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From:   =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>
To:     Gregory David <gregory.david@p1sec.com>
Cc:     git@vger.kernel.org
Subject: Re: bugreport - SEGFAULT on 'git show-branch --current --reflog=3'
Date:   Wed, 13 Apr 2022 20:46:01 +0200
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On Wed, Apr 13 2022, Gregory David wrote:

> [[PGP Signed Part:Undecided]]
> Thanks a lot Aevar!
>
> Don't you mean this:
>
> diff --git a/builtin/show-branch.c b/builtin/show-branch.c
> index 330b0553b9..2a5c31729d 100644
> --- a/builtin/show-branch.c
> +++ b/builtin/show-branch.c
> @@ -881,7 +881,7 @@ int cmd_show_branch(int ac, const char **av, const
> char *prefix)
>                                        get_color_reset_code(), ref_name[i]);
>                         }
>
> -                       if (!reflog) {
> +                       if (!reflog || !rev[i]) {
>                                 /* header lines never need name */
>                                 show_one_commit(rev[i], 1);

No, but my "suggested" fix was just enough to compile and get past the
segfault, i.e. we don't reach the puts(reflog_msg[i]) branch, but of
course rev[i] may be NULL too, I didn't check.

For this one though: I haven't tried it, but reading show_one_commit()
one of the first things we do is dereference the 1st argument, so surely
that will segfault too...