From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 08 Jun 2007 00:42:36 GMT
Subject: Re: [PATCH/RFC] filter-branch: support skipping of commits more easily
Message-ID: <7v7iqfnuo3.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.64.0706080058160.4046@racer.site>

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

> When commit-filter echoes just "skip", just skip that commit by mapping 
> its object name to the same (possibly rewritten) object name(s) its 
> parent(s) are mapped to.
>
> IOW, given A-B-C, if commit-filter says "skip" upon B, the rewritten 
> branch will look like this: A'-C'.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>
> 	Of course, if you think of "patchsets", this behaviour might
> 	be unexpected, since the children will still contain everything
> 	which was changed in the skipped revisions, and not changed in
> 	_them_.

I think that is fine; in effect, by saying "skip" B, you are
squashing B-C into C'.

Does this mean that, given

          C---D---E
         /   /
	A---B

and if commit-filter says "skip" on D, the written history would
look like this?

          C'------E'
         /       /
	A'--B'--'

The new commit E' would become an evil merge that has difference
between D and E in the original history?

I am not objecting; just trying to get a mental picture.