remote-helpers: return successfully if everything up-to-date

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5540-http-push.sh

@@ -58,7 +58,7 @@ test_expect_success 'push to remote repository with packed refs' '
 	 test $HEAD = $(git rev-parse --verify HEAD))
 '
 
-test_expect_failure 'push already up-to-date' '
+test_expect_success 'push already up-to-date' '
 	git push
 '
 

transport-helper.c

@@ -263,6 +263,8 @@ static int push_refs(struct transport *transport,
 		strbuf_addstr(&buf, ref->name);
 		strbuf_addch(&buf, '\n');
 	}
+	if (buf.len == 0)
+		return 0;
 
 	transport->verbose = flags & TRANSPORT_PUSH_VERBOSE ? 1 : 0;
 	standard_options(transport);