fetch: refactor fetch_refs into two functions

Refactor the fetch_refs function into a function that does the fetching
of refs and another function that stores them.  This is in preparation
for allowing additional processing of the fetched refs before updating
the local ref store.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -968,9 +968,21 @@ static int fetch_refs(struct transport *transport, struct ref *ref_map)
 	if (ret)
 		ret = transport_fetch_refs(transport, ref_map);
 	if (!ret)
-		ret |= store_updated_refs(transport->url,
-				transport->remote->name,
-				ref_map);
+		/*
+		 * Keep the new pack's ".keep" file around to allow the caller
+		 * time to update refs to reference the new objects.
+		 */
+		return 0;
+	transport_unlock_pack(transport);
+	return ret;
+}
+
+/* Update local refs based on the ref values fetched from a remote */
+static int consume_refs(struct transport *transport, struct ref *ref_map)
+{
+	int ret = store_updated_refs(transport->url,
+				     transport->remote->name,
+				     ref_map);
 	transport_unlock_pack(transport);
 	return ret;
 }
@@ -1116,7 +1128,8 @@ static void backfill_tags(struct transport *transport, struct ref *ref_map)
 	transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
 	transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 	transport_set_option(transport, TRANS_OPT_DEEPEN_RELATIVE, NULL);
-	fetch_refs(transport, ref_map);
+	if (!fetch_refs(transport, ref_map))
+		consume_refs(transport, ref_map);
 
 	if (gsecondary) {
 		transport_disconnect(gsecondary);
@@ -1165,7 +1178,7 @@ static int do_fetch(struct transport *transport,
 				   transport->url);
 		}
 	}
-	if (fetch_refs(transport, ref_map)) {
+	if (fetch_refs(transport, ref_map) || consume_refs(transport, ref_map)) {
 		free_refs(ref_map);
 		retcode = 1;
 		goto cleanup;