hash: provide per-algorithm null OIDs
Up until recently, object IDs did not have an algorithm member, only a
hash. Consequently, it was possible to share one null (all-zeros)
object ID among all hash algorithms. Now that we're going to be
handling objects from multiple hash algorithms, it's important to make
sure that all object IDs have a correct algorithm field.
Introduce a per-algorithm null OID, and add it to struct hash_algo.
Introduce a wrapper function as well, and use it everywhere we used to
use the null_oid constant.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/parse-options-cb.c b/parse-options-cb.c
index 4542d4d..3c811e1 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -140,7 +140,7 @@ int parse_opt_object_id(const struct option *opt, const char *arg, int unset)
struct object_id *target = opt->value;
if (unset) {
- *target = null_oid;
+ oidcpy(target, null_oid());
return 0;
}
if (!arg)
