Re: [PATCH 3/3] revision: avoid leak when preparing bloom filter for "/"

[Derrick Stolee <stolee@gmail.com>]

On 8/4/2020 3:50 AM, Jeff King wrote:
> If we're given an empty pathspec, we refuse to set up bloom filters, as
> described in f3c2a36810 (revision: empty pathspecs should not use Bloom
> filters, 2020-07-01).
> 
> But before the empty string check, we drop any trailing slash by
> allocating a new string without it. So a pathspec consisting only of "/"
> will allocate that string, but then still cause us to bail, leaking the
> new string. Let's make sure to free it.
> 
> Signed-off-by: Jeff King <peff@peff.net>
> ---
> Just noticed while reading the function to fix the previous patch.
> 
> I'm not even sure if it's possible to get here with a pathspec of "/",
> since we'd probably give a "/ is outside repository" error before then.
> 
> So maybe this case doesn't even matter. If it doesn't, then it might
> simplify the function a bit to do the empty-pathspec check before
> handling trailing slashes. But handling it does help make it more clear
> this function is doing the right thing no matter what input it is given,
> so that's what I went with here.

Works for me. Thanks for your careful attention here.

-Stolee

>  revision.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/revision.c b/revision.c
> index 5ed86e4524..b80868556b 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -702,6 +702,7 @@ static void prepare_to_use_bloom_filter(struct rev_info *revs)
>  	len = strlen(path);
>  	if (!len) {
>  		revs->bloom_filter_settings = NULL;
> +		free(path_alloc);
>  		return;
>  	}
>  
>