Re: [PATCH 02/11] t: allow skipping expected object ID in `ref-store update-ref`

> We require the caller to pass both the old and new expected object ID to
> our `test-tool ref-store update-ref` helper. When trying to update a
> symbolic reference though it's impossible to specify the expected object
> ID, which means that the test would instead have to force-update the
> reference. This is currently impossible though.
>
> Update the helper to optionally skip verification of the old object ID
> in case the test passes in an empty old object ID as input.
>
> Signed-off-by: Patrick Steinhardt <ps@pks.im>
> ---
>  t/helper/test-ref-store.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)

> diff --git a/t/helper/test-ref-store.c b/t/helper/test-ref-store.c
> index 7400f560ab6..7dc83137584 100644
> --- a/t/helper/test-ref-store.c
> +++ b/t/helper/test-ref-store.c
> @@ -322,16 +322,19 @@ static int cmd_update_ref(struct ref_store *refs, const char **argv)
>  	const char *new_sha1_buf = notnull(*argv++, "new-sha1");
>  	const char *old_sha1_buf = notnull(*argv++, "old-sha1");
>  	unsigned int flags = arg_flags(*argv++, "flags", transaction_flags);
> -	struct object_id old_oid;
> +	struct object_id old_oid, *old_oid_ptr = NULL;
>  	struct object_id new_oid;
>  
> -	if (get_oid_hex(old_sha1_buf, &old_oid))
> -		die("cannot parse %s as %s", old_sha1_buf, the_hash_algo->name);
> +	if (*old_sha1_buf) {
> +		if (get_oid_hex(old_sha1_buf, &old_oid))
> +			die("cannot parse %s as %s", old_sha1_buf, the_hash_algo->name);
> +		old_oid_ptr = &old_oid;
> +	}
>  	if (get_oid_hex(new_sha1_buf, &new_oid))
>  		die("cannot parse %s as %s", new_sha1_buf, the_hash_algo->name);
>  
>  	return refs_update_ref(refs, msg, refname,
> -			       &new_oid, &old_oid,
> +			       &new_oid, old_oid_ptr,
>  			       flags, UPDATE_REFS_DIE_ON_ERR);
>  }