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

[Michael J Gruber <git@drmicha.warpmail.net>]

Junio C Hamano venit, vidit, dixit 01.04.2011 21:26:
> Michael J Gruber <git@drmicha.warpmail.net> writes:
> 
>> 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.
> 

I think I misunderstood what you intended "-B -D" to do (and I even
didn't know about -B until -D came up; my understanding of "-B" is still
fishy). I just didn't want to let this die before 1.7.5. Thanks for
taking this up and clarifying it.

Michael