Re: [PATCH] show-branch: fix SEGFAULT on both --current & --reflog

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 22, 2022, 18:43 UTC
Message-ID: <xmqq4k2l9cwo.fsf@gitster.g>
In-Reply-To: <xmqqv8v19ght.fsf@gitster.g>

Junio C Hamano <gitster@pobox.com> writes:

Show 7 quoted lines

>> It seems that it has been introduced in: Commit 1aa68d6735
>> (show-branch: --current includes the current branch., 2006-01-11)
>
> Yes, the commit should have noticed the invalid combination of
> options were given and errored out.  Since omission of such a check
> lead to a segfaulting bug without producing any useful output, it
> is safe to make it an error to give these options at the same time.

Actually, no, the commit couldn't have been the culprit. Back when 1aa58d6735 was written, "--reflog" option did not even exist.

If we want to find a commit to blame, it is 76a44c5c (show-branch --reflog: show the reflog message at the top., 2007-01-19). That commit should have caught invalid combination. It did attempt to catch some invalid combinations (like --more in the reflog mode), but apparently forgot to notice that --current does not make sense to be used in the new mode it was adding.

Thanks.