1 files changed, 25 insertions, 8 deletions

diff --git a/ui/widget.js b/ui/widget.js
index 726f70735..c101e59d4 100644
--- a/ui/widget.js
+++ b/ui/widget.js
@@ -26,6 +26,7 @@
 }( function( $ ) {
 
 var widgetUuid = 0;
+var widgetHasOwnProperty = Array.prototype.hasOwnProperty;
 var widgetSlice = Array.prototype.slice;
 
 $.cleanData = ( function( orig ) {
@@ -64,7 +65,7 @@ $.widget = function( name, base, prototype ) {
 	}
 
 	// Create selector for plugin
-	$.expr[ ":" ][ fullName.toLowerCase() ] = function( elem ) {
+	$.expr.pseudos[ fullName.toLowerCase() ] = function( elem ) {
 		return !!$.data( elem, fullName );
 	};
 
@@ -183,7 +184,7 @@ $.widget.extend = function( target ) {
 	for ( ; inputIndex < inputLength; inputIndex++ ) {
 		for ( key in input[ inputIndex ] ) {
 			value = input[ inputIndex ][ key ];
-			if ( input[ inputIndex ].hasOwnProperty( key ) && value !== undefined ) {
+			if ( widgetHasOwnProperty.call( input[ inputIndex ], key ) && value !== undefined ) {
 
 				// Clone objects
 				if ( $.isPlainObject( value ) ) {
@@ -493,12 +494,30 @@ $.Widget.prototype = {
 			classes: this.options.classes || {}
 		}, options );
 
+		function bindRemoveEvent() {
+			options.element.each( function( _, element ) {
+				var isTracked = $.map( that.classesElementLookup, function( elements ) {
+					return elements;
+				} )
+					.some( function( elements ) {
+						return elements.is( element );
+					} );
+
+				if ( !isTracked ) {
+					that._on( $( element ), {
+						remove: "_untrackClassesElement"
+					} );
+				}
+			} );
+		}
+
 		function processClassString( classes, checkOption ) {
 			var current, i;
 			for ( i = 0; i < classes.length; i++ ) {
 				current = that.classesElementLookup[ classes[ i ] ] || $();
 				if ( options.add ) {
-					current = $( $.unique( current.get().concat( options.element.get() ) ) );
+					bindRemoveEvent();
+					current = $( $.uniqueSort( current.get().concat( options.element.get() ) ) );
 				} else {
 					current = $( current.not( options.element ).get() );
 				}
@@ -510,10 +529,6 @@ $.Widget.prototype = {
 			}
 		}
 
-		this._on( options.element, {
-			"remove": "_untrackClassesElement"
-		} );
-
 		if ( options.keys ) {
 			processClassString( options.keys.match( /\S+/g ) || [], true );
 		}
@@ -531,6 +546,8 @@ $.Widget.prototype = {
 				that.classesElementLookup[ key ] = $( value.not( event.target ).get() );
 			}
 		} );
+
+		this._off( $( event.target ) );
 	},
 
 	_removeClass: function( element, keys, extra ) {
@@ -611,7 +628,7 @@ $.Widget.prototype = {
 	_off: function( element, eventName ) {
 		eventName = ( eventName || "" ).split( " " ).join( this.eventNamespace + " " ) +
 			this.eventNamespace;
-		element.off( eventName ).off( eventName );
+		element.off( eventName );
 
 		// Clear the stack to avoid memory leaks (#10056)
 		this.bindings = $( this.bindings.not( element ).get() );