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| author |  Kirill Smelkov <kirr@mns.spb.ru> | 2010-11-11 21:08:23 +0300 |
|---|---|---|
| committer |  Junio C Hamano <gitster@pobox.com> | 2010-11-12 16:03:27 -0800 |
| commit | 15431ca651050ba315fa4e2e74527f6d115e706c (patch) | |
| tree | 0bb3612efc438456a7a744125bcee2f16704c001 | |
| parent | Documentation: document show -s (diff) | |
| download | tgif-15431ca651050ba315fa4e2e74527f6d115e706c.tar.xz | |
setup: make sure git_dir path is in a permanent buffer, getenv(3) case
getenv(3) returns not-permanent buffer which may be changed by e.g.
putenv(3) call (*).
In practice I've noticed this when trying to do `git commit -m abc`
inside msysgit under wine, getting
$ git commit -m abc
fatal: could not open 'DIR=.git/COMMIT_EDITMSG': No such file or directory
^^^^
(notice introduced 'DIR=' artifact.)
The problem was showing itself only with -m option, and actually, as
debugging showed, originally
git_dir = getenv("GIT_DIR")
returned pointer to
"GIT_DIR=.git\0"
^
git_dir
, we stored it in git_dir, than, after processing -m git-commit option,
we did setenv("GIT_EDITOR", ":") which as (*) says changed environment
variables memory layout - something like this
"...\0GIT_DIR=.git\0"
^
git_dir
and oops - we got wrong git_dir.
Avoid that by strdupping getenv("GIT_DIR") result like we did in 06f354
(setup: make sure git dir path is in a permanent buffer). Unfortunately
this also shows that other getenv usage inside git needs auditing...
(*) from man 3 getenv:
The implementation of getenv() is not required to be reentrant. The
string pointed to by the return value of getenv() may be statically
allocated, and can be modified by a subsequent call to getenv(),
putenv(3), setenv(3), or unsetenv(3).
Cc: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | environment.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/environment.c b/environment.c index de5581fe51..18aded6dc4 100644 --- a/environment.c +++ b/environment.c @@ -87,6 +87,7 @@ const char * const local_repo_env[LOCAL_REPO_ENV_SIZE + 1] = { static void setup_git_env(void) { git_dir = getenv(GIT_DIR_ENVIRONMENT); + git_dir = git_dir ? xstrdup(git_dir) : NULL; if (!git_dir) { git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT); git_dir = git_dir ? xstrdup(git_dir) : NULL; |