Merge branch 'jk/gc-auto-after-fetch'

Help "fetch only" repositories that do not trigger "gc --auto"
often enough.

* jk/gc-auto-after-fetch:
  fetch-pack: avoid repeatedly re-scanning pack directory
  fetch: run gc --auto after fetching

fetch-pack.c

@@ -594,6 +594,9 @@ static int everything_local(struct fetch_pack_args *args,
 	for (ref = *refs; ref; ref = ref->next) {
 		struct object *o;
 
+		if (!has_sha1_file(ref->old_sha1))
+			continue;
+
 		o = parse_object(ref->old_sha1);
 		if (!o)
 			continue;