Ticket #53562: 53562.diff

src/js/_enqueues/wp/customize/controls.js

@@ -906 +906 @@
                         'WebkitTransition': 'webkitTransitionEnd'
                 };
                 prop = _.find( _.keys( transitions ), function( prop ) {
-                        return ! _.isUndefined( el.style[ prop ] );
+                        return ! _.isUndefined( el.style[ prop ] ) && ! _.isEmpty( el.style[ prop ] );
                 } );
                 if ( prop ) {
                         return transitions[ prop ];