Widget: option-method should work as getter only when argument length is 1. Fixes #9601 - Widget: calling _setOption with undefined as 3rd argument makes it a getter

(cherry picked from commit ecde7cd)

Author: dekajp

tests/unit/widget/widget_core.js

@@ -535,7 +535,7 @@ test( ".option() - delegate to ._setOptions()", function() {
 });
 
 test( ".option() - delegate to ._setOption()", function() {
-	expect( 2 );
+	expect( 3 );
 	var div,
 		calls = [];
 	$.widget( "ui.testWidget", {
@@ -554,6 +554,11 @@ test( ".option() - delegate to ._setOption()", function() {
 	deepEqual( calls, [{ key: "foo", val: "bar" }],
 		"_setOption called for single option" );
 
+	calls = [];
+	div.testWidget( "option", "foo", undefined );
+	deepEqual( calls, [{ key: "foo", val: undefined }],
+		"_setOption called for single option where value is undefined" );
+
 	calls = [];
 	div.testWidget( "option", {
 		bar: "qux",
@@ -566,9 +571,9 @@ test( ".option() - delegate to ._setOption()", function() {
 });
 
 test( ".option() - deep option setter", function() {
-	expect( 6 );
+	expect( 9 );
 	$.widget( "ui.testWidget", {} );
-	var div = $( "<div>" ).testWidget();
+	var result, div = $( "<div>" ).testWidget();
 	function deepOption( from, to, msg ) {
 		div.data( "ui-testWidget" ).options.foo = from;
 		$.ui.testWidget.prototype._setOption = function( key, value ) {
@@ -580,6 +585,12 @@ test( ".option() - deep option setter", function() {
 	deepOption( { bar: "baz" }, { bar: "qux" }, "one deep" );
 	div.testWidget( "option", "foo.bar", "qux" );
 
+	deepOption( { bar: "baz" }, { bar: undefined }, "one deep - value = undefined" );
+
+	result = div.testWidget( "option", "foo.bar", undefined );
+
+	deepEqual ( result, div, "option should return widget on successful set operation" );
+
 	deepOption( null, { bar: "baz" }, "null" );
 	div.testWidget( "option", "foo.bar", "baz" );
 

ui/jquery.ui.widget.js

@@ -315,12 +315,12 @@ $.Widget.prototype = {
 					curOption = curOption[ parts[ i ] ];
 				}
 				key = parts.pop();
-				if ( value === undefined ) {
+				if ( arguments.length === 1 ) {
 					return curOption[ key ] === undefined ? null : curOption[ key ];
 				}
 				curOption[ key ] = value;
 			} else {
-				if ( value === undefined ) {
+				if ( arguments.length === 1 ) {
 					return this.options[ key ] === undefined ? null : this.options[ key ];
 				}
 				options[ key ] = value;