epic fsck SIGSEGV! (was Recovering from epic fail (deleted .git/objects/pack))

From: R. Tyler Ballance <tyler@slide.com>
Date: Dec 10, 2008, 22:52 UTC
Message-ID: <1228949523.27061.20.camel@starfruit.local>
In-Reply-To: <493FAA5A.8070801@viscovery.net>

On Wed, 2008-12-10 at 12:39 +0100, Johannes Sixt wrote:

Show 14 quoted lines

> R. Tyler Ballance schrieb:
> > On Tue, 2008-12-09 at 16:19 -0800, Junio C Hamano wrote:
> >> See if "fsck --full" complains after that.  If the repository was not
> >> repacked during that period, all objects created by the activity by the
> >> unfortunate developer would be loose, so ...
> > 
> > tyler@ccnet:~/source/slide/brian_main> time git fsck --full
> > Segmentation fault
> 
> Please make a backup (tarball) of the repository that shows this segfault.
> 'git fsck' is not supposed to segfault, no matter what garbage is thrown
> at it.
> 
> Can you make a backtrace of this failing 'git fsck --full' invocation?

I decided to endure the 30 minutes long this took on machine, and ran the operation in gdb. As a result, I got the SIGSEGV again, and a 13MB stacktrace.

In fact, the stack trace was probably longer, but this happened while I
printed out `bt full`:
        #80496 0x00000000004244bc in fsck_handle_ref (refname=0x162aa61
        "refs/heads/master", sha1=0x162aa39 "S\236\024(f\210��V\027�'�E
        \025�u�g",
            flag=<value optimized out>, cb_data=<value optimized out>)
        at builtin-fsck.c:118
                obj = <value optimized out>
        #80497 0x000000000047f61c in do_for_each_ref (base=0x4a7022
        "refs/", fn=0x424450 <fsck_handle_ref>, trim=0, cb_data=0x0) at
        refs.c:582
        [1]    29388 segmentation fault (core dumped)  gdb git
        tyler@ccnet:~/source/slide/brian_main> 
        
The "full" trace is here:
http://pineapple.monkeypox.org/scratch/git-1.6.0.2-fsck-sigsegv.trace

I think I'm going to need to have a drink :-/

-- 
-R. Tyler Ballance
Slide, Inc.