updated core to 7.53

modules/system/system.queue.inc

@@ -231,7 +231,7 @@ class SystemQueue implements DrupalReliableQueueInterface {
     // until an item is successfully claimed or we are reasonably sure there
     // are no unclaimed items left.
     while (TRUE) {
-      $item = db_query_range('SELECT data, item_id FROM {queue} q WHERE expire = 0 AND name = :name ORDER BY created ASC', 0, 1, array(':name' => $this->name))->fetchObject();
+      $item = db_query_range('SELECT data, item_id FROM {queue} q WHERE expire = 0 AND name = :name ORDER BY created, item_id ASC', 0, 1, array(':name' => $this->name))->fetchObject();
       if ($item) {
         // Try to update the item. Only one thread can succeed in UPDATEing the
         // same row. We cannot rely on REQUEST_TIME because items might be
@@ -326,6 +326,7 @@ class MemoryQueue implements DrupalQueueInterface {
     $item->created = time();
     $item->expire = 0;
     $this->queue[$item->item_id] = $item;
+    return TRUE;
   }
 
   public function numberOfItems() {