From: Petr Baudis <pasky@ucw.cz>
Date: Fri, 12 Sep 2008 10:58:39 GMT
Subject: Re: [ANNOUNCE] TopGit v0.3
Message-ID: <20080912105839.GV10360@machine.or.cz>
In-Reply-To: <20080911054030.GA6602@glandium.org>

  Hi,

On Thu, Sep 11, 2008 at 07:40:30AM +0200, Mike Hommey wrote:
> I just saw Martin Krafft's talk at debconf 8, showing TopGit, and I
> wonder why TopGit needs to keep top-bases/* references ? Isn't
> git merge-base enough for this ?

  the top-bases/ references are to determine what to base the patch
against. Consider patch structure like:

	         .---- A ----.
	vanilla <             > C
	         `---- B ----'

  Then, top-bases/C will consist of branches A and B, merging updates in
these branches over time, and you can get the current image of C's patch
by diffing top-bases/C and heads/C. There is no way how to get this by
using git merge-base, since that gives you only kind of "multi-way
diff" - I'm not even sure what would you call merge-base on in this
example.

-- 
				Petr "Pasky" Baudis
The next generation of interesting software will be done
on the Macintosh, not the IBM PC.  -- Bill Gates