From: John Keeping <john@keeping.me.uk>
Date: Mon, 06 May 2013 14:49:58 GMT
Subject: Re: Segfault in git merge-tree (1.8.2.2)
Message-ID: <20130506144958.GD25912@serenity.lan>
In-Reply-To: <20130506142923.GC25912@serenity.lan>

On Mon, May 06, 2013 at 03:29:23PM +0100, John Keeping wrote:
> On Mon, May 06, 2013 at 04:13:28PM +0200, Andreas Jacobsen wrote:
> > Sure, here you go, this time built from the HEAD I found on github
> > (7d3ccdffb5d28970dd7a4d177cfcca690ccd0c22) with:
> > 
> > NO_GETTEXT=1 make prefix=/usr/local/Cellar/git/HEAD CC=cc CFLAGS='-O0
> > -g' install (this is homebrew's setup, but I built it manually rather
> > than using the recipe.)
> > 
> > And the gdb output:
> > 
> > (gdb) set args merge-tree 027058e6ac8d03e029c4e1455bf90f63cd20e65b
> > FETCH_HEAD master
> > (gdb) run
> > Starting program: /usr/local/bin/git merge-tree
> > 027058e6ac8d03e029c4e1455bf90f63cd20e65b FETCH_HEAD master
> > Reading symbols for shared libraries +++++.............................. done
> > 
> > Program received signal EXC_BAD_ACCESS, Could not access memory.
> > Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000
> > 0x000000010006f1a3 in add_merge_entry (entry=0x100432ba0) at
> > builtin/merge-tree.c:24
> > 24 *merge_result_end = entry;
> 
> Thanks.  I have an idea of what's going on, but the set up is in an
> earlier pass and it only fails the next time it gets into
> add_merge_entry.
> 
> Can you try adding the following patch on top?  Hopefully the added
> debug is in the right caller, otherwise the new assert at the top will
> point us to the right one.

Actually, don't worry about it.  I've tracked down the problem and have
a failing test case for t4300.  Patch to follow shortly.