git/compat/precompose_utf8.c, branch v2.31.2

MacOS: precompose_argv_prefix()

2021-02-03T22:09:37Z

The following sequence leads to a "BUG" assertion running under MacOS: DIR=git-test-restore-p Adiarnfd=$(printf 'A\314\210') DIRNAME=xx${Adiarnfd}yy mkdir $DIR && cd $DIR && git init && mkdir $DIRNAME && cd $DIRNAME && echo "Initial" >file && git add file && echo "One more line" >>file && echo y | git restore -p . Initialized empty Git repository in /tmp/git-test-restore-p/.git/ BUG: pathspec.c:495: error initializing pathspec_item Cannot close git diff-index --cached --numstat [snip] The command `git restore` is run from a directory inside a Git repo. Git needs to split the $CWD into 2 parts: The path to the repo and "the rest", if any. "The rest" becomes a "prefix" later used inside the pathspec code. As an example, "/path/to/repo/dir-inside-repå" would determine "/path/to/repo" as the root of the repo, the place where the configuration file .git/config is found. The rest becomes the prefix ("dir-inside-repå"), from where the pathspec machinery expands the ".", more about this later. If there is a decomposed form, (making the decomposing visible like this), "dir-inside-rep°a" doesn't match "dir-inside-repå". Git commands need to: (a) read the configuration variable "core.precomposeunicode" (b) precocompose argv[] (c) precompose the prefix, if there was any The first commit, 76759c7dff53 "git on Mac OS and precomposed unicode" addressed (a) and (b). The call to precompose_argv() was added into parse-options.c, because that seemed to be a good place when the patch was written. Commands that don't use parse-options need to do (a) and (b) themselfs. The commands `diff-files`, `diff-index`, `diff-tree` and `diff` learned (a) and (b) in commit 90a78b83e0b8 "diff: run arguments through precompose_argv" Branch names (or refs in general) using decomposed code points resulting in decomposed file names had been fixed in commit 8e712ef6fc97 "Honor core.precomposeUnicode in more places" The bug report from above shows 2 things: - more commands need to handle precomposed unicode - (c) should be implemented for all commands using pathspecs Solution: precompose_argv() now handles the prefix (if needed), and is renamed into precompose_argv_prefix(). Inside this function the config variable core.precomposeunicode is read into the global variable precomposed_unicode, as before. This reading is skipped if precomposed_unicode had been read before. The original patch for preocomposed unicode, 76759c7dff53, placed precompose_argv() into parse-options.c Now add it into git.c::run_builtin() as well. Existing precompose calls in diff-files.c and others may become redundant, and if we audit the callflows that reach these places to make sure that they can never be reached without going through the new call added to run_builtin(), we might be able to remove these existing ones. But in this commit, we do not bother to do so and leave these precompose callsites as they are. Because precompose() is idempotent and can be called on an already precomposed string safely, this is safer than removing existing calls without fully vetting the callflows. There is certainly room for cleanups - this change intends to be a bug fix. Cleanups needs more tests in e.g. t/t3910-mac-os-precompose.sh, and should be done in future commits. [1] git-bugreport-2021-01-06-1209.txt (git can't deal with special characters) [2] https://lore.kernel.org/git/A102844A-9501-4A86-854D-E3B387D378AA@icloud.com/ Reported-by: Daniel Troger Helped-By: Philippe Blain Signed-off-by: Torsten Bögershausen Signed-off-by: Junio C Hamano

Support working-tree-encoding "UTF-16LE-BOM"

2019-01-31T18:27:52Z

Users who want UTF-16 files in the working tree set the .gitattributes like this: test.txt working-tree-encoding=UTF-16 The unicode standard itself defines 3 allowed ways how to encode UTF-16. The following 3 versions convert all back to 'g' 'i' 't' in UTF-8: a) UTF-16, without BOM, big endian: $ printf "\000g\000i\000t" | iconv -f UTF-16 -t UTF-8 | od -c 0000000 g i t b) UTF-16, with BOM, little endian: $ printf "\377\376g\000i\000t\000" | iconv -f UTF-16 -t UTF-8 | od -c 0000000 g i t c) UTF-16, with BOM, big endian: $ printf "\376\377\000g\000i\000t" | iconv -f UTF-16 -t UTF-8 | od -c 0000000 g i t Git uses libiconv to convert from UTF-8 in the index into ITF-16 in the working tree. After a checkout, the resulting file has a BOM and is encoded in "UTF-16", in the version (c) above. This is what iconv generates, more details follow below. iconv (and libiconv) can generate UTF-16, UTF-16LE or UTF-16BE: d) UTF-16 $ printf 'git' | iconv -f UTF-8 -t UTF-16 | od -c 0000000 376 377 \0 g \0 i \0 t e) UTF-16LE $ printf 'git' | iconv -f UTF-8 -t UTF-16LE | od -c 0000000 g \0 i \0 t \0 f) UTF-16BE $ printf 'git' | iconv -f UTF-8 -t UTF-16BE | od -c 0000000 \0 g \0 i \0 t There is no way to generate version (b) from above in a Git working tree, but that is what some applications need. (All fully unicode aware applications should be able to read all 3 variants, but in practise we are not there yet). When producing UTF-16 as an output, iconv generates the big endian version with a BOM. (big endian is probably chosen for historical reasons). iconv can produce UTF-16 files with little endianess by using "UTF-16LE" as encoding, and that file does not have a BOM. Not all users (especially under Windows) are happy with this. Some tools are not fully unicode aware and can only handle version (b). Today there is no way to produce version (b) with iconv (or libiconv). Looking into the history of iconv, it seems as if version (c) will be used in all future iconv versions (for compatibility reasons). Solve this dilemma and introduce a Git-specific "UTF-16LE-BOM". libiconv can not handle the encoding, so Git pick it up, handles the BOM and uses libiconv to convert the rest of the stream. (UTF-16BE-BOM is added for consistency) Rported-by: Adrián Gimeno Balaguer Signed-off-by: Torsten Bögershausen Signed-off-by: Junio C Hamano

config: don't include config.h by default

2017-06-15T19:56:22Z

Stop including config.h by default in cache.h. Instead only include config.h in those files which require use of the config system. Signed-off-by: Brandon Williams Signed-off-by: Junio C Hamano

typofix: assorted typofixes in comments, documentation and messages

2016-05-06T20:16:37Z

Many instances of duplicate words (e.g. "the the path") and a few typoes are fixed, originally in multiple patches. wildmatch: fix duplicate words of "the" t: fix duplicate words of "output" transport-helper: fix duplicate words of "read" Git.pm: fix duplicate words of "return" path: fix duplicate words of "look" pack-protocol.txt: fix duplicate words of "the" precompose-utf8: fix typo of "sequences" split-index: fix typo worktree.c: fix typo remote-ext: fix typo utf8: fix duplicate words of "the" git-cvsserver: fix duplicate words Signed-off-by: Li Peng Signed-off-by: Junio C Hamano

config: rename git_config_set_or_die to git_config_set

2016-02-22T18:23:55Z

Rename git_config_set_or_die functions to git_config_set, leading to the new default behavior of dying whenever a configuration error occurs. By now all callers that shall die on error have been transitioned to the _or_die variants, thus making this patch a simple rename of the functions. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

compat: die when unable to set core.precomposeunicode

2016-02-22T18:23:54Z

When calling `git_config_set` to set 'core.precomposeunicode' we ignore the return value of the function, which may indicate that we were unable to write the value back to disk. As the function is only called by init-db we can and should die when an error occurs. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano

probe_utf8_pathname_composition: use internal strbuf

2015-10-05T18:06:49Z

When we are initializing a .git directory, we may call probe_utf8_pathname_composition to detect utf8 mangling. We pass in a path buffer for it to use, and it blindly strcpy()s into it, not knowing whether the buffer is large enough to hold the result or not. In practice this isn't a big deal, because the buffer we pass in already contains "$GIT_DIR/config", and we append only a few extra bytes to it. But we can easily do the right thing just by calling git_path_buf ourselves. Technically this results in a different pathname (before we appended our utf8 characters to the "config" path, and now they get their own files in $GIT_DIR), but that should not matter for our purposes. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

precompose_utf8: drop unused variable

2015-10-05T18:05:51Z

The result of iconv is assigned to a variable, but we never use it (instead, we check errno and whether the function consumed all bytes). Let's drop the assignment, as it triggers gcc's -Wunused-but-set-variable. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Set core.precomposeunicode to true on e.g. HFS+

2013-08-27T14:41:32Z

When core.precomposeunicode was introduced in 76759c7d, it was set to false on a unicode decomposing file system like HFS+ to be compatible with older versions of Git. The Mac OS users need to find out that this configuration exist and change it manually from false to true. A smoother workflow can be achieved, so set core.precomposeunicode to true on a decomposing file system. Signed-off-by: Torsten Bögershausen Signed-off-by: Junio C Hamano

utf8.c: add reencode_string_len() that can handle NULs in string

2013-04-18T23:28:28Z

Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano