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@xxxxxxxxx>
Signed-off-by: Kirill Smelkov <kirr@xxxxxxxxxx>
---
environment.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/environment.c b/environment.c
index eaf908b..d5021e8 100644
--- a/environment.c
+++ b/environment.c
@@ -88,6 +88,7 @@ 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;
--
1.7.3.2.161.g3089c
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html