Ticket #19779: 19779-2.diff

wp-admin/includes/post.php

@@ -973 +973 @@
 }
 
 function _edit_attachments_query_helper($where) {
-        return $where .= ' AND post_parent < 1';
+        global $wpdb;
+        return $where .= " AND {$wpdb->posts}.post_parent < 1";
 }
 
 /**