From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 04 Nov 2008 23:45:25 GMT
Subject: Re: git log -S doesn't find some commits
Message-ID: <7vod0voy22.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <alpine.DEB.1.00.0811050014310.30769@pacific.mpi-cbg.de>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

> On Tue, 4 Nov 2008, Bernt Hansen wrote:
>
>> Commits B, C, and D are not included in the git log -S output even
>> though with gitk you can see that 'org-publish-validate-link' is in the
>> patch.
>
> It is not sufficient for it to be in the patch, it has to be added or 
> deleted in whole.  So for example if you had a line
>
> 	org-publish-validate-link Hello
>
> and you changed it to
>
> 	org-publish-validate-link World
>
> git log -SWorld will find the commit, but git log 
> -Sorg-publish-validate-link will not.

It seems nobody has looked at the actual commits, but Dscho got it 80%
right.

There seems to be a misconception on what -S<foo> does.  It does *NOT*
grep for string <foo> in the patch text.  It counts number of <foo> in
preimage and postimage and decides that the commit is worth showing iff
they differ.

If you look at, for example (B):

    http://repo.or.cz/w/org-mode.git?a=commitdiff;h=837c81ce51

You can see that in org-publish.el, org-publish-validate-link appears once
as removed and once as added, so the total number of the appearance of the
symbol in preimage and postimage are the same.