Re: [PATCH 14/26] setup_bare_git_dir(): fix memory leak

[Stefan Beller <sbeller@xxxxxxxxxx>]

On Wed, Apr 26, 2017 at 1:20 PM, Johannes Schindelin
<johannes.schindelin@xxxxxx> wrote:
> Reported by Coverity.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
> ---
>  setup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/setup.c b/setup.c
> index 0309c278218..0320a9ad14c 100644
> --- a/setup.c
> +++ b/setup.c
> @@ -748,7 +748,7 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
>
>         /* --work-tree is set without --git-dir; use discovered one */
>         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
> -               const char *gitdir;
> +               static const char *gitdir;

This alone doesn't fix the memleak if the code were called multiple times.
As by having it static it will be init'd to NULL, we could introduce a

    static const char *gitdir; /* must live until the end of time because ... */
    if (!gitdir)
        die("BUG: called setup_bare_git_dir twice?");

I tried looking into setup_explicit_git_dir that is called with gitdir here
and it looks like it duplicates the memory in most cases, so maybe we
can even get away with no static variable here and instead either inline
the gitdir computation in the arguments of setup_explicit_git_dir
or have a variable here that holds the returns of setup_explicit_git_dir
such that we can free after?

Thanks,
Stefan