updated core to 7.72

modules/forum/forum.info

@@ -9,7 +9,7 @@ files[] = forum.test
 configure = admin/structure/forum
 stylesheets[all][] = forum.css
 
-; Information added by Drupal.org packaging script on 2019-04-17
-version = "7.66"
+; Information added by Drupal.org packaging script on 2020-06-17
+version = "7.72"
 project = "drupal"
-datestamp = "1555533576"
+datestamp = "1592419104"

modules/forum/forum.module

@@ -922,7 +922,8 @@ function forum_get_topics($tid, $sortby, $forum_per_page) {
   );
 
   $order = _forum_get_topic_order($sortby);
-  for ($i = 0; $i < count($forum_topic_list_header); $i++) {
+  // Skip element with index 0 which is NULL.
+  for ($i = 1; $i < count($forum_topic_list_header); $i++) {
     if ($forum_topic_list_header[$i]['field'] == $order['field']) {
       $forum_topic_list_header[$i]['sort'] = $order['sort'];
     }