From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 16 Jul 2009 20:41:46 GMT
Subject: Re: [PATCHv2 2/2] pull: support rebased upstream + fetch + pull --rebase
Message-ID: <7vhbxc8inp.fsf@alter.siamese.dyndns.org>
In-Reply-To: <alpine.DEB.1.00.0907161035060.3155@pacific.mpi-cbg.de>

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

> How about
>
> 	oldremoteref="$(git rev-list --boundary HEAD --not \
> 			$(git rev-list -g $remoteref | sed 's/$/^@/') |
> 		sed -e '/^[^-]/d' -e q)"
>
> Explanation: the "git rev-list -g $remoteref" lists the previous commits 
> the remote ref pointed to, and the ^@ appended to them means all their 
> parents.  Now, the outer rev-list says to take everything in HEAD but 
> _not_ in those parents, showing the boundary commits.  The "sed" call 
> lists the first such boundary commit (which must, by construction, be one 
> of the commits shown by the first rev-list).

Hmm, I am not sure about that "(which must..." part.  When you have

          Y---X
         /
	B---o---o---o---H

wouldn't "rev-list --boundary H --not X^@" give B, not X nor Y?