Ticket #25047: 25047.patch

src/wp-includes/js/heartbeat.js

@@ -427 +427 @@
                  */
                 this.enqueue = function( handle, data, dont_overwrite ) {
                         if ( handle ) {
-                                if ( queue.hasOwnProperty( handle ) && dont_overwrite )
+                                if ( dont_overwrite && queue.isQueued( handle ) )
                                         return false;
 
                                 queue[handle] = data;
@@ -443 +443 @@
                  * $return mixed The data queued with that handle or null
                  */
                 this.isQueued = function( handle ) {
+                        if (! queue.hasOwnProperty( handle ))
+                                return null;
+
                         return queue[handle];
                 };
         };