Re: bugreport - SEGFAULT on 'git show-branch --current --reflog=3'

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Apr 13, 2022, 18:46 UTC
Message-ID: <220413.86wnfses7c.gmgdl@evledraar.gmail.com>
In-Reply-To: <6d510d78-9b0b-c463-889b-cd3855ccdd1b@p1sec.com>

On Wed, Apr 13 2022, Gregory David wrote:

Show 18 quoted lines

> [[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...