Subject: Re: [PATCH] Do not trust PWD blindly

From: Johannes Sixt <[email-masked]>
Date: Sun, 10 Jul 2011 22:47:08 +0200

Am 09.07.2011 19:38, schrieb Johannes Schindelin:
> 
> At least on Windows, chdir() does not update PWD.

Very strange wording. chdir() should not update PWD even on POSIX.

> Unfortunately, stat()
> does not fill any ino or dev fields anymore, so get_pwd_cwd() is not
> able to tell.
> 
> But there is a telltale: both ino and dev are 0 when they are not filled
> correctly, so let's be extra cautious.
> 
> This happens to fix a bug in "get-receive-pack working_directory/" when
> the GIT_DIR would not be set correctly due to absolute_path(".")
> returning the wrong value.
> 
> Signed-off-by: Johannes Schindelin <[email-masked]>
> ---
> 
> 	On Fri, 8 Jul 2011, Pat Thoyts wrote:
> 
> 	> ! t5516-fetch-push      (60 receive.denyCurrentBranch = updateInstead)
> 
> 	This patch fixes that.
> 
> 	Hannes, I have no idea whether you meant 10c4c881 to fix anything 
> 	on Windows.

I think this fix worked for me because when git is called from CMD, PWD
is not in the enviornment and the if (pwd && ...) branch is never taken.

> 
>  abspath.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/abspath.c b/abspath.c
> index 01858eb..37287f8 100644
> --- a/abspath.c
> +++ b/abspath.c
> @@ -102,7 +102,8 @@ static const char *get_pwd_cwd(void)
>  	pwd = getenv("PWD");
>  	if (pwd && strcmp(pwd, cwd)) {
>  		stat(cwd, &cwd_stat);
> -		if (!stat(pwd, &pwd_stat) &&
> +		if ((cwd_stat.st_dev || cwd_stat.st_ino) &&
> +		    !stat(pwd, &pwd_stat) &&
>  		    pwd_stat.st_dev == cwd_stat.st_dev &&
>  		    pwd_stat.st_ino == cwd_stat.st_ino) {
>  			strlcpy(cwd, pwd, PATH_MAX);

Acked-by: Johannes Sixt <[email-masked]>

-- Hannes