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From: Roland Dreier <rdreier@cisco.com>
To: Ken Moffat <zarniwhoop@ntlworld.com>
Cc: Rene Herman <rene.herman@keyaccess.nl>, Adrian Bunk <bunk@kernel.org>,
       Linux Kernel <linux-kernel@vger.kernel.org>,
       Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: GIT bisection range errors
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	<20080508222545.GH22887@cs181133002.pp.htv.fi>
	<48238087.7000509@keyaccess.nl> <20080508225645.GA24725@deepthought>
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Date: Thu, 08 May 2008 16:33:04 -0700
In-Reply-To: <20080508225645.GA24725@deepthought> (Ken Moffat's message of
	"Thu, 8 May 2008 23:56:45 +0100")
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 > > $ git checkout -b rc v2.6.26-rc1
 > > $ git bisect start
 > > $ git bisect bad
 > > $ git bisect good v2.6.25
 > >
 > > Yet, during this I'm finding myself at 2.6.25-rc6 and 2.6.25-rc8
 > > as the last two results (both good...).

 >  I reported a similar thing at the beginning of April
 > http://lkml.org/lkml/2008/4/2/390 - 2.6.25-rc1 bad, 2.6.24 good, git
 > dropped me back at 2.6.24-rc4 (again, according to the top level
 > Makefile).

This is normal and expected, due to the distributed nature of git and
the fact that git-bisect operates on the full topology of history and
not just a linear sequence of commits.

Imagine history like:

    A---B---C---D
     \         /
      \       /
       \     /
        E---F

where B is good and D is bad.  Now, when you bisect, there is no way to
know whether, say, E is good or bad and hence the bisect process may
present E as a tree to try.

Now, if B is the 2.6.25 release, then since E branched off before B, it
will have a Makefile that says 2.6.25-rcX.  Which is exactly the
behavior you are seeing.

In short, everything looks fine and is behaving as expected.

 - R.