Re: [PATCH v2 3/3] diff: turn skip_stat_unmatch on selectively

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 28, 2014, 22:51 UTC
Message-ID: <xmqq7g9jlny6.fsf@gitster.dls.corp.google.com>
In-Reply-To: <xmqqd2jdm1jj.fsf@gitster.dls.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

Show 20 quoted lines

> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> skip_stat_unmatch flag is added in fb13227 (git-diff: squelch "empty"
>> diffs - 2007-08-03) to ignore empty diffs caused by stat-only
>> dirtiness. In some diff case, stat is not involved at all. While
>> the code is written in a way that no expensive I/O is done, we still
>> need to move all file pairs from the old queue to the new queue in
>> diffcore_skip_stat_unmatch().
>>
>> Only enable it when worktree is involved: "diff" and "diff <rev>".
>> This should help track down how skip_stat_unmatch is actually used
>> when bugs occur.
>>
>> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
>> ---
>>  This replaces 'diff: turn off skip_stat_unmatch on "diff --cached"'
>>  The previous patch obviously leaves skip_stat_unmatch on in "diff
>>  <rev> <rev>" and maybe other cases.
>
> Oops, I lost track.  Sorry.

Together with {1,2}/3 applied on maint-1.8.4, this sems to break t3417 (there may be others, but I didn't have time to check).