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

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

1 files changed, 514 insertions, 0 deletions

diff --git a/third_party/git/Documentation/RelNotes/2.4.0.txt b/third_party/git/Documentation/RelNotes/2.4.0.txt
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+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).