Subject: Re: [PATCH] bundle-uri: plug leak in unbundle_from_file()

From: Patrick Steinhardt <[email-masked]>
Date: Mon, 26 Aug 2024 11:51:00 +0200

On Mon, Aug 26, 2024 at 10:30:52AM +0200, Toon Claes wrote:
> When the function returns early, the variable bundle_ref is not released
> through strbuf_release().
> 
> Fix this leak. And while at it, remove assignments in the conditions of
> the "if" statements as suggested in the CodingGuidelines.
> 
> Signed-off-by: Toon Claes <[email-masked]>
> ---
>  bundle-uri.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/bundle-uri.c b/bundle-uri.c
> index 1e0ee156ba..eb49cba182 100644
> --- a/bundle-uri.c
> +++ b/bundle-uri.c
> @@ -367,17 +367,21 @@ static int unbundle_from_file(struct repository *r, const char *file)
>  	struct strbuf bundle_ref = STRBUF_INIT;
>  	size_t bundle_prefix_len;
> 
> -	if ((bundle_fd = read_bundle_header(file, &header)) < 0)
> -		return 1;
> +	bundle_fd = read_bundle_header(file, &header);
> +	if (bundle_fd < 0) {
> +		result = 1;
> +		goto cleanup;
> +	}
> 
>  	/*
>  	 * Skip the reachability walk here, since we will be adding
>  	 * a reachable ref pointing to the new tips, which will reach
>  	 * the prerequisite commits.
>  	 */
> -	if ((result = unbundle(r, &header, bundle_fd, NULL,
> -			       VERIFY_BUNDLE_QUIET | (fetch_pack_fsck_objects() ? VERIFY_BUNDLE_FSCK : 0))))
> -		return 1;
> +	result = unbundle(r, &header, bundle_fd, NULL,
> +			  VERIFY_BUNDLE_QUIET | (fetch_pack_fsck_objects() ? VERIFY_BUNDLE_FSCK : 0));
> +	if (result)
> +		goto cleanup;

This changes the returned error code from `1` to whatever `unbundle()`
returns. Is this intentional? If so, the commit message should explain
why this change is safe.

Other than that this looks good to me, and the fix does not conflict
with any of my leak-plugging series.

Thanks!

Patrick