories.
+
+Both `--cacheinfo` and `--info-only` behave similarly: the index is updated
+but the object database isn't.  `--cacheinfo` is useful when the object is
+in the database but the file isn't available locally.  `--info-only` is
+useful when the file is available, but you do not wish to update the
+object database.
+
+
+USING --INDEX-INFO
+------------------
+
+`--index-info` is a more powerful mechanism that lets you feed
+multiple entry definitions from the standard input, and designed
+specifically for scripts.  It can take inputs of three formats:
+
+    . mode SP type SP sha1          TAB path
++
+This format is to stuff `git ls-tree` output into the index.
+
+    . mode         SP sha1 SP stage TAB path
++
+This format is to put higher order stages into the
+index file and matches 'git ls-files --stage' output.
+
+    . mode         SP sha1          TAB path
++
+This format is no longer produced by any Git command, but is
+and will continue to be supported by `update-index --index-info`.
+
+To place a higher stage entry to the index, the path should
+first be removed by feeding a mode=0 entry for the path, and
+then feeding necessary input lines in the third format.
+
+For example, starting with this index:
+
+------------
+$ git ls-files -s
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 0       frotz
+------------
+
+you can feed the following input to `--index-info`:
+
+------------
+$ git update-index --index-info
+0 0000000000000000000000000000000000000000	frotz
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1	frotz
+100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2	frotz
+------------
+
+The first line of the input feeds 0 as the mode to remove the
+path; the SHA-1 does not matter as long as it is well formatted.
+Then the second and third line feeds stage 1 and stage 2 entries
+for that path.  After the above, we would end up with this:
+
+------------
+$ git ls-files -s
+100644 8a1218a1024a212bb3db30becd860315f9f3ac52 1	frotz
+100755 8a1218a1024a212bb3db30becd860315f9f3ac52 2	frotz
+------------
+
+
+USING ``ASSUME UNCHANGED'' BIT
+------------------------------
+
+Many operations in Git depend on your filesystem to have an
+efficient `lstat(2)` implementation, so that `st_mtime`
+information for working tree files can be cheaply checked to see
+if the file contents have changed from the version recorded in
+the index file.  Unfortunately, some filesystems have
+inefficient `lstat(2)`.  If your filesystem is one of them, you
+can set "assume unchanged" bit to paths you have not changed to
+cause Git not to do this check.  Note that setting this bit on a
+path does not mean Git will check the contents of the file to
+see if it has changed -- it makes Git to omit any checking and
+assume it has *not* changed.  When you make changes to working
+tree files, you have to explicitly tell Git about it by dropping
+"assume unchanged" bit, either before or after you modify them.
+
+In order to set "assume unchanged" bit, use `--assume-unchanged`
+option.  To unset, use `--no-assume-unchanged`. To see which files
+have the "assume unchanged" bit set, use `git ls-files -v`
+(see linkgit:git-ls-files[1]).
+
+The command looks at `core.ignorestat` configuration variable.  When
+this is true, paths updated with `git update-index paths...` and
+paths updated with other Git commands that update both index and
+working tree (e.g. 'git apply --index', 'git checkout-index -u',
+and 'git read-tree -u') are automatically marked as "assume
+unchanged".  Note that "assume unchanged" bit is *not* set if
+`git update-index --refresh` finds the working tree file matches
+the index (use `git update-index --really-refresh` if you want
+to mark them as "assume unchanged").
+
+
+EXAMPLES
+--------
+To update and refresh only the files already checked out:
+
+----------------
+$ git checkout-index -n -f -a && git update-index --ignore-missing --refresh
+----------------
+
+On an inefficient filesystem with `core.ignorestat` set::
++
+------------
+$ git update-index --really-refresh              <1>
+$ git update-index --no-assume-unchanged foo.c   <2>
+$ git diff --name-only                           <3>
+$ edit foo.c
+$ git diff --name-only                           <4>
+M foo.c
+$ git update-index foo.c                         <5>
+$ git diff --name-only                           <6>
+$ edit foo.c
+$ git diff --name-only                           <7>
+$ git update-index --no-assume-unchanged foo.c   <8>
+$ git diff --name-only                           <9>
+M foo.c
+------------
++
+<1> forces lstat(2) to set "assume unchanged" bits for paths that match index.
+<2> mark the path to be edited.
+<3> this does lstat(2) and finds index matches the path.
+<4> this does lstat(2) and finds index does *not* match the path.
+<5> registering the new version to index sets "assume unchanged" bit.
+<6> and it is assumed unchanged.
+<7> even after you edit it.
+<8> you can tell about the change after the fact.
+<9> now it checks with lstat(2) and finds it has been changed.
+
+
+SKIP-WORKTREE BIT
+-----------------
+
+Skip-worktree bit can be defined in one (long) sentence: When reading
+an entry, if it is marked as skip-worktree, then Git pretends its
+working directory version is up to date and read the index version
+instead.
+
+To elaborate, "reading" means checking for file existence, reading
+file attributes or file content. The working directory version may be
+present or absent. If present, its content may match against the index
+version or not. Writing is not affected by this bit, content safety
+is still first priority. Note that Git _can_ update working directory
+file, that is marked skip-worktree, if it is safe to do so (i.e.
+working directory version matches index version)
+
+Although this bit looks similar to assume-unchanged bit, its goal is
+different from assume-unchanged bit's. Skip-worktree also takes
+precedence over assume-unchanged bit when both are set.
+
+SPLIT INDEX
+-----------
+
+This mode is designed for repositories with very large indexes, and
+aims at reducing the time it takes to repeatedly write these indexes.
+
+In this mode, the index is split into two files, $GIT_DIR/index and
+$GIT_DIR/sharedindex.<SHA-1>. Changes are accumulated in
+$GIT_DIR/index, the split index, while the shared index file contains
+all index entries and stays unchanged.
+
+All changes in the split index are pushed back to the shared index
+file when the number of entries in the split index reaches a level
+specified by the splitIndex.maxPercentChange config variable (see
+linkgit:git-config[1]).
+
+Each time a new shared index file is created, the old shared index
+files are deleted if their modification time is older than what is
+specified by the splitIndex.sharedIndexExpire config variable (see
+linkgit:git-config[1]).
+
+To avoid deleting a shared index file that is still used, its
+modification time is updated to the current time everytime a new split
+index based on the shared index file is either created or read from.
+
+UNTRACKED CACHE
+---------------
+
+This cache is meant to speed up commands that involve determining
+untracked files such as `git status`.
+
+This feature works by recording the mtime of the working tree
+directories and then omitting reading directories and stat calls
+against files in those directories whose mtime hasn't changed. For
+this to work the underlying operating system and file system must
+change the `st_mtime` field of directories if files in the directory
+are added, modified or deleted.
+
+You can test whether the filesystem supports that with the
+`--test-untracked-cache` option. The `--untracked-cache` option used
+to implicitly perform that test in older versions of Git, but that's
+no longer the case.
+
+If you want to enable (or disable) this feature, it is easier to use
+the `core.untrackedCache` configuration variable (see
+linkgit:git-config[1]) than using the `--untracked-cache` option to
+`git update-index` in each repository, especially if you want to do so
+across all repositories you use, because you can set the configuration
+variable to `true` (or `false`) in your `$HOME/.gitconfig` just once
+and have it affect all repositories you touch.
+
+When the `core.untrackedCache` configuration variable is changed, the
+untracked cache is added to or removed from the index the next time a
+command reads the index; while when `--[no-|force-]untracked-cache`
+are used, the untracked cache is immediately added to or removed from
+the index.
+
+Before 2.17, the untracked cache had a bug where replacing a directory
+with a symlink to another directory could cause it to incorrectly show
+files tracked by git as untracked. See the "status: add a failing test
+showing a core.untrackedCache bug" commit to git.git. A workaround for
+that is (and this might work for other undiscovered bugs in the
+future):
+
+----------------
+$ git -c core.untrackedCache=false status
+----------------
+
+This bug has also been shown to affect non-symlink cases of replacing
+a directory with a file when it comes to the internal structures of
+the untracked cache, but no case has been reported where this resulted in
+wrong "git status" output.
+
+There are also cases where existing indexes written by git versions
+before 2.17 will reference directories that don't exist anymore,
+potentially causing many "could not open directory" warnings to be
+printed on "git status". These are new warnings for existing issues
+that were previously silently discarded.
+
+As with the bug described above the solution is to one-off do a "git
+status" run with `core.untrackedCache=false` to flush out the leftover
+bad data.
+
+FILE SYSTEM MONITOR
+-------------------
+
+This feature is intended to speed up git operations for repos that have
+large working directories.
+
+It enables git to work together with a file system monitor (see the
+"fsmonitor-watchman" section of linkgit:githooks[5]) that can
+inform it as to what files have been modified. This enables git to avoid
+having to lstat() every file to find modified files.
+
+When used in conjunction with the untracked cache, it can further improve
+performance by avoiding the cost of scanning the entire working directory
+looking for new files.
+
+If you want to enable (or disable) this feature, it is easier to use
+the `core.fsmonitor` configuration variable (see
+linkgit:git-config[1]) than using the `--fsmonitor` option to
+`git update-index` in each repository, especially if you want to do so
+across all repositories you use, because you can set the configuration
+variable in your `$HOME/.gitconfig` just once and have it affect all
+repositories you touch.
+
+When the `core.fsmonitor` configuration variable is changed, the
+file system monitor is added to or removed from the index the next time
+a command reads the index. When `--[no-]fsmonitor` are used, the file
+system monitor is immediately added to or removed from the index.
+
+CONFIGURATION
+-------------
+
+The command honors `core.filemode` configuration variable.  If
+your repository is on a filesystem whose executable bits are
+unreliable, this should be set to 'false' (see linkgit:git-config[1]).
+This causes the command to ignore differences in file modes recorded
+in the index and the file mode on the filesystem if they differ only on
+executable bit.   On such an unfortunate filesystem, you may
+need to use 'git update-index --chmod='.
+
+Quite similarly, if `core.symlinks` configuration variable is set
+to 'false' (see linkgit:git-config[1]), symbolic links are checked out
+as plain files, and this command does not modify a recorded file mode
+from symbolic link to regular file.
+
+The command looks at `core.ignorestat` configuration variable.  See
+'Using "assume unchanged" bit' section above.
+
+The command also looks at `core.trustctime` configuration variable.
+It can be useful when the inode change time is regularly modified by
+something outside Git (file system crawlers and backup systems use
+ctime for marking files processed) (see linkgit:git-config[1]).
+
+The untracked cache extension can be enabled by the
+`core.untrackedCache` configuration variable (see
+linkgit:git-config[1]).
+
+SEE ALSO
+--------
+linkgit:git-config[1],
+linkgit:git-add[1],
+linkgit:git-ls-files[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-update-ref.txt b/third_party/git/Documentation/git-update-ref.txt
new file mode 100644
index 0000000000..9671423117
--- /dev/null
+++ b/third_party/git/Documentation/git-update-ref.txt
@@ -0,0 +1,152 @@
+git-update-ref(1)
+=================
+
+NAME
+----
+git-update-ref - Update the object name stored in a ref safely
+
+SYNOPSIS
+--------
+[verse]
+'git update-ref' [-m <reason>] [--no-deref] (-d <ref> [<oldvalue>] | [--create-reflog] <ref> <newvalue> [<oldvalue>] | --stdin [-z])
+
+DESCRIPTION
+-----------
+Given two arguments, stores the <newvalue> in the <ref>, possibly
+dereferencing the symbolic refs.  E.g. `git update-ref HEAD
+<newvalue>` updates the current branch head to the new object.
+
+Given three arguments, stores the <newvalue> in the <ref>,
+possibly dereferencing the symbolic refs, after verifying that
+the current value of the <ref> matches <oldvalue>.
+E.g. `git update-ref refs/heads/master <newvalue> <oldvalue>`
+updates the master branch head to <newvalue> only if its current
+value is <oldvalue>.  You can specify 40 "0" or an empty string
+as <oldvalue> to make sure that the ref you are creating does
+not exist.
+
+It also allows a "ref" file to be a symbolic pointer to another
+ref file by starting with the four-byte header sequence of
+"ref:".
+
+More importantly, it allows the update of a ref file to follow
+these symbolic pointers, whether they are symlinks or these
+"regular file symbolic refs".  It follows *real* symlinks only
+if they start with "refs/": otherwise it will just try to read
+them and update them as a regular file (i.e. it will allow the
+filesystem to follow them, but will overwrite such a symlink to
+somewhere else with a regular filename).
+
+If --no-deref is given, <ref> itself is overwritten, rather than
+the result of following the symbolic pointers.
+
+In general, using
+
+	git update-ref HEAD "$head"
+
+should be a _lot_ safer than doing
+
+	echo "$head" > "$GIT_DIR/HEAD"
+
+both from a symlink following standpoint *and* an error checking
+standpoint.  The "refs/" rule for symlinks means that symlinks
+that point to "outside" the tree are safe: they'll be followed
+for reading but not for writing (so we'll never write through a
+ref symlink to some other tree, if you have copied a whole
+archive by creating a symlink tree).
+
+With `-d` flag, it deletes the named <ref> after verifying it
+still contains <oldvalue>.
+
+With `--stdin`, update-ref reads instructions from standard input and
+performs all modifications together.  Specify commands of the form:
+
+	update SP <ref> SP <newvalue> [SP <oldvalue>] LF
+	create SP <ref> SP <newvalue> LF
+	delete SP <ref> [SP <oldvalue>] LF
+	verify SP <ref> [SP <oldvalue>] LF
+	option SP <opt> LF
+
+With `--create-reflog`, update-ref will create a reflog for each ref
+even if one would not ordinarily be created.
+
+Quote fields containing whitespace as if they were strings in C source
+code; i.e., surrounded by double-quotes and with backslash escapes.
+Use 40 "0" characters or the empty string to specify a zero value.  To
+specify a missing value, omit the value and its preceding SP entirely.
+
+Alternatively, use `-z` to specify in NUL-terminated format, without
+quoting:
+
+	update SP <ref> NUL <newvalue> NUL [<oldvalue>] NUL
+	create SP <ref> NUL <newvalue> NUL
+	delete SP <ref> NUL [<oldvalue>] NUL
+	verify SP <ref> NUL [<oldvalue>] NUL
+	option SP <opt> NUL
+
+In this format, use 40 "0" to specify a zero value, and use the empty
+string to specify a missing value.
+
+In either format, values can be specified in any form that Git
+recognizes as an object name.  Commands in any other format or a
+repeated <ref> produce an error.  Command meanings are:
+
+update::
+	Set <ref> to <newvalue> after verifying <oldvalue>, if given.
+	Specify a zero <newvalue> to ensure the ref does not exist
+	after the update and/or a zero <oldvalue> to make sure the
+	ref does not exist before the update.
+
+create::
+	Create <ref> with <newvalue> after verifying it does not
+	exist.  The given <newvalue> may not be zero.
+
+delete::
+	Delete <ref> after verifying it exists with <oldvalue>, if
+	given.  If given, <oldvalue> may not be zero.
+
+verify::
+	Verify <ref> against <oldvalue> but do not change it.  If
+	<oldvalue> zero or missing, the ref must not exist.
+
+option::
+	Modify behavior of the next command naming a <ref>.
+	The only valid option is `no-deref` to avoid dereferencing
+	a symbolic ref.
+
+If all <ref>s can be locked with matching <oldvalue>s
+simultaneously, all modifications are performed.  Otherwise, no
+modifications are performed.  Note that while each individual
+<ref> is updated or deleted atomically, a concurrent reader may
+still see a subset of the modifications.
+
+LOGGING UPDATES
+---------------
+If config parameter "core.logAllRefUpdates" is true and the ref is one under
+"refs/heads/", "refs/remotes/", "refs/notes/", or the symbolic ref HEAD; or
+the file "$GIT_DIR/logs/<ref>" exists then `git update-ref` will append
+a line to the log file "$GIT_DIR/logs/<ref>" (dereferencing all
+symbolic refs before creating the log name) describing the change
+in ref value.  Log lines are formatted as:
+
+    oldsha1 SP newsha1 SP committer LF
+
+Where "oldsha1" is the 40 character hexadecimal value previously
+stored in <ref>, "newsha1" is the 40 character hexadecimal value of
+<newvalue> and "committer" is the committer's name, email address
+and date in the standard Git committer ident format.
+
+Optionally with -m:
+
+    oldsha1 SP newsha1 SP committer TAB message LF
+
+Where all fields are as described above and "message" is the
+value supplied to the -m option.
+
+An update will fail (without changing <ref>) if the current user is
+unable to create a new log file, append to the existing log file
+or does not have committer information available.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-update-server-info.txt b/third_party/git/Documentation/git-update-server-info.txt
new file mode 100644
index 0000000000..969bb2e15f
--- /dev/null
+++ b/third_party/git/Documentation/git-update-server-info.txt
@@ -0,0 +1,35 @@
+git-update-server-info(1)
+=========================
+
+NAME
+----
+git-update-server-info - Update auxiliary info file to help dumb servers
+
+
+SYNOPSIS
+--------
+[verse]
+'git update-server-info'
+
+DESCRIPTION
+-----------
+A dumb server that does not do on-the-fly pack generations must
+have some auxiliary information files in $GIT_DIR/info and
+$GIT_OBJECT_DIRECTORY/info directories to help clients discover
+what references and packs the server has.  This command
+generates such auxiliary files.
+
+OUTPUT
+------
+
+Currently the command updates the following files.  Please see
+linkgit:gitrepository-layout[5] for description of
+what they are for:
+
+* objects/info/packs
+
+* info/refs
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-upload-archive.txt b/third_party/git/Documentation/git-upload-archive.txt
new file mode 100644
index 0000000000..fba0f1c1b2
--- /dev/null
+++ b/third_party/git/Documentation/git-upload-archive.txt
@@ -0,0 +1,62 @@
+git-upload-archive(1)
+=====================
+
+NAME
+----
+git-upload-archive - Send archive back to git-archive
+
+
+SYNOPSIS
+--------
+[verse]
+'git upload-archive' <directory>
+
+DESCRIPTION
+-----------
+Invoked by 'git archive --remote' and sends a generated archive to the
+other end over the Git protocol.
+
+This command is usually not invoked directly by the end user.  The UI
+for the protocol is on the 'git archive' side, and the program pair
+is meant to be used to get an archive from a remote repository.
+
+SECURITY
+--------
+
+In order to protect the privacy of objects that have been removed from
+history but may not yet have been pruned, `git-upload-archive` avoids
+serving archives for commits and trees that are not reachable from the
+repository's refs.  However, because calculating object reachability is
+computationally expensive, `git-upload-archive` implements a stricter
+but easier-to-check set of rules:
+
+  1. Clients may request a commit or tree that is pointed to directly by
+     a ref. E.g., `git archive --remote=origin v1.0`.
+
+  2. Clients may request a sub-tree within a commit or tree using the
+     `ref:path` syntax. E.g., `git archive --remote=origin v1.0:Documentation`.
+
+  3. Clients may _not_ use other sha1 expressions, even if the end
+     result is reachable. E.g., neither a relative commit like `master^`
+     nor a literal sha1 like `abcd1234` is allowed, even if the result
+     is reachable from the refs.
+
+Note that rule 3 disallows many cases that do not have any privacy
+implications. These rules are subject to change in future versions of
+git, and the server accessed by `git archive --remote` may or may not
+follow these exact rules.
+
+If the config option `uploadArchive.allowUnreachable` is true, these
+rules are ignored, and clients may use arbitrary sha1 expressions.
+This is useful if you do not care about the privacy of unreachable
+objects, or if your object database is already publicly available for
+access via non-smart-http.
+
+OPTIONS
+-------
+<directory>::
+	The repository to get a tar archive from.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-upload-pack.txt b/third_party/git/Documentation/git-upload-pack.txt
new file mode 100644
index 0000000000..9822c1eb1a
--- /dev/null
+++ b/third_party/git/Documentation/git-upload-pack.txt
@@ -0,0 +1,53 @@
+git-upload-pack(1)
+==================
+
+NAME
+----
+git-upload-pack - Send objects packed back to git-fetch-pack
+
+
+SYNOPSIS
+--------
+[verse]
+'git-upload-pack' [--[no-]strict] [--timeout=<n>] [--stateless-rpc]
+		  [--advertise-refs] <directory>
+
+DESCRIPTION
+-----------
+Invoked by 'git fetch-pack', learns what
+objects the other side is missing, and sends them after packing.
+
+This command is usually not invoked directly by the end user.
+The UI for the protocol is on the 'git fetch-pack' side, and the
+program pair is meant to be used to pull updates from a remote
+repository.  For push operations, see 'git send-pack'.
+
+OPTIONS
+-------
+
+--[no-]strict::
+	Do not try <directory>/.git/ if <directory> is no Git directory.
+
+--timeout=<n>::
+	Interrupt transfer after <n> seconds of inactivity.
+
+--stateless-rpc::
+	Perform only a single read-write cycle with stdin and stdout.
+	This fits with the HTTP POST request processing model where
+	a program may read the request, write a response, and must exit.
+
+--advertise-refs::
+	Only the initial ref advertisement is output, and the program exits
+	immediately. This fits with the HTTP GET request model, where
+	no request content is received but a response must be produced.
+
+<directory>::
+	The repository to sync from.
+
+SEE ALSO
+--------
+linkgit:gitnamespaces[7]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-var.txt b/third_party/git/Documentation/git-var.txt
new file mode 100644
index 0000000000..6072f936ab
--- /dev/null
+++ b/third_party/git/Documentation/git-var.txt
@@ -0,0 +1,70 @@
+git-var(1)
+==========
+
+NAME
+----
+git-var - Show a Git logical variable
+
+
+SYNOPSIS
+--------
+[verse]
+'git var' ( -l | <variable> )
+
+DESCRIPTION
+-----------
+Prints a Git logical variable.
+
+OPTIONS
+-------
+-l::
+	Cause the logical variables to be listed. In addition, all the
+	variables of the Git configuration file .git/config are listed
+	as well. (However, the configuration variables listing functionality
+	is deprecated in favor of `git config -l`.)
+
+EXAMPLES
+--------
+	$ git var GIT_AUTHOR_IDENT
+	Eric W. Biederman <ebiederm@lnxi.com> 1121223278 -0600
+
+
+VARIABLES
+---------
+GIT_AUTHOR_IDENT::
+    The author of a piece of code.
+
+GIT_COMMITTER_IDENT::
+    The person who put a piece of code into Git.
+
+GIT_EDITOR::
+    Text editor for use by Git commands.  The value is meant to be
+    interpreted by the shell when it is used.  Examples: `~/bin/vi`,
+    `$SOME_ENVIRONMENT_VARIABLE`, `"C:\Program Files\Vim\gvim.exe"
+    --nofork`.  The order of preference is the `$GIT_EDITOR`
+    environment variable, then `core.editor` configuration, then
+    `$VISUAL`, then `$EDITOR`, and then the default chosen at compile
+    time, which is usually 'vi'.
+ifdef::git-default-editor[]
+    The build you are using chose '{git-default-editor}' as the default.
+endif::git-default-editor[]
+
+GIT_PAGER::
+    Text viewer for use by Git commands (e.g., 'less').  The value
+    is meant to be interpreted by the shell.  The order of preference
+    is the `$GIT_PAGER` environment variable, then `core.pager`
+    configuration, then `$PAGER`, and then the default chosen at
+    compile time (usually 'less').
+ifdef::git-default-pager[]
+    The build you are using chose '{git-default-pager}' as the default.
+endif::git-default-pager[]
+
+SEE ALSO
+--------
+linkgit:git-commit-tree[1]
+linkgit:git-tag[1]
+linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-verify-commit.txt b/third_party/git/Documentation/git-verify-commit.txt
new file mode 100644
index 0000000000..92097f6673
--- /dev/null
+++ b/third_party/git/Documentation/git-verify-commit.txt
@@ -0,0 +1,32 @@
+git-verify-commit(1)
+====================
+
+NAME
+----
+git-verify-commit - Check the GPG signature of commits
+
+SYNOPSIS
+--------
+[verse]
+'git verify-commit' <commit>...
+
+DESCRIPTION
+-----------
+Validates the GPG signature created by 'git commit -S'.
+
+OPTIONS
+-------
+--raw::
+	Print the raw gpg status output to standard error instead of the normal
+	human-readable output.
+
+-v::
+--verbose::
+	Print the contents of the commit object before validating it.
+
+<commit>...::
+	SHA-1 identifiers of Git commit objects.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-verify-pack.txt b/third_party/git/Documentation/git-verify-pack.txt
new file mode 100644
index 0000000000..61ca6d04c2
--- /dev/null
+++ b/third_party/git/Documentation/git-verify-pack.txt
@@ -0,0 +1,53 @@
+git-verify-pack(1)
+==================
+
+NAME
+----
+git-verify-pack - Validate packed Git archive files
+
+
+SYNOPSIS
+--------
+[verse]
+'git verify-pack' [-v|--verbose] [-s|--stat-only] [--] <pack>.idx ...
+
+
+DESCRIPTION
+-----------
+Reads given idx file for packed Git archive created with the
+'git pack-objects' command and verifies idx file and the
+corresponding pack file.
+
+OPTIONS
+-------
+<pack>.idx ...::
+	The idx files to verify.
+
+-v::
+--verbose::
+	After verifying the pack, show list of objects contained
+	in the pack and a histogram of delta chain length.
+
+-s::
+--stat-only::
+	Do not verify the pack contents; only show the histogram of delta
+	chain length.  With `--verbose`, list of objects is also shown.
+
+\--::
+	Do not interpret any more arguments as options.
+
+OUTPUT FORMAT
+-------------
+When specifying the -v option the format used is:
+
+	SHA-1 type size size-in-packfile offset-in-packfile
+
+for objects that are not deltified in the pack, and
+
+	SHA-1 type size size-in-packfile offset-in-packfile depth base-SHA-1
+
+for objects that are deltified.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-verify-tag.txt b/third_party/git/Documentation/git-verify-tag.txt
new file mode 100644
index 0000000000..0b8075dad9
--- /dev/null
+++ b/third_party/git/Documentation/git-verify-tag.txt
@@ -0,0 +1,32 @@
+git-verify-tag(1)
+=================
+
+NAME
+----
+git-verify-tag - Check the GPG signature of tags
+
+SYNOPSIS
+--------
+[verse]
+'git verify-tag' [--format=<format>] <tag>...
+
+DESCRIPTION
+-----------
+Validates the gpg signature created by 'git tag'.
+
+OPTIONS
+-------
+--raw::
+	Print the raw gpg status output to standard error instead of the normal
+	human-readable output.
+
+-v::
+--verbose::
+	Print the contents of the tag object before validating it.
+
+<tag>...::
+	SHA-1 identifiers of Git tag objects.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-web--browse.txt b/third_party/git/Documentation/git-web--browse.txt
new file mode 100644
index 0000000000..8d162b56c5
--- /dev/null
+++ b/third_party/git/Documentation/git-web--browse.txt
@@ -0,0 +1,124 @@
+git-web{litdd}browse(1)
+=======================
+
+NAME
+----
+git-web--browse - Git helper script to launch a web browser
+
+SYNOPSIS
+--------
+[verse]
+'git web{litdd}browse' [<options>] <url|file>...
+
+DESCRIPTION
+-----------
+
+This script tries, as much as possible, to display the URLs and FILEs
+that are passed as arguments, as HTML pages in new tabs on an already
+opened web browser.
+
+The following browsers (or commands) are currently supported:
+
+* firefox (this is the default under X Window when not using KDE)
+* iceweasel
+* seamonkey
+* iceape
+* chromium (also supported as chromium-browser)
+* google-chrome (also supported as chrome)
+* konqueror (this is the default under KDE, see 'Note about konqueror' below)
+* opera
+* w3m (this is the default outside graphical environments)
+* elinks
+* links
+* lynx
+* dillo
+* open (this is the default under Mac OS X GUI)
+* start (this is the default under MinGW)
+* cygstart (this is the default under Cygwin)
+* xdg-open
+
+Custom commands may also be specified.
+
+OPTIONS
+-------
+-b <browser>::
+--browser=<browser>::
+	Use the specified browser. It must be in the list of supported
+	browsers.
+
+-t <browser>::
+--tool=<browser>::
+	Same as above.
+
+-c <conf.var>::
+--config=<conf.var>::
+	CONF.VAR is looked up in the Git config files. If it's set,
+	then its value specifies the browser that should be used.
+
+CONFIGURATION VARIABLES
+-----------------------
+
+CONF.VAR (from -c option) and web.browser
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The web browser can be specified using a configuration variable passed
+with the -c (or --config) command-line option, or the `web.browser`
+configuration variable if the former is not used.
+
+browser.<tool>.path
+~~~~~~~~~~~~~~~~~~~
+
+You can explicitly provide a full path to your preferred browser by
+setting the configuration variable `browser.<tool>.path`. For example,
+you can configure the absolute path to firefox by setting
+'browser.firefox.path'. Otherwise, 'git web{litdd}browse' assumes the tool
+is available in PATH.
+
+browser.<tool>.cmd
+~~~~~~~~~~~~~~~~~~
+
+When the browser, specified by options or configuration variables, is
+not among the supported ones, then the corresponding
+`browser.<tool>.cmd` configuration variable will be looked up. If this
+variable exists then 'git web{litdd}browse' will treat the specified tool
+as a custom command and will use a shell eval to run the command with
+the URLs passed as arguments.
+
+NOTE ABOUT KONQUEROR
+--------------------
+
+When 'konqueror' is specified by a command-line option or a
+configuration variable, we launch 'kfmclient' to try to open the HTML
+man page on an already opened konqueror in a new tab if possible.
+
+For consistency, we also try such a trick if 'browser.konqueror.path' is
+set to something like `A_PATH_TO/konqueror`. That means we will try to
+launch `A_PATH_TO/kfmclient` instead.
+
+If you really want to use 'konqueror', then you can use something like
+the following:
+
+------------------------------------------------
+	[web]
+		browser = konq
+
+	[browser "konq"]
+		cmd = A_PATH_TO/konqueror
+------------------------------------------------
+
+Note about git-config --global
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Note that these configuration variables should probably be set using
+the `--global` flag, for example like this:
+
+------------------------------------------------
+$ git config --global web.browser firefox
+------------------------------------------------
+
+as they are probably more user specific than repository specific.
+See linkgit:git-config[1] for more information about this.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-whatchanged.txt b/third_party/git/Documentation/git-whatchanged.txt
new file mode 100644
index 0000000000..8b63ceb00e
--- /dev/null
+++ b/third_party/git/Documentation/git-whatchanged.txt
@@ -0,0 +1,43 @@
+git-whatchanged(1)
+==================
+
+NAME
+----
+git-whatchanged - Show logs with difference each commit introduces
+
+
+SYNOPSIS
+--------
+[verse]
+'git whatchanged' <option>...
+
+DESCRIPTION
+-----------
+
+Shows commit logs and diff output each commit introduces.
+
+New users are encouraged to use linkgit:git-log[1] instead.  The
+`whatchanged` command is essentially the same as linkgit:git-log[1]
+but defaults to show the raw format diff output and to skip merges.
+
+The command is kept primarily for historical reasons; fingers of
+many people who learned Git long before `git log` was invented by
+reading Linux kernel mailing list are trained to type it.
+
+
+Examples
+--------
+`git whatchanged -p v2.6.12.. include/scsi drivers/scsi`::
+
+	Show as patches the commits since version 'v2.6.12' that changed
+	any file in the include/scsi or drivers/scsi subdirectories
+
+`git whatchanged --since="2 weeks ago" -- gitk`::
+
+	Show the changes during the last two weeks to the file 'gitk'.
+	The "--" is necessary to avoid confusion with the *branch* named
+	'gitk'
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-worktree.txt b/third_party/git/Documentation/git-worktree.txt
new file mode 100644
index 0000000000..85d92c9761
--- /dev/null
+++ b/third_party/git/Documentation/git-worktree.txt
@@ -0,0 +1,382 @@
+git-worktree(1)
+===============
+
+NAME
+----
+git-worktree - Manage multiple working trees
+
+
+SYNOPSIS
+--------
+[verse]
+'git worktree add' [-f] [--detach] [--checkout] [--lock] [-b <new-branch>] <path> [<commit-ish>]
+'git worktree list' [--porcelain]
+'git worktree lock' [--reason <string>] <worktree>
+'git worktree move' <worktree> <new-path>
+'git worktree prune' [-n] [-v] [--expire <expire>]
+'git worktree remove' [-f] <worktree>
+'git worktree unlock' <worktree>
+
+DESCRIPTION
+-----------
+
+Manage multiple working trees attached to the same repository.
+
+A git repository can support multiple working trees, allowing you to check
+out more than one branch at a time.  With `git worktree add` a new working
+tree is associated with the repository.  This new working tree is called a
+"linked working tree" as opposed to the "main working tree" prepared by "git
+init" or "git clone".  A repository has one main working tree (if it's not a
+bare repository) and zero or more linked working trees. When you are done
+with a linked working tree, remove it with `git worktree remove`.
+
+If a working tree is deleted without using `git worktree remove`, then
+its associated administrative files, which reside in the repository
+(see "DETAILS" below), will eventually be removed automatically (see
+`gc.worktreePruneExpire` in linkgit:git-config[1]), or you can run
+`git worktree prune` in the main or any linked working tree to
+clean up any stale administrative files.
+
+If a linked working tree is stored on a portable device or network share
+which is not always mounted, you can prevent its administrative files from
+being pruned by issuing the `git worktree lock` command, optionally
+specifying `--reason` to explain why the working tree is locked.
+
+COMMANDS
+--------
+add <path> [<commit-ish>]::
+
+Create `<path>` and checkout `<commit-ish>` into it. The new working directory
+is linked to the current repository, sharing everything except working
+directory specific files such as HEAD, index, etc. `-` may also be
+specified as `<commit-ish>`; it is synonymous with `@{-1}`.
++
+If <commit-ish> is a branch name (call it `<branch>`) and is not found,
+and neither `-b` nor `-B` nor `--detach` are used, but there does
+exist a tracking branch in exactly one remote (call it `<remote>`)
+with a matching name, treat as equivalent to:
++
+------------
+$ git worktree add --track -b <branch> <path> <remote>/<branch>
+------------
++
+If the branch exists in multiple remotes and one of them is named by
+the `checkout.defaultRemote` configuration variable, we'll use that
+one for the purposes of disambiguation, even if the `<branch>` isn't
+unique across all remotes. Set it to
+e.g. `checkout.defaultRemote=origin` to always checkout remote
+branches from there if `<branch>` is ambiguous but exists on the
+'origin' remote. See also `checkout.defaultRemote` in
+linkgit:git-config[1].
++
+If `<commit-ish>` is omitted and neither `-b` nor `-B` nor `--detach` used,
+then, as a convenience, the new worktree is associated with a branch
+(call it `<branch>`) named after `$(basename <path>)`.  If `<branch>`
+doesn't exist, a new branch based on HEAD is automatically created as
+if `-b <branch>` was given.  If `<branch>` does exist, it will be
+checked out in the new worktree, if it's not checked out anywhere
+else, otherwise the command will refuse to create the worktree (unless
+`--force` is used).
+
+list::
+
+List details of each worktree.  The main worktree is listed first, followed by
+each of the linked worktrees.  The output details include if the worktree is
+bare, the revision currently checked out, and the branch currently checked out
+(or 'detached HEAD' if none).
+
+lock::
+
+If a working tree is on a portable device or network share which
+is not always mounted, lock it to prevent its administrative
+files from being pruned automatically. This also prevents it from
+being moved or deleted. Optionally, specify a reason for the lock
+with `--reason`.
+
+move::
+
+Move a working tree to a new location. Note that the main working tree
+or linked working trees containing submodules cannot be moved.
+
+prune::
+
+Prune working tree information in $GIT_DIR/worktrees.
+
+remove::
+
+Remove a working tree. Only clean working trees (no untracked files
+and no modification in tracked files) can be removed. Unclean working
+trees or ones with submodules can be removed with `--force`. The main
+working tree cannot be removed.
+
+unlock::
+
+Unlock a working tree, allowing it to be pruned, moved or deleted.
+
+OPTIONS
+-------
+
+-f::
+--force::
+	By default, `add` refuses to create a new working tree when
+	`<commit-ish>` is a branch name and is already checked out by
+	another working tree, or if `<path>` is already assigned to some
+	working tree but is missing (for instance, if `<path>` was deleted
+	manually). This option overrides these safeguards. To add a missing but
+	locked working tree path, specify `--force` twice.
++
+`move` refuses to move a locked working tree unless `--force` is specified
+twice.
++
+`remove` refuses to remove an unclean working tree unless `--force` is used.
+To remove a locked working tree, specify `--force` twice.
+
+-b <new-branch>::
+-B <new-branch>::
+	With `add`, create a new branch named `<new-branch>` starting at
+	`<commit-ish>`, and check out `<new-branch>` into the new working tree.
+	If `<commit-ish>` is omitted, it defaults to HEAD.
+	By default, `-b` refuses to create a new branch if it already
+	exists. `-B` overrides this safeguard, resetting `<new-branch>` to
+	`<commit-ish>`.
+
+--detach::
+	With `add`, detach HEAD in the new working tree. See "DETACHED HEAD"
+	in linkgit:git-checkout[1].
+
+--[no-]checkout::
+	By default, `add` checks out `<commit-ish>`, however, `--no-checkout` can
+	be used to suppress checkout in order to make customizations,
+	such as configuring sparse-checkout. See "Sparse checkout"
+	in linkgit:git-read-tree[1].
+
+--[no-]guess-remote::
+	With `worktree add <path>`, without `<commit-ish>`, instead
+	of creating a new branch from HEAD, if there exists a tracking
+	branch in exactly one remote matching the basename of `<path>`,
+	base the new branch on the remote-tracking branch, and mark
+	the remote-tracking branch as "upstream" from the new branch.
++
+This can also be set up as the default behaviour by using the
+`worktree.guessRemote` config option.
+
+--[no-]track::
+	When creating a new branch, if `<commit-ish>` is a branch,
+	mark it as "upstream" from the new branch.  This is the
+	default if `<commit-ish>` is a remote-tracking branch.  See
+	"--track" in linkgit:git-branch[1] for details.
+
+--lock::
+	Keep the working tree locked after creation. This is the
+	equivalent of `git worktree lock` after `git worktree add`,
+	but without race condition.
+
+-n::
+--dry-run::
+	With `prune`, do not remove anything; just report what it would
+	remove.
+
+--porcelain::
+	With `list`, output in an easy-to-parse format for scripts.
+	This format will remain stable across Git versions and regardless of user
+	configuration.  See below for details.
+
+-q::
+--quiet::
+	With 'add', suppress feedback messages.
+
+-v::
+--verbose::
+	With `prune`, report all removals.
+
+--expire <time>::
+	With `prune`, only expire unused working trees older than <time>.
+
+--reason <string>::
+	With `lock`, an explanation why the working tree is locked.
+
+<worktree>::
+	Working trees can be identified by path, either relative or
+	absolute.
++
+If the last path components in the working tree's path is unique among
+working trees, it can be used to identify worktrees. For example if
+you only have two working trees, at "/abc/def/ghi" and "/abc/def/ggg",
+then "ghi" or "def/ghi" is enough to point to the former working tree.
+
+REFS
+----
+In multiple working trees, some refs may be shared between all working
+trees, some refs are local. One example is HEAD is different for all
+working trees. This section is about the sharing rules and how to access
+refs of one working tree from another.
+
+In general, all pseudo refs are per working tree and all refs starting
+with "refs/" are shared. Pseudo refs are ones like HEAD which are
+directly under GIT_DIR instead of inside GIT_DIR/refs. There is one
+exception to this: refs inside refs/bisect and refs/worktree is not
+shared.
+
+Refs that are per working tree can still be accessed from another
+working tree via two special paths, main-worktree and worktrees. The
+former gives access to per-worktree refs of the main working tree,
+while the latter to all linked working trees.
+
+For example, main-worktree/HEAD or main-worktree/refs/bisect/good
+resolve to the same value as the main working tree's HEAD and
+refs/bisect/good respectively. Similarly, worktrees/foo/HEAD or
+worktrees/bar/refs/bisect/bad are the same as
+GIT_COMMON_DIR/worktrees/foo/HEAD and
+GIT_COMMON_DIR/worktrees/bar/refs/bisect/bad.
+
+To access refs, it's best not to look inside GIT_DIR directly. Instead
+use commands such as linkgit:git-rev-parse[1] or linkgit:git-update-ref[1]
+which will handle refs correctly.
+
+CONFIGURATION FILE
+------------------
+By default, the repository "config" file is shared across all working
+trees. If the config variables `core.bare` or `core.worktree` are
+already present in the config file, they will be applied to the main
+working trees only.
+
+In order to have configuration specific to working trees, you can turn
+on "worktreeConfig" extension, e.g.:
+
+------------
+$ git config extensions.worktreeConfig true
+------------
+
+In this mode, specific configuration stays in the path pointed by `git
+rev-parse --git-path config.worktree`. You can add or update
+configuration in this file with `git config --worktree`. Older Git
+versions will refuse to access repositories with this extension.
+
+Note that in this file, the exception for `core.bare` and `core.worktree`
+is gone. If you have them in $GIT_DIR/config before, you must move
+them to the `config.worktree` of the main working tree. You may also
+take this opportunity to review and move other configuration that you
+do not want to share to all working trees:
+
+ - `core.worktree` and `core.bare` should never be shared
+
+ - `core.sparseCheckout` is recommended per working tree, unless you
+   are sure you always use sparse checkout for all working trees.
+
+DETAILS
+-------
+Each linked working tree has a private sub-directory in the repository's
+$GIT_DIR/worktrees directory.  The private sub-directory's name is usually
+the base name of the linked working tree's path, possibly appended with a
+number to make it unique.  For example, when `$GIT_DIR=/path/main/.git` the
+command `git worktree add /path/other/test-next next` creates the linked
+working tree in `/path/other/test-next` and also creates a
+`$GIT_DIR/worktrees/test-next` directory (or `$GIT_DIR/worktrees/test-next1`
+if `test-next` is already taken).
+
+Within a linked working tree, $GIT_DIR is set to point to this private
+directory (e.g. `/path/main/.git/worktrees/test-next` in the example) and
+$GIT_COMMON_DIR is set to point back to the main working tree's $GIT_DIR
+(e.g. `/path/main/.git`). These settings are made in a `.git` file located at
+the top directory of the linked working tree.
+
+Path resolution via `git rev-parse --git-path` uses either
+$GIT_DIR or $GIT_COMMON_DIR depending on the path. For example, in the
+linked working tree `git rev-parse --git-path HEAD` returns
+`/path/main/.git/worktrees/test-next/HEAD` (not
+`/path/other/test-next/.git/HEAD` or `/path/main/.git/HEAD`) while `git
+rev-parse --git-path refs/heads/master` uses
+$GIT_COMMON_DIR and returns `/path/main/.git/refs/heads/master`,
+since refs are shared across all working trees, except refs/bisect and
+refs/worktree.
+
+See linkgit:gitrepository-layout[5] for more information. The rule of
+thumb is do not make any assumption about whether a path belongs to
+$GIT_DIR or $GIT_COMMON_DIR when you need to directly access something
+inside $GIT_DIR. Use `git rev-parse --git-path` to get the final path.
+
+If you manually move a linked working tree, you need to update the 'gitdir' file
+in the entry's directory. For example, if a linked working tree is moved
+to `/newpath/test-next` and its `.git` file points to
+`/path/main/.git/worktrees/test-next`, then update
+`/path/main/.git/worktrees/test-next/gitdir` to reference `/newpath/test-next`
+instead.
+
+To prevent a $GIT_DIR/worktrees entry from being pruned (which
+can be useful in some situations, such as when the
+entry's working tree is stored on a portable device), use the
+`git worktree lock` command, which adds a file named
+'locked' to the entry's directory. The file contains the reason in
+plain text. For example, if a linked working tree's `.git` file points
+to `/path/main/.git/worktrees/test-next` then a file named
+`/path/main/.git/worktrees/test-next/locked` will prevent the
+`test-next` entry from being pruned.  See
+linkgit:gitrepository-layout[5] for details.
+
+When extensions.worktreeConfig is enabled, the config file
+`.git/worktrees/<id>/config.worktree` is read after `.git/config` is.
+
+LIST OUTPUT FORMAT
+------------------
+The worktree list command has two output formats.  The default format shows the
+details on a single line with columns.  For example:
+
+------------
+$ git worktree list
+/path/to/bare-source            (bare)
+/path/to/linked-worktree        abcd1234 [master]
+/path/to/other-linked-worktree  1234abc  (detached HEAD)
+------------
+
+Porcelain Format
+~~~~~~~~~~~~~~~~
+The porcelain format has a line per attribute.  Attributes are listed with a
+label and value separated by a single space.  Boolean attributes (like 'bare'
+and 'detached') are listed as a label only, and are only present if and only
+if the value is true.  The first attribute of a worktree is always `worktree`,
+an empty line indicates the end of the record.  For example:
+
+------------
+$ git worktree list --porcelain
+worktree /path/to/bare-source
+bare
+
+worktree /path/to/linked-worktree
+HEAD abcd1234abcd1234abcd1234abcd1234abcd1234
+branch refs/heads/master
+
+worktree /path/to/other-linked-worktree
+HEAD 1234abc1234abc1234abc1234abc1234abc1234a
+detached
+
+------------
+
+EXAMPLES
+--------
+You are in the middle of a refactoring session and your boss comes in and
+demands that you fix something immediately. You might typically use
+linkgit:git-stash[1] to store your changes away temporarily, however, your
+working tree is in such a state of disarray (with new, moved, and removed
+files, and other bits and pieces strewn around) that you don't want to risk
+disturbing any of it. Instead, you create a temporary linked working tree to
+make the emergency fix, remove it when done, and then resume your earlier
+refactoring session.
+
+------------
+$ git worktree add -b emergency-fix ../temp master
+$ pushd ../temp
+# ... hack hack hack ...
+$ git commit -a -m 'emergency fix for boss'
+$ popd
+$ git worktree remove ../temp
+------------
+
+BUGS
+----
+Multiple checkout in general is still experimental, and the support
+for submodules is incomplete. It is NOT recommended to make multiple
+checkouts of a superproject.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git-write-tree.txt b/third_party/git/Documentation/git-write-tree.txt
new file mode 100644
index 0000000000..f22041a9dc
--- /dev/null
+++ b/third_party/git/Documentation/git-write-tree.txt
@@ -0,0 +1,42 @@
+git-write-tree(1)
+=================
+
+NAME
+----
+git-write-tree - Create a tree object from the current index
+
+
+SYNOPSIS
+--------
+[verse]
+'git write-tree' [--missing-ok] [--prefix=<prefix>/]
+
+DESCRIPTION
+-----------
+Creates a tree object using the current index. The name of the new
+tree object is printed to standard output.
+
+The index must be in a fully merged state.
+
+Conceptually, 'git write-tree' sync()s the current index contents
+into a set of tree files.
+In order to have that match what is actually in your directory right
+now, you need to have done a 'git update-index' phase before you did the
+'git write-tree'.
+
+
+OPTIONS
+-------
+--missing-ok::
+	Normally 'git write-tree' ensures that the objects referenced by the
+	directory exist in the object database.  This option disables this
+	check.
+
+--prefix=<prefix>/::
+	Writes a tree object that represents a subdirectory
+	`<prefix>`.  This can be used to write the tree object
+	for a subproject that is in the named subdirectory.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/git.txt b/third_party/git/Documentation/git.txt
new file mode 100644
index 0000000000..9b82564d1a
--- /dev/null
+++ b/third_party/git/Documentation/git.txt
@@ -0,0 +1,947 @@
+git(1)
+======
+
+NAME
+----
+git - the stupid content tracker
+
+
+SYNOPSIS
+--------
+[verse]
+'git' [--version] [--help] [-C <path>] [-c <name>=<value>]
+    [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]
+    [-p|--paginate|-P|--no-pager] [--no-replace-objects] [--bare]
+    [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]
+    [--super-prefix=<path>]
+    <command> [<args>]
+
+DESCRIPTION
+-----------
+Git is a fast, scalable, distributed revision control system with an
+unusually rich command set that provides both high-level operations
+and full access to internals.
+
+See linkgit:gittutorial[7] to get started, then see
+linkgit:giteveryday[7] for a useful minimum set of
+commands.  The link:user-manual.html[Git User's Manual] has a more
+in-depth introduction.
+
+After you mastered the basic concepts, you can come back to this
+page to learn what commands Git offers.  You can learn more about
+individual Git commands with "git help command".  linkgit:gitcli[7]
+manual page gives you an overview of the command-line command syntax.
+
+A formatted and hyperlinked copy of the latest Git documentation
+can be viewed at https://git.github.io/htmldocs/git.html
+or https://git-scm.com/docs.
+
+
+OPTIONS
+-------
+--version::
+	Prints the Git suite version that the 'git' program came from.
+
+--help::
+	Prints the synopsis and a list of the most commonly used
+	commands. If the option `--all` or `-a` is given then all
+	available commands are printed. If a Git command is named this
+	option will bring up the manual page for that command.
++
+Other options are available to control how the manual page is
+displayed. See linkgit:git-help[1] for more information,
+because `git --help ...` is converted internally into `git
+help ...`.
+
+-C <path>::
+	Run as if git was started in '<path>' instead of the current working
+	directory.  When multiple `-C` options are given, each subsequent
+	non-absolute `-C <path>` is interpreted relative to the preceding `-C
+	<path>`.  If '<path>' is present but empty, e.g. `-C ""`, then the
+	current working directory is left unchanged.
++
+This option affects options that expect path name like `--git-dir` and
+`--work-tree` in that their interpretations of the path names would be
+made relative to the working directory caused by the `-C` option. For
+example the following invocations are equivalent:
+
+    git --git-dir=a.git --work-tree=b -C c status
+    git --git-dir=c/a.git --work-tree=c/b status
+
+-c <name>=<value>::
+	Pass a configuration parameter to the command. The value
+	given will override values from configuration files.
+	The <name> is expected in the same format as listed by
+	'git config' (subkeys separated by dots).
++
+Note that omitting the `=` in `git -c foo.bar ...` is allowed and sets
+`foo.bar` to the boolean true value (just like `[foo]bar` would in a
+config file). Including the equals but with an empty value (like `git -c
+foo.bar= ...`) sets `foo.bar` to the empty string which `git config
+--type=bool` will convert to `false`.
+
+--exec-path[=<path>]::
+	Path to wherever your core Git programs are installed.
+	This can also be controlled by setting the GIT_EXEC_PATH
+	environment variable. If no path is given, 'git' will print
+	the current setting and then exit.
+
+--html-path::
+	Print the path, without trailing slash, where Git's HTML
+	documentation is installed and exit.
+
+--man-path::
+	Print the manpath (see `man(1)`) for the man pages for
+	this version of Git and exit.
+
+--info-path::
+	Print the path where the Info files documenting this
+	version of Git are installed and exit.
+
+-p::
+--paginate::
+	Pipe all output into 'less' (or if set, $PAGER) if standard
+	output is a terminal.  This overrides the `pager.<cmd>`
+	configuration options (see the "Configuration Mechanism" section
+	below).
+
+-P::
+--no-pager::
+	Do not pipe Git output into a pager.
+
+--git-dir=<path>::
+	Set the path to the repository. This can also be controlled by
+	setting the `GIT_DIR` environment variable. It can be an absolute
+	path or relative path to current working directory.
+
+--work-tree=<path>::
+	Set the path to the working tree. It can be an absolute path
+	or a path relative to the current working directory.
+	This can also be controlled by setting the GIT_WORK_TREE
+	environment variable and the core.worktree configuration
+	variable (see core.worktree in linkgit:git-config[1] for a
+	more detailed discussion).
+
+--namespace=<path>::
+	Set the Git namespace.  See linkgit:gitnamespaces[7] for more
+	details.  Equivalent to setting the `GIT_NAMESPACE` environment
+	variable.
+
+--super-prefix=<path>::
+	Currently for internal use only.  Set a prefix which gives a path from
+	above a repository down to its root.  One use is to give submodules
+	context about the superproject that invoked it.
+
+--bare::
+	Treat the repository as a bare repository.  If GIT_DIR
+	environment is not set, it is set to the current working
+	directory.
+
+--no-replace-objects::
+	Do not use replacement refs to replace Git objects. See
+	linkgit:git-replace[1] for more information.
+
+--literal-pathspecs::
+	Treat pathspecs literally (i.e. no globbing, no pathspec magic).
+	This is equivalent to setting the `GIT_LITERAL_PATHSPECS` environment
+	variable to `1`.
+
+--glob-pathspecs::
+	Add "glob" magic to all pathspec. This is equivalent to setting
+	the `GIT_GLOB_PATHSPECS` environment variable to `1`. Disabling
+	globbing on individual pathspecs can be done using pathspec
+	magic ":(literal)"
+
+--noglob-pathspecs::
+	Add "literal" magic to all pathspec. This is equivalent to setting
+	the `GIT_NOGLOB_PATHSPECS` environment variable to `1`. Enabling
+	globbing on individual pathspecs can be done using pathspec
+	magic ":(glob)"
+
+--icase-pathspecs::
+	Add "icase" magic to all pathspec. This is equivalent to setting
+	the `GIT_ICASE_PATHSPECS` environment variable to `1`.
+
+--no-optional-locks::
+	Do not perform optional operations that require locks. This is
+	equivalent to setting the `GIT_OPTIONAL_LOCKS` to `0`.
+
+--list-cmds=group[,group...]::
+	List commands by group. This is an internal/experimental
+	option and may change or be removed in the future. Supported
+	groups are: builtins, parseopt (builtin commands that use
+	parse-options), main (all commands in libexec directory),
+	others (all other commands in `$PATH` that have git- prefix),
+	list-<category> (see categories in command-list.txt),
+	nohelpers (exclude helper commands), alias and config
+	(retrieve command list from config variable completion.commands)
+
+GIT COMMANDS
+------------
+
+We divide Git into high level ("porcelain") commands and low level
+("plumbing") commands.
+
+High-level commands (porcelain)
+-------------------------------
+
+We separate the porcelain commands into the main commands and some
+ancillary user utilities.
+
+Main porcelain commands
+~~~~~~~~~~~~~~~~~~~~~~~
+
+include::cmds-mainporcelain.txt[]
+
+Ancillary Commands
+~~~~~~~~~~~~~~~~~~
+Manipulators:
+
+include::cmds-ancillarymanipulators.txt[]
+
+Interrogators:
+
+include::cmds-ancillaryinterrogators.txt[]
+
+
+Interacting with Others
+~~~~~~~~~~~~~~~~~~~~~~~
+
+These commands are to interact with foreign SCM and with other
+people via patch over e-mail.
+
+include::cmds-foreignscminterface.txt[]
+
+Reset, restore and revert
+~~~~~~~~~~~~~~~~~~~~~~~~~
+There are three commands with similar names: `git reset`,
+`git restore` and `git revert`.
+
+* linkgit:git-revert[1] is about making a new commit that reverts the
+  changes made by other commits.
+
+* linkgit:git-restore[1] is about restoring files in the working tree
+  from either the index or another commit. This command does not
+  update your branch. The command can also be used to restore files in
+  the index from another commit.
+
+* linkgit:git-reset[1] is about updating your branch, moving the tip
+  in order to add or remove commits from the branch. This operation
+  changes the commit history.
++
+`git reset` can also be used to restore the index, overlapping with
+`git restore`.
+
+
+Low-level commands (plumbing)
+-----------------------------
+
+Although Git includes its
+own porcelain layer, its low-level commands are sufficient to support
+development of alternative porcelains.  Developers of such porcelains
+might start by reading about linkgit:git-update-index[1] and
+linkgit:git-read-tree[1].
+
+The interface (input, output, set of options and the semantics)
+to these low-level commands are meant to be a lot more stable
+than Porcelain level commands, because these commands are
+primarily for scripted use.  The interface to Porcelain commands
+on the other hand are subject to change in order to improve the
+end user experience.
+
+The following description divides
+the low-level commands into commands that manipulate objects (in
+the repository, index, and working tree), commands that interrogate and
+compare objects, and commands that move objects and references between
+repositories.
+
+
+Manipulation commands
+~~~~~~~~~~~~~~~~~~~~~
+
+include::cmds-plumbingmanipulators.txt[]
+
+
+Interrogation commands
+~~~~~~~~~~~~~~~~~~~~~~
+
+include::cmds-plumbinginterrogators.txt[]
+
+In general, the interrogate commands do not touch the files in
+the working tree.
+
+
+Synching repositories
+~~~~~~~~~~~~~~~~~~~~~
+
+include::cmds-synchingrepositories.txt[]
+
+The following are helper commands used by the above; end users
+typically do not use them directly.
+
+include::cmds-synchelpers.txt[]
+
+
+Internal helper commands
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+These are internal helper commands used by other commands; end
+users typically do not use them directly.
+
+include::cmds-purehelpers.txt[]
+
+
+Configuration Mechanism
+-----------------------
+
+Git uses a simple text format to store customizations that are per
+repository and are per user.  Such a configuration file may look
+like this:
+
+------------
+#
+# A '#' or ';' character indicates a comment.
+#
+
+; core variables
+[core]
+	; Don't trust file modes
+	filemode = false
+
+; user identity
+[user]
+	name = "Junio C Hamano"
+	email = "gitster@pobox.com"
+
+------------
+
+Various commands read from the configuration file and adjust
+their operation accordingly.  See linkgit:git-config[1] for a
+list and more details about the configuration mechanism.
+
+
+Identifier Terminology
+----------------------
+<object>::
+	Indicates the object name for any type of object.
+
+<blob>::
+	Indicates a blob object name.
+
+<tree>::
+	Indicates a tree object name.
+
+<commit>::
+	Indicates a commit object name.
+
+<tree-ish>::
+	Indicates a tree, commit or tag object name.  A
+	command that takes a <tree-ish> argument ultimately wants to
+	operate on a <tree> object but automatically dereferences
+	<commit> and <tag> objects that point at a <tree>.
+
+<commit-ish>::
+	Indicates a commit or tag object name.  A
+	command that takes a <commit-ish> argument ultimately wants to
+	operate on a <commit> object but automatically dereferences
+	<tag> objects that point at a <commit>.
+
+<type>::
+	Indicates that an object type is required.
+	Currently one of: `blob`, `tree`, `commit`, or `tag`.
+
+<file>::
+	Indicates a filename - almost always relative to the
+	root of the tree structure `GIT_INDEX_FILE` describes.
+
+Symbolic Identifiers
+--------------------
+Any Git command accepting any <object> can also use the following
+symbolic notation:
+
+HEAD::
+	indicates the head of the current branch.
+
+<tag>::
+	a valid tag 'name'
+	(i.e. a `refs/tags/<tag>` reference).
+
+<head>::
+	a valid head 'name'
+	(i.e. a `refs/heads/<head>` reference).
+
+For a more complete list of ways to spell object names, see
+"SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
+
+
+File/Directory Structure
+------------------------
+
+Please see the linkgit:gitrepository-layout[5] document.
+
+Read linkgit:githooks[5] for more details about each hook.
+
+Higher level SCMs may provide and manage additional information in the
+`$GIT_DIR`.
+
+
+Terminology
+-----------
+Please see linkgit:gitglossary[7].
+
+
+Environment Variables
+---------------------
+Various Git commands use the following environment variables:
+
+The Git Repository
+~~~~~~~~~~~~~~~~~~
+These environment variables apply to 'all' core Git commands. Nb: it
+is worth noting that they may be used/overridden by SCMS sitting above
+Git so take care if using a foreign front-end.
+
+`GIT_INDEX_FILE`::
+	This environment allows the specification of an alternate
+	index file. If not specified, the default of `$GIT_DIR/index`
+	is used.
+
+`GIT_INDEX_VERSION`::
+	This environment variable allows the specification of an index
+	version for new repositories.  It won't affect existing index
+	files.  By default index file version 2 or 3 is used. See
+	linkgit:git-update-index[1] for more information.
+
+`GIT_OBJECT_DIRECTORY`::
+	If the object storage directory is specified via this
+	environment variable then the sha1 directories are created
+	underneath - otherwise the default `$GIT_DIR/objects`
+	directory is used.
+
+`GIT_ALTERNATE_OBJECT_DIRECTORIES`::
+	Due to the immutable nature of Git objects, old objects can be
+	archived into shared, read-only directories. This variable
+	specifies a ":" separated (on Windows ";" separated) list
+	of Git object directories which can be used to search for Git
+	objects. New objects will not be written to these directories.
++
+Entries that begin with `"` (double-quote) will be interpreted
+as C-style quoted paths, removing leading and trailing
+double-quotes and respecting backslash escapes. E.g., the value
+`"path-with-\"-and-:-in-it":vanilla-path` has two paths:
+`path-with-"-and-:-in-it` and `vanilla-path`.
+
+`GIT_DIR`::
+	If the `GIT_DIR` environment variable is set then it
+	specifies a path to use instead of the default `.git`
+	for the base of the repository.
+	The `--git-dir` command-line option also sets this value.
+
+`GIT_WORK_TREE`::
+	Set the path to the root of the working tree.
+	This can also be controlled by the `--work-tree` command-line
+	option and the core.worktree configuration variable.
+
+`GIT_NAMESPACE`::
+	Set the Git namespace; see linkgit:gitnamespaces[7] for details.
+	The `--namespace` command-line option also sets this value.
+
+`GIT_CEILING_DIRECTORIES`::
+	This should be a colon-separated list of absolute paths.  If
+	set, it is a list of directories that Git should not chdir up
+	into while looking for a repository directory (useful for
+	excluding slow-loading network directories).  It will not
+	exclude the current working directory or a GIT_DIR set on the
+	command line or in the environment.  Normally, Git has to read
+	the entries in this list and resolve any symlink that
+	might be present in order to compare them with the current
+	directory.  However, if even this access is slow, you
+	can add an empty entry to the list to tell Git that the
+	subsequent entries are not symlinks and needn't be resolved;
+	e.g.,
+	`GIT_CEILING_DIRECTORIES=/maybe/symlink::/very/slow/non/symlink`.
+
+`GIT_DISCOVERY_ACROSS_FILESYSTEM`::
+	When run in a directory that does not have ".git" repository
+	directory, Git tries to find such a directory in the parent
+	directories to find the top of the working tree, but by default it
+	does not cross filesystem boundaries.  This environment variable
+	can be set to true to tell Git not to stop at filesystem
+	boundaries.  Like `GIT_CEILING_DIRECTORIES`, this will not affect
+	an explicit repository directory set via `GIT_DIR` or on the
+	command line.
+
+`GIT_COMMON_DIR`::
+	If this variable is set to a path, non-worktree files that are
+	normally in $GIT_DIR will be taken from this path
+	instead. Worktree-specific files such as HEAD or index are
+	taken from $GIT_DIR. See linkgit:gitrepository-layout[5] and
+	linkgit:git-worktree[1] for
+	details. This variable has lower precedence than other path
+	variables such as GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY...
+
+Git Commits
+~~~~~~~~~~~
+`GIT_AUTHOR_NAME`::
+`GIT_AUTHOR_EMAIL`::
+`GIT_AUTHOR_DATE`::
+`GIT_COMMITTER_NAME`::
+`GIT_COMMITTER_EMAIL`::
+`GIT_COMMITTER_DATE`::
+'EMAIL'::
+	see linkgit:git-commit-tree[1]
+
+Git Diffs
+~~~~~~~~~
+`GIT_DIFF_OPTS`::
+	Only valid setting is "--unified=??" or "-u??" to set the
+	number of context lines shown when a unified diff is created.
+	This takes precedence over any "-U" or "--unified" option
+	value passed on the Git diff command line.
+
+`GIT_EXTERNAL_DIFF`::
+	When the environment variable `GIT_EXTERNAL_DIFF` is set, the
+	program named by it is called, instead of the diff invocation
+	described above.  For a path that is added, removed, or modified,
+	`GIT_EXTERNAL_DIFF` is called with 7 parameters:
+
+	path old-file old-hex old-mode new-file new-hex new-mode
++
+where:
+
+	<old|new>-file:: are files GIT_EXTERNAL_DIFF can use to read the
+                         contents of <old|new>,
+	<old|new>-hex:: are the 40-hexdigit SHA-1 hashes,
+	<old|new>-mode:: are the octal representation of the file modes.
++
+The file parameters can point at the user's working file
+(e.g. `new-file` in "git-diff-files"), `/dev/null` (e.g. `old-file`
+when a new file is added), or a temporary file (e.g. `old-file` in the
+index).  `GIT_EXTERNAL_DIFF` should not worry about unlinking the
+temporary file --- it is removed when `GIT_EXTERNAL_DIFF` exits.
++
+For a path that is unmerged, `GIT_EXTERNAL_DIFF` is called with 1
+parameter, <path>.
++
+For each path `GIT_EXTERNAL_DIFF` is called, two environment variables,
+`GIT_DIFF_PATH_COUNTER` and `GIT_DIFF_PATH_TOTAL` are set.
+
+`GIT_DIFF_PATH_COUNTER`::
+	A 1-based counter incremented by one for every path.
+
+`GIT_DIFF_PATH_TOTAL`::
+	The total number of paths.
+
+other
+~~~~~
+`GIT_MERGE_VERBOSITY`::
+	A number controlling the amount of output shown by
+	the recursive merge strategy.  Overrides merge.verbosity.
+	See linkgit:git-merge[1]
+
+`GIT_PAGER`::
+	This environment variable overrides `$PAGER`. If it is set
+	to an empty string or to the value "cat", Git will not launch
+	a pager.  See also the `core.pager` option in
+	linkgit:git-config[1].
+
+`GIT_EDITOR`::
+	This environment variable overrides `$EDITOR` and `$VISUAL`.
+	It is used by several Git commands when, on interactive mode,
+	an editor is to be launched. See also linkgit:git-var[1]
+	and the `core.editor` option in linkgit:git-config[1].
+
+`GIT_SSH`::
+`GIT_SSH_COMMAND`::
+	If either of these environment variables is set then 'git fetch'
+	and 'git push' will use the specified command instead of 'ssh'
+	when they need to connect to a remote system.
+	The command-line parameters passed to the configured command are
+	determined by the ssh variant.  See `ssh.variant` option in
+	linkgit:git-config[1] for details.
++
+`$GIT_SSH_COMMAND` takes precedence over `$GIT_SSH`, and is interpreted
+by the shell, which allows additional arguments to be included.
+`$GIT_SSH` on the other hand must be just the path to a program
+(which can be a wrapper shell script, if additional arguments are
+needed).
++
+Usually it is easier to configure any desired options through your
+personal `.ssh/config` file.  Please consult your ssh documentation
+for further details.
+
+`GIT_SSH_VARIANT`::
+	If this environment variable is set, it overrides Git's autodetection
+	whether `GIT_SSH`/`GIT_SSH_COMMAND`/`core.sshCommand` refer to OpenSSH,
+	plink or tortoiseplink. This variable overrides the config setting
+	`ssh.variant` that serves the same purpose.
+
+`GIT_ASKPASS`::
+	If this environment variable is set, then Git commands which need to
+	acquire passwords or passphrases (e.g. for HTTP or IMAP authentication)
+	will call this program with a suitable prompt as command-line argument
+	and read the password from its STDOUT. See also the `core.askPass`
+	option in linkgit:git-config[1].
+
+`GIT_TERMINAL_PROMPT`::
+	If this environment variable is set to `0`, git will not prompt
+	on the terminal (e.g., when asking for HTTP authentication).
+
+`GIT_CONFIG_NOSYSTEM`::
+	Whether to skip reading settings from the system-wide
+	`$(prefix)/etc/gitconfig` file.  This environment variable can
+	be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a
+	predictable environment for a picky script, or you can set it
+	temporarily to avoid using a buggy `/etc/gitconfig` file while
+	waiting for someone with sufficient permissions to fix it.
+
+`GIT_FLUSH`::
+	If this environment variable is set to "1", then commands such
+	as 'git blame' (in incremental mode), 'git rev-list', 'git log',
+	'git check-attr' and 'git check-ignore' will
+	force a flush of the output stream after each record have been
+	flushed. If this
+	variable is set to "0", the output of these commands will be done
+	using completely buffered I/O.   If this environment variable is
+	not set, Git will choose buffered or record-oriented flushing
+	based on whether stdout appears to be redirected to a file or not.
+
+`GIT_TRACE`::
+	Enables general trace messages, e.g. alias expansion, built-in
+	command execution and external command execution.
++
+If this variable is set to "1", "2" or "true" (comparison
+is case insensitive), trace messages will be printed to
+stderr.
++
+If the variable is set to an integer value greater than 2
+and lower than 10 (strictly) then Git will interpret this
+value as an open file descriptor and will try to write the
+trace messages into this file descriptor.
++
+Alternatively, if the variable is set to an absolute path
+(starting with a '/' character), Git will interpret this
+as a file path and will try to append the trace messages
+to it.
++
+Unsetting the variable, or setting it to empty, "0" or
+"false" (case insensitive) disables trace messages.
+
+`GIT_TRACE_FSMONITOR`::
+	Enables trace messages for the filesystem monitor extension.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_PACK_ACCESS`::
+	Enables trace messages for all accesses to any packs. For each
+	access, the pack file name and an offset in the pack is
+	recorded. This may be helpful for troubleshooting some
+	pack-related performance problems.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_PACKET`::
+	Enables trace messages for all packets coming in or out of a
+	given program. This can help with debugging object negotiation
+	or other protocol issues. Tracing is turned off at a packet
+	starting with "PACK" (but see `GIT_TRACE_PACKFILE` below).
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_PACKFILE`::
+	Enables tracing of packfiles sent or received by a
+	given program. Unlike other trace output, this trace is
+	verbatim: no headers, and no quoting of binary data. You almost
+	certainly want to direct into a file (e.g.,
+	`GIT_TRACE_PACKFILE=/tmp/my.pack`) rather than displaying it on
+	the terminal or mixing it with other trace output.
++
+Note that this is currently only implemented for the client side
+of clones and fetches.
+
+`GIT_TRACE_PERFORMANCE`::
+	Enables performance related trace messages, e.g. total execution
+	time of each Git command.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_SETUP`::
+	Enables trace messages printing the .git, working tree and current
+	working directory after Git has completed its setup phase.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_SHALLOW`::
+	Enables trace messages that can help debugging fetching /
+	cloning of shallow repositories.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_CURL`::
+	Enables a curl full trace dump of all incoming and outgoing data,
+	including descriptive information, of the git transport protocol.
+	This is similar to doing curl `--trace-ascii` on the command line.
+	This option overrides setting the `GIT_CURL_VERBOSE` environment
+	variable.
+	See `GIT_TRACE` for available trace output options.
+
+`GIT_TRACE_CURL_NO_DATA`::
+	When a curl trace is enabled (see `GIT_TRACE_CURL` above), do not dump
+	data (that is, only dump info lines and headers).
+
+`GIT_TRACE2`::
+	Enables more detailed trace messages from the "trace2" library.
+	Output from `GIT_TRACE2` is a simple text-based format for human
+	readability.
++
+If this variable is set to "1", "2" or "true" (comparison
+is case insensitive), trace messages will be printed to
+stderr.
++
+If the variable is set to an integer value greater than 2
+and lower than 10 (strictly) then Git will interpret this
+value as an open file descriptor and will try to write the
+trace messages into this file descriptor.
++
+Alternatively, if the variable is set to an absolute path
+(starting with a '/' character), Git will interpret this
+as a file path and will try to append the trace messages
+to it.  If the path already exists and is a directory, the
+trace messages will be written to files (one per process)
+in that directory, named according to the last component
+of the SID and an optional counter (to avoid filename
+collisions).
++
+In addition, if the variable is set to
+`af_unix:[<socket_type>:]<absolute-pathname>`, Git will try
+to open the path as a Unix Domain Socket.  The socket type
+can be either `stream` or `dgram`.
++
+Unsetting the variable, or setting it to empty, "0" or
+"false" (case insensitive) disables trace messages.
++
+See link:technical/api-trace2.html[Trace2 documentation]
+for full details.
+
+
+`GIT_TRACE2_EVENT`::
+	This setting writes a JSON-based format that is suited for machine
+	interpretation.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
+
+`GIT_TRACE2_PERF`::
+	In addition to the text-based messages available in `GIT_TRACE2`, this
+	setting writes a column-based format for understanding nesting
+	regions.
+	See `GIT_TRACE2` for available trace output options and
+	link:technical/api-trace2.html[Trace2 documentation] for full details.
+
+`GIT_REDACT_COOKIES`::
+	This can be set to a comma-separated list of strings. When a curl trace
+	is enabled (see `GIT_TRACE_CURL` above), whenever a "Cookies:" header
+	sent by the client is dumped, values of cookies whose key is in that
+	list (case-sensitive) are redacted.
+
+`GIT_LITERAL_PATHSPECS`::
+	Setting this variable to `1` will cause Git to treat all
+	pathspecs literally, rather than as glob patterns. For example,
+	running `GIT_LITERAL_PATHSPECS=1 git log -- '*.c'` will search
+	for commits that touch the path `*.c`, not any paths that the
+	glob `*.c` matches. You might want this if you are feeding
+	literal paths to Git (e.g., paths previously given to you by
+	`git ls-tree`, `--raw` diff output, etc).
+
+`GIT_GLOB_PATHSPECS`::
+	Setting this variable to `1` will cause Git to treat all
+	pathspecs as glob patterns (aka "glob" magic).
+
+`GIT_NOGLOB_PATHSPECS`::
+	Setting this variable to `1` will cause Git to treat all
+	pathspecs as literal (aka "literal" magic).
+
+`GIT_ICASE_PATHSPECS`::
+	Setting this variable to `1` will cause Git to treat all
+	pathspecs as case-insensitive.
+
+`GIT_REFLOG_ACTION`::
+	When a ref is updated, reflog entries are created to keep
+	track of the reason why the ref was updated (which is
+	typically the name of the high-level command that updated
+	the ref), in addition to the old and new values of the ref.
+	A scripted Porcelain command can use set_reflog_action
+	helper function in `git-sh-setup` to set its name to this
+	variable when it is invoked as the top level command by the
+	end user, to be recorded in the body of the reflog.
+
+`GIT_REF_PARANOIA`::
+	If set to `1`, include broken or badly named refs when iterating
+	over lists of refs. In a normal, non-corrupted repository, this
+	does nothing. However, enabling it may help git to detect and
+	abort some operations in the presence of broken refs. Git sets
+	this variable automatically when performing destructive
+	operations like linkgit:git-prune[1]. You should not need to set
+	it yourself unless you want to be paranoid about making sure
+	an operation has touched every ref (e.g., because you are
+	cloning a repository to make a backup).
+
+`GIT_ALLOW_PROTOCOL`::
+	If set to a colon-separated list of protocols, behave as if
+	`protocol.allow` is set to `never`, and each of the listed
+	protocols has `protocol.<name>.allow` set to `always`
+	(overriding any existing configuration). In other words, any
+	protocol not mentioned will be disallowed (i.e., this is a
+	whitelist, not a blacklist). See the description of
+	`protocol.allow` in linkgit:git-config[1] for more details.
+
+`GIT_PROTOCOL_FROM_USER`::
+	Set to 0 to prevent protocols used by fetch/push/clone which are
+	configured to the `user` state.  This is useful to restrict recursive
+	submodule initialization from an untrusted repository or for programs
+	which feed potentially-untrusted URLS to git commands.  See
+	linkgit:git-config[1] for more details.
+
+`GIT_PROTOCOL`::
+	For internal use only.  Used in handshaking the wire protocol.
+	Contains a colon ':' separated list of keys with optional values
+	'key[=value]'.  Presence of unknown keys and values must be
+	ignored.
+
+`GIT_OPTIONAL_LOCKS`::
+	If set to `0`, Git will complete any requested operation without
+	performing any optional sub-operations that require taking a lock.
+	For example, this will prevent `git status` from refreshing the
+	index as a side effect. This is useful for processes running in
+	the background which do not want to cause lock contention with
+	other operations on the repository.  Defaults to `1`.
+
+`GIT_REDIRECT_STDIN`::
+`GIT_REDIRECT_STDOUT`::
+`GIT_REDIRECT_STDERR`::
+	Windows-only: allow redirecting the standard input/output/error
+	handles to paths specified by the environment variables. This is
+	particularly useful in multi-threaded applications where the
+	canonical way to pass standard handles via `CreateProcess()` is
+	not an option because it would require the handles to be marked
+	inheritable (and consequently *every* spawned process would
+	inherit them, possibly blocking regular Git operations). The
+	primary intended use case is to use named pipes for communication
+	(e.g. `\\.\pipe\my-git-stdin-123`).
++
+Two special values are supported: `off` will simply close the
+corresponding standard handle, and if `GIT_REDIRECT_STDERR` is
+`2>&1`, standard error will be redirected to the same handle as
+standard output.
+
+`GIT_PRINT_SHA1_ELLIPSIS` (deprecated)::
+	If set to `yes`, print an ellipsis following an
+	(abbreviated) SHA-1 value.  This affects indications of
+	detached HEADs (linkgit:git-checkout[1]) and the raw
+	diff output (linkgit:git-diff[1]).  Printing an
+	ellipsis in the cases mentioned is no longer considered
+	adequate and support for it is likely to be removed in the
+	foreseeable future (along with the variable).
+
+Discussion[[Discussion]]
+------------------------
+
+More detail on the following is available from the
+link:user-manual.html#git-concepts[Git concepts chapter of the
+user-manual] and linkgit:gitcore-tutorial[7].
+
+A Git project normally consists of a working directory with a ".git"
+subdirectory at the top level.  The .git directory contains, among other
+things, a compressed object database representing the complete history
+of the project, an "index" file which links that history to the current
+contents of the working tree, and named pointers into that history such
+as tags and branch heads.
+
+The object database contains objects of three main types: blobs, which
+hold file data; trees, which point to blobs and other trees to build up
+directory hierarchies; and commits, which each reference a single tree
+and some number of parent commits.
+
+The commit, equivalent to what other systems call a "changeset" or
+"version", represents a step in the project's history, and each parent
+represents an immediately preceding step.  Commits with more than one
+parent represent merges of independent lines of development.
+
+All objects are named by the SHA-1 hash of their contents, normally
+written as a string of 40 hex digits.  Such names are globally unique.
+The entire history leading up to a commit can be vouched for by signing
+just that commit.  A fourth object type, the tag, is provided for this
+purpose.
+
+When first created, objects are stored in individual files, but for
+efficiency may later be compressed together into "pack files".
+
+Named pointers called refs mark interesting points in history.  A ref
+may contain the SHA-1 name of an object or the name of another ref.  Refs
+with names beginning `ref/head/` contain the SHA-1 name of the most
+recent commit (or "head") of a branch under development.  SHA-1 names of
+tags of interest are stored under `ref/tags/`.  A special ref named
+`HEAD` contains the name of the currently checked-out branch.
+
+The index file is initialized with a list of all paths and, for each
+path, a blob object and a set of attributes.  The blob object represents
+the contents of the file as of the head of the current branch.  The
+attributes (last modified time, size, etc.) are taken from the
+corresponding file in the working tree.  Subsequent changes to the
+working tree can be found by comparing these attributes.  The index may
+be updated with new content, and new commits may be created from the
+content stored in the index.
+
+The index is also capable of storing multiple entries (called "stages")
+for a given pathname.  These stages are used to hold the various
+unmerged version of a file when a merge is in progress.
+
+FURTHER DOCUMENTATION
+---------------------
+
+See the references in the "description" section to get started
+using Git.  The following is probably more detail than necessary
+for a first-time user.
+
+The link:user-manual.html#git-concepts[Git concepts chapter of the
+user-manual] and linkgit:gitcore-tutorial[7] both provide
+introductions to the underlying Git architecture.
+
+See linkgit:gitworkflows[7] for an overview of recommended workflows.
+
+See also the link:howto-index.html[howto] documents for some useful
+examples.
+
+The internals are documented in the
+link:technical/api-index.html[Git API documentation].
+
+Users migrating from CVS may also want to
+read linkgit:gitcvs-migration[7].
+
+
+Authors
+-------
+Git was started by Linus Torvalds, and is currently maintained by Junio
+C Hamano. Numerous contributions have come from the Git mailing list
+<git@vger.kernel.org>.  http://www.openhub.net/p/git/contributors/summary
+gives you a more complete list of contributors.
+
+If you have a clone of git.git itself, the
+output of linkgit:git-shortlog[1] and linkgit:git-blame[1] can show you
+the authors for specific parts of the project.
+
+Reporting Bugs
+--------------
+
+Report bugs to the Git mailing list <git@vger.kernel.org> where the
+development and maintenance is primarily done.  You do not have to be
+subscribed to the list to send a message there.  See the list archive
+at https://public-inbox.org/git for previous bug reports and other
+discussions.
+
+Issues which are security relevant should be disclosed privately to
+the Git Security mailing list <git-security@googlegroups.com>.
+
+SEE ALSO
+--------
+linkgit:gittutorial[7], linkgit:gittutorial-2[7],
+linkgit:giteveryday[7], linkgit:gitcvs-migration[7],
+linkgit:gitglossary[7], linkgit:gitcore-tutorial[7],
+linkgit:gitcli[7], link:user-manual.html[The Git User's Manual],
+linkgit:gitworkflows[7]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitattributes.txt b/third_party/git/Documentation/gitattributes.txt
new file mode 100644
index 0000000000..fb1d188d44
--- /dev/null
+++ b/third_party/git/Documentation/gitattributes.txt
@@ -0,0 +1,1294 @@
+gitattributes(5)
+================
+
+NAME
+----
+gitattributes - Defining attributes per path
+
+SYNOPSIS
+--------
+$GIT_DIR/info/attributes, .gitattributes
+
+
+DESCRIPTION
+-----------
+
+A `gitattributes` file is a simple text file that gives
+`attributes` to pathnames.
+
+Each line in `gitattributes` file is of form:
+
+	pattern attr1 attr2 ...
+
+That is, a pattern followed by an attributes list,
+separated by whitespaces. Leading and trailing whitespaces are
+ignored. Lines that begin with '#' are ignored. Patterns
+that begin with a double quote are quoted in C style.
+When the pattern matches the path in question, the attributes
+listed on the line are given to the path.
+
+Each attribute can be in one of these states for a given path:
+
+Set::
+
+	The path has the attribute with special value "true";
+	this is specified by listing only the name of the
+	attribute in the attribute list.
+
+Unset::
+
+	The path has the attribute with special value "false";
+	this is specified by listing the name of the attribute
+	prefixed with a dash `-` in the attribute list.
+
+Set to a value::
+
+	The path has the attribute with specified string value;
+	this is specified by listing the name of the attribute
+	followed by an equal sign `=` and its value in the
+	attribute list.
+
+Unspecified::
+
+	No pattern matches the path, and nothing says if
+	the path has or does not have the attribute, the
+	attribute for the path is said to be Unspecified.
+
+When more than one pattern matches the path, a later line
+overrides an earlier line.  This overriding is done per
+attribute.
+
+The rules by which the pattern matches paths are the same as in
+`.gitignore` files (see linkgit:gitignore[5]), with a few exceptions:
+
+  - negative patterns are forbidden
+
+  - patterns that match a directory do not recursively match paths
+    inside that directory (so using the trailing-slash `path/` syntax is
+    pointless in an attributes file; use `path/**` instead)
+
+When deciding what attributes are assigned to a path, Git
+consults `$GIT_DIR/info/attributes` file (which has the highest
+precedence), `.gitattributes` file in the same directory as the
+path in question, and its parent directories up to the toplevel of the
+work tree (the further the directory that contains `.gitattributes`
+is from the path in question, the lower its precedence). Finally
+global and system-wide files are considered (they have the lowest
+precedence).
+
+When the `.gitattributes` file is missing from the work tree, the
+path in the index is used as a fall-back.  During checkout process,
+`.gitattributes` in the index is used and then the file in the
+working tree is used as a fall-back.
+
+If you wish to affect only a single repository (i.e., to assign
+attributes to files that are particular to
+one user's workflow for that repository), then
+attributes should be placed in the `$GIT_DIR/info/attributes` file.
+Attributes which should be version-controlled and distributed to other
+repositories (i.e., attributes of interest to all users) should go into
+`.gitattributes` files. Attributes that should affect all repositories
+for a single user should be placed in a file specified by the
+`core.attributesFile` configuration option (see linkgit:git-config[1]).
+Its default value is $XDG_CONFIG_HOME/git/attributes. If $XDG_CONFIG_HOME
+is either not set or empty, $HOME/.config/git/attributes is used instead.
+Attributes for all users on a system should be placed in the
+`$(prefix)/etc/gitattributes` file.
+
+Sometimes you would need to override a setting of an attribute
+for a path to `Unspecified` state.  This can be done by listing
+the name of the attribute prefixed with an exclamation point `!`.
+
+
+EFFECTS
+-------
+
+Certain operations by Git can be influenced by assigning
+particular attributes to a path.  Currently, the following
+operations are attributes-aware.
+
+Checking-out and checking-in
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+These attributes affect how the contents stored in the
+repository are copied to the working tree files when commands
+such as 'git switch', 'git checkout'  and 'git merge' run.
+They also affect how
+Git stores the contents you prepare in the working tree in the
+repository upon 'git add' and 'git commit'.
+
+`text`
+^^^^^^
+
+This attribute enables and controls end-of-line normalization.  When a
+text file is normalized, its line endings are converted to LF in the
+repository.  To control what line ending style is used in the working
+directory, use the `eol` attribute for a single file and the
+`core.eol` configuration variable for all text files.
+Note that setting `core.autocrlf` to `true` or `input` overrides
+`core.eol` (see the definitions of those options in
+linkgit:git-config[1]).
+
+Set::
+
+	Setting the `text` attribute on a path enables end-of-line
+	normalization and marks the path as a text file.  End-of-line
+	conversion takes place without guessing the content type.
+
+Unset::
+
+	Unsetting the `text` attribute on a path tells Git not to
+	attempt any end-of-line conversion upon checkin or checkout.
+
+Set to string value "auto"::
+
+	When `text` is set to "auto", the path is marked for automatic
+	end-of-line conversion.  If Git decides that the content is
+	text, its line endings are converted to LF on checkin.
+	When the file has been committed with CRLF, no conversion is done.
+
+Unspecified::
+
+	If the `text` attribute is unspecified, Git uses the
+	`core.autocrlf` configuration variable to determine if the
+	file should be converted.
+
+Any other value causes Git to act as if `text` has been left
+unspecified.
+
+`eol`
+^^^^^
+
+This attribute sets a specific line-ending style to be used in the
+working directory.  It enables end-of-line conversion without any
+content checks, effectively setting the `text` attribute.  Note that
+setting this attribute on paths which are in the index with CRLF line
+endings may make the paths to be considered dirty.  Adding the path to
+the index again will normalize the line endings in the index.
+
+Set to string value "crlf"::
+
+	This setting forces Git to normalize line endings for this
+	file on checkin and convert them to CRLF when the file is
+	checked out.
+
+Set to string value "lf"::
+
+	This setting forces Git to normalize line endings to LF on
+	checkin and prevents conversion to CRLF when the file is
+	checked out.
+
+Backwards compatibility with `crlf` attribute
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+For backwards compatibility, the `crlf` attribute is interpreted as
+follows:
+
+------------------------
+crlf		text
+-crlf		-text
+crlf=input	eol=lf
+------------------------
+
+End-of-line conversion
+^^^^^^^^^^^^^^^^^^^^^^
+
+While Git normally leaves file contents alone, it can be configured to
+normalize line endings to LF in the repository and, optionally, to
+convert them to CRLF when files are checked out.
+
+If you simply want to have CRLF line endings in your working directory
+regardless of the repository you are working with, you can set the
+config variable "core.autocrlf" without using any attributes.
+
+------------------------
+[core]
+	autocrlf = true
+------------------------
+
+This does not force normalization of text files, but does ensure
+that text files that you introduce to the repository have their line
+endings normalized to LF when they are added, and that files that are
+already normalized in the repository stay normalized.
+
+If you want to ensure that text files that any contributor introduces to
+the repository have their line endings normalized, you can set the
+`text` attribute to "auto" for _all_ files.
+
+------------------------
+*	text=auto
+------------------------
+
+The attributes allow a fine-grained control, how the line endings
+are converted.
+Here is an example that will make Git normalize .txt, .vcproj and .sh
+files, ensure that .vcproj files have CRLF and .sh files have LF in
+the working directory, and prevent .jpg files from being normalized
+regardless of their content.
+
+------------------------
+*               text=auto
+*.txt		text
+*.vcproj	text eol=crlf
+*.sh		text eol=lf
+*.jpg		-text
+------------------------
+
+NOTE: When `text=auto` conversion is enabled in a cross-platform
+project using push and pull to a central repository the text files
+containing CRLFs should be normalized.
+
+From a clean working directory:
+
+-------------------------------------------------
+$ echo "* text=auto" >.gitattributes
+$ git add --renormalize .
+$ git status        # Show files that will be normalized
+$ git commit -m "Introduce end-of-line normalization"
+-------------------------------------------------
+
+If any files that should not be normalized show up in 'git status',
+unset their `text` attribute before running 'git add -u'.
+
+------------------------
+manual.pdf	-text
+------------------------
+
+Conversely, text files that Git does not detect can have normalization
+enabled manually.
+
+------------------------
+weirdchars.txt	text
+------------------------
+
+If `core.safecrlf` is set to "true" or "warn", Git verifies if
+the conversion is reversible for the current setting of
+`core.autocrlf`.  For "true", Git rejects irreversible
+conversions; for "warn", Git only prints a warning but accepts
+an irreversible conversion.  The safety triggers to prevent such
+a conversion done to the files in the work tree, but there are a
+few exceptions.  Even though...
+
+- 'git add' itself does not touch the files in the work tree, the
+  next checkout would, so the safety triggers;
+
+- 'git apply' to update a text file with a patch does touch the files
+  in the work tree, but the operation is about text files and CRLF
+  conversion is about fixing the line ending inconsistencies, so the
+  safety does not trigger;
+
+- 'git diff' itself does not touch the files in the work tree, it is
+  often run to inspect the changes you intend to next 'git add'.  To
+  catch potential problems early, safety triggers.
+
+
+`working-tree-encoding`
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Git recognizes files encoded in ASCII or one of its supersets (e.g.
+UTF-8, ISO-8859-1, ...) as text files. Files encoded in certain other
+encodings (e.g. UTF-16) are interpreted as binary and consequently
+built-in Git text processing tools (e.g. 'git diff') as well as most Git
+web front ends do not visualize the contents of these files by default.
+
+In these cases you can tell Git the encoding of a file in the working
+directory with the `working-tree-encoding` attribute. If a file with this
+attribute is added to Git, then Git reencodes the content from the
+specified encoding to UTF-8. Finally, Git stores the UTF-8 encoded
+content in its internal data structure (called "the index"). On checkout
+the content is reencoded back to the specified encoding.
+
+Please note that using the `working-tree-encoding` attribute may have a
+number of pitfalls:
+
+- Alternative Git implementations (e.g. JGit or libgit2) and older Git
+  versions (as of March 2018) do not support the `working-tree-encoding`
+  attribute. If you decide to use the `working-tree-encoding` attribute
+  in your repository, then it is strongly recommended to ensure that all
+  clients working with the repository support it.
++
+For example, Microsoft Visual Studio resources files (`*.rc`) or
+PowerShell script files (`*.ps1`) are sometimes encoded in UTF-16.
+If you declare `*.ps1` as files as UTF-16 and you add `foo.ps1` with
+a `working-tree-encoding` enabled Git client, then `foo.ps1` will be
+stored as UTF-8 internally. A client without `working-tree-encoding`
+support will checkout `foo.ps1` as UTF-8 encoded file. This will
+typically cause trouble for the users of this file.
++
+If a Git client that does not support the `working-tree-encoding`
+attribute adds a new file `bar.ps1`, then `bar.ps1` will be
+stored "as-is" internally (in this example probably as UTF-16).
+A client with `working-tree-encoding` support will interpret the
+internal contents as UTF-8 and try to convert it to UTF-16 on checkout.
+That operation will fail and cause an error.
+
+- Reencoding content to non-UTF encodings can cause errors as the
+  conversion might not be UTF-8 round trip safe. If you suspect your
+  encoding to not be round trip safe, then add it to
+  `core.checkRoundtripEncoding` to make Git check the round trip
+  encoding (see linkgit:git-config[1]). SHIFT-JIS (Japanese character
+  set) is known to have round trip issues with UTF-8 and is checked by
+  default.
+
+- Reencoding content requires resources that might slow down certain
+  Git operations (e.g 'git checkout' or 'git add').
+
+Use the `working-tree-encoding` attribute only if you cannot store a file
+in UTF-8 encoding and if you want Git to be able to process the content
+as text.
+
+As an example, use the following attributes if your '*.ps1' files are
+UTF-16 encoded with byte order mark (BOM) and you want Git to perform
+automatic line ending conversion based on your platform.
+
+------------------------
+*.ps1		text working-tree-encoding=UTF-16
+------------------------
+
+Use the following attributes if your '*.ps1' files are UTF-16 little
+endian encoded without BOM and you want Git to use Windows line endings
+in the working directory (use `UTF-16LE-BOM` instead of `UTF-16LE` if
+you want UTF-16 little endian with BOM).
+Please note, it is highly recommended to
+explicitly define the line endings with `eol` if the `working-tree-encoding`
+attribute is used to avoid ambiguity.
+
+------------------------
+*.ps1		text working-tree-encoding=UTF-16LE eol=CRLF
+------------------------
+
+You can get a list of all available encodings on your platform with the
+following command:
+
+------------------------
+iconv --list
+------------------------
+
+If you do not know the encoding of a file, then you can use the `file`
+command to guess the encoding:
+
+------------------------
+file foo.ps1
+------------------------
+
+
+`ident`
+^^^^^^^
+
+When the attribute `ident` is set for a path, Git replaces
+`$Id$` in the blob object with `$Id:`, followed by the
+40-character hexadecimal blob object name, followed by a dollar
+sign `$` upon checkout.  Any byte sequence that begins with
+`$Id:` and ends with `$` in the worktree file is replaced
+with `$Id$` upon check-in.
+
+
+`filter`
+^^^^^^^^
+
+A `filter` attribute can be set to a string value that names a
+filter driver specified in the configuration.
+
+A filter driver consists of a `clean` command and a `smudge`
+command, either of which can be left unspecified.  Upon
+checkout, when the `smudge` command is specified, the command is
+fed the blob object from its standard input, and its standard
+output is used to update the worktree file.  Similarly, the
+`clean` command is used to convert the contents of worktree file
+upon checkin. By default these commands process only a single
+blob and terminate. If a long running `process` filter is used
+in place of `clean` and/or `smudge` filters, then Git can process
+all blobs with a single filter command invocation for the entire
+life of a single Git command, for example `git add --all`. If a
+long running `process` filter is configured then it always takes
+precedence over a configured single blob filter. See section
+below for the description of the protocol used to communicate with
+a `process` filter.
+
+One use of the content filtering is to massage the content into a shape
+that is more convenient for the platform, filesystem, and the user to use.
+For this mode of operation, the key phrase here is "more convenient" and
+not "turning something unusable into usable".  In other words, the intent
+is that if someone unsets the filter driver definition, or does not have
+the appropriate filter program, the project should still be usable.
+
+Another use of the content filtering is to store the content that cannot
+be directly used in the repository (e.g. a UUID that refers to the true
+content stored outside Git, or an encrypted content) and turn it into a
+usable form upon checkout (e.g. download the external content, or decrypt
+the encrypted content).
+
+These two filters behave differently, and by default, a filter is taken as
+the former, massaging the contents into more convenient shape.  A missing
+filter driver definition in the config, or a filter driver that exits with
+a non-zero status, is not an error but makes the filter a no-op passthru.
+
+You can declare that a filter turns a content that by itself is unusable
+into a usable content by setting the filter.<driver>.required configuration
+variable to `true`.
+
+Note: Whenever the clean filter is changed, the repo should be renormalized:
+$ git add --renormalize .
+
+For example, in .gitattributes, you would assign the `filter`
+attribute for paths.
+
+------------------------
+*.c	filter=indent
+------------------------
+
+Then you would define a "filter.indent.clean" and "filter.indent.smudge"
+configuration in your .git/config to specify a pair of commands to
+modify the contents of C programs when the source files are checked
+in ("clean" is run) and checked out (no change is made because the
+command is "cat").
+
+------------------------
+[filter "indent"]
+	clean = indent
+	smudge = cat
+------------------------
+
+For best results, `clean` should not alter its output further if it is
+run twice ("clean->clean" should be equivalent to "clean"), and
+multiple `smudge` commands should not alter `clean`'s output
+("smudge->smudge->clean" should be equivalent to "clean").  See the
+section on merging below.
+
+The "indent" filter is well-behaved in this regard: it will not modify
+input that is already correctly indented.  In this case, the lack of a
+smudge filter means that the clean filter _must_ accept its own output
+without modifying it.
+
+If a filter _must_ succeed in order to make the stored contents usable,
+you can declare that the filter is `required`, in the configuration:
+
+------------------------
+[filter "crypt"]
+	clean = openssl enc ...
+	smudge = openssl enc -d ...
+	required
+------------------------
+
+Sequence "%f" on the filter command line is replaced with the name of
+the file the filter is working on.  A filter might use this in keyword
+substitution.  For example:
+
+------------------------
+[filter "p4"]
+	clean = git-p4-filter --clean %f
+	smudge = git-p4-filter --smudge %f
+------------------------
+
+Note that "%f" is the name of the path that is being worked on. Depending
+on the version that is being filtered, the corresponding file on disk may
+not exist, or may have different contents. So, smudge and clean commands
+should not try to access the file on disk, but only act as filters on the
+content provided to them on standard input.
+
+Long Running Filter Process
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If the filter command (a string value) is defined via
+`filter.<driver>.process` then Git can process all blobs with a
+single filter invocation for the entire life of a single Git
+command. This is achieved by using the long-running process protocol
+(described in technical/long-running-process-protocol.txt).
+
+When Git encounters the first file that needs to be cleaned or smudged,
+it starts the filter and performs the handshake. In the handshake, the
+welcome message sent by Git is "git-filter-client", only version 2 is
+suppported, and the supported capabilities are "clean", "smudge", and
+"delay".
+
+Afterwards Git sends a list of "key=value" pairs terminated with
+a flush packet. The list will contain at least the filter command
+(based on the supported capabilities) and the pathname of the file
+to filter relative to the repository root. Right after the flush packet
+Git sends the content split in zero or more pkt-line packets and a
+flush packet to terminate content. Please note, that the filter
+must not send any response before it received the content and the
+final flush packet. Also note that the "value" of a "key=value" pair
+can contain the "=" character whereas the key would never contain
+that character.
+------------------------
+packet:          git> command=smudge
+packet:          git> pathname=path/testfile.dat
+packet:          git> 0000
+packet:          git> CONTENT
+packet:          git> 0000
+------------------------
+
+The filter is expected to respond with a list of "key=value" pairs
+terminated with a flush packet. If the filter does not experience
+problems then the list must contain a "success" status. Right after
+these packets the filter is expected to send the content in zero
+or more pkt-line packets and a flush packet at the end. Finally, a
+second list of "key=value" pairs terminated with a flush packet
+is expected. The filter can change the status in the second list
+or keep the status as is with an empty list. Please note that the
+empty list must be terminated with a flush packet regardless.
+
+------------------------
+packet:          git< status=success
+packet:          git< 0000
+packet:          git< SMUDGED_CONTENT
+packet:          git< 0000
+packet:          git< 0000  # empty list, keep "status=success" unchanged!
+------------------------
+
+If the result content is empty then the filter is expected to respond
+with a "success" status and a flush packet to signal the empty content.
+------------------------
+packet:          git< status=success
+packet:          git< 0000
+packet:          git< 0000  # empty content!
+packet:          git< 0000  # empty list, keep "status=success" unchanged!
+------------------------
+
+In case the filter cannot or does not want to process the content,
+it is expected to respond with an "error" status.
+------------------------
+packet:          git< status=error
+packet:          git< 0000
+------------------------
+
+If the filter experiences an error during processing, then it can
+send the status "error" after the content was (partially or
+completely) sent.
+------------------------
+packet:          git< status=success
+packet:          git< 0000
+packet:          git< HALF_WRITTEN_ERRONEOUS_CONTENT
+packet:          git< 0000
+packet:          git< status=error
+packet:          git< 0000
+------------------------
+
+In case the filter cannot or does not want to process the content
+as well as any future content for the lifetime of the Git process,
+then it is expected to respond with an "abort" status at any point
+in the protocol.
+------------------------
+packet:          git< status=abort
+packet:          git< 0000
+------------------------
+
+Git neither stops nor restarts the filter process in case the
+"error"/"abort" status is set. However, Git sets its exit code
+according to the `filter.<driver>.required` flag, mimicking the
+behavior of the `filter.<driver>.clean` / `filter.<driver>.smudge`
+mechanism.
+
+If the filter dies during the communication or does not adhere to
+the protocol then Git will stop the filter process and restart it
+with the next file that needs to be processed. Depending on the
+`filter.<driver>.required` flag Git will interpret that as error.
+
+Delay
+^^^^^
+
+If the filter supports the "delay" capability, then Git can send the
+flag "can-delay" after the filter command and pathname. This flag
+denotes that the filter can delay filtering the current blob (e.g. to
+compensate network latencies) by responding with no content but with
+the status "delayed" and a flush packet.
+------------------------
+packet:          git> command=smudge
+packet:          git> pathname=path/testfile.dat
+packet:          git> can-delay=1
+packet:          git> 0000
+packet:          git> CONTENT
+packet:          git> 0000
+packet:          git< status=delayed
+packet:          git< 0000
+------------------------
+
+If the filter supports the "delay" capability then it must support the
+"list_available_blobs" command. If Git sends this command, then the
+filter is expected to return a list of pathnames representing blobs
+that have been delayed earlier and are now available.
+The list must be terminated with a flush packet followed
+by a "success" status that is also terminated with a flush packet. If
+no blobs for the delayed paths are available, yet, then the filter is
+expected to block the response until at least one blob becomes
+available. The filter can tell Git that it has no more delayed blobs
+by sending an empty list. As soon as the filter responds with an empty
+list, Git stops asking. All blobs that Git has not received at this
+point are considered missing and will result in an error.
+
+------------------------
+packet:          git> command=list_available_blobs
+packet:          git> 0000
+packet:          git< pathname=path/testfile.dat
+packet:          git< pathname=path/otherfile.dat
+packet:          git< 0000
+packet:          git< status=success
+packet:          git< 0000
+------------------------
+
+After Git received the pathnames, it will request the corresponding
+blobs again. These requests contain a pathname and an empty content
+section. The filter is expected to respond with the smudged content
+in the usual way as explained above.
+------------------------
+packet:          git> command=smudge
+packet:          git> pathname=path/testfile.dat
+packet:          git> 0000
+packet:          git> 0000  # empty content!
+packet:          git< status=success
+packet:          git< 0000
+packet:          git< SMUDGED_CONTENT
+packet:          git< 0000
+packet:          git< 0000  # empty list, keep "status=success" unchanged!
+------------------------
+
+Example
+^^^^^^^
+
+A long running filter demo implementation can be found in
+`contrib/long-running-filter/example.pl` located in the Git
+core repository. If you develop your own long running filter
+process then the `GIT_TRACE_PACKET` environment variables can be
+very helpful for debugging (see linkgit:git[1]).
+
+Please note that you cannot use an existing `filter.<driver>.clean`
+or `filter.<driver>.smudge` command with `filter.<driver>.process`
+because the former two use a different inter process communication
+protocol than the latter one.
+
+
+Interaction between checkin/checkout attributes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In the check-in codepath, the worktree file is first converted
+with `filter` driver (if specified and corresponding driver
+defined), then the result is processed with `ident` (if
+specified), and then finally with `text` (again, if specified
+and applicable).
+
+In the check-out codepath, the blob content is first converted
+with `text`, and then `ident` and fed to `filter`.
+
+
+Merging branches with differing checkin/checkout attributes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you have added attributes to a file that cause the canonical
+repository format for that file to change, such as adding a
+clean/smudge filter or text/eol/ident attributes, merging anything
+where the attribute is not in place would normally cause merge
+conflicts.
+
+To prevent these unnecessary merge conflicts, Git can be told to run a
+virtual check-out and check-in of all three stages of a file when
+resolving a three-way merge by setting the `merge.renormalize`
+configuration variable.  This prevents changes caused by check-in
+conversion from causing spurious merge conflicts when a converted file
+is merged with an unconverted file.
+
+As long as a "smudge->clean" results in the same output as a "clean"
+even on files that are already smudged, this strategy will
+automatically resolve all filter-related conflicts.  Filters that do
+not act in this way may cause additional merge conflicts that must be
+resolved manually.
+
+
+Generating diff text
+~~~~~~~~~~~~~~~~~~~~
+
+`diff`
+^^^^^^
+
+The attribute `diff` affects how Git generates diffs for particular
+files. It can tell Git whether to generate a textual patch for the path
+or to treat the path as a binary file.  It can also affect what line is
+shown on the hunk header `@@ -k,l +n,m @@` line, tell Git to use an
+external command to generate the diff, or ask Git to convert binary
+files to a text format before generating the diff.
+
+Set::
+
+	A path to which the `diff` attribute is set is treated
+	as text, even when they contain byte values that
+	normally never appear in text files, such as NUL.
+
+Unset::
+
+	A path to which the `diff` attribute is unset will
+	generate `Binary files differ` (or a binary patch, if
+	binary patches are enabled).
+
+Unspecified::
+
+	A path to which the `diff` attribute is unspecified
+	first gets its contents inspected, and if it looks like
+	text and is smaller than core.bigFileThreshold, it is treated
+	as text. Otherwise it would generate `Binary files differ`.
+
+String::
+
+	Diff is shown using the specified diff driver.  Each driver may
+	specify one or more options, as described in the following
+	section. The options for the diff driver "foo" are defined
+	by the configuration variables in the "diff.foo" section of the
+	Git config file.
+
+
+Defining an external diff driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The definition of a diff driver is done in `gitconfig`, not
+`gitattributes` file, so strictly speaking this manual page is a
+wrong place to talk about it.  However...
+
+To define an external diff driver `jcdiff`, add a section to your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+----------------------------------------------------------------
+[diff "jcdiff"]
+	command = j-c-diff
+----------------------------------------------------------------
+
+When Git needs to show you a diff for the path with `diff`
+attribute set to `jcdiff`, it calls the command you specified
+with the above configuration, i.e. `j-c-diff`, with 7
+parameters, just like `GIT_EXTERNAL_DIFF` program is called.
+See linkgit:git[1] for details.
+
+
+Defining a custom hunk-header
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Each group of changes (called a "hunk") in the textual diff output
+is prefixed with a line of the form:
+
+	@@ -k,l +n,m @@ TEXT
+
+This is called a 'hunk header'.  The "TEXT" portion is by default a line
+that begins with an alphabet, an underscore or a dollar sign; this
+matches what GNU 'diff -p' output uses.  This default selection however
+is not suited for some contents, and you can use a customized pattern
+to make a selection.
+
+First, in .gitattributes, you would assign the `diff` attribute
+for paths.
+
+------------------------
+*.tex	diff=tex
+------------------------
+
+Then, you would define a "diff.tex.xfuncname" configuration to
+specify a regular expression that matches a line that you would
+want to appear as the hunk header "TEXT". Add a section to your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+------------------------
+[diff "tex"]
+	xfuncname = "^(\\\\(sub)*section\\{.*)$"
+------------------------
+
+Note.  A single level of backslashes are eaten by the
+configuration file parser, so you would need to double the
+backslashes; the pattern above picks a line that begins with a
+backslash, and zero or more occurrences of `sub` followed by
+`section` followed by open brace, to the end of line.
+
+There are a few built-in patterns to make this easier, and `tex`
+is one of them, so you do not have to write the above in your
+configuration file (you still need to enable this with the
+attribute mechanism, via `.gitattributes`).  The following built in
+patterns are available:
+
+- `ada` suitable for source code in the Ada language.
+
+- `bibtex` suitable for files with BibTeX coded references.
+
+- `cpp` suitable for source code in the C and C++ languages.
+
+- `csharp` suitable for source code in the C# language.
+
+- `css` suitable for cascading style sheets.
+
+- `fortran` suitable for source code in the Fortran language.
+
+- `fountain` suitable for Fountain documents.
+
+- `golang` suitable for source code in the Go language.
+
+- `html` suitable for HTML/XHTML documents.
+
+- `java` suitable for source code in the Java language.
+
+- `matlab` suitable for source code in the MATLAB and Octave languages.
+
+- `objc` suitable for source code in the Objective-C language.
+
+- `pascal` suitable for source code in the Pascal/Delphi language.
+
+- `perl` suitable for source code in the Perl language.
+
+- `php` suitable for source code in the PHP language.
+
+- `python` suitable for source code in the Python language.
+
+- `ruby` suitable for source code in the Ruby language.
+
+- `rust` suitable for source code in the Rust language.
+
+- `tex` suitable for source code for LaTeX documents.
+
+
+Customizing word diff
+^^^^^^^^^^^^^^^^^^^^^
+
+You can customize the rules that `git diff --word-diff` uses to
+split words in a line, by specifying an appropriate regular expression
+in the "diff.*.wordRegex" configuration variable.  For example, in TeX
+a backslash followed by a sequence of letters forms a command, but
+several such commands can be run together without intervening
+whitespace.  To separate them, use a regular expression in your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+------------------------
+[diff "tex"]
+	wordRegex = "\\\\[a-zA-Z]+|[{}]|\\\\.|[^\\{}[:space:]]+"
+------------------------
+
+A built-in pattern is provided for all languages listed in the
+previous section.
+
+
+Performing text diffs of binary files
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes it is desirable to see the diff of a text-converted
+version of some binary files. For example, a word processor
+document can be converted to an ASCII text representation, and
+the diff of the text shown. Even though this conversion loses
+some information, the resulting diff is useful for human
+viewing (but cannot be applied directly).
+
+The `textconv` config option is used to define a program for
+performing such a conversion. The program should take a single
+argument, the name of a file to convert, and produce the
+resulting text on stdout.
+
+For example, to show the diff of the exif information of a
+file instead of the binary information (assuming you have the
+exif tool installed), add the following section to your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file):
+
+------------------------
+[diff "jpg"]
+	textconv = exif
+------------------------
+
+NOTE: The text conversion is generally a one-way conversion;
+in this example, we lose the actual image contents and focus
+just on the text data. This means that diffs generated by
+textconv are _not_ suitable for applying. For this reason,
+only `git diff` and the `git log` family of commands (i.e.,
+log, whatchanged, show) will perform text conversion. `git
+format-patch` will never generate this output. If you want to
+send somebody a text-converted diff of a binary file (e.g.,
+because it quickly conveys the changes you have made), you
+should generate it separately and send it as a comment _in
+addition to_ the usual binary diff that you might send.
+
+Because text conversion can be slow, especially when doing a
+large number of them with `git log -p`, Git provides a mechanism
+to cache the output and use it in future diffs.  To enable
+caching, set the "cachetextconv" variable in your diff driver's
+config. For example:
+
+------------------------
+[diff "jpg"]
+	textconv = exif
+	cachetextconv = true
+------------------------
+
+This will cache the result of running "exif" on each blob
+indefinitely. If you change the textconv config variable for a
+diff driver, Git will automatically invalidate the cache entries
+and re-run the textconv filter. If you want to invalidate the
+cache manually (e.g., because your version of "exif" was updated
+and now produces better output), you can remove the cache
+manually with `git update-ref -d refs/notes/textconv/jpg` (where
+"jpg" is the name of the diff driver, as in the example above).
+
+Choosing textconv versus external diff
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you want to show differences between binary or specially-formatted
+blobs in your repository, you can choose to use either an external diff
+command, or to use textconv to convert them to a diff-able text format.
+Which method you choose depends on your exact situation.
+
+The advantage of using an external diff command is flexibility. You are
+not bound to find line-oriented changes, nor is it necessary for the
+output to resemble unified diff. You are free to locate and report
+changes in the most appropriate way for your data format.
+
+A textconv, by comparison, is much more limiting. You provide a
+transformation of the data into a line-oriented text format, and Git
+uses its regular diff tools to generate the output. There are several
+advantages to choosing this method:
+
+1. Ease of use. It is often much simpler to write a binary to text
+   transformation than it is to perform your own diff. In many cases,
+   existing programs can be used as textconv filters (e.g., exif,
+   odt2txt).
+
+2. Git diff features. By performing only the transformation step
+   yourself, you can still utilize many of Git's diff features,
+   including colorization, word-diff, and combined diffs for merges.
+
+3. Caching. Textconv caching can speed up repeated diffs, such as those
+   you might trigger by running `git log -p`.
+
+
+Marking files as binary
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Git usually guesses correctly whether a blob contains text or binary
+data by examining the beginning of the contents. However, sometimes you
+may want to override its decision, either because a blob contains binary
+data later in the file, or because the content, while technically
+composed of text characters, is opaque to a human reader. For example,
+many postscript files contain only ASCII characters, but produce noisy
+and meaningless diffs.
+
+The simplest way to mark a file as binary is to unset the diff
+attribute in the `.gitattributes` file:
+
+------------------------
+*.ps -diff
+------------------------
+
+This will cause Git to generate `Binary files differ` (or a binary
+patch, if binary patches are enabled) instead of a regular diff.
+
+However, one may also want to specify other diff driver attributes. For
+example, you might want to use `textconv` to convert postscript files to
+an ASCII representation for human viewing, but otherwise treat them as
+binary files. You cannot specify both `-diff` and `diff=ps` attributes.
+The solution is to use the `diff.*.binary` config option:
+
+------------------------
+[diff "ps"]
+  textconv = ps2ascii
+  binary = true
+------------------------
+
+Performing a three-way merge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+`merge`
+^^^^^^^
+
+The attribute `merge` affects how three versions of a file are
+merged when a file-level merge is necessary during `git merge`,
+and other commands such as `git revert` and `git cherry-pick`.
+
+Set::
+
+	Built-in 3-way merge driver is used to merge the
+	contents in a way similar to 'merge' command of `RCS`
+	suite.  This is suitable for ordinary text files.
+
+Unset::
+
+	Take the version from the current branch as the
+	tentative merge result, and declare that the merge has
+	conflicts.  This is suitable for binary files that do
+	not have a well-defined merge semantics.
+
+Unspecified::
+
+	By default, this uses the same built-in 3-way merge
+	driver as is the case when the `merge` attribute is set.
+	However, the `merge.default` configuration variable can name
+	different merge driver to be used with paths for which the
+	`merge` attribute is unspecified.
+
+String::
+
+	3-way merge is performed using the specified custom
+	merge driver.  The built-in 3-way merge driver can be
+	explicitly specified by asking for "text" driver; the
+	built-in "take the current branch" driver can be
+	requested with "binary".
+
+
+Built-in merge drivers
+^^^^^^^^^^^^^^^^^^^^^^
+
+There are a few built-in low-level merge drivers defined that
+can be asked for via the `merge` attribute.
+
+text::
+
+	Usual 3-way file level merge for text files.  Conflicted
+	regions are marked with conflict markers `<<<<<<<`,
+	`=======` and `>>>>>>>`.  The version from your branch
+	appears before the `=======` marker, and the version
+	from the merged branch appears after the `=======`
+	marker.
+
+binary::
+
+	Keep the version from your branch in the work tree, but
+	leave the path in the conflicted state for the user to
+	sort out.
+
+union::
+
+	Run 3-way file level merge for text files, but take
+	lines from both versions, instead of leaving conflict
+	markers.  This tends to leave the added lines in the
+	resulting file in random order and the user should
+	verify the result. Do not use this if you do not
+	understand the implications.
+
+
+Defining a custom merge driver
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The definition of a merge driver is done in the `.git/config`
+file, not in the `gitattributes` file, so strictly speaking this
+manual page is a wrong place to talk about it.  However...
+
+To define a custom merge driver `filfre`, add a section to your
+`$GIT_DIR/config` file (or `$HOME/.gitconfig` file) like this:
+
+----------------------------------------------------------------
+[merge "filfre"]
+	name = feel-free merge driver
+	driver = filfre %O %A %B %L %P
+	recursive = binary
+----------------------------------------------------------------
+
+The `merge.*.name` variable gives the driver a human-readable
+name.
+
+The `merge.*.driver` variable's value is used to construct a
+command to run to merge ancestor's version (`%O`), current
+version (`%A`) and the other branches' version (`%B`).  These
+three tokens are replaced with the names of temporary files that
+hold the contents of these versions when the command line is
+built. Additionally, %L will be replaced with the conflict marker
+size (see below).
+
+The merge driver is expected to leave the result of the merge in
+the file named with `%A` by overwriting it, and exit with zero
+status if it managed to merge them cleanly, or non-zero if there
+were conflicts.
+
+The `merge.*.recursive` variable specifies what other merge
+driver to use when the merge driver is called for an internal
+merge between common ancestors, when there are more than one.
+When left unspecified, the driver itself is used for both
+internal merge and the final merge.
+
+The merge driver can learn the pathname in which the merged result
+will be stored via placeholder `%P`.
+
+
+`conflict-marker-size`
+^^^^^^^^^^^^^^^^^^^^^^
+
+This attribute controls the length of conflict markers left in
+the work tree file during a conflicted merge.  Only setting to
+the value to a positive integer has any meaningful effect.
+
+For example, this line in `.gitattributes` can be used to tell the merge
+machinery to leave much longer (instead of the usual 7-character-long)
+conflict markers when merging the file `Documentation/git-merge.txt`
+results in a conflict.
+
+------------------------
+Documentation/git-merge.txt	conflict-marker-size=32
+------------------------
+
+
+Checking whitespace errors
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+`whitespace`
+^^^^^^^^^^^^
+
+The `core.whitespace` configuration variable allows you to define what
+'diff' and 'apply' should consider whitespace errors for all paths in
+the project (See linkgit:git-config[1]).  This attribute gives you finer
+control per path.
+
+Set::
+
+	Notice all types of potential whitespace errors known to Git.
+	The tab width is taken from the value of the `core.whitespace`
+	configuration variable.
+
+Unset::
+
+	Do not notice anything as error.
+
+Unspecified::
+
+	Use the value of the `core.whitespace` configuration variable to
+	decide what to notice as error.
+
+String::
+
+	Specify a comma separate list of common whitespace problems to
+	notice in the same format as the `core.whitespace` configuration
+	variable.
+
+
+Creating an archive
+~~~~~~~~~~~~~~~~~~~
+
+`export-ignore`
+^^^^^^^^^^^^^^^
+
+Files and directories with the attribute `export-ignore` won't be added to
+archive files.
+
+`export-subst`
+^^^^^^^^^^^^^^
+
+If the attribute `export-subst` is set for a file then Git will expand
+several placeholders when adding this file to an archive.  The
+expansion depends on the availability of a commit ID, i.e., if
+linkgit:git-archive[1] has been given a tree instead of a commit or a
+tag then no replacement will be done.  The placeholders are the same
+as those for the option `--pretty=format:` of linkgit:git-log[1],
+except that they need to be wrapped like this: `$Format:PLACEHOLDERS$`
+in the file.  E.g. the string `$Format:%H$` will be replaced by the
+commit hash.
+
+
+Packing objects
+~~~~~~~~~~~~~~~
+
+`delta`
+^^^^^^^
+
+Delta compression will not be attempted for blobs for paths with the
+attribute `delta` set to false.
+
+
+Viewing files in GUI tools
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+`encoding`
+^^^^^^^^^^
+
+The value of this attribute specifies the character encoding that should
+be used by GUI tools (e.g. linkgit:gitk[1] and linkgit:git-gui[1]) to
+display the contents of the relevant file. Note that due to performance
+considerations linkgit:gitk[1] does not use this attribute unless you
+manually enable per-file encodings in its options.
+
+If this attribute is not set or has an invalid value, the value of the
+`gui.encoding` configuration variable is used instead
+(See linkgit:git-config[1]).
+
+
+USING MACRO ATTRIBUTES
+----------------------
+
+You do not want any end-of-line conversions applied to, nor textual diffs
+produced for, any binary file you track.  You would need to specify e.g.
+
+------------
+*.jpg -text -diff
+------------
+
+but that may become cumbersome, when you have many attributes.  Using
+macro attributes, you can define an attribute that, when set, also
+sets or unsets a number of other attributes at the same time.  The
+system knows a built-in macro attribute, `binary`:
+
+------------
+*.jpg binary
+------------
+
+Setting the "binary" attribute also unsets the "text" and "diff"
+attributes as above.  Note that macro attributes can only be "Set",
+though setting one might have the effect of setting or unsetting other
+attributes or even returning other attributes to the "Unspecified"
+state.
+
+
+DEFINING MACRO ATTRIBUTES
+-------------------------
+
+Custom macro attributes can be defined only in top-level gitattributes
+files (`$GIT_DIR/info/attributes`, the `.gitattributes` file at the
+top level of the working tree, or the global or system-wide
+gitattributes files), not in `.gitattributes` files in working tree
+subdirectories.  The built-in macro attribute "binary" is equivalent
+to:
+
+------------
+[attr]binary -diff -merge -text
+------------
+
+
+EXAMPLES
+--------
+
+If you have these three `gitattributes` file:
+
+----------------------------------------------------------------
+(in $GIT_DIR/info/attributes)
+
+a*	foo !bar -baz
+
+(in .gitattributes)
+abc	foo bar baz
+
+(in t/.gitattributes)
+ab*	merge=filfre
+abc	-foo -bar
+*.c	frotz
+----------------------------------------------------------------
+
+the attributes given to path `t/abc` are computed as follows:
+
+1. By examining `t/.gitattributes` (which is in the same
+   directory as the path in question), Git finds that the first
+   line matches.  `merge` attribute is set.  It also finds that
+   the second line matches, and attributes `foo` and `bar`
+   are unset.
+
+2. Then it examines `.gitattributes` (which is in the parent
+   directory), and finds that the first line matches, but
+   `t/.gitattributes` file already decided how `merge`, `foo`
+   and `bar` attributes should be given to this path, so it
+   leaves `foo` and `bar` unset.  Attribute `baz` is set.
+
+3. Finally it examines `$GIT_DIR/info/attributes`.  This file
+   is used to override the in-tree settings.  The first line is
+   a match, and `foo` is set, `bar` is reverted to unspecified
+   state, and `baz` is unset.
+
+As the result, the attributes assignment to `t/abc` becomes:
+
+----------------------------------------------------------------
+foo	set to true
+bar	unspecified
+baz	set to false
+merge	set to string value "filfre"
+frotz	unspecified
+----------------------------------------------------------------
+
+
+SEE ALSO
+--------
+linkgit:git-check-attr[1].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitcli.txt b/third_party/git/Documentation/gitcli.txt
new file mode 100644
index 0000000000..1ed3ca33b7
--- /dev/null
+++ b/third_party/git/Documentation/gitcli.txt
@@ -0,0 +1,226 @@
+gitcli(7)
+=========
+
+NAME
+----
+gitcli - Git command-line interface and conventions
+
+SYNOPSIS
+--------
+gitcli
+
+
+DESCRIPTION
+-----------
+
+This manual describes the convention used throughout Git CLI.
+
+Many commands take revisions (most often "commits", but sometimes
+"tree-ish", depending on the context and command) and paths as their
+arguments.  Here are the rules:
+
+ * Revisions come first and then paths.
+   E.g. in `git diff v1.0 v2.0 arch/x86 include/asm-x86`,
+   `v1.0` and `v2.0` are revisions and `arch/x86` and `include/asm-x86`
+   are paths.
+
+ * When an argument can be misunderstood as either a revision or a path,
+   they can be disambiguated by placing `--` between them.
+   E.g. `git diff -- HEAD` is, "I have a file called HEAD in my work
+   tree.  Please show changes between the version I staged in the index
+   and what I have in the work tree for that file", not "show difference
+   between the HEAD commit and the work tree as a whole".  You can say
+   `git diff HEAD --` to ask for the latter.
+
+ * Without disambiguating `--`, Git makes a reasonable guess, but errors
+   out and asking you to disambiguate when ambiguous.  E.g. if you have a
+   file called HEAD in your work tree, `git diff HEAD` is ambiguous, and
+   you have to say either `git diff HEAD --` or `git diff -- HEAD` to
+   disambiguate.
++
+When writing a script that is expected to handle random user-input, it is
+a good practice to make it explicit which arguments are which by placing
+disambiguating `--` at appropriate places.
+
+ * Many commands allow wildcards in paths, but you need to protect
+   them from getting globbed by the shell.  These two mean different
+   things:
++
+--------------------------------
+$ git restore *.c
+$ git restore \*.c
+--------------------------------
++
+The former lets your shell expand the fileglob, and you are asking
+the dot-C files in your working tree to be overwritten with the version
+in the index.  The latter passes the `*.c` to Git, and you are asking
+the paths in the index that match the pattern to be checked out to your
+working tree.  After running `git add hello.c; rm hello.c`, you will _not_
+see `hello.c` in your working tree with the former, but with the latter
+you will.
+
+ * Just as the filesystem '.' (period) refers to the current directory,
+   using a '.' as a repository name in Git (a dot-repository) is a relative
+   path and means your current repository.
+
+Here are the rules regarding the "flags" that you should follow when you are
+scripting Git:
+
+ * it's preferred to use the non-dashed form of Git commands, which means that
+   you should prefer `git foo` to `git-foo`.
+
+ * splitting short options to separate words (prefer `git foo -a -b`
+   to `git foo -ab`, the latter may not even work).
+
+ * when a command-line option takes an argument, use the 'stuck' form.  In
+   other words, write `git foo -oArg` instead of `git foo -o Arg` for short
+   options, and `git foo --long-opt=Arg` instead of `git foo --long-opt Arg`
+   for long options.  An option that takes optional option-argument must be
+   written in the 'stuck' form.
+
+ * when you give a revision parameter to a command, make sure the parameter is
+   not ambiguous with a name of a file in the work tree.  E.g. do not write
+   `git log -1 HEAD` but write `git log -1 HEAD --`; the former will not work
+   if you happen to have a file called `HEAD` in the work tree.
+
+ * many commands allow a long option `--option` to be abbreviated
+   only to their unique prefix (e.g. if there is no other option
+   whose name begins with `opt`, you may be able to spell `--opt` to
+   invoke the `--option` flag), but you should fully spell them out
+   when writing your scripts; later versions of Git may introduce a
+   new option whose name shares the same prefix, e.g. `--optimize`,
+   to make a short prefix that used to be unique no longer unique.
+
+
+ENHANCED OPTION PARSER
+----------------------
+From the Git 1.5.4 series and further, many Git commands (not all of them at the
+time of the writing though) come with an enhanced option parser.
+
+Here is a list of the facilities provided by this option parser.
+
+
+Magic Options
+~~~~~~~~~~~~~
+Commands which have the enhanced option parser activated all understand a
+couple of magic command-line options:
+
+-h::
+	gives a pretty printed usage of the command.
++
+---------------------------------------------
+$ git describe -h
+usage: git describe [<options>] <commit-ish>*
+   or: git describe [<options>] --dirty
+
+    --contains            find the tag that comes after the commit
+    --debug               debug search strategy on stderr
+    --all                 use any ref
+    --tags                use any tag, even unannotated
+    --long                always use long format
+    --abbrev[=<n>]        use <n> digits to display SHA-1s
+---------------------------------------------
+
+--help-all::
+	Some Git commands take options that are only used for plumbing or that
+	are deprecated, and such options are hidden from the default usage. This
+	option gives the full list of options.
+
+
+Negating options
+~~~~~~~~~~~~~~~~
+Options with long option names can be negated by prefixing `--no-`. For
+example, `git branch` has the option `--track` which is 'on' by default. You
+can use `--no-track` to override that behaviour. The same goes for `--color`
+and `--no-color`.
+
+
+Aggregating short options
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Commands that support the enhanced option parser allow you to aggregate short
+options. This means that you can for example use `git rm -rf` or
+`git clean -fdx`.
+
+
+Abbreviating long options
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Commands that support the enhanced option parser accepts unique
+prefix of a long option as if it is fully spelled out, but use this
+with a caution.  For example, `git commit --amen` behaves as if you
+typed `git commit --amend`, but that is true only until a later version
+of Git introduces another option that shares the same prefix,
+e.g. `git commit --amenity` option.
+
+
+Separating argument from the option
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+You can write the mandatory option parameter to an option as a separate
+word on the command line.  That means that all the following uses work:
+
+----------------------------
+$ git foo --long-opt=Arg
+$ git foo --long-opt Arg
+$ git foo -oArg
+$ git foo -o Arg
+----------------------------
+
+However, this is *NOT* allowed for switches with an optional value, where the
+'stuck' form must be used:
+----------------------------
+$ git describe --abbrev HEAD     # correct
+$ git describe --abbrev=10 HEAD  # correct
+$ git describe --abbrev 10 HEAD  # NOT WHAT YOU MEANT
+----------------------------
+
+
+NOTES ON FREQUENTLY CONFUSED OPTIONS
+------------------------------------
+
+Many commands that can work on files in the working tree
+and/or in the index can take `--cached` and/or `--index`
+options.  Sometimes people incorrectly think that, because
+the index was originally called cache, these two are
+synonyms.  They are *not* -- these two options mean very
+different things.
+
+ * The `--cached` option is used to ask a command that
+   usually works on files in the working tree to *only* work
+   with the index.  For example, `git grep`, when used
+   without a commit to specify from which commit to look for
+   strings in, usually works on files in the working tree,
+   but with the `--cached` option, it looks for strings in
+   the index.
+
+ * The `--index` option is used to ask a command that
+   usually works on files in the working tree to *also*
+   affect the index.  For example, `git stash apply` usually
+   merges changes recorded in a stash entry to the working tree,
+   but with the `--index` option, it also merges changes to
+   the index as well.
+
+`git apply` command can be used with `--cached` and
+`--index` (but not at the same time).  Usually the command
+only affects the files in the working tree, but with
+`--index`, it patches both the files and their index
+entries, and with `--cached`, it modifies only the index
+entries.
+
+See also http://marc.info/?l=git&m=116563135620359 and
+http://marc.info/?l=git&m=119150393620273 for further
+information.
+
+Some other commands that also work on files in the working tree and/or
+in the index can take `--staged` and/or `--worktree`.
+
+* `--staged` is exactly like `--cached`, which is used to ask a
+  command to only work on the index, not the working tree.
+
+* `--worktree` is the opposite, to ask a command to work on the
+  working tree only, not the index.
+
+* The two options can be specified together to ask a command to work
+  on both the index and the working tree.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitcore-tutorial.txt b/third_party/git/Documentation/gitcore-tutorial.txt
new file mode 100644
index 0000000000..f880d21dfb
--- /dev/null
+++ b/third_party/git/Documentation/gitcore-tutorial.txt
@@ -0,0 +1,1660 @@
+gitcore-tutorial(7)
+===================
+
+NAME
+----
+gitcore-tutorial - A Git core tutorial for developers
+
+SYNOPSIS
+--------
+git *
+
+DESCRIPTION
+-----------
+
+This tutorial explains how to use the "core" Git commands to set up and
+work with a Git repository.
+
+If you just need to use Git as a revision control system you may prefer
+to start with "A Tutorial Introduction to Git" (linkgit:gittutorial[7]) or
+link:user-manual.html[the Git User Manual].
+
+However, an understanding of these low-level tools can be helpful if
+you want to understand Git's internals.
+
+The core Git is often called "plumbing", with the prettier user
+interfaces on top of it called "porcelain". You may not want to use the
+plumbing directly very often, but it can be good to know what the
+plumbing does when the porcelain isn't flushing.
+
+Back when this document was originally written, many porcelain
+commands were shell scripts. For simplicity, it still uses them as
+examples to illustrate how plumbing is fit together to form the
+porcelain commands. The source tree includes some of these scripts in
+contrib/examples/ for reference. Although these are not implemented as
+shell scripts anymore, the description of what the plumbing layer
+commands do is still valid.
+
+[NOTE]
+Deeper technical details are often marked as Notes, which you can
+skip on your first reading.
+
+
+Creating a Git repository
+-------------------------
+
+Creating a new Git repository couldn't be easier: all Git repositories start
+out empty, and the only thing you need to do is find yourself a
+subdirectory that you want to use as a working tree - either an empty
+one for a totally new project, or an existing working tree that you want
+to import into Git.
+
+For our first example, we're going to start a totally new repository from
+scratch, with no pre-existing files, and we'll call it 'git-tutorial'.
+To start up, create a subdirectory for it, change into that
+subdirectory, and initialize the Git infrastructure with 'git init':
+
+------------------------------------------------
+$ mkdir git-tutorial
+$ cd git-tutorial
+$ git init
+------------------------------------------------
+
+to which Git will reply
+
+----------------
+Initialized empty Git repository in .git/
+----------------
+
+which is just Git's way of saying that you haven't been doing anything
+strange, and that it will have created a local `.git` directory setup for
+your new project. You will now have a `.git` directory, and you can
+inspect that with 'ls'. For your new empty project, it should show you
+three entries, among other things:
+
+ - a file called `HEAD`, that has `ref: refs/heads/master` in it.
+   This is similar to a symbolic link and points at
+   `refs/heads/master` relative to the `HEAD` file.
++
+Don't worry about the fact that the file that the `HEAD` link points to
+doesn't even exist yet -- you haven't created the commit that will
+start your `HEAD` development branch yet.
+
+ - a subdirectory called `objects`, which will contain all the
+   objects of your project. You should never have any real reason to
+   look at the objects directly, but you might want to know that these
+   objects are what contains all the real 'data' in your repository.
+
+ - a subdirectory called `refs`, which contains references to objects.
+
+In particular, the `refs` subdirectory will contain two other
+subdirectories, named `heads` and `tags` respectively. They do
+exactly what their names imply: they contain references to any number
+of different 'heads' of development (aka 'branches'), and to any
+'tags' that you have created to name specific versions in your
+repository.
+
+One note: the special `master` head is the default branch, which is
+why the `.git/HEAD` file was created points to it even if it
+doesn't yet exist. Basically, the `HEAD` link is supposed to always
+point to the branch you are working on right now, and you always
+start out expecting to work on the `master` branch.
+
+However, this is only a convention, and you can name your branches
+anything you want, and don't have to ever even 'have' a `master`
+branch. A number of the Git tools will assume that `.git/HEAD` is
+valid, though.
+
+[NOTE]
+An 'object' is identified by its 160-bit SHA-1 hash, aka 'object name',
+and a reference to an object is always the 40-byte hex
+representation of that SHA-1 name. The files in the `refs`
+subdirectory are expected to contain these hex references
+(usually with a final `\n` at the end), and you should thus
+expect to see a number of 41-byte files containing these
+references in these `refs` subdirectories when you actually start
+populating your tree.
+
+[NOTE]
+An advanced user may want to take a look at linkgit:gitrepository-layout[5]
+after finishing this tutorial.
+
+You have now created your first Git repository. Of course, since it's
+empty, that's not very useful, so let's start populating it with data.
+
+
+Populating a Git repository
+---------------------------
+
+We'll keep this simple and stupid, so we'll start off with populating a
+few trivial files just to get a feel for it.
+
+Start off with just creating any random files that you want to maintain
+in your Git repository. We'll start off with a few bad examples, just to
+get a feel for how this works:
+
+------------------------------------------------
+$ echo "Hello World" >hello
+$ echo "Silly example" >example
+------------------------------------------------
+
+you have now created two files in your working tree (aka 'working directory'),
+but to actually check in your hard work, you will have to go through two steps:
+
+ - fill in the 'index' file (aka 'cache') with the information about your
+   working tree state.
+
+ - commit that index file as an object.
+
+The first step is trivial: when you want to tell Git about any changes
+to your working tree, you use the 'git update-index' program. That
+program normally just takes a list of filenames you want to update, but
+to avoid trivial mistakes, it refuses to add new entries to the index
+(or remove existing ones) unless you explicitly tell it that you're
+adding a new entry with the `--add` flag (or removing an entry with the
+`--remove`) flag.
+
+So to populate the index with the two files you just created, you can do
+
+------------------------------------------------
+$ git update-index --add hello example
+------------------------------------------------
+
+and you have now told Git to track those two files.
+
+In fact, as you did that, if you now look into your object directory,
+you'll notice that Git will have added two new objects to the object
+database. If you did exactly the steps above, you should now be able to do
+
+
+----------------
+$ ls .git/objects/??/*
+----------------
+
+and see two files:
+
+----------------
+.git/objects/55/7db03de997c86a4a028e1ebd3a1ceb225be238
+.git/objects/f2/4c74a2e500f5ee1332c86b94199f52b1d1d962
+----------------
+
+which correspond with the objects with names of `557db...` and
+`f24c7...` respectively.
+
+If you want to, you can use 'git cat-file' to look at those objects, but
+you'll have to use the object name, not the filename of the object:
+
+----------------
+$ git cat-file -t 557db03de997c86a4a028e1ebd3a1ceb225be238
+----------------
+
+where the `-t` tells 'git cat-file' to tell you what the "type" of the
+object is. Git will tell you that you have a "blob" object (i.e., just a
+regular file), and you can see the contents with
+
+----------------
+$ git cat-file blob 557db03
+----------------
+
+which will print out "Hello World". The object `557db03` is nothing
+more than the contents of your file `hello`.
+
+[NOTE]
+Don't confuse that object with the file `hello` itself. The
+object is literally just those specific *contents* of the file, and
+however much you later change the contents in file `hello`, the object
+we just looked at will never change. Objects are immutable.
+
+[NOTE]
+The second example demonstrates that you can
+abbreviate the object name to only the first several
+hexadecimal digits in most places.
+
+Anyway, as we mentioned previously, you normally never actually take a
+look at the objects themselves, and typing long 40-character hex
+names is not something you'd normally want to do. The above digression
+was just to show that 'git update-index' did something magical, and
+actually saved away the contents of your files into the Git object
+database.
+
+Updating the index did something else too: it created a `.git/index`
+file. This is the index that describes your current working tree, and
+something you should be very aware of. Again, you normally never worry
+about the index file itself, but you should be aware of the fact that
+you have not actually really "checked in" your files into Git so far,
+you've only *told* Git about them.
+
+However, since Git knows about them, you can now start using some of the
+most basic Git commands to manipulate the files or look at their status.
+
+In particular, let's not even check in the two files into Git yet, we'll
+start off by adding another line to `hello` first:
+
+------------------------------------------------
+$ echo "It's a new day for git" >>hello
+------------------------------------------------
+
+and you can now, since you told Git about the previous state of `hello`, ask
+Git what has changed in the tree compared to your old index, using the
+'git diff-files' command:
+
+------------
+$ git diff-files
+------------
+
+Oops. That wasn't very readable. It just spit out its own internal
+version of a 'diff', but that internal version really just tells you
+that it has noticed that "hello" has been modified, and that the old object
+contents it had have been replaced with something else.
+
+To make it readable, we can tell 'git diff-files' to output the
+differences as a patch, using the `-p` flag:
+
+------------
+$ git diff-files -p
+diff --git a/hello b/hello
+index 557db03..263414f 100644
+--- a/hello
++++ b/hello
+@@ -1 +1,2 @@
+ Hello World
++It's a new day for git
+------------
+
+i.e. the diff of the change we caused by adding another line to `hello`.
+
+In other words, 'git diff-files' always shows us the difference between
+what is recorded in the index, and what is currently in the working
+tree. That's very useful.
+
+A common shorthand for `git diff-files -p` is to just write `git
+diff`, which will do the same thing.
+
+------------
+$ git diff
+diff --git a/hello b/hello
+index 557db03..263414f 100644
+--- a/hello
++++ b/hello
+@@ -1 +1,2 @@
+ Hello World
++It's a new day for git
+------------
+
+
+Committing Git state
+--------------------
+
+Now, we want to go to the next stage in Git, which is to take the files
+that Git knows about in the index, and commit them as a real tree. We do
+that in two phases: creating a 'tree' object, and committing that 'tree'
+object as a 'commit' object together with an explanation of what the
+tree was all about, along with information of how we came to that state.
+
+Creating a tree object is trivial, and is done with 'git write-tree'.
+There are no options or other input: `git write-tree` will take the
+current index state, and write an object that describes that whole
+index. In other words, we're now tying together all the different
+filenames with their contents (and their permissions), and we're
+creating the equivalent of a Git "directory" object:
+
+------------------------------------------------
+$ git write-tree
+------------------------------------------------
+
+and this will just output the name of the resulting tree, in this case
+(if you have done exactly as I've described) it should be
+
+----------------
+8988da15d077d4829fc51d8544c097def6644dbb
+----------------
+
+which is another incomprehensible object name. Again, if you want to,
+you can use `git cat-file -t 8988d...` to see that this time the object
+is not a "blob" object, but a "tree" object (you can also use
+`git cat-file` to actually output the raw object contents, but you'll see
+mainly a binary mess, so that's less interesting).
+
+However -- normally you'd never use 'git write-tree' on its own, because
+normally you always commit a tree into a commit object using the
+'git commit-tree' command. In fact, it's easier to not actually use
+'git write-tree' on its own at all, but to just pass its result in as an
+argument to 'git commit-tree'.
+
+'git commit-tree' normally takes several arguments -- it wants to know
+what the 'parent' of a commit was, but since this is the first commit
+ever in this new repository, and it has no parents, we only need to pass in
+the object name of the tree. However, 'git commit-tree' also wants to get a
+commit message on its standard input, and it will write out the resulting
+object name for the commit to its standard output.
+
+And this is where we create the `.git/refs/heads/master` file
+which is pointed at by `HEAD`. This file is supposed to contain
+the reference to the top-of-tree of the master branch, and since
+that's exactly what 'git commit-tree' spits out, we can do this
+all with a sequence of simple shell commands:
+
+------------------------------------------------
+$ tree=$(git write-tree)
+$ commit=$(echo 'Initial commit' | git commit-tree $tree)
+$ git update-ref HEAD $commit
+------------------------------------------------
+
+In this case this creates a totally new commit that is not related to
+anything else. Normally you do this only *once* for a project ever, and
+all later commits will be parented on top of an earlier commit.
+
+Again, normally you'd never actually do this by hand. There is a
+helpful script called `git commit` that will do all of this for you. So
+you could have just written `git commit`
+instead, and it would have done the above magic scripting for you.
+
+
+Making a change
+---------------
+
+Remember how we did the 'git update-index' on file `hello` and then we
+changed `hello` afterward, and could compare the new state of `hello` with the
+state we saved in the index file?
+
+Further, remember how I said that 'git write-tree' writes the contents
+of the *index* file to the tree, and thus what we just committed was in
+fact the *original* contents of the file `hello`, not the new ones. We did
+that on purpose, to show the difference between the index state, and the
+state in the working tree, and how they don't have to match, even
+when we commit things.
+
+As before, if we do `git diff-files -p` in our git-tutorial project,
+we'll still see the same difference we saw last time: the index file
+hasn't changed by the act of committing anything. However, now that we
+have committed something, we can also learn to use a new command:
+'git diff-index'.
+
+Unlike 'git diff-files', which showed the difference between the index
+file and the working tree, 'git diff-index' shows the differences
+between a committed *tree* and either the index file or the working
+tree. In other words, 'git diff-index' wants a tree to be diffed
+against, and before we did the commit, we couldn't do that, because we
+didn't have anything to diff against.
+
+But now we can do
+
+----------------
+$ git diff-index -p HEAD
+----------------
+
+(where `-p` has the same meaning as it did in 'git diff-files'), and it
+will show us the same difference, but for a totally different reason.
+Now we're comparing the working tree not against the index file,
+but against the tree we just wrote. It just so happens that those two
+are obviously the same, so we get the same result.
+
+Again, because this is a common operation, you can also just shorthand
+it with
+
+----------------
+$ git diff HEAD
+----------------
+
+which ends up doing the above for you.
+
+In other words, 'git diff-index' normally compares a tree against the
+working tree, but when given the `--cached` flag, it is told to
+instead compare against just the index cache contents, and ignore the
+current working tree state entirely. Since we just wrote the index
+file to HEAD, doing `git diff-index --cached -p HEAD` should thus return
+an empty set of differences, and that's exactly what it does.
+
+[NOTE]
+================
+'git diff-index' really always uses the index for its
+comparisons, and saying that it compares a tree against the working
+tree is thus not strictly accurate. In particular, the list of
+files to compare (the "meta-data") *always* comes from the index file,
+regardless of whether the `--cached` flag is used or not. The `--cached`
+flag really only determines whether the file *contents* to be compared
+come from the working tree or not.
+
+This is not hard to understand, as soon as you realize that Git simply
+never knows (or cares) about files that it is not told about
+explicitly. Git will never go *looking* for files to compare, it
+expects you to tell it what the files are, and that's what the index
+is there for.
+================
+
+However, our next step is to commit the *change* we did, and again, to
+understand what's going on, keep in mind the difference between "working
+tree contents", "index file" and "committed tree". We have changes
+in the working tree that we want to commit, and we always have to
+work through the index file, so the first thing we need to do is to
+update the index cache:
+
+------------------------------------------------
+$ git update-index hello
+------------------------------------------------
+
+(note how we didn't need the `--add` flag this time, since Git knew
+about the file already).
+
+Note what happens to the different 'git diff-{asterisk}' versions here.
+After we've updated `hello` in the index, `git diff-files -p` now shows no
+differences, but `git diff-index -p HEAD` still *does* show that the
+current state is different from the state we committed. In fact, now
+'git diff-index' shows the same difference whether we use the `--cached`
+flag or not, since now the index is coherent with the working tree.
+
+Now, since we've updated `hello` in the index, we can commit the new
+version. We could do it by writing the tree by hand again, and
+committing the tree (this time we'd have to use the `-p HEAD` flag to
+tell commit that the HEAD was the *parent* of the new commit, and that
+this wasn't an initial commit any more), but you've done that once
+already, so let's just use the helpful script this time:
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+which starts an editor for you to write the commit message and tells you
+a bit about what you have done.
+
+Write whatever message you want, and all the lines that start with '#'
+will be pruned out, and the rest will be used as the commit message for
+the change. If you decide you don't want to commit anything after all at
+this point (you can continue to edit things and update the index), you
+can just leave an empty message. Otherwise `git commit` will commit
+the change for you.
+
+You've now made your first real Git commit. And if you're interested in
+looking at what `git commit` really does, feel free to investigate:
+it's a few very simple shell scripts to generate the helpful (?) commit
+message headers, and a few one-liners that actually do the
+commit itself ('git commit').
+
+
+Inspecting Changes
+------------------
+
+While creating changes is useful, it's even more useful if you can tell
+later what changed. The most useful command for this is another of the
+'diff' family, namely 'git diff-tree'.
+
+'git diff-tree' can be given two arbitrary trees, and it will tell you the
+differences between them. Perhaps even more commonly, though, you can
+give it just a single commit object, and it will figure out the parent
+of that commit itself, and show the difference directly. Thus, to get
+the same diff that we've already seen several times, we can now do
+
+----------------
+$ git diff-tree -p HEAD
+----------------
+
+(again, `-p` means to show the difference as a human-readable patch),
+and it will show what the last commit (in `HEAD`) actually changed.
+
+[NOTE]
+============
+Here is an ASCII art by Jon Loeliger that illustrates how
+various 'diff-{asterisk}' commands compare things.
+
+                      diff-tree
+                       +----+
+                       |    |
+                       |    |
+                       V    V
+                    +-----------+
+                    | Object DB |
+                    |  Backing  |
+                    |   Store   |
+                    +-----------+
+                      ^    ^
+                      |    |
+                      |    |  diff-index --cached
+                      |    |
+          diff-index  |    V
+                      |  +-----------+
+                      |  |   Index   |
+                      |  |  "cache"  |
+                      |  +-----------+
+                      |    ^
+                      |    |
+                      |    |  diff-files
+                      |    |
+                      V    V
+                    +-----------+
+                    |  Working  |
+                    | Directory |
+                    +-----------+
+============
+
+More interestingly, you can also give 'git diff-tree' the `--pretty` flag,
+which tells it to also show the commit message and author and date of the
+commit, and you can tell it to show a whole series of diffs.
+Alternatively, you can tell it to be "silent", and not show the diffs at
+all, but just show the actual commit message.
+
+In fact, together with the 'git rev-list' program (which generates a
+list of revisions), 'git diff-tree' ends up being a veritable fount of
+changes.  You can emulate `git log`, `git log -p`, etc. with a trivial
+script that pipes the output of `git rev-list` to `git diff-tree --stdin`,
+which was exactly how early versions of `git log` were implemented.
+
+
+Tagging a version
+-----------------
+
+In Git, there are two kinds of tags, a "light" one, and an "annotated tag".
+
+A "light" tag is technically nothing more than a branch, except we put
+it in the `.git/refs/tags/` subdirectory instead of calling it a `head`.
+So the simplest form of tag involves nothing more than
+
+------------------------------------------------
+$ git tag my-first-tag
+------------------------------------------------
+
+which just writes the current `HEAD` into the `.git/refs/tags/my-first-tag`
+file, after which point you can then use this symbolic name for that
+particular state. You can, for example, do
+
+----------------
+$ git diff my-first-tag
+----------------
+
+to diff your current state against that tag which at this point will
+obviously be an empty diff, but if you continue to develop and commit
+stuff, you can use your tag as an "anchor-point" to see what has changed
+since you tagged it.
+
+An "annotated tag" is actually a real Git object, and contains not only a
+pointer to the state you want to tag, but also a small tag name and
+message, along with optionally a PGP signature that says that yes,
+you really did
+that tag. You create these annotated tags with either the `-a` or
+`-s` flag to 'git tag':
+
+----------------
+$ git tag -s <tagname>
+----------------
+
+which will sign the current `HEAD` (but you can also give it another
+argument that specifies the thing to tag, e.g., you could have tagged the
+current `mybranch` point by using `git tag <tagname> mybranch`).
+
+You normally only do signed tags for major releases or things
+like that, while the light-weight tags are useful for any marking you
+want to do -- any time you decide that you want to remember a certain
+point, just create a private tag for it, and you have a nice symbolic
+name for the state at that point.
+
+
+Copying repositories
+--------------------
+
+Git repositories are normally totally self-sufficient and relocatable.
+Unlike CVS, for example, there is no separate notion of
+"repository" and "working tree". A Git repository normally *is* the
+working tree, with the local Git information hidden in the `.git`
+subdirectory. There is nothing else. What you see is what you got.
+
+[NOTE]
+You can tell Git to split the Git internal information from
+the directory that it tracks, but we'll ignore that for now: it's not
+how normal projects work, and it's really only meant for special uses.
+So the mental model of "the Git information is always tied directly to
+the working tree that it describes" may not be technically 100%
+accurate, but it's a good model for all normal use.
+
+This has two implications:
+
+ - if you grow bored with the tutorial repository you created (or you've
+   made a mistake and want to start all over), you can just do simple
++
+----------------
+$ rm -rf git-tutorial
+----------------
++
+and it will be gone. There's no external repository, and there's no
+history outside the project you created.
+
+ - if you want to move or duplicate a Git repository, you can do so. There
+   is 'git clone' command, but if all you want to do is just to
+   create a copy of your repository (with all the full history that
+   went along with it), you can do so with a regular
+   `cp -a git-tutorial new-git-tutorial`.
++
+Note that when you've moved or copied a Git repository, your Git index
+file (which caches various information, notably some of the "stat"
+information for the files involved) will likely need to be refreshed.
+So after you do a `cp -a` to create a new copy, you'll want to do
++
+----------------
+$ git update-index --refresh
+----------------
++
+in the new repository to make sure that the index file is up to date.
+
+Note that the second point is true even across machines. You can
+duplicate a remote Git repository with *any* regular copy mechanism, be it
+'scp', 'rsync' or 'wget'.
+
+When copying a remote repository, you'll want to at a minimum update the
+index cache when you do this, and especially with other peoples'
+repositories you often want to make sure that the index cache is in some
+known state (you don't know *what* they've done and not yet checked in),
+so usually you'll precede the 'git update-index' with a
+
+----------------
+$ git read-tree --reset HEAD
+$ git update-index --refresh
+----------------
+
+which will force a total index re-build from the tree pointed to by `HEAD`.
+It resets the index contents to `HEAD`, and then the 'git update-index'
+makes sure to match up all index entries with the checked-out files.
+If the original repository had uncommitted changes in its
+working tree, `git update-index --refresh` notices them and
+tells you they need to be updated.
+
+The above can also be written as simply
+
+----------------
+$ git reset
+----------------
+
+and in fact a lot of the common Git command combinations can be scripted
+with the `git xyz` interfaces.  You can learn things by just looking
+at what the various git scripts do.  For example, `git reset` used to be
+the above two lines implemented in 'git reset', but some things like
+'git status' and 'git commit' are slightly more complex scripts around
+the basic Git commands.
+
+Many (most?) public remote repositories will not contain any of
+the checked out files or even an index file, and will *only* contain the
+actual core Git files. Such a repository usually doesn't even have the
+`.git` subdirectory, but has all the Git files directly in the
+repository.
+
+To create your own local live copy of such a "raw" Git repository, you'd
+first create your own subdirectory for the project, and then copy the
+raw repository contents into the `.git` directory. For example, to
+create your own copy of the Git repository, you'd do the following
+
+----------------
+$ mkdir my-git
+$ cd my-git
+$ rsync -rL rsync://rsync.kernel.org/pub/scm/git/git.git/ .git
+----------------
+
+followed by
+
+----------------
+$ git read-tree HEAD
+----------------
+
+to populate the index. However, now you have populated the index, and
+you have all the Git internal files, but you will notice that you don't
+actually have any of the working tree files to work on. To get
+those, you'd check them out with
+
+----------------
+$ git checkout-index -u -a
+----------------
+
+where the `-u` flag means that you want the checkout to keep the index
+up to date (so that you don't have to refresh it afterward), and the
+`-a` flag means "check out all files" (if you have a stale copy or an
+older version of a checked out tree you may also need to add the `-f`
+flag first, to tell 'git checkout-index' to *force* overwriting of any old
+files).
+
+Again, this can all be simplified with
+
+----------------
+$ git clone git://git.kernel.org/pub/scm/git/git.git/ my-git
+$ cd my-git
+$ git checkout
+----------------
+
+which will end up doing all of the above for you.
+
+You have now successfully copied somebody else's (mine) remote
+repository, and checked it out.
+
+
+Creating a new branch
+---------------------
+
+Branches in Git are really nothing more than pointers into the Git
+object database from within the `.git/refs/` subdirectory, and as we
+already discussed, the `HEAD` branch is nothing but a symlink to one of
+these object pointers.
+
+You can at any time create a new branch by just picking an arbitrary
+point in the project history, and just writing the SHA-1 name of that
+object into a file under `.git/refs/heads/`. You can use any filename you
+want (and indeed, subdirectories), but the convention is that the
+"normal" branch is called `master`. That's just a convention, though,
+and nothing enforces it.
+
+To show that as an example, let's go back to the git-tutorial repository we
+used earlier, and create a branch in it. You do that by simply just
+saying that you want to check out a new branch:
+
+------------
+$ git switch -c mybranch
+------------
+
+will create a new branch based at the current `HEAD` position, and switch
+to it.
+
+[NOTE]
+================================================
+If you make the decision to start your new branch at some
+other point in the history than the current `HEAD`, you can do so by
+just telling 'git checkout' what the base of the checkout would be.
+In other words, if you have an earlier tag or branch, you'd just do
+
+------------
+$ git switch -c mybranch earlier-commit
+------------
+
+and it would create the new branch `mybranch` at the earlier commit,
+and check out the state at that time.
+================================================
+
+You can always just jump back to your original `master` branch by doing
+
+------------
+$ git switch master
+------------
+
+(or any other branch-name, for that matter) and if you forget which
+branch you happen to be on, a simple
+
+------------
+$ cat .git/HEAD
+------------
+
+will tell you where it's pointing.  To get the list of branches
+you have, you can say
+
+------------
+$ git branch
+------------
+
+which used to be nothing more than a simple script around `ls .git/refs/heads`.
+There will be an asterisk in front of the branch you are currently on.
+
+Sometimes you may wish to create a new branch _without_ actually
+checking it out and switching to it. If so, just use the command
+
+------------
+$ git branch <branchname> [startingpoint]
+------------
+
+which will simply _create_ the branch, but will not do anything further.
+You can then later -- once you decide that you want to actually develop
+on that branch -- switch to that branch with a regular 'git switch'
+with the branchname as the argument.
+
+
+Merging two branches
+--------------------
+
+One of the ideas of having a branch is that you do some (possibly
+experimental) work in it, and eventually merge it back to the main
+branch. So assuming you created the above `mybranch` that started out
+being the same as the original `master` branch, let's make sure we're in
+that branch, and do some work there.
+
+------------------------------------------------
+$ git switch mybranch
+$ echo "Work, work, work" >>hello
+$ git commit -m "Some work." -i hello
+------------------------------------------------
+
+Here, we just added another line to `hello`, and we used a shorthand for
+doing both `git update-index hello` and `git commit` by just giving the
+filename directly to `git commit`, with an `-i` flag (it tells
+Git to 'include' that file in addition to what you have done to
+the index file so far when making the commit).  The `-m` flag is to give the
+commit log message from the command line.
+
+Now, to make it a bit more interesting, let's assume that somebody else
+does some work in the original branch, and simulate that by going back
+to the master branch, and editing the same file differently there:
+
+------------
+$ git switch master
+------------
+
+Here, take a moment to look at the contents of `hello`, and notice how they
+don't contain the work we just did in `mybranch` -- because that work
+hasn't happened in the `master` branch at all. Then do
+
+------------
+$ echo "Play, play, play" >>hello
+$ echo "Lots of fun" >>example
+$ git commit -m "Some fun." -i hello example
+------------
+
+since the master branch is obviously in a much better mood.
+
+Now, you've got two branches, and you decide that you want to merge the
+work done. Before we do that, let's introduce a cool graphical tool that
+helps you view what's going on:
+
+----------------
+$ gitk --all
+----------------
+
+will show you graphically both of your branches (that's what the `--all`
+means: normally it will just show you your current `HEAD`) and their
+histories. You can also see exactly how they came to be from a common
+source.
+
+Anyway, let's exit 'gitk' (`^Q` or the File menu), and decide that we want
+to merge the work we did on the `mybranch` branch into the `master`
+branch (which is currently our `HEAD` too). To do that, there's a nice
+script called 'git merge', which wants to know which branches you want
+to resolve and what the merge is all about:
+
+------------
+$ git merge -m "Merge work in mybranch" mybranch
+------------
+
+where the first argument is going to be used as the commit message if
+the merge can be resolved automatically.
+
+Now, in this case we've intentionally created a situation where the
+merge will need to be fixed up by hand, though, so Git will do as much
+of it as it can automatically (which in this case is just merge the `example`
+file, which had no differences in the `mybranch` branch), and say:
+
+----------------
+	Auto-merging hello
+	CONFLICT (content): Merge conflict in hello
+	Automatic merge failed; fix conflicts and then commit the result.
+----------------
+
+It tells you that it did an "Automatic merge", which
+failed due to conflicts in `hello`.
+
+Not to worry. It left the (trivial) conflict in `hello` in the same form you
+should already be well used to if you've ever used CVS, so let's just
+open `hello` in our editor (whatever that may be), and fix it up somehow.
+I'd suggest just making it so that `hello` contains all four lines:
+
+------------
+Hello World
+It's a new day for git
+Play, play, play
+Work, work, work
+------------
+
+and once you're happy with your manual merge, just do a
+
+------------
+$ git commit -i hello
+------------
+
+which will very loudly warn you that you're now committing a merge
+(which is correct, so never mind), and you can write a small merge
+message about your adventures in 'git merge'-land.
+
+After you're done, start up `gitk --all` to see graphically what the
+history looks like. Notice that `mybranch` still exists, and you can
+switch to it, and continue to work with it if you want to. The
+`mybranch` branch will not contain the merge, but next time you merge it
+from the `master` branch, Git will know how you merged it, so you'll not
+have to do _that_ merge again.
+
+Another useful tool, especially if you do not always work in X-Window
+environment, is `git show-branch`.
+
+------------------------------------------------
+$ git show-branch --topo-order --more=1 master mybranch
+* [master] Merge work in mybranch
+ ! [mybranch] Some work.
+--
+-  [master] Merge work in mybranch
+*+ [mybranch] Some work.
+*  [master^] Some fun.
+------------------------------------------------
+
+The first two lines indicate that it is showing the two branches
+with the titles of their top-of-the-tree commits, you are currently on
+`master` branch (notice the asterisk `*` character), and the first
+column for the later output lines is used to show commits contained in the
+`master` branch, and the second column for the `mybranch`
+branch. Three commits are shown along with their titles.
+All of them have non blank characters in the first column (`*`
+shows an ordinary commit on the current branch, `-` is a merge commit), which
+means they are now part of the `master` branch. Only the "Some
+work" commit has the plus `+` character in the second column,
+because `mybranch` has not been merged to incorporate these
+commits from the master branch.  The string inside brackets
+before the commit log message is a short name you can use to
+name the commit.  In the above example, 'master' and 'mybranch'
+are branch heads.  'master^' is the first parent of 'master'
+branch head.  Please see linkgit:gitrevisions[7] if you want to
+see more complex cases.
+
+[NOTE]
+Without the '--more=1' option, 'git show-branch' would not output the
+'[master^]' commit, as '[mybranch]' commit is a common ancestor of
+both 'master' and 'mybranch' tips.  Please see linkgit:git-show-branch[1]
+for details.
+
+[NOTE]
+If there were more commits on the 'master' branch after the merge, the
+merge commit itself would not be shown by 'git show-branch' by
+default.  You would need to provide `--sparse` option to make the
+merge commit visible in this case.
+
+Now, let's pretend you are the one who did all the work in
+`mybranch`, and the fruit of your hard work has finally been merged
+to the `master` branch. Let's go back to `mybranch`, and run
+'git merge' to get the "upstream changes" back to your branch.
+
+------------
+$ git switch mybranch
+$ git merge -m "Merge upstream changes." master
+------------
+
+This outputs something like this (the actual commit object names
+would be different)
+
+----------------
+Updating from ae3a2da... to a80b4aa....
+Fast-forward (no commit created; -m option ignored)
+ example | 1 +
+ hello   | 1 +
+ 2 files changed, 2 insertions(+)
+----------------
+
+Because your branch did not contain anything more than what had
+already been merged into the `master` branch, the merge operation did
+not actually do a merge. Instead, it just updated the top of
+the tree of your branch to that of the `master` branch. This is
+often called 'fast-forward' merge.
+
+You can run `gitk --all` again to see how the commit ancestry
+looks like, or run 'show-branch', which tells you this.
+
+------------------------------------------------
+$ git show-branch master mybranch
+! [master] Merge work in mybranch
+ * [mybranch] Merge work in mybranch
+--
+-- [master] Merge work in mybranch
+------------------------------------------------
+
+
+Merging external work
+---------------------
+
+It's usually much more common that you merge with somebody else than
+merging with your own branches, so it's worth pointing out that Git
+makes that very easy too, and in fact, it's not that different from
+doing a 'git merge'. In fact, a remote merge ends up being nothing
+more than "fetch the work from a remote repository into a temporary tag"
+followed by a 'git merge'.
+
+Fetching from a remote repository is done by, unsurprisingly,
+'git fetch':
+
+----------------
+$ git fetch <remote-repository>
+----------------
+
+One of the following transports can be used to name the
+repository to download from:
+
+SSH::
+	`remote.machine:/path/to/repo.git/` or
++
+`ssh://remote.machine/path/to/repo.git/`
++
+This transport can be used for both uploading and downloading,
+and requires you to have a log-in privilege over `ssh` to the
+remote machine.  It finds out the set of objects the other side
+lacks by exchanging the head commits both ends have and
+transfers (close to) minimum set of objects.  It is by far the
+most efficient way to exchange Git objects between repositories.
+
+Local directory::
+	`/path/to/repo.git/`
++
+This transport is the same as SSH transport but uses 'sh' to run
+both ends on the local machine instead of running other end on
+the remote machine via 'ssh'.
+
+Git Native::
+	`git://remote.machine/path/to/repo.git/`
++
+This transport was designed for anonymous downloading.  Like SSH
+transport, it finds out the set of objects the downstream side
+lacks and transfers (close to) minimum set of objects.
+
+HTTP(S)::
+	`http://remote.machine/path/to/repo.git/`
++
+Downloader from http and https URL
+first obtains the topmost commit object name from the remote site
+by looking at the specified refname under `repo.git/refs/` directory,
+and then tries to obtain the
+commit object by downloading from `repo.git/objects/xx/xxx...`
+using the object name of that commit object.  Then it reads the
+commit object to find out its parent commits and the associate
+tree object; it repeats this process until it gets all the
+necessary objects.  Because of this behavior, they are
+sometimes also called 'commit walkers'.
++
+The 'commit walkers' are sometimes also called 'dumb
+transports', because they do not require any Git aware smart
+server like Git Native transport does.  Any stock HTTP server
+that does not even support directory index would suffice.  But
+you must prepare your repository with 'git update-server-info'
+to help dumb transport downloaders.
+
+Once you fetch from the remote repository, you `merge` that
+with your current branch.
+
+However -- it's such a common thing to `fetch` and then
+immediately `merge`, that it's called `git pull`, and you can
+simply do
+
+----------------
+$ git pull <remote-repository>
+----------------
+
+and optionally give a branch-name for the remote end as a second
+argument.
+
+[NOTE]
+You could do without using any branches at all, by
+keeping as many local repositories as you would like to have
+branches, and merging between them with 'git pull', just like
+you merge between branches. The advantage of this approach is
+that it lets you keep a set of files for each `branch` checked
+out and you may find it easier to switch back and forth if you
+juggle multiple lines of development simultaneously. Of
+course, you will pay the price of more disk usage to hold
+multiple working trees, but disk space is cheap these days.
+
+It is likely that you will be pulling from the same remote
+repository from time to time. As a short hand, you can store
+the remote repository URL in the local repository's config file
+like this:
+
+------------------------------------------------
+$ git config remote.linus.url http://www.kernel.org/pub/scm/git/git.git/
+------------------------------------------------
+
+and use the "linus" keyword with 'git pull' instead of the full URL.
+
+Examples.
+
+. `git pull linus`
+. `git pull linus tag v0.99.1`
+
+the above are equivalent to:
+
+. `git pull http://www.kernel.org/pub/scm/git/git.git/ HEAD`
+. `git pull http://www.kernel.org/pub/scm/git/git.git/ tag v0.99.1`
+
+
+How does the merge work?
+------------------------
+
+We said this tutorial shows what plumbing does to help you cope
+with the porcelain that isn't flushing, but we so far did not
+talk about how the merge really works.  If you are following
+this tutorial the first time, I'd suggest to skip to "Publishing
+your work" section and come back here later.
+
+OK, still with me?  To give us an example to look at, let's go
+back to the earlier repository with "hello" and "example" file,
+and bring ourselves back to the pre-merge state:
+
+------------
+$ git show-branch --more=2 master mybranch
+! [master] Merge work in mybranch
+ * [mybranch] Merge work in mybranch
+--
+-- [master] Merge work in mybranch
++* [master^2] Some work.
++* [master^] Some fun.
+------------
+
+Remember, before running 'git merge', our `master` head was at
+"Some fun." commit, while our `mybranch` head was at "Some
+work." commit.
+
+------------
+$ git switch -C mybranch master^2
+$ git switch master
+$ git reset --hard master^
+------------
+
+After rewinding, the commit structure should look like this:
+
+------------
+$ git show-branch
+* [master] Some fun.
+ ! [mybranch] Some work.
+--
+*  [master] Some fun.
+ + [mybranch] Some work.
+*+ [master^] Initial commit
+------------
+
+Now we are ready to experiment with the merge by hand.
+
+`git merge` command, when merging two branches, uses 3-way merge
+algorithm.  First, it finds the common ancestor between them.
+The command it uses is 'git merge-base':
+
+------------
+$ mb=$(git merge-base HEAD mybranch)
+------------
+
+The command writes the commit object name of the common ancestor
+to the standard output, so we captured its output to a variable,
+because we will be using it in the next step.  By the way, the common
+ancestor commit is the "Initial commit" commit in this case.  You can
+tell it by:
+
+------------
+$ git name-rev --name-only --tags $mb
+my-first-tag
+------------
+
+After finding out a common ancestor commit, the second step is
+this:
+
+------------
+$ git read-tree -m -u $mb HEAD mybranch
+------------
+
+This is the same 'git read-tree' command we have already seen,
+but it takes three trees, unlike previous examples.  This reads
+the contents of each tree into different 'stage' in the index
+file (the first tree goes to stage 1, the second to stage 2,
+etc.).  After reading three trees into three stages, the paths
+that are the same in all three stages are 'collapsed' into stage
+0.  Also paths that are the same in two of three stages are
+collapsed into stage 0, taking the SHA-1 from either stage 2 or
+stage 3, whichever is different from stage 1 (i.e. only one side
+changed from the common ancestor).
+
+After 'collapsing' operation, paths that are different in three
+trees are left in non-zero stages.  At this point, you can
+inspect the index file with this command:
+
+------------
+$ git ls-files --stage
+100644 7f8b141b65fdcee47321e399a2598a235a032422 0	example
+100644 557db03de997c86a4a028e1ebd3a1ceb225be238 1	hello
+100644 ba42a2a96e3027f3333e13ede4ccf4498c3ae942 2	hello
+100644 cc44c73eb783565da5831b4d820c962954019b69 3	hello
+------------
+
+In our example of only two files, we did not have unchanged
+files so only 'example' resulted in collapsing.  But in real-life
+large projects, when only a small number of files change in one commit,
+this 'collapsing' tends to trivially merge most of the paths
+fairly quickly, leaving only a handful of real changes in non-zero
+stages.
+
+To look at only non-zero stages, use `--unmerged` flag:
+
+------------
+$ git ls-files --unmerged
+100644 557db03de997c86a4a028e1ebd3a1ceb225be238 1	hello
+100644 ba42a2a96e3027f3333e13ede4ccf4498c3ae942 2	hello
+100644 cc44c73eb783565da5831b4d820c962954019b69 3	hello
+------------
+
+The next step of merging is to merge these three versions of the
+file, using 3-way merge.  This is done by giving
+'git merge-one-file' command as one of the arguments to
+'git merge-index' command:
+
+------------
+$ git merge-index git-merge-one-file hello
+Auto-merging hello
+ERROR: Merge conflict in hello
+fatal: merge program failed
+------------
+
+'git merge-one-file' script is called with parameters to
+describe those three versions, and is responsible to leave the
+merge results in the working tree.
+It is a fairly straightforward shell script, and
+eventually calls 'merge' program from RCS suite to perform a
+file-level 3-way merge.  In this case, 'merge' detects
+conflicts, and the merge result with conflict marks is left in
+the working tree..  This can be seen if you run `ls-files
+--stage` again at this point:
+
+------------
+$ git ls-files --stage
+100644 7f8b141b65fdcee47321e399a2598a235a032422 0	example
+100644 557db03de997c86a4a028e1ebd3a1ceb225be238 1	hello
+100644 ba42a2a96e3027f3333e13ede4ccf4498c3ae942 2	hello
+100644 cc44c73eb783565da5831b4d820c962954019b69 3	hello
+------------
+
+This is the state of the index file and the working file after
+'git merge' returns control back to you, leaving the conflicting
+merge for you to resolve.  Notice that the path `hello` is still
+unmerged, and what you see with 'git diff' at this point is
+differences since stage 2 (i.e. your version).
+
+
+Publishing your work
+--------------------
+
+So, we can use somebody else's work from a remote repository, but
+how can *you* prepare a repository to let other people pull from
+it?
+
+You do your real work in your working tree that has your
+primary repository hanging under it as its `.git` subdirectory.
+You *could* make that repository accessible remotely and ask
+people to pull from it, but in practice that is not the way
+things are usually done. A recommended way is to have a public
+repository, make it reachable by other people, and when the
+changes you made in your primary working tree are in good shape,
+update the public repository from it. This is often called
+'pushing'.
+
+[NOTE]
+This public repository could further be mirrored, and that is
+how Git repositories at `kernel.org` are managed.
+
+Publishing the changes from your local (private) repository to
+your remote (public) repository requires a write privilege on
+the remote machine. You need to have an SSH account there to
+run a single command, 'git-receive-pack'.
+
+First, you need to create an empty repository on the remote
+machine that will house your public repository. This empty
+repository will be populated and be kept up to date by pushing
+into it later. Obviously, this repository creation needs to be
+done only once.
+
+[NOTE]
+'git push' uses a pair of commands,
+'git send-pack' on your local machine, and 'git-receive-pack'
+on the remote machine. The communication between the two over
+the network internally uses an SSH connection.
+
+Your private repository's Git directory is usually `.git`, but
+your public repository is often named after the project name,
+i.e. `<project>.git`. Let's create such a public repository for
+project `my-git`. After logging into the remote machine, create
+an empty directory:
+
+------------
+$ mkdir my-git.git
+------------
+
+Then, make that directory into a Git repository by running
+'git init', but this time, since its name is not the usual
+`.git`, we do things slightly differently:
+
+------------
+$ GIT_DIR=my-git.git git init
+------------
+
+Make sure this directory is available for others you want your
+changes to be pulled via the transport of your choice. Also
+you need to make sure that you have the 'git-receive-pack'
+program on the `$PATH`.
+
+[NOTE]
+Many installations of sshd do not invoke your shell as the login
+shell when you directly run programs; what this means is that if
+your login shell is 'bash', only `.bashrc` is read and not
+`.bash_profile`. As a workaround, make sure `.bashrc` sets up
+`$PATH` so that you can run 'git-receive-pack' program.
+
+[NOTE]
+If you plan to publish this repository to be accessed over http,
+you should do `mv my-git.git/hooks/post-update.sample
+my-git.git/hooks/post-update` at this point.
+This makes sure that every time you push into this
+repository, `git update-server-info` is run.
+
+Your "public repository" is now ready to accept your changes.
+Come back to the machine you have your private repository. From
+there, run this command:
+
+------------
+$ git push <public-host>:/path/to/my-git.git master
+------------
+
+This synchronizes your public repository to match the named
+branch head (i.e. `master` in this case) and objects reachable
+from them in your current repository.
+
+As a real example, this is how I update my public Git
+repository. Kernel.org mirror network takes care of the
+propagation to other publicly visible machines:
+
+------------
+$ git push master.kernel.org:/pub/scm/git/git.git/
+------------
+
+
+Packing your repository
+-----------------------
+
+Earlier, we saw that one file under `.git/objects/??/` directory
+is stored for each Git object you create. This representation
+is efficient to create atomically and safely, but
+not so convenient to transport over the network. Since Git objects are
+immutable once they are created, there is a way to optimize the
+storage by "packing them together". The command
+
+------------
+$ git repack
+------------
+
+will do it for you. If you followed the tutorial examples, you
+would have accumulated about 17 objects in `.git/objects/??/`
+directories by now. 'git repack' tells you how many objects it
+packed, and stores the packed file in the `.git/objects/pack`
+directory.
+
+[NOTE]
+You will see two files, `pack-*.pack` and `pack-*.idx`,
+in `.git/objects/pack` directory. They are closely related to
+each other, and if you ever copy them by hand to a different
+repository for whatever reason, you should make sure you copy
+them together. The former holds all the data from the objects
+in the pack, and the latter holds the index for random
+access.
+
+If you are paranoid, running 'git verify-pack' command would
+detect if you have a corrupt pack, but do not worry too much.
+Our programs are always perfect ;-).
+
+Once you have packed objects, you do not need to leave the
+unpacked objects that are contained in the pack file anymore.
+
+------------
+$ git prune-packed
+------------
+
+would remove them for you.
+
+You can try running `find .git/objects -type f` before and after
+you run `git prune-packed` if you are curious.  Also `git
+count-objects` would tell you how many unpacked objects are in
+your repository and how much space they are consuming.
+
+[NOTE]
+`git pull` is slightly cumbersome for HTTP transport, as a
+packed repository may contain relatively few objects in a
+relatively large pack. If you expect many HTTP pulls from your
+public repository you might want to repack & prune often, or
+never.
+
+If you run `git repack` again at this point, it will say
+"Nothing new to pack.". Once you continue your development and
+accumulate the changes, running `git repack` again will create a
+new pack, that contains objects created since you packed your
+repository the last time. We recommend that you pack your project
+soon after the initial import (unless you are starting your
+project from scratch), and then run `git repack` every once in a
+while, depending on how active your project is.
+
+When a repository is synchronized via `git push` and `git pull`
+objects packed in the source repository are usually stored
+unpacked in the destination.
+While this allows you to use different packing strategies on
+both ends, it also means you may need to repack both
+repositories every once in a while.
+
+
+Working with Others
+-------------------
+
+Although Git is a truly distributed system, it is often
+convenient to organize your project with an informal hierarchy
+of developers. Linux kernel development is run this way. There
+is a nice illustration (page 17, "Merges to Mainline") in
+https://web.archive.org/web/20120915203609/http://www.xenotime.net/linux/mentor/linux-mentoring-2006.pdf[Randy Dunlap's presentation].
+
+It should be stressed that this hierarchy is purely *informal*.
+There is nothing fundamental in Git that enforces the "chain of
+patch flow" this hierarchy implies. You do not have to pull
+from only one remote repository.
+
+A recommended workflow for a "project lead" goes like this:
+
+1. Prepare your primary repository on your local machine. Your
+   work is done there.
+
+2. Prepare a public repository accessible to others.
++
+If other people are pulling from your repository over dumb
+transport protocols (HTTP), you need to keep this repository
+'dumb transport friendly'.  After `git init`,
+`$GIT_DIR/hooks/post-update.sample` copied from the standard templates
+would contain a call to 'git update-server-info'
+but you need to manually enable the hook with
+`mv post-update.sample post-update`.  This makes sure
+'git update-server-info' keeps the necessary files up to date.
+
+3. Push into the public repository from your primary
+   repository.
+
+4. 'git repack' the public repository. This establishes a big
+   pack that contains the initial set of objects as the
+   baseline, and possibly 'git prune' if the transport
+   used for pulling from your repository supports packed
+   repositories.
+
+5. Keep working in your primary repository. Your changes
+   include modifications of your own, patches you receive via
+   e-mails, and merges resulting from pulling the "public"
+   repositories of your "subsystem maintainers".
++
+You can repack this private repository whenever you feel like.
+
+6. Push your changes to the public repository, and announce it
+   to the public.
+
+7. Every once in a while, 'git repack' the public repository.
+   Go back to step 5. and continue working.
+
+
+A recommended work cycle for a "subsystem maintainer" who works
+on that project and has an own "public repository" goes like this:
+
+1. Prepare your work repository, by running 'git clone' on the public
+   repository of the "project lead". The URL used for the
+   initial cloning is stored in the remote.origin.url
+   configuration variable.
+
+2. Prepare a public repository accessible to others, just like
+   the "project lead" person does.
+
+3. Copy over the packed files from "project lead" public
+   repository to your public repository, unless the "project
+   lead" repository lives on the same machine as yours.  In the
+   latter case, you can use `objects/info/alternates` file to
+   point at the repository you are borrowing from.
+
+4. Push into the public repository from your primary
+   repository. Run 'git repack', and possibly 'git prune' if the
+   transport used for pulling from your repository supports
+   packed repositories.
+
+5. Keep working in your primary repository. Your changes
+   include modifications of your own, patches you receive via
+   e-mails, and merges resulting from pulling the "public"
+   repositories of your "project lead" and possibly your
+   "sub-subsystem maintainers".
++
+You can repack this private repository whenever you feel
+like.
+
+6. Push your changes to your public repository, and ask your
+   "project lead" and possibly your "sub-subsystem
+   maintainers" to pull from it.
+
+7. Every once in a while, 'git repack' the public repository.
+   Go back to step 5. and continue working.
+
+
+A recommended work cycle for an "individual developer" who does
+not have a "public" repository is somewhat different. It goes
+like this:
+
+1. Prepare your work repository, by 'git clone' the public
+   repository of the "project lead" (or a "subsystem
+   maintainer", if you work on a subsystem). The URL used for
+   the initial cloning is stored in the remote.origin.url
+   configuration variable.
+
+2. Do your work in your repository on 'master' branch.
+
+3. Run `git fetch origin` from the public repository of your
+   upstream every once in a while. This does only the first
+   half of `git pull` but does not merge. The head of the
+   public repository is stored in `.git/refs/remotes/origin/master`.
+
+4. Use `git cherry origin` to see which ones of your patches
+   were accepted, and/or use `git rebase origin` to port your
+   unmerged changes forward to the updated upstream.
+
+5. Use `git format-patch origin` to prepare patches for e-mail
+   submission to your upstream and send it out. Go back to
+   step 2. and continue.
+
+
+Working with Others, Shared Repository Style
+--------------------------------------------
+
+If you are coming from a CVS background, the style of cooperation
+suggested in the previous section may be new to you. You do not
+have to worry. Git supports the "shared public repository" style of
+cooperation you are probably more familiar with as well.
+
+See linkgit:gitcvs-migration[7] for the details.
+
+Bundling your work together
+---------------------------
+
+It is likely that you will be working on more than one thing at
+a time.  It is easy to manage those more-or-less independent tasks
+using branches with Git.
+
+We have already seen how branches work previously,
+with "fun and work" example using two branches.  The idea is the
+same if there are more than two branches.  Let's say you started
+out from "master" head, and have some new code in the "master"
+branch, and two independent fixes in the "commit-fix" and
+"diff-fix" branches:
+
+------------
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+  * [master] Release candidate #1
+---
+ +  [diff-fix] Fix rename detection.
+ +  [diff-fix~1] Better common substring algorithm.
++   [commit-fix] Fix commit message normalization.
+  * [master] Release candidate #1
+++* [diff-fix~2] Pretty-print messages.
+------------
+
+Both fixes are tested well, and at this point, you want to merge
+in both of them.  You could merge in 'diff-fix' first and then
+'commit-fix' next, like this:
+
+------------
+$ git merge -m "Merge fix in diff-fix" diff-fix
+$ git merge -m "Merge fix in commit-fix" commit-fix
+------------
+
+Which would result in:
+
+------------
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+  * [master] Merge fix in commit-fix
+---
+  - [master] Merge fix in commit-fix
++ * [commit-fix] Fix commit message normalization.
+  - [master~1] Merge fix in diff-fix
+ +* [diff-fix] Fix rename detection.
+ +* [diff-fix~1] Better common substring algorithm.
+  * [master~2] Release candidate #1
+++* [master~3] Pretty-print messages.
+------------
+
+However, there is no particular reason to merge in one branch
+first and the other next, when what you have are a set of truly
+independent changes (if the order mattered, then they are not
+independent by definition).  You could instead merge those two
+branches into the current branch at once.  First let's undo what
+we just did and start over.  We would want to get the master
+branch before these two merges by resetting it to 'master~2':
+
+------------
+$ git reset --hard master~2
+------------
+
+You can make sure `git show-branch` matches the state before
+those two 'git merge' you just did.  Then, instead of running
+two 'git merge' commands in a row, you would merge these two
+branch heads (this is known as 'making an Octopus'):
+
+------------
+$ git merge commit-fix diff-fix
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+  * [master] Octopus merge of branches 'diff-fix' and 'commit-fix'
+---
+  - [master] Octopus merge of branches 'diff-fix' and 'commit-fix'
++ * [commit-fix] Fix commit message normalization.
+ +* [diff-fix] Fix rename detection.
+ +* [diff-fix~1] Better common substring algorithm.
+  * [master~1] Release candidate #1
+++* [master~2] Pretty-print messages.
+------------
+
+Note that you should not do Octopus just because you can.  An octopus
+is a valid thing to do and often makes it easier to view the
+commit history if you are merging more than two independent
+changes at the same time.  However, if you have merge conflicts
+with any of the branches you are merging in and need to hand
+resolve, that is an indication that the development happened in
+those branches were not independent after all, and you should
+merge two at a time, documenting how you resolved the conflicts,
+and the reason why you preferred changes made in one side over
+the other.  Otherwise it would make the project history harder
+to follow, not easier.
+
+SEE ALSO
+--------
+linkgit:gittutorial[7],
+linkgit:gittutorial-2[7],
+linkgit:gitcvs-migration[7],
+linkgit:git-help[1],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitcredentials.txt b/third_party/git/Documentation/gitcredentials.txt
new file mode 100644
index 0000000000..adc759612d
--- /dev/null
+++ b/third_party/git/Documentation/gitcredentials.txt
@@ -0,0 +1,194 @@
+gitcredentials(7)
+=================
+
+NAME
+----
+gitcredentials - providing usernames and passwords to Git
+
+SYNOPSIS
+--------
+------------------
+git config credential.https://example.com.username myusername
+git config credential.helper "$helper $options"
+------------------
+
+DESCRIPTION
+-----------
+
+Git will sometimes need credentials from the user in order to perform
+operations; for example, it may need to ask for a username and password
+in order to access a remote repository over HTTP. This manual describes
+the mechanisms Git uses to request these credentials, as well as some
+features to avoid inputting these credentials repeatedly.
+
+REQUESTING CREDENTIALS
+----------------------
+
+Without any credential helpers defined, Git will try the following
+strategies to ask the user for usernames and passwords:
+
+1. If the `GIT_ASKPASS` environment variable is set, the program
+   specified by the variable is invoked. A suitable prompt is provided
+   to the program on the command line, and the user's input is read
+   from its standard output.
+
+2. Otherwise, if the `core.askPass` configuration variable is set, its
+   value is used as above.
+
+3. Otherwise, if the `SSH_ASKPASS` environment variable is set, its
+   value is used as above.
+
+4. Otherwise, the user is prompted on the terminal.
+
+AVOIDING REPETITION
+-------------------
+
+It can be cumbersome to input the same credentials over and over.  Git
+provides two methods to reduce this annoyance:
+
+1. Static configuration of usernames for a given authentication context.
+
+2. Credential helpers to cache or store passwords, or to interact with
+   a system password wallet or keychain.
+
+The first is simple and appropriate if you do not have secure storage available
+for a password. It is generally configured by adding this to your config:
+
+---------------------------------------
+[credential "https://example.com"]
+	username = me
+---------------------------------------
+
+Credential helpers, on the other hand, are external programs from which Git can
+request both usernames and passwords; they typically interface with secure
+storage provided by the OS or other programs.
+
+To use a helper, you must first select one to use. Git currently
+includes the following helpers:
+
+cache::
+
+	Cache credentials in memory for a short period of time. See
+	linkgit:git-credential-cache[1] for details.
+
+store::
+
+	Store credentials indefinitely on disk. See
+	linkgit:git-credential-store[1] for details.
+
+You may also have third-party helpers installed; search for
+`credential-*` in the output of `git help -a`, and consult the
+documentation of individual helpers.  Once you have selected a helper,
+you can tell Git to use it by putting its name into the
+credential.helper variable.
+
+1. Find a helper.
++
+-------------------------------------------
+$ git help -a | grep credential-
+credential-foo
+-------------------------------------------
+
+2. Read its description.
++
+-------------------------------------------
+$ git help credential-foo
+-------------------------------------------
+
+3. Tell Git to use it.
++
+-------------------------------------------
+$ git config --global credential.helper foo
+-------------------------------------------
+
+
+CREDENTIAL CONTEXTS
+-------------------
+
+Git considers each credential to have a context defined by a URL. This context
+is used to look up context-specific configuration, and is passed to any
+helpers, which may use it as an index into secure storage.
+
+For instance, imagine we are accessing `https://example.com/foo.git`. When Git
+looks into a config file to see if a section matches this context, it will
+consider the two a match if the context is a more-specific subset of the
+pattern in the config file. For example, if you have this in your config file:
+
+--------------------------------------
+[credential "https://example.com"]
+	username = foo
+--------------------------------------
+
+then we will match: both protocols are the same, both hosts are the same, and
+the "pattern" URL does not care about the path component at all. However, this
+context would not match:
+
+--------------------------------------
+[credential "https://kernel.org"]
+	username = foo
+--------------------------------------
+
+because the hostnames differ. Nor would it match `foo.example.com`; Git
+compares hostnames exactly, without considering whether two hosts are part of
+the same domain. Likewise, a config entry for `http://example.com` would not
+match: Git compares the protocols exactly.
+
+If the "pattern" URL does include a path component, then this too must match
+exactly: the context `https://example.com/bar/baz.git` will match a config
+entry for `https://example.com/bar/baz.git` (in addition to matching the config
+entry for `https://example.com`) but will not match a config entry for
+`https://example.com/bar`.
+
+
+CONFIGURATION OPTIONS
+---------------------
+
+Options for a credential context can be configured either in
+`credential.*` (which applies to all credentials), or
+`credential.<url>.*`, where <url> matches the context as described
+above.
+
+The following options are available in either location:
+
+helper::
+
+	The name of an external credential helper, and any associated options.
+	If the helper name is not an absolute path, then the string `git
+	credential-` is prepended. The resulting string is executed by the
+	shell (so, for example, setting this to `foo --option=bar` will execute
+	`git credential-foo --option=bar` via the shell. See the manual of
+	specific helpers for examples of their use.
++
+If there are multiple instances of the `credential.helper` configuration
+variable, each helper will be tried in turn, and may provide a username,
+password, or nothing. Once Git has acquired both a username and a
+password, no more helpers will be tried.
++
+If `credential.helper` is configured to the empty string, this resets
+the helper list to empty (so you may override a helper set by a
+lower-priority config file by configuring the empty-string helper,
+followed by whatever set of helpers you would like).
+
+username::
+
+	A default username, if one is not provided in the URL.
+
+useHttpPath::
+
+	By default, Git does not consider the "path" component of an http URL
+	to be worth matching via external helpers. This means that a credential
+	stored for `https://example.com/foo.git` will also be used for
+	`https://example.com/bar.git`. If you do want to distinguish these
+	cases, set this option to `true`.
+
+
+CUSTOM HELPERS
+--------------
+
+You can write your own custom helpers to interface with any system in
+which you keep credentials. See the documentation for Git's
+link:technical/api-credentials.html[credentials API] for details.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitcvs-migration.txt b/third_party/git/Documentation/gitcvs-migration.txt
new file mode 100644
index 0000000000..1cd1283d0f
--- /dev/null
+++ b/third_party/git/Documentation/gitcvs-migration.txt
@@ -0,0 +1,206 @@
+gitcvs-migration(7)
+===================
+
+NAME
+----
+gitcvs-migration - Git for CVS users
+
+SYNOPSIS
+--------
+[verse]
+'git cvsimport' *
+
+DESCRIPTION
+-----------
+
+Git differs from CVS in that every working tree contains a repository with
+a full copy of the project history, and no repository is inherently more
+important than any other.  However, you can emulate the CVS model by
+designating a single shared repository which people can synchronize with;
+this document explains how to do that.
+
+Some basic familiarity with Git is required. Having gone through
+linkgit:gittutorial[7] and
+linkgit:gitglossary[7] should be sufficient.
+
+Developing against a shared repository
+--------------------------------------
+
+Suppose a shared repository is set up in /pub/repo.git on the host
+foo.com.  Then as an individual committer you can clone the shared
+repository over ssh with:
+
+------------------------------------------------
+$ git clone foo.com:/pub/repo.git/ my-project
+$ cd my-project
+------------------------------------------------
+
+and hack away.  The equivalent of 'cvs update' is
+
+------------------------------------------------
+$ git pull origin
+------------------------------------------------
+
+which merges in any work that others might have done since the clone
+operation.  If there are uncommitted changes in your working tree, commit
+them first before running git pull.
+
+[NOTE]
+================================
+The 'pull' command knows where to get updates from because of certain
+configuration variables that were set by the first 'git clone'
+command; see `git config -l` and the linkgit:git-config[1] man
+page for details.
+================================
+
+You can update the shared repository with your changes by first committing
+your changes, and then using the 'git push' command:
+
+------------------------------------------------
+$ git push origin master
+------------------------------------------------
+
+to "push" those commits to the shared repository.  If someone else has
+updated the repository more recently, 'git push', like 'cvs commit', will
+complain, in which case you must pull any changes before attempting the
+push again.
+
+In the 'git push' command above we specify the name of the remote branch
+to update (`master`).  If we leave that out, 'git push' tries to update
+any branches in the remote repository that have the same name as a branch
+in the local repository.  So the last 'push' can be done with either of:
+
+------------
+$ git push origin
+$ git push foo.com:/pub/project.git/
+------------
+
+as long as the shared repository does not have any branches
+other than `master`.
+
+Setting Up a Shared Repository
+------------------------------
+
+We assume you have already created a Git repository for your project,
+possibly created from scratch or from a tarball (see
+linkgit:gittutorial[7]), or imported from an already existing CVS
+repository (see the next section).
+
+Assume your existing repo is at /home/alice/myproject.  Create a new "bare"
+repository (a repository without a working tree) and fetch your project into
+it:
+
+------------------------------------------------
+$ mkdir /pub/my-repo.git
+$ cd /pub/my-repo.git
+$ git --bare init --shared
+$ git --bare fetch /home/alice/myproject master:master
+------------------------------------------------
+
+Next, give every team member read/write access to this repository.  One
+easy way to do this is to give all the team members ssh access to the
+machine where the repository is hosted.  If you don't want to give them a
+full shell on the machine, there is a restricted shell which only allows
+users to do Git pushes and pulls; see linkgit:git-shell[1].
+
+Put all the committers in the same group, and make the repository
+writable by that group:
+
+------------------------------------------------
+$ chgrp -R $group /pub/my-repo.git
+------------------------------------------------
+
+Make sure committers have a umask of at most 027, so that the directories
+they create are writable and searchable by other group members.
+
+Importing a CVS archive
+-----------------------
+
+NOTE: These instructions use the `git-cvsimport` script which ships with
+git, but other importers may provide better results. See the note in
+linkgit:git-cvsimport[1] for other options.
+
+First, install version 2.1 or higher of cvsps from
+https://github.com/andreyvit/cvsps[https://github.com/andreyvit/cvsps] and make
+sure it is in your path.  Then cd to a checked out CVS working directory
+of the project you are interested in and run linkgit:git-cvsimport[1]:
+
+-------------------------------------------
+$ git cvsimport -C <destination> <module>
+-------------------------------------------
+
+This puts a Git archive of the named CVS module in the directory
+<destination>, which will be created if necessary.
+
+The import checks out from CVS every revision of every file.  Reportedly
+cvsimport can average some twenty revisions per second, so for a
+medium-sized project this should not take more than a couple of minutes.
+Larger projects or remote repositories may take longer.
+
+The main trunk is stored in the Git branch named `origin`, and additional
+CVS branches are stored in Git branches with the same names.  The most
+recent version of the main trunk is also left checked out on the `master`
+branch, so you can start adding your own changes right away.
+
+The import is incremental, so if you call it again next month it will
+fetch any CVS updates that have been made in the meantime.  For this to
+work, you must not modify the imported branches; instead, create new
+branches for your own changes, and merge in the imported branches as
+necessary.
+
+If you want a shared repository, you will need to make a bare clone
+of the imported directory, as described above. Then treat the imported
+directory as another development clone for purposes of merging
+incremental imports.
+
+Advanced Shared Repository Management
+-------------------------------------
+
+Git allows you to specify scripts called "hooks" to be run at certain
+points.  You can use these, for example, to send all commits to the shared
+repository to a mailing list.  See linkgit:githooks[5].
+
+You can enforce finer grained permissions using update hooks.  See
+link:howto/update-hook-example.html[Controlling access to branches using
+update hooks].
+
+Providing CVS Access to a Git Repository
+----------------------------------------
+
+It is also possible to provide true CVS access to a Git repository, so
+that developers can still use CVS; see linkgit:git-cvsserver[1] for
+details.
+
+Alternative Development Models
+------------------------------
+
+CVS users are accustomed to giving a group of developers commit access to
+a common repository.  As we've seen, this is also possible with Git.
+However, the distributed nature of Git allows other development models,
+and you may want to first consider whether one of them might be a better
+fit for your project.
+
+For example, you can choose a single person to maintain the project's
+primary public repository.  Other developers then clone this repository
+and each work in their own clone.  When they have a series of changes that
+they're happy with, they ask the maintainer to pull from the branch
+containing the changes.  The maintainer reviews their changes and pulls
+them into the primary repository, which other developers pull from as
+necessary to stay coordinated.  The Linux kernel and other projects use
+variants of this model.
+
+With a small group, developers may just pull changes from each other's
+repositories without the need for a central maintainer.
+
+SEE ALSO
+--------
+linkgit:gittutorial[7],
+linkgit:gittutorial-2[7],
+linkgit:gitcore-tutorial[7],
+linkgit:gitglossary[7],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitdiffcore.txt b/third_party/git/Documentation/gitdiffcore.txt
new file mode 100644
index 0000000000..c970d9fe43
--- /dev/null
+++ b/third_party/git/Documentation/gitdiffcore.txt
@@ -0,0 +1,292 @@
+gitdiffcore(7)
+==============
+
+NAME
+----
+gitdiffcore - Tweaking diff output
+
+SYNOPSIS
+--------
+[verse]
+'git diff' *
+
+DESCRIPTION
+-----------
+
+The diff commands 'git diff-index', 'git diff-files', and 'git diff-tree'
+can be told to manipulate differences they find in
+unconventional ways before showing 'diff' output.  The manipulation
+is collectively called "diffcore transformation".  This short note
+describes what they are and how to use them to produce 'diff' output
+that is easier to understand than the conventional kind.
+
+
+The chain of operation
+----------------------
+
+The 'git diff-{asterisk}' family works by first comparing two sets of
+files:
+
+ - 'git diff-index' compares contents of a "tree" object and the
+   working directory (when `--cached` flag is not used) or a
+   "tree" object and the index file (when `--cached` flag is
+   used);
+
+ - 'git diff-files' compares contents of the index file and the
+   working directory;
+
+ - 'git diff-tree' compares contents of two "tree" objects;
+
+In all of these cases, the commands themselves first optionally limit
+the two sets of files by any pathspecs given on their command-lines,
+and compare corresponding paths in the two resulting sets of files.
+
+The pathspecs are used to limit the world diff operates in.  They remove
+the filepairs outside the specified sets of pathnames.  E.g. If the
+input set of filepairs included:
+
+------------------------------------------------
+:100644 100644 bcd1234... 0123456... M junkfile
+------------------------------------------------
+
+but the command invocation was `git diff-files myfile`, then the
+junkfile entry would be removed from the list because only "myfile"
+is under consideration.
+
+The result of comparison is passed from these commands to what is
+internally called "diffcore", in a format similar to what is output
+when the -p option is not used.  E.g.
+
+------------------------------------------------
+in-place edit  :100644 100644 bcd1234... 0123456... M file0
+create         :000000 100644 0000000... 1234567... A file4
+delete         :100644 000000 1234567... 0000000... D file5
+unmerged       :000000 000000 0000000... 0000000... U file6
+------------------------------------------------
+
+The diffcore mechanism is fed a list of such comparison results
+(each of which is called "filepair", although at this point each
+of them talks about a single file), and transforms such a list
+into another list.  There are currently 5 such transformations:
+
+- diffcore-break
+- diffcore-rename
+- diffcore-merge-broken
+- diffcore-pickaxe
+- diffcore-order
+
+These are applied in sequence.  The set of filepairs 'git diff-{asterisk}'
+commands find are used as the input to diffcore-break, and
+the output from diffcore-break is used as the input to the
+next transformation.  The final result is then passed to the
+output routine and generates either diff-raw format (see Output
+format sections of the manual for 'git diff-{asterisk}' commands) or
+diff-patch format.
+
+
+diffcore-break: For Splitting Up Complete Rewrites
+--------------------------------------------------
+
+The second transformation in the chain is diffcore-break, and is
+controlled by the -B option to the 'git diff-{asterisk}' commands.  This is
+used to detect a filepair that represents "complete rewrite" and
+break such filepair into two filepairs that represent delete and
+create.  E.g.  If the input contained this filepair:
+
+------------------------------------------------
+:100644 100644 bcd1234... 0123456... M file0
+------------------------------------------------
+
+and if it detects that the file "file0" is completely rewritten,
+it changes it to:
+
+------------------------------------------------
+:100644 000000 bcd1234... 0000000... D file0
+:000000 100644 0000000... 0123456... A file0
+------------------------------------------------
+
+For the purpose of breaking a filepair, diffcore-break examines
+the extent of changes between the contents of the files before
+and after modification (i.e. the contents that have "bcd1234..."
+and "0123456..." as their SHA-1 content ID, in the above
+example).  The amount of deletion of original contents and
+insertion of new material are added together, and if it exceeds
+the "break score", the filepair is broken into two.  The break
+score defaults to 50% of the size of the smaller of the original
+and the result (i.e. if the edit shrinks the file, the size of
+the result is used; if the edit lengthens the file, the size of
+the original is used), and can be customized by giving a number
+after "-B" option (e.g. "-B75" to tell it to use 75%).
+
+
+diffcore-rename: For Detecting Renames and Copies
+-------------------------------------------------
+
+This transformation is used to detect renames and copies, and is
+controlled by the -M option (to detect renames) and the -C option
+(to detect copies as well) to the 'git diff-{asterisk}' commands.  If the
+input contained these filepairs:
+
+------------------------------------------------
+:100644 000000 0123456... 0000000... D fileX
+:000000 100644 0000000... 0123456... A file0
+------------------------------------------------
+
+and the contents of the deleted file fileX is similar enough to
+the contents of the created file file0, then rename detection
+merges these filepairs and creates:
+
+------------------------------------------------
+:100644 100644 0123456... 0123456... R100 fileX file0
+------------------------------------------------
+
+When the "-C" option is used, the original contents of modified files,
+and deleted files (and also unmodified files, if the
+"--find-copies-harder" option is used) are considered as candidates
+of the source files in rename/copy operation.  If the input were like
+these filepairs, that talk about a modified file fileY and a newly
+created file file0:
+
+------------------------------------------------
+:100644 100644 0123456... 1234567... M fileY
+:000000 100644 0000000... bcd3456... A file0
+------------------------------------------------
+
+the original contents of fileY and the resulting contents of
+file0 are compared, and if they are similar enough, they are
+changed to:
+
+------------------------------------------------
+:100644 100644 0123456... 1234567... M fileY
+:100644 100644 0123456... bcd3456... C100 fileY file0
+------------------------------------------------
+
+In both rename and copy detection, the same "extent of changes"
+algorithm used in diffcore-break is used to determine if two
+files are "similar enough", and can be customized to use
+a similarity score different from the default of 50% by giving a
+number after the "-M" or "-C" option (e.g. "-M8" to tell it to use
+8/10 = 80%).
+
+Note.  When the "-C" option is used with `--find-copies-harder`
+option, 'git diff-{asterisk}' commands feed unmodified filepairs to
+diffcore mechanism as well as modified ones.  This lets the copy
+detector consider unmodified files as copy source candidates at
+the expense of making it slower.  Without `--find-copies-harder`,
+'git diff-{asterisk}' commands can detect copies only if the file that was
+copied happened to have been modified in the same changeset.
+
+
+diffcore-merge-broken: For Putting Complete Rewrites Back Together
+------------------------------------------------------------------
+
+This transformation is used to merge filepairs broken by
+diffcore-break, and not transformed into rename/copy by
+diffcore-rename, back into a single modification.  This always
+runs when diffcore-break is used.
+
+For the purpose of merging broken filepairs back, it uses a
+different "extent of changes" computation from the ones used by
+diffcore-break and diffcore-rename.  It counts only the deletion
+from the original, and does not count insertion.  If you removed
+only 10 lines from a 100-line document, even if you added 910
+new lines to make a new 1000-line document, you did not do a
+complete rewrite.  diffcore-break breaks such a case in order to
+help diffcore-rename to consider such filepairs as candidate of
+rename/copy detection, but if filepairs broken that way were not
+matched with other filepairs to create rename/copy, then this
+transformation merges them back into the original
+"modification".
+
+The "extent of changes" parameter can be tweaked from the
+default 80% (that is, unless more than 80% of the original
+material is deleted, the broken pairs are merged back into a
+single modification) by giving a second number to -B option,
+like these:
+
+* -B50/60 (give 50% "break score" to diffcore-break, use 60%
+  for diffcore-merge-broken).
+
+* -B/60 (the same as above, since diffcore-break defaults to 50%).
+
+Note that earlier implementation left a broken pair as a separate
+creation and deletion patches.  This was an unnecessary hack and
+the latest implementation always merges all the broken pairs
+back into modifications, but the resulting patch output is
+formatted differently for easier review in case of such
+a complete rewrite by showing the entire contents of old version
+prefixed with '-', followed by the entire contents of new
+version prefixed with '+'.
+
+
+diffcore-pickaxe: For Detecting Addition/Deletion of Specified String
+---------------------------------------------------------------------
+
+This transformation limits the set of filepairs to those that change
+specified strings between the preimage and the postimage in a certain
+way.  -S<block of text> and -G<regular expression> options are used to
+specify different ways these strings are sought.
+
+"-S<block of text>" detects filepairs whose preimage and postimage
+have different number of occurrences of the specified block of text.
+By definition, it will not detect in-file moves.  Also, when a
+changeset moves a file wholesale without affecting the interesting
+string, diffcore-rename kicks in as usual, and `-S` omits the filepair
+(since the number of occurrences of that string didn't change in that
+rename-detected filepair).  When used with `--pickaxe-regex`, treat
+the <block of text> as an extended POSIX regular expression to match,
+instead of a literal string.
+
+"-G<regular expression>" (mnemonic: grep) detects filepairs whose
+textual diff has an added or a deleted line that matches the given
+regular expression.  This means that it will detect in-file (or what
+rename-detection considers the same file) moves, which is noise.  The
+implementation runs diff twice and greps, and this can be quite
+expensive.  To speed things up binary files without textconv filters
+will be ignored.
+
+When `-S` or `-G` are used without `--pickaxe-all`, only filepairs
+that match their respective criterion are kept in the output.  When
+`--pickaxe-all` is used, if even one filepair matches their respective
+criterion in a changeset, the entire changeset is kept.  This behavior
+is designed to make reviewing changes in the context of the whole
+changeset easier.
+
+diffcore-order: For Sorting the Output Based on Filenames
+---------------------------------------------------------
+
+This is used to reorder the filepairs according to the user's
+(or project's) taste, and is controlled by the -O option to the
+'git diff-{asterisk}' commands.
+
+This takes a text file each of whose lines is a shell glob
+pattern.  Filepairs that match a glob pattern on an earlier line
+in the file are output before ones that match a later line, and
+filepairs that do not match any glob pattern are output last.
+
+As an example, a typical orderfile for the core Git probably
+would look like this:
+
+------------------------------------------------
+README
+Makefile
+Documentation
+*.h
+*.c
+t
+------------------------------------------------
+
+SEE ALSO
+--------
+linkgit:git-diff[1],
+linkgit:git-diff-files[1],
+linkgit:git-diff-index[1],
+linkgit:git-diff-tree[1],
+linkgit:git-format-patch[1],
+linkgit:git-log[1],
+linkgit:gitglossary[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/giteveryday.txt b/third_party/git/Documentation/giteveryday.txt
new file mode 100644
index 0000000000..1bd919f92b
--- /dev/null
+++ b/third_party/git/Documentation/giteveryday.txt
@@ -0,0 +1,455 @@
+giteveryday(7)
+==============
+
+NAME
+----
+giteveryday - A useful minimum set of commands for Everyday Git
+
+SYNOPSIS
+--------
+
+Everyday Git With 20 Commands Or So
+
+DESCRIPTION
+-----------
+
+Git users can broadly be grouped into four categories for the purposes of
+describing here a small set of useful command for everyday Git.
+
+*	<<STANDALONE,Individual Developer (Standalone)>> commands are essential
+	for anybody who makes a commit, even for somebody who works alone.
+
+*	If you work with other people, you will need commands listed in
+	the <<PARTICIPANT,Individual Developer (Participant)>> section as well.
+
+*	People who play the <<INTEGRATOR,Integrator>> role need to learn some
+	more commands in addition to the above.
+
+*	<<ADMINISTRATION,Repository Administration>> commands are for system
+	administrators who are responsible for the care and feeding
+	of Git repositories.
+
+
+Individual Developer (Standalone)[[STANDALONE]]
+-----------------------------------------------
+
+A standalone individual developer does not exchange patches with
+other people, and works alone in a single repository, using the
+following commands.
+
+  * linkgit:git-init[1] to create a new repository.
+
+  * linkgit:git-log[1] to see what happened.
+
+  * linkgit:git-switch[1] and linkgit:git-branch[1] to switch
+    branches.
+
+  * linkgit:git-add[1] to manage the index file.
+
+  * linkgit:git-diff[1] and linkgit:git-status[1] to see what
+    you are in the middle of doing.
+
+  * linkgit:git-commit[1] to advance the current branch.
+
+  * linkgit:git-restore[1] to undo changes.
+
+  * linkgit:git-merge[1] to merge between local branches.
+
+  * linkgit:git-rebase[1] to maintain topic branches.
+
+  * linkgit:git-tag[1] to mark a known point.
+
+Examples
+~~~~~~~~
+
+Use a tarball as a starting point for a new repository.::
++
+------------
+$ tar zxf frotz.tar.gz
+$ cd frotz
+$ git init
+$ git add . <1>
+$ git commit -m "import of frotz source tree."
+$ git tag v2.43 <2>
+------------
++
+<1> add everything under the current directory.
+<2> make a lightweight, unannotated tag.
+
+Create a topic branch and develop.::
++
+------------
+$ git switch -c alsa-audio <1>
+$ edit/compile/test
+$ git restore curses/ux_audio_oss.c <2>
+$ git add curses/ux_audio_alsa.c <3>
+$ edit/compile/test
+$ git diff HEAD <4>
+$ git commit -a -s <5>
+$ edit/compile/test
+$ git diff HEAD^ <6>
+$ git commit -a --amend <7>
+$ git switch master <8>
+$ git merge alsa-audio <9>
+$ git log --since='3 days ago' <10>
+$ git log v2.43.. curses/ <11>
+------------
++
+<1> create a new topic branch.
+<2> revert your botched changes in `curses/ux_audio_oss.c`.
+<3> you need to tell Git if you added a new file; removal and
+modification will be caught if you do `git commit -a` later.
+<4> to see what changes you are committing.
+<5> commit everything, as you have tested, with your sign-off.
+<6> look at all your changes including the previous commit.
+<7> amend the previous commit, adding all your new changes,
+using your original message.
+<8> switch to the master branch.
+<9> merge a topic branch into your master branch.
+<10> review commit logs; other forms to limit output can be
+combined and include `-10` (to show up to 10 commits),
+`--until=2005-12-10`, etc.
+<11> view only the changes that touch what's in `curses/`
+directory, since `v2.43` tag.
+
+
+Individual Developer (Participant)[[PARTICIPANT]]
+-------------------------------------------------
+
+A developer working as a participant in a group project needs to
+learn how to communicate with others, and uses these commands in
+addition to the ones needed by a standalone developer.
+
+  * linkgit:git-clone[1] from the upstream to prime your local
+    repository.
+
+  * linkgit:git-pull[1] and linkgit:git-fetch[1] from "origin"
+    to keep up-to-date with the upstream.
+
+  * linkgit:git-push[1] to shared repository, if you adopt CVS
+    style shared repository workflow.
+
+  * linkgit:git-format-patch[1] to prepare e-mail submission, if
+    you adopt Linux kernel-style public forum workflow.
+
+  * linkgit:git-send-email[1] to send your e-mail submission without
+    corruption by your MUA.
+
+  * linkgit:git-request-pull[1] to create a summary of changes
+    for your upstream to pull.
+
+
+Examples
+~~~~~~~~
+
+Clone the upstream and work on it.  Feed changes to upstream.::
++
+------------
+$ git clone git://git.kernel.org/pub/scm/.../torvalds/linux-2.6 my2.6
+$ cd my2.6
+$ git switch -c mine master <1>
+$ edit/compile/test; git commit -a -s <2>
+$ git format-patch master <3>
+$ git send-email --to="person <email@example.com>" 00*.patch <4>
+$ git switch master <5>
+$ git pull <6>
+$ git log -p ORIG_HEAD.. arch/i386 include/asm-i386 <7>
+$ git ls-remote --heads http://git.kernel.org/.../jgarzik/libata-dev.git <8>
+$ git pull git://git.kernel.org/pub/.../jgarzik/libata-dev.git ALL <9>
+$ git reset --hard ORIG_HEAD <10>
+$ git gc <11>
+------------
++
+<1> checkout a new branch `mine` from master.
+<2> repeat as needed.
+<3> extract patches from your branch, relative to master,
+<4> and email them.
+<5> return to `master`, ready to see what's new
+<6> `git pull` fetches from `origin` by default and merges into the
+current branch.
+<7> immediately after pulling, look at the changes done upstream
+since last time we checked, only in the
+area we are interested in.
+<8> check the branch names in an external repository (if not known).
+<9> fetch from a specific branch `ALL` from a specific repository
+and merge it.
+<10> revert the pull.
+<11> garbage collect leftover objects from reverted pull.
+
+
+Push into another repository.::
++
+------------
+satellite$ git clone mothership:frotz frotz <1>
+satellite$ cd frotz
+satellite$ git config --get-regexp '^(remote|branch)\.' <2>
+remote.origin.url mothership:frotz
+remote.origin.fetch refs/heads/*:refs/remotes/origin/*
+branch.master.remote origin
+branch.master.merge refs/heads/master
+satellite$ git config remote.origin.push \
+	   +refs/heads/*:refs/remotes/satellite/* <3>
+satellite$ edit/compile/test/commit
+satellite$ git push origin <4>
+
+mothership$ cd frotz
+mothership$ git switch master
+mothership$ git merge satellite/master <5>
+------------
++
+<1> mothership machine has a frotz repository under your home
+directory; clone from it to start a repository on the satellite
+machine.
+<2> clone sets these configuration variables by default.
+It arranges `git pull` to fetch and store the branches of mothership
+machine to local `remotes/origin/*` remote-tracking branches.
+<3> arrange `git push` to push all local branches to
+their corresponding branch of the mothership machine.
+<4> push will stash all our work away on `remotes/satellite/*`
+remote-tracking branches on the mothership machine.  You could use this
+as a back-up method. Likewise, you can pretend that mothership
+"fetched" from you (useful when access is one sided).
+<5> on mothership machine, merge the work done on the satellite
+machine into the master branch.
+
+Branch off of a specific tag.::
++
+------------
+$ git switch -c private2.6.14 v2.6.14 <1>
+$ edit/compile/test; git commit -a
+$ git checkout master
+$ git cherry-pick v2.6.14..private2.6.14 <2>
+------------
++
+<1> create a private branch based on a well known (but somewhat behind)
+tag.
+<2> forward port all changes in `private2.6.14` branch to `master` branch
+without a formal "merging". Or longhand +
+`git format-patch -k -m --stdout v2.6.14..private2.6.14 |
+  git am -3 -k`
+
+An alternate participant submission mechanism is using the
+`git request-pull` or pull-request mechanisms (e.g as used on
+GitHub (www.github.com) to notify your upstream of your
+contribution.
+
+Integrator[[INTEGRATOR]]
+------------------------
+
+A fairly central person acting as the integrator in a group
+project receives changes made by others, reviews and integrates
+them and publishes the result for others to use, using these
+commands in addition to the ones needed by participants.
+
+This section can also be used by those who respond to `git
+request-pull` or pull-request on GitHub (www.github.com) to
+integrate the work of others into their history. A sub-area
+lieutenant for a repository will act both as a participant and
+as an integrator.
+
+
+  * linkgit:git-am[1] to apply patches e-mailed in from your
+    contributors.
+
+  * linkgit:git-pull[1] to merge from your trusted lieutenants.
+
+  * linkgit:git-format-patch[1] to prepare and send suggested
+    alternative to contributors.
+
+  * linkgit:git-revert[1] to undo botched commits.
+
+  * linkgit:git-push[1] to publish the bleeding edge.
+
+
+Examples
+~~~~~~~~
+
+A typical integrator's Git day.::
++
+------------
+$ git status <1>
+$ git branch --no-merged master <2>
+$ mailx <3>
+& s 2 3 4 5 ./+to-apply
+& s 7 8 ./+hold-linus
+& q
+$ git switch -c topic/one master
+$ git am -3 -i -s ./+to-apply <4>
+$ compile/test
+$ git switch -c hold/linus && git am -3 -i -s ./+hold-linus <5>
+$ git switch topic/one && git rebase master <6>
+$ git switch -C pu next <7>
+$ git merge topic/one topic/two && git merge hold/linus <8>
+$ git switch maint
+$ git cherry-pick master~4 <9>
+$ compile/test
+$ git tag -s -m "GIT 0.99.9x" v0.99.9x <10>
+$ git fetch ko && for branch in master maint next pu <11>
+    do
+	git show-branch ko/$branch $branch <12>
+    done
+$ git push --follow-tags ko <13>
+------------
++
+<1> see what you were in the middle of doing, if anything.
+<2> see which branches haven't been merged into `master` yet.
+Likewise for any other integration branches e.g. `maint`, `next`
+and `pu` (potential updates).
+<3> read mails, save ones that are applicable, and save others
+that are not quite ready (other mail readers are available).
+<4> apply them, interactively, with your sign-offs.
+<5> create topic branch as needed and apply, again with sign-offs.
+<6> rebase internal topic branch that has not been merged to the
+master or exposed as a part of a stable branch.
+<7> restart `pu` every time from the next.
+<8> and bundle topic branches still cooking.
+<9> backport a critical fix.
+<10> create a signed tag.
+<11> make sure master was not accidentally rewound beyond that
+already pushed out.
+<12> In the output from `git show-branch`, `master` should have
+everything `ko/master` has, and `next` should have
+everything `ko/next` has, etc.
+<13> push out the bleeding edge, together with new tags that point
+into the pushed history.
+
+In this example, the `ko` shorthand points at the Git maintainer's
+repository at kernel.org, and looks like this:
+
+------------
+(in .git/config)
+[remote "ko"]
+	url = kernel.org:/pub/scm/git/git.git
+	fetch = refs/heads/*:refs/remotes/ko/*
+	push = refs/heads/master
+	push = refs/heads/next
+	push = +refs/heads/pu
+	push = refs/heads/maint
+------------
+
+
+Repository Administration[[ADMINISTRATION]]
+-------------------------------------------
+
+A repository administrator uses the following tools to set up
+and maintain access to the repository by developers.
+
+  * linkgit:git-daemon[1] to allow anonymous download from
+    repository.
+
+  * linkgit:git-shell[1] can be used as a 'restricted login shell'
+    for shared central repository users.
+
+  * linkgit:git-http-backend[1] provides a server side implementation
+    of Git-over-HTTP ("Smart http") allowing both fetch and push services.
+
+  * linkgit:gitweb[1] provides a web front-end to Git repositories,
+    which can be set-up using the linkgit:git-instaweb[1] script.
+
+link:howto/update-hook-example.html[update hook howto] has a good
+example of managing a shared central repository.
+
+In addition there are a number of other widely deployed hosting, browsing
+and reviewing solutions such as:
+
+  * gitolite, gerrit code review, cgit and others.
+
+Examples
+~~~~~~~~
+We assume the following in /etc/services::
++
+------------
+$ grep 9418 /etc/services
+git		9418/tcp		# Git Version Control System
+------------
+
+Run git-daemon to serve /pub/scm from inetd.::
++
+------------
+$ grep git /etc/inetd.conf
+git	stream	tcp	nowait	nobody \
+  /usr/bin/git-daemon git-daemon --inetd --export-all /pub/scm
+------------
++
+The actual configuration line should be on one line.
+
+Run git-daemon to serve /pub/scm from xinetd.::
++
+------------
+$ cat /etc/xinetd.d/git-daemon
+# default: off
+# description: The Git server offers access to Git repositories
+service git
+{
+	disable = no
+	type            = UNLISTED
+	port            = 9418
+	socket_type     = stream
+	wait            = no
+	user            = nobody
+	server          = /usr/bin/git-daemon
+	server_args     = --inetd --export-all --base-path=/pub/scm
+	log_on_failure  += USERID
+}
+------------
++
+Check your xinetd(8) documentation and setup, this is from a Fedora system.
+Others might be different.
+
+Give push/pull only access to developers using git-over-ssh.::
+
+e.g. those using:
+`$ git push/pull ssh://host.xz/pub/scm/project`
++
+------------
+$ grep git /etc/passwd <1>
+alice:x:1000:1000::/home/alice:/usr/bin/git-shell
+bob:x:1001:1001::/home/bob:/usr/bin/git-shell
+cindy:x:1002:1002::/home/cindy:/usr/bin/git-shell
+david:x:1003:1003::/home/david:/usr/bin/git-shell
+$ grep git /etc/shells <2>
+/usr/bin/git-shell
+------------
++
+<1> log-in shell is set to /usr/bin/git-shell, which does not
+allow anything but `git push` and `git pull`.  The users require
+ssh access to the machine.
+<2> in many distributions /etc/shells needs to list what is used
+as the login shell.
+
+CVS-style shared repository.::
++
+------------
+$ grep git /etc/group <1>
+git:x:9418:alice,bob,cindy,david
+$ cd /home/devo.git
+$ ls -l <2>
+  lrwxrwxrwx   1 david git    17 Dec  4 22:40 HEAD -> refs/heads/master
+  drwxrwsr-x   2 david git  4096 Dec  4 22:40 branches
+  -rw-rw-r--   1 david git    84 Dec  4 22:40 config
+  -rw-rw-r--   1 david git    58 Dec  4 22:40 description
+  drwxrwsr-x   2 david git  4096 Dec  4 22:40 hooks
+  -rw-rw-r--   1 david git 37504 Dec  4 22:40 index
+  drwxrwsr-x   2 david git  4096 Dec  4 22:40 info
+  drwxrwsr-x   4 david git  4096 Dec  4 22:40 objects
+  drwxrwsr-x   4 david git  4096 Nov  7 14:58 refs
+  drwxrwsr-x   2 david git  4096 Dec  4 22:40 remotes
+$ ls -l hooks/update <3>
+  -r-xr-xr-x   1 david git  3536 Dec  4 22:40 update
+$ cat info/allowed-users <4>
+refs/heads/master	alice\|cindy
+refs/heads/doc-update	bob
+refs/tags/v[0-9]*	david
+------------
++
+<1> place the developers into the same git group.
+<2> and make the shared repository writable by the group.
+<3> use update-hook example by Carl from Documentation/howto/
+for branch policy control.
+<4> alice and cindy can push into master, only bob can push into doc-update.
+david is the release manager and is the only person who can
+create and push version tags.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitglossary.txt b/third_party/git/Documentation/gitglossary.txt
new file mode 100644
index 0000000000..571f640f5c
--- /dev/null
+++ b/third_party/git/Documentation/gitglossary.txt
@@ -0,0 +1,27 @@
+gitglossary(7)
+==============
+
+NAME
+----
+gitglossary - A Git Glossary
+
+SYNOPSIS
+--------
+*
+
+DESCRIPTION
+-----------
+
+include::glossary-content.txt[]
+
+SEE ALSO
+--------
+linkgit:gittutorial[7],
+linkgit:gittutorial-2[7],
+linkgit:gitcvs-migration[7],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/githooks.txt b/third_party/git/Documentation/githooks.txt
new file mode 100644
index 0000000000..82cd573776
--- /dev/null
+++ b/third_party/git/Documentation/githooks.txt
@@ -0,0 +1,521 @@
+githooks(5)
+===========
+
+NAME
+----
+githooks - Hooks used by Git
+
+SYNOPSIS
+--------
+$GIT_DIR/hooks/* (or \`git config core.hooksPath`/*)
+
+
+DESCRIPTION
+-----------
+
+Hooks are programs you can place in a hooks directory to trigger
+actions at certain points in git's execution. Hooks that don't have
+the executable bit set are ignored.
+
+By default the hooks directory is `$GIT_DIR/hooks`, but that can be
+changed via the `core.hooksPath` configuration variable (see
+linkgit:git-config[1]).
+
+Before Git invokes a hook, it changes its working directory to either
+$GIT_DIR in a bare repository or the root of the working tree in a non-bare
+repository. An exception are hooks triggered during a push ('pre-receive',
+'update', 'post-receive', 'post-update', 'push-to-checkout') which are always
+executed in $GIT_DIR.
+
+Hooks can get their arguments via the environment, command-line
+arguments, and stdin. See the documentation for each hook below for
+details.
+
+`git init` may copy hooks to the new repository, depending on its
+configuration. See the "TEMPLATE DIRECTORY" section in
+linkgit:git-init[1] for details. When the rest of this document refers
+to "default hooks" it's talking about the default template shipped
+with Git.
+
+The currently supported hooks are described below.
+
+HOOKS
+-----
+
+applypatch-msg
+~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-am[1].  It takes a single
+parameter, the name of the file that holds the proposed commit
+log message.  Exiting with a non-zero status causes `git am` to abort
+before applying the patch.
+
+The hook is allowed to edit the message file in place, and can
+be used to normalize the message into some project standard
+format. It can also be used to refuse the commit after inspecting
+the message file.
+
+The default 'applypatch-msg' hook, when enabled, runs the
+'commit-msg' hook, if the latter is enabled.
+
+pre-applypatch
+~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-am[1].  It takes no parameter, and is
+invoked after the patch is applied, but before a commit is made.
+
+If it exits with non-zero status, then the working tree will not be
+committed after applying the patch.
+
+It can be used to inspect the current working tree and refuse to
+make a commit if it does not pass certain test.
+
+The default 'pre-applypatch' hook, when enabled, runs the
+'pre-commit' hook, if the latter is enabled.
+
+post-applypatch
+~~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-am[1].  It takes no parameter,
+and is invoked after the patch is applied and a commit is made.
+
+This hook is meant primarily for notification, and cannot affect
+the outcome of `git am`.
+
+pre-commit
+~~~~~~~~~~
+
+This hook is invoked by linkgit:git-commit[1], and can be bypassed
+with the `--no-verify` option.  It takes no parameters, and is
+invoked before obtaining the proposed commit log message and
+making a commit.  Exiting with a non-zero status from this script
+causes the `git commit` command to abort before creating a commit.
+
+The default 'pre-commit' hook, when enabled, catches introduction
+of lines with trailing whitespaces and aborts the commit when
+such a line is found.
+
+All the `git commit` hooks are invoked with the environment
+variable `GIT_EDITOR=:` if the command will not bring up an editor
+to modify the commit message.
+
+The default 'pre-commit' hook, when enabled--and with the
+`hooks.allownonascii` config option unset or set to false--prevents
+the use of non-ASCII filenames.
+
+prepare-commit-msg
+~~~~~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-commit[1] right after preparing the
+default log message, and before the editor is started.
+
+It takes one to three parameters.  The first is the name of the file
+that contains the commit log message.  The second is the source of the commit
+message, and can be: `message` (if a `-m` or `-F` option was
+given); `template` (if a `-t` option was given or the
+configuration option `commit.template` is set); `merge` (if the
+commit is a merge or a `.git/MERGE_MSG` file exists); `squash`
+(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by
+a commit SHA-1 (if a `-c`, `-C` or `--amend` option was given).
+
+If the exit status is non-zero, `git commit` will abort.
+
+The purpose of the hook is to edit the message file in place, and
+it is not suppressed by the `--no-verify` option.  A non-zero exit
+means a failure of the hook and aborts the commit.  It should not
+be used as replacement for pre-commit hook.
+
+The sample `prepare-commit-msg` hook that comes with Git removes the
+help message found in the commented portion of the commit template.
+
+commit-msg
+~~~~~~~~~~
+
+This hook is invoked by linkgit:git-commit[1] and linkgit:git-merge[1], and can be
+bypassed with the `--no-verify` option.  It takes a single parameter,
+the name of the file that holds the proposed commit log message.
+Exiting with a non-zero status causes the command to abort.
+
+The hook is allowed to edit the message file in place, and can be used
+to normalize the message into some project standard format. It
+can also be used to refuse the commit after inspecting the message
+file.
+
+The default 'commit-msg' hook, when enabled, detects duplicate
+"Signed-off-by" lines, and aborts the commit if one is found.
+
+post-commit
+~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-commit[1]. It takes no parameters, and is
+invoked after a commit is made.
+
+This hook is meant primarily for notification, and cannot affect
+the outcome of `git commit`.
+
+pre-rebase
+~~~~~~~~~~
+
+This hook is called by linkgit:git-rebase[1] and can be used to prevent a
+branch from getting rebased.  The hook may be called with one or
+two parameters.  The first parameter is the upstream from which
+the series was forked.  The second parameter is the branch being
+rebased, and is not set when rebasing the current branch.
+
+post-checkout
+~~~~~~~~~~~~~
+
+This hook is invoked when a linkgit:git-checkout[1] or
+linkgit:git-switch[1] is run after having updated the
+worktree.  The hook is given three parameters: the ref of the previous HEAD,
+the ref of the new HEAD (which may or may not have changed), and a flag
+indicating whether the checkout was a branch checkout (changing branches,
+flag=1) or a file checkout (retrieving a file from the index, flag=0).
+This hook cannot affect the outcome of `git switch` or `git checkout`.
+
+It is also run after linkgit:git-clone[1], unless the `--no-checkout` (`-n`) option is
+used. The first parameter given to the hook is the null-ref, the second the
+ref of the new HEAD and the flag is always 1. Likewise for `git worktree add`
+unless `--no-checkout` is used.
+
+This hook can be used to perform repository validity checks, auto-display
+differences from the previous HEAD if different, or set working dir metadata
+properties.
+
+post-merge
+~~~~~~~~~~
+
+This hook is invoked by linkgit:git-merge[1], which happens when a `git pull`
+is done on a local repository.  The hook takes a single parameter, a status
+flag specifying whether or not the merge being done was a squash merge.
+This hook cannot affect the outcome of `git merge` and is not executed,
+if the merge failed due to conflicts.
+
+This hook can be used in conjunction with a corresponding pre-commit hook to
+save and restore any form of metadata associated with the working tree
+(e.g.: permissions/ownership, ACLS, etc).  See contrib/hooks/setgitperms.perl
+for an example of how to do this.
+
+pre-push
+~~~~~~~~
+
+This hook is called by linkgit:git-push[1] and can be used to prevent
+a push from taking place.  The hook is called with two parameters
+which provide the name and location of the destination remote, if a
+named remote is not being used both values will be the same.
+
+Information about what is to be pushed is provided on the hook's standard
+input with lines of the form:
+
+  <local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF
+
+For instance, if the command +git push origin master:foreign+ were run the
+hook would receive a line like the following:
+
+  refs/heads/master 67890 refs/heads/foreign 12345
+
+although the full, 40-character SHA-1s would be supplied.  If the foreign ref
+does not yet exist the `<remote SHA-1>` will be 40 `0`.  If a ref is to be
+deleted, the `<local ref>` will be supplied as `(delete)` and the `<local
+SHA-1>` will be 40 `0`.  If the local commit was specified by something other
+than a name which could be expanded (such as `HEAD~`, or a SHA-1) it will be
+supplied as it was originally given.
+
+If this hook exits with a non-zero status, `git push` will abort without
+pushing anything.  Information about why the push is rejected may be sent
+to the user by writing to standard error.
+
+[[pre-receive]]
+pre-receive
+~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-receive-pack[1] when it reacts to
+`git push` and updates reference(s) in its repository.
+Just before starting to update refs on the remote repository, the
+pre-receive hook is invoked.  Its exit status determines the success
+or failure of the update.
+
+This hook executes once for the receive operation. It takes no
+arguments, but for each ref to be updated it receives on standard
+input a line of the format:
+
+  <old-value> SP <new-value> SP <ref-name> LF
+
+where `<old-value>` is the old object name stored in the ref,
+`<new-value>` is the new object name to be stored in the ref and
+`<ref-name>` is the full name of the ref.
+When creating a new ref, `<old-value>` is 40 `0`.
+
+If the hook exits with non-zero status, none of the refs will be
+updated. If the hook exits with zero, updating of individual refs can
+still be prevented by the <<update,'update'>> hook.
+
+Both standard output and standard error output are forwarded to
+`git send-pack` on the other end, so you can simply `echo` messages
+for the user.
+
+The number of push options given on the command line of
+`git push --push-option=...` can be read from the environment
+variable `GIT_PUSH_OPTION_COUNT`, and the options themselves are
+found in `GIT_PUSH_OPTION_0`, `GIT_PUSH_OPTION_1`,...
+If it is negotiated to not use the push options phase, the
+environment variables will not be set. If the client selects
+to use push options, but doesn't transmit any, the count variable
+will be set to zero, `GIT_PUSH_OPTION_COUNT=0`.
+
+See the section on "Quarantine Environment" in
+linkgit:git-receive-pack[1] for some caveats.
+
+[[update]]
+update
+~~~~~~
+
+This hook is invoked by linkgit:git-receive-pack[1] when it reacts to
+`git push` and updates reference(s) in its repository.
+Just before updating the ref on the remote repository, the update hook
+is invoked.  Its exit status determines the success or failure of
+the ref update.
+
+The hook executes once for each ref to be updated, and takes
+three parameters:
+
+ - the name of the ref being updated,
+ - the old object name stored in the ref,
+ - and the new object name to be stored in the ref.
+
+A zero exit from the update hook allows the ref to be updated.
+Exiting with a non-zero status prevents `git receive-pack`
+from updating that ref.
+
+This hook can be used to prevent 'forced' update on certain refs by
+making sure that the object name is a commit object that is a
+descendant of the commit object named by the old object name.
+That is, to enforce a "fast-forward only" policy.
+
+It could also be used to log the old..new status.  However, it
+does not know the entire set of branches, so it would end up
+firing one e-mail per ref when used naively, though.  The
+<<post-receive,'post-receive'>> hook is more suited to that.
+
+In an environment that restricts the users' access only to git
+commands over the wire, this hook can be used to implement access
+control without relying on filesystem ownership and group
+membership. See linkgit:git-shell[1] for how you might use the login
+shell to restrict the user's access to only git commands.
+
+Both standard output and standard error output are forwarded to
+`git send-pack` on the other end, so you can simply `echo` messages
+for the user.
+
+The default 'update' hook, when enabled--and with
+`hooks.allowunannotated` config option unset or set to false--prevents
+unannotated tags to be pushed.
+
+[[post-receive]]
+post-receive
+~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-receive-pack[1] when it reacts to
+`git push` and updates reference(s) in its repository.
+It executes on the remote repository once after all the refs have
+been updated.
+
+This hook executes once for the receive operation.  It takes no
+arguments, but gets the same information as the
+<<pre-receive,'pre-receive'>>
+hook does on its standard input.
+
+This hook does not affect the outcome of `git receive-pack`, as it
+is called after the real work is done.
+
+This supersedes the <<post-update,'post-update'>> hook in that it gets
+both old and new values of all the refs in addition to their
+names.
+
+Both standard output and standard error output are forwarded to
+`git send-pack` on the other end, so you can simply `echo` messages
+for the user.
+
+The default 'post-receive' hook is empty, but there is
+a sample script `post-receive-email` provided in the `contrib/hooks`
+directory in Git distribution, which implements sending commit
+emails.
+
+The number of push options given on the command line of
+`git push --push-option=...` can be read from the environment
+variable `GIT_PUSH_OPTION_COUNT`, and the options themselves are
+found in `GIT_PUSH_OPTION_0`, `GIT_PUSH_OPTION_1`,...
+If it is negotiated to not use the push options phase, the
+environment variables will not be set. If the client selects
+to use push options, but doesn't transmit any, the count variable
+will be set to zero, `GIT_PUSH_OPTION_COUNT=0`.
+
+[[post-update]]
+post-update
+~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-receive-pack[1] when it reacts to
+`git push` and updates reference(s) in its repository.
+It executes on the remote repository once after all the refs have
+been updated.
+
+It takes a variable number of parameters, each of which is the
+name of ref that was actually updated.
+
+This hook is meant primarily for notification, and cannot affect
+the outcome of `git receive-pack`.
+
+The 'post-update' hook can tell what are the heads that were pushed,
+but it does not know what their original and updated values are,
+so it is a poor place to do log old..new. The
+<<post-receive,'post-receive'>> hook does get both original and
+updated values of the refs. You might consider it instead if you need
+them.
+
+When enabled, the default 'post-update' hook runs
+`git update-server-info` to keep the information used by dumb
+transports (e.g., HTTP) up to date.  If you are publishing
+a Git repository that is accessible via HTTP, you should
+probably enable this hook.
+
+Both standard output and standard error output are forwarded to
+`git send-pack` on the other end, so you can simply `echo` messages
+for the user.
+
+push-to-checkout
+~~~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-receive-pack[1] when it reacts to
+`git push` and updates reference(s) in its repository, and when
+the push tries to update the branch that is currently checked out
+and the `receive.denyCurrentBranch` configuration variable is set to
+`updateInstead`.  Such a push by default is refused if the working
+tree and the index of the remote repository has any difference from
+the currently checked out commit; when both the working tree and the
+index match the current commit, they are updated to match the newly
+pushed tip of the branch.  This hook is to be used to override the
+default behaviour.
+
+The hook receives the commit with which the tip of the current
+branch is going to be updated.  It can exit with a non-zero status
+to refuse the push (when it does so, it must not modify the index or
+the working tree).  Or it can make any necessary changes to the
+working tree and to the index to bring them to the desired state
+when the tip of the current branch is updated to the new commit, and
+exit with a zero status.
+
+For example, the hook can simply run `git read-tree -u -m HEAD "$1"`
+in order to emulate `git fetch` that is run in the reverse direction
+with `git push`, as the two-tree form of `git read-tree -u -m` is
+essentially the same as `git switch` or `git checkout`
+that switches branches while
+keeping the local changes in the working tree that do not interfere
+with the difference between the branches.
+
+
+pre-auto-gc
+~~~~~~~~~~~
+
+This hook is invoked by `git gc --auto` (see linkgit:git-gc[1]). It
+takes no parameter, and exiting with non-zero status from this script
+causes the `git gc --auto` to abort.
+
+post-rewrite
+~~~~~~~~~~~~
+
+This hook is invoked by commands that rewrite commits
+(linkgit:git-commit[1] when called with `--amend` and
+linkgit:git-rebase[1]; currently `git filter-branch` does 'not' call
+it!).  Its first argument denotes the command it was invoked by:
+currently one of `amend` or `rebase`.  Further command-dependent
+arguments may be passed in the future.
+
+The hook receives a list of the rewritten commits on stdin, in the
+format
+
+  <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF
+
+The 'extra-info' is again command-dependent.  If it is empty, the
+preceding SP is also omitted.  Currently, no commands pass any
+'extra-info'.
+
+The hook always runs after the automatic note copying (see
+"notes.rewrite.<command>" in linkgit:git-config[1]) has happened, and
+thus has access to these notes.
+
+The following command-specific comments apply:
+
+rebase::
+	For the 'squash' and 'fixup' operation, all commits that were
+	squashed are listed as being rewritten to the squashed commit.
+	This means that there will be several lines sharing the same
+	'new-sha1'.
++
+The commits are guaranteed to be listed in the order that they were
+processed by rebase.
+
+sendemail-validate
+~~~~~~~~~~~~~~~~~~
+
+This hook is invoked by linkgit:git-send-email[1].  It takes a single parameter,
+the name of the file that holds the e-mail to be sent.  Exiting with a
+non-zero status causes `git send-email` to abort before sending any
+e-mails.
+
+fsmonitor-watchman
+~~~~~~~~~~~~~~~~~~
+
+This hook is invoked when the configuration option `core.fsmonitor` is
+set to `.git/hooks/fsmonitor-watchman`.  It takes two arguments, a version
+(currently 1) and the time in elapsed nanoseconds since midnight,
+January 1, 1970.
+
+The hook should output to stdout the list of all files in the working
+directory that may have changed since the requested time.  The logic
+should be inclusive so that it does not miss any potential changes.
+The paths should be relative to the root of the working directory
+and be separated by a single NUL.
+
+It is OK to include files which have not actually changed.  All changes
+including newly-created and deleted files should be included. When
+files are renamed, both the old and the new name should be included.
+
+Git will limit what files it checks for changes as well as which
+directories are checked for untracked files based on the path names
+given.
+
+An optimized way to tell git "all files have changed" is to return
+the filename `/`.
+
+The exit status determines whether git will use the data from the
+hook to limit its search.  On error, it will fall back to verifying
+all files and folders.
+
+p4-pre-submit
+~~~~~~~~~~~~~
+
+This hook is invoked by `git-p4 submit`. It takes no parameters and nothing
+from standard input. Exiting with non-zero status from this script prevent
+`git-p4 submit` from launching. Run `git-p4 submit --help` for details.
+
+post-index-change
+~~~~~~~~~~~~~~~~~
+
+This hook is invoked when the index is written in read-cache.c
+do_write_locked_index.
+
+The first parameter passed to the hook is the indicator for the
+working directory being updated.  "1" meaning working directory
+was updated or "0" when the working directory was not updated.
+
+The second parameter passed to the hook is the indicator for whether
+or not the index was updated and the skip-worktree bit could have
+changed.  "1" meaning skip-worktree bits could have been updated
+and "0" meaning they were not.
+
+Only one parameter should be set to "1" when the hook runs.  The hook
+running passing "1", "1" should not be possible.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitignore.txt b/third_party/git/Documentation/gitignore.txt
new file mode 100644
index 0000000000..d47b1ae296
--- /dev/null
+++ b/third_party/git/Documentation/gitignore.txt
@@ -0,0 +1,238 @@
+gitignore(5)
+============
+
+NAME
+----
+gitignore - Specifies intentionally untracked files to ignore
+
+SYNOPSIS
+--------
+$XDG_CONFIG_HOME/git/ignore, $GIT_DIR/info/exclude, .gitignore
+
+DESCRIPTION
+-----------
+
+A `gitignore` file specifies intentionally untracked files that
+Git should ignore.
+Files already tracked by Git are not affected; see the NOTES
+below for details.
+
+Each line in a `gitignore` file specifies a pattern.
+When deciding whether to ignore a path, Git normally checks
+`gitignore` patterns from multiple sources, with the following
+order of precedence, from highest to lowest (within one level of
+precedence, the last matching pattern decides the outcome):
+
+ * Patterns read from the command line for those commands that support
+   them.
+
+ * Patterns read from a `.gitignore` file in the same directory
+   as the path, or in any parent directory, with patterns in the
+   higher level files (up to the toplevel of the work tree) being overridden
+   by those in lower level files down to the directory containing the file.
+   These patterns match relative to the location of the
+   `.gitignore` file.  A project normally includes such
+   `.gitignore` files in its repository, containing patterns for
+   files generated as part of the project build.
+
+ * Patterns read from `$GIT_DIR/info/exclude`.
+
+ * Patterns read from the file specified by the configuration
+   variable `core.excludesFile`.
+
+Which file to place a pattern in depends on how the pattern is meant to
+be used.
+
+ * Patterns which should be version-controlled and distributed to
+   other repositories via clone (i.e., files that all developers will want
+   to ignore) should go into a `.gitignore` file.
+
+ * Patterns which are
+   specific to a particular repository but which do not need to be shared
+   with other related repositories (e.g., auxiliary files that live inside
+   the repository but are specific to one user's workflow) should go into
+   the `$GIT_DIR/info/exclude` file.
+
+ * Patterns which a user wants Git to
+   ignore in all situations (e.g., backup or temporary files generated by
+   the user's editor of choice) generally go into a file specified by
+   `core.excludesFile` in the user's `~/.gitconfig`. Its default value is
+   $XDG_CONFIG_HOME/git/ignore. If $XDG_CONFIG_HOME is either not set or
+   empty, $HOME/.config/git/ignore is used instead.
+
+The underlying Git plumbing tools, such as
+'git ls-files' and 'git read-tree', read
+`gitignore` patterns specified by command-line options, or from
+files specified by command-line options.  Higher-level Git
+tools, such as 'git status' and 'git add',
+use patterns from the sources specified above.
+
+PATTERN FORMAT
+--------------
+
+ - A blank line matches no files, so it can serve as a separator
+   for readability.
+
+ - A line starting with # serves as a comment.
+   Put a backslash ("`\`") in front of the first hash for patterns
+   that begin with a hash.
+
+ - Trailing spaces are ignored unless they are quoted with backslash
+   ("`\`").
+
+ - An optional prefix "`!`" which negates the pattern; any
+   matching file excluded by a previous pattern will become
+   included again. It is not possible to re-include a file if a parent
+   directory of that file is excluded. Git doesn't list excluded
+   directories for performance reasons, so any patterns on contained
+   files have no effect, no matter where they are defined.
+   Put a backslash ("`\`") in front of the first "`!`" for patterns
+   that begin with a literal "`!`", for example, "`\!important!.txt`".
+
+ - The slash '/' is used as the directory separator. Separators may
+   occur at the beginning, middle or end of the `.gitignore` search pattern.
+
+ - If there is a separator at the beginning or middle (or both) of the
+   pattern, then the pattern is relative to the directory level of the
+   particular `.gitignore` file itself. Otherwise the pattern may also
+   match at any level below the `.gitignore` level.
+
+ - If there is a separator at the end of the pattern then the pattern
+   will only match directories, otherwise the pattern can match both
+   files and directories.
+
+ - For example, a pattern `doc/frotz/` matches `doc/frotz` directory,
+   but not `a/doc/frotz` directory; however `frotz/` matches `frotz`
+   and `a/frotz` that is a directory (all paths are relative from
+   the `.gitignore` file).
+
+ - An asterisk "`*`" matches anything except a slash.
+   The character "`?`" matches any one character except "`/`".
+   The range notation, e.g. `[a-zA-Z]`, can be used to match
+   one of the characters in a range. See fnmatch(3) and the
+   FNM_PATHNAME flag for a more detailed description.
+
+Two consecutive asterisks ("`**`") in patterns matched against
+full pathname may have special meaning:
+
+ - A leading "`**`" followed by a slash means match in all
+   directories. For example, "`**/foo`" matches file or directory
+   "`foo`" anywhere, the same as pattern "`foo`". "`**/foo/bar`"
+   matches file or directory "`bar`" anywhere that is directly
+   under directory "`foo`".
+
+ - A trailing "`/**`" matches everything inside. For example,
+   "`abc/**`" matches all files inside directory "`abc`", relative
+   to the location of the `.gitignore` file, with infinite depth.
+
+ - A slash followed by two consecutive asterisks then a slash
+   matches zero or more directories. For example, "`a/**/b`"
+   matches "`a/b`", "`a/x/b`", "`a/x/y/b`" and so on.
+
+ - Other consecutive asterisks are considered regular asterisks and
+   will match according to the previous rules.
+
+CONFIGURATION
+-------------
+
+The optional configuration variable `core.excludesFile` indicates a path to a
+file containing patterns of file names to exclude, similar to
+`$GIT_DIR/info/exclude`.  Patterns in the exclude file are used in addition to
+those in `$GIT_DIR/info/exclude`.
+
+NOTES
+-----
+
+The purpose of gitignore files is to ensure that certain files
+not tracked by Git remain untracked.
+
+To stop tracking a file that is currently tracked, use
+'git rm --cached'.
+
+EXAMPLES
+--------
+
+ - The pattern `hello.*` matches any file or folder
+   whose name begins with `hello`. If one wants to restrict
+   this only to the directory and not in its subdirectories,
+   one can prepend the pattern with a slash, i.e. `/hello.*`;
+   the pattern now matches `hello.txt`, `hello.c` but not
+   `a/hello.java`.
+
+ - The pattern `foo/` will match a directory `foo` and
+   paths underneath it, but will not match a regular file
+   or a symbolic link `foo` (this is consistent with the
+   way how pathspec works in general in Git)
+
+ - The pattern `doc/frotz` and `/doc/frotz` have the same effect
+   in any `.gitignore` file. In other words, a leading slash
+   is not relevant  if there is already a middle slash in
+   the pattern.
+
+ - The pattern "foo/*", matches "foo/test.json"
+   (a regular file), "foo/bar" (a directory), but it does not match
+   "foo/bar/hello.c" (a regular file), as the asterisk in the
+   pattern does not match "bar/hello.c" which has a slash in it.
+
+--------------------------------------------------------------
+    $ git status
+    [...]
+    # Untracked files:
+    [...]
+    #       Documentation/foo.html
+    #       Documentation/gitignore.html
+    #       file.o
+    #       lib.a
+    #       src/internal.o
+    [...]
+    $ cat .git/info/exclude
+    # ignore objects and archives, anywhere in the tree.
+    *.[oa]
+    $ cat Documentation/.gitignore
+    # ignore generated html files,
+    *.html
+    # except foo.html which is maintained by hand
+    !foo.html
+    $ git status
+    [...]
+    # Untracked files:
+    [...]
+    #       Documentation/foo.html
+    [...]
+--------------------------------------------------------------
+
+Another example:
+
+--------------------------------------------------------------
+    $ cat .gitignore
+    vmlinux*
+    $ ls arch/foo/kernel/vm*
+    arch/foo/kernel/vmlinux.lds.S
+    $ echo '!/vmlinux*' >arch/foo/kernel/.gitignore
+--------------------------------------------------------------
+
+The second .gitignore prevents Git from ignoring
+`arch/foo/kernel/vmlinux.lds.S`.
+
+Example to exclude everything except a specific directory `foo/bar`
+(note the `/*` - without the slash, the wildcard would also exclude
+everything within `foo/bar`):
+
+--------------------------------------------------------------
+    $ cat .gitignore
+    # exclude everything except directory foo/bar
+    /*
+    !/foo
+    /foo/*
+    !/foo/bar
+--------------------------------------------------------------
+
+SEE ALSO
+--------
+linkgit:git-rm[1],
+linkgit:gitrepository-layout[5],
+linkgit:git-check-ignore[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitk.txt b/third_party/git/Documentation/gitk.txt
new file mode 100644
index 0000000000..1eabb0aaf3
--- /dev/null
+++ b/third_party/git/Documentation/gitk.txt
@@ -0,0 +1,202 @@
+gitk(1)
+=======
+
+NAME
+----
+gitk - The Git repository browser
+
+SYNOPSIS
+--------
+[verse]
+'gitk' [<options>] [<revision range>] [--] [<path>...]
+
+DESCRIPTION
+-----------
+Displays changes in a repository or a selected set of commits. This includes
+visualizing the commit graph, showing information related to each commit, and
+the files in the trees of each revision.
+
+OPTIONS
+-------
+
+To control which revisions to show, gitk supports most options
+applicable to the 'git rev-list' command.  It also supports a few
+options applicable to the 'git diff-*' commands to control how the
+changes each commit introduces are shown.  Finally, it supports some
+gitk-specific options.
+
+gitk generally only understands options with arguments in the
+'sticked' form (see linkgit:gitcli[7]) due to limitations in the
+command-line parser.
+
+rev-list options and arguments
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This manual page describes only the most frequently used options.  See
+linkgit:git-rev-list[1] for a complete list.
+
+--all::
+
+	Show all refs (branches, tags, etc.).
+
+--branches[=<pattern>]::
+--tags[=<pattern>]::
+--remotes[=<pattern>]::
+
+	Pretend as if all the branches (tags, remote branches, resp.)
+	are listed on the command line as '<commit>'. If '<pattern>'
+	is given, limit refs to ones matching given shell glob. If
+	pattern lacks '?', '{asterisk}', or '[', '/{asterisk}' at the
+	end is implied.
+
+--since=<date>::
+
+	Show commits more recent than a specific date.
+
+--until=<date>::
+
+	Show commits older than a specific date.
+
+--date-order::
+
+	Sort commits by date when possible.
+
+--merge::
+
+	After an attempt to merge stops with conflicts, show the commits on
+	the history between two branches (i.e. the HEAD and the MERGE_HEAD)
+	that modify the conflicted files and do not exist on all the heads
+	being merged.
+
+--left-right::
+
+	Mark which side of a symmetric difference a commit is reachable
+	from.  Commits from the left side are prefixed with a `<`
+	symbol and those from the right with a `>` symbol.
+
+--full-history::
+
+	When filtering history with '<path>...', does not prune some
+	history.  (See "History simplification" in linkgit:git-log[1]
+	for a more detailed explanation.)
+
+--simplify-merges::
+
+	Additional option to `--full-history` to remove some needless
+	merges from the resulting history, as there are no selected
+	commits contributing to this merge.  (See "History
+	simplification" in linkgit:git-log[1] for a more detailed
+	explanation.)
+
+--ancestry-path::
+
+	When given a range of commits to display
+	(e.g. 'commit1..commit2' or 'commit2 {caret}commit1'), only
+	display commits that exist directly on the ancestry chain
+	between the 'commit1' and 'commit2', i.e. commits that are
+	both descendants of 'commit1', and ancestors of 'commit2'.
+	(See "History simplification" in linkgit:git-log[1] for a more
+	detailed explanation.)
+
+-L<start>,<end>:<file>::
+-L:<funcname>:<file>::
+
+	Trace the evolution of the line range given by "<start>,<end>"
+	(or the function name regex <funcname>) within the <file>.  You may
+	not give any pathspec limiters.  This is currently limited to
+	a walk starting from a single revision, i.e., you may only
+	give zero or one positive revision arguments.
+	You can specify this option more than once.
++
+*Note:* gitk (unlike linkgit:git-log[1]) currently only understands
+this option if you specify it "glued together" with its argument.  Do
+*not* put a space after `-L`.
++
+include::line-range-format.txt[]
+
+<revision range>::
+
+	Limit the revisions to show. This can be either a single revision
+	meaning show from the given revision and back, or it can be a range in
+	the form "'<from>'..'<to>'" to show all revisions between '<from>' and
+	back to '<to>'. Note, more advanced revision selection can be applied.
+	For a more complete list of ways to spell object names, see
+	linkgit:gitrevisions[7].
+
+<path>...::
+
+	Limit commits to the ones touching files in the given paths. Note, to
+	avoid ambiguity with respect to revision names use "--" to separate the paths
+	from any preceding options.
+
+gitk-specific options
+~~~~~~~~~~~~~~~~~~~~~
+
+--argscmd=<command>::
+
+	Command to be run each time gitk has to determine the revision
+	range to show.  The command is expected to print on its
+	standard output a list of additional revisions to be shown,
+	one per line.  Use this instead of explicitly specifying a
+	'<revision range>' if the set of commits to show may vary
+	between refreshes.
+
+--select-commit=<ref>::
+
+	Select the specified commit after loading the graph.
+	Default behavior is equivalent to specifying '--select-commit=HEAD'.
+
+Examples
+--------
+gitk v2.6.12.. include/scsi drivers/scsi::
+
+	Show the changes since version 'v2.6.12' that changed any
+	file in the include/scsi or drivers/scsi subdirectories
+
+gitk --since="2 weeks ago" \-- gitk::
+
+	Show the changes during the last two weeks to the file 'gitk'.
+	The "--" is necessary to avoid confusion with the *branch* named
+	'gitk'
+
+gitk --max-count=100 --all \-- Makefile::
+
+	Show at most 100 changes made to the file 'Makefile'. Instead of only
+	looking for changes in the current branch look in all branches.
+
+Files
+-----
+User configuration and preferences are stored at:
+
+* `$XDG_CONFIG_HOME/git/gitk` if it exists, otherwise
+* `$HOME/.gitk` if it exists
+
+If neither of the above exist then `$XDG_CONFIG_HOME/git/gitk` is created and
+used by default. If '$XDG_CONFIG_HOME' is not set it defaults to
+`$HOME/.config` in all cases.
+
+History
+-------
+Gitk was the first graphical repository browser. It's written in
+tcl/tk.
+
+'gitk' is actually maintained as an independent project, but stable
+versions are distributed as part of the Git suite for the convenience
+of end users.
+
+gitk-git/ comes from Paul Mackerras's gitk project:
+
+	git://ozlabs.org/~paulus/gitk
+
+SEE ALSO
+--------
+'qgit(1)'::
+	A repository browser written in C++ using Qt.
+
+'tig(1)'::
+	A minimal repository browser and Git tool output highlighter written
+	in C using Ncurses.
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitmodules.txt b/third_party/git/Documentation/gitmodules.txt
new file mode 100644
index 0000000000..a66e95b70c
--- /dev/null
+++ b/third_party/git/Documentation/gitmodules.txt
@@ -0,0 +1,127 @@
+gitmodules(5)
+=============
+
+NAME
+----
+gitmodules - Defining submodule properties
+
+SYNOPSIS
+--------
+$GIT_WORK_DIR/.gitmodules
+
+
+DESCRIPTION
+-----------
+
+The `.gitmodules` file, located in the top-level directory of a Git
+working tree, is a text file with a syntax matching the requirements
+of linkgit:git-config[1].
+
+The file contains one subsection per submodule, and the subsection value
+is the name of the submodule. The name is set to the path where the
+submodule has been added unless it was customized with the `--name`
+option of 'git submodule add'. Each submodule section also contains the
+following required keys:
+
+submodule.<name>.path::
+	Defines the path, relative to the top-level directory of the Git
+	working tree, where the submodule is expected to be checked out.
+	The path name must not end with a `/`. All submodule paths must
+	be unique within the .gitmodules file.
+
+submodule.<name>.url::
+	Defines a URL from which the submodule repository can be cloned.
+	This may be either an absolute URL ready to be passed to
+	linkgit:git-clone[1] or (if it begins with ./ or ../) a location
+	relative to the superproject's origin repository.
+
+In addition, there are a number of optional keys:
+
+submodule.<name>.update::
+	Defines the default update procedure for the named submodule,
+	i.e. how the submodule is updated by "git submodule update"
+	command in the superproject. This is only used by `git
+	submodule init` to initialize the configuration variable of
+	the same name. Allowed values here are 'checkout', 'rebase',
+	'merge' or 'none'. See description of 'update' command in
+	linkgit:git-submodule[1] for their meaning. Note that the
+	'!command' form is intentionally ignored here for security
+	reasons.
+
+submodule.<name>.branch::
+	A remote branch name for tracking updates in the upstream submodule.
+	If the option is not specified, it defaults to 'master'.  A special
+	value of `.` is used to indicate that the name of the branch in the
+	submodule should be the same name as the current branch in the
+	current repository.  See the `--remote` documentation in
+	linkgit:git-submodule[1] for details.
+
+submodule.<name>.fetchRecurseSubmodules::
+	This option can be used to control recursive fetching of this
+	submodule. If this option is also present in the submodules entry in
+	.git/config of the superproject, the setting there will override the
+	one found in .gitmodules.
+	Both settings can be overridden on the command line by using the
+	"--[no-]recurse-submodules" option to "git fetch" and "git pull".
+
+submodule.<name>.ignore::
+	Defines under what circumstances "git status" and the diff family show
+	a submodule as modified. The following values are supported:
++
+--
+	all;; The submodule will never be considered modified (but will
+	    nonetheless show up in the output of status and commit when it has
+	    been staged).
+
+	dirty;; All changes to the submodule's work tree will be ignored, only
+	    committed differences between the HEAD of the submodule and its
+	    recorded state in the superproject are taken into account.
+
+	untracked;; Only untracked files in submodules will be ignored.
+	    Committed differences and modifications to tracked files will show
+	    up.
+
+	none;; No modifiations to submodules are ignored, all of committed
+	    differences, and modifications to tracked and untracked files are
+	    shown. This is the default option.
+
+If this option is also present in the submodules entry in .git/config
+of the superproject, the setting there will override the one found in
+.gitmodules.
+
+Both settings can be overridden on the command line by using the
+"--ignore-submodule" option. The 'git submodule' commands are not
+affected by this setting.
+--
+
+submodule.<name>.shallow::
+	When set to true, a clone of this submodule will be performed as a
+	shallow clone (with a history depth of 1) unless the user explicitly
+	asks for a non-shallow clone.
+
+
+EXAMPLES
+--------
+
+Consider the following .gitmodules file:
+
+	[submodule "libfoo"]
+		path = include/foo
+		url = git://foo.com/git/lib.git
+
+	[submodule "libbar"]
+		path = include/bar
+		url = git://bar.com/git/lib.git
+
+
+This defines two submodules, `libfoo` and `libbar`. These are expected to
+be checked out in the paths `include/foo` and `include/bar`, and for both
+submodules a URL is specified which can be used for cloning the submodules.
+
+SEE ALSO
+--------
+linkgit:git-submodule[1] linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitnamespaces.txt b/third_party/git/Documentation/gitnamespaces.txt
new file mode 100644
index 0000000000..b614969ad2
--- /dev/null
+++ b/third_party/git/Documentation/gitnamespaces.txt
@@ -0,0 +1,64 @@
+gitnamespaces(7)
+================
+
+NAME
+----
+gitnamespaces - Git namespaces
+
+SYNOPSIS
+--------
+[verse]
+GIT_NAMESPACE=<namespace> 'git upload-pack'
+GIT_NAMESPACE=<namespace> 'git receive-pack'
+
+
+DESCRIPTION
+-----------
+
+Git supports dividing the refs of a single repository into multiple
+namespaces, each of which has its own branches, tags, and HEAD.  Git can
+expose each namespace as an independent repository to pull from and push
+to, while sharing the object store, and exposing all the refs to
+operations such as linkgit:git-gc[1].
+
+Storing multiple repositories as namespaces of a single repository
+avoids storing duplicate copies of the same objects, such as when
+storing multiple branches of the same source.  The alternates mechanism
+provides similar support for avoiding duplicates, but alternates do not
+prevent duplication between new objects added to the repositories
+without ongoing maintenance, while namespaces do.
+
+To specify a namespace, set the `GIT_NAMESPACE` environment variable to
+the namespace.  For each ref namespace, Git stores the corresponding
+refs in a directory under `refs/namespaces/`.  For example,
+`GIT_NAMESPACE=foo` will store refs under `refs/namespaces/foo/`.  You
+can also specify namespaces via the `--namespace` option to
+linkgit:git[1].
+
+Note that namespaces which include a `/` will expand to a hierarchy of
+namespaces; for example, `GIT_NAMESPACE=foo/bar` will store refs under
+`refs/namespaces/foo/refs/namespaces/bar/`.  This makes paths in
+`GIT_NAMESPACE` behave hierarchically, so that cloning with
+`GIT_NAMESPACE=foo/bar` produces the same result as cloning with
+`GIT_NAMESPACE=foo` and cloning from that repo with `GIT_NAMESPACE=bar`.  It
+also avoids ambiguity with strange namespace paths such as `foo/refs/heads/`,
+which could otherwise generate directory/file conflicts within the `refs`
+directory.
+
+linkgit:git-upload-pack[1] and linkgit:git-receive-pack[1] rewrite the
+names of refs as specified by `GIT_NAMESPACE`.  git-upload-pack and
+git-receive-pack will ignore all references outside the specified
+namespace.
+
+The smart HTTP server, linkgit:git-http-backend[1], will pass
+GIT_NAMESPACE through to the backend programs; see
+linkgit:git-http-backend[1] for sample configuration to expose
+repository namespaces as repositories.
+
+For a simple local test, you can use linkgit:git-remote-ext[1]:
+
+----------
+git clone ext::'git --namespace=foo %s /tmp/prefixed.git'
+----------
+
+include::transfer-data-leaks.txt[]
diff --git a/third_party/git/Documentation/gitremote-helpers.txt b/third_party/git/Documentation/gitremote-helpers.txt
new file mode 100644
index 0000000000..43f80c8068
--- /dev/null
+++ b/third_party/git/Documentation/gitremote-helpers.txt
@@ -0,0 +1,520 @@
+gitremote-helpers(7)
+====================
+
+NAME
+----
+gitremote-helpers - Helper programs to interact with remote repositories
+
+SYNOPSIS
+--------
+[verse]
+'git remote-<transport>' <repository> [<URL>]
+
+DESCRIPTION
+-----------
+
+Remote helper programs are normally not used directly by end users,
+but they are invoked by Git when it needs to interact with remote
+repositories Git does not support natively.  A given helper will
+implement a subset of the capabilities documented here. When Git
+needs to interact with a repository using a remote helper, it spawns
+the helper as an independent process, sends commands to the helper's
+standard input, and expects results from the helper's standard
+output. Because a remote helper runs as an independent process from
+Git, there is no need to re-link Git to add a new helper, nor any
+need to link the helper with the implementation of Git.
+
+Every helper must support the "capabilities" command, which Git
+uses to determine what other commands the helper will accept.  Those
+other commands can be used to discover and update remote refs,
+transport objects between the object database and the remote repository,
+and update the local object store.
+
+Git comes with a "curl" family of remote helpers, that handle various
+transport protocols, such as 'git-remote-http', 'git-remote-https',
+'git-remote-ftp' and 'git-remote-ftps'. They implement the capabilities
+'fetch', 'option', and 'push'.
+
+INVOCATION
+----------
+
+Remote helper programs are invoked with one or (optionally) two
+arguments. The first argument specifies a remote repository as in Git;
+it is either the name of a configured remote or a URL. The second
+argument specifies a URL; it is usually of the form
+'<transport>://<address>', but any arbitrary string is possible.
+The `GIT_DIR` environment variable is set up for the remote helper
+and can be used to determine where to store additional data or from
+which directory to invoke auxiliary Git commands.
+
+When Git encounters a URL of the form '<transport>://<address>', where
+'<transport>' is a protocol that it cannot handle natively, it
+automatically invokes 'git remote-<transport>' with the full URL as
+the second argument. If such a URL is encountered directly on the
+command line, the first argument is the same as the second, and if it
+is encountered in a configured remote, the first argument is the name
+of that remote.
+
+A URL of the form '<transport>::<address>' explicitly instructs Git to
+invoke 'git remote-<transport>' with '<address>' as the second
+argument. If such a URL is encountered directly on the command line,
+the first argument is '<address>', and if it is encountered in a
+configured remote, the first argument is the name of that remote.
+
+Additionally, when a configured remote has `remote.<name>.vcs` set to
+'<transport>', Git explicitly invokes 'git remote-<transport>' with
+'<name>' as the first argument. If set, the second argument is
+`remote.<name>.url`; otherwise, the second argument is omitted.
+
+INPUT FORMAT
+------------
+
+Git sends the remote helper a list of commands on standard input, one
+per line.  The first command is always the 'capabilities' command, in
+response to which the remote helper must print a list of the
+capabilities it supports (see below) followed by a blank line.  The
+response to the capabilities command determines what commands Git uses
+in the remainder of the command stream.
+
+The command stream is terminated by a blank line.  In some cases
+(indicated in the documentation of the relevant commands), this blank
+line is followed by a payload in some other protocol (e.g., the pack
+protocol), while in others it indicates the end of input.
+
+Capabilities
+~~~~~~~~~~~~
+
+Each remote helper is expected to support only a subset of commands.
+The operations a helper supports are declared to Git in the response
+to the `capabilities` command (see COMMANDS, below).
+
+In the following, we list all defined capabilities and for
+each we list which commands a helper with that capability
+must provide.
+
+Capabilities for Pushing
+^^^^^^^^^^^^^^^^^^^^^^^^
+'connect'::
+	Can attempt to connect to 'git receive-pack' (for pushing),
+	'git upload-pack', etc for communication using
+	git's native packfile protocol. This
+	requires a bidirectional, full-duplex connection.
++
+Supported commands: 'connect'.
+
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
+'push'::
+	Can discover remote refs and push local commits and the
+	history leading up to them to new or existing remote refs.
++
+Supported commands: 'list for-push', 'push'.
+
+'export'::
+	Can discover remote refs and push specified objects from a
+	fast-import stream to remote refs.
++
+Supported commands: 'list for-push', 'export'.
+
+If a helper advertises 'connect', Git will use it if possible and
+fall back to another capability if the helper requests so when
+connecting (see the 'connect' command under COMMANDS).
+When choosing between 'push' and 'export', Git prefers 'push'.
+Other frontends may have some other order of preference.
+
+'no-private-update'::
+	When using the 'refspec' capability, git normally updates the
+	private ref on successful push. This update is disabled when
+	the remote-helper declares the capability 'no-private-update'.
+
+
+Capabilities for Fetching
+^^^^^^^^^^^^^^^^^^^^^^^^^
+'connect'::
+	Can try to connect to 'git upload-pack' (for fetching),
+	'git receive-pack', etc for communication using the
+	Git's native packfile protocol. This
+	requires a bidirectional, full-duplex connection.
++
+Supported commands: 'connect'.
+
+'stateless-connect'::
+	Experimental; for internal use only.
+	Can attempt to connect to a remote server for communication
+	using git's wire-protocol version 2.  See the documentation
+	for the stateless-connect command for more information.
++
+Supported commands: 'stateless-connect'.
+
+'fetch'::
+	Can discover remote refs and transfer objects reachable from
+	them to the local object store.
++
+Supported commands: 'list', 'fetch'.
+
+'import'::
+	Can discover remote refs and output objects reachable from
+	them as a stream in fast-import format.
++
+Supported commands: 'list', 'import'.
+
+'check-connectivity'::
+	Can guarantee that when a clone is requested, the received
+	pack is self contained and is connected.
+
+If a helper advertises 'connect', Git will use it if possible and
+fall back to another capability if the helper requests so when
+connecting (see the 'connect' command under COMMANDS).
+When choosing between 'fetch' and 'import', Git prefers 'fetch'.
+Other frontends may have some other order of preference.
+
+Miscellaneous capabilities
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+'option'::
+	For specifying settings like `verbosity` (how much output to
+	write to stderr) and `depth` (how much history is wanted in the
+	case of a shallow clone) that affect how other commands are
+	carried out.
+
+'refspec' <refspec>::
+	For remote helpers that implement 'import' or 'export', this capability
+	allows the refs to be constrained to a private namespace, instead of
+	writing to refs/heads or refs/remotes directly.
+	It is recommended that all importers providing the 'import'
+	capability use this. It's mandatory for 'export'.
++
+A helper advertising the capability
+`refspec refs/heads/*:refs/svn/origin/branches/*`
+is saying that, when it is asked to `import refs/heads/topic`, the
+stream it outputs will update the `refs/svn/origin/branches/topic`
+ref.
++
+This capability can be advertised multiple times.  The first
+applicable refspec takes precedence.  The left-hand of refspecs
+advertised with this capability must cover all refs reported by
+the list command.  If no 'refspec' capability is advertised,
+there is an implied `refspec *:*`.
++
+When writing remote-helpers for decentralized version control
+systems, it is advised to keep a local copy of the repository to
+interact with, and to let the private namespace refs point to this
+local repository, while the refs/remotes namespace is used to track
+the remote repository.
+
+'bidi-import'::
+	This modifies the 'import' capability.
+	The fast-import commands 'cat-blob' and 'ls' can be used by remote-helpers
+	to retrieve information about blobs and trees that already exist in
+	fast-import's memory. This requires a channel from fast-import to the
+	remote-helper.
+	If it is advertised in addition to "import", Git establishes a pipe from
+	fast-import to the remote-helper's stdin.
+	It follows that Git and fast-import are both connected to the
+	remote-helper's stdin. Because Git can send multiple commands to
+	the remote-helper it is required that helpers that use 'bidi-import'
+	buffer all 'import' commands of a batch before sending data to fast-import.
+	This is to prevent mixing commands and fast-import responses on the
+	helper's stdin.
+
+'export-marks' <file>::
+	This modifies the 'export' capability, instructing Git to dump the
+	internal marks table to <file> when complete. For details,
+	read up on `--export-marks=<file>` in linkgit:git-fast-export[1].
+
+'import-marks' <file>::
+	This modifies the 'export' capability, instructing Git to load the
+	marks specified in <file> before processing any input. For details,
+	read up on `--import-marks=<file>` in linkgit:git-fast-export[1].
+
+'signed-tags'::
+	This modifies the 'export' capability, instructing Git to pass
+	`--signed-tags=verbatim` to linkgit:git-fast-export[1].  In the
+	absence of this capability, Git will use `--signed-tags=warn-strip`.
+
+
+
+COMMANDS
+--------
+
+Commands are given by the caller on the helper's standard input, one per line.
+
+'capabilities'::
+	Lists the capabilities of the helper, one per line, ending
+	with a blank line. Each capability may be preceded with '*',
+	which marks them mandatory for Git versions using the remote
+	helper to understand. Any unknown mandatory capability is a
+	fatal error.
++
+Support for this command is mandatory.
+
+'list'::
+	Lists the refs, one per line, in the format "<value> <name>
+	[<attr> ...]". The value may be a hex sha1 hash, "@<dest>" for
+	a symref, or "?" to indicate that the helper could not get the
+	value of the ref. A space-separated list of attributes follows
+	the name; unrecognized attributes are ignored. The list ends
+	with a blank line.
++
+See REF LIST ATTRIBUTES for a list of currently defined attributes.
++
+Supported if the helper has the "fetch" or "import" capability.
+
+'list for-push'::
+	Similar to 'list', except that it is used if and only if
+	the caller wants to the resulting ref list to prepare
+	push commands.
+	A helper supporting both push and fetch can use this
+	to distinguish for which operation the output of 'list'
+	is going to be used, possibly reducing the amount
+	of work that needs to be performed.
++
+Supported if the helper has the "push" or "export" capability.
+
+'option' <name> <value>::
+	Sets the transport helper option <name> to <value>.  Outputs a
+	single line containing one of 'ok' (option successfully set),
+	'unsupported' (option not recognized) or 'error <msg>'
+	(option <name> is supported but <value> is not valid
+	for it).  Options should be set before other commands,
+	and may influence the behavior of those commands.
++
+See OPTIONS for a list of currently defined options.
++
+Supported if the helper has the "option" capability.
+
+'fetch' <sha1> <name>::
+	Fetches the given object, writing the necessary objects
+	to the database.  Fetch commands are sent in a batch, one
+	per line, terminated with a blank line.
+	Outputs a single blank line when all fetch commands in the
+	same batch are complete. Only objects which were reported
+	in the output of 'list' with a sha1 may be fetched this way.
++
+Optionally may output a 'lock <file>' line indicating a file under
+GIT_DIR/objects/pack which is keeping a pack until refs can be
+suitably updated.
++
+If option 'check-connectivity' is requested, the helper must output
+'connectivity-ok' if the clone is self-contained and connected.
++
+Supported if the helper has the "fetch" capability.
+
+'push' +<src>:<dst>::
+	Pushes the given local <src> commit or branch to the
+	remote branch described by <dst>.  A batch sequence of
+	one or more 'push' commands is terminated with a blank line
+	(if there is only one reference to push, a single 'push' command
+	is followed by a blank line). For example, the following would
+	be two batches of 'push', the first asking the remote-helper
+	to push the local ref 'master' to the remote ref 'master' and
+	the local `HEAD` to the remote 'branch', and the second
+	asking to push ref 'foo' to ref 'bar' (forced update requested
+	by the '+').
++
+------------
+push refs/heads/master:refs/heads/master
+push HEAD:refs/heads/branch
+\n
+push +refs/heads/foo:refs/heads/bar
+\n
+------------
++
+Zero or more protocol options may be entered after the last 'push'
+command, before the batch's terminating blank line.
++
+When the push is complete, outputs one or more 'ok <dst>' or
+'error <dst> <why>?' lines to indicate success or failure of
+each pushed ref.  The status report output is terminated by
+a blank line.  The option field <why> may be quoted in a C
+style string if it contains an LF.
++
+Supported if the helper has the "push" capability.
+
+'import' <name>::
+	Produces a fast-import stream which imports the current value
+	of the named ref. It may additionally import other refs as
+	needed to construct the history efficiently. The script writes
+	to a helper-specific private namespace. The value of the named
+	ref should be written to a location in this namespace derived
+	by applying the refspecs from the "refspec" capability to the
+	name of the ref.
++
+Especially useful for interoperability with a foreign versioning
+system.
++
+Just like 'push', a batch sequence of one or more 'import' is
+terminated with a blank line. For each batch of 'import', the remote
+helper should produce a fast-import stream terminated by a 'done'
+command.
++
+Note that if the 'bidi-import' capability is used the complete batch
+sequence has to be buffered before starting to send data to fast-import
+to prevent mixing of commands and fast-import responses on the helper's
+stdin.
++
+Supported if the helper has the "import" capability.
+
+'export'::
+	Instructs the remote helper that any subsequent input is
+	part of a fast-import stream (generated by 'git fast-export')
+	containing objects which should be pushed to the remote.
++
+Especially useful for interoperability with a foreign versioning
+system.
++
+The 'export-marks' and 'import-marks' capabilities, if specified,
+affect this command in so far as they are passed on to 'git
+fast-export', which then will load/store a table of marks for
+local objects. This can be used to implement for incremental
+operations.
++
+Supported if the helper has the "export" capability.
+
+'connect' <service>::
+	Connects to given service. Standard input and standard output
+	of helper are connected to specified service (git prefix is
+	included in service name so e.g. fetching uses 'git-upload-pack'
+	as service) on remote side. Valid replies to this command are
+	empty line (connection established), 'fallback' (no smart
+	transport support, fall back to dumb transports) and just
+	exiting with error message printed (can't connect, don't
+	bother trying to fall back). After line feed terminating the
+	positive (empty) response, the output of service starts. After
+	the connection ends, the remote helper exits.
++
+Supported if the helper has the "connect" capability.
+
+'stateless-connect' <service>::
+	Experimental; for internal use only.
+	Connects to the given remote service for communication using
+	git's wire-protocol version 2.  Valid replies to this command
+	are empty line (connection established), 'fallback' (no smart
+	transport support, fall back to dumb transports) and just
+	exiting with error message printed (can't connect, don't bother
+	trying to fall back).  After line feed terminating the positive
+	(empty) response, the output of the service starts.  Messages
+	(both request and response) must consist of zero or more
+	PKT-LINEs, terminating in a flush packet. The client must not
+	expect the server to store any state in between request-response
+	pairs.  After the connection ends, the remote helper exits.
++
+Supported if the helper has the "stateless-connect" capability.
+
+If a fatal error occurs, the program writes the error message to
+stderr and exits. The caller should expect that a suitable error
+message has been printed if the child closes the connection without
+completing a valid response for the current command.
+
+Additional commands may be supported, as may be determined from
+capabilities reported by the helper.
+
+REF LIST ATTRIBUTES
+-------------------
+
+The 'list' command produces a list of refs in which each ref
+may be followed by a list of attributes. The following ref list
+attributes are defined.
+
+'unchanged'::
+	This ref is unchanged since the last import or fetch, although
+	the helper cannot necessarily determine what value that produced.
+
+OPTIONS
+-------
+
+The following options are defined and (under suitable circumstances)
+set by Git if the remote helper has the 'option' capability.
+
+'option verbosity' <n>::
+	Changes the verbosity of messages displayed by the helper.
+	A value of 0 for <n> means that processes operate
+	quietly, and the helper produces only error output.
+	1 is the default level of verbosity, and higher values
+	of <n> correspond to the number of -v flags passed on the
+	command line.
+
+'option progress' {'true'|'false'}::
+	Enables (or disables) progress messages displayed by the
+	transport helper during a command.
+
+'option depth' <depth>::
+	Deepens the history of a shallow repository.
+
+'option deepen-since <timestamp>::
+	Deepens the history of a shallow repository based on time.
+
+'option deepen-not <ref>::
+	Deepens the history of a shallow repository excluding ref.
+	Multiple options add up.
+
+'option deepen-relative {'true'|'false'}::
+	Deepens the history of a shallow repository relative to
+	current boundary. Only valid when used with "option depth".
+
+'option followtags' {'true'|'false'}::
+	If enabled the helper should automatically fetch annotated
+	tag objects if the object the tag points at was transferred
+	during the fetch command.  If the tag is not fetched by
+	the helper a second fetch command will usually be sent to
+	ask for the tag specifically.  Some helpers may be able to
+	use this option to avoid a second network connection.
+
+'option dry-run' {'true'|'false'}:
+	If true, pretend the operation completed successfully,
+	but don't actually change any repository data.  For most
+	helpers this only applies to the 'push', if supported.
+
+'option servpath <c-style-quoted-path>'::
+	Sets service path (--upload-pack, --receive-pack etc.) for
+	next connect. Remote helper may support this option, but
+	must not rely on this option being set before
+	connect request occurs.
+
+'option check-connectivity' {'true'|'false'}::
+	Request the helper to check connectivity of a clone.
+
+'option force' {'true'|'false'}::
+	Request the helper to perform a force update.  Defaults to
+	'false'.
+
+'option cloning' {'true'|'false'}::
+	Notify the helper this is a clone request (i.e. the current
+	repository is guaranteed empty).
+
+'option update-shallow' {'true'|'false'}::
+	Allow to extend .git/shallow if the new refs require it.
+
+'option pushcert' {'true'|'false'}::
+	GPG sign pushes.
+
+'option push-option <string>::
+	Transmit <string> as a push option. As the push option
+	must not contain LF or NUL characters, the string is not encoded.
+
+'option from-promisor' {'true'|'false'}::
+	Indicate that these objects are being fetched from a promisor.
+
+'option no-dependents' {'true'|'false'}::
+	Indicate that only the objects wanted need to be fetched, not
+	their dependents.
+
+SEE ALSO
+--------
+linkgit:git-remote[1]
+
+linkgit:git-remote-ext[1]
+
+linkgit:git-remote-fd[1]
+
+linkgit:git-fast-import[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitrepository-layout.txt b/third_party/git/Documentation/gitrepository-layout.txt
new file mode 100644
index 0000000000..216b11ee88
--- /dev/null
+++ b/third_party/git/Documentation/gitrepository-layout.txt
@@ -0,0 +1,308 @@
+gitrepository-layout(5)
+=======================
+
+NAME
+----
+gitrepository-layout - Git Repository Layout
+
+SYNOPSIS
+--------
+$GIT_DIR/*
+
+DESCRIPTION
+-----------
+
+A Git repository comes in two different flavours:
+
+ * a `.git` directory at the root of the working tree;
+
+ * a `<project>.git` directory that is a 'bare' repository
+   (i.e. without its own working tree), that is typically used for
+   exchanging histories with others by pushing into it and fetching
+   from it.
+
+*Note*: Also you can have a plain text file `.git` at the root of
+your working tree, containing `gitdir: <path>` to point at the real
+directory that has the repository.  This mechanism is often used for
+a working tree of a submodule checkout, to allow you in the
+containing superproject to `git checkout` a branch that does not
+have the submodule.  The `checkout` has to remove the entire
+submodule working tree, without losing the submodule repository.
+
+These things may exist in a Git repository.
+
+objects::
+	Object store associated with this repository.  Usually
+	an object store is self sufficient (i.e. all the objects
+	that are referred to by an object found in it are also
+	found in it), but there are a few ways to violate it.
++
+. You could have an incomplete but locally usable repository
+by creating a shallow clone.  See linkgit:git-clone[1].
+. You could be using the `objects/info/alternates` or
+`$GIT_ALTERNATE_OBJECT_DIRECTORIES` mechanisms to 'borrow'
+objects from other object stores.  A repository with this kind
+of incomplete object store is not suitable to be published for
+use with dumb transports but otherwise is OK as long as
+`objects/info/alternates` points at the object stores it
+borrows from.
++
+This directory is ignored if $GIT_COMMON_DIR is set and
+"$GIT_COMMON_DIR/objects" will be used instead.
+
+objects/[0-9a-f][0-9a-f]::
+	A newly created object is stored in its own file.
+	The objects are splayed over 256 subdirectories using
+	the first two characters of the sha1 object name to
+	keep the number of directory entries in `objects`
+	itself to a manageable number. Objects found
+	here are often called 'unpacked' (or 'loose') objects.
+
+objects/pack::
+	Packs (files that store many object in compressed form,
+	along with index files to allow them to be randomly
+	accessed) are found in this directory.
+
+objects/info::
+	Additional information about the object store is
+	recorded in this directory.
+
+objects/info/packs::
+	This file is to help dumb transports discover what packs
+	are available in this object store.  Whenever a pack is
+	added or removed, `git update-server-info` should be run
+	to keep this file up to date if the repository is
+	published for dumb transports.  'git repack' does this
+	by default.
+
+objects/info/alternates::
+	This file records paths to alternate object stores that
+	this object store borrows objects from, one pathname per
+	line. Note that not only native Git tools use it locally,
+	but the HTTP fetcher also tries to use it remotely; this
+	will usually work if you have relative paths (relative
+	to the object database, not to the repository!) in your
+	alternates file, but it will not work if you use absolute
+	paths unless the absolute path in filesystem and web URL
+	is the same. See also `objects/info/http-alternates`.
+
+objects/info/http-alternates::
+	This file records URLs to alternate object stores that
+	this object store borrows objects from, to be used when
+	the repository is fetched over HTTP.
+
+refs::
+	References are stored in subdirectories of this
+	directory.  The 'git prune' command knows to preserve
+	objects reachable from refs found in this directory and
+	its subdirectories.
+	This directory is ignored (except refs/bisect and
+	refs/worktree) if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/refs" will be used instead.
+
+refs/heads/`name`::
+	records tip-of-the-tree commit objects of branch `name`
+
+refs/tags/`name`::
+	records any object name (not necessarily a commit
+	object, or a tag object that points at a commit object).
+
+refs/remotes/`name`::
+	records tip-of-the-tree commit objects of branches copied
+	from a remote repository.
+
+refs/replace/`<obj-sha1>`::
+	records the SHA-1 of the object that replaces `<obj-sha1>`.
+	This is similar to info/grafts and is internally used and
+	maintained by linkgit:git-replace[1]. Such refs can be exchanged
+	between repositories while grafts are not.
+
+packed-refs::
+	records the same information as refs/heads/, refs/tags/,
+	and friends record in a more efficient way.  See
+	linkgit:git-pack-refs[1]. This file is ignored if $GIT_COMMON_DIR
+	is set and "$GIT_COMMON_DIR/packed-refs" will be used instead.
+
+HEAD::
+	A symref (see glossary) to the `refs/heads/` namespace
+	describing the currently active branch.  It does not mean
+	much if the repository is not associated with any working tree
+	(i.e. a 'bare' repository), but a valid Git repository
+	*must* have the HEAD file; some porcelains may use it to
+	guess the designated "default" branch of the repository
+	(usually 'master').  It is legal if the named branch
+	'name' does not (yet) exist.  In some legacy setups, it is
+	a symbolic link instead of a symref that points at the current
+	branch.
++
+HEAD can also record a specific commit directly, instead of
+being a symref to point at the current branch.  Such a state
+is often called 'detached HEAD.'  See linkgit:git-checkout[1]
+for details.
+
+config::
+	Repository specific configuration file. This file is ignored
+	if $GIT_COMMON_DIR is set and "$GIT_COMMON_DIR/config" will be
+	used instead.
+
+config.worktree::
+	Working directory specific configuration file for the main
+	working directory in multiple working directory setup (see
+	linkgit:git-worktree[1]).
+
+branches::
+	A slightly deprecated way to store shorthands to be used
+	to specify a URL to 'git fetch', 'git pull' and 'git push'.
+	A file can be stored as `branches/<name>` and then
+	'name' can be given to these commands in place of
+	'repository' argument.  See the REMOTES section in
+	linkgit:git-fetch[1] for details.  This mechanism is legacy
+	and not likely to be found in modern repositories. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/branches" will be used instead.
+
+
+hooks::
+	Hooks are customization scripts used by various Git
+	commands.  A handful of sample hooks are installed when
+	'git init' is run, but all of them are disabled by
+	default.  To enable, the `.sample` suffix has to be
+	removed from the filename by renaming.
+	Read linkgit:githooks[5] for more details about
+	each hook. This directory is ignored if $GIT_COMMON_DIR is set
+	and "$GIT_COMMON_DIR/hooks" will be used instead.
+
+common::
+	When multiple working trees are used, most of files in
+	$GIT_DIR are per-worktree with a few known exceptions. All
+	files under 'common' however will be shared between all
+	working trees.
+
+index::
+	The current index file for the repository.  It is
+	usually not found in a bare repository.
+
+sharedindex.<SHA-1>::
+	The shared index part, to be referenced by $GIT_DIR/index and
+	other temporary index files. Only valid in split index mode.
+
+info::
+	Additional information about the repository is recorded
+	in this directory. This directory is ignored if $GIT_COMMON_DIR
+	is set and "$GIT_COMMON_DIR/info" will be used instead.
+
+info/refs::
+	This file helps dumb transports discover what refs are
+	available in this repository.  If the repository is
+	published for dumb transports, this file should be
+	regenerated by 'git update-server-info' every time a tag
+	or branch is created or modified.  This is normally done
+	from the `hooks/update` hook, which is run by the
+	'git-receive-pack' command when you 'git push' into the
+	repository.
+
+info/grafts::
+	This file records fake commit ancestry information, to
+	pretend the set of parents a commit has is different
+	from how the commit was actually created.  One record
+	per line describes a commit and its fake parents by
+	listing their 40-byte hexadecimal object names separated
+	by a space and terminated by a newline.
++
+Note that the grafts mechanism is outdated and can lead to problems
+transferring objects between repositories; see linkgit:git-replace[1]
+for a more flexible and robust system to do the same thing.
+
+info/exclude::
+	This file, by convention among Porcelains, stores the
+	exclude pattern list. `.gitignore` is the per-directory
+	ignore file.  'git status', 'git add', 'git rm' and
+	'git clean' look at it but the core Git commands do not look
+	at it.  See also: linkgit:gitignore[5].
+
+info/attributes::
+	Defines which attributes to assign to a path, similar to per-directory
+	`.gitattributes` files.   See also: linkgit:gitattributes[5].
+
+info/sparse-checkout::
+	This file stores sparse checkout patterns.
+	See also: linkgit:git-read-tree[1].
+
+remotes::
+	Stores shorthands for URL and default refnames for use
+	when interacting with remote repositories via 'git fetch',
+	'git pull' and 'git push' commands.  See the REMOTES section
+	in linkgit:git-fetch[1] for details.  This mechanism is legacy
+	and not likely to be found in modern repositories. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/remotes" will be used instead.
+
+logs::
+	Records of changes made to refs are stored in this directory.
+	See linkgit:git-update-ref[1] for more information. This
+	directory is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/logs" will be used instead.
+
+logs/refs/heads/`name`::
+	Records all changes made to the branch tip named `name`.
+
+logs/refs/tags/`name`::
+	Records all changes made to the tag named `name`.
+
+shallow::
+	This is similar to `info/grafts` but is internally used
+	and maintained by shallow clone mechanism.  See `--depth`
+	option to linkgit:git-clone[1] and linkgit:git-fetch[1]. This
+	file is ignored if $GIT_COMMON_DIR is set and
+	"$GIT_COMMON_DIR/shallow" will be used instead.
+
+commondir::
+	If this file exists, $GIT_COMMON_DIR (see linkgit:git[1]) will
+	be set to the path specified in this file if it is not
+	explicitly set. If the specified path is relative, it is
+	relative to $GIT_DIR. The repository with commondir is
+	incomplete without the repository pointed by "commondir".
+
+modules::
+	Contains the git-repositories of the submodules.
+
+worktrees::
+	Contains administrative data for linked
+	working trees. Each subdirectory contains the working tree-related
+	part of a linked working tree. This directory is ignored if
+	$GIT_COMMON_DIR is set, in which case
+	"$GIT_COMMON_DIR/worktrees" will be used instead.
+
+worktrees/<id>/gitdir::
+	A text file containing the absolute path back to the .git file
+	that points to here. This is used to check if the linked
+	repository has been manually removed and there is no need to
+	keep this directory any more. The mtime of this file should be
+	updated every time the linked repository is accessed.
+
+worktrees/<id>/locked::
+	If this file exists, the linked working tree may be on a
+	portable device and not available. The presence of this file
+	prevents `worktrees/<id>` from being pruned either automatically
+	or manually by `git worktree prune`. The file may contain a string
+	explaining why the repository is locked.
+
+worktrees/<id>/config.worktree::
+	Working directory specific configuration file.
+
+include::technical/repository-version.txt[]
+
+SEE ALSO
+--------
+linkgit:git-init[1],
+linkgit:git-clone[1],
+linkgit:git-fetch[1],
+linkgit:git-pack-refs[1],
+linkgit:git-gc[1],
+linkgit:git-checkout[1],
+linkgit:gitglossary[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitrevisions.txt b/third_party/git/Documentation/gitrevisions.txt
new file mode 100644
index 0000000000..d407b7dee1
--- /dev/null
+++ b/third_party/git/Documentation/gitrevisions.txt
@@ -0,0 +1,36 @@
+gitrevisions(7)
+===============
+
+NAME
+----
+gitrevisions - Specifying revisions and ranges for Git
+
+SYNOPSIS
+--------
+gitrevisions
+
+
+DESCRIPTION
+-----------
+
+Many Git commands take revision parameters as arguments. Depending on
+the command, they denote a specific commit or, for commands which
+walk the revision graph (such as linkgit:git-log[1]), all commits which are
+reachable from that commit. For commands that walk the revision graph one can
+also specify a range of revisions explicitly.
+
+In addition, some Git commands (such as linkgit:git-show[1] and
+linkgit:git-push[1]) can also take revision parameters which denote
+other objects than commits, e.g. blobs ("files") or trees
+("directories of files").
+
+include::revisions.txt[]
+
+
+SEE ALSO
+--------
+linkgit:git-rev-parse[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitsubmodules.txt b/third_party/git/Documentation/gitsubmodules.txt
new file mode 100644
index 0000000000..0a890205b8
--- /dev/null
+++ b/third_party/git/Documentation/gitsubmodules.txt
@@ -0,0 +1,283 @@
+gitsubmodules(7)
+================
+
+NAME
+----
+gitsubmodules - mounting one repository inside another
+
+SYNOPSIS
+--------
+ .gitmodules, $GIT_DIR/config
+------------------
+git submodule
+git <command> --recurse-submodules
+------------------
+
+DESCRIPTION
+-----------
+
+A submodule is a repository embedded inside another repository.
+The submodule has its own history; the repository it is embedded
+in is called a superproject.
+
+On the filesystem, a submodule usually (but not always - see FORMS below)
+consists of (i) a Git directory located under the `$GIT_DIR/modules/`
+directory of its superproject, (ii) a working directory inside the
+superproject's working directory, and a `.git` file at the root of
+the submodule's working directory pointing to (i).
+
+Assuming the submodule has a Git directory at `$GIT_DIR/modules/foo/`
+and a working directory at `path/to/bar/`, the superproject tracks the
+submodule via a `gitlink` entry in the tree at `path/to/bar` and an entry
+in its `.gitmodules` file (see linkgit:gitmodules[5]) of the form
+`submodule.foo.path = path/to/bar`.
+
+The `gitlink` entry contains the object name of the commit that the
+superproject expects the submodule's working directory to be at.
+
+The section `submodule.foo.*` in the `.gitmodules` file gives additional
+hints to Git's porcelain layer. For example, the `submodule.foo.url`
+setting specifies where to obtain the submodule.
+
+Submodules can be used for at least two different use cases:
+
+1. Using another project while maintaining independent history.
+  Submodules allow you to contain the working tree of another project
+  within your own working tree while keeping the history of both
+  projects separate. Also, since submodules are fixed to an arbitrary
+  version, the other project can be independently developed without
+  affecting the superproject, allowing the superproject project to
+  fix itself to new versions only when desired.
+
+2. Splitting a (logically single) project into multiple
+   repositories and tying them back together. This can be used to
+   overcome current limitations of Git's implementation to have
+   finer grained access:
+
+    * Size of the Git repository:
+      In its current form Git scales up poorly for large repositories containing
+      content that is not compressed by delta computation between trees.
+      For example, you can use submodules to hold large binary assets
+      and these repositories can be shallowly cloned such that you do not
+      have a large history locally.
+    * Transfer size:
+      In its current form Git requires the whole working tree present. It
+      does not allow partial trees to be transferred in fetch or clone.
+      If the project you work on consists of multiple repositories tied
+      together as submodules in a superproject, you can avoid fetching the
+      working trees of the repositories you are not interested in.
+    * Access control:
+      By restricting user access to submodules, this can be used to implement
+      read/write policies for different users.
+
+The configuration of submodules
+-------------------------------
+
+Submodule operations can be configured using the following mechanisms
+(from highest to lowest precedence):
+
+ * The command line for those commands that support taking submodules
+   as part of their pathspecs. Most commands have a boolean flag
+   `--recurse-submodules` which specify whether to recurse into submodules.
+   Examples are `grep` and `checkout`.
+   Some commands take enums, such as `fetch` and `push`, where you can
+   specify how submodules are affected.
+
+ * The configuration inside the submodule. This includes `$GIT_DIR/config`
+   in the submodule, but also settings in the tree such as a `.gitattributes`
+   or `.gitignore` files that specify behavior of commands inside the
+   submodule.
++
+For example an effect from the submodule's `.gitignore` file
+would be observed when you run `git status --ignore-submodules=none` in
+the superproject. This collects information from the submodule's working
+directory by running `status` in the submodule while paying attention
+to the `.gitignore` file of the submodule.
++
+The submodule's `$GIT_DIR/config` file would come into play when running
+`git push --recurse-submodules=check` in the superproject, as this would
+check if the submodule has any changes not published to any remote. The
+remotes are configured in the submodule as usual in the `$GIT_DIR/config`
+file.
+
+ * The configuration file `$GIT_DIR/config` in the superproject.
+   Git only recurses into active submodules (see "ACTIVE SUBMODULES"
+   section below).
++
+If the submodule is not yet initialized, then the configuration
+inside the submodule does not exist yet, so where to
+obtain the submodule from is configured here for example.
+
+ * The `.gitmodules` file inside the superproject. A project usually
+   uses this file to suggest defaults for the upstream collection
+   of repositories for the mapping that is required between a
+   submodule's name and its path.
++
+This file mainly serves as the mapping between the name and path of submodules
+in the superproject, such that the submodule's Git directory can be
+located.
++
+If the submodule has never been initialized, this is the only place
+where submodule configuration is found. It serves as the last fallback
+to specify where to obtain the submodule from.
+
+FORMS
+-----
+
+Submodules can take the following forms:
+
+ * The basic form described in DESCRIPTION with a Git directory,
+a working directory, a `gitlink`, and a `.gitmodules` entry.
+
+ * "Old-form" submodule: A working directory with an embedded
+`.git` directory, and the tracking `gitlink` and `.gitmodules` entry in
+the superproject. This is typically found in repositories generated
+using older versions of Git.
++
+It is possible to construct these old form repositories manually.
++
+When deinitialized or deleted (see below), the submodule's Git
+directory is automatically moved to `$GIT_DIR/modules/<name>/`
+of the superproject.
+
+ * Deinitialized submodule: A `gitlink`, and a `.gitmodules` entry,
+but no submodule working directory. The submodule's Git directory
+may be there as after deinitializing the Git directory is kept around.
+The directory which is supposed to be the working directory is empty instead.
++
+A submodule can be deinitialized by running `git submodule deinit`.
+Besides emptying the working directory, this command only modifies
+the superproject's `$GIT_DIR/config` file, so the superproject's history
+is not affected. This can be undone using `git submodule init`.
+
+ * Deleted submodule: A submodule can be deleted by running
+`git rm <submodule path> && git commit`. This can be undone
+using `git revert`.
++
+The deletion removes the superproject's tracking data, which are
+both the `gitlink` entry and the section in the `.gitmodules` file.
+The submodule's working directory is removed from the file
+system, but the Git directory is kept around as it to make it
+possible to checkout past commits without requiring fetching
+from another repository.
++
+To completely remove a submodule, manually delete
+`$GIT_DIR/modules/<name>/`.
+
+ACTIVE SUBMODULES
+-----------------
+
+A submodule is considered active,
+
+  1. if `submodule.<name>.active` is set to `true`
++
+or
+
+  2. if the submodule's path matches the pathspec in `submodule.active`
++
+or
+
+  3. if `submodule.<name>.url` is set.
+
+and these are evaluated in this order.
+
+For example:
+
+  [submodule "foo"]
+    active = false
+    url = https://example.org/foo
+  [submodule "bar"]
+    active = true
+    url = https://example.org/bar
+  [submodule "baz"]
+    url = https://example.org/baz
+
+In the above config only the submodule 'bar' and 'baz' are active,
+'bar' due to (1) and 'baz' due to (3). 'foo' is inactive because
+(1) takes precedence over (3)
+
+Note that (3) is a historical artefact and will be ignored if the
+(1) and (2) specify that the submodule is not active. In other words,
+if we have a `submodule.<name>.active` set to `false` or if the
+submodule's path is excluded in the pathspec in `submodule.active`, the
+url doesn't matter whether it is present or not. This is illustrated in
+the example that follows.
+
+  [submodule "foo"]
+    active = true
+    url = https://example.org/foo
+  [submodule "bar"]
+    url = https://example.org/bar
+  [submodule "baz"]
+    url = https://example.org/baz
+  [submodule "bob"]
+    ignore = true
+  [submodule]
+    active = b*
+    active = :(exclude) baz
+
+In here all submodules except 'baz' (foo, bar, bob) are active.
+'foo' due to its own active flag and all the others due to the
+submodule active pathspec, which specifies that any submodule
+starting with 'b' except 'baz' are also active, regardless of the
+presence of the .url field.
+
+Workflow for a third party library
+----------------------------------
+
+  # add a submodule
+  git submodule add <url> <path>
+
+  # occasionally update the submodule to a new version:
+  git -C <path> checkout <new version>
+  git add <path>
+  git commit -m "update submodule to new version"
+
+  # See the list of submodules in a superproject
+  git submodule status
+
+  # See FORMS on removing submodules
+
+
+Workflow for an artificially split repo
+--------------------------------------
+
+  # Enable recursion for relevant commands, such that
+  # regular commands recurse into submodules by default
+  git config --global submodule.recurse true
+
+  # Unlike the other commands below clone still needs
+  # its own recurse flag:
+  git clone --recurse <URL> <directory>
+  cd <directory>
+
+  # Get to know the code:
+  git grep foo
+  git ls-files
+
+  # Get new code
+  git fetch
+  git pull --rebase
+
+  # change worktree
+  git checkout
+  git reset
+
+Implementation details
+----------------------
+
+When cloning or pulling a repository containing submodules the submodules
+will not be checked out by default; You can instruct 'clone' to recurse
+into submodules. The 'init' and 'update' subcommands of 'git submodule'
+will maintain submodules checked out and at an appropriate revision in
+your working tree. Alternatively you can set 'submodule.recurse' to have
+'checkout' recursing into submodules.
+
+
+SEE ALSO
+--------
+linkgit:git-submodule[1], linkgit:gitmodules[5].
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gittutorial-2.txt b/third_party/git/Documentation/gittutorial-2.txt
new file mode 100644
index 0000000000..8bdb7d0bd3
--- /dev/null
+++ b/third_party/git/Documentation/gittutorial-2.txt
@@ -0,0 +1,436 @@
+gittutorial-2(7)
+================
+
+NAME
+----
+gittutorial-2 - A tutorial introduction to Git: part two
+
+SYNOPSIS
+--------
+[verse]
+git *
+
+DESCRIPTION
+-----------
+
+You should work through linkgit:gittutorial[7] before reading this tutorial.
+
+The goal of this tutorial is to introduce two fundamental pieces of
+Git's architecture--the object database and the index file--and to
+provide the reader with everything necessary to understand the rest
+of the Git documentation.
+
+The Git object database
+-----------------------
+
+Let's start a new project and create a small amount of history:
+
+------------------------------------------------
+$ mkdir test-project
+$ cd test-project
+$ git init
+Initialized empty Git repository in .git/
+$ echo 'hello world' > file.txt
+$ git add .
+$ git commit -a -m "initial commit"
+[master (root-commit) 54196cc] initial commit
+ 1 file changed, 1 insertion(+)
+ create mode 100644 file.txt
+$ echo 'hello world!' >file.txt
+$ git commit -a -m "add emphasis"
+[master c4d59f3] add emphasis
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+------------------------------------------------
+
+What are the 7 digits of hex that Git responded to the commit with?
+
+We saw in part one of the tutorial that commits have names like this.
+It turns out that every object in the Git history is stored under
+a 40-digit hex name.  That name is the SHA-1 hash of the object's
+contents; among other things, this ensures that Git will never store
+the same data twice (since identical data is given an identical SHA-1
+name), and that the contents of a Git object will never change (since
+that would change the object's name as well). The 7 char hex strings
+here are simply the abbreviation of such 40 character long strings.
+Abbreviations can be used everywhere where the 40 character strings
+can be used, so long as they are unambiguous.
+
+It is expected that the content of the commit object you created while
+following the example above generates a different SHA-1 hash than
+the one shown above because the commit object records the time when
+it was created and the name of the person performing the commit.
+
+We can ask Git about this particular object with the `cat-file`
+command. Don't copy the 40 hex digits from this example but use those
+from your own version. Note that you can shorten it to only a few
+characters to save yourself typing all 40 hex digits:
+
+------------------------------------------------
+$ git cat-file -t 54196cc2
+commit
+$ git cat-file commit 54196cc2
+tree 92b8b694ffb1675e5975148e1121810081dbdffe
+author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500
+committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500
+
+initial commit
+------------------------------------------------
+
+A tree can refer to one or more "blob" objects, each corresponding to
+a file.  In addition, a tree can also refer to other tree objects,
+thus creating a directory hierarchy.  You can examine the contents of
+any tree using ls-tree (remember that a long enough initial portion
+of the SHA-1 will also work):
+
+------------------------------------------------
+$ git ls-tree 92b8b694
+100644 blob 3b18e512dba79e4c8300dd08aeb37f8e728b8dad    file.txt
+------------------------------------------------
+
+Thus we see that this tree has one file in it.  The SHA-1 hash is a
+reference to that file's data:
+
+------------------------------------------------
+$ git cat-file -t 3b18e512
+blob
+------------------------------------------------
+
+A "blob" is just file data, which we can also examine with cat-file:
+
+------------------------------------------------
+$ git cat-file blob 3b18e512
+hello world
+------------------------------------------------
+
+Note that this is the old file data; so the object that Git named in
+its response to the initial tree was a tree with a snapshot of the
+directory state that was recorded by the first commit.
+
+All of these objects are stored under their SHA-1 names inside the Git
+directory:
+
+------------------------------------------------
+$ find .git/objects/
+.git/objects/
+.git/objects/pack
+.git/objects/info
+.git/objects/3b
+.git/objects/3b/18e512dba79e4c8300dd08aeb37f8e728b8dad
+.git/objects/92
+.git/objects/92/b8b694ffb1675e5975148e1121810081dbdffe
+.git/objects/54
+.git/objects/54/196cc2703dc165cbd373a65a4dcf22d50ae7f7
+.git/objects/a0
+.git/objects/a0/423896973644771497bdc03eb99d5281615b51
+.git/objects/d0
+.git/objects/d0/492b368b66bdabf2ac1fd8c92b39d3db916e59
+.git/objects/c4
+.git/objects/c4/d59f390b9cfd4318117afde11d601c1085f241
+------------------------------------------------
+
+and the contents of these files is just the compressed data plus a
+header identifying their length and their type.  The type is either a
+blob, a tree, a commit, or a tag.
+
+The simplest commit to find is the HEAD commit, which we can find
+from .git/HEAD:
+
+------------------------------------------------
+$ cat .git/HEAD
+ref: refs/heads/master
+------------------------------------------------
+
+As you can see, this tells us which branch we're currently on, and it
+tells us this by naming a file under the .git directory, which itself
+contains a SHA-1 name referring to a commit object, which we can
+examine with cat-file:
+
+------------------------------------------------
+$ cat .git/refs/heads/master
+c4d59f390b9cfd4318117afde11d601c1085f241
+$ git cat-file -t c4d59f39
+commit
+$ git cat-file commit c4d59f39
+tree d0492b368b66bdabf2ac1fd8c92b39d3db916e59
+parent 54196cc2703dc165cbd373a65a4dcf22d50ae7f7
+author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143418702 -0500
+committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143418702 -0500
+
+add emphasis
+------------------------------------------------
+
+The "tree" object here refers to the new state of the tree:
+
+------------------------------------------------
+$ git ls-tree d0492b36
+100644 blob a0423896973644771497bdc03eb99d5281615b51    file.txt
+$ git cat-file blob a0423896
+hello world!
+------------------------------------------------
+
+and the "parent" object refers to the previous commit:
+
+------------------------------------------------
+$ git cat-file commit 54196cc2
+tree 92b8b694ffb1675e5975148e1121810081dbdffe
+author J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500
+committer J. Bruce Fields <bfields@puzzle.fieldses.org> 1143414668 -0500
+
+initial commit
+------------------------------------------------
+
+The tree object is the tree we examined first, and this commit is
+unusual in that it lacks any parent.
+
+Most commits have only one parent, but it is also common for a commit
+to have multiple parents.   In that case the commit represents a
+merge, with the parent references pointing to the heads of the merged
+branches.
+
+Besides blobs, trees, and commits, the only remaining type of object
+is a "tag", which we won't discuss here; refer to linkgit:git-tag[1]
+for details.
+
+So now we know how Git uses the object database to represent a
+project's history:
+
+  * "commit" objects refer to "tree" objects representing the
+    snapshot of a directory tree at a particular point in the
+    history, and refer to "parent" commits to show how they're
+    connected into the project history.
+  * "tree" objects represent the state of a single directory,
+    associating directory names to "blob" objects containing file
+    data and "tree" objects containing subdirectory information.
+  * "blob" objects contain file data without any other structure.
+  * References to commit objects at the head of each branch are
+    stored in files under .git/refs/heads/.
+  * The name of the current branch is stored in .git/HEAD.
+
+Note, by the way, that lots of commands take a tree as an argument.
+But as we can see above, a tree can be referred to in many different
+ways--by the SHA-1 name for that tree, by the name of a commit that
+refers to the tree, by the name of a branch whose head refers to that
+tree, etc.--and most such commands can accept any of these names.
+
+In command synopses, the word "tree-ish" is sometimes used to
+designate such an argument.
+
+The index file
+--------------
+
+The primary tool we've been using to create commits is `git-commit
+-a`, which creates a commit including every change you've made to
+your working tree.  But what if you want to commit changes only to
+certain files?  Or only certain changes to certain files?
+
+If we look at the way commits are created under the cover, we'll see
+that there are more flexible ways creating commits.
+
+Continuing with our test-project, let's modify file.txt again:
+
+------------------------------------------------
+$ echo "hello world, again" >>file.txt
+------------------------------------------------
+
+but this time instead of immediately making the commit, let's take an
+intermediate step, and ask for diffs along the way to keep track of
+what's happening:
+
+------------------------------------------------
+$ git diff
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,2 @@
+ hello world!
++hello world, again
+$ git add file.txt
+$ git diff
+------------------------------------------------
+
+The last diff is empty, but no new commits have been made, and the
+head still doesn't contain the new line:
+
+------------------------------------------------
+$ git diff HEAD
+diff --git a/file.txt b/file.txt
+index a042389..513feba 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,2 @@
+ hello world!
++hello world, again
+------------------------------------------------
+
+So 'git diff' is comparing against something other than the head.
+The thing that it's comparing against is actually the index file,
+which is stored in .git/index in a binary format, but whose contents
+we can examine with ls-files:
+
+------------------------------------------------
+$ git ls-files --stage
+100644 513feba2e53ebbd2532419ded848ba19de88ba00 0       file.txt
+$ git cat-file -t 513feba2
+blob
+$ git cat-file blob 513feba2
+hello world!
+hello world, again
+------------------------------------------------
+
+So what our 'git add' did was store a new blob and then put
+a reference to it in the index file.  If we modify the file again,
+we'll see that the new modifications are reflected in the 'git diff'
+output:
+
+------------------------------------------------
+$ echo 'again?' >>file.txt
+$ git diff
+index 513feba..ba3da7b 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1,3 @@
+ hello world!
+ hello world, again
++again?
+------------------------------------------------
+
+With the right arguments, 'git diff' can also show us the difference
+between the working directory and the last commit, or between the
+index and the last commit:
+
+------------------------------------------------
+$ git diff HEAD
+diff --git a/file.txt b/file.txt
+index a042389..ba3da7b 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,3 @@
+ hello world!
++hello world, again
++again?
+$ git diff --cached
+diff --git a/file.txt b/file.txt
+index a042389..513feba 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1 +1,2 @@
+ hello world!
++hello world, again
+------------------------------------------------
+
+At any time, we can create a new commit using 'git commit' (without
+the "-a" option), and verify that the state committed only includes the
+changes stored in the index file, not the additional change that is
+still only in our working tree:
+
+------------------------------------------------
+$ git commit -m "repeat"
+$ git diff HEAD
+diff --git a/file.txt b/file.txt
+index 513feba..ba3da7b 100644
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1,3 @@
+ hello world!
+ hello world, again
++again?
+------------------------------------------------
+
+So by default 'git commit' uses the index to create the commit, not
+the working tree; the "-a" option to commit tells it to first update
+the index with all changes in the working tree.
+
+Finally, it's worth looking at the effect of 'git add' on the index
+file:
+
+------------------------------------------------
+$ echo "goodbye, world" >closing.txt
+$ git add closing.txt
+------------------------------------------------
+
+The effect of the 'git add' was to add one entry to the index file:
+
+------------------------------------------------
+$ git ls-files --stage
+100644 8b9743b20d4b15be3955fc8d5cd2b09cd2336138 0       closing.txt
+100644 513feba2e53ebbd2532419ded848ba19de88ba00 0       file.txt
+------------------------------------------------
+
+And, as you can see with cat-file, this new entry refers to the
+current contents of the file:
+
+------------------------------------------------
+$ git cat-file blob 8b9743b2
+goodbye, world
+------------------------------------------------
+
+The "status" command is a useful way to get a quick summary of the
+situation:
+
+------------------------------------------------
+$ git status
+On branch master
+Changes to be committed:
+  (use "git restore --staged <file>..." to unstage)
+
+	new file:   closing.txt
+
+Changes not staged for commit:
+  (use "git add <file>..." to update what will be committed)
+  (use "git restore <file>..." to discard changes in working directory)
+
+	modified:   file.txt
+
+------------------------------------------------
+
+Since the current state of closing.txt is cached in the index file,
+it is listed as "Changes to be committed".  Since file.txt has
+changes in the working directory that aren't reflected in the index,
+it is marked "changed but not updated".  At this point, running "git
+commit" would create a commit that added closing.txt (with its new
+contents), but that didn't modify file.txt.
+
+Also, note that a bare `git diff` shows the changes to file.txt, but
+not the addition of closing.txt, because the version of closing.txt
+in the index file is identical to the one in the working directory.
+
+In addition to being the staging area for new commits, the index file
+is also populated from the object database when checking out a
+branch, and is used to hold the trees involved in a merge operation.
+See linkgit:gitcore-tutorial[7] and the relevant man
+pages for details.
+
+What next?
+----------
+
+At this point you should know everything necessary to read the man
+pages for any of the git commands; one good place to start would be
+with the commands mentioned in linkgit:giteveryday[7].  You
+should be able to find any unknown jargon in linkgit:gitglossary[7].
+
+The link:user-manual.html[Git User's Manual] provides a more
+comprehensive introduction to Git.
+
+linkgit:gitcvs-migration[7] explains how to
+import a CVS repository into Git, and shows how to use Git in a
+CVS-like way.
+
+For some interesting examples of Git use, see the
+link:howto-index.html[howtos].
+
+For Git developers, linkgit:gitcore-tutorial[7] goes
+into detail on the lower-level Git mechanisms involved in, for
+example, creating a new commit.
+
+SEE ALSO
+--------
+linkgit:gittutorial[7],
+linkgit:gitcvs-migration[7],
+linkgit:gitcore-tutorial[7],
+linkgit:gitglossary[7],
+linkgit:git-help[1],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gittutorial.txt b/third_party/git/Documentation/gittutorial.txt
new file mode 100644
index 0000000000..59ef5cef1f
--- /dev/null
+++ b/third_party/git/Documentation/gittutorial.txt
@@ -0,0 +1,677 @@
+gittutorial(7)
+==============
+
+NAME
+----
+gittutorial - A tutorial introduction to Git
+
+SYNOPSIS
+--------
+[verse]
+git *
+
+DESCRIPTION
+-----------
+
+This tutorial explains how to import a new project into Git, make
+changes to it, and share changes with other developers.
+
+If you are instead primarily interested in using Git to fetch a project,
+for example, to test the latest version, you may prefer to start with
+the first two chapters of link:user-manual.html[The Git User's Manual].
+
+First, note that you can get documentation for a command such as
+`git log --graph` with:
+
+------------------------------------------------
+$ man git-log
+------------------------------------------------
+
+or:
+
+------------------------------------------------
+$ git help log
+------------------------------------------------
+
+With the latter, you can use the manual viewer of your choice; see
+linkgit:git-help[1] for more information.
+
+It is a good idea to introduce yourself to Git with your name and
+public email address before doing any operation.  The easiest
+way to do so is:
+
+------------------------------------------------
+$ git config --global user.name "Your Name Comes Here"
+$ git config --global user.email you@yourdomain.example.com
+------------------------------------------------
+
+
+Importing a new project
+-----------------------
+
+Assume you have a tarball project.tar.gz with your initial work.  You
+can place it under Git revision control as follows.
+
+------------------------------------------------
+$ tar xzf project.tar.gz
+$ cd project
+$ git init
+------------------------------------------------
+
+Git will reply
+
+------------------------------------------------
+Initialized empty Git repository in .git/
+------------------------------------------------
+
+You've now initialized the working directory--you may notice a new
+directory created, named ".git".
+
+Next, tell Git to take a snapshot of the contents of all files under the
+current directory (note the '.'), with 'git add':
+
+------------------------------------------------
+$ git add .
+------------------------------------------------
+
+This snapshot is now stored in a temporary staging area which Git calls
+the "index".  You can permanently store the contents of the index in the
+repository with 'git commit':
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+This will prompt you for a commit message.  You've now stored the first
+version of your project in Git.
+
+Making changes
+--------------
+
+Modify some files, then add their updated contents to the index:
+
+------------------------------------------------
+$ git add file1 file2 file3
+------------------------------------------------
+
+You are now ready to commit.  You can see what is about to be committed
+using 'git diff' with the --cached option:
+
+------------------------------------------------
+$ git diff --cached
+------------------------------------------------
+
+(Without --cached, 'git diff' will show you any changes that
+you've made but not yet added to the index.)  You can also get a brief
+summary of the situation with 'git status':
+
+------------------------------------------------
+$ git status
+On branch master
+Changes to be committed:
+Your branch is up to date with 'origin/master'.
+  (use "git restore --staged <file>..." to unstage)
+
+	modified:   file1
+	modified:   file2
+	modified:   file3
+
+------------------------------------------------
+
+If you need to make any further adjustments, do so now, and then add any
+newly modified content to the index.  Finally, commit your changes with:
+
+------------------------------------------------
+$ git commit
+------------------------------------------------
+
+This will again prompt you for a message describing the change, and then
+record a new version of the project.
+
+Alternatively, instead of running 'git add' beforehand, you can use
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+which will automatically notice any modified (but not new) files, add
+them to the index, and commit, all in one step.
+
+A note on commit messages: Though not required, it's a good idea to
+begin the commit message with a single short (less than 50 character)
+line summarizing the change, followed by a blank line and then a more
+thorough description. The text up to the first blank line in a commit
+message is treated as the commit title, and that title is used
+throughout Git.  For example, linkgit:git-format-patch[1] turns a
+commit into email, and it uses the title on the Subject line and the
+rest of the commit in the body.
+
+Git tracks content not files
+----------------------------
+
+Many revision control systems provide an `add` command that tells the
+system to start tracking changes to a new file.  Git's `add` command
+does something simpler and more powerful: 'git add' is used both for new
+and newly modified files, and in both cases it takes a snapshot of the
+given files and stages that content in the index, ready for inclusion in
+the next commit.
+
+Viewing project history
+-----------------------
+
+At any point you can view the history of your changes using
+
+------------------------------------------------
+$ git log
+------------------------------------------------
+
+If you also want to see complete diffs at each step, use
+
+------------------------------------------------
+$ git log -p
+------------------------------------------------
+
+Often the overview of the change is useful to get a feel of
+each step
+
+------------------------------------------------
+$ git log --stat --summary
+------------------------------------------------
+
+Managing branches
+-----------------
+
+A single Git repository can maintain multiple branches of
+development.  To create a new branch named "experimental", use
+
+------------------------------------------------
+$ git branch experimental
+------------------------------------------------
+
+If you now run
+
+------------------------------------------------
+$ git branch
+------------------------------------------------
+
+you'll get a list of all existing branches:
+
+------------------------------------------------
+  experimental
+* master
+------------------------------------------------
+
+The "experimental" branch is the one you just created, and the
+"master" branch is a default branch that was created for you
+automatically.  The asterisk marks the branch you are currently on;
+type
+
+------------------------------------------------
+$ git switch experimental
+------------------------------------------------
+
+to switch to the experimental branch.  Now edit a file, commit the
+change, and switch back to the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+$ git switch master
+------------------------------------------------
+
+Check that the change you made is no longer visible, since it was
+made on the experimental branch and you're back on the master branch.
+
+You can make a different change on the master branch:
+
+------------------------------------------------
+(edit file)
+$ git commit -a
+------------------------------------------------
+
+at this point the two branches have diverged, with different changes
+made in each.  To merge the changes made in experimental into master, run
+
+------------------------------------------------
+$ git merge experimental
+------------------------------------------------
+
+If the changes don't conflict, you're done.  If there are conflicts,
+markers will be left in the problematic files showing the conflict;
+
+------------------------------------------------
+$ git diff
+------------------------------------------------
+
+will show this.  Once you've edited the files to resolve the
+conflicts,
+
+------------------------------------------------
+$ git commit -a
+------------------------------------------------
+
+will commit the result of the merge. Finally,
+
+------------------------------------------------
+$ gitk
+------------------------------------------------
+
+will show a nice graphical representation of the resulting history.
+
+At this point you could delete the experimental branch with
+
+------------------------------------------------
+$ git branch -d experimental
+------------------------------------------------
+
+This command ensures that the changes in the experimental branch are
+already in the current branch.
+
+If you develop on a branch crazy-idea, then regret it, you can always
+delete the branch with
+
+-------------------------------------
+$ git branch -D crazy-idea
+-------------------------------------
+
+Branches are cheap and easy, so this is a good way to try something
+out.
+
+Using Git for collaboration
+---------------------------
+
+Suppose that Alice has started a new project with a Git repository in
+/home/alice/project, and that Bob, who has a home directory on the
+same machine, wants to contribute.
+
+Bob begins with:
+
+------------------------------------------------
+bob$ git clone /home/alice/project myrepo
+------------------------------------------------
+
+This creates a new directory "myrepo" containing a clone of Alice's
+repository.  The clone is on an equal footing with the original
+project, possessing its own copy of the original project's history.
+
+Bob then makes some changes and commits them:
+
+------------------------------------------------
+(edit files)
+bob$ git commit -a
+(repeat as necessary)
+------------------------------------------------
+
+When he's ready, he tells Alice to pull changes from the repository
+at /home/bob/myrepo.  She does this with:
+
+------------------------------------------------
+alice$ cd /home/alice/project
+alice$ git pull /home/bob/myrepo master
+------------------------------------------------
+
+This merges the changes from Bob's "master" branch into Alice's
+current branch.  If Alice has made her own changes in the meantime,
+then she may need to manually fix any conflicts.
+
+The "pull" command thus performs two operations: it fetches changes
+from a remote branch, then merges them into the current branch.
+
+Note that in general, Alice would want her local changes committed before
+initiating this "pull".  If Bob's work conflicts with what Alice did since
+their histories forked, Alice will use her working tree and the index to
+resolve conflicts, and existing local changes will interfere with the
+conflict resolution process (Git will still perform the fetch but will
+refuse to merge --- Alice will have to get rid of her local changes in
+some way and pull again when this happens).
+
+Alice can peek at what Bob did without merging first, using the "fetch"
+command; this allows Alice to inspect what Bob did, using a special
+symbol "FETCH_HEAD", in order to determine if he has anything worth
+pulling, like this:
+
+------------------------------------------------
+alice$ git fetch /home/bob/myrepo master
+alice$ git log -p HEAD..FETCH_HEAD
+------------------------------------------------
+
+This operation is safe even if Alice has uncommitted local changes.
+The range notation "HEAD..FETCH_HEAD" means "show everything that is reachable
+from the FETCH_HEAD but exclude anything that is reachable from HEAD".
+Alice already knows everything that leads to her current state (HEAD),
+and reviews what Bob has in his state (FETCH_HEAD) that she has not
+seen with this command.
+
+If Alice wants to visualize what Bob did since their histories forked
+she can issue the following command:
+
+------------------------------------------------
+$ gitk HEAD..FETCH_HEAD
+------------------------------------------------
+
+This uses the same two-dot range notation we saw earlier with 'git log'.
+
+Alice may want to view what both of them did since they forked.
+She can use three-dot form instead of the two-dot form:
+
+------------------------------------------------
+$ gitk HEAD...FETCH_HEAD
+------------------------------------------------
+
+This means "show everything that is reachable from either one, but
+exclude anything that is reachable from both of them".
+
+Please note that these range notation can be used with both gitk
+and "git log".
+
+After inspecting what Bob did, if there is nothing urgent, Alice may
+decide to continue working without pulling from Bob.  If Bob's history
+does have something Alice would immediately need, Alice may choose to
+stash her work-in-progress first, do a "pull", and then finally unstash
+her work-in-progress on top of the resulting history.
+
+When you are working in a small closely knit group, it is not
+unusual to interact with the same repository over and over
+again.  By defining 'remote' repository shorthand, you can make
+it easier:
+
+------------------------------------------------
+alice$ git remote add bob /home/bob/myrepo
+------------------------------------------------
+
+With this, Alice can perform the first part of the "pull" operation
+alone using the 'git fetch' command without merging them with her own
+branch, using:
+
+-------------------------------------
+alice$ git fetch bob
+-------------------------------------
+
+Unlike the longhand form, when Alice fetches from Bob using a
+remote repository shorthand set up with 'git remote', what was
+fetched is stored in a remote-tracking branch, in this case
+`bob/master`.  So after this:
+
+-------------------------------------
+alice$ git log -p master..bob/master
+-------------------------------------
+
+shows a list of all the changes that Bob made since he branched from
+Alice's master branch.
+
+After examining those changes, Alice
+could merge the changes into her master branch:
+
+-------------------------------------
+alice$ git merge bob/master
+-------------------------------------
+
+This `merge` can also be done by 'pulling from her own remote-tracking
+branch', like this:
+
+-------------------------------------
+alice$ git pull . remotes/bob/master
+-------------------------------------
+
+Note that git pull always merges into the current branch,
+regardless of what else is given on the command line.
+
+Later, Bob can update his repo with Alice's latest changes using
+
+-------------------------------------
+bob$ git pull
+-------------------------------------
+
+Note that he doesn't need to give the path to Alice's repository;
+when Bob cloned Alice's repository, Git stored the location of her
+repository in the repository configuration, and that location is
+used for pulls:
+
+-------------------------------------
+bob$ git config --get remote.origin.url
+/home/alice/project
+-------------------------------------
+
+(The complete configuration created by 'git clone' is visible using
+`git config -l`, and the linkgit:git-config[1] man page
+explains the meaning of each option.)
+
+Git also keeps a pristine copy of Alice's master branch under the
+name "origin/master":
+
+-------------------------------------
+bob$ git branch -r
+  origin/master
+-------------------------------------
+
+If Bob later decides to work from a different host, he can still
+perform clones and pulls using the ssh protocol:
+
+-------------------------------------
+bob$ git clone alice.org:/home/alice/project myrepo
+-------------------------------------
+
+Alternatively, Git has a native protocol, or can use http;
+see linkgit:git-pull[1] for details.
+
+Git can also be used in a CVS-like mode, with a central repository
+that various users push changes to; see linkgit:git-push[1] and
+linkgit:gitcvs-migration[7].
+
+Exploring history
+-----------------
+
+Git history is represented as a series of interrelated commits.  We
+have already seen that the 'git log' command can list those commits.
+Note that first line of each git log entry also gives a name for the
+commit:
+
+-------------------------------------
+$ git log
+commit c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+Author: Junio C Hamano <junkio@cox.net>
+Date:   Tue May 16 17:18:22 2006 -0700
+
+    merge-base: Clarify the comments on post processing.
+-------------------------------------
+
+We can give this name to 'git show' to see the details about this
+commit.
+
+-------------------------------------
+$ git show c82a22c39cbc32576f64f5c6b3f24b99ea8149c7
+-------------------------------------
+
+But there are other ways to refer to commits.  You can use any initial
+part of the name that is long enough to uniquely identify the commit:
+
+-------------------------------------
+$ git show c82a22c39c	# the first few characters of the name are
+			# usually enough
+$ git show HEAD		# the tip of the current branch
+$ git show experimental	# the tip of the "experimental" branch
+-------------------------------------
+
+Every commit usually has one "parent" commit
+which points to the previous state of the project:
+
+-------------------------------------
+$ git show HEAD^  # to see the parent of HEAD
+$ git show HEAD^^ # to see the grandparent of HEAD
+$ git show HEAD~4 # to see the great-great grandparent of HEAD
+-------------------------------------
+
+Note that merge commits may have more than one parent:
+
+-------------------------------------
+$ git show HEAD^1 # show the first parent of HEAD (same as HEAD^)
+$ git show HEAD^2 # show the second parent of HEAD
+-------------------------------------
+
+You can also give commits names of your own; after running
+
+-------------------------------------
+$ git tag v2.5 1b2e1d63ff
+-------------------------------------
+
+you can refer to 1b2e1d63ff by the name "v2.5".  If you intend to
+share this name with other people (for example, to identify a release
+version), you should create a "tag" object, and perhaps sign it; see
+linkgit:git-tag[1] for details.
+
+Any Git command that needs to know a commit can take any of these
+names.  For example:
+
+-------------------------------------
+$ git diff v2.5 HEAD	 # compare the current HEAD to v2.5
+$ git branch stable v2.5 # start a new branch named "stable" based
+			 # at v2.5
+$ git reset --hard HEAD^ # reset your current branch and working
+			 # directory to its state at HEAD^
+-------------------------------------
+
+Be careful with that last command: in addition to losing any changes
+in the working directory, it will also remove all later commits from
+this branch.  If this branch is the only branch containing those
+commits, they will be lost.  Also, don't use 'git reset' on a
+publicly-visible branch that other developers pull from, as it will
+force needless merges on other developers to clean up the history.
+If you need to undo changes that you have pushed, use 'git revert'
+instead.
+
+The 'git grep' command can search for strings in any version of your
+project, so
+
+-------------------------------------
+$ git grep "hello" v2.5
+-------------------------------------
+
+searches for all occurrences of "hello" in v2.5.
+
+If you leave out the commit name, 'git grep' will search any of the
+files it manages in your current directory.  So
+
+-------------------------------------
+$ git grep "hello"
+-------------------------------------
+
+is a quick way to search just the files that are tracked by Git.
+
+Many Git commands also take sets of commits, which can be specified
+in a number of ways.  Here are some examples with 'git log':
+
+-------------------------------------
+$ git log v2.5..v2.6            # commits between v2.5 and v2.6
+$ git log v2.5..                # commits since v2.5
+$ git log --since="2 weeks ago" # commits from the last 2 weeks
+$ git log v2.5.. Makefile       # commits since v2.5 which modify
+				# Makefile
+-------------------------------------
+
+You can also give 'git log' a "range" of commits where the first is not
+necessarily an ancestor of the second; for example, if the tips of
+the branches "stable" and "master" diverged from a common
+commit some time ago, then
+
+-------------------------------------
+$ git log stable..master
+-------------------------------------
+
+will list commits made in the master branch but not in the
+stable branch, while
+
+-------------------------------------
+$ git log master..stable
+-------------------------------------
+
+will show the list of commits made on the stable branch but not
+the master branch.
+
+The 'git log' command has a weakness: it must present commits in a
+list.  When the history has lines of development that diverged and
+then merged back together, the order in which 'git log' presents
+those commits is meaningless.
+
+Most projects with multiple contributors (such as the Linux kernel,
+or Git itself) have frequent merges, and 'gitk' does a better job of
+visualizing their history.  For example,
+
+-------------------------------------
+$ gitk --since="2 weeks ago" drivers/
+-------------------------------------
+
+allows you to browse any commits from the last 2 weeks of commits
+that modified files under the "drivers" directory.  (Note: you can
+adjust gitk's fonts by holding down the control key while pressing
+"-" or "+".)
+
+Finally, most commands that take filenames will optionally allow you
+to precede any filename by a commit, to specify a particular version
+of the file:
+
+-------------------------------------
+$ git diff v2.5:Makefile HEAD:Makefile.in
+-------------------------------------
+
+You can also use 'git show' to see any such file:
+
+-------------------------------------
+$ git show v2.5:Makefile
+-------------------------------------
+
+Next Steps
+----------
+
+This tutorial should be enough to perform basic distributed revision
+control for your projects.  However, to fully understand the depth
+and power of Git you need to understand two simple ideas on which it
+is based:
+
+  * The object database is the rather elegant system used to
+    store the history of your project--files, directories, and
+    commits.
+
+  * The index file is a cache of the state of a directory tree,
+    used to create commits, check out working directories, and
+    hold the various trees involved in a merge.
+
+Part two of this tutorial explains the object
+database, the index file, and a few other odds and ends that you'll
+need to make the most of Git. You can find it at linkgit:gittutorial-2[7].
+
+If you don't want to continue with that right away, a few other
+digressions that may be interesting at this point are:
+
+  * linkgit:git-format-patch[1], linkgit:git-am[1]: These convert
+    series of git commits into emailed patches, and vice versa,
+    useful for projects such as the Linux kernel which rely heavily
+    on emailed patches.
+
+  * linkgit:git-bisect[1]: When there is a regression in your
+    project, one way to track down the bug is by searching through
+    the history to find the exact commit that's to blame.  Git bisect
+    can help you perform a binary search for that commit.  It is
+    smart enough to perform a close-to-optimal search even in the
+    case of complex non-linear history with lots of merged branches.
+
+  * linkgit:gitworkflows[7]: Gives an overview of recommended
+    workflows.
+
+  * linkgit:giteveryday[7]: Everyday Git with 20 Commands Or So.
+
+  * linkgit:gitcvs-migration[7]: Git for CVS users.
+
+SEE ALSO
+--------
+linkgit:gittutorial-2[7],
+linkgit:gitcvs-migration[7],
+linkgit:gitcore-tutorial[7],
+linkgit:gitglossary[7],
+linkgit:git-help[1],
+linkgit:gitworkflows[7],
+linkgit:giteveryday[7],
+link:user-manual.html[The Git User's Manual]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitweb.conf.txt b/third_party/git/Documentation/gitweb.conf.txt
new file mode 100644
index 0000000000..35317e71c8
--- /dev/null
+++ b/third_party/git/Documentation/gitweb.conf.txt
@@ -0,0 +1,970 @@
+gitweb.conf(5)
+==============
+
+NAME
+----
+gitweb.conf - Gitweb (Git web interface) configuration file
+
+SYNOPSIS
+--------
+/etc/gitweb.conf, /etc/gitweb-common.conf, $GITWEBDIR/gitweb_config.perl
+
+DESCRIPTION
+-----------
+
+The gitweb CGI script for viewing Git repositories over the web uses a
+perl script fragment as its configuration file.  You can set variables
+using "`our $variable = value`"; text from a "#" character until the
+end of a line is ignored.  See *perlsyn*(1) for details.
+
+An example:
+
+------------------------------------------------
+# gitweb configuration file for http://git.example.org
+#
+our $projectroot = "/srv/git"; # FHS recommendation
+our $site_name = 'Example.org >> Repos';
+------------------------------------------------
+
+
+The configuration file is used to override the default settings that
+were built into gitweb at the time the 'gitweb.cgi' script was generated.
+
+While one could just alter the configuration settings in the gitweb
+CGI itself, those changes would be lost upon upgrade.  Configuration
+settings might also be placed into a file in the same directory as the
+CGI script with the default name 'gitweb_config.perl' -- allowing
+one to have multiple gitweb instances with different configurations by
+the use of symlinks.
+
+Note that some configuration can be controlled on per-repository rather than
+gitweb-wide basis: see "Per-repository gitweb configuration" subsection on
+linkgit:gitweb[1] manpage.
+
+
+DISCUSSION
+----------
+Gitweb reads configuration data from the following sources in the
+following order:
+
+ * built-in values (some set during build stage),
+
+ * common system-wide configuration file (defaults to
+   `/etc/gitweb-common.conf`),
+
+ * either per-instance configuration file (defaults to 'gitweb_config.perl'
+   in the same directory as the installed gitweb), or if it does not exists
+   then fallback system-wide configuration file (defaults to `/etc/gitweb.conf`).
+
+Values obtained in later configuration files override values obtained earlier
+in the above sequence.
+
+Locations of the common system-wide configuration file, the fallback
+system-wide configuration file and the per-instance configuration file
+are defined at compile time using build-time Makefile configuration
+variables, respectively `GITWEB_CONFIG_COMMON`, `GITWEB_CONFIG_SYSTEM`
+and `GITWEB_CONFIG`.
+
+You can also override locations of gitweb configuration files during
+runtime by setting the following environment variables:
+`GITWEB_CONFIG_COMMON`, `GITWEB_CONFIG_SYSTEM` and `GITWEB_CONFIG`
+to a non-empty value.
+
+
+The syntax of the configuration files is that of Perl, since these files are
+handled by sourcing them as fragments of Perl code (the language that
+gitweb itself is written in). Variables are typically set using the
+`our` qualifier (as in "`our $variable = <value>;`") to avoid syntax
+errors if a new version of gitweb no longer uses a variable and therefore
+stops declaring it.
+
+You can include other configuration file using read_config_file()
+subroutine.  For example, one might want to put gitweb configuration
+related to access control for viewing repositories via Gitolite (one
+of Git repository management tools) in a separate file, e.g. in
+`/etc/gitweb-gitolite.conf`.  To include it, put
+
+--------------------------------------------------
+read_config_file("/etc/gitweb-gitolite.conf");
+--------------------------------------------------
+
+somewhere in gitweb configuration file used, e.g. in per-installation
+gitweb configuration file.  Note that read_config_file() checks itself
+that the file it reads exists, and does nothing if it is not found.
+It also handles errors in included file.
+
+
+The default configuration with no configuration file at all may work
+perfectly well for some installations.  Still, a configuration file is
+useful for customizing or tweaking the behavior of gitweb in many ways, and
+some optional features will not be present unless explicitly enabled using
+the configurable `%features` variable (see also "Configuring gitweb
+features" section below).
+
+
+CONFIGURATION VARIABLES
+-----------------------
+Some configuration variables have their default values (embedded in the CGI
+script) set during building gitweb -- if that is the case, this fact is put
+in their description.  See gitweb's 'INSTALL' file for instructions on building
+and installing gitweb.
+
+
+Location of repositories
+~~~~~~~~~~~~~~~~~~~~~~~~
+The configuration variables described below control how gitweb finds
+Git repositories, and how repositories are displayed and accessed.
+
+See also "Repositories" and later subsections in linkgit:gitweb[1] manpage.
+
+$projectroot::
+	Absolute filesystem path which will be prepended to project path;
+	the path to repository is `$projectroot/$project`.  Set to
+	`$GITWEB_PROJECTROOT` during installation.  This variable has to be
+	set correctly for gitweb to find repositories.
++
+For example, if `$projectroot` is set to "/srv/git" by putting the following
+in gitweb config file:
++
+----------------------------------------------------------------------------
+our $projectroot = "/srv/git";
+----------------------------------------------------------------------------
++
+then
++
+------------------------------------------------
+http://git.example.com/gitweb.cgi?p=foo/bar.git
+------------------------------------------------
++
+and its path_info based equivalent
++
+------------------------------------------------
+http://git.example.com/gitweb.cgi/foo/bar.git
+------------------------------------------------
++
+will map to the path `/srv/git/foo/bar.git` on the filesystem.
+
+$projects_list::
+	Name of a plain text file listing projects, or a name of directory
+	to be scanned for projects.
++
+Project list files should list one project per line, with each line
+having the following format
++
+-----------------------------------------------------------------------------
+<URI-encoded filesystem path to repository> SP <URI-encoded repository owner>
+-----------------------------------------------------------------------------
++
+The default value of this variable is determined by the `GITWEB_LIST`
+makefile variable at installation time.  If this variable is empty, gitweb
+will fall back to scanning the `$projectroot` directory for repositories.
+
+$project_maxdepth::
+	If `$projects_list` variable is unset, gitweb will recursively
+	scan filesystem for Git repositories.  The `$project_maxdepth`
+	is used to limit traversing depth, relative to `$projectroot`
+	(starting point); it means that directories which are further
+	from `$projectroot` than `$project_maxdepth` will be skipped.
++
+It is purely performance optimization, originally intended for MacOS X,
+where recursive directory traversal is slow.  Gitweb follows symbolic
+links, but it detects cycles, ignoring any duplicate files and directories.
++
+The default value of this variable is determined by the build-time
+configuration variable `GITWEB_PROJECT_MAXDEPTH`, which defaults to
+2007.
+
+$export_ok::
+	Show repository only if this file exists (in repository).  Only
+	effective if this variable evaluates to true.  Can be set when
+	building gitweb by setting `GITWEB_EXPORT_OK`.  This path is
+	relative to `GIT_DIR`.  git-daemon[1] uses 'git-daemon-export-ok',
+	unless started with `--export-all`.  By default this variable is
+	not set, which means that this feature is turned off.
+
+$export_auth_hook::
+	Function used to determine which repositories should be shown.
+	This subroutine should take one parameter, the full path to
+	a project, and if it returns true, that project will be included
+	in the projects list and can be accessed through gitweb as long
+	as it fulfills the other requirements described by $export_ok,
+	$projects_list, and $projects_maxdepth.  Example:
++
+----------------------------------------------------------------------------
+our $export_auth_hook = sub { return -e "$_[0]/git-daemon-export-ok"; };
+----------------------------------------------------------------------------
++
+though the above might be done by using `$export_ok` instead
++
+----------------------------------------------------------------------------
+our $export_ok = "git-daemon-export-ok";
+----------------------------------------------------------------------------
++
+If not set (default), it means that this feature is disabled.
++
+See also more involved example in "Controlling access to Git repositories"
+subsection on linkgit:gitweb[1] manpage.
+
+$strict_export::
+	Only allow viewing of repositories also shown on the overview page.
+	This for example makes `$export_ok` file decide if repository is
+	available and not only if it is shown.  If `$projects_list` points to
+	file with list of project, only those repositories listed would be
+	available for gitweb.  Can be set during building gitweb via
+	`GITWEB_STRICT_EXPORT`.  By default this variable is not set, which
+	means that you can directly access those repositories that are hidden
+	from projects list page (e.g. the are not listed in the $projects_list
+	file).
+
+
+Finding files
+~~~~~~~~~~~~~
+The following configuration variables tell gitweb where to find files.
+The values of these variables are paths on the filesystem.
+
+$GIT::
+	Core git executable to use.  By default set to `$GIT_BINDIR/git`, which
+	in turn is by default set to `$(bindir)/git`.  If you use Git installed
+	from a binary package, you should usually set this to "/usr/bin/git".
+	This can just be "git" if your web server has a sensible PATH; from
+	security point of view it is better to use absolute path to git binary.
+	If you have multiple Git versions installed it can be used to choose
+	which one to use.  Must be (correctly) set for gitweb to be able to
+	work.
+
+$mimetypes_file::
+	File to use for (filename extension based) guessing of MIME types before
+	trying `/etc/mime.types`.  *NOTE* that this path, if relative, is taken
+	as relative to the current Git repository, not to CGI script.  If unset,
+	only `/etc/mime.types` is used (if present on filesystem).  If no mimetypes
+	file is found, mimetype guessing based on extension of file is disabled.
+	Unset by default.
+
+$highlight_bin::
+	Path to the highlight executable to use (it must be the one from
+	http://www.andre-simon.de[] due to assumptions about parameters and output).
+	By default set to 'highlight'; set it to full path to highlight
+	executable if it is not installed on your web server's PATH.
+	Note that 'highlight' feature must be set for gitweb to actually
+	use syntax highlighting.
++
+*NOTE*: for a file to be highlighted, its syntax type must be detected
+and that syntax must be supported by "highlight".  The default syntax
+detection is minimal, and there are many supported syntax types with no
+detection by default.  There are three options for adding syntax
+detection.  The first and second priority are `%highlight_basename` and
+`%highlight_ext`, which detect based on basename (the full filename, for
+example "Makefile") and extension (for example "sh").  The keys of these
+hashes are the basename and extension, respectively, and the value for a
+given key is the name of the syntax to be passed via `--syntax <syntax>`
+to "highlight".  The last priority is the "highlight" configuration of
+`Shebang` regular expressions to detect the language based on the first
+line in the file, (for example, matching the line "#!/bin/bash").  See
+the highlight documentation and the default config at
+/etc/highlight/filetypes.conf for more details.
++
+For example if repositories you are hosting use "phtml" extension for
+PHP files, and you want to have correct syntax-highlighting for those
+files, you can add the following to gitweb configuration:
++
+---------------------------------------------------------
+our %highlight_ext;
+$highlight_ext{'phtml'} = 'php';
+---------------------------------------------------------
+
+
+Links and their targets
+~~~~~~~~~~~~~~~~~~~~~~~
+The configuration variables described below configure some of gitweb links:
+their target and their look (text or image), and where to find page
+prerequisites (stylesheet, favicon, images, scripts).  Usually they are left
+at their default values, with the possible exception of `@stylesheets`
+variable.
+
+@stylesheets::
+	List of URIs of stylesheets (relative to the base URI of a page). You
+	might specify more than one stylesheet, for example to use "gitweb.css"
+	as base with site specific modifications in a separate stylesheet
+	to make it easier to upgrade gitweb.  For example, you can add
+	a `site` stylesheet by putting
++
+----------------------------------------------------------------------------
+push @stylesheets, "gitweb-site.css";
+----------------------------------------------------------------------------
++
+in the gitweb config file.  Those values that are relative paths are
+relative to base URI of gitweb.
++
+This list should contain the URI of gitweb's standard stylesheet.  The default
+URI of gitweb stylesheet can be set at build time using the `GITWEB_CSS`
+makefile variable.  Its default value is `static/gitweb.css`
+(or `static/gitweb.min.css` if the `CSSMIN` variable is defined,
+i.e. if CSS minifier is used during build).
++
+*Note*: there is also a legacy `$stylesheet` configuration variable, which was
+used by older gitweb.  If `$stylesheet` variable is defined, only CSS stylesheet
+given by this variable is used by gitweb.
+
+$logo::
+	Points to the location where you put 'git-logo.png' on your web
+	server, or to be more the generic URI of logo, 72x27 size).  This image
+	is displayed in the top right corner of each gitweb page and used as
+	a logo for the Atom feed.  Relative to the base URI of gitweb (as a path).
+	Can be adjusted when building gitweb using `GITWEB_LOGO` variable
+	By default set to `static/git-logo.png`.
+
+$favicon::
+	Points to the location where you put 'git-favicon.png' on your web
+	server, or to be more the generic URI of favicon, which will be served
+	as "image/png" type.  Web browsers that support favicons (website icons)
+	may display them in the browser's URL bar and next to the site name in
+	bookmarks.  Relative to the base URI of gitweb.  Can be adjusted at
+	build time using `GITWEB_FAVICON` variable.
+	By default set to `static/git-favicon.png`.
+
+$javascript::
+	Points to the location where you put 'gitweb.js' on your web server,
+	or to be more generic the URI of JavaScript code used by gitweb.
+	Relative to the base URI of gitweb.  Can be set at build time using
+	the `GITWEB_JS` build-time configuration variable.
++
+The default value is either `static/gitweb.js`, or `static/gitweb.min.js` if
+the `JSMIN` build variable was defined, i.e. if JavaScript minifier was used
+at build time.  *Note* that this single file is generated from multiple
+individual JavaScript "modules".
+
+$home_link::
+	Target of the home link on the top of all pages (the first part of view
+	"breadcrumbs").  By default it is set to the absolute URI of a current page
+	(to the value of `$my_uri` variable, or to "/" if `$my_uri` is undefined
+	or is an empty string).
+
+$home_link_str::
+	Label for the "home link" at the top of all pages, leading to `$home_link`
+	(usually the main gitweb page, which contains the projects list).  It is
+	used as the first component of gitweb's "breadcrumb trail":
+	`<home link> / <project> / <action>`.  Can be set at build time using
+	the `GITWEB_HOME_LINK_STR` variable.  By default it is set to "projects",
+	as this link leads to the list of projects.  Another popular choice is to
+	set it to the name of site.  Note that it is treated as raw HTML so it
+	should not be set from untrusted sources.
+
+@extra_breadcrumbs::
+	Additional links to be added to the start of the breadcrumb trail before
+	the home link, to pages that are logically "above" the gitweb projects
+	list, such as the organization and department which host the gitweb
+	server. Each element of the list is a reference to an array, in which
+	element 0 is the link text (equivalent to `$home_link_str`) and element
+	1 is the target URL (equivalent to `$home_link`).
++
+For example, the following setting produces a breadcrumb trail like
+"home / dev / projects / ..." where "projects" is the home link.
++
+----------------------------------------------------------------------------
+    our @extra_breadcrumbs = (
+      [ 'home' => 'https://www.example.org/' ],
+      [ 'dev'  => 'https://dev.example.org/' ],
+    );
+----------------------------------------------------------------------------
+
+$logo_url::
+$logo_label::
+	URI and label (title) for the Git logo link (or your site logo,
+	if you chose to use different logo image). By default, these both
+	refer to Git homepage, https://git-scm.com[]; in the past, they pointed
+	to Git documentation at https://www.kernel.org[].
+
+
+Changing gitweb's look
+~~~~~~~~~~~~~~~~~~~~~~
+You can adjust how pages generated by gitweb look using the variables described
+below.  You can change the site name, add common headers and footers for all
+pages, and add a description of this gitweb installation on its main page
+(which is the projects list page), etc.
+
+$site_name::
+	Name of your site or organization, to appear in page titles.  Set it
+	to something descriptive for clearer bookmarks etc.  If this variable
+	is not set or is, then gitweb uses the value of the `SERVER_NAME`
+	`CGI` environment variable, setting site name to "$SERVER_NAME Git",
+	or "Untitled Git" if this variable is not set (e.g. if running gitweb
+	as standalone script).
++
+Can be set using the `GITWEB_SITENAME` at build time.  Unset by default.
+
+$site_html_head_string::
+	HTML snippet to be included in the <head> section of each page.
+	Can be set using `GITWEB_SITE_HTML_HEAD_STRING` at build time.
+	No default value.
+
+$site_header::
+	Name of a file with HTML to be included at the top of each page.
+	Relative to the directory containing the 'gitweb.cgi' script.
+	Can be set using `GITWEB_SITE_HEADER` at build time.  No default
+	value.
+
+$site_footer::
+	Name of a file with HTML to be included at the bottom of each page.
+	Relative to the directory containing the 'gitweb.cgi' script.
+	Can be set using `GITWEB_SITE_FOOTER` at build time.  No default
+	value.
+
+$home_text::
+	Name of a HTML file which, if it exists, is included on the
+	gitweb projects overview page ("projects_list" view).  Relative to
+	the directory containing the gitweb.cgi script.  Default value
+	can be adjusted during build time using `GITWEB_HOMETEXT` variable.
+	By default set to 'indextext.html'.
+
+$projects_list_description_width::
+	The width (in characters) of the "Description" column of the projects list.
+	Longer descriptions will be truncated (trying to cut at word boundary);
+	the full description is available in the 'title' attribute (usually shown on
+	mouseover).  The default is 25, which might be too small if you
+	use long project descriptions.
+
+$default_projects_order::
+	Default value of ordering of projects on projects list page, which
+	means the ordering used if you don't explicitly sort projects list
+	(if there is no "o" CGI query parameter in the URL).  Valid values
+	are "none" (unsorted), "project" (projects are by project name,
+	i.e. path to repository relative to `$projectroot`), "descr"
+	(project description), "owner", and "age" (by date of most current
+	commit).
++
+Default value is "project".  Unknown value means unsorted.
+
+
+Changing gitweb's behavior
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+These configuration variables control _internal_ gitweb behavior.
+
+$default_blob_plain_mimetype::
+	Default mimetype for the blob_plain (raw) view, if mimetype checking
+	doesn't result in some other type; by default "text/plain".
+	Gitweb guesses mimetype of a file to display based on extension
+	of its filename, using `$mimetypes_file` (if set and file exists)
+	and `/etc/mime.types` files (see *mime.types*(5) manpage; only
+	filename extension rules are supported by gitweb).
+
+$default_text_plain_charset::
+	Default charset for text files. If this is not set, the web server
+	configuration will be used.  Unset by default.
+
+$fallback_encoding::
+	Gitweb assumes this charset when a line contains non-UTF-8 characters.
+	The fallback decoding is used without error checking, so it can be even
+	"utf-8". The value must be a valid encoding; see the *Encoding::Supported*(3pm)
+	man page for a list. The default is "latin1", aka. "iso-8859-1".
+
+@diff_opts::
+	Rename detection options for git-diff and git-diff-tree. The default is
+	(\'-M'); set it to (\'-C') or (\'-C', \'-C') to also detect copies,
+	or set it to () i.e. empty list if you don't want to have renames
+	detection.
++
+*Note* that rename and especially copy detection can be quite
+CPU-intensive.  Note also that non Git tools can have problems with
+patches generated with options mentioned above, especially when they
+involve file copies (\'-C') or criss-cross renames (\'-B').
+
+
+Some optional features and policies
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Most of features are configured via `%feature` hash; however some of extra
+gitweb features can be turned on and configured using variables described
+below.  This list beside configuration variables that control how gitweb
+looks does contain variables configuring administrative side of gitweb
+(e.g. cross-site scripting prevention; admittedly this as side effect
+affects how "summary" pages look like, or load limiting).
+
+@git_base_url_list::
+	List of Git base URLs.  These URLs are used to generate URLs
+	describing from where to fetch a project, which are shown on
+	project summary page.  The full fetch URL is "`$git_base_url/$project`",
+	for each element of this list. You can set up multiple base URLs
+	(for example one for `git://` protocol, and one for `http://`
+	protocol).
++
+Note that per repository configuration can be set in `$GIT_DIR/cloneurl`
+file, or as values of multi-value `gitweb.url` configuration variable in
+project config.  Per-repository configuration takes precedence over value
+composed from `@git_base_url_list` elements and project name.
++
+You can setup one single value (single entry/item in this list) at build
+time by setting the `GITWEB_BASE_URL` build-time configuration variable.
+By default it is set to (), i.e. an empty list.  This means that gitweb
+would not try to create project URL (to fetch) from project name.
+
+$projects_list_group_categories::
+	Whether to enable the grouping of projects by category on the project
+	list page. The category of a project is determined by the
+	`$GIT_DIR/category` file or the `gitweb.category` variable in each
+	repository's configuration.  Disabled by default (set to 0).
+
+$project_list_default_category::
+	Default category for projects for which none is specified.  If this is
+	set to the empty string, such projects will remain uncategorized and
+	listed at the top, above categorized projects.  Used only if project
+	categories are enabled, which means if `$projects_list_group_categories`
+	is true.  By default set to "" (empty string).
+
+$prevent_xss::
+	If true, some gitweb features are disabled to prevent content in
+	repositories from launching cross-site scripting (XSS) attacks.  Set this
+	to true if you don't trust the content of your repositories.
+	False by default (set to 0).
+
+$maxload::
+	Used to set the maximum load that we will still respond to gitweb queries.
+	If the server load exceeds this value then gitweb will return
+	"503 Service Unavailable" error.  The server load is taken to be 0
+	if gitweb cannot determine its value.  Currently it works only on Linux,
+	where it uses `/proc/loadavg`; the load there is the number of active
+	tasks on the system -- processes that are actually running -- averaged
+	over the last minute.
++
+Set `$maxload` to undefined value (`undef`) to turn this feature off.
+The default value is 300.
+
+$omit_age_column::
+	If true, omit the column with date of the most current commit on the
+	projects list page. It can save a bit of I/O and a fork per repository.
+
+$omit_owner::
+	If true prevents displaying information about repository owner.
+
+$per_request_config::
+	If this is set to code reference, it will be run once for each request.
+	You can set parts of configuration that change per session this way.
+	For example, one might use the following code in a gitweb configuration
+	file
++
+--------------------------------------------------------------------------------
+our $per_request_config = sub {
+	$ENV{GL_USER} = $cgi->remote_user || "gitweb";
+};
+--------------------------------------------------------------------------------
++
+If `$per_request_config` is not a code reference, it is interpreted as boolean
+value.  If it is true gitweb will process config files once per request,
+and if it is false gitweb will process config files only once, each time it
+is executed.  True by default (set to 1).
++
+*NOTE*: `$my_url`, `$my_uri`, and `$base_url` are overwritten with their default
+values before every request, so if you want to change them, be sure to set
+this variable to true or a code reference effecting the desired changes.
++
+This variable matters only when using persistent web environments that
+serve multiple requests using single gitweb instance, like mod_perl,
+FastCGI or Plackup.
+
+
+Other variables
+~~~~~~~~~~~~~~~
+Usually you should not need to change (adjust) any of configuration
+variables described below; they should be automatically set by gitweb to
+correct value.
+
+
+$version::
+	Gitweb version, set automatically when creating gitweb.cgi from
+	gitweb.perl. You might want to modify it if you are running modified
+	gitweb, for example
++
+---------------------------------------------------
+our $version .= " with caching";
+---------------------------------------------------
++
+if you run modified version of gitweb with caching support.  This variable
+is purely informational, used e.g. in the "generator" meta header in HTML
+header.
+
+$my_url::
+$my_uri::
+	Full URL and absolute URL of the gitweb script;
+	in earlier versions of gitweb you might have need to set those
+	variables, but now there should be no need to do it.  See
+	`$per_request_config` if you need to set them still.
+
+$base_url::
+	Base URL for relative URLs in pages generated by gitweb,
+	(e.g. `$logo`, `$favicon`, `@stylesheets` if they are relative URLs),
+	needed and used '<base href="$base_url">' only for URLs with nonempty
+	PATH_INFO.  Usually gitweb sets its value correctly,
+	and there is no need to set this variable, e.g. to $my_uri or "/".
+	See `$per_request_config` if you need to override it anyway.
+
+
+CONFIGURING GITWEB FEATURES
+---------------------------
+Many gitweb features can be enabled (or disabled) and configured using the
+`%feature` hash.  Names of gitweb features are keys of this hash.
+
+Each `%feature` hash element is a hash reference and has the following
+structure:
+----------------------------------------------------------------------
+"<feature_name>" => {
+	"sub" => <feature-sub (subroutine)>,
+	"override" => <allow-override (boolean)>,
+	"default" => [ <options>... ]
+},
+----------------------------------------------------------------------
+Some features cannot be overridden per project.  For those
+features the structure of appropriate `%feature` hash element has a simpler
+form:
+----------------------------------------------------------------------
+"<feature_name>" => {
+	"override" => 0,
+	"default" => [ <options>... ]
+},
+----------------------------------------------------------------------
+As one can see it lacks the \'sub' element.
+
+The meaning of each part of feature configuration is described
+below:
+
+default::
+	List (array reference) of feature parameters (if there are any),
+	used also to toggle (enable or disable) given feature.
++
+Note that it is currently *always* an array reference, even if
+feature doesn't accept any configuration parameters, and \'default'
+is used only to turn it on or off.  In such case you turn feature on
+by setting this element to `[1]`, and torn it off by setting it to
+`[0]`.  See also the passage about the "blame" feature in the "Examples"
+section.
++
+To disable features that accept parameters (are configurable), you
+need to set this element to empty list i.e. `[]`.
+
+override::
+	If this field has a true value then the given feature is
+	overridable, which means that it can be configured
+	(or enabled/disabled) on a per-repository basis.
++
+Usually given "<feature>" is configurable via the `gitweb.<feature>`
+config variable in the per-repository Git configuration file.
++
+*Note* that no feature is overridable by default.
+
+sub::
+	Internal detail of implementation.  What is important is that
+	if this field is not present then per-repository override for
+	given feature is not supported.
++
+You wouldn't need to ever change it in gitweb config file.
+
+
+Features in `%feature`
+~~~~~~~~~~~~~~~~~~~~~~
+The gitweb features that are configurable via `%feature` hash are listed
+below.  This should be a complete list, but ultimately the authoritative
+and complete list is in gitweb.cgi source code, with features described
+in the comments.
+
+blame::
+	Enable the "blame" and "blame_incremental" blob views, showing for
+	each line the last commit that modified it; see linkgit:git-blame[1].
+	This can be very CPU-intensive and is therefore disabled by default.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.blame` configuration variable (boolean).
+
+snapshot::
+	Enable and configure the "snapshot" action, which allows user to
+	download a compressed archive of any tree or commit, as produced
+	by linkgit:git-archive[1] and possibly additionally compressed.
+	This can potentially generate high traffic if you have large project.
++
+The value of \'default' is a list of names of snapshot formats,
+defined in `%known_snapshot_formats` hash, that you wish to offer.
+Supported formats include "tgz", "tbz2", "txz" (gzip/bzip2/xz
+compressed tar archive) and "zip"; please consult gitweb sources for
+a definitive list.  By default only "tgz" is offered.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.snapshot` configuration variable, which contains
+a comma separated list of formats or "none" to disable snapshots.
+Unknown values are ignored.
+
+grep::
+	Enable grep search, which lists the files in currently selected
+	tree (directory) containing the given string; see linkgit:git-grep[1].
+	This can be potentially CPU-intensive, of course.  Enabled by default.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.grep` configuration variable (boolean).
+
+pickaxe::
+	Enable the so called pickaxe search, which will list the commits
+	that introduced or removed a given string in a file.  This can be
+	practical and quite faster alternative to "blame" action, but it is
+	still potentially CPU-intensive.  Enabled by default.
++
+The pickaxe search is described in linkgit:git-log[1] (the
+description of `-S<string>` option, which refers to pickaxe entry in
+linkgit:gitdiffcore[7] for more details).
++
+This feature can be configured on a per-repository basis by setting
+repository's `gitweb.pickaxe` configuration variable (boolean).
+
+show-sizes::
+	Enable showing size of blobs (ordinary files) in a "tree" view, in a
+	separate column, similar to what `ls -l` does; see description of
+	`-l` option in linkgit:git-ls-tree[1] manpage.  This costs a bit of
+	I/O.  Enabled by default.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.showSizes` configuration variable (boolean).
+
+patches::
+	Enable and configure "patches" view, which displays list of commits in email
+	(plain text) output format; see also linkgit:git-format-patch[1].
+	The value is the maximum number of patches in a patchset generated
+	in "patches" view.  Set the 'default' field to a list containing single
+	item of or to an empty list to disable patch view, or to a list
+	containing a single negative number to remove any limit.
+	Default value is 16.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.patches` configuration variable (integer).
+
+avatar::
+	Avatar support.  When this feature is enabled, views such as
+	"shortlog" or "commit" will display an avatar associated with
+	the email of each committer and author.
++
+Currently available providers are *"gravatar"* and *"picon"*.
+Only one provider at a time can be selected ('default' is one element list).
+If an unknown provider is specified, the feature is disabled.
+*Note* that some providers might require extra Perl packages to be
+installed; see `gitweb/INSTALL` for more details.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.avatar` configuration variable.
++
+See also `%avatar_size` with pixel sizes for icons and avatars
+("default" is used for one-line like "log" and "shortlog", "double"
+is used for two-line like "commit", "commitdiff" or "tag").  If the
+default font sizes or lineheights are changed (e.g. via adding extra
+CSS stylesheet in `@stylesheets`), it may be appropriate to change
+these values.
+
+highlight::
+	Server-side syntax highlight support in "blob" view.  It requires
+	`$highlight_bin` program to be available (see the description of
+	this variable in the "Configuration variables" section above),
+	and therefore is disabled by default.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.highlight` configuration variable (boolean).
+
+remote_heads::
+	Enable displaying remote heads (remote-tracking branches) in the "heads"
+	list.  In most cases the list of remote-tracking branches is an
+	unnecessary internal private detail, and this feature is therefore
+	disabled by default.  linkgit:git-instaweb[1], which is usually used
+	to browse local repositories, enables and uses this feature.
++
+This feature can be configured on a per-repository basis via
+repository's `gitweb.remote_heads` configuration variable (boolean).
+
+
+The remaining features cannot be overridden on a per project basis.
+
+search::
+	Enable text search, which will list the commits which match author,
+	committer or commit text to a given string; see the description of
+	`--author`, `--committer` and `--grep` options in linkgit:git-log[1]
+	manpage.  Enabled by default.
++
+Project specific override is not supported.
+
+forks::
+	If this feature is enabled, gitweb considers projects in
+	subdirectories of project root (basename) to be forks of existing
+	projects.  For each project +$projname.git+, projects in the
+	+$projname/+ directory and its subdirectories will not be
+	shown in the main projects list.  Instead, a \'\+' mark is shown
+	next to +$projname+, which links to a "forks" view that lists all
+	the forks (all projects in +$projname/+ subdirectory).  Additionally
+	a "forks" view for a project is linked from project summary page.
++
+If the project list is taken from a file (+$projects_list+ points to a
+file), forks are only recognized if they are listed after the main project
+in that file.
++
+Project specific override is not supported.
+
+actions::
+	Insert custom links to the action bar of all project pages.  This
+	allows you to link to third-party scripts integrating into gitweb.
++
+The "default" value consists of a list of triplets in the form
+`("<label>", "<link>", "<position>")` where "position" is the label
+after which to insert the link, "link" is a format string where `%n`
+expands to the project name, `%f` to the project path within the
+filesystem (i.e. "$projectroot/$project"), `%h` to the current hash
+(\'h' gitweb parameter) and `%b` to the current hash base
+(\'hb' gitweb parameter); `%%` expands to \'%'.
++
+For example, at the time this page was written, the http://repo.or.cz[]
+Git hosting site set it to the following to enable graphical log
+(using the third party tool *git-browser*):
++
+----------------------------------------------------------------------
+$feature{'actions'}{'default'} =
+	[ ('graphiclog', '/git-browser/by-commit.html?r=%n', 'summary')];
+----------------------------------------------------------------------
++
+This adds a link titled "graphiclog" after the "summary" link, leading to
+`git-browser` script, passing `r=<project>` as a query parameter.
++
+Project specific override is not supported.
+
+timed::
+	Enable displaying how much time and how many Git commands it took to
+	generate and display each page in the page footer (at the bottom of
+	page).  For example the footer might contain: "This page took 6.53325
+	seconds and 13 Git commands to generate."  Disabled by default.
++
+Project specific override is not supported.
+
+javascript-timezone::
+	Enable and configure the ability to change a common time zone for dates
+	in gitweb output via JavaScript.  Dates in gitweb output include
+	authordate and committerdate in "commit", "commitdiff" and "log"
+	views, and taggerdate in "tag" view.  Enabled by default.
++
+The value is a list of three values: a default time zone (for if the client
+hasn't selected some other time zone and saved it in a cookie), a name of cookie
+where to store selected time zone, and a CSS class used to mark up
+dates for manipulation.  If you want to turn this feature off, set "default"
+to empty list: `[]`.
++
+Typical gitweb config files will only change starting (default) time zone,
+and leave other elements at their default values:
++
+---------------------------------------------------------------------------
+$feature{'javascript-timezone'}{'default'}[0] = "utc";
+---------------------------------------------------------------------------
++
+The example configuration presented here is guaranteed to be backwards
+and forward compatible.
++
+Time zone values can be "local" (for local time zone that browser uses), "utc"
+(what gitweb uses when JavaScript or this feature is disabled), or numerical
+time zones in the form of "+/-HHMM", such as "+0200".
++
+Project specific override is not supported.
+
+extra-branch-refs::
+	List of additional directories under "refs" which are going to
+	be used as branch refs. For example if you have a gerrit setup
+	where all branches under refs/heads/ are official,
+	push-after-review ones and branches under refs/sandbox/,
+	refs/wip and refs/other are user ones where permissions are
+	much wider, then you might want to set this variable as
+	follows:
++
+--------------------------------------------------------------------------------
+$feature{'extra-branch-refs'}{'default'} =
+	['sandbox', 'wip', 'other'];
+--------------------------------------------------------------------------------
++
+This feature can be configured on per-repository basis after setting
+$feature{'extra-branch-refs'}{'override'} to true, via repository's
+`gitweb.extraBranchRefs` configuration variable, which contains a
+space separated list of refs. An example:
++
+--------------------------------------------------------------------------------
+[gitweb]
+	extraBranchRefs = sandbox wip other
+--------------------------------------------------------------------------------
++
+The gitweb.extraBranchRefs is actually a multi-valued configuration
+variable, so following example is also correct and the result is the
+same as of the snippet above:
++
+--------------------------------------------------------------------------------
+[gitweb]
+	extraBranchRefs = sandbox
+	extraBranchRefs = wip other
+--------------------------------------------------------------------------------
++
+It is an error to specify a ref that does not pass "git check-ref-format"
+scrutiny. Duplicated values are filtered.
+
+
+EXAMPLES
+--------
+
+To enable blame, pickaxe search, and snapshot support (allowing "tar.gz" and
+"zip" snapshots), while allowing individual projects to turn them off, put
+the following in your GITWEB_CONFIG file:
+
+--------------------------------------------------------------------------------
+$feature{'blame'}{'default'} = [1];
+$feature{'blame'}{'override'} = 1;
+
+$feature{'pickaxe'}{'default'} = [1];
+$feature{'pickaxe'}{'override'} = 1;
+
+$feature{'snapshot'}{'default'} = ['zip', 'tgz'];
+$feature{'snapshot'}{'override'} = 1;
+--------------------------------------------------------------------------------
+
+If you allow overriding for the snapshot feature, you can specify which
+snapshot formats are globally disabled. You can also add any command-line
+options you want (such as setting the compression level). For instance, you
+can disable Zip compressed snapshots and set *gzip*(1) to run at level 6 by
+adding the following lines to your gitweb configuration file:
+
+	$known_snapshot_formats{'zip'}{'disabled'} = 1;
+	$known_snapshot_formats{'tgz'}{'compressor'} = ['gzip','-6'];
+
+BUGS
+----
+Debugging would be easier if the fallback configuration file
+(`/etc/gitweb.conf`) and environment variable to override its location
+('GITWEB_CONFIG_SYSTEM') had names reflecting their "fallback" role.
+The current names are kept to avoid breaking working setups.
+
+ENVIRONMENT
+-----------
+The location of per-instance and system-wide configuration files can be
+overridden using the following environment variables:
+
+GITWEB_CONFIG::
+	Sets location of per-instance configuration file.
+GITWEB_CONFIG_SYSTEM::
+	Sets location of fallback system-wide configuration file.
+	This file is read only if per-instance one does not exist.
+GITWEB_CONFIG_COMMON::
+	Sets location of common system-wide configuration file.
+
+
+FILES
+-----
+gitweb_config.perl::
+	This is default name of per-instance configuration file.  The
+	format of this file is described above.
+/etc/gitweb.conf::
+	This is default name of fallback system-wide configuration
+	file.  This file is used only if per-instance configuration
+	variable is not found.
+/etc/gitweb-common.conf::
+	This is default name of common system-wide configuration
+	file.
+
+
+SEE ALSO
+--------
+linkgit:gitweb[1], linkgit:git-instaweb[1]
+
+'gitweb/README', 'gitweb/INSTALL'
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitweb.txt b/third_party/git/Documentation/gitweb.txt
new file mode 100644
index 0000000000..3cc9b034c4
--- /dev/null
+++ b/third_party/git/Documentation/gitweb.txt
@@ -0,0 +1,703 @@
+gitweb(1)
+=========
+
+NAME
+----
+gitweb - Git web interface (web frontend to Git repositories)
+
+SYNOPSIS
+--------
+To get started with gitweb, run linkgit:git-instaweb[1] from a Git repository.
+This would configure and start your web server, and run web browser pointing to
+gitweb.
+
+
+DESCRIPTION
+-----------
+Gitweb provides a web interface to Git repositories.  Its features include:
+
+* Viewing multiple Git repositories with common root.
+* Browsing every revision of the repository.
+* Viewing the contents of files in the repository at any revision.
+* Viewing the revision log of branches, history of files and directories,
+  see what was changed when, by who.
+* Viewing the blame/annotation details of any file (if enabled).
+* Generating RSS and Atom feeds of commits, for any branch.
+  The feeds are auto-discoverable in modern web browsers.
+* Viewing everything that was changed in a revision, and step through
+  revisions one at a time, viewing the history of the repository.
+* Finding commits which commit messages matches given search term.
+
+See http://repo.or.cz/w/git.git/tree/HEAD:/gitweb/[] for gitweb source code,
+browsed using gitweb itself.
+
+
+CONFIGURATION
+-------------
+Various aspects of gitweb's behavior can be controlled through the configuration
+file `gitweb_config.perl` or `/etc/gitweb.conf`.  See the linkgit:gitweb.conf[5]
+for details.
+
+Repositories
+~~~~~~~~~~~~
+Gitweb can show information from one or more Git repositories.  These
+repositories have to be all on local filesystem, and have to share common
+repository root, i.e. be all under a single parent repository (but see also
+"Advanced web server setup" section, "Webserver configuration with multiple
+projects' root" subsection).
+
+-----------------------------------------------------------------------
+our $projectroot = '/path/to/parent/directory';
+-----------------------------------------------------------------------
+
+The default value for `$projectroot` is `/pub/git`.  You can change it during
+building gitweb via `GITWEB_PROJECTROOT` build configuration variable.
+
+By default all Git repositories under `$projectroot` are visible and available
+to gitweb.  The list of projects is generated by default by scanning the
+`$projectroot` directory for Git repositories (for object databases to be
+more exact; gitweb is not interested in a working area, and is best suited
+to showing "bare" repositories).
+
+The name of the repository in gitweb is the path to its `$GIT_DIR` (its object
+database) relative to `$projectroot`.  Therefore the repository $repo can be
+found at "$projectroot/$repo".
+
+
+Projects list file format
+~~~~~~~~~~~~~~~~~~~~~~~~~
+Instead of having gitweb find repositories by scanning filesystem
+starting from $projectroot, you can provide a pre-generated list of
+visible projects by setting `$projects_list` to point to a plain text
+file with a list of projects (with some additional info).
+
+This file uses the following format:
+
+* One record (for project / repository) per line; does not support line
+continuation (newline escaping).
+
+* Leading and trailing whitespace are ignored.
+
+* Whitespace separated fields; any run of whitespace can be used as field
+separator (rules for Perl's "`split(" ", $line)`").
+
+* Fields use modified URI encoding, defined in RFC 3986, section 2.1
+(Percent-Encoding), or rather "Query string encoding" (see
+https://en.wikipedia.org/wiki/Query_string#URL_encoding[]), the difference
+being that SP (" ") can be encoded as "{plus}" (and therefore "{plus}" has to be
+also percent-encoded).
++
+Reserved characters are: "%" (used for encoding), "{plus}" (can be used to
+encode SPACE), all whitespace characters as defined in Perl, including SP,
+TAB and LF, (used to separate fields in a record).
+
+* Currently recognized fields are:
+<repository path>::
+	path to repository GIT_DIR, relative to `$projectroot`
+<repository owner>::
+	displayed as repository owner, preferably full name, or email,
+	or both
+
+You can generate the projects list index file using the project_index action
+(the 'TXT' link on projects list page) directly from gitweb; see also
+"Generating projects list using gitweb" section below.
+
+Example contents:
+-----------------------------------------------------------------------
+foo.git       Joe+R+Hacker+<joe@example.com>
+foo/bar.git   O+W+Ner+<owner@example.org>
+-----------------------------------------------------------------------
+
+
+By default this file controls only which projects are *visible* on projects
+list page (note that entries that do not point to correctly recognized Git
+repositories won't be displayed by gitweb).  Even if a project is not
+visible on projects list page, you can view it nevertheless by hand-crafting
+a gitweb URL.  By setting `$strict_export` configuration variable (see
+linkgit:gitweb.conf[5]) to true value you can allow viewing only of
+repositories also shown on the overview page (i.e. only projects explicitly
+listed in projects list file will be accessible).
+
+
+Generating projects list using gitweb
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+We assume that GITWEB_CONFIG has its default Makefile value, namely
+'gitweb_config.perl'. Put the following in 'gitweb_make_index.perl' file:
+----------------------------------------------------------------------------
+read_config_file("gitweb_config.perl");
+$projects_list = $projectroot;
+----------------------------------------------------------------------------
+
+Then create the following script to get list of project in the format
+suitable for GITWEB_LIST build configuration variable (or
+`$projects_list` variable in gitweb config):
+
+----------------------------------------------------------------------------
+#!/bin/sh
+
+export GITWEB_CONFIG="gitweb_make_index.perl"
+export GATEWAY_INTERFACE="CGI/1.1"
+export HTTP_ACCEPT="*/*"
+export REQUEST_METHOD="GET"
+export QUERY_STRING="a=project_index"
+
+perl -- /var/www/cgi-bin/gitweb.cgi
+----------------------------------------------------------------------------
+
+Run this script and save its output to a file.  This file could then be used
+as projects list file, which means that you can set `$projects_list` to its
+filename.
+
+
+Controlling access to Git repositories
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+By default all Git repositories under `$projectroot` are visible and
+available to gitweb.  You can however configure how gitweb controls access
+to repositories.
+
+* As described in "Projects list file format" section, you can control which
+projects are *visible* by selectively including repositories in projects
+list file, and setting `$projects_list` gitweb configuration variable to
+point to it.  With `$strict_export` set, projects list file can be used to
+control which repositories are *available* as well.
+
+* You can configure gitweb to only list and allow viewing of the explicitly
+exported repositories, via `$export_ok` variable in gitweb config file; see
+linkgit:gitweb.conf[5] manpage.  If it evaluates to true, gitweb shows
+repositories only if this file named by `$export_ok` exists in its object
+database (if directory has the magic file named `$export_ok`).
++
+For example linkgit:git-daemon[1] by default (unless `--export-all` option
+is used) allows pulling only for those repositories that have
+'git-daemon-export-ok' file.  Adding
++
+--------------------------------------------------------------------------
+our $export_ok = "git-daemon-export-ok";
+--------------------------------------------------------------------------
++
+makes gitweb show and allow access only to those repositories that can be
+fetched from via `git://` protocol.
+
+* Finally, it is possible to specify an arbitrary perl subroutine that will
+be called for each repository to determine if it can be exported.  The
+subroutine receives an absolute path to the project (repository) as its only
+parameter (i.e. "$projectroot/$project").
++
+For example, if you use mod_perl to run the script, and have dumb
+HTTP protocol authentication configured for your repositories, you
+can use the following hook to allow access only if the user is
+authorized to read the files:
++
+--------------------------------------------------------------------------
+$export_auth_hook = sub {
+	use Apache2::SubRequest ();
+	use Apache2::Const -compile => qw(HTTP_OK);
+	my $path = "$_[0]/HEAD";
+	my $r    = Apache2::RequestUtil->request;
+	my $sub  = $r->lookup_file($path);
+	return $sub->filename eq $path
+	    && $sub->status == Apache2::Const::HTTP_OK;
+};
+--------------------------------------------------------------------------
+
+
+Per-repository gitweb configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+You can configure individual repositories shown in gitweb by creating file
+in the `GIT_DIR` of Git repository, or by setting some repo configuration
+variable (in `GIT_DIR/config`, see linkgit:git-config[1]).
+
+You can use the following files in repository:
+
+README.html::
+	A html file (HTML fragment) which is included on the gitweb project
+	"summary" page inside `<div>` block element. You can use it for longer
+	description of a project, to provide links (for example to project's
+	homepage), etc. This is recognized only if XSS prevention is off
+	(`$prevent_xss` is false, see linkgit:gitweb.conf[5]); a way to include
+	a README safely when XSS prevention is on may be worked out in the
+	future.
+
+description (or `gitweb.description`)::
+	Short (shortened to `$projects_list_description_width` in the projects
+	list page, which is 25 characters by default; see
+	linkgit:gitweb.conf[5]) single line description of a project (of a
+	repository).  Plain text file; HTML will be escaped.  By default set to
++
+-------------------------------------------------------------------------------
+Unnamed repository; edit this file to name it for gitweb.
+-------------------------------------------------------------------------------
++
+from the template during repository creation, usually installed in
+`/usr/share/git-core/templates/`.  You can use the `gitweb.description` repo
+configuration variable, but the file takes precedence.
+
+category (or `gitweb.category`)::
+	Singe line category of a project, used to group projects if
+	`$projects_list_group_categories` is enabled.  By default (file and
+	configuration variable absent), uncategorized projects are put in the
+	`$project_list_default_category` category.  You can use the
+	`gitweb.category` repo configuration variable, but the file takes
+	precedence.
++
+The configuration variables `$projects_list_group_categories` and
+`$project_list_default_category` are described in linkgit:gitweb.conf[5]
+
+cloneurl (or multiple-valued `gitweb.url`)::
+	File with repository URL (used for clone and fetch), one per line.
+	Displayed in the project summary page. You can use multiple-valued
+	`gitweb.url` repository configuration variable for that, but the file
+	takes precedence.
++
+This is per-repository enhancement / version of global prefix-based
+`@git_base_url_list` gitweb configuration variable (see
+linkgit:gitweb.conf[5]).
+
+gitweb.owner::
+	You can use the `gitweb.owner` repository configuration variable to set
+	repository's owner.  It is displayed in the project list and summary
+	page.
++
+If it's not set, filesystem directory's owner is used (via GECOS field,
+i.e. real name field from *getpwuid*(3)) if `$projects_list` is unset
+(gitweb scans `$projectroot` for repositories); if `$projects_list`
+points to file with list of repositories, then project owner defaults to
+value from this file for given repository.
+
+various `gitweb.*` config variables (in config)::
+	Read description of `%feature` hash for detailed list, and descriptions.
+	See also "Configuring gitweb features" section in linkgit:gitweb.conf[5]
+
+
+ACTIONS, AND URLS
+-----------------
+Gitweb can use path_info (component) based URLs, or it can pass all necessary
+information via query parameters.  The typical gitweb URLs are broken down in to
+five components:
+
+-----------------------------------------------------------------------
+.../gitweb.cgi/<repo>/<action>/<revision>:/<path>?<arguments>
+-----------------------------------------------------------------------
+
+repo::
+	The repository the action will be performed on.
++
+All actions except for those that list all available projects,
+in whatever form, require this parameter.
+
+action::
+	The action that will be run.  Defaults to 'projects_list' if repo
+	is not set, and to 'summary' otherwise.
+
+revision::
+	Revision shown.  Defaults to HEAD.
+
+path::
+	The path within the <repository> that the action is performed on,
+	for those actions that require it.
+
+arguments::
+	Any arguments that control the behaviour of the action.
+
+Some actions require or allow to specify two revisions, and sometimes even two
+pathnames.  In most general form such path_info (component) based gitweb URL
+looks like this:
+
+-----------------------------------------------------------------------
+.../gitweb.cgi/<repo>/<action>/<revision_from>:/<path_from>..<revision_to>:/<path_to>?<arguments>
+-----------------------------------------------------------------------
+
+
+Each action is implemented as a subroutine, and must be present in %actions
+hash.  Some actions are disabled by default, and must be turned on via feature
+mechanism.  For example to enable 'blame' view add the following to gitweb
+configuration file:
+
+-----------------------------------------------------------------------
+$feature{'blame'}{'default'} = [1];
+-----------------------------------------------------------------------
+
+
+Actions:
+~~~~~~~~
+The standard actions are:
+
+project_list::
+	Lists the available Git repositories.  This is the default command if no
+	repository is specified in the URL.
+
+summary::
+	Displays summary about given repository.  This is the default command if
+	no action is specified in URL, and only repository is specified.
+
+heads::
+remotes::
+	Lists all local or all remote-tracking branches in given repository.
++
+The latter is not available by default, unless configured.
+
+tags::
+	List all tags (lightweight and annotated) in given repository.
+
+blob::
+tree::
+	Shows the files and directories in a given repository path, at given
+	revision.  This is default command if no action is specified in the URL,
+	and path is given.
+
+blob_plain::
+	Returns the raw data for the file in given repository, at given path and
+	revision.  Links to this action are marked 'raw'.
+
+blobdiff::
+	Shows the difference between two revisions of the same file.
+
+blame::
+blame_incremental::
+	Shows the blame (also called annotation) information for a file. On a
+	per line basis it shows the revision in which that line was last changed
+	and the user that committed the change.  The incremental version (which
+	if configured is used automatically when JavaScript is enabled) uses
+	Ajax to incrementally add blame info to the contents of given file.
++
+This action is disabled by default for performance reasons.
+
+commit::
+commitdiff::
+	Shows information about a specific commit in a repository.  The 'commit'
+	view shows information about commit in more detail, the 'commitdiff'
+	action shows changeset for given commit.
+
+patch::
+	Returns the commit in plain text mail format, suitable for applying with
+	linkgit:git-am[1].
+
+tag::
+	Display specific annotated tag (tag object).
+
+log::
+shortlog::
+	Shows log information (commit message or just commit subject) for a
+	given branch (starting from given revision).
++
+The 'shortlog' view is more compact; it shows one commit per line.
+
+history::
+	Shows history of the file or directory in a given repository path,
+	starting from given revision (defaults to HEAD, i.e. default branch).
++
+This view is similar to 'shortlog' view.
+
+rss::
+atom::
+	Generates an RSS (or Atom) feed of changes to repository.
+
+
+WEBSERVER CONFIGURATION
+-----------------------
+This section explains how to configure some common webservers to run gitweb. In
+all cases, `/path/to/gitweb` in the examples is the directory you ran installed
+gitweb in, and contains `gitweb_config.perl`.
+
+If you've configured a web server that isn't listed here for gitweb, please send
+in the instructions so they can be included in a future release.
+
+Apache as CGI
+~~~~~~~~~~~~~
+Apache must be configured to support CGI scripts in the directory in
+which gitweb is installed.  Let's assume that it is `/var/www/cgi-bin`
+directory.
+
+-----------------------------------------------------------------------
+ScriptAlias /cgi-bin/ "/var/www/cgi-bin/"
+
+<Directory "/var/www/cgi-bin">
+    Options Indexes FollowSymlinks ExecCGI
+    AllowOverride None
+    Order allow,deny
+    Allow from all
+</Directory>
+-----------------------------------------------------------------------
+
+With that configuration the full path to browse repositories would be:
+
+  http://server/cgi-bin/gitweb.cgi
+
+Apache with mod_perl, via ModPerl::Registry
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+You can use mod_perl with gitweb.  You must install Apache::Registry
+(for mod_perl 1.x) or ModPerl::Registry (for mod_perl 2.x) to enable
+this support.
+
+Assuming that gitweb is installed to `/var/www/perl`, the following
+Apache configuration (for mod_perl 2.x) is suitable.
+
+-----------------------------------------------------------------------
+Alias /perl "/var/www/perl"
+
+<Directory "/var/www/perl">
+    SetHandler perl-script
+    PerlResponseHandler ModPerl::Registry
+    PerlOptions +ParseHeaders
+    Options Indexes FollowSymlinks +ExecCGI
+    AllowOverride None
+    Order allow,deny
+    Allow from all
+</Directory>
+-----------------------------------------------------------------------
+
+With that configuration the full path to browse repositories would be:
+
+  http://server/perl/gitweb.cgi
+
+Apache with FastCGI
+~~~~~~~~~~~~~~~~~~~
+Gitweb works with Apache and FastCGI.  First you need to rename, copy
+or symlink gitweb.cgi to gitweb.fcgi.  Let's assume that gitweb is
+installed in `/usr/share/gitweb` directory.  The following Apache
+configuration is suitable (UNTESTED!)
+
+-----------------------------------------------------------------------
+FastCgiServer /usr/share/gitweb/gitweb.cgi
+ScriptAlias /gitweb /usr/share/gitweb/gitweb.cgi
+
+Alias /gitweb/static /usr/share/gitweb/static
+<Directory /usr/share/gitweb/static>
+    SetHandler default-handler
+</Directory>
+-----------------------------------------------------------------------
+
+With that configuration the full path to browse repositories would be:
+
+  http://server/gitweb
+
+
+ADVANCED WEB SERVER SETUP
+-------------------------
+All of those examples use request rewriting, and need `mod_rewrite`
+(or equivalent; examples below are written for Apache).
+
+Single URL for gitweb and for fetching
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If you want to have one URL for both gitweb and your `http://`
+repositories, you can configure Apache like this:
+
+-----------------------------------------------------------------------
+<VirtualHost *:80>
+    ServerName    git.example.org
+    DocumentRoot  /pub/git
+    SetEnv        GITWEB_CONFIG   /etc/gitweb.conf
+
+    # turning on mod rewrite
+    RewriteEngine on
+
+    # make the front page an internal rewrite to the gitweb script
+    RewriteRule ^/$  /cgi-bin/gitweb.cgi
+
+    # make access for "dumb clients" work
+    RewriteRule ^/(.*\.git/(?!/?(HEAD|info|objects|refs)).*)?$ \
+		/cgi-bin/gitweb.cgi%{REQUEST_URI}  [L,PT]
+</VirtualHost>
+-----------------------------------------------------------------------
+
+The above configuration expects your public repositories to live under
+`/pub/git` and will serve them as `http://git.domain.org/dir-under-pub-git`,
+both as clonable Git URL and as browseable gitweb interface.  If you then
+start your linkgit:git-daemon[1] with `--base-path=/pub/git --export-all`
+then you can even use the `git://` URL with exactly the same path.
+
+Setting the environment variable `GITWEB_CONFIG` will tell gitweb to use the
+named file (i.e. in this example `/etc/gitweb.conf`) as a configuration for
+gitweb.  You don't really need it in above example; it is required only if
+your configuration file is in different place than built-in (during
+compiling gitweb) 'gitweb_config.perl' or `/etc/gitweb.conf`.  See
+linkgit:gitweb.conf[5] for details, especially information about precedence
+rules.
+
+If you use the rewrite rules from the example you *might* also need
+something like the following in your gitweb configuration file
+(`/etc/gitweb.conf` following example):
+----------------------------------------------------------------------------
+@stylesheets = ("/some/absolute/path/gitweb.css");
+$my_uri    = "/";
+$home_link = "/";
+$per_request_config = 1;
+----------------------------------------------------------------------------
+Nowadays though gitweb should create HTML base tag when needed (to set base
+URI for relative links), so it should work automatically.
+
+
+Webserver configuration with multiple projects' root
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If you want to use gitweb with several project roots you can edit your
+Apache virtual host and gitweb configuration files in the following way.
+
+The virtual host configuration (in Apache configuration file) should look
+like this:
+--------------------------------------------------------------------------
+<VirtualHost *:80>
+    ServerName    git.example.org
+    DocumentRoot  /pub/git
+    SetEnv        GITWEB_CONFIG  /etc/gitweb.conf
+
+    # turning on mod rewrite
+    RewriteEngine on
+
+    # make the front page an internal rewrite to the gitweb script
+    RewriteRule ^/$  /cgi-bin/gitweb.cgi  [QSA,L,PT]
+
+    # look for a public_git folder in unix users' home
+    # http://git.example.org/~<user>/
+    RewriteRule ^/\~([^\/]+)(/|/gitweb.cgi)?$	/cgi-bin/gitweb.cgi \
+		[QSA,E=GITWEB_PROJECTROOT:/home/$1/public_git/,L,PT]
+
+    # http://git.example.org/+<user>/
+    #RewriteRule ^/\+([^\/]+)(/|/gitweb.cgi)?$	/cgi-bin/gitweb.cgi \
+		 [QSA,E=GITWEB_PROJECTROOT:/home/$1/public_git/,L,PT]
+
+    # http://git.example.org/user/<user>/
+    #RewriteRule ^/user/([^\/]+)/(gitweb.cgi)?$	/cgi-bin/gitweb.cgi \
+		 [QSA,E=GITWEB_PROJECTROOT:/home/$1/public_git/,L,PT]
+
+    # defined list of project roots
+    RewriteRule ^/scm(/|/gitweb.cgi)?$ /cgi-bin/gitweb.cgi \
+		[QSA,E=GITWEB_PROJECTROOT:/pub/scm/,L,PT]
+    RewriteRule ^/var(/|/gitweb.cgi)?$ /cgi-bin/gitweb.cgi \
+		[QSA,E=GITWEB_PROJECTROOT:/var/git/,L,PT]
+
+    # make access for "dumb clients" work
+    RewriteRule ^/(.*\.git/(?!/?(HEAD|info|objects|refs)).*)?$ \
+		/cgi-bin/gitweb.cgi%{REQUEST_URI}  [L,PT]
+</VirtualHost>
+--------------------------------------------------------------------------
+
+Here actual project root is passed to gitweb via `GITWEB_PROJECT_ROOT`
+environment variable from a web server, so you need to put the following
+line in gitweb configuration file (`/etc/gitweb.conf` in above example):
+--------------------------------------------------------------------------
+$projectroot = $ENV{'GITWEB_PROJECTROOT'} || "/pub/git";
+--------------------------------------------------------------------------
+*Note* that this requires to be set for each request, so either
+`$per_request_config` must be false, or the above must be put in code
+referenced by `$per_request_config`;
+
+These configurations enable two things. First, each unix user (`<user>`) of
+the server will be able to browse through gitweb Git repositories found in
+`~/public_git/` with the following url:
+
+  http://git.example.org/~<user>/
+
+If you do not want this feature on your server just remove the second
+rewrite rule.
+
+If you already use `mod_userdir` in your virtual host or you don't want to
+use the \'~' as first character, just comment or remove the second rewrite
+rule, and uncomment one of the following according to what you want.
+
+Second, repositories found in `/pub/scm/` and `/var/git/` will be accessible
+through `http://git.example.org/scm/` and `http://git.example.org/var/`.
+You can add as many project roots as you want by adding rewrite rules like
+the third and the fourth.
+
+
+PATH_INFO usage
+~~~~~~~~~~~~~~~
+If you enable PATH_INFO usage in gitweb by putting
+----------------------------------------------------------------------------
+$feature{'pathinfo'}{'default'} = [1];
+----------------------------------------------------------------------------
+in your gitweb configuration file, it is possible to set up your server so
+that it consumes and produces URLs in the form
+
+  http://git.example.com/project.git/shortlog/sometag
+
+i.e. without 'gitweb.cgi' part, by using a configuration such as the
+following.  This configuration assumes that `/var/www/gitweb` is the
+DocumentRoot of your webserver, contains the gitweb.cgi script and
+complementary static files (stylesheet, favicon, JavaScript):
+
+----------------------------------------------------------------------------
+<VirtualHost *:80>
+	ServerAlias git.example.com
+
+	DocumentRoot /var/www/gitweb
+
+	<Directory /var/www/gitweb>
+		Options ExecCGI
+		AddHandler cgi-script cgi
+
+		DirectoryIndex gitweb.cgi
+
+		RewriteEngine On
+		RewriteCond %{REQUEST_FILENAME} !-f
+		RewriteCond %{REQUEST_FILENAME} !-d
+		RewriteRule ^.* /gitweb.cgi/$0 [L,PT]
+	</Directory>
+</VirtualHost>
+----------------------------------------------------------------------------
+The rewrite rule guarantees that existing static files will be properly
+served, whereas any other URL will be passed to gitweb as PATH_INFO
+parameter.
+
+*Notice* that in this case you don't need special settings for
+`@stylesheets`, `$my_uri` and `$home_link`, but you lose "dumb client"
+access to your project .git dirs (described in "Single URL for gitweb and
+for fetching" section).  A possible workaround for the latter is the
+following: in your project root dir (e.g. `/pub/git`) have the projects
+named *without* a .git extension (e.g. `/pub/git/project` instead of
+`/pub/git/project.git`) and configure Apache as follows:
+----------------------------------------------------------------------------
+<VirtualHost *:80>
+	ServerAlias git.example.com
+
+	DocumentRoot /var/www/gitweb
+
+	AliasMatch ^(/.*?)(\.git)(/.*)?$ /pub/git$1$3
+	<Directory /var/www/gitweb>
+		Options ExecCGI
+		AddHandler cgi-script cgi
+
+		DirectoryIndex gitweb.cgi
+
+		RewriteEngine On
+		RewriteCond %{REQUEST_FILENAME} !-f
+		RewriteCond %{REQUEST_FILENAME} !-d
+		RewriteRule ^.* /gitweb.cgi/$0 [L,PT]
+	</Directory>
+</VirtualHost>
+----------------------------------------------------------------------------
+
+The additional AliasMatch makes it so that
+
+  http://git.example.com/project.git
+
+will give raw access to the project's Git dir (so that the project can be
+cloned), while
+
+  http://git.example.com/project
+
+will provide human-friendly gitweb access.
+
+This solution is not 100% bulletproof, in the sense that if some project has
+a named ref (branch, tag) starting with `git/`, then paths such as
+
+  http://git.example.com/project/command/abranch..git/abranch
+
+will fail with a 404 error.
+
+
+BUGS
+----
+Please report any bugs or feature requests to git@vger.kernel.org,
+putting "gitweb" in the subject of email.
+
+SEE ALSO
+--------
+linkgit:gitweb.conf[5], linkgit:git-instaweb[1]
+
+`gitweb/README`, `gitweb/INSTALL`
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/gitworkflows.txt b/third_party/git/Documentation/gitworkflows.txt
new file mode 100644
index 0000000000..abc0dc6bc7
--- /dev/null
+++ b/third_party/git/Documentation/gitworkflows.txt
@@ -0,0 +1,479 @@
+gitworkflows(7)
+===============
+
+NAME
+----
+gitworkflows - An overview of recommended workflows with Git
+
+SYNOPSIS
+--------
+[verse]
+git *
+
+
+DESCRIPTION
+-----------
+
+This document attempts to write down and motivate some of the workflow
+elements used for `git.git` itself.  Many ideas apply in general,
+though the full workflow is rarely required for smaller projects with
+fewer people involved.
+
+We formulate a set of 'rules' for quick reference, while the prose
+tries to motivate each of them.  Do not always take them literally;
+you should value good reasons for your actions higher than manpages
+such as this one.
+
+
+SEPARATE CHANGES
+----------------
+
+As a general rule, you should try to split your changes into small
+logical steps, and commit each of them.  They should be consistent,
+working independently of any later commits, pass the test suite, etc.
+This makes the review process much easier, and the history much more
+useful for later inspection and analysis, for example with
+linkgit:git-blame[1] and linkgit:git-bisect[1].
+
+To achieve this, try to split your work into small steps from the very
+beginning. It is always easier to squash a few commits together than
+to split one big commit into several.  Don't be afraid of making too
+small or imperfect steps along the way. You can always go back later
+and edit the commits with `git rebase --interactive` before you
+publish them.  You can use `git stash push --keep-index` to run the
+test suite independent of other uncommitted changes; see the EXAMPLES
+section of linkgit:git-stash[1].
+
+
+MANAGING BRANCHES
+-----------------
+
+There are two main tools that can be used to include changes from one
+branch on another: linkgit:git-merge[1] and
+linkgit:git-cherry-pick[1].
+
+Merges have many advantages, so we try to solve as many problems as
+possible with merges alone.  Cherry-picking is still occasionally
+useful; see "Merging upwards" below for an example.
+
+Most importantly, merging works at the branch level, while
+cherry-picking works at the commit level.  This means that a merge can
+carry over the changes from 1, 10, or 1000 commits with equal ease,
+which in turn means the workflow scales much better to a large number
+of contributors (and contributions).  Merges are also easier to
+understand because a merge commit is a "promise" that all changes from
+all its parents are now included.
+
+There is a tradeoff of course: merges require a more careful branch
+management.  The following subsections discuss the important points.
+
+
+Graduation
+~~~~~~~~~~
+
+As a given feature goes from experimental to stable, it also
+"graduates" between the corresponding branches of the software.
+`git.git` uses the following 'integration branches':
+
+* 'maint' tracks the commits that should go into the next "maintenance
+  release", i.e., update of the last released stable version;
+
+* 'master' tracks the commits that should go into the next release;
+
+* 'next' is intended as a testing branch for topics being tested for
+  stability for master.
+
+There is a fourth official branch that is used slightly differently:
+
+* 'pu' (proposed updates) is an integration branch for things that are
+  not quite ready for inclusion yet (see "Integration Branches"
+  below).
+
+Each of the four branches is usually a direct descendant of the one
+above it.
+
+Conceptually, the feature enters at an unstable branch (usually 'next'
+or 'pu'), and "graduates" to 'master' for the next release once it is
+considered stable enough.
+
+
+Merging upwards
+~~~~~~~~~~~~~~~
+
+The "downwards graduation" discussed above cannot be done by actually
+merging downwards, however, since that would merge 'all' changes on
+the unstable branch into the stable one.  Hence the following:
+
+.Merge upwards
+[caption="Rule: "]
+=====================================
+Always commit your fixes to the oldest supported branch that requires
+them.  Then (periodically) merge the integration branches upwards into each
+other.
+=====================================
+
+This gives a very controlled flow of fixes.  If you notice that you
+have applied a fix to e.g. 'master' that is also required in 'maint',
+you will need to cherry-pick it (using linkgit:git-cherry-pick[1])
+downwards.  This will happen a few times and is nothing to worry about
+unless you do it very frequently.
+
+
+Topic branches
+~~~~~~~~~~~~~~
+
+Any nontrivial feature will require several patches to implement, and
+may get extra bugfixes or improvements during its lifetime.
+
+Committing everything directly on the integration branches leads to many
+problems: Bad commits cannot be undone, so they must be reverted one
+by one, which creates confusing histories and further error potential
+when you forget to revert part of a group of changes.  Working in
+parallel mixes up the changes, creating further confusion.
+
+Use of "topic branches" solves these problems.  The name is pretty
+self explanatory, with a caveat that comes from the "merge upwards"
+rule above:
+
+.Topic branches
+[caption="Rule: "]
+=====================================
+Make a side branch for every topic (feature, bugfix, ...). Fork it off
+at the oldest integration branch that you will eventually want to merge it
+into.
+=====================================
+
+Many things can then be done very naturally:
+
+* To get the feature/bugfix into an integration branch, simply merge
+  it.  If the topic has evolved further in the meantime, merge again.
+  (Note that you do not necessarily have to merge it to the oldest
+  integration branch first.  For example, you can first merge a bugfix
+  to 'next', give it some testing time, and merge to 'maint' when you
+  know it is stable.)
+
+* If you find you need new features from the branch 'other' to continue
+  working on your topic, merge 'other' to 'topic'.  (However, do not
+  do this "just habitually", see below.)
+
+* If you find you forked off the wrong branch and want to move it
+  "back in time", use linkgit:git-rebase[1].
+
+Note that the last point clashes with the other two: a topic that has
+been merged elsewhere should not be rebased.  See the section on
+RECOVERING FROM UPSTREAM REBASE in linkgit:git-rebase[1].
+
+We should point out that "habitually" (regularly for no real reason)
+merging an integration branch into your topics -- and by extension,
+merging anything upstream into anything downstream on a regular basis
+-- is frowned upon:
+
+.Merge to downstream only at well-defined points
+[caption="Rule: "]
+=====================================
+Do not merge to downstream except with a good reason: upstream API
+changes affect your branch; your branch no longer merges to upstream
+cleanly; etc.
+=====================================
+
+Otherwise, the topic that was merged to suddenly contains more than a
+single (well-separated) change.  The many resulting small merges will
+greatly clutter up history.  Anyone who later investigates the history
+of a file will have to find out whether that merge affected the topic
+in development.  An upstream might even inadvertently be merged into a
+"more stable" branch.  And so on.
+
+
+Throw-away integration
+~~~~~~~~~~~~~~~~~~~~~~
+
+If you followed the last paragraph, you will now have many small topic
+branches, and occasionally wonder how they interact.  Perhaps the
+result of merging them does not even work?  But on the other hand, we
+want to avoid merging them anywhere "stable" because such merges
+cannot easily be undone.
+
+The solution, of course, is to make a merge that we can undo: merge
+into a throw-away branch.
+
+.Throw-away integration branches
+[caption="Rule: "]
+=====================================
+To test the interaction of several topics, merge them into a
+throw-away branch.  You must never base any work on such a branch!
+=====================================
+
+If you make it (very) clear that this branch is going to be deleted
+right after the testing, you can even publish this branch, for example
+to give the testers a chance to work with it, or other developers a
+chance to see if their in-progress work will be compatible.  `git.git`
+has such an official throw-away integration branch called 'pu'.
+
+
+Branch management for a release
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Assuming you are using the merge approach discussed above, when you
+are releasing your project you will need to do some additional branch
+management work.
+
+A feature release is created from the 'master' branch, since 'master'
+tracks the commits that should go into the next feature release.
+
+The 'master' branch is supposed to be a superset of 'maint'. If this
+condition does not hold, then 'maint' contains some commits that
+are not included on 'master'. The fixes represented by those commits
+will therefore not be included in your feature release.
+
+To verify that 'master' is indeed a superset of 'maint', use git log:
+
+.Verify 'master' is a superset of 'maint'
+[caption="Recipe: "]
+=====================================
+`git log master..maint`
+=====================================
+
+This command should not list any commits.  Otherwise, check out
+'master' and merge 'maint' into it.
+
+Now you can proceed with the creation of the feature release. Apply a
+tag to the tip of 'master' indicating the release version:
+
+.Release tagging
+[caption="Recipe: "]
+=====================================
+`git tag -s -m "Git X.Y.Z" vX.Y.Z master`
+=====================================
+
+You need to push the new tag to a public Git server (see
+"DISTRIBUTED WORKFLOWS" below). This makes the tag available to
+others tracking your project. The push could also trigger a
+post-update hook to perform release-related items such as building
+release tarballs and preformatted documentation pages.
+
+Similarly, for a maintenance release, 'maint' is tracking the commits
+to be released. Therefore, in the steps above simply tag and push
+'maint' rather than 'master'.
+
+
+Maintenance branch management after a feature release
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+After a feature release, you need to manage your maintenance branches.
+
+First, if you wish to continue to release maintenance fixes for the
+feature release made before the recent one, then you must create
+another branch to track commits for that previous release.
+
+To do this, the current maintenance branch is copied to another branch
+named with the previous release version number (e.g. maint-X.Y.(Z-1)
+where X.Y.Z is the current release).
+
+.Copy maint
+[caption="Recipe: "]
+=====================================
+`git branch maint-X.Y.(Z-1) maint`
+=====================================
+
+The 'maint' branch should now be fast-forwarded to the newly released
+code so that maintenance fixes can be tracked for the current release:
+
+.Update maint to new release
+[caption="Recipe: "]
+=====================================
+* `git checkout maint`
+* `git merge --ff-only master`
+=====================================
+
+If the merge fails because it is not a fast-forward, then it is
+possible some fixes on 'maint' were missed in the feature release.
+This will not happen if the content of the branches was verified as
+described in the previous section.
+
+
+Branch management for next and pu after a feature release
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+After a feature release, the integration branch 'next' may optionally be
+rewound and rebuilt from the tip of 'master' using the surviving
+topics on 'next':
+
+.Rewind and rebuild next
+[caption="Recipe: "]
+=====================================
+* `git switch -C next master`
+* `git merge ai/topic_in_next1`
+* `git merge ai/topic_in_next2`
+* ...
+=====================================
+
+The advantage of doing this is that the history of 'next' will be
+clean. For example, some topics merged into 'next' may have initially
+looked promising, but were later found to be undesirable or premature.
+In such a case, the topic is reverted out of 'next' but the fact
+remains in the history that it was once merged and reverted. By
+recreating 'next', you give another incarnation of such topics a clean
+slate to retry, and a feature release is a good point in history to do
+so.
+
+If you do this, then you should make a public announcement indicating
+that 'next' was rewound and rebuilt.
+
+The same rewind and rebuild process may be followed for 'pu'. A public
+announcement is not necessary since 'pu' is a throw-away branch, as
+described above.
+
+
+DISTRIBUTED WORKFLOWS
+---------------------
+
+After the last section, you should know how to manage topics.  In
+general, you will not be the only person working on the project, so
+you will have to share your work.
+
+Roughly speaking, there are two important workflows: merge and patch.
+The important difference is that the merge workflow can propagate full
+history, including merges, while patches cannot.  Both workflows can
+be used in parallel: in `git.git`, only subsystem maintainers use
+the merge workflow, while everyone else sends patches.
+
+Note that the maintainer(s) may impose restrictions, such as
+"Signed-off-by" requirements, that all commits/patches submitted for
+inclusion must adhere to.  Consult your project's documentation for
+more information.
+
+
+Merge workflow
+~~~~~~~~~~~~~~
+
+The merge workflow works by copying branches between upstream and
+downstream.  Upstream can merge contributions into the official
+history; downstream base their work on the official history.
+
+There are three main tools that can be used for this:
+
+* linkgit:git-push[1] copies your branches to a remote repository,
+  usually to one that can be read by all involved parties;
+
+* linkgit:git-fetch[1] that copies remote branches to your repository;
+  and
+
+* linkgit:git-pull[1] that does fetch and merge in one go.
+
+Note the last point.  Do 'not' use 'git pull' unless you actually want
+to merge the remote branch.
+
+Getting changes out is easy:
+
+.Push/pull: Publishing branches/topics
+[caption="Recipe: "]
+=====================================
+`git push <remote> <branch>` and tell everyone where they can fetch
+from.
+=====================================
+
+You will still have to tell people by other means, such as mail.  (Git
+provides the linkgit:git-request-pull[1] to send preformatted pull
+requests to upstream maintainers to simplify this task.)
+
+If you just want to get the newest copies of the integration branches,
+staying up to date is easy too:
+
+.Push/pull: Staying up to date
+[caption="Recipe: "]
+=====================================
+Use `git fetch <remote>` or `git remote update` to stay up to date.
+=====================================
+
+Then simply fork your topic branches from the stable remotes as
+explained earlier.
+
+If you are a maintainer and would like to merge other people's topic
+branches to the integration branches, they will typically send a
+request to do so by mail.  Such a request looks like
+
+-------------------------------------
+Please pull from
+    <url> <branch>
+-------------------------------------
+
+In that case, 'git pull' can do the fetch and merge in one go, as
+follows.
+
+.Push/pull: Merging remote topics
+[caption="Recipe: "]
+=====================================
+`git pull <url> <branch>`
+=====================================
+
+Occasionally, the maintainer may get merge conflicts when they try to
+pull changes from downstream.  In this case, they can ask downstream to
+do the merge and resolve the conflicts themselves (perhaps they will
+know better how to resolve them).  It is one of the rare cases where
+downstream 'should' merge from upstream.
+
+
+Patch workflow
+~~~~~~~~~~~~~~
+
+If you are a contributor that sends changes upstream in the form of
+emails, you should use topic branches as usual (see above).  Then use
+linkgit:git-format-patch[1] to generate the corresponding emails
+(highly recommended over manually formatting them because it makes the
+maintainer's life easier).
+
+.format-patch/am: Publishing branches/topics
+[caption="Recipe: "]
+=====================================
+* `git format-patch -M upstream..topic` to turn them into preformatted
+  patch files
+* `git send-email --to=<recipient> <patches>`
+=====================================
+
+See the linkgit:git-format-patch[1] and linkgit:git-send-email[1]
+manpages for further usage notes.
+
+If the maintainer tells you that your patch no longer applies to the
+current upstream, you will have to rebase your topic (you cannot use a
+merge because you cannot format-patch merges):
+
+.format-patch/am: Keeping topics up to date
+[caption="Recipe: "]
+=====================================
+`git pull --rebase <url> <branch>`
+=====================================
+
+You can then fix the conflicts during the rebase.  Presumably you have
+not published your topic other than by mail, so rebasing it is not a
+problem.
+
+If you receive such a patch series (as maintainer, or perhaps as a
+reader of the mailing list it was sent to), save the mails to files,
+create a new topic branch and use 'git am' to import the commits:
+
+.format-patch/am: Importing patches
+[caption="Recipe: "]
+=====================================
+`git am < patch`
+=====================================
+
+One feature worth pointing out is the three-way merge, which can help
+if you get conflicts: `git am -3` will use index information contained
+in patches to figure out the merge base.  See linkgit:git-am[1] for
+other options.
+
+
+SEE ALSO
+--------
+linkgit:gittutorial[7],
+linkgit:git-push[1],
+linkgit:git-pull[1],
+linkgit:git-merge[1],
+linkgit:git-rebase[1],
+linkgit:git-format-patch[1],
+linkgit:git-send-email[1],
+linkgit:git-am[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/third_party/git/Documentation/glossary-content.txt b/third_party/git/Documentation/glossary-content.txt
new file mode 100644
index 0000000000..090c888335
--- /dev/null
+++ b/third_party/git/Documentation/glossary-content.txt
@@ -0,0 +1,671 @@
+[[def_alternate_object_database]]alternate object database::
+	Via the alternates mechanism, a <<def_repository,repository>>
+	can inherit part of its <<def_object_database,object database>>
+	from another object database, which is called an "alternate".
+
+[[def_bare_repository]]bare repository::
+	A bare repository is normally an appropriately
+	named <<def_directory,directory>> with a `.git` suffix that does not
+	have a locally checked-out copy of any of the files under
+	revision control. That is, all of the Git
+	administrative and control files that would normally be present in the
+	hidden `.git` sub-directory are directly present in the
+	`repository.git` directory instead,
+	and no other files are present and checked out. Usually publishers of
+	public repositories make bare repositories available.
+
+[[def_blob_object]]blob object::
+	Untyped <<def_object,object>>, e.g. the contents of a file.
+
+[[def_branch]]branch::
+	A "branch" is an active line of development.  The most recent
+	<<def_commit,commit>> on a branch is referred to as the tip of
+	that branch.  The tip of the branch is referenced by a branch
+	<<def_head,head>>, which moves forward as additional development
+	is done on the branch.  A single Git
+	<<def_repository,repository>> can track an arbitrary number of
+	branches, but your <<def_working_tree,working tree>> is
+	associated with just one of them (the "current" or "checked out"
+	branch), and <<def_HEAD,HEAD>> points to that branch.
+
+[[def_cache]]cache::
+	Obsolete for: <<def_index,index>>.
+
+[[def_chain]]chain::
+	A list of objects, where each <<def_object,object>> in the list contains
+	a reference to its successor (for example, the successor of a
+	<<def_commit,commit>> could be one of its <<def_parent,parents>>).
+
+[[def_changeset]]changeset::
+	BitKeeper/cvsps speak for "<<def_commit,commit>>". Since Git does not
+	store changes, but states, it really does not make sense to use the term
+	"changesets" with Git.
+
+[[def_checkout]]checkout::
+	The action of updating all or part of the
+	<<def_working_tree,working tree>> with a <<def_tree_object,tree object>>
+	or <<def_blob_object,blob>> from the
+	<<def_object_database,object database>>, and updating the
+	<<def_index,index>> and <<def_HEAD,HEAD>> if the whole working tree has
+	been pointed at a new <<def_branch,branch>>.
+
+[[def_cherry-picking]]cherry-picking::
+	In <<def_SCM,SCM>> jargon, "cherry pick" means to choose a subset of
+	changes out of a series of changes (typically commits) and record them
+	as a new series of changes on top of a different codebase. In Git, this is
+	performed by the "git cherry-pick" command to extract the change introduced
+	by an existing <<def_commit,commit>> and to record it based on the tip
+	of the current <<def_branch,branch>> as a new commit.
+
+[[def_clean]]clean::
+	A <<def_working_tree,working tree>> is clean, if it
+	corresponds to the <<def_revision,revision>> referenced by the current
+	<<def_head,head>>. Also see "<<def_dirty,dirty>>".
+
+[[def_commit]]commit::
+	As a noun: A single point in the
+	Git history; the entire history of a project is represented as a
+	set of interrelated commits.  The word "commit" is often
+	used by Git in the same places other revision control systems
+	use the words "revision" or "version".  Also used as a short
+	hand for <<def_commit_object,commit object>>.
++
+As a verb: The action of storing a new snapshot of the project's
+state in the Git history, by creating a new commit representing the current
+state of the <<def_index,index>> and advancing <<def_HEAD,HEAD>>
+to point at the new commit.
+
+[[def_commit_object]]commit object::
+	An <<def_object,object>> which contains the information about a
+	particular <<def_revision,revision>>, such as <<def_parent,parents>>, committer,
+	author, date and the <<def_tree_object,tree object>> which corresponds
+	to the top <<def_directory,directory>> of the stored
+	revision.
+
+[[def_commit-ish]]commit-ish (also committish)::
+	A <<def_commit_object,commit object>> or an
+	<<def_object,object>> that can be recursively dereferenced to
+	a commit object.
+	The following are all commit-ishes:
+	a commit object,
+	a <<def_tag_object,tag object>> that points to a commit
+	object,
+	a tag object that points to a tag object that points to a
+	commit object,
+	etc.
+
+[[def_core_git]]core Git::
+	Fundamental data structures and utilities of Git. Exposes only limited
+	source code management tools.
+
+[[def_DAG]]DAG::
+	Directed acyclic graph. The <<def_commit_object,commit objects>> form a
+	directed acyclic graph, because they have parents (directed), and the
+	graph of commit objects is acyclic (there is no <<def_chain,chain>>
+	which begins and ends with the same <<def_object,object>>).
+
+[[def_dangling_object]]dangling object::
+	An <<def_unreachable_object,unreachable object>> which is not
+	<<def_reachable,reachable>> even from other unreachable objects; a
+	dangling object has no references to it from any
+	reference or <<def_object,object>> in the <<def_repository,repository>>.
+
+[[def_detached_HEAD]]detached HEAD::
+	Normally the <<def_HEAD,HEAD>> stores the name of a
+	<<def_branch,branch>>, and commands that operate on the
+	history HEAD represents operate on the history leading to the
+	tip of the branch the HEAD points at.  However, Git also
+	allows you to <<def_checkout,check out>> an arbitrary
+	<<def_commit,commit>> that isn't necessarily the tip of any
+	particular branch.  The HEAD in such a state is called
+	"detached".
++
+Note that commands that operate on the history of the current branch
+(e.g. `git commit` to build a new history on top of it) still work
+while the HEAD is detached. They update the HEAD to point at the tip
+of the updated history without affecting any branch.  Commands that
+update or inquire information _about_ the current branch (e.g. `git
+branch --set-upstream-to` that sets what remote-tracking branch the
+current branch integrates with) obviously do not work, as there is no
+(real) current branch to ask about in this state.
+
+[[def_directory]]directory::
+	The list you get with "ls" :-)
+
+[[def_dirty]]dirty::
+	A <<def_working_tree,working tree>> is said to be "dirty" if
+	it contains modifications which have not been <<def_commit,committed>> to the current
+	<<def_branch,branch>>.
+
+[[def_evil_merge]]evil merge::
+	An evil merge is a <<def_merge,merge>> that introduces changes that
+	do not appear in any <<def_parent,parent>>.
+
+[[def_fast_forward]]fast-forward::
+	A fast-forward is a special type of <<def_merge,merge>> where you have a
+	<<def_revision,revision>> and you are "merging" another
+	<<def_branch,branch>>'s changes that happen to be a descendant of what
+	you have. In such a case, you do not make a new <<def_merge,merge>>
+	<<def_commit,commit>> but instead just update to his
+	revision. This will happen frequently on a
+	<<def_remote_tracking_branch,remote-tracking branch>> of a remote
+	<<def_repository,repository>>.
+
+[[def_fetch]]fetch::
+	Fetching a <<def_branch,branch>> means to get the
+	branch's <<def_head_ref,head ref>> from a remote
+	<<def_repository,repository>>, to find out which objects are
+	missing from the local <<def_object_database,object database>>,
+	and to get them, too.  See also linkgit:git-fetch[1].
+
+[[def_file_system]]file system::
+	Linus Torvalds originally designed Git to be a user space file system,
+	i.e. the infrastructure to hold files and directories. That ensured the
+	efficiency and speed of Git.
+
+[[def_git_archive]]Git archive::
+	Synonym for <<def_repository,repository>> (for arch people).
+
+[[def_gitfile]]gitfile::
+	A plain file `.git` at the root of a working tree that
+	points at the directory that is the real repository.
+
+[[def_grafts]]grafts::
+	Grafts enables two otherwise different lines of development to be joined
+	together by recording fake ancestry information for commits. This way
+	you can make Git pretend the set of <<def_parent,parents>> a <<def_commit,commit>> has
+	is different from what was recorded when the commit was
+	created. Configured via the `.git/info/grafts` file.
++
+Note that the grafts mechanism is outdated and can lead to problems
+transferring objects between repositories; see linkgit:git-replace[1]
+for a more flexible and robust system to do the same thing.
+
+[[def_hash]]hash::
+	In Git's context, synonym for <<def_object_name,object name>>.
+
+[[def_head]]head::
+	A <<def_ref,named reference>> to the <<def_commit,commit>> at the tip of a
+	<<def_branch,branch>>.  Heads are stored in a file in
+	`$GIT_DIR/refs/heads/` directory, except when using packed refs. (See
+	linkgit:git-pack-refs[1].)
+
+[[def_HEAD]]HEAD::
+	The current <<def_branch,branch>>.  In more detail: Your <<def_working_tree,
+	working tree>> is normally derived from the state of the tree
+	referred to by HEAD.  HEAD is a reference to one of the
+	<<def_head,heads>> in your repository, except when using a
+	<<def_detached_HEAD,detached HEAD>>, in which case it directly
+	references an arbitrary commit.
+
+[[def_head_ref]]head ref::
+	A synonym for <<def_head,head>>.
+
+[[def_hook]]hook::
+	During the normal execution of several Git commands, call-outs are made
+	to optional scripts that allow a developer to add functionality or
+	checking. Typically, the hooks allow for a command to be pre-verified
+	and potentially aborted, and allow for a post-notification after the
+	operation is done. The hook scripts are found in the
+	`$GIT_DIR/hooks/` directory, and are enabled by simply
+	removing the `.sample` suffix from the filename. In earlier versions
+	of Git you had to make them executable.
+
+[[def_index]]index::
+	A collection of files with stat information, whose contents are stored
+	as objects. The index is a stored version of your
+	<<def_working_tree,working tree>>. Truth be told, it can also contain a second, and even
+	a third version of a working tree, which are used
+	when <<def_merge,merging>>.
+
+[[def_index_entry]]index entry::
+	The information regarding a particular file, stored in the
+	<<def_index,index>>. An index entry can be unmerged, if a
+	<<def_merge,merge>> was started, but not yet finished (i.e. if
+	the index contains multiple versions of that file).
+
+[[def_master]]master::
+	The default development <<def_branch,branch>>. Whenever you
+	create a Git <<def_repository,repository>>, a branch named
+	"master" is created, and becomes the active branch. In most
+	cases, this contains the local development, though that is
+	purely by convention and is not required.
+
+[[def_merge]]merge::
+	As a verb: To bring the contents of another
+	<<def_branch,branch>> (possibly from an external
+	<<def_repository,repository>>) into the current branch.  In the
+	case where the merged-in branch is from a different repository,
+	this is done by first <<def_fetch,fetching>> the remote branch
+	and then merging the result into the current branch.  This
+	combination of fetch and merge operations is called a
+	<<def_pull,pull>>.  Merging is performed by an automatic process
+	that identifies changes made since the branches diverged, and
+	then applies all those changes together.  In cases where changes
+	conflict, manual intervention may be required to complete the
+	merge.
++
+As a noun: unless it is a <<def_fast_forward,fast-forward>>, a
+successful merge results in the creation of a new <<def_commit,commit>>
+representing the result of the merge, and having as
+<<def_parent,parents>> the tips of the merged <<def_branch,branches>>.
+This commit is referred to as a "merge commit", or sometimes just a
+"merge".
+
+[[def_object]]object::
+	The unit of storage in Git. It is uniquely identified by the
+	<<def_SHA1,SHA-1>> of its contents. Consequently, an
+	object cannot be changed.
+
+[[def_object_database]]object database::
+	Stores a set of "objects", and an individual <<def_object,object>> is
+	identified by its <<def_object_name,object name>>. The objects usually
+	live in `$GIT_DIR/objects/`.
+
+[[def_object_identifier]]object identifier::
+	Synonym for <<def_object_name,object name>>.
+
+[[def_object_name]]object name::
+	The unique identifier of an <<def_object,object>>.  The
+	object name is usually represented by a 40 character
+	hexadecimal string.  Also colloquially called <<def_SHA1,SHA-1>>.
+
+[[def_object_type]]object type::
+	One of the identifiers "<<def_commit_object,commit>>",
+	"<<def_tree_object,tree>>", "<<def_tag_object,tag>>" or
+	"<<def_blob_object,blob>>" describing the type of an
+	<<def_object,object>>.
+
+[[def_octopus]]octopus::
+	To <<def_merge,merge>> more than two <<def_branch,branches>>.
+
+[[def_origin]]origin::
+	The default upstream <<def_repository,repository>>. Most projects have
+	at least one upstream project which they track. By default
+	'origin' is used for that purpose. New upstream updates
+	will be fetched into <<def_remote_tracking_branch,remote-tracking branches>> named
+	origin/name-of-upstream-branch, which you can see using
+	`git branch -r`.
+
+[[def_overlay]]overlay::
+	Only update and add files to the working directory, but don't
+	delete them, similar to how 'cp -R' would update the contents
+	in the destination directory.  This is the default mode in a
+	<<def_checkout,checkout>> when checking out files from the
+	<<def_index,index>> or a <<def_tree-ish,tree-ish>>.  In
+	contrast, no-overlay mode also deletes tracked files not
+	present in the source, similar to 'rsync --delete'.
+
+[[def_pack]]pack::
+	A set of objects which have been compressed into one file (to save space
+	or to transmit them efficiently).
+
+[[def_pack_index]]pack index::
+	The list of identifiers, and other information, of the objects in a
+	<<def_pack,pack>>, to assist in efficiently accessing the contents of a
+	pack.
+
+[[def_pathspec]]pathspec::
+	Pattern used to limit paths in Git commands.
++
+Pathspecs are used on the command line of "git ls-files", "git
+ls-tree", "git add", "git grep", "git diff", "git checkout",
+and many other commands to
+limit the scope of operations to some subset of the tree or
+worktree.  See the documentation of each command for whether
+paths are relative to the current directory or toplevel.  The
+pathspec syntax is as follows:
++
+--
+
+* any path matches itself
+* the pathspec up to the last slash represents a
+  directory prefix.  The scope of that pathspec is
+  limited to that subtree.
+* the rest of the pathspec is a pattern for the remainder
+  of the pathname.  Paths relative to the directory
+  prefix will be matched against that pattern using fnmatch(3);
+  in particular, '*' and '?' _can_ match directory separators.
+
+--
++
+For example, Documentation/*.jpg will match all .jpg files
+in the Documentation subtree,
+including Documentation/chapter_1/figure_1.jpg.
++
+A pathspec that begins with a colon `:` has special meaning.  In the
+short form, the leading colon `:` is followed by zero or more "magic
+signature" letters (which optionally is terminated by another colon `:`),
+and the remainder is the pattern to match against the path.
+The "magic signature" consists of ASCII symbols that are neither
+alphanumeric, glob, regex special characters nor colon.
+The optional colon that terminates the "magic signature" can be
+omitted if the pattern begins with a character that does not belong to
+"magic signature" symbol set and is not a colon.
++
+In the long form, the leading colon `:` is followed by an open
+parenthesis `(`, a comma-separated list of zero or more "magic words",
+and a close parentheses `)`, and the remainder is the pattern to match
+against the path.
++
+A pathspec with only a colon means "there is no pathspec". This form
+should not be combined with other pathspec.
++
+--
+top;;
+	The magic word `top` (magic signature: `/`) makes the pattern
+	match from the root of the working tree, even when you are
+	running the command from inside a subdirectory.
+
+literal;;
+	Wildcards in the pattern such as `*` or `?` are treated
+	as literal characters.
+
+icase;;
+	Case insensitive match.
+
+glob;;
+	Git treats the pattern as a shell glob suitable for
+	consumption by fnmatch(3) with the FNM_PATHNAME flag:
+	wildcards in the pattern will not match a / in the pathname.
+	For example, "Documentation/{asterisk}.html" matches
+	"Documentation/git.html" but not "Documentation/ppc/ppc.html"
+	or "tools/perf/Documentation/perf.html".
++
+Two consecutive asterisks ("`**`") in patterns matched against
+full pathname may have special meaning:
+
+ - A leading "`**`" followed by a slash means match in all
+   directories. For example, "`**/foo`" matches file or directory
+   "`foo`" anywhere, the same as pattern "`foo`". "`**/foo/bar`"
+   matches file or directory "`bar`" anywhere that is directly
+   under directory "`foo`".
+
+ - A trailing "`/**`" matches everything inside. For example,
+   "`abc/**`" matches all files inside directory "abc", relative
+   to the location of the `.gitignore` file, with infinite depth.
+
+ - A slash followed by two consecutive asterisks then a slash
+   matches zero or more directories. For example, "`a/**/b`"
+   matches "`a/b`", "`a/x/b`", "`a/x/y/b`" and so on.
+
+ - Other consecutive asterisks are considered invalid.
++
+Glob magic is incompatible with literal magic.
+
+attr;;
+After `attr:` comes a space separated list of "attribute
+requirements", all of which must be met in order for the
+path to be considered a match; this is in addition to the
+usual non-magic pathspec pattern matching.
+See linkgit:gitattributes[5].
++
+Each of the attribute requirements for the path takes one of
+these forms:
+
+- "`ATTR`" requires that the attribute `ATTR` be set.
+
+- "`-ATTR`" requires that the attribute `ATTR` be unset.
+
+- "`ATTR=VALUE`" requires that the attribute `ATTR` be
+  set to the string `VALUE`.
+
+- "`!ATTR`" requires that the attribute `ATTR` be
+  unspecified.
++
+Note that when matching against a tree object, attributes are still
+obtained from working tree, not from the given tree object.
+
+exclude;;
+	After a path matches any non-exclude pathspec, it will be run
+	through all exclude pathspecs (magic signature: `!` or its
+	synonym `^`). If it matches, the path is ignored.  When there
+	is no non-exclude pathspec, the exclusion is applied to the
+	result set as if invoked without any pathspec.
+--
+
+[[def_parent]]parent::
+	A <<def_commit_object,commit object>> contains a (possibly empty) list
+	of the logical predecessor(s) in the line of development, i.e. its
+	parents.
+
+[[def_pickaxe]]pickaxe::
+	The term <<def_pickaxe,pickaxe>> refers to an option to the diffcore
+	routines that help select changes that add or delete a given text
+	string. With the `--pickaxe-all` option, it can be used to view the full
+	<<def_changeset,changeset>> that introduced or removed, say, a
+	particular line of text. See linkgit:git-diff[1].
+
+[[def_plumbing]]plumbing::
+	Cute name for <<def_core_git,core Git>>.
+
+[[def_porcelain]]porcelain::
+	Cute name for programs and program suites depending on
+	<<def_core_git,core Git>>, presenting a high level access to
+	core Git. Porcelains expose more of a <<def_SCM,SCM>>
+	interface than the <<def_plumbing,plumbing>>.
+
+[[def_per_worktree_ref]]per-worktree ref::
+	Refs that are per-<<def_working_tree,worktree>>, rather than
+	global.  This is presently only <<def_HEAD,HEAD>> and any refs
+	that start with `refs/bisect/`, but might later include other
+	unusual refs.
+
+[[def_pseudoref]]pseudoref::
+	Pseudorefs are a class of files under `$GIT_DIR` which behave
+	like refs for the purposes of rev-parse, but which are treated
+	specially by git.  Pseudorefs both have names that are all-caps,
+	and always start with a line consisting of a
+	<<def_SHA1,SHA-1>> followed by whitespace.  So, HEAD is not a
+	pseudoref, because it is sometimes a symbolic ref.  They might
+	optionally contain some additional data.  `MERGE_HEAD` and
+	`CHERRY_PICK_HEAD` are examples.  Unlike
+	<<def_per_worktree_ref,per-worktree refs>>, these files cannot
+	be symbolic refs, and never have reflogs.  They also cannot be
+	updated through the normal ref update machinery.  Instead,
+	they are updated by directly writing to the files.  However,
+	they can be read as if they were refs, so `git rev-parse
+	MERGE_HEAD` will work.
+
+[[def_pull]]pull::
+	Pulling a <<def_branch,branch>> means to <<def_fetch,fetch>> it and
+	<<def_merge,merge>> it.  See also linkgit:git-pull[1].
+
+[[def_push]]push::
+	Pushing a <<def_branch,branch>> means to get the branch's
+	<<def_head_ref,head ref>> from a remote <<def_repository,repository>>,
+	find out if it is an ancestor to the branch's local
+	head ref, and in that case, putting all
+	objects, which are <<def_reachable,reachable>> from the local
+	head ref, and which are missing from the remote
+	repository, into the remote
+	<<def_object_database,object database>>, and updating the remote
+	head ref. If the remote <<def_head,head>> is not an
+	ancestor to the local head, the push fails.
+
+[[def_reachable]]reachable::
+	All of the ancestors of a given <<def_commit,commit>> are said to be
+	"reachable" from that commit. More
+	generally, one <<def_object,object>> is reachable from
+	another if we can reach the one from the other by a <<def_chain,chain>>
+	that follows <<def_tag,tags>> to whatever they tag,
+	<<def_commit_object,commits>> to their parents or trees, and
+	<<def_tree_object,trees>> to the trees or <<def_blob_object,blobs>>
+	that they contain.
+
+[[def_rebase]]rebase::
+	To reapply a series of changes from a <<def_branch,branch>> to a
+	different base, and reset the <<def_head,head>> of that branch
+	to the result.
+
+[[def_ref]]ref::
+	A name that begins with `refs/` (e.g. `refs/heads/master`)
+	that points to an <<def_object_name,object name>> or another
+	ref (the latter is called a <<def_symref,symbolic ref>>).
+	For convenience, a ref can sometimes be abbreviated when used
+	as an argument to a Git command; see linkgit:gitrevisions[7]
+	for details.
+	Refs are stored in the <<def_repository,repository>>.
++
+The ref namespace is hierarchical.
+Different subhierarchies are used for different purposes (e.g. the
+`refs/heads/` hierarchy is used to represent local branches).
++
+There are a few special-purpose refs that do not begin with `refs/`.
+The most notable example is `HEAD`.
+
+[[def_reflog]]reflog::
+	A reflog shows the local "history" of a ref.  In other words,
+	it can tell you what the 3rd last revision in _this_ repository
+	was, and what was the current state in _this_ repository,
+	yesterday 9:14pm.  See linkgit:git-reflog[1] for details.
+
+[[def_refspec]]refspec::
+	A "refspec" is used by <<def_fetch,fetch>> and
+	<<def_push,push>> to describe the mapping between remote
+	<<def_ref,ref>> and local ref.
+
+[[def_remote]]remote repository::
+	A <<def_repository,repository>> which is used to track the same
+	project but resides somewhere else. To communicate with remotes,
+	see <<def_fetch,fetch>> or <<def_push,push>>.
+
+[[def_remote_tracking_branch]]remote-tracking branch::
+	A <<def_ref,ref>> that is used to follow changes from another
+	<<def_repository,repository>>. It typically looks like
+	'refs/remotes/foo/bar' (indicating that it tracks a branch named
+	'bar' in a remote named 'foo'), and matches the right-hand-side of
+	a configured fetch <<def_refspec,refspec>>. A remote-tracking
+	branch should not contain direct modifications or have local
+	commits made to it.
+
+[[def_repository]]repository::
+	A collection of <<def_ref,refs>> together with an
+	<<def_object_database,object database>> containing all objects
+	which are <<def_reachable,reachable>> from the refs, possibly
+	accompanied by meta data from one or more <<def_porcelain,porcelains>>. A
+	repository can share an object database with other repositories
+	via <<def_alternate_object_database,alternates mechanism>>.
+
+[[def_resolve]]resolve::
+	The action of fixing up manually what a failed automatic
+	<<def_merge,merge>> left behind.
+
+[[def_revision]]revision::
+	Synonym for <<def_commit,commit>> (the noun).
+
+[[def_rewind]]rewind::
+	To throw away part of the development, i.e. to assign the
+	<<def_head,head>> to an earlier <<def_revision,revision>>.
+
+[[def_SCM]]SCM::
+	Source code management (tool).
+
+[[def_SHA1]]SHA-1::
+	"Secure Hash Algorithm 1"; a cryptographic hash function.
+	In the context of Git used as a synonym for <<def_object_name,object name>>.
+
+[[def_shallow_clone]]shallow clone::
+	Mostly a synonym to <<def_shallow_repository,shallow repository>>
+	but the phrase makes it more explicit that it was created by
+	running `git clone --depth=...` command.
+
+[[def_shallow_repository]]shallow repository::
+	A shallow <<def_repository,repository>> has an incomplete
+	history some of whose <<def_commit,commits>> have <<def_parent,parents>> cauterized away (in other
+	words, Git is told to pretend that these commits do not have the
+	parents, even though they are recorded in the <<def_commit_object,commit
+	object>>). This is sometimes useful when you are interested only in the
+	recent history of a project even though the real history recorded in the
+	upstream is much larger. A shallow repository
+	is created by giving the `--depth` option to linkgit:git-clone[1], and
+	its history can be later deepened with linkgit:git-fetch[1].
+
+[[def_stash]]stash entry::
+	An <<def_object,object>> used to temporarily store the contents of a
+	<<def_dirty,dirty>> working directory and the index for future reuse.
+
+[[def_submodule]]submodule::
+	A <<def_repository,repository>> that holds the history of a
+	separate project inside another repository (the latter of
+	which is called <<def_superproject, superproject>>).
+
+[[def_superproject]]superproject::
+	A <<def_repository,repository>> that references repositories
+	of other projects in its working tree as <<def_submodule,submodules>>.
+	The superproject knows about the names of (but does not hold
+	copies of) commit objects of the contained submodules.
+
+[[def_symref]]symref::
+	Symbolic reference: instead of containing the <<def_SHA1,SHA-1>>
+	id itself, it is of the format 'ref: refs/some/thing' and when
+	referenced, it recursively dereferences to this reference.
+	'<<def_HEAD,HEAD>>' is a prime example of a symref. Symbolic
+	references are manipulated with the linkgit:git-symbolic-ref[1]
+	command.
+
+[[def_tag]]tag::
+	A <<def_ref,ref>> under `refs/tags/` namespace that points to an
+	object of an arbitrary type (typically a tag points to either a
+	<<def_tag_object,tag>> or a <<def_commit_object,commit object>>).
+	In contrast to a <<def_head,head>>, a tag is not updated by
+	the `commit` command. A Git tag has nothing to do with a Lisp
+	tag (which would be called an <<def_object_type,object type>>
+	in Git's context). A tag is most typically used to mark a particular
+	point in the commit ancestry <<def_chain,chain>>.
+
+[[def_tag_object]]tag object::
+	An <<def_object,object>> containing a <<def_ref,ref>> pointing to
+	another object, which can contain a message just like a
+	<<def_commit_object,commit object>>. It can also contain a (PGP)
+	signature, in which case it is called a "signed tag object".
+
+[[def_topic_branch]]topic branch::
+	A regular Git <<def_branch,branch>> that is used by a developer to
+	identify a conceptual line of development. Since branches are very easy
+	and inexpensive, it is often desirable to have several small branches
+	that each contain very well defined concepts or small incremental yet
+	related changes.
+
+[[def_tree]]tree::
+	Either a <<def_working_tree,working tree>>, or a <<def_tree_object,tree
+	object>> together with the dependent <<def_blob_object,blob>> and tree objects
+	(i.e. a stored representation of a working tree).
+
+[[def_tree_object]]tree object::
+	An <<def_object,object>> containing a list of file names and modes along
+	with refs to the associated blob and/or tree objects. A
+	<<def_tree,tree>> is equivalent to a <<def_directory,directory>>.
+
+[[def_tree-ish]]tree-ish (also treeish)::
+	A <<def_tree_object,tree object>> or an <<def_object,object>>
+	that can be recursively dereferenced to a tree object.
+	Dereferencing a <<def_commit_object,commit object>> yields the
+	tree object corresponding to the <<def_revision,revision>>'s
+	top <<def_directory,directory>>.
+	The following are all tree-ishes:
+	a <<def_commit-ish,commit-ish>>,
+	a tree object,
+	a <<def_tag_object,tag object>> that points to a tree object,
+	a tag object that points to a tag object that points to a tree
+	object,
+	etc.
+
+[[def_unmerged_index]]unmerged index::
+	An <<def_index,index>> which contains unmerged
+	<<def_index_entry,index entries>>.
+
+[[def_unreachable_object]]unreachable object::
+	An <<def_object,object>> which is not <<def_reachable,reachable>> from a
+	<<def_branch,branch>>, <<def_tag,tag>>, or any other reference.
+
+[[def_upstream_branch]]upstream branch::
+	The default <<def_branch,branch>> that is merged into the branch in
+	question (or the branch in question is rebased onto). It is configured
+	via branch.<name>.remote and branch.<name>.merge. If the upstream branch
+	of 'A' is 'origin/B' sometimes we say "'A' is tracking 'origin/B'".
+
+[[def_working_tree]]working tree::
+	The tree of actual checked out files.  The working tree normally
+	contains the contents of the <<def_HEAD,HEAD>> commit's tree,
+	plus any local changes that you have made but not yet committed.
diff --git a/third_party/git/Documentation/howto-index.sh b/third_party/git/Documentation/howto-index.sh
new file mode 100755
index 0000000000..167b363668
--- /dev/null
+++ b/third_party/git/Documentation/howto-index.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+
+cat <<\EOF
+Git Howto Index
+===============
+
+Here is a collection of mailing list postings made by various
+people describing how they use Git in their workflow.
+
+EOF
+
+for txt
+do
+	title=$(expr "$txt" : '.*/\(.*\)\.txt$')
+	from=$(sed -ne '
+	/^$/q
+	/^From:[ 	]/{
+		s///
+		s/^[ 	]*//
+		s/[ 	]*$//
+		s/^/by /
+		p
+	}
+	' "$txt")
+
+	abstract=$(sed -ne '
+	/^Abstract:[ 	]/{
+		s/^[^ 	]*//
+		x
+		s/.*//
+		x
+		: again
+		/^[ 	]/{
+			s/^[ 	]*//
+			H
+			n
+			b again
+		}
+		x
+		p
+		q
+	}' "$txt")
+
+	if grep 'Content-type: text/asciidoc' >/dev/null $txt
+	then
+		file=$(expr "$txt" : '\(.*\)\.txt$').html
+	else
+		file="$txt"
+	fi
+
+	echo "* link:$file[$title] $from
+$abstract
+
+"
+
+done
diff --git a/third_party/git/Documentation/howto/keep-canonical-history-correct.txt b/third_party/git/Documentation/howto/keep-canonical-history-correct.txt
new file mode 100644
index 0000000000..35d48ef714
--- /dev/null
+++ b/third_party/git/Documentation/howto/keep-canonical-history-correct.txt
@@ -0,0 +1,216 @@
+From: Junio C Hamano <gitster@pobox.com>
+Date: Wed, 07 May 2014 13:15:39 -0700
+Subject: Beginner question on "Pull is mostly evil"
+Abstract: This how-to explains a method for keeping a
+ project's history correct when using git pull.
+Content-type: text/asciidoc
+
+Keep authoritative canonical history correct with git pull
+==========================================================
+
+Sometimes a new project integrator will end up with project history
+that appears to be "backwards" from what other project developers
+expect. This howto presents a suggested integration workflow for
+maintaining a central repository.
+
+Suppose that that central repository has this history:
+
+------------
+    ---o---o---A
+------------
+
+which ends at commit `A` (time flows from left to right and each node
+in the graph is a commit, lines between them indicating parent-child
+relationship).
+
+Then you clone it and work on your own commits, which leads you to
+have this history in *your* repository:
+
+------------
+    ---o---o---A---B---C
+------------
+
+Imagine your coworker did the same and built on top of `A` in *his*
+repository in the meantime, and then pushed it to the
+central repository:
+
+------------
+    ---o---o---A---X---Y---Z
+------------
+
+Now, if you `git push` at this point, because your history that leads
+to `C` lacks `X`, `Y` and `Z`, it will fail.  You need to somehow make
+the tip of your history a descendant of `Z`.
+
+One suggested way to solve the problem is "fetch and then merge", aka
+`git pull`. When you fetch, your repository will have a history like
+this:
+
+------------
+    ---o---o---A---B---C
+		\
+		 X---Y---Z
+------------
+
+Once you run merge after that, while still on *your* branch, i.e. `C`,
+you will create a merge `M` and make the history look like this:
+
+------------
+    ---o---o---A---B---C---M
+		\         /
+		 X---Y---Z
+------------
+
+`M` is a descendant of `Z`, so you can push to update the central
+repository.  Such a merge `M` does not lose any commit in both
+histories, so in that sense it may not be wrong, but when people want
+to talk about "the authoritative canonical history that is shared
+among the project participants", i.e. "the trunk", they often view
+it as "commits you see by following the first-parent chain", and use
+this command to view it:
+
+------------
+    $ git log --first-parent
+------------
+
+For all other people who observed the central repository after your
+coworker pushed `Z` but before you pushed `M`, the commit on the trunk
+used to be `o-o-A-X-Y-Z`.  But because you made `M` while you were on
+`C`, `M`'s first parent is `C`, so by pushing `M` to advance the
+central repository, you made `X-Y-Z` a side branch, not on the trunk.
+
+You would rather want to have a history of this shape:
+
+------------
+    ---o---o---A---X---Y---Z---M'
+		\             /
+		 B-----------C
+------------
+
+so that in the first-parent chain, it is clear that the project first
+did `X` and then `Y` and then `Z` and merged a change that consists of
+two commits `B` and `C` that achieves a single goal.  You may have
+worked on fixing the bug #12345 with these two patches, and the merge
+`M'` with swapped parents can say in its log message "Merge
+fix-bug-12345". Having a way to tell `git pull` to create a merge
+but record the parents in reverse order may be a way to do so.
+
+Note that I said "achieves a single goal" above, because this is
+important.  "Swapping the merge order" only covers a special case
+where the project does not care too much about having unrelated
+things done on a single merge but cares a lot about first-parent
+chain.
+
+There are multiple schools of thought about the "trunk" management.
+
+ 1. Some projects want to keep a completely linear history without any
+    merges.  Obviously, swapping the merge order would not match their
+    taste.  You would need to flatten your history on top of the
+    updated upstream to result in a history of this shape instead:
++
+------------
+    ---o---o---A---X---Y---Z---B---C
+------------
++
+with `git pull --rebase` or something.
+
+ 2. Some projects tolerate merges in their history, but do not worry
+    too much about the first-parent order, and allow fast-forward
+    merges.  To them, swapping the merge order does not hurt, but
+    it is unnecessary.
+
+ 3. Some projects want each commit on the "trunk" to do one single
+    thing.  The output of `git log --first-parent` in such a project
+    would show either a merge of a side branch that completes a single
+    theme, or a single commit that completes a single theme by itself.
+    If your two commits `B` and `C` (or they may even be two groups of
+    commits) were solving two independent issues, then the merge `M'`
+    we made in the earlier example by swapping the merge order is
+    still not up to the project standard.  It merges two unrelated
+    efforts `B` and `C` at the same time.
+
+For projects in the last category (Git itself is one of them),
+individual developers would want to prepare a history more like
+this:
+
+------------
+		 C0--C1--C2     topic-c
+		/
+    ---o---o---A                master
+		\
+		 B0--B1--B2     topic-b
+------------
+
+That is, keeping separate topics on separate branches, perhaps like
+so:
+
+------------
+    $ git clone $URL work && cd work
+    $ git checkout -b topic-b master
+    $ ... work to create B0, B1 and B2 to complete one theme
+    $ git checkout -b topic-c master
+    $ ... same for the theme of topic-c
+------------
+
+And then
+
+------------
+    $ git checkout master
+    $ git pull --ff-only
+------------
+
+would grab `X`, `Y` and `Z` from the upstream and advance your master
+branch:
+
+------------
+		 C0--C1--C2     topic-c
+		/
+    ---o---o---A---X---Y---Z    master
+		\
+		 B0--B1--B2     topic-b
+------------
+
+And then you would merge these two branches separately:
+
+------------
+    $ git merge topic-b
+    $ git merge topic-c
+------------
+
+to result in
+
+------------
+		 C0--C1---------C2
+		/                 \
+    ---o---o---A---X---Y---Z---M---N
+		\             /
+		 B0--B1-----B2
+------------
+
+and push it back to the central repository.
+
+It is very much possible that while you are merging topic-b and
+topic-c, somebody again advanced the history in the central repository
+to put `W` on top of `Z`, and make your `git push` fail.
+
+In such a case, you would rewind to discard `M` and `N`, update the
+tip of your 'master' again and redo the two merges:
+
+------------
+    $ git reset --hard origin/master
+    $ git pull --ff-only
+    $ git merge topic-b
+    $ git merge topic-c
+------------
+
+The procedure will result in a history that looks like this:
+
+------------
+		 C0--C1--------------C2
+		/                     \
+    ---o---o---A---X---Y---Z---W---M'--N'
+		\                 /
+		 B0--B1---------B2
+------------
+
+See also http://git-blame.blogspot.com/2013/09/fun-with-first-parent-history.html
diff --git a/third_party/git/Documentation/howto/maintain-git.txt b/third_party/git/Documentation/howto/maintain-git.txt
new file mode 100644
index 0000000000..ca4378740c
--- /dev/null
+++ b/third_party/git/Documentation/howto/maintain-git.txt
@@ -0,0 +1,449 @@
+From: Junio C Hamano <gitster@pobox.com>
+Date: Wed, 21 Nov 2007 16:32:55 -0800
+Subject: Addendum to "MaintNotes"
+Abstract: Imagine that Git development is racing along as usual, when our friendly
+ neighborhood maintainer is struck down by a wayward bus. Out of the
+ hordes of suckers (loyal developers), you have been tricked (chosen) to
+ step up as the new maintainer. This howto will show you "how to" do it.
+Content-type: text/asciidoc
+
+How to maintain Git
+===================
+
+Activities
+----------
+
+The maintainer's Git time is spent on three activities.
+
+ - Communication (45%)
+
+   Mailing list discussions on general design, fielding user
+   questions, diagnosing bug reports; reviewing, commenting on,
+   suggesting alternatives to, and rejecting patches.
+
+ - Integration (50%)
+
+   Applying new patches from the contributors while spotting and
+   correcting minor mistakes, shuffling the integration and
+   testing branches, pushing the results out, cutting the
+   releases, and making announcements.
+
+ - Own development (5%)
+
+   Scratching my own itch and sending proposed patch series out.
+
+The Policy
+----------
+
+The policy on Integration is informally mentioned in "A Note
+from the maintainer" message, which is periodically posted to
+this mailing list after each feature release is made.
+
+ - Feature releases are numbered as vX.Y.0 and are meant to
+   contain bugfixes and enhancements in any area, including
+   functionality, performance and usability, without regression.
+
+ - One release cycle for a feature release is expected to last for
+   eight to ten weeks.
+
+ - Maintenance releases are numbered as vX.Y.Z and are meant
+   to contain only bugfixes for the corresponding vX.Y.0 feature
+   release and earlier maintenance releases vX.Y.W (W < Z).
+
+ - 'master' branch is used to prepare for the next feature
+   release. In other words, at some point, the tip of 'master'
+   branch is tagged with vX.Y.0.
+
+ - 'maint' branch is used to prepare for the next maintenance
+   release.  After the feature release vX.Y.0 is made, the tip
+   of 'maint' branch is set to that release, and bugfixes will
+   accumulate on the branch, and at some point, the tip of the
+   branch is tagged with vX.Y.1, vX.Y.2, and so on.
+
+ - 'next' branch is used to publish changes (both enhancements
+   and fixes) that (1) have worthwhile goal, (2) are in a fairly
+   good shape suitable for everyday use, (3) but have not yet
+   demonstrated to be regression free.  New changes are tested
+   in 'next' before merged to 'master'.
+
+ - 'pu' branch is used to publish other proposed changes that do
+   not yet pass the criteria set for 'next'.
+
+ - The tips of 'master' and 'maint' branches will not be rewound to
+   allow people to build their own customization on top of them.
+   Early in a new development cycle, 'next' is rewound to the tip of
+   'master' once, but otherwise it will not be rewound until the end
+   of the cycle.
+
+ - Usually 'master' contains all of 'maint' and 'next' contains all
+   of 'master'.  'pu' contains all the topics merged to 'next', but
+   is rebuilt directly on 'master'.
+
+ - The tip of 'master' is meant to be more stable than any
+   tagged releases, and the users are encouraged to follow it.
+
+ - The 'next' branch is where new action takes place, and the
+   users are encouraged to test it so that regressions and bugs
+   are found before new topics are merged to 'master'.
+
+Note that before v1.9.0 release, the version numbers used to be
+structured slightly differently.  vX.Y.Z were feature releases while
+vX.Y.Z.W were maintenance releases for vX.Y.Z.
+
+
+A Typical Git Day
+-----------------
+
+A typical Git day for the maintainer implements the above policy
+by doing the following:
+
+ - Scan mailing list.  Respond with review comments, suggestions
+   etc.  Kibitz.  Collect potentially usable patches from the
+   mailing list.  Patches about a single topic go to one mailbox (I
+   read my mail in Gnus, and type \C-o to save/append messages in
+   files in mbox format).
+
+ - Write his own patches to address issues raised on the list but
+   nobody has stepped up solving.  Send it out just like other
+   contributors do, and pick them up just like patches from other
+   contributors (see above).
+
+ - Review the patches in the saved mailboxes.  Edit proposed log
+   message for typofixes and clarifications, and add Acks
+   collected from the list.  Edit patch to incorporate "Oops,
+   that should have been like this" fixes from the discussion.
+
+ - Classify the collected patches and handle 'master' and
+   'maint' updates:
+
+   - Obviously correct fixes that pertain to the tip of 'maint'
+     are directly applied to 'maint'.
+
+   - Obviously correct fixes that pertain to the tip of 'master'
+     are directly applied to 'master'.
+
+   - Other topics are not handled in this step.
+
+   This step is done with "git am".
+
+     $ git checkout master    ;# or "git checkout maint"
+     $ git am -sc3 mailbox
+     $ make test
+
+   In practice, almost no patch directly goes to 'master' or
+   'maint'.
+
+ - Review the last issue of "What's cooking" message, review the
+   topics ready for merging (topic->master and topic->maint).  Use
+   "Meta/cook -w" script (where Meta/ contains a checkout of the
+   'todo' branch) to aid this step.
+
+   And perform the merge.  Use "Meta/Reintegrate -e" script (see
+   later) to aid this step.
+
+     $ Meta/cook -w last-issue-of-whats-cooking.mbox
+
+     $ git checkout master    ;# or "git checkout maint"
+     $ echo ai/topic | Meta/Reintegrate -e ;# "git merge ai/topic"
+     $ git log -p ORIG_HEAD.. ;# final review
+     $ git diff ORIG_HEAD..   ;# final review
+     $ make test              ;# final review
+
+ - Handle the remaining patches:
+
+   - Anything unobvious that is applicable to 'master' (in other
+     words, does not depend on anything that is still in 'next'
+     and not in 'master') is applied to a new topic branch that
+     is forked from the tip of 'master'.  This includes both
+     enhancements and unobvious fixes to 'master'.  A topic
+     branch is named as ai/topic where "ai" is two-letter string
+     named after author's initial and "topic" is a descriptive name
+     of the topic (in other words, "what's the series is about").
+
+   - An unobvious fix meant for 'maint' is applied to a new
+     topic branch that is forked from the tip of 'maint'.  The
+     topic is named as ai/maint-topic.
+
+   - Changes that pertain to an existing topic are applied to
+     the branch, but:
+
+     - obviously correct ones are applied first;
+
+     - questionable ones are discarded or applied to near the tip;
+
+   - Replacement patches to an existing topic are accepted only
+     for commits not in 'next'.
+
+   The above except the "replacement" are all done with:
+
+     $ git checkout ai/topic ;# or "git checkout -b ai/topic master"
+     $ git am -sc3 mailbox
+
+   while patch replacement is often done by:
+
+     $ git format-patch ai/topic~$n..ai/topic ;# export existing
+
+   then replace some parts with the new patch, and reapplying:
+
+     $ git checkout ai/topic
+     $ git reset --hard ai/topic~$n
+     $ git am -sc3 -s 000*.txt
+
+   The full test suite is always run for 'maint' and 'master'
+   after patch application; for topic branches the tests are run
+   as time permits.
+
+ - Merge maint to master as needed:
+
+     $ git checkout master
+     $ git merge maint
+     $ make test
+
+ - Merge master to next as needed:
+
+     $ git checkout next
+     $ git merge master
+     $ make test
+
+ - Review the last issue of "What's cooking" again and see if topics
+   that are ready to be merged to 'next' are still in good shape
+   (e.g. has there any new issue identified on the list with the
+   series?)
+
+ - Prepare 'jch' branch, which is used to represent somewhere
+   between 'master' and 'pu' and often is slightly ahead of 'next'.
+
+     $ Meta/Reintegrate master..pu >Meta/redo-jch.sh
+
+   The result is a script that lists topics to be merged in order to
+   rebuild 'pu' as the input to Meta/Reintegrate script.  Remove
+   later topics that should not be in 'jch' yet.  Add a line that
+   consists of '### match next' before the name of the first topic
+   in the output that should be in 'jch' but not in 'next' yet.
+
+ - Now we are ready to start merging topics to 'next'.  For each
+   branch whose tip is not merged to 'next', one of three things can
+   happen:
+
+   - The commits are all next-worthy; merge the topic to next;
+   - The new parts are of mixed quality, but earlier ones are
+     next-worthy; merge the early parts to next;
+   - Nothing is next-worthy; do not do anything.
+
+   This step is aided with Meta/redo-jch.sh script created earlier.
+   If a topic that was already in 'next' gained a patch, the script
+   would list it as "ai/topic~1".  To include the new patch to the
+   updated 'next', drop the "~1" part; to keep it excluded, do not
+   touch the line.  If a topic that was not in 'next' should be
+   merged to 'next', add it at the end of the list.  Then:
+
+     $ git checkout -B jch master
+     $ Meta/redo-jch.sh -c1
+
+   to rebuild the 'jch' branch from scratch.  "-c1" tells the script
+   to stop merging at the first line that begins with '###'
+   (i.e. the "### match next" line you added earlier).
+
+   At this point, build-test the result.  It may reveal semantic
+   conflicts (e.g. a topic renamed a variable, another added a new
+   reference to the variable under its old name), in which case
+   prepare an appropriate merge-fix first (see appendix), and
+   rebuild the 'jch' branch from scratch, starting at the tip of
+   'master'.
+
+   Then do the same to 'next'
+
+     $ git checkout next
+     $ sh Meta/redo-jch.sh -c1 -e
+
+   The "-e" option allows the merge message that comes from the
+   history of the topic and the comments in the "What's cooking" to
+   be edited.  The resulting tree should match 'jch' as the same set
+   of topics are merged on 'master'; otherwise there is a mismerge.
+   Investigate why and do not proceed until the mismerge is found
+   and rectified.
+
+     $ git diff jch next
+
+   When all is well, clean up the redo-jch.sh script with
+
+     $ sh Meta/redo-jch.sh -u
+
+   This removes topics listed in the script that have already been
+   merged to 'master'.  This may lose '### match next' marker;
+   add it again to the appropriate place when it happens.
+
+ - Rebuild 'pu'.
+
+     $ Meta/Reintegrate master..pu >Meta/redo-pu.sh
+
+   Edit the result by adding new topics that are not still in 'pu'
+   in the script.  Then
+
+     $ git checkout -B pu jch
+     $ sh Meta/redo-pu.sh
+
+   When all is well, clean up the redo-pu.sh script with
+
+     $ sh Meta/redo-pu.sh -u
+
+   Double check by running
+
+     $ git branch --no-merged pu
+
+   to see there is no unexpected leftover topics.
+
+   At this point, build-test the result for semantic conflicts, and
+   if there are, prepare an appropriate merge-fix first (see
+   appendix), and rebuild the 'pu' branch from scratch, starting at
+   the tip of 'jch'.
+
+ - Update "What's cooking" message to review the updates to
+   existing topics, newly added topics and graduated topics.
+
+   This step is helped with Meta/cook script.
+
+     $ Meta/cook
+
+   This script inspects the history between master..pu, finds tips
+   of topic branches, compares what it found with the current
+   contents in Meta/whats-cooking.txt, and updates that file.
+   Topics not listed in the file but are found in master..pu are
+   added to the "New topics" section, topics listed in the file that
+   are no longer found in master..pu are moved to the "Graduated to
+   master" section, and topics whose commits changed their states
+   (e.g. used to be only in 'pu', now merged to 'next') are updated
+   with change markers "<<" and ">>".
+
+   Look for lines enclosed in "<<" and ">>"; they hold contents from
+   old file that are replaced by this integration round.  After
+   verifying them, remove the old part.  Review the description for
+   each topic and update its doneness and plan as needed.  To review
+   the updated plan, run
+
+     $ Meta/cook -w
+
+   which will pick up comments given to the topics, such as "Will
+   merge to 'next'", etc. (see Meta/cook script to learn what kind
+   of phrases are supported).
+
+ - Compile, test and install all four (five) integration branches;
+   Meta/Dothem script may aid this step.
+
+ - Format documentation if the 'master' branch was updated;
+   Meta/dodoc.sh script may aid this step.
+
+ - Push the integration branches out to public places; Meta/pushall
+   script may aid this step.
+
+Observations
+------------
+
+Some observations to be made.
+
+ * Each topic is tested individually, and also together with other
+   topics cooking first in 'pu', then in 'jch' and then in 'next'.
+   Until it matures, no part of it is merged to 'master'.
+
+ * A topic already in 'next' can get fixes while still in
+   'next'.  Such a topic will have many merges to 'next' (in
+   other words, "git log --first-parent next" will show many
+   "Merge branch 'ai/topic' to next" for the same topic.
+
+ * An unobvious fix for 'maint' is cooked in 'next' and then
+   merged to 'master' to make extra sure it is Ok and then
+   merged to 'maint'.
+
+ * Even when 'next' becomes empty (in other words, all topics
+   prove stable and are merged to 'master' and "git diff master
+   next" shows empty), it has tons of merge commits that will
+   never be in 'master'.
+
+ * In principle, "git log --first-parent master..next" should
+   show nothing but merges (in practice, there are fixup commits
+   and reverts that are not merges).
+
+ * Commits near the tip of a topic branch that are not in 'next'
+   are fair game to be discarded, replaced or rewritten.
+   Commits already merged to 'next' will not be.
+
+ * Being in the 'next' branch is not a guarantee for a topic to
+   be included in the next feature release.  Being in the
+   'master' branch typically is.
+
+
+Appendix
+--------
+
+Preparing a "merge-fix"
+~~~~~~~~~~~~~~~~~~~~~~~
+
+A merge of two topics may not textually conflict but still have
+conflict at the semantic level. A classic example is for one topic
+to rename an variable and all its uses, while another topic adds a
+new use of the variable under its old name. When these two topics
+are merged together, the reference to the variable newly added by
+the latter topic will still use the old name in the result.
+
+The Meta/Reintegrate script that is used by redo-jch and redo-pu
+scripts implements a crude but usable way to work this issue around.
+When the script merges branch $X, it checks if "refs/merge-fix/$X"
+exists, and if so, the effect of it is squashed into the result of
+the mechanical merge.  In other words,
+
+     $ echo $X | Meta/Reintegrate
+
+is roughly equivalent to this sequence:
+
+     $ git merge --rerere-autoupdate $X
+     $ git commit
+     $ git cherry-pick -n refs/merge-fix/$X
+     $ git commit --amend
+
+The goal of this "prepare a merge-fix" step is to come up with a
+commit that can be squashed into a result of mechanical merge to
+correct semantic conflicts.
+
+After finding that the result of merging branch "ai/topic" to an
+integration branch had such a semantic conflict, say pu~4, check the
+problematic merge out on a detached HEAD, edit the working tree to
+fix the semantic conflict, and make a separate commit to record the
+fix-up:
+
+     $ git checkout pu~4
+     $ git show -s --pretty=%s ;# double check
+     Merge branch 'ai/topic' to pu
+     $ edit
+     $ git commit -m 'merge-fix/ai/topic' -a
+
+Then make a reference "refs/merge-fix/ai/topic" to point at this
+result:
+
+     $ git update-ref refs/merge-fix/ai/topic HEAD
+
+Then double check the result by asking Meta/Reintegrate to redo the
+merge:
+
+     $ git checkout pu~5 ;# the parent of the problem merge
+     $ echo ai/topic | Meta/Reintegrate
+     $ git diff pu~4
+
+This time, because you prepared refs/merge-fix/ai/topic, the
+resulting merge should have been tweaked to include the fix for the
+semantic conflict.
+
+Note that this assumes that the order in which conflicting branches
+are merged does not change.  If the reason why merging ai/topic
+branch needs this merge-fix is because another branch merged earlier
+to the integration branch changed the underlying assumption ai/topic
+branch made (e.g. ai/topic branch added a site to refer to a
+variable, while the other branch renamed that variable and adjusted
+existing use sites), and if you changed redo-jch (or redo-pu) script
+to merge ai/topic branch before the other branch, then the above
+merge-fix should not be applied while merging ai/topic, but should
+instead be applied while merging the other branch.  You would need
+to move the fix to apply to the other branch, perhaps like this:
+
+      $ mf=refs/merge-fix
+      $ git update-ref $mf/$the_other_branch $mf/ai/topic
+      $ git update-ref -d $mf/ai/topic
diff --git a/third_party/git/Documentation/howto/new-command.txt b/third_party/git/Documentation/howto/new-command.txt
new file mode 100644
index 0000000000..15a4c8031f
--- /dev/null
+++ b/third_party/git/Documentation/howto/new-command.txt
@@ -0,0 +1,106 @@
+From: Eric S. Raymond <esr@thyrsus.com>
+Abstract: This is how-to documentation for people who want to add extension
+ commands to Git.  It should be read alongside api-builtin.txt.
+Content-type: text/asciidoc
+
+How to integrate new subcommands
+================================
+
+This is how-to documentation for people who want to add extension
+commands to Git.  It should be read alongside api-builtin.txt.
+
+Runtime environment
+-------------------
+
+Git subcommands are standalone executables that live in the Git exec
+path, normally /usr/lib/git-core.  The git executable itself is a
+thin wrapper that knows where the subcommands live, and runs them by
+passing command-line arguments to them.
+
+(If "git foo" is not found in the Git exec path, the wrapper
+will look in the rest of your $PATH for it.  Thus, it's possible
+to write local Git extensions that don't live in system space.)
+
+Implementation languages
+------------------------
+
+Most subcommands are written in C or shell.  A few are written in
+Perl.
+
+While we strongly encourage coding in portable C for portability,
+these specific scripting languages are also acceptable.  We won't
+accept more without a very strong technical case, as we don't want
+to broaden the Git suite's required dependencies.  Import utilities,
+surgical tools, remote helpers and other code at the edges of the
+Git suite are more lenient and we allow Python (and even Tcl/tk),
+but they should not be used for core functions.
+
+This may change in the future.  Especially Python is not allowed in
+core because we need better Python integration in the Git Windows
+installer before we can be confident people in that environment
+won't experience an unacceptably large loss of capability.
+
+C commands are normally written as single modules, named after the
+command, that link a collection of functions called libgit.  Thus,
+your command 'git-foo' would normally be implemented as a single
+"git-foo.c" (or "builtin/foo.c" if it is to be linked to the main
+binary); this organization makes it easy for people reading the code
+to find things.
+
+See the CodingGuidelines document for other guidance on what we consider
+good practice in C and shell, and api-builtin.txt for the support
+functions available to built-in commands written in C.
+
+What every extension command needs
+----------------------------------
+
+You must have a man page, written in asciidoc (this is what Git help
+followed by your subcommand name will display).  Be aware that there is
+a local asciidoc configuration and macros which you should use.  It's
+often helpful to start by cloning an existing page and replacing the
+text content.
+
+You must have a test, written to report in TAP (Test Anything Protocol).
+Tests are executables (usually shell scripts) that live in the 't'
+subdirectory of the tree.  Each test name begins with 't' and a sequence
+number that controls where in the test sequence it will be executed;
+conventionally the rest of the name stem is that of the command
+being tested.
+
+Read the file t/README to learn more about the conventions to be used
+in writing tests, and the test support library.
+
+Integrating a command
+---------------------
+
+Here are the things you need to do when you want to merge a new
+subcommand into the Git tree.
+
+1. Don't forget to sign off your patch!
+
+2. Append your command name to one of the variables BUILTIN_OBJS,
+EXTRA_PROGRAMS, SCRIPT_SH, SCRIPT_PERL or SCRIPT_PYTHON.
+
+3. Drop its test in the t directory.
+
+4. If your command is implemented in an interpreted language with a
+p-code intermediate form, make sure .gitignore in the main directory
+includes a pattern entry that ignores such files.  Python .pyc and
+.pyo files will already be covered.
+
+5. If your command has any dependency on a particular version of
+your language, document it in the INSTALL file.
+
+6. There is a file command-list.txt in the distribution main directory
+that categorizes commands by type, so they can be listed in appropriate
+subsections in the documentation's summary command list.  Add an entry
+for yours.  To understand the categories, look at command-list.txt
+in the main directory.  If the new command is part of the typical Git
+workflow and you believe it common enough to be mentioned in 'git help',
+map this command to a common group in the column [common].
+
+7. Give the maintainer one paragraph to include in the RelNotes file
+to describe the new feature; a good place to do so is in the cover
+letter [PATCH 0/n].
+
+That's all there is to it.
diff --git a/third_party/git/Documentation/howto/rebase-from-internal-branch.txt b/third_party/git/Documentation/howto/rebase-from-internal-branch.txt
new file mode 100644
index 0000000000..02cb5f758d
--- /dev/null
+++ b/third_party/git/Documentation/howto/rebase-from-internal-branch.txt
@@ -0,0 +1,164 @@
+From:	Junio C Hamano <gitster@pobox.com>
+To:	git@vger.kernel.org
+Cc:	Petr Baudis <pasky@suse.cz>, Linus Torvalds <torvalds@osdl.org>
+Subject: Re: sending changesets from the middle of a git tree
+Date:	Sun, 14 Aug 2005 18:37:39 -0700
+Abstract: In this article, JC talks about how he rebases the
+ public "pu" branch using the core Git tools when he updates
+ the "master" branch, and how "rebase" works.  Also discussed
+ is how this applies to individual developers who sends patches
+ upstream.
+Content-type: text/asciidoc
+
+How to rebase from an internal branch
+=====================================
+
+--------------------------------------
+Petr Baudis <pasky@suse.cz> writes:
+
+> Dear diary, on Sun, Aug 14, 2005 at 09:57:13AM CEST, I got a letter
+> where Junio C Hamano <junkio@cox.net> told me that...
+>> Linus Torvalds <torvalds@osdl.org> writes:
+>>
+>> > Junio, maybe you want to talk about how you move patches from your "pu"
+>> > branch to the real branches.
+>>
+> Actually, wouldn't this be also precisely for what StGIT is intended to?
+--------------------------------------
+
+Exactly my feeling.  I was sort of waiting for Catalin to speak
+up.  With its basing philosophical ancestry on quilt, this is
+the kind of task StGIT is designed to do.
+
+I just have done a simpler one, this time using only the core
+Git tools.
+
+I had a handful of commits that were ahead of master in pu, and I
+wanted to add some documentation bypassing my usual habit of
+placing new things in pu first.  At the beginning, the commit
+ancestry graph looked like this:
+
+                             *"pu" head
+    master --> #1 --> #2 --> #3
+
+So I started from master, made a bunch of edits, and committed:
+
+    $ git checkout master
+    $ cd Documentation; ed git.txt ...
+    $ cd ..; git add Documentation/*.txt
+    $ git commit -s
+
+After the commit, the ancestry graph would look like this:
+
+                              *"pu" head
+    master^ --> #1 --> #2 --> #3
+          \
+            \---> master
+
+The old master is now master^ (the first parent of the master).
+The new master commit holds my documentation updates.
+
+Now I have to deal with "pu" branch.
+
+This is the kind of situation I used to have all the time when
+Linus was the maintainer and I was a contributor, when you look
+at "master" branch being the "maintainer" branch, and "pu"
+branch being the "contributor" branch.  Your work started at the
+tip of the "maintainer" branch some time ago, you made a lot of
+progress in the meantime, and now the maintainer branch has some
+other commits you do not have yet.  And "git rebase" was written
+with the explicit purpose of helping to maintain branches like
+"pu".  You _could_ merge master to pu and keep going, but if you
+eventually want to cherrypick and merge some but not necessarily
+all changes back to the master branch, it often makes later
+operations for _you_ easier if you rebase (i.e. carry forward
+your changes) "pu" rather than merge.  So I ran "git rebase":
+
+    $ git checkout pu
+    $ git rebase master pu
+
+What this does is to pick all the commits since the current
+branch (note that I now am on "pu" branch) forked from the
+master branch, and forward port these changes.
+
+    master^ --> #1 --> #2 --> #3
+          \                                  *"pu" head
+            \---> master --> #1' --> #2' --> #3'
+
+The diff between master^ and #1 is applied to master and
+committed to create #1' commit with the commit information (log,
+author and date) taken from commit #1.  On top of that #2' and #3'
+commits are made similarly out of #2 and #3 commits.
+
+Old #3 is not recorded in any of the .git/refs/heads/ file
+anymore, so after doing this you will have dangling commit if
+you ran fsck-cache, which is normal.  After testing "pu", you
+can run "git prune" to get rid of those original three commits.
+
+While I am talking about "git rebase", I should talk about how
+to do cherrypicking using only the core Git tools.
+
+Let's go back to the earlier picture, with different labels.
+
+You, as an individual developer, cloned upstream repository and
+made a couple of commits on top of it.
+
+                              *your "master" head
+   upstream --> #1 --> #2 --> #3
+
+You would want changes #2 and #3 incorporated in the upstream,
+while you feel that #1 may need further improvements.  So you
+prepare #2 and #3 for e-mail submission.
+
+    $ git format-patch master^^ master
+
+This creates two files, 0001-XXXX.patch and 0002-XXXX.patch.  Send
+them out "To: " your project maintainer and "Cc: " your mailing
+list.  You could use contributed script git-send-email if
+your host has necessary perl modules for this, but your usual
+MUA would do as long as it does not corrupt whitespaces in the
+patch.
+
+Then you would wait, and you find out that the upstream picked
+up your changes, along with other changes.
+
+   where                      *your "master" head
+  upstream --> #1 --> #2 --> #3
+    used   \
+   to be     \--> #A --> #2' --> #3' --> #B --> #C
+                                                *upstream head
+
+The two commits #2' and #3' in the above picture record the same
+changes your e-mail submission for #2 and #3 contained, but
+probably with the new sign-off line added by the upstream
+maintainer and definitely with different committer and ancestry
+information, they are different objects from #2 and #3 commits.
+
+You fetch from upstream, but not merge.
+
+    $ git fetch upstream
+
+This leaves the updated upstream head in .git/FETCH_HEAD but
+does not touch your .git/HEAD or .git/refs/heads/master.
+You run "git rebase" now.
+
+    $ git rebase FETCH_HEAD master
+
+Earlier, I said that rebase applies all the commits from your
+branch on top of the upstream head.  Well, I lied.  "git rebase"
+is a bit smarter than that and notices that #2 and #3 need not
+be applied, so it only applies #1.  The commit ancestry graph
+becomes something like this:
+
+   where                     *your old "master" head
+  upstream --> #1 --> #2 --> #3
+    used   \                      your new "master" head*
+   to be     \--> #A --> #2' --> #3' --> #B --> #C --> #1'
+                                                *upstream
+                                                head
+
+Again, "git prune" would discard the disused commits #1-#3 and
+you continue on starting from the new "master" head, which is
+the #1' commit.
+
+-jc
diff --git a/third_party/git/Documentation/howto/rebuild-from-update-hook.txt b/third_party/git/Documentation/howto/rebuild-from-update-hook.txt
new file mode 100644
index 0000000000..db219f5c07
--- /dev/null
+++ b/third_party/git/Documentation/howto/rebuild-from-update-hook.txt
@@ -0,0 +1,90 @@
+Subject: [HOWTO] Using post-update hook
+Message-ID: <7vy86o6usx.fsf@assigned-by-dhcp.cox.net>
+From: Junio C Hamano <gitster@pobox.com>
+Date: Fri, 26 Aug 2005 18:19:10 -0700
+Abstract: In this how-to article, JC talks about how he
+ uses the post-update hook to automate Git documentation page
+ shown at https://www.kernel.org/pub/software/scm/git/docs/.
+Content-type: text/asciidoc
+
+How to rebuild from update hook
+===============================
+
+The pages under https://www.kernel.org/pub/software/scm/git/docs/
+are built from Documentation/ directory of the git.git project
+and needed to be kept up-to-date.  The www.kernel.org/ servers
+are mirrored and I was told that the origin of the mirror is on
+the machine $some.kernel.org, on which I was given an account
+when I took over Git maintainership from Linus.
+
+The directories relevant to this how-to are these two:
+
+    /pub/scm/git/git.git/	The public Git repository.
+    /pub/software/scm/git/docs/	The HTML documentation page.
+
+So I made a repository to generate the documentation under my
+home directory over there.
+
+    $ cd
+    $ mkdir doc-git && cd doc-git
+    $ git clone /pub/scm/git/git.git/ docgen
+
+What needs to happen is to update the $HOME/doc-git/docgen/
+working tree, build HTML docs there and install the result in
+/pub/software/scm/git/docs/ directory.  So I wrote a little
+script:
+
+    $ cat >dododoc.sh <<\EOF
+    #!/bin/sh
+    cd $HOME/doc-git/docgen || exit
+
+    unset GIT_DIR
+
+    git pull /pub/scm/git/git.git/ master &&
+    cd Documentation &&
+    make install-webdoc
+    EOF
+
+Initially I used to run this by hand whenever I push into the
+public Git repository.  Then I did a cron job that ran twice a
+day.  The current round uses the post-update hook mechanism,
+like this:
+
+    $ cat >/pub/scm/git/git.git/hooks/post-update <<\EOF
+    #!/bin/sh
+    #
+    # An example hook script to prepare a packed repository for use over
+    # dumb transports.
+    #
+    # To enable this hook, make this file executable by "chmod +x post-update".
+
+    case " $* " in
+    *' refs/heads/master '*)
+            echo $HOME/doc-git/dododoc.sh | at now
+            ;;
+    esac
+    exec git-update-server-info
+    EOF
+    $ chmod +x /pub/scm/git/git.git/hooks/post-update
+
+There are four things worth mentioning:
+
+ - The update-hook is run after the repository accepts a "git
+   push", under my user privilege.  It is given the full names
+   of refs that have been updated as arguments.  My post-update
+   runs the dododoc.sh script only when the master head is
+   updated.
+
+ - When update-hook is run, GIT_DIR is set to '.' by the calling
+   receive-pack.  This is inherited by the dododoc.sh run via
+   the "at" command, and needs to be unset; otherwise, "git
+   pull" it does into $HOME/doc-git/docgen/ repository would not
+   work correctly.
+
+ - The stdout of update hook script is not connected to git
+   push; I run the heavy part of the command inside "at", to
+   receive the execution report via e-mail.
+
+ - This is still crude and does not protect against simultaneous
+   make invocations stomping on each other.  I would need to add
+   some locking mechanism for this.
diff --git a/third_party/git/Documentation/howto/recover-corrupted-blob-object.txt b/third_party/git/Documentation/howto/recover-corrupted-blob-object.txt
new file mode 100644
index 0000000000..1b3b188d3c
--- /dev/null
+++ b/third_party/git/Documentation/howto/recover-corrupted-blob-object.txt
@@ -0,0 +1,144 @@
+Date: Fri, 9 Nov 2007 08:28:38 -0800 (PST)
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Subject: corrupt object on git-gc
+Abstract: Some tricks to reconstruct blob objects in order to fix
+ a corrupted repository.
+Content-type: text/asciidoc
+
+How to recover a corrupted blob object
+======================================
+
+-----------------------------------------------------------
+On Fri, 9 Nov 2007, Yossi Leybovich wrote:
+>
+> Did not help still the repository look for this object?
+> Any one know how can I track this object and understand which file is it
+-----------------------------------------------------------
+
+So exactly *because* the SHA-1 hash is cryptographically secure, the hash
+itself doesn't actually tell you anything, in order to fix a corrupt
+object you basically have to find the "original source" for it.
+
+The easiest way to do that is almost always to have backups, and find the
+same object somewhere else. Backups really are a good idea, and Git makes
+it pretty easy (if nothing else, just clone the repository somewhere else,
+and make sure that you do *not* use a hard-linked clone, and preferably
+not the same disk/machine).
+
+But since you don't seem to have backups right now, the good news is that
+especially with a single blob being corrupt, these things *are* somewhat
+debuggable.
+
+First off, move the corrupt object away, and *save* it. The most common
+cause of corruption so far has been memory corruption, but even so, there
+are people who would be interested in seeing the corruption - but it's
+basically impossible to judge the corruption until we can also see the
+original object, so right now the corrupt object is useless, but it's very
+interesting for the future, in the hope that you can re-create a
+non-corrupt version.
+
+-----------------------------------------------------------
+So:
+
+> ib]$ mv .git/objects/4b/9458b3786228369c63936db65827de3cc06200 ../
+-----------------------------------------------------------
+
+This is the right thing to do, although it's usually best to save it under
+it's full SHA-1 name (you just dropped the "4b" from the result ;).
+
+Let's see what that tells us:
+
+-----------------------------------------------------------
+> ib]$ git-fsck --full
+> broken link from    tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+>              to    blob 4b9458b3786228369c63936db65827de3cc06200
+> missing blob 4b9458b3786228369c63936db65827de3cc06200
+-----------------------------------------------------------
+
+Ok, I removed the "dangling commit" messages, because they are just
+messages about the fact that you probably have rebased etc, so they're not
+at all interesting. But what remains is still very useful. In particular,
+we now know which tree points to it!
+
+Now you can do
+
+	git ls-tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+
+which will show something like
+
+	100644 blob 8d14531846b95bfa3564b58ccfb7913a034323b8    .gitignore
+	100644 blob ebf9bf84da0aab5ed944264a5db2a65fe3a3e883    .mailmap
+	100644 blob ca442d313d86dc67e0a2e5d584b465bd382cbf5c    COPYING
+	100644 blob ee909f2cc49e54f0799a4739d24c4cb9151ae453    CREDITS
+	040000 tree 0f5f709c17ad89e72bdbbef6ea221c69807009f6    Documentation
+	100644 blob 1570d248ad9237e4fa6e4d079336b9da62d9ba32    Kbuild
+	100644 blob 1c7c229a092665b11cd46a25dbd40feeb31661d9    MAINTAINERS
+	...
+
+and you should now have a line that looks like
+
+	10064 blob 4b9458b3786228369c63936db65827de3cc06200	my-magic-file
+
+in the output. This already tells you a *lot* it tells you what file the
+corrupt blob came from!
+
+Now, it doesn't tell you quite enough, though: it doesn't tell what
+*version* of the file didn't get correctly written! You might be really
+lucky, and it may be the version that you already have checked out in your
+working tree, in which case fixing this problem is really simple, just do
+
+	git hash-object -w my-magic-file
+
+again, and if it outputs the missing SHA-1 (4b945..) you're now all done!
+
+But that's the really lucky case, so let's assume that it was some older
+version that was broken. How do you tell which version it was?
+
+The easiest way to do it is to do
+
+	git log --raw --all --full-history -- subdirectory/my-magic-file
+
+and that will show you the whole log for that file (please realize that
+the tree you had may not be the top-level tree, so you need to figure out
+which subdirectory it was in on your own), and because you're asking for
+raw output, you'll now get something like
+
+	commit abc
+	Author:
+	Date:
+	  ..
+	:100644 100644 4b9458b... newsha... M  somedirectory/my-magic-file
+
+
+	commit xyz
+	Author:
+	Date:
+
+	  ..
+	:100644 100644 oldsha... 4b9458b... M	somedirectory/my-magic-file
+
+and this actually tells you what the *previous* and *subsequent* versions
+of that file were! So now you can look at those ("oldsha" and "newsha"
+respectively), and hopefully you have done commits often, and can
+re-create the missing my-magic-file version by looking at those older and
+newer versions!
+
+If you can do that, you can now recreate the missing object with
+
+	git hash-object -w <recreated-file>
+
+and your repository is good again!
+
+(Btw, you could have ignored the fsck, and started with doing a
+
+	git log --raw --all
+
+and just looked for the sha of the missing object (4b9458b..) in that
+whole thing. It's up to you - Git does *have* a lot of information, it is
+just missing one particular blob version.
+
+Trying to recreate trees and especially commits is *much* harder. So you
+were lucky that it's a blob. It's quite possible that you can recreate the
+thing.
+
+			Linus
diff --git a/third_party/git/Documentation/howto/recover-corrupted-object-harder.txt b/third_party/git/Documentation/howto/recover-corrupted-object-harder.txt
new file mode 100644
index 0000000000..8994e2559e
--- /dev/null
+++ b/third_party/git/Documentation/howto/recover-corrupted-object-harder.txt
@@ -0,0 +1,479 @@
+Date: Wed, 16 Oct 2013 04:34:01 -0400
+From: Jeff King <peff@peff.net>
+Subject: pack corruption post-mortem
+Abstract: Recovering a corrupted object when no good copy is available.
+Content-type: text/asciidoc
+
+How to recover an object from scratch
+=====================================
+
+I was recently presented with a repository with a corrupted packfile,
+and was asked if the data was recoverable. This post-mortem describes
+the steps I took to investigate and fix the problem. I thought others
+might find the process interesting, and it might help somebody in the
+same situation.
+
+********************************
+Note: In this case, no good copy of the repository was available. For
+the much easier case where you can get the corrupted object from
+elsewhere, see link:recover-corrupted-blob-object.html[this howto].
+********************************
+
+I started with an fsck, which found a problem with exactly one object
+(I've used $pack and $obj below to keep the output readable, and also
+because I'll refer to them later):
+
+-----------
+    $ git fsck
+    error: $pack SHA1 checksum mismatch
+    error: index CRC mismatch for object $obj from $pack at offset 51653873
+    error: inflate: data stream error (incorrect data check)
+    error: cannot unpack $obj from $pack at offset 51653873
+-----------
+
+The pack checksum failing means a byte is munged somewhere, and it is
+presumably in the object mentioned (since both the index checksum and
+zlib were failing).
+
+Reading the zlib source code, I found that "incorrect data check" means
+that the adler-32 checksum at the end of the zlib data did not match the
+inflated data. So stepping the data through zlib would not help, as it
+did not fail until the very end, when we realize the CRC does not match.
+The problematic bytes could be anywhere in the object data.
+
+The first thing I did was pull the broken data out of the packfile. I
+needed to know how big the object was, which I found out with:
+
+------------
+    $ git show-index <$idx | cut -d' ' -f1 | sort -n | grep -A1 51653873
+    51653873
+    51664736
+------------
+
+Show-index gives us the list of objects and their offsets. We throw away
+everything but the offsets, and then sort them so that our interesting
+offset (which we got from the fsck output above) is followed immediately
+by the offset of the next object. Now we know that the object data is
+10863 bytes long, and we can grab it with:
+
+------------
+  dd if=$pack of=object bs=1 skip=51653873 count=10863
+------------
+
+I inspected a hexdump of the data, looking for any obvious bogosity
+(e.g., a 4K run of zeroes would be a good sign of filesystem
+corruption). But everything looked pretty reasonable.
+
+Note that the "object" file isn't fit for feeding straight to zlib; it
+has the git packed object header, which is variable-length. We want to
+strip that off so we can start playing with the zlib data directly. You
+can either work your way through it manually (the format is described in
+link:../technical/pack-format.html[Documentation/technical/pack-format.txt]),
+or you can walk through it in a debugger. I did the latter, creating a
+valid pack like:
+
+------------
+    # pack magic and version
+    printf 'PACK\0\0\0\2' >tmp.pack
+    # pack has one object
+    printf '\0\0\0\1' >>tmp.pack
+    # now add our object data
+    cat object >>tmp.pack
+    # and then append the pack trailer
+    /path/to/git.git/t/helper/test-tool sha1 -b <tmp.pack >trailer
+    cat trailer >>tmp.pack
+------------
+
+and then running "git index-pack tmp.pack" in the debugger (stop at
+unpack_raw_entry). Doing this, I found that there were 3 bytes of header
+(and the header itself had a sane type and size). So I stripped those
+off with:
+
+------------
+    dd if=object of=zlib bs=1 skip=3
+------------
+
+I ran the result through zlib's inflate using a custom C program. And
+while it did report the error, I did get the right number of output
+bytes (i.e., it matched git's size header that we decoded above). But
+feeding the result back to "git hash-object" didn't produce the same
+sha1. So there were some wrong bytes, but I didn't know which. The file
+happened to be C source code, so I hoped I could notice something
+obviously wrong with it, but I didn't. I even got it to compile!
+
+I also tried comparing it to other versions of the same path in the
+repository, hoping that there would be some part of the diff that didn't
+make sense. Unfortunately, this happened to be the only revision of this
+particular file in the repository, so I had nothing to compare against.
+
+So I took a different approach. Working under the guess that the
+corruption was limited to a single byte, I wrote a program to munge each
+byte individually, and try inflating the result. Since the object was
+only 10K compressed, that worked out to about 2.5M attempts, which took
+a few minutes.
+
+The program I used is here:
+
+----------------------------------------------
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <zlib.h>
+
+static int try_zlib(unsigned char *buf, int len)
+{
+	/* make this absurdly large so we don't have to loop */
+	static unsigned char out[1024*1024];
+	z_stream z;
+	int ret;
+
+	memset(&z, 0, sizeof(z));
+	inflateInit(&z);
+
+	z.next_in = buf;
+	z.avail_in = len;
+	z.next_out = out;
+	z.avail_out = sizeof(out);
+
+	ret = inflate(&z, 0);
+	inflateEnd(&z);
+	return ret >= 0;
+}
+
+/* eye candy */
+static int counter = 0;
+static void progress(int sig)
+{
+	fprintf(stderr, "\r%d", counter);
+	alarm(1);
+}
+
+int main(void)
+{
+	/* oversized so we can read the whole buffer in */
+	unsigned char buf[1024*1024];
+	int len;
+	unsigned i, j;
+
+	signal(SIGALRM, progress);
+	alarm(1);
+
+	len = read(0, buf, sizeof(buf));
+	for (i = 0; i < len; i++) {
+		unsigned char c = buf[i];
+		for (j = 0; j <= 0xff; j++) {
+			buf[i] = j;
+
+			counter++;
+			if (try_zlib(buf, len))
+				printf("i=%d, j=%x\n", i, j);
+		}
+		buf[i] = c;
+	}
+
+	alarm(0);
+	fprintf(stderr, "\n");
+	return 0;
+}
+----------------------------------------------
+
+I compiled and ran with:
+
+-------
+  gcc -Wall -Werror -O3 munge.c -o munge -lz
+  ./munge <zlib
+-------
+
+
+There were a few false positives early on (if you write "no data" in the
+zlib header, zlib thinks it's just fine :) ). But I got a hit about
+halfway through:
+
+-------
+  i=5642, j=c7
+-------
+
+I let it run to completion, and got a few more hits at the end (where it
+was munging the CRC to match our broken data). So there was a good
+chance this middle hit was the source of the problem.
+
+I confirmed by tweaking the byte in a hex editor, zlib inflating the
+result (no errors!), and then piping the output into "git hash-object",
+which reported the sha1 of the broken object. Success!
+
+I fixed the packfile itself with:
+
+-------
+  chmod +w $pack
+  printf '\xc7' | dd of=$pack bs=1 seek=51659518 conv=notrunc
+  chmod -w $pack
+-------
+
+The `\xc7` comes from the replacement byte our "munge" program found.
+The offset 51659518 is derived by taking the original object offset
+(51653873), adding the replacement offset found by "munge" (5642), and
+then adding back in the 3 bytes of git header we stripped.
+
+After that, "git fsck" ran clean.
+
+As for the corruption itself, I was lucky that it was indeed a single
+byte. In fact, it turned out to be a single bit. The byte 0xc7 was
+corrupted to 0xc5. So presumably it was caused by faulty hardware, or a
+cosmic ray.
+
+And the aborted attempt to look at the inflated output to see what was
+wrong? I could have looked forever and never found it. Here's the diff
+between what the corrupted data inflates to, versus the real data:
+
+--------------
+  -       cp = strtok (arg, "+");
+  +       cp = strtok (arg, ".");
+--------------
+
+It tweaked one byte and still ended up as valid, readable C that just
+happened to do something totally different! One takeaway is that on a
+less unlucky day, looking at the zlib output might have actually been
+helpful, as most random changes would actually break the C code.
+
+But more importantly, git's hashing and checksumming noticed a problem
+that easily could have gone undetected in another system. The result
+still compiled, but would have caused an interesting bug (that would
+have been blamed on some random commit).
+
+
+The adventure continues...
+--------------------------
+
+I ended up doing this again! Same entity, new hardware. The assumption
+at this point is that the old disk corrupted the packfile, and then the
+corruption was migrated to the new hardware (because it was done by
+rsync or similar, and no fsck was done at the time of migration).
+
+This time, the affected blob was over 20 megabytes, which was far too
+large to do a brute-force on. I followed the instructions above to
+create the `zlib` file. I then used the `inflate` program below to pull
+the corrupted data from that. Examining that output gave me a hint about
+where in the file the corruption was. But now I was working with the
+file itself, not the zlib contents. So knowing the sha1 of the object
+and the approximate area of the corruption, I used the `sha1-munge`
+program below to brute-force the correct byte.
+
+Here's the inflate program (it's essentially `gunzip` but without the
+`.gz` header processing):
+
+--------------------------
+#include <stdio.h>
+#include <string.h>
+#include <zlib.h>
+#include <stdlib.h>
+
+int main(int argc, char **argv)
+{
+	/*
+	 * oversized so we can read the whole buffer in;
+	 * this could actually be switched to streaming
+	 * to avoid any memory limitations
+	 */
+	static unsigned char buf[25 * 1024 * 1024];
+	static unsigned char out[25 * 1024 * 1024];
+	int len;
+	z_stream z;
+	int ret;
+
+	len = read(0, buf, sizeof(buf));
+	memset(&z, 0, sizeof(z));
+	inflateInit(&z);
+
+	z.next_in = buf;
+	z.avail_in = len;
+	z.next_out = out;
+	z.avail_out = sizeof(out);
+
+	ret = inflate(&z, 0);
+	if (ret != Z_OK && ret != Z_STREAM_END)
+		fprintf(stderr, "initial inflate failed (%d)\n", ret);
+
+	fprintf(stderr, "outputting %lu bytes", z.total_out);
+	fwrite(out, 1, z.total_out, stdout);
+	return 0;
+}
+--------------------------
+
+And here is the `sha1-munge` program:
+
+--------------------------
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <signal.h>
+#include <openssl/sha.h>
+#include <stdlib.h>
+
+/* eye candy */
+static int counter = 0;
+static void progress(int sig)
+{
+	fprintf(stderr, "\r%d", counter);
+	alarm(1);
+}
+
+static const signed char hexval_table[256] = {
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 18-1f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 20-27 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 28-2f */
+	  0,  1,  2,  3,  4,  5,  6,  7,		/* 30-37 */
+	  8,  9, -1, -1, -1, -1, -1, -1,		/* 38-3f */
+	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 40-47 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 48-4f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 50-57 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 58-5f */
+	 -1, 10, 11, 12, 13, 14, 15, -1,		/* 60-67 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 68-67 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 70-77 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 78-7f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 80-87 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 88-8f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 90-97 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 98-9f */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a0-a7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* a8-af */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b0-b7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* b8-bf */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c0-c7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* c8-cf */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d0-d7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* d8-df */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e0-e7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* e8-ef */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f0-f7 */
+	 -1, -1, -1, -1, -1, -1, -1, -1,		/* f8-ff */
+};
+
+static inline unsigned int hexval(unsigned char c)
+{
+return hexval_table[c];
+}
+
+static int get_sha1_hex(const char *hex, unsigned char *sha1)
+{
+	int i;
+	for (i = 0; i < 20; i++) {
+		unsigned int val;
+		/*
+		 * hex[1]=='\0' is caught when val is checked below,
+		 * but if hex[0] is NUL we have to avoid reading
+		 * past the end of the string:
+		 */
+		if (!hex[0])
+			return -1;
+		val = (hexval(hex[0]) << 4) | hexval(hex[1]);
+		if (val & ~0xff)
+			return -1;
+		*sha1++ = val;
+		hex += 2;
+	}
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	/* oversized so we can read the whole buffer in */
+	static unsigned char buf[25 * 1024 * 1024];
+	char header[32];
+	int header_len;
+	unsigned char have[20], want[20];
+	int start, len;
+	SHA_CTX orig;
+	unsigned i, j;
+
+	if (!argv[1] || get_sha1_hex(argv[1], want)) {
+		fprintf(stderr, "usage: sha1-munge <sha1> [start] <file.in\n");
+		return 1;
+	}
+
+	if (argv[2])
+		start = atoi(argv[2]);
+	else
+		start = 0;
+
+	len = read(0, buf, sizeof(buf));
+	header_len = sprintf(header, "blob %d", len) + 1;
+	fprintf(stderr, "using header: %s\n", header);
+
+	/*
+	 * We keep a running sha1 so that if you are munging
+	 * near the end of the file, we do not have to re-sha1
+	 * the unchanged earlier bytes
+	 */
+	SHA1_Init(&orig);
+	SHA1_Update(&orig, header, header_len);
+	if (start)
+		SHA1_Update(&orig, buf, start);
+
+	signal(SIGALRM, progress);
+	alarm(1);
+
+	for (i = start; i < len; i++) {
+		unsigned char c;
+		SHA_CTX x;
+
+#if 0
+		/*
+		 * deletion -- this would not actually work in practice,
+		 * I think, because we've already committed to a
+		 * particular size in the header. Ditto for addition
+		 * below. In those cases, you'd have to do the whole
+		 * sha1 from scratch, or possibly keep three running
+		 * "orig" sha1 computations going.
+		 */
+		memcpy(&x, &orig, sizeof(x));
+		SHA1_Update(&x, buf + i + 1, len - i - 1);
+		SHA1_Final(have, &x);
+		if (!memcmp(have, want, 20))
+			printf("i=%d, deletion\n", i);
+#endif
+
+		/*
+		 * replacement -- note that this tries each of the 256
+		 * possible bytes. If you suspect a single-bit flip,
+		 * it would be much shorter to just try the 8
+		 * bit-flipped variants.
+		 */
+		c = buf[i];
+		for (j = 0; j <= 0xff; j++) {
+			buf[i] = j;
+
+			memcpy(&x, &orig, sizeof(x));
+			SHA1_Update(&x, buf + i, len - i);
+			SHA1_Final(have, &x);
+			if (!memcmp(have, want, 20))
+				printf("i=%d, j=%02x\n", i, j);
+		}
+		buf[i] = c;
+
+#if 0
+		/* addition */
+		for (j = 0; j <= 0xff; j++) {
+			unsigned char extra = j;
+			memcpy(&x, &orig, sizeof(x));
+			SHA1_Update(&x, &extra, 1);
+			SHA1_Update(&x, buf + i, len - i);
+			SHA1_Final(have, &x);
+			if (!memcmp(have, want, 20))
+				printf("i=%d, addition=%02x", i, j);
+		}
+#endif
+
+		SHA1_Update(&orig, buf + i, 1);
+		counter++;
+	}
+
+	alarm(0);
+	fprintf(stderr, "\r%d\n", counter);
+	return 0;
+}
+--------------------------
diff --git a/third_party/git/Documentation/howto/revert-a-faulty-merge.txt b/third_party/git/Documentation/howto/revert-a-faulty-merge.txt
new file mode 100644
index 0000000000..19f59cc888
--- /dev/null
+++ b/third_party/git/Documentation/howto/revert-a-faulty-merge.txt
@@ -0,0 +1,273 @@
+Date: Fri, 19 Dec 2008 00:45:19 -0800
+From: Linus Torvalds <torvalds@linux-foundation.org>, Junio C Hamano <gitster@pobox.com>
+Subject: Re: Odd merge behaviour involving reverts
+Abstract: Sometimes a branch that was already merged to the mainline
+ is later found to be faulty.  Linus and Junio give guidance on
+ recovering from such a premature merge and continuing development
+ after the offending branch is fixed.
+Message-ID: <7vocz8a6zk.fsf@gitster.siamese.dyndns.org>
+References: <alpine.LFD.2.00.0812181949450.14014@localhost.localdomain>
+Content-type: text/asciidoc
+
+How to revert a faulty merge
+============================
+
+Alan <alan@clueserver.org> said:
+
+    I have a master branch.  We have a branch off of that that some
+    developers are doing work on.  They claim it is ready. We merge it
+    into the master branch.  It breaks something so we revert the merge.
+    They make changes to the code.  they get it to a point where they say
+    it is ok and we merge again.
+
+    When examined, we find that code changes made before the revert are
+    not in the master branch, but code changes after are in the master
+    branch.
+
+and asked for help recovering from this situation.
+
+The history immediately after the "revert of the merge" would look like
+this:
+
+ ---o---o---o---M---x---x---W
+               /
+       ---A---B
+
+where A and B are on the side development that was not so good, M is the
+merge that brings these premature changes into the mainline, x are changes
+unrelated to what the side branch did and already made on the mainline,
+and W is the "revert of the merge M" (doesn't W look M upside down?).
+IOW, `"diff W^..W"` is similar to `"diff -R M^..M"`.
+
+Such a "revert" of a merge can be made with:
+
+    $ git revert -m 1 M
+
+After the developers of the side branch fix their mistakes, the history
+may look like this:
+
+ ---o---o---o---M---x---x---W---x
+               /
+       ---A---B-------------------C---D
+
+where C and D are to fix what was broken in A and B, and you may already
+have some other changes on the mainline after W.
+
+If you merge the updated side branch (with D at its tip), none of the
+changes made in A or B will be in the result, because they were reverted
+by W.  That is what Alan saw.
+
+Linus explains the situation:
+
+    Reverting a regular commit just effectively undoes what that commit
+    did, and is fairly straightforward. But reverting a merge commit also
+    undoes the _data_ that the commit changed, but it does absolutely
+    nothing to the effects on _history_ that the merge had.
+
+    So the merge will still exist, and it will still be seen as joining
+    the two branches together, and future merges will see that merge as
+    the last shared state - and the revert that reverted the merge brought
+    in will not affect that at all.
+
+    So a "revert" undoes the data changes, but it's very much _not_ an
+    "undo" in the sense that it doesn't undo the effects of a commit on
+    the repository history.
+
+    So if you think of "revert" as "undo", then you're going to always
+    miss this part of reverts. Yes, it undoes the data, but no, it doesn't
+    undo history.
+
+In such a situation, you would want to first revert the previous revert,
+which would make the history look like this:
+
+ ---o---o---o---M---x---x---W---x---Y
+               /
+       ---A---B-------------------C---D
+
+where Y is the revert of W.  Such a "revert of the revert" can be done
+with:
+
+    $ git revert W
+
+This history would (ignoring possible conflicts between what W and W..Y
+changed) be equivalent to not having W or Y at all in the history:
+
+ ---o---o---o---M---x---x-------x----
+               /
+       ---A---B-------------------C---D
+
+and merging the side branch again will not have conflict arising from an
+earlier revert and revert of the revert.
+
+ ---o---o---o---M---x---x-------x-------*
+               /                       /
+       ---A---B-------------------C---D
+
+Of course the changes made in C and D still can conflict with what was
+done by any of the x, but that is just a normal merge conflict.
+
+On the other hand, if the developers of the side branch discarded their
+faulty A and B, and redone the changes on top of the updated mainline
+after the revert, the history would have looked like this:
+
+ ---o---o---o---M---x---x---W---x---x
+               /                 \
+       ---A---B                   A'--B'--C'
+
+If you reverted the revert in such a case as in the previous example:
+
+ ---o---o---o---M---x---x---W---x---x---Y---*
+               /                 \         /
+       ---A---B                   A'--B'--C'
+
+where Y is the revert of W, A' and B' are rerolled A and B, and there may
+also be a further fix-up C' on the side branch.  `"diff Y^..Y"` is similar
+to `"diff -R W^..W"` (which in turn means it is similar to `"diff M^..M"`),
+and `"diff A'^..C'"` by definition would be similar but different from that,
+because it is a rerolled series of the earlier change.  There will be a
+lot of overlapping changes that result in conflicts.  So do not do "revert
+of revert" blindly without thinking..
+
+ ---o---o---o---M---x---x---W---x---x
+               /                 \
+       ---A---B                   A'--B'--C'
+
+In the history with rebased side branch, W (and M) are behind the merge
+base of the updated branch and the tip of the mainline, and they should
+merge without the past faulty merge and its revert getting in the way.
+
+To recap, these are two very different scenarios, and they want two very
+different resolution strategies:
+
+ - If the faulty side branch was fixed by adding corrections on top, then
+   doing a revert of the previous revert would be the right thing to do.
+
+ - If the faulty side branch whose effects were discarded by an earlier
+   revert of a merge was rebuilt from scratch (i.e. rebasing and fixing,
+   as you seem to have interpreted), then re-merging the result without
+   doing anything else fancy would be the right thing to do.
+   (See the ADDENDUM below for how to rebuild a branch from scratch
+   without changing its original branching-off point.)
+
+However, there are things to keep in mind when reverting a merge (and
+reverting such a revert).
+
+For example, think about what reverting a merge (and then reverting the
+revert) does to bisectability. Ignore the fact that the revert of a revert
+is undoing it - just think of it as a "single commit that does a lot".
+Because that is what it does.
+
+When you have a problem you are chasing down, and you hit a "revert this
+merge", what you're hitting is essentially a single commit that contains
+all the changes (but obviously in reverse) of all the commits that got
+merged. So it's debugging hell, because now you don't have lots of small
+changes that you can try to pinpoint which _part_ of it changes.
+
+But does it all work? Sure it does. You can revert a merge, and from a
+purely technical angle, Git did it very naturally and had no real
+troubles. It just considered it a change from "state before merge" to
+"state after merge", and that was it. Nothing complicated, nothing odd,
+nothing really dangerous. Git will do it without even thinking about it.
+
+So from a technical angle, there's nothing wrong with reverting a merge,
+but from a workflow angle it's something that you generally should try to
+avoid.
+
+If at all possible, for example, if you find a problem that got merged
+into the main tree, rather than revert the merge, try _really_ hard to
+bisect the problem down into the branch you merged, and just fix it, or
+try to revert the individual commit that caused it.
+
+Yes, it's more complex, and no, it's not always going to work (sometimes
+the answer is: "oops, I really shouldn't have merged it, because it wasn't
+ready yet, and I really need to undo _all_ of the merge"). So then you
+really should revert the merge, but when you want to re-do the merge, you
+now need to do it by reverting the revert.
+
+ADDENDUM
+
+Sometimes you have to rewrite one of a topic branch's commits *and* you can't
+change the topic's branching-off point.  Consider the following situation:
+
+ P---o---o---M---x---x---W---x
+  \         /
+   A---B---C
+
+where commit W reverted commit M because it turned out that commit B was wrong
+and needs to be rewritten, but you need the rewritten topic to still branch
+from commit P (perhaps P is a branching-off point for yet another branch, and
+you want be able to merge the topic into both branches).
+
+The natural thing to do in this case is to checkout the A-B-C branch and use
+"rebase -i P" to change commit B.  However this does not rewrite commit A,
+because "rebase -i" by default fast-forwards over any initial commits selected
+with the "pick" command.  So you end up with this:
+
+ P---o---o---M---x---x---W---x
+  \         /
+   A---B---C   <-- old branch
+    \
+     B'---C'   <-- naively rewritten branch
+
+To merge A-B'-C' into the mainline branch you would still have to first revert
+commit W in order to pick up the changes in A, but then it's likely that the
+changes in B' will conflict with the original B changes re-introduced by the
+reversion of W.
+
+However, you can avoid these problems if you recreate the entire branch,
+including commit A:
+
+   A'---B'---C'  <-- completely rewritten branch
+  /
+ P---o---o---M---x---x---W---x
+  \         /
+   A---B---C
+
+You can merge A'-B'-C' into the mainline branch without worrying about first
+reverting W.  Mainline's history would look like this:
+
+   A'---B'---C'------------------
+  /                              \
+ P---o---o---M---x---x---W---x---M2
+  \         /
+   A---B---C
+
+But if you don't actually need to change commit A, then you need some way to
+recreate it as a new commit with the same changes in it.  The rebase command's
+--no-ff option provides a way to do this:
+
+    $ git rebase [-i] --no-ff P
+
+The --no-ff option creates a new branch A'-B'-C' with all-new commits (all the
+SHA IDs will be different) even if in the interactive case you only actually
+modify commit B.  You can then merge this new branch directly into the mainline
+branch and be sure you'll get all of the branch's changes.
+
+You can also use --no-ff in cases where you just add extra commits to the topic
+to fix it up.  Let's revisit the situation discussed at the start of this howto:
+
+ P---o---o---M---x---x---W---x
+  \         /
+   A---B---C----------------D---E   <-- fixed-up topic branch
+
+At this point, you can use --no-ff to recreate the topic branch:
+
+    $ git checkout E
+    $ git rebase --no-ff P
+
+yielding
+
+   A'---B'---C'------------D'---E'  <-- recreated topic branch
+  /
+ P---o---o---M---x---x---W---x
+  \         /
+   A---B---C----------------D---E
+
+You can merge the recreated branch into the mainline without reverting commit W,
+and mainline's history will look like this:
+
+   A'---B'---C'------------D'---E'
+  /                              \
+ P---o---o---M---x---x---W---x---M2
+  \         /
+   A---B---C
diff --git a/third_party/git/Documentation/howto/revert-branch-rebase.txt b/third_party/git/Documentation/howto/revert-branch-rebase.txt
new file mode 100644
index 0000000000..149508e13b
--- /dev/null
+++ b/third_party/git/Documentation/howto/revert-branch-rebase.txt
@@ -0,0 +1,187 @@
+From: Junio C Hamano <gitster@pobox.com>
+To: git@vger.kernel.org
+Subject: [HOWTO] Reverting an existing commit
+Abstract: In this article, JC gives a small real-life example of using
+ 'git revert' command, and using a temporary branch and tag for safety
+ and easier sanity checking.
+Date: Mon, 29 Aug 2005 21:39:02 -0700
+Content-type: text/asciidoc
+Message-ID: <7voe7g3uop.fsf@assigned-by-dhcp.cox.net>
+
+How to revert an existing commit
+================================
+
+One of the changes I pulled into the 'master' branch turns out to
+break building Git with GCC 2.95.  While they were well-intentioned
+portability fixes, keeping things working with gcc-2.95 was also
+important.  Here is what I did to revert the change in the 'master'
+branch and to adjust the 'pu' branch, using core Git tools and
+barebone Porcelain.
+
+First, prepare a throw-away branch in case I screw things up.
+
+------------------------------------------------
+$ git checkout -b revert-c99 master
+------------------------------------------------
+
+Now I am on the 'revert-c99' branch.  Let's figure out which commit to
+revert.  I happen to know that the top of the 'master' branch is a
+merge, and its second parent (i.e. foreign commit I merged from) has
+the change I would want to undo.  Further I happen to know that that
+merge introduced 5 commits or so:
+
+------------------------------------------------
+$ git show-branch --more=4 master master^2 | head
+* [master] Merge refs/heads/portable from http://www.cs.berkeley....
+ ! [master^2] Replace C99 array initializers with code.
+--
+-  [master] Merge refs/heads/portable from http://www.cs.berkeley....
+*+ [master^2] Replace C99 array initializers with code.
+*+ [master^2~1] Replace unsetenv() and setenv() with older putenv().
+*+ [master^2~2] Include sys/time.h in daemon.c.
+*+ [master^2~3] Fix ?: statements.
+*+ [master^2~4] Replace zero-length array decls with [].
+*  [master~1] tutorial note about git branch
+------------------------------------------------
+
+The '--more=4' above means "after we reach the merge base of refs,
+show until we display four more common commits".  That last commit
+would have been where the "portable" branch was forked from the main
+git.git repository, so this would show everything on both branches
+since then.  I just limited the output to the first handful using
+'head'.
+
+Now I know 'master^2~4' (pronounce it as "find the second parent of
+the 'master', and then go four generations back following the first
+parent") is the one I would want to revert.  Since I also want to say
+why I am reverting it, the '-n' flag is given to 'git revert'.  This
+prevents it from actually making a commit, and instead 'git revert'
+leaves the commit log message it wanted to use in '.msg' file:
+
+------------------------------------------------
+$ git revert -n master^2~4
+$ cat .msg
+Revert "Replace zero-length array decls with []."
+
+This reverts 6c5f9baa3bc0d63e141e0afc23110205379905a4 commit.
+$ git diff HEAD ;# to make sure what we are reverting makes sense.
+$ make CC=gcc-2.95 clean test ;# make sure it fixed the breakage.
+$ make clean test ;# make sure it did not cause other breakage.
+------------------------------------------------
+
+The reverted change makes sense (from reading the 'diff' output), does
+fix the problem (from 'make CC=gcc-2.95' test), and does not cause new
+breakage (from the last 'make test').  I'm ready to commit:
+
+------------------------------------------------
+$ git commit -a -s ;# read .msg into the log,
+                    # and explain why I am reverting.
+------------------------------------------------
+
+I could have screwed up in any of the above steps, but in the worst
+case I could just have done 'git checkout master' to start over.
+Fortunately I did not have to; what I have in the current branch
+'revert-c99' is what I want.  So merge that back into 'master':
+
+------------------------------------------------
+$ git checkout master
+$ git merge revert-c99 ;# this should be a fast-forward
+Updating from 10d781b9caa4f71495c7b34963bef137216f86a8 to e3a693c...
+ cache.h        |    8 ++++----
+ commit.c       |    2 +-
+ ls-files.c     |    2 +-
+ receive-pack.c |    2 +-
+ server-info.c  |    2 +-
+ 5 files changed, 8 insertions(+), 8 deletions(-)
+------------------------------------------------
+
+There is no need to redo the test at this point.  We fast-forwarded
+and we know 'master' matches 'revert-c99' exactly.  In fact:
+
+------------------------------------------------
+$ git diff master..revert-c99
+------------------------------------------------
+
+says nothing.
+
+Then we rebase the 'pu' branch as usual.
+
+------------------------------------------------
+$ git checkout pu
+$ git tag pu-anchor pu
+$ git rebase master
+* Applying: Redo "revert" using three-way merge machinery.
+First trying simple merge strategy to cherry-pick.
+* Applying: Remove git-apply-patch-script.
+First trying simple merge strategy to cherry-pick.
+Simple cherry-pick fails; trying Automatic cherry-pick.
+Removing Documentation/git-apply-patch-script.txt
+Removing git-apply-patch-script
+* Applying: Document "git cherry-pick" and "git revert"
+First trying simple merge strategy to cherry-pick.
+* Applying: mailinfo and applymbox updates
+First trying simple merge strategy to cherry-pick.
+* Applying: Show commits in topo order and name all commits.
+First trying simple merge strategy to cherry-pick.
+* Applying: More documentation updates.
+First trying simple merge strategy to cherry-pick.
+------------------------------------------------
+
+The temporary tag 'pu-anchor' is me just being careful, in case 'git
+rebase' screws up.  After this, I can do these for sanity check:
+
+------------------------------------------------
+$ git diff pu-anchor..pu ;# make sure we got the master fix.
+$ make CC=gcc-2.95 clean test ;# make sure it fixed the breakage.
+$ make clean test ;# make sure it did not cause other breakage.
+------------------------------------------------
+
+Everything is in the good order.  I do not need the temporary branch
+or tag anymore, so remove them:
+
+------------------------------------------------
+$ rm -f .git/refs/tags/pu-anchor
+$ git branch -d revert-c99
+------------------------------------------------
+
+It was an emergency fix, so we might as well merge it into the
+'release candidate' branch, although I expect the next release would
+be some days off:
+
+------------------------------------------------
+$ git checkout rc
+$ git pull . master
+Packing 0 objects
+Unpacking 0 objects
+
+* commit-ish: e3a693c...	refs/heads/master from .
+Trying to merge e3a693c... into 8c1f5f0... using 10d781b...
+Committed merge 7fb9b7262a1d1e0a47bbfdcbbcf50ce0635d3f8f
+ cache.h        |    8 ++++----
+ commit.c       |    2 +-
+ ls-files.c     |    2 +-
+ receive-pack.c |    2 +-
+ server-info.c  |    2 +-
+ 5 files changed, 8 insertions(+), 8 deletions(-)
+------------------------------------------------
+
+And the final repository status looks like this:
+
+------------------------------------------------
+$ git show-branch --more=1 master pu rc
+! [master] Revert "Replace zero-length array decls with []."
+ ! [pu] git-repack: Add option to repack all objects.
+  * [rc] Merge refs/heads/master from .
+---
+ +  [pu] git-repack: Add option to repack all objects.
+ +  [pu~1] More documentation updates.
+ +  [pu~2] Show commits in topo order and name all commits.
+ +  [pu~3] mailinfo and applymbox updates
+ +  [pu~4] Document "git cherry-pick" and "git revert"
+ +  [pu~5] Remove git-apply-patch-script.
+ +  [pu~6] Redo "revert" using three-way merge machinery.
+  - [rc] Merge refs/heads/master from .
+++* [master] Revert "Replace zero-length array decls with []."
+  - [rc~1] Merge refs/heads/master from .
+... [master~1] Merge refs/heads/portable from http://www.cs.berkeley....
+------------------------------------------------
diff --git a/third_party/git/Documentation/howto/separating-topic-branches.txt b/third_party/git/Documentation/howto/separating-topic-branches.txt
new file mode 100644
index 0000000000..bd1027433b
--- /dev/null
+++ b/third_party/git/Documentation/howto/separating-topic-branches.txt
@@ -0,0 +1,94 @@
+From: Junio C Hamano <gitster@pobox.com>
+Subject: Separating topic branches
+Abstract: In this article, JC describes how to separate topic branches.
+Content-type: text/asciidoc
+
+How to separate topic branches
+==============================
+
+This text was originally a footnote to a discussion about the
+behaviour of the git diff commands.
+
+Often I find myself doing that [running diff against something other
+than HEAD] while rewriting messy development history.  For example, I
+start doing some work without knowing exactly where it leads, and end
+up with a history like this:
+
+            "master"
+        o---o
+             \                    "topic"
+              o---o---o---o---o---o
+
+At this point, "topic" contains something I know I want, but it
+contains two concepts that turned out to be completely independent.
+And often, one topic component is larger than the other.  It may
+contain more than two topics.
+
+In order to rewrite this mess to be more manageable, I would first do
+"diff master..topic", to extract the changes into a single patch, start
+picking pieces from it to get logically self-contained units, and
+start building on top of "master":
+
+        $ git diff master..topic >P.diff
+        $ git checkout -b topicA master
+        ... pick and apply pieces from P.diff to build
+        ... commits on topicA branch.
+
+              o---o---o
+             /        "topicA"
+        o---o"master"
+             \                    "topic"
+              o---o---o---o---o---o
+
+Before doing each commit on "topicA" HEAD, I run "diff HEAD"
+before update-index the affected paths, or "diff --cached HEAD"
+after.  Also I would run "diff --cached master" to make sure
+that the changes are only the ones related to "topicA".  Usually
+I do this for smaller topics first.
+
+After that, I'd do the remainder of the original "topic", but
+for that, I do not start from the patchfile I extracted by
+comparing "master" and "topic" I used initially.  Still on
+"topicA", I extract "diff topic", and use it to rebuild the
+other topic:
+
+        $ git diff -R topic >P.diff ;# --cached also would work fine
+        $ git checkout -b topicB master
+        ... pick and apply pieces from P.diff to build
+        ... commits on topicB branch.
+
+                                "topicB"
+               o---o---o---o---o
+              /
+             /o---o---o
+            |/        "topicA"
+        o---o"master"
+             \                    "topic"
+              o---o---o---o---o---o
+
+After I am done, I'd try a pretend-merge between "topicA" and
+"topicB" in order to make sure I have not missed anything:
+
+        $ git pull . topicA ;# merge it into current "topicB"
+        $ git diff topic
+                                "topicB"
+               o---o---o---o---o---* (pretend merge)
+              /                   /
+             /o---o---o----------'
+            |/        "topicA"
+        o---o"master"
+             \                    "topic"
+              o---o---o---o---o---o
+
+The last diff better not to show anything other than cleanups
+for crufts.  Then I can finally clean things up:
+
+        $ git branch -D topic
+        $ git reset --hard HEAD^ ;# nuke pretend merge
+
+                                "topicB"
+               o---o---o---o---o
+              /
+             /o---o---o
+            |/        "topicA"
+        o---o"master"
diff --git a/third_party/git/Documentation/howto/setup-git-server-over-http.txt b/third_party/git/Documentation/howto/setup-git-server-over-http.txt
new file mode 100644
index 0000000000..bfe6f9b500
--- /dev/null
+++ b/third_party/git/Documentation/howto/setup-git-server-over-http.txt
@@ -0,0 +1,285 @@
+From: Rutger Nijlunsing <rutger@nospam.com>
+Subject: Setting up a Git repository which can be pushed into and pulled from over HTTP(S).
+Date: Thu, 10 Aug 2006 22:00:26 +0200
+Content-type: text/asciidoc
+
+How to setup Git server over http
+=================================
+
+NOTE: This document is from 2006.  A lot has happened since then, and this
+document is now relevant mainly if your web host is not CGI capable.
+Almost everyone else should instead look at linkgit:git-http-backend[1].
+
+Since Apache is one of those packages people like to compile
+themselves while others prefer the bureaucrat's dream Debian, it is
+impossible to give guidelines which will work for everyone. Just send
+some feedback to the mailing list at git@vger.kernel.org to get this
+document tailored to your favorite distro.
+
+
+What's needed:
+
+- Have an Apache web-server
+
+  On Debian:
+    $ apt-get install apache2
+    To get apache2 by default started,
+    edit /etc/default/apache2 and set NO_START=0
+
+- can edit the configuration of it.
+
+  This could be found under /etc/httpd, or refer to your Apache documentation.
+
+  On Debian: this means being able to edit files under /etc/apache2
+
+- can restart it.
+
+  'apachectl --graceful' might do. If it doesn't, just stop and
+  restart apache. Be warning that active connections to your server
+  might be aborted by this.
+
+  On Debian:
+    $ /etc/init.d/apache2 restart
+  or
+    $ /etc/init.d/apache2 force-reload
+    (which seems to do the same)
+  This adds symlinks from the /etc/apache2/mods-enabled to
+  /etc/apache2/mods-available.
+
+- have permissions to chown a directory
+
+- have Git installed on the client, and
+
+- either have Git installed on the server or have a webdav client on
+  the client.
+
+In effect, this means you're going to be root, or that you're using a
+preconfigured WebDAV server.
+
+
+Step 1: setup a bare Git repository
+-----------------------------------
+
+At the time of writing, git-http-push cannot remotely create a Git
+repository. So we have to do that at the server side with Git. Another
+option is to generate an empty bare repository at the client and copy
+it to the server with a WebDAV client (which is the only option if Git
+is not installed on the server).
+
+Create the directory under the DocumentRoot of the directories served
+by Apache. As an example we take /usr/local/apache2, but try "grep
+DocumentRoot /where/ever/httpd.conf" to find your root:
+
+    $ cd /usr/local/apache/htdocs
+    $ mkdir my-new-repo.git
+
+  On Debian:
+
+    $ cd /var/www
+    $ mkdir my-new-repo.git
+
+
+Initialize a bare repository
+
+    $ cd my-new-repo.git
+    $ git --bare init
+
+
+Change the ownership to your web-server's credentials. Use `"grep ^User
+httpd.conf"` and `"grep ^Group httpd.conf"` to find out:
+
+    $ chown -R www.www .
+
+  On Debian:
+
+    $ chown -R www-data.www-data .
+
+
+If you do not know which user Apache runs as, you can alternatively do
+a "chmod -R a+w .", inspect the files which are created later on, and
+set the permissions appropriately.
+
+Restart apache2, and check whether http://server/my-new-repo.git gives
+a directory listing. If not, check whether apache started up
+successfully.
+
+
+Step 2: enable DAV on this repository
+-------------------------------------
+
+First make sure the dav_module is loaded. For this, insert in httpd.conf:
+
+    LoadModule dav_module libexec/httpd/libdav.so
+    AddModule mod_dav.c
+
+Also make sure that this line exists which is the file used for
+locking DAV operations:
+
+  DAVLockDB "/usr/local/apache2/temp/DAV.lock"
+
+  On Debian these steps can be performed with:
+
+    Enable the dav and dav_fs modules of apache:
+    $ a2enmod dav_fs
+    (just to be sure. dav_fs might be unneeded, I don't know)
+    $ a2enmod dav
+    The DAV lock is located in /etc/apache2/mods-available/dav_fs.conf:
+      DAVLockDB /var/lock/apache2/DAVLock
+
+Of course, it can point somewhere else, but the string is actually just a
+prefix in some Apache configurations, and therefore the _directory_ has to
+be writable by the user Apache runs as.
+
+Then, add something like this to your httpd.conf
+
+  <Location /my-new-repo.git>
+     DAV on
+     AuthType Basic
+     AuthName "Git"
+     AuthUserFile /usr/local/apache2/conf/passwd.git
+     Require valid-user
+  </Location>
+
+  On Debian:
+    Create (or add to) /etc/apache2/conf.d/git.conf :
+
+    <Location /my-new-repo.git>
+       DAV on
+       AuthType Basic
+       AuthName "Git"
+       AuthUserFile /etc/apache2/passwd.git
+       Require valid-user
+    </Location>
+
+    Debian automatically reads all files under /etc/apache2/conf.d.
+
+The password file can be somewhere else, but it has to be readable by
+Apache and preferably not readable by the world.
+
+Create this file by
+    $ htpasswd -c /usr/local/apache2/conf/passwd.git <user>
+
+    On Debian:
+      $ htpasswd -c /etc/apache2/passwd.git <user>
+
+You will be asked a password, and the file is created. Subsequent calls
+to htpasswd should omit the '-c' option, since you want to append to the
+existing file.
+
+You need to restart Apache.
+
+Now go to http://<username>@<servername>/my-new-repo.git in your
+browser to check whether it asks for a password and accepts the right
+password.
+
+On Debian:
+
+   To test the WebDAV part, do:
+
+   $ apt-get install litmus
+   $ litmus http://<servername>/my-new-repo.git <username> <password>
+
+   Most tests should pass.
+
+A command-line tool to test WebDAV is cadaver. If you prefer GUIs, for
+example, konqueror can open WebDAV URLs as "webdav://..." or
+"webdavs://...".
+
+If you're into Windows, from XP onwards Internet Explorer supports
+WebDAV. For this, do Internet Explorer -> Open Location ->
+http://<servername>/my-new-repo.git [x] Open as webfolder -> login .
+
+
+Step 3: setup the client
+------------------------
+
+Make sure that you have HTTP support, i.e. your Git was built with
+libcurl (version more recent than 7.10). The command 'git http-push' with
+no argument should display a usage message.
+
+Then, add the following to your $HOME/.netrc (you can do without, but will be
+asked to input your password a _lot_ of times):
+
+    machine <servername>
+    login <username>
+    password <password>
+
+...and set permissions:
+     chmod 600 ~/.netrc
+
+If you want to access the web-server by its IP, you have to type that in,
+instead of the server name.
+
+To check whether all is OK, do:
+
+   curl --netrc --location -v http://<username>@<servername>/my-new-repo.git/HEAD
+
+...this should give something like 'ref: refs/heads/master', which is
+the content of the file HEAD on the server.
+
+Now, add the remote in your existing repository which contains the project
+you want to export:
+
+   $ git-config remote.upload.url \
+       http://<username>@<servername>/my-new-repo.git/
+
+It is important to put the last '/'; Without it, the server will send
+a redirect which git-http-push does not (yet) understand, and git-http-push
+will repeat the request infinitely.
+
+
+Step 4: make the initial push
+-----------------------------
+
+From your client repository, do
+
+   $ git push upload master
+
+This pushes branch 'master' (which is assumed to be the branch you
+want to export) to repository called 'upload', which we previously
+defined with git-config.
+
+
+Using a proxy:
+--------------
+
+If you have to access the WebDAV server from behind an HTTP(S) proxy,
+set the variable 'all_proxy' to `http://proxy-host.com:port`, or
+`http://login-on-proxy:passwd-on-proxy@proxy-host.com:port`. See 'man
+curl' for details.
+
+
+Troubleshooting:
+----------------
+
+If git-http-push says
+
+   Error: no DAV locking support on remote repo http://...
+
+then it means the web-server did not accept your authentication. Make sure
+that the user name and password matches in httpd.conf, .netrc and the URL
+you are uploading to.
+
+If git-http-push shows you an error (22/502) when trying to MOVE a blob,
+it means that your web-server somehow does not recognize its name in the
+request; This can happen when you start Apache, but then disable the
+network interface. A simple restart of Apache helps.
+
+Errors like (22/502) are of format (curl error code/http error
+code). So (22/404) means something like 'not found' at the server.
+
+Reading /usr/local/apache2/logs/error_log is often helpful.
+
+  On Debian: Read /var/log/apache2/error.log instead.
+
+If you access HTTPS locations, Git may fail verifying the SSL
+certificate (this is return code 60). Setting http.sslVerify=false can
+help diagnosing the problem, but removes security checks.
+
+
+Debian References: http://www.debian-administration.org/articles/285
+
+Authors
+  Johannes Schindelin <Johannes.Schindelin@gmx.de>
+  Rutger Nijlunsing <git@wingding.demon.nl>
+  Matthieu Moy <Matthieu.Moy@imag.fr>
diff --git a/third_party/git/Documentation/howto/update-hook-example.txt b/third_party/git/Documentation/howto/update-hook-example.txt
new file mode 100644
index 0000000000..89821ec74f
--- /dev/null
+++ b/third_party/git/Documentation/howto/update-hook-example.txt
@@ -0,0 +1,192 @@
+From: Junio C Hamano <gitster@pobox.com> and Carl Baldwin <cnb@fc.hp.com>
+Subject: control access to branches.
+Date: Thu, 17 Nov 2005 23:55:32 -0800
+Message-ID: <7vfypumlu3.fsf@assigned-by-dhcp.cox.net>
+Abstract: An example hooks/update script is presented to
+ implement repository maintenance policies, such as who can push
+ into which branch and who can make a tag.
+Content-type: text/asciidoc
+
+How to use the update hook
+==========================
+
+When your developer runs git-push into the repository,
+git-receive-pack is run (either locally or over ssh) as that
+developer, so is hooks/update script.  Quoting from the relevant
+section of the documentation:
+
+    Before each ref is updated, if $GIT_DIR/hooks/update file exists
+    and executable, it is called with three parameters:
+
+           $GIT_DIR/hooks/update refname sha1-old sha1-new
+
+    The refname parameter is relative to $GIT_DIR; e.g. for the
+    master head this is "refs/heads/master".  Two sha1 are the
+    object names for the refname before and after the update.  Note
+    that the hook is called before the refname is updated, so either
+    sha1-old is 0{40} (meaning there is no such ref yet), or it
+    should match what is recorded in refname.
+
+So if your policy is (1) always require fast-forward push
+(i.e. never allow "git-push repo +branch:branch"), (2) you
+have a list of users allowed to update each branch, and (3) you
+do not let tags to be overwritten, then you can use something
+like this as your hooks/update script.
+
+[jc: editorial note.  This is a much improved version by Carl
+since I posted the original outline]
+
+----------------------------------------------------
+#!/bin/bash
+
+umask 002
+
+# If you are having trouble with this access control hook script
+# you can try setting this to true.  It will tell you exactly
+# why a user is being allowed/denied access.
+
+verbose=false
+
+# Default shell globbing messes things up downstream
+GLOBIGNORE=*
+
+function grant {
+  $verbose && echo >&2 "-Grant-		$1"
+  echo grant
+  exit 0
+}
+
+function deny {
+  $verbose && echo >&2 "-Deny-		$1"
+  echo deny
+  exit 1
+}
+
+function info {
+  $verbose && echo >&2 "-Info-		$1"
+}
+
+# Implement generic branch and tag policies.
+# - Tags should not be updated once created.
+# - Branches should only be fast-forwarded unless their pattern starts with '+'
+case "$1" in
+  refs/tags/*)
+    git rev-parse --verify -q "$1" &&
+    deny >/dev/null "You can't overwrite an existing tag"
+    ;;
+  refs/heads/*)
+    # No rebasing or rewinding
+    if expr "$2" : '0*$' >/dev/null; then
+      info "The branch '$1' is new..."
+    else
+      # updating -- make sure it is a fast-forward
+      mb=$(git merge-base "$2" "$3")
+      case "$mb,$2" in
+        "$2,$mb") info "Update is fast-forward" ;;
+	*)	  noff=y; info "This is not a fast-forward update.";;
+      esac
+    fi
+    ;;
+  *)
+    deny >/dev/null \
+    "Branch is not under refs/heads or refs/tags.  What are you trying to do?"
+    ;;
+esac
+
+# Implement per-branch controls based on username
+allowed_users_file=$GIT_DIR/info/allowed-users
+username=$(id -u -n)
+info "The user is: '$username'"
+
+if test -f "$allowed_users_file"
+then
+  rc=$(cat $allowed_users_file | grep -v '^#' | grep -v '^$' |
+    while read heads user_patterns
+    do
+      # does this rule apply to us?
+      head_pattern=${heads#+}
+      matchlen=$(expr "$1" : "${head_pattern#+}")
+      test "$matchlen" = ${#1} || continue
+
+      # if non-ff, $heads must be with the '+' prefix
+      test -n "$noff" &&
+      test "$head_pattern" = "$heads" && continue
+
+      info "Found matching head pattern: '$head_pattern'"
+      for user_pattern in $user_patterns; do
+        info "Checking user: '$username' against pattern: '$user_pattern'"
+        matchlen=$(expr "$username" : "$user_pattern")
+        if test "$matchlen" = "${#username}"
+        then
+          grant "Allowing user: '$username' with pattern: '$user_pattern'"
+        fi
+      done
+      deny "The user is not in the access list for this branch"
+    done
+  )
+  case "$rc" in
+    grant) grant >/dev/null "Granting access based on $allowed_users_file" ;;
+    deny)  deny  >/dev/null "Denying  access based on $allowed_users_file" ;;
+    *) ;;
+  esac
+fi
+
+allowed_groups_file=$GIT_DIR/info/allowed-groups
+groups=$(id -G -n)
+info "The user belongs to the following groups:"
+info "'$groups'"
+
+if test -f "$allowed_groups_file"
+then
+  rc=$(cat $allowed_groups_file | grep -v '^#' | grep -v '^$' |
+    while read heads group_patterns
+    do
+      # does this rule apply to us?
+      head_pattern=${heads#+}
+      matchlen=$(expr "$1" : "${head_pattern#+}")
+      test "$matchlen" = ${#1} || continue
+
+      # if non-ff, $heads must be with the '+' prefix
+      test -n "$noff" &&
+      test "$head_pattern" = "$heads" && continue
+
+      info "Found matching head pattern: '$head_pattern'"
+      for group_pattern in $group_patterns; do
+        for groupname in $groups; do
+          info "Checking group: '$groupname' against pattern: '$group_pattern'"
+          matchlen=$(expr "$groupname" : "$group_pattern")
+          if test "$matchlen" = "${#groupname}"
+          then
+            grant "Allowing group: '$groupname' with pattern: '$group_pattern'"
+          fi
+        done
+      done
+      deny "None of the user's groups are in the access list for this branch"
+    done
+  )
+  case "$rc" in
+    grant) grant >/dev/null "Granting access based on $allowed_groups_file" ;;
+    deny)  deny  >/dev/null "Denying  access based on $allowed_groups_file" ;;
+    *) ;;
+  esac
+fi
+
+deny >/dev/null "There are no more rules to check.  Denying access"
+----------------------------------------------------
+
+This uses two files, $GIT_DIR/info/allowed-users and
+allowed-groups, to describe which heads can be pushed into by
+whom.  The format of each file would look like this:
+
+    refs/heads/master   junio
+    +refs/heads/pu      junio
+    refs/heads/cogito$  pasky
+    refs/heads/bw/.*    linus
+    refs/heads/tmp/.*   .*
+    refs/tags/v[0-9].*  junio
+
+With this, Linus can push or create "bw/penguin" or "bw/zebra"
+or "bw/panda" branches, Pasky can do only "cogito", and JC can
+do master and pu branches and make versioned tags.  And anybody
+can do tmp/blah branches. The '+' sign at the pu record means
+that JC can make non-fast-forward pushes on it.
diff --git a/third_party/git/Documentation/howto/use-git-daemon.txt b/third_party/git/Documentation/howto/use-git-daemon.txt
new file mode 100644
index 0000000000..7af2e52cf3
--- /dev/null
+++ b/third_party/git/Documentation/howto/use-git-daemon.txt
@@ -0,0 +1,54 @@
+Content-type: text/asciidoc
+
+How to use git-daemon
+=====================
+
+Git can be run in inetd mode and in stand alone mode. But all you want is
+let a coworker pull from you, and therefore need to set up a Git server
+real quick, right?
+
+Note that git-daemon is not really chatty at the moment, especially when
+things do not go according to plan (e.g. a socket could not be bound).
+
+Another word of warning: if you run
+
+	$ git ls-remote git://127.0.0.1/rule-the-world.git
+
+and you see a message like
+
+	fatal: The remote end hung up unexpectedly
+
+it only means that _something_ went wrong. To find out _what_ went wrong,
+you have to ask the server. (Git refuses to be more precise for your
+security only. Take off your shoes now. You have any coins in your pockets?
+Sorry, not allowed -- who knows what you planned to do with them?)
+
+With these two caveats, let's see an example:
+
+	$ git daemon --reuseaddr --verbose --base-path=/home/gitte/git \
+	  --export-all -- /home/gitte/git/rule-the-world.git
+
+(Of course, unless your user name is `gitte` _and_ your repository is in
+~/rule-the-world.git, you have to adjust the paths. If your repository is
+not bare, be aware that you have to type the path to the .git directory!)
+
+This invocation tries to reuse the address if it is already taken
+(this can save you some debugging, because otherwise killing and restarting
+git-daemon could just silently fail to bind to a socket).
+
+Also, it is (relatively) verbose when somebody actually connects to it.
+It also sets the base path, which means that all the projects which can be
+accessed using this daemon have to reside in or under that path.
+
+The option `--export-all` just means that you _don't_ have to create a
+file named `git-daemon-export-ok` in each exported repository. (Otherwise,
+git-daemon would complain loudly, and refuse to cooperate.)
+
+Last of all, the repository which should be exported is specified. It is
+a good practice to put the paths after a "--" separator.
+
+Now, test your daemon with
+
+	$ git ls-remote git://127.0.0.1/rule-the-world.git
+
+If this does not work, find out why, and submit a patch to this document.
diff --git a/third_party/git/Documentation/howto/using-merge-subtree.txt b/third_party/git/Documentation/howto/using-merge-subtree.txt
new file mode 100644
index 0000000000..a499a94ac2
--- /dev/null
+++ b/third_party/git/Documentation/howto/using-merge-subtree.txt
@@ -0,0 +1,75 @@
+Date: Sat, 5 Jan 2008 20:17:40 -0500
+From: Sean <seanlkml@sympatico.ca>
+To: Miklos Vajna <vmiklos@frugalware.org>
+Cc: git@vger.kernel.org
+Subject: how to use git merge -s subtree?
+Abstract: In this article, Sean demonstrates how one can use the subtree merge
+ strategy.
+Content-type: text/asciidoc
+Message-ID: <BAYC1-PASMTP12374B54BA370A1E1C6E78AE4E0@CEZ.ICE>
+
+How to use the subtree merge strategy
+=====================================
+
+There are situations where you want to include contents in your project
+from an independently developed project. You can just pull from the
+other project as long as there are no conflicting paths.
+
+The problematic case is when there are conflicting files. Potential
+candidates are Makefiles and other standard filenames. You could merge
+these files but probably you do not want to.  A better solution for this
+problem can be to merge the project as its own subdirectory. This is not
+supported by the 'recursive' merge strategy, so just pulling won't work.
+
+What you want is the 'subtree' merge strategy, which helps you in such a
+situation.
+
+In this example, let's say you have the repository at `/path/to/B` (but
+it can be a URL as well, if you want). You want to merge the 'master'
+branch of that repository to the `dir-B` subdirectory in your current
+branch.
+
+Here is the command sequence you need:
+
+----------------
+$ git remote add -f Bproject /path/to/B <1>
+$ git merge -s ours --no-commit --allow-unrelated-histories Bproject/master <2>
+$ git read-tree --prefix=dir-B/ -u Bproject/master <3>
+$ git commit -m "Merge B project as our subdirectory" <4>
+
+$ git pull -s subtree Bproject master <5>
+----------------
+<1> name the other project "Bproject", and fetch.
+<2> prepare for the later step to record the result as a merge.
+<3> read "master" branch of Bproject to the subdirectory "dir-B".
+<4> record the merge result.
+<5> maintain the result with subsequent merges using "subtree"
+
+The first four commands are used for the initial merge, while the last
+one is to merge updates from 'B project'.
+
+Comparing 'subtree' merge with submodules
+-----------------------------------------
+
+- The benefit of using subtree merge is that it requires less
+  administrative burden from the users of your repository. It works with
+  older (before Git v1.5.2) clients and you have the code right after
+  clone.
+
+- However if you use submodules then you can choose not to transfer the
+  submodule objects. This may be a problem with the subtree merge.
+
+- Also, in case you make changes to the other project, it is easier to
+  submit changes if you just use submodules.
+
+Additional tips
+---------------
+
+- If you made changes to the other project in your repository, they may
+  want to merge from your project. This is possible using subtree -- it
+  can shift up the paths in your tree and then they can merge only the
+  relevant parts of your tree.
+
+- Please note that if the other project merges from you, then it will
+  connect its history to yours, which can be something they don't want
+  to.
diff --git a/third_party/git/Documentation/howto/using-signed-tag-in-pull-request.txt b/third_party/git/Documentation/howto/using-signed-tag-in-pull-request.txt
new file mode 100644
index 0000000000..bbf040eda8
--- /dev/null
+++ b/third_party/git/Documentation/howto/using-signed-tag-in-pull-request.txt
@@ -0,0 +1,217 @@
+From: Junio C Hamano <gitster@pobox.com>
+Date: Tue, 17 Jan 2011 13:00:00 -0800
+Subject: Using signed tag in pull requests
+Abstract: Beginning v1.7.9, a contributor can push a signed tag to her
+ publishing repository and ask her integrator to pull it. This assures the
+ integrator that the pulled history is authentic and allows others to
+ later validate it.
+Content-type: text/asciidoc
+
+How to use a signed tag in pull requests
+========================================
+
+A typical distributed workflow using Git is for a contributor to fork a
+project, build on it, publish the result to her public repository, and ask
+the "upstream" person (often the owner of the project where she forked
+from) to pull from her public repository. Requesting such a "pull" is made
+easy by the `git request-pull` command.
+
+Earlier, a typical pull request may have started like this:
+
+------------
+ The following changes since commit 406da78032179...:
+
+   Froboz 3.2 (2011-09-30 14:20:57 -0700)
+
+ are available in the Git repository at:
+
+   example.com:/git/froboz.git for-xyzzy
+------------
+
+followed by a shortlog of the changes and a diffstat.
+
+The request was for a branch name (e.g. `for-xyzzy`) in the public
+repository of the contributor, and even though it stated where the
+contributor forked her work from, the message did not say anything about
+the commit to expect at the tip of the for-xyzzy branch. If the site that
+hosts the public repository of the contributor cannot be fully trusted, it
+was unnecessarily hard to make sure what was pulled by the integrator was
+genuinely what the contributor had produced for the project. Also there
+was no easy way for third-party auditors to later verify the resulting
+history.
+
+Starting from Git release v1.7.9, a contributor can add a signed tag to
+the commit at the tip of the history and ask the integrator to pull that
+signed tag. When the integrator runs `git pull`, the signed tag is
+automatically verified to assure that the history is not tampered with.
+In addition, the resulting merge commit records the content of the signed
+tag, so that other people can verify that the branch merged by the
+integrator was signed by the contributor, without fetching the signed tag
+used to validate the pull request separately and keeping it in the refs
+namespace.
+
+This document describes the workflow between the contributor and the
+integrator, using Git v1.7.9 or later.
+
+
+A contributor or a lieutenant
+-----------------------------
+
+After preparing her work to be pulled, the contributor uses `git tag -s`
+to create a signed tag:
+
+------------
+ $ git checkout work
+ $ ... "git pull" from sublieutenants, "git commit" your own work ...
+ $ git tag -s -m "Completed frotz feature" frotz-for-xyzzy work
+------------
+
+Note that this example uses the `-m` option to create a signed tag with
+just a one-liner message, but this is for illustration purposes only. It
+is advisable to compose a well-written explanation of what the topic does
+to justify why it is worthwhile for the integrator to pull it, as this
+message will eventually become part of the final history after the
+integrator responds to the pull request (as we will see later).
+
+Then she pushes the tag out to her public repository:
+
+------------
+ $ git push example.com:/git/froboz.git/ +frotz-for-xyzzy
+------------
+
+There is no need to push the `work` branch or anything else.
+
+Note that the above command line used a plus sign at the beginning of
+`+frotz-for-xyzzy` to allow forcing the update of a tag, as the same
+contributor may want to reuse a signed tag with the same name after the
+previous pull request has already been responded to.
+
+The contributor then prepares a message to request a "pull":
+
+------------
+ $ git request-pull v3.2 example.com:/git/froboz.git/ frotz-for-xyzzy >msg.txt
+------------
+
+The arguments are:
+
+. the version of the integrator's commit the contributor based her work on;
+. the URL of the repository, to which the contributor has pushed what she
+  wants to get pulled; and
+. the name of the tag the contributor wants to get pulled (earlier, she could
+  write only a branch name here).
+
+The resulting msg.txt file begins like so:
+
+------------
+ The following changes since commit 406da78032179...:
+
+   Froboz 3.2 (2011-09-30 14:20:57 -0700)
+
+ are available in the Git repository at:
+
+   example.com:/git/froboz.git tags/frotz-for-xyzzy
+
+ for you to fetch changes up to 703f05ad5835c...:
+
+   Add tests and documentation for frotz (2011-12-02 10:02:52 -0800)
+
+ -----------------------------------------------
+ Completed frotz feature
+ -----------------------------------------------
+------------
+
+followed by a shortlog of the changes and a diffstat.  Comparing this with
+the earlier illustration of the output from the traditional `git request-pull`
+command, the reader should notice that:
+
+. The tip commit to expect is shown to the integrator; and
+. The signed tag message is shown prominently between the dashed lines
+  before the shortlog.
+
+The latter is why the contributor would want to justify why pulling her
+work is worthwhile when creating the signed tag.  The contributor then
+opens her favorite MUA, reads msg.txt, edits and sends it to her upstream
+integrator.
+
+
+Integrator
+----------
+
+After receiving such a pull request message, the integrator fetches and
+integrates the tag named in the request, with:
+
+------------
+ $ git pull example.com:/git/froboz.git/ tags/frotz-for-xyzzy
+------------
+
+This operation will always open an editor to allow the integrator to fine
+tune the commit log message when merging a signed tag.  Also, pulling a
+signed tag will always create a merge commit even when the integrator does
+not have any new commit since the contributor's work forked (i.e. 'fast
+forward'), so that the integrator can properly explain what the merge is
+about and why it was made.
+
+In the editor, the integrator will see something like this:
+
+------------
+ Merge tag 'frotz-for-xyzzy' of example.com:/git/froboz.git/
+
+ Completed frotz feature
+ # gpg: Signature made Fri 02 Dec 2011 10:03:01 AM PST using RSA key ID 96AFE6CB
+ # gpg: Good signature from "Con Tributor <nitfol@example.com>"
+------------
+
+Notice that the message recorded in the signed tag "Completed frotz
+feature" appears here, and again that is why it is important for the
+contributor to explain her work well when creating the signed tag.
+
+As usual, the lines commented with `#` are stripped out. The resulting
+commit records the signed tag used for this validation in a hidden field
+so that it can later be used by others to audit the history. There is no
+need for the integrator to keep a separate copy of the tag in his
+repository (i.e. `git tag -l` won't list the `frotz-for-xyzzy` tag in the
+above example), and there is no need to publish the tag to his public
+repository, either.
+
+After the integrator responds to the pull request and her work becomes
+part of the permanent history, the contributor can remove the tag from
+her public repository, if she chooses, in order to keep the tag namespace
+of her public repository clean, with:
+
+------------
+ $ git push example.com:/git/froboz.git :frotz-for-xyzzy
+------------
+
+
+Auditors
+--------
+
+The `--show-signature` option can be given to `git log` or `git show` and
+shows the verification status of the embedded signed tag in merge commits
+created when the integrator responded to a pull request of a signed tag.
+
+A typical output from `git show --show-signature` may look like this:
+
+------------
+ $ git show --show-signature
+ commit 02306ef6a3498a39118aef9df7975bdb50091585
+ merged tag 'frotz-for-xyzzy'
+ gpg: Signature made Fri 06 Jan 2012 12:41:49 PM PST using RSA key ID 96AFE6CB
+ gpg: Good signature from "Con Tributor <nitfol@example.com>"
+ Merge: 406da78 703f05a
+ Author: Inte Grator <xyzzy@example.com>
+ Date:   Tue Jan 17 13:49:41 2012 -0800
+
+     Merge tag 'frotz-for-xyzzy' of example.com:/git/froboz.git/
+
+     Completed frotz feature
+
+     * tag 'frotz-for-xyzzy' (100 commits)
+       Add tests and documentation for frotz
+       ...
+------------
+
+There is no need for the auditor to explicitly fetch the contributor's
+signature, or to even be aware of what tag(s) the contributor and integrator
+used to communicate the signature.  All the required information is recorded
+as part of the merge commit.
diff --git a/third_party/git/Documentation/i18n.txt b/third_party/git/Documentation/i18n.txt
new file mode 100644
index 0000000000..7e36e5b55b
--- /dev/null
+++ b/third_party/git/Documentation/i18n.txt
@@ -0,0 +1,70 @@
+Git is to some extent character encoding agnostic.
+
+ - The contents of the blob objects are uninterpreted sequences
+   of bytes.  There is no encoding translation at the core
+   level.
+
+ - Path names are encoded in UTF-8 normalization form C. This
+   applies to tree objects, the index file, ref names, as well as
+   path names in command line arguments, environment variables
+   and config files (`.git/config` (see linkgit:git-config[1]),
+   linkgit:gitignore[5], linkgit:gitattributes[5] and
+   linkgit:gitmodules[5]).
++
+Note that Git at the core level treats path names simply as
+sequences of non-NUL bytes, there are no path name encoding
+conversions (except on Mac and Windows). Therefore, using
+non-ASCII path names will mostly work even on platforms and file
+systems that use legacy extended ASCII encodings. However,
+repositories created on such systems will not work properly on
+UTF-8-based systems (e.g. Linux, Mac, Windows) and vice versa.
+Additionally, many Git-based tools simply assume path names to
+be UTF-8 and will fail to display other encodings correctly.
+
+ - Commit log messages are typically encoded in UTF-8, but other
+   extended ASCII encodings are also supported. This includes
+   ISO-8859-x, CP125x and many others, but _not_ UTF-16/32,
+   EBCDIC and CJK multi-byte encodings (GBK, Shift-JIS, Big5,
+   EUC-x, CP9xx etc.).
+
+Although we encourage that the commit log messages are encoded
+in UTF-8, both the core and Git Porcelain are designed not to
+force UTF-8 on projects.  If all participants of a particular
+project find it more convenient to use legacy encodings, Git
+does not forbid it.  However, there are a few things to keep in
+mind.
+
+. 'git commit' and 'git commit-tree' issues
+  a warning if the commit log message given to it does not look
+  like a valid UTF-8 string, unless you explicitly say your
+  project uses a legacy encoding.  The way to say this is to
+  have i18n.commitencoding in `.git/config` file, like this:
++
+------------
+[i18n]
+	commitEncoding = ISO-8859-1
+------------
++
+Commit objects created with the above setting record the value
+of `i18n.commitEncoding` in its `encoding` header.  This is to
+help other people who look at them later.  Lack of this header
+implies that the commit log message is encoded in UTF-8.
+
+. 'git log', 'git show', 'git blame' and friends look at the
+  `encoding` header of a commit object, and try to re-code the
+  log message into UTF-8 unless otherwise specified.  You can
+  specify the desired output encoding with
+  `i18n.logOutputEncoding` in `.git/config` file, like this:
++
+------------
+[i18n]
+	logOutputEncoding = ISO-8859-1
+------------
++
+If you do not have this configuration variable, the value of
+`i18n.commitEncoding` is used instead.
+
+Note that we deliberately chose not to re-code the commit log
+message when a commit is made to force UTF-8 at the commit
+object level, because re-coding to UTF-8 is not necessarily a
+reversible operation.
diff --git a/third_party/git/Documentation/install-doc-quick.sh b/third_party/git/Documentation/install-doc-quick.sh
new file mode 100755
index 0000000000..17231d8e59
--- /dev/null
+++ b/third_party/git/Documentation/install-doc-quick.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+# This requires git-manpages and/or git-htmldocs repositories
+
+repository=${1?repository}
+destdir=${2?destination}
+GIT_MAN_REF=${3?master}
+
+GIT_DIR=
+for d in "$repository/.git" "$repository"
+do
+	if GIT_DIR="$d" git rev-parse "$GIT_MAN_REF" >/dev/null 2>&1
+	then
+		GIT_DIR="$d"
+		export GIT_DIR
+		break
+	fi
+done
+
+if test -z "$GIT_DIR"
+then
+	echo >&2 "Neither $repository nor $repository/.git is a repository"
+	exit 1
+fi
+
+GIT_WORK_TREE=$(pwd)
+GIT_INDEX_FILE=$(pwd)/.quick-doc.$$
+export GIT_INDEX_FILE GIT_WORK_TREE
+rm -f "$GIT_INDEX_FILE"
+trap 'rm -f "$GIT_INDEX_FILE"' 0
+
+git read-tree "$GIT_MAN_REF"
+git checkout-index -a -f --prefix="$destdir"/
+
+if test -n "$GZ"
+then
+	git ls-tree -r --name-only "$GIT_MAN_REF" |
+	xargs printf "$destdir/%s\n" |
+	xargs gzip -f
+fi
+rm -f "$GIT_INDEX_FILE"
diff --git a/third_party/git/Documentation/install-webdoc.sh b/third_party/git/Documentation/install-webdoc.sh
new file mode 100755
index 0000000000..ed8b4ff3e5
--- /dev/null
+++ b/third_party/git/Documentation/install-webdoc.sh
@@ -0,0 +1,39 @@
+#!/bin/sh
+
+T="$1"
+
+for h in \
+	*.txt *.html \
+	howto/*.txt howto/*.html \
+	technical/*.txt technical/*.html \
+	RelNotes/*.txt *.css
+do
+	if test ! -f "$h"
+	then
+		: did not match
+	elif test -f "$T/$h" &&
+		$DIFF -u -I'^Last updated ' "$T/$h" "$h"
+	then
+		:; # up to date
+	else
+		echo >&2 "# install $h $T/$h"
+		rm -f "$T/$h"
+		mkdir -p $(dirname "$T/$h")
+		cp "$h" "$T/$h"
+	fi
+done
+strip_leading=$(echo "$T/" | sed -e 's|.|.|g')
+for th in \
+	"$T"/*.html "$T"/*.txt \
+	"$T"/howto/*.txt "$T"/howto/*.html \
+	"$T"/technical/*.txt "$T"/technical/*.html
+do
+	h=$(expr "$th" : "$strip_leading"'\(.*\)')
+	case "$h" in
+	RelNotes-*.txt | index.html) continue ;;
+	esac
+	test -f "$h" && continue
+	echo >&2 "# rm -f $th"
+	rm -f "$th"
+done
+ln -sf git.html "$T/index.html"
diff --git a/third_party/git/Documentation/line-range-format.txt b/third_party/git/Documentation/line-range-format.txt
new file mode 100644
index 0000000000..829676ff98
--- /dev/null
+++ b/third_party/git/Documentation/line-range-format.txt
@@ -0,0 +1,30 @@
+<start> and <end> can take one of these forms:
+
+- number
++
+If <start> or <end> is a number, it specifies an
+absolute line number (lines count from 1).
++
+
+- /regex/
++
+This form will use the first line matching the given
+POSIX regex. If <start> is a regex, it will search from the end of
+the previous `-L` range, if any, otherwise from the start of file.
+If <start> is ``^/regex/'', it will search from the start of file.
+If <end> is a regex, it will search
+starting at the line given by <start>.
++
+
+- +offset or -offset
++
+This is only valid for <end> and will specify a number
+of lines before or after the line given by <start>.
+
++
+If ``:<funcname>'' is given in place of <start> and <end>, it is a
+regular expression that denotes the range from the first funcname line
+that matches <funcname>, up to the next funcname line. ``:<funcname>''
+searches from the end of the previous `-L` range, if any, otherwise
+from the start of file. ``^:<funcname>'' searches from the start of
+file.
diff --git a/third_party/git/Documentation/lint-gitlink.perl b/third_party/git/Documentation/lint-gitlink.perl
new file mode 100755
index 0000000000..476cc30b83
--- /dev/null
+++ b/third_party/git/Documentation/lint-gitlink.perl
@@ -0,0 +1,71 @@
+#!/usr/bin/perl
+
+use File::Find;
+use Getopt::Long;
+
+my $basedir = ".";
+GetOptions("basedir=s" => \$basedir)
+	or die("Cannot parse command line arguments\n");
+
+my $found_errors = 0;
+
+sub report {
+	my ($where, $what, $error) = @_;
+	print "$where: $error: $what\n";
+	$found_errors = 1;
+}
+
+sub grab_section {
+	my ($page) = @_;
+	open my $fh, "<", "$basedir/$page.txt";
+	my $firstline = <$fh>;
+	chomp $firstline;
+	close $fh;
+	my ($section) = ($firstline =~ /.*\((\d)\)$/);
+	return $section;
+}
+
+sub lint {
+	my ($file) = @_;
+	open my $fh, "<", $file
+		or return;
+	while (<$fh>) {
+		my $where = "$file:$.";
+		while (s/linkgit:((.*?)\[(\d)\])//) {
+			my ($target, $page, $section) = ($1, $2, $3);
+
+			# De-AsciiDoc
+			$page =~ s/{litdd}/--/g;
+
+			if ($page !~ /^git/) {
+				report($where, $target, "nongit link");
+				next;
+			}
+			if (! -f "$basedir/$page.txt") {
+				report($where, $target, "no such source");
+				next;
+			}
+			$real_section = grab_section($page);
+			if ($real_section != $section) {
+				report($where, $target,
+					"wrong section (should be $real_section)");
+				next;
+			}
+		}
+	}
+	close $fh;
+}
+
+sub lint_it {
+	lint($File::Find::name) if -f && /\.txt$/;
+}
+
+if (!@ARGV) {
+	find({ wanted => \&lint_it, no_chdir => 1 }, $basedir);
+} else {
+	for (@ARGV) {
+		lint($_);
+	}
+}
+
+exit $found_errors;
diff --git a/third_party/git/Documentation/mailmap.txt b/third_party/git/Documentation/mailmap.txt
new file mode 100644
index 0000000000..4a8c276529
--- /dev/null
+++ b/third_party/git/Documentation/mailmap.txt
@@ -0,0 +1,75 @@
+If the file `.mailmap` exists at the toplevel of the repository, or at
+the location pointed to by the mailmap.file or mailmap.blob
+configuration options, it
+is used to map author and committer names and email addresses to
+canonical real names and email addresses.
+
+In the simple form, each line in the file consists of the canonical
+real name of an author, whitespace, and an email address used in the
+commit (enclosed by '<' and '>') to map to the name. For example:
+--
+	Proper Name <commit@email.xx>
+--
+
+The more complex forms are:
+--
+	<proper@email.xx> <commit@email.xx>
+--
+which allows mailmap to replace only the email part of a commit, and:
+--
+	Proper Name <proper@email.xx> <commit@email.xx>
+--
+which allows mailmap to replace both the name and the email of a
+commit matching the specified commit email address, and:
+--
+	Proper Name <proper@email.xx> Commit Name <commit@email.xx>
+--
+which allows mailmap to replace both the name and the email of a
+commit matching both the specified commit name and email address.
+
+Example 1: Your history contains commits by two authors, Jane
+and Joe, whose names appear in the repository under several forms:
+
+------------
+Joe Developer <joe@example.com>
+Joe R. Developer <joe@example.com>
+Jane Doe <jane@example.com>
+Jane Doe <jane@laptop.(none)>
+Jane D. <jane@desktop.(none)>
+------------
+
+Now suppose that Joe wants his middle name initial used, and Jane
+prefers her family name fully spelled out. A proper `.mailmap` file
+would look like:
+
+------------
+Jane Doe         <jane@desktop.(none)>
+Joe R. Developer <joe@example.com>
+------------
+
+Note how there is no need for an entry for `<jane@laptop.(none)>`, because the
+real name of that author is already correct.
+
+Example 2: Your repository contains commits from the following
+authors:
+
+------------
+nick1 <bugs@company.xx>
+nick2 <bugs@company.xx>
+nick2 <nick2@company.xx>
+santa <me@company.xx>
+claus <me@company.xx>
+CTO <cto@coompany.xx>
+------------
+
+Then you might want a `.mailmap` file that looks like:
+------------
+<cto@company.xx>                       <cto@coompany.xx>
+Some Dude <some@dude.xx>         nick1 <bugs@company.xx>
+Other Author <other@author.xx>   nick2 <bugs@company.xx>
+Other Author <other@author.xx>         <nick2@company.xx>
+Santa Claus <santa.claus@northpole.xx> <me@company.xx>
+------------
+
+Use hash '#' for comments that are either on their own line, or after
+the email address.
diff --git a/third_party/git/Documentation/manpage-1.72.xsl b/third_party/git/Documentation/manpage-1.72.xsl
new file mode 100644
index 0000000000..b4d315cb8c
--- /dev/null
+++ b/third_party/git/Documentation/manpage-1.72.xsl
@@ -0,0 +1,14 @@
+<!-- manpage-1.72.xsl:
+     special settings for manpages rendered from asciidoc+docbook
+     handles peculiarities in docbook-xsl 1.72.0 -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<xsl:import href="manpage-base.xsl"/>
+
+<!-- these are the special values for the roff control characters
+     needed for docbook-xsl 1.72.0 -->
+<xsl:param name="git.docbook.backslash">&#x2593;</xsl:param>
+<xsl:param name="git.docbook.dot"      >&#x2302;</xsl:param>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-base-url.xsl.in b/third_party/git/Documentation/manpage-base-url.xsl.in
new file mode 100644
index 0000000000..e800904df3
--- /dev/null
+++ b/third_party/git/Documentation/manpage-base-url.xsl.in
@@ -0,0 +1,10 @@
+<!-- manpage-base-url.xsl:
+     special settings for manpages rendered from newer docbook -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- set a base URL for relative links -->
+<xsl:param name="man.base.url.for.relative.links"
+	>@@MAN_BASE_URL@@</xsl:param>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-base.xsl b/third_party/git/Documentation/manpage-base.xsl
new file mode 100644
index 0000000000..a264fa6160
--- /dev/null
+++ b/third_party/git/Documentation/manpage-base.xsl
@@ -0,0 +1,35 @@
+<!-- manpage-base.xsl:
+     special formatting for manpages rendered from asciidoc+docbook -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- these params silence some output from xmlto -->
+<xsl:param name="man.output.quietly" select="1"/>
+<xsl:param name="refentry.meta.get.quietly" select="1"/>
+
+<!-- convert asciidoc callouts to man page format;
+     git.docbook.backslash and git.docbook.dot params
+     must be supplied by another XSL file or other means -->
+<xsl:template match="co">
+	<xsl:value-of select="concat(
+			      $git.docbook.backslash,'fB(',
+			      substring-after(@id,'-'),')',
+			      $git.docbook.backslash,'fR')"/>
+</xsl:template>
+<xsl:template match="calloutlist">
+	<xsl:value-of select="$git.docbook.dot"/>
+	<xsl:text>sp&#10;</xsl:text>
+	<xsl:apply-templates/>
+	<xsl:text>&#10;</xsl:text>
+</xsl:template>
+<xsl:template match="callout">
+	<xsl:value-of select="concat(
+			      $git.docbook.backslash,'fB',
+			      substring-after(@arearefs,'-'),
+			      '. ',$git.docbook.backslash,'fR')"/>
+	<xsl:apply-templates/>
+	<xsl:value-of select="$git.docbook.dot"/>
+	<xsl:text>br&#10;</xsl:text>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-bold-literal.xsl b/third_party/git/Documentation/manpage-bold-literal.xsl
new file mode 100644
index 0000000000..608eb5df62
--- /dev/null
+++ b/third_party/git/Documentation/manpage-bold-literal.xsl
@@ -0,0 +1,17 @@
+<!-- manpage-bold-literal.xsl:
+     special formatting for manpages rendered from asciidoc+docbook -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- render literal text as bold (instead of plain or monospace);
+     this makes literal text easier to distinguish in manpages
+     viewed on a tty -->
+<xsl:template match="literal">
+	<xsl:value-of select="$git.docbook.backslash"/>
+	<xsl:text>fB</xsl:text>
+	<xsl:apply-templates/>
+	<xsl:value-of select="$git.docbook.backslash"/>
+	<xsl:text>fR</xsl:text>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-normal.xsl b/third_party/git/Documentation/manpage-normal.xsl
new file mode 100644
index 0000000000..a48f5b11f3
--- /dev/null
+++ b/third_party/git/Documentation/manpage-normal.xsl
@@ -0,0 +1,13 @@
+<!-- manpage-normal.xsl:
+     special settings for manpages rendered from asciidoc+docbook
+     handles anything we want to keep away from docbook-xsl 1.72.0 -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<xsl:import href="manpage-base.xsl"/>
+
+<!-- these are the normal values for the roff control characters -->
+<xsl:param name="git.docbook.backslash">\</xsl:param>
+<xsl:param name="git.docbook.dot"	>.</xsl:param>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-quote-apos.xsl b/third_party/git/Documentation/manpage-quote-apos.xsl
new file mode 100644
index 0000000000..aeb8839f33
--- /dev/null
+++ b/third_party/git/Documentation/manpage-quote-apos.xsl
@@ -0,0 +1,16 @@
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- work around newer groff/man setups using a prettier apostrophe
+     that unfortunately does not quote anything when cut&pasting
+     examples to the shell -->
+<xsl:template name="escape.apostrophe">
+  <xsl:param name="content"/>
+  <xsl:call-template name="string.subst">
+    <xsl:with-param name="string" select="$content"/>
+    <xsl:with-param name="target">'</xsl:with-param>
+    <xsl:with-param name="replacement">\(aq</xsl:with-param>
+  </xsl:call-template>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/manpage-suppress-sp.xsl b/third_party/git/Documentation/manpage-suppress-sp.xsl
new file mode 100644
index 0000000000..a63c7632a8
--- /dev/null
+++ b/third_party/git/Documentation/manpage-suppress-sp.xsl
@@ -0,0 +1,21 @@
+<!-- manpage-suppress-sp.xsl:
+     special settings for manpages rendered from asciidoc+docbook
+     handles erroneous, inline .sp in manpage output of some
+     versions of docbook-xsl -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<!-- attempt to work around spurious .sp at the tail of the line
+     that some versions of docbook stylesheets seem to add -->
+<xsl:template match="simpara">
+  <xsl:variable name="content">
+    <xsl:apply-templates/>
+  </xsl:variable>
+  <xsl:value-of select="normalize-space($content)"/>
+  <xsl:if test="not(ancestor::authorblurb) and
+                not(ancestor::personblurb)">
+    <xsl:text>&#10;&#10;</xsl:text>
+  </xsl:if>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/merge-options.txt b/third_party/git/Documentation/merge-options.txt
new file mode 100644
index 0000000000..79a00d2a4a
--- /dev/null
+++ b/third_party/git/Documentation/merge-options.txt
@@ -0,0 +1,158 @@
+--commit::
+--no-commit::
+	Perform the merge and commit the result. This option can
+	be used to override --no-commit.
++
+With --no-commit perform the merge and stop just before creating
+a merge commit, to give the user a chance to inspect and further
+tweak the merge result before committing.
++
+Note that fast-forward updates do not create a merge commit and
+therefore there is no way to stop those merges with --no-commit.
+Thus, if you want to ensure your branch is not changed or updated
+by the merge command, use --no-ff with --no-commit.
+
+--edit::
+-e::
+--no-edit::
+	Invoke an editor before committing successful mechanical merge to
+	further edit the auto-generated merge message, so that the user
+	can explain and justify the merge. The `--no-edit` option can be
+	used to accept the auto-generated message (this is generally
+	discouraged).
+ifndef::git-pull[]
+The `--edit` (or `-e`) option is still useful if you are
+giving a draft message with the `-m` option from the command line
+and want to edit it in the editor.
+endif::git-pull[]
++
+Older scripts may depend on the historical behaviour of not allowing the
+user to edit the merge log message. They will see an editor opened when
+they run `git merge`. To make it easier to adjust such scripts to the
+updated behaviour, the environment variable `GIT_MERGE_AUTOEDIT` can be
+set to `no` at the beginning of them.
+
+--cleanup=<mode>::
+	This option determines how the merge message will be cleaned up before
+	commiting. See linkgit:git-commit[1] for more details. In addition, if
+	the '<mode>' is given a value of `scissors`, scissors will be appended
+	to `MERGE_MSG` before being passed on to the commit machinery in the
+	case of a merge conflict.
+
+--ff::
+	When the merge resolves as a fast-forward, only update the branch
+	pointer, without creating a merge commit.  This is the default
+	behavior.
+
+--no-ff::
+	Create a merge commit even when the merge resolves as a
+	fast-forward.  This is the default behaviour when merging an
+	annotated (and possibly signed) tag that is not stored in
+	its natural place in 'refs/tags/' hierarchy.
+
+--ff-only::
+	Refuse to merge and exit with a non-zero status unless the
+	current `HEAD` is already up to date or the merge can be
+	resolved as a fast-forward.
+
+-S[<keyid>]::
+--gpg-sign[=<keyid>]::
+	GPG-sign the resulting merge commit. The `keyid` argument is
+	optional and defaults to the committer identity; if specified,
+	it must be stuck to the option without a space.
+
+--log[=<n>]::
+--no-log::
+	In addition to branch names, populate the log message with
+	one-line descriptions from at most <n> actual commits that are being
+	merged. See also linkgit:git-fmt-merge-msg[1].
++
+With --no-log do not list one-line descriptions from the
+actual commits being merged.
+
+--signoff::
+--no-signoff::
+	Add Signed-off-by line by the committer at the end of the commit
+	log message.  The meaning of a signoff depends on the project,
+	but it typically certifies that committer has
+	the rights to submit this work under the same license and
+	agrees to a Developer Certificate of Origin
+	(see http://developercertificate.org/ for more information).
++
+With --no-signoff do not add a Signed-off-by line.
+
+--stat::
+-n::
+--no-stat::
+	Show a diffstat at the end of the merge. The diffstat is also
+	controlled by the configuration option merge.stat.
++
+With -n or --no-stat do not show a diffstat at the end of the
+merge.
+
+--squash::
+--no-squash::
+	Produce the working tree and index state as if a real merge
+	happened (except for the merge information), but do not actually
+	make a commit, move the `HEAD`, or record `$GIT_DIR/MERGE_HEAD`
+	(to cause the next `git commit` command to create a merge
+	commit).  This allows you to create a single commit on top of
+	the current branch whose effect is the same as merging another
+	branch (or more in case of an octopus).
++
+With --no-squash perform the merge and commit the result. This
+option can be used to override --squash.
++
+With --squash, --commit is not allowed, and will fail.
+
+-s <strategy>::
+--strategy=<strategy>::
+	Use the given merge strategy; can be supplied more than
+	once to specify them in the order they should be tried.
+	If there is no `-s` option, a built-in list of strategies
+	is used instead ('git merge-recursive' when merging a single
+	head, 'git merge-octopus' otherwise).
+
+-X <option>::
+--strategy-option=<option>::
+	Pass merge strategy specific option through to the merge
+	strategy.
+
+--verify-signatures::
+--no-verify-signatures::
+	Verify that the tip commit of the side branch being merged is
+	signed with a valid key, i.e. a key that has a valid uid: in the
+	default trust model, this means the signing key has been signed by
+	a trusted key.  If the tip commit of the side branch is not signed
+	with a valid key, the merge is aborted.
+
+--summary::
+--no-summary::
+	Synonyms to --stat and --no-stat; these are deprecated and will be
+	removed in the future.
+
+ifndef::git-pull[]
+-q::
+--quiet::
+	Operate quietly. Implies --no-progress.
+
+-v::
+--verbose::
+	Be verbose.
+
+--progress::
+--no-progress::
+	Turn progress on/off explicitly. If neither is specified,
+	progress is shown if standard error is connected to a terminal.
+	Note that not all merge strategies may support progress
+	reporting.
+
+endif::git-pull[]
+
+--allow-unrelated-histories::
+	By default, `git merge` command refuses to merge histories
+	that do not share a common ancestor.  This option can be
+	used to override this safety when merging histories of two
+	projects that started their lives independently. As that is
+	a very rare occasion, no configuration variable to enable
+	this by default exists and will not be added.
diff --git a/third_party/git/Documentation/merge-strategies.txt b/third_party/git/Documentation/merge-strategies.txt
new file mode 100644
index 0000000000..aa66cbe41e
--- /dev/null
+++ b/third_party/git/Documentation/merge-strategies.txt
@@ -0,0 +1,136 @@
+MERGE STRATEGIES
+----------------
+
+The merge mechanism (`git merge` and `git pull` commands) allows the
+backend 'merge strategies' to be chosen with `-s` option.  Some strategies
+can also take their own options, which can be passed by giving `-X<option>`
+arguments to `git merge` and/or `git pull`.
+
+resolve::
+	This can only resolve two heads (i.e. the current branch
+	and another branch you pulled from) using a 3-way merge
+	algorithm.  It tries to carefully detect criss-cross
+	merge ambiguities and is considered generally safe and
+	fast.
+
+recursive::
+	This can only resolve two heads using a 3-way merge
+	algorithm.  When there is more than one common
+	ancestor that can be used for 3-way merge, it creates a
+	merged tree of the common ancestors and uses that as
+	the reference tree for the 3-way merge.  This has been
+	reported to result in fewer merge conflicts without
+	causing mismerges by tests done on actual merge commits
+	taken from Linux 2.6 kernel development history.
+	Additionally this can detect and handle merges involving
+	renames, but currently cannot make use of detected
+	copies.  This is the default merge strategy when pulling
+	or merging one branch.
++
+The 'recursive' strategy can take the following options:
+
+ours;;
+	This option forces conflicting hunks to be auto-resolved cleanly by
+	favoring 'our' version.  Changes from the other tree that do not
+	conflict with our side are reflected to the merge result.
+	For a binary file, the entire contents are taken from our side.
++
+This should not be confused with the 'ours' merge strategy, which does not
+even look at what the other tree contains at all.  It discards everything
+the other tree did, declaring 'our' history contains all that happened in it.
+
+theirs;;
+	This is the opposite of 'ours'; note that, unlike 'ours', there is
+	no 'theirs' merge strategy to confuse this merge option with.
+
+patience;;
+	With this option, 'merge-recursive' spends a little extra time
+	to avoid mismerges that sometimes occur due to unimportant
+	matching lines (e.g., braces from distinct functions).  Use
+	this when the branches to be merged have diverged wildly.
+	See also linkgit:git-diff[1] `--patience`.
+
+diff-algorithm=[patience|minimal|histogram|myers];;
+	Tells 'merge-recursive' to use a different diff algorithm, which
+	can help avoid mismerges that occur due to unimportant matching
+	lines (such as braces from distinct functions).  See also
+	linkgit:git-diff[1] `--diff-algorithm`.
+
+ignore-space-change;;
+ignore-all-space;;
+ignore-space-at-eol;;
+ignore-cr-at-eol;;
+	Treats lines with the indicated type of whitespace change as
+	unchanged for the sake of a three-way merge.  Whitespace
+	changes mixed with other changes to a line are not ignored.
+	See also linkgit:git-diff[1] `-b`, `-w`,
+	`--ignore-space-at-eol`, and `--ignore-cr-at-eol`.
++
+* If 'their' version only introduces whitespace changes to a line,
+  'our' version is used;
+* If 'our' version introduces whitespace changes but 'their'
+  version includes a substantial change, 'their' version is used;
+* Otherwise, the merge proceeds in the usual way.
+
+renormalize;;
+	This runs a virtual check-out and check-in of all three stages
+	of a file when resolving a three-way merge.  This option is
+	meant to be used when merging branches with different clean
+	filters or end-of-line normalization rules.  See "Merging
+	branches with differing checkin/checkout attributes" in
+	linkgit:gitattributes[5] for details.
+
+no-renormalize;;
+	Disables the `renormalize` option.  This overrides the
+	`merge.renormalize` configuration variable.
+
+no-renames;;
+	Turn off rename detection. This overrides the `merge.renames`
+	configuration variable.
+	See also linkgit:git-diff[1] `--no-renames`.
+
+find-renames[=<n>];;
+	Turn on rename detection, optionally setting the similarity
+	threshold.  This is the default. This overrides the
+	'merge.renames' configuration variable.
+	See also linkgit:git-diff[1] `--find-renames`.
+
+rename-threshold=<n>;;
+	Deprecated synonym for `find-renames=<n>`.
+
+subtree[=<path>];;
+	This option is a more advanced form of 'subtree' strategy, where
+	the strategy makes a guess on how two trees must be shifted to
+	match with each other when merging.  Instead, the specified path
+	is prefixed (or stripped from the beginning) to make the shape of
+	two trees to match.
+
+octopus::
+	This resolves cases with more than two heads, but refuses to do
+	a complex merge that needs manual resolution.  It is
+	primarily meant to be used for bundling topic branch
+	heads together.  This is the default merge strategy when
+	pulling or merging more than one branch.
+
+ours::
+	This resolves any number of heads, but the resulting tree of the
+	merge is always that of the current branch head, effectively
+	ignoring all changes from all other branches.  It is meant to
+	be used to supersede old development history of side
+	branches.  Note that this is different from the -Xours option to
+	the 'recursive' merge strategy.
+
+subtree::
+	This is a modified recursive strategy. When merging trees A and
+	B, if B corresponds to a subtree of A, B is first adjusted to
+	match the tree structure of A, instead of reading the trees at
+	the same level. This adjustment is also done to the common
+	ancestor tree.
+
+With the strategies that use 3-way merge (including the default, 'recursive'),
+if a change is made on both branches, but later reverted on one of the
+branches, that change will be present in the merged result; some people find
+this behavior confusing.  It occurs because only the heads and the merge base
+are considered when performing a merge, not the individual commits.  The merge
+algorithm therefore considers the reverted change as no change at all, and
+substitutes the changed version instead.
diff --git a/third_party/git/Documentation/pretty-formats.txt b/third_party/git/Documentation/pretty-formats.txt
new file mode 100644
index 0000000000..079598307a
--- /dev/null
+++ b/third_party/git/Documentation/pretty-formats.txt
@@ -0,0 +1,308 @@
+PRETTY FORMATS
+--------------
+
+If the commit is a merge, and if the pretty-format
+is not 'oneline', 'email' or 'raw', an additional line is
+inserted before the 'Author:' line.  This line begins with
+"Merge: " and the sha1s of ancestral commits are printed,
+separated by spaces.  Note that the listed commits may not
+necessarily be the list of the *direct* parent commits if you
+have limited your view of history: for example, if you are
+only interested in changes related to a certain directory or
+file.
+
+There are several built-in formats, and you can define
+additional formats by setting a pretty.<name>
+config option to either another format name, or a
+'format:' string, as described below (see
+linkgit:git-config[1]). Here are the details of the
+built-in formats:
+
+* 'oneline'
+
+	  <sha1> <title line>
++
+This is designed to be as compact as possible.
+
+* 'short'
+
+	  commit <sha1>
+	  Author: <author>
+
+	      <title line>
+
+* 'medium'
+
+	  commit <sha1>
+	  Author: <author>
+	  Date:   <author date>
+
+	      <title line>
+
+	      <full commit message>
+
+* 'full'
+
+	  commit <sha1>
+	  Author: <author>
+	  Commit: <committer>
+
+	      <title line>
+
+	      <full commit message>
+
+* 'fuller'
+
+	  commit <sha1>
+	  Author:     <author>
+	  AuthorDate: <author date>
+	  Commit:     <committer>
+	  CommitDate: <committer date>
+
+	       <title line>
+
+	       <full commit message>
+
+* 'email'
+
+	  From <sha1> <date>
+	  From: <author>
+	  Date: <author date>
+	  Subject: [PATCH] <title line>
+
+	  <full commit message>
+
+* 'raw'
++
+The 'raw' format shows the entire commit exactly as
+stored in the commit object.  Notably, the SHA-1s are
+displayed in full, regardless of whether --abbrev or
+--no-abbrev are used, and 'parents' information show the
+true parent commits, without taking grafts or history
+simplification into account. Note that this format affects the way
+commits are displayed, but not the way the diff is shown e.g. with
+`git log --raw`. To get full object names in a raw diff format,
+use `--no-abbrev`.
+
+* 'format:<string>'
++
+The 'format:<string>' format allows you to specify which information
+you want to show. It works a little bit like printf format,
+with the notable exception that you get a newline with '%n'
+instead of '\n'.
++
+E.g, 'format:"The author of %h was %an, %ar%nThe title was >>%s<<%n"'
+would show something like this:
++
+-------
+The author of fe6e0ee was Junio C Hamano, 23 hours ago
+The title was >>t4119: test autocomputing -p<n> for traditional diff input.<<
+
+-------
++
+The placeholders are:
+
+- Placeholders that expand to a single literal character:
+'%n':: newline
+'%%':: a raw '%'
+'%x00':: print a byte from a hex code
+
+- Placeholders that affect formatting of later placeholders:
+'%Cred':: switch color to red
+'%Cgreen':: switch color to green
+'%Cblue':: switch color to blue
+'%Creset':: reset color
+'%C(...)':: color specification, as described under Values in the
+	    "CONFIGURATION FILE" section of linkgit:git-config[1].  By
+	    default, colors are shown only when enabled for log output
+	    (by `color.diff`, `color.ui`, or `--color`, and respecting
+	    the `auto` settings of the former if we are going to a
+	    terminal). `%C(auto,...)` is accepted as a historical
+	    synonym for the default (e.g., `%C(auto,red)`). Specifying
+	    `%C(always,...)` will show the colors even when color is
+	    not otherwise enabled (though consider just using
+	    `--color=always` to enable color for the whole output,
+	    including this format and anything else git might color).
+	    `auto` alone (i.e. `%C(auto)`) will turn on auto coloring
+	    on the next placeholders until the color is switched
+	    again.
+'%m':: left (`<`), right (`>`) or boundary (`-`) mark
+'%w([<w>[,<i1>[,<i2>]]])':: switch line wrapping, like the -w option of
+			    linkgit:git-shortlog[1].
+'%<(<N>[,trunc|ltrunc|mtrunc])':: make the next placeholder take at
+				  least N columns, padding spaces on
+				  the right if necessary.  Optionally
+				  truncate at the beginning (ltrunc),
+				  the middle (mtrunc) or the end
+				  (trunc) if the output is longer than
+				  N columns.  Note that truncating
+				  only works correctly with N >= 2.
+'%<|(<N>)':: make the next placeholder take at least until Nth
+	     columns, padding spaces on the right if necessary
+'%>(<N>)', '%>|(<N>)':: similar to '%<(<N>)', '%<|(<N>)' respectively,
+			but padding spaces on the left
+'%>>(<N>)', '%>>|(<N>)':: similar to '%>(<N>)', '%>|(<N>)'
+			  respectively, except that if the next
+			  placeholder takes more spaces than given and
+			  there are spaces on its left, use those
+			  spaces
+'%><(<N>)', '%><|(<N>)':: similar to '%<(<N>)', '%<|(<N>)'
+			  respectively, but padding both sides
+			  (i.e. the text is centered)
+
+- Placeholders that expand to information extracted from the commit:
+'%H':: commit hash
+'%h':: abbreviated commit hash
+'%T':: tree hash
+'%t':: abbreviated tree hash
+'%P':: parent hashes
+'%p':: abbreviated parent hashes
+'%an':: author name
+'%aN':: author name (respecting .mailmap, see linkgit:git-shortlog[1]
+	or linkgit:git-blame[1])
+'%ae':: author email
+'%aE':: author email (respecting .mailmap, see linkgit:git-shortlog[1]
+	or linkgit:git-blame[1])
+'%ad':: author date (format respects --date= option)
+'%aD':: author date, RFC2822 style
+'%ar':: author date, relative
+'%at':: author date, UNIX timestamp
+'%ai':: author date, ISO 8601-like format
+'%aI':: author date, strict ISO 8601 format
+'%cn':: committer name
+'%cN':: committer name (respecting .mailmap, see
+	linkgit:git-shortlog[1] or linkgit:git-blame[1])
+'%ce':: committer email
+'%cE':: committer email (respecting .mailmap, see
+	linkgit:git-shortlog[1] or linkgit:git-blame[1])
+'%cd':: committer date (format respects --date= option)
+'%cD':: committer date, RFC2822 style
+'%cr':: committer date, relative
+'%ct':: committer date, UNIX timestamp
+'%ci':: committer date, ISO 8601-like format
+'%cI':: committer date, strict ISO 8601 format
+'%d':: ref names, like the --decorate option of linkgit:git-log[1]
+'%D':: ref names without the " (", ")" wrapping.
+'%S':: ref name given on the command line by which the commit was reached
+       (like `git log --source`), only works with `git log`
+'%e':: encoding
+'%s':: subject
+'%f':: sanitized subject line, suitable for a filename
+'%b':: body
+'%B':: raw body (unwrapped subject and body)
+ifndef::git-rev-list[]
+'%N':: commit notes
+endif::git-rev-list[]
+'%GG':: raw verification message from GPG for a signed commit
+'%G?':: show "G" for a good (valid) signature,
+	"B" for a bad signature,
+	"U" for a good signature with unknown validity,
+	"X" for a good signature that has expired,
+	"Y" for a good signature made by an expired key,
+	"R" for a good signature made by a revoked key,
+	"E" if the signature cannot be checked (e.g. missing key)
+	and "N" for no signature
+'%GS':: show the name of the signer for a signed commit
+'%GK':: show the key used to sign a signed commit
+'%GF':: show the fingerprint of the key used to sign a signed commit
+'%GP':: show the fingerprint of the primary key whose subkey was used
+	to sign a signed commit
+'%gD':: reflog selector, e.g., `refs/stash@{1}` or `refs/stash@{2
+	minutes ago`}; the format follows the rules described for the
+	`-g` option. The portion before the `@` is the refname as
+	given on the command line (so `git log -g refs/heads/master`
+	would yield `refs/heads/master@{0}`).
+'%gd':: shortened reflog selector; same as `%gD`, but the refname
+	portion is shortened for human readability (so
+	`refs/heads/master` becomes just `master`).
+'%gn':: reflog identity name
+'%gN':: reflog identity name (respecting .mailmap, see
+	linkgit:git-shortlog[1] or linkgit:git-blame[1])
+'%ge':: reflog identity email
+'%gE':: reflog identity email (respecting .mailmap, see
+	linkgit:git-shortlog[1] or linkgit:git-blame[1])
+'%gs':: reflog subject
+'%(trailers[:options])':: display the trailers of the body as
+			  interpreted by
+			  linkgit:git-interpret-trailers[1]. The
+			  `trailers` string may be followed by a colon
+			  and zero or more comma-separated options:
+** 'key=<K>': only show trailers with specified key. Matching is done
+   case-insensitively and trailing colon is optional. If option is
+   given multiple times trailer lines matching any of the keys are
+   shown. This option automatically enables the `only` option so that
+   non-trailer lines in the trailer block are hidden. If that is not
+   desired it can be disabled with `only=false`.  E.g.,
+   `%(trailers:key=Reviewed-by)` shows trailer lines with key
+   `Reviewed-by`.
+** 'only[=val]': select whether non-trailer lines from the trailer
+   block should be included. The `only` keyword may optionally be
+   followed by an equal sign and one of `true`, `on`, `yes` to omit or
+   `false`, `off`, `no` to show the non-trailer lines. If option is
+   given without value it is enabled. If given multiple times the last
+   value is used.
+** 'separator=<SEP>': specify a separator inserted between trailer
+   lines. When this option is not given each trailer line is
+   terminated with a line feed character. The string SEP may contain
+   the literal formatting codes described above. To use comma as
+   separator one must use `%x2C` as it would otherwise be parsed as
+   next option. If separator option is given multiple times only the
+   last one is used. E.g., `%(trailers:key=Ticket,separator=%x2C )`
+   shows all trailer lines whose key is "Ticket" separated by a comma
+   and a space.
+** 'unfold[=val]': make it behave as if interpret-trailer's `--unfold`
+   option was given. In same way as to for `only` it can be followed
+   by an equal sign and explicit value. E.g.,
+   `%(trailers:only,unfold=true)` unfolds and shows all trailer lines.
+** 'valueonly[=val]': skip over the key part of the trailer line and only
+   show the value part. Also this optionally allows explicit value.
+
+NOTE: Some placeholders may depend on other options given to the
+revision traversal engine. For example, the `%g*` reflog options will
+insert an empty string unless we are traversing reflog entries (e.g., by
+`git log -g`). The `%d` and `%D` placeholders will use the "short"
+decoration format if `--decorate` was not already provided on the command
+line.
+
+If you add a `+` (plus sign) after '%' of a placeholder, a line-feed
+is inserted immediately before the expansion if and only if the
+placeholder expands to a non-empty string.
+
+If you add a `-` (minus sign) after '%' of a placeholder, all consecutive
+line-feeds immediately preceding the expansion are deleted if and only if the
+placeholder expands to an empty string.
+
+If you add a ` ` (space) after '%' of a placeholder, a space
+is inserted immediately before the expansion if and only if the
+placeholder expands to a non-empty string.
+
+* 'tformat:'
++
+The 'tformat:' format works exactly like 'format:', except that it
+provides "terminator" semantics instead of "separator" semantics. In
+other words, each commit has the message terminator character (usually a
+newline) appended, rather than a separator placed between entries.
+This means that the final entry of a single-line format will be properly
+terminated with a new line, just as the "oneline" format does.
+For example:
++
+---------------------
+$ git log -2 --pretty=format:%h 4da45bef \
+  | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
+4da45be
+7134973 -- NO NEWLINE
+
+$ git log -2 --pretty=tformat:%h 4da45bef \
+  | perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
+4da45be
+7134973
+---------------------
++
+In addition, any unrecognized string that has a `%` in it is interpreted
+as if it has `tformat:` in front of it.  For example, these two are
+equivalent:
++
+---------------------
+$ git log -2 --pretty=tformat:%h 4da45bef
+$ git log -2 --pretty=%h 4da45bef
+---------------------
diff --git a/third_party/git/Documentation/pretty-options.txt b/third_party/git/Documentation/pretty-options.txt
new file mode 100644
index 0000000000..e44fc8f738
--- /dev/null
+++ b/third_party/git/Documentation/pretty-options.txt
@@ -0,0 +1,96 @@
+--pretty[=<format>]::
+--format=<format>::
+
+	Pretty-print the contents of the commit logs in a given format,
+	where '<format>' can be one of 'oneline', 'short', 'medium',
+	'full', 'fuller', 'email', 'raw', 'format:<string>'
+	and 'tformat:<string>'.  When '<format>' is none of the above,
+	and has '%placeholder' in it, it acts as if
+	'--pretty=tformat:<format>' were given.
++
+See the "PRETTY FORMATS" section for some additional details for each
+format.  When '=<format>' part is omitted, it defaults to 'medium'.
++
+Note: you can specify the default pretty format in the repository
+configuration (see linkgit:git-config[1]).
+
+--abbrev-commit::
+	Instead of showing the full 40-byte hexadecimal commit object
+	name, show only a partial prefix.  Non default number of
+	digits can be specified with "--abbrev=<n>" (which also modifies
+	diff output, if it is displayed).
++
+This should make "--pretty=oneline" a whole lot more readable for
+people using 80-column terminals.
+
+--no-abbrev-commit::
+	Show the full 40-byte hexadecimal commit object name. This negates
+	`--abbrev-commit` and those options which imply it such as
+	"--oneline". It also overrides the `log.abbrevCommit` variable.
+
+--oneline::
+	This is a shorthand for "--pretty=oneline --abbrev-commit"
+	used together.
+
+--encoding=<encoding>::
+	The commit objects record the encoding used for the log message
+	in their encoding header; this option can be used to tell the
+	command to re-code the commit log message in the encoding
+	preferred by the user.  For non plumbing commands this
+	defaults to UTF-8. Note that if an object claims to be encoded
+	in `X` and we are outputting in `X`, we will output the object
+	verbatim; this means that invalid sequences in the original
+	commit may be copied to the output.
+
+--expand-tabs=<n>::
+--expand-tabs::
+--no-expand-tabs::
+	Perform a tab expansion (replace each tab with enough spaces
+	to fill to the next display column that is multiple of '<n>')
+	in the log message before showing it in the output.
+	`--expand-tabs` is a short-hand for `--expand-tabs=8`, and
+	`--no-expand-tabs` is a short-hand for `--expand-tabs=0`,
+	which disables tab expansion.
++
+By default, tabs are expanded in pretty formats that indent the log
+message by 4 spaces (i.e.  'medium', which is the default, 'full',
+and 'fuller').
+
+ifndef::git-rev-list[]
+--notes[=<treeish>]::
+	Show the notes (see linkgit:git-notes[1]) that annotate the
+	commit, when showing the commit log message.  This is the default
+	for `git log`, `git show` and `git whatchanged` commands when
+	there is no `--pretty`, `--format`, or `--oneline` option given
+	on the command line.
++
+By default, the notes shown are from the notes refs listed in the
+`core.notesRef` and `notes.displayRef` variables (or corresponding
+environment overrides). See linkgit:git-config[1] for more details.
++
+With an optional '<treeish>' argument, use the treeish to find the notes
+to display.  The treeish can specify the full refname when it begins
+with `refs/notes/`; when it begins with `notes/`, `refs/` and otherwise
+`refs/notes/` is prefixed to form a full name of the ref.
++
+Multiple --notes options can be combined to control which notes are
+being displayed. Examples: "--notes=foo" will show only notes from
+"refs/notes/foo"; "--notes=foo --notes" will show both notes from
+"refs/notes/foo" and from the default notes ref(s).
+
+--no-notes::
+	Do not show notes. This negates the above `--notes` option, by
+	resetting the list of notes refs from which notes are shown.
+	Options are parsed in the order given on the command line, so e.g.
+	"--notes --notes=foo --no-notes --notes=bar" will only show notes
+	from "refs/notes/bar".
+
+--show-notes[=<treeish>]::
+--[no-]standard-notes::
+	These options are deprecated. Use the above --notes/--no-notes
+	options instead.
+endif::git-rev-list[]
+
+--show-signature::
+	Check the validity of a signed commit object by passing the signature
+	to `gpg --verify` and show the output.
diff --git a/third_party/git/Documentation/pull-fetch-param.txt b/third_party/git/Documentation/pull-fetch-param.txt
new file mode 100644
index 0000000000..7d3a60f5b9
--- /dev/null
+++ b/third_party/git/Documentation/pull-fetch-param.txt
@@ -0,0 +1,102 @@
+<repository>::
+	The "remote" repository that is the source of a fetch
+	or pull operation.  This parameter can be either a URL
+	(see the section <<URLS,GIT URLS>> below) or the name
+	of a remote (see the section <<REMOTES,REMOTES>> below).
+
+ifndef::git-pull[]
+<group>::
+	A name referring to a list of repositories as the value
+	of remotes.<group> in the configuration file.
+	(See linkgit:git-config[1]).
+endif::git-pull[]
+
+<refspec>::
+	Specifies which refs to fetch and which local refs to update.
+	When no <refspec>s appear on the command line, the refs to fetch
+	are read from `remote.<repository>.fetch` variables instead
+ifndef::git-pull[]
+	(see <<CRTB,CONFIGURED REMOTE-TRACKING BRANCHES>> below).
+endif::git-pull[]
+ifdef::git-pull[]
+	(see linkgit:git-fetch[1]).
+endif::git-pull[]
++
+The format of a <refspec> parameter is an optional plus
+`+`, followed by the source <src>, followed
+by a colon `:`, followed by the destination ref <dst>.
+The colon can be omitted when <dst> is empty.  <src> is
+typically a ref, but it can also be a fully spelled hex object
+name.
++
+`tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`;
+it requests fetching everything up to the given tag.
++
+The remote ref that matches <src>
+is fetched, and if <dst> is not an empty string, an attempt
+is made to update the local ref that matches it.
++
+Whether that update is allowed without `--force` depends on the ref
+namespace it's being fetched to, the type of object being fetched, and
+whether the update is considered to be a fast-forward. Generally, the
+same rules apply for fetching as when pushing, see the `<refspec>...`
+section of linkgit:git-push[1] for what those are. Exceptions to those
+rules particular to 'git fetch' are noted below.
++
+Until Git version 2.20, and unlike when pushing with
+linkgit:git-push[1], any updates to `refs/tags/*` would be accepted
+without `+` in the refspec (or `--force`). When fetching, we promiscuously
+considered all tag updates from a remote to be forced fetches.  Since
+Git version 2.20, fetching to update `refs/tags/*` works the same way
+as when pushing. I.e. any updates will be rejected without `+` in the
+refspec (or `--force`).
++
+Unlike when pushing with linkgit:git-push[1], any updates outside of
+`refs/{tags,heads}/*` will be accepted without `+` in the refspec (or
+`--force`), whether that's swapping e.g. a tree object for a blob, or
+a commit for another commit that's doesn't have the previous commit as
+an ancestor etc.
++
+Unlike when pushing with linkgit:git-push[1], there is no
+configuration which'll amend these rules, and nothing like a
+`pre-fetch` hook analogous to the `pre-receive` hook.
++
+As with pushing with linkgit:git-push[1], all of the rules described
+above about what's not allowed as an update can be overridden by
+adding an the optional leading `+` to a refspec (or using `--force`
+command line option). The only exception to this is that no amount of
+forcing will make the `refs/heads/*` namespace accept a non-commit
+object.
++
+[NOTE]
+When the remote branch you want to fetch is known to
+be rewound and rebased regularly, it is expected that
+its new tip will not be descendant of its previous tip
+(as stored in your remote-tracking branch the last time
+you fetched).  You would want
+to use the `+` sign to indicate non-fast-forward updates
+will be needed for such branches.  There is no way to
+determine or declare that a branch will be made available
+in a repository with this behavior; the pulling user simply
+must know this is the expected usage pattern for a branch.
+ifdef::git-pull[]
++
+[NOTE]
+There is a difference between listing multiple <refspec>
+directly on 'git pull' command line and having multiple
+`remote.<repository>.fetch` entries in your configuration
+for a <repository> and running a
+'git pull' command without any explicit <refspec> parameters.
+<refspec>s listed explicitly on the command line are always
+merged into the current branch after fetching.  In other words,
+if you list more than one remote ref, 'git pull' will create
+an Octopus merge.  On the other hand, if you do not list any
+explicit <refspec> parameter on the command line, 'git pull'
+will fetch all the <refspec>s it finds in the
+`remote.<repository>.fetch` configuration and merge
+only the first <refspec> found into the current branch.
+This is because making an
+Octopus from remote refs is rarely done, while keeping track
+of multiple remote heads in one-go by fetching more than one
+is often useful.
+endif::git-pull[]
diff --git a/third_party/git/Documentation/rev-list-options.txt b/third_party/git/Documentation/rev-list-options.txt
new file mode 100644
index 0000000000..bb1251c036
--- /dev/null
+++ b/third_party/git/Documentation/rev-list-options.txt
@@ -0,0 +1,1002 @@
+Commit Limiting
+~~~~~~~~~~~~~~~
+
+Besides specifying a range of commits that should be listed using the
+special notations explained in the description, additional commit
+limiting may be applied.
+
+Using more options generally further limits the output (e.g.
+`--since=<date1>` limits to commits newer than `<date1>`, and using it
+with `--grep=<pattern>` further limits to commits whose log message
+has a line that matches `<pattern>`), unless otherwise noted.
+
+Note that these are applied before commit
+ordering and formatting options, such as `--reverse`.
+
+-<number>::
+-n <number>::
+--max-count=<number>::
+	Limit the number of commits to output.
+
+--skip=<number>::
+	Skip 'number' commits before starting to show the commit output.
+
+--since=<date>::
+--after=<date>::
+	Show commits more recent than a specific date.
+
+--until=<date>::
+--before=<date>::
+	Show commits older than a specific date.
+
+ifdef::git-rev-list[]
+--max-age=<timestamp>::
+--min-age=<timestamp>::
+	Limit the commits output to specified time range.
+endif::git-rev-list[]
+
+--author=<pattern>::
+--committer=<pattern>::
+	Limit the commits output to ones with author/committer
+	header lines that match the specified pattern (regular
+	expression).  With more than one `--author=<pattern>`,
+	commits whose author matches any of the given patterns are
+	chosen (similarly for multiple `--committer=<pattern>`).
+
+--grep-reflog=<pattern>::
+	Limit the commits output to ones with reflog entries that
+	match the specified pattern (regular expression). With
+	more than one `--grep-reflog`, commits whose reflog message
+	matches any of the given patterns are chosen.  It is an
+	error to use this option unless `--walk-reflogs` is in use.
+
+--grep=<pattern>::
+	Limit the commits output to ones with log message that
+	matches the specified pattern (regular expression).  With
+	more than one `--grep=<pattern>`, commits whose message
+	matches any of the given patterns are chosen (but see
+	`--all-match`).
+ifndef::git-rev-list[]
++
+When `--show-notes` is in effect, the message from the notes is
+matched as if it were part of the log message.
+endif::git-rev-list[]
+
+--all-match::
+	Limit the commits output to ones that match all given `--grep`,
+	instead of ones that match at least one.
+
+--invert-grep::
+	Limit the commits output to ones with log message that do not
+	match the pattern specified with `--grep=<pattern>`.
+
+-i::
+--regexp-ignore-case::
+	Match the regular expression limiting patterns without regard to letter
+	case.
+
+--basic-regexp::
+	Consider the limiting patterns to be basic regular expressions;
+	this is the default.
+
+-E::
+--extended-regexp::
+	Consider the limiting patterns to be extended regular expressions
+	instead of the default basic regular expressions.
+
+-F::
+--fixed-strings::
+	Consider the limiting patterns to be fixed strings (don't interpret
+	pattern as a regular expression).
+
+-P::
+--perl-regexp::
+	Consider the limiting patterns to be Perl-compatible regular
+	expressions.
++
+Support for these types of regular expressions is an optional
+compile-time dependency. If Git wasn't compiled with support for them
+providing this option will cause it to die.
+
+--remove-empty::
+	Stop when a given path disappears from the tree.
+
+--merges::
+	Print only merge commits. This is exactly the same as `--min-parents=2`.
+
+--no-merges::
+	Do not print commits with more than one parent. This is
+	exactly the same as `--max-parents=1`.
+
+--min-parents=<number>::
+--max-parents=<number>::
+--no-min-parents::
+--no-max-parents::
+	Show only commits which have at least (or at most) that many parent
+	commits. In particular, `--max-parents=1` is the same as `--no-merges`,
+	`--min-parents=2` is the same as `--merges`.  `--max-parents=0`
+	gives all root commits and `--min-parents=3` all octopus merges.
++
+`--no-min-parents` and `--no-max-parents` reset these limits (to no limit)
+again.  Equivalent forms are `--min-parents=0` (any commit has 0 or more
+parents) and `--max-parents=-1` (negative numbers denote no upper limit).
+
+--first-parent::
+	Follow only the first parent commit upon seeing a merge
+	commit.  This option can give a better overview when
+	viewing the evolution of a particular topic branch,
+	because merges into a topic branch tend to be only about
+	adjusting to updated upstream from time to time, and
+	this option allows you to ignore the individual commits
+	brought in to your history by such a merge. Cannot be
+	combined with --bisect.
+
+--not::
+	Reverses the meaning of the '{caret}' prefix (or lack thereof)
+	for all following revision specifiers, up to the next `--not`.
+
+--all::
+	Pretend as if all the refs in `refs/`, along with `HEAD`, are
+	listed on the command line as '<commit>'.
+
+--branches[=<pattern>]::
+	Pretend as if all the refs in `refs/heads` are listed
+	on the command line as '<commit>'. If '<pattern>' is given, limit
+	branches to ones matching given shell glob. If pattern lacks '?',
+	'{asterisk}', or '[', '/{asterisk}' at the end is implied.
+
+--tags[=<pattern>]::
+	Pretend as if all the refs in `refs/tags` are listed
+	on the command line as '<commit>'. If '<pattern>' is given, limit
+	tags to ones matching given shell glob. If pattern lacks '?', '{asterisk}',
+	or '[', '/{asterisk}' at the end is implied.
+
+--remotes[=<pattern>]::
+	Pretend as if all the refs in `refs/remotes` are listed
+	on the command line as '<commit>'. If '<pattern>' is given, limit
+	remote-tracking branches to ones matching given shell glob.
+	If pattern lacks '?', '{asterisk}', or '[', '/{asterisk}' at the end is implied.
+
+--glob=<glob-pattern>::
+	Pretend as if all the refs matching shell glob '<glob-pattern>'
+	are listed on the command line as '<commit>'. Leading 'refs/',
+	is automatically prepended if missing. If pattern lacks '?', '{asterisk}',
+	or '[', '/{asterisk}' at the end is implied.
+
+--exclude=<glob-pattern>::
+
+	Do not include refs matching '<glob-pattern>' that the next `--all`,
+	`--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
+	consider. Repetitions of this option accumulate exclusion patterns
+	up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
+	`--glob` option (other options or arguments do not clear
+	accumulated patterns).
++
+The patterns given should not begin with `refs/heads`, `refs/tags`, or
+`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
+respectively, and they must begin with `refs/` when applied to `--glob`
+or `--all`. If a trailing '/{asterisk}' is intended, it must be given
+explicitly.
+
+--reflog::
+	Pretend as if all objects mentioned by reflogs are listed on the
+	command line as `<commit>`.
+
+--alternate-refs::
+	Pretend as if all objects mentioned as ref tips of alternate
+	repositories were listed on the command line. An alternate
+	repository is any repository whose object directory is specified
+	in `objects/info/alternates`.  The set of included objects may
+	be modified by `core.alternateRefsCommand`, etc. See
+	linkgit:git-config[1].
+
+--single-worktree::
+	By default, all working trees will be examined by the
+	following options when there are more than one (see
+	linkgit:git-worktree[1]): `--all`, `--reflog` and
+	`--indexed-objects`.
+	This option forces them to examine the current working tree
+	only.
+
+--ignore-missing::
+	Upon seeing an invalid object name in the input, pretend as if
+	the bad input was not given.
+
+ifndef::git-rev-list[]
+--bisect::
+	Pretend as if the bad bisection ref `refs/bisect/bad`
+	was listed and as if it was followed by `--not` and the good
+	bisection refs `refs/bisect/good-*` on the command
+	line. Cannot be combined with --first-parent.
+endif::git-rev-list[]
+
+--stdin::
+	In addition to the '<commit>' listed on the command
+	line, read them from the standard input. If a `--` separator is
+	seen, stop reading commits and start reading paths to limit the
+	result.
+
+ifdef::git-rev-list[]
+--quiet::
+	Don't print anything to standard output.  This form
+	is primarily meant to allow the caller to
+	test the exit status to see if a range of objects is fully
+	connected (or not).  It is faster than redirecting stdout
+	to `/dev/null` as the output does not have to be formatted.
+endif::git-rev-list[]
+
+--cherry-mark::
+	Like `--cherry-pick` (see below) but mark equivalent commits
+	with `=` rather than omitting them, and inequivalent ones with `+`.
+
+--cherry-pick::
+	Omit any commit that introduces the same change as
+	another commit on the ``other side'' when the set of
+	commits are limited with symmetric difference.
++
+For example, if you have two branches, `A` and `B`, a usual way
+to list all commits on only one side of them is with
+`--left-right` (see the example below in the description of
+the `--left-right` option). However, it shows the commits that were
+cherry-picked from the other branch (for example, ``3rd on b'' may be
+cherry-picked from branch A). With this option, such pairs of commits are
+excluded from the output.
+
+--left-only::
+--right-only::
+	List only commits on the respective side of a symmetric difference,
+	i.e. only those which would be marked `<` resp. `>` by
+	`--left-right`.
++
+For example, `--cherry-pick --right-only A...B` omits those
+commits from `B` which are in `A` or are patch-equivalent to a commit in
+`A`. In other words, this lists the `+` commits from `git cherry A B`.
+More precisely, `--cherry-pick --right-only --no-merges` gives the exact
+list.
+
+--cherry::
+	A synonym for `--right-only --cherry-mark --no-merges`; useful to
+	limit the output to the commits on our side and mark those that
+	have been applied to the other side of a forked history with
+	`git log --cherry upstream...mybranch`, similar to
+	`git cherry upstream mybranch`.
+
+-g::
+--walk-reflogs::
+	Instead of walking the commit ancestry chain, walk
+	reflog entries from the most recent one to older ones.
+	When this option is used you cannot specify commits to
+	exclude (that is, '{caret}commit', 'commit1..commit2',
+	and 'commit1\...commit2' notations cannot be used).
++
+With `--pretty` format other than `oneline` (for obvious reasons),
+this causes the output to have two extra lines of information
+taken from the reflog.  The reflog designator in the output may be shown
+as `ref@{Nth}` (where `Nth` is the reverse-chronological index in the
+reflog) or as `ref@{timestamp}` (with the timestamp for that entry),
+depending on a few rules:
++
+--
+1. If the starting point is specified as `ref@{Nth}`, show the index
+   format.
++
+2. If the starting point was specified as `ref@{now}`, show the
+   timestamp format.
++
+3. If neither was used, but `--date` was given on the command line, show
+   the timestamp in the format requested by `--date`.
++
+4. Otherwise, show the index format.
+--
++
+Under `--pretty=oneline`, the commit message is
+prefixed with this information on the same line.
+This option cannot be combined with `--reverse`.
+See also linkgit:git-reflog[1].
+
+--merge::
+	After a failed merge, show refs that touch files having a
+	conflict and don't exist on all heads to merge.
+
+--boundary::
+	Output excluded boundary commits. Boundary commits are
+	prefixed with `-`.
+
+ifdef::git-rev-list[]
+--use-bitmap-index::
+
+	Try to speed up the traversal using the pack bitmap index (if
+	one is available). Note that when traversing with `--objects`,
+	trees and blobs will not have their associated path printed.
+
+--progress=<header>::
+	Show progress reports on stderr as objects are considered. The
+	`<header>` text will be printed with each progress update.
+endif::git-rev-list[]
+
+History Simplification
+~~~~~~~~~~~~~~~~~~~~~~
+
+Sometimes you are only interested in parts of the history, for example the
+commits modifying a particular <path>. But there are two parts of
+'History Simplification', one part is selecting the commits and the other
+is how to do it, as there are various strategies to simplify the history.
+
+The following options select the commits to be shown:
+
+<paths>::
+	Commits modifying the given <paths> are selected.
+
+--simplify-by-decoration::
+	Commits that are referred by some branch or tag are selected.
+
+Note that extra commits can be shown to give a meaningful history.
+
+The following options affect the way the simplification is performed:
+
+Default mode::
+	Simplifies the history to the simplest history explaining the
+	final state of the tree. Simplest because it prunes some side
+	branches if the end result is the same (i.e. merging branches
+	with the same content)
+
+--full-history::
+	Same as the default mode, but does not prune some history.
+
+--dense::
+	Only the selected commits are shown, plus some to have a
+	meaningful history.
+
+--sparse::
+	All commits in the simplified history are shown.
+
+--simplify-merges::
+	Additional option to `--full-history` to remove some needless
+	merges from the resulting history, as there are no selected
+	commits contributing to this merge.
+
+--ancestry-path::
+	When given a range of commits to display (e.g. 'commit1..commit2'
+	or 'commit2 {caret}commit1'), only display commits that exist
+	directly on the ancestry chain between the 'commit1' and
+	'commit2', i.e. commits that are both descendants of 'commit1',
+	and ancestors of 'commit2'.
+
+A more detailed explanation follows.
+
+Suppose you specified `foo` as the <paths>.  We shall call commits
+that modify `foo` !TREESAME, and the rest TREESAME.  (In a diff
+filtered for `foo`, they look different and equal, respectively.)
+
+In the following, we will always refer to the same example history to
+illustrate the differences between simplification settings.  We assume
+that you are filtering for a file `foo` in this commit graph:
+-----------------------------------------------------------------------
+	  .-A---M---N---O---P---Q
+	 /     /   /   /   /   /
+	I     B   C   D   E   Y
+	 \   /   /   /   /   /
+	  `-------------'   X
+-----------------------------------------------------------------------
+The horizontal line of history A---Q is taken to be the first parent of
+each merge.  The commits are:
+
+* `I` is the initial commit, in which `foo` exists with contents
+  ``asdf'', and a file `quux` exists with contents ``quux''. Initial
+  commits are compared to an empty tree, so `I` is !TREESAME.
+
+* In `A`, `foo` contains just ``foo''.
+
+* `B` contains the same change as `A`.  Its merge `M` is trivial and
+  hence TREESAME to all parents.
+
+* `C` does not change `foo`, but its merge `N` changes it to ``foobar'',
+  so it is not TREESAME to any parent.
+
+* `D` sets `foo` to ``baz''. Its merge `O` combines the strings from
+  `N` and `D` to ``foobarbaz''; i.e., it is not TREESAME to any parent.
+
+* `E` changes `quux` to ``xyzzy'', and its merge `P` combines the
+  strings to ``quux xyzzy''. `P` is TREESAME to `O`, but not to `E`.
+
+* `X` is an independent root commit that added a new file `side`, and `Y`
+  modified it. `Y` is TREESAME to `X`. Its merge `Q` added `side` to `P`, and
+  `Q` is TREESAME to `P`, but not to `Y`.
+
+`rev-list` walks backwards through history, including or excluding
+commits based on whether `--full-history` and/or parent rewriting
+(via `--parents` or `--children`) are used. The following settings
+are available.
+
+Default mode::
+	Commits are included if they are not TREESAME to any parent
+	(though this can be changed, see `--sparse` below).  If the
+	commit was a merge, and it was TREESAME to one parent, follow
+	only that parent.  (Even if there are several TREESAME
+	parents, follow only one of them.)  Otherwise, follow all
+	parents.
++
+This results in:
++
+-----------------------------------------------------------------------
+	  .-A---N---O
+	 /     /   /
+	I---------D
+-----------------------------------------------------------------------
++
+Note how the rule to only follow the TREESAME parent, if one is
+available, removed `B` from consideration entirely.  `C` was
+considered via `N`, but is TREESAME.  Root commits are compared to an
+empty tree, so `I` is !TREESAME.
++
+Parent/child relations are only visible with `--parents`, but that does
+not affect the commits selected in default mode, so we have shown the
+parent lines.
+
+--full-history without parent rewriting::
+	This mode differs from the default in one point: always follow
+	all parents of a merge, even if it is TREESAME to one of them.
+	Even if more than one side of the merge has commits that are
+	included, this does not imply that the merge itself is!  In
+	the example, we get
++
+-----------------------------------------------------------------------
+	I  A  B  N  D  O  P  Q
+-----------------------------------------------------------------------
++
+`M` was excluded because it is TREESAME to both parents.  `E`,
+`C` and `B` were all walked, but only `B` was !TREESAME, so the others
+do not appear.
++
+Note that without parent rewriting, it is not really possible to talk
+about the parent/child relationships between the commits, so we show
+them disconnected.
+
+--full-history with parent rewriting::
+	Ordinary commits are only included if they are !TREESAME
+	(though this can be changed, see `--sparse` below).
++
+Merges are always included.  However, their parent list is rewritten:
+Along each parent, prune away commits that are not included
+themselves.  This results in
++
+-----------------------------------------------------------------------
+	  .-A---M---N---O---P---Q
+	 /     /   /   /   /
+	I     B   /   D   /
+	 \   /   /   /   /
+	  `-------------'
+-----------------------------------------------------------------------
++
+Compare to `--full-history` without rewriting above.  Note that `E`
+was pruned away because it is TREESAME, but the parent list of P was
+rewritten to contain `E`'s parent `I`.  The same happened for `C` and
+`N`, and `X`, `Y` and `Q`.
+
+In addition to the above settings, you can change whether TREESAME
+affects inclusion:
+
+--dense::
+	Commits that are walked are included if they are not TREESAME
+	to any parent.
+
+--sparse::
+	All commits that are walked are included.
++
+Note that without `--full-history`, this still simplifies merges: if
+one of the parents is TREESAME, we follow only that one, so the other
+sides of the merge are never walked.
+
+--simplify-merges::
+	First, build a history graph in the same way that
+	`--full-history` with parent rewriting does (see above).
++
+Then simplify each commit `C` to its replacement `C'` in the final
+history according to the following rules:
++
+--
+* Set `C'` to `C`.
++
+* Replace each parent `P` of `C'` with its simplification `P'`.  In
+  the process, drop parents that are ancestors of other parents or that are
+  root commits TREESAME to an empty tree, and remove duplicates, but take care
+  to never drop all parents that we are TREESAME to.
++
+* If after this parent rewriting, `C'` is a root or merge commit (has
+  zero or >1 parents), a boundary commit, or !TREESAME, it remains.
+  Otherwise, it is replaced with its only parent.
+--
++
+The effect of this is best shown by way of comparing to
+`--full-history` with parent rewriting.  The example turns into:
++
+-----------------------------------------------------------------------
+	  .-A---M---N---O
+	 /     /       /
+	I     B       D
+	 \   /       /
+	  `---------'
+-----------------------------------------------------------------------
++
+Note the major differences in `N`, `P`, and `Q` over `--full-history`:
++
+--
+* `N`'s parent list had `I` removed, because it is an ancestor of the
+  other parent `M`.  Still, `N` remained because it is !TREESAME.
++
+* `P`'s parent list similarly had `I` removed.  `P` was then
+  removed completely, because it had one parent and is TREESAME.
++
+* `Q`'s parent list had `Y` simplified to `X`. `X` was then removed, because it
+  was a TREESAME root. `Q` was then removed completely, because it had one
+  parent and is TREESAME.
+--
+
+Finally, there is a fifth simplification mode available:
+
+--ancestry-path::
+	Limit the displayed commits to those directly on the ancestry
+	chain between the ``from'' and ``to'' commits in the given commit
+	range. I.e. only display commits that are ancestor of the ``to''
+	commit and descendants of the ``from'' commit.
++
+As an example use case, consider the following commit history:
++
+-----------------------------------------------------------------------
+	    D---E-------F
+	   /     \       \
+	  B---C---G---H---I---J
+	 /                     \
+	A-------K---------------L--M
+-----------------------------------------------------------------------
++
+A regular 'D..M' computes the set of commits that are ancestors of `M`,
+but excludes the ones that are ancestors of `D`. This is useful to see
+what happened to the history leading to `M` since `D`, in the sense
+that ``what does `M` have that did not exist in `D`''. The result in this
+example would be all the commits, except `A` and `B` (and `D` itself,
+of course).
++
+When we want to find out what commits in `M` are contaminated with the
+bug introduced by `D` and need fixing, however, we might want to view
+only the subset of 'D..M' that are actually descendants of `D`, i.e.
+excluding `C` and `K`. This is exactly what the `--ancestry-path`
+option does. Applied to the 'D..M' range, it results in:
++
+-----------------------------------------------------------------------
+		E-------F
+		 \       \
+		  G---H---I---J
+			       \
+				L--M
+-----------------------------------------------------------------------
+
+The `--simplify-by-decoration` option allows you to view only the
+big picture of the topology of the history, by omitting commits
+that are not referenced by tags.  Commits are marked as !TREESAME
+(in other words, kept after history simplification rules described
+above) if (1) they are referenced by tags, or (2) they change the
+contents of the paths given on the command line.  All other
+commits are marked as TREESAME (subject to be simplified away).
+
+ifdef::git-rev-list[]
+Bisection Helpers
+~~~~~~~~~~~~~~~~~
+
+--bisect::
+	Limit output to the one commit object which is roughly halfway between
+	included and excluded commits. Note that the bad bisection ref
+	`refs/bisect/bad` is added to the included commits (if it
+	exists) and the good bisection refs `refs/bisect/good-*` are
+	added to the excluded commits (if they exist). Thus, supposing there
+	are no refs in `refs/bisect/`, if
++
+-----------------------------------------------------------------------
+	$ git rev-list --bisect foo ^bar ^baz
+-----------------------------------------------------------------------
++
+outputs 'midpoint', the output of the two commands
++
+-----------------------------------------------------------------------
+	$ git rev-list foo ^midpoint
+	$ git rev-list midpoint ^bar ^baz
+-----------------------------------------------------------------------
++
+would be of roughly the same length.  Finding the change which
+introduces a regression is thus reduced to a binary search: repeatedly
+generate and test new 'midpoint's until the commit chain is of length
+one. Cannot be combined with --first-parent.
+
+--bisect-vars::
+	This calculates the same as `--bisect`, except that refs in
+	`refs/bisect/` are not used, and except that this outputs
+	text ready to be eval'ed by the shell. These lines will assign the
+	name of the midpoint revision to the variable `bisect_rev`, and the
+	expected number of commits to be tested after `bisect_rev` is tested
+	to `bisect_nr`, the expected number of commits to be tested if
+	`bisect_rev` turns out to be good to `bisect_good`, the expected
+	number of commits to be tested if `bisect_rev` turns out to be bad to
+	`bisect_bad`, and the number of commits we are bisecting right now to
+	`bisect_all`.
+
+--bisect-all::
+	This outputs all the commit objects between the included and excluded
+	commits, ordered by their distance to the included and excluded
+	commits. Refs in `refs/bisect/` are not used. The farthest
+	from them is displayed first. (This is the only one displayed by
+	`--bisect`.)
++
+This is useful because it makes it easy to choose a good commit to
+test when you want to avoid to test some of them for some reason (they
+may not compile for example).
++
+This option can be used along with `--bisect-vars`, in this case,
+after all the sorted commit objects, there will be the same text as if
+`--bisect-vars` had been used alone.
+endif::git-rev-list[]
+
+
+Commit Ordering
+~~~~~~~~~~~~~~~
+
+By default, the commits are shown in reverse chronological order.
+
+--date-order::
+	Show no parents before all of its children are shown, but
+	otherwise show commits in the commit timestamp order.
+
+--author-date-order::
+	Show no parents before all of its children are shown, but
+	otherwise show commits in the author timestamp order.
+
+--topo-order::
+	Show no parents before all of its children are shown, and
+	avoid showing commits on multiple lines of history
+	intermixed.
++
+For example, in a commit history like this:
++
+----------------------------------------------------------------
+
+    ---1----2----4----7
+	\	       \
+	 3----5----6----8---
+
+----------------------------------------------------------------
++
+where the numbers denote the order of commit timestamps, `git
+rev-list` and friends with `--date-order` show the commits in the
+timestamp order: 8 7 6 5 4 3 2 1.
++
+With `--topo-order`, they would show 8 6 5 3 7 4 2 1 (or 8 7 4 2 6 5
+3 1); some older commits are shown before newer ones in order to
+avoid showing the commits from two parallel development track mixed
+together.
+
+--reverse::
+	Output the commits chosen to be shown (see Commit Limiting
+	section above) in reverse order. Cannot be combined with
+	`--walk-reflogs`.
+
+Object Traversal
+~~~~~~~~~~~~~~~~
+
+These options are mostly targeted for packing of Git repositories.
+
+ifdef::git-rev-list[]
+--objects::
+	Print the object IDs of any object referenced by the listed
+	commits.  `--objects foo ^bar` thus means ``send me
+	all object IDs which I need to download if I have the commit
+	object _bar_ but not _foo_''.
+
+--in-commit-order::
+	Print tree and blob ids in order of the commits. The tree
+	and blob ids are printed after they are first referenced
+	by a commit.
+
+--objects-edge::
+	Similar to `--objects`, but also print the IDs of excluded
+	commits prefixed with a ``-'' character.  This is used by
+	linkgit:git-pack-objects[1] to build a ``thin'' pack, which records
+	objects in deltified form based on objects contained in these
+	excluded commits to reduce network traffic.
+
+--objects-edge-aggressive::
+	Similar to `--objects-edge`, but it tries harder to find excluded
+	commits at the cost of increased time.  This is used instead of
+	`--objects-edge` to build ``thin'' packs for shallow repositories.
+
+--indexed-objects::
+	Pretend as if all trees and blobs used by the index are listed
+	on the command line.  Note that you probably want to use
+	`--objects`, too.
+
+--unpacked::
+	Only useful with `--objects`; print the object IDs that are not
+	in packs.
+
+--object-names::
+	Only useful with `--objects`; print the names of the object IDs
+	that are found. This is the default behavior.
+
+--no-object-names::
+	Only useful with `--objects`; does not print the names of the object
+	IDs that are found. This inverts `--object-names`. This flag allows
+	the output to be more easily parsed by commands such as
+	linkgit:git-cat-file[1].
+
+--filter=<filter-spec>::
+	Only useful with one of the `--objects*`; omits objects (usually
+	blobs) from the list of printed objects.  The '<filter-spec>'
+	may be one of the following:
++
+The form '--filter=blob:none' omits all blobs.
++
+The form '--filter=blob:limit=<n>[kmg]' omits blobs larger than n bytes
+or units.  n may be zero.  The suffixes k, m, and g can be used to name
+units in KiB, MiB, or GiB.  For example, 'blob:limit=1k' is the same
+as 'blob:limit=1024'.
++
+The form '--filter=sparse:oid=<blob-ish>' uses a sparse-checkout
+specification contained in the blob (or blob-expression) '<blob-ish>'
+to omit blobs that would not be not required for a sparse checkout on
+the requested refs.
++
+The form '--filter=tree:<depth>' omits all blobs and trees whose depth
+from the root tree is >= <depth> (minimum depth if an object is located
+at multiple depths in the commits traversed). <depth>=0 will not include
+any trees or blobs unless included explicitly in the command-line (or
+standard input when --stdin is used). <depth>=1 will include only the
+tree and blobs which are referenced directly by a commit reachable from
+<commit> or an explicitly-given object. <depth>=2 is like <depth>=1
+while also including trees and blobs one more level removed from an
+explicitly-given commit or tree.
++
+Note that the form '--filter=sparse:path=<path>' that wants to read
+from an arbitrary path on the filesystem has been dropped for security
+reasons.
+
+--no-filter::
+	Turn off any previous `--filter=` argument.
+
+--filter-print-omitted::
+	Only useful with `--filter=`; prints a list of the objects omitted
+	by the filter.  Object IDs are prefixed with a ``~'' character.
+
+--missing=<missing-action>::
+	A debug option to help with future "partial clone" development.
+	This option specifies how missing objects are handled.
++
+The form '--missing=error' requests that rev-list stop with an error if
+a missing object is encountered.  This is the default action.
++
+The form '--missing=allow-any' will allow object traversal to continue
+if a missing object is encountered.  Missing objects will silently be
+omitted from the results.
++
+The form '--missing=allow-promisor' is like 'allow-any', but will only
+allow object traversal to continue for EXPECTED promisor missing objects.
+Unexpected missing objects will raise an error.
++
+The form '--missing=print' is like 'allow-any', but will also print a
+list of the missing objects.  Object IDs are prefixed with a ``?'' character.
+
+--exclude-promisor-objects::
+	(For internal use only.)  Prefilter object traversal at
+	promisor boundary.  This is used with partial clone.  This is
+	stronger than `--missing=allow-promisor` because it limits the
+	traversal, rather than just silencing errors about missing
+	objects.
+endif::git-rev-list[]
+
+--no-walk[=(sorted|unsorted)]::
+	Only show the given commits, but do not traverse their ancestors.
+	This has no effect if a range is specified. If the argument
+	`unsorted` is given, the commits are shown in the order they were
+	given on the command line. Otherwise (if `sorted` or no argument
+	was given), the commits are shown in reverse chronological order
+	by commit time.
+	Cannot be combined with `--graph`.
+
+--do-walk::
+	Overrides a previous `--no-walk`.
+
+Commit Formatting
+~~~~~~~~~~~~~~~~~
+
+ifdef::git-rev-list[]
+Using these options, linkgit:git-rev-list[1] will act similar to the
+more specialized family of commit log tools: linkgit:git-log[1],
+linkgit:git-show[1], and linkgit:git-whatchanged[1]
+endif::git-rev-list[]
+
+include::pretty-options.txt[]
+
+--relative-date::
+	Synonym for `--date=relative`.
+
+--date=<format>::
+	Only takes effect for dates shown in human-readable format, such
+	as when using `--pretty`. `log.date` config variable sets a default
+	value for the log command's `--date` option. By default, dates
+	are shown in the original time zone (either committer's or
+	author's). If `-local` is appended to the format (e.g.,
+	`iso-local`), the user's local time zone is used instead.
++
+--
+`--date=relative` shows dates relative to the current time,
+e.g. ``2 hours ago''. The `-local` option has no effect for
+`--date=relative`.
+
+`--date=local` is an alias for `--date=default-local`.
+
+`--date=iso` (or `--date=iso8601`) shows timestamps in a ISO 8601-like format.
+The differences to the strict ISO 8601 format are:
+
+	- a space instead of the `T` date/time delimiter
+	- a space between time and time zone
+	- no colon between hours and minutes of the time zone
+
+`--date=iso-strict` (or `--date=iso8601-strict`) shows timestamps in strict
+ISO 8601 format.
+
+`--date=rfc` (or `--date=rfc2822`) shows timestamps in RFC 2822
+format, often found in email messages.
+
+`--date=short` shows only the date, but not the time, in `YYYY-MM-DD` format.
+
+`--date=raw` shows the date as seconds since the epoch (1970-01-01
+00:00:00 UTC), followed by a space, and then the timezone as an offset
+from UTC (a `+` or `-` with four digits; the first two are hours, and
+the second two are minutes). I.e., as if the timestamp were formatted
+with `strftime("%s %z")`).
+Note that the `-local` option does not affect the seconds-since-epoch
+value (which is always measured in UTC), but does switch the accompanying
+timezone value.
+
+`--date=human` shows the timezone if the timezone does not match the
+current time-zone, and doesn't print the whole date if that matches
+(ie skip printing year for dates that are "this year", but also skip
+the whole date itself if it's in the last few days and we can just say
+what weekday it was).  For older dates the hour and minute is also
+omitted.
+
+`--date=unix` shows the date as a Unix epoch timestamp (seconds since
+1970).  As with `--raw`, this is always in UTC and therefore `-local`
+has no effect.
+
+`--date=format:...` feeds the format `...` to your system `strftime`,
+except for %z and %Z, which are handled internally.
+Use `--date=format:%c` to show the date in your system locale's
+preferred format.  See the `strftime` manual for a complete list of
+format placeholders. When using `-local`, the correct syntax is
+`--date=format-local:...`.
+
+`--date=default` is the default format, and is similar to
+`--date=rfc2822`, with a few exceptions:
+--
+	- there is no comma after the day-of-week
+
+	- the time zone is omitted when the local time zone is used
+
+ifdef::git-rev-list[]
+--header::
+	Print the contents of the commit in raw-format; each record is
+	separated with a NUL character.
+endif::git-rev-list[]
+
+--parents::
+	Print also the parents of the commit (in the form "commit parent...").
+	Also enables parent rewriting, see 'History Simplification' above.
+
+--children::
+	Print also the children of the commit (in the form "commit child...").
+	Also enables parent rewriting, see 'History Simplification' above.
+
+ifdef::git-rev-list[]
+--timestamp::
+	Print the raw commit timestamp.
+endif::git-rev-list[]
+
+--left-right::
+	Mark which side of a symmetric difference a commit is reachable from.
+	Commits from the left side are prefixed with `<` and those from
+	the right with `>`.  If combined with `--boundary`, those
+	commits are prefixed with `-`.
++
+For example, if you have this topology:
++
+-----------------------------------------------------------------------
+	     y---b---b  branch B
+	    / \ /
+	   /   .
+	  /   / \
+	 o---x---a---a  branch A
+-----------------------------------------------------------------------
++
+you would get an output like this:
++
+-----------------------------------------------------------------------
+	$ git rev-list --left-right --boundary --pretty=oneline A...B
+
+	>bbbbbbb... 3rd on b
+	>bbbbbbb... 2nd on b
+	<aaaaaaa... 3rd on a
+	<aaaaaaa... 2nd on a
+	-yyyyyyy... 1st on b
+	-xxxxxxx... 1st on a
+-----------------------------------------------------------------------
+
+--graph::
+	Draw a text-based graphical representation of the commit history
+	on the left hand side of the output.  This may cause extra lines
+	to be printed in between commits, in order for the graph history
+	to be drawn properly.
+	Cannot be combined with `--no-walk`.
++
+This enables parent rewriting, see 'History Simplification' above.
++
+This implies the `--topo-order` option by default, but the
+`--date-order` option may also be specified.
+
+--show-linear-break[=<barrier>]::
+	When --graph is not used, all history branches are flattened
+	which can make it hard to see that the two consecutive commits
+	do not belong to a linear branch. This option puts a barrier
+	in between them in that case. If `<barrier>` is specified, it
+	is the string that will be shown instead of the default one.
+
+ifdef::git-rev-list[]
+--count::
+	Print a number stating how many commits would have been
+	listed, and suppress all other output.  When used together
+	with `--left-right`, instead print the counts for left and
+	right commits, separated by a tab. When used together with
+	`--cherry-mark`, omit patch equivalent commits from these
+	counts and print the count for equivalent commits separated
+	by a tab.
+endif::git-rev-list[]
+
+ifndef::git-rev-list[]
+Diff Formatting
+~~~~~~~~~~~~~~~
+
+Listed below are options that control the formatting of diff output.
+Some of them are specific to linkgit:git-rev-list[1], however other diff
+options may be given. See linkgit:git-diff-files[1] for more options.
+
+-c::
+	With this option, diff output for a merge commit
+	shows the differences from each of the parents to the merge result
+	simultaneously instead of showing pairwise diff between a parent
+	and the result one at a time. Furthermore, it lists only files
+	which were modified from all parents.
+
+--cc::
+	This flag implies the `-c` option and further compresses the
+	patch output by omitting uninteresting hunks whose contents in
+	the parents have only two variants and the merge result picks
+	one of them without modification.
+
+--combined-all-paths::
+	This flag causes combined diffs (used for merge commits) to
+	list the name of the file from all parents.  It thus only has
+	effect when -c or --cc are specified, and is likely only
+	useful if filename changes are detected (i.e. when either
+	rename or copy detection have been requested).
+
+-m::
+	This flag makes the merge commits show the full diff like
+	regular commits; for each merge parent, a separate log entry
+	and diff is generated. An exception is that only diff against
+	the first parent is shown when `--first-parent` option is given;
+	in that case, the output represents the changes the merge
+	brought _into_ the then-current branch.
+
+-r::
+	Show recursive diffs.
+
+-t::
+	Show the tree objects in the diff output. This implies `-r`.
+endif::git-rev-list[]
diff --git a/third_party/git/Documentation/revisions.txt b/third_party/git/Documentation/revisions.txt
new file mode 100644
index 0000000000..97f995e5a9
--- /dev/null
+++ b/third_party/git/Documentation/revisions.txt
@@ -0,0 +1,377 @@
+SPECIFYING REVISIONS
+--------------------
+
+A revision parameter '<rev>' typically, but not necessarily, names a
+commit object.  It uses what is called an 'extended SHA-1'
+syntax.  Here are various ways to spell object names.  The
+ones listed near the end of this list name trees and
+blobs contained in a commit.
+
+NOTE: This document shows the "raw" syntax as seen by git. The shell
+and other UIs might require additional quoting to protect special
+characters and to avoid word splitting.
+
+'<sha1>', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e'::
+  The full SHA-1 object name (40-byte hexadecimal string), or
+  a leading substring that is unique within the repository.
+  E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
+  name the same commit object if there is no other object in
+  your repository whose object name starts with dae86e.
+
+'<describeOutput>', e.g. 'v1.7.4.2-679-g3bee7fb'::
+  Output from `git describe`; i.e. a closest tag, optionally
+  followed by a dash and a number of commits, followed by a dash, a
+  'g', and an abbreviated object name.
+
+'<refname>', e.g. 'master', 'heads/master', 'refs/heads/master'::
+  A symbolic ref name.  E.g. 'master' typically means the commit
+  object referenced by 'refs/heads/master'.  If you
+  happen to have both 'heads/master' and 'tags/master', you can
+  explicitly say 'heads/master' to tell Git which one you mean.
+  When ambiguous, a '<refname>' is disambiguated by taking the
+  first match in the following rules:
+
+  . If '$GIT_DIR/<refname>' exists, that is what you mean (this is usually
+    useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD`, `MERGE_HEAD`
+    and `CHERRY_PICK_HEAD`);
+
+  . otherwise, 'refs/<refname>' if it exists;
+
+  . otherwise, 'refs/tags/<refname>' if it exists;
+
+  . otherwise, 'refs/heads/<refname>' if it exists;
+
+  . otherwise, 'refs/remotes/<refname>' if it exists;
+
+  . otherwise, 'refs/remotes/<refname>/HEAD' if it exists.
++
+`HEAD` names the commit on which you based the changes in the working tree.
+`FETCH_HEAD` records the branch which you fetched from a remote repository
+with your last `git fetch` invocation.
+`ORIG_HEAD` is created by commands that move your `HEAD` in a drastic
+way, to record the position of the `HEAD` before their operation, so that
+you can easily change the tip of the branch back to the state before you ran
+them.
+`MERGE_HEAD` records the commit(s) which you are merging into your branch
+when you run `git merge`.
+`CHERRY_PICK_HEAD` records the commit which you are cherry-picking
+when you run `git cherry-pick`.
++
+Note that any of the 'refs/*' cases above may come either from
+the `$GIT_DIR/refs` directory or from the `$GIT_DIR/packed-refs` file.
+While the ref name encoding is unspecified, UTF-8 is preferred as
+some output processing may assume ref names in UTF-8.
+
+'@'::
+  '@' alone is a shortcut for `HEAD`.
+
+'[<refname>]@{<date>}', e.g. 'master@\{yesterday\}', 'HEAD@{5 minutes ago}'::
+  A ref followed by the suffix '@' with a date specification
+  enclosed in a brace
+  pair (e.g. '\{yesterday\}', '{1 month 2 weeks 3 days 1 hour 1
+  second ago}' or '{1979-02-26 18:30:00}') specifies the value
+  of the ref at a prior point in time.  This suffix may only be
+  used immediately following a ref name and the ref must have an
+  existing log ('$GIT_DIR/logs/<ref>'). Note that this looks up the state
+  of your *local* ref at a given time; e.g., what was in your local
+  'master' branch last week. If you want to look at commits made during
+  certain times, see `--since` and `--until`.
+
+'<refname>@{<n>}', e.g. 'master@\{1\}'::
+  A ref followed by the suffix '@' with an ordinal specification
+  enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies
+  the n-th prior value of that ref.  For example 'master@\{1\}'
+  is the immediate prior value of 'master' while 'master@\{5\}'
+  is the 5th prior value of 'master'. This suffix may only be used
+  immediately following a ref name and the ref must have an existing
+  log ('$GIT_DIR/logs/<refname>').
+
+'@{<n>}', e.g. '@\{1\}'::
+  You can use the '@' construct with an empty ref part to get at a
+  reflog entry of the current branch. For example, if you are on
+  branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'.
+
+'@{-<n>}', e.g. '@{-1}'::
+  The construct '@{-<n>}' means the <n>th branch/commit checked out
+  before the current one.
+
+'[<branchname>]@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}'::
+  The suffix '@\{upstream\}' to a branchname (short form '<branchname>@\{u\}')
+  refers to the branch that the branch specified by branchname is set to build on
+  top of (configured with `branch.<name>.remote` and
+  `branch.<name>.merge`).  A missing branchname defaults to the
+  current one. These suffixes are also accepted when spelled in uppercase, and
+  they mean the same thing no matter the case.
+
+'[<branchname>]@\{push\}', e.g. 'master@\{push\}', '@\{push\}'::
+  The suffix '@\{push}' reports the branch "where we would push to" if
+  `git push` were run while `branchname` was checked out (or the current
+  `HEAD` if no branchname is specified). Since our push destination is
+  in a remote repository, of course, we report the local tracking branch
+  that corresponds to that branch (i.e., something in `refs/remotes/`).
++
+Here's an example to make it more clear:
++
+------------------------------
+$ git config push.default current
+$ git config remote.pushdefault myfork
+$ git switch -c mybranch origin/master
+
+$ git rev-parse --symbolic-full-name @{upstream}
+refs/remotes/origin/master
+
+$ git rev-parse --symbolic-full-name @{push}
+refs/remotes/myfork/mybranch
+------------------------------
++
+Note in the example that we set up a triangular workflow, where we pull
+from one location and push to another. In a non-triangular workflow,
+'@\{push}' is the same as '@\{upstream}', and there is no need for it.
++
+This suffix is also accepted when spelled in uppercase, and means the same
+thing no matter the case.
+
+'<rev>{caret}[<n>]', e.g. 'HEAD{caret}, v1.5.1{caret}0'::
+  A suffix '{caret}' to a revision parameter means the first parent of
+  that commit object.  '{caret}<n>' means the <n>th parent (i.e.
+  '<rev>{caret}'
+  is equivalent to '<rev>{caret}1').  As a special rule,
+  '<rev>{caret}0' means the commit itself and is used when '<rev>' is the
+  object name of a tag object that refers to a commit object.
+
+'<rev>{tilde}[<n>]', e.g. 'HEAD{tilde}, master{tilde}3'::
+  A suffix '{tilde}' to a revision parameter means the first parent of
+  that commit object.
+  A suffix '{tilde}<n>' to a revision parameter means the commit
+  object that is the <n>th generation ancestor of the named
+  commit object, following only the first parents.  I.e. '<rev>{tilde}3' is
+  equivalent to '<rev>{caret}{caret}{caret}' which is equivalent to
+  '<rev>{caret}1{caret}1{caret}1'.  See below for an illustration of
+  the usage of this form.
+
+'<rev>{caret}{<type>}', e.g. 'v0.99.8{caret}\{commit\}'::
+  A suffix '{caret}' followed by an object type name enclosed in
+  brace pair means dereference the object at '<rev>' recursively until
+  an object of type '<type>' is found or the object cannot be
+  dereferenced anymore (in which case, barf).
+  For example, if '<rev>' is a commit-ish, '<rev>{caret}\{commit\}'
+  describes the corresponding commit object.
+  Similarly, if '<rev>' is a tree-ish, '<rev>{caret}\{tree\}'
+  describes the corresponding tree object.
+  '<rev>{caret}0'
+  is a short-hand for '<rev>{caret}\{commit\}'.
++
+'<rev>{caret}\{object\}' can be used to make sure '<rev>' names an
+object that exists, without requiring '<rev>' to be a tag, and
+without dereferencing '<rev>'; because a tag is already an object,
+it does not have to be dereferenced even once to get to an object.
++
+'<rev>{caret}\{tag\}' can be used to ensure that '<rev>' identifies an
+existing tag object.
+
+'<rev>{caret}{}', e.g. 'v0.99.8{caret}{}'::
+  A suffix '{caret}' followed by an empty brace pair
+  means the object could be a tag,
+  and dereference the tag recursively until a non-tag object is
+  found.
+
+'<rev>{caret}{/<text>}', e.g. 'HEAD^{/fix nasty bug}'::
+  A suffix '{caret}' to a revision parameter, followed by a brace
+  pair that contains a text led by a slash,
+  is the same as the ':/fix nasty bug' syntax below except that
+  it returns the youngest matching commit which is reachable from
+  the '<rev>' before '{caret}'.
+
+':/<text>', e.g. ':/fix nasty bug'::
+  A colon, followed by a slash, followed by a text, names
+  a commit whose commit message matches the specified regular expression.
+  This name returns the youngest matching commit which is
+  reachable from any ref, including HEAD.
+  The regular expression can match any part of the
+  commit message. To match messages starting with a string, one can use
+  e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what
+  is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a
+  literal '!' character, followed by 'foo'. Any other sequence beginning with
+  ':/!' is reserved for now.
+  Depending on the given text, the shell's word splitting rules might
+  require additional quoting.
+
+'<rev>:<path>', e.g. 'HEAD:README', 'master:./README'::
+  A suffix ':' followed by a path names the blob or tree
+  at the given path in the tree-ish object named by the part
+  before the colon.
+  A path starting with './' or '../' is relative to the current working directory.
+  The given path will be converted to be relative to the working tree's root directory.
+  This is most useful to address a blob or tree from a commit or tree that has
+  the same tree structure as the working tree.
+
+':[<n>:]<path>', e.g. ':0:README', ':README'::
+  A colon, optionally followed by a stage number (0 to 3) and a
+  colon, followed by a path, names a blob object in the
+  index at the given path. A missing stage number (and the colon
+  that follows it) names a stage 0 entry. During a merge, stage
+  1 is the common ancestor, stage 2 is the target branch's version
+  (typically the current branch), and stage 3 is the version from
+  the branch which is being merged.
+
+Here is an illustration, by Jon Loeliger.  Both commit nodes B
+and C are parents of commit node A.  Parent commits are ordered
+left-to-right.
+
+........................................
+G   H   I   J
+ \ /     \ /
+  D   E   F
+   \  |  / \
+    \ | /   |
+     \|/    |
+      B     C
+       \   /
+        \ /
+         A
+........................................
+
+    A =      = A^0
+    B = A^   = A^1     = A~1
+    C = A^2  = A^2
+    D = A^^  = A^1^1   = A~2
+    E = B^2  = A^^2
+    F = B^3  = A^^3
+    G = A^^^ = A^1^1^1 = A~3
+    H = D^2  = B^^2    = A^^^2  = A~2^2
+    I = F^   = B^3^    = A^^3^
+    J = F^2  = B^3^2   = A^^3^2
+
+
+SPECIFYING RANGES
+-----------------
+
+History traversing commands such as `git log` operate on a set
+of commits, not just a single commit.
+
+For these commands,
+specifying a single revision, using the notation described in the
+previous section, means the set of commits `reachable` from the given
+commit.
+
+A commit's reachable set is the commit itself and the commits in
+its ancestry chain.
+
+
+Commit Exclusions
+~~~~~~~~~~~~~~~~~
+
+'{caret}<rev>' (caret) Notation::
+ To exclude commits reachable from a commit, a prefix '{caret}'
+ notation is used.  E.g. '{caret}r1 r2' means commits reachable
+ from 'r2' but exclude the ones reachable from 'r1' (i.e. 'r1' and
+ its ancestors).
+
+Dotted Range Notations
+~~~~~~~~~~~~~~~~~~~~~~
+
+The '..' (two-dot) Range Notation::
+ The '{caret}r1 r2' set operation appears so often that there is a shorthand
+ for it.  When you have two commits 'r1' and 'r2' (named according
+ to the syntax explained in SPECIFYING REVISIONS above), you can ask
+ for commits that are reachable from r2 excluding those that are reachable
+ from r1 by '{caret}r1 r2' and it can be written as 'r1..r2'.
+
+The '...' (three-dot) Symmetric Difference Notation::
+ A similar notation 'r1\...r2' is called symmetric difference
+ of 'r1' and 'r2' and is defined as
+ 'r1 r2 --not $(git merge-base --all r1 r2)'.
+ It is the set of commits that are reachable from either one of
+ 'r1' (left side) or 'r2' (right side) but not from both.
+
+In these two shorthand notations, you can omit one end and let it default to HEAD.
+For example, 'origin..' is a shorthand for 'origin..HEAD' and asks "What
+did I do since I forked from the origin branch?"  Similarly, '..origin'
+is a shorthand for 'HEAD..origin' and asks "What did the origin do since
+I forked from them?"  Note that '..' would mean 'HEAD..HEAD' which is an
+empty range that is both reachable and unreachable from HEAD.
+
+Other <rev>{caret} Parent Shorthand Notations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Three other shorthands exist, particularly useful for merge commits,
+for naming a set that is formed by a commit and its parent commits.
+
+The 'r1{caret}@' notation means all parents of 'r1'.
+
+The 'r1{caret}!' notation includes commit 'r1' but excludes all of its parents.
+By itself, this notation denotes the single commit 'r1'.
+
+The '<rev>{caret}-[<n>]' notation includes '<rev>' but excludes the <n>th
+parent (i.e. a shorthand for '<rev>{caret}<n>..<rev>'), with '<n>' = 1 if
+not given. This is typically useful for merge commits where you
+can just pass '<commit>{caret}-' to get all the commits in the branch
+that was merged in merge commit '<commit>' (including '<commit>'
+itself).
+
+While '<rev>{caret}<n>' was about specifying a single commit parent, these
+three notations also consider its parents. For example you can say
+'HEAD{caret}2{caret}@', however you cannot say 'HEAD{caret}@{caret}2'.
+
+Revision Range Summary
+----------------------
+
+'<rev>'::
+	Include commits that are reachable from <rev> (i.e. <rev> and its
+	ancestors).
+
+'{caret}<rev>'::
+	Exclude commits that are reachable from <rev> (i.e. <rev> and its
+	ancestors).
+
+'<rev1>..<rev2>'::
+	Include commits that are reachable from <rev2> but exclude
+	those that are reachable from <rev1>.  When either <rev1> or
+	<rev2> is omitted, it defaults to `HEAD`.
+
+'<rev1>\...<rev2>'::
+	Include commits that are reachable from either <rev1> or
+	<rev2> but exclude those that are reachable from both.  When
+	either <rev1> or <rev2> is omitted, it defaults to `HEAD`.
+
+'<rev>{caret}@', e.g. 'HEAD{caret}@'::
+  A suffix '{caret}' followed by an at sign is the same as listing
+  all parents of '<rev>' (meaning, include anything reachable from
+  its parents, but not the commit itself).
+
+'<rev>{caret}!', e.g. 'HEAD{caret}!'::
+  A suffix '{caret}' followed by an exclamation mark is the same
+  as giving commit '<rev>' and then all its parents prefixed with
+  '{caret}' to exclude them (and their ancestors).
+
+'<rev>{caret}-<n>', e.g. 'HEAD{caret}-, HEAD{caret}-2'::
+	Equivalent to '<rev>{caret}<n>..<rev>', with '<n>' = 1 if not
+	given.
+
+Here are a handful of examples using the Loeliger illustration above,
+with each step in the notation's expansion and selection carefully
+spelt out:
+
+....
+   Args   Expanded arguments    Selected commits
+   D                            G H D
+   D F                          G H I J D F
+   ^G D                         H D
+   ^D B                         E I J F B
+   ^D B C                       E I J F B C
+   C                            I J F C
+   B..C   = ^B C                C
+   B...C  = B ^F C              G H D E B C
+   B^-    = B^..B
+	  = ^B^1 B              E I J F B
+   C^@    = C^1
+	  = F                   I J F
+   B^@    = B^1 B^2 B^3
+	  = D E F               D G H E F I J
+   C^!    = C ^C^@
+	  = C ^C^1
+	  = C ^F                C
+   B^!    = B ^B^@
+	  = B ^B^1 ^B^2 ^B^3
+	  = B ^D ^E ^F          B
+   F^! D  = F ^I ^J D           G H D F
+....
diff --git a/third_party/git/Documentation/sequencer.txt b/third_party/git/Documentation/sequencer.txt
new file mode 100644
index 0000000000..3bceb56474
--- /dev/null
+++ b/third_party/git/Documentation/sequencer.txt
@@ -0,0 +1,16 @@
+--continue::
+	Continue the operation in progress using the information in
+	`.git/sequencer`.  Can be used to continue after resolving
+	conflicts in a failed cherry-pick or revert.
+
+--skip::
+	Skip the current commit and continue with the rest of the
+	sequence.
+
+--quit::
+	Forget about the current operation in progress.  Can be used
+	to clear the sequencer state after a failed cherry-pick or
+	revert.
+
+--abort::
+	Cancel the operation and return to the pre-sequence state.
diff --git a/third_party/git/Documentation/technical/.gitignore b/third_party/git/Documentation/technical/.gitignore
new file mode 100644
index 0000000000..8aa891daee
--- /dev/null
+++ b/third_party/git/Documentation/technical/.gitignore
@@ -0,0 +1 @@
+api-index.txt
diff --git a/third_party/git/Documentation/technical/api-allocation-growing.txt b/third_party/git/Documentation/technical/api-allocation-growing.txt
new file mode 100644
index 0000000000..5a59b54844
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-allocation-growing.txt
@@ -0,0 +1,39 @@
+allocation growing API
+======================
+
+Dynamically growing an array using realloc() is error prone and boring.
+
+Define your array with:
+
+* a pointer (`item`) that points at the array, initialized to `NULL`
+  (although please name the variable based on its contents, not on its
+  type);
+
+* an integer variable (`alloc`) that keeps track of how big the current
+  allocation is, initialized to `0`;
+
+* another integer variable (`nr`) to keep track of how many elements the
+  array currently has, initialized to `0`.
+
+Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
+alloc)`.  This ensures that the array can hold at least `n` elements by
+calling `realloc(3)` and adjusting `alloc` variable.
+
+------------
+sometype *item;
+size_t nr;
+size_t alloc
+
+for (i = 0; i < nr; i++)
+	if (we like item[i] already)
+		return;
+
+/* we did not like any existing one, so add one */
+ALLOC_GROW(item, nr + 1, alloc);
+item[nr++] = value you like;
+------------
+
+You are responsible for updating the `nr` variable.
+
+If you need to specify the number of elements to allocate explicitly
+then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.
diff --git a/third_party/git/Documentation/technical/api-argv-array.txt b/third_party/git/Documentation/technical/api-argv-array.txt
new file mode 100644
index 0000000000..870c8edbfb
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-argv-array.txt
@@ -0,0 +1,65 @@
+argv-array API
+==============
+
+The argv-array API allows one to dynamically build and store
+NULL-terminated lists.  An argv-array maintains the invariant that the
+`argv` member always points to a non-NULL array, and that the array is
+always NULL-terminated at the element pointed to by `argv[argc]`. This
+makes the result suitable for passing to functions expecting to receive
+argv from main(), or the link:api-run-command.html[run-command API].
+
+The string-list API (documented in string-list.h) is similar, but cannot be
+used for these purposes; instead of storing a straight string pointer,
+it contains an item structure with a `util` field that is not compatible
+with the traditional argv interface.
+
+Each `argv_array` manages its own memory. Any strings pushed into the
+array are duplicated, and all memory is freed by argv_array_clear().
+
+Data Structures
+---------------
+
+`struct argv_array`::
+
+	A single array. This should be initialized by assignment from
+	`ARGV_ARRAY_INIT`, or by calling `argv_array_init`. The `argv`
+	member contains the actual array; the `argc` member contains the
+	number of elements in the array, not including the terminating
+	NULL.
+
+Functions
+---------
+
+`argv_array_init`::
+	Initialize an array. This is no different than assigning from
+	`ARGV_ARRAY_INIT`.
+
+`argv_array_push`::
+	Push a copy of a string onto the end of the array.
+
+`argv_array_pushl`::
+	Push a list of strings onto the end of the array. The arguments
+	should be a list of `const char *` strings, terminated by a NULL
+	argument.
+
+`argv_array_pushf`::
+	Format a string and push it onto the end of the array. This is a
+	convenience wrapper combining `strbuf_addf` and `argv_array_push`.
+
+`argv_array_pushv`::
+	Push a null-terminated array of strings onto the end of the array.
+
+`argv_array_pop`::
+	Remove the final element from the array. If there are no
+	elements in the array, do nothing.
+
+`argv_array_clear`::
+	Free all memory associated with the array and return it to the
+	initial, empty state.
+
+`argv_array_detach`::
+	Disconnect the `argv` member from the `argv_array` struct and
+	return it. The caller is responsible for freeing the memory used
+	by the array, and by the strings it references. After detaching,
+	the `argv_array` is in a reinitialized state and can be pushed
+	into again.
diff --git a/third_party/git/Documentation/technical/api-config.txt b/third_party/git/Documentation/technical/api-config.txt
new file mode 100644
index 0000000000..7d20716c32
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-config.txt
@@ -0,0 +1,319 @@
+config API
+==========
+
+The config API gives callers a way to access Git configuration files
+(and files which have the same syntax). See linkgit:git-config[1] for a
+discussion of the config file syntax.
+
+General Usage
+-------------
+
+Config files are parsed linearly, and each variable found is passed to a
+caller-provided callback function. The callback function is responsible
+for any actions to be taken on the config option, and is free to ignore
+some options. It is not uncommon for the configuration to be parsed
+several times during the run of a Git program, with different callbacks
+picking out different variables useful to themselves.
+
+A config callback function takes three parameters:
+
+- the name of the parsed variable. This is in canonical "flat" form: the
+  section, subsection, and variable segments will be separated by dots,
+  and the section and variable segments will be all lowercase. E.g.,
+  `core.ignorecase`, `diff.SomeType.textconv`.
+
+- the value of the found variable, as a string. If the variable had no
+  value specified, the value will be NULL (typically this means it
+  should be interpreted as boolean true).
+
+- a void pointer passed in by the caller of the config API; this can
+  contain callback-specific data
+
+A config callback should return 0 for success, or -1 if the variable
+could not be parsed properly.
+
+Basic Config Querying
+---------------------
+
+Most programs will simply want to look up variables in all config files
+that Git knows about, using the normal precedence rules. To do this,
+call `git_config` with a callback function and void data pointer.
+
+`git_config` will read all config sources in order of increasing
+priority. Thus a callback should typically overwrite previously-seen
+entries with new ones (e.g., if both the user-wide `~/.gitconfig` and
+repo-specific `.git/config` contain `color.ui`, the config machinery
+will first feed the user-wide one to the callback, and then the
+repo-specific one; by overwriting, the higher-priority repo-specific
+value is left at the end).
+
+The `config_with_options` function lets the caller examine config
+while adjusting some of the default behavior of `git_config`. It should
+almost never be used by "regular" Git code that is looking up
+configuration variables. It is intended for advanced callers like
+`git-config`, which are intentionally tweaking the normal config-lookup
+process. It takes two extra parameters:
+
+`config_source`::
+If this parameter is non-NULL, it specifies the source to parse for
+configuration, rather than looking in the usual files. See `struct
+git_config_source` in `config.h` for details. Regular `git_config` defaults
+to `NULL`.
+
+`opts`::
+Specify options to adjust the behavior of parsing config files. See `struct
+config_options` in `config.h` for details. As an example: regular `git_config`
+sets `opts.respect_includes` to `1` by default.
+
+Reading Specific Files
+----------------------
+
+To read a specific file in git-config format, use
+`git_config_from_file`. This takes the same callback and data parameters
+as `git_config`.
+
+Querying For Specific Variables
+-------------------------------
+
+For programs wanting to query for specific variables in a non-callback
+manner, the config API provides two functions `git_config_get_value`
+and `git_config_get_value_multi`. They both read values from an internal
+cache generated previously from reading the config files.
+
+`int git_config_get_value(const char *key, const char **value)`::
+
+	Finds the highest-priority value for the configuration variable `key`,
+	stores the pointer to it in `value` and returns 0. When the
+	configuration variable `key` is not found, returns 1 without touching
+	`value`. The caller should not free or modify `value`, as it is owned
+	by the cache.
+
+`const struct string_list *git_config_get_value_multi(const char *key)`::
+
+	Finds and returns the value list, sorted in order of increasing priority
+	for the configuration variable `key`. When the configuration variable
+	`key` is not found, returns NULL. The caller should not free or modify
+	the returned pointer, as it is owned by the cache.
+
+`void git_config_clear(void)`::
+
+	Resets and invalidates the config cache.
+
+The config API also provides type specific API functions which do conversion
+as well as retrieval for the queried variable, including:
+
+`int git_config_get_int(const char *key, int *dest)`::
+
+	Finds and parses the value to an integer for the configuration variable
+	`key`. Dies on error; otherwise, stores the value of the parsed integer in
+	`dest` and returns 0. When the configuration variable `key` is not found,
+	returns 1 without touching `dest`.
+
+`int git_config_get_ulong(const char *key, unsigned long *dest)`::
+
+	Similar to `git_config_get_int` but for unsigned longs.
+
+`int git_config_get_bool(const char *key, int *dest)`::
+
+	Finds and parses the value into a boolean value, for the configuration
+	variable `key` respecting keywords like "true" and "false". Integer
+	values are converted into true/false values (when they are non-zero or
+	zero, respectively). Other values cause a die(). If parsing is successful,
+	stores the value of the parsed result in `dest` and returns 0. When the
+	configuration variable `key` is not found, returns 1 without touching
+	`dest`.
+
+`int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)`::
+
+	Similar to `git_config_get_bool`, except that integers are copied as-is,
+	and `is_bool` flag is unset.
+
+`int git_config_get_maybe_bool(const char *key, int *dest)`::
+
+	Similar to `git_config_get_bool`, except that it returns -1 on error
+	rather than dying.
+
+`int git_config_get_string_const(const char *key, const char **dest)`::
+
+	Allocates and copies the retrieved string into the `dest` parameter for
+	the configuration variable `key`; if NULL string is given, prints an
+	error message and returns -1. When the configuration variable `key` is
+	not found, returns 1 without touching `dest`.
+
+`int git_config_get_string(const char *key, char **dest)`::
+
+	Similar to `git_config_get_string_const`, except that retrieved value
+	copied into the `dest` parameter is a mutable string.
+
+`int git_config_get_pathname(const char *key, const char **dest)`::
+
+	Similar to `git_config_get_string`, but expands `~` or `~user` into
+	the user's home directory when found at the beginning of the path.
+
+`git_die_config(const char *key, const char *err, ...)`::
+
+	First prints the error message specified by the caller in `err` and then
+	dies printing the line number and the file name of the highest priority
+	value for the configuration variable `key`.
+
+`void git_die_config_linenr(const char *key, const char *filename, int linenr)`::
+
+	Helper function which formats the die error message according to the
+	parameters entered. Used by `git_die_config()`. It can be used by callers
+	handling `git_config_get_value_multi()` to print the correct error message
+	for the desired value.
+
+See test-config.c for usage examples.
+
+Value Parsing Helpers
+---------------------
+
+To aid in parsing string values, the config API provides callbacks with
+a number of helper functions, including:
+
+`git_config_int`::
+Parse the string to an integer, including unit factors. Dies on error;
+otherwise, returns the parsed result.
+
+`git_config_ulong`::
+Identical to `git_config_int`, but for unsigned longs.
+
+`git_config_bool`::
+Parse a string into a boolean value, respecting keywords like "true" and
+"false". Integer values are converted into true/false values (when they
+are non-zero or zero, respectively). Other values cause a die(). If
+parsing is successful, the return value is the result.
+
+`git_config_bool_or_int`::
+Same as `git_config_bool`, except that integers are returned as-is, and
+an `is_bool` flag is unset.
+
+`git_parse_maybe_bool`::
+Same as `git_config_bool`, except that it returns -1 on error rather
+than dying.
+
+`git_config_string`::
+Allocates and copies the value string into the `dest` parameter; if no
+string is given, prints an error message and returns -1.
+
+`git_config_pathname`::
+Similar to `git_config_string`, but expands `~` or `~user` into the
+user's home directory when found at the beginning of the path.
+
+Include Directives
+------------------
+
+By default, the config parser does not respect include directives.
+However, a caller can use the special `git_config_include` wrapper
+callback to support them. To do so, you simply wrap your "real" callback
+function and data pointer in a `struct config_include_data`, and pass
+the wrapper to the regular config-reading functions. For example:
+
+-------------------------------------------
+int read_file_with_include(const char *file, config_fn_t fn, void *data)
+{
+	struct config_include_data inc = CONFIG_INCLUDE_INIT;
+	inc.fn = fn;
+	inc.data = data;
+	return git_config_from_file(git_config_include, file, &inc);
+}
+-------------------------------------------
+
+`git_config` respects includes automatically. The lower-level
+`git_config_from_file` does not.
+
+Custom Configsets
+-----------------
+
+A `config_set` can be used to construct an in-memory cache for
+config-like files that the caller specifies (i.e., files like `.gitmodules`,
+`~/.gitconfig` etc.). For example,
+
+----------------------------------------
+struct config_set gm_config;
+git_configset_init(&gm_config);
+int b;
+/* we add config files to the config_set */
+git_configset_add_file(&gm_config, ".gitmodules");
+git_configset_add_file(&gm_config, ".gitmodules_alt");
+
+if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
+	/* hack hack hack */
+}
+
+/* when we are done with the configset */
+git_configset_clear(&gm_config);
+----------------------------------------
+
+Configset API provides functions for the above mentioned work flow, including:
+
+`void git_configset_init(struct config_set *cs)`::
+
+	Initializes the config_set `cs`.
+
+`int git_configset_add_file(struct config_set *cs, const char *filename)`::
+
+	Parses the file and adds the variable-value pairs to the `config_set`,
+	dies if there is an error in parsing the file. Returns 0 on success, or
+	-1 if the file does not exist or is inaccessible. The user has to decide
+	if he wants to free the incomplete configset or continue using it when
+	the function returns -1.
+
+`int git_configset_get_value(struct config_set *cs, const char *key, const char **value)`::
+
+	Finds the highest-priority value for the configuration variable `key`
+	and config set `cs`, stores the pointer to it in `value` and returns 0.
+	When the configuration variable `key` is not found, returns 1 without
+	touching `value`. The caller should not free or modify `value`, as it
+	is owned by the cache.
+
+`const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)`::
+
+	Finds and returns the value list, sorted in order of increasing priority
+	for the configuration variable `key` and config set `cs`. When the
+	configuration variable `key` is not found, returns NULL. The caller
+	should not free or modify the returned pointer, as it is owned by the cache.
+
+`void git_configset_clear(struct config_set *cs)`::
+
+	Clears `config_set` structure, removes all saved variable-value pairs.
+
+In addition to above functions, the `config_set` API provides type specific
+functions in the vein of `git_config_get_int` and family but with an extra
+parameter, pointer to struct `config_set`.
+They all behave similarly to the `git_config_get*()` family described in
+"Querying For Specific Variables" above.
+
+Writing Config Files
+--------------------
+
+Git gives multiple entry points in the Config API to write config values to
+files namely `git_config_set_in_file` and `git_config_set`, which write to
+a specific config file or to `.git/config` respectively. They both take a
+key/value pair as parameter.
+In the end they both call `git_config_set_multivar_in_file` which takes four
+parameters:
+
+- the name of the file, as a string, to which key/value pairs will be written.
+
+- the name of key, as a string. This is in canonical "flat" form: the section,
+  subsection, and variable segments will be separated by dots, and the section
+  and variable segments will be all lowercase.
+  E.g., `core.ignorecase`, `diff.SomeType.textconv`.
+
+- the value of the variable, as a string. If value is equal to NULL, it will
+  remove the matching key from the config file.
+
+- the value regex, as a string. It will disregard key/value pairs where value
+  does not match.
+
+- a multi_replace value, as an int. If value is equal to zero, nothing or only
+  one matching key/value is replaced, else all matching key/values (regardless
+  how many) are removed, before the new pair is written.
+
+It returns 0 on success.
+
+Also, there are functions `git_config_rename_section` and
+`git_config_rename_section_in_file` with parameters `old_name` and `new_name`
+for renaming or removing sections in the config files. If NULL is passed
+through `new_name` parameter, the section will be removed from the config file.
diff --git a/third_party/git/Documentation/technical/api-credentials.txt b/third_party/git/Documentation/technical/api-credentials.txt
new file mode 100644
index 0000000000..75368f26ca
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-credentials.txt
@@ -0,0 +1,271 @@
+credentials API
+===============
+
+The credentials API provides an abstracted way of gathering username and
+password credentials from the user (even though credentials in the wider
+world can take many forms, in this document the word "credential" always
+refers to a username and password pair).
+
+This document describes two interfaces: the C API that the credential
+subsystem provides to the rest of Git, and the protocol that Git uses to
+communicate with system-specific "credential helpers". If you are
+writing Git code that wants to look up or prompt for credentials, see
+the section "C API" below. If you want to write your own helper, see
+the section on "Credential Helpers" below.
+
+Typical setup
+-------------
+
+------------
++-----------------------+
+| Git code (C)          |--- to server requiring --->
+|                       |        authentication
+|.......................|
+| C credential API      |--- prompt ---> User
++-----------------------+
+	^      |
+	| pipe |
+	|      v
++-----------------------+
+| Git credential helper |
++-----------------------+
+------------
+
+The Git code (typically a remote-helper) will call the C API to obtain
+credential data like a login/password pair (credential_fill). The
+API will itself call a remote helper (e.g. "git credential-cache" or
+"git credential-store") that may retrieve credential data from a
+store. If the credential helper cannot find the information, the C API
+will prompt the user. Then, the caller of the API takes care of
+contacting the server, and does the actual authentication.
+
+C API
+-----
+
+The credential C API is meant to be called by Git code which needs to
+acquire or store a credential. It is centered around an object
+representing a single credential and provides three basic operations:
+fill (acquire credentials by calling helpers and/or prompting the user),
+approve (mark a credential as successfully used so that it can be stored
+for later use), and reject (mark a credential as unsuccessful so that it
+can be erased from any persistent storage).
+
+Data Structures
+~~~~~~~~~~~~~~~
+
+`struct credential`::
+
+	This struct represents a single username/password combination
+	along with any associated context. All string fields should be
+	heap-allocated (or NULL if they are not known or not applicable).
+	The meaning of the individual context fields is the same as
+	their counterparts in the helper protocol; see the section below
+	for a description of each field.
++
+The `helpers` member of the struct is a `string_list` of helpers.  Each
+string specifies an external helper which will be run, in order, to
+either acquire or store credentials. See the section on credential
+helpers below. This list is filled-in by the API functions
+according to the corresponding configuration variables before
+consulting helpers, so there usually is no need for a caller to
+modify the helpers field at all.
++
+This struct should always be initialized with `CREDENTIAL_INIT` or
+`credential_init`.
+
+
+Functions
+~~~~~~~~~
+
+`credential_init`::
+
+	Initialize a credential structure, setting all fields to empty.
+
+`credential_clear`::
+
+	Free any resources associated with the credential structure,
+	returning it to a pristine initialized state.
+
+`credential_fill`::
+
+	Instruct the credential subsystem to fill the username and
+	password fields of the passed credential struct by first
+	consulting helpers, then asking the user. After this function
+	returns, the username and password fields of the credential are
+	guaranteed to be non-NULL. If an error occurs, the function will
+	die().
+
+`credential_reject`::
+
+	Inform the credential subsystem that the provided credentials
+	have been rejected. This will cause the credential subsystem to
+	notify any helpers of the rejection (which allows them, for
+	example, to purge the invalid credentials from storage).  It
+	will also free() the username and password fields of the
+	credential and set them to NULL (readying the credential for
+	another call to `credential_fill`). Any errors from helpers are
+	ignored.
+
+`credential_approve`::
+
+	Inform the credential subsystem that the provided credentials
+	were successfully used for authentication.  This will cause the
+	credential subsystem to notify any helpers of the approval, so
+	that they may store the result to be used again.  Any errors
+	from helpers are ignored.
+
+`credential_from_url`::
+
+	Parse a URL into broken-down credential fields.
+
+Example
+~~~~~~~
+
+The example below shows how the functions of the credential API could be
+used to login to a fictitious "foo" service on a remote host:
+
+-----------------------------------------------------------------------
+int foo_login(struct foo_connection *f)
+{
+	int status;
+	/*
+	 * Create a credential with some context; we don't yet know the
+	 * username or password.
+	 */
+
+	struct credential c = CREDENTIAL_INIT;
+	c.protocol = xstrdup("foo");
+	c.host = xstrdup(f->hostname);
+
+	/*
+	 * Fill in the username and password fields by contacting
+	 * helpers and/or asking the user. The function will die if it
+	 * fails.
+	 */
+	credential_fill(&c);
+
+	/*
+	 * Otherwise, we have a username and password. Try to use it.
+	 */
+	status = send_foo_login(f, c.username, c.password);
+	switch (status) {
+	case FOO_OK:
+		/* It worked. Store the credential for later use. */
+		credential_accept(&c);
+		break;
+	case FOO_BAD_LOGIN:
+		/* Erase the credential from storage so we don't try it
+		 * again. */
+		credential_reject(&c);
+		break;
+	default:
+		/*
+		 * Some other error occurred. We don't know if the
+		 * credential is good or bad, so report nothing to the
+		 * credential subsystem.
+		 */
+	}
+
+	/* Free any associated resources. */
+	credential_clear(&c);
+
+	return status;
+}
+-----------------------------------------------------------------------
+
+
+Credential Helpers
+------------------
+
+Credential helpers are programs executed by Git to fetch or save
+credentials from and to long-term storage (where "long-term" is simply
+longer than a single Git process; e.g., credentials may be stored
+in-memory for a few minutes, or indefinitely on disk).
+
+Each helper is specified by a single string in the configuration
+variable `credential.helper` (and others, see linkgit:git-config[1]).
+The string is transformed by Git into a command to be executed using
+these rules:
+
+  1. If the helper string begins with "!", it is considered a shell
+     snippet, and everything after the "!" becomes the command.
+
+  2. Otherwise, if the helper string begins with an absolute path, the
+     verbatim helper string becomes the command.
+
+  3. Otherwise, the string "git credential-" is prepended to the helper
+     string, and the result becomes the command.
+
+The resulting command then has an "operation" argument appended to it
+(see below for details), and the result is executed by the shell.
+
+Here are some example specifications:
+
+----------------------------------------------------
+# run "git credential-foo"
+foo
+
+# same as above, but pass an argument to the helper
+foo --bar=baz
+
+# the arguments are parsed by the shell, so use shell
+# quoting if necessary
+foo --bar="whitespace arg"
+
+# you can also use an absolute path, which will not use the git wrapper
+/path/to/my/helper --with-arguments
+
+# or you can specify your own shell snippet
+!f() { echo "password=`cat $HOME/.secret`"; }; f
+----------------------------------------------------
+
+Generally speaking, rule (3) above is the simplest for users to specify.
+Authors of credential helpers should make an effort to assist their
+users by naming their program "git-credential-$NAME", and putting it in
+the $PATH or $GIT_EXEC_PATH during installation, which will allow a user
+to enable it with `git config credential.helper $NAME`.
+
+When a helper is executed, it will have one "operation" argument
+appended to its command line, which is one of:
+
+`get`::
+
+	Return a matching credential, if any exists.
+
+`store`::
+
+	Store the credential, if applicable to the helper.
+
+`erase`::
+
+	Remove a matching credential, if any, from the helper's storage.
+
+The details of the credential will be provided on the helper's stdin
+stream. The exact format is the same as the input/output format of the
+`git credential` plumbing command (see the section `INPUT/OUTPUT
+FORMAT` in linkgit:git-credential[1] for a detailed specification).
+
+For a `get` operation, the helper should produce a list of attributes
+on stdout in the same format. A helper is free to produce a subset, or
+even no values at all if it has nothing useful to provide. Any provided
+attributes will overwrite those already known about by Git.  If a helper
+outputs a `quit` attribute with a value of `true` or `1`, no further
+helpers will be consulted, nor will the user be prompted (if no
+credential has been provided, the operation will then fail).
+
+For a `store` or `erase` operation, the helper's output is ignored.
+If it fails to perform the requested operation, it may complain to
+stderr to inform the user. If it does not support the requested
+operation (e.g., a read-only store), it should silently ignore the
+request.
+
+If a helper receives any other operation, it should silently ignore the
+request. This leaves room for future operations to be added (older
+helpers will just ignore the new requests).
+
+See also
+--------
+
+linkgit:gitcredentials[7]
+
+linkgit:git-config[1] (See configuration variables `credential.*`)
diff --git a/third_party/git/Documentation/technical/api-diff.txt b/third_party/git/Documentation/technical/api-diff.txt
new file mode 100644
index 0000000000..30fc0e9c93
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-diff.txt
@@ -0,0 +1,174 @@
+diff API
+========
+
+The diff API is for programs that compare two sets of files (e.g. two
+trees, one tree and the index) and present the found difference in
+various ways.  The calling program is responsible for feeding the API
+pairs of files, one from the "old" set and the corresponding one from
+"new" set, that are different.  The library called through this API is
+called diffcore, and is responsible for two things.
+
+* finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and
+  changes that touch a string (`-S`), as specified by the caller.
+
+* outputting the differences in various formats, as specified by the
+  caller.
+
+Calling sequence
+----------------
+
+* Prepare `struct diff_options` to record the set of diff options, and
+  then call `repo_diff_setup()` to initialize this structure.  This
+  sets up the vanilla default.
+
+* Fill in the options structure to specify desired output format, rename
+  detection, etc.  `diff_opt_parse()` can be used to parse options given
+  from the command line in a way consistent with existing git-diff
+  family of programs.
+
+* Call `diff_setup_done()`; this inspects the options set up so far for
+  internal consistency and make necessary tweaking to it (e.g. if
+  textual patch output was asked, recursive behaviour is turned on);
+  the callback set_default in diff_options can be used to tweak this more.
+
+* As you find different pairs of files, call `diff_change()` to feed
+  modified files, `diff_addremove()` to feed created or deleted files,
+  or `diff_unmerge()` to feed a file whose state is 'unmerged' to the
+  API.  These are thin wrappers to a lower-level `diff_queue()` function
+  that is flexible enough to record any of these kinds of changes.
+
+* Once you finish feeding the pairs of files, call `diffcore_std()`.
+  This will tell the diffcore library to go ahead and do its work.
+
+* Calling `diff_flush()` will produce the output.
+
+
+Data structures
+---------------
+
+* `struct diff_filespec`
+
+This is the internal representation for a single file (blob).  It
+records the blob object name (if known -- for a work tree file it
+typically is a NUL SHA-1), filemode and pathname.  This is what the
+`diff_addremove()`, `diff_change()` and `diff_unmerge()` synthesize and
+feed `diff_queue()` function with.
+
+* `struct diff_filepair`
+
+This records a pair of `struct diff_filespec`; the filespec for a file
+in the "old" set (i.e. preimage) is called `one`, and the filespec for a
+file in the "new" set (i.e. postimage) is called `two`.  A change that
+represents file creation has NULL in `one`, and file deletion has NULL
+in `two`.
+
+A `filepair` starts pointing at `one` and `two` that are from the same
+filename, but `diffcore_std()` can break pairs and match component
+filespecs with other filespecs from a different filepair to form new
+filepair.  This is called 'rename detection'.
+
+* `struct diff_queue`
+
+This is a collection of filepairs.  Notable members are:
+
+`queue`::
+
+	An array of pointers to `struct diff_filepair`.  This
+	dynamically grows as you add filepairs;
+
+`alloc`::
+
+	The allocated size of the `queue` array;
+
+`nr`::
+
+	The number of elements in the `queue` array.
+
+
+* `struct diff_options`
+
+This describes the set of options the calling program wants to affect
+the operation of diffcore library with.
+
+Notable members are:
+
+`output_format`::
+	The output format used when `diff_flush()` is run.
+
+`context`::
+	Number of context lines to generate in patch output.
+
+`break_opt`, `detect_rename`, `rename-score`, `rename_limit`::
+	Affects the way detection logic for complete rewrites, renames
+	and copies.
+
+`abbrev`::
+	Number of hexdigits to abbreviate raw format output to.
+
+`pickaxe`::
+	A constant string (can and typically does contain newlines to
+	look for a block of text, not just a single line) to filter out
+	the filepairs that do not change the number of strings contained
+	in its preimage and postimage of the diff_queue.
+
+`flags`::
+	This is mostly a collection of boolean options that affects the
+	operation, but some do not have anything to do with the diffcore
+	library.
+
+`touched_flags`::
+	Records whether a flag has been changed due to user request
+	(rather than just set/unset by default).
+
+`set_default`::
+	Callback which allows tweaking the options in diff_setup_done().
+
+BINARY, TEXT;;
+	Affects the way how a file that is seemingly binary is treated.
+
+FULL_INDEX;;
+	Tells the patch output format not to use abbreviated object
+	names on the "index" lines.
+
+FIND_COPIES_HARDER;;
+	Tells the diffcore library that the caller is feeding unchanged
+	filepairs to allow copies from unmodified files be detected.
+
+COLOR_DIFF;;
+	Output should be colored.
+
+COLOR_DIFF_WORDS;;
+	Output is a colored word-diff.
+
+NO_INDEX;;
+	Tells diff-files that the input is not tracked files but files
+	in random locations on the filesystem.
+
+ALLOW_EXTERNAL;;
+	Tells output routine that it is Ok to call user specified patch
+	output routine.  Plumbing disables this to ensure stable output.
+
+QUIET;;
+	Do not show any output.
+
+REVERSE_DIFF;;
+	Tells the library that the calling program is feeding the
+	filepairs reversed; `one` is two, and `two` is one.
+
+EXIT_WITH_STATUS;;
+	For communication between the calling program and the options
+	parser; tell the calling program to signal the presence of
+	difference using program exit code.
+
+HAS_CHANGES;;
+	Internal; used for optimization to see if there is any change.
+
+SILENT_ON_REMOVE;;
+	Affects if diff-files shows removed files.
+
+RECURSIVE, TREE_IN_RECURSIVE;;
+	Tells if tree traversal done by tree-diff should recursively
+	descend into a tree object pair that are different in preimage
+	and postimage set.
+
+(JC)
diff --git a/third_party/git/Documentation/technical/api-directory-listing.txt b/third_party/git/Documentation/technical/api-directory-listing.txt
new file mode 100644
index 0000000000..5abb8e8b1f
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-directory-listing.txt
@@ -0,0 +1,130 @@
+directory listing API
+=====================
+
+The directory listing API is used to enumerate paths in the work tree,
+optionally taking `.git/info/exclude` and `.gitignore` files per
+directory into account.
+
+Data structure
+--------------
+
+`struct dir_struct` structure is used to pass directory traversal
+options to the library and to record the paths discovered.  A single
+`struct dir_struct` is used regardless of whether or not the traversal
+recursively descends into subdirectories.
+
+The notable options are:
+
+`exclude_per_dir`::
+
+	The name of the file to be read in each directory for excluded
+	files (typically `.gitignore`).
+
+`flags`::
+
+	A bit-field of options:
+
+`DIR_SHOW_IGNORED`:::
+
+	Return just ignored files in `entries[]`, not untracked
+	files. This flag is mutually exclusive with
+	`DIR_SHOW_IGNORED_TOO`.
+
+`DIR_SHOW_IGNORED_TOO`:::
+
+	Similar to `DIR_SHOW_IGNORED`, but return ignored files in
+	`ignored[]` in addition to untracked files in
+	`entries[]`. This flag is mutually exclusive with
+	`DIR_SHOW_IGNORED`.
+
+`DIR_KEEP_UNTRACKED_CONTENTS`:::
+
+	Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is set, the
+	untracked contents of untracked directories are also returned in
+	`entries[]`.
+
+`DIR_SHOW_IGNORED_TOO_MODE_MATCHING`:::
+
+	Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if
+	this is set, returns ignored files and directories that match
+	an exclude pattern. If a directory matches an exclude pattern,
+	then the directory is returned and the contained paths are
+	not. A directory that does not match an exclude pattern will
+	not be returned even if all of its contents are ignored. In
+	this case, the contents are returned as individual entries.
++
+If this is set, files and directories that explicitly match an ignore
+pattern are reported. Implicitly ignored directories (directories that
+do not match an ignore pattern, but whose contents are all ignored)
+are not reported, instead all of the contents are reported.
+
+`DIR_COLLECT_IGNORED`:::
+
+	Special mode for git-add. Return ignored files in `ignored[]` and
+	untracked files in `entries[]`. Only returns ignored files that match
+	pathspec exactly (no wildcards). Does not recurse into ignored
+	directories.
+
+`DIR_SHOW_OTHER_DIRECTORIES`:::
+
+	Include a directory that is not tracked.
+
+`DIR_HIDE_EMPTY_DIRECTORIES`:::
+
+	Do not include a directory that is not tracked and is empty.
+
+`DIR_NO_GITLINKS`:::
+
+	If set, recurse into a directory that looks like a Git
+	directory.  Otherwise it is shown as a directory.
+
+The result of the enumeration is left in these fields:
+
+`entries[]`::
+
+	An array of `struct dir_entry`, each element of which describes
+	a path.
+
+`nr`::
+
+	The number of members in `entries[]` array.
+
+`alloc`::
+
+	Internal use; keeps track of allocation of `entries[]` array.
+
+`ignored[]`::
+
+	An array of `struct dir_entry`, used for ignored paths with the
+	`DIR_SHOW_IGNORED_TOO` and `DIR_COLLECT_IGNORED` flags.
+
+`ignored_nr`::
+
+	The number of members in `ignored[]` array.
+
+Calling sequence
+----------------
+
+Note: index may be looked at for .gitignore files that are CE_SKIP_WORKTREE
+marked. If you to exclude files, make sure you have loaded index first.
+
+* Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0,
+  sizeof(dir))`.
+
+* To add single exclude pattern, call `add_exclude_list()` and then
+  `add_exclude()`.
+
+* To add patterns from a file (e.g. `.git/info/exclude`), call
+  `add_excludes_from_file()` , and/or set `dir.exclude_per_dir`.  A
+  short-hand function `setup_standard_excludes()` can be used to set
+  up the standard set of exclude settings.
+
+* Set options described in the Data Structure section above.
+
+* Call `read_directory()`.
+
+* Use `dir.entries[]`.
+
+* Call `clear_directory()` when none of the contained elements are no longer in use.
+
+(JC)
diff --git a/third_party/git/Documentation/technical/api-error-handling.txt b/third_party/git/Documentation/technical/api-error-handling.txt
new file mode 100644
index 0000000000..ceeedd485c
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-error-handling.txt
@@ -0,0 +1,75 @@
+Error reporting in git
+======================
+
+`die`, `usage`, `error`, and `warning` report errors of various
+kinds.
+
+- `die` is for fatal application errors.  It prints a message to
+  the user and exits with status 128.
+
+- `usage` is for errors in command line usage.  After printing its
+  message, it exits with status 129.  (See also `usage_with_options`
+  in the link:api-parse-options.html[parse-options API].)
+
+- `error` is for non-fatal library errors.  It prints a message
+  to the user and returns -1 for convenience in signaling the error
+  to the caller.
+
+- `warning` is for reporting situations that probably should not
+  occur but which the user (and Git) can continue to work around
+  without running into too many problems.  Like `error`, it
+  returns -1 after reporting the situation to the caller.
+
+Customizable error handlers
+---------------------------
+
+The default behavior of `die` and `error` is to write a message to
+stderr and then exit or return as appropriate.  This behavior can be
+overridden using `set_die_routine` and `set_error_routine`.  For
+example, "git daemon" uses set_die_routine to write the reason `die`
+was called to syslog before exiting.
+
+Library errors
+--------------
+
+Functions return a negative integer on error.  Details beyond that
+vary from function to function:
+
+- Some functions return -1 for all errors.  Others return a more
+  specific value depending on how the caller might want to react
+  to the error.
+
+- Some functions report the error to stderr with `error`,
+  while others leave that for the caller to do.
+
+- errno is not meaningful on return from most functions (except
+  for thin wrappers for system calls).
+
+Check the function's API documentation to be sure.
+
+Caller-handled errors
+---------------------
+
+An increasing number of functions take a parameter 'struct strbuf *err'.
+On error, such functions append a message about what went wrong to the
+'err' strbuf.  The message is meant to be complete enough to be passed
+to `die` or `error` as-is.  For example:
+
+	if (ref_transaction_commit(transaction, &err))
+		die("%s", err.buf);
+
+The 'err' parameter will be untouched if no error occurred, so multiple
+function calls can be chained:
+
+	t = ref_transaction_begin(&err);
+	if (!t ||
+	    ref_transaction_update(t, "HEAD", ..., &err) ||
+	    ret_transaction_commit(t, &err))
+		die("%s", err.buf);
+
+The 'err' parameter must be a pointer to a valid strbuf.  To silence
+a message, pass a strbuf that is explicitly ignored:
+
+	if (thing_that_can_fail_in_an_ignorable_way(..., &err))
+		/* This failure is okay. */
+		strbuf_reset(&err);
diff --git a/third_party/git/Documentation/technical/api-gitattributes.txt b/third_party/git/Documentation/technical/api-gitattributes.txt
new file mode 100644
index 0000000000..45f0df600f
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-gitattributes.txt
@@ -0,0 +1,154 @@
+gitattributes API
+=================
+
+gitattributes mechanism gives a uniform way to associate various
+attributes to set of paths.
+
+
+Data Structure
+--------------
+
+`struct git_attr`::
+
+	An attribute is an opaque object that is identified by its name.
+	Pass the name to `git_attr()` function to obtain the object of
+	this type.  The internal representation of this structure is
+	of no interest to the calling programs.  The name of the
+	attribute can be retrieved by calling `git_attr_name()`.
+
+`struct attr_check_item`::
+
+	This structure represents one attribute and its value.
+
+`struct attr_check`::
+
+	This structure represents a collection of `attr_check_item`.
+	It is passed to `git_check_attr()` function, specifying the
+	attributes to check, and receives their values.
+
+
+Attribute Values
+----------------
+
+An attribute for a path can be in one of four states: Set, Unset,
+Unspecified or set to a string, and `.value` member of `struct
+attr_check_item` records it.  There are three macros to check these:
+
+`ATTR_TRUE()`::
+
+	Returns true if the attribute is Set for the path.
+
+`ATTR_FALSE()`::
+
+	Returns true if the attribute is Unset for the path.
+
+`ATTR_UNSET()`::
+
+	Returns true if the attribute is Unspecified for the path.
+
+If none of the above returns true, `.value` member points at a string
+value of the attribute for the path.
+
+
+Querying Specific Attributes
+----------------------------
+
+* Prepare `struct attr_check` using attr_check_initl()
+  function, enumerating the names of attributes whose values you are
+  interested in, terminated with a NULL pointer.  Alternatively, an
+  empty `struct attr_check` can be prepared by calling
+  `attr_check_alloc()` function and then attributes you want to
+  ask about can be added to it with `attr_check_append()`
+  function.
+
+* Call `git_check_attr()` to check the attributes for the path.
+
+* Inspect `attr_check` structure to see how each of the
+  attribute in the array is defined for the path.
+
+
+Example
+-------
+
+To see how attributes "crlf" and "ident" are set for different paths.
+
+. Prepare a `struct attr_check` with two elements (because
+  we are checking two attributes):
+
+------------
+static struct attr_check *check;
+static void setup_check(void)
+{
+	if (check)
+		return; /* already done */
+	check = attr_check_initl("crlf", "ident", NULL);
+}
+------------
+
+. Call `git_check_attr()` with the prepared `struct attr_check`:
+
+------------
+	const char *path;
+
+	setup_check();
+	git_check_attr(path, check);
+------------
+
+. Act on `.value` member of the result, left in `check->items[]`:
+
+------------
+	const char *value = check->items[0].value;
+
+	if (ATTR_TRUE(value)) {
+		The attribute is Set, by listing only the name of the
+		attribute in the gitattributes file for the path.
+	} else if (ATTR_FALSE(value)) {
+		The attribute is Unset, by listing the name of the
+		attribute prefixed with a dash - for the path.
+	} else if (ATTR_UNSET(value)) {
+		The attribute is neither set nor unset for the path.
+	} else if (!strcmp(value, "input")) {
+		If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
+		true, the value is a string set in the gitattributes
+		file for the path by saying "attr=value".
+	} else if (... other check using value as string ...) {
+		...
+	}
+------------
+
+To see how attributes in argv[] are set for different paths, only
+the first step in the above would be different.
+
+------------
+static struct attr_check *check;
+static void setup_check(const char **argv)
+{
+	check = attr_check_alloc();
+	while (*argv) {
+		struct git_attr *attr = git_attr(*argv);
+		attr_check_append(check, attr);
+		argv++;
+	}
+}
+------------
+
+
+Querying All Attributes
+-----------------------
+
+To get the values of all attributes associated with a file:
+
+* Prepare an empty `attr_check` structure by calling
+  `attr_check_alloc()`.
+
+* Call `git_all_attrs()`, which populates the `attr_check`
+  with the attributes attached to the path.
+
+* Iterate over the `attr_check.items[]` array to examine
+  the attribute names and values.  The name of the attribute
+  described by an `attr_check.items[]` object can be retrieved via
+  `git_attr_name(check->items[i].attr)`.  (Please note that no items
+  will be returned for unset attributes, so `ATTR_UNSET()` will return
+  false for all returned `attr_check.items[]` objects.)
+
+* Free the `attr_check` struct by calling `attr_check_free()`.
diff --git a/third_party/git/Documentation/technical/api-grep.txt b/third_party/git/Documentation/technical/api-grep.txt
new file mode 100644
index 0000000000..a69cc8964d
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-grep.txt
@@ -0,0 +1,8 @@
+grep API
+========
+
+Talk about <grep.h>, things like:
+
+* grep_buffer()
+
+(JC)
diff --git a/third_party/git/Documentation/technical/api-history-graph.txt b/third_party/git/Documentation/technical/api-history-graph.txt
new file mode 100644
index 0000000000..d0d1707c8c
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-history-graph.txt
@@ -0,0 +1,173 @@
+history graph API
+=================
+
+The graph API is used to draw a text-based representation of the commit
+history.  The API generates the graph in a line-by-line fashion.
+
+Functions
+---------
+
+Core functions:
+
+* `graph_init()` creates a new `struct git_graph`
+
+* `graph_update()` moves the graph to a new commit.
+
+* `graph_next_line()` outputs the next line of the graph into a strbuf.  It
+  does not add a terminating newline.
+
+* `graph_padding_line()` outputs a line of vertical padding in the graph.  It
+  is similar to `graph_next_line()`, but is guaranteed to never print the line
+  containing the current commit.  Where `graph_next_line()` would print the
+  commit line next, `graph_padding_line()` prints a line that simply extends
+  all branch lines downwards one row, leaving their positions unchanged.
+
+* `graph_is_commit_finished()` determines if the graph has output all lines
+  necessary for the current commit.  If `graph_update()` is called before all
+  lines for the current commit have been printed, the next call to
+  `graph_next_line()` will output an ellipsis, to indicate that a portion of
+  the graph was omitted.
+
+The following utility functions are wrappers around `graph_next_line()` and
+`graph_is_commit_finished()`.  They always print the output to stdout.
+They can all be called with a NULL graph argument, in which case no graph
+output will be printed.
+
+* `graph_show_commit()` calls `graph_next_line()` and
+  `graph_is_commit_finished()` until one of them return non-zero.  This prints
+  all graph lines up to, and including, the line containing this commit.
+  Output is printed to stdout.  The last line printed does not contain a
+  terminating newline.
+
+* `graph_show_oneline()` calls `graph_next_line()` and prints the result to
+  stdout.  The line printed does not contain a terminating newline.
+
+* `graph_show_padding()` calls `graph_padding_line()` and prints the result to
+  stdout.  The line printed does not contain a terminating newline.
+
+* `graph_show_remainder()` calls `graph_next_line()` until
+  `graph_is_commit_finished()` returns non-zero.  Output is printed to stdout.
+  The last line printed does not contain a terminating newline.  Returns 1 if
+  output was printed, and 0 if no output was necessary.
+
+* `graph_show_strbuf()` prints the specified strbuf to stdout, prefixing all
+  lines but the first with a graph line.  The caller is responsible for
+  ensuring graph output for the first line has already been printed to stdout.
+  (This can be done with `graph_show_commit()` or `graph_show_oneline()`.)  If
+  a NULL graph is supplied, the strbuf is printed as-is.
+
+* `graph_show_commit_msg()` is similar to `graph_show_strbuf()`, but it also
+  prints the remainder of the graph, if more lines are needed after the strbuf
+  ends.  It is better than directly calling `graph_show_strbuf()` followed by
+  `graph_show_remainder()` since it properly handles buffers that do not end in
+  a terminating newline.  The output printed by `graph_show_commit_msg()` will
+  end in a newline if and only if the strbuf ends in a newline.
+
+Data structure
+--------------
+`struct git_graph` is an opaque data type used to store the current graph
+state.
+
+Calling sequence
+----------------
+
+* Create a `struct git_graph` by calling `graph_init()`.  When using the
+  revision walking API, this is done automatically by `setup_revisions()` if
+  the '--graph' option is supplied.
+
+* Use the revision walking API to walk through a group of contiguous commits.
+  The `get_revision()` function automatically calls `graph_update()` each time
+  it is invoked.
+
+* For each commit, call `graph_next_line()` repeatedly, until
+  `graph_is_commit_finished()` returns non-zero.  Each call to
+  `graph_next_line()` will output a single line of the graph.  The resulting
+  lines will not contain any newlines.  `graph_next_line()` returns 1 if the
+  resulting line contains the current commit, or 0 if this is merely a line
+  needed to adjust the graph before or after the current commit.  This return
+  value can be used to determine where to print the commit summary information
+  alongside the graph output.
+
+Limitations
+-----------
+
+* `graph_update()` must be called with commits in topological order.  It should
+  not be called on a commit if it has already been invoked with an ancestor of
+  that commit, or the graph output will be incorrect.
+
+* `graph_update()` must be called on a contiguous group of commits.  If
+  `graph_update()` is called on a particular commit, it should later be called
+  on all parents of that commit.  Parents must not be skipped, or the graph
+  output will appear incorrect.
++
+`graph_update()` may be used on a pruned set of commits only if the parent list
+has been rewritten so as to include only ancestors from the pruned set.
+
+* The graph API does not currently support reverse commit ordering.  In
+  order to implement reverse ordering, the graphing API needs an
+  (efficient) mechanism to find the children of a commit.
+
+Sample usage
+------------
+
+------------
+struct commit *commit;
+struct git_graph *graph = graph_init(opts);
+
+while ((commit = get_revision(opts)) != NULL) {
+	while (!graph_is_commit_finished(graph))
+	{
+		struct strbuf sb;
+		int is_commit_line;
+
+		strbuf_init(&sb, 0);
+		is_commit_line = graph_next_line(graph, &sb);
+		fputs(sb.buf, stdout);
+
+		if (is_commit_line)
+			log_tree_commit(opts, commit);
+		else
+			putchar(opts->diffopt.line_termination);
+	}
+}
+------------
+
+Sample output
+-------------
+
+The following is an example of the output from the graph API.  This output does
+not include any commit summary information--callers are responsible for
+outputting that information, if desired.
+
+------------
+*
+*
+*
+|\
+* |
+| | *
+| \ \
+|  \ \
+*-. \ \
+|\ \ \ \
+| | * | |
+| | | | | *
+| | | | | *
+| | | | | *
+| | | | | |\
+| | | | | | *
+| * | | | | |
+| | | | | *  \
+| | | | | |\  |
+| | | | * | | |
+| | | | * | | |
+* | | | | | | |
+| |/ / / / / /
+|/| / / / / /
+* | | | | | |
+|/ / / / / /
+* | | | | |
+| | | | | *
+| | | | |/
+| | | | *
+------------
diff --git a/third_party/git/Documentation/technical/api-index-skel.txt b/third_party/git/Documentation/technical/api-index-skel.txt
new file mode 100644
index 0000000000..eda8c195c1
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-index-skel.txt
@@ -0,0 +1,13 @@
+Git API Documents
+=================
+
+Git has grown a set of internal API over time.  This collection
+documents them.
+
+////////////////////////////////////////////////////////////////
+// table of contents begin
+////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////
+// table of contents end
+////////////////////////////////////////////////////////////////
diff --git a/third_party/git/Documentation/technical/api-index.sh b/third_party/git/Documentation/technical/api-index.sh
new file mode 100755
index 0000000000..9c3f4131b8
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-index.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+(
+	c=////////////////////////////////////////////////////////////////
+	skel=api-index-skel.txt
+	sed -e '/^\/\/ table of contents begin/q' "$skel"
+	echo "$c"
+
+	ls api-*.txt |
+	while read filename
+	do
+		case "$filename" in
+		api-index-skel.txt | api-index.txt) continue ;;
+		esac
+		title=$(sed -e 1q "$filename")
+		html=${filename%.txt}.html
+		echo "* link:$html[$title]"
+	done
+	echo "$c"
+	sed -n -e '/^\/\/ table of contents end/,$p' "$skel"
+) >api-index.txt+
+
+if test -f api-index.txt && cmp api-index.txt api-index.txt+ >/dev/null
+then
+	rm -f api-index.txt+
+else
+	mv api-index.txt+ api-index.txt
+fi
diff --git a/third_party/git/Documentation/technical/api-merge.txt b/third_party/git/Documentation/technical/api-merge.txt
new file mode 100644
index 0000000000..9dc1bed768
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-merge.txt
@@ -0,0 +1,104 @@
+merge API
+=========
+
+The merge API helps a program to reconcile two competing sets of
+improvements to some files (e.g., unregistered changes from the work
+tree versus changes involved in switching to a new branch), reporting
+conflicts if found.  The library called through this API is
+responsible for a few things.
+
+ * determining which trees to merge (recursive ancestor consolidation);
+
+ * lining up corresponding files in the trees to be merged (rename
+   detection, subtree shifting), reporting edge cases like add/add
+   and rename/rename conflicts to the user;
+
+ * performing a three-way merge of corresponding files, taking
+   path-specific merge drivers (specified in `.gitattributes`)
+   into account.
+
+Data structures
+---------------
+
+* `mmbuffer_t`, `mmfile_t`
+
+These store data usable for use by the xdiff backend, for writing and
+for reading, respectively.  See `xdiff/xdiff.h` for the definitions
+and `diff.c` for examples.
+
+* `struct ll_merge_options`
+
+This describes the set of options the calling program wants to affect
+the operation of a low-level (single file) merge.  Some options:
+
+`virtual_ancestor`::
+	Behave as though this were part of a merge between common
+	ancestors in a recursive merge.
+	If a helper program is specified by the
+	`[merge "<driver>"] recursive` configuration, it will
+	be used (see linkgit:gitattributes[5]).
+
+`variant`::
+	Resolve local conflicts automatically in favor
+	of one side or the other (as in 'git merge-file'
+	`--ours`/`--theirs`/`--union`).  Can be `0`,
+	`XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`, or
+	`XDL_MERGE_FAVOR_UNION`.
+
+`renormalize`::
+	Resmudge and clean the "base", "theirs" and "ours" files
+	before merging.  Use this when the merge is likely to have
+	overlapped with a change in smudge/clean or end-of-line
+	normalization rules.
+
+Low-level (single file) merge
+-----------------------------
+
+`ll_merge`::
+
+	Perform a three-way single-file merge in core.  This is
+	a thin wrapper around `xdl_merge` that takes the path and
+	any merge backend specified in `.gitattributes` or
+	`.git/info/attributes` into account.  Returns 0 for a
+	clean merge.
+
+Calling sequence:
+
+* Prepare a `struct ll_merge_options` to record options.
+  If you have no special requests, skip this and pass `NULL`
+  as the `opts` parameter to use the default options.
+
+* Allocate an mmbuffer_t variable for the result.
+
+* Allocate and fill variables with the file's original content
+  and two modified versions (using `read_mmfile`, for example).
+
+* Call `ll_merge()`.
+
+* Read the merged content from `result_buf.ptr` and `result_buf.size`.
+
+* Release buffers when finished.  A simple
+  `free(ancestor.ptr); free(ours.ptr); free(theirs.ptr);
+  free(result_buf.ptr);` will do.
+
+If the modifications do not merge cleanly, `ll_merge` will return a
+nonzero value and `result_buf` will generally include a description of
+the conflict bracketed by markers such as the traditional `<<<<<<<`
+and `>>>>>>>`.
+
+The `ancestor_label`, `our_label`, and `their_label` parameters are
+used to label the different sides of a conflict if the merge driver
+supports this.
+
+Everything else
+---------------
+
+Talk about <merge-recursive.h> and merge_file():
+
+ - merge_trees() to merge with rename detection
+ - merge_recursive() for ancestor consolidation
+ - try_merge_command() for other strategies
+ - conflict format
+ - merge options
+
+(Daniel, Miklos, Stephan, JC)
diff --git a/third_party/git/Documentation/technical/api-object-access.txt b/third_party/git/Documentation/technical/api-object-access.txt
new file mode 100644
index 0000000000..5b29622d00
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-object-access.txt
@@ -0,0 +1,15 @@
+object access API
+=================
+
+Talk about <sha1-file.c> and <object.h> family, things like
+
+* read_sha1_file()
+* read_object_with_reference()
+* has_sha1_file()
+* write_sha1_file()
+* pretend_object_file()
+* lookup_{object,commit,tag,blob,tree}
+* parse_{object,commit,tag,blob,tree}
+* Use of object flags
+
+(JC, Shawn, Daniel, Dscho, Linus)
diff --git a/third_party/git/Documentation/technical/api-oid-array.txt b/third_party/git/Documentation/technical/api-oid-array.txt
new file mode 100644
index 0000000000..c97428c2c3
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-oid-array.txt
@@ -0,0 +1,90 @@
+oid-array API
+==============
+
+The oid-array API provides storage and manipulation of sets of object
+identifiers. The emphasis is on storage and processing efficiency,
+making them suitable for large lists. Note that the ordering of items is
+not preserved over some operations.
+
+Data Structures
+---------------
+
+`struct oid_array`::
+
+	A single array of object IDs. This should be initialized by
+	assignment from `OID_ARRAY_INIT`.  The `oid` member contains
+	the actual data. The `nr` member contains the number of items in
+	the set.  The `alloc` and `sorted` members are used internally,
+	and should not be needed by API callers.
+
+Functions
+---------
+
+`oid_array_append`::
+	Add an item to the set. The object ID will be placed at the end of
+	the array (but note that some operations below may lose this
+	ordering).
+
+`oid_array_lookup`::
+	Perform a binary search of the array for a specific object ID.
+	If found, returns the offset (in number of elements) of the
+	object ID. If not found, returns a negative integer. If the array
+	is not sorted, this function has the side effect of sorting it.
+
+`oid_array_clear`::
+	Free all memory associated with the array and return it to the
+	initial, empty state.
+
+`oid_array_for_each`::
+	Iterate over each element of the list, executing the callback
+	function for each one. Does not sort the list, so any custom
+	hash order is retained. If the callback returns a non-zero
+	value, the iteration ends immediately and the callback's
+	return is propagated; otherwise, 0 is returned.
+
+`oid_array_for_each_unique`::
+	Iterate over each unique element of the list in sorted order,
+	but otherwise behave like `oid_array_for_each`. If the array
+	is not sorted, this function has the side effect of sorting
+	it.
+
+`oid_array_filter`::
+	Apply the callback function `want` to each entry in the array,
+	retaining only the entries for which the function returns true.
+	Preserve the order of the entries that are retained.
+
+Examples
+--------
+
+-----------------------------------------
+int print_callback(const struct object_id *oid,
+		    void *data)
+{
+	printf("%s\n", oid_to_hex(oid));
+	return 0; /* always continue */
+}
+
+void some_func(void)
+{
+	struct sha1_array hashes = OID_ARRAY_INIT;
+	struct object_id oid;
+
+	/* Read objects into our set */
+	while (read_object_from_stdin(oid.hash))
+		oid_array_append(&hashes, &oid);
+
+	/* Check if some objects are in our set */
+	while (read_object_from_stdin(oid.hash)) {
+		if (oid_array_lookup(&hashes, &oid) >= 0)
+			printf("it's in there!\n");
+
+	/*
+	 * Print the unique set of objects. We could also have
+	 * avoided adding duplicate objects in the first place,
+	 * but we would end up re-sorting the array repeatedly.
+	 * Instead, this will sort once and then skip duplicates
+	 * in linear time.
+	 */
+	oid_array_for_each_unique(&hashes, print_callback, NULL);
+}
+-----------------------------------------
diff --git a/third_party/git/Documentation/technical/api-parse-options.txt b/third_party/git/Documentation/technical/api-parse-options.txt
new file mode 100644
index 0000000000..2e2e7c10c6
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-parse-options.txt
@@ -0,0 +1,313 @@
+parse-options API
+=================
+
+The parse-options API is used to parse and massage options in Git
+and to provide a usage help with consistent look.
+
+Basics
+------
+
+The argument vector `argv[]` may usually contain mandatory or optional
+'non-option arguments', e.g. a filename or a branch, and 'options'.
+Options are optional arguments that start with a dash and
+that allow to change the behavior of a command.
+
+* There are basically three types of options:
+  'boolean' options,
+  options with (mandatory) 'arguments' and
+  options with 'optional arguments'
+  (i.e. a boolean option that can be adjusted).
+
+* There are basically two forms of options:
+  'Short options' consist of one dash (`-`) and one alphanumeric
+  character.
+  'Long options' begin with two dashes (`--`) and some
+  alphanumeric characters.
+
+* Options are case-sensitive.
+  Please define 'lower-case long options' only.
+
+The parse-options API allows:
+
+* 'stuck' and 'separate form' of options with arguments.
+  `-oArg` is stuck, `-o Arg` is separate form.
+  `--option=Arg` is stuck, `--option Arg` is separate form.
+
+* Long options may be 'abbreviated', as long as the abbreviation
+  is unambiguous.
+
+* Short options may be bundled, e.g. `-a -b` can be specified as `-ab`.
+
+* Boolean long options can be 'negated' (or 'unset') by prepending
+  `no-`, e.g. `--no-abbrev` instead of `--abbrev`. Conversely,
+  options that begin with `no-` can be 'negated' by removing it.
+  Other long options can be unset (e.g., set string to NULL, set
+  integer to 0) by prepending `no-`.
+
+* Options and non-option arguments can clearly be separated using the `--`
+  option, e.g. `-a -b --option -- --this-is-a-file` indicates that
+  `--this-is-a-file` must not be processed as an option.
+
+Steps to parse options
+----------------------
+
+. `#include "parse-options.h"`
+
+. define a NULL-terminated
+  `static const char * const builtin_foo_usage[]` array
+  containing alternative usage strings
+
+. define `builtin_foo_options` array as described below
+  in section 'Data Structure'.
+
+. in `cmd_foo(int argc, const char **argv, const char *prefix)`
+  call
+
+	argc = parse_options(argc, argv, prefix, builtin_foo_options, builtin_foo_usage, flags);
++
+`parse_options()` will filter out the processed options of `argv[]` and leave the
+non-option arguments in `argv[]`.
+`argc` is updated appropriately because of the assignment.
++
+You can also pass NULL instead of a usage array as the fifth parameter of
+parse_options(), to avoid displaying a help screen with usage info and
+option list.  This should only be done if necessary, e.g. to implement
+a limited parser for only a subset of the options that needs to be run
+before the full parser, which in turn shows the full help message.
++
+Flags are the bitwise-or of:
+
+`PARSE_OPT_KEEP_DASHDASH`::
+	Keep the `--` that usually separates options from
+	non-option arguments.
+
+`PARSE_OPT_STOP_AT_NON_OPTION`::
+	Usually the whole argument vector is massaged and reordered.
+	Using this flag, processing is stopped at the first non-option
+	argument.
+
+`PARSE_OPT_KEEP_ARGV0`::
+	Keep the first argument, which contains the program name.  It's
+	removed from argv[] by default.
+
+`PARSE_OPT_KEEP_UNKNOWN`::
+	Keep unknown arguments instead of erroring out.  This doesn't
+	work for all combinations of arguments as users might expect
+	it to do.  E.g. if the first argument in `--unknown --known`
+	takes a value (which we can't know), the second one is
+	mistakenly interpreted as a known option.  Similarly, if
+	`PARSE_OPT_STOP_AT_NON_OPTION` is set, the second argument in
+	`--unknown value` will be mistakenly interpreted as a
+	non-option, not as a value belonging to the unknown option,
+	the parser early.  That's why parse_options() errors out if
+	both options are set.
+
+`PARSE_OPT_NO_INTERNAL_HELP`::
+	By default, parse_options() handles `-h`, `--help` and
+	`--help-all` internally, by showing a help screen.  This option
+	turns it off and allows one to add custom handlers for these
+	options, or to just leave them unknown.
+
+Data Structure
+--------------
+
+The main data structure is an array of the `option` struct,
+say `static struct option builtin_add_options[]`.
+There are some macros to easily define options:
+
+`OPT__ABBREV(&int_var)`::
+	Add `--abbrev[=<n>]`.
+
+`OPT__COLOR(&int_var, description)`::
+	Add `--color[=<when>]` and `--no-color`.
+
+`OPT__DRY_RUN(&int_var, description)`::
+	Add `-n, --dry-run`.
+
+`OPT__FORCE(&int_var, description)`::
+	Add `-f, --force`.
+
+`OPT__QUIET(&int_var, description)`::
+	Add `-q, --quiet`.
+
+`OPT__VERBOSE(&int_var, description)`::
+	Add `-v, --verbose`.
+
+`OPT_GROUP(description)`::
+	Start an option group. `description` is a short string that
+	describes the group or an empty string.
+	Start the description with an upper-case letter.
+
+`OPT_BOOL(short, long, &int_var, description)`::
+	Introduce a boolean option. `int_var` is set to one with
+	`--option` and set to zero with `--no-option`.
+
+`OPT_COUNTUP(short, long, &int_var, description)`::
+	Introduce a count-up option.
+	Each use of `--option` increments `int_var`, starting from zero
+	(even if initially negative), and `--no-option` resets it to
+	zero. To determine if `--option` or `--no-option` was encountered at
+	all, initialize `int_var` to a negative value, and if it is still
+	negative after parse_options(), then neither `--option` nor
+	`--no-option` was seen.
+
+`OPT_BIT(short, long, &int_var, description, mask)`::
+	Introduce a boolean option.
+	If used, `int_var` is bitwise-ored with `mask`.
+
+`OPT_NEGBIT(short, long, &int_var, description, mask)`::
+	Introduce a boolean option.
+	If used, `int_var` is bitwise-anded with the inverted `mask`.
+
+`OPT_SET_INT(short, long, &int_var, description, integer)`::
+	Introduce an integer option.
+	`int_var` is set to `integer` with `--option`, and
+	reset to zero with `--no-option`.
+
+`OPT_STRING(short, long, &str_var, arg_str, description)`::
+	Introduce an option with string argument.
+	The string argument is put into `str_var`.
+
+`OPT_STRING_LIST(short, long, &struct string_list, arg_str, description)`::
+	Introduce an option with string argument.
+	The string argument is stored as an element in `string_list`.
+	Use of `--no-option` will clear the list of preceding values.
+
+`OPT_INTEGER(short, long, &int_var, description)`::
+	Introduce an option with integer argument.
+	The integer is put into `int_var`.
+
+`OPT_MAGNITUDE(short, long, &unsigned_long_var, description)`::
+	Introduce an option with a size argument. The argument must be a
+	non-negative integer and may include a suffix of 'k', 'm' or 'g' to
+	scale the provided value by 1024, 1024^2 or 1024^3 respectively.
+	The scaled value is put into `unsigned_long_var`.
+
+`OPT_EXPIRY_DATE(short, long, &timestamp_t_var, description)`::
+	Introduce an option with expiry date argument, see `parse_expiry_date()`.
+	The timestamp is put into `timestamp_t_var`.
+
+`OPT_CALLBACK(short, long, &var, arg_str, description, func_ptr)`::
+	Introduce an option with argument.
+	The argument will be fed into the function given by `func_ptr`
+	and the result will be put into `var`.
+	See 'Option Callbacks' below for a more elaborate description.
+
+`OPT_FILENAME(short, long, &var, description)`::
+	Introduce an option with a filename argument.
+	The filename will be prefixed by passing the filename along with
+	the prefix argument of `parse_options()` to `prefix_filename()`.
+
+`OPT_ARGUMENT(long, &int_var, description)`::
+	Introduce a long-option argument that will be kept in `argv[]`.
+	If this option was seen, `int_var` will be set to one (except
+	if a `NULL` pointer was passed).
+
+`OPT_NUMBER_CALLBACK(&var, description, func_ptr)`::
+	Recognize numerical options like -123 and feed the integer as
+	if it was an argument to the function given by `func_ptr`.
+	The result will be put into `var`.  There can be only one such
+	option definition.  It cannot be negated and it takes no
+	arguments.  Short options that happen to be digits take
+	precedence over it.
+
+`OPT_COLOR_FLAG(short, long, &int_var, description)`::
+	Introduce an option that takes an optional argument that can
+	have one of three values: "always", "never", or "auto".  If the
+	argument is not given, it defaults to "always".  The `--no-` form
+	works like `--long=never`; it cannot take an argument.  If
+	"always", set `int_var` to 1; if "never", set `int_var` to 0; if
+	"auto", set `int_var` to 1 if stdout is a tty or a pager,
+	0 otherwise.
+
+`OPT_NOOP_NOARG(short, long)`::
+	Introduce an option that has no effect and takes no arguments.
+	Use it to hide deprecated options that are still to be recognized
+	and ignored silently.
+
+`OPT_PASSTHRU(short, long, &char_var, arg_str, description, flags)`::
+	Introduce an option that will be reconstructed into a char* string,
+	which must be initialized to NULL. This is useful when you need to
+	pass the command-line option to another command. Any previous value
+	will be overwritten, so this should only be used for options where
+	the last one specified on the command line wins.
+
+`OPT_PASSTHRU_ARGV(short, long, &argv_array_var, arg_str, description, flags)`::
+	Introduce an option where all instances of it on the command-line will
+	be reconstructed into an argv_array. This is useful when you need to
+	pass the command-line option, which can be specified multiple times,
+	to another command.
+
+`OPT_CMDMODE(short, long, &int_var, description, enum_val)`::
+	Define an "operation mode" option, only one of which in the same
+	group of "operating mode" options that share the same `int_var`
+	can be given by the user. `enum_val` is set to `int_var` when the
+	option is used, but an error is reported if other "operating mode"
+	option has already set its value to the same `int_var`.
+
+
+The last element of the array must be `OPT_END()`.
+
+If not stated otherwise, interpret the arguments as follows:
+
+* `short` is a character for the short option
+  (e.g. `'e'` for `-e`, use `0` to omit),
+
+* `long` is a string for the long option
+  (e.g. `"example"` for `--example`, use `NULL` to omit),
+
+* `int_var` is an integer variable,
+
+* `str_var` is a string variable (`char *`),
+
+* `arg_str` is the string that is shown as argument
+  (e.g. `"branch"` will result in `<branch>`).
+  If set to `NULL`, three dots (`...`) will be displayed.
+
+* `description` is a short string to describe the effect of the option.
+  It shall begin with a lower-case letter and a full stop (`.`) shall be
+  omitted at the end.
+
+Option Callbacks
+----------------
+
+The function must be defined in this form:
+
+	int func(const struct option *opt, const char *arg, int unset)
+
+The callback mechanism is as follows:
+
+* Inside `func`, the only interesting member of the structure
+  given by `opt` is the void pointer `opt->value`.
+  `*opt->value` will be the value that is saved into `var`, if you
+  use `OPT_CALLBACK()`.
+  For example, do `*(unsigned long *)opt->value = 42;` to get 42
+  into an `unsigned long` variable.
+
+* Return value `0` indicates success and non-zero return
+  value will invoke `usage_with_options()` and, thus, die.
+
+* If the user negates the option, `arg` is `NULL` and `unset` is 1.
+
+Sophisticated option parsing
+----------------------------
+
+If you need, for example, option callbacks with optional arguments
+or without arguments at all, or if you need other special cases,
+that are not handled by the macros above, you need to specify the
+members of the `option` structure manually.
+
+This is not covered in this document, but well documented
+in `parse-options.h` itself.
+
+Examples
+--------
+
+See `test-parse-options.c` and
+`builtin/add.c`,
+`builtin/clone.c`,
+`builtin/commit.c`,
+`builtin/fetch.c`,
+`builtin/fsck.c`,
+`builtin/rm.c`
+for real-world examples.
diff --git a/third_party/git/Documentation/technical/api-quote.txt b/third_party/git/Documentation/technical/api-quote.txt
new file mode 100644
index 0000000000..e8a1bce94e
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-quote.txt
@@ -0,0 +1,10 @@
+quote API
+=========
+
+Talk about <quote.h>, things like
+
+* sq_quote and unquote
+* c_style quote and unquote
+* quoting for foreign languages
+
+(JC)
diff --git a/third_party/git/Documentation/technical/api-ref-iteration.txt b/third_party/git/Documentation/technical/api-ref-iteration.txt
new file mode 100644
index 0000000000..ad9d019ff9
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-ref-iteration.txt
@@ -0,0 +1,78 @@
+ref iteration API
+=================
+
+
+Iteration of refs is done by using an iterate function which will call a
+callback function for every ref. The callback function has this
+signature:
+
+	int handle_one_ref(const char *refname, const struct object_id *oid,
+			   int flags, void *cb_data);
+
+There are different kinds of iterate functions which all take a
+callback of this type. The callback is then called for each found ref
+until the callback returns nonzero. The returned value is then also
+returned by the iterate function.
+
+Iteration functions
+-------------------
+
+* `head_ref()` just iterates the head ref.
+
+* `for_each_ref()` iterates all refs.
+
+* `for_each_ref_in()` iterates all refs which have a defined prefix and
+  strips that prefix from the passed variable refname.
+
+* `for_each_tag_ref()`, `for_each_branch_ref()`, `for_each_remote_ref()`,
+  `for_each_replace_ref()` iterate refs from the respective area.
+
+* `for_each_glob_ref()` iterates all refs that match the specified glob
+  pattern.
+
+* `for_each_glob_ref_in()` the previous and `for_each_ref_in()` combined.
+
+* Use `refs_` API for accessing submodules. The submodule ref store could
+  be obtained with `get_submodule_ref_store()`.
+
+* `for_each_rawref()` can be used to learn about broken ref and symref.
+
+* `for_each_reflog()` iterates each reflog file.
+
+Submodules
+----------
+
+If you want to iterate the refs of a submodule you first need to add the
+submodules object database. You can do this by a code-snippet like
+this:
+
+	const char *path = "path/to/submodule"
+	if (add_submodule_odb(path))
+		die("Error submodule '%s' not populated.", path);
+
+`add_submodule_odb()` will return zero on success. If you
+do not do this you will get an error for each ref that it does not point
+to a valid object.
+
+Note: As a side-effect of this you cannot safely assume that all
+objects you lookup are available in superproject. All submodule objects
+will be available the same way as the superprojects objects.
+
+Example:
+--------
+
+----
+static int handle_remote_ref(const char *refname,
+		const unsigned char *sha1, int flags, void *cb_data)
+{
+	struct strbuf *output = cb_data;
+	strbuf_addf(output, "%s\n", refname);
+	return 0;
+}
+
+...
+
+	struct strbuf output = STRBUF_INIT;
+	for_each_remote_ref(handle_remote_ref, &output);
+	printf("%s", output.buf);
+----
diff --git a/third_party/git/Documentation/technical/api-remote.txt b/third_party/git/Documentation/technical/api-remote.txt
new file mode 100644
index 0000000000..f10941b2e8
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-remote.txt
@@ -0,0 +1,127 @@
+Remotes configuration API
+=========================
+
+The API in remote.h gives access to the configuration related to
+remotes. It handles all three configuration mechanisms historically
+and currently used by Git, and presents the information in a uniform
+fashion. Note that the code also handles plain URLs without any
+configuration, giving them just the default information.
+
+struct remote
+-------------
+
+`name`::
+
+	The user's nickname for the remote
+
+`url`::
+
+	An array of all of the url_nr URLs configured for the remote
+
+`pushurl`::
+
+	An array of all of the pushurl_nr push URLs configured for the remote
+
+`push`::
+
+	 An array of refspecs configured for pushing, with
+	 push_refspec being the literal strings, and push_refspec_nr
+	 being the quantity.
+
+`fetch`::
+
+	An array of refspecs configured for fetching, with
+	fetch_refspec being the literal strings, and fetch_refspec_nr
+	being the quantity.
+
+`fetch_tags`::
+
+	The setting for whether to fetch tags (as a separate rule from
+	the configured refspecs); -1 means never to fetch tags, 0
+	means to auto-follow tags based on the default heuristic, 1
+	means to always auto-follow tags, and 2 means to fetch all
+	tags.
+
+`receivepack`, `uploadpack`::
+
+	The configured helper programs to run on the remote side, for
+	Git-native protocols.
+
+`http_proxy`::
+
+	The proxy to use for curl (http, https, ftp, etc.) URLs.
+
+`http_proxy_authmethod`::
+
+	The method used for authenticating against `http_proxy`.
+
+struct remotes can be found by name with remote_get(), and iterated
+through with for_each_remote(). remote_get(NULL) will return the
+default remote, given the current branch and configuration.
+
+struct refspec
+--------------
+
+A struct refspec holds the parsed interpretation of a refspec.  If it
+will force updates (starts with a '+'), force is true.  If it is a
+pattern (sides end with '*') pattern is true.  src and dest are the
+two sides (including '*' characters if present); if there is only one
+side, it is src, and dst is NULL; if sides exist but are empty (i.e.,
+the refspec either starts or ends with ':'), the corresponding side is
+"".
+
+An array of strings can be parsed into an array of struct refspecs
+using parse_fetch_refspec() or parse_push_refspec().
+
+remote_find_tracking(), given a remote and a struct refspec with
+either src or dst filled out, will fill out the other such that the
+result is in the "fetch" specification for the remote (note that this
+evaluates patterns and returns a single result).
+
+struct branch
+-------------
+
+Note that this may end up moving to branch.h
+
+struct branch holds the configuration for a branch. It can be looked
+up with branch_get(name) for "refs/heads/{name}", or with
+branch_get(NULL) for HEAD.
+
+It contains:
+
+`name`::
+
+	The short name of the branch.
+
+`refname`::
+
+	The full path for the branch ref.
+
+`remote_name`::
+
+	The name of the remote listed in the configuration.
+
+`merge_name`::
+
+	An array of the "merge" lines in the configuration.
+
+`merge`::
+
+	An array of the struct refspecs used for the merge lines. That
+	is, merge[i]->dst is a local tracking ref which should be
+	merged into this branch by default.
+
+`merge_nr`::
+
+	The number of merge configurations
+
+branch_has_merge_config() returns true if the given branch has merge
+configuration given.
+
+Other stuff
+-----------
+
+There is other stuff in remote.h that is related, in general, to the
+process of interacting with remotes.
+
+(Daniel Barkalow)
diff --git a/third_party/git/Documentation/technical/api-revision-walking.txt b/third_party/git/Documentation/technical/api-revision-walking.txt
new file mode 100644
index 0000000000..03f9ea6ac4
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-revision-walking.txt
@@ -0,0 +1,72 @@
+revision walking API
+====================
+
+The revision walking API offers functions to build a list of revisions
+and then iterate over that list.
+
+Calling sequence
+----------------
+
+The walking API has a given calling sequence: first you need to
+initialize a rev_info structure, then add revisions to control what kind
+of revision list do you want to get, finally you can iterate over the
+revision list.
+
+Functions
+---------
+
+`repo_init_revisions`::
+
+	Initialize a rev_info structure with default values. The third
+	parameter may be NULL or can be prefix path, and then the `.prefix`
+	variable will be set to it. This is typically the first function you
+	want to call when you want to deal with a revision list. After calling
+	this function, you are free to customize options, like set
+	`.ignore_merges` to 0 if you don't want to ignore merges, and so on. See
+	`revision.h` for a complete list of available options.
+
+`add_pending_object`::
+
+	This function can be used if you want to add commit objects as revision
+	information. You can use the `UNINTERESTING` object flag to indicate if
+	you want to include or exclude the given commit (and commits reachable
+	from the given commit) from the revision list.
++
+NOTE: If you have the commits as a string list then you probably want to
+use setup_revisions(), instead of parsing each string and using this
+function.
+
+`setup_revisions`::
+
+	Parse revision information, filling in the `rev_info` structure, and
+	removing the used arguments from the argument list. Returns the number
+	of arguments left that weren't recognized, which are also moved to the
+	head of the argument list. The last parameter is used in case no
+	parameter given by the first two arguments.
+
+`prepare_revision_walk`::
+
+	Prepares the rev_info structure for a walk. You should check if it
+	returns any error (non-zero return code) and if it does not, you can
+	start using get_revision() to do the iteration.
+
+`get_revision`::
+
+	Takes a pointer to a `rev_info` structure and iterates over it,
+	returning a `struct commit *` each time you call it. The end of the
+	revision list is indicated by returning a NULL pointer.
+
+`reset_revision_walk`::
+
+	Reset the flags used by the revision walking api. You can use
+	this to do multiple sequential revision walks.
+
+Data structures
+---------------
+
+Talk about <revision.h>, things like:
+
+* two diff_options, one for path limiting, another for output;
+* remaining functions;
+
+(Linus, JC, Dscho)
diff --git a/third_party/git/Documentation/technical/api-run-command.txt b/third_party/git/Documentation/technical/api-run-command.txt
new file mode 100644
index 0000000000..8bf3e37f53
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-run-command.txt
@@ -0,0 +1,264 @@
+run-command API
+===============
+
+The run-command API offers a versatile tool to run sub-processes with
+redirected input and output as well as with a modified environment
+and an alternate current directory.
+
+A similar API offers the capability to run a function asynchronously,
+which is primarily used to capture the output that the function
+produces in the caller in order to process it.
+
+
+Functions
+---------
+
+`child_process_init`::
+
+	Initialize a struct child_process variable.
+
+`start_command`::
+
+	Start a sub-process. Takes a pointer to a `struct child_process`
+	that specifies the details and returns pipe FDs (if requested).
+	See below for details.
+
+`finish_command`::
+
+	Wait for the completion of a sub-process that was started with
+	start_command().
+
+`run_command`::
+
+	A convenience function that encapsulates a sequence of
+	start_command() followed by finish_command(). Takes a pointer
+	to a `struct child_process` that specifies the details.
+
+`run_command_v_opt`, `run_command_v_opt_cd_env`::
+
+	Convenience functions that encapsulate a sequence of
+	start_command() followed by finish_command(). The argument argv
+	specifies the program and its arguments. The argument opt is zero
+	or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`,
+	`RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE`
+	that correspond to the members .no_stdin, .git_cmd,
+	.stdout_to_stderr, .silent_exec_failure of `struct child_process`.
+	The argument dir corresponds the member .dir. The argument env
+	corresponds to the member .env.
+
+`child_process_clear`::
+
+	Release the memory associated with the struct child_process.
+	Most users of the run-command API don't need to call this
+	function explicitly because `start_command` invokes it on
+	failure and `finish_command` calls it automatically already.
+
+The functions above do the following:
+
+. If a system call failed, errno is set and -1 is returned. A diagnostic
+  is printed.
+
+. If the program was not found, then -1 is returned and errno is set to
+  ENOENT; a diagnostic is printed only if .silent_exec_failure is 0.
+
+. Otherwise, the program is run. If it terminates regularly, its exit
+  code is returned. No diagnostic is printed, even if the exit code is
+  non-zero.
+
+. If the program terminated due to a signal, then the return value is the
+  signal number + 128, ie. the same value that a POSIX shell's $? would
+  report.  A diagnostic is printed.
+
+
+`start_async`::
+
+	Run a function asynchronously. Takes a pointer to a `struct
+	async` that specifies the details and returns a set of pipe FDs
+	for communication with the function. See below for details.
+
+`finish_async`::
+
+	Wait for the completion of an asynchronous function that was
+	started with start_async().
+
+`run_hook`::
+
+	Run a hook.
+	The first argument is a pathname to an index file, or NULL
+	if the hook uses the default index file or no index is needed.
+	The second argument is the name of the hook.
+	The further arguments correspond to the hook arguments.
+	The last argument has to be NULL to terminate the arguments list.
+	If the hook does not exist or is not executable, the return
+	value will be zero.
+	If it is executable, the hook will be executed and the exit
+	status of the hook is returned.
+	On execution, .stdout_to_stderr and .no_stdin will be set.
+	(See below.)
+
+
+Data structures
+---------------
+
+* `struct child_process`
+
+This describes the arguments, redirections, and environment of a
+command to run in a sub-process.
+
+The caller:
+
+1. allocates and clears (using child_process_init() or
+   CHILD_PROCESS_INIT) a struct child_process variable;
+2. initializes the members;
+3. calls start_command();
+4. processes the data;
+5. closes file descriptors (if necessary; see below);
+6. calls finish_command().
+
+The .argv member is set up as an array of string pointers (NULL
+terminated), of which .argv[0] is the program name to run (usually
+without a path). If the command to run is a git command, set argv[0] to
+the command name without the 'git-' prefix and set .git_cmd = 1.
+
+Note that the ownership of the memory pointed to by .argv stays with the
+caller, but it should survive until `finish_command` completes. If the
+.argv member is NULL, `start_command` will point it at the .args
+`argv_array` (so you may use one or the other, but you must use exactly
+one). The memory in .args will be cleaned up automatically during
+`finish_command` (or during `start_command` when it is unsuccessful).
+
+The members .in, .out, .err are used to redirect stdin, stdout,
+stderr as follows:
+
+. Specify 0 to request no special redirection. No new file descriptor
+  is allocated. The child process simply inherits the channel from the
+  parent.
+
+. Specify -1 to have a pipe allocated; start_command() replaces -1
+  by the pipe FD in the following way:
+
+	.in: Returns the writable pipe end into which the caller writes;
+		the readable end of the pipe becomes the child's stdin.
+
+	.out, .err: Returns the readable pipe end from which the caller
+		reads; the writable end of the pipe end becomes child's
+		stdout/stderr.
+
+  The caller of start_command() must close the so returned FDs
+  after it has completed reading from/writing to it!
+
+. Specify a file descriptor > 0 to be used by the child:
+
+	.in: The FD must be readable; it becomes child's stdin.
+	.out: The FD must be writable; it becomes child's stdout.
+	.err: The FD must be writable; it becomes child's stderr.
+
+  The specified FD is closed by start_command(), even if it fails to
+  run the sub-process!
+
+. Special forms of redirection are available by setting these members
+  to 1:
+
+	.no_stdin, .no_stdout, .no_stderr: The respective channel is
+		redirected to /dev/null.
+
+	.stdout_to_stderr: stdout of the child is redirected to its
+		stderr. This happens after stderr is itself redirected.
+		So stdout will follow stderr to wherever it is
+		redirected.
+
+To modify the environment of the sub-process, specify an array of
+string pointers (NULL terminated) in .env:
+
+. If the string is of the form "VAR=value", i.e. it contains '='
+  the variable is added to the child process's environment.
+
+. If the string does not contain '=', it names an environment
+  variable that will be removed from the child process's environment.
+
+If the .env member is NULL, `start_command` will point it at the
+.env_array `argv_array` (so you may use one or the other, but not both).
+The memory in .env_array will be cleaned up automatically during
+`finish_command` (or during `start_command` when it is unsuccessful).
+
+To specify a new initial working directory for the sub-process,
+specify it in the .dir member.
+
+If the program cannot be found, the functions return -1 and set
+errno to ENOENT. Normally, an error message is printed, but if
+.silent_exec_failure is set to 1, no message is printed for this
+special error condition.
+
+
+* `struct async`
+
+This describes a function to run asynchronously, whose purpose is
+to produce output that the caller reads.
+
+The caller:
+
+1. allocates and clears (memset(&asy, 0, sizeof(asy));) a
+   struct async variable;
+2. initializes .proc and .data;
+3. calls start_async();
+4. processes communicates with proc through .in and .out;
+5. closes .in and .out;
+6. calls finish_async().
+
+The members .in, .out are used to provide a set of fd's for
+communication between the caller and the callee as follows:
+
+. Specify 0 to have no file descriptor passed.  The callee will
+  receive -1 in the corresponding argument.
+
+. Specify < 0 to have a pipe allocated; start_async() replaces
+  with the pipe FD in the following way:
+
+	.in: Returns the writable pipe end into which the caller
+	writes; the readable end of the pipe becomes the function's
+	in argument.
+
+	.out: Returns the readable pipe end from which the caller
+	reads; the writable end of the pipe becomes the function's
+	out argument.
+
+  The caller of start_async() must close the returned FDs after it
+  has completed reading from/writing from them.
+
+. Specify a file descriptor > 0 to be used by the function:
+
+	.in: The FD must be readable; it becomes the function's in.
+	.out: The FD must be writable; it becomes the function's out.
+
+  The specified FD is closed by start_async(), even if it fails to
+  run the function.
+
+The function pointer in .proc has the following signature:
+
+	int proc(int in, int out, void *data);
+
+. in, out specifies a set of file descriptors to which the function
+  must read/write the data that it needs/produces.  The function
+  *must* close these descriptors before it returns.  A descriptor
+  may be -1 if the caller did not configure a descriptor for that
+  direction.
+
+. data is the value that the caller has specified in the .data member
+  of struct async.
+
+. The return value of the function is 0 on success and non-zero
+  on failure. If the function indicates failure, finish_async() will
+  report failure as well.
+
+
+There are serious restrictions on what the asynchronous function can do
+because this facility is implemented by a thread in the same address
+space on most platforms (when pthreads is available), but by a pipe to
+a forked process otherwise:
+
+. It cannot change the program's state (global variables, environment,
+  etc.) in a way that the caller notices; in other words, .in and .out
+  are the only communication channels to the caller.
+
+. It must not change the program's state that the caller of the
+  facility also uses.
diff --git a/third_party/git/Documentation/technical/api-setup.txt b/third_party/git/Documentation/technical/api-setup.txt
new file mode 100644
index 0000000000..eb1fa9853e
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-setup.txt
@@ -0,0 +1,47 @@
+setup API
+=========
+
+Talk about
+
+* setup_git_directory()
+* setup_git_directory_gently()
+* is_inside_git_dir()
+* is_inside_work_tree()
+* setup_work_tree()
+
+(Dscho)
+
+Pathspec
+--------
+
+See glossary-context.txt for the syntax of pathspec. In memory, a
+pathspec set is represented by "struct pathspec" and is prepared by
+parse_pathspec(). This function takes several arguments:
+
+- magic_mask specifies what features that are NOT supported by the
+  following code. If a user attempts to use such a feature,
+  parse_pathspec() can reject it early.
+
+- flags specifies other things that the caller wants parse_pathspec to
+  perform.
+
+- prefix and args come from cmd_* functions
+
+parse_pathspec() helps catch unsupported features and reject them
+politely. At a lower level, different pathspec-related functions may
+not support the same set of features. Such pathspec-sensitive
+functions are guarded with GUARD_PATHSPEC(), which will die in an
+unfriendly way when an unsupported feature is requested.
+
+The command designers are supposed to make sure that GUARD_PATHSPEC()
+never dies. They have to make sure all unsupported features are caught
+by parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC()
+should give the designers all pathspec-sensitive codepaths and what
+features they support.
+
+A similar process is applied when a new pathspec magic is added. The
+designer lifts the GUARD_PATHSPEC restriction in the functions that
+support the new magic. At the same time (s)he has to make sure this
+new feature will be caught at parse_pathspec() in commands that cannot
+handle the new magic in some cases. grepping parse_pathspec() should
+help.
diff --git a/third_party/git/Documentation/technical/api-sigchain.txt b/third_party/git/Documentation/technical/api-sigchain.txt
new file mode 100644
index 0000000000..9e1189ef01
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-sigchain.txt
@@ -0,0 +1,41 @@
+sigchain API
+============
+
+Code often wants to set a signal handler to clean up temporary files or
+other work-in-progress when we die unexpectedly. For multiple pieces of
+code to do this without conflicting, each piece of code must remember
+the old value of the handler and restore it either when:
+
+  1. The work-in-progress is finished, and the handler is no longer
+     necessary. The handler should revert to the original behavior
+     (either another handler, SIG_DFL, or SIG_IGN).
+
+  2. The signal is received. We should then do our cleanup, then chain
+     to the next handler (or die if it is SIG_DFL).
+
+Sigchain is a tiny library for keeping a stack of handlers. Your handler
+and installation code should look something like:
+
+------------------------------------------
+  void clean_foo_on_signal(int sig)
+  {
+	  clean_foo();
+	  sigchain_pop(sig);
+	  raise(sig);
+  }
+
+  void other_func()
+  {
+	  sigchain_push_common(clean_foo_on_signal);
+	  mess_up_foo();
+	  clean_foo();
+  }
+------------------------------------------
+
+Handlers are given the typedef of sigchain_fun. This is the same type
+that is given to signal() or sigaction(). It is perfectly reasonable to
+push SIG_DFL or SIG_IGN onto the stack.
+
+You can sigchain_push and sigchain_pop individual signals. For
+convenience, sigchain_push_common will push the handler onto the stack
+for many common signals.
diff --git a/third_party/git/Documentation/technical/api-submodule-config.txt b/third_party/git/Documentation/technical/api-submodule-config.txt
new file mode 100644
index 0000000000..fb06089393
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-submodule-config.txt
@@ -0,0 +1,66 @@
+submodule config cache API
+==========================
+
+The submodule config cache API allows to read submodule
+configurations/information from specified revisions. Internally
+information is lazily read into a cache that is used to avoid
+unnecessary parsing of the same .gitmodules files. Lookups can be done by
+submodule path or name.
+
+Usage
+-----
+
+To initialize the cache with configurations from the worktree the caller
+typically first calls `gitmodules_config()` to read values from the
+worktree .gitmodules and then to overlay the local git config values
+`parse_submodule_config_option()` from the config parsing
+infrastructure.
+
+The caller can look up information about submodules by using the
+`submodule_from_path()` or `submodule_from_name()` functions. They return
+a `struct submodule` which contains the values. The API automatically
+initializes and allocates the needed infrastructure on-demand. If the
+caller does only want to lookup values from revisions the initialization
+can be skipped.
+
+If the internal cache might grow too big or when the caller is done with
+the API, all internally cached values can be freed with submodule_free().
+
+Data Structures
+---------------
+
+`struct submodule`::
+
+	This structure is used to return the information about one
+	submodule for a certain revision. It is returned by the lookup
+	functions.
+
+Functions
+---------
+
+`void submodule_free(struct repository *r)`::
+
+	Use these to free the internally cached values.
+
+`int parse_submodule_config_option(const char *var, const char *value)`::
+
+	Can be passed to the config parsing infrastructure to parse
+	local (worktree) submodule configurations.
+
+`const struct submodule *submodule_from_path(const unsigned char *treeish_name, const char *path)`::
+
+	Given a tree-ish in the superproject and a path, return the
+	submodule that is bound at the path in the named tree.
+
+`const struct submodule *submodule_from_name(const unsigned char *treeish_name, const char *name)`::
+
+	The same as above but lookup by name.
+
+Whenever a submodule configuration is parsed in `parse_submodule_config_option`
+via e.g. `gitmodules_config()`, it will overwrite the null_sha1 entry.
+So in the normal case, when HEAD:.gitmodules is parsed first and then overlayed
+with the repository configuration, the null_sha1 entry contains the local
+configuration of a submodule (e.g. consolidated values from local git
+configuration and the .gitmodules file in the worktree).
+
+For an example usage see test-submodule-config.c.
diff --git a/third_party/git/Documentation/technical/api-trace.txt b/third_party/git/Documentation/technical/api-trace.txt
new file mode 100644
index 0000000000..fadb5979c4
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-trace.txt
@@ -0,0 +1,140 @@
+trace API
+=========
+
+The trace API can be used to print debug messages to stderr or a file. Trace
+code is inactive unless explicitly enabled by setting `GIT_TRACE*` environment
+variables.
+
+The trace implementation automatically adds `timestamp file:line ... \n` to
+all trace messages. E.g.:
+
+------------
+23:59:59.123456 git.c:312               trace: built-in: git 'foo'
+00:00:00.000001 builtin/foo.c:99        foo: some message
+------------
+
+Data Structures
+---------------
+
+`struct trace_key`::
+
+	Defines a trace key (or category). The default (for API functions that
+	don't take a key) is `GIT_TRACE`.
++
+E.g. to define a trace key controlled by environment variable `GIT_TRACE_FOO`:
++
+------------
+static struct trace_key trace_foo = TRACE_KEY_INIT(FOO);
+
+static void trace_print_foo(const char *message)
+{
+	trace_printf_key(&trace_foo, "%s", message);
+}
+------------
++
+Note: don't use `const` as the trace implementation stores internal state in
+the `trace_key` structure.
+
+Functions
+---------
+
+`int trace_want(struct trace_key *key)`::
+
+	Checks whether the trace key is enabled. Used to prevent expensive
+	string formatting before calling one of the printing APIs.
+
+`void trace_disable(struct trace_key *key)`::
+
+	Disables tracing for the specified key, even if the environment
+	variable was set.
+
+`void trace_printf(const char *format, ...)`::
+`void trace_printf_key(struct trace_key *key, const char *format, ...)`::
+
+	Prints a formatted message, similar to printf.
+
+`void trace_argv_printf(const char **argv, const char *format, ...)``::
+
+	Prints a formatted message, followed by a quoted list of arguments.
+
+`void trace_strbuf(struct trace_key *key, const struct strbuf *data)`::
+
+	Prints the strbuf, without additional formatting (i.e. doesn't
+	choke on `%` or even `\0`).
+
+`uint64_t getnanotime(void)`::
+
+	Returns nanoseconds since the epoch (01/01/1970), typically used
+	for performance measurements.
++
+Currently there are high precision timer implementations for Linux (using
+`clock_gettime(CLOCK_MONOTONIC)`) and Windows (`QueryPerformanceCounter`).
+Other platforms use `gettimeofday` as time source.
+
+`void trace_performance(uint64_t nanos, const char *format, ...)`::
+`void trace_performance_since(uint64_t start, const char *format, ...)`::
+
+	Prints the elapsed time (in nanoseconds), or elapsed time since
+	`start`, followed by a formatted message. Enabled via environment
+	variable `GIT_TRACE_PERFORMANCE`. Used for manual profiling, e.g.:
++
+------------
+uint64_t start = getnanotime();
+/* code section to measure */
+trace_performance_since(start, "foobar");
+------------
++
+------------
+uint64_t t = 0;
+for (;;) {
+	/* ignore */
+	t -= getnanotime();
+	/* code section to measure */
+	t += getnanotime();
+	/* ignore */
+}
+trace_performance(t, "frotz");
+------------
+
+Bugs & Caveats
+--------------
+
+GIT_TRACE_* environment variables can be used to tell Git to show
+trace output to its standard error stream. Git can often spawn a pager
+internally to run its subcommand and send its standard output and
+standard error to it.
+
+Because GIT_TRACE_PERFORMANCE trace is generated only at the very end
+of the program with atexit(), which happens after the pager exits, it
+would not work well if you send its log to the standard error output
+and let Git spawn the pager at the same time.
+
+As a work around, you can for example use '--no-pager', or set
+GIT_TRACE_PERFORMANCE to another file descriptor which is redirected
+to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its
+absolute path.
+
+For example instead of the following command which by default may not
+print any performance information:
+
+------------
+GIT_TRACE_PERFORMANCE=2 git log -1
+------------
+
+you may want to use:
+
+------------
+GIT_TRACE_PERFORMANCE=2 git --no-pager log -1
+------------
+
+or:
+
+------------
+GIT_TRACE_PERFORMANCE=3 3>&2 git log -1
+------------
+
+or:
+
+------------
+GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1
+------------
diff --git a/third_party/git/Documentation/technical/api-trace2.txt b/third_party/git/Documentation/technical/api-trace2.txt
new file mode 100644
index 0000000000..71eb081fed
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-trace2.txt
@@ -0,0 +1,1378 @@
+= Trace2 API
+
+The Trace2 API can be used to print debug, performance, and telemetry
+information to stderr or a file.  The Trace2 feature is inactive unless
+explicitly enabled by enabling one or more Trace2 Targets.
+
+The Trace2 API is intended to replace the existing (Trace1)
+printf-style tracing provided by the existing `GIT_TRACE` and
+`GIT_TRACE_PERFORMANCE` facilities.  During initial implementation,
+Trace2 and Trace1 may operate in parallel.
+
+The Trace2 API defines a set of high-level messages with known fields,
+such as (`start`: `argv`) and (`exit`: {`exit-code`, `elapsed-time`}).
+
+Trace2 instrumentation throughout the Git code base sends Trace2
+messages to the enabled Trace2 Targets.  Targets transform these
+messages content into purpose-specific formats and write events to
+their data streams.  In this manner, the Trace2 API can drive
+many different types of analysis.
+
+Targets are defined using a VTable allowing easy extension to other
+formats in the future.  This might be used to define a binary format,
+for example.
+
+Trace2 is controlled using `trace2.*` config values in the system and
+global config files and `GIT_TRACE2*` environment variables.  Trace2 does
+not read from repo local or worktree config files or respect `-c`
+command line config settings.
+
+== Trace2 Targets
+
+Trace2 defines the following set of Trace2 Targets.
+Format details are given in a later section.
+
+=== The Normal Format Target
+
+The normal format target is a tradition printf format and similar
+to GIT_TRACE format.  This format is enabled with the `GIT_TRACE2`
+environment variable or the `trace2.normalTarget` system or global
+config setting.
+
+For example
+
+------------
+$ export GIT_TRACE2=~/log.normal
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+or
+
+------------
+$ git config --global trace2.normalTarget ~/log.normal
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
+------------
+$ cat ~/log.normal
+12:28:42.620009 common-main.c:38                  version 2.20.1.155.g426c96fcdb
+12:28:42.620989 common-main.c:39                  start git version
+12:28:42.621101 git.c:432                         cmd_name version (version)
+12:28:42.621215 git.c:662                         exit elapsed:0.001227 code:0
+12:28:42.621250 trace2/tr2_tgt_normal.c:124       atexit elapsed:0.001265 code:0
+------------
+
+=== The Performance Format Target
+
+The performance format target (PERF) is a column-based format to
+replace GIT_TRACE_PERFORMANCE and is suitable for development and
+testing, possibly to complement tools like gprof.  This format is
+enabled with the `GIT_TRACE2_PERF` environment variable or the
+`trace2.perfTarget` system or global config setting.
+
+For example
+
+------------
+$ export GIT_TRACE2_PERF=~/log.perf
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+or
+
+------------
+$ git config --global trace2.perfTarget ~/log.perf
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
+------------
+$ cat ~/log.perf
+12:28:42.620675 common-main.c:38                  | d0 | main                     | version      |     |           |           |            | 2.20.1.155.g426c96fcdb
+12:28:42.621001 common-main.c:39                  | d0 | main                     | start        |     |  0.001173 |           |            | git version
+12:28:42.621111 git.c:432                         | d0 | main                     | cmd_name     |     |           |           |            | version (version)
+12:28:42.621225 git.c:662                         | d0 | main                     | exit         |     |  0.001227 |           |            | code:0
+12:28:42.621259 trace2/tr2_tgt_perf.c:211         | d0 | main                     | atexit       |     |  0.001265 |           |            | code:0
+------------
+
+=== The Event Format Target
+
+The event format target is a JSON-based format of event data suitable
+for telemetry analysis.  This format is enabled with the `GIT_TRACE2_EVENT`
+environment variable or the `trace2.eventTarget` system or global config
+setting.
+
+For example
+
+------------
+$ export GIT_TRACE2_EVENT=~/log.event
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+or
+
+------------
+$ git config --global trace2.eventTarget ~/log.event
+$ git version
+git version 2.20.1.155.g426c96fcdb
+------------
+
+yields
+
+------------
+$ cat ~/log.event
+{"event":"version","sid":"sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"20190408T191610.507018Z-H9b68c35f-P000059a8","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+------------
+
+=== Enabling a Target
+
+To enable a target, set the corresponding environment variable or
+system or global config value to one of the following:
+
+include::../trace2-target-values.txt[]
+
+If the target already exists and is a directory, the traces will be
+written to files (one per process) underneath the given directory. They
+will be named according to the last component of the SID (optionally
+followed by a counter to avoid filename collisions).
+
+== Trace2 API
+
+All public Trace2 functions and macros are defined in `trace2.h` and
+`trace2.c`.  All public symbols are prefixed with `trace2_`.
+
+There are no public Trace2 data structures.
+
+The Trace2 code also defines a set of private functions and data types
+in the `trace2/` directory.  These symbols are prefixed with `tr2_`
+and should only be used by functions in `trace2.c`.
+
+== Conventions for Public Functions and Macros
+
+The functions defined by the Trace2 API are declared and documented
+in `trace2.h`.  It defines the API functions and wrapper macros for
+Trace2.
+
+Some functions have a `_fl()` suffix to indicate that they take `file`
+and `line-number` arguments.
+
+Some functions have a `_va_fl()` suffix to indicate that they also
+take a `va_list` argument.
+
+Some functions have a `_printf_fl()` suffix to indicate that they also
+take a varargs argument.
+
+There are CPP wrapper macros and ifdefs to hide most of these details.
+See `trace2.h` for more details.  The following discussion will only
+describe the simplified forms.
+
+== Public API
+
+All Trace2 API functions send a messsage to all of the active
+Trace2 Targets.  This section describes the set of available
+messages.
+
+It helps to divide these functions into groups for discussion
+purposes.
+
+=== Basic Command Messages
+
+These are concerned with the lifetime of the overall git process.
+
+`void trace2_initialize_clock()`::
+
+	Initialize the Trace2 start clock and nothing else.  This should
+	be called at the very top of main() to capture the process start
+	time and reduce startup order dependencies.
+
+`void trace2_initialize()`::
+
+	Determines if any Trace2 Targets should be enabled and
+	initializes the Trace2 facility.  This includes setting up the
+	Trace2 thread local storage (TLS).
++
+This function emits a "version" message containing the version of git
+and the Trace2 protocol.
++
+This function should be called from `main()` as early as possible in
+the life of the process after essential process initialization.
+
+`int trace2_is_enabled()`::
+
+	Returns 1 if Trace2 is enabled (at least one target is
+	active).
+
+`void trace2_cmd_start(int argc, const char **argv)`::
+
+	Emits a "start" message containing the process command line
+	arguments.
+
+`int trace2_cmd_exit(int exit_code)`::
+
+	Emits an "exit" message containing the process exit-code and
+	elapsed time.
++
+Returns the exit-code.
+
+`void trace2_cmd_error(const char *fmt, va_list ap)`::
+
+	Emits an "error" message containing a formatted error message.
+
+`void trace2_cmd_path(const char *pathname)`::
+
+	Emits a "cmd_path" message with the full pathname of the
+	current process.
+
+=== Command Detail Messages
+
+These are concerned with describing the specific Git command
+after the command line, config, and environment are inspected.
+
+`void trace2_cmd_name(const char *name)`::
+
+	Emits a "cmd_name" message with the canonical name of the
+	command, for example "status" or "checkout".
+
+`void trace2_cmd_mode(const char *mode)`::
+
+	Emits a "cmd_mode" message with a qualifier name to further
+	describe the current git command.
++
+This message is intended to be used with git commands having multiple
+major modes.  For example, a "checkout" command can checkout a new
+branch or it can checkout a single file, so the checkout code could
+emit a cmd_mode message of "branch" or "file".
+
+`void trace2_cmd_alias(const char *alias, const char **argv_expansion)`::
+
+	Emits an "alias" message containing the alias used and the
+	argument expansion.
+
+`void trace2_def_param(const char *parameter, const char *value)`::
+
+	Emits a "def_param" message containing a key/value pair.
++
+This message is intended to report some global aspect of the current
+command, such as a configuration setting or command line switch that
+significantly affects program performance or behavior, such as
+`core.abbrev`, `status.showUntrackedFiles`, or `--no-ahead-behind`.
+
+`void trace2_cmd_list_config()`::
+
+	Emits a "def_param" messages for "important" configuration
+	settings.
++
+The environment variable `GIT_TRACE2_CONFIG_PARAMS` or the `trace2.configParams`
+config value can be set to a
+list of patterns of important configuration settings, for example:
+`core.*,remote.*.url`.  This function will iterate over all config
+settings and emit a "def_param" message for each match.
+
+`void trace2_cmd_set_config(const char *key, const char *value)`::
+
+	Emits a "def_param" message for a new or updated key/value
+	pair IF `key` is considered important.
++
+This is used to hook into `git_config_set()` and catch any
+configuration changes and update a value previously reported by
+`trace2_cmd_list_config()`.
+
+`void trace2_def_repo(struct repository *repo)`::
+
+	Registers a repository with the Trace2 layer.  Assigns a
+	unique "repo-id" to `repo->trace2_repo_id`.
++
+Emits a "worktree" messages containing the repo-id and the worktree
+pathname.
++
+Region and data messages (described later) may refer to this repo-id.
++
+The main/top-level repository will have repo-id value 1 (aka "r1").
++
+The repo-id field is in anticipation of future in-proc submodule
+repositories.
+
+=== Child Process Messages
+
+These are concerned with the various spawned child processes,
+including shell scripts, git commands, editors, pagers, and hooks.
+
+`void trace2_child_start(struct child_process *cmd)`::
+
+	Emits a "child_start" message containing the "child-id",
+	"child-argv", and "child-classification".
++
+Before calling this, set `cmd->trace2_child_class` to a name
+describing the type of child process, for example "editor".
++
+This function assigns a unique "child-id" to `cmd->trace2_child_id`.
+This field is used later during the "child_exit" message to associate
+it with the "child_start" message.
++
+This function should be called before spawning the child process.
+
+`void trace2_child_exit(struct child_proess *cmd, int child_exit_code)`::
+
+	Emits a "child_exit" message containing the "child-id",
+	the child's elapsed time and exit-code.
++
+The reported elapsed time includes the process creation overhead and
+time spend waiting for it to exit, so it may be slightly longer than
+the time reported by the child itself.
++
+This function should be called after reaping the child process.
+
+`int trace2_exec(const char *exe, const char **argv)`::
+
+	Emits a "exec" message containing the "exec-id" and the
+	argv of the new process.
++
+This function should be called before calling one of the `exec()`
+variants, such as `execvp()`.
++
+This function returns a unique "exec-id".  This value is used later
+if the exec() fails and a "exec-result" message is necessary.
+
+`void trace2_exec_result(int exec_id, int error_code)`::
+
+	Emits a "exec_result" message containing the "exec-id"
+	and the error code.
++
+On Unix-based systems, `exec()` does not return if successful.
+This message is used to indicate that the `exec()` failed and
+that the current program is continuing.
+
+=== Git Thread Messages
+
+These messages are concerned with Git thread usage.
+
+`void trace2_thread_start(const char *thread_name)`::
+
+	Emits a "thread_start" message.
++
+The `thread_name` field should be a descriptive name, such as the
+unique name of the thread-proc.  A unique "thread-id" will be added
+to the name to uniquely identify thread instances.
++
+Region and data messages (described later) may refer to this thread
+name.
++
+This function must be called by the thread-proc of the new thread
+(so that TLS data is properly initialized) and not by the caller
+of `pthread_create()`.
+
+`void trace2_thread_exit()`::
+
+	Emits a "thread_exit" message containing the thread name
+	and the thread elapsed time.
++
+This function must be called by the thread-proc before it returns
+(so that the coorect TLS data is used and cleaned up.  It should
+not be called by the caller of `pthread_join()`.
+
+=== Region and Data Messages
+
+These are concerned with recording performance data
+over regions or spans of code.
+
+`void trace2_region_enter(const char *category, const char *label, const struct repository *repo)`::
+
+`void trace2_region_enter_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)`::
+
+`void trace2_region_enter_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)`::
+
+	Emits a thread-relative "region_enter" message with optional
+	printf string.
++
+This function pushes a new region nesting stack level on the current
+thread and starts a clock for the new stack frame.
++
+The `category` field is an arbitrary category name used to classify
+regions by feature area, such as "status" or "index".  At this time
+it is only just printed along with the rest of the message.  It may
+be used in the future to filter messages.
++
+The `label` field is an arbitrary label used to describe the activity
+being started, such as "read_recursive" or "do_read_index".
++
+The `repo` field, if set, will be used to get the "repo-id", so that
+recursive oerations can be attributed to the correct repository.
+
+`void trace2_region_leave(const char *category, const char *label, const struct repository *repo)`::
+
+`void trace2_region_leave_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)`::
+
+`void trace2_region_leave_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)`::
+
+	Emits a thread-relative "region_leave" message with optional
+	printf string.
++
+This function pops the region nesting stack on the current thread
+and reports the elapsed time of the stack frame.
++
+The `category`, `label`, and `repo` fields are the same as above.
+The `category` and `label` do not need to match the correpsonding
+"region_enter" message, but it makes the data stream easier to
+understand.
+
+`void trace2_data_string(const char *category, const struct repository *repo, const char *key, const char * value)`::
+
+`void trace2_data_intmax(const char *category, const struct repository *repo, const char *key, intmax value)`::
+
+`void trace2_data_json(const char *category, const struct repository *repo, const char *key, const struct json_writer *jw)`::
+
+	Emits a region- and thread-relative "data" or "data_json" message.
++
+This is a key/value pair message containing information about the
+current thread, region stack, and repository.  This could be used
+to print the number of files in a directory during a multi-threaded
+recursive tree walk.
+
+`void trace2_printf(const char *fmt, ...)`::
+
+`void trace2_printf_va(const char *fmt, va_list ap)`::
+
+	Emits a region- and thread-relative "printf" message.
+
+== Trace2 Target Formats
+
+=== NORMAL Format
+
+Events are written as lines of the form:
+
+------------
+[<time> SP <filename>:<line> SP+] <event-name> [[SP] <event-message>] LF
+------------
+
+`<event-name>`::
+
+	is the event name.
+
+`<event-message>`::
+	is a free-form printf message intended for human consumption.
++
+Note that this may contain embedded LF or CRLF characters that are
+not escaped, so the event may spill across multiple lines.
+
+If `GIT_TRACE2_BRIEF` or `trace2.normalBrief` is true, the `time`, `filename`,
+and `line` fields are omitted.
+
+This target is intended to be more of a summary (like GIT_TRACE) and
+less detailed than the other targets.  It ignores thread, region, and
+data messages, for example.
+
+=== PERF Format
+
+Events are written as lines of the form:
+
+------------
+[<time> SP <filename>:<line> SP+
+    BAR SP] d<depth> SP
+    BAR SP <thread-name> SP+
+    BAR SP <event-name> SP+
+    BAR SP [r<repo-id>] SP+
+    BAR SP [<t_abs>] SP+
+    BAR SP [<t_rel>] SP+
+    BAR SP [<category>] SP+
+    BAR SP DOTS* <perf-event-message>
+    LF
+------------
+
+`<depth>`::
+	is the git process depth.  This is the number of parent
+	git processes.  A top-level git command has depth value "d0".
+	A child of it has depth value "d1".  A second level child
+	has depth value "d2" and so on.
+
+`<thread-name>`::
+	is a unique name for the thread.  The primary thread
+	is called "main".  Other thread names are of the form "th%d:%s"
+	and include a unique number and the name of the thread-proc.
+
+`<event-name>`::
+	is the event name.
+
+`<repo-id>`::
+	when present, is a number indicating the repository
+	in use.  A `def_repo` event is emitted when a repository is
+	opened.  This defines the repo-id and associated worktree.
+	Subsequent repo-specific events will reference this repo-id.
++
+Currently, this is always "r1" for the main repository.
+This field is in anticipation of in-proc submodules in the future.
+
+`<t_abs>`::
+	when present, is the absolute time in seconds since the
+	program started.
+
+`<t_rel>`::
+	when present, is time in seconds relative to the start of
+	the current region.  For a thread-exit event, it is the elapsed
+	time of the thread.
+
+`<category>`::
+	is present on region and data events and is used to
+	indicate a broad category, such as "index" or "status".
+
+`<perf-event-message>`::
+	is a free-form printf message intended for human consumption.
+
+------------
+15:33:33.532712 wt-status.c:2310                  | d0 | main                     | region_enter | r1  |  0.126064 |           | status     | label:print
+15:33:33.532712 wt-status.c:2331                  | d0 | main                     | region_leave | r1  |  0.127568 |  0.001504 | status     | label:print
+------------
+
+If `GIT_TRACE2_PERF_BRIEF` or `trace2.perfBrief` is true, the `time`, `file`,
+and `line` fields are omitted.
+
+------------
+d0 | main                     | region_leave | r1  |  0.011717 |  0.009122 | index      | label:preload
+------------
+
+The PERF target is intended for interactive performance analysis
+during development and is quite noisy.
+
+=== EVENT Format
+
+Each event is a JSON-object containing multiple key/value pairs
+written as a single line and followed by a LF.
+
+------------
+'{' <key> ':' <value> [',' <key> ':' <value>]* '}' LF
+------------
+
+Some key/value pairs are common to all events and some are
+event-specific.
+
+==== Common Key/Value Pairs
+
+The following key/value pairs are common to all events:
+
+------------
+{
+	"event":"version",
+	"sid":"20190408T191827.272759Z-H9b68c35f-P00003510",
+	"thread":"main",
+	"time":"2019-04-08T19:18:27.282761Z",
+	"file":"common-main.c",
+	"line":42,
+	...
+}
+------------
+
+`"event":<event>`::
+	is the event name.
+
+`"sid":<sid>`::
+	is the session-id.  This is a unique string to identify the
+	process instance to allow all events emitted by a process to
+	be identified.  A session-id is used instead of a PID because
+	PIDs are recycled by the OS.  For child git processes, the
+	session-id is prepended with the session-id of the parent git
+	process to allow parent-child relationships to be identified
+	during post-processing.
+
+`"thread":<thread>`::
+	is the thread name.
+
+`"time":<time>`::
+	is the UTC time of the event.
+
+`"file":<filename>`::
+	is source file generating the event.
+
+`"line":<line-number>`::
+	is the integer source line number generating the event.
+
+`"repo":<repo-id>`::
+	when present, is the integer repo-id as described previously.
+
+If `GIT_TRACE2_EVENT_BRIEF` or `trace2.eventBrief` is true, the `file`
+and `line` fields are omitted from all events and the `time` field is
+only present on the "start" and "atexit" events.
+
+==== Event-Specific Key/Value Pairs
+
+`"version"`::
+	This event gives the version of the executable and the EVENT format.
++
+------------
+{
+	"event":"version",
+	...
+	"evt":"1",		       # EVENT format version
+	"exe":"2.20.1.155.g426c96fcdb" # git version
+}
+------------
+
+`"start"`::
+	This event contains the complete argv received by main().
++
+------------
+{
+	"event":"start",
+	...
+	"t_abs":0.001227, # elapsed time in seconds
+	"argv":["git","version"]
+}
+------------
+
+`"exit"`::
+	This event is emitted when git calls `exit()`.
++
+------------
+{
+	"event":"exit",
+	...
+	"t_abs":0.001227, # elapsed time in seconds
+	"code":0	  # exit code
+}
+------------
+
+`"atexit"`::
+	This event is emitted by the Trace2 `atexit` routine during
+	final shutdown.  It should be the last event emitted by the
+	process.
++
+(The elapsed time reported here is greater than the time reported in
+the "exit" event because it runs after all other atexit tasks have
+completed.)
++
+------------
+{
+	"event":"atexit",
+	...
+	"t_abs":0.001227, # elapsed time in seconds
+	"code":0          # exit code
+}
+------------
+
+`"signal"`::
+	This event is emitted when the program is terminated by a user
+	signal.  Depending on the platform, the signal event may
+	prevent the "atexit" event from being generated.
++
+------------
+{
+	"event":"signal",
+	...
+	"t_abs":0.001227,  # elapsed time in seconds
+	"signo":13         # SIGTERM, SIGINT, etc.
+}
+------------
+
+`"error"`::
+	This event is emitted when one of the `error()`, `die()`,
+	or `usage()` functions are called.
++
+------------
+{
+	"event":"error",
+	...
+	"msg":"invalid option: --cahced", # formatted error message
+	"fmt":"invalid option: %s"	  # error format string
+}
+------------
++
+The error event may be emitted more than once.  The format string
+allows post-processors to group errors by type without worrying
+about specific error arguments.
+
+`"cmd_path"`::
+	This event contains the discovered full path of the git
+	executable (on platforms that are configured to resolve it).
++
+------------
+{
+	"event":"cmd_path",
+	...
+	"path":"C:/work/gfw/git.exe"
+}
+------------
+
+`"cmd_name"`::
+	This event contains the command name for this git process
+	and the hierarchy of commands from parent git processes.
++
+------------
+{
+	"event":"cmd_name",
+	...
+	"name":"pack-objects",
+	"hierarchy":"push/pack-objects"
+}
+------------
++
+Normally, the "name" field contains the canonical name of the
+command.  When a canonical name is not available, one of
+these special values are used:
++
+------------
+"_query_"            # "git --html-path"
+"_run_dashed_"       # when "git foo" tries to run "git-foo"
+"_run_shell_alias_"  # alias expansion to a shell command
+"_run_git_alias_"    # alias expansion to a git command
+"_usage_"            # usage error
+------------
+
+`"cmd_mode"`::
+	This event, when present, describes the command variant This
+	event may be emitted more than once.
++
+------------
+{
+	"event":"cmd_mode",
+	...
+	"name":"branch"
+}
+------------
++
+The "name" field is an arbitrary string to describe the command mode.
+For example, checkout can checkout a branch or an individual file.
+And these variations typically have different performance
+characteristics that are not comparable.
+
+`"alias"`::
+	This event is present when an alias is expanded.
++
+------------
+{
+	"event":"alias",
+	...
+	"alias":"l",		 # registered alias
+	"argv":["log","--graph"] # alias expansion
+}
+------------
+
+`"child_start"`::
+	This event describes a child process that is about to be
+	spawned.
++
+------------
+{
+	"event":"child_start",
+	...
+	"child_id":2,
+	"child_class":"?",
+	"use_shell":false,
+	"argv":["git","rev-list","--objects","--stdin","--not","--all","--quiet"]
+
+	"hook_name":"<hook_name>"  # present when child_class is "hook"
+	"cd":"<path>"		   # present when cd is required
+}
+------------
++
+The "child_id" field can be used to match this child_start with the
+corresponding child_exit event.
++
+The "child_class" field is a rough classification, such as "editor",
+"pager", "transport/*", and "hook".  Unclassified children are classified
+with "?".
+
+`"child_exit"`::
+	This event is generated after the current process has returned
+	from the waitpid() and collected the exit information from the
+	child.
++
+------------
+{
+	"event":"child_exit",
+	...
+	"child_id":2,
+	"pid":14708,	 # child PID
+	"code":0,	 # child exit-code
+	"t_rel":0.110605 # observed run-time of child process
+}
+------------
++
+Note that the session-id of the child process is not available to
+the current/spawning process, so the child's PID is reported here as
+a hint for post-processing.  (But it is only a hint because the child
+proces may be a shell script which doesn't have a session-id.)
++
+Note that the `t_rel` field contains the observed run time in seconds
+for the child process (starting before the fork/exec/spawn and
+stopping after the waitpid() and includes OS process creation overhead).
+So this time will be slightly larger than the atexit time reported by
+the child process itself.
+
+`"exec"`::
+	This event is generated before git attempts to `exec()`
+	another command rather than starting a child process.
++
+------------
+{
+	"event":"exec",
+	...
+	"exec_id":0,
+	"exe":"git",
+	"argv":["foo", "bar"]
+}
+------------
++
+The "exec_id" field is a command-unique id and is only useful if the
+`exec()` fails and a corresponding exec_result event is generated.
+
+`"exec_result"`::
+	This event is generated if the `exec()` fails and control
+	returns to the current git command.
++
+------------
+{
+	"event":"exec_result",
+	...
+	"exec_id":0,
+	"code":1      # error code (errno) from exec()
+}
+------------
+
+`"thread_start"`::
+	This event is generated when a thread is started.  It is
+	generated from *within* the new thread's thread-proc (for TLS
+	reasons).
++
+------------
+{
+	"event":"thread_start",
+	...
+	"thread":"th02:preload_thread" # thread name
+}
+------------
+
+`"thread_exit"`::
+	This event is generated when a thread exits.  It is generated
+	from *within* the thread's thread-proc (for TLS reasons).
++
+------------
+{
+	"event":"thread_exit",
+	...
+	"thread":"th02:preload_thread", # thread name
+	"t_rel":0.007328                # thread elapsed time
+}
+------------
+
+`"def_param"`::
+	This event is generated to log a global parameter.
++
+------------
+{
+	"event":"def_param",
+	...
+	"param":"core.abbrev",
+	"value":"7"
+}
+------------
+
+`"def_repo"`::
+	This event defines a repo-id and associates it with the root
+	of the worktree.
++
+------------
+{
+	"event":"def_repo",
+	...
+	"repo":1,
+	"worktree":"/Users/jeffhost/work/gfw"
+}
+------------
++
+As stated earlier, the repo-id is currently always 1, so there will
+only be one def_repo event.  Later, if in-proc submodules are
+supported, a def_repo event should be emitted for each submodule
+visited.
+
+`"region_enter"`::
+	This event is generated when entering a region.
++
+------------
+{
+	"event":"region_enter",
+	...
+	"repo":1,                # optional
+	"nesting":1,             # current region stack depth
+	"category":"index",      # optional
+	"label":"do_read_index", # optional
+	"msg":".git/index"       # optional
+}
+------------
++
+The `category` field may be used in a future enhancement to
+do category-based filtering.
++
+`GIT_TRACE2_EVENT_NESTING` or `trace2.eventNesting` can be used to
+filter deeply nested regions and data events.  It defaults to "2".
+
+`"region_leave"`::
+	This event is generated when leaving a region.
++
+------------
+{
+	"event":"region_leave",
+	...
+	"repo":1,                # optional
+	"t_rel":0.002876,        # time spent in region in seconds
+	"nesting":1,             # region stack depth
+	"category":"index",      # optional
+	"label":"do_read_index", # optional
+	"msg":".git/index"       # optional
+}
+------------
+
+`"data"`::
+	This event is generated to log a thread- and region-local
+	key/value pair.
++
+------------
+{
+	"event":"data",
+	...
+	"repo":1,              # optional
+	"t_abs":0.024107,      # absolute elapsed time
+	"t_rel":0.001031,      # elapsed time in region/thread
+	"nesting":2,           # region stack depth
+	"category":"index",
+	"key":"read/cache_nr",
+	"value":"3552"
+}
+------------
++
+The "value" field may be an integer or a string.
+
+`"data-json"`::
+	This event is generated to log a pre-formatted JSON string
+	containing structured data.
++
+------------
+{
+	"event":"data_json",
+	...
+	"repo":1,              # optional
+	"t_abs":0.015905,
+	"t_rel":0.015905,
+	"nesting":1,
+	"category":"process",
+	"key":"windows/ancestry",
+	"value":["bash.exe","bash.exe"]
+}
+------------
+
+== Example Trace2 API Usage
+
+Here is a hypothetical usage of the Trace2 API showing the intended
+usage (without worrying about the actual Git details).
+
+Initialization::
+
+	Initialization happens in `main()`.  Behind the scenes, an
+	`atexit` and `signal` handler are registered.
++
+----------------
+int main(int argc, const char **argv)
+{
+	int exit_code;
+
+	trace2_initialize();
+	trace2_cmd_start(argv);
+
+	exit_code = cmd_main(argc, argv);
+
+	trace2_cmd_exit(exit_code);
+
+	return exit_code;
+}
+----------------
+
+Command Details::
+
+	After the basics are established, additional command
+	information can be sent to Trace2 as it is discovered.
++
+----------------
+int cmd_checkout(int argc, const char **argv)
+{
+	trace2_cmd_name("checkout");
+	trace2_cmd_mode("branch");
+	trace2_def_repo(the_repository);
+
+	// emit "def_param" messages for "interesting" config settings.
+	trace2_cmd_list_config();
+
+	if (do_something())
+	    trace2_cmd_error("Path '%s': cannot do something", path);
+
+	return 0;
+}
+----------------
+
+Child Processes::
+
+	Wrap code spawning child processes.
++
+----------------
+void run_child(...)
+{
+	int child_exit_code;
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	...
+	cmd.trace2_child_class = "editor";
+
+	trace2_child_start(&cmd);
+	child_exit_code = spawn_child_and_wait_for_it();
+	trace2_child_exit(&cmd, child_exit_code);
+}
+----------------
++
+For example, the following fetch command spawned ssh, index-pack,
+rev-list, and gc.  This example also shows that fetch took
+5.199 seconds and of that 4.932 was in ssh.
++
+----------------
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
+$ git fetch origin
+...
+----------------
++
+----------------
+$ cat ~/log.normal
+version 2.20.1.vfs.1.1.47.g534dbe1ad1
+start git fetch origin
+worktree /Users/jeffhost/work/gfw
+cmd_name fetch (fetch)
+child_start[0] ssh git@github.com ...
+child_start[1] git index-pack ...
+... (Trace2 events from child processes omitted)
+child_exit[1] pid:14707 code:0 elapsed:0.076353
+child_exit[0] pid:14706 code:0 elapsed:4.931869
+child_start[2] git rev-list ...
+... (Trace2 events from child process omitted)
+child_exit[2] pid:14708 code:0 elapsed:0.110605
+child_start[3] git gc --auto
+... (Trace2 events from child process omitted)
+child_exit[3] pid:14709 code:0 elapsed:0.006240
+exit elapsed:5.198503 code:0
+atexit elapsed:5.198541 code:0
+----------------
++
+When a git process is a (direct or indirect) child of another
+git process, it inherits Trace2 context information.  This
+allows the child to print the command hierarchy.  This example
+shows gc as child[3] of fetch.  When the gc process reports
+its name as "gc", it also reports the hierarchy as "fetch/gc".
+(In this example, trace2 messages from the child process is
+indented for clarity.)
++
+----------------
+$ export GIT_TRACE2_BRIEF=1
+$ export GIT_TRACE2=~/log.normal
+$ git fetch origin
+...
+----------------
++
+----------------
+$ cat ~/log.normal
+version 2.20.1.160.g5676107ecd.dirty
+start git fetch official
+worktree /Users/jeffhost/work/gfw
+cmd_name fetch (fetch)
+...
+child_start[3] git gc --auto
+    version 2.20.1.160.g5676107ecd.dirty
+    start /Users/jeffhost/work/gfw/git gc --auto
+    worktree /Users/jeffhost/work/gfw
+    cmd_name gc (fetch/gc)
+    exit elapsed:0.001959 code:0
+    atexit elapsed:0.001997 code:0
+child_exit[3] pid:20303 code:0 elapsed:0.007564
+exit elapsed:3.868938 code:0
+atexit elapsed:3.868970 code:0
+----------------
+
+Regions::
+
+	Regions can be use to time an interesting section of code.
++
+----------------
+void wt_status_collect(struct wt_status *s)
+{
+	trace2_region_enter("status", "worktrees", s->repo);
+	wt_status_collect_changes_worktree(s);
+	trace2_region_leave("status", "worktrees", s->repo);
+
+	trace2_region_enter("status", "index", s->repo);
+	wt_status_collect_changes_index(s);
+	trace2_region_leave("status", "index", s->repo);
+
+	trace2_region_enter("status", "untracked", s->repo);
+	wt_status_collect_untracked(s);
+	trace2_region_leave("status", "untracked", s->repo);
+}
+
+void wt_status_print(struct wt_status *s)
+{
+	trace2_region_enter("status", "print", s->repo);
+	switch (s->status_format) {
+	    ...
+	}
+	trace2_region_leave("status", "print", s->repo);
+}
+----------------
++
+In this example, scanning for untracked files ran from +0.012568 to
++0.027149 (since the process started) and took 0.014581 seconds.
++
+----------------
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
+$ git status
+...
+
+$ cat ~/log.perf
+d0 | main                     | version      |     |           |           |            | 2.20.1.160.g5676107ecd.dirty
+d0 | main                     | start        |     |  0.001173 |           |            | git status
+d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
+d0 | main                     | cmd_name     |     |           |           |            | status (status)
+...
+d0 | main                     | region_enter | r1  |  0.010988 |           | status     | label:worktrees
+d0 | main                     | region_leave | r1  |  0.011236 |  0.000248 | status     | label:worktrees
+d0 | main                     | region_enter | r1  |  0.011260 |           | status     | label:index
+d0 | main                     | region_leave | r1  |  0.012542 |  0.001282 | status     | label:index
+d0 | main                     | region_enter | r1  |  0.012568 |           | status     | label:untracked
+d0 | main                     | region_leave | r1  |  0.027149 |  0.014581 | status     | label:untracked
+d0 | main                     | region_enter | r1  |  0.027411 |           | status     | label:print
+d0 | main                     | region_leave | r1  |  0.028741 |  0.001330 | status     | label:print
+d0 | main                     | exit         |     |  0.028778 |           |            | code:0
+d0 | main                     | atexit       |     |  0.028809 |           |            | code:0
+----------------
++
+Regions may be nested.  This causes messages to be indented in the
+PERF target, for example.
+Elapsed times are relative to the start of the correpsonding nesting
+level as expected.  For example, if we add region message to:
++
+----------------
+static enum path_treatment read_directory_recursive(struct dir_struct *dir,
+	struct index_state *istate, const char *base, int baselen,
+	struct untracked_cache_dir *untracked, int check_only,
+	int stop_at_first_file, const struct pathspec *pathspec)
+{
+	enum path_treatment state, subdir_state, dir_state = path_none;
+
+	trace2_region_enter_printf("dir", "read_recursive", NULL, "%.*s", baselen, base);
+	...
+	trace2_region_leave_printf("dir", "read_recursive", NULL, "%.*s", baselen, base);
+	return dir_state;
+}
+----------------
++
+We can further investigate the time spent scanning for untracked files.
++
+----------------
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
+$ git status
+...
+$ cat ~/log.perf
+d0 | main                     | version      |     |           |           |            | 2.20.1.162.gb4ccea44db.dirty
+d0 | main                     | start        |     |  0.001173 |           |            | git status
+d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
+d0 | main                     | cmd_name     |     |           |           |            | status (status)
+...
+d0 | main                     | region_enter | r1  |  0.015047 |           | status     | label:untracked
+d0 | main                     | region_enter |     |  0.015132 |           | dir        | ..label:read_recursive
+d0 | main                     | region_enter |     |  0.016341 |           | dir        | ....label:read_recursive vcs-svn/
+d0 | main                     | region_leave |     |  0.016422 |  0.000081 | dir        | ....label:read_recursive vcs-svn/
+d0 | main                     | region_enter |     |  0.016446 |           | dir        | ....label:read_recursive xdiff/
+d0 | main                     | region_leave |     |  0.016522 |  0.000076 | dir        | ....label:read_recursive xdiff/
+d0 | main                     | region_enter |     |  0.016612 |           | dir        | ....label:read_recursive git-gui/
+d0 | main                     | region_enter |     |  0.016698 |           | dir        | ......label:read_recursive git-gui/po/
+d0 | main                     | region_enter |     |  0.016810 |           | dir        | ........label:read_recursive git-gui/po/glossary/
+d0 | main                     | region_leave |     |  0.016863 |  0.000053 | dir        | ........label:read_recursive git-gui/po/glossary/
+...
+d0 | main                     | region_enter |     |  0.031876 |           | dir        | ....label:read_recursive builtin/
+d0 | main                     | region_leave |     |  0.032270 |  0.000394 | dir        | ....label:read_recursive builtin/
+d0 | main                     | region_leave |     |  0.032414 |  0.017282 | dir        | ..label:read_recursive
+d0 | main                     | region_leave | r1  |  0.032454 |  0.017407 | status     | label:untracked
+...
+d0 | main                     | exit         |     |  0.034279 |           |            | code:0
+d0 | main                     | atexit       |     |  0.034322 |           |            | code:0
+----------------
++
+Trace2 regions are similar to the existing trace_performance_enter()
+and trace_performance_leave() routines, but are thread safe and
+maintain per-thread stacks of timers.
+
+Data Messages::
+
+	Data messages added to a region.
++
+----------------
+int read_index_from(struct index_state *istate, const char *path,
+	const char *gitdir)
+{
+	trace2_region_enter_printf("index", "do_read_index", the_repository, "%s", path);
+
+	...
+
+	trace2_data_intmax("index", the_repository, "read/version", istate->version);
+	trace2_data_intmax("index", the_repository, "read/cache_nr", istate->cache_nr);
+
+	trace2_region_leave_printf("index", "do_read_index", the_repository, "%s", path);
+}
+----------------
++
+This example shows that the index contained 3552 entries.
++
+----------------
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
+$ git status
+...
+$ cat ~/log.perf
+d0 | main                     | version      |     |           |           |            | 2.20.1.156.gf9916ae094.dirty
+d0 | main                     | start        |     |  0.001173 |           |            | git status
+d0 | main                     | def_repo     | r1  |           |           |            | worktree:/Users/jeffhost/work/gfw
+d0 | main                     | cmd_name     |     |           |           |            | status (status)
+d0 | main                     | region_enter | r1  |  0.001791 |           | index      | label:do_read_index .git/index
+d0 | main                     | data         | r1  |  0.002494 |  0.000703 | index      | ..read/version:2
+d0 | main                     | data         | r1  |  0.002520 |  0.000729 | index      | ..read/cache_nr:3552
+d0 | main                     | region_leave | r1  |  0.002539 |  0.000748 | index      | label:do_read_index .git/index
+...
+----------------
+
+Thread Events::
+
+	Thread messages added to a thread-proc.
++
+For example, the multithreaded preload-index code can be
+instrumented with a region around the thread pool and then
+per-thread start and exit events within the threadproc.
++
+----------------
+static void *preload_thread(void *_data)
+{
+	// start the per-thread clock and emit a message.
+	trace2_thread_start("preload_thread");
+
+	// report which chunk of the array this thread was assigned.
+	trace2_data_intmax("index", the_repository, "offset", p->offset);
+	trace2_data_intmax("index", the_repository, "count", nr);
+
+	do {
+	    ...
+	} while (--nr > 0);
+	...
+
+	// report elapsed time taken by this thread.
+	trace2_thread_exit();
+	return NULL;
+}
+
+void preload_index(struct index_state *index,
+	const struct pathspec *pathspec,
+	unsigned int refresh_flags)
+{
+	trace2_region_enter("index", "preload", the_repository);
+
+	for (i = 0; i < threads; i++) {
+	    ... /* create thread */
+	}
+
+	for (i = 0; i < threads; i++) {
+	    ... /* join thread */
+	}
+
+	trace2_region_leave("index", "preload", the_repository);
+}
+----------------
++
+In this example preload_index() was executed by the `main` thread
+and started the `preload` region.  Seven threads, named
+`th01:preload_thread` through `th07:preload_thread`, were started.
+Events from each thread are atomically appended to the shared target
+stream as they occur so they may appear in random order with respect
+other threads. Finally, the main thread waits for the threads to
+finish and leaves the region.
++
+Data events are tagged with the active thread name.  They are used
+to report the per-thread parameters.
++
+----------------
+$ export GIT_TRACE2_PERF_BRIEF=1
+$ export GIT_TRACE2_PERF=~/log.perf
+$ git status
+...
+$ cat ~/log.perf
+...
+d0 | main                     | region_enter | r1  |  0.002595 |           | index      | label:preload
+d0 | th01:preload_thread      | thread_start |     |  0.002699 |           |            |
+d0 | th02:preload_thread      | thread_start |     |  0.002721 |           |            |
+d0 | th01:preload_thread      | data         | r1  |  0.002736 |  0.000037 | index      | offset:0
+d0 | th02:preload_thread      | data         | r1  |  0.002751 |  0.000030 | index      | offset:2032
+d0 | th03:preload_thread      | thread_start |     |  0.002711 |           |            |
+d0 | th06:preload_thread      | thread_start |     |  0.002739 |           |            |
+d0 | th01:preload_thread      | data         | r1  |  0.002766 |  0.000067 | index      | count:508
+d0 | th06:preload_thread      | data         | r1  |  0.002856 |  0.000117 | index      | offset:2540
+d0 | th03:preload_thread      | data         | r1  |  0.002824 |  0.000113 | index      | offset:1016
+d0 | th04:preload_thread      | thread_start |     |  0.002710 |           |            |
+d0 | th02:preload_thread      | data         | r1  |  0.002779 |  0.000058 | index      | count:508
+d0 | th06:preload_thread      | data         | r1  |  0.002966 |  0.000227 | index      | count:508
+d0 | th07:preload_thread      | thread_start |     |  0.002741 |           |            |
+d0 | th07:preload_thread      | data         | r1  |  0.003017 |  0.000276 | index      | offset:3048
+d0 | th05:preload_thread      | thread_start |     |  0.002712 |           |            |
+d0 | th05:preload_thread      | data         | r1  |  0.003067 |  0.000355 | index      | offset:1524
+d0 | th05:preload_thread      | data         | r1  |  0.003090 |  0.000378 | index      | count:508
+d0 | th07:preload_thread      | data         | r1  |  0.003037 |  0.000296 | index      | count:504
+d0 | th03:preload_thread      | data         | r1  |  0.002971 |  0.000260 | index      | count:508
+d0 | th04:preload_thread      | data         | r1  |  0.002983 |  0.000273 | index      | offset:508
+d0 | th04:preload_thread      | data         | r1  |  0.007311 |  0.004601 | index      | count:508
+d0 | th05:preload_thread      | thread_exit  |     |  0.008781 |  0.006069 |            |
+d0 | th01:preload_thread      | thread_exit  |     |  0.009561 |  0.006862 |            |
+d0 | th03:preload_thread      | thread_exit  |     |  0.009742 |  0.007031 |            |
+d0 | th06:preload_thread      | thread_exit  |     |  0.009820 |  0.007081 |            |
+d0 | th02:preload_thread      | thread_exit  |     |  0.010274 |  0.007553 |            |
+d0 | th07:preload_thread      | thread_exit  |     |  0.010477 |  0.007736 |            |
+d0 | th04:preload_thread      | thread_exit  |     |  0.011657 |  0.008947 |            |
+d0 | main                     | region_leave | r1  |  0.011717 |  0.009122 | index      | label:preload
+...
+d0 | main                     | exit         |     |  0.029996 |           |            | code:0
+d0 | main                     | atexit       |     |  0.030027 |           |            | code:0
+----------------
++
+In this example, the preload region took 0.009122 seconds.  The 7 threads
+took between 0.006069 and 0.008947 seconds to work on their portion of
+the index.  Thread "th01" worked on 508 items at offset 0.  Thread "th02"
+worked on 508 items at offset 2032.  Thread "th04" worked on 508 itemts
+at offset 508.
++
+This example also shows that thread names are assigned in a racy manner
+as each thread starts and allocates TLS storage.
+
+== Future Work
+
+=== Relationship to the Existing Trace Api (api-trace.txt)
+
+There are a few issues to resolve before we can completely
+switch to Trace2.
+
+* Updating existing tests that assume GIT_TRACE format messages.
+
+* How to best handle custom GIT_TRACE_<key> messages?
+
+** The GIT_TRACE_<key> mechanism allows each <key> to write to a
+different file (in addition to just stderr).
+
+** Do we want to maintain that ability or simply write to the existing
+Trace2 targets (and convert <key> to a "category").
diff --git a/third_party/git/Documentation/technical/api-tree-walking.txt b/third_party/git/Documentation/technical/api-tree-walking.txt
new file mode 100644
index 0000000000..bde18622a8
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-tree-walking.txt
@@ -0,0 +1,147 @@
+tree walking API
+================
+
+The tree walking API is used to traverse and inspect trees.
+
+Data Structures
+---------------
+
+`struct name_entry`::
+
+	An entry in a tree. Each entry has a sha1 identifier, pathname, and
+	mode.
+
+`struct tree_desc`::
+
+	A semi-opaque data structure used to maintain the current state of the
+	walk.
++
+* `buffer` is a pointer into the memory representation of the tree. It always
+points at the current entry being visited.
+
+* `size` counts the number of bytes left in the `buffer`.
+
+* `entry` points to the current entry being visited.
+
+`struct traverse_info`::
+
+	A structure used to maintain the state of a traversal.
++
+* `prev` points to the traverse_info which was used to descend into the
+current tree. If this is the top-level tree `prev` will point to
+a dummy traverse_info.
+
+* `name` is the entry for the current tree (if the tree is a subtree).
+
+* `pathlen` is the length of the full path for the current tree.
+
+* `conflicts` can be used by callbacks to maintain directory-file conflicts.
+
+* `fn` is a callback called for each entry in the tree. See Traversing for more
+information.
+
+* `data` can be anything the `fn` callback would want to use.
+
+* `show_all_errors` tells whether to stop at the first error or not.
+
+Initializing
+------------
+
+`init_tree_desc`::
+
+	Initialize a `tree_desc` and decode its first entry. The buffer and
+	size parameters are assumed to be the same as the buffer and size
+	members of `struct tree`.
+
+`fill_tree_descriptor`::
+
+	Initialize a `tree_desc` and decode its first entry given the
+	object ID of a tree. Returns the `buffer` member if the latter
+	is a valid tree identifier and NULL otherwise.
+
+`setup_traverse_info`::
+
+	Initialize a `traverse_info` given the pathname of the tree to start
+	traversing from. The `base` argument is assumed to be the `path`
+	member of the `name_entry` being recursed into unless the tree is a
+	top-level tree in which case the empty string ("") is used.
+
+Walking
+-------
+
+`tree_entry`::
+
+	Visit the next entry in a tree. Returns 1 when there are more entries
+	left to visit and 0 when all entries have been visited. This is
+	commonly used in the test of a while loop.
+
+`tree_entry_len`::
+
+	Calculate the length of a tree entry's pathname. This utilizes the
+	memory structure of a tree entry to avoid the overhead of using a
+	generic strlen().
+
+`update_tree_entry`::
+
+	Walk to the next entry in a tree. This is commonly used in conjunction
+	with `tree_entry_extract` to inspect the current entry.
+
+`tree_entry_extract`::
+
+	Decode the entry currently being visited (the one pointed to by
+	`tree_desc's` `entry` member) and return the sha1 of the entry. The
+	`pathp` and `modep` arguments are set to the entry's pathname and mode
+	respectively.
+
+`get_tree_entry`::
+
+	Find an entry in a tree given a pathname and the sha1 of a tree to
+	search. Returns 0 if the entry is found and -1 otherwise. The third
+	and fourth parameters are set to the entry's sha1 and mode
+	respectively.
+
+Traversing
+----------
+
+`traverse_trees`::
+
+	Traverse `n` number of trees in parallel. The `fn` callback member of
+	`traverse_info` is called once for each tree entry.
+
+`traverse_callback_t`::
+	The arguments passed to the traverse callback are as follows:
++
+* `n` counts the number of trees being traversed.
+
+* `mask` has its nth bit set if something exists in the nth entry.
+
+* `dirmask` has its nth bit set if the nth tree's entry is a directory.
+
+* `entry` is an array of size `n` where the nth entry is from the nth tree.
+
+* `info` maintains the state of the traversal.
+
++
+Returning a negative value will terminate the traversal. Otherwise the
+return value is treated as an update mask. If the nth bit is set the nth tree
+will be updated and if the bit is not set the nth tree entry will be the
+same in the next callback invocation.
+
+`make_traverse_path`::
+
+	Generate the full pathname of a tree entry based from the root of the
+	traversal. For example, if the traversal has recursed into another
+	tree named "bar" the pathname of an entry "baz" in the "bar"
+	tree would be "bar/baz".
+
+`traverse_path_len`::
+
+	Calculate the length of a pathname returned by `make_traverse_path`.
+	This utilizes the memory structure of a tree entry to avoid the
+	overhead of using a generic strlen().
+
+Authors
+-------
+
+Written by Junio C Hamano <gitster@pobox.com> and Linus Torvalds
+<torvalds@linux-foundation.org>
diff --git a/third_party/git/Documentation/technical/api-xdiff-interface.txt b/third_party/git/Documentation/technical/api-xdiff-interface.txt
new file mode 100644
index 0000000000..6296ecad1d
--- /dev/null
+++ b/third_party/git/Documentation/technical/api-xdiff-interface.txt
@@ -0,0 +1,7 @@
+xdiff interface API
+===================
+
+Talk about our calling convention to xdiff library, including
+xdiff_emit_consume_fn.
+
+(Dscho, JC)
diff --git a/third_party/git/Documentation/technical/bitmap-format.txt b/third_party/git/Documentation/technical/bitmap-format.txt
new file mode 100644
index 0000000000..f8c18a0f7a
--- /dev/null
+++ b/third_party/git/Documentation/technical/bitmap-format.txt
@@ -0,0 +1,164 @@
+GIT bitmap v1 format
+====================
+
+	- A header appears at the beginning:
+
+		4-byte signature: {'B', 'I', 'T', 'M'}
+
+		2-byte version number (network byte order)
+			The current implementation only supports version 1
+			of the bitmap index (the same one as JGit).
+
+		2-byte flags (network byte order)
+
+			The following flags are supported:
+
+			- BITMAP_OPT_FULL_DAG (0x1) REQUIRED
+			This flag must always be present. It implies that the bitmap
+			index has been generated for a packfile with full closure
+			(i.e. where every single object in the packfile can find
+			 its parent links inside the same packfile). This is a
+			requirement for the bitmap index format, also present in JGit,
+			that greatly reduces the complexity of the implementation.
+
+			- BITMAP_OPT_HASH_CACHE (0x4)
+			If present, the end of the bitmap file contains
+			`N` 32-bit name-hash values, one per object in the
+			pack. The format and meaning of the name-hash is
+			described below.
+
+		4-byte entry count (network byte order)
+
+			The total count of entries (bitmapped commits) in this bitmap index.
+
+		20-byte checksum
+
+			The SHA1 checksum of the pack this bitmap index belongs to.
+
+	- 4 EWAH bitmaps that act as type indexes
+
+		Type indexes are serialized after the hash cache in the shape
+		of four EWAH bitmaps stored consecutively (see Appendix A for
+		the serialization format of an EWAH bitmap).
+
+		There is a bitmap for each Git object type, stored in the following
+		order:
+
+			- Commits
+			- Trees
+			- Blobs
+			- Tags
+
+		In each bitmap, the `n`th bit is set to true if the `n`th object
+		in the packfile is of that type.
+
+		The obvious consequence is that the OR of all 4 bitmaps will result
+		in a full set (all bits set), and the AND of all 4 bitmaps will
+		result in an empty bitmap (no bits set).
+
+	- N entries with compressed bitmaps, one for each indexed commit
+
+		Where `N` is the total amount of entries in this bitmap index.
+		Each entry contains the following:
+
+		- 4-byte object position (network byte order)
+			The position **in the index for the packfile** where the
+			bitmap for this commit is found.
+
+		- 1-byte XOR-offset
+			The xor offset used to compress this bitmap. For an entry
+			in position `x`, a XOR offset of `y` means that the actual
+			bitmap representing this commit is composed by XORing the
+			bitmap for this entry with the bitmap in entry `x-y` (i.e.
+			the bitmap `y` entries before this one).
+
+			Note that this compression can be recursive. In order to
+			XOR this entry with a previous one, the previous entry needs
+			to be decompressed first, and so on.
+
+			The hard-limit for this offset is 160 (an entry can only be
+			xor'ed against one of the 160 entries preceding it). This
+			number is always positive, and hence entries are always xor'ed
+			with **previous** bitmaps, not bitmaps that will come afterwards
+			in the index.
+
+		- 1-byte flags for this bitmap
+			At the moment the only available flag is `0x1`, which hints
+			that this bitmap can be re-used when rebuilding bitmap indexes
+			for the repository.
+
+		- The compressed bitmap itself, see Appendix A.
+
+== Appendix A: Serialization format for an EWAH bitmap
+
+Ewah bitmaps are serialized in the same protocol as the JAVAEWAH
+library, making them backwards compatible with the JGit
+implementation:
+
+	- 4-byte number of bits of the resulting UNCOMPRESSED bitmap
+
+	- 4-byte number of words of the COMPRESSED bitmap, when stored
+
+	- N x 8-byte words, as specified by the previous field
+
+		This is the actual content of the compressed bitmap.
+
+	- 4-byte position of the current RLW for the compressed
+		bitmap
+
+All words are stored in network byte order for their corresponding
+sizes.
+
+The compressed bitmap is stored in a form of run-length encoding, as
+follows.  It consists of a concatenation of an arbitrary number of
+chunks.  Each chunk consists of one or more 64-bit words
+
+     H  L_1  L_2  L_3 .... L_M
+
+H is called RLW (run length word).  It consists of (from lower to higher
+order bits):
+
+     - 1 bit: the repeated bit B
+
+     - 32 bits: repetition count K (unsigned)
+
+     - 31 bits: literal word count M (unsigned)
+
+The bitstream represented by the above chunk is then:
+
+     - K repetitions of B
+
+     - The bits stored in `L_1` through `L_M`.  Within a word, bits at
+       lower order come earlier in the stream than those at higher
+       order.
+
+The next word after `L_M` (if any) must again be a RLW, for the next
+chunk.  For efficient appending to the bitstream, the EWAH stores a
+pointer to the last RLW in the stream.
+
+
+== Appendix B: Optional Bitmap Sections
+
+These sections may or may not be present in the `.bitmap` file; their
+presence is indicated by the header flags section described above.
+
+Name-hash cache
+---------------
+
+If the BITMAP_OPT_HASH_CACHE flag is set, the end of the bitmap contains
+a cache of 32-bit values, one per object in the pack. The value at
+position `i` is the hash of the pathname at which the `i`th object
+(counting in index order) in the pack can be found.  This can be fed
+into the delta heuristics to compare objects with similar pathnames.
+
+The hash algorithm used is:
+
+    hash = 0;
+    while ((c = *name++))
+	    if (!isspace(c))
+		    hash = (hash >> 2) + (c << 24);
+
+Note that this hashing scheme is tied to the BITMAP_OPT_HASH_CACHE flag.
+If implementations want to choose a different hashing scheme, they are
+free to do so, but MUST allocate a new header flag (because comparing
+hashes made under two different schemes would be pointless).
diff --git a/third_party/git/Documentation/technical/commit-graph-format.txt b/third_party/git/Documentation/technical/commit-graph-format.txt
new file mode 100644
index 0000000000..a4f17441ae
--- /dev/null
+++ b/third_party/git/Documentation/technical/commit-graph-format.txt
@@ -0,0 +1,104 @@
+Git commit graph format
+=======================
+
+The Git commit graph stores a list of commit OIDs and some associated
+metadata, including:
+
+- The generation number of the commit. Commits with no parents have
+  generation number 1; commits with parents have generation number
+  one more than the maximum generation number of its parents. We
+  reserve zero as special, and can be used to mark a generation
+  number invalid or as "not computed".
+
+- The root tree OID.
+
+- The commit date.
+
+- The parents of the commit, stored using positional references within
+  the graph file.
+
+These positional references are stored as unsigned 32-bit integers
+corresponding to the array position within the list of commit OIDs. Due
+to some special constants we use to track parents, we can store at most
+(1 << 30) + (1 << 29) + (1 << 28) - 1 (around 1.8 billion) commits.
+
+== Commit graph files have the following format:
+
+In order to allow extensions that add extra data to the graph, we organize
+the body into "chunks" and provide a binary lookup table at the beginning
+of the body. The header includes certain values, such as number of chunks
+and hash type.
+
+All 4-byte numbers are in network order.
+
+HEADER:
+
+  4-byte signature:
+      The signature is: {'C', 'G', 'P', 'H'}
+
+  1-byte version number:
+      Currently, the only valid version is 1.
+
+  1-byte Hash Version (1 = SHA-1)
+      We infer the hash length (H) from this value.
+
+  1-byte number (C) of "chunks"
+
+  1-byte number (B) of base commit-graphs
+      We infer the length (H*B) of the Base Graphs chunk
+      from this value.
+
+CHUNK LOOKUP:
+
+  (C + 1) * 12 bytes listing the table of contents for the chunks:
+      First 4 bytes describe the chunk id. Value 0 is a terminating label.
+      Other 8 bytes provide the byte-offset in current file for chunk to
+      start. (Chunks are ordered contiguously in the file, so you can infer
+      the length using the next chunk position if necessary.) Each chunk
+      ID appears at most once.
+
+  The remaining data in the body is described one chunk at a time, and
+  these chunks may be given in any order. Chunks are required unless
+  otherwise specified.
+
+CHUNK DATA:
+
+  OID Fanout (ID: {'O', 'I', 'D', 'F'}) (256 * 4 bytes)
+      The ith entry, F[i], stores the number of OIDs with first
+      byte at most i. Thus F[255] stores the total
+      number of commits (N).
+
+  OID Lookup (ID: {'O', 'I', 'D', 'L'}) (N * H bytes)
+      The OIDs for all commits in the graph, sorted in ascending order.
+
+  Commit Data (ID: {'C', 'D', 'A', 'T' }) (N * (H + 16) bytes)
+    * The first H bytes are for the OID of the root tree.
+    * The next 8 bytes are for the positions of the first two parents
+      of the ith commit. Stores value 0x7000000 if no parent in that
+      position. If there are more than two parents, the second value
+      has its most-significant bit on and the other bits store an array
+      position into the Extra Edge List chunk.
+    * The next 8 bytes store the generation number of the commit and
+      the commit time in seconds since EPOCH. The generation number
+      uses the higher 30 bits of the first 4 bytes, while the commit
+      time uses the 32 bits of the second 4 bytes, along with the lowest
+      2 bits of the lowest byte, storing the 33rd and 34th bit of the
+      commit time.
+
+  Extra Edge List (ID: {'E', 'D', 'G', 'E'}) [Optional]
+      This list of 4-byte values store the second through nth parents for
+      all octopus merges. The second parent value in the commit data stores
+      an array position within this list along with the most-significant bit
+      on. Starting at that array position, iterate through this list of commit
+      positions for the parents until reaching a value with the most-significant
+      bit on. The other bits correspond to the position of the last parent.
+
+  Base Graphs List (ID: {'B', 'A', 'S', 'E'}) [Optional]
+      This list of H-byte hashes describe a set of B commit-graph files that
+      form a commit-graph chain. The graph position for the ith commit in this
+      file's OID Lookup chunk is equal to i plus the number of commits in all
+      base graphs.  If B is non-zero, this chunk must exist.
+
+TRAILER:
+
+	H-byte HASH-checksum of all of the above.
diff --git a/third_party/git/Documentation/technical/commit-graph.txt b/third_party/git/Documentation/technical/commit-graph.txt
new file mode 100644
index 0000000000..729fbcb32f
--- /dev/null
+++ b/third_party/git/Documentation/technical/commit-graph.txt
@@ -0,0 +1,350 @@
+Git Commit Graph Design Notes
+=============================
+
+Git walks the commit graph for many reasons, including:
+
+1. Listing and filtering commit history.
+2. Computing merge bases.
+
+These operations can become slow as the commit count grows. The merge
+base calculation shows up in many user-facing commands, such as 'merge-base'
+or 'status' and can take minutes to compute depending on history shape.
+
+There are two main costs here:
+
+1. Decompressing and parsing commits.
+2. Walking the entire graph to satisfy topological order constraints.
+
+The commit-graph file is a supplemental data structure that accelerates
+commit graph walks. If a user downgrades or disables the 'core.commitGraph'
+config setting, then the existing ODB is sufficient. The file is stored
+as "commit-graph" either in the .git/objects/info directory or in the info
+directory of an alternate.
+
+The commit-graph file stores the commit graph structure along with some
+extra metadata to speed up graph walks. By listing commit OIDs in lexi-
+cographic order, we can identify an integer position for each commit and
+refer to the parents of a commit using those integer positions. We use
+binary search to find initial commits and then use the integer positions
+for fast lookups during the walk.
+
+A consumer may load the following info for a commit from the graph:
+
+1. The commit OID.
+2. The list of parents, along with their integer position.
+3. The commit date.
+4. The root tree OID.
+5. The generation number (see definition below).
+
+Values 1-4 satisfy the requirements of parse_commit_gently().
+
+Define the "generation number" of a commit recursively as follows:
+
+ * A commit with no parents (a root commit) has generation number one.
+
+ * A commit with at least one parent has generation number one more than
+   the largest generation number among its parents.
+
+Equivalently, the generation number of a commit A is one more than the
+length of a longest path from A to a root commit. The recursive definition
+is easier to use for computation and observing the following property:
+
+    If A and B are commits with generation numbers N and M, respectively,
+    and N <= M, then A cannot reach B. That is, we know without searching
+    that B is not an ancestor of A because it is further from a root commit
+    than A.
+
+    Conversely, when checking if A is an ancestor of B, then we only need
+    to walk commits until all commits on the walk boundary have generation
+    number at most N. If we walk commits using a priority queue seeded by
+    generation numbers, then we always expand the boundary commit with highest
+    generation number and can easily detect the stopping condition.
+
+This property can be used to significantly reduce the time it takes to
+walk commits and determine topological relationships. Without generation
+numbers, the general heuristic is the following:
+
+    If A and B are commits with commit time X and Y, respectively, and
+    X < Y, then A _probably_ cannot reach B.
+
+This heuristic is currently used whenever the computation is allowed to
+violate topological relationships due to clock skew (such as "git log"
+with default order), but is not used when the topological order is
+required (such as merge base calculations, "git log --graph").
+
+In practice, we expect some commits to be created recently and not stored
+in the commit graph. We can treat these commits as having "infinite"
+generation number and walk until reaching commits with known generation
+number.
+
+We use the macro GENERATION_NUMBER_INFINITY = 0xFFFFFFFF to mark commits not
+in the commit-graph file. If a commit-graph file was written by a version
+of Git that did not compute generation numbers, then those commits will
+have generation number represented by the macro GENERATION_NUMBER_ZERO = 0.
+
+Since the commit-graph file is closed under reachability, we can guarantee
+the following weaker condition on all commits:
+
+    If A and B are commits with generation numbers N amd M, respectively,
+    and N < M, then A cannot reach B.
+
+Note how the strict inequality differs from the inequality when we have
+fully-computed generation numbers. Using strict inequality may result in
+walking a few extra commits, but the simplicity in dealing with commits
+with generation number *_INFINITY or *_ZERO is valuable.
+
+We use the macro GENERATION_NUMBER_MAX = 0x3FFFFFFF to for commits whose
+generation numbers are computed to be at least this value. We limit at
+this value since it is the largest value that can be stored in the
+commit-graph file using the 30 bits available to generation numbers. This
+presents another case where a commit can have generation number equal to
+that of a parent.
+
+Design Details
+--------------
+
+- The commit-graph file is stored in a file named 'commit-graph' in the
+  .git/objects/info directory. This could be stored in the info directory
+  of an alternate.
+
+- The core.commitGraph config setting must be on to consume graph files.
+
+- The file format includes parameters for the object ID hash function,
+  so a future change of hash algorithm does not require a change in format.
+
+- Commit grafts and replace objects can change the shape of the commit
+  history. The latter can also be enabled/disabled on the fly using
+  `--no-replace-objects`. This leads to difficultly storing both possible
+  interpretations of a commit id, especially when computing generation
+  numbers. The commit-graph will not be read or written when
+  replace-objects or grafts are present.
+
+- Shallow clones create grafts of commits by dropping their parents. This
+  leads the commit-graph to think those commits have generation number 1.
+  If and when those commits are made unshallow, those generation numbers
+  become invalid. Since shallow clones are intended to restrict the commit
+  history to a very small set of commits, the commit-graph feature is less
+  helpful for these clones, anyway. The commit-graph will not be read or
+  written when shallow commits are present.
+
+Commit Graphs Chains
+--------------------
+
+Typically, repos grow with near-constant velocity (commits per day). Over time,
+the number of commits added by a fetch operation is much smaller than the
+number of commits in the full history. By creating a "chain" of commit-graphs,
+we enable fast writes of new commit data without rewriting the entire commit
+history -- at least, most of the time.
+
+## File Layout
+
+A commit-graph chain uses multiple files, and we use a fixed naming convention
+to organize these files. Each commit-graph file has a name
+`$OBJDIR/info/commit-graphs/graph-{hash}.graph` where `{hash}` is the hex-
+valued hash stored in the footer of that file (which is a hash of the file's
+contents before that hash). For a chain of commit-graph files, a plain-text
+file at `$OBJDIR/info/commit-graphs/commit-graph-chain` contains the
+hashes for the files in order from "lowest" to "highest".
+
+For example, if the `commit-graph-chain` file contains the lines
+
+```
+	{hash0}
+	{hash1}
+	{hash2}
+```
+
+then the commit-graph chain looks like the following diagram:
+
+ +-----------------------+
+ |  graph-{hash2}.graph  |
+ +-----------------------+
+	  |
+ +-----------------------+
+ |                       |
+ |  graph-{hash1}.graph  |
+ |                       |
+ +-----------------------+
+	  |
+ +-----------------------+
+ |                       |
+ |                       |
+ |                       |
+ |  graph-{hash0}.graph  |
+ |                       |
+ |                       |
+ |                       |
+ +-----------------------+
+
+Let X0 be the number of commits in `graph-{hash0}.graph`, X1 be the number of
+commits in `graph-{hash1}.graph`, and X2 be the number of commits in
+`graph-{hash2}.graph`. If a commit appears in position i in `graph-{hash2}.graph`,
+then we interpret this as being the commit in position (X0 + X1 + i), and that
+will be used as its "graph position". The commits in `graph-{hash2}.graph` use these
+positions to refer to their parents, which may be in `graph-{hash1}.graph` or
+`graph-{hash0}.graph`. We can navigate to an arbitrary commit in position j by checking
+its containment in the intervals [0, X0), [X0, X0 + X1), [X0 + X1, X0 + X1 +
+X2).
+
+Each commit-graph file (except the base, `graph-{hash0}.graph`) contains data
+specifying the hashes of all files in the lower layers. In the above example,
+`graph-{hash1}.graph` contains `{hash0}` while `graph-{hash2}.graph` contains
+`{hash0}` and `{hash1}`.
+
+## Merging commit-graph files
+
+If we only added a new commit-graph file on every write, we would run into a
+linear search problem through many commit-graph files.  Instead, we use a merge
+strategy to decide when the stack should collapse some number of levels.
+
+The diagram below shows such a collapse. As a set of new commits are added, it
+is determined by the merge strategy that the files should collapse to
+`graph-{hash1}`. Thus, the new commits, the commits in `graph-{hash2}` and
+the commits in `graph-{hash1}` should be combined into a new `graph-{hash3}`
+file.
+
+			    +---------------------+
+			    |                     |
+			    |    (new commits)    |
+			    |                     |
+			    +---------------------+
+			    |                     |
+ +-----------------------+  +---------------------+
+ |  graph-{hash2} |->|                     |
+ +-----------------------+  +---------------------+
+	  |                 |                     |
+ +-----------------------+  +---------------------+
+ |                       |  |                     |
+ |  graph-{hash1} |->|                     |
+ |                       |  |                     |
+ +-----------------------+  +---------------------+
+	  |                  tmp_graphXXX
+ +-----------------------+
+ |                       |
+ |                       |
+ |                       |
+ |  graph-{hash0} |
+ |                       |
+ |                       |
+ |                       |
+ +-----------------------+
+
+During this process, the commits to write are combined, sorted and we write the
+contents to a temporary file, all while holding a `commit-graph-chain.lock`
+lock-file.  When the file is flushed, we rename it to `graph-{hash3}`
+according to the computed `{hash3}`. Finally, we write the new chain data to
+`commit-graph-chain.lock`:
+
+```
+	{hash3}
+	{hash0}
+```
+
+We then close the lock-file.
+
+## Merge Strategy
+
+When writing a set of commits that do not exist in the commit-graph stack of
+height N, we default to creating a new file at level N + 1. We then decide to
+merge with the Nth level if one of two conditions hold:
+
+  1. `--size-multiple=<X>` is specified or X = 2, and the number of commits in
+     level N is less than X times the number of commits in level N + 1.
+
+  2. `--max-commits=<C>` is specified with non-zero C and the number of commits
+     in level N + 1 is more than C commits.
+
+This decision cascades down the levels: when we merge a level we create a new
+set of commits that then compares to the next level.
+
+The first condition bounds the number of levels to be logarithmic in the total
+number of commits.  The second condition bounds the total number of commits in
+a `graph-{hashN}` file and not in the `commit-graph` file, preventing
+significant performance issues when the stack merges and another process only
+partially reads the previous stack.
+
+The merge strategy values (2 for the size multiple, 64,000 for the maximum
+number of commits) could be extracted into config settings for full
+flexibility.
+
+## Deleting graph-{hash} files
+
+After a new tip file is written, some `graph-{hash}` files may no longer
+be part of a chain. It is important to remove these files from disk, eventually.
+The main reason to delay removal is that another process could read the
+`commit-graph-chain` file before it is rewritten, but then look for the
+`graph-{hash}` files after they are deleted.
+
+To allow holding old split commit-graphs for a while after they are unreferenced,
+we update the modified times of the files when they become unreferenced. Then,
+we scan the `$OBJDIR/info/commit-graphs/` directory for `graph-{hash}`
+files whose modified times are older than a given expiry window. This window
+defaults to zero, but can be changed using command-line arguments or a config
+setting.
+
+## Chains across multiple object directories
+
+In a repo with alternates, we look for the `commit-graph-chain` file starting
+in the local object directory and then in each alternate. The first file that
+exists defines our chain. As we look for the `graph-{hash}` files for
+each `{hash}` in the chain file, we follow the same pattern for the host
+directories.
+
+This allows commit-graphs to be split across multiple forks in a fork network.
+The typical case is a large "base" repo with many smaller forks.
+
+As the base repo advances, it will likely update and merge its commit-graph
+chain more frequently than the forks. If a fork updates their commit-graph after
+the base repo, then it should "reparent" the commit-graph chain onto the new
+chain in the base repo. When reading each `graph-{hash}` file, we track
+the object directory containing it. During a write of a new commit-graph file,
+we check for any changes in the source object directory and read the
+`commit-graph-chain` file for that source and create a new file based on those
+files. During this "reparent" operation, we necessarily need to collapse all
+levels in the fork, as all of the files are invalid against the new base file.
+
+It is crucial to be careful when cleaning up "unreferenced" `graph-{hash}.graph`
+files in this scenario. It falls to the user to define the proper settings for
+their custom environment:
+
+ 1. When merging levels in the base repo, the unreferenced files may still be
+    referenced by chains from fork repos.
+
+ 2. The expiry time should be set to a length of time such that every fork has
+    time to recompute their commit-graph chain to "reparent" onto the new base
+    file(s).
+
+ 3. If the commit-graph chain is updated in the base, the fork will not have
+    access to the new chain until its chain is updated to reference those files.
+    (This may change in the future [5].)
+
+Related Links
+-------------
+[0] https://bugs.chromium.org/p/git/issues/detail?id=8
+    Chromium work item for: Serialized Commit Graph
+
+[1] https://public-inbox.org/git/20110713070517.GC18566@sigill.intra.peff.net/
+    An abandoned patch that introduced generation numbers.
+
+[2] https://public-inbox.org/git/20170908033403.q7e6dj7benasrjes@sigill.intra.peff.net/
+    Discussion about generation numbers on commits and how they interact
+    with fsck.
+
+[3] https://public-inbox.org/git/20170908034739.4op3w4f2ma5s65ku@sigill.intra.peff.net/
+    More discussion about generation numbers and not storing them inside
+    commit objects. A valuable quote:
+
+    "I think we should be moving more in the direction of keeping
+     repo-local caches for optimizations. Reachability bitmaps have been
+     a big performance win. I think we should be doing the same with our
+     properties of commits. Not just generation numbers, but making it
+     cheap to access the graph structure without zlib-inflating whole
+     commit objects (i.e., packv4 or something like the "metapacks" I
+     proposed a few years ago)."
+
+[4] https://public-inbox.org/git/20180108154822.54829-1-git@jeffhostetler.com/T/#u
+    A patch to remove the ahead-behind calculation from 'status'.
+
+[5] https://public-inbox.org/git/f27db281-abad-5043-6d71-cbb083b1c877@gmail.com/
+    A discussion of a "two-dimensional graph position" that can allow reading
+    multiple commit-graph chains at the same time.
diff --git a/third_party/git/Documentation/technical/directory-rename-detection.txt b/third_party/git/Documentation/technical/directory-rename-detection.txt
new file mode 100644
index 0000000000..844629c8c4
--- /dev/null
+++ b/third_party/git/Documentation/technical/directory-rename-detection.txt
@@ -0,0 +1,115 @@
+Directory rename detection
+==========================
+
+Rename detection logic in diffcore-rename that checks for renames of
+individual files is aggregated and analyzed in merge-recursive for cases
+where combinations of renames indicate that a full directory has been
+renamed.
+
+Scope of abilities
+------------------
+
+It is perhaps easiest to start with an example:
+
+  * When all of x/a, x/b and x/c have moved to z/a, z/b and z/c, it is
+    likely that x/d added in the meantime would also want to move to z/d by
+    taking the hint that the entire directory 'x' moved to 'z'.
+
+More interesting possibilities exist, though, such as:
+
+  * one side of history renames x -> z, and the other renames some file to
+    x/e, causing the need for the merge to do a transitive rename.
+
+  * one side of history renames x -> z, but also renames all files within x.
+    For example, x/a -> z/alpha, x/b -> z/bravo, etc.
+
+  * both 'x' and 'y' being merged into a single directory 'z', with a
+    directory rename being detected for both x->z and y->z.
+
+  * not all files in a directory being renamed to the same location;
+    i.e. perhaps most the files in 'x' are now found under 'z', but a few
+    are found under 'w'.
+
+  * a directory being renamed, which also contained a subdirectory that was
+    renamed to some entirely different location.  (And perhaps the inner
+    directory itself contained inner directories that were renamed to yet
+    other locations).
+
+  * combinations of the above; see t/t6043-merge-rename-directories.sh for
+    various interesting cases.
+
+Limitations -- applicability of directory renames
+-------------------------------------------------
+
+In order to prevent edge and corner cases resulting in either conflicts
+that cannot be represented in the index or which might be too complex for
+users to try to understand and resolve, a couple basic rules limit when
+directory rename detection applies:
+
+  1) If a given directory still exists on both sides of a merge, we do
+     not consider it to have been renamed.
+
+  2) If a subset of to-be-renamed files have a file or directory in the
+     way (or would be in the way of each other), "turn off" the directory
+     rename for those specific sub-paths and report the conflict to the
+     user.
+
+  3) If the other side of history did a directory rename to a path that
+     your side of history renamed away, then ignore that particular
+     rename from the other side of history for any implicit directory
+     renames (but warn the user).
+
+Limitations -- detailed rules and testcases
+-------------------------------------------
+
+t/t6043-merge-rename-directories.sh contains extensive tests and commentary
+which generate and explore the rules listed above.  It also lists a few
+additional rules:
+
+  a) If renames split a directory into two or more others, the directory
+     with the most renames, "wins".
+
+  b) Avoid directory-rename-detection for a path, if that path is the
+     source of a rename on either side of a merge.
+
+  c) Only apply implicit directory renames to directories if the other side
+     of history is the one doing the renaming.
+
+Limitations -- support in different commands
+--------------------------------------------
+
+Directory rename detection is supported by 'merge' and 'cherry-pick'.
+Other git commands which users might be surprised to see limited or no
+directory rename detection support in:
+
+  * diff
+
+    Folks have requested in the past that `git diff` detect directory
+    renames and somehow simplify its output.  It is not clear whether this
+    would be desirable or how the output should be simplified, so this was
+    simply not implemented.  Further, to implement this, directory rename
+    detection logic would need to move from merge-recursive to
+    diffcore-rename.
+
+  * am
+
+    git-am tries to avoid a full three way merge, instead calling
+    git-apply.  That prevents us from detecting renames at all, which may
+    defeat the directory rename detection.  There is a fallback, though; if
+    the initial git-apply fails and the user has specified the -3 option,
+    git-am will fall back to a three way merge.  However, git-am lacks the
+    necessary information to do a "real" three way merge.  Instead, it has
+    to use build_fake_ancestor() to get a merge base that is missing files
+    whose rename may have been important to detect for directory rename
+    detection to function.
+
+  * rebase
+
+    Since am-based rebases work by first generating a bunch of patches
+    (which no longer record what the original commits were and thus don't
+    have the necessary info from which we can find a real merge-base), and
+    then calling git-am, this implies that am-based rebases will not always
+    successfully detect directory renames either (see the 'am' section
+    above).  merged-based rebases (rebase -m) and cherry-pick-based rebases
+    (rebase -i) are not affected by this shortcoming, and fully support
+    directory rename detection.
diff --git a/third_party/git/Documentation/technical/hash-function-transition.txt b/third_party/git/Documentation/technical/hash-function-transition.txt
new file mode 100644
index 0000000000..2ae8fa470a
--- /dev/null
+++ b/third_party/git/Documentation/technical/hash-function-transition.txt
@@ -0,0 +1,827 @@
+Git hash function transition
+============================
+
+Objective
+---------
+Migrate Git from SHA-1 to a stronger hash function.
+
+Background
+----------
+At its core, the Git version control system is a content addressable
+filesystem. It uses the SHA-1 hash function to name content. For
+example, files, directories, and revisions are referred to by hash
+values unlike in other traditional version control systems where files
+or versions are referred to via sequential numbers. The use of a hash
+function to address its content delivers a few advantages:
+
+* Integrity checking is easy. Bit flips, for example, are easily
+  detected, as the hash of corrupted content does not match its name.
+* Lookup of objects is fast.
+
+Using a cryptographically secure hash function brings additional
+advantages:
+
+* Object names can be signed and third parties can trust the hash to
+  address the signed object and all objects it references.
+* Communication using Git protocol and out of band communication
+  methods have a short reliable string that can be used to reliably
+  address stored content.
+
+Over time some flaws in SHA-1 have been discovered by security
+researchers. On 23 February 2017 the SHAttered attack
+(https://shattered.io) demonstrated a practical SHA-1 hash collision.
+
+Git v2.13.0 and later subsequently moved to a hardened SHA-1
+implementation by default, which isn't vulnerable to the SHAttered
+attack.
+
+Thus Git has in effect already migrated to a new hash that isn't SHA-1
+and doesn't share its vulnerabilities, its new hash function just
+happens to produce exactly the same output for all known inputs,
+except two PDFs published by the SHAttered researchers, and the new
+implementation (written by those researchers) claims to detect future
+cryptanalytic collision attacks.
+
+Regardless, it's considered prudent to move past any variant of SHA-1
+to a new hash. There's no guarantee that future attacks on SHA-1 won't
+be published in the future, and those attacks may not have viable
+mitigations.
+
+If SHA-1 and its variants were to be truly broken, Git's hash function
+could not be considered cryptographically secure any more. This would
+impact the communication of hash values because we could not trust
+that a given hash value represented the known good version of content
+that the speaker intended.
+
+SHA-1 still possesses the other properties such as fast object lookup
+and safe error checking, but other hash functions are equally suitable
+that are believed to be cryptographically secure.
+
+Goals
+-----
+1. The transition to SHA-256 can be done one local repository at a time.
+   a. Requiring no action by any other party.
+   b. A SHA-256 repository can communicate with SHA-1 Git servers
+      (push/fetch).
+   c. Users can use SHA-1 and SHA-256 identifiers for objects
+      interchangeably (see "Object names on the command line", below).
+   d. New signed objects make use of a stronger hash function than
+      SHA-1 for their security guarantees.
+2. Allow a complete transition away from SHA-1.
+   a. Local metadata for SHA-1 compatibility can be removed from a
+      repository if compatibility with SHA-1 is no longer needed.
+3. Maintainability throughout the process.
+   a. The object format is kept simple and consistent.
+   b. Creation of a generalized repository conversion tool.
+
+Non-Goals
+---------
+1. Add SHA-256 support to Git protocol. This is valuable and the
+   logical next step but it is out of scope for this initial design.
+2. Transparently improving the security of existing SHA-1 signed
+   objects.
+3. Intermixing objects using multiple hash functions in a single
+   repository.
+4. Taking the opportunity to fix other bugs in Git's formats and
+   protocols.
+5. Shallow clones and fetches into a SHA-256 repository. (This will
+   change when we add SHA-256 support to Git protocol.)
+6. Skip fetching some submodules of a project into a SHA-256
+   repository. (This also depends on SHA-256 support in Git
+   protocol.)
+
+Overview
+--------
+We introduce a new repository format extension. Repositories with this
+extension enabled use SHA-256 instead of SHA-1 to name their objects.
+This affects both object names and object content --- both the names
+of objects and all references to other objects within an object are
+switched to the new hash function.
+
+SHA-256 repositories cannot be read by older versions of Git.
+
+Alongside the packfile, a SHA-256 repository stores a bidirectional
+mapping between SHA-256 and SHA-1 object names. The mapping is generated
+locally and can be verified using "git fsck". Object lookups use this
+mapping to allow naming objects using either their SHA-1 and SHA-256 names
+interchangeably.
+
+"git cat-file" and "git hash-object" gain options to display an object
+in its sha1 form and write an object given its sha1 form. This
+requires all objects referenced by that object to be present in the
+object database so that they can be named using the appropriate name
+(using the bidirectional hash mapping).
+
+Fetches from a SHA-1 based server convert the fetched objects into
+SHA-256 form and record the mapping in the bidirectional mapping table
+(see below for details). Pushes to a SHA-1 based server convert the
+objects being pushed into sha1 form so the server does not have to be
+aware of the hash function the client is using.
+
+Detailed Design
+---------------
+Repository format extension
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+A SHA-256 repository uses repository format version `1` (see
+Documentation/technical/repository-version.txt) with extensions
+`objectFormat` and `compatObjectFormat`:
+
+	[core]
+		repositoryFormatVersion = 1
+	[extensions]
+		objectFormat = sha256
+		compatObjectFormat = sha1
+
+The combination of setting `core.repositoryFormatVersion=1` and
+populating `extensions.*` ensures that all versions of Git later than
+`v0.99.9l` will die instead of trying to operate on the SHA-256
+repository, instead producing an error message.
+
+	# Between v0.99.9l and v2.7.0
+	$ git status
+	fatal: Expected git repo version <= 0, found 1
+	# After v2.7.0
+	$ git status
+	fatal: unknown repository extensions found:
+		objectformat
+		compatobjectformat
+
+See the "Transition plan" section below for more details on these
+repository extensions.
+
+Object names
+~~~~~~~~~~~~
+Objects can be named by their 40 hexadecimal digit sha1-name or 64
+hexadecimal digit sha256-name, plus names derived from those (see
+gitrevisions(7)).
+
+The sha1-name of an object is the SHA-1 of the concatenation of its
+type, length, a nul byte, and the object's sha1-content. This is the
+traditional <sha1> used in Git to name objects.
+
+The sha256-name of an object is the SHA-256 of the concatenation of its
+type, length, a nul byte, and the object's sha256-content.
+
+Object format
+~~~~~~~~~~~~~
+The content as a byte sequence of a tag, commit, or tree object named
+by sha1 and sha256 differ because an object named by sha256-name refers to
+other objects by their sha256-names and an object named by sha1-name
+refers to other objects by their sha1-names.
+
+The sha256-content of an object is the same as its sha1-content, except
+that objects referenced by the object are named using their sha256-names
+instead of sha1-names. Because a blob object does not refer to any
+other object, its sha1-content and sha256-content are the same.
+
+The format allows round-trip conversion between sha256-content and
+sha1-content.
+
+Object storage
+~~~~~~~~~~~~~~
+Loose objects use zlib compression and packed objects use the packed
+format described in Documentation/technical/pack-format.txt, just like
+today. The content that is compressed and stored uses sha256-content
+instead of sha1-content.
+
+Pack index
+~~~~~~~~~~
+Pack index (.idx) files use a new v3 format that supports multiple
+hash functions. They have the following format (all integers are in
+network byte order):
+
+- A header appears at the beginning and consists of the following:
+  - The 4-byte pack index signature: '\377t0c'
+  - 4-byte version number: 3
+  - 4-byte length of the header section, including the signature and
+    version number
+  - 4-byte number of objects contained in the pack
+  - 4-byte number of object formats in this pack index: 2
+  - For each object format:
+    - 4-byte format identifier (e.g., 'sha1' for SHA-1)
+    - 4-byte length in bytes of shortened object names. This is the
+      shortest possible length needed to make names in the shortened
+      object name table unambiguous.
+    - 4-byte integer, recording where tables relating to this format
+      are stored in this index file, as an offset from the beginning.
+  - 4-byte offset to the trailer from the beginning of this file.
+  - Zero or more additional key/value pairs (4-byte key, 4-byte
+    value). Only one key is supported: 'PSRC'. See the "Loose objects
+    and unreachable objects" section for supported values and how this
+    is used.  All other keys are reserved. Readers must ignore
+    unrecognized keys.
+- Zero or more NUL bytes. This can optionally be used to improve the
+  alignment of the full object name table below.
+- Tables for the first object format:
+  - A sorted table of shortened object names.  These are prefixes of
+    the names of all objects in this pack file, packed together
+    without offset values to reduce the cache footprint of the binary
+    search for a specific object name.
+
+  - A table of full object names in pack order. This allows resolving
+    a reference to "the nth object in the pack file" (from a
+    reachability bitmap or from the next table of another object
+    format) to its object name.
+
+  - A table of 4-byte values mapping object name order to pack order.
+    For an object in the table of sorted shortened object names, the
+    value at the corresponding index in this table is the index in the
+    previous table for that same object.
+
+    This can be used to look up the object in reachability bitmaps or
+    to look up its name in another object format.
+
+  - A table of 4-byte CRC32 values of the packed object data, in the
+    order that the objects appear in the pack file. This is to allow
+    compressed data to be copied directly from pack to pack during
+    repacking without undetected data corruption.
+
+  - A table of 4-byte offset values. For an object in the table of
+    sorted shortened object names, the value at the corresponding
+    index in this table indicates where that object can be found in
+    the pack file. These are usually 31-bit pack file offsets, but
+    large offsets are encoded as an index into the next table with the
+    most significant bit set.
+
+  - A table of 8-byte offset entries (empty for pack files less than
+    2 GiB). Pack files are organized with heavily used objects toward
+    the front, so most object references should not need to refer to
+    this table.
+- Zero or more NUL bytes.
+- Tables for the second object format, with the same layout as above,
+  up to and not including the table of CRC32 values.
+- Zero or more NUL bytes.
+- The trailer consists of the following:
+  - A copy of the 20-byte SHA-256 checksum at the end of the
+    corresponding packfile.
+
+  - 20-byte SHA-256 checksum of all of the above.
+
+Loose object index
+~~~~~~~~~~~~~~~~~~
+A new file $GIT_OBJECT_DIR/loose-object-idx contains information about
+all loose objects. Its format is
+
+  # loose-object-idx
+  (sha256-name SP sha1-name LF)*
+
+where the object names are in hexadecimal format. The file is not
+sorted.
+
+The loose object index is protected against concurrent writes by a
+lock file $GIT_OBJECT_DIR/loose-object-idx.lock. To add a new loose
+object:
+
+1. Write the loose object to a temporary file, like today.
+2. Open loose-object-idx.lock with O_CREAT | O_EXCL to acquire the lock.
+3. Rename the loose object into place.
+4. Open loose-object-idx with O_APPEND and write the new object
+5. Unlink loose-object-idx.lock to release the lock.
+
+To remove entries (e.g. in "git pack-refs" or "git-prune"):
+
+1. Open loose-object-idx.lock with O_CREAT | O_EXCL to acquire the
+   lock.
+2. Write the new content to loose-object-idx.lock.
+3. Unlink any loose objects being removed.
+4. Rename to replace loose-object-idx, releasing the lock.
+
+Translation table
+~~~~~~~~~~~~~~~~~
+The index files support a bidirectional mapping between sha1-names
+and sha256-names. The lookup proceeds similarly to ordinary object
+lookups. For example, to convert a sha1-name to a sha256-name:
+
+ 1. Look for the object in idx files. If a match is present in the
+    idx's sorted list of truncated sha1-names, then:
+    a. Read the corresponding entry in the sha1-name order to pack
+       name order mapping.
+    b. Read the corresponding entry in the full sha1-name table to
+       verify we found the right object. If it is, then
+    c. Read the corresponding entry in the full sha256-name table.
+       That is the object's sha256-name.
+ 2. Check for a loose object. Read lines from loose-object-idx until
+    we find a match.
+
+Step (1) takes the same amount of time as an ordinary object lookup:
+O(number of packs * log(objects per pack)). Step (2) takes O(number of
+loose objects) time. To maintain good performance it will be necessary
+to keep the number of loose objects low. See the "Loose objects and
+unreachable objects" section below for more details.
+
+Since all operations that make new objects (e.g., "git commit") add
+the new objects to the corresponding index, this mapping is possible
+for all objects in the object store.
+
+Reading an object's sha1-content
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The sha1-content of an object can be read by converting all sha256-names
+its sha256-content references to sha1-names using the translation table.
+
+Fetch
+~~~~~
+Fetching from a SHA-1 based server requires translating between SHA-1
+and SHA-256 based representations on the fly.
+
+SHA-1s named in the ref advertisement that are present on the client
+can be translated to SHA-256 and looked up as local objects using the
+translation table.
+
+Negotiation proceeds as today. Any "have"s generated locally are
+converted to SHA-1 before being sent to the server, and SHA-1s
+mentioned by the server are converted to SHA-256 when looking them up
+locally.
+
+After negotiation, the server sends a packfile containing the
+requested objects. We convert the packfile to SHA-256 format using
+the following steps:
+
+1. index-pack: inflate each object in the packfile and compute its
+   SHA-1. Objects can contain deltas in OBJ_REF_DELTA format against
+   objects the client has locally. These objects can be looked up
+   using the translation table and their sha1-content read as
+   described above to resolve the deltas.
+2. topological sort: starting at the "want"s from the negotiation
+   phase, walk through objects in the pack and emit a list of them,
+   excluding blobs, in reverse topologically sorted order, with each
+   object coming later in the list than all objects it references.
+   (This list only contains objects reachable from the "wants". If the
+   pack from the server contained additional extraneous objects, then
+   they will be discarded.)
+3. convert to sha256: open a new (sha256) packfile. Read the topologically
+   sorted list just generated. For each object, inflate its
+   sha1-content, convert to sha256-content, and write it to the sha256
+   pack. Record the new sha1<->sha256 mapping entry for use in the idx.
+4. sort: reorder entries in the new pack to match the order of objects
+   in the pack the server generated and include blobs. Write a sha256 idx
+   file
+5. clean up: remove the SHA-1 based pack file, index, and
+   topologically sorted list obtained from the server in steps 1
+   and 2.
+
+Step 3 requires every object referenced by the new object to be in the
+translation table. This is why the topological sort step is necessary.
+
+As an optimization, step 1 could write a file describing what non-blob
+objects each object it has inflated from the packfile references. This
+makes the topological sort in step 2 possible without inflating the
+objects in the packfile for a second time. The objects need to be
+inflated again in step 3, for a total of two inflations.
+
+Step 4 is probably necessary for good read-time performance. "git
+pack-objects" on the server optimizes the pack file for good data
+locality (see Documentation/technical/pack-heuristics.txt).
+
+Details of this process are likely to change. It will take some
+experimenting to get this to perform well.
+
+Push
+~~~~
+Push is simpler than fetch because the objects referenced by the
+pushed objects are already in the translation table. The sha1-content
+of each object being pushed can be read as described in the "Reading
+an object's sha1-content" section to generate the pack written by git
+send-pack.
+
+Signed Commits
+~~~~~~~~~~~~~~
+We add a new field "gpgsig-sha256" to the commit object format to allow
+signing commits without relying on SHA-1. It is similar to the
+existing "gpgsig" field. Its signed payload is the sha256-content of the
+commit object with any "gpgsig" and "gpgsig-sha256" fields removed.
+
+This means commits can be signed
+1. using SHA-1 only, as in existing signed commit objects
+2. using both SHA-1 and SHA-256, by using both gpgsig-sha256 and gpgsig
+   fields.
+3. using only SHA-256, by only using the gpgsig-sha256 field.
+
+Old versions of "git verify-commit" can verify the gpgsig signature in
+cases (1) and (2) without modifications and view case (3) as an
+ordinary unsigned commit.
+
+Signed Tags
+~~~~~~~~~~~
+We add a new field "gpgsig-sha256" to the tag object format to allow
+signing tags without relying on SHA-1. Its signed payload is the
+sha256-content of the tag with its gpgsig-sha256 field and "-----BEGIN PGP
+SIGNATURE-----" delimited in-body signature removed.
+
+This means tags can be signed
+1. using SHA-1 only, as in existing signed tag objects
+2. using both SHA-1 and SHA-256, by using gpgsig-sha256 and an in-body
+   signature.
+3. using only SHA-256, by only using the gpgsig-sha256 field.
+
+Mergetag embedding
+~~~~~~~~~~~~~~~~~~
+The mergetag field in the sha1-content of a commit contains the
+sha1-content of a tag that was merged by that commit.
+
+The mergetag field in the sha256-content of the same commit contains the
+sha256-content of the same tag.
+
+Submodules
+~~~~~~~~~~
+To convert recorded submodule pointers, you need to have the converted
+submodule repository in place. The translation table of the submodule
+can be used to look up the new hash.
+
+Loose objects and unreachable objects
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Fast lookups in the loose-object-idx require that the number of loose
+objects not grow too high.
+
+"git gc --auto" currently waits for there to be 6700 loose objects
+present before consolidating them into a packfile. We will need to
+measure to find a more appropriate threshold for it to use.
+
+"git gc --auto" currently waits for there to be 50 packs present
+before combining packfiles. Packing loose objects more aggressively
+may cause the number of pack files to grow too quickly. This can be
+mitigated by using a strategy similar to Martin Fick's exponential
+rolling garbage collection script:
+https://gerrit-review.googlesource.com/c/gerrit/+/35215
+
+"git gc" currently expels any unreachable objects it encounters in
+pack files to loose objects in an attempt to prevent a race when
+pruning them (in case another process is simultaneously writing a new
+object that refers to the about-to-be-deleted object). This leads to
+an explosion in the number of loose objects present and disk space
+usage due to the objects in delta form being replaced with independent
+loose objects.  Worse, the race is still present for loose objects.
+
+Instead, "git gc" will need to move unreachable objects to a new
+packfile marked as UNREACHABLE_GARBAGE (using the PSRC field; see
+below). To avoid the race when writing new objects referring to an
+about-to-be-deleted object, code paths that write new objects will
+need to copy any objects from UNREACHABLE_GARBAGE packs that they
+refer to new, non-UNREACHABLE_GARBAGE packs (or loose objects).
+UNREACHABLE_GARBAGE are then safe to delete if their creation time (as
+indicated by the file's mtime) is long enough ago.
+
+To avoid a proliferation of UNREACHABLE_GARBAGE packs, they can be
+combined under certain circumstances. If "gc.garbageTtl" is set to
+greater than one day, then packs created within a single calendar day,
+UTC, can be coalesced together. The resulting packfile would have an
+mtime before midnight on that day, so this makes the effective maximum
+ttl the garbageTtl + 1 day. If "gc.garbageTtl" is less than one day,
+then we divide the calendar day into intervals one-third of that ttl
+in duration. Packs created within the same interval can be coalesced
+together. The resulting packfile would have an mtime before the end of
+the interval, so this makes the effective maximum ttl equal to the
+garbageTtl * 4/3.
+
+This rule comes from Thirumala Reddy Mutchukota's JGit change
+https://git.eclipse.org/r/90465.
+
+The UNREACHABLE_GARBAGE setting goes in the PSRC field of the pack
+index. More generally, that field indicates where a pack came from:
+
+ - 1 (PACK_SOURCE_RECEIVE) for a pack received over the network
+ - 2 (PACK_SOURCE_AUTO) for a pack created by a lightweight
+   "gc --auto" operation
+ - 3 (PACK_SOURCE_GC) for a pack created by a full gc
+ - 4 (PACK_SOURCE_UNREACHABLE_GARBAGE) for potential garbage
+   discovered by gc
+ - 5 (PACK_SOURCE_INSERT) for locally created objects that were
+   written directly to a pack file, e.g. from "git add ."
+
+This information can be useful for debugging and for "gc --auto" to
+make appropriate choices about which packs to coalesce.
+
+Caveats
+-------
+Invalid objects
+~~~~~~~~~~~~~~~
+The conversion from sha1-content to sha256-content retains any
+brokenness in the original object (e.g., tree entry modes encoded with
+leading 0, tree objects whose paths are not sorted correctly, and
+commit objects without an author or committer). This is a deliberate
+feature of the design to allow the conversion to round-trip.
+
+More profoundly broken objects (e.g., a commit with a truncated "tree"
+header line) cannot be converted but were not usable by current Git
+anyway.
+
+Shallow clone and submodules
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Because it requires all referenced objects to be available in the
+locally generated translation table, this design does not support
+shallow clone or unfetched submodules. Protocol improvements might
+allow lifting this restriction.
+
+Alternates
+~~~~~~~~~~
+For the same reason, a sha256 repository cannot borrow objects from a
+sha1 repository using objects/info/alternates or
+$GIT_ALTERNATE_OBJECT_REPOSITORIES.
+
+git notes
+~~~~~~~~~
+The "git notes" tool annotates objects using their sha1-name as key.
+This design does not describe a way to migrate notes trees to use
+sha256-names. That migration is expected to happen separately (for
+example using a file at the root of the notes tree to describe which
+hash it uses).
+
+Server-side cost
+~~~~~~~~~~~~~~~~
+Until Git protocol gains SHA-256 support, using SHA-256 based storage
+on public-facing Git servers is strongly discouraged. Once Git
+protocol gains SHA-256 support, SHA-256 based servers are likely not
+to support SHA-1 compatibility, to avoid what may be a very expensive
+hash reencode during clone and to encourage peers to modernize.
+
+The design described here allows fetches by SHA-1 clients of a
+personal SHA-256 repository because it's not much more difficult than
+allowing pushes from that repository. This support needs to be guarded
+by a configuration option --- servers like git.kernel.org that serve a
+large number of clients would not be expected to bear that cost.
+
+Meaning of signatures
+~~~~~~~~~~~~~~~~~~~~~
+The signed payload for signed commits and tags does not explicitly
+name the hash used to identify objects. If some day Git adopts a new
+hash function with the same length as the current SHA-1 (40
+hexadecimal digit) or SHA-256 (64 hexadecimal digit) objects then the
+intent behind the PGP signed payload in an object signature is
+unclear:
+
+	object e7e07d5a4fcc2a203d9873968ad3e6bd4d7419d7
+	type commit
+	tag v2.12.0
+	tagger Junio C Hamano <gitster@pobox.com> 1487962205 -0800
+
+	Git 2.12
+
+Does this mean Git v2.12.0 is the commit with sha1-name
+e7e07d5a4fcc2a203d9873968ad3e6bd4d7419d7 or the commit with
+new-40-digit-hash-name e7e07d5a4fcc2a203d9873968ad3e6bd4d7419d7?
+
+Fortunately SHA-256 and SHA-1 have different lengths. If Git starts
+using another hash with the same length to name objects, then it will
+need to change the format of signed payloads using that hash to
+address this issue.
+
+Object names on the command line
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+To support the transition (see Transition plan below), this design
+supports four different modes of operation:
+
+ 1. ("dark launch") Treat object names input by the user as SHA-1 and
+    convert any object names written to output to SHA-1, but store
+    objects using SHA-256.  This allows users to test the code with no
+    visible behavior change except for performance.  This allows
+    allows running even tests that assume the SHA-1 hash function, to
+    sanity-check the behavior of the new mode.
+
+ 2. ("early transition") Allow both SHA-1 and SHA-256 object names in
+    input. Any object names written to output use SHA-1. This allows
+    users to continue to make use of SHA-1 to communicate with peers
+    (e.g. by email) that have not migrated yet and prepares for mode 3.
+
+ 3. ("late transition") Allow both SHA-1 and SHA-256 object names in
+    input. Any object names written to output use SHA-256. In this
+    mode, users are using a more secure object naming method by
+    default.  The disruption is minimal as long as most of their peers
+    are in mode 2 or mode 3.
+
+ 4. ("post-transition") Treat object names input by the user as
+    SHA-256 and write output using SHA-256. This is safer than mode 3
+    because there is less risk that input is incorrectly interpreted
+    using the wrong hash function.
+
+The mode is specified in configuration.
+
+The user can also explicitly specify which format to use for a
+particular revision specifier and for output, overriding the mode. For
+example:
+
+git --output-format=sha1 log abac87a^{sha1}..f787cac^{sha256}
+
+Choice of Hash
+--------------
+In early 2005, around the time that Git was written,  Xiaoyun Wang,
+Yiqun Lisa Yin, and Hongbo Yu announced an attack finding SHA-1
+collisions in 2^69 operations. In August they published details.
+Luckily, no practical demonstrations of a collision in full SHA-1 were
+published until 10 years later, in 2017.
+
+Git v2.13.0 and later subsequently moved to a hardened SHA-1
+implementation by default that mitigates the SHAttered attack, but
+SHA-1 is still believed to be weak.
+
+The hash to replace this hardened SHA-1 should be stronger than SHA-1
+was: we would like it to be trustworthy and useful in practice for at
+least 10 years.
+
+Some other relevant properties:
+
+1. A 256-bit hash (long enough to match common security practice; not
+   excessively long to hurt performance and disk usage).
+
+2. High quality implementations should be widely available (e.g., in
+   OpenSSL and Apple CommonCrypto).
+
+3. The hash function's properties should match Git's needs (e.g. Git
+   requires collision and 2nd preimage resistance and does not require
+   length extension resistance).
+
+4. As a tiebreaker, the hash should be fast to compute (fortunately
+   many contenders are faster than SHA-1).
+
+We choose SHA-256.
+
+Transition plan
+---------------
+Some initial steps can be implemented independently of one another:
+- adding a hash function API (vtable)
+- teaching fsck to tolerate the gpgsig-sha256 field
+- excluding gpgsig-* from the fields copied by "git commit --amend"
+- annotating tests that depend on SHA-1 values with a SHA1 test
+  prerequisite
+- using "struct object_id", GIT_MAX_RAWSZ, and GIT_MAX_HEXSZ
+  consistently instead of "unsigned char *" and the hardcoded
+  constants 20 and 40.
+- introducing index v3
+- adding support for the PSRC field and safer object pruning
+
+
+The first user-visible change is the introduction of the objectFormat
+extension (without compatObjectFormat). This requires:
+- implementing the loose-object-idx
+- teaching fsck about this mode of operation
+- using the hash function API (vtable) when computing object names
+- signing objects and verifying signatures
+- rejecting attempts to fetch from or push to an incompatible
+  repository
+
+Next comes introduction of compatObjectFormat:
+- translating object names between object formats
+- translating object content between object formats
+- generating and verifying signatures in the compat format
+- adding appropriate index entries when adding a new object to the
+  object store
+- --output-format option
+- ^{sha1} and ^{sha256} revision notation
+- configuration to specify default input and output format (see
+  "Object names on the command line" above)
+
+The next step is supporting fetches and pushes to SHA-1 repositories:
+- allow pushes to a repository using the compat format
+- generate a topologically sorted list of the SHA-1 names of fetched
+  objects
+- convert the fetched packfile to sha256 format and generate an idx
+  file
+- re-sort to match the order of objects in the fetched packfile
+
+The infrastructure supporting fetch also allows converting an existing
+repository. In converted repositories and new clones, end users can
+gain support for the new hash function without any visible change in
+behavior (see "dark launch" in the "Object names on the command line"
+section). In particular this allows users to verify SHA-256 signatures
+on objects in the repository, and it should ensure the transition code
+is stable in production in preparation for using it more widely.
+
+Over time projects would encourage their users to adopt the "early
+transition" and then "late transition" modes to take advantage of the
+new, more futureproof SHA-256 object names.
+
+When objectFormat and compatObjectFormat are both set, commands
+generating signatures would generate both SHA-1 and SHA-256 signatures
+by default to support both new and old users.
+
+In projects using SHA-256 heavily, users could be encouraged to adopt
+the "post-transition" mode to avoid accidentally making implicit use
+of SHA-1 object names.
+
+Once a critical mass of users have upgraded to a version of Git that
+can verify SHA-256 signatures and have converted their existing
+repositories to support verifying them, we can add support for a
+setting to generate only SHA-256 signatures. This is expected to be at
+least a year later.
+
+That is also a good moment to advertise the ability to convert
+repositories to use SHA-256 only, stripping out all SHA-1 related
+metadata. This improves performance by eliminating translation
+overhead and security by avoiding the possibility of accidentally
+relying on the safety of SHA-1.
+
+Updating Git's protocols to allow a server to specify which hash
+functions it supports is also an important part of this transition. It
+is not discussed in detail in this document but this transition plan
+assumes it happens. :)
+
+Alternatives considered
+-----------------------
+Upgrading everyone working on a particular project on a flag day
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Projects like the Linux kernel are large and complex enough that
+flipping the switch for all projects based on the repository at once
+is infeasible.
+
+Not only would all developers and server operators supporting
+developers have to switch on the same flag day, but supporting tooling
+(continuous integration, code review, bug trackers, etc) would have to
+be adapted as well. This also makes it difficult to get early feedback
+from some project participants testing before it is time for mass
+adoption.
+
+Using hash functions in parallel
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+(e.g. https://public-inbox.org/git/22708.8913.864049.452252@chiark.greenend.org.uk/ )
+Objects newly created would be addressed by the new hash, but inside
+such an object (e.g. commit) it is still possible to address objects
+using the old hash function.
+* You cannot trust its history (needed for bisectability) in the
+  future without further work
+* Maintenance burden as the number of supported hash functions grows
+  (they will never go away, so they accumulate). In this proposal, by
+  comparison, converted objects lose all references to SHA-1.
+
+Signed objects with multiple hashes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Instead of introducing the gpgsig-sha256 field in commit and tag objects
+for sha256-content based signatures, an earlier version of this design
+added "hash sha256 <sha256-name>" fields to strengthen the existing
+sha1-content based signatures.
+
+In other words, a single signature was used to attest to the object
+content using both hash functions. This had some advantages:
+* Using one signature instead of two speeds up the signing process.
+* Having one signed payload with both hashes allows the signer to
+  attest to the sha1-name and sha256-name referring to the same object.
+* All users consume the same signature. Broken signatures are likely
+  to be detected quickly using current versions of git.
+
+However, it also came with disadvantages:
+* Verifying a signed object requires access to the sha1-names of all
+  objects it references, even after the transition is complete and
+  translation table is no longer needed for anything else. To support
+  this, the design added fields such as "hash sha1 tree <sha1-name>"
+  and "hash sha1 parent <sha1-name>" to the sha256-content of a signed
+  commit, complicating the conversion process.
+* Allowing signed objects without a sha1 (for after the transition is
+  complete) complicated the design further, requiring a "nohash sha1"
+  field to suppress including "hash sha1" fields in the sha256-content
+  and signed payload.
+
+Lazily populated translation table
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Some of the work of building the translation table could be deferred to
+push time, but that would significantly complicate and slow down pushes.
+Calculating the sha1-name at object creation time at the same time it is
+being streamed to disk and having its sha256-name calculated should be
+an acceptable cost.
+
+Document History
+----------------
+
+2017-03-03
+bmwill@google.com, jonathantanmy@google.com, jrnieder@gmail.com,
+sbeller@google.com
+
+Initial version sent to
+http://public-inbox.org/git/20170304011251.GA26789@aiede.mtv.corp.google.com
+
+2017-03-03 jrnieder@gmail.com
+Incorporated suggestions from jonathantanmy and sbeller:
+* describe purpose of signed objects with each hash type
+* redefine signed object verification using object content under the
+  first hash function
+
+2017-03-06 jrnieder@gmail.com
+* Use SHA3-256 instead of SHA2 (thanks, Linus and brian m. carlson).[1][2]
+* Make sha3-based signatures a separate field, avoiding the need for
+  "hash" and "nohash" fields (thanks to peff[3]).
+* Add a sorting phase to fetch (thanks to Junio for noticing the need
+  for this).
+* Omit blobs from the topological sort during fetch (thanks to peff).
+* Discuss alternates, git notes, and git servers in the caveats
+  section (thanks to Junio Hamano, brian m. carlson[4], and Shawn
+  Pearce).
+* Clarify language throughout (thanks to various commenters,
+  especially Junio).
+
+2017-09-27 jrnieder@gmail.com, sbeller@google.com
+* use placeholder NewHash instead of SHA3-256
+* describe criteria for picking a hash function.
+* include a transition plan (thanks especially to Brandon Williams
+  for fleshing these ideas out)
+* define the translation table (thanks, Shawn Pearce[5], Jonathan
+  Tan, and Masaya Suzuki)
+* avoid loose object overhead by packing more aggressively in
+  "git gc --auto"
+
+Later history:
+
+ See the history of this file in git.git for the history of subsequent
+ edits. This document history is no longer being maintained as it
+ would now be superfluous to the commit log
+
+[1] http://public-inbox.org/git/CA+55aFzJtejiCjV0e43+9oR3QuJK2PiFiLQemytoLpyJWe6P9w@mail.gmail.com/
+[2] http://public-inbox.org/git/CA+55aFz+gkAsDZ24zmePQuEs1XPS9BP_s8O7Q4wQ7LV7X5-oDA@mail.gmail.com/
+[3] http://public-inbox.org/git/20170306084353.nrns455dvkdsfgo5@sigill.intra.peff.net/
+[4] http://public-inbox.org/git/20170304224936.rqqtkdvfjgyezsht@genre.crustytoothpaste.net
+[5] https://public-inbox.org/git/CAJo=hJtoX9=AyLHHpUJS7fueV9ciZ_MNpnEPHUz8Whui6g9F0A@mail.gmail.com/
diff --git a/third_party/git/Documentation/technical/http-protocol.txt b/third_party/git/Documentation/technical/http-protocol.txt
new file mode 100644
index 0000000000..9c5b6f0fac
--- /dev/null
+++ b/third_party/git/Documentation/technical/http-protocol.txt
@@ -0,0 +1,518 @@
+HTTP transfer protocols
+=======================
+
+Git supports two HTTP based transfer protocols.  A "dumb" protocol
+which requires only a standard HTTP server on the server end of the
+connection, and a "smart" protocol which requires a Git aware CGI
+(or server module).  This document describes both protocols.
+
+As a design feature smart clients can automatically upgrade "dumb"
+protocol URLs to smart URLs.  This permits all users to have the
+same published URL, and the peers automatically select the most
+efficient transport available to them.
+
+
+URL Format
+----------
+
+URLs for Git repositories accessed by HTTP use the standard HTTP
+URL syntax documented by RFC 1738, so they are of the form:
+
+  http://<host>:<port>/<path>?<searchpart>
+
+Within this documentation the placeholder `$GIT_URL` will stand for
+the http:// repository URL entered by the end-user.
+
+Servers SHOULD handle all requests to locations matching `$GIT_URL`, as
+both the "smart" and "dumb" HTTP protocols used by Git operate
+by appending additional path components onto the end of the user
+supplied `$GIT_URL` string.
+
+An example of a dumb client requesting for a loose object:
+
+  $GIT_URL:     http://example.com:8080/git/repo.git
+  URL request:  http://example.com:8080/git/repo.git/objects/d0/49f6c27a2244e12041955e262a404c7faba355
+
+An example of a smart request to a catch-all gateway:
+
+  $GIT_URL:     http://example.com/daemon.cgi?svc=git&q=
+  URL request:  http://example.com/daemon.cgi?svc=git&q=/info/refs&service=git-receive-pack
+
+An example of a request to a submodule:
+
+  $GIT_URL:     http://example.com/git/repo.git/path/submodule.git
+  URL request:  http://example.com/git/repo.git/path/submodule.git/info/refs
+
+Clients MUST strip a trailing `/`, if present, from the user supplied
+`$GIT_URL` string to prevent empty path tokens (`//`) from appearing
+in any URL sent to a server.  Compatible clients MUST expand
+`$GIT_URL/info/refs` as `foo/info/refs` and not `foo//info/refs`.
+
+
+Authentication
+--------------
+
+Standard HTTP authentication is used if authentication is required
+to access a repository, and MAY be configured and enforced by the
+HTTP server software.
+
+Because Git repositories are accessed by standard path components
+server administrators MAY use directory based permissions within
+their HTTP server to control repository access.
+
+Clients SHOULD support Basic authentication as described by RFC 2617.
+Servers SHOULD support Basic authentication by relying upon the
+HTTP server placed in front of the Git server software.
+
+Servers SHOULD NOT require HTTP cookies for the purposes of
+authentication or access control.
+
+Clients and servers MAY support other common forms of HTTP based
+authentication, such as Digest authentication.
+
+
+SSL
+---
+
+Clients and servers SHOULD support SSL, particularly to protect
+passwords when relying on Basic HTTP authentication.
+
+
+Session State
+-------------
+
+The Git over HTTP protocol (much like HTTP itself) is stateless
+from the perspective of the HTTP server side.  All state MUST be
+retained and managed by the client process.  This permits simple
+round-robin load-balancing on the server side, without needing to
+worry about state management.
+
+Clients MUST NOT require state management on the server side in
+order to function correctly.
+
+Servers MUST NOT require HTTP cookies in order to function correctly.
+Clients MAY store and forward HTTP cookies during request processing
+as described by RFC 2616 (HTTP/1.1).  Servers SHOULD ignore any
+cookies sent by a client.
+
+
+General Request Processing
+--------------------------
+
+Except where noted, all standard HTTP behavior SHOULD be assumed
+by both client and server.  This includes (but is not necessarily
+limited to):
+
+If there is no repository at `$GIT_URL`, or the resource pointed to by a
+location matching `$GIT_URL` does not exist, the server MUST NOT respond
+with `200 OK` response.  A server SHOULD respond with
+`404 Not Found`, `410 Gone`, or any other suitable HTTP status code
+which does not imply the resource exists as requested.
+
+If there is a repository at `$GIT_URL`, but access is not currently
+permitted, the server MUST respond with the `403 Forbidden` HTTP
+status code.
+
+Servers SHOULD support both HTTP 1.0 and HTTP 1.1.
+Servers SHOULD support chunked encoding for both request and response
+bodies.
+
+Clients SHOULD support both HTTP 1.0 and HTTP 1.1.
+Clients SHOULD support chunked encoding for both request and response
+bodies.
+
+Servers MAY return ETag and/or Last-Modified headers.
+
+Clients MAY revalidate cached entities by including If-Modified-Since
+and/or If-None-Match request headers.
+
+Servers MAY return `304 Not Modified` if the relevant headers appear
+in the request and the entity has not changed.  Clients MUST treat
+`304 Not Modified` identical to `200 OK` by reusing the cached entity.
+
+Clients MAY reuse a cached entity without revalidation if the
+Cache-Control and/or Expires header permits caching.  Clients and
+servers MUST follow RFC 2616 for cache controls.
+
+
+Discovering References
+----------------------
+
+All HTTP clients MUST begin either a fetch or a push exchange by
+discovering the references available on the remote repository.
+
+Dumb Clients
+~~~~~~~~~~~~
+
+HTTP clients that only support the "dumb" protocol MUST discover
+references by making a request for the special info/refs file of
+the repository.
+
+Dumb HTTP clients MUST make a `GET` request to `$GIT_URL/info/refs`,
+without any search/query parameters.
+
+   C: GET $GIT_URL/info/refs HTTP/1.0
+
+   S: 200 OK
+   S:
+   S: 95dcfa3633004da0049d3d0fa03f80589cbcaf31	refs/heads/maint
+   S: d049f6c27a2244e12041955e262a404c7faba355	refs/heads/master
+   S: 2cb58b79488a98d2721cea644875a8dd0026b115	refs/tags/v1.0
+   S: a3c2e2402b99163d1d59756e5f207ae21cccba4c	refs/tags/v1.0^{}
+
+The Content-Type of the returned info/refs entity SHOULD be
+`text/plain; charset=utf-8`, but MAY be any content type.
+Clients MUST NOT attempt to validate the returned Content-Type.
+Dumb servers MUST NOT return a return type starting with
+`application/x-git-`.
+
+Cache-Control headers MAY be returned to disable caching of the
+returned entity.
+
+When examining the response clients SHOULD only examine the HTTP
+status code.  Valid responses are `200 OK`, or `304 Not Modified`.
+
+The returned content is a UNIX formatted text file describing
+each ref and its known value.  The file SHOULD be sorted by name
+according to the C locale ordering.  The file SHOULD NOT include
+the default ref named `HEAD`.
+
+  info_refs   =  *( ref_record )
+  ref_record  =  any_ref / peeled_ref
+
+  any_ref     =  obj-id HTAB refname LF
+  peeled_ref  =  obj-id HTAB refname LF
+		 obj-id HTAB refname "^{}" LF
+
+Smart Clients
+~~~~~~~~~~~~~
+
+HTTP clients that support the "smart" protocol (or both the
+"smart" and "dumb" protocols) MUST discover references by making
+a parameterized request for the info/refs file of the repository.
+
+The request MUST contain exactly one query parameter,
+`service=$servicename`, where `$servicename` MUST be the service
+name the client wishes to contact to complete the operation.
+The request MUST NOT contain additional query parameters.
+
+   C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
+
+dumb server reply:
+
+   S: 200 OK
+   S:
+   S: 95dcfa3633004da0049d3d0fa03f80589cbcaf31	refs/heads/maint
+   S: d049f6c27a2244e12041955e262a404c7faba355	refs/heads/master
+   S: 2cb58b79488a98d2721cea644875a8dd0026b115	refs/tags/v1.0
+   S: a3c2e2402b99163d1d59756e5f207ae21cccba4c	refs/tags/v1.0^{}
+
+smart server reply:
+
+   S: 200 OK
+   S: Content-Type: application/x-git-upload-pack-advertisement
+   S: Cache-Control: no-cache
+   S:
+   S: 001e# service=git-upload-pack\n
+   S: 0000
+   S: 004895dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint\0multi_ack\n
+   S: 0042d049f6c27a2244e12041955e262a404c7faba355 refs/heads/master\n
+   S: 003c2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0\n
+   S: 003fa3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}\n
+   S: 0000
+
+The client may send Extra Parameters (see
+Documentation/technical/pack-protocol.txt) as a colon-separated string
+in the Git-Protocol HTTP header.
+
+Dumb Server Response
+^^^^^^^^^^^^^^^^^^^^
+Dumb servers MUST respond with the dumb server reply format.
+
+See the prior section under dumb clients for a more detailed
+description of the dumb server response.
+
+Smart Server Response
+^^^^^^^^^^^^^^^^^^^^^
+If the server does not recognize the requested service name, or the
+requested service name has been disabled by the server administrator,
+the server MUST respond with the `403 Forbidden` HTTP status code.
+
+Otherwise, smart servers MUST respond with the smart server reply
+format for the requested service name.
+
+Cache-Control headers SHOULD be used to disable caching of the
+returned entity.
+
+The Content-Type MUST be `application/x-$servicename-advertisement`.
+Clients SHOULD fall back to the dumb protocol if another content
+type is returned.  When falling back to the dumb protocol clients
+SHOULD NOT make an additional request to `$GIT_URL/info/refs`, but
+instead SHOULD use the response already in hand.  Clients MUST NOT
+continue if they do not support the dumb protocol.
+
+Clients MUST validate the status code is either `200 OK` or
+`304 Not Modified`.
+
+Clients MUST validate the first five bytes of the response entity
+matches the regex `^[0-9a-f]{4}#`.  If this test fails, clients
+MUST NOT continue.
+
+Clients MUST parse the entire response as a sequence of pkt-line
+records.
+
+Clients MUST verify the first pkt-line is `# service=$servicename`.
+Servers MUST set $servicename to be the request parameter value.
+Servers SHOULD include an LF at the end of this line.
+Clients MUST ignore an LF at the end of the line.
+
+Servers MUST terminate the response with the magic `0000` end
+pkt-line marker.
+
+The returned response is a pkt-line stream describing each ref and
+its known value.  The stream SHOULD be sorted by name according to
+the C locale ordering.  The stream SHOULD include the default ref
+named `HEAD` as the first ref.  The stream MUST include capability
+declarations behind a NUL on the first ref.
+
+The returned response contains "version 1" if "version=1" was sent as an
+Extra Parameter.
+
+  smart_reply     =  PKT-LINE("# service=$servicename" LF)
+		     "0000"
+		     *1("version 1")
+		     ref_list
+		     "0000"
+  ref_list        =  empty_list / non_empty_list
+
+  empty_list      =  PKT-LINE(zero-id SP "capabilities^{}" NUL cap-list LF)
+
+  non_empty_list  =  PKT-LINE(obj-id SP name NUL cap_list LF)
+		     *ref_record
+
+  cap-list        =  capability *(SP capability)
+  capability      =  1*(LC_ALPHA / DIGIT / "-" / "_")
+  LC_ALPHA        =  %x61-7A
+
+  ref_record      =  any_ref / peeled_ref
+  any_ref         =  PKT-LINE(obj-id SP name LF)
+  peeled_ref      =  PKT-LINE(obj-id SP name LF)
+		     PKT-LINE(obj-id SP name "^{}" LF
+
+
+Smart Service git-upload-pack
+------------------------------
+This service reads from the repository pointed to by `$GIT_URL`.
+
+Clients MUST first perform ref discovery with
+`$GIT_URL/info/refs?service=git-upload-pack`.
+
+   C: POST $GIT_URL/git-upload-pack HTTP/1.0
+   C: Content-Type: application/x-git-upload-pack-request
+   C:
+   C: 0032want 0a53e9ddeaddad63ad106860237bbf53411d11a7\n
+   C: 0032have 441b40d833fdfa93eb2908e52742248faf0ee993\n
+   C: 0000
+
+   S: 200 OK
+   S: Content-Type: application/x-git-upload-pack-result
+   S: Cache-Control: no-cache
+   S:
+   S: ....ACK %s, continue
+   S: ....NAK
+
+Clients MUST NOT reuse or revalidate a cached response.
+Servers MUST include sufficient Cache-Control headers
+to prevent caching of the response.
+
+Servers SHOULD support all capabilities defined here.
+
+Clients MUST send at least one "want" command in the request body.
+Clients MUST NOT reference an id in a "want" command which did not
+appear in the response obtained through ref discovery unless the
+server advertises capability `allow-tip-sha1-in-want` or
+`allow-reachable-sha1-in-want`.
+
+  compute_request   =  want_list
+		       have_list
+		       request_end
+  request_end       =  "0000" / "done"
+
+  want_list         =  PKT-LINE(want SP cap_list LF)
+		       *(want_pkt)
+  want_pkt          =  PKT-LINE(want LF)
+  want              =  "want" SP id
+  cap_list          =  capability *(SP capability)
+
+  have_list         =  *PKT-LINE("have" SP id LF)
+
+TODO: Document this further.
+
+The Negotiation Algorithm
+~~~~~~~~~~~~~~~~~~~~~~~~~
+The computation to select the minimal pack proceeds as follows
+(C = client, S = server):
+
+'init step:'
+
+C: Use ref discovery to obtain the advertised refs.
+
+C: Place any object seen into set `advertised`.
+
+C: Build an empty set, `common`, to hold the objects that are later
+   determined to be on both ends.
+
+C: Build a set, `want`, of the objects from `advertised` the client
+   wants to fetch, based on what it saw during ref discovery.
+
+C: Start a queue, `c_pending`, ordered by commit time (popping newest
+   first).  Add all client refs.  When a commit is popped from
+   the queue its parents SHOULD be automatically inserted back.
+   Commits MUST only enter the queue once.
+
+'one compute step:'
+
+C: Send one `$GIT_URL/git-upload-pack` request:
+
+   C: 0032want <want #1>...............................
+   C: 0032want <want #2>...............................
+   ....
+   C: 0032have <common #1>.............................
+   C: 0032have <common #2>.............................
+   ....
+   C: 0032have <have #1>...............................
+   C: 0032have <have #2>...............................
+   ....
+   C: 0000
+
+The stream is organized into "commands", with each command
+appearing by itself in a pkt-line.  Within a command line,
+the text leading up to the first space is the command name,
+and the remainder of the line to the first LF is the value.
+Command lines are terminated with an LF as the last byte of
+the pkt-line value.
+
+Commands MUST appear in the following order, if they appear
+at all in the request stream:
+
+* "want"
+* "have"
+
+The stream is terminated by a pkt-line flush (`0000`).
+
+A single "want" or "have" command MUST have one hex formatted
+SHA-1 as its value.  Multiple SHA-1s MUST be sent by sending
+multiple commands.
+
+The `have` list is created by popping the first 32 commits
+from `c_pending`.  Less can be supplied if `c_pending` empties.
+
+If the client has sent 256 "have" commits and has not yet
+received one of those back from `s_common`, or the client has
+emptied `c_pending` it SHOULD include a "done" command to let
+the server know it won't proceed:
+
+   C: 0009done
+
+S: Parse the git-upload-pack request:
+
+Verify all objects in `want` are directly reachable from refs.
+
+The server MAY walk backwards through history or through
+the reflog to permit slightly stale requests.
+
+If no "want" objects are received, send an error:
+TODO: Define error if no "want" lines are requested.
+
+If any "want" object is not reachable, send an error:
+TODO: Define error if an invalid "want" is requested.
+
+Create an empty list, `s_common`.
+
+If "have" was sent:
+
+Loop through the objects in the order supplied by the client.
+
+For each object, if the server has the object reachable from
+a ref, add it to `s_common`.  If a commit is added to `s_common`,
+do not add any ancestors, even if they also appear in `have`.
+
+S: Send the git-upload-pack response:
+
+If the server has found a closed set of objects to pack or the
+request ends with "done", it replies with the pack.
+TODO: Document the pack based response
+
+   S: PACK...
+
+The returned stream is the side-band-64k protocol supported
+by the git-upload-pack service, and the pack is embedded into
+stream 1.  Progress messages from the server side MAY appear
+in stream 2.
+
+Here a "closed set of objects" is defined to have at least
+one path from every "want" to at least one "common" object.
+
+If the server needs more information, it replies with a
+status continue response:
+TODO: Document the non-pack response
+
+C: Parse the upload-pack response:
+   TODO: Document parsing response
+
+'Do another compute step.'
+
+
+Smart Service git-receive-pack
+------------------------------
+This service reads from the repository pointed to by `$GIT_URL`.
+
+Clients MUST first perform ref discovery with
+`$GIT_URL/info/refs?service=git-receive-pack`.
+
+   C: POST $GIT_URL/git-receive-pack HTTP/1.0
+   C: Content-Type: application/x-git-receive-pack-request
+   C:
+   C: ....0a53e9ddeaddad63ad106860237bbf53411d11a7 441b40d833fdfa93eb2908e52742248faf0ee993 refs/heads/maint\0 report-status
+   C: 0000
+   C: PACK....
+
+   S: 200 OK
+   S: Content-Type: application/x-git-receive-pack-result
+   S: Cache-Control: no-cache
+   S:
+   S: ....
+
+Clients MUST NOT reuse or revalidate a cached response.
+Servers MUST include sufficient Cache-Control headers
+to prevent caching of the response.
+
+Servers SHOULD support all capabilities defined here.
+
+Clients MUST send at least one command in the request body.
+Within the command portion of the request body clients SHOULD send
+the id obtained through ref discovery as old_id.
+
+  update_request  =  command_list
+		     "PACK" <binary data>
+
+  command_list    =  PKT-LINE(command NUL cap_list LF)
+		     *(command_pkt)
+  command_pkt     =  PKT-LINE(command LF)
+  cap_list        =  *(SP capability) SP
+
+  command         =  create / delete / update
+  create          =  zero-id SP new_id SP name
+  delete          =  old_id SP zero-id SP name
+  update          =  old_id SP new_id SP name
+
+TODO: Document this further.
+
+
+References
+----------
+
+http://www.ietf.org/rfc/rfc1738.txt[RFC 1738: Uniform Resource Locators (URL)]
+http://www.ietf.org/rfc/rfc2616.txt[RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1]
+link:technical/pack-protocol.html
+link:technical/protocol-capabilities.html
diff --git a/third_party/git/Documentation/technical/index-format.txt b/third_party/git/Documentation/technical/index-format.txt
new file mode 100644
index 0000000000..7c4d67aa6a
--- /dev/null
+++ b/third_party/git/Documentation/technical/index-format.txt
@@ -0,0 +1,357 @@
+Git index format
+================
+
+== The Git index file has the following format
+
+  All binary numbers are in network byte order. Version 2 is described
+  here unless stated otherwise.
+
+   - A 12-byte header consisting of
+
+     4-byte signature:
+       The signature is { 'D', 'I', 'R', 'C' } (stands for "dircache")
+
+     4-byte version number:
+       The current supported versions are 2, 3 and 4.
+
+     32-bit number of index entries.
+
+   - A number of sorted index entries (see below).
+
+   - Extensions
+
+     Extensions are identified by signature. Optional extensions can
+     be ignored if Git does not understand them.
+
+     Git currently supports cached tree and resolve undo extensions.
+
+     4-byte extension signature. If the first byte is 'A'..'Z' the
+     extension is optional and can be ignored.
+
+     32-bit size of the extension
+
+     Extension data
+
+   - 160-bit SHA-1 over the content of the index file before this
+     checksum.
+
+== Index entry
+
+  Index entries are sorted in ascending order on the name field,
+  interpreted as a string of unsigned bytes (i.e. memcmp() order, no
+  localization, no special casing of directory separator '/'). Entries
+  with the same name are sorted by their stage field.
+
+  32-bit ctime seconds, the last time a file's metadata changed
+    this is stat(2) data
+
+  32-bit ctime nanosecond fractions
+    this is stat(2) data
+
+  32-bit mtime seconds, the last time a file's data changed
+    this is stat(2) data
+
+  32-bit mtime nanosecond fractions
+    this is stat(2) data
+
+  32-bit dev
+    this is stat(2) data
+
+  32-bit ino
+    this is stat(2) data
+
+  32-bit mode, split into (high to low bits)
+
+    4-bit object type
+      valid values in binary are 1000 (regular file), 1010 (symbolic link)
+      and 1110 (gitlink)
+
+    3-bit unused
+
+    9-bit unix permission. Only 0755 and 0644 are valid for regular files.
+    Symbolic links and gitlinks have value 0 in this field.
+
+  32-bit uid
+    this is stat(2) data
+
+  32-bit gid
+    this is stat(2) data
+
+  32-bit file size
+    This is the on-disk size from stat(2), truncated to 32-bit.
+
+  160-bit SHA-1 for the represented object
+
+  A 16-bit 'flags' field split into (high to low bits)
+
+    1-bit assume-valid flag
+
+    1-bit extended flag (must be zero in version 2)
+
+    2-bit stage (during merge)
+
+    12-bit name length if the length is less than 0xFFF; otherwise 0xFFF
+    is stored in this field.
+
+  (Version 3 or later) A 16-bit field, only applicable if the
+  "extended flag" above is 1, split into (high to low bits).
+
+    1-bit reserved for future
+
+    1-bit skip-worktree flag (used by sparse checkout)
+
+    1-bit intent-to-add flag (used by "git add -N")
+
+    13-bit unused, must be zero
+
+  Entry path name (variable length) relative to top level directory
+    (without leading slash). '/' is used as path separator. The special
+    path components ".", ".." and ".git" (without quotes) are disallowed.
+    Trailing slash is also disallowed.
+
+    The exact encoding is undefined, but the '.' and '/' characters
+    are encoded in 7-bit ASCII and the encoding cannot contain a NUL
+    byte (iow, this is a UNIX pathname).
+
+  (Version 4) In version 4, the entry path name is prefix-compressed
+    relative to the path name for the previous entry (the very first
+    entry is encoded as if the path name for the previous entry is an
+    empty string).  At the beginning of an entry, an integer N in the
+    variable width encoding (the same encoding as the offset is encoded
+    for OFS_DELTA pack entries; see pack-format.txt) is stored, followed
+    by a NUL-terminated string S.  Removing N bytes from the end of the
+    path name for the previous entry, and replacing it with the string S
+    yields the path name for this entry.
+
+  1-8 nul bytes as necessary to pad the entry to a multiple of eight bytes
+  while keeping the name NUL-terminated.
+
+  (Version 4) In version 4, the padding after the pathname does not
+  exist.
+
+  Interpretation of index entries in split index mode is completely
+  different. See below for details.
+
+== Extensions
+
+=== Cached tree
+
+  Cached tree extension contains pre-computed hashes for trees that can
+  be derived from the index. It helps speed up tree object generation
+  from index for a new commit.
+
+  When a path is updated in index, the path must be invalidated and
+  removed from tree cache.
+
+  The signature for this extension is { 'T', 'R', 'E', 'E' }.
+
+  A series of entries fill the entire extension; each of which
+  consists of:
+
+  - NUL-terminated path component (relative to its parent directory);
+
+  - ASCII decimal number of entries in the index that is covered by the
+    tree this entry represents (entry_count);
+
+  - A space (ASCII 32);
+
+  - ASCII decimal number that represents the number of subtrees this
+    tree has;
+
+  - A newline (ASCII 10); and
+
+  - 160-bit object name for the object that would result from writing
+    this span of index as a tree.
+
+  An entry can be in an invalidated state and is represented by having
+  a negative number in the entry_count field. In this case, there is no
+  object name and the next entry starts immediately after the newline.
+  When writing an invalid entry, -1 should always be used as entry_count.
+
+  The entries are written out in the top-down, depth-first order.  The
+  first entry represents the root level of the repository, followed by the
+  first subtree--let's call this A--of the root level (with its name
+  relative to the root level), followed by the first subtree of A (with
+  its name relative to A), ...
+
+=== Resolve undo
+
+  A conflict is represented in the index as a set of higher stage entries.
+  When a conflict is resolved (e.g. with "git add path"), these higher
+  stage entries will be removed and a stage-0 entry with proper resolution
+  is added.
+
+  When these higher stage entries are removed, they are saved in the
+  resolve undo extension, so that conflicts can be recreated (e.g. with
+  "git checkout -m"), in case users want to redo a conflict resolution
+  from scratch.
+
+  The signature for this extension is { 'R', 'E', 'U', 'C' }.
+
+  A series of entries fill the entire extension; each of which
+  consists of:
+
+  - NUL-terminated pathname the entry describes (relative to the root of
+    the repository, i.e. full pathname);
+
+  - Three NUL-terminated ASCII octal numbers, entry mode of entries in
+    stage 1 to 3 (a missing stage is represented by "0" in this field);
+    and
+
+  - At most three 160-bit object names of the entry in stages from 1 to 3
+    (nothing is written for a missing stage).
+
+=== Split index
+
+  In split index mode, the majority of index entries could be stored
+  in a separate file. This extension records the changes to be made on
+  top of that to produce the final index.
+
+  The signature for this extension is { 'l', 'i', 'n', 'k' }.
+
+  The extension consists of:
+
+  - 160-bit SHA-1 of the shared index file. The shared index file path
+    is $GIT_DIR/sharedindex.<SHA-1>. If all 160 bits are zero, the
+    index does not require a shared index file.
+
+  - An ewah-encoded delete bitmap, each bit represents an entry in the
+    shared index. If a bit is set, its corresponding entry in the
+    shared index will be removed from the final index.  Note, because
+    a delete operation changes index entry positions, but we do need
+    original positions in replace phase, it's best to just mark
+    entries for removal, then do a mass deletion after replacement.
+
+  - An ewah-encoded replace bitmap, each bit represents an entry in
+    the shared index. If a bit is set, its corresponding entry in the
+    shared index will be replaced with an entry in this index
+    file. All replaced entries are stored in sorted order in this
+    index. The first "1" bit in the replace bitmap corresponds to the
+    first index entry, the second "1" bit to the second entry and so
+    on. Replaced entries may have empty path names to save space.
+
+  The remaining index entries after replaced ones will be added to the
+  final index. These added entries are also sorted by entry name then
+  stage.
+
+== Untracked cache
+
+  Untracked cache saves the untracked file list and necessary data to
+  verify the cache. The signature for this extension is { 'U', 'N',
+  'T', 'R' }.
+
+  The extension starts with
+
+  - A sequence of NUL-terminated strings, preceded by the size of the
+    sequence in variable width encoding. Each string describes the
+    environment where the cache can be used.
+
+  - Stat data of $GIT_DIR/info/exclude. See "Index entry" section from
+    ctime field until "file size".
+
+  - Stat data of core.excludesfile
+
+  - 32-bit dir_flags (see struct dir_struct)
+
+  - 160-bit SHA-1 of $GIT_DIR/info/exclude. Null SHA-1 means the file
+    does not exist.
+
+  - 160-bit SHA-1 of core.excludesfile. Null SHA-1 means the file does
+    not exist.
+
+  - NUL-terminated string of per-dir exclude file name. This usually
+    is ".gitignore".
+
+  - The number of following directory blocks, variable width
+    encoding. If this number is zero, the extension ends here with a
+    following NUL.
+
+  - A number of directory blocks in depth-first-search order, each
+    consists of
+
+    - The number of untracked entries, variable width encoding.
+
+    - The number of sub-directory blocks, variable width encoding.
+
+    - The directory name terminated by NUL.
+
+    - A number of untracked file/dir names terminated by NUL.
+
+The remaining data of each directory block is grouped by type:
+
+  - An ewah bitmap, the n-th bit marks whether the n-th directory has
+    valid untracked cache entries.
+
+  - An ewah bitmap, the n-th bit records "check-only" bit of
+    read_directory_recursive() for the n-th directory.
+
+  - An ewah bitmap, the n-th bit indicates whether SHA-1 and stat data
+    is valid for the n-th directory and exists in the next data.
+
+  - An array of stat data. The n-th data corresponds with the n-th
+    "one" bit in the previous ewah bitmap.
+
+  - An array of SHA-1. The n-th SHA-1 corresponds with the n-th "one" bit
+    in the previous ewah bitmap.
+
+  - One NUL.
+
+== File System Monitor cache
+
+  The file system monitor cache tracks files for which the core.fsmonitor
+  hook has told us about changes.  The signature for this extension is
+  { 'F', 'S', 'M', 'N' }.
+
+  The extension starts with
+
+  - 32-bit version number: the current supported version is 1.
+
+  - 64-bit time: the extension data reflects all changes through the given
+	time which is stored as the nanoseconds elapsed since midnight,
+	January 1, 1970.
+
+  - 32-bit bitmap size: the size of the CE_FSMONITOR_VALID bitmap.
+
+  - An ewah bitmap, the n-th bit indicates whether the n-th index entry
+    is not CE_FSMONITOR_VALID.
+
+== End of Index Entry
+
+  The End of Index Entry (EOIE) is used to locate the end of the variable
+  length index entries and the begining of the extensions. Code can take
+  advantage of this to quickly locate the index extensions without having
+  to parse through all of the index entries.
+
+  Because it must be able to be loaded before the variable length cache
+  entries and other index extensions, this extension must be written last.
+  The signature for this extension is { 'E', 'O', 'I', 'E' }.
+
+  The extension consists of:
+
+  - 32-bit offset to the end of the index entries
+
+  - 160-bit SHA-1 over the extension types and their sizes (but not
+	their contents).  E.g. if we have "TREE" extension that is N-bytes
+	long, "REUC" extension that is M-bytes long, followed by "EOIE",
+	then the hash would be:
+
+	SHA-1("TREE" + <binary representation of N> +
+		"REUC" + <binary representation of M>)
+
+== Index Entry Offset Table
+
+  The Index Entry Offset Table (IEOT) is used to help address the CPU
+  cost of loading the index by enabling multi-threading the process of
+  converting cache entries from the on-disk format to the in-memory format.
+  The signature for this extension is { 'I', 'E', 'O', 'T' }.
+
+  The extension consists of:
+
+  - 32-bit version (currently 1)
+
+  - A number of index offset entries each consisting of:
+
+    - 32-bit offset from the begining of the file to the first cache entry
+	in this block of entries.
+
+    - 32-bit count of cache entries in this block
diff --git a/third_party/git/Documentation/technical/long-running-process-protocol.txt b/third_party/git/Documentation/technical/long-running-process-protocol.txt
new file mode 100644
index 0000000000..aa0aa9af1c
--- /dev/null
+++ b/third_party/git/Documentation/technical/long-running-process-protocol.txt
@@ -0,0 +1,50 @@
+Long-running process protocol
+=============================
+
+This protocol is used when Git needs to communicate with an external
+process throughout the entire life of a single Git command. All
+communication is in pkt-line format (see technical/protocol-common.txt)
+over standard input and standard output.
+
+Handshake
+---------
+
+Git starts by sending a welcome message (for example,
+"git-filter-client"), a list of supported protocol version numbers, and
+a flush packet. Git expects to read the welcome message with "server"
+instead of "client" (for example, "git-filter-server"), exactly one
+protocol version number from the previously sent list, and a flush
+packet. All further communication will be based on the selected version.
+The remaining protocol description below documents "version=2". Please
+note that "version=42" in the example below does not exist and is only
+there to illustrate how the protocol would look like with more than one
+version.
+
+After the version negotiation Git sends a list of all capabilities that
+it supports and a flush packet. Git expects to read a list of desired
+capabilities, which must be a subset of the supported capabilities list,
+and a flush packet as response:
+------------------------
+packet:          git> git-filter-client
+packet:          git> version=2
+packet:          git> version=42
+packet:          git> 0000
+packet:          git< git-filter-server
+packet:          git< version=2
+packet:          git< 0000
+packet:          git> capability=clean
+packet:          git> capability=smudge
+packet:          git> capability=not-yet-invented
+packet:          git> 0000
+packet:          git< capability=clean
+packet:          git< capability=smudge
+packet:          git< 0000
+------------------------
+
+Shutdown
+--------
+
+Git will close
+the command pipe on exit. The filter is expected to detect EOF
+and exit gracefully on its own. Git will wait until the filter
+process has stopped.
diff --git a/third_party/git/Documentation/technical/multi-pack-index.txt b/third_party/git/Documentation/technical/multi-pack-index.txt
new file mode 100644
index 0000000000..d7e57639f7
--- /dev/null
+++ b/third_party/git/Documentation/technical/multi-pack-index.txt
@@ -0,0 +1,109 @@
+Multi-Pack-Index (MIDX) Design Notes
+====================================
+
+The Git object directory contains a 'pack' directory containing
+packfiles (with suffix ".pack") and pack-indexes (with suffix
+".idx"). The pack-indexes provide a way to lookup objects and
+navigate to their offset within the pack, but these must come
+in pairs with the packfiles. This pairing depends on the file
+names, as the pack-index differs only in suffix with its pack-
+file. While the pack-indexes provide fast lookup per packfile,
+this performance degrades as the number of packfiles increases,
+because abbreviations need to inspect every packfile and we are
+more likely to have a miss on our most-recently-used packfile.
+For some large repositories, repacking into a single packfile
+is not feasible due to storage space or excessive repack times.
+
+The multi-pack-index (MIDX for short) stores a list of objects
+and their offsets into multiple packfiles. It contains:
+
+- A list of packfile names.
+- A sorted list of object IDs.
+- A list of metadata for the ith object ID including:
+  - A value j referring to the jth packfile.
+  - An offset within the jth packfile for the object.
+- If large offsets are required, we use another list of large
+  offsets similar to version 2 pack-indexes.
+
+Thus, we can provide O(log N) lookup time for any number
+of packfiles.
+
+Design Details
+--------------
+
+- The MIDX is stored in a file named 'multi-pack-index' in the
+  .git/objects/pack directory. This could be stored in the pack
+  directory of an alternate. It refers only to packfiles in that
+  same directory.
+
+- The pack.multiIndex config setting must be on to consume MIDX files.
+
+- The file format includes parameters for the object ID hash
+  function, so a future change of hash algorithm does not require
+  a change in format.
+
+- The MIDX keeps only one record per object ID. If an object appears
+  in multiple packfiles, then the MIDX selects the copy in the most-
+  recently modified packfile.
+
+- If there exist packfiles in the pack directory not registered in
+  the MIDX, then those packfiles are loaded into the `packed_git`
+  list and `packed_git_mru` cache.
+
+- The pack-indexes (.idx files) remain in the pack directory so we
+  can delete the MIDX file, set core.midx to false, or downgrade
+  without any loss of information.
+
+- The MIDX file format uses a chunk-based approach (similar to the
+  commit-graph file) that allows optional data to be added.
+
+Future Work
+-----------
+
+- Add a 'verify' subcommand to the 'git midx' builtin to verify the
+  contents of the multi-pack-index file match the offsets listed in
+  the corresponding pack-indexes.
+
+- The multi-pack-index allows many packfiles, especially in a context
+  where repacking is expensive (such as a very large repo), or
+  unexpected maintenance time is unacceptable (such as a high-demand
+  build machine). However, the multi-pack-index needs to be rewritten
+  in full every time. We can extend the format to be incremental, so
+  writes are fast. By storing a small "tip" multi-pack-index that
+  points to large "base" MIDX files, we can keep writes fast while
+  still reducing the number of binary searches required for object
+  lookups.
+
+- The reachability bitmap is currently paired directly with a single
+  packfile, using the pack-order as the object order to hopefully
+  compress the bitmaps well using run-length encoding. This could be
+  extended to pair a reachability bitmap with a multi-pack-index. If
+  the multi-pack-index is extended to store a "stable object order"
+  (a function Order(hash) = integer that is constant for a given hash,
+  even as the multi-pack-index is updated) then a reachability bitmap
+  could point to a multi-pack-index and be updated independently.
+
+- Packfiles can be marked as "special" using empty files that share
+  the initial name but replace ".pack" with ".keep" or ".promisor".
+  We can add an optional chunk of data to the multi-pack-index that
+  records flags of information about the packfiles. This allows new
+  states, such as 'repacked' or 'redeltified', that can help with
+  pack maintenance in a multi-pack environment. It may also be
+  helpful to organize packfiles by object type (commit, tree, blob,
+  etc.) and use this metadata to help that maintenance.
+
+- The partial clone feature records special "promisor" packs that
+  may point to objects that are not stored locally, but available
+  on request to a server. The multi-pack-index does not currently
+  track these promisor packs.
+
+Related Links
+-------------
+[0] https://bugs.chromium.org/p/git/issues/detail?id=6
+    Chromium work item for: Multi-Pack Index (MIDX)
+
+[1] https://public-inbox.org/git/20180107181459.222909-1-dstolee@microsoft.com/
+    An earlier RFC for the multi-pack-index feature
+
+[2] https://public-inbox.org/git/alpine.DEB.2.20.1803091557510.23109@alexmv-linux/
+    Git Merge 2018 Contributor's summit notes (includes discussion of MIDX)
diff --git a/third_party/git/Documentation/technical/pack-format.txt b/third_party/git/Documentation/technical/pack-format.txt
new file mode 100644
index 0000000000..cab5bdd2ff
--- /dev/null
+++ b/third_party/git/Documentation/technical/pack-format.txt
@@ -0,0 +1,331 @@
+Git pack format
+===============
+
+== pack-*.pack files have the following format:
+
+   - A header appears at the beginning and consists of the following:
+
+     4-byte signature:
+         The signature is: {'P', 'A', 'C', 'K'}
+
+     4-byte version number (network byte order):
+	 Git currently accepts version number 2 or 3 but
+         generates version 2 only.
+
+     4-byte number of objects contained in the pack (network byte order)
+
+     Observation: we cannot have more than 4G versions ;-) and
+     more than 4G objects in a pack.
+
+   - The header is followed by number of object entries, each of
+     which looks like this:
+
+     (undeltified representation)
+     n-byte type and length (3-bit type, (n-1)*7+4-bit length)
+     compressed data
+
+     (deltified representation)
+     n-byte type and length (3-bit type, (n-1)*7+4-bit length)
+     20-byte base object name if OBJ_REF_DELTA or a negative relative
+	 offset from the delta object's position in the pack if this
+	 is an OBJ_OFS_DELTA object
+     compressed delta data
+
+     Observation: length of each object is encoded in a variable
+     length format and is not constrained to 32-bit or anything.
+
+  - The trailer records 20-byte SHA-1 checksum of all of the above.
+
+=== Object types
+
+Valid object types are:
+
+- OBJ_COMMIT (1)
+- OBJ_TREE (2)
+- OBJ_BLOB (3)
+- OBJ_TAG (4)
+- OBJ_OFS_DELTA (6)
+- OBJ_REF_DELTA (7)
+
+Type 5 is reserved for future expansion. Type 0 is invalid.
+
+=== Deltified representation
+
+Conceptually there are only four object types: commit, tree, tag and
+blob. However to save space, an object could be stored as a "delta" of
+another "base" object. These representations are assigned new types
+ofs-delta and ref-delta, which is only valid in a pack file.
+
+Both ofs-delta and ref-delta store the "delta" to be applied to
+another object (called 'base object') to reconstruct the object. The
+difference between them is, ref-delta directly encodes 20-byte base
+object name. If the base object is in the same pack, ofs-delta encodes
+the offset of the base object in the pack instead.
+
+The base object could also be deltified if it's in the same pack.
+Ref-delta can also refer to an object outside the pack (i.e. the
+so-called "thin pack"). When stored on disk however, the pack should
+be self contained to avoid cyclic dependency.
+
+The delta data is a sequence of instructions to reconstruct an object
+from the base object. If the base object is deltified, it must be
+converted to canonical form first. Each instruction appends more and
+more data to the target object until it's complete. There are two
+supported instructions so far: one for copy a byte range from the
+source object and one for inserting new data embedded in the
+instruction itself.
+
+Each instruction has variable length. Instruction type is determined
+by the seventh bit of the first octet. The following diagrams follow
+the convention in RFC 1951 (Deflate compressed data format).
+
+==== Instruction to copy from base object
+
+  +----------+---------+---------+---------+---------+-------+-------+-------+
+  | 1xxxxxxx | offset1 | offset2 | offset3 | offset4 | size1 | size2 | size3 |
+  +----------+---------+---------+---------+---------+-------+-------+-------+
+
+This is the instruction format to copy a byte range from the source
+object. It encodes the offset to copy from and the number of bytes to
+copy. Offset and size are in little-endian order.
+
+All offset and size bytes are optional. This is to reduce the
+instruction size when encoding small offsets or sizes. The first seven
+bits in the first octet determines which of the next seven octets is
+present. If bit zero is set, offset1 is present. If bit one is set
+offset2 is present and so on.
+
+Note that a more compact instruction does not change offset and size
+encoding. For example, if only offset2 is omitted like below, offset3
+still contains bits 16-23. It does not become offset2 and contains
+bits 8-15 even if it's right next to offset1.
+
+  +----------+---------+---------+
+  | 10000101 | offset1 | offset3 |
+  +----------+---------+---------+
+
+In its most compact form, this instruction only takes up one byte
+(0x80) with both offset and size omitted, which will have default
+values zero. There is another exception: size zero is automatically
+converted to 0x10000.
+
+==== Instruction to add new data
+
+  +----------+============+
+  | 0xxxxxxx |    data    |
+  +----------+============+
+
+This is the instruction to construct target object without the base
+object. The following data is appended to the target object. The first
+seven bits of the first octet determines the size of data in
+bytes. The size must be non-zero.
+
+==== Reserved instruction
+
+  +----------+============
+  | 00000000 |
+  +----------+============
+
+This is the instruction reserved for future expansion.
+
+== Original (version 1) pack-*.idx files have the following format:
+
+  - The header consists of 256 4-byte network byte order
+    integers.  N-th entry of this table records the number of
+    objects in the corresponding pack, the first byte of whose
+    object name is less than or equal to N.  This is called the
+    'first-level fan-out' table.
+
+  - The header is followed by sorted 24-byte entries, one entry
+    per object in the pack.  Each entry is:
+
+    4-byte network byte order integer, recording where the
+    object is stored in the packfile as the offset from the
+    beginning.
+
+    20-byte object name.
+
+  - The file is concluded with a trailer:
+
+    A copy of the 20-byte SHA-1 checksum at the end of
+    corresponding packfile.
+
+    20-byte SHA-1-checksum of all of the above.
+
+Pack Idx file:
+
+	--  +--------------------------------+
+fanout	    | fanout[0] = 2 (for example)    |-.
+table	    +--------------------------------+ |
+	    | fanout[1]                      | |
+	    +--------------------------------+ |
+	    | fanout[2]                      | |
+	    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
+	    | fanout[255] = total objects    |---.
+	--  +--------------------------------+ | |
+main	    | offset                         | | |
+index	    | object name 00XXXXXXXXXXXXXXXX | | |
+table	    +--------------------------------+ | |
+	    | offset                         | | |
+	    | object name 00XXXXXXXXXXXXXXXX | | |
+	    +--------------------------------+<+ |
+	  .-| offset                         |   |
+	  | | object name 01XXXXXXXXXXXXXXXX |   |
+	  | +--------------------------------+   |
+	  | | offset                         |   |
+	  | | object name 01XXXXXXXXXXXXXXXX |   |
+	  | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~   |
+	  | | offset                         |   |
+	  | | object name FFXXXXXXXXXXXXXXXX |   |
+	--| +--------------------------------+<--+
+trailer	  | | packfile checksum              |
+	  | +--------------------------------+
+	  | | idxfile checksum               |
+	  | +--------------------------------+
+          .-------.
+                  |
+Pack file entry: <+
+
+     packed object header:
+	1-byte size extension bit (MSB)
+	       type (next 3 bit)
+	       size0 (lower 4-bit)
+        n-byte sizeN (as long as MSB is set, each 7-bit)
+		size0..sizeN form 4+7+7+..+7 bit integer, size0
+		is the least significant part, and sizeN is the
+		most significant part.
+     packed object data:
+        If it is not DELTA, then deflated bytes (the size above
+		is the size before compression).
+	If it is REF_DELTA, then
+	  20-byte base object name SHA-1 (the size above is the
+		size of the delta data that follows).
+          delta data, deflated.
+	If it is OFS_DELTA, then
+	  n-byte offset (see below) interpreted as a negative
+		offset from the type-byte of the header of the
+		ofs-delta entry (the size above is the size of
+		the delta data that follows).
+	  delta data, deflated.
+
+     offset encoding:
+	  n bytes with MSB set in all but the last one.
+	  The offset is then the number constructed by
+	  concatenating the lower 7 bit of each byte, and
+	  for n >= 2 adding 2^7 + 2^14 + ... + 2^(7*(n-1))
+	  to the result.
+
+
+
+== Version 2 pack-*.idx files support packs larger than 4 GiB, and
+   have some other reorganizations.  They have the format:
+
+  - A 4-byte magic number '\377tOc' which is an unreasonable
+    fanout[0] value.
+
+  - A 4-byte version number (= 2)
+
+  - A 256-entry fan-out table just like v1.
+
+  - A table of sorted 20-byte SHA-1 object names.  These are
+    packed together without offset values to reduce the cache
+    footprint of the binary search for a specific object name.
+
+  - A table of 4-byte CRC32 values of the packed object data.
+    This is new in v2 so compressed data can be copied directly
+    from pack to pack during repacking without undetected
+    data corruption.
+
+  - A table of 4-byte offset values (in network byte order).
+    These are usually 31-bit pack file offsets, but large
+    offsets are encoded as an index into the next table with
+    the msbit set.
+
+  - A table of 8-byte offset entries (empty for pack files less
+    than 2 GiB).  Pack files are organized with heavily used
+    objects toward the front, so most object references should
+    not need to refer to this table.
+
+  - The same trailer as a v1 pack file:
+
+    A copy of the 20-byte SHA-1 checksum at the end of
+    corresponding packfile.
+
+    20-byte SHA-1-checksum of all of the above.
+
+== multi-pack-index (MIDX) files have the following format:
+
+The multi-pack-index files refer to multiple pack-files and loose objects.
+
+In order to allow extensions that add extra data to the MIDX, we organize
+the body into "chunks" and provide a lookup table at the beginning of the
+body. The header includes certain length values, such as the number of packs,
+the number of base MIDX files, hash lengths and types.
+
+All 4-byte numbers are in network order.
+
+HEADER:
+
+	4-byte signature:
+	    The signature is: {'M', 'I', 'D', 'X'}
+
+	1-byte version number:
+	    Git only writes or recognizes version 1.
+
+	1-byte Object Id Version
+	    Git only writes or recognizes version 1 (SHA1).
+
+	1-byte number of "chunks"
+
+	1-byte number of base multi-pack-index files:
+	    This value is currently always zero.
+
+	4-byte number of pack files
+
+CHUNK LOOKUP:
+
+	(C + 1) * 12 bytes providing the chunk offsets:
+	    First 4 bytes describe chunk id. Value 0 is a terminating label.
+	    Other 8 bytes provide offset in current file for chunk to start.
+	    (Chunks are provided in file-order, so you can infer the length
+	    using the next chunk position if necessary.)
+
+	The remaining data in the body is described one chunk at a time, and
+	these chunks may be given in any order. Chunks are required unless
+	otherwise specified.
+
+CHUNK DATA:
+
+	Packfile Names (ID: {'P', 'N', 'A', 'M'})
+	    Stores the packfile names as concatenated, null-terminated strings.
+	    Packfiles must be listed in lexicographic order for fast lookups by
+	    name. This is the only chunk not guaranteed to be a multiple of four
+	    bytes in length, so should be the last chunk for alignment reasons.
+
+	OID Fanout (ID: {'O', 'I', 'D', 'F'})
+	    The ith entry, F[i], stores the number of OIDs with first
+	    byte at most i. Thus F[255] stores the total
+	    number of objects.
+
+	OID Lookup (ID: {'O', 'I', 'D', 'L'})
+	    The OIDs for all objects in the MIDX are stored in lexicographic
+	    order in this chunk.
+
+	Object Offsets (ID: {'O', 'O', 'F', 'F'})
+	    Stores two 4-byte values for every object.
+	    1: The pack-int-id for the pack storing this object.
+	    2: The offset within the pack.
+		If all offsets are less than 2^31, then the large offset chunk
+		will not exist and offsets are stored as in IDX v1.
+		If there is at least one offset value larger than 2^32-1, then
+		the large offset chunk must exist. If the large offset chunk
+		exists and the 31st bit is on, then removing that bit reveals
+		the row in the large offsets containing the 8-byte offset of
+		this object.
+
+	[Optional] Object Large Offsets (ID: {'L', 'O', 'F', 'F'})
+	    8-byte offsets into large packfiles.
+
+TRAILER:
+
+	20-byte SHA1-checksum of the above contents.
diff --git a/third_party/git/Documentation/technical/pack-heuristics.txt b/third_party/git/Documentation/technical/pack-heuristics.txt
new file mode 100644
index 0000000000..95a07db6e8
--- /dev/null
+++ b/third_party/git/Documentation/technical/pack-heuristics.txt
@@ -0,0 +1,460 @@
+Concerning Git's Packing Heuristics
+===================================
+
+        Oh, here's a really stupid question:
+
+                  Where do I go
+               to learn the details
+	    of Git's packing heuristics?
+
+Be careful what you ask!
+
+Followers of the Git, please open the Git IRC Log and turn to
+February 10, 2006.
+
+It's a rare occasion, and we are joined by the King Git Himself,
+Linus Torvalds (linus).  Nathaniel Smith, (njs`), has the floor
+and seeks enlightenment.  Others are present, but silent.
+
+Let's listen in!
+
+    <njs`> Oh, here's a really stupid question -- where do I go to
+	learn the details of Git's packing heuristics?  google avails
+        me not, reading the source didn't help a lot, and wading
+        through the whole mailing list seems less efficient than any
+        of that.
+
+It is a bold start!  A plea for help combined with a simultaneous
+tri-part attack on some of the tried and true mainstays in the quest
+for enlightenment.  Brash accusations of google being useless. Hubris!
+Maligning the source.  Heresy!  Disdain for the mailing list archives.
+Woe.
+
+    <pasky> yes, the packing-related delta stuff is somewhat
+        mysterious even for me ;)
+
+Ah!  Modesty after all.
+
+    <linus> njs, I don't think the docs exist. That's something where
+	 I don't think anybody else than me even really got involved.
+	 Most of the rest of Git others have been busy with (especially
+	 Junio), but packing nobody touched after I did it.
+
+It's cryptic, yet vague.  Linus in style for sure.  Wise men
+interpret this as an apology.  A few argue it is merely a
+statement of fact.
+
+    <njs`> I guess the next step is "read the source again", but I
+        have to build up a certain level of gumption first :-)
+
+Indeed!  On both points.
+
+    <linus> The packing heuristic is actually really really simple.
+
+Bait...
+
+    <linus> But strange.
+
+And switch.  That ought to do it!
+
+    <linus> Remember: Git really doesn't follow files. So what it does is
+        - generate a list of all objects
+        - sort the list according to magic heuristics
+        - walk the list, using a sliding window, seeing if an object
+          can be diffed against another object in the window
+        - write out the list in recency order
+
+The traditional understatement:
+
+    <njs`> I suspect that what I'm missing is the precise definition of
+        the word "magic"
+
+The traditional insight:
+
+    <pasky> yes
+
+And Babel-like confusion flowed.
+
+    <njs`> oh, hmm, and I'm not sure what this sliding window means either
+
+    <pasky> iirc, it appeared to me to be just the sha1 of the object
+        when reading the code casually ...
+
+        ... which simply doesn't sound as a very good heuristics, though ;)
+
+    <njs`> .....and recency order.  okay, I think it's clear I didn't
+       even realize how much I wasn't realizing :-)
+
+Ah, grasshopper!  And thus the enlightenment begins anew.
+
+    <linus> The "magic" is actually in theory totally arbitrary.
+        ANY order will give you a working pack, but no, it's not
+	ordered by SHA-1.
+
+        Before talking about the ordering for the sliding delta
+        window, let's talk about the recency order. That's more
+        important in one way.
+
+    <njs`> Right, but if all you want is a working way to pack things
+        together, you could just use cat and save yourself some
+        trouble...
+
+Waaait for it....
+
+    <linus> The recency ordering (which is basically: put objects
+        _physically_ into the pack in the order that they are
+        "reachable" from the head) is important.
+
+    <njs`> okay
+
+    <linus> It's important because that's the thing that gives packs
+        good locality. It keeps the objects close to the head (whether
+        they are old or new, but they are _reachable_ from the head)
+        at the head of the pack. So packs actually have absolutely
+        _wonderful_ IO patterns.
+
+Read that again, because it is important.
+
+    <linus> But recency ordering is totally useless for deciding how
+        to actually generate the deltas, so the delta ordering is
+        something else.
+
+        The delta ordering is (wait for it):
+        - first sort by the "basename" of the object, as defined by
+          the name the object was _first_ reached through when
+          generating the object list
+        - within the same basename, sort by size of the object
+        - but always sort different types separately (commits first).
+
+        That's not exactly it, but it's very close.
+
+    <njs`> The "_first_ reached" thing is not too important, just you
+        need some way to break ties since the same objects may be
+        reachable many ways, yes?
+
+And as if to clarify:
+
+    <linus> The point is that it's all really just any random
+        heuristic, and the ordering is totally unimportant for
+        correctness, but it helps a lot if the heuristic gives
+        "clumping" for things that are likely to delta well against
+        each other.
+
+It is an important point, so secretly, I did my own research and have
+included my results below.  To be fair, it has changed some over time.
+And through the magic of Revisionistic History, I draw upon this entry
+from The Git IRC Logs on my father's birthday, March 1:
+
+    <gitster> The quote from the above linus should be rewritten a
+        bit (wait for it):
+        - first sort by type.  Different objects never delta with
+	  each other.
+        - then sort by filename/dirname.  hash of the basename
+          occupies the top BITS_PER_INT-DIR_BITS bits, and bottom
+          DIR_BITS are for the hash of leading path elements.
+        - then if we are doing "thin" pack, the objects we are _not_
+          going to pack but we know about are sorted earlier than
+          other objects.
+        - and finally sort by size, larger to smaller.
+
+In one swell-foop, clarification and obscurification!  Nonetheless,
+authoritative.  Cryptic, yet concise.  It even solicits notions of
+quotes from The Source Code.  Clearly, more study is needed.
+
+    <gitster> That's the sort order.  What this means is:
+        - we do not delta different object types.
+	- we prefer to delta the objects with the same full path, but
+          allow files with the same name from different directories.
+	- we always prefer to delta against objects we are not going
+          to send, if there are some.
+	- we prefer to delta against larger objects, so that we have
+          lots of removals.
+
+        The penultimate rule is for "thin" packs.  It is used when
+        the other side is known to have such objects.
+
+There it is again. "Thin" packs.  I'm thinking to myself, "What
+is a 'thin' pack?"  So I ask:
+
+    <jdl> What is a "thin" pack?
+
+    <gitster> Use of --objects-edge to rev-list as the upstream of
+        pack-objects.  The pack transfer protocol negotiates that.
+
+Woo hoo!  Cleared that _right_ up!
+
+    <gitster> There are two directions - push and fetch.
+
+There!  Did you see it?  It is not '"push" and "pull"'!  How often the
+confusion has started here.  So casually mentioned, too!
+
+    <gitster> For push, git-send-pack invokes git-receive-pack on the
+        other end.  The receive-pack says "I have up to these commits".
+        send-pack looks at them, and computes what are missing from
+        the other end.  So "thin" could be the default there.
+
+        In the other direction, fetch, git-fetch-pack and
+        git-clone-pack invokes git-upload-pack on the other end
+	(via ssh or by talking to the daemon).
+
+	There are two cases: fetch-pack with -k and clone-pack is one,
+        fetch-pack without -k is the other.  clone-pack and fetch-pack
+        with -k will keep the downloaded packfile without expanded, so
+        we do not use thin pack transfer.  Otherwise, the generated
+        pack will have delta without base object in the same pack.
+
+        But fetch-pack without -k will explode the received pack into
+        individual objects, so we automatically ask upload-pack to
+        give us a thin pack if upload-pack supports it.
+
+OK then.
+
+Uh.
+
+Let's return to the previous conversation still in progress.
+
+    <njs`> and "basename" means something like "the tail of end of
+        path of file objects and dir objects, as per basename(3), and
+        we just declare all commit and tag objects to have the same
+        basename" or something?
+
+Luckily, that too is a point that gitster clarified for us!
+
+If I might add, the trick is to make files that _might_ be similar be
+located close to each other in the hash buckets based on their file
+names.  It used to be that "foo/Makefile", "bar/baz/quux/Makefile" and
+"Makefile" all landed in the same bucket due to their common basename,
+"Makefile". However, now they land in "close" buckets.
+
+The algorithm allows not just for the _same_ bucket, but for _close_
+buckets to be considered delta candidates.  The rationale is
+essentially that files, like Makefiles, often have very similar
+content no matter what directory they live in.
+
+    <linus> I played around with different delta algorithms, and with
+        making the "delta window" bigger, but having too big of a
+        sliding window makes it very expensive to generate the pack:
+        you need to compare every object with a _ton_ of other objects.
+
+        There are a number of other trivial heuristics too, which
+        basically boil down to "don't bother even trying to delta this
+        pair" if we can tell before-hand that the delta isn't worth it
+        (due to size differences, where we can take a previous delta
+        result into account to decide that "ok, no point in trying
+        that one, it will be worse").
+
+        End result: packing is actually very size efficient. It's
+        somewhat CPU-wasteful, but on the other hand, since you're
+        really only supposed to do it maybe once a month (and you can
+        do it during the night), nobody really seems to care.
+
+Nice Engineering Touch, there.  Find when it doesn't matter, and
+proclaim it a non-issue.  Good style too!
+
+    <njs`> So, just to repeat to see if I'm following, we start by
+        getting a list of the objects we want to pack, we sort it by
+        this heuristic (basically lexicographically on the tuple
+        (type, basename, size)).
+
+        Then we walk through this list, and calculate a delta of
+        each object against the last n (tunable parameter) objects,
+        and pick the smallest of these deltas.
+
+Vastly simplified, but the essence is there!
+
+    <linus> Correct.
+
+    <njs`> And then once we have picked a delta or fulltext to
+        represent each object, we re-sort by recency, and write them
+        out in that order.
+
+    <linus> Yup. Some other small details:
+
+And of course there is the "Other Shoe" Factor too.
+
+    <linus> - We limit the delta depth to another magic value (right
+        now both the window and delta depth magic values are just "10")
+
+    <njs`> Hrm, my intuition is that you'd end up with really _bad_ IO
+        patterns, because the things you want are near by, but to
+        actually reconstruct them you may have to jump all over in
+        random ways.
+
+    <linus> - When we write out a delta, and we haven't yet written
+        out the object it is a delta against, we write out the base
+        object first.  And no, when we reconstruct them, we actually
+        get nice IO patterns, because:
+        - larger objects tend to be "more recent" (Linus' law: files grow)
+        - we actively try to generate deltas from a larger object to a
+          smaller one
+        - this means that the top-of-tree very seldom has deltas
+          (i.e. deltas in _practice_ are "backwards deltas")
+
+Again, we should reread that whole paragraph.  Not just because
+Linus has slipped Linus's Law in there on us, but because it is
+important.  Let's make sure we clarify some of the points here:
+
+    <njs`> So the point is just that in practice, delta order and
+        recency order match each other quite well.
+
+    <linus> Yes. There's another nice side to this (and yes, it was
+	designed that way ;):
+        - the reason we generate deltas against the larger object is
+	  actually a big space saver too!
+
+    <njs`> Hmm, but your last comment (if "we haven't yet written out
+        the object it is a delta against, we write out the base object
+        first"), seems like it would make these facts mostly
+        irrelevant because even if in practice you would not have to
+        wander around much, in fact you just brute-force say that in
+        the cases where you might have to wander, don't do that :-)
+
+    <linus> Yes and no. Notice the rule: we only write out the base
+        object first if the delta against it was more recent.  That
+        means that you can actually have deltas that refer to a base
+        object that is _not_ close to the delta object, but that only
+        happens when the delta is needed to generate an _old_ object.
+
+    <linus> See?
+
+Yeah, no.  I missed that on the first two or three readings myself.
+
+    <linus> This keeps the front of the pack dense. The front of the
+        pack never contains data that isn't relevant to a "recent"
+        object.  The size optimization comes from our use of xdelta
+        (but is true for many other delta algorithms): removing data
+        is cheaper (in size) than adding data.
+
+        When you remove data, you only need to say "copy bytes n--m".
+	In contrast, in a delta that _adds_ data, you have to say "add
+        these bytes: 'actual data goes here'"
+
+    *** njs` has quit: Read error: 104 (Connection reset by peer)
+
+    <linus> Uhhuh. I hope I didn't blow njs` mind.
+
+    *** njs` has joined channel #git
+
+    <pasky> :)
+
+The silent observers are amused.  Of course.
+
+And as if njs` was expected to be omniscient:
+
+    <linus> njs - did you miss anything?
+
+OK, I'll spell it out.  That's Geek Humor.  If njs` was not actually
+connected for a little bit there, how would he know if missed anything
+while he was disconnected?  He's a benevolent dictator with a sense of
+humor!  Well noted!
+
+    <njs`> Stupid router.  Or gremlins, or whatever.
+
+It's a cheap shot at Cisco.  Take 'em when you can.
+
+    <njs`> Yes and no. Notice the rule: we only write out the base
+        object first if the delta against it was more recent.
+
+        I'm getting lost in all these orders, let me re-read :-)
+	So the write-out order is from most recent to least recent?
+        (Conceivably it could be the opposite way too, I'm not sure if
+        we've said) though my connection back at home is logging, so I
+        can just read what you said there :-)
+
+And for those of you paying attention, the Omniscient Trick has just
+been detailed!
+
+    <linus> Yes, we always write out most recent first
+
+    <njs`> And, yeah, I got the part about deeper-in-history stuff
+        having worse IO characteristics, one sort of doesn't care.
+
+    <linus> With the caveat that if the "most recent" needs an older
+        object to delta against (hey, shrinking sometimes does
+        happen), we write out the old object with the delta.
+
+    <njs`> (if only it happened more...)
+
+    <linus> Anyway, the pack-file could easily be denser still, but
+	because it's used both for streaming (the Git protocol) and
+        for on-disk, it has a few pessimizations.
+
+Actually, it is a made-up word. But it is a made-up word being
+used as setup for a later optimization, which is a real word:
+
+    <linus> In particular, while the pack-file is then compressed,
+        it's compressed just one object at a time, so the actual
+        compression factor is less than it could be in theory. But it
+        means that it's all nice random-access with a simple index to
+        do "object name->location in packfile" translation.
+
+    <njs`> I'm assuming the real win for delta-ing large->small is
+        more homogeneous statistics for gzip to run over?
+
+        (You have to put the bytes in one place or another, but
+        putting them in a larger blob wins on compression)
+
+        Actually, what is the compression strategy -- each delta
+        individually gzipped, the whole file gzipped, somewhere in
+        between, no compression at all, ....?
+
+        Right.
+
+Reality IRC sets in.  For example:
+
+    <pasky> I'll read the rest in the morning, I really have to go
+        sleep or there's no hope whatsoever for me at the today's
+        exam... g'nite all.
+
+Heh.
+
+    <linus> pasky: g'nite
+
+    <njs`> pasky: 'luck
+
+    <linus> Right: large->small matters exactly because of compression
+        behaviour. If it was non-compressed, it probably wouldn't make
+        any difference.
+
+    <njs`> yeah
+
+    <linus> Anyway: I'm not even trying to claim that the pack-files
+        are perfect, but they do tend to have a nice balance of
+        density vs ease-of use.
+
+Gasp!  OK, saved.  That's a fair Engineering trade off.  Close call!
+In fact, Linus reflects on some Basic Engineering Fundamentals,
+design options, etc.
+
+    <linus> More importantly, they allow Git to still _conceptually_
+        never deal with deltas at all, and be a "whole object" store.
+
+        Which has some problems (we discussed bad huge-file
+	behaviour on the Git lists the other day), but it does mean
+	that the basic Git concepts are really really simple and
+        straightforward.
+
+        It's all been quite stable.
+
+        Which I think is very much a result of having very simple
+        basic ideas, so that there's never any confusion about what's
+        going on.
+
+        Bugs happen, but they are "simple" bugs. And bugs that
+        actually get some object store detail wrong are almost always
+        so obvious that they never go anywhere.
+
+    <njs`> Yeah.
+
+Nuff said.
+
+    <linus> Anyway.  I'm off for bed. It's not 6AM here, but I've got
+	 three kids, and have to get up early in the morning to send
+	 them off. I need my beauty sleep.
+
+    <njs`> :-)
+
+    <njs`> appreciate the infodump, I really was failing to find the
+	details on Git packs :-)
+
+And now you know the rest of the story.
diff --git a/third_party/git/Documentation/technical/pack-protocol.txt b/third_party/git/Documentation/technical/pack-protocol.txt
new file mode 100644
index 0000000000..c73e72de0e
--- /dev/null
+++ b/third_party/git/Documentation/technical/pack-protocol.txt
@@ -0,0 +1,674 @@
+Packfile transfer protocols
+===========================
+
+Git supports transferring data in packfiles over the ssh://, git://, http:// and
+file:// transports.  There exist two sets of protocols, one for pushing
+data from a client to a server and another for fetching data from a
+server to a client.  The three transports (ssh, git, file) use the same
+protocol to transfer data. http is documented in http-protocol.txt.
+
+The processes invoked in the canonical Git implementation are 'upload-pack'
+on the server side and 'fetch-pack' on the client side for fetching data;
+then 'receive-pack' on the server and 'send-pack' on the client for pushing
+data.  The protocol functions to have a server tell a client what is
+currently on the server, then for the two to negotiate the smallest amount
+of data to send in order to fully update one or the other.
+
+pkt-line Format
+---------------
+
+The descriptions below build on the pkt-line format described in
+protocol-common.txt. When the grammar indicate `PKT-LINE(...)`, unless
+otherwise noted the usual pkt-line LF rules apply: the sender SHOULD
+include a LF, but the receiver MUST NOT complain if it is not present.
+
+An error packet is a special pkt-line that contains an error string.
+
+----
+  error-line     =  PKT-LINE("ERR" SP explanation-text)
+----
+
+Throughout the protocol, where `PKT-LINE(...)` is expected, an error packet MAY
+be sent. Once this packet is sent by a client or a server, the data transfer
+process defined in this protocol is terminated.
+
+Transports
+----------
+There are three transports over which the packfile protocol is
+initiated.  The Git transport is a simple, unauthenticated server that
+takes the command (almost always 'upload-pack', though Git
+servers can be configured to be globally writable, in which 'receive-
+pack' initiation is also allowed) with which the client wishes to
+communicate and executes it and connects it to the requesting
+process.
+
+In the SSH transport, the client just runs the 'upload-pack'
+or 'receive-pack' process on the server over the SSH protocol and then
+communicates with that invoked process over the SSH connection.
+
+The file:// transport runs the 'upload-pack' or 'receive-pack'
+process locally and communicates with it over a pipe.
+
+Extra Parameters
+----------------
+
+The protocol provides a mechanism in which clients can send additional
+information in its first message to the server. These are called "Extra
+Parameters", and are supported by the Git, SSH, and HTTP protocols.
+
+Each Extra Parameter takes the form of `<key>=<value>` or `<key>`.
+
+Servers that receive any such Extra Parameters MUST ignore all
+unrecognized keys. Currently, the only Extra Parameter recognized is
+"version" with a value of '1' or '2'.  See protocol-v2.txt for more
+information on protocol version 2.
+
+Git Transport
+-------------
+
+The Git transport starts off by sending the command and repository
+on the wire using the pkt-line format, followed by a NUL byte and a
+hostname parameter, terminated by a NUL byte.
+
+   0033git-upload-pack /project.git\0host=myserver.com\0
+
+The transport may send Extra Parameters by adding an additional NUL
+byte, and then adding one or more NUL-terminated strings:
+
+   003egit-upload-pack /project.git\0host=myserver.com\0\0version=1\0
+
+--
+   git-proto-request = request-command SP pathname NUL
+		       [ host-parameter NUL ] [ NUL extra-parameters ]
+   request-command   = "git-upload-pack" / "git-receive-pack" /
+		       "git-upload-archive"   ; case sensitive
+   pathname          = *( %x01-ff ) ; exclude NUL
+   host-parameter    = "host=" hostname [ ":" port ]
+   extra-parameters  = 1*extra-parameter
+   extra-parameter   = 1*( %x01-ff ) NUL
+--
+
+host-parameter is used for the
+git-daemon name based virtual hosting.  See --interpolated-path
+option to git daemon, with the %H/%CH format characters.
+
+Basically what the Git client is doing to connect to an 'upload-pack'
+process on the server side over the Git protocol is this:
+
+   $ echo -e -n \
+     "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" |
+     nc -v example.com 9418
+
+
+SSH Transport
+-------------
+
+Initiating the upload-pack or receive-pack processes over SSH is
+executing the binary on the server via SSH remote execution.
+It is basically equivalent to running this:
+
+   $ ssh git.example.com "git-upload-pack '/project.git'"
+
+For a server to support Git pushing and pulling for a given user over
+SSH, that user needs to be able to execute one or both of those
+commands via the SSH shell that they are provided on login.  On some
+systems, that shell access is limited to only being able to run those
+two commands, or even just one of them.
+
+In an ssh:// format URI, it's absolute in the URI, so the '/' after
+the host name (or port number) is sent as an argument, which is then
+read by the remote git-upload-pack exactly as is, so it's effectively
+an absolute path in the remote filesystem.
+
+       git clone ssh://user@example.com/project.git
+		    |
+		    v
+    ssh user@example.com "git-upload-pack '/project.git'"
+
+In a "user@host:path" format URI, its relative to the user's home
+directory, because the Git client will run:
+
+     git clone user@example.com:project.git
+		    |
+		    v
+  ssh user@example.com "git-upload-pack 'project.git'"
+
+The exception is if a '~' is used, in which case
+we execute it without the leading '/'.
+
+      ssh://user@example.com/~alice/project.git,
+		     |
+		     v
+   ssh user@example.com "git-upload-pack '~alice/project.git'"
+
+Depending on the value of the `protocol.version` configuration variable,
+Git may attempt to send Extra Parameters as a colon-separated string in
+the GIT_PROTOCOL environment variable. This is done only if
+the `ssh.variant` configuration variable indicates that the ssh command
+supports passing environment variables as an argument.
+
+A few things to remember here:
+
+- The "command name" is spelled with dash (e.g. git-upload-pack), but
+  this can be overridden by the client;
+
+- The repository path is always quoted with single quotes.
+
+Fetching Data From a Server
+---------------------------
+
+When one Git repository wants to get data that a second repository
+has, the first can 'fetch' from the second.  This operation determines
+what data the server has that the client does not then streams that
+data down to the client in packfile format.
+
+
+Reference Discovery
+-------------------
+
+When the client initially connects the server will immediately respond
+with a version number (if "version=1" is sent as an Extra Parameter),
+and a listing of each reference it has (all branches and tags) along
+with the object name that each reference currently points to.
+
+   $ echo -e -n "0044git-upload-pack /schacon/gitbook.git\0host=example.com\0\0version=1\0" |
+      nc -v example.com 9418
+   000aversion 1
+   00887217a7c7e582c46cec22a130adf4b9d7d950fba0 HEAD\0multi_ack thin-pack
+		side-band side-band-64k ofs-delta shallow no-progress include-tag
+   00441d3fcd5ced445d1abc402225c0b8a1299641f497 refs/heads/integration
+   003f7217a7c7e582c46cec22a130adf4b9d7d950fba0 refs/heads/master
+   003cb88d2441cac0977faf98efc80305012112238d9d refs/tags/v0.9
+   003c525128480b96c89e6418b1e40909bf6c5b2d580f refs/tags/v1.0
+   003fe92df48743b7bc7d26bcaabfddde0a1e20cae47c refs/tags/v1.0^{}
+   0000
+
+The returned response is a pkt-line stream describing each ref and
+its current value.  The stream MUST be sorted by name according to
+the C locale ordering.
+
+If HEAD is a valid ref, HEAD MUST appear as the first advertised
+ref.  If HEAD is not a valid ref, HEAD MUST NOT appear in the
+advertisement list at all, but other refs may still appear.
+
+The stream MUST include capability declarations behind a NUL on the
+first ref. The peeled value of a ref (that is "ref^{}") MUST be
+immediately after the ref itself, if presented. A conforming server
+MUST peel the ref if it's an annotated tag.
+
+----
+  advertised-refs  =  *1("version 1")
+		      (no-refs / list-of-refs)
+		      *shallow
+		      flush-pkt
+
+  no-refs          =  PKT-LINE(zero-id SP "capabilities^{}"
+		      NUL capability-list)
+
+  list-of-refs     =  first-ref *other-ref
+  first-ref        =  PKT-LINE(obj-id SP refname
+		      NUL capability-list)
+
+  other-ref        =  PKT-LINE(other-tip / other-peeled)
+  other-tip        =  obj-id SP refname
+  other-peeled     =  obj-id SP refname "^{}"
+
+  shallow          =  PKT-LINE("shallow" SP obj-id)
+
+  capability-list  =  capability *(SP capability)
+  capability       =  1*(LC_ALPHA / DIGIT / "-" / "_")
+  LC_ALPHA         =  %x61-7A
+----
+
+Server and client MUST use lowercase for obj-id, both MUST treat obj-id
+as case-insensitive.
+
+See protocol-capabilities.txt for a list of allowed server capabilities
+and descriptions.
+
+Packfile Negotiation
+--------------------
+After reference and capabilities discovery, the client can decide to
+terminate the connection by sending a flush-pkt, telling the server it can
+now gracefully terminate, and disconnect, when it does not need any pack
+data. This can happen with the ls-remote command, and also can happen when
+the client already is up to date.
+
+Otherwise, it enters the negotiation phase, where the client and
+server determine what the minimal packfile necessary for transport is,
+by telling the server what objects it wants, its shallow objects
+(if any), and the maximum commit depth it wants (if any).  The client
+will also send a list of the capabilities it wants to be in effect,
+out of what the server said it could do with the first 'want' line.
+
+----
+  upload-request    =  want-list
+		       *shallow-line
+		       *1depth-request
+		       [filter-request]
+		       flush-pkt
+
+  want-list         =  first-want
+		       *additional-want
+
+  shallow-line      =  PKT-LINE("shallow" SP obj-id)
+
+  depth-request     =  PKT-LINE("deepen" SP depth) /
+		       PKT-LINE("deepen-since" SP timestamp) /
+		       PKT-LINE("deepen-not" SP ref)
+
+  first-want        =  PKT-LINE("want" SP obj-id SP capability-list)
+  additional-want   =  PKT-LINE("want" SP obj-id)
+
+  depth             =  1*DIGIT
+
+  filter-request    =  PKT-LINE("filter" SP filter-spec)
+----
+
+Clients MUST send all the obj-ids it wants from the reference
+discovery phase as 'want' lines. Clients MUST send at least one
+'want' command in the request body. Clients MUST NOT mention an
+obj-id in a 'want' command which did not appear in the response
+obtained through ref discovery.
+
+The client MUST write all obj-ids which it only has shallow copies
+of (meaning that it does not have the parents of a commit) as
+'shallow' lines so that the server is aware of the limitations of
+the client's history.
+
+The client now sends the maximum commit history depth it wants for
+this transaction, which is the number of commits it wants from the
+tip of the history, if any, as a 'deepen' line.  A depth of 0 is the
+same as not making a depth request. The client does not want to receive
+any commits beyond this depth, nor does it want objects needed only to
+complete those commits. Commits whose parents are not received as a
+result are defined as shallow and marked as such in the server. This
+information is sent back to the client in the next step.
+
+The client can optionally request that pack-objects omit various
+objects from the packfile using one of several filtering techniques.
+These are intended for use with partial clone and partial fetch
+operations. An object that does not meet a filter-spec value is
+omitted unless explicitly requested in a 'want' line. See `rev-list`
+for possible filter-spec values.
+
+Once all the 'want's and 'shallow's (and optional 'deepen') are
+transferred, clients MUST send a flush-pkt, to tell the server side
+that it is done sending the list.
+
+Otherwise, if the client sent a positive depth request, the server
+will determine which commits will and will not be shallow and
+send this information to the client. If the client did not request
+a positive depth, this step is skipped.
+
+----
+  shallow-update   =  *shallow-line
+		      *unshallow-line
+		      flush-pkt
+
+  shallow-line     =  PKT-LINE("shallow" SP obj-id)
+
+  unshallow-line   =  PKT-LINE("unshallow" SP obj-id)
+----
+
+If the client has requested a positive depth, the server will compute
+the set of commits which are no deeper than the desired depth. The set
+of commits start at the client's wants.
+
+The server writes 'shallow' lines for each
+commit whose parents will not be sent as a result. The server writes
+an 'unshallow' line for each commit which the client has indicated is
+shallow, but is no longer shallow at the currently requested depth
+(that is, its parents will now be sent). The server MUST NOT mark
+as unshallow anything which the client has not indicated was shallow.
+
+Now the client will send a list of the obj-ids it has using 'have'
+lines, so the server can make a packfile that only contains the objects
+that the client needs. In multi_ack mode, the canonical implementation
+will send up to 32 of these at a time, then will send a flush-pkt. The
+canonical implementation will skip ahead and send the next 32 immediately,
+so that there is always a block of 32 "in-flight on the wire" at a time.
+
+----
+  upload-haves      =  have-list
+		       compute-end
+
+  have-list         =  *have-line
+  have-line         =  PKT-LINE("have" SP obj-id)
+  compute-end       =  flush-pkt / PKT-LINE("done")
+----
+
+If the server reads 'have' lines, it then will respond by ACKing any
+of the obj-ids the client said it had that the server also has. The
+server will ACK obj-ids differently depending on which ack mode is
+chosen by the client.
+
+In multi_ack mode:
+
+  * the server will respond with 'ACK obj-id continue' for any common
+    commits.
+
+  * once the server has found an acceptable common base commit and is
+    ready to make a packfile, it will blindly ACK all 'have' obj-ids
+    back to the client.
+
+  * the server will then send a 'NAK' and then wait for another response
+    from the client - either a 'done' or another list of 'have' lines.
+
+In multi_ack_detailed mode:
+
+  * the server will differentiate the ACKs where it is signaling
+    that it is ready to send data with 'ACK obj-id ready' lines, and
+    signals the identified common commits with 'ACK obj-id common' lines.
+
+Without either multi_ack or multi_ack_detailed:
+
+ * upload-pack sends "ACK obj-id" on the first common object it finds.
+   After that it says nothing until the client gives it a "done".
+
+ * upload-pack sends "NAK" on a flush-pkt if no common object
+   has been found yet.  If one has been found, and thus an ACK
+   was already sent, it's silent on the flush-pkt.
+
+After the client has gotten enough ACK responses that it can determine
+that the server has enough information to send an efficient packfile
+(in the canonical implementation, this is determined when it has received
+enough ACKs that it can color everything left in the --date-order queue
+as common with the server, or the --date-order queue is empty), or the
+client determines that it wants to give up (in the canonical implementation,
+this is determined when the client sends 256 'have' lines without getting
+any of them ACKed by the server - meaning there is nothing in common and
+the server should just send all of its objects), then the client will send
+a 'done' command.  The 'done' command signals to the server that the client
+is ready to receive its packfile data.
+
+However, the 256 limit *only* turns on in the canonical client
+implementation if we have received at least one "ACK %s continue"
+during a prior round.  This helps to ensure that at least one common
+ancestor is found before we give up entirely.
+
+Once the 'done' line is read from the client, the server will either
+send a final 'ACK obj-id' or it will send a 'NAK'. 'obj-id' is the object
+name of the last commit determined to be common. The server only sends
+ACK after 'done' if there is at least one common base and multi_ack or
+multi_ack_detailed is enabled. The server always sends NAK after 'done'
+if there is no common base found.
+
+Instead of 'ACK' or 'NAK', the server may send an error message (for
+example, if it does not recognize an object in a 'want' line received
+from the client).
+
+Then the server will start sending its packfile data.
+
+----
+  server-response = *ack_multi ack / nak
+  ack_multi       = PKT-LINE("ACK" SP obj-id ack_status)
+  ack_status      = "continue" / "common" / "ready"
+  ack             = PKT-LINE("ACK" SP obj-id)
+  nak             = PKT-LINE("NAK")
+----
+
+A simple clone may look like this (with no 'have' lines):
+
+----
+   C: 0054want 74730d410fcb6603ace96f1dc55ea6196122532d multi_ack \
+     side-band-64k ofs-delta\n
+   C: 0032want 7d1665144a3a975c05f1f43902ddaf084e784dbe\n
+   C: 0032want 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a\n
+   C: 0032want 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01\n
+   C: 0032want 74730d410fcb6603ace96f1dc55ea6196122532d\n
+   C: 0000
+   C: 0009done\n
+
+   S: 0008NAK\n
+   S: [PACKFILE]
+----
+
+An incremental update (fetch) response might look like this:
+
+----
+   C: 0054want 74730d410fcb6603ace96f1dc55ea6196122532d multi_ack \
+     side-band-64k ofs-delta\n
+   C: 0032want 7d1665144a3a975c05f1f43902ddaf084e784dbe\n
+   C: 0032want 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a\n
+   C: 0000
+   C: 0032have 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01\n
+   C: [30 more have lines]
+   C: 0032have 74730d410fcb6603ace96f1dc55ea6196122532d\n
+   C: 0000
+
+   S: 003aACK 7e47fe2bd8d01d481f44d7af0531bd93d3b21c01 continue\n
+   S: 003aACK 74730d410fcb6603ace96f1dc55ea6196122532d continue\n
+   S: 0008NAK\n
+
+   C: 0009done\n
+
+   S: 0031ACK 74730d410fcb6603ace96f1dc55ea6196122532d\n
+   S: [PACKFILE]
+----
+
+
+Packfile Data
+-------------
+
+Now that the client and server have finished negotiation about what
+the minimal amount of data that needs to be sent to the client is, the server
+will construct and send the required data in packfile format.
+
+See pack-format.txt for what the packfile itself actually looks like.
+
+If 'side-band' or 'side-band-64k' capabilities have been specified by
+the client, the server will send the packfile data multiplexed.
+
+Each packet starting with the packet-line length of the amount of data
+that follows, followed by a single byte specifying the sideband the
+following data is coming in on.
+
+In 'side-band' mode, it will send up to 999 data bytes plus 1 control
+code, for a total of up to 1000 bytes in a pkt-line.  In 'side-band-64k'
+mode it will send up to 65519 data bytes plus 1 control code, for a
+total of up to 65520 bytes in a pkt-line.
+
+The sideband byte will be a '1', '2' or a '3'. Sideband '1' will contain
+packfile data, sideband '2' will be used for progress information that the
+client will generally print to stderr and sideband '3' is used for error
+information.
+
+If no 'side-band' capability was specified, the server will stream the
+entire packfile without multiplexing.
+
+
+Pushing Data To a Server
+------------------------
+
+Pushing data to a server will invoke the 'receive-pack' process on the
+server, which will allow the client to tell it which references it should
+update and then send all the data the server will need for those new
+references to be complete.  Once all the data is received and validated,
+the server will then update its references to what the client specified.
+
+Authentication
+--------------
+
+The protocol itself contains no authentication mechanisms.  That is to be
+handled by the transport, such as SSH, before the 'receive-pack' process is
+invoked.  If 'receive-pack' is configured over the Git transport, those
+repositories will be writable by anyone who can access that port (9418) as
+that transport is unauthenticated.
+
+Reference Discovery
+-------------------
+
+The reference discovery phase is done nearly the same way as it is in the
+fetching protocol. Each reference obj-id and name on the server is sent
+in packet-line format to the client, followed by a flush-pkt.  The only
+real difference is that the capability listing is different - the only
+possible values are 'report-status', 'delete-refs', 'ofs-delta' and
+'push-options'.
+
+Reference Update Request and Packfile Transfer
+----------------------------------------------
+
+Once the client knows what references the server is at, it can send a
+list of reference update requests.  For each reference on the server
+that it wants to update, it sends a line listing the obj-id currently on
+the server, the obj-id the client would like to update it to and the name
+of the reference.
+
+This list is followed by a flush-pkt.
+
+----
+  update-requests   =  *shallow ( command-list | push-cert )
+
+  shallow           =  PKT-LINE("shallow" SP obj-id)
+
+  command-list      =  PKT-LINE(command NUL capability-list)
+		       *PKT-LINE(command)
+		       flush-pkt
+
+  command           =  create / delete / update
+  create            =  zero-id SP new-id  SP name
+  delete            =  old-id  SP zero-id SP name
+  update            =  old-id  SP new-id  SP name
+
+  old-id            =  obj-id
+  new-id            =  obj-id
+
+  push-cert         = PKT-LINE("push-cert" NUL capability-list LF)
+		      PKT-LINE("certificate version 0.1" LF)
+		      PKT-LINE("pusher" SP ident LF)
+		      PKT-LINE("pushee" SP url LF)
+		      PKT-LINE("nonce" SP nonce LF)
+		      *PKT-LINE("push-option" SP push-option LF)
+		      PKT-LINE(LF)
+		      *PKT-LINE(command LF)
+		      *PKT-LINE(gpg-signature-lines LF)
+		      PKT-LINE("push-cert-end" LF)
+
+  push-option       =  1*( VCHAR | SP )
+----
+
+If the server has advertised the 'push-options' capability and the client has
+specified 'push-options' as part of the capability list above, the client then
+sends its push options followed by a flush-pkt.
+
+----
+  push-options      =  *PKT-LINE(push-option) flush-pkt
+----
+
+For backwards compatibility with older Git servers, if the client sends a push
+cert and push options, it MUST send its push options both embedded within the
+push cert and after the push cert. (Note that the push options within the cert
+are prefixed, but the push options after the cert are not.) Both these lists
+MUST be the same, modulo the prefix.
+
+After that the packfile that
+should contain all the objects that the server will need to complete the new
+references will be sent.
+
+----
+  packfile          =  "PACK" 28*(OCTET)
+----
+
+If the receiving end does not support delete-refs, the sending end MUST
+NOT ask for delete command.
+
+If the receiving end does not support push-cert, the sending end
+MUST NOT send a push-cert command.  When a push-cert command is
+sent, command-list MUST NOT be sent; the commands recorded in the
+push certificate is used instead.
+
+The packfile MUST NOT be sent if the only command used is 'delete'.
+
+A packfile MUST be sent if either create or update command is used,
+even if the server already has all the necessary objects.  In this
+case the client MUST send an empty packfile.   The only time this
+is likely to happen is if the client is creating
+a new branch or a tag that points to an existing obj-id.
+
+The server will receive the packfile, unpack it, then validate each
+reference that is being updated that it hasn't changed while the request
+was being processed (the obj-id is still the same as the old-id), and
+it will run any update hooks to make sure that the update is acceptable.
+If all of that is fine, the server will then update the references.
+
+Push Certificate
+----------------
+
+A push certificate begins with a set of header lines.  After the
+header and an empty line, the protocol commands follow, one per
+line. Note that the trailing LF in push-cert PKT-LINEs is _not_
+optional; it must be present.
+
+Currently, the following header fields are defined:
+
+`pusher` ident::
+	Identify the GPG key in "Human Readable Name <email@address>"
+	format.
+
+`pushee` url::
+	The repository URL (anonymized, if the URL contains
+	authentication material) the user who ran `git push`
+	intended to push into.
+
+`nonce` nonce::
+	The 'nonce' string the receiving repository asked the
+	pushing user to include in the certificate, to prevent
+	replay attacks.
+
+The GPG signature lines are a detached signature for the contents
+recorded in the push certificate before the signature block begins.
+The detached signature is used to certify that the commands were
+given by the pusher, who must be the signer.
+
+Report Status
+-------------
+
+After receiving the pack data from the sender, the receiver sends a
+report if 'report-status' capability is in effect.
+It is a short listing of what happened in that update.  It will first
+list the status of the packfile unpacking as either 'unpack ok' or
+'unpack [error]'.  Then it will list the status for each of the references
+that it tried to update.  Each line is either 'ok [refname]' if the
+update was successful, or 'ng [refname] [error]' if the update was not.
+
+----
+  report-status     = unpack-status
+		      1*(command-status)
+		      flush-pkt
+
+  unpack-status     = PKT-LINE("unpack" SP unpack-result)
+  unpack-result     = "ok" / error-msg
+
+  command-status    = command-ok / command-fail
+  command-ok        = PKT-LINE("ok" SP refname)
+  command-fail      = PKT-LINE("ng" SP refname SP error-msg)
+
+  error-msg         = 1*(OCTECT) ; where not "ok"
+----
+
+Updates can be unsuccessful for a number of reasons.  The reference can have
+changed since the reference discovery phase was originally sent, meaning
+someone pushed in the meantime.  The reference being pushed could be a
+non-fast-forward reference and the update hooks or configuration could be
+set to not allow that, etc.  Also, some references can be updated while others
+can be rejected.
+
+An example client/server communication might look like this:
+
+----
+   S: 006274730d410fcb6603ace96f1dc55ea6196122532d refs/heads/local\0report-status delete-refs ofs-delta\n
+   S: 003e7d1665144a3a975c05f1f43902ddaf084e784dbe refs/heads/debug\n
+   S: 003f74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/master\n
+   S: 003d74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/team\n
+   S: 0000
+
+   C: 00677d1665144a3a975c05f1f43902ddaf084e784dbe 74730d410fcb6603ace96f1dc55ea6196122532d refs/heads/debug\n
+   C: 006874730d410fcb6603ace96f1dc55ea6196122532d 5a3f6be755bbb7deae50065988cbfa1ffa9ab68a refs/heads/master\n
+   C: 0000
+   C: [PACKDATA]
+
+   S: 000eunpack ok\n
+   S: 0018ok refs/heads/debug\n
+   S: 002ang refs/heads/master non-fast-forward\n
+----
diff --git a/third_party/git/Documentation/technical/partial-clone.txt b/third_party/git/Documentation/technical/partial-clone.txt
new file mode 100644
index 0000000000..896c7b3878
--- /dev/null
+++ b/third_party/git/Documentation/technical/partial-clone.txt
@@ -0,0 +1,324 @@
+Partial Clone Design Notes
+==========================
+
+The "Partial Clone" feature is a performance optimization for Git that
+allows Git to function without having a complete copy of the repository.
+The goal of this work is to allow Git better handle extremely large
+repositories.
+
+During clone and fetch operations, Git downloads the complete contents
+and history of the repository.  This includes all commits, trees, and
+blobs for the complete life of the repository.  For extremely large
+repositories, clones can take hours (or days) and consume 100+GiB of disk
+space.
+
+Often in these repositories there are many blobs and trees that the user
+does not need such as:
+
+  1. files outside of the user's work area in the tree.  For example, in
+     a repository with 500K directories and 3.5M files in every commit,
+     we can avoid downloading many objects if the user only needs a
+     narrow "cone" of the source tree.
+
+  2. large binary assets.  For example, in a repository where large build
+     artifacts are checked into the tree, we can avoid downloading all
+     previous versions of these non-mergeable binary assets and only
+     download versions that are actually referenced.
+
+Partial clone allows us to avoid downloading such unneeded objects *in
+advance* during clone and fetch operations and thereby reduce download
+times and disk usage.  Missing objects can later be "demand fetched"
+if/when needed.
+
+Use of partial clone requires that the user be online and the origin
+remote be available for on-demand fetching of missing objects.  This may
+or may not be problematic for the user.  For example, if the user can
+stay within the pre-selected subset of the source tree, they may not
+encounter any missing objects.  Alternatively, the user could try to
+pre-fetch various objects if they know that they are going offline.
+
+
+Non-Goals
+---------
+
+Partial clone is a mechanism to limit the number of blobs and trees downloaded
+*within* a given range of commits -- and is therefore independent of and not
+intended to conflict with existing DAG-level mechanisms to limit the set of
+requested commits (i.e. shallow clone, single branch, or fetch '<refspec>').
+
+
+Design Overview
+---------------
+
+Partial clone logically consists of the following parts:
+
+- A mechanism for the client to describe unneeded or unwanted objects to
+  the server.
+
+- A mechanism for the server to omit such unwanted objects from packfiles
+  sent to the client.
+
+- A mechanism for the client to gracefully handle missing objects (that
+  were previously omitted by the server).
+
+- A mechanism for the client to backfill missing objects as needed.
+
+
+Design Details
+--------------
+
+- A new pack-protocol capability "filter" is added to the fetch-pack and
+  upload-pack negotiation.
++
+This uses the existing capability discovery mechanism.
+See "filter" in Documentation/technical/pack-protocol.txt.
+
+- Clients pass a "filter-spec" to clone and fetch which is passed to the
+  server to request filtering during packfile construction.
++
+There are various filters available to accommodate different situations.
+See "--filter=<filter-spec>" in Documentation/rev-list-options.txt.
+
+- On the server pack-objects applies the requested filter-spec as it
+  creates "filtered" packfiles for the client.
++
+These filtered packfiles are *incomplete* in the traditional sense because
+they may contain objects that reference objects not contained in the
+packfile and that the client doesn't already have.  For example, the
+filtered packfile may contain trees or tags that reference missing blobs
+or commits that reference missing trees.
+
+- On the client these incomplete packfiles are marked as "promisor packfiles"
+  and treated differently by various commands.
+
+- On the client a repository extension is added to the local config to
+  prevent older versions of git from failing mid-operation because of
+  missing objects that they cannot handle.
+  See "extensions.partialClone" in Documentation/technical/repository-version.txt"
+
+
+Handling Missing Objects
+------------------------
+
+- An object may be missing due to a partial clone or fetch, or missing due
+  to repository corruption.  To differentiate these cases, the local
+  repository specially indicates such filtered packfiles obtained from the
+  promisor remote as "promisor packfiles".
++
+These promisor packfiles consist of a "<name>.promisor" file with
+arbitrary contents (like the "<name>.keep" files), in addition to
+their "<name>.pack" and "<name>.idx" files.
+
+- The local repository considers a "promisor object" to be an object that
+  it knows (to the best of its ability) that the promisor remote has promised
+  that it has, either because the local repository has that object in one of
+  its promisor packfiles, or because another promisor object refers to it.
++
+When Git encounters a missing object, Git can see if it is a promisor object
+and handle it appropriately.  If not, Git can report a corruption.
++
+This means that there is no need for the client to explicitly maintain an
+expensive-to-modify list of missing objects.[a]
+
+- Since almost all Git code currently expects any referenced object to be
+  present locally and because we do not want to force every command to do
+  a dry-run first, a fallback mechanism is added to allow Git to attempt
+  to dynamically fetch missing objects from the promisor remote.
++
+When the normal object lookup fails to find an object, Git invokes
+fetch-object to try to get the object from the server and then retry
+the object lookup.  This allows objects to be "faulted in" without
+complicated prediction algorithms.
++
+For efficiency reasons, no check as to whether the missing object is
+actually a promisor object is performed.
++
+Dynamic object fetching tends to be slow as objects are fetched one at
+a time.
+
+- `checkout` (and any other command using `unpack-trees`) has been taught
+  to bulk pre-fetch all required missing blobs in a single batch.
+
+- `rev-list` has been taught to print missing objects.
++
+This can be used by other commands to bulk prefetch objects.
+For example, a "git log -p A..B" may internally want to first do
+something like "git rev-list --objects --quiet --missing=print A..B"
+and prefetch those objects in bulk.
+
+- `fsck` has been updated to be fully aware of promisor objects.
+
+- `repack` in GC has been updated to not touch promisor packfiles at all,
+  and to only repack other objects.
+
+- The global variable "fetch_if_missing" is used to control whether an
+  object lookup will attempt to dynamically fetch a missing object or
+  report an error.
++
+We are not happy with this global variable and would like to remove it,
+but that requires significant refactoring of the object code to pass an
+additional flag.  We hope that concurrent efforts to add an ODB API can
+encompass this.
+
+
+Fetching Missing Objects
+------------------------
+
+- Fetching of objects is done using the existing transport mechanism using
+  transport_fetch_refs(), setting a new transport option
+  TRANS_OPT_NO_DEPENDENTS to indicate that only the objects themselves are
+  desired, not any object that they refer to.
++
+Because some transports invoke fetch_pack() in the same process, fetch_pack()
+has been updated to not use any object flags when the corresponding argument
+(no_dependents) is set.
+
+- The local repository sends a request with the hashes of all requested
+  objects as "want" lines, and does not perform any packfile negotiation.
+  It then receives a packfile.
+
+- Because we are reusing the existing fetch-pack mechanism, fetching
+  currently fetches all objects referred to by the requested objects, even
+  though they are not necessary.
+
+
+Current Limitations
+-------------------
+
+- The remote used for a partial clone (or the first partial fetch
+  following a regular clone) is marked as the "promisor remote".
++
+We are currently limited to a single promisor remote and only that
+remote may be used for subsequent partial fetches.
++
+We accept this limitation because we believe initial users of this
+feature will be using it on repositories with a strong single central
+server.
+
+- Dynamic object fetching will only ask the promisor remote for missing
+  objects.  We assume that the promisor remote has a complete view of the
+  repository and can satisfy all such requests.
+
+- Repack essentially treats promisor and non-promisor packfiles as 2
+  distinct partitions and does not mix them.  Repack currently only works
+  on non-promisor packfiles and loose objects.
+
+- Dynamic object fetching invokes fetch-pack once *for each item*
+  because most algorithms stumble upon a missing object and need to have
+  it resolved before continuing their work.  This may incur significant
+  overhead -- and multiple authentication requests -- if many objects are
+  needed.
+
+- Dynamic object fetching currently uses the existing pack protocol V0
+  which means that each object is requested via fetch-pack.  The server
+  will send a full set of info/refs when the connection is established.
+  If there are large number of refs, this may incur significant overhead.
+
+
+Future Work
+-----------
+
+- Allow more than one promisor remote and define a strategy for fetching
+  missing objects from specific promisor remotes or of iterating over the
+  set of promisor remotes until a missing object is found.
++
+A user might want to have multiple geographically-close cache servers
+for fetching missing blobs while continuing to do filtered `git-fetch`
+commands from the central server, for example.
++
+Or the user might want to work in a triangular work flow with multiple
+promisor remotes that each have an incomplete view of the repository.
+
+- Allow repack to work on promisor packfiles (while keeping them distinct
+  from non-promisor packfiles).
+
+- Allow non-pathname-based filters to make use of packfile bitmaps (when
+  present).  This was just an omission during the initial implementation.
+
+- Investigate use of a long-running process to dynamically fetch a series
+  of objects, such as proposed in [5,6] to reduce process startup and
+  overhead costs.
++
+It would be nice if pack protocol V2 could allow that long-running
+process to make a series of requests over a single long-running
+connection.
+
+- Investigate pack protocol V2 to avoid the info/refs broadcast on
+  each connection with the server to dynamically fetch missing objects.
+
+- Investigate the need to handle loose promisor objects.
++
+Objects in promisor packfiles are allowed to reference missing objects
+that can be dynamically fetched from the server.  An assumption was
+made that loose objects are only created locally and therefore should
+not reference a missing object.  We may need to revisit that assumption
+if, for example, we dynamically fetch a missing tree and store it as a
+loose object rather than a single object packfile.
++
+This does not necessarily mean we need to mark loose objects as promisor;
+it may be sufficient to relax the object lookup or is-promisor functions.
+
+
+Non-Tasks
+---------
+
+- Every time the subject of "demand loading blobs" comes up it seems
+  that someone suggests that the server be allowed to "guess" and send
+  additional objects that may be related to the requested objects.
++
+No work has gone into actually doing that; we're just documenting that
+it is a common suggestion.  We're not sure how it would work and have
+no plans to work on it.
++
+It is valid for the server to send more objects than requested (even
+for a dynamic object fetch), but we are not building on that.
+
+
+Footnotes
+---------
+
+[a] expensive-to-modify list of missing objects:  Earlier in the design of
+    partial clone we discussed the need for a single list of missing objects.
+    This would essentially be a sorted linear list of OIDs that the were
+    omitted by the server during a clone or subsequent fetches.
+
+This file would need to be loaded into memory on every object lookup.
+It would need to be read, updated, and re-written (like the .git/index)
+on every explicit "git fetch" command *and* on any dynamic object fetch.
+
+The cost to read, update, and write this file could add significant
+overhead to every command if there are many missing objects.  For example,
+if there are 100M missing blobs, this file would be at least 2GiB on disk.
+
+With the "promisor" concept, we *infer* a missing object based upon the
+type of packfile that references it.
+
+
+Related Links
+-------------
+[0] https://crbug.com/git/2
+    Bug#2: Partial Clone
+
+[1] https://public-inbox.org/git/20170113155253.1644-1-benpeart@microsoft.com/ +
+    Subject: [RFC] Add support for downloading blobs on demand +
+    Date: Fri, 13 Jan 2017 10:52:53 -0500
+
+[2] https://public-inbox.org/git/cover.1506714999.git.jonathantanmy@google.com/ +
+    Subject: [PATCH 00/18] Partial clone (from clone to lazy fetch in 18 patches) +
+    Date: Fri, 29 Sep 2017 13:11:36 -0700
+
+[3] https://public-inbox.org/git/20170426221346.25337-1-jonathantanmy@google.com/ +
+    Subject: Proposal for missing blob support in Git repos +
+    Date: Wed, 26 Apr 2017 15:13:46 -0700
+
+[4] https://public-inbox.org/git/1488999039-37631-1-git-send-email-git@jeffhostetler.com/ +
+    Subject: [PATCH 00/10] RFC Partial Clone and Fetch +
+    Date: Wed,  8 Mar 2017 18:50:29 +0000
+
+[5] https://public-inbox.org/git/20170505152802.6724-1-benpeart@microsoft.com/ +
+    Subject: [PATCH v7 00/10] refactor the filter process code into a reusable module +
+    Date: Fri,  5 May 2017 11:27:52 -0400
+
+[6] https://public-inbox.org/git/20170714132651.170708-1-benpeart@microsoft.com/ +
+    Subject: [RFC/PATCH v2 0/1] Add support for downloading blobs on demand +
+    Date: Fri, 14 Jul 2017 09:26:50 -0400
diff --git a/third_party/git/Documentation/technical/protocol-capabilities.txt b/third_party/git/Documentation/technical/protocol-capabilities.txt
new file mode 100644
index 0000000000..2b267c0da6
--- /dev/null
+++ b/third_party/git/Documentation/technical/protocol-capabilities.txt
@@ -0,0 +1,337 @@
+Git Protocol Capabilities
+=========================
+
+NOTE: this document describes capabilities for versions 0 and 1 of the pack
+protocol. For version 2, please refer to the link:protocol-v2.html[protocol-v2]
+doc.
+
+Servers SHOULD support all capabilities defined in this document.
+
+On the very first line of the initial server response of either
+receive-pack and upload-pack the first reference is followed by
+a NUL byte and then a list of space delimited server capabilities.
+These allow the server to declare what it can and cannot support
+to the client.
+
+Client will then send a space separated list of capabilities it wants
+to be in effect. The client MUST NOT ask for capabilities the server
+did not say it supports.
+
+Server MUST diagnose and abort if capabilities it does not understand
+was sent.  Server MUST NOT ignore capabilities that client requested
+and server advertised.  As a consequence of these rules, server MUST
+NOT advertise capabilities it does not understand.
+
+The 'atomic', 'report-status', 'delete-refs', 'quiet', and 'push-cert'
+capabilities are sent and recognized by the receive-pack (push to server)
+process.
+
+The 'ofs-delta' and 'side-band-64k' capabilities are sent and recognized
+by both upload-pack and receive-pack protocols.  The 'agent' capability
+may optionally be sent in both protocols.
+
+All other capabilities are only recognized by the upload-pack (fetch
+from server) process.
+
+multi_ack
+---------
+
+The 'multi_ack' capability allows the server to return "ACK obj-id
+continue" as soon as it finds a commit that it can use as a common
+base, between the client's wants and the client's have set.
+
+By sending this early, the server can potentially head off the client
+from walking any further down that particular branch of the client's
+repository history.  The client may still need to walk down other
+branches, sending have lines for those, until the server has a
+complete cut across the DAG, or the client has said "done".
+
+Without multi_ack, a client sends have lines in --date-order until
+the server has found a common base.  That means the client will send
+have lines that are already known by the server to be common, because
+they overlap in time with another branch that the server hasn't found
+a common base on yet.
+
+For example suppose the client has commits in caps that the server
+doesn't and the server has commits in lower case that the client
+doesn't, as in the following diagram:
+
+       +---- u ---------------------- x
+      /              +----- y
+     /              /
+    a -- b -- c -- d -- E -- F
+       \
+	+--- Q -- R -- S
+
+If the client wants x,y and starts out by saying have F,S, the server
+doesn't know what F,S is.  Eventually the client says "have d" and
+the server sends "ACK d continue" to let the client know to stop
+walking down that line (so don't send c-b-a), but it's not done yet,
+it needs a base for x. The client keeps going with S-R-Q, until a
+gets reached, at which point the server has a clear base and it all
+ends.
+
+Without multi_ack the client would have sent that c-b-a chain anyway,
+interleaved with S-R-Q.
+
+multi_ack_detailed
+------------------
+This is an extension of multi_ack that permits client to better
+understand the server's in-memory state. See pack-protocol.txt,
+section "Packfile Negotiation" for more information.
+
+no-done
+-------
+This capability should only be used with the smart HTTP protocol. If
+multi_ack_detailed and no-done are both present, then the sender is
+free to immediately send a pack following its first "ACK obj-id ready"
+message.
+
+Without no-done in the smart HTTP protocol, the server session would
+end and the client has to make another trip to send "done" before
+the server can send the pack. no-done removes the last round and
+thus slightly reduces latency.
+
+thin-pack
+---------
+
+A thin pack is one with deltas which reference base objects not
+contained within the pack (but are known to exist at the receiving
+end). This can reduce the network traffic significantly, but it
+requires the receiving end to know how to "thicken" these packs by
+adding the missing bases to the pack.
+
+The upload-pack server advertises 'thin-pack' when it can generate
+and send a thin pack. A client requests the 'thin-pack' capability
+when it understands how to "thicken" it, notifying the server that
+it can receive such a pack. A client MUST NOT request the
+'thin-pack' capability if it cannot turn a thin pack into a
+self-contained pack.
+
+Receive-pack, on the other hand, is assumed by default to be able to
+handle thin packs, but can ask the client not to use the feature by
+advertising the 'no-thin' capability. A client MUST NOT send a thin
+pack if the server advertises the 'no-thin' capability.
+
+The reasons for this asymmetry are historical. The receive-pack
+program did not exist until after the invention of thin packs, so
+historically the reference implementation of receive-pack always
+understood thin packs. Adding 'no-thin' later allowed receive-pack
+to disable the feature in a backwards-compatible manner.
+
+
+side-band, side-band-64k
+------------------------
+
+This capability means that server can send, and client understand multiplexed
+progress reports and error info interleaved with the packfile itself.
+
+These two options are mutually exclusive. A modern client always
+favors 'side-band-64k'.
+
+Either mode indicates that the packfile data will be streamed broken
+up into packets of up to either 1000 bytes in the case of 'side_band',
+or 65520 bytes in the case of 'side_band_64k'. Each packet is made up
+of a leading 4-byte pkt-line length of how much data is in the packet,
+followed by a 1-byte stream code, followed by the actual data.
+
+The stream code can be one of:
+
+ 1 - pack data
+ 2 - progress messages
+ 3 - fatal error message just before stream aborts
+
+The "side-band-64k" capability came about as a way for newer clients
+that can handle much larger packets to request packets that are
+actually crammed nearly full, while maintaining backward compatibility
+for the older clients.
+
+Further, with side-band and its up to 1000-byte messages, it's actually
+999 bytes of payload and 1 byte for the stream code. With side-band-64k,
+same deal, you have up to 65519 bytes of data and 1 byte for the stream
+code.
+
+The client MUST send only maximum of one of "side-band" and "side-
+band-64k".  Server MUST diagnose it as an error if client requests
+both.
+
+ofs-delta
+---------
+
+Server can send, and client understand PACKv2 with delta referring to
+its base by position in pack rather than by an obj-id.  That is, they can
+send/read OBJ_OFS_DELTA (aka type 6) in a packfile.
+
+agent
+-----
+
+The server may optionally send a capability of the form `agent=X` to
+notify the client that the server is running version `X`. The client may
+optionally return its own agent string by responding with an `agent=Y`
+capability (but it MUST NOT do so if the server did not mention the
+agent capability). The `X` and `Y` strings may contain any printable
+ASCII characters except space (i.e., the byte range 32 < x < 127), and
+are typically of the form "package/version" (e.g., "git/1.8.3.1"). The
+agent strings are purely informative for statistics and debugging
+purposes, and MUST NOT be used to programmatically assume the presence
+or absence of particular features.
+
+symref
+------
+
+This parameterized capability is used to inform the receiver which symbolic ref
+points to which ref; for example, "symref=HEAD:refs/heads/master" tells the
+receiver that HEAD points to master. This capability can be repeated to
+represent multiple symrefs.
+
+Servers SHOULD include this capability for the HEAD symref if it is one of the
+refs being sent.
+
+Clients MAY use the parameters from this capability to select the proper initial
+branch when cloning a repository.
+
+shallow
+-------
+
+This capability adds "deepen", "shallow" and "unshallow" commands to
+the  fetch-pack/upload-pack protocol so clients can request shallow
+clones.
+
+deepen-since
+------------
+
+This capability adds "deepen-since" command to fetch-pack/upload-pack
+protocol so the client can request shallow clones that are cut at a
+specific time, instead of depth. Internally it's equivalent of doing
+"rev-list --max-age=<timestamp>" on the server side. "deepen-since"
+cannot be used with "deepen".
+
+deepen-not
+----------
+
+This capability adds "deepen-not" command to fetch-pack/upload-pack
+protocol so the client can request shallow clones that are cut at a
+specific revision, instead of depth. Internally it's equivalent of
+doing "rev-list --not <rev>" on the server side. "deepen-not"
+cannot be used with "deepen", but can be used with "deepen-since".
+
+deepen-relative
+---------------
+
+If this capability is requested by the client, the semantics of
+"deepen" command is changed. The "depth" argument is the depth from
+the current shallow boundary, instead of the depth from remote refs.
+
+no-progress
+-----------
+
+The client was started with "git clone -q" or something, and doesn't
+want that side band 2.  Basically the client just says "I do not
+wish to receive stream 2 on sideband, so do not send it to me, and if
+you did, I will drop it on the floor anyway".  However, the sideband
+channel 3 is still used for error responses.
+
+include-tag
+-----------
+
+The 'include-tag' capability is about sending annotated tags if we are
+sending objects they point to.  If we pack an object to the client, and
+a tag object points exactly at that object, we pack the tag object too.
+In general this allows a client to get all new annotated tags when it
+fetches a branch, in a single network connection.
+
+Clients MAY always send include-tag, hardcoding it into a request when
+the server advertises this capability. The decision for a client to
+request include-tag only has to do with the client's desires for tag
+data, whether or not a server had advertised objects in the
+refs/tags/* namespace.
+
+Servers MUST pack the tags if their referrant is packed and the client
+has requested include-tags.
+
+Clients MUST be prepared for the case where a server has ignored
+include-tag and has not actually sent tags in the pack.  In such
+cases the client SHOULD issue a subsequent fetch to acquire the tags
+that include-tag would have otherwise given the client.
+
+The server SHOULD send include-tag, if it supports it, regardless
+of whether or not there are tags available.
+
+report-status
+-------------
+
+The receive-pack process can receive a 'report-status' capability,
+which tells it that the client wants a report of what happened after
+a packfile upload and reference update.  If the pushing client requests
+this capability, after unpacking and updating references the server
+will respond with whether the packfile unpacked successfully and if
+each reference was updated successfully.  If any of those were not
+successful, it will send back an error message.  See pack-protocol.txt
+for example messages.
+
+delete-refs
+-----------
+
+If the server sends back the 'delete-refs' capability, it means that
+it is capable of accepting a zero-id value as the target
+value of a reference update.  It is not sent back by the client, it
+simply informs the client that it can be sent zero-id values
+to delete references.
+
+quiet
+-----
+
+If the receive-pack server advertises the 'quiet' capability, it is
+capable of silencing human-readable progress output which otherwise may
+be shown when processing the received pack. A send-pack client should
+respond with the 'quiet' capability to suppress server-side progress
+reporting if the local progress reporting is also being suppressed
+(e.g., via `push -q`, or if stderr does not go to a tty).
+
+atomic
+------
+
+If the server sends the 'atomic' capability it is capable of accepting
+atomic pushes. If the pushing client requests this capability, the server
+will update the refs in one atomic transaction. Either all refs are
+updated or none.
+
+push-options
+------------
+
+If the server sends the 'push-options' capability it is able to accept
+push options after the update commands have been sent, but before the
+packfile is streamed. If the pushing client requests this capability,
+the server will pass the options to the pre- and post- receive hooks
+that process this push request.
+
+allow-tip-sha1-in-want
+----------------------
+
+If the upload-pack server advertises this capability, fetch-pack may
+send "want" lines with SHA-1s that exist at the server but are not
+advertised by upload-pack.
+
+allow-reachable-sha1-in-want
+----------------------------
+
+If the upload-pack server advertises this capability, fetch-pack may
+send "want" lines with SHA-1s that exist at the server but are not
+advertised by upload-pack.
+
+push-cert=<nonce>
+-----------------
+
+The receive-pack server that advertises this capability is willing
+to accept a signed push certificate, and asks the <nonce> to be
+included in the push certificate.  A send-pack client MUST NOT
+send a push-cert packet unless the receive-pack server advertises
+this capability.
+
+filter
+------
+
+If the upload-pack server advertises the 'filter' capability,
+fetch-pack may send "filter" commands to request a partial clone
+or partial fetch and request that the server omit various objects
+from the packfile.
diff --git a/third_party/git/Documentation/technical/protocol-common.txt b/third_party/git/Documentation/technical/protocol-common.txt
new file mode 100644
index 0000000000..ecedb34bba
--- /dev/null
+++ b/third_party/git/Documentation/technical/protocol-common.txt
@@ -0,0 +1,99 @@
+Documentation Common to Pack and Http Protocols
+===============================================
+
+ABNF Notation
+-------------
+
+ABNF notation as described by RFC 5234 is used within the protocol documents,
+except the following replacement core rules are used:
+----
+  HEXDIG    =  DIGIT / "a" / "b" / "c" / "d" / "e" / "f"
+----
+
+We also define the following common rules:
+----
+  NUL       =  %x00
+  zero-id   =  40*"0"
+  obj-id    =  40*(HEXDIGIT)
+
+  refname  =  "HEAD"
+  refname /=  "refs/" <see discussion below>
+----
+
+A refname is a hierarchical octet string beginning with "refs/" and
+not violating the 'git-check-ref-format' command's validation rules.
+More specifically, they:
+
+. They can include slash `/` for hierarchical (directory)
+  grouping, but no slash-separated component can begin with a
+  dot `.`.
+
+. They must contain at least one `/`. This enforces the presence of a
+  category like `heads/`, `tags/` etc. but the actual names are not
+  restricted.
+
+. They cannot have two consecutive dots `..` anywhere.
+
+. They cannot have ASCII control characters (i.e. bytes whose
+  values are lower than \040, or \177 `DEL`), space, tilde `~`,
+  caret `^`, colon `:`, question-mark `?`, asterisk `*`,
+  or open bracket `[` anywhere.
+
+. They cannot end with a slash `/` or a dot `.`.
+
+. They cannot end with the sequence `.lock`.
+
+. They cannot contain a sequence `@{`.
+
+. They cannot contain a `\\`.
+
+
+pkt-line Format
+---------------
+
+Much (but not all) of the payload is described around pkt-lines.
+
+A pkt-line is a variable length binary string.  The first four bytes
+of the line, the pkt-len, indicates the total length of the line,
+in hexadecimal.  The pkt-len includes the 4 bytes used to contain
+the length's hexadecimal representation.
+
+A pkt-line MAY contain binary data, so implementors MUST ensure
+pkt-line parsing/formatting routines are 8-bit clean.
+
+A non-binary line SHOULD BE terminated by an LF, which if present
+MUST be included in the total length. Receivers MUST treat pkt-lines
+with non-binary data the same whether or not they contain the trailing
+LF (stripping the LF if present, and not complaining when it is
+missing).
+
+The maximum length of a pkt-line's data component is 65516 bytes.
+Implementations MUST NOT send pkt-line whose length exceeds 65520
+(65516 bytes of payload + 4 bytes of length data).
+
+Implementations SHOULD NOT send an empty pkt-line ("0004").
+
+A pkt-line with a length field of 0 ("0000"), called a flush-pkt,
+is a special case and MUST be handled differently than an empty
+pkt-line ("0004").
+
+----
+  pkt-line     =  data-pkt / flush-pkt
+
+  data-pkt     =  pkt-len pkt-payload
+  pkt-len      =  4*(HEXDIG)
+  pkt-payload  =  (pkt-len - 4)*(OCTET)
+
+  flush-pkt    = "0000"
+----
+
+Examples (as C-style strings):
+
+----
+  pkt-line          actual value
+  ---------------------------------
+  "0006a\n"         "a\n"
+  "0005a"           "a"
+  "000bfoobar\n"    "foobar\n"
+  "0004"            ""
+----
diff --git a/third_party/git/Documentation/technical/protocol-v2.txt b/third_party/git/Documentation/technical/protocol-v2.txt
new file mode 100644
index 0000000000..40f91f6b1e
--- /dev/null
+++ b/third_party/git/Documentation/technical/protocol-v2.txt
@@ -0,0 +1,455 @@
+Git Wire Protocol, Version 2
+============================
+
+This document presents a specification for a version 2 of Git's wire
+protocol.  Protocol v2 will improve upon v1 in the following ways:
+
+  * Instead of multiple service names, multiple commands will be
+    supported by a single service
+  * Easily extendable as capabilities are moved into their own section
+    of the protocol, no longer being hidden behind a NUL byte and
+    limited by the size of a pkt-line
+  * Separate out other information hidden behind NUL bytes (e.g. agent
+    string as a capability and symrefs can be requested using 'ls-refs')
+  * Reference advertisement will be omitted unless explicitly requested
+  * ls-refs command to explicitly request some refs
+  * Designed with http and stateless-rpc in mind.  With clear flush
+    semantics the http remote helper can simply act as a proxy
+
+In protocol v2 communication is command oriented.  When first contacting a
+server a list of capabilities will advertised.  Some of these capabilities
+will be commands which a client can request be executed.  Once a command
+has completed, a client can reuse the connection and request that other
+commands be executed.
+
+Packet-Line Framing
+-------------------
+
+All communication is done using packet-line framing, just as in v1.  See
+`Documentation/technical/pack-protocol.txt` and
+`Documentation/technical/protocol-common.txt` for more information.
+
+In protocol v2 these special packets will have the following semantics:
+
+  * '0000' Flush Packet (flush-pkt) - indicates the end of a message
+  * '0001' Delimiter Packet (delim-pkt) - separates sections of a message
+
+Initial Client Request
+----------------------
+
+In general a client can request to speak protocol v2 by sending
+`version=2` through the respective side-channel for the transport being
+used which inevitably sets `GIT_PROTOCOL`.  More information can be
+found in `pack-protocol.txt` and `http-protocol.txt`.  In all cases the
+response from the server is the capability advertisement.
+
+Git Transport
+~~~~~~~~~~~~~
+
+When using the git:// transport, you can request to use protocol v2 by
+sending "version=2" as an extra parameter:
+
+   003egit-upload-pack /project.git\0host=myserver.com\0\0version=2\0
+
+SSH and File Transport
+~~~~~~~~~~~~~~~~~~~~~~
+
+When using either the ssh:// or file:// transport, the GIT_PROTOCOL
+environment variable must be set explicitly to include "version=2".
+
+HTTP Transport
+~~~~~~~~~~~~~~
+
+When using the http:// or https:// transport a client makes a "smart"
+info/refs request as described in `http-protocol.txt` and requests that
+v2 be used by supplying "version=2" in the `Git-Protocol` header.
+
+   C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
+   C: Git-Protocol: version=2
+
+A v2 server would reply:
+
+   S: 200 OK
+   S: <Some headers>
+   S: ...
+   S:
+   S: 000eversion 2\n
+   S: <capability-advertisement>
+
+Subsequent requests are then made directly to the service
+`$GIT_URL/git-upload-pack`. (This works the same for git-receive-pack).
+
+Capability Advertisement
+------------------------
+
+A server which decides to communicate (based on a request from a client)
+using protocol version 2, notifies the client by sending a version string
+in its initial response followed by an advertisement of its capabilities.
+Each capability is a key with an optional value.  Clients must ignore all
+unknown keys.  Semantics of unknown values are left to the definition of
+each key.  Some capabilities will describe commands which can be requested
+to be executed by the client.
+
+    capability-advertisement = protocol-version
+			       capability-list
+			       flush-pkt
+
+    protocol-version = PKT-LINE("version 2" LF)
+    capability-list = *capability
+    capability = PKT-LINE(key[=value] LF)
+
+    key = 1*(ALPHA | DIGIT | "-_")
+    value = 1*(ALPHA | DIGIT | " -_.,?\/{}[]()<>!@#$%^&*+=:;")
+
+Command Request
+---------------
+
+After receiving the capability advertisement, a client can then issue a
+request to select the command it wants with any particular capabilities
+or arguments.  There is then an optional section where the client can
+provide any command specific parameters or queries.  Only a single
+command can be requested at a time.
+
+    request = empty-request | command-request
+    empty-request = flush-pkt
+    command-request = command
+		      capability-list
+		      [command-args]
+		      flush-pkt
+    command = PKT-LINE("command=" key LF)
+    command-args = delim-pkt
+		   *command-specific-arg
+
+    command-specific-args are packet line framed arguments defined by
+    each individual command.
+
+The server will then check to ensure that the client's request is
+comprised of a valid command as well as valid capabilities which were
+advertised.  If the request is valid the server will then execute the
+command.  A server MUST wait till it has received the client's entire
+request before issuing a response.  The format of the response is
+determined by the command being executed, but in all cases a flush-pkt
+indicates the end of the response.
+
+When a command has finished, and the client has received the entire
+response from the server, a client can either request that another
+command be executed or can terminate the connection.  A client may
+optionally send an empty request consisting of just a flush-pkt to
+indicate that no more requests will be made.
+
+Capabilities
+------------
+
+There are two different types of capabilities: normal capabilities,
+which can be used to convey information or alter the behavior of a
+request, and commands, which are the core actions that a client wants to
+perform (fetch, push, etc).
+
+Protocol version 2 is stateless by default.  This means that all commands
+must only last a single round and be stateless from the perspective of the
+server side, unless the client has requested a capability indicating that
+state should be maintained by the server.  Clients MUST NOT require state
+management on the server side in order to function correctly.  This
+permits simple round-robin load-balancing on the server side, without
+needing to worry about state management.
+
+agent
+~~~~~
+
+The server can advertise the `agent` capability with a value `X` (in the
+form `agent=X`) to notify the client that the server is running version
+`X`.  The client may optionally send its own agent string by including
+the `agent` capability with a value `Y` (in the form `agent=Y`) in its
+request to the server (but it MUST NOT do so if the server did not
+advertise the agent capability). The `X` and `Y` strings may contain any
+printable ASCII characters except space (i.e., the byte range 32 < x <
+127), and are typically of the form "package/version" (e.g.,
+"git/1.8.3.1"). The agent strings are purely informative for statistics
+and debugging purposes, and MUST NOT be used to programmatically assume
+the presence or absence of particular features.
+
+ls-refs
+~~~~~~~
+
+`ls-refs` is the command used to request a reference advertisement in v2.
+Unlike the current reference advertisement, ls-refs takes in arguments
+which can be used to limit the refs sent from the server.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+ls-refs takes in the following arguments:
+
+    symrefs
+	In addition to the object pointed by it, show the underlying ref
+	pointed by it when showing a symbolic ref.
+    peel
+	Show peeled tags.
+    ref-prefix <prefix>
+	When specified, only references having a prefix matching one of
+	the provided prefixes are displayed.
+
+The output of ls-refs is as follows:
+
+    output = *ref
+	     flush-pkt
+    ref = PKT-LINE(obj-id SP refname *(SP ref-attribute) LF)
+    ref-attribute = (symref | peeled)
+    symref = "symref-target:" symref-target
+    peeled = "peeled:" obj-id
+
+fetch
+~~~~~
+
+`fetch` is the command used to fetch a packfile in v2.  It can be looked
+at as a modified version of the v1 fetch where the ref-advertisement is
+stripped out (since the `ls-refs` command fills that role) and the
+message format is tweaked to eliminate redundancies and permit easy
+addition of future extensions.
+
+Additional features not supported in the base command will be advertised
+as the value of the command in the capability advertisement in the form
+of a space separated list of features: "<command>=<feature 1> <feature 2>"
+
+A `fetch` request can take the following arguments:
+
+    want <oid>
+	Indicates to the server an object which the client wants to
+	retrieve.  Wants can be anything and are not limited to
+	advertised objects.
+
+    have <oid>
+	Indicates to the server an object which the client has locally.
+	This allows the server to make a packfile which only contains
+	the objects that the client needs. Multiple 'have' lines can be
+	supplied.
+
+    done
+	Indicates to the server that negotiation should terminate (or
+	not even begin if performing a clone) and that the server should
+	use the information supplied in the request to construct the
+	packfile.
+
+    thin-pack
+	Request that a thin pack be sent, which is a pack with deltas
+	which reference base objects not contained within the pack (but
+	are known to exist at the receiving end). This can reduce the
+	network traffic significantly, but it requires the receiving end
+	to know how to "thicken" these packs by adding the missing bases
+	to the pack.
+
+    no-progress
+	Request that progress information that would normally be sent on
+	side-band channel 2, during the packfile transfer, should not be
+	sent.  However, the side-band channel 3 is still used for error
+	responses.
+
+    include-tag
+	Request that annotated tags should be sent if the objects they
+	point to are being sent.
+
+    ofs-delta
+	Indicate that the client understands PACKv2 with delta referring
+	to its base by position in pack rather than by an oid.  That is,
+	they can read OBJ_OFS_DELTA (ake type 6) in a packfile.
+
+If the 'shallow' feature is advertised the following arguments can be
+included in the clients request as well as the potential addition of the
+'shallow-info' section in the server's response as explained below.
+
+    shallow <oid>
+	A client must notify the server of all commits for which it only
+	has shallow copies (meaning that it doesn't have the parents of
+	a commit) by supplying a 'shallow <oid>' line for each such
+	object so that the server is aware of the limitations of the
+	client's history.  This is so that the server is aware that the
+	client may not have all objects reachable from such commits.
+
+    deepen <depth>
+	Requests that the fetch/clone should be shallow having a commit
+	depth of <depth> relative to the remote side.
+
+    deepen-relative
+	Requests that the semantics of the "deepen" command be changed
+	to indicate that the depth requested is relative to the client's
+	current shallow boundary, instead of relative to the requested
+	commits.
+
+    deepen-since <timestamp>
+	Requests that the shallow clone/fetch should be cut at a
+	specific time, instead of depth.  Internally it's equivalent to
+	doing "git rev-list --max-age=<timestamp>". Cannot be used with
+	"deepen".
+
+    deepen-not <rev>
+	Requests that the shallow clone/fetch should be cut at a
+	specific revision specified by '<rev>', instead of a depth.
+	Internally it's equivalent of doing "git rev-list --not <rev>".
+	Cannot be used with "deepen", but can be used with
+	"deepen-since".
+
+If the 'filter' feature is advertised, the following argument can be
+included in the client's request:
+
+    filter <filter-spec>
+	Request that various objects from the packfile be omitted
+	using one of several filtering techniques. These are intended
+	for use with partial clone and partial fetch operations. See
+	`rev-list` for possible "filter-spec" values. When communicating
+	with other processes, senders SHOULD translate scaled integers
+	(e.g. "1k") into a fully-expanded form (e.g. "1024") to aid
+	interoperability with older receivers that may not understand
+	newly-invented scaling suffixes. However, receivers SHOULD
+	accept the following suffixes: 'k', 'm', and 'g' for 1024,
+	1048576, and 1073741824, respectively.
+
+If the 'ref-in-want' feature is advertised, the following argument can
+be included in the client's request as well as the potential addition of
+the 'wanted-refs' section in the server's response as explained below.
+
+    want-ref <ref>
+	Indicates to the server that the client wants to retrieve a
+	particular ref, where <ref> is the full name of a ref on the
+	server.
+
+If the 'sideband-all' feature is advertised, the following argument can be
+included in the client's request:
+
+    sideband-all
+	Instruct the server to send the whole response multiplexed, not just
+	the packfile section. All non-flush and non-delim PKT-LINE in the
+	response (not only in the packfile section) will then start with a byte
+	indicating its sideband (1, 2, or 3), and the server may send "0005\2"
+	(a PKT-LINE of sideband 2 with no payload) as a keepalive packet.
+
+The response of `fetch` is broken into a number of sections separated by
+delimiter packets (0001), with each section beginning with its section
+header.
+
+    output = *section
+    section = (acknowledgments | shallow-info | wanted-refs | packfile)
+	      (flush-pkt | delim-pkt)
+
+    acknowledgments = PKT-LINE("acknowledgments" LF)
+		      (nak | *ack)
+		      (ready)
+    ready = PKT-LINE("ready" LF)
+    nak = PKT-LINE("NAK" LF)
+    ack = PKT-LINE("ACK" SP obj-id LF)
+
+    shallow-info = PKT-LINE("shallow-info" LF)
+		   *PKT-LINE((shallow | unshallow) LF)
+    shallow = "shallow" SP obj-id
+    unshallow = "unshallow" SP obj-id
+
+    wanted-refs = PKT-LINE("wanted-refs" LF)
+		  *PKT-LINE(wanted-ref LF)
+    wanted-ref = obj-id SP refname
+
+    packfile = PKT-LINE("packfile" LF)
+	       *PKT-LINE(%x01-03 *%x00-ff)
+
+    acknowledgments section
+	* If the client determines that it is finished with negotiations
+	  by sending a "done" line, the acknowledgments sections MUST be
+	  omitted from the server's response.
+
+	* Always begins with the section header "acknowledgments"
+
+	* The server will respond with "NAK" if none of the object ids sent
+	  as have lines were common.
+
+	* The server will respond with "ACK obj-id" for all of the
+	  object ids sent as have lines which are common.
+
+	* A response cannot have both "ACK" lines as well as a "NAK"
+	  line.
+
+	* The server will respond with a "ready" line indicating that
+	  the server has found an acceptable common base and is ready to
+	  make and send a packfile (which will be found in the packfile
+	  section of the same response)
+
+	* If the server has found a suitable cut point and has decided
+	  to send a "ready" line, then the server can decide to (as an
+	  optimization) omit any "ACK" lines it would have sent during
+	  its response.  This is because the server will have already
+	  determined the objects it plans to send to the client and no
+	  further negotiation is needed.
+
+    shallow-info section
+	* If the client has requested a shallow fetch/clone, a shallow
+	  client requests a fetch or the server is shallow then the
+	  server's response may include a shallow-info section.  The
+	  shallow-info section will be included if (due to one of the
+	  above conditions) the server needs to inform the client of any
+	  shallow boundaries or adjustments to the clients already
+	  existing shallow boundaries.
+
+	* Always begins with the section header "shallow-info"
+
+	* If a positive depth is requested, the server will compute the
+	  set of commits which are no deeper than the desired depth.
+
+	* The server sends a "shallow obj-id" line for each commit whose
+	  parents will not be sent in the following packfile.
+
+	* The server sends an "unshallow obj-id" line for each commit
+	  which the client has indicated is shallow, but is no longer
+	  shallow as a result of the fetch (due to its parents being
+	  sent in the following packfile).
+
+	* The server MUST NOT send any "unshallow" lines for anything
+	  which the client has not indicated was shallow as a part of
+	  its request.
+
+	* This section is only included if a packfile section is also
+	  included in the response.
+
+    wanted-refs section
+	* This section is only included if the client has requested a
+	  ref using a 'want-ref' line and if a packfile section is also
+	  included in the response.
+
+	* Always begins with the section header "wanted-refs".
+
+	* The server will send a ref listing ("<oid> <refname>") for
+	  each reference requested using 'want-ref' lines.
+
+	* The server MUST NOT send any refs which were not requested
+	  using 'want-ref' lines.
+
+    packfile section
+	* This section is only included if the client has sent 'want'
+	  lines in its request and either requested that no more
+	  negotiation be done by sending 'done' or if the server has
+	  decided it has found a sufficient cut point to produce a
+	  packfile.
+
+	* Always begins with the section header "packfile"
+
+	* The transmission of the packfile begins immediately after the
+	  section header
+
+	* The data transfer of the packfile is always multiplexed, using
+	  the same semantics of the 'side-band-64k' capability from
+	  protocol version 1.  This means that each packet, during the
+	  packfile data stream, is made up of a leading 4-byte pkt-line
+	  length (typical of the pkt-line format), followed by a 1-byte
+	  stream code, followed by the actual data.
+
+	  The stream code can be one of:
+		1 - pack data
+		2 - progress messages
+		3 - fatal error message just before stream aborts
+
+server-option
+~~~~~~~~~~~~~
+
+If advertised, indicates that any number of server specific options can be
+included in a request.  This is done by sending each option as a
+"server-option=<option>" capability line in the capability-list section of
+a request.
+
+The provided options must not contain a NUL or LF character.
diff --git a/third_party/git/Documentation/technical/racy-git.txt b/third_party/git/Documentation/technical/racy-git.txt
new file mode 100644
index 0000000000..4a8be4d144
--- /dev/null
+++ b/third_party/git/Documentation/technical/racy-git.txt
@@ -0,0 +1,201 @@
+Use of index and Racy Git problem
+=================================
+
+Background
+----------
+
+The index is one of the most important data structures in Git.
+It represents a virtual working tree state by recording list of
+paths and their object names and serves as a staging area to
+write out the next tree object to be committed.  The state is
+"virtual" in the sense that it does not necessarily have to, and
+often does not, match the files in the working tree.
+
+There are cases Git needs to examine the differences between the
+virtual working tree state in the index and the files in the
+working tree.  The most obvious case is when the user asks `git
+diff` (or its low level implementation, `git diff-files`) or
+`git-ls-files --modified`.  In addition, Git internally checks
+if the files in the working tree are different from what are
+recorded in the index to avoid stomping on local changes in them
+during patch application, switching branches, and merging.
+
+In order to speed up this comparison between the files in the
+working tree and the index entries, the index entries record the
+information obtained from the filesystem via `lstat(2)` system
+call when they were last updated.  When checking if they differ,
+Git first runs `lstat(2)` on the files and compares the result
+with this information (this is what was originally done by the
+`ce_match_stat()` function, but the current code does it in
+`ce_match_stat_basic()` function).  If some of these "cached
+stat information" fields do not match, Git can tell that the
+files are modified without even looking at their contents.
+
+Note: not all members in `struct stat` obtained via `lstat(2)`
+are used for this comparison.  For example, `st_atime` obviously
+is not useful.  Currently, Git compares the file type (regular
+files vs symbolic links) and executable bits (only for regular
+files) from `st_mode` member, `st_mtime` and `st_ctime`
+timestamps, `st_uid`, `st_gid`, `st_ino`, and `st_size` members.
+With a `USE_STDEV` compile-time option, `st_dev` is also
+compared, but this is not enabled by default because this member
+is not stable on network filesystems.  With `USE_NSEC`
+compile-time option, `st_mtim.tv_nsec` and `st_ctim.tv_nsec`
+members are also compared. On Linux, this is not enabled by default
+because in-core timestamps can have finer granularity than
+on-disk timestamps, resulting in meaningless changes when an
+inode is evicted from the inode cache.  See commit 8ce13b0
+of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
+([PATCH] Sync in core time granularity with filesystems,
+2005-01-04). This patch is included in kernel 2.6.11 and newer, but
+only fixes the issue for file systems with exactly 1 ns or 1 s
+resolution. Other file systems are still broken in current Linux
+kernels (e.g. CEPH, CIFS, NTFS, UDF), see
+https://lkml.org/lkml/2015/6/9/714
+
+Racy Git
+--------
+
+There is one slight problem with the optimization based on the
+cached stat information.  Consider this sequence:
+
+  : modify 'foo'
+  $ git update-index 'foo'
+  : modify 'foo' again, in-place, without changing its size
+
+The first `update-index` computes the object name of the
+contents of file `foo` and updates the index entry for `foo`
+along with the `struct stat` information.  If the modification
+that follows it happens very fast so that the file's `st_mtime`
+timestamp does not change, after this sequence, the cached stat
+information the index entry records still exactly match what you
+would see in the filesystem, even though the file `foo` is now
+different.
+This way, Git can incorrectly think files in the working tree
+are unmodified even though they actually are.  This is called
+the "racy Git" problem (discovered by Pasky), and the entries
+that appear clean when they may not be because of this problem
+are called "racily clean".
+
+To avoid this problem, Git does two things:
+
+. When the cached stat information says the file has not been
+  modified, and the `st_mtime` is the same as (or newer than)
+  the timestamp of the index file itself (which is the time `git
+  update-index foo` finished running in the above example), it
+  also compares the contents with the object registered in the
+  index entry to make sure they match.
+
+. When the index file is updated that contains racily clean
+  entries, cached `st_size` information is truncated to zero
+  before writing a new version of the index file.
+
+Because the index file itself is written after collecting all
+the stat information from updated paths, `st_mtime` timestamp of
+it is usually the same as or newer than any of the paths the
+index contains.  And no matter how quick the modification that
+follows `git update-index foo` finishes, the resulting
+`st_mtime` timestamp on `foo` cannot get a value earlier
+than the index file.  Therefore, index entries that can be
+racily clean are limited to the ones that have the same
+timestamp as the index file itself.
+
+The callers that want to check if an index entry matches the
+corresponding file in the working tree continue to call
+`ce_match_stat()`, but with this change, `ce_match_stat()` uses
+`ce_modified_check_fs()` to see if racily clean ones are
+actually clean after comparing the cached stat information using
+`ce_match_stat_basic()`.
+
+The problem the latter solves is this sequence:
+
+  $ git update-index 'foo'
+  : modify 'foo' in-place without changing its size
+  : wait for enough time
+  $ git update-index 'bar'
+
+Without the latter, the timestamp of the index file gets a newer
+value, and falsely clean entry `foo` would not be caught by the
+timestamp comparison check done with the former logic anymore.
+The latter makes sure that the cached stat information for `foo`
+would never match with the file in the working tree, so later
+checks by `ce_match_stat_basic()` would report that the index entry
+does not match the file and Git does not have to fall back on more
+expensive `ce_modified_check_fs()`.
+
+
+Runtime penalty
+---------------
+
+The runtime penalty of falling back to `ce_modified_check_fs()`
+from `ce_match_stat()` can be very expensive when there are many
+racily clean entries.  An obvious way to artificially create
+this situation is to give the same timestamp to all the files in
+the working tree in a large project, run `git update-index` on
+them, and give the same timestamp to the index file:
+
+  $ date >.datestamp
+  $ git ls-files | xargs touch -r .datestamp
+  $ git ls-files | git update-index --stdin
+  $ touch -r .datestamp .git/index
+
+This will make all index entries racily clean.  The linux project, for
+example, there are over 20,000 files in the working tree.  On my
+Athlon 64 X2 3800+, after the above:
+
+  $ /usr/bin/time git diff-files
+  1.68user 0.54system 0:02.22elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
+  0inputs+0outputs (0major+67111minor)pagefaults 0swaps
+  $ git update-index MAINTAINERS
+  $ /usr/bin/time git diff-files
+  0.02user 0.12system 0:00.14elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k
+  0inputs+0outputs (0major+935minor)pagefaults 0swaps
+
+Running `git update-index` in the middle checked the racily
+clean entries, and left the cached `st_mtime` for all the paths
+intact because they were actually clean (so this step took about
+the same amount of time as the first `git diff-files`).  After
+that, they are not racily clean anymore but are truly clean, so
+the second invocation of `git diff-files` fully took advantage
+of the cached stat information.
+
+
+Avoiding runtime penalty
+------------------------
+
+In order to avoid the above runtime penalty, post 1.4.2 Git used
+to have a code that made sure the index file
+got timestamp newer than the youngest files in the index when
+there are many young files with the same timestamp as the
+resulting index file would otherwise would have by waiting
+before finishing writing the index file out.
+
+I suspected that in practice the situation where many paths in the
+index are all racily clean was quite rare.  The only code paths
+that can record recent timestamp for large number of paths are:
+
+. Initial `git add .` of a large project.
+
+. `git checkout` of a large project from an empty index into an
+  unpopulated working tree.
+
+Note: switching branches with `git checkout` keeps the cached
+stat information of existing working tree files that are the
+same between the current branch and the new branch, which are
+all older than the resulting index file, and they will not
+become racily clean.  Only the files that are actually checked
+out can become racily clean.
+
+In a large project where raciness avoidance cost really matters,
+however, the initial computation of all object names in the
+index takes more than one second, and the index file is written
+out after all that happens.  Therefore the timestamp of the
+index file will be more than one seconds later than the
+youngest file in the working tree.  This means that in these
+cases there actually will not be any racily clean entry in
+the resulting index.
+
+Based on this discussion, the current code does not use the
+"workaround" to avoid the runtime penalty that does not exist in
+practice anymore.  This was done with commit 0fc82cff on Aug 15,
+2006.
diff --git a/third_party/git/Documentation/technical/repository-version.txt b/third_party/git/Documentation/technical/repository-version.txt
new file mode 100644
index 0000000000..7844ef30ff
--- /dev/null
+++ b/third_party/git/Documentation/technical/repository-version.txt
@@ -0,0 +1,102 @@
+== Git Repository Format Versions
+
+Every git repository is marked with a numeric version in the
+`core.repositoryformatversion` key of its `config` file. This version
+specifies the rules for operating on the on-disk repository data. An
+implementation of git which does not understand a particular version
+advertised by an on-disk repository MUST NOT operate on that repository;
+doing so risks not only producing wrong results, but actually losing
+data.
+
+Because of this rule, version bumps should be kept to an absolute
+minimum. Instead, we generally prefer these strategies:
+
+  - bumping format version numbers of individual data files (e.g.,
+    index, packfiles, etc). This restricts the incompatibilities only to
+    those files.
+
+  - introducing new data that gracefully degrades when used by older
+    clients (e.g., pack bitmap files are ignored by older clients, which
+    simply do not take advantage of the optimization they provide).
+
+A whole-repository format version bump should only be part of a change
+that cannot be independently versioned. For instance, if one were to
+change the reachability rules for objects, or the rules for locking
+refs, that would require a bump of the repository format version.
+
+Note that this applies only to accessing the repository's disk contents
+directly. An older client which understands only format `0` may still
+connect via `git://` to a repository using format `1`, as long as the
+server process understands format `1`.
+
+The preferred strategy for rolling out a version bump (whether whole
+repository or for a single file) is to teach git to read the new format,
+and allow writing the new format with a config switch or command line
+option (for experimentation or for those who do not care about backwards
+compatibility with older gits). Then after a long period to allow the
+reading capability to become common, we may switch to writing the new
+format by default.
+
+The currently defined format versions are:
+
+=== Version `0`
+
+This is the format defined by the initial version of git, including but
+not limited to the format of the repository directory, the repository
+configuration file, and the object and ref storage. Specifying the
+complete behavior of git is beyond the scope of this document.
+
+=== Version `1`
+
+This format is identical to version `0`, with the following exceptions:
+
+  1. When reading the `core.repositoryformatversion` variable, a git
+     implementation which supports version 1 MUST also read any
+     configuration keys found in the `extensions` section of the
+     configuration file.
+
+  2. If a version-1 repository specifies any `extensions.*` keys that
+     the running git has not implemented, the operation MUST NOT
+     proceed. Similarly, if the value of any known key is not understood
+     by the implementation, the operation MUST NOT proceed.
+
+Note that if no extensions are specified in the config file, then
+`core.repositoryformatversion` SHOULD be set to `0` (setting it to `1`
+provides no benefit, and makes the repository incompatible with older
+implementations of git).
+
+This document will serve as the master list for extensions. Any
+implementation wishing to define a new extension should make a note of
+it here, in order to claim the name.
+
+The defined extensions are:
+
+==== `noop`
+
+This extension does not change git's behavior at all. It is useful only
+for testing format-1 compatibility.
+
+==== `preciousObjects`
+
+When the config key `extensions.preciousObjects` is set to `true`,
+objects in the repository MUST NOT be deleted (e.g., by `git-prune` or
+`git repack -d`).
+
+==== `partialclone`
+
+When the config key `extensions.partialclone` is set, it indicates
+that the repo was created with a partial clone (or later performed
+a partial fetch) and that the remote may have omitted sending
+certain unwanted objects.  Such a remote is called a "promisor remote"
+and it promises that all such omitted objects can be fetched from it
+in the future.
+
+The value of this key is the name of the promisor remote.
+
+==== `worktreeConfig`
+
+If set, by default "git config" reads from both "config" and
+"config.worktree" file from GIT_DIR in that order. In
+multiple working directory mode, "config" file is shared while
+"config.worktree" is per-working directory (i.e., it's in
+GIT_COMMON_DIR/worktrees/<id>/config.worktree)
diff --git a/third_party/git/Documentation/technical/rerere.txt b/third_party/git/Documentation/technical/rerere.txt
new file mode 100644
index 0000000000..aa22d7ace8
--- /dev/null
+++ b/third_party/git/Documentation/technical/rerere.txt
@@ -0,0 +1,186 @@
+Rerere
+======
+
+This document describes the rerere logic.
+
+Conflict normalization
+----------------------
+
+To ensure recorded conflict resolutions can be looked up in the rerere
+database, even when branches are merged in a different order,
+different branches are merged that result in the same conflict, or
+when different conflict style settings are used, rerere normalizes the
+conflicts before writing them to the rerere database.
+
+Different conflict styles and branch names are normalized by stripping
+the labels from the conflict markers, and removing the common ancestor
+version from the `diff3` conflict style. Branches that are merged
+in different order are normalized by sorting the conflict hunks.  More
+on each of those steps in the following sections.
+
+Once these two normalization operations are applied, a conflict ID is
+calculated based on the normalized conflict, which is later used by
+rerere to look up the conflict in the rerere database.
+
+Removing the common ancestor version
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Say we have three branches AB, AC and AC2.  The common ancestor of
+these branches has a file with a line containing the string "A" (for
+brevity this is called "line A" in the rest of the document).  In
+branch AB this line is changed to "B", in AC, this line is changed to
+"C", and branch AC2 is forked off of AC, after the line was changed to
+"C".
+
+Forking a branch ABAC off of branch AB and then merging AC into it, we
+get a conflict like the following:
+
+    <<<<<<< HEAD
+    B
+    =======
+    C
+    >>>>>>> AC
+
+Doing the analogous with AC2 (forking a branch ABAC2 off of branch AB
+and then merging branch AC2 into it), using the diff3 conflict style,
+we get a conflict like the following:
+
+    <<<<<<< HEAD
+    B
+    ||||||| merged common ancestors
+    A
+    =======
+    C
+    >>>>>>> AC2
+
+By resolving this conflict, to leave line D, the user declares:
+
+    After examining what branches AB and AC did, I believe that making
+    line A into line D is the best thing to do that is compatible with
+    what AB and AC wanted to do.
+
+As branch AC2 refers to the same commit as AC, the above implies that
+this is also compatible what AB and AC2 wanted to do.
+
+By extension, this means that rerere should recognize that the above
+conflicts are the same.  To do this, the labels on the conflict
+markers are stripped, and the common ancestor version is removed.  The above
+examples would both result in the following normalized conflict:
+
+    <<<<<<<
+    B
+    =======
+    C
+    >>>>>>>
+
+Sorting hunks
+~~~~~~~~~~~~~
+
+As before, lets imagine that a common ancestor had a file with line A
+its early part, and line X in its late part.  And then four branches
+are forked that do these things:
+
+    - AB: changes A to B
+    - AC: changes A to C
+    - XY: changes X to Y
+    - XZ: changes X to Z
+
+Now, forking a branch ABAC off of branch AB and then merging AC into
+it, and forking a branch ACAB off of branch AC and then merging AB
+into it, would yield the conflict in a different order.  The former
+would say "A became B or C, what now?" while the latter would say "A
+became C or B, what now?"
+
+As a reminder, the act of merging AC into ABAC and resolving the
+conflict to leave line D means that the user declares:
+
+    After examining what branches AB and AC did, I believe that
+    making line A into line D is the best thing to do that is
+    compatible with what AB and AC wanted to do.
+
+So the conflict we would see when merging AB into ACAB should be
+resolved the same way---it is the resolution that is in line with that
+declaration.
+
+Imagine that similarly previously a branch XYXZ was forked from XY,
+and XZ was merged into it, and resolved "X became Y or Z" into "X
+became W".
+
+Now, if a branch ABXY was forked from AB and then merged XY, then ABXY
+would have line B in its early part and line Y in its later part.
+Such a merge would be quite clean.  We can construct 4 combinations
+using these four branches ((AB, AC) x (XY, XZ)).
+
+Merging ABXY and ACXZ would make "an early A became B or C, a late X
+became Y or Z" conflict, while merging ACXY and ABXZ would make "an
+early A became C or B, a late X became Y or Z".  We can see there are
+4 combinations of ("B or C", "C or B") x ("X or Y", "Y or X").
+
+By sorting, the conflict is given its canonical name, namely, "an
+early part became B or C, a late part becames X or Y", and whenever
+any of these four patterns appear, and we can get to the same conflict
+and resolution that we saw earlier.
+
+Without the sorting, we'd have to somehow find a previous resolution
+from combinatorial explosion.
+
+Conflict ID calculation
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Once the conflict normalization is done, the conflict ID is calculated
+as the sha1 hash of the conflict hunks appended to each other,
+separated by <NUL> characters.  The conflict markers are stripped out
+before the sha1 is calculated.  So in the example above, where we
+merge branch AC which changes line A to line C, into branch AB, which
+changes line A to line C, the conflict ID would be
+SHA1('B<NUL>C<NUL>').
+
+If there are multiple conflicts in one file, the sha1 is calculated
+the same way with all hunks appended to each other, in the order in
+which they appear in the file, separated by a <NUL> character.
+
+Nested conflicts
+~~~~~~~~~~~~~~~~
+
+Nested conflicts are handled very similarly to "simple" conflicts.
+Similar to simple conflicts, the conflict is first normalized by
+stripping the labels from conflict markers, stripping the common ancestor
+version, and the sorting the conflict hunks, both for the outer and the
+inner conflict.  This is done recursively, so any number of nested
+conflicts can be handled.
+
+Note that this only works for conflict markers that "cleanly nest".  If
+there are any unmatched conflict markers, rerere will fail to handle
+the conflict and record a conflict resolution.
+
+The only difference is in how the conflict ID is calculated.  For the
+inner conflict, the conflict markers themselves are not stripped out
+before calculating the sha1.
+
+Say we have the following conflict for example:
+
+    <<<<<<< HEAD
+    1
+    =======
+    <<<<<<< HEAD
+    3
+    =======
+    2
+    >>>>>>> branch-2
+    >>>>>>> branch-3~
+
+After stripping out the labels of the conflict markers, and sorting
+the hunks, the conflict would look as follows:
+
+    <<<<<<<
+    1
+    =======
+    <<<<<<<
+    2
+    =======
+    3
+    >>>>>>>
+    >>>>>>>
+
+and finally the conflict ID would be calculated as:
+`sha1('1<NUL><<<<<<<\n3\n=======\n2\n>>>>>>><NUL>')`
diff --git a/third_party/git/Documentation/technical/send-pack-pipeline.txt b/third_party/git/Documentation/technical/send-pack-pipeline.txt
new file mode 100644
index 0000000000..9b5a0bc186
--- /dev/null
+++ b/third_party/git/Documentation/technical/send-pack-pipeline.txt
@@ -0,0 +1,63 @@
+Git-send-pack internals
+=======================
+
+Overall operation
+-----------------
+
+. Connects to the remote side and invokes git-receive-pack.
+
+. Learns what refs the remote has and what commit they point at.
+  Matches them to the refspecs we are pushing.
+
+. Checks if there are non-fast-forwards.  Unlike fetch-pack,
+  the repository send-pack runs in is supposed to be a superset
+  of the recipient in fast-forward cases, so there is no need
+  for want/have exchanges, and fast-forward check can be done
+  locally.  Tell the result to the other end.
+
+. Calls pack_objects() which generates a packfile and sends it
+  over to the other end.
+
+. If the remote side is new enough (v1.1.0 or later), wait for
+  the unpack and hook status from the other end.
+
+. Exit with appropriate error codes.
+
+
+Pack_objects pipeline
+---------------------
+
+This function gets one file descriptor (`fd`) which is either a
+socket (over the network) or a pipe (local).  What's written to
+this fd goes to git-receive-pack to be unpacked.
+
+    send-pack ---> fd ---> receive-pack
+
+The function pack_objects creates a pipe and then forks.  The
+forked child execs pack-objects with --revs to receive revision
+parameters from its standard input. This process will write the
+packfile to the other end.
+
+    send-pack
+       |
+       pack_objects() ---> fd ---> receive-pack
+          | ^ (pipe)
+	  v |
+         (child)
+
+The child dup2's to arrange its standard output to go back to
+the other end, and read its standard input to come from the
+pipe.  After that it exec's pack-objects.  On the other hand,
+the parent process, before starting to feed the child pipeline,
+closes the reading side of the pipe and fd to receive-pack.
+
+    send-pack
+       |
+       pack_objects(parent)
+          |
+	  v [0]
+         pack-objects [0] ---> receive-pack
+
+
+[jc: the pipeline was much more complex and needed documentation before
+ I understood an earlier bug, but now it is trivial and straightforward.]
diff --git a/third_party/git/Documentation/technical/shallow.txt b/third_party/git/Documentation/technical/shallow.txt
new file mode 100644
index 0000000000..01dedfe9ff
--- /dev/null
+++ b/third_party/git/Documentation/technical/shallow.txt
@@ -0,0 +1,60 @@
+Shallow commits
+===============
+
+.Definition
+*********************************************************
+Shallow commits do have parents, but not in the shallow
+repo, and therefore grafts are introduced pretending that
+these commits have no parents.
+*********************************************************
+
+$GIT_DIR/shallow lists commit object names and tells Git to
+pretend as if they are root commits (e.g. "git log" traversal
+stops after showing them; "git fsck" does not complain saying
+the commits listed on their "parent" lines do not exist).
+
+Each line contains exactly one SHA-1. When read, a commit_graft
+will be constructed, which has nr_parent < 0 to make it easier
+to discern from user provided grafts.
+
+Note that the shallow feature could not be changed easily to
+use replace refs: a commit containing a `mergetag` is not allowed
+to be replaced, not even by a root commit. Such a commit can be
+made shallow, though. Also, having a `shallow` file explicitly
+listing all the commits made shallow makes it a *lot* easier to
+do shallow-specific things such as to deepen the history.
+
+Since fsck-objects relies on the library to read the objects,
+it honours shallow commits automatically.
+
+There are some unfinished ends of the whole shallow business:
+
+- maybe we have to force non-thin packs when fetching into a
+  shallow repo (ATM they are forced non-thin).
+
+- A special handling of a shallow upstream is needed. At some
+  stage, upload-pack has to check if it sends a shallow commit,
+  and it should send that information early (or fail, if the
+  client does not support shallow repositories). There is no
+  support at all for this in this patch series.
+
+- Instead of locking $GIT_DIR/shallow at the start, just
+  the timestamp of it is noted, and when it comes to writing it,
+  a check is performed if the mtime is still the same, dying if
+  it is not.
+
+- It is unclear how "push into/from a shallow repo" should behave.
+
+- If you deepen a history, you'd want to get the tags of the
+  newly stored (but older!) commits. This does not work right now.
+
+To make a shallow clone, you can call "git-clone --depth 20 repo".
+The result contains only commit chains with a length of at most 20.
+It also writes an appropriate $GIT_DIR/shallow.
+
+You can deepen a shallow repository with "git-fetch --depth 20
+repo branch", which will fetch branch from repo, but stop at depth
+20, updating $GIT_DIR/shallow.
+
+The special depth 2147483647 (or 0x7fffffff, the largest positive
+number a signed 32-bit integer can contain) means infinite depth.
diff --git a/third_party/git/Documentation/technical/signature-format.txt b/third_party/git/Documentation/technical/signature-format.txt
new file mode 100644
index 0000000000..2c9406a56a
--- /dev/null
+++ b/third_party/git/Documentation/technical/signature-format.txt
@@ -0,0 +1,186 @@
+Git signature format
+====================
+
+== Overview
+
+Git uses cryptographic signatures in various places, currently objects (tags,
+commits, mergetags) and transactions (pushes). In every case, the command which
+is about to create an object or transaction determines a payload from that,
+calls gpg to obtain a detached signature for the payload (`gpg -bsa`) and
+embeds the signature into the object or transaction.
+
+Signatures always begin with `-----BEGIN PGP SIGNATURE-----`
+and end with `-----END PGP SIGNATURE-----`, unless gpg is told to
+produce RFC1991 signatures which use `MESSAGE` instead of `SIGNATURE`.
+
+The signed payload and the way the signature is embedded depends
+on the type of the object resp. transaction.
+
+== Tag signatures
+
+- created by: `git tag -s`
+- payload: annotated tag object
+- embedding: append the signature to the unsigned tag object
+- example: tag `signedtag` with subject `signed tag`
+
+----
+object 04b871796dc0420f8e7561a895b52484b701d51a
+type commit
+tag signedtag
+tagger C O Mitter <committer@example.com> 1465981006 +0000
+
+signed tag
+
+signed tag message body
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v1
+
+iQEcBAABAgAGBQJXYRhOAAoJEGEJLoW3InGJklkIAIcnhL7RwEb/+QeX9enkXhxn
+rxfdqrvWd1K80sl2TOt8Bg/NYwrUBw/RWJ+sg/hhHp4WtvE1HDGHlkEz3y11Lkuh
+8tSxS3qKTxXUGozyPGuE90sJfExhZlW4knIQ1wt/yWqM+33E9pN4hzPqLwyrdods
+q8FWEqPPUbSJXoMbRPw04S5jrLtZSsUWbRYjmJCHzlhSfFWW4eFd37uquIaLUBS0
+rkC3Jrx7420jkIpgFcTI2s60uhSQLzgcCwdA2ukSYIRnjg/zDkj8+3h/GaROJ72x
+lZyI6HWixKJkWw8lE9aAOD9TmTW9sFJwcVAzmAuFX2kUreDUKMZduGcoRYGpD7E=
+=jpXa
+-----END PGP SIGNATURE-----
+----
+
+- verify with: `git verify-tag [-v]` or `git tag -v`
+
+----
+gpg: Signature made Wed Jun 15 10:56:46 2016 CEST using RSA key ID B7227189
+gpg: Good signature from "Eris Discordia <discord@example.net>"
+gpg: WARNING: This key is not certified with a trusted signature!
+gpg:          There is no indication that the signature belongs to the owner.
+Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
+object 04b871796dc0420f8e7561a895b52484b701d51a
+type commit
+tag signedtag
+tagger C O Mitter <committer@example.com> 1465981006 +0000
+
+signed tag
+
+signed tag message body
+----
+
+== Commit signatures
+
+- created by: `git commit -S`
+- payload: commit object
+- embedding: header entry `gpgsig`
+  (content is preceded by a space)
+- example: commit with subject `signed commit`
+
+----
+tree eebfed94e75e7760540d1485c740902590a00332
+parent 04b871796dc0420f8e7561a895b52484b701d51a
+author A U Thor <author@example.com> 1465981137 +0000
+committer C O Mitter <committer@example.com> 1465981137 +0000
+gpgsig -----BEGIN PGP SIGNATURE-----
+ Version: GnuPG v1
+
+ iQEcBAABAgAGBQJXYRjRAAoJEGEJLoW3InGJ3IwIAIY4SA6GxY3BjL60YyvsJPh/
+ HRCJwH+w7wt3Yc/9/bW2F+gF72kdHOOs2jfv+OZhq0q4OAN6fvVSczISY/82LpS7
+ DVdMQj2/YcHDT4xrDNBnXnviDO9G7am/9OE77kEbXrp7QPxvhjkicHNwy2rEflAA
+ zn075rtEERDHr8nRYiDh8eVrefSO7D+bdQ7gv+7GsYMsd2auJWi1dHOSfTr9HIF4
+ HJhWXT9d2f8W+diRYXGh4X0wYiGg6na/soXc+vdtDYBzIxanRqjg8jCAeo1eOTk1
+ EdTwhcTZlI0x5pvJ3H0+4hA2jtldVtmPM4OTB0cTrEWBad7XV6YgiyuII73Ve3I=
+ =jKHM
+ -----END PGP SIGNATURE-----
+
+signed commit
+
+signed commit message body
+----
+
+- verify with: `git verify-commit [-v]` (or `git show --show-signature`)
+
+----
+gpg: Signature made Wed Jun 15 10:58:57 2016 CEST using RSA key ID B7227189
+gpg: Good signature from "Eris Discordia <discord@example.net>"
+gpg: WARNING: This key is not certified with a trusted signature!
+gpg:          There is no indication that the signature belongs to the owner.
+Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
+tree eebfed94e75e7760540d1485c740902590a00332
+parent 04b871796dc0420f8e7561a895b52484b701d51a
+author A U Thor <author@example.com> 1465981137 +0000
+committer C O Mitter <committer@example.com> 1465981137 +0000
+
+signed commit
+
+signed commit message body
+----
+
+== Mergetag signatures
+
+- created by: `git merge` on signed tag
+- payload/embedding: the whole signed tag object is embedded into
+  the (merge) commit object as header entry `mergetag`
+- example: merge of the signed tag `signedtag` as above
+
+----
+tree c7b1cff039a93f3600a1d18b82d26688668c7dea
+parent c33429be94b5f2d3ee9b0adad223f877f174b05d
+parent 04b871796dc0420f8e7561a895b52484b701d51a
+author A U Thor <author@example.com> 1465982009 +0000
+committer C O Mitter <committer@example.com> 1465982009 +0000
+mergetag object 04b871796dc0420f8e7561a895b52484b701d51a
+ type commit
+ tag signedtag
+ tagger C O Mitter <committer@example.com> 1465981006 +0000
+
+ signed tag
+
+ signed tag message body
+ -----BEGIN PGP SIGNATURE-----
+ Version: GnuPG v1
+
+ iQEcBAABAgAGBQJXYRhOAAoJEGEJLoW3InGJklkIAIcnhL7RwEb/+QeX9enkXhxn
+ rxfdqrvWd1K80sl2TOt8Bg/NYwrUBw/RWJ+sg/hhHp4WtvE1HDGHlkEz3y11Lkuh
+ 8tSxS3qKTxXUGozyPGuE90sJfExhZlW4knIQ1wt/yWqM+33E9pN4hzPqLwyrdods
+ q8FWEqPPUbSJXoMbRPw04S5jrLtZSsUWbRYjmJCHzlhSfFWW4eFd37uquIaLUBS0
+ rkC3Jrx7420jkIpgFcTI2s60uhSQLzgcCwdA2ukSYIRnjg/zDkj8+3h/GaROJ72x
+ lZyI6HWixKJkWw8lE9aAOD9TmTW9sFJwcVAzmAuFX2kUreDUKMZduGcoRYGpD7E=
+ =jpXa
+ -----END PGP SIGNATURE-----
+
+Merge tag 'signedtag' into downstream
+
+signed tag
+
+signed tag message body
+
+# gpg: Signature made Wed Jun 15 08:56:46 2016 UTC using RSA key ID B7227189
+# gpg: Good signature from "Eris Discordia <discord@example.net>"
+# gpg: WARNING: This key is not certified with a trusted signature!
+# gpg:          There is no indication that the signature belongs to the owner.
+# Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
+----
+
+- verify with: verification is embedded in merge commit message by default,
+  alternatively with `git show --show-signature`:
+
+----
+commit 9863f0c76ff78712b6800e199a46aa56afbcbd49
+merged tag 'signedtag'
+gpg: Signature made Wed Jun 15 10:56:46 2016 CEST using RSA key ID B7227189
+gpg: Good signature from "Eris Discordia <discord@example.net>"
+gpg: WARNING: This key is not certified with a trusted signature!
+gpg:          There is no indication that the signature belongs to the owner.
+Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
+Merge: c33429b 04b8717
+Author: A U Thor <author@example.com>
+Date:   Wed Jun 15 09:13:29 2016 +0000
+
+    Merge tag 'signedtag' into downstream
+
+    signed tag
+
+    signed tag message body
+
+    # gpg: Signature made Wed Jun 15 08:56:46 2016 UTC using RSA key ID B7227189
+    # gpg: Good signature from "Eris Discordia <discord@example.net>"
+    # gpg: WARNING: This key is not certified with a trusted signature!
+    # gpg:          There is no indication that the signature belongs to the owner.
+    # Primary key fingerprint: D4BE 2231 1AD3 131E 5EDA  29A4 6109 2E85 B722 7189
+----
diff --git a/third_party/git/Documentation/technical/trivial-merge.txt b/third_party/git/Documentation/technical/trivial-merge.txt
new file mode 100644
index 0000000000..1f1c33d0da
--- /dev/null
+++ b/third_party/git/Documentation/technical/trivial-merge.txt
@@ -0,0 +1,121 @@
+Trivial merge rules
+===================
+
+This document describes the outcomes of the trivial merge logic in read-tree.
+
+One-way merge
+-------------
+
+This replaces the index with a different tree, keeping the stat info
+for entries that don't change, and allowing -u to make the minimum
+required changes to the working tree to have it match.
+
+Entries marked '+' have stat information. Spaces marked '*' don't
+affect the result.
+
+   index   tree    result
+   -----------------------
+   *       (empty) (empty)
+   (empty) tree    tree
+   index+  tree    tree
+   index+  index   index+
+
+Two-way merge
+-------------
+
+It is permitted for the index to lack an entry; this does not prevent
+any case from applying.
+
+If the index exists, it is an error for it not to match either the old
+or the result.
+
+If multiple cases apply, the one used is listed first.
+
+A result which changes the index is an error if the index is not empty
+and not up to date.
+
+Entries marked '+' have stat information. Spaces marked '*' don't
+affect the result.
+
+ case  index   old     new     result
+ -------------------------------------
+ 0/2   (empty) *       (empty) (empty)
+ 1/3   (empty) *       new     new
+ 4/5   index+  (empty) (empty) index+
+ 6/7   index+  (empty) index   index+
+ 10    index+  index   (empty) (empty)
+ 14/15 index+  old     old     index+
+ 18/19 index+  old     index   index+
+ 20    index+  index   new     new
+
+Three-way merge
+---------------
+
+It is permitted for the index to lack an entry; this does not prevent
+any case from applying.
+
+If the index exists, it is an error for it not to match either the
+head or (if the merge is trivial) the result.
+
+If multiple cases apply, the one used is listed first.
+
+A result of "no merge" means that index is left in stage 0, ancest in
+stage 1, head in stage 2, and remote in stage 3 (if any of these are
+empty, no entry is left for that stage). Otherwise, the given entry is
+left in stage 0, and there are no other entries.
+
+A result of "no merge" is an error if the index is not empty and not
+up to date.
+
+*empty* means that the tree must not have a directory-file conflict
+ with the entry.
+
+For multiple ancestors, a '+' means that this case applies even if
+only one ancestor or remote fits; a '^' means all of the ancestors
+must be the same.
+
+ case  ancest    head    remote    result
+ ----------------------------------------
+ 1     (empty)+  (empty) (empty)   (empty)
+ 2ALT  (empty)+  *empty* remote    remote
+ 2     (empty)^  (empty) remote    no merge
+ 3ALT  (empty)+  head    *empty*   head
+ 3     (empty)^  head    (empty)   no merge
+ 4     (empty)^  head    remote    no merge
+ 5ALT  *         head    head      head
+ 6     ancest+   (empty) (empty)   no merge
+ 8     ancest^   (empty) ancest    no merge
+ 7     ancest+   (empty) remote    no merge
+ 10    ancest^   ancest  (empty)   no merge
+ 9     ancest+   head    (empty)   no merge
+ 16    anc1/anc2 anc1    anc2      no merge
+ 13    ancest+   head    ancest    head
+ 14    ancest+   ancest  remote    remote
+ 11    ancest+   head    remote    no merge
+
+Only #2ALT and #3ALT use *empty*, because these are the only cases
+where there can be conflicts that didn't exist before. Note that we
+allow directory-file conflicts between things in different stages
+after the trivial merge.
+
+A possible alternative for #6 is (empty), which would make it like
+#1. This is not used, due to the likelihood that it arises due to
+moving the file to multiple different locations or moving and deleting
+it in different branches.
+
+Case #1 is included for completeness, and also in case we decide to
+put on '+' markings; any path that is never mentioned at all isn't
+handled.
+
+Note that #16 is when both #13 and #14 apply; in this case, we refuse
+the trivial merge, because we can't tell from this data which is
+right. This is a case of a reverted patch (in some direction, maybe
+multiple times), and the right answer depends on looking at crossings
+of history or common ancestors of the ancestors.
+
+Note that, between #6, #7, #9, and #11, all cases not otherwise
+covered are handled in this table.
+
+For #8 and #10, there is alternative behavior, not currently
+implemented, where the result is (empty). As currently implemented,
+the automatic merge will generally give this effect.
diff --git a/third_party/git/Documentation/texi.xsl b/third_party/git/Documentation/texi.xsl
new file mode 100644
index 0000000000..0f8ff07eca
--- /dev/null
+++ b/third_party/git/Documentation/texi.xsl
@@ -0,0 +1,26 @@
+<!-- texi.xsl:
+     convert refsection elements into refsect elements that docbook2texi can
+     understand -->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+		version="1.0">
+
+<xsl:output method="xml"
+	    encoding="UTF-8"
+	    doctype-public="-//OASIS//DTD DocBook XML V4.5//EN"
+	    doctype-system="http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" />
+
+<xsl:template match="//refsection">
+	<xsl:variable name="element">refsect<xsl:value-of select="count(ancestor-or-self::refsection)" /></xsl:variable>
+	<xsl:element name="{$element}">
+		<xsl:apply-templates select="@*|node()" />
+	</xsl:element>
+</xsl:template>
+
+<!-- Copy all other nodes through. -->
+<xsl:template match="node()|@*">
+	<xsl:copy>
+		<xsl:apply-templates select="@*|node()" />
+	</xsl:copy>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/third_party/git/Documentation/trace2-target-values.txt b/third_party/git/Documentation/trace2-target-values.txt
new file mode 100644
index 0000000000..27d3c64e66
--- /dev/null
+++ b/third_party/git/Documentation/trace2-target-values.txt
@@ -0,0 +1,10 @@
+--
+* `0` or `false` - Disables the target.
+* `1` or `true` - Writes to `STDERR`.
+* `[2-9]` - Writes to the already opened file descriptor.
+* `<absolute-pathname>` - Writes to the file in append mode.
+* `af_unix:[<socket_type>:]<absolute-pathname>` - Write to a
+Unix DomainSocket (on platforms that support them).  Socket
+type can be either `stream` or `dgram`; if omitted Git will
+try both.
+--
diff --git a/third_party/git/Documentation/transfer-data-leaks.txt b/third_party/git/Documentation/transfer-data-leaks.txt
new file mode 100644
index 0000000000..914bacc39e
--- /dev/null
+++ b/third_party/git/Documentation/transfer-data-leaks.txt
@@ -0,0 +1,30 @@
+SECURITY
+--------
+The fetch and push protocols are not designed to prevent one side from
+stealing data from the other repository that was not intended to be
+shared. If you have private data that you need to protect from a malicious
+peer, your best option is to store it in another repository. This applies
+to both clients and servers. In particular, namespaces on a server are not
+effective for read access control; you should only grant read access to a
+namespace to clients that you would trust with read access to the entire
+repository.
+
+The known attack vectors are as follows:
+
+. The victim sends "have" lines advertising the IDs of objects it has that
+  are not explicitly intended to be shared but can be used to optimize the
+  transfer if the peer also has them. The attacker chooses an object ID X
+  to steal and sends a ref to X, but isn't required to send the content of
+  X because the victim already has it. Now the victim believes that the
+  attacker has X, and it sends the content of X back to the attacker
+  later. (This attack is most straightforward for a client to perform on a
+  server, by creating a ref to X in the namespace the client has access
+  to and then fetching it. The most likely way for a server to perform it
+  on a client is to "merge" X into a public branch and hope that the user
+  does additional work on this branch and pushes it back to the server
+  without noticing the merge.)
+
+. As in #1, the attacker chooses an object ID X to steal. The victim sends
+  an object Y that the attacker already has, and the attacker falsely
+  claims to have X and not Y, so the victim sends Y as a delta against X.
+  The delta reveals regions of X that are similar to Y to the attacker.
diff --git a/third_party/git/Documentation/urls-remotes.txt b/third_party/git/Documentation/urls-remotes.txt
new file mode 100644
index 0000000000..bd184cd653
--- /dev/null
+++ b/third_party/git/Documentation/urls-remotes.txt
@@ -0,0 +1,94 @@
+include::urls.txt[]
+
+REMOTES[[REMOTES]]
+------------------
+
+The name of one of the following can be used instead
+of a URL as `<repository>` argument:
+
+* a remote in the Git configuration file: `$GIT_DIR/config`,
+* a file in the `$GIT_DIR/remotes` directory, or
+* a file in the `$GIT_DIR/branches` directory.
+
+All of these also allow you to omit the refspec from the command line
+because they each contain a refspec which git will use by default.
+
+Named remote in configuration file
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can choose to provide the name of a remote which you had previously
+configured using linkgit:git-remote[1], linkgit:git-config[1]
+or even by a manual edit to the `$GIT_DIR/config` file.  The URL of
+this remote will be used to access the repository.  The refspec
+of this remote will be used by default when you do
+not provide a refspec on the command line.  The entry in the
+config file would appear like this:
+
+------------
+	[remote "<name>"]
+		url = <url>
+		pushurl = <pushurl>
+		push = <refspec>
+		fetch = <refspec>
+------------
+
+The `<pushurl>` is used for pushes only. It is optional and defaults
+to `<url>`.
+
+Named file in `$GIT_DIR/remotes`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can choose to provide the name of a
+file in `$GIT_DIR/remotes`.  The URL
+in this file will be used to access the repository.  The refspec
+in this file will be used as default when you do not
+provide a refspec on the command line.  This file should have the
+following format:
+
+------------
+	URL: one of the above URL format
+	Push: <refspec>
+	Pull: <refspec>
+
+------------
+
+`Push:` lines are used by 'git push' and
+`Pull:` lines are used by 'git pull' and 'git fetch'.
+Multiple `Push:` and `Pull:` lines may
+be specified for additional branch mappings.
+
+Named file in `$GIT_DIR/branches`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can choose to provide the name of a
+file in `$GIT_DIR/branches`.
+The URL in this file will be used to access the repository.
+This file should have the following format:
+
+
+------------
+	<url>#<head>
+------------
+
+`<url>` is required; `#<head>` is optional.
+
+Depending on the operation, git will use one of the following
+refspecs, if you don't provide one on the command line.
+`<branch>` is the name of this file in `$GIT_DIR/branches` and
+`<head>` defaults to `master`.
+
+git fetch uses:
+
+------------
+	refs/heads/<head>:refs/heads/<branch>
+------------
+
+git push uses:
+
+------------
+	HEAD:refs/heads/<head>
+------------
+
+
+
+
diff --git a/third_party/git/Documentation/urls.txt b/third_party/git/Documentation/urls.txt
new file mode 100644
index 0000000000..bc354fe2dc
--- /dev/null
+++ b/third_party/git/Documentation/urls.txt
@@ -0,0 +1,105 @@
+GIT URLS[[URLS]]
+----------------
+
+In general, URLs contain information about the transport protocol, the
+address of the remote server, and the path to the repository.
+Depending on the transport protocol, some of this information may be
+absent.
+
+Git supports ssh, git, http, and https protocols (in addition, ftp,
+and ftps can be used for fetching, but this is inefficient and
+deprecated; do not use it).
+
+The native transport (i.e. git:// URL) does no authentication and
+should be used with caution on unsecured networks.
+
+The following syntaxes may be used with them:
+
+- ssh://{startsb}user@{endsb}host.xz{startsb}:port{endsb}/path/to/repo.git/
+- git://host.xz{startsb}:port{endsb}/path/to/repo.git/
+- http{startsb}s{endsb}://host.xz{startsb}:port{endsb}/path/to/repo.git/
+- ftp{startsb}s{endsb}://host.xz{startsb}:port{endsb}/path/to/repo.git/
+
+An alternative scp-like syntax may also be used with the ssh protocol:
+
+- {startsb}user@{endsb}host.xz:path/to/repo.git/
+
+This syntax is only recognized if there are no slashes before the
+first colon. This helps differentiate a local path that contains a
+colon. For example the local path `foo:bar` could be specified as an
+absolute path or `./foo:bar` to avoid being misinterpreted as an ssh
+url.
+
+The ssh and git protocols additionally support ~username expansion:
+
+- ssh://{startsb}user@{endsb}host.xz{startsb}:port{endsb}/~{startsb}user{endsb}/path/to/repo.git/
+- git://host.xz{startsb}:port{endsb}/~{startsb}user{endsb}/path/to/repo.git/
+- {startsb}user@{endsb}host.xz:/~{startsb}user{endsb}/path/to/repo.git/
+
+For local repositories, also supported by Git natively, the following
+syntaxes may be used:
+
+- /path/to/repo.git/
+- \file:///path/to/repo.git/
+
+ifndef::git-clone[]
+These two syntaxes are mostly equivalent, except when cloning, when
+the former implies --local option. See linkgit:git-clone[1] for
+details.
+endif::git-clone[]
+
+ifdef::git-clone[]
+These two syntaxes are mostly equivalent, except the former implies
+--local option.
+endif::git-clone[]
+
+When Git doesn't know how to handle a certain transport protocol, it
+attempts to use the 'remote-<transport>' remote helper, if one
+exists. To explicitly request a remote helper, the following syntax
+may be used:
+
+- <transport>::<address>
+
+where <address> may be a path, a server and path, or an arbitrary
+URL-like string recognized by the specific remote helper being
+invoked. See linkgit:gitremote-helpers[7] for details.
+
+If there are a large number of similarly-named remote repositories and
+you want to use a different format for them (such that the URLs you
+use will be rewritten into URLs that work), you can create a
+configuration section of the form:
+
+------------
+	[url "<actual url base>"]
+		insteadOf = <other url base>
+------------
+
+For example, with this:
+
+------------
+	[url "git://git.host.xz/"]
+		insteadOf = host.xz:/path/to/
+		insteadOf = work:
+------------
+
+a URL like "work:repo.git" or like "host.xz:/path/to/repo.git" will be
+rewritten in any context that takes a URL to be "git://git.host.xz/repo.git".
+
+If you want to rewrite URLs for push only, you can create a
+configuration section of the form:
+
+------------
+	[url "<actual url base>"]
+		pushInsteadOf = <other url base>
+------------
+
+For example, with this:
+
+------------
+	[url "ssh://example.org/"]
+		pushInsteadOf = git://example.org/
+------------
+
+a URL like "git://example.org/path/to/repo.git" will be rewritten to
+"ssh://example.org/path/to/repo.git" for pushes, but pulls will still
+use the original URL.
diff --git a/third_party/git/Documentation/user-manual.conf b/third_party/git/Documentation/user-manual.conf
new file mode 100644
index 0000000000..d87294de2f
--- /dev/null
+++ b/third_party/git/Documentation/user-manual.conf
@@ -0,0 +1,21 @@
+[titles]
+	underlines="__","==","--","~~","^^"
+
+[attributes]
+caret=^
+startsb=&#91;
+endsb=&#93;
+tilde=&#126;
+
+[linkgit-inlinemacro]
+<ulink url="{target}.html">{target}{0?({0})}</ulink>
+
+ifdef::backend-docbook[]
+# "unbreak" docbook-xsl v1.68 for manpages. v1.69 works with or without this.
+[listingblock]
+<example><title>{title}</title>
+<literallayout class="monospaced">
+|
+</literallayout>
+{title#}</example>
+endif::backend-docbook[]
diff --git a/third_party/git/Documentation/user-manual.txt b/third_party/git/Documentation/user-manual.txt
new file mode 100644
index 0000000000..8bce75b2cf
--- /dev/null
+++ b/third_party/git/Documentation/user-manual.txt
@@ -0,0 +1,4691 @@
+Git User Manual
+===============
+
+Git is a fast distributed revision control system.
+
+This manual is designed to be readable by someone with basic UNIX
+command-line skills, but no previous knowledge of Git.
+
+<<repositories-and-branches>> and <<exploring-git-history>> explain how
+to fetch and study a project using git--read these chapters to learn how
+to build and test a particular version of a software project, search for
+regressions, and so on.
+
+People needing to do actual development will also want to read
+<<Developing-With-git>> and <<sharing-development>>.
+
+Further chapters cover more specialized topics.
+
+Comprehensive reference documentation is available through the man
+pages, or linkgit:git-help[1] command.  For example, for the command
+`git clone <repo>`, you can either use:
+
+------------------------------------------------
+$ man git-clone
+------------------------------------------------
+
+or:
+
+------------------------------------------------
+$ git help clone
+------------------------------------------------
+
+With the latter, you can use the manual viewer of your choice; see
+linkgit:git-help[1] for more information.
+
+See also <<git-quick-start>> for a brief overview of Git commands,
+without any explanation.
+
+Finally, see <<todo>> for ways that you can help make this manual more
+complete.
+
+
+[[repositories-and-branches]]
+Repositories and Branches
+=========================
+
+[[how-to-get-a-git-repository]]
+How to get a Git repository
+---------------------------
+
+It will be useful to have a Git repository to experiment with as you
+read this manual.
+
+The best way to get one is by using the linkgit:git-clone[1] command to
+download a copy of an existing repository.  If you don't already have a
+project in mind, here are some interesting examples:
+
+------------------------------------------------
+	# Git itself (approx. 40MB download):
+$ git clone git://git.kernel.org/pub/scm/git/git.git
+	# the Linux kernel (approx. 640MB download):
+$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
+------------------------------------------------
+
+The initial clone may be time-consuming for a large project, but you
+will only need to clone once.
+
+The clone command creates a new directory named after the project
+(`git` or `linux` in the examples above).  After you cd into this
+directory, you will see that it contains a copy of the project files,
+called the <<def_working_tree,working tree>>, together with a special
+top-level directory named `.git`, which contains all the information
+about the history of the project.
+
+[[how-to-check-out]]
+How to check out a different version of a project
+-------------------------------------------------
+
+Git is best thought of as a tool for storing the history of a collection
+of files.  It stores the history as a compressed collection of
+interrelated snapshots of the project's contents.  In Git each such
+version is called a <<def_commit,commit>>.
+
+Those snapshots aren't necessarily all arranged in a single line from
+oldest to newest; instead, work may simultaneously proceed along
+parallel lines of development, called <<def_branch,branches>>, which may
+merge and diverge.
+
+A single Git repository can track development on multiple branches.  It
+does this by keeping a list of <<def_head,heads>> which reference the
+latest commit on each branch; the linkgit:git-branch[1] command shows
+you the list of branch heads:
+
+------------------------------------------------
+$ git branch
+* master
+------------------------------------------------
+
+A freshly cloned repository contains a single branch head, by default
+named "master", with the working directory initialized to the state of
+the project referred to by that branch head.
+
+Most projects also use <<def_tag,tags>>.  Tags, like heads, are
+references into the project's history, and can be listed using the
+linkgit:git-tag[1] command:
+
+------------------------------------------------
+$ git tag -l
+v2.6.11
+v2.6.11-tree
+v2.6.12
+v2.6.12-rc2
+v2.6.12-rc3
+v2.6.12-rc4
+v2.6.12-rc5
+v2.6.12-rc6
+v2.6.13
+...
+------------------------------------------------
+
+Tags are expected to always point at the same version of a project,
+while heads are expected to advance as development progresses.
+
+Create a new branch head pointing to one of these versions and check it
+out using linkgit:git-switch[1]:
+
+------------------------------------------------
+$ git switch -c new v2.6.13
+------------------------------------------------
+
+The working directory then reflects the contents that the project had
+when it was tagged v2.6.13, and linkgit:git-branch[1] shows two
+branches, with an asterisk marking the currently checked-out branch:
+
+------------------------------------------------
+$ git branch
+  master
+* new
+------------------------------------------------
+
+If you decide that you'd rather see version 2.6.17, you can modify
+the current branch to point at v2.6.17 instead, with
+
+------------------------------------------------
+$ git reset --hard v2.6.17
+------------------------------------------------
+
+Note that if the current branch head was your only reference to a
+particular point in history, then resetting that branch may leave you
+with no way to find the history it used to point to; so use this command
+carefully.
+
+[[understanding-commits]]
+Understanding History: Commits
+------------------------------
+
+Every change in the history of a project is represented by a commit.
+The linkgit:git-show[1] command shows the most recent commit on the
+current branch:
+
+------------------------------------------------
+$ git show
+commit 17cf781661e6d38f737f15f53ab552f1e95960d7
+Author: Linus Torvalds <torvalds@ppc970.osdl.org.(none)>
+Date:   Tue Apr 19 14:11:06 2005 -0700
+
+    Remove duplicate getenv(DB_ENVIRONMENT) call
+
+    Noted by Tony Luck.
+
+diff --git a/init-db.c b/init-db.c
+index 65898fa..b002dc6 100644
+--- a/init-db.c
++++ b/init-db.c
+@@ -7,7 +7,7 @@
+ 
+ int main(int argc, char **argv)
+ {
+-	char *sha1_dir = getenv(DB_ENVIRONMENT), *path;
++	char *sha1_dir, *path;
+ 	int len, i;
+ 
+ 	if (mkdir(".git", 0755) < 0) {
+------------------------------------------------
+
+As you can see, a commit shows who made the latest change, what they
+did, and why.
+
+Every commit has a 40-hexdigit id, sometimes called the "object name" or the
+"SHA-1 id", shown on the first line of the `git show` output.  You can usually
+refer to a commit by a shorter name, such as a tag or a branch name, but this
+longer name can also be useful.  Most importantly, it is a globally unique
+name for this commit: so if you tell somebody else the object name (for
+example in email), then you are guaranteed that name will refer to the same
+commit in their repository that it does in yours (assuming their repository
+has that commit at all).  Since the object name is computed as a hash over the
+contents of the commit, you are guaranteed that the commit can never change
+without its name also changing.
+
+In fact, in <<git-concepts>> we shall see that everything stored in Git
+history, including file data and directory contents, is stored in an object
+with a name that is a hash of its contents.
+
+[[understanding-reachability]]
+Understanding history: commits, parents, and reachability
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Every commit (except the very first commit in a project) also has a
+parent commit which shows what happened before this commit.
+Following the chain of parents will eventually take you back to the
+beginning of the project.
+
+However, the commits do not form a simple list; Git allows lines of
+development to diverge and then reconverge, and the point where two
+lines of development reconverge is called a "merge".  The commit
+representing a merge can therefore have more than one parent, with
+each parent representing the most recent commit on one of the lines
+of development leading to that point.
+
+The best way to see how this works is using the linkgit:gitk[1]
+command; running gitk now on a Git repository and looking for merge
+commits will help understand how Git organizes history.
+
+In the following, we say that commit X is "reachable" from commit Y
+if commit X is an ancestor of commit Y.  Equivalently, you could say
+that Y is a descendant of X, or that there is a chain of parents
+leading from commit Y to commit X.
+
+[[history-diagrams]]
+Understanding history: History diagrams
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+We will sometimes represent Git history using diagrams like the one
+below.  Commits are shown as "o", and the links between them with
+lines drawn with - / and \.  Time goes left to right:
+
+
+................................................
+         o--o--o <-- Branch A
+        /
+ o--o--o <-- master
+        \
+         o--o--o <-- Branch B
+................................................
+
+If we need to talk about a particular commit, the character "o" may
+be replaced with another letter or number.
+
+[[what-is-a-branch]]
+Understanding history: What is a branch?
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When we need to be precise, we will use the word "branch" to mean a line
+of development, and "branch head" (or just "head") to mean a reference
+to the most recent commit on a branch.  In the example above, the branch
+head named "A" is a pointer to one particular commit, but we refer to
+the line of three commits leading up to that point as all being part of
+"branch A".
+
+However, when no confusion will result, we often just use the term
+"branch" both for branches and for branch heads.
+
+[[manipulating-branches]]
+Manipulating branches
+---------------------
+
+Creating, deleting, and modifying branches is quick and easy; here's
+a summary of the commands:
+
+`git branch`::
+	list all branches.
+`git branch <branch>`::
+	create a new branch named `<branch>`, referencing the same
+	point in history as the current branch.
+`git branch <branch> <start-point>`::
+	create a new branch named `<branch>`, referencing
+	`<start-point>`, which may be specified any way you like,
+	including using a branch name or a tag name.
+`git branch -d <branch>`::
+	delete the branch `<branch>`; if the branch is not fully
+	merged in its upstream branch or contained in the current branch,
+	this command will fail with a warning.
+`git branch -D <branch>`::
+	delete the branch `<branch>` irrespective of its merged status.
+`git switch <branch>`::
+	make the current branch `<branch>`, updating the working
+	directory to reflect the version referenced by `<branch>`.
+`git switch -c <new> <start-point>`::
+	create a new branch `<new>` referencing `<start-point>`, and
+	check it out.
+
+The special symbol "HEAD" can always be used to refer to the current
+branch.  In fact, Git uses a file named `HEAD` in the `.git` directory
+to remember which branch is current:
+
+------------------------------------------------
+$ cat .git/HEAD
+ref: refs/heads/master
+------------------------------------------------
+
+[[detached-head]]
+Examining an old version without creating a new branch
+------------------------------------------------------
+
+The `git switch` command normally expects a branch head, but will also
+accept an arbitrary commit when invoked with --detach; for example,
+you can check out the commit referenced by a tag:
+
+------------------------------------------------
+$ git switch --detach v2.6.17
+Note: checking out 'v2.6.17'.
+
+You are in 'detached HEAD' state. You can look around, make experimental
+changes and commit them, and you can discard any commits you make in this
+state without impacting any branches by performing another switch.
+
+If you want to create a new branch to retain commits you create, you may
+do so (now or later) by using -c with the switch command again. Example:
+
+  git switch -c new_branch_name
+
+HEAD is now at 427abfa Linux v2.6.17
+------------------------------------------------
+
+The HEAD then refers to the SHA-1 of the commit instead of to a branch,
+and git branch shows that you are no longer on a branch:
+
+------------------------------------------------
+$ cat .git/HEAD
+427abfa28afedffadfca9dd8b067eb6d36bac53f
+$ git branch
+* (detached from v2.6.17)
+  master
+------------------------------------------------
+
+In this case we say that the HEAD is "detached".
+
+This is an easy way to check out a particular version without having to
+make up a name for the new branch.   You can still create a new branch
+(or tag) for this version later if you decide to.
+
+[[examining-remote-branches]]
+Examining branches from a remote repository
+-------------------------------------------
+
+The "master" branch that was created at the time you cloned is a copy
+of the HEAD in the repository that you cloned from.  That repository
+may also have had other branches, though, and your local repository
+keeps branches which track each of those remote branches, called
+remote-tracking branches, which you
+can view using the `-r` option to linkgit:git-branch[1]:
+
+------------------------------------------------
+$ git branch -r
+  origin/HEAD
+  origin/html
+  origin/maint
+  origin/man
+  origin/master
+  origin/next
+  origin/pu
+  origin/todo
+------------------------------------------------
+
+In this example, "origin" is called a remote repository, or "remote"
+for short. The branches of this repository are called "remote
+branches" from our point of view. The remote-tracking branches listed
+above were created based on the remote branches at clone time and will
+be updated by `git fetch` (hence `git pull`) and `git push`. See
+<<Updating-a-repository-With-git-fetch>> for details.
+
+You might want to build on one of these remote-tracking branches
+on a branch of your own, just as you would for a tag:
+
+------------------------------------------------
+$ git switch -c my-todo-copy origin/todo
+------------------------------------------------
+
+You can also check out `origin/todo` directly to examine it or
+write a one-off patch.  See <<detached-head,detached head>>.
+
+Note that the name "origin" is just the name that Git uses by default
+to refer to the repository that you cloned from.
+
+[[how-git-stores-references]]
+Naming branches, tags, and other references
+-------------------------------------------
+
+Branches, remote-tracking branches, and tags are all references to
+commits.  All references are named with a slash-separated path name
+starting with `refs`; the names we've been using so far are actually
+shorthand:
+
+	- The branch `test` is short for `refs/heads/test`.
+	- The tag `v2.6.18` is short for `refs/tags/v2.6.18`.
+	- `origin/master` is short for `refs/remotes/origin/master`.
+
+The full name is occasionally useful if, for example, there ever
+exists a tag and a branch with the same name.
+
+(Newly created refs are actually stored in the `.git/refs` directory,
+under the path given by their name.  However, for efficiency reasons
+they may also be packed together in a single file; see
+linkgit:git-pack-refs[1]).
+
+As another useful shortcut, the "HEAD" of a repository can be referred
+to just using the name of that repository.  So, for example, "origin"
+is usually a shortcut for the HEAD branch in the repository "origin".
+
+For the complete list of paths which Git checks for references, and
+the order it uses to decide which to choose when there are multiple
+references with the same shorthand name, see the "SPECIFYING
+REVISIONS" section of linkgit:gitrevisions[7].
+
+[[Updating-a-repository-With-git-fetch]]
+Updating a repository with git fetch
+------------------------------------
+
+After you clone a repository and commit a few changes of your own, you
+may wish to check the original repository for updates.
+
+The `git-fetch` command, with no arguments, will update all of the
+remote-tracking branches to the latest version found in the original
+repository.  It will not touch any of your own branches--not even the
+"master" branch that was created for you on clone.
+
+[[fetching-branches]]
+Fetching branches from other repositories
+-----------------------------------------
+
+You can also track branches from repositories other than the one you
+cloned from, using linkgit:git-remote[1]:
+
+-------------------------------------------------
+$ git remote add staging git://git.kernel.org/.../gregkh/staging.git
+$ git fetch staging
+...
+From git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
+ * [new branch]      master     -> staging/master
+ * [new branch]      staging-linus -> staging/staging-linus
+ * [new branch]      staging-next -> staging/staging-next
+-------------------------------------------------
+
+New remote-tracking branches will be stored under the shorthand name
+that you gave `git remote add`, in this case `staging`:
+
+-------------------------------------------------
+$ git branch -r
+  origin/HEAD -> origin/master
+  origin/master
+  staging/master
+  staging/staging-linus
+  staging/staging-next
+-------------------------------------------------
+
+If you run `git fetch <remote>` later, the remote-tracking branches
+for the named `<remote>` will be updated.
+
+If you examine the file `.git/config`, you will see that Git has added
+a new stanza:
+
+-------------------------------------------------
+$ cat .git/config
+...
+[remote "staging"]
+	url = git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
+	fetch = +refs/heads/*:refs/remotes/staging/*
+...
+-------------------------------------------------
+
+This is what causes Git to track the remote's branches; you may modify
+or delete these configuration options by editing `.git/config` with a
+text editor.  (See the "CONFIGURATION FILE" section of
+linkgit:git-config[1] for details.)
+
+[[exploring-git-history]]
+Exploring Git history
+=====================
+
+Git is best thought of as a tool for storing the history of a
+collection of files.  It does this by storing compressed snapshots of
+the contents of a file hierarchy, together with "commits" which show
+the relationships between these snapshots.
+
+Git provides extremely flexible and fast tools for exploring the
+history of a project.
+
+We start with one specialized tool that is useful for finding the
+commit that introduced a bug into a project.
+
+[[using-bisect]]
+How to use bisect to find a regression
+--------------------------------------
+
+Suppose version 2.6.18 of your project worked, but the version at
+"master" crashes.  Sometimes the best way to find the cause of such a
+regression is to perform a brute-force search through the project's
+history to find the particular commit that caused the problem.  The
+linkgit:git-bisect[1] command can help you do this:
+
+-------------------------------------------------
+$ git bisect start
+$ git bisect good v2.6.18
+$ git bisect bad master
+Bisecting: 3537 revisions left to test after this
+[65934a9a028b88e83e2b0f8b36618fe503349f8e] BLOCK: Make USB storage depend on SCSI rather than selecting it [try #6]
+-------------------------------------------------
+
+If you run `git branch` at this point, you'll see that Git has
+temporarily moved you in "(no branch)". HEAD is now detached from any
+branch and points directly to a commit (with commit id 65934) that
+is reachable from "master" but not from v2.6.18. Compile and test it,
+and see whether it crashes. Assume it does crash. Then:
+
+-------------------------------------------------
+$ git bisect bad
+Bisecting: 1769 revisions left to test after this
+[7eff82c8b1511017ae605f0c99ac275a7e21b867] i2c-core: Drop useless bitmaskings
+-------------------------------------------------
+
+checks out an older version.  Continue like this, telling Git at each
+stage whether the version it gives you is good or bad, and notice
+that the number of revisions left to test is cut approximately in
+half each time.
+
+After about 13 tests (in this case), it will output the commit id of
+the guilty commit.  You can then examine the commit with
+linkgit:git-show[1], find out who wrote it, and mail them your bug
+report with the commit id.  Finally, run
+
+-------------------------------------------------
+$ git bisect reset
+-------------------------------------------------
+
+to return you to the branch you were on before.
+
+Note that the version which `git bisect` checks out for you at each
+point is just a suggestion, and you're free to try a different
+version if you think it would be a good idea.  For example,
+occasionally you may land on a commit that broke something unrelated;
+run
+
+-------------------------------------------------
+$ git bisect visualize
+-------------------------------------------------
+
+which will run gitk and label the commit it chose with a marker that
+says "bisect".  Choose a safe-looking commit nearby, note its commit
+id, and check it out with:
+
+-------------------------------------------------
+$ git reset --hard fb47ddb2db
+-------------------------------------------------
+
+then test, run `bisect good` or `bisect bad` as appropriate, and
+continue.
+
+Instead of `git bisect visualize` and then `git reset --hard
+fb47ddb2db`, you might just want to tell Git that you want to skip
+the current commit:
+
+-------------------------------------------------
+$ git bisect skip
+-------------------------------------------------
+
+In this case, though, Git may not eventually be able to tell the first
+bad one between some first skipped commits and a later bad commit.
+
+There are also ways to automate the bisecting process if you have a
+test script that can tell a good from a bad commit. See
+linkgit:git-bisect[1] for more information about this and other `git
+bisect` features.
+
+[[naming-commits]]
+Naming commits
+--------------
+
+We have seen several ways of naming commits already:
+
+	- 40-hexdigit object name
+	- branch name: refers to the commit at the head of the given
+	  branch
+	- tag name: refers to the commit pointed to by the given tag
+	  (we've seen branches and tags are special cases of
+	  <<how-git-stores-references,references>>).
+	- HEAD: refers to the head of the current branch
+
+There are many more; see the "SPECIFYING REVISIONS" section of the
+linkgit:gitrevisions[7] man page for the complete list of ways to
+name revisions.  Some examples:
+
+-------------------------------------------------
+$ git show fb47ddb2 # the first few characters of the object name
+		    # are usually enough to specify it uniquely
+$ git show HEAD^    # the parent of the HEAD commit
+$ git show HEAD^^   # the grandparent
+$ git show HEAD~4   # the great-great-grandparent
+-------------------------------------------------
+
+Recall that merge commits may have more than one parent; by default,
+`^` and `~` follow the first parent listed in the commit, but you can
+also choose:
+
+-------------------------------------------------
+$ git show HEAD^1   # show the first parent of HEAD
+$ git show HEAD^2   # show the second parent of HEAD
+-------------------------------------------------
+
+In addition to HEAD, there are several other special names for
+commits:
+
+Merges (to be discussed later), as well as operations such as
+`git reset`, which change the currently checked-out commit, generally
+set ORIG_HEAD to the value HEAD had before the current operation.
+
+The `git fetch` operation always stores the head of the last fetched
+branch in FETCH_HEAD.  For example, if you run `git fetch` without
+specifying a local branch as the target of the operation
+
+-------------------------------------------------
+$ git fetch git://example.com/proj.git theirbranch
+-------------------------------------------------
+
+the fetched commits will still be available from FETCH_HEAD.
+
+When we discuss merges we'll also see the special name MERGE_HEAD,
+which refers to the other branch that we're merging in to the current
+branch.
+
+The linkgit:git-rev-parse[1] command is a low-level command that is
+occasionally useful for translating some name for a commit to the object
+name for that commit:
+
+-------------------------------------------------
+$ git rev-parse origin
+e05db0fd4f31dde7005f075a84f96b360d05984b
+-------------------------------------------------
+
+[[creating-tags]]
+Creating tags
+-------------
+
+We can also create a tag to refer to a particular commit; after
+running
+
+-------------------------------------------------
+$ git tag stable-1 1b2e1d63ff
+-------------------------------------------------
+
+You can use `stable-1` to refer to the commit 1b2e1d63ff.
+
+This creates a "lightweight" tag.  If you would also like to include a
+comment with the tag, and possibly sign it cryptographically, then you
+should create a tag object instead; see the linkgit:git-tag[1] man page
+for details.
+
+[[browsing-revisions]]
+Browsing revisions
+------------------
+
+The linkgit:git-log[1] command can show lists of commits.  On its
+own, it shows all commits reachable from the parent commit; but you
+can also make more specific requests:
+
+-------------------------------------------------
+$ git log v2.5..	# commits since (not reachable from) v2.5
+$ git log test..master	# commits reachable from master but not test
+$ git log master..test	# ...reachable from test but not master
+$ git log master...test	# ...reachable from either test or master,
+			#    but not both
+$ git log --since="2 weeks ago" # commits from the last 2 weeks
+$ git log Makefile      # commits which modify Makefile
+$ git log fs/		# ... which modify any file under fs/
+$ git log -S'foo()'	# commits which add or remove any file data
+			# matching the string 'foo()'
+-------------------------------------------------
+
+And of course you can combine all of these; the following finds
+commits since v2.5 which touch the `Makefile` or any file under `fs`:
+
+-------------------------------------------------
+$ git log v2.5.. Makefile fs/
+-------------------------------------------------
+
+You can also ask git log to show patches:
+
+-------------------------------------------------
+$ git log -p
+-------------------------------------------------
+
+See the `--pretty` option in the linkgit:git-log[1] man page for more
+display options.
+
+Note that git log starts with the most recent commit and works
+backwards through the parents; however, since Git history can contain
+multiple independent lines of development, the particular order that
+commits are listed in may be somewhat arbitrary.
+
+[[generating-diffs]]
+Generating diffs
+----------------
+
+You can generate diffs between any two versions using
+linkgit:git-diff[1]:
+
+-------------------------------------------------
+$ git diff master..test
+-------------------------------------------------
+
+That will produce the diff between the tips of the two branches.  If
+you'd prefer to find the diff from their common ancestor to test, you
+can use three dots instead of two:
+
+-------------------------------------------------
+$ git diff master...test
+-------------------------------------------------
+
+Sometimes what you want instead is a set of patches; for this you can
+use linkgit:git-format-patch[1]:
+
+-------------------------------------------------
+$ git format-patch master..test
+-------------------------------------------------
+
+will generate a file with a patch for each commit reachable from test
+but not from master.
+
+[[viewing-old-file-versions]]
+Viewing old file versions
+-------------------------
+
+You can always view an old version of a file by just checking out the
+correct revision first.  But sometimes it is more convenient to be
+able to view an old version of a single file without checking
+anything out; this command does that:
+
+-------------------------------------------------
+$ git show v2.5:fs/locks.c
+-------------------------------------------------
+
+Before the colon may be anything that names a commit, and after it
+may be any path to a file tracked by Git.
+
+[[history-examples]]
+Examples
+--------
+
+[[counting-commits-on-a-branch]]
+Counting the number of commits on a branch
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Suppose you want to know how many commits you've made on `mybranch`
+since it diverged from `origin`:
+
+-------------------------------------------------
+$ git log --pretty=oneline origin..mybranch | wc -l
+-------------------------------------------------
+
+Alternatively, you may often see this sort of thing done with the
+lower-level command linkgit:git-rev-list[1], which just lists the SHA-1's
+of all the given commits:
+
+-------------------------------------------------
+$ git rev-list origin..mybranch | wc -l
+-------------------------------------------------
+
+[[checking-for-equal-branches]]
+Check whether two branches point at the same history
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Suppose you want to check whether two branches point at the same point
+in history.
+
+-------------------------------------------------
+$ git diff origin..master
+-------------------------------------------------
+
+will tell you whether the contents of the project are the same at the
+two branches; in theory, however, it's possible that the same project
+contents could have been arrived at by two different historical
+routes.  You could compare the object names:
+
+-------------------------------------------------
+$ git rev-list origin
+e05db0fd4f31dde7005f075a84f96b360d05984b
+$ git rev-list master
+e05db0fd4f31dde7005f075a84f96b360d05984b
+-------------------------------------------------
+
+Or you could recall that the `...` operator selects all commits
+reachable from either one reference or the other but not
+both; so
+
+-------------------------------------------------
+$ git log origin...master
+-------------------------------------------------
+
+will return no commits when the two branches are equal.
+
+[[finding-tagged-descendants]]
+Find first tagged version including a given fix
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Suppose you know that the commit e05db0fd fixed a certain problem.
+You'd like to find the earliest tagged release that contains that
+fix.
+
+Of course, there may be more than one answer--if the history branched
+after commit e05db0fd, then there could be multiple "earliest" tagged
+releases.
+
+You could just visually inspect the commits since e05db0fd:
+
+-------------------------------------------------
+$ gitk e05db0fd..
+-------------------------------------------------
+
+or you can use linkgit:git-name-rev[1], which will give the commit a
+name based on any tag it finds pointing to one of the commit's
+descendants:
+
+-------------------------------------------------
+$ git name-rev --tags e05db0fd
+e05db0fd tags/v1.5.0-rc1^0~23
+-------------------------------------------------
+
+The linkgit:git-describe[1] command does the opposite, naming the
+revision using a tag on which the given commit is based:
+
+-------------------------------------------------
+$ git describe e05db0fd
+v1.5.0-rc0-260-ge05db0f
+-------------------------------------------------
+
+but that may sometimes help you guess which tags might come after the
+given commit.
+
+If you just want to verify whether a given tagged version contains a
+given commit, you could use linkgit:git-merge-base[1]:
+
+-------------------------------------------------
+$ git merge-base e05db0fd v1.5.0-rc1
+e05db0fd4f31dde7005f075a84f96b360d05984b
+-------------------------------------------------
+
+The merge-base command finds a common ancestor of the given commits,
+and always returns one or the other in the case where one is a
+descendant of the other; so the above output shows that e05db0fd
+actually is an ancestor of v1.5.0-rc1.
+
+Alternatively, note that
+
+-------------------------------------------------
+$ git log v1.5.0-rc1..e05db0fd
+-------------------------------------------------
+
+will produce empty output if and only if v1.5.0-rc1 includes e05db0fd,
+because it outputs only commits that are not reachable from v1.5.0-rc1.
+
+As yet another alternative, the linkgit:git-show-branch[1] command lists
+the commits reachable from its arguments with a display on the left-hand
+side that indicates which arguments that commit is reachable from.
+So, if you run something like
+
+-------------------------------------------------
+$ git show-branch e05db0fd v1.5.0-rc0 v1.5.0-rc1 v1.5.0-rc2
+! [e05db0fd] Fix warnings in sha1_file.c - use C99 printf format if
+available
+ ! [v1.5.0-rc0] GIT v1.5.0 preview
+  ! [v1.5.0-rc1] GIT v1.5.0-rc1
+   ! [v1.5.0-rc2] GIT v1.5.0-rc2
+...
+-------------------------------------------------
+
+then a line like
+
+-------------------------------------------------
++ ++ [e05db0fd] Fix warnings in sha1_file.c - use C99 printf format if
+available
+-------------------------------------------------
+
+shows that e05db0fd is reachable from itself, from v1.5.0-rc1,
+and from v1.5.0-rc2, and not from v1.5.0-rc0.
+
+[[showing-commits-unique-to-a-branch]]
+Showing commits unique to a given branch
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Suppose you would like to see all the commits reachable from the branch
+head named `master` but not from any other head in your repository.
+
+We can list all the heads in this repository with
+linkgit:git-show-ref[1]:
+
+-------------------------------------------------
+$ git show-ref --heads
+bf62196b5e363d73353a9dcf094c59595f3153b7 refs/heads/core-tutorial
+db768d5504c1bb46f63ee9d6e1772bd047e05bf9 refs/heads/maint
+a07157ac624b2524a059a3414e99f6f44bebc1e7 refs/heads/master
+24dbc180ea14dc1aebe09f14c8ecf32010690627 refs/heads/tutorial-2
+1e87486ae06626c2f31eaa63d26fc0fd646c8af2 refs/heads/tutorial-fixes
+-------------------------------------------------
+
+We can get just the branch-head names, and remove `master`, with
+the help of the standard utilities cut and grep:
+
+-------------------------------------------------
+$ git show-ref --heads | cut -d' ' -f2 | grep -v '^refs/heads/master'
+refs/heads/core-tutorial
+refs/heads/maint
+refs/heads/tutorial-2
+refs/heads/tutorial-fixes
+-------------------------------------------------
+
+And then we can ask to see all the commits reachable from master
+but not from these other heads:
+
+-------------------------------------------------
+$ gitk master --not $( git show-ref --heads | cut -d' ' -f2 |
+				grep -v '^refs/heads/master' )
+-------------------------------------------------
+
+Obviously, endless variations are possible; for example, to see all
+commits reachable from some head but not from any tag in the repository:
+
+-------------------------------------------------
+$ gitk $( git show-ref --heads ) --not  $( git show-ref --tags )
+-------------------------------------------------
+
+(See linkgit:gitrevisions[7] for explanations of commit-selecting
+syntax such as `--not`.)
+
+[[making-a-release]]
+Creating a changelog and tarball for a software release
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The linkgit:git-archive[1] command can create a tar or zip archive from
+any version of a project; for example:
+
+-------------------------------------------------
+$ git archive -o latest.tar.gz --prefix=project/ HEAD
+-------------------------------------------------
+
+will use HEAD to produce a gzipped tar archive in which each filename
+is preceded by `project/`.  The output file format is inferred from
+the output file extension if possible, see linkgit:git-archive[1] for
+details.
+
+Versions of Git older than 1.7.7 don't know about the `tar.gz` format,
+you'll need to use gzip explicitly:
+
+-------------------------------------------------
+$ git archive --format=tar --prefix=project/ HEAD | gzip >latest.tar.gz
+-------------------------------------------------
+
+If you're releasing a new version of a software project, you may want
+to simultaneously make a changelog to include in the release
+announcement.
+
+Linus Torvalds, for example, makes new kernel releases by tagging them,
+then running:
+
+-------------------------------------------------
+$ release-script 2.6.12 2.6.13-rc6 2.6.13-rc7
+-------------------------------------------------
+
+where release-script is a shell script that looks like:
+
+-------------------------------------------------
+#!/bin/sh
+stable="$1"
+last="$2"
+new="$3"
+echo "# git tag v$new"
+echo "git archive --prefix=linux-$new/ v$new | gzip -9 > ../linux-$new.tar.gz"
+echo "git diff v$stable v$new | gzip -9 > ../patch-$new.gz"
+echo "git log --no-merges v$new ^v$last > ../ChangeLog-$new"
+echo "git shortlog --no-merges v$new ^v$last > ../ShortLog"
+echo "git diff --stat --summary -M v$last v$new > ../diffstat-$new"
+-------------------------------------------------
+
+and then he just cut-and-pastes the output commands after verifying that
+they look OK.
+
+[[Finding-commits-With-given-Content]]
+Finding commits referencing a file with given content
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Somebody hands you a copy of a file, and asks which commits modified a
+file such that it contained the given content either before or after the
+commit.  You can find out with this:
+
+-------------------------------------------------
+$  git log --raw --abbrev=40 --pretty=oneline |
+	grep -B 1 `git hash-object filename`
+-------------------------------------------------
+
+Figuring out why this works is left as an exercise to the (advanced)
+student.  The linkgit:git-log[1], linkgit:git-diff-tree[1], and
+linkgit:git-hash-object[1] man pages may prove helpful.
+
+[[Developing-With-git]]
+Developing with Git
+===================
+
+[[telling-git-your-name]]
+Telling Git your name
+---------------------
+
+Before creating any commits, you should introduce yourself to Git.
+The easiest way to do so is to use linkgit:git-config[1]:
+
+------------------------------------------------
+$ git config --global user.name 'Your Name Comes Here'
+$ git config --global user.email 'you@yourdomain.example.com'
+------------------------------------------------
+
+Which will add the following to a file named `.gitconfig` in your
+home directory:
+
+------------------------------------------------
+[user]
+	name = Your Name Comes Here
+	email = you@yourdomain.example.com
+------------------------------------------------
+
+See the "CONFIGURATION FILE" section of linkgit:git-config[1] for
+details on the configuration file.  The file is plain text, so you can
+also edit it with your favorite editor.
+
+
+[[creating-a-new-repository]]
+Creating a new repository
+-------------------------
+
+Creating a new repository from scratch is very easy:
+
+-------------------------------------------------
+$ mkdir project
+$ cd project
+$ git init
+-------------------------------------------------
+
+If you have some initial content (say, a tarball):
+
+-------------------------------------------------
+$ tar xzvf project.tar.gz
+$ cd project
+$ git init
+$ git add . # include everything below ./ in the first commit:
+$ git commit
+-------------------------------------------------
+
+[[how-to-make-a-commit]]
+How to make a commit
+--------------------
+
+Creating a new commit takes three steps:
+
+	1. Making some changes to the working directory using your
+	   favorite editor.
+	2. Telling Git about your changes.
+	3. Creating the commit using the content you told Git about
+	   in step 2.
+
+In practice, you can interleave and repeat steps 1 and 2 as many
+times as you want: in order to keep track of what you want committed
+at step 3, Git maintains a snapshot of the tree's contents in a
+special staging area called "the index."
+
+At the beginning, the content of the index will be identical to
+that of the HEAD.  The command `git diff --cached`, which shows
+the difference between the HEAD and the index, should therefore
+produce no output at that point.
+
+Modifying the index is easy:
+
+To update the index with the contents of a new or modified file, use
+
+-------------------------------------------------
+$ git add path/to/file
+-------------------------------------------------
+
+To remove a file from the index and from the working tree, use
+
+-------------------------------------------------
+$ git rm path/to/file
+-------------------------------------------------
+
+After each step you can verify that
+
+-------------------------------------------------
+$ git diff --cached
+-------------------------------------------------
+
+always shows the difference between the HEAD and the index file--this
+is what you'd commit if you created the commit now--and that
+
+-------------------------------------------------
+$ git diff
+-------------------------------------------------
+
+shows the difference between the working tree and the index file.
+
+Note that `git add` always adds just the current contents of a file
+to the index; further changes to the same file will be ignored unless
+you run `git add` on the file again.
+
+When you're ready, just run
+
+-------------------------------------------------
+$ git commit
+-------------------------------------------------
+
+and Git will prompt you for a commit message and then create the new
+commit.  Check to make sure it looks like what you expected with
+
+-------------------------------------------------
+$ git show
+-------------------------------------------------
+
+As a special shortcut,
+
+-------------------------------------------------
+$ git commit -a
+-------------------------------------------------
+
+will update the index with any files that you've modified or removed
+and create a commit, all in one step.
+
+A number of commands are useful for keeping track of what you're
+about to commit:
+
+-------------------------------------------------
+$ git diff --cached # difference between HEAD and the index; what
+		    # would be committed if you ran "commit" now.
+$ git diff	    # difference between the index file and your
+		    # working directory; changes that would not
+		    # be included if you ran "commit" now.
+$ git diff HEAD	    # difference between HEAD and working tree; what
+		    # would be committed if you ran "commit -a" now.
+$ git status	    # a brief per-file summary of the above.
+-------------------------------------------------
+
+You can also use linkgit:git-gui[1] to create commits, view changes in
+the index and the working tree files, and individually select diff hunks
+for inclusion in the index (by right-clicking on the diff hunk and
+choosing "Stage Hunk For Commit").
+
+[[creating-good-commit-messages]]
+Creating good commit messages
+-----------------------------
+
+Though not required, it's a good idea to begin the commit message
+with a single short (less than 50 character) line summarizing the
+change, followed by a blank line and then a more thorough
+description.  The text up to the first blank line in a commit
+message is treated as the commit title, and that title is used
+throughout Git.  For example, linkgit:git-format-patch[1] turns a
+commit into email, and it uses the title on the Subject line and the
+rest of the commit in the body.
+
+
+[[ignoring-files]]
+Ignoring files
+--------------
+
+A project will often generate files that you do 'not' want to track with Git.
+This typically includes files generated by a build process or temporary
+backup files made by your editor. Of course, 'not' tracking files with Git
+is just a matter of 'not' calling `git add` on them. But it quickly becomes
+annoying to have these untracked files lying around; e.g. they make
+`git add .` practically useless, and they keep showing up in the output of
+`git status`.
+
+You can tell Git to ignore certain files by creating a file called
+`.gitignore` in the top level of your working directory, with contents
+such as:
+
+-------------------------------------------------
+# Lines starting with '#' are considered comments.
+# Ignore any file named foo.txt.
+foo.txt
+# Ignore (generated) html files,
+*.html
+# except foo.html which is maintained by hand.
+!foo.html
+# Ignore objects and archives.
+*.[oa]
+-------------------------------------------------
+
+See linkgit:gitignore[5] for a detailed explanation of the syntax.  You can
+also place .gitignore files in other directories in your working tree, and they
+will apply to those directories and their subdirectories.  The `.gitignore`
+files can be added to your repository like any other files (just run `git add
+.gitignore` and `git commit`, as usual), which is convenient when the exclude
+patterns (such as patterns matching build output files) would also make sense
+for other users who clone your repository.
+
+If you wish the exclude patterns to affect only certain repositories
+(instead of every repository for a given project), you may instead put
+them in a file in your repository named `.git/info/exclude`, or in any
+file specified by the `core.excludesFile` configuration variable.
+Some Git commands can also take exclude patterns directly on the
+command line.  See linkgit:gitignore[5] for the details.
+
+[[how-to-merge]]
+How to merge
+------------
+
+You can rejoin two diverging branches of development using
+linkgit:git-merge[1]:
+
+-------------------------------------------------
+$ git merge branchname
+-------------------------------------------------
+
+merges the development in the branch `branchname` into the current
+branch.
+
+A merge is made by combining the changes made in `branchname` and the
+changes made up to the latest commit in your current branch since
+their histories forked. The work tree is overwritten by the result of
+the merge when this combining is done cleanly, or overwritten by a
+half-merged results when this combining results in conflicts.
+Therefore, if you have uncommitted changes touching the same files as
+the ones impacted by the merge, Git will refuse to proceed. Most of
+the time, you will want to commit your changes before you can merge,
+and if you don't, then linkgit:git-stash[1] can take these changes
+away while you're doing the merge, and reapply them afterwards.
+
+If the changes are independent enough, Git will automatically complete
+the merge and commit the result (or reuse an existing commit in case
+of <<fast-forwards,fast-forward>>, see below). On the other hand,
+if there are conflicts--for example, if the same file is
+modified in two different ways in the remote branch and the local
+branch--then you are warned; the output may look something like this:
+
+-------------------------------------------------
+$ git merge next
+ 100% (4/4) done
+Auto-merged file.txt
+CONFLICT (content): Merge conflict in file.txt
+Automatic merge failed; fix conflicts and then commit the result.
+-------------------------------------------------
+
+Conflict markers are left in the problematic files, and after
+you resolve the conflicts manually, you can update the index
+with the contents and run Git commit, as you normally would when
+creating a new file.
+
+If you examine the resulting commit using gitk, you will see that it
+has two parents, one pointing to the top of the current branch, and
+one to the top of the other branch.
+
+[[resolving-a-merge]]
+Resolving a merge
+-----------------
+
+When a merge isn't resolved automatically, Git leaves the index and
+the working tree in a special state that gives you all the
+information you need to help resolve the merge.
+
+Files with conflicts are marked specially in the index, so until you
+resolve the problem and update the index, linkgit:git-commit[1] will
+fail:
+
+-------------------------------------------------
+$ git commit
+file.txt: needs merge
+-------------------------------------------------
+
+Also, linkgit:git-status[1] will list those files as "unmerged", and the
+files with conflicts will have conflict markers added, like this:
+
+-------------------------------------------------
+<<<<<<< HEAD:file.txt
+Hello world
+=======
+Goodbye
+>>>>>>> 77976da35a11db4580b80ae27e8d65caf5208086:file.txt
+-------------------------------------------------
+
+All you need to do is edit the files to resolve the conflicts, and then
+
+-------------------------------------------------
+$ git add file.txt
+$ git commit
+-------------------------------------------------
+
+Note that the commit message will already be filled in for you with
+some information about the merge.  Normally you can just use this
+default message unchanged, but you may add additional commentary of
+your own if desired.
+
+The above is all you need to know to resolve a simple merge.  But Git
+also provides more information to help resolve conflicts:
+
+[[conflict-resolution]]
+Getting conflict-resolution help during a merge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+All of the changes that Git was able to merge automatically are
+already added to the index file, so linkgit:git-diff[1] shows only
+the conflicts.  It uses an unusual syntax:
+
+-------------------------------------------------
+$ git diff
+diff --cc file.txt
+index 802992c,2b60207..0000000
+--- a/file.txt
++++ b/file.txt
+@@@ -1,1 -1,1 +1,5 @@@
+++<<<<<<< HEAD:file.txt
+ +Hello world
+++=======
++ Goodbye
+++>>>>>>> 77976da35a11db4580b80ae27e8d65caf5208086:file.txt
+-------------------------------------------------
+
+Recall that the commit which will be committed after we resolve this
+conflict will have two parents instead of the usual one: one parent
+will be HEAD, the tip of the current branch; the other will be the
+tip of the other branch, which is stored temporarily in MERGE_HEAD.
+
+During the merge, the index holds three versions of each file.  Each of
+these three "file stages" represents a different version of the file:
+
+-------------------------------------------------
+$ git show :1:file.txt	# the file in a common ancestor of both branches
+$ git show :2:file.txt	# the version from HEAD.
+$ git show :3:file.txt	# the version from MERGE_HEAD.
+-------------------------------------------------
+
+When you ask linkgit:git-diff[1] to show the conflicts, it runs a
+three-way diff between the conflicted merge results in the work tree with
+stages 2 and 3 to show only hunks whose contents come from both sides,
+mixed (in other words, when a hunk's merge results come only from stage 2,
+that part is not conflicting and is not shown.  Same for stage 3).
+
+The diff above shows the differences between the working-tree version of
+file.txt and the stage 2 and stage 3 versions.  So instead of preceding
+each line by a single `+` or `-`, it now uses two columns: the first
+column is used for differences between the first parent and the working
+directory copy, and the second for differences between the second parent
+and the working directory copy.  (See the "COMBINED DIFF FORMAT" section
+of linkgit:git-diff-files[1] for a details of the format.)
+
+After resolving the conflict in the obvious way (but before updating the
+index), the diff will look like:
+
+-------------------------------------------------
+$ git diff
+diff --cc file.txt
+index 802992c,2b60207..0000000
+--- a/file.txt
++++ b/file.txt
+@@@ -1,1 -1,1 +1,1 @@@
+- Hello world
+ -Goodbye
+++Goodbye world
+-------------------------------------------------
+
+This shows that our resolved version deleted "Hello world" from the
+first parent, deleted "Goodbye" from the second parent, and added
+"Goodbye world", which was previously absent from both.
+
+Some special diff options allow diffing the working directory against
+any of these stages:
+
+-------------------------------------------------
+$ git diff -1 file.txt		# diff against stage 1
+$ git diff --base file.txt	# same as the above
+$ git diff -2 file.txt		# diff against stage 2
+$ git diff --ours file.txt	# same as the above
+$ git diff -3 file.txt		# diff against stage 3
+$ git diff --theirs file.txt	# same as the above.
+-------------------------------------------------
+
+The linkgit:git-log[1] and linkgit:gitk[1] commands also provide special help
+for merges:
+
+-------------------------------------------------
+$ git log --merge
+$ gitk --merge
+-------------------------------------------------
+
+These will display all commits which exist only on HEAD or on
+MERGE_HEAD, and which touch an unmerged file.
+
+You may also use linkgit:git-mergetool[1], which lets you merge the
+unmerged files using external tools such as Emacs or kdiff3.
+
+Each time you resolve the conflicts in a file and update the index:
+
+-------------------------------------------------
+$ git add file.txt
+-------------------------------------------------
+
+the different stages of that file will be "collapsed", after which
+`git diff` will (by default) no longer show diffs for that file.
+
+[[undoing-a-merge]]
+Undoing a merge
+---------------
+
+If you get stuck and decide to just give up and throw the whole mess
+away, you can always return to the pre-merge state with
+
+-------------------------------------------------
+$ git merge --abort
+-------------------------------------------------
+
+Or, if you've already committed the merge that you want to throw away,
+
+-------------------------------------------------
+$ git reset --hard ORIG_HEAD
+-------------------------------------------------
+
+However, this last command can be dangerous in some cases--never
+throw away a commit you have already committed if that commit may
+itself have been merged into another branch, as doing so may confuse
+further merges.
+
+[[fast-forwards]]
+Fast-forward merges
+-------------------
+
+There is one special case not mentioned above, which is treated
+differently.  Normally, a merge results in a merge commit, with two
+parents, one pointing at each of the two lines of development that
+were merged.
+
+However, if the current branch is an ancestor of the other--so every commit
+present in the current branch is already contained in the other branch--then Git
+just performs a "fast-forward"; the head of the current branch is moved forward
+to point at the head of the merged-in branch, without any new commits being
+created.
+
+[[fixing-mistakes]]
+Fixing mistakes
+---------------
+
+If you've messed up the working tree, but haven't yet committed your
+mistake, you can return the entire working tree to the last committed
+state with
+
+-------------------------------------------------
+$ git restore --staged --worktree :/
+-------------------------------------------------
+
+If you make a commit that you later wish you hadn't, there are two
+fundamentally different ways to fix the problem:
+
+	1. You can create a new commit that undoes whatever was done
+	by the old commit.  This is the correct thing if your
+	mistake has already been made public.
+
+	2. You can go back and modify the old commit.  You should
+	never do this if you have already made the history public;
+	Git does not normally expect the "history" of a project to
+	change, and cannot correctly perform repeated merges from
+	a branch that has had its history changed.
+
+[[reverting-a-commit]]
+Fixing a mistake with a new commit
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Creating a new commit that reverts an earlier change is very easy;
+just pass the linkgit:git-revert[1] command a reference to the bad
+commit; for example, to revert the most recent commit:
+
+-------------------------------------------------
+$ git revert HEAD
+-------------------------------------------------
+
+This will create a new commit which undoes the change in HEAD.  You
+will be given a chance to edit the commit message for the new commit.
+
+You can also revert an earlier change, for example, the next-to-last:
+
+-------------------------------------------------
+$ git revert HEAD^
+-------------------------------------------------
+
+In this case Git will attempt to undo the old change while leaving
+intact any changes made since then.  If more recent changes overlap
+with the changes to be reverted, then you will be asked to fix
+conflicts manually, just as in the case of <<resolving-a-merge,
+resolving a merge>>.
+
+[[fixing-a-mistake-by-rewriting-history]]
+Fixing a mistake by rewriting history
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If the problematic commit is the most recent commit, and you have not
+yet made that commit public, then you may just
+<<undoing-a-merge,destroy it using `git reset`>>.
+
+Alternatively, you
+can edit the working directory and update the index to fix your
+mistake, just as if you were going to <<how-to-make-a-commit,create a
+new commit>>, then run
+
+-------------------------------------------------
+$ git commit --amend
+-------------------------------------------------
+
+which will replace the old commit by a new commit incorporating your
+changes, giving you a chance to edit the old commit message first.
+
+Again, you should never do this to a commit that may already have
+been merged into another branch; use linkgit:git-revert[1] instead in
+that case.
+
+It is also possible to replace commits further back in the history, but
+this is an advanced topic to be left for
+<<cleaning-up-history,another chapter>>.
+
+[[checkout-of-path]]
+Checking out an old version of a file
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In the process of undoing a previous bad change, you may find it
+useful to check out an older version of a particular file using
+linkgit:git-restore[1]. The command
+
+-------------------------------------------------
+$ git restore --source=HEAD^ path/to/file
+-------------------------------------------------
+
+replaces path/to/file by the contents it had in the commit HEAD^, and
+also updates the index to match.  It does not change branches.
+
+If you just want to look at an old version of the file, without
+modifying the working directory, you can do that with
+linkgit:git-show[1]:
+
+-------------------------------------------------
+$ git show HEAD^:path/to/file
+-------------------------------------------------
+
+which will display the given version of the file.
+
+[[interrupted-work]]
+Temporarily setting aside work in progress
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+While you are in the middle of working on something complicated, you
+find an unrelated but obvious and trivial bug.  You would like to fix it
+before continuing.  You can use linkgit:git-stash[1] to save the current
+state of your work, and after fixing the bug (or, optionally after doing
+so on a different branch and then coming back), unstash the
+work-in-progress changes.
+
+------------------------------------------------
+$ git stash push -m "work in progress for foo feature"
+------------------------------------------------
+
+This command will save your changes away to the `stash`, and
+reset your working tree and the index to match the tip of your
+current branch.  Then you can make your fix as usual.
+
+------------------------------------------------
+... edit and test ...
+$ git commit -a -m "blorpl: typofix"
+------------------------------------------------
+
+After that, you can go back to what you were working on with
+`git stash pop`:
+
+------------------------------------------------
+$ git stash pop
+------------------------------------------------
+
+
+[[ensuring-good-performance]]
+Ensuring good performance
+-------------------------
+
+On large repositories, Git depends on compression to keep the history
+information from taking up too much space on disk or in memory.  Some
+Git commands may automatically run linkgit:git-gc[1], so you don't
+have to worry about running it manually.  However, compressing a large
+repository may take a while, so you may want to call `gc` explicitly
+to avoid automatic compression kicking in when it is not convenient.
+
+
+[[ensuring-reliability]]
+Ensuring reliability
+--------------------
+
+[[checking-for-corruption]]
+Checking the repository for corruption
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The linkgit:git-fsck[1] command runs a number of self-consistency checks
+on the repository, and reports on any problems.  This may take some
+time.
+
+-------------------------------------------------
+$ git fsck
+dangling commit 7281251ddd2a61e38657c827739c57015671a6b3
+dangling commit 2706a059f258c6b245f298dc4ff2ccd30ec21a63
+dangling commit 13472b7c4b80851a1bc551779171dcb03655e9b5
+dangling blob 218761f9d90712d37a9c5e36f406f92202db07eb
+dangling commit bf093535a34a4d35731aa2bd90fe6b176302f14f
+dangling commit 8e4bec7f2ddaa268bef999853c25755452100f8e
+dangling tree d50bb86186bf27b681d25af89d3b5b68382e4085
+dangling tree b24c2473f1fd3d91352a624795be026d64c8841f
+...
+-------------------------------------------------
+
+You will see informational messages on dangling objects. They are objects
+that still exist in the repository but are no longer referenced by any of
+your branches, and can (and will) be removed after a while with `gc`.
+You can run `git fsck --no-dangling` to suppress these messages, and still
+view real errors.
+
+[[recovering-lost-changes]]
+Recovering lost changes
+~~~~~~~~~~~~~~~~~~~~~~~
+
+[[reflogs]]
+Reflogs
+^^^^^^^
+
+Say you modify a branch with <<fixing-mistakes,`git reset --hard`>>,
+and then realize that the branch was the only reference you had to
+that point in history.
+
+Fortunately, Git also keeps a log, called a "reflog", of all the
+previous values of each branch.  So in this case you can still find the
+old history using, for example,
+
+-------------------------------------------------
+$ git log master@{1}
+-------------------------------------------------
+
+This lists the commits reachable from the previous version of the
+`master` branch head.  This syntax can be used with any Git command
+that accepts a commit, not just with `git log`.  Some other examples:
+
+-------------------------------------------------
+$ git show master@{2}		# See where the branch pointed 2,
+$ git show master@{3}		# 3, ... changes ago.
+$ gitk master@{yesterday}	# See where it pointed yesterday,
+$ gitk master@{"1 week ago"}	# ... or last week
+$ git log --walk-reflogs master	# show reflog entries for master
+-------------------------------------------------
+
+A separate reflog is kept for the HEAD, so
+
+-------------------------------------------------
+$ git show HEAD@{"1 week ago"}
+-------------------------------------------------
+
+will show what HEAD pointed to one week ago, not what the current branch
+pointed to one week ago.  This allows you to see the history of what
+you've checked out.
+
+The reflogs are kept by default for 30 days, after which they may be
+pruned.  See linkgit:git-reflog[1] and linkgit:git-gc[1] to learn
+how to control this pruning, and see the "SPECIFYING REVISIONS"
+section of linkgit:gitrevisions[7] for details.
+
+Note that the reflog history is very different from normal Git history.
+While normal history is shared by every repository that works on the
+same project, the reflog history is not shared: it tells you only about
+how the branches in your local repository have changed over time.
+
+[[dangling-object-recovery]]
+Examining dangling objects
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In some situations the reflog may not be able to save you.  For example,
+suppose you delete a branch, then realize you need the history it
+contained.  The reflog is also deleted; however, if you have not yet
+pruned the repository, then you may still be able to find the lost
+commits in the dangling objects that `git fsck` reports.  See
+<<dangling-objects>> for the details.
+
+-------------------------------------------------
+$ git fsck
+dangling commit 7281251ddd2a61e38657c827739c57015671a6b3
+dangling commit 2706a059f258c6b245f298dc4ff2ccd30ec21a63
+dangling commit 13472b7c4b80851a1bc551779171dcb03655e9b5
+...
+-------------------------------------------------
+
+You can examine
+one of those dangling commits with, for example,
+
+------------------------------------------------
+$ gitk 7281251ddd --not --all
+------------------------------------------------
+
+which does what it sounds like: it says that you want to see the commit
+history that is described by the dangling commit(s), but not the
+history that is described by all your existing branches and tags.  Thus
+you get exactly the history reachable from that commit that is lost.
+(And notice that it might not be just one commit: we only report the
+"tip of the line" as being dangling, but there might be a whole deep
+and complex commit history that was dropped.)
+
+If you decide you want the history back, you can always create a new
+reference pointing to it, for example, a new branch:
+
+------------------------------------------------
+$ git branch recovered-branch 7281251ddd
+------------------------------------------------
+
+Other types of dangling objects (blobs and trees) are also possible, and
+dangling objects can arise in other situations.
+
+
+[[sharing-development]]
+Sharing development with others
+===============================
+
+[[getting-updates-With-git-pull]]
+Getting updates with git pull
+-----------------------------
+
+After you clone a repository and commit a few changes of your own, you
+may wish to check the original repository for updates and merge them
+into your own work.
+
+We have already seen <<Updating-a-repository-With-git-fetch,how to
+keep remote-tracking branches up to date>> with linkgit:git-fetch[1],
+and how to merge two branches.  So you can merge in changes from the
+original repository's master branch with:
+
+-------------------------------------------------
+$ git fetch
+$ git merge origin/master
+-------------------------------------------------
+
+However, the linkgit:git-pull[1] command provides a way to do this in
+one step:
+
+-------------------------------------------------
+$ git pull origin master
+-------------------------------------------------
+
+In fact, if you have `master` checked out, then this branch has been
+configured by `git clone` to get changes from the HEAD branch of the
+origin repository.  So often you can
+accomplish the above with just a simple
+
+-------------------------------------------------
+$ git pull
+-------------------------------------------------
+
+This command will fetch changes from the remote branches to your
+remote-tracking branches `origin/*`, and merge the default branch into
+the current branch.
+
+More generally, a branch that is created from a remote-tracking branch
+will pull
+by default from that branch.  See the descriptions of the
+`branch.<name>.remote` and `branch.<name>.merge` options in
+linkgit:git-config[1], and the discussion of the `--track` option in
+linkgit:git-checkout[1], to learn how to control these defaults.
+
+In addition to saving you keystrokes, `git pull` also helps you by
+producing a default commit message documenting the branch and
+repository that you pulled from.
+
+(But note that no such commit will be created in the case of a
+<<fast-forwards,fast-forward>>; instead, your branch will just be
+updated to point to the latest commit from the upstream branch.)
+
+The `git pull` command can also be given `.` as the "remote" repository,
+in which case it just merges in a branch from the current repository; so
+the commands
+
+-------------------------------------------------
+$ git pull . branch
+$ git merge branch
+-------------------------------------------------
+
+are roughly equivalent.
+
+[[submitting-patches]]
+Submitting patches to a project
+-------------------------------
+
+If you just have a few changes, the simplest way to submit them may
+just be to send them as patches in email:
+
+First, use linkgit:git-format-patch[1]; for example:
+
+-------------------------------------------------
+$ git format-patch origin
+-------------------------------------------------
+
+will produce a numbered series of files in the current directory, one
+for each patch in the current branch but not in `origin/HEAD`.
+
+`git format-patch` can include an initial "cover letter". You can insert
+commentary on individual patches after the three dash line which
+`format-patch` places after the commit message but before the patch
+itself.  If you use `git notes` to track your cover letter material,
+`git format-patch --notes` will include the commit's notes in a similar
+manner.
+
+You can then import these into your mail client and send them by
+hand.  However, if you have a lot to send at once, you may prefer to
+use the linkgit:git-send-email[1] script to automate the process.
+Consult the mailing list for your project first to determine
+their requirements for submitting patches.
+
+[[importing-patches]]
+Importing patches to a project
+------------------------------
+
+Git also provides a tool called linkgit:git-am[1] (am stands for
+"apply mailbox"), for importing such an emailed series of patches.
+Just save all of the patch-containing messages, in order, into a
+single mailbox file, say `patches.mbox`, then run
+
+-------------------------------------------------
+$ git am -3 patches.mbox
+-------------------------------------------------
+
+Git will apply each patch in order; if any conflicts are found, it
+will stop, and you can fix the conflicts as described in
+"<<resolving-a-merge,Resolving a merge>>".  (The `-3` option tells
+Git to perform a merge; if you would prefer it just to abort and
+leave your tree and index untouched, you may omit that option.)
+
+Once the index is updated with the results of the conflict
+resolution, instead of creating a new commit, just run
+
+-------------------------------------------------
+$ git am --continue
+-------------------------------------------------
+
+and Git will create the commit for you and continue applying the
+remaining patches from the mailbox.
+
+The final result will be a series of commits, one for each patch in
+the original mailbox, with authorship and commit log message each
+taken from the message containing each patch.
+
+[[public-repositories]]
+Public Git repositories
+-----------------------
+
+Another way to submit changes to a project is to tell the maintainer
+of that project to pull the changes from your repository using
+linkgit:git-pull[1].  In the section "<<getting-updates-With-git-pull,
+Getting updates with `git pull`>>" we described this as a way to get
+updates from the "main" repository, but it works just as well in the
+other direction.
+
+If you and the maintainer both have accounts on the same machine, then
+you can just pull changes from each other's repositories directly;
+commands that accept repository URLs as arguments will also accept a
+local directory name:
+
+-------------------------------------------------
+$ git clone /path/to/repository
+$ git pull /path/to/other/repository
+-------------------------------------------------
+
+or an ssh URL:
+
+-------------------------------------------------
+$ git clone ssh://yourhost/~you/repository
+-------------------------------------------------
+
+For projects with few developers, or for synchronizing a few private
+repositories, this may be all you need.
+
+However, the more common way to do this is to maintain a separate public
+repository (usually on a different host) for others to pull changes
+from.  This is usually more convenient, and allows you to cleanly
+separate private work in progress from publicly visible work.
+
+You will continue to do your day-to-day work in your personal
+repository, but periodically "push" changes from your personal
+repository into your public repository, allowing other developers to
+pull from that repository.  So the flow of changes, in a situation
+where there is one other developer with a public repository, looks
+like this:
+
+                        you push
+  your personal repo ------------------> your public repo
+	^                                     |
+	|                                     |
+	| you pull                            | they pull
+	|                                     |
+	|                                     |
+        |               they push             V
+  their public repo <------------------- their repo
+
+We explain how to do this in the following sections.
+
+[[setting-up-a-public-repository]]
+Setting up a public repository
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Assume your personal repository is in the directory `~/proj`.  We
+first create a new clone of the repository and tell `git daemon` that it
+is meant to be public:
+
+-------------------------------------------------
+$ git clone --bare ~/proj proj.git
+$ touch proj.git/git-daemon-export-ok
+-------------------------------------------------
+
+The resulting directory proj.git contains a "bare" git repository--it is
+just the contents of the `.git` directory, without any files checked out
+around it.
+
+Next, copy `proj.git` to the server where you plan to host the
+public repository.  You can use scp, rsync, or whatever is most
+convenient.
+
+[[exporting-via-git]]
+Exporting a Git repository via the Git protocol
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This is the preferred method.
+
+If someone else administers the server, they should tell you what
+directory to put the repository in, and what `git://` URL it will
+appear at.  You can then skip to the section
+"<<pushing-changes-to-a-public-repository,Pushing changes to a public
+repository>>", below.
+
+Otherwise, all you need to do is start linkgit:git-daemon[1]; it will
+listen on port 9418.  By default, it will allow access to any directory
+that looks like a Git directory and contains the magic file
+git-daemon-export-ok.  Passing some directory paths as `git daemon`
+arguments will further restrict the exports to those paths.
+
+You can also run `git daemon` as an inetd service; see the
+linkgit:git-daemon[1] man page for details.  (See especially the
+examples section.)
+
+[[exporting-via-http]]
+Exporting a git repository via HTTP
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The Git protocol gives better performance and reliability, but on a
+host with a web server set up, HTTP exports may be simpler to set up.
+
+All you need to do is place the newly created bare Git repository in
+a directory that is exported by the web server, and make some
+adjustments to give web clients some extra information they need:
+
+-------------------------------------------------
+$ mv proj.git /home/you/public_html/proj.git
+$ cd proj.git
+$ git --bare update-server-info
+$ mv hooks/post-update.sample hooks/post-update
+-------------------------------------------------
+
+(For an explanation of the last two lines, see
+linkgit:git-update-server-info[1] and linkgit:githooks[5].)
+
+Advertise the URL of `proj.git`.  Anybody else should then be able to
+clone or pull from that URL, for example with a command line like:
+
+-------------------------------------------------
+$ git clone http://yourserver.com/~you/proj.git
+-------------------------------------------------
+
+(See also
+link:howto/setup-git-server-over-http.html[setup-git-server-over-http]
+for a slightly more sophisticated setup using WebDAV which also
+allows pushing over HTTP.)
+
+[[pushing-changes-to-a-public-repository]]
+Pushing changes to a public repository
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Note that the two techniques outlined above (exporting via
+<<exporting-via-http,http>> or <<exporting-via-git,git>>) allow other
+maintainers to fetch your latest changes, but they do not allow write
+access, which you will need to update the public repository with the
+latest changes created in your private repository.
+
+The simplest way to do this is using linkgit:git-push[1] and ssh; to
+update the remote branch named `master` with the latest state of your
+branch named `master`, run
+
+-------------------------------------------------
+$ git push ssh://yourserver.com/~you/proj.git master:master
+-------------------------------------------------
+
+or just
+
+-------------------------------------------------
+$ git push ssh://yourserver.com/~you/proj.git master
+-------------------------------------------------
+
+As with `git fetch`, `git push` will complain if this does not result in a
+<<fast-forwards,fast-forward>>; see the following section for details on
+handling this case.
+
+Note that the target of a `push` is normally a
+<<def_bare_repository,bare>> repository.  You can also push to a
+repository that has a checked-out working tree, but a push to update the
+currently checked-out branch is denied by default to prevent confusion.
+See the description of the receive.denyCurrentBranch option
+in linkgit:git-config[1] for details.
+
+As with `git fetch`, you may also set up configuration options to
+save typing; so, for example:
+
+-------------------------------------------------
+$ git remote add public-repo ssh://yourserver.com/~you/proj.git
+-------------------------------------------------
+
+adds the following to `.git/config`:
+
+-------------------------------------------------
+[remote "public-repo"]
+	url = yourserver.com:proj.git
+	fetch = +refs/heads/*:refs/remotes/example/*
+-------------------------------------------------
+
+which lets you do the same push with just
+
+-------------------------------------------------
+$ git push public-repo master
+-------------------------------------------------
+
+See the explanations of the `remote.<name>.url`,
+`branch.<name>.remote`, and `remote.<name>.push` options in
+linkgit:git-config[1] for details.
+
+[[forcing-push]]
+What to do when a push fails
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If a push would not result in a <<fast-forwards,fast-forward>> of the
+remote branch, then it will fail with an error like:
+
+-------------------------------------------------
+ ! [rejected]        master -> master (non-fast-forward)
+error: failed to push some refs to '...'
+hint: Updates were rejected because the tip of your current branch is behind
+hint: its remote counterpart. Integrate the remote changes (e.g.
+hint: 'git pull ...') before pushing again.
+hint: See the 'Note about fast-forwards' in 'git push --help' for details.
+-------------------------------------------------
+
+This can happen, for example, if you:
+
+	- use `git reset --hard` to remove already-published commits, or
+	- use `git commit --amend` to replace already-published commits
+	  (as in <<fixing-a-mistake-by-rewriting-history>>), or
+	- use `git rebase` to rebase any already-published commits (as
+	  in <<using-git-rebase>>).
+
+You may force `git push` to perform the update anyway by preceding the
+branch name with a plus sign:
+
+-------------------------------------------------
+$ git push ssh://yourserver.com/~you/proj.git +master
+-------------------------------------------------
+
+Note the addition of the `+` sign.  Alternatively, you can use the
+`-f` flag to force the remote update, as in:
+
+-------------------------------------------------
+$ git push -f ssh://yourserver.com/~you/proj.git master
+-------------------------------------------------
+
+Normally whenever a branch head in a public repository is modified, it
+is modified to point to a descendant of the commit that it pointed to
+before.  By forcing a push in this situation, you break that convention.
+(See <<problems-With-rewriting-history>>.)
+
+Nevertheless, this is a common practice for people that need a simple
+way to publish a work-in-progress patch series, and it is an acceptable
+compromise as long as you warn other developers that this is how you
+intend to manage the branch.
+
+It's also possible for a push to fail in this way when other people have
+the right to push to the same repository.  In that case, the correct
+solution is to retry the push after first updating your work: either by a
+pull, or by a fetch followed by a rebase; see the
+<<setting-up-a-shared-repository,next section>> and
+linkgit:gitcvs-migration[7] for more.
+
+[[setting-up-a-shared-repository]]
+Setting up a shared repository
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Another way to collaborate is by using a model similar to that
+commonly used in CVS, where several developers with special rights
+all push to and pull from a single shared repository.  See
+linkgit:gitcvs-migration[7] for instructions on how to
+set this up.
+
+However, while there is nothing wrong with Git's support for shared
+repositories, this mode of operation is not generally recommended,
+simply because the mode of collaboration that Git supports--by
+exchanging patches and pulling from public repositories--has so many
+advantages over the central shared repository:
+
+	- Git's ability to quickly import and merge patches allows a
+	  single maintainer to process incoming changes even at very
+	  high rates.  And when that becomes too much, `git pull` provides
+	  an easy way for that maintainer to delegate this job to other
+	  maintainers while still allowing optional review of incoming
+	  changes.
+	- Since every developer's repository has the same complete copy
+	  of the project history, no repository is special, and it is
+	  trivial for another developer to take over maintenance of a
+	  project, either by mutual agreement, or because a maintainer
+	  becomes unresponsive or difficult to work with.
+	- The lack of a central group of "committers" means there is
+	  less need for formal decisions about who is "in" and who is
+	  "out".
+
+[[setting-up-gitweb]]
+Allowing web browsing of a repository
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The gitweb cgi script provides users an easy way to browse your
+project's revisions, file contents and logs without having to install
+Git. Features like RSS/Atom feeds and blame/annotation details may
+optionally be enabled.
+
+The linkgit:git-instaweb[1] command provides a simple way to start
+browsing the repository using gitweb. The default server when using
+instaweb is lighttpd.
+
+See the file gitweb/INSTALL in the Git source tree and
+linkgit:gitweb[1] for instructions on details setting up a permanent
+installation with a CGI or Perl capable server.
+
+[[how-to-get-a-git-repository-with-minimal-history]]
+How to get a Git repository with minimal history
+------------------------------------------------
+
+A <<def_shallow_clone,shallow clone>>, with its truncated
+history, is useful when one is interested only in recent history
+of a project and getting full history from the upstream is
+expensive.
+
+A <<def_shallow_clone,shallow clone>> is created by specifying
+the linkgit:git-clone[1] `--depth` switch. The depth can later be
+changed with the linkgit:git-fetch[1] `--depth` switch, or full
+history restored with `--unshallow`.
+
+Merging inside a <<def_shallow_clone,shallow clone>> will work as long
+as a merge base is in the recent history.
+Otherwise, it will be like merging unrelated histories and may
+have to result in huge conflicts.  This limitation may make such
+a repository unsuitable to be used in merge based workflows.
+
+[[sharing-development-examples]]
+Examples
+--------
+
+[[maintaining-topic-branches]]
+Maintaining topic branches for a Linux subsystem maintainer
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This describes how Tony Luck uses Git in his role as maintainer of the
+IA64 architecture for the Linux kernel.
+
+He uses two public branches:
+
+ - A "test" tree into which patches are initially placed so that they
+   can get some exposure when integrated with other ongoing development.
+   This tree is available to Andrew for pulling into -mm whenever he
+   wants.
+
+ - A "release" tree into which tested patches are moved for final sanity
+   checking, and as a vehicle to send them upstream to Linus (by sending
+   him a "please pull" request.)
+
+He also uses a set of temporary branches ("topic branches"), each
+containing a logical grouping of patches.
+
+To set this up, first create your work tree by cloning Linus's public
+tree:
+
+-------------------------------------------------
+$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git work
+$ cd work
+-------------------------------------------------
+
+Linus's tree will be stored in the remote-tracking branch named origin/master,
+and can be updated using linkgit:git-fetch[1]; you can track other
+public trees using linkgit:git-remote[1] to set up a "remote" and
+linkgit:git-fetch[1] to keep them up to date; see
+<<repositories-and-branches>>.
+
+Now create the branches in which you are going to work; these start out
+at the current tip of origin/master branch, and should be set up (using
+the `--track` option to linkgit:git-branch[1]) to merge changes in from
+Linus by default.
+
+-------------------------------------------------
+$ git branch --track test origin/master
+$ git branch --track release origin/master
+-------------------------------------------------
+
+These can be easily kept up to date using linkgit:git-pull[1].
+
+-------------------------------------------------
+$ git switch test && git pull
+$ git switch release && git pull
+-------------------------------------------------
+
+Important note!  If you have any local changes in these branches, then
+this merge will create a commit object in the history (with no local
+changes Git will simply do a "fast-forward" merge).  Many people dislike
+the "noise" that this creates in the Linux history, so you should avoid
+doing this capriciously in the `release` branch, as these noisy commits
+will become part of the permanent history when you ask Linus to pull
+from the release branch.
+
+A few configuration variables (see linkgit:git-config[1]) can
+make it easy to push both branches to your public tree.  (See
+<<setting-up-a-public-repository>>.)
+
+-------------------------------------------------
+$ cat >> .git/config <<EOF
+[remote "mytree"]
+	url =  master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux.git
+	push = release
+	push = test
+EOF
+-------------------------------------------------
+
+Then you can push both the test and release trees using
+linkgit:git-push[1]:
+
+-------------------------------------------------
+$ git push mytree
+-------------------------------------------------
+
+or push just one of the test and release branches using:
+
+-------------------------------------------------
+$ git push mytree test
+-------------------------------------------------
+
+or
+
+-------------------------------------------------
+$ git push mytree release
+-------------------------------------------------
+
+Now to apply some patches from the community.  Think of a short
+snappy name for a branch to hold this patch (or related group of
+patches), and create a new branch from a recent stable tag of
+Linus's branch. Picking a stable base for your branch will:
+1) help you: by avoiding inclusion of unrelated and perhaps lightly
+tested changes
+2) help future bug hunters that use `git bisect` to find problems
+
+-------------------------------------------------
+$ git switch -c speed-up-spinlocks v2.6.35
+-------------------------------------------------
+
+Now you apply the patch(es), run some tests, and commit the change(s).  If
+the patch is a multi-part series, then you should apply each as a separate
+commit to this branch.
+
+-------------------------------------------------
+$ ... patch ... test  ... commit [ ... patch ... test ... commit ]*
+-------------------------------------------------
+
+When you are happy with the state of this change, you can merge it into the
+"test" branch in preparation to make it public:
+
+-------------------------------------------------
+$ git switch test && git merge speed-up-spinlocks
+-------------------------------------------------
+
+It is unlikely that you would have any conflicts here ... but you might if you
+spent a while on this step and had also pulled new versions from upstream.
+
+Sometime later when enough time has passed and testing done, you can pull the
+same branch into the `release` tree ready to go upstream.  This is where you
+see the value of keeping each patch (or patch series) in its own branch.  It
+means that the patches can be moved into the `release` tree in any order.
+
+-------------------------------------------------
+$ git switch release && git merge speed-up-spinlocks
+-------------------------------------------------
+
+After a while, you will have a number of branches, and despite the
+well chosen names you picked for each of them, you may forget what
+they are for, or what status they are in.  To get a reminder of what
+changes are in a specific branch, use:
+
+-------------------------------------------------
+$ git log linux..branchname | git shortlog
+-------------------------------------------------
+
+To see whether it has already been merged into the test or release branches,
+use:
+
+-------------------------------------------------
+$ git log test..branchname
+-------------------------------------------------
+
+or
+
+-------------------------------------------------
+$ git log release..branchname
+-------------------------------------------------
+
+(If this branch has not yet been merged, you will see some log entries.
+If it has been merged, then there will be no output.)
+
+Once a patch completes the great cycle (moving from test to release,
+then pulled by Linus, and finally coming back into your local
+`origin/master` branch), the branch for this change is no longer needed.
+You detect this when the output from:
+
+-------------------------------------------------
+$ git log origin..branchname
+-------------------------------------------------
+
+is empty.  At this point the branch can be deleted:
+
+-------------------------------------------------
+$ git branch -d branchname
+-------------------------------------------------
+
+Some changes are so trivial that it is not necessary to create a separate
+branch and then merge into each of the test and release branches.  For
+these changes, just apply directly to the `release` branch, and then
+merge that into the `test` branch.
+
+After pushing your work to `mytree`, you can use
+linkgit:git-request-pull[1] to prepare a "please pull" request message
+to send to Linus:
+
+-------------------------------------------------
+$ git push mytree
+$ git request-pull origin mytree release
+-------------------------------------------------
+
+Here are some of the scripts that simplify all this even further.
+
+-------------------------------------------------
+==== update script ====
+# Update a branch in my Git tree.  If the branch to be updated
+# is origin, then pull from kernel.org.  Otherwise merge
+# origin/master branch into test|release branch
+
+case "$1" in
+test|release)
+	git checkout $1 && git pull . origin
+	;;
+origin)
+	before=$(git rev-parse refs/remotes/origin/master)
+	git fetch origin
+	after=$(git rev-parse refs/remotes/origin/master)
+	if [ $before != $after ]
+	then
+		git log $before..$after | git shortlog
+	fi
+	;;
+*)
+	echo "usage: $0 origin|test|release" 1>&2
+	exit 1
+	;;
+esac
+-------------------------------------------------
+
+-------------------------------------------------
+==== merge script ====
+# Merge a branch into either the test or release branch
+
+pname=$0
+
+usage()
+{
+	echo "usage: $pname branch test|release" 1>&2
+	exit 1
+}
+
+git show-ref -q --verify -- refs/heads/"$1" || {
+	echo "Can't see branch <$1>" 1>&2
+	usage
+}
+
+case "$2" in
+test|release)
+	if [ $(git log $2..$1 | wc -c) -eq 0 ]
+	then
+		echo $1 already merged into $2 1>&2
+		exit 1
+	fi
+	git checkout $2 && git pull . $1
+	;;
+*)
+	usage
+	;;
+esac
+-------------------------------------------------
+
+-------------------------------------------------
+==== status script ====
+# report on status of my ia64 Git tree
+
+gb=$(tput setab 2)
+rb=$(tput setab 1)
+restore=$(tput setab 9)
+
+if [ `git rev-list test..release | wc -c` -gt 0 ]
+then
+	echo $rb Warning: commits in release that are not in test $restore
+	git log test..release
+fi
+
+for branch in `git show-ref --heads | sed 's|^.*/||'`
+do
+	if [ $branch = test -o $branch = release ]
+	then
+		continue
+	fi
+
+	echo -n $gb ======= $branch ====== $restore " "
+	status=
+	for ref in test release origin/master
+	do
+		if [ `git rev-list $ref..$branch | wc -c` -gt 0 ]
+		then
+			status=$status${ref:0:1}
+		fi
+	done
+	case $status in
+	trl)
+		echo $rb Need to pull into test $restore
+		;;
+	rl)
+		echo "In test"
+		;;
+	l)
+		echo "Waiting for linus"
+		;;
+	"")
+		echo $rb All done $restore
+		;;
+	*)
+		echo $rb "<$status>" $restore
+		;;
+	esac
+	git log origin/master..$branch | git shortlog
+done
+-------------------------------------------------
+
+
+[[cleaning-up-history]]
+Rewriting history and maintaining patch series
+==============================================
+
+Normally commits are only added to a project, never taken away or
+replaced.  Git is designed with this assumption, and violating it will
+cause Git's merge machinery (for example) to do the wrong thing.
+
+However, there is a situation in which it can be useful to violate this
+assumption.
+
+[[patch-series]]
+Creating the perfect patch series
+---------------------------------
+
+Suppose you are a contributor to a large project, and you want to add a
+complicated feature, and to present it to the other developers in a way
+that makes it easy for them to read your changes, verify that they are
+correct, and understand why you made each change.
+
+If you present all of your changes as a single patch (or commit), they
+may find that it is too much to digest all at once.
+
+If you present them with the entire history of your work, complete with
+mistakes, corrections, and dead ends, they may be overwhelmed.
+
+So the ideal is usually to produce a series of patches such that:
+
+	1. Each patch can be applied in order.
+
+	2. Each patch includes a single logical change, together with a
+	   message explaining the change.
+
+	3. No patch introduces a regression: after applying any initial
+	   part of the series, the resulting project still compiles and
+	   works, and has no bugs that it didn't have before.
+
+	4. The complete series produces the same end result as your own
+	   (probably much messier!) development process did.
+
+We will introduce some tools that can help you do this, explain how to
+use them, and then explain some of the problems that can arise because
+you are rewriting history.
+
+[[using-git-rebase]]
+Keeping a patch series up to date using git rebase
+--------------------------------------------------
+
+Suppose that you create a branch `mywork` on a remote-tracking branch
+`origin`, and create some commits on top of it:
+
+-------------------------------------------------
+$ git switch -c mywork origin
+$ vi file.txt
+$ git commit
+$ vi otherfile.txt
+$ git commit
+...
+-------------------------------------------------
+
+You have performed no merges into mywork, so it is just a simple linear
+sequence of patches on top of `origin`:
+
+................................................
+ o--o--O <-- origin
+        \
+	 a--b--c <-- mywork
+................................................
+
+Some more interesting work has been done in the upstream project, and
+`origin` has advanced:
+
+................................................
+ o--o--O--o--o--o <-- origin
+        \
+         a--b--c <-- mywork
+................................................
+
+At this point, you could use `pull` to merge your changes back in;
+the result would create a new merge commit, like this:
+
+................................................
+ o--o--O--o--o--o <-- origin
+        \        \
+         a--b--c--m <-- mywork
+................................................
+
+However, if you prefer to keep the history in mywork a simple series of
+commits without any merges, you may instead choose to use
+linkgit:git-rebase[1]:
+
+-------------------------------------------------
+$ git switch mywork
+$ git rebase origin
+-------------------------------------------------
+
+This will remove each of your commits from mywork, temporarily saving
+them as patches (in a directory named `.git/rebase-apply`), update mywork to
+point at the latest version of origin, then apply each of the saved
+patches to the new mywork.  The result will look like:
+
+
+................................................
+ o--o--O--o--o--o <-- origin
+		 \
+		  a'--b'--c' <-- mywork
+................................................
+
+In the process, it may discover conflicts.  In that case it will stop
+and allow you to fix the conflicts; after fixing conflicts, use `git add`
+to update the index with those contents, and then, instead of
+running `git commit`, just run
+
+-------------------------------------------------
+$ git rebase --continue
+-------------------------------------------------
+
+and Git will continue applying the rest of the patches.
+
+At any point you may use the `--abort` option to abort this process and
+return mywork to the state it had before you started the rebase:
+
+-------------------------------------------------
+$ git rebase --abort
+-------------------------------------------------
+
+If you need to reorder or edit a number of commits in a branch, it may
+be easier to use `git rebase -i`, which allows you to reorder and
+squash commits, as well as marking them for individual editing during
+the rebase.  See <<interactive-rebase>> for details, and
+<<reordering-patch-series>> for alternatives.
+
+[[rewriting-one-commit]]
+Rewriting a single commit
+-------------------------
+
+We saw in <<fixing-a-mistake-by-rewriting-history>> that you can replace the
+most recent commit using
+
+-------------------------------------------------
+$ git commit --amend
+-------------------------------------------------
+
+which will replace the old commit by a new commit incorporating your
+changes, giving you a chance to edit the old commit message first.
+This is useful for fixing typos in your last commit, or for adjusting
+the patch contents of a poorly staged commit.
+
+If you need to amend commits from deeper in your history, you can
+use <<interactive-rebase,interactive rebase's `edit` instruction>>.
+
+[[reordering-patch-series]]
+Reordering or selecting from a patch series
+-------------------------------------------
+
+Sometimes you want to edit a commit deeper in your history.  One
+approach is to use `git format-patch` to create a series of patches
+and then reset the state to before the patches:
+
+-------------------------------------------------
+$ git format-patch origin
+$ git reset --hard origin
+-------------------------------------------------
+
+Then modify, reorder, or eliminate patches as needed before applying
+them again with linkgit:git-am[1]:
+
+-------------------------------------------------
+$ git am *.patch
+-------------------------------------------------
+
+[[interactive-rebase]]
+Using interactive rebases
+-------------------------
+
+You can also edit a patch series with an interactive rebase.  This is
+the same as <<reordering-patch-series,reordering a patch series using
+`format-patch`>>, so use whichever interface you like best.
+
+Rebase your current HEAD on the last commit you want to retain as-is.
+For example, if you want to reorder the last 5 commits, use:
+
+-------------------------------------------------
+$ git rebase -i HEAD~5
+-------------------------------------------------
+
+This will open your editor with a list of steps to be taken to perform
+your rebase.
+
+-------------------------------------------------
+pick deadbee The oneline of this commit
+pick fa1afe1 The oneline of the next commit
+...
+
+# Rebase c0ffeee..deadbee onto c0ffeee
+#
+# Commands:
+#  p, pick = use commit
+#  r, reword = use commit, but edit the commit message
+#  e, edit = use commit, but stop for amending
+#  s, squash = use commit, but meld into previous commit
+#  f, fixup = like "squash", but discard this commit's log message
+#  x, exec = run command (the rest of the line) using shell
+#
+# These lines can be re-ordered; they are executed from top to bottom.
+#
+# If you remove a line here THAT COMMIT WILL BE LOST.
+#
+# However, if you remove everything, the rebase will be aborted.
+#
+# Note that empty commits are commented out
+-------------------------------------------------
+
+As explained in the comments, you can reorder commits, squash them
+together, edit commit messages, etc. by editing the list.  Once you
+are satisfied, save the list and close your editor, and the rebase
+will begin.
+
+The rebase will stop where `pick` has been replaced with `edit` or
+when a step in the list fails to mechanically resolve conflicts and
+needs your help.  When you are done editing and/or resolving conflicts
+you can continue with `git rebase --continue`.  If you decide that
+things are getting too hairy, you can always bail out with `git rebase
+--abort`.  Even after the rebase is complete, you can still recover
+the original branch by using the <<reflogs,reflog>>.
+
+For a more detailed discussion of the procedure and additional tips,
+see the "INTERACTIVE MODE" section of linkgit:git-rebase[1].
+
+[[patch-series-tools]]
+Other tools
+-----------
+
+There are numerous other tools, such as StGit, which exist for the
+purpose of maintaining a patch series.  These are outside of the scope of
+this manual.
+
+[[problems-With-rewriting-history]]
+Problems with rewriting history
+-------------------------------
+
+The primary problem with rewriting the history of a branch has to do
+with merging.  Suppose somebody fetches your branch and merges it into
+their branch, with a result something like this:
+
+................................................
+ o--o--O--o--o--o <-- origin
+        \        \
+         t--t--t--m <-- their branch:
+................................................
+
+Then suppose you modify the last three commits:
+
+................................................
+	 o--o--o <-- new head of origin
+	/
+ o--o--O--o--o--o <-- old head of origin
+................................................
+
+If we examined all this history together in one repository, it will
+look like:
+
+................................................
+	 o--o--o <-- new head of origin
+	/
+ o--o--O--o--o--o <-- old head of origin
+        \        \
+         t--t--t--m <-- their branch:
+................................................
+
+Git has no way of knowing that the new head is an updated version of
+the old head; it treats this situation exactly the same as it would if
+two developers had independently done the work on the old and new heads
+in parallel.  At this point, if someone attempts to merge the new head
+in to their branch, Git will attempt to merge together the two (old and
+new) lines of development, instead of trying to replace the old by the
+new.  The results are likely to be unexpected.
+
+You may still choose to publish branches whose history is rewritten,
+and it may be useful for others to be able to fetch those branches in
+order to examine or test them, but they should not attempt to pull such
+branches into their own work.
+
+For true distributed development that supports proper merging,
+published branches should never be rewritten.
+
+[[bisect-merges]]
+Why bisecting merge commits can be harder than bisecting linear history
+-----------------------------------------------------------------------
+
+The linkgit:git-bisect[1] command correctly handles history that
+includes merge commits.  However, when the commit that it finds is a
+merge commit, the user may need to work harder than usual to figure out
+why that commit introduced a problem.
+
+Imagine this history:
+
+................................................
+      ---Z---o---X---...---o---A---C---D
+          \                       /
+           o---o---Y---...---o---B
+................................................
+
+Suppose that on the upper line of development, the meaning of one
+of the functions that exists at Z is changed at commit X.  The
+commits from Z leading to A change both the function's
+implementation and all calling sites that exist at Z, as well
+as new calling sites they add, to be consistent.  There is no
+bug at A.
+
+Suppose that in the meantime on the lower line of development somebody
+adds a new calling site for that function at commit Y.  The
+commits from Z leading to B all assume the old semantics of that
+function and the callers and the callee are consistent with each
+other.  There is no bug at B, either.
+
+Suppose further that the two development lines merge cleanly at C,
+so no conflict resolution is required.
+
+Nevertheless, the code at C is broken, because the callers added
+on the lower line of development have not been converted to the new
+semantics introduced on the upper line of development.  So if all
+you know is that D is bad, that Z is good, and that
+linkgit:git-bisect[1] identifies C as the culprit, how will you
+figure out that the problem is due to this change in semantics?
+
+When the result of a `git bisect` is a non-merge commit, you should
+normally be able to discover the problem by examining just that commit.
+Developers can make this easy by breaking their changes into small
+self-contained commits.  That won't help in the case above, however,
+because the problem isn't obvious from examination of any single
+commit; instead, a global view of the development is required.  To
+make matters worse, the change in semantics in the problematic
+function may be just one small part of the changes in the upper
+line of development.
+
+On the other hand, if instead of merging at C you had rebased the
+history between Z to B on top of A, you would have gotten this
+linear history:
+
+................................................................
+    ---Z---o---X--...---o---A---o---o---Y*--...---o---B*--D*
+................................................................
+
+Bisecting between Z and D* would hit a single culprit commit Y*,
+and understanding why Y* was broken would probably be easier.
+
+Partly for this reason, many experienced Git users, even when
+working on an otherwise merge-heavy project, keep the history
+linear by rebasing against the latest upstream version before
+publishing.
+
+[[advanced-branch-management]]
+Advanced branch management
+==========================
+
+[[fetching-individual-branches]]
+Fetching individual branches
+----------------------------
+
+Instead of using linkgit:git-remote[1], you can also choose just
+to update one branch at a time, and to store it locally under an
+arbitrary name:
+
+-------------------------------------------------
+$ git fetch origin todo:my-todo-work
+-------------------------------------------------
+
+The first argument, `origin`, just tells Git to fetch from the
+repository you originally cloned from.  The second argument tells Git
+to fetch the branch named `todo` from the remote repository, and to
+store it locally under the name `refs/heads/my-todo-work`.
+
+You can also fetch branches from other repositories; so
+
+-------------------------------------------------
+$ git fetch git://example.com/proj.git master:example-master
+-------------------------------------------------
+
+will create a new branch named `example-master` and store in it the
+branch named `master` from the repository at the given URL.  If you
+already have a branch named example-master, it will attempt to
+<<fast-forwards,fast-forward>> to the commit given by example.com's
+master branch.  In more detail:
+
+[[fetch-fast-forwards]]
+git fetch and fast-forwards
+---------------------------
+
+In the previous example, when updating an existing branch, `git fetch`
+checks to make sure that the most recent commit on the remote
+branch is a descendant of the most recent commit on your copy of the
+branch before updating your copy of the branch to point at the new
+commit.  Git calls this process a <<fast-forwards,fast-forward>>.
+
+A fast-forward looks something like this:
+
+................................................
+ o--o--o--o <-- old head of the branch
+           \
+            o--o--o <-- new head of the branch
+................................................
+
+
+In some cases it is possible that the new head will *not* actually be
+a descendant of the old head.  For example, the developer may have
+realized she made a serious mistake, and decided to backtrack,
+resulting in a situation like:
+
+................................................
+ o--o--o--o--a--b <-- old head of the branch
+           \
+            o--o--o <-- new head of the branch
+................................................
+
+In this case, `git fetch` will fail, and print out a warning.
+
+In that case, you can still force Git to update to the new head, as
+described in the following section.  However, note that in the
+situation above this may mean losing the commits labeled `a` and `b`,
+unless you've already created a reference of your own pointing to
+them.
+
+[[forcing-fetch]]
+Forcing git fetch to do non-fast-forward updates
+------------------------------------------------
+
+If git fetch fails because the new head of a branch is not a
+descendant of the old head, you may force the update with:
+
+-------------------------------------------------
+$ git fetch git://example.com/proj.git +master:refs/remotes/example/master
+-------------------------------------------------
+
+Note the addition of the `+` sign.  Alternatively, you can use the `-f`
+flag to force updates of all the fetched branches, as in:
+
+-------------------------------------------------
+$ git fetch -f origin
+-------------------------------------------------
+
+Be aware that commits that the old version of example/master pointed at
+may be lost, as we saw in the previous section.
+
+[[remote-branch-configuration]]
+Configuring remote-tracking branches
+------------------------------------
+
+We saw above that `origin` is just a shortcut to refer to the
+repository that you originally cloned from.  This information is
+stored in Git configuration variables, which you can see using
+linkgit:git-config[1]:
+
+-------------------------------------------------
+$ git config -l
+core.repositoryformatversion=0
+core.filemode=true
+core.logallrefupdates=true
+remote.origin.url=git://git.kernel.org/pub/scm/git/git.git
+remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
+branch.master.remote=origin
+branch.master.merge=refs/heads/master
+-------------------------------------------------
+
+If there are other repositories that you also use frequently, you can
+create similar configuration options to save typing; for example,
+
+-------------------------------------------------
+$ git remote add example git://example.com/proj.git
+-------------------------------------------------
+
+adds the following to `.git/config`:
+
+-------------------------------------------------
+[remote "example"]
+	url = git://example.com/proj.git
+	fetch = +refs/heads/*:refs/remotes/example/*
+-------------------------------------------------
+
+Also note that the above configuration can be performed by directly
+editing the file `.git/config` instead of using linkgit:git-remote[1].
+
+After configuring the remote, the following three commands will do the
+same thing:
+
+-------------------------------------------------
+$ git fetch git://example.com/proj.git +refs/heads/*:refs/remotes/example/*
+$ git fetch example +refs/heads/*:refs/remotes/example/*
+$ git fetch example
+-------------------------------------------------
+
+See linkgit:git-config[1] for more details on the configuration
+options mentioned above and linkgit:git-fetch[1] for more details on
+the refspec syntax.
+
+
+[[git-concepts]]
+Git concepts
+============
+
+Git is built on a small number of simple but powerful ideas.  While it
+is possible to get things done without understanding them, you will find
+Git much more intuitive if you do.
+
+We start with the most important, the  <<def_object_database,object
+database>> and the <<def_index,index>>.
+
+[[the-object-database]]
+The Object Database
+-------------------
+
+
+We already saw in <<understanding-commits>> that all commits are stored
+under a 40-digit "object name".  In fact, all the information needed to
+represent the history of a project is stored in objects with such names.
+In each case the name is calculated by taking the SHA-1 hash of the
+contents of the object.  The SHA-1 hash is a cryptographic hash function.
+What that means to us is that it is impossible to find two different
+objects with the same name.  This has a number of advantages; among
+others:
+
+- Git can quickly determine whether two objects are identical or not,
+  just by comparing names.
+- Since object names are computed the same way in every repository, the
+  same content stored in two repositories will always be stored under
+  the same name.
+- Git can detect errors when it reads an object, by checking that the
+  object's name is still the SHA-1 hash of its contents.
+
+(See <<object-details>> for the details of the object formatting and
+SHA-1 calculation.)
+
+There are four different types of objects: "blob", "tree", "commit", and
+"tag".
+
+- A <<def_blob_object,"blob" object>> is used to store file data.
+- A <<def_tree_object,"tree" object>> ties one or more
+  "blob" objects into a directory structure. In addition, a tree object
+  can refer to other tree objects, thus creating a directory hierarchy.
+- A <<def_commit_object,"commit" object>> ties such directory hierarchies
+  together into a <<def_DAG,directed acyclic graph>> of revisions--each
+  commit contains the object name of exactly one tree designating the
+  directory hierarchy at the time of the commit. In addition, a commit
+  refers to "parent" commit objects that describe the history of how we
+  arrived at that directory hierarchy.
+- A <<def_tag_object,"tag" object>> symbolically identifies and can be
+  used to sign other objects. It contains the object name and type of
+  another object, a symbolic name (of course!) and, optionally, a
+  signature.
+
+The object types in some more detail:
+
+[[commit-object]]
+Commit Object
+~~~~~~~~~~~~~
+
+The "commit" object links a physical state of a tree with a description
+of how we got there and why.  Use the `--pretty=raw` option to
+linkgit:git-show[1] or linkgit:git-log[1] to examine your favorite
+commit:
+
+------------------------------------------------
+$ git show -s --pretty=raw 2be7fcb476
+commit 2be7fcb4764f2dbcee52635b91fedb1b3dcf7ab4
+tree fb3a8bdd0ceddd019615af4d57a53f43d8cee2bf
+parent 257a84d9d02e90447b149af58b271c19405edb6a
+author Dave Watson <dwatson@mimvista.com> 1187576872 -0400
+committer Junio C Hamano <gitster@pobox.com> 1187591163 -0700
+
+    Fix misspelling of 'suppress' in docs
+
+    Signed-off-by: Junio C Hamano <gitster@pobox.com>
+------------------------------------------------
+
+As you can see, a commit is defined by:
+
+- a tree: The SHA-1 name of a tree object (as defined below), representing
+  the contents of a directory at a certain point in time.
+- parent(s): The SHA-1 name(s) of some number of commits which represent the
+  immediately previous step(s) in the history of the project.  The
+  example above has one parent; merge commits may have more than
+  one.  A commit with no parents is called a "root" commit, and
+  represents the initial revision of a project.  Each project must have
+  at least one root.  A project can also have multiple roots, though
+  that isn't common (or necessarily a good idea).
+- an author: The name of the person responsible for this change, together
+  with its date.
+- a committer: The name of the person who actually created the commit,
+  with the date it was done.  This may be different from the author, for
+  example, if the author was someone who wrote a patch and emailed it
+  to the person who used it to create the commit.
+- a comment describing this commit.
+
+Note that a commit does not itself contain any information about what
+actually changed; all changes are calculated by comparing the contents
+of the tree referred to by this commit with the trees associated with
+its parents.  In particular, Git does not attempt to record file renames
+explicitly, though it can identify cases where the existence of the same
+file data at changing paths suggests a rename.  (See, for example, the
+`-M` option to linkgit:git-diff[1]).
+
+A commit is usually created by linkgit:git-commit[1], which creates a
+commit whose parent is normally the current HEAD, and whose tree is
+taken from the content currently stored in the index.
+
+[[tree-object]]
+Tree Object
+~~~~~~~~~~~
+
+The ever-versatile linkgit:git-show[1] command can also be used to
+examine tree objects, but linkgit:git-ls-tree[1] will give you more
+details:
+
+------------------------------------------------
+$ git ls-tree fb3a8bdd0ce
+100644 blob 63c918c667fa005ff12ad89437f2fdc80926e21c    .gitignore
+100644 blob 5529b198e8d14decbe4ad99db3f7fb632de0439d    .mailmap
+100644 blob 6ff87c4664981e4397625791c8ea3bbb5f2279a3    COPYING
+040000 tree 2fb783e477100ce076f6bf57e4a6f026013dc745    Documentation
+100755 blob 3c0032cec592a765692234f1cba47dfdcc3a9200    GIT-VERSION-GEN
+100644 blob 289b046a443c0647624607d471289b2c7dcd470b    INSTALL
+100644 blob 4eb463797adc693dc168b926b6932ff53f17d0b1    Makefile
+100644 blob 548142c327a6790ff8821d67c2ee1eff7a656b52    README
+...
+------------------------------------------------
+
+As you can see, a tree object contains a list of entries, each with a
+mode, object type, SHA-1 name, and name, sorted by name.  It represents
+the contents of a single directory tree.
+
+The object type may be a blob, representing the contents of a file, or
+another tree, representing the contents of a subdirectory.  Since trees
+and blobs, like all other objects, are named by the SHA-1 hash of their
+contents, two trees have the same SHA-1 name if and only if their
+contents (including, recursively, the contents of all subdirectories)
+are identical.  This allows Git to quickly determine the differences
+between two related tree objects, since it can ignore any entries with
+identical object names.
+
+(Note: in the presence of submodules, trees may also have commits as
+entries.  See <<submodules>> for documentation.)
+
+Note that the files all have mode 644 or 755: Git actually only pays
+attention to the executable bit.
+
+[[blob-object]]
+Blob Object
+~~~~~~~~~~~
+
+You can use linkgit:git-show[1] to examine the contents of a blob; take,
+for example, the blob in the entry for `COPYING` from the tree above:
+
+------------------------------------------------
+$ git show 6ff87c4664
+
+ Note that the only valid version of the GPL as far as this project
+ is concerned is _this_ particular version of the license (ie v2, not
+ v2.2 or v3.x or whatever), unless explicitly otherwise stated.
+...
+------------------------------------------------
+
+A "blob" object is nothing but a binary blob of data.  It doesn't refer
+to anything else or have attributes of any kind.
+
+Since the blob is entirely defined by its data, if two files in a
+directory tree (or in multiple different versions of the repository)
+have the same contents, they will share the same blob object. The object
+is totally independent of its location in the directory tree, and
+renaming a file does not change the object that file is associated with.
+
+Note that any tree or blob object can be examined using
+linkgit:git-show[1] with the <revision>:<path> syntax.  This can
+sometimes be useful for browsing the contents of a tree that is not
+currently checked out.
+
+[[trust]]
+Trust
+~~~~~
+
+If you receive the SHA-1 name of a blob from one source, and its contents
+from another (possibly untrusted) source, you can still trust that those
+contents are correct as long as the SHA-1 name agrees.  This is because
+the SHA-1 is designed so that it is infeasible to find different contents
+that produce the same hash.
+
+Similarly, you need only trust the SHA-1 name of a top-level tree object
+to trust the contents of the entire directory that it refers to, and if
+you receive the SHA-1 name of a commit from a trusted source, then you
+can easily verify the entire history of commits reachable through
+parents of that commit, and all of those contents of the trees referred
+to by those commits.
+
+So to introduce some real trust in the system, the only thing you need
+to do is to digitally sign just 'one' special note, which includes the
+name of a top-level commit.  Your digital signature shows others
+that you trust that commit, and the immutability of the history of
+commits tells others that they can trust the whole history.
+
+In other words, you can easily validate a whole archive by just
+sending out a single email that tells the people the name (SHA-1 hash)
+of the top commit, and digitally sign that email using something
+like GPG/PGP.
+
+To assist in this, Git also provides the tag object...
+
+[[tag-object]]
+Tag Object
+~~~~~~~~~~
+
+A tag object contains an object, object type, tag name, the name of the
+person ("tagger") who created the tag, and a message, which may contain
+a signature, as can be seen using linkgit:git-cat-file[1]:
+
+------------------------------------------------
+$ git cat-file tag v1.5.0
+object 437b1b20df4b356c9342dac8d38849f24ef44f27
+type commit
+tag v1.5.0
+tagger Junio C Hamano <junkio@cox.net> 1171411200 +0000
+
+GIT 1.5.0
+-----BEGIN PGP SIGNATURE-----
+Version: GnuPG v1.4.6 (GNU/Linux)
+
+iD8DBQBF0lGqwMbZpPMRm5oRAuRiAJ9ohBLd7s2kqjkKlq1qqC57SbnmzQCdG4ui
+nLE/L9aUXdWeTFPron96DLA=
+=2E+0
+-----END PGP SIGNATURE-----
+------------------------------------------------
+
+See the linkgit:git-tag[1] command to learn how to create and verify tag
+objects.  (Note that linkgit:git-tag[1] can also be used to create
+"lightweight tags", which are not tag objects at all, but just simple
+references whose names begin with `refs/tags/`).
+
+[[pack-files]]
+How Git stores objects efficiently: pack files
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Newly created objects are initially created in a file named after the
+object's SHA-1 hash (stored in `.git/objects`).
+
+Unfortunately this system becomes inefficient once a project has a
+lot of objects.  Try this on an old project:
+
+------------------------------------------------
+$ git count-objects
+6930 objects, 47620 kilobytes
+------------------------------------------------
+
+The first number is the number of objects which are kept in
+individual files.  The second is the amount of space taken up by
+those "loose" objects.
+
+You can save space and make Git faster by moving these loose objects in
+to a "pack file", which stores a group of objects in an efficient
+compressed format; the details of how pack files are formatted can be
+found in link:technical/pack-format.html[pack format].
+
+To put the loose objects into a pack, just run git repack:
+
+------------------------------------------------
+$ git repack
+Counting objects: 6020, done.
+Delta compression using up to 4 threads.
+Compressing objects: 100% (6020/6020), done.
+Writing objects: 100% (6020/6020), done.
+Total 6020 (delta 4070), reused 0 (delta 0)
+------------------------------------------------
+
+This creates a single "pack file" in .git/objects/pack/
+containing all currently unpacked objects.  You can then run
+
+------------------------------------------------
+$ git prune
+------------------------------------------------
+
+to remove any of the "loose" objects that are now contained in the
+pack.  This will also remove any unreferenced objects (which may be
+created when, for example, you use `git reset` to remove a commit).
+You can verify that the loose objects are gone by looking at the
+`.git/objects` directory or by running
+
+------------------------------------------------
+$ git count-objects
+0 objects, 0 kilobytes
+------------------------------------------------
+
+Although the object files are gone, any commands that refer to those
+objects will work exactly as they did before.
+
+The linkgit:git-gc[1] command performs packing, pruning, and more for
+you, so is normally the only high-level command you need.
+
+[[dangling-objects]]
+Dangling objects
+~~~~~~~~~~~~~~~~
+
+The linkgit:git-fsck[1] command will sometimes complain about dangling
+objects.  They are not a problem.
+
+The most common cause of dangling objects is that you've rebased a
+branch, or you have pulled from somebody else who rebased a branch--see
+<<cleaning-up-history>>.  In that case, the old head of the original
+branch still exists, as does everything it pointed to. The branch
+pointer itself just doesn't, since you replaced it with another one.
+
+There are also other situations that cause dangling objects. For
+example, a "dangling blob" may arise because you did a `git add` of a
+file, but then, before you actually committed it and made it part of the
+bigger picture, you changed something else in that file and committed
+that *updated* thing--the old state that you added originally ends up
+not being pointed to by any commit or tree, so it's now a dangling blob
+object.
+
+Similarly, when the "recursive" merge strategy runs, and finds that
+there are criss-cross merges and thus more than one merge base (which is
+fairly unusual, but it does happen), it will generate one temporary
+midway tree (or possibly even more, if you had lots of criss-crossing
+merges and more than two merge bases) as a temporary internal merge
+base, and again, those are real objects, but the end result will not end
+up pointing to them, so they end up "dangling" in your repository.
+
+Generally, dangling objects aren't anything to worry about. They can
+even be very useful: if you screw something up, the dangling objects can
+be how you recover your old tree (say, you did a rebase, and realized
+that you really didn't want to--you can look at what dangling objects
+you have, and decide to reset your head to some old dangling state).
+
+For commits, you can just use:
+
+------------------------------------------------
+$ gitk <dangling-commit-sha-goes-here> --not --all
+------------------------------------------------
+
+This asks for all the history reachable from the given commit but not
+from any branch, tag, or other reference.  If you decide it's something
+you want, you can always create a new reference to it, e.g.,
+
+------------------------------------------------
+$ git branch recovered-branch <dangling-commit-sha-goes-here>
+------------------------------------------------
+
+For blobs and trees, you can't do the same, but you can still examine
+them.  You can just do
+
+------------------------------------------------
+$ git show <dangling-blob/tree-sha-goes-here>
+------------------------------------------------
+
+to show what the contents of the blob were (or, for a tree, basically
+what the `ls` for that directory was), and that may give you some idea
+of what the operation was that left that dangling object.
+
+Usually, dangling blobs and trees aren't very interesting. They're
+almost always the result of either being a half-way mergebase (the blob
+will often even have the conflict markers from a merge in it, if you
+have had conflicting merges that you fixed up by hand), or simply
+because you interrupted a `git fetch` with ^C or something like that,
+leaving _some_ of the new objects in the object database, but just
+dangling and useless.
+
+Anyway, once you are sure that you're not interested in any dangling
+state, you can just prune all unreachable objects:
+
+------------------------------------------------
+$ git prune
+------------------------------------------------
+
+and they'll be gone. (You should only run `git prune` on a quiescent
+repository--it's kind of like doing a filesystem fsck recovery: you
+don't want to do that while the filesystem is mounted.
+`git prune` is designed not to cause any harm in such cases of concurrent
+accesses to a repository but you might receive confusing or scary messages.)
+
+[[recovering-from-repository-corruption]]
+Recovering from repository corruption
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By design, Git treats data trusted to it with caution.  However, even in
+the absence of bugs in Git itself, it is still possible that hardware or
+operating system errors could corrupt data.
+
+The first defense against such problems is backups.  You can back up a
+Git directory using clone, or just using cp, tar, or any other backup
+mechanism.
+
+As a last resort, you can search for the corrupted objects and attempt
+to replace them by hand.  Back up your repository before attempting this
+in case you corrupt things even more in the process.
+
+We'll assume that the problem is a single missing or corrupted blob,
+which is sometimes a solvable problem.  (Recovering missing trees and
+especially commits is *much* harder).
+
+Before starting, verify that there is corruption, and figure out where
+it is with linkgit:git-fsck[1]; this may be time-consuming.
+
+Assume the output looks like this:
+
+------------------------------------------------
+$ git fsck --full --no-dangling
+broken link from    tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+              to    blob 4b9458b3786228369c63936db65827de3cc06200
+missing blob 4b9458b3786228369c63936db65827de3cc06200
+------------------------------------------------
+
+Now you know that blob 4b9458b3 is missing, and that the tree 2d9263c6
+points to it.  If you could find just one copy of that missing blob
+object, possibly in some other repository, you could move it into
+`.git/objects/4b/9458b3...` and be done.  Suppose you can't.  You can
+still examine the tree that pointed to it with linkgit:git-ls-tree[1],
+which might output something like:
+
+------------------------------------------------
+$ git ls-tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+100644 blob 8d14531846b95bfa3564b58ccfb7913a034323b8	.gitignore
+100644 blob ebf9bf84da0aab5ed944264a5db2a65fe3a3e883	.mailmap
+100644 blob ca442d313d86dc67e0a2e5d584b465bd382cbf5c	COPYING
+...
+100644 blob 4b9458b3786228369c63936db65827de3cc06200	myfile
+...
+------------------------------------------------
+
+So now you know that the missing blob was the data for a file named
+`myfile`.  And chances are you can also identify the directory--let's
+say it's in `somedirectory`.  If you're lucky the missing copy might be
+the same as the copy you have checked out in your working tree at
+`somedirectory/myfile`; you can test whether that's right with
+linkgit:git-hash-object[1]:
+
+------------------------------------------------
+$ git hash-object -w somedirectory/myfile
+------------------------------------------------
+
+which will create and store a blob object with the contents of
+somedirectory/myfile, and output the SHA-1 of that object.  if you're
+extremely lucky it might be 4b9458b3786228369c63936db65827de3cc06200, in
+which case you've guessed right, and the corruption is fixed!
+
+Otherwise, you need more information.  How do you tell which version of
+the file has been lost?
+
+The easiest way to do this is with:
+
+------------------------------------------------
+$ git log --raw --all --full-history -- somedirectory/myfile
+------------------------------------------------
+
+Because you're asking for raw output, you'll now get something like
+
+------------------------------------------------
+commit abc
+Author:
+Date:
+...
+:100644 100644 4b9458b newsha M somedirectory/myfile
+
+
+commit xyz
+Author:
+Date:
+
+...
+:100644 100644 oldsha 4b9458b M somedirectory/myfile
+------------------------------------------------
+
+This tells you that the immediately following version of the file was
+"newsha", and that the immediately preceding version was "oldsha".
+You also know the commit messages that went with the change from oldsha
+to 4b9458b and with the change from 4b9458b to newsha.
+
+If you've been committing small enough changes, you may now have a good
+shot at reconstructing the contents of the in-between state 4b9458b.
+
+If you can do that, you can now recreate the missing object with
+
+------------------------------------------------
+$ git hash-object -w <recreated-file>
+------------------------------------------------
+
+and your repository is good again!
+
+(Btw, you could have ignored the `fsck`, and started with doing a
+
+------------------------------------------------
+$ git log --raw --all
+------------------------------------------------
+
+and just looked for the sha of the missing object (4b9458b) in that
+whole thing. It's up to you--Git does *have* a lot of information, it is
+just missing one particular blob version.
+
+[[the-index]]
+The index
+---------
+
+The index is a binary file (generally kept in `.git/index`) containing a
+sorted list of path names, each with permissions and the SHA-1 of a blob
+object; linkgit:git-ls-files[1] can show you the contents of the index:
+
+-------------------------------------------------
+$ git ls-files --stage
+100644 63c918c667fa005ff12ad89437f2fdc80926e21c 0	.gitignore
+100644 5529b198e8d14decbe4ad99db3f7fb632de0439d 0	.mailmap
+100644 6ff87c4664981e4397625791c8ea3bbb5f2279a3 0	COPYING
+100644 a37b2152bd26be2c2289e1f57a292534a51a93c7 0	Documentation/.gitignore
+100644 fbefe9a45b00a54b58d94d06eca48b03d40a50e0 0	Documentation/Makefile
+...
+100644 2511aef8d89ab52be5ec6a5e46236b4b6bcd07ea 0	xdiff/xtypes.h
+100644 2ade97b2574a9f77e7ae4002a4e07a6a38e46d07 0	xdiff/xutils.c
+100644 d5de8292e05e7c36c4b68857c1cf9855e3d2f70a 0	xdiff/xutils.h
+-------------------------------------------------
+
+Note that in older documentation you may see the index called the
+"current directory cache" or just the "cache".  It has three important
+properties:
+
+1. The index contains all the information necessary to generate a single
+(uniquely determined) tree object.
++
+For example, running linkgit:git-commit[1] generates this tree object
+from the index, stores it in the object database, and uses it as the
+tree object associated with the new commit.
+
+2. The index enables fast comparisons between the tree object it defines
+and the working tree.
++
+It does this by storing some additional data for each entry (such as
+the last modified time).  This data is not displayed above, and is not
+stored in the created tree object, but it can be used to determine
+quickly which files in the working directory differ from what was
+stored in the index, and thus save Git from having to read all of the
+data from such files to look for changes.
+
+3. It can efficiently represent information about merge conflicts
+between different tree objects, allowing each pathname to be
+associated with sufficient information about the trees involved that
+you can create a three-way merge between them.
++
+We saw in <<conflict-resolution>> that during a merge the index can
+store multiple versions of a single file (called "stages").  The third
+column in the linkgit:git-ls-files[1] output above is the stage
+number, and will take on values other than 0 for files with merge
+conflicts.
+
+The index is thus a sort of temporary staging area, which is filled with
+a tree which you are in the process of working on.
+
+If you blow the index away entirely, you generally haven't lost any
+information as long as you have the name of the tree that it described.
+
+[[submodules]]
+Submodules
+==========
+
+Large projects are often composed of smaller, self-contained modules.  For
+example, an embedded Linux distribution's source tree would include every
+piece of software in the distribution with some local modifications; a movie
+player might need to build against a specific, known-working version of a
+decompression library; several independent programs might all share the same
+build scripts.
+
+With centralized revision control systems this is often accomplished by
+including every module in one single repository.  Developers can check out
+all modules or only the modules they need to work with.  They can even modify
+files across several modules in a single commit while moving things around
+or updating APIs and translations.
+
+Git does not allow partial checkouts, so duplicating this approach in Git
+would force developers to keep a local copy of modules they are not
+interested in touching.  Commits in an enormous checkout would be slower
+than you'd expect as Git would have to scan every directory for changes.
+If modules have a lot of local history, clones would take forever.
+
+On the plus side, distributed revision control systems can much better
+integrate with external sources.  In a centralized model, a single arbitrary
+snapshot of the external project is exported from its own revision control
+and then imported into the local revision control on a vendor branch.  All
+the history is hidden.  With distributed revision control you can clone the
+entire external history and much more easily follow development and re-merge
+local changes.
+
+Git's submodule support allows a repository to contain, as a subdirectory, a
+checkout of an external project.  Submodules maintain their own identity;
+the submodule support just stores the submodule repository location and
+commit ID, so other developers who clone the containing project
+("superproject") can easily clone all the submodules at the same revision.
+Partial checkouts of the superproject are possible: you can tell Git to
+clone none, some or all of the submodules.
+
+The linkgit:git-submodule[1] command is available since Git 1.5.3.  Users
+with Git 1.5.2 can look up the submodule commits in the repository and
+manually check them out; earlier versions won't recognize the submodules at
+all.
+
+To see how submodule support works, create four example
+repositories that can be used later as a submodule:
+
+-------------------------------------------------
+$ mkdir ~/git
+$ cd ~/git
+$ for i in a b c d
+do
+	mkdir $i
+	cd $i
+	git init
+	echo "module $i" > $i.txt
+	git add $i.txt
+	git commit -m "Initial commit, submodule $i"
+	cd ..
+done
+-------------------------------------------------
+
+Now create the superproject and add all the submodules:
+
+-------------------------------------------------
+$ mkdir super
+$ cd super
+$ git init
+$ for i in a b c d
+do
+	git submodule add ~/git/$i $i
+done
+-------------------------------------------------
+
+NOTE: Do not use local URLs here if you plan to publish your superproject!
+
+See what files `git submodule` created:
+
+-------------------------------------------------
+$ ls -a
+.  ..  .git  .gitmodules  a  b  c  d
+-------------------------------------------------
+
+The `git submodule add <repo> <path>` command does a couple of things:
+
+- It clones the submodule from `<repo>` to the given `<path>` under the
+  current directory and by default checks out the master branch.
+- It adds the submodule's clone path to the linkgit:gitmodules[5] file and
+  adds this file to the index, ready to be committed.
+- It adds the submodule's current commit ID to the index, ready to be
+  committed.
+
+Commit the superproject:
+
+-------------------------------------------------
+$ git commit -m "Add submodules a, b, c and d."
+-------------------------------------------------
+
+Now clone the superproject:
+
+-------------------------------------------------
+$ cd ..
+$ git clone super cloned
+$ cd cloned
+-------------------------------------------------
+
+The submodule directories are there, but they're empty:
+
+-------------------------------------------------
+$ ls -a a
+.  ..
+$ git submodule status
+-d266b9873ad50488163457f025db7cdd9683d88b a
+-e81d457da15309b4fef4249aba9b50187999670d b
+-c1536a972b9affea0f16e0680ba87332dc059146 c
+-d96249ff5d57de5de093e6baff9e0aafa5276a74 d
+-------------------------------------------------
+
+NOTE: The commit object names shown above would be different for you, but they
+should match the HEAD commit object names of your repositories.  You can check
+it by running `git ls-remote ../a`.
+
+Pulling down the submodules is a two-step process. First run `git submodule
+init` to add the submodule repository URLs to `.git/config`:
+
+-------------------------------------------------
+$ git submodule init
+-------------------------------------------------
+
+Now use `git submodule update` to clone the repositories and check out the
+commits specified in the superproject:
+
+-------------------------------------------------
+$ git submodule update
+$ cd a
+$ ls -a
+.  ..  .git  a.txt
+-------------------------------------------------
+
+One major difference between `git submodule update` and `git submodule add` is
+that `git submodule update` checks out a specific commit, rather than the tip
+of a branch. It's like checking out a tag: the head is detached, so you're not
+working on a branch.
+
+-------------------------------------------------
+$ git branch
+* (detached from d266b98)
+  master
+-------------------------------------------------
+
+If you want to make a change within a submodule and you have a detached head,
+then you should create or checkout a branch, make your changes, publish the
+change within the submodule, and then update the superproject to reference the
+new commit:
+
+-------------------------------------------------
+$ git switch master
+-------------------------------------------------
+
+or
+
+-------------------------------------------------
+$ git switch -c fix-up
+-------------------------------------------------
+
+then
+
+-------------------------------------------------
+$ echo "adding a line again" >> a.txt
+$ git commit -a -m "Updated the submodule from within the superproject."
+$ git push
+$ cd ..
+$ git diff
+diff --git a/a b/a
+index d266b98..261dfac 160000
+--- a/a
++++ b/a
+@@ -1 +1 @@
+-Subproject commit d266b9873ad50488163457f025db7cdd9683d88b
++Subproject commit 261dfac35cb99d380eb966e102c1197139f7fa24
+$ git add a
+$ git commit -m "Updated submodule a."
+$ git push
+-------------------------------------------------
+
+You have to run `git submodule update` after `git pull` if you want to update
+submodules, too.
+
+Pitfalls with submodules
+------------------------
+
+Always publish the submodule change before publishing the change to the
+superproject that references it. If you forget to publish the submodule change,
+others won't be able to clone the repository:
+
+-------------------------------------------------
+$ cd ~/git/super/a
+$ echo i added another line to this file >> a.txt
+$ git commit -a -m "doing it wrong this time"
+$ cd ..
+$ git add a
+$ git commit -m "Updated submodule a again."
+$ git push
+$ cd ~/git/cloned
+$ git pull
+$ git submodule update
+error: pathspec '261dfac35cb99d380eb966e102c1197139f7fa24' did not match any file(s) known to git.
+Did you forget to 'git add'?
+Unable to checkout '261dfac35cb99d380eb966e102c1197139f7fa24' in submodule path 'a'
+-------------------------------------------------
+
+In older Git versions it could be easily forgotten to commit new or modified
+files in a submodule, which silently leads to similar problems as not pushing
+the submodule changes. Starting with Git 1.7.0 both `git status` and `git diff`
+in the superproject show submodules as modified when they contain new or
+modified files to protect against accidentally committing such a state. `git
+diff` will also add a `-dirty` to the work tree side when generating patch
+output or used with the `--submodule` option:
+
+-------------------------------------------------
+$ git diff
+diff --git a/sub b/sub
+--- a/sub
++++ b/sub
+@@ -1 +1 @@
+-Subproject commit 3f356705649b5d566d97ff843cf193359229a453
++Subproject commit 3f356705649b5d566d97ff843cf193359229a453-dirty
+$ git diff --submodule
+Submodule sub 3f35670..3f35670-dirty:
+-------------------------------------------------
+
+You also should not rewind branches in a submodule beyond commits that were
+ever recorded in any superproject.
+
+It's not safe to run `git submodule update` if you've made and committed
+changes within a submodule without checking out a branch first. They will be
+silently overwritten:
+
+-------------------------------------------------
+$ cat a.txt
+module a
+$ echo line added from private2 >> a.txt
+$ git commit -a -m "line added inside private2"
+$ cd ..
+$ git submodule update
+Submodule path 'a': checked out 'd266b9873ad50488163457f025db7cdd9683d88b'
+$ cd a
+$ cat a.txt
+module a
+-------------------------------------------------
+
+NOTE: The changes are still visible in the submodule's reflog.
+
+If you have uncommitted changes in your submodule working tree, `git
+submodule update` will not overwrite them.  Instead, you get the usual
+warning about not being able switch from a dirty branch.
+
+[[low-level-operations]]
+Low-level Git operations
+========================
+
+Many of the higher-level commands were originally implemented as shell
+scripts using a smaller core of low-level Git commands.  These can still
+be useful when doing unusual things with Git, or just as a way to
+understand its inner workings.
+
+[[object-manipulation]]
+Object access and manipulation
+------------------------------
+
+The linkgit:git-cat-file[1] command can show the contents of any object,
+though the higher-level linkgit:git-show[1] is usually more useful.
+
+The linkgit:git-commit-tree[1] command allows constructing commits with
+arbitrary parents and trees.
+
+A tree can be created with linkgit:git-write-tree[1] and its data can be
+accessed by linkgit:git-ls-tree[1].  Two trees can be compared with
+linkgit:git-diff-tree[1].
+
+A tag is created with linkgit:git-mktag[1], and the signature can be
+verified by linkgit:git-verify-tag[1], though it is normally simpler to
+use linkgit:git-tag[1] for both.
+
+[[the-workflow]]
+The Workflow
+------------
+
+High-level operations such as linkgit:git-commit[1] and
+linkgit:git-restore[1] work by moving data
+between the working tree, the index, and the object database.  Git
+provides low-level operations which perform each of these steps
+individually.
+
+Generally, all Git operations work on the index file. Some operations
+work *purely* on the index file (showing the current state of the
+index), but most operations move data between the index file and either
+the database or the working directory. Thus there are four main
+combinations:
+
+[[working-directory-to-index]]
+working directory -> index
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The linkgit:git-update-index[1] command updates the index with
+information from the working directory.  You generally update the
+index information by just specifying the filename you want to update,
+like so:
+
+-------------------------------------------------
+$ git update-index filename
+-------------------------------------------------
+
+but to avoid common mistakes with filename globbing etc., the command
+will not normally add totally new entries or remove old entries,
+i.e. it will normally just update existing cache entries.
+
+To tell Git that yes, you really do realize that certain files no
+longer exist, or that new files should be added, you
+should use the `--remove` and `--add` flags respectively.
+
+NOTE! A `--remove` flag does 'not' mean that subsequent filenames will
+necessarily be removed: if the files still exist in your directory
+structure, the index will be updated with their new status, not
+removed. The only thing `--remove` means is that update-index will be
+considering a removed file to be a valid thing, and if the file really
+does not exist any more, it will update the index accordingly.
+
+As a special case, you can also do `git update-index --refresh`, which
+will refresh the "stat" information of each index to match the current
+stat information. It will 'not' update the object status itself, and
+it will only update the fields that are used to quickly test whether
+an object still matches its old backing store object.
+
+The previously introduced linkgit:git-add[1] is just a wrapper for
+linkgit:git-update-index[1].
+
+[[index-to-object-database]]
+index -> object database
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+You write your current index file to a "tree" object with the program
+
+-------------------------------------------------
+$ git write-tree
+-------------------------------------------------
+
+that doesn't come with any options--it will just write out the
+current index into the set of tree objects that describe that state,
+and it will return the name of the resulting top-level tree. You can
+use that tree to re-generate the index at any time by going in the
+other direction:
+
+[[object-database-to-index]]
+object database -> index
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+You read a "tree" file from the object database, and use that to
+populate (and overwrite--don't do this if your index contains any
+unsaved state that you might want to restore later!) your current
+index.  Normal operation is just
+
+-------------------------------------------------
+$ git read-tree <SHA-1 of tree>
+-------------------------------------------------
+
+and your index file will now be equivalent to the tree that you saved
+earlier. However, that is only your 'index' file: your working
+directory contents have not been modified.
+
+[[index-to-working-directory]]
+index -> working directory
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You update your working directory from the index by "checking out"
+files. This is not a very common operation, since normally you'd just
+keep your files updated, and rather than write to your working
+directory, you'd tell the index files about the changes in your
+working directory (i.e. `git update-index`).
+
+However, if you decide to jump to a new version, or check out somebody
+else's version, or just restore a previous tree, you'd populate your
+index file with read-tree, and then you need to check out the result
+with
+
+-------------------------------------------------
+$ git checkout-index filename
+-------------------------------------------------
+
+or, if you want to check out all of the index, use `-a`.
+
+NOTE! `git checkout-index` normally refuses to overwrite old files, so
+if you have an old version of the tree already checked out, you will
+need to use the `-f` flag ('before' the `-a` flag or the filename) to
+'force' the checkout.
+
+
+Finally, there are a few odds and ends which are not purely moving
+from one representation to the other:
+
+[[tying-it-all-together]]
+Tying it all together
+~~~~~~~~~~~~~~~~~~~~~
+
+To commit a tree you have instantiated with `git write-tree`, you'd
+create a "commit" object that refers to that tree and the history
+behind it--most notably the "parent" commits that preceded it in
+history.
+
+Normally a "commit" has one parent: the previous state of the tree
+before a certain change was made. However, sometimes it can have two
+or more parent commits, in which case we call it a "merge", due to the
+fact that such a commit brings together ("merges") two or more
+previous states represented by other commits.
+
+In other words, while a "tree" represents a particular directory state
+of a working directory, a "commit" represents that state in time,
+and explains how we got there.
+
+You create a commit object by giving it the tree that describes the
+state at the time of the commit, and a list of parents:
+
+-------------------------------------------------
+$ git commit-tree <tree> -p <parent> [(-p <parent2>)...]
+-------------------------------------------------
+
+and then giving the reason for the commit on stdin (either through
+redirection from a pipe or file, or by just typing it at the tty).
+
+`git commit-tree` will return the name of the object that represents
+that commit, and you should save it away for later use. Normally,
+you'd commit a new `HEAD` state, and while Git doesn't care where you
+save the note about that state, in practice we tend to just write the
+result to the file pointed at by `.git/HEAD`, so that we can always see
+what the last committed state was.
+
+Here is a picture that illustrates how various pieces fit together:
+
+------------
+
+                     commit-tree
+                      commit obj
+                       +----+
+                       |    |
+                       |    |
+                       V    V
+                    +-----------+
+                    | Object DB |
+                    |  Backing  |
+                    |   Store   |
+                    +-----------+
+                       ^
+           write-tree  |     |
+             tree obj  |     |
+                       |     |  read-tree
+                       |     |  tree obj
+                             V
+                    +-----------+
+                    |   Index   |
+                    |  "cache"  |
+                    +-----------+
+         update-index  ^
+             blob obj  |     |
+                       |     |
+    checkout-index -u  |     |  checkout-index
+             stat      |     |  blob obj
+                             V
+                    +-----------+
+                    |  Working  |
+                    | Directory |
+                    +-----------+
+
+------------
+
+
+[[examining-the-data]]
+Examining the data
+------------------
+
+You can examine the data represented in the object database and the
+index with various helper tools. For every object, you can use
+linkgit:git-cat-file[1] to examine details about the
+object:
+
+-------------------------------------------------
+$ git cat-file -t <objectname>
+-------------------------------------------------
+
+shows the type of the object, and once you have the type (which is
+usually implicit in where you find the object), you can use
+
+-------------------------------------------------
+$ git cat-file blob|tree|commit|tag <objectname>
+-------------------------------------------------
+
+to show its contents. NOTE! Trees have binary content, and as a result
+there is a special helper for showing that content, called
+`git ls-tree`, which turns the binary content into a more easily
+readable form.
+
+It's especially instructive to look at "commit" objects, since those
+tend to be small and fairly self-explanatory. In particular, if you
+follow the convention of having the top commit name in `.git/HEAD`,
+you can do
+
+-------------------------------------------------
+$ git cat-file commit HEAD
+-------------------------------------------------
+
+to see what the top commit was.
+
+[[merging-multiple-trees]]
+Merging multiple trees
+----------------------
+
+Git can help you perform a three-way merge, which can in turn be
+used for a many-way merge by repeating the merge procedure several
+times.  The usual situation is that you only do one three-way merge
+(reconciling two lines of history) and commit the result, but if
+you like to, you can merge several branches in one go.
+
+To perform a three-way merge, you start with the two commits you
+want to merge, find their closest common parent (a third commit),
+and compare the trees corresponding to these three commits.
+
+To get the "base" for the merge, look up the common parent of two
+commits:
+
+-------------------------------------------------
+$ git merge-base <commit1> <commit2>
+-------------------------------------------------
+
+This prints the name of a commit they are both based on. You should
+now look up the tree objects of those commits, which you can easily
+do with
+
+-------------------------------------------------
+$ git cat-file commit <commitname> | head -1
+-------------------------------------------------
+
+since the tree object information is always the first line in a commit
+object.
+
+Once you know the three trees you are going to merge (the one "original"
+tree, aka the common tree, and the two "result" trees, aka the branches
+you want to merge), you do a "merge" read into the index. This will
+complain if it has to throw away your old index contents, so you should
+make sure that you've committed those--in fact you would normally
+always do a merge against your last commit (which should thus match what
+you have in your current index anyway).
+
+To do the merge, do
+
+-------------------------------------------------
+$ git read-tree -m -u <origtree> <yourtree> <targettree>
+-------------------------------------------------
+
+which will do all trivial merge operations for you directly in the
+index file, and you can just write the result out with
+`git write-tree`.
+
+
+[[merging-multiple-trees-2]]
+Merging multiple trees, continued
+---------------------------------
+
+Sadly, many merges aren't trivial. If there are files that have
+been added, moved or removed, or if both branches have modified the
+same file, you will be left with an index tree that contains "merge
+entries" in it. Such an index tree can 'NOT' be written out to a tree
+object, and you will have to resolve any such merge clashes using
+other tools before you can write out the result.
+
+You can examine such index state with `git ls-files --unmerged`
+command.  An example:
+
+------------------------------------------------
+$ git read-tree -m $orig HEAD $target
+$ git ls-files --unmerged
+100644 263414f423d0e4d70dae8fe53fa34614ff3e2860 1	hello.c
+100644 06fa6a24256dc7e560efa5687fa84b51f0263c3a 2	hello.c
+100644 cc44c73eb783565da5831b4d820c962954019b69 3	hello.c
+------------------------------------------------
+
+Each line of the `git ls-files --unmerged` output begins with
+the blob mode bits, blob SHA-1, 'stage number', and the
+filename.  The 'stage number' is Git's way to say which tree it
+came from: stage 1 corresponds to the `$orig` tree, stage 2 to
+the `HEAD` tree, and stage 3 to the `$target` tree.
+
+Earlier we said that trivial merges are done inside
+`git read-tree -m`.  For example, if the file did not change
+from `$orig` to `HEAD` or `$target`, or if the file changed
+from `$orig` to `HEAD` and `$orig` to `$target` the same way,
+obviously the final outcome is what is in `HEAD`.  What the
+above example shows is that file `hello.c` was changed from
+`$orig` to `HEAD` and `$orig` to `$target` in a different way.
+You could resolve this by running your favorite 3-way merge
+program, e.g.  `diff3`, `merge`, or Git's own merge-file, on
+the blob objects from these three stages yourself, like this:
+
+------------------------------------------------
+$ git cat-file blob 263414f >hello.c~1
+$ git cat-file blob 06fa6a2 >hello.c~2
+$ git cat-file blob cc44c73 >hello.c~3
+$ git merge-file hello.c~2 hello.c~1 hello.c~3
+------------------------------------------------
+
+This would leave the merge result in `hello.c~2` file, along
+with conflict markers if there are conflicts.  After verifying
+the merge result makes sense, you can tell Git what the final
+merge result for this file is by:
+
+-------------------------------------------------
+$ mv -f hello.c~2 hello.c
+$ git update-index hello.c
+-------------------------------------------------
+
+When a path is in the "unmerged" state, running `git update-index` for
+that path tells Git to mark the path resolved.
+
+The above is the description of a Git merge at the lowest level,
+to help you understand what conceptually happens under the hood.
+In practice, nobody, not even Git itself, runs `git cat-file` three times
+for this.  There is a `git merge-index` program that extracts the
+stages to temporary files and calls a "merge" script on it:
+
+-------------------------------------------------
+$ git merge-index git-merge-one-file hello.c
+-------------------------------------------------
+
+and that is what higher level `git merge -s resolve` is implemented with.
+
+[[hacking-git]]
+Hacking Git
+===========
+
+This chapter covers internal details of the Git implementation which
+probably only Git developers need to understand.
+
+[[object-details]]
+Object storage format
+---------------------
+
+All objects have a statically determined "type" which identifies the
+format of the object (i.e. how it is used, and how it can refer to other
+objects).  There are currently four different object types: "blob",
+"tree", "commit", and "tag".
+
+Regardless of object type, all objects share the following
+characteristics: they are all deflated with zlib, and have a header
+that not only specifies their type, but also provides size information
+about the data in the object.  It's worth noting that the SHA-1 hash
+that is used to name the object is the hash of the original data
+plus this header, so `sha1sum` 'file' does not match the object name
+for 'file'.
+
+As a result, the general consistency of an object can always be tested
+independently of the contents or the type of the object: all objects can
+be validated by verifying that (a) their hashes match the content of the
+file and (b) the object successfully inflates to a stream of bytes that
+forms a sequence of
+`<ascii type without space> + <space> + <ascii decimal size> +
+<byte\0> + <binary object data>`.
+
+The structured objects can further have their structure and
+connectivity to other objects verified. This is generally done with
+the `git fsck` program, which generates a full dependency graph
+of all objects, and verifies their internal consistency (in addition
+to just verifying their superficial consistency through the hash).
+
+[[birdview-on-the-source-code]]
+A birds-eye view of Git's source code
+-------------------------------------
+
+It is not always easy for new developers to find their way through Git's
+source code.  This section gives you a little guidance to show where to
+start.
+
+A good place to start is with the contents of the initial commit, with:
+
+----------------------------------------------------
+$ git switch --detach e83c5163
+----------------------------------------------------
+
+The initial revision lays the foundation for almost everything Git has
+today, but is small enough to read in one sitting.
+
+Note that terminology has changed since that revision.  For example, the
+README in that revision uses the word "changeset" to describe what we
+now call a <<def_commit_object,commit>>.
+
+Also, we do not call it "cache" any more, but rather "index"; however, the
+file is still called `cache.h`.  Remark: Not much reason to change it now,
+especially since there is no good single name for it anyway, because it is
+basically _the_ header file which is included by _all_ of Git's C sources.
+
+If you grasp the ideas in that initial commit, you should check out a
+more recent version and skim `cache.h`, `object.h` and `commit.h`.
+
+In the early days, Git (in the tradition of UNIX) was a bunch of programs
+which were extremely simple, and which you used in scripts, piping the
+output of one into another. This turned out to be good for initial
+development, since it was easier to test new things.  However, recently
+many of these parts have become builtins, and some of the core has been
+"libified", i.e. put into libgit.a for performance, portability reasons,
+and to avoid code duplication.
+
+By now, you know what the index is (and find the corresponding data
+structures in `cache.h`), and that there are just a couple of object types
+(blobs, trees, commits and tags) which inherit their common structure from
+`struct object`, which is their first member (and thus, you can cast e.g.
+`(struct object *)commit` to achieve the _same_ as `&commit->object`, i.e.
+get at the object name and flags).
+
+Now is a good point to take a break to let this information sink in.
+
+Next step: get familiar with the object naming.  Read <<naming-commits>>.
+There are quite a few ways to name an object (and not only revisions!).
+All of these are handled in `sha1_name.c`. Just have a quick look at
+the function `get_sha1()`. A lot of the special handling is done by
+functions like `get_sha1_basic()` or the likes.
+
+This is just to get you into the groove for the most libified part of Git:
+the revision walker.
+
+Basically, the initial version of `git log` was a shell script:
+
+----------------------------------------------------------------
+$ git-rev-list --pretty $(git-rev-parse --default HEAD "$@") | \
+	LESS=-S ${PAGER:-less}
+----------------------------------------------------------------
+
+What does this mean?
+
+`git rev-list` is the original version of the revision walker, which
+_always_ printed a list of revisions to stdout.  It is still functional,
+and needs to, since most new Git commands start out as scripts using
+`git rev-list`.
+
+`git rev-parse` is not as important any more; it was only used to filter out
+options that were relevant for the different plumbing commands that were
+called by the script.
+
+Most of what `git rev-list` did is contained in `revision.c` and
+`revision.h`.  It wraps the options in a struct named `rev_info`, which
+controls how and what revisions are walked, and more.
+
+The original job of `git rev-parse` is now taken by the function
+`setup_revisions()`, which parses the revisions and the common command-line
+options for the revision walker. This information is stored in the struct
+`rev_info` for later consumption. You can do your own command-line option
+parsing after calling `setup_revisions()`. After that, you have to call
+`prepare_revision_walk()` for initialization, and then you can get the
+commits one by one with the function `get_revision()`.
+
+If you are interested in more details of the revision walking process,
+just have a look at the first implementation of `cmd_log()`; call
+`git show v1.3.0~155^2~4` and scroll down to that function (note that you
+no longer need to call `setup_pager()` directly).
+
+Nowadays, `git log` is a builtin, which means that it is _contained_ in the
+command `git`.  The source side of a builtin is
+
+- a function called `cmd_<bla>`, typically defined in `builtin/<bla.c>`
+  (note that older versions of Git used to have it in `builtin-<bla>.c`
+  instead), and declared in `builtin.h`.
+
+- an entry in the `commands[]` array in `git.c`, and
+
+- an entry in `BUILTIN_OBJECTS` in the `Makefile`.
+
+Sometimes, more than one builtin is contained in one source file.  For
+example, `cmd_whatchanged()` and `cmd_log()` both reside in `builtin/log.c`,
+since they share quite a bit of code.  In that case, the commands which are
+_not_ named like the `.c` file in which they live have to be listed in
+`BUILT_INS` in the `Makefile`.
+
+`git log` looks more complicated in C than it does in the original script,
+but that allows for a much greater flexibility and performance.
+
+Here again it is a good point to take a pause.
+
+Lesson three is: study the code.  Really, it is the best way to learn about
+the organization of Git (after you know the basic concepts).
+
+So, think about something which you are interested in, say, "how can I
+access a blob just knowing the object name of it?".  The first step is to
+find a Git command with which you can do it.  In this example, it is either
+`git show` or `git cat-file`.
+
+For the sake of clarity, let's stay with `git cat-file`, because it
+
+- is plumbing, and
+
+- was around even in the initial commit (it literally went only through
+  some 20 revisions as `cat-file.c`, was renamed to `builtin/cat-file.c`
+  when made a builtin, and then saw less than 10 versions).
+
+So, look into `builtin/cat-file.c`, search for `cmd_cat_file()` and look what
+it does.
+
+------------------------------------------------------------------
+        git_config(git_default_config);
+        if (argc != 3)
+		usage("git cat-file [-t|-s|-e|-p|<type>] <sha1>");
+        if (get_sha1(argv[2], sha1))
+                die("Not a valid object name %s", argv[2]);
+------------------------------------------------------------------
+
+Let's skip over the obvious details; the only really interesting part
+here is the call to `get_sha1()`.  It tries to interpret `argv[2]` as an
+object name, and if it refers to an object which is present in the current
+repository, it writes the resulting SHA-1 into the variable `sha1`.
+
+Two things are interesting here:
+
+- `get_sha1()` returns 0 on _success_.  This might surprise some new
+  Git hackers, but there is a long tradition in UNIX to return different
+  negative numbers in case of different errors--and 0 on success.
+
+- the variable `sha1` in the function signature of `get_sha1()` is `unsigned
+  char *`, but is actually expected to be a pointer to `unsigned
+  char[20]`.  This variable will contain the 160-bit SHA-1 of the given
+  commit.  Note that whenever a SHA-1 is passed as `unsigned char *`, it
+  is the binary representation, as opposed to the ASCII representation in
+  hex characters, which is passed as `char *`.
+
+You will see both of these things throughout the code.
+
+Now, for the meat:
+
+-----------------------------------------------------------------------------
+        case 0:
+                buf = read_object_with_reference(sha1, argv[1], &size, NULL);
+-----------------------------------------------------------------------------
+
+This is how you read a blob (actually, not only a blob, but any type of
+object).  To know how the function `read_object_with_reference()` actually
+works, find the source code for it (something like `git grep
+read_object_with | grep ":[a-z]"` in the Git repository), and read
+the source.
+
+To find out how the result can be used, just read on in `cmd_cat_file()`:
+
+-----------------------------------
+        write_or_die(1, buf, size);
+-----------------------------------
+
+Sometimes, you do not know where to look for a feature.  In many such cases,
+it helps to search through the output of `git log`, and then `git show` the
+corresponding commit.
+
+Example: If you know that there was some test case for `git bundle`, but
+do not remember where it was (yes, you _could_ `git grep bundle t/`, but that
+does not illustrate the point!):
+
+------------------------
+$ git log --no-merges t/
+------------------------
+
+In the pager (`less`), just search for "bundle", go a few lines back,
+and see that it is in commit 18449ab0.  Now just copy this object name,
+and paste it into the command line
+
+-------------------
+$ git show 18449ab0
+-------------------
+
+Voila.
+
+Another example: Find out what to do in order to make some script a
+builtin:
+
+-------------------------------------------------
+$ git log --no-merges --diff-filter=A builtin/*.c
+-------------------------------------------------
+
+You see, Git is actually the best tool to find out about the source of Git
+itself!
+
+[[glossary]]
+Git Glossary
+============
+
+[[git-explained]]
+Git explained
+-------------
+
+include::glossary-content.txt[]
+
+[[git-quick-start]]
+Appendix A: Git Quick Reference
+===============================
+
+This is a quick summary of the major commands; the previous chapters
+explain how these work in more detail.
+
+[[quick-creating-a-new-repository]]
+Creating a new repository
+-------------------------
+
+From a tarball:
+
+-----------------------------------------------
+$ tar xzf project.tar.gz
+$ cd project
+$ git init
+Initialized empty Git repository in .git/
+$ git add .
+$ git commit
+-----------------------------------------------
+
+From a remote repository:
+
+-----------------------------------------------
+$ git clone git://example.com/pub/project.git
+$ cd project
+-----------------------------------------------
+
+[[managing-branches]]
+Managing branches
+-----------------
+
+-----------------------------------------------
+$ git branch			# list all local branches in this repo
+$ git switch test	        # switch working directory to branch "test"
+$ git branch new		# create branch "new" starting at current HEAD
+$ git branch -d new		# delete branch "new"
+-----------------------------------------------
+
+Instead of basing a new branch on current HEAD (the default), use:
+
+-----------------------------------------------
+$ git branch new test    # branch named "test"
+$ git branch new v2.6.15 # tag named v2.6.15
+$ git branch new HEAD^   # commit before the most recent
+$ git branch new HEAD^^  # commit before that
+$ git branch new test~10 # ten commits before tip of branch "test"
+-----------------------------------------------
+
+Create and switch to a new branch at the same time:
+
+-----------------------------------------------
+$ git switch -c new v2.6.15
+-----------------------------------------------
+
+Update and examine branches from the repository you cloned from:
+
+-----------------------------------------------
+$ git fetch		# update
+$ git branch -r		# list
+  origin/master
+  origin/next
+  ...
+$ git switch -c masterwork origin/master
+-----------------------------------------------
+
+Fetch a branch from a different repository, and give it a new
+name in your repository:
+
+-----------------------------------------------
+$ git fetch git://example.com/project.git theirbranch:mybranch
+$ git fetch git://example.com/project.git v2.6.15:mybranch
+-----------------------------------------------
+
+Keep a list of repositories you work with regularly:
+
+-----------------------------------------------
+$ git remote add example git://example.com/project.git
+$ git remote			# list remote repositories
+example
+origin
+$ git remote show example	# get details
+* remote example
+  URL: git://example.com/project.git
+  Tracked remote branches
+    master
+    next
+    ...
+$ git fetch example		# update branches from example
+$ git branch -r			# list all remote branches
+-----------------------------------------------
+
+
+[[exploring-history]]
+Exploring history
+-----------------
+
+-----------------------------------------------
+$ gitk			    # visualize and browse history
+$ git log		    # list all commits
+$ git log src/		    # ...modifying src/
+$ git log v2.6.15..v2.6.16  # ...in v2.6.16, not in v2.6.15
+$ git log master..test	    # ...in branch test, not in branch master
+$ git log test..master	    # ...in branch master, but not in test
+$ git log test...master	    # ...in one branch, not in both
+$ git log -S'foo()'	    # ...where difference contain "foo()"
+$ git log --since="2 weeks ago"
+$ git log -p		    # show patches as well
+$ git show		    # most recent commit
+$ git diff v2.6.15..v2.6.16 # diff between two tagged versions
+$ git diff v2.6.15..HEAD    # diff with current head
+$ git grep "foo()"	    # search working directory for "foo()"
+$ git grep v2.6.15 "foo()"  # search old tree for "foo()"
+$ git show v2.6.15:a.txt    # look at old version of a.txt
+-----------------------------------------------
+
+Search for regressions:
+
+-----------------------------------------------
+$ git bisect start
+$ git bisect bad		# current version is bad
+$ git bisect good v2.6.13-rc2	# last known good revision
+Bisecting: 675 revisions left to test after this
+				# test here, then:
+$ git bisect good		# if this revision is good, or
+$ git bisect bad		# if this revision is bad.
+				# repeat until done.
+-----------------------------------------------
+
+[[making-changes]]
+Making changes
+--------------
+
+Make sure Git knows who to blame:
+
+------------------------------------------------
+$ cat >>~/.gitconfig <<\EOF
+[user]
+	name = Your Name Comes Here
+	email = you@yourdomain.example.com
+EOF
+------------------------------------------------
+
+Select file contents to include in the next commit, then make the
+commit:
+
+-----------------------------------------------
+$ git add a.txt    # updated file
+$ git add b.txt    # new file
+$ git rm c.txt     # old file
+$ git commit
+-----------------------------------------------
+
+Or, prepare and create the commit in one step:
+
+-----------------------------------------------
+$ git commit d.txt # use latest content only of d.txt
+$ git commit -a	   # use latest content of all tracked files
+-----------------------------------------------
+
+[[merging]]
+Merging
+-------
+
+-----------------------------------------------
+$ git merge test   # merge branch "test" into the current branch
+$ git pull git://example.com/project.git master
+		   # fetch and merge in remote branch
+$ git pull . test  # equivalent to git merge test
+-----------------------------------------------
+
+[[sharing-your-changes]]
+Sharing your changes
+--------------------
+
+Importing or exporting patches:
+
+-----------------------------------------------
+$ git format-patch origin..HEAD # format a patch for each commit
+				# in HEAD but not in origin
+$ git am mbox # import patches from the mailbox "mbox"
+-----------------------------------------------
+
+Fetch a branch in a different Git repository, then merge into the
+current branch:
+
+-----------------------------------------------
+$ git pull git://example.com/project.git theirbranch
+-----------------------------------------------
+
+Store the fetched branch into a local branch before merging into the
+current branch:
+
+-----------------------------------------------
+$ git pull git://example.com/project.git theirbranch:mybranch
+-----------------------------------------------
+
+After creating commits on a local branch, update the remote
+branch with your commits:
+
+-----------------------------------------------
+$ git push ssh://example.com/project.git mybranch:theirbranch
+-----------------------------------------------
+
+When remote and local branch are both named "test":
+
+-----------------------------------------------
+$ git push ssh://example.com/project.git test
+-----------------------------------------------
+
+Shortcut version for a frequently used remote repository:
+
+-----------------------------------------------
+$ git remote add example ssh://example.com/project.git
+$ git push example test
+-----------------------------------------------
+
+[[repository-maintenance]]
+Repository maintenance
+----------------------
+
+Check for corruption:
+
+-----------------------------------------------
+$ git fsck
+-----------------------------------------------
+
+Recompress, remove unused cruft:
+
+-----------------------------------------------
+$ git gc
+-----------------------------------------------
+
+
+[[todo]]
+Appendix B: Notes and todo list for this manual
+===============================================
+
+[[todo-list]]
+Todo list
+---------
+
+This is a work in progress.
+
+The basic requirements:
+
+- It must be readable in order, from beginning to end, by someone
+  intelligent with a basic grasp of the UNIX command line, but without
+  any special knowledge of Git.  If necessary, any other prerequisites
+  should be specifically mentioned as they arise.
+- Whenever possible, section headings should clearly describe the task
+  they explain how to do, in language that requires no more knowledge
+  than necessary: for example, "importing patches into a project" rather
+  than "the `git am` command"
+
+Think about how to create a clear chapter dependency graph that will
+allow people to get to important topics without necessarily reading
+everything in between.
+
+Scan `Documentation/` for other stuff left out; in particular:
+
+- howto's
+- some of `technical/`?
+- hooks
+- list of commands in linkgit:git[1]
+
+Scan email archives for other stuff left out
+
+Scan man pages to see if any assume more background than this manual
+provides.
+
+Add more good examples.  Entire sections of just cookbook examples
+might be a good idea; maybe make an "advanced examples" section a
+standard end-of-chapter section?
+
+Include cross-references to the glossary, where appropriate.
+
+Add a section on working with other version control systems, including
+CVS, Subversion, and just imports of series of release tarballs.
+
+Write a chapter on using plumbing and writing scripts.
+
+Alternates, clone -reference, etc.
+
+More on recovery from repository corruption.  See:
+	http://marc.info/?l=git&m=117263864820799&w=2
+	http://marc.info/?l=git&m=117147855503798&w=2