Re: [PATCH] Segmentation fault on non-commit objects.

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Davide,

[please remove the trailing period character in the commit subject]

On Tue, 29 Oct 2019, Davide Berardi wrote:

> Fixed segmentation fault that can be triggered using
> $ git clone --branch $object $repository
> with object pointing to a non-commit (e.g. a blob).
>
> Signed-off-by: Davide Berardi <berardi.dav@gmail.com>
> ---
> builtin/clone.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/builtin/clone.c b/builtin/clone.c
> index f665b28ccc..6ad2d8fe77 100644
> --- a/builtin/clone.c
> +++ b/builtin/clone.c
> @@ -720,6 +720,9 @@ static void update_head(const struct ref *our, const
> struct ref *remote,
> 	} else if (our) {
> 		struct commit *c = lookup_commit_reference(the_repository,
> 							   &our->old_oid);
> +		/* Check if --branch specifies a non-commit. */
> +		if (c == NULL)
> +			die(_("unable to update HEAD (cannot find commit)"));

Could the error message maybe repeat whatever the user specified for
`$object`? That would probably be more helpful. Maybe even say "not a
commit"?

Ciao,
Johannes

> 		/* --branch specifies a non-branch (i.e. tags), detach HEAD */
> 		update_ref(msg, "HEAD", &c->object.oid, NULL, REF_NO_DEREF,
> 			   UPDATE_REFS_DIE_ON_ERR);
> --
> 2.23.0
>
>
>