Ticket #30818: 30818.diff

wp-admin/js/customize-widgets.js

@@ -685 +685 @@
                          * Handle selecting a sidebar to move to
                          */
                         this.container.find( '.widget-area-select' ).on( 'click keypress', 'li', function( e ) {
-                                if ( event.type === 'keypress' && ( event.which !== 13 && event.which !== 32 ) ) {
+                                if ( e.type === 'keypress' && ( e.which !== 13 && e.which !== 32 ) ) {
                                         return;
                                 }
                                 e.preventDefault();