Re: [PATCH] hash binary sha1 into patch id

From

Jonathan Nieder <jrnieder@gmail.com>

Date

Aug 13, 2010, 20:00 UTC

Message-ID

<20100813200031.GD2003@burratino>

In-Reply-To

<20100813094027.GA20906@localhost>

Clemens Buchacher wrote:

> Since commit 2f82f760 (Take binary diffs into account for "git rebase"), binary
> files are included in patch ID computation. Binary files are diffed using the
> text diff algorithm, however

[...]

> Instead of hashing the diff of binary files, use the post-image sha1, which is
> just as unique. As a result, performance is much improved.

Maybe it should use both the pre- and post-image?

> diff --git a/diff.c b/diff.c
> index 17873f3..20fc6db 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -3758,6 +3758,12 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
>  					len2, p->two->path);
>  		git_SHA1_Update(&ctx, buffer, len1);
>  
> +		if (diff_filespec_is_binary(p->two)) {
> +			len1 = sprintf(buffer, "%s", sha1_to_hex(p->two->sha1));
> +			git_SHA1_Update(&ctx, buffer, len1);

i.e., maybe also

			git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);