Index: modules/aggregator/aggregator.admin.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/aggregator/aggregator.admin.inc,v
retrieving revision 1.22
diff -u -r1.22 aggregator.admin.inc
--- modules/aggregator/aggregator.admin.inc	22 Dec 2008 19:38:30 -0000	1.22
+++ modules/aggregator/aggregator.admin.inc	24 Dec 2008 20:07:46 -0000
@@ -52,9 +52,13 @@
  * @see aggregator_form_feed_validate()
  * @see aggregator_form_feed_submit()
  */
-function aggregator_form_feed(&$form_state, $feed = NULL) {
+function aggregator_form_feed(&$form_state, stdClass $feed = NULL) {
   $period = drupal_map_assoc(array(900, 1800, 3600, 7200, 10800, 21600, 32400, 43200, 64800, 86400, 172800, 259200, 604800, 1209600, 2419200), 'format_interval');
 
+  if (empty($feed)) {
+    $feed = new stdClass();
+  }
+
   if (empty($feed->refresh)) {
     $feed->refresh = 3600;
   }