From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tzvetan Mikov <tmikov@gmail.com>
Subject: Re: [PATCH] line-log: fix crash when --first-parent is used
Date: Mon, 3 Nov 2014 14:09:35 -0800
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Cc: git@vger.kernel.org, Thomas Rast <trast@inf.ethz.ch>,
	Eric Sunshine <sunshine@sunshineco.com>,
	Eric Vander Weele <ericvw@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
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On Mon, Nov 3, 2014 at 12:58 PM, Junio C Hamano <gitster@pobox.com> wrote:

>> line-log tries to access all parents of a commit, but only the first
>> parent has been loaded if "--first-parent" is specified, resulting
>> in a crash.
>>
>> Limit the number of parents to one if "--first-parent" is specified.
>>

> [...]
> Tzvetan, can we have a test for this one?

Here is a sequence of commands to reproduce the crash:

git init
echo "1" > a.txt && git add a.txt && git commit -m "a"
git checkout -b branch
echo "2" > b.txt && git add b.txt && git commit -m "b"
git checkout master
git merge branch --no-ff -m "merge"
git log --first-parent -L 1,1:a.txt

I am not sure whether you have a requirement for a formal test
included with the patch, but if there is one, I am happy to
rework it.

This is a very simple fix for the crash, though possibly
a "real" comprehensive fix may be needed. I am not sure.
The real cause is that with "--first-parent" some commit
objects are never loaded from disk but may still be accessed.

(sorry about my formatting - have to use GMail)

regards,
Tzvetan