Re: [PATCH] git-describe: Die early if there are no possible descriptions

> If we found no refs that may be used for git-describe with the current
> options, then die early instead of pointlessly walking the whole history.
> 
> Signed-off-by: Bj?rn Steinbrink <B.Steinbrink@gmx.de>
> ---
> In git.git with all the tags dropped, this makes "git describe" go down
> from 0.244 to 0.003 seconds for me. This is especially noticeable with
> "git submodule" which calls describe with increasing levels of allowed
> refs to be matched. Without tags, this means that it walks the whole
> history in the submodule twice (first annotated, then plain tags), just
> to find out that it can't describe the thing anyway.
> 
> I'm not particularly sure about found_names actually counting the found
> names, it was just out of the thought that maybe the walking code could
> make use of it, but I didn't actually check that and ran out of time, so
> I'm sending this version, hoping that it doesn't suck too much.

> @@ -39,6 +40,8 @@ static void add_to_known_names(const char *path,
>  			       const unsigned char *sha1)
>  {
>  	struct commit_name *e = commit->util;
> +	if (!e)
> +		found_names++;
>  	if (!e || e->prio < prio) {
>  		size_t len = strlen(path)+1;
>  		free(e);