From: Eric Sunshine <sunshine@sunshineco.com>
Date: Tue, 17 Nov 2015 23:01:25 GMT
Subject: Re: [PATCH v2] blame: avoid checking if a file exists on the working tree if a revision is provided
Message-ID: <CAPig+cQcmtZJmm_FGMNL4OCTgdFZGyLjVrwbfCCp+0kwBeFuRQ@mail.gmail.com>
In-Reply-To: <20151117224809.GE27862@sigill.intra.peff.net>

On Tue, Nov 17, 2015 at 5:48 PM, Jeff King <peff@peff.net> wrote:
> On Tue, Nov 17, 2015 at 12:11:25AM -0500, Eric Sunshine wrote:
>> > blame content even if the path provided does match an existing
>> > blob on said revision.
>>
>> git-blame documentation does not advertise "blame <file> <rev>" as a
>> valid invocation. It does advertise "blame <rev> -- <file>", and this
>> case already works correctly even when <file> does not exist in the
>> worktree.
>
> Hmm. Out of curiosity I tried:
>
>   git blame v2.4.0 -- t/t6031-merge-recursive.sh
>
> and it segfaults. This bisects to Max's recent 1b0d400 (blame: extract
> find_single_final, 2015-10-30), but I do not see anything obviously
> wrong with it from a quick glance.

In the original code, sb->final received was assigned value of obj,
which may have gone through deref_tag(), however, after 1b0d400,
sb->final is unconditionally assigned the original value of obj, not
the (potentially) deref'd value.