Jeff King <peff@xxxxxxxx> writes:
> Here's a fix which can be applied on top of jt/clone-unborn-head. It
> could equally well be applied as part of the merge (with a minor
> adjustment in the context), but I think it ought to be squashed into
> Jonathan's patch 1 anyway.
Will queue but we are not merging the topic to 'next' yet, so I'll
ask Jonathan to remember making it a part of the series if it needs
to be updated later.
Thanks.
>
> -- >8 --
> Subject: [PATCH] ls-refs: don't peel NULL oid
>
> When the "unborn" feature is enabled, upload-pack serving an ls-refs
> command will pass a NULL oid into send_ref(). In this case, there is no
> point trying to peel the ref, since we know it points to nothing.
>
> For now this is a harmless waste of cycles (we re-resolve HEAD and find
> out that indeed, it points to nothing). But after merging with another
> topic that contains 36a317929b (refs: switch peel_ref() to
> peel_iterated_oid(), 2021-01-20), we'd actually end up passing NULL to
> peel_object(), which segfaults!
>
> Signed-off-by: Jeff King <peff@xxxxxxxx>
> ---
> ls-refs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/ls-refs.c b/ls-refs.c
> index 4077adeb6a..bc91f03653 100644
> --- a/ls-refs.c
> +++ b/ls-refs.c
> @@ -66,7 +66,7 @@ static int send_ref(const char *refname, const struct object_id *oid,
> strip_namespace(symref_target));
> }
>
> - if (data->peel) {
> + if (data->peel && oid) {
> struct object_id peeled;
> if (!peel_ref(refname, &peeled))
> strbuf_addf(&refline, " peeled:%s", oid_to_hex(&peeled));
