Re: git merge-tree segfault

From: Klas Lindberg <klas.lindberg@gmail.com>
Date: Oct 30, 2010, 16:27 UTC
Message-ID: <AANLkTikPPGYit4h_heg3j+bz_p8ug9TGwnH62+i-prFL@mail.gmail.com>
In-Reply-To: <SNT124-w295B9D20AA43A06DEFD13BC4440@phx.gbl>

On Thu, Oct 28, 2010 at 10:25 PM, Tim Mazid <timmazid@hotmail.com> wrote:

Show 41 quoted lines

>
>> Date: Thu, 28 Oct 2010 22:16:03 +0200
>> Subject: git merge-tree segfault
>> From: klas.lindberg@gmail.com
>> To: git@vger.kernel.org
>>
>> I haven't tried this on newer versions of git, but the release notes
>> for later releases don't mention merge-tree anywhere, so...
>>
>> git version: 1.7.0
>> uname -a: Linux tor 2.6.32-trunk-amd64 #1 SMP Sun Jan 10 22:40:40 UTC
>> 2010 x86_64 GNU/Linux
>> distro: Debian GNU/Linux squeeze/sid
>>
>> Unpack the attached tree, cd into it and run:
>> git merge-tree common master other
>>
>> I get the following result:
>> added in local
>> our 100644 d68dd4031d2ad5b7a3829ad7df6635e27a7daa22 t1.txt
>> Segmentation fault
>>
>> The exit code:
>> 139
>>
>> BR / Klas
>
>
> Confirm this bug with arbitrary repository and arbitrary revs.
>
> git version: 1.7.1
> uname -a: Linux Imperial-SSD-Overlord 2.6.35-trunk-amd64 #1 SMP
> Tue Aug 17 08:22:25 UTC 2010 x86_64 GNU/Linux
> distro: Debian GNU/Linux unstable/experimental
>
> Same exit code; 139.
>
> Regards,
> Tim.
>
>

I made some more tests and discovered that the order of parameters to merge-tree is important:

 * Let the tree contain one commit.
 * Let the tree contain branches "common", "this" and "that". All of
them point to the single commit.

 * Check out "this" and add/commit a file "text". "text" does not
appear in "that".
 * Running "git merge-tree common this that" triggers the bug.
 * Running "git merge-tree common that this" does NOT trigger the bug.

BR / Klas