On Sat, Jan 5, 2013 at 1:35 AM, David Michael <fedora.dm0@xxxxxxxxx> wrote:
> It is possible for this pointer of the GIT_DIR environment variable to
> survive unduplicated until further getenv calls are made. The standards
> allow for subsequent calls of getenv to overwrite the string located at
> its returned pointer, and this can result in broken git operations on
> certain platforms.
>
> Signed-off-by: David Michael <fedora.dm0@xxxxxxxxx>
> ---
>
> I have encountered an issue with consecutive calls to getenv
> overwriting earlier values. Most notably, it prevents a plain "git
> clone" from working.
>
> Long story short: This value of GIT_DIR gets passed around setup.c
> until it reaches check_repository_format_gently. This function calls
> git_config_early, which eventually runs getenv("HOME"). When it
> returns back to check_repository_format_gently, the gitdir variable
> contains my home directory path. The end result is that I wind up
> with ~/objects/ etc. and a failed repository clone. (Simply adding a
> bare getenv("GIT_DIR") afterwards to reset the pointer also corrects
> the problem.)
>
> Since other platforms are apparently working, yet this getenv behavior
> is supported by the standards, I am left wondering if this could be a
> symptom of something else being broken on my platform (z/OS). Can
> anyone more familiar with this part of git identify any condition that
> obviously should not be occurring?
>
> Thanks.
I have some patches of a similar nature here:
https://github.com/kusma/git/commits/work/getenv-safety
These were written for an earlier version of the UTF-8 patches for Git
for Windows, where we were looking into allowing getenv to use a
static buffer to convert the environment variables from UTF-16 (which
is what Windows maintains) to UTF-8. We ended converting the
environment on start-up instead, so these weren't needed for us. But
perhaps they can be of use to someone else?
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