From: Michael Hendricks <michael@ndrix.org>
Date: Thu, 30 Apr 2009 19:18:57 GMT
Subject: detecting cycles in Git's commit graph
Message-ID: <20090430191857.GA55192@ginosko.grantstreet.com>

Are there any tools for detecting cycles in the commit graph which
have been caused by grafts?  I thought 'git fsck' might do it, but it
doesn't seem to.

While importing some historic code into a new Git repository, my
import scripts accidentally created a cycle in the commit graph by
using grafts.  Essentially, I had commits like:

    A -- B -- C

I accidentally created a graft marking commit C as commit B's second
parent.  There were 15,000 grafts so it took me a while to track down
the one causing the cycle.  The initial symptom was that 'git log
--graph B' produced no output.

I wasn't able to find any existing tools to locate these kinds of
faulty grafts.

Thanks for any pointers.

-- 
Michael