Subject: Re: [PATCH] index-pack: do not segfault when keep_name is NULL

From: Junio C Hamano <[email-masked]>
Date: Mon, 17 Mar 2014 15:07:01 -0700

Nguyễn Thái Ngọc Duy  <[email-masked]> writes:

> keep_name is used to print error messages a couple lines down. Reset
> it to the real path returned by odb_pack_keep() if it's set to NULL by
> caller.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
> ---
>  One of these moments I will make git log and friends optionally recognize
>  "Diff-Options:" line in commit message. Adding -U14 in this case
>  should help the reviewer to see how those error messages are printed.
>
>  builtin/index-pack.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/index-pack.c b/builtin/index-pack.c
> index a6b1c17..d95c3dc 100644
> --- a/builtin/index-pack.c
> +++ b/builtin/index-pack.c
> @@ -1283,9 +1283,10 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
>  	if (keep_msg) {
>  		int keep_fd, keep_msg_len = strlen(keep_msg);
>  
> -		if (!keep_name)
> +		if (!keep_name) {
>  			keep_fd = odb_pack_keep(name, sizeof(name), sha1);
> -		else
> +			keep_name = name;
> +		} else
>  			keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);

I think this fixes the right problem in a wrong way that hurts
longer-term maintainability.  Why not do

	keep_name ? keep_name : name

at the place where the name is used?  Otherwise you will have to
worry about affecting later codepaths that may want to try to use
!keep_name to switch between two codepaths, no?

>  		if (keep_fd < 0) {