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/range-diff.c b/range-diff.c
index 116fb07..1a4471f 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -445,7 +445,7 @@ static struct diff_filespec *get_filespec(const char *name, const char *p)
{
struct diff_filespec *spec = alloc_filespec(name);
- fill_filespec(spec, &null_oid, 0, 0100644);
+ fill_filespec(spec, null_oid(), 0, 0100644);
spec->data = (char *)p;
spec->size = strlen(p);
spec->should_munmap = 0;
