Ticket #31964: before-unload-makeitwork2.patch

wp-admin/js/updates.js

@@ -547 +547 @@
 
         } );
 
-        $( window ).on( 'beforeunload', wp.updates.beforeunload );
+        $( window ).on( 'beforeunload', function() { return wp.updates.beforeunload(); } );
 
 })( jQuery, window.wp, window.pagenow, window.ajaxurl );