Re: [PATCH v2] diff: Fix modified lines stats with --stat and --numstat

[Taylor Blau <me@ttaylorr.com>]

On Sun, Sep 20, 2020 at 09:09:46AM -0400, Thomas Guyot-Sionnest wrote:
> In builtin_diffstat(), when both files are coming from "stdin" (which
> could be better described as the file's content being written directly
> into the file object), oideq() compares two null hashes and ignores the
> actual differences for the statistics.
>
> This patch checks if is_stdin flag is set on both sides and compare
> contents directly.
>
> Signed-off-by: Thomas Guyot-Sionnest <tguyot@gmail.com>
> ---
> Range-diff:
> 1:  479c2835fc ! 1:  1f25713d44 diff: Fix modified lines stats with --stat and --numstat
>     @@ -20,8 +20,12 @@
>       	}
>
>      -	same_contents = oideq(&one->oid, &two->oid);
>     ++	/* What is_stdin really means is that the file's content is only
>     ++	 * in the filespec's buffer and its oid is zero. We can't compare
>     ++	 * oid's if both are null and we can just diff the buffers */
>      +	if (one->is_stdin && two->is_stdin)
>     -+		same_contents = !strcmp(one->data, two->data);
>     ++		same_contents = (one->size == two->size ?
>     ++			!memcmp(one->data, two->data, one->size) : 0);
>      +	else
>      +		same_contents = oideq(&one->oid, &two->oid);

After reading your explanation in [1], this version makes more sense to
me.

Thanks.

[1]: https://lore.kernel.org/git/f4c4cb48-f4b5-3d4d-066d-b94e961dcbb5@gmail.com/

Taylor