Re: [PATCH] bisect: use "$GIT_DIR/BISECT_START" to check if we are bisecting

[Junio C Hamano <gitster@pobox.com>]

Christian Couder <chriscool@tuxfamily.org> writes:

> It seems simpler and safer to use the BISECT_START file everywhere
> to decide if we are bisecting or not, instead of using it in some
> places and BISECT_NAMES in other places.
>
> In commit 6459c7c6786aa9bda0c7a095c9db66c36da0e5f0 (Nov 18 2007,
> Bisect: use "$GIT_DIR/BISECT_NAMES" to check if we are bisecting.),
> we decided to use BISECT_NAMES but code changed a lot and we now
> have to check BISECT_START first in the "bisect_start" function
> anyway.
>
> This patch also makes things a little bit safer by creating
> the BISECT_START file first and deleting it last, and also by
> adding checks in "bisect_clean_state".
>
> Signed-off-by: Christian Couder <chriscool@tuxfamily.org>

What's the breakage scenario that this patch fixes?

> diff --git a/git-bisect.sh b/git-bisect.sh
> index 4bcbace..991b2ef 100755
> --- a/git-bisect.sh
> +++ b/git-bisect.sh
> @@ -44,7 +44,7 @@ sq() {
>  }
>  
>  bisect_autostart() {
> -	test -f "$GIT_DIR/BISECT_NAMES" || {
> +	test -s "$GIT_DIR/BISECT_START" || {

The reason you ignore an existing but empty BISECT_START file is...?