fetch_refs_via_pack: call report_unmatched_refs

"git fetch" currently doesn't bother to check that it got all refs it
sought, because the common case of requesting a nonexistent ref triggers
a die() in get_fetch_map.  However, there's at least one case that
slipped through: "git fetch REMOTE SHA1" if the server doesn't allow
requests for unadvertised objects.  Make fetch_refs_via_pack (which is
on the "git fetch" code path) call report_unmatched_refs so that we at
least get an error message in that case.

Signed-off-by: Matt McCutchen <matt@mattmccutchen.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5516-fetch-push.sh

@@ -1098,7 +1098,8 @@ test_expect_success 'fetch exact SHA1' '
 		test_must_fail git cat-file -t $the_commit &&
 
 		# fetching the hidden object should fail by default
-		test_must_fail git fetch -v ../testrepo $the_commit:refs/heads/copy &&
+		test_must_fail git fetch -v ../testrepo $the_commit:refs/heads/copy 2>err &&
+		test_i18ngrep "no such remote ref" err &&
 		test_must_fail git rev-parse --verify refs/heads/copy &&
 
 		# the server side can allow it to succeed

transport.c

@@ -204,6 +204,7 @@ static struct ref *get_refs_via_connect(struct transport *transport, int for_pus
 static int fetch_refs_via_pack(struct transport *transport,
 			       int nr_heads, struct ref **to_fetch)
 {
+	int ret = 0;
 	struct git_transport_data *data = transport->data;
 	struct ref *refs;
 	char *dest = xstrdup(transport->url);
@@ -241,19 +242,22 @@ static int fetch_refs_via_pack(struct transport *transport,
 			  &transport->pack_lockfile);
 	close(data->fd[0]);
 	close(data->fd[1]);
-	if (finish_connect(data->conn)) {
+	if (finish_connect(data->conn))
-		free_refs(refs);
+		ret = -1;
-		refs = NULL;
-	}
 	data->conn = NULL;
 	data->got_remote_heads = 0;
 	data->options.self_contained_and_connected =
 		args.self_contained_and_connected;
 
+	if (refs == NULL)
+		ret = -1;
+	if (report_unmatched_refs(to_fetch, nr_heads))
+		ret = -1;
+
 	free_refs(refs_tmp);
 	free_refs(refs);
 	free(dest);
-	return (refs ? 0 : -1);
+	return ret;
 }
 
 static int push_had_errors(struct ref *ref)