Re: [PATCH] Make setup_git_env() resolve .git file when $GIT_DIR is not specified

> This makes reinitializing on a .git file repository work.
>
> This is probably the only case that setup_git_env() (via
> set_git_dir()) is called on a .git file. Other cases in
> setup_git_dir_gently() and enter_repo() both cover .git file case
> explicitly because they need to verify the target repo is valid.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> Reported-by: Ximin Luo <infinity0@gmx.com>
> ---
>  Slight change in the patch to xstrdup(gitfile) because read_gitfile
>  returns a static buffer.

>
>  environment.c   | 9 ++++-----
>  t/t0001-init.sh | 4 ++++
>  2 files changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/environment.c b/environment.c
> index 5398c36..378254c 100644
> --- a/environment.c
> +++ b/environment.c
> @@ -123,14 +123,13 @@ static char *expand_namespace(const char *raw_namespace)
>  
>  static void setup_git_env(void)
>  {
> +	const char *gitfile;
> +
>  	git_dir = getenv(GIT_DIR_ENVIRONMENT);
> -	git_dir = git_dir ? xstrdup(git_dir) : NULL;
> -	if (!git_dir) {
> -		git_dir = read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
> -		git_dir = git_dir ? xstrdup(git_dir) : NULL;
> -	}
>  	if (!git_dir)
>  		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
> +	gitfile = read_gitfile(git_dir);
> +	git_dir = xstrdup(gitfile ? gitfile : git_dir);
>  	git_object_dir = getenv(DB_ENVIRONMENT);
>  	if (!git_object_dir) {
>  		git_object_dir = xmalloc(strlen(git_dir) + 9);
> diff --git a/t/t0001-init.sh b/t/t0001-init.sh
> index ad66410..9fb582b 100755
> --- a/t/t0001-init.sh
> +++ b/t/t0001-init.sh
> @@ -379,6 +379,10 @@ test_expect_success 'init with separate gitdir' '
>  	test -d realgitdir/refs
>  '
>  
> +test_expect_success 're-init on .git file' '
> +	( cd newdir && git init )
> +'
> +
>  test_expect_success 're-init to update git link' '
>  	(
>  	cd newdir &&