Re: [PATCH] git diff -D: omit the preimage of deletes

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 1, 2011, 19:26 UTC
Message-ID: <7vbp0pg4d7.fsf@alter.siamese.dyndns.org>
In-Reply-To: <b6975fdc80a338e47c1426e8bf8450b68130b84a.1301664623.git.git@drmicha.warpmail.net>

Michael J Gruber <git@drmicha.warpmail.net> writes:

Show 13 quoted lines

> diff --git a/diff.c b/diff.c
> index 5422c43..9ea1de1 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -4205,7 +4211,7 @@ void diffcore_std(struct diff_options *options)
>  			diffcore_break(options->break_opt);
>  		if (options->detect_rename)
>  			diffcore_rename(options);
> -		if (options->break_opt != -1)
> +		if (options->break_opt != -1 && !options->irreversible_delete)
>  			diffcore_merge_broken();
>  	}
>  	if (options->pickaxe)

Thanks, but this hunk looks fishy.

What happens to a path that was tentatively broken for the purpose of rename detection with -B -M (break to match with another file) but then found to be with no counterpart after all after running diffcore_rename(), which now needs to get merged back? Such a path is shown as a normal patch when the dissimlarity between the preimage and postimage is not large enough and merge-broken is the step that combines such a broken but unmatched pair back.

I would have expected that the patch relative to jc/diff-irreversible-delete topic would consist only of changes to diff.c:emit_rewrite_diff(), docs and tests.