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

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

1 files changed, 185 insertions, 0 deletions

diff --git a/third_party/git/Documentation/diff-format.txt b/third_party/git/Documentation/diff-format.txt
new file mode 100644
index 000000000000..4d846d73463c
--- /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.