+struct object *peel_to_type(const char *name, int namelen,
+ struct object *o, enum object_type expected_type)
+{
+ if (name && !namelen)
+ namelen = strlen(name);
+ if (!o) {
+ unsigned char sha1[20];
+ if (get_sha1_1(name, namelen, sha1))
+ return NULL;
+ o = parse_object(sha1);
+ }
+ while (1) {
+ if (!o || (!o->parsed && !parse_object(o->sha1)))
+ return NULL;
+ if (o->type == expected_type)
+ return o;
+ if (o->type == OBJ_TAG)
+ o = ((struct tag*) o)->tagged;
+ else if (o->type == OBJ_COMMIT)
+ o = &(((struct commit *) o)->tree->object);
+ else {
+ if (name)
+ error("%.*s: expected %s type, but the object "
+ "dereferences to %s type",
+ namelen, name, typename(expected_type),
+ typename(o->type));
+ return NULL;
+ }
+ }
+}
+