Resizable: Fix aspectRatio cannot be changed after initialization.

Fixes #4186
Closes gh-1750

Author: sergeir82

tests/unit/resizable/options.js

@@ -155,6 +155,28 @@ QUnit.test( "aspectRatio: Resizing can move objects", function( assert ) {
 	assert.equal( target.position().top, 0, "compare top - no movement" );
 } );
 
+QUnit.test( "aspectRatio: aspectRatio can be changed after initialization", function( assert ) {
+	assert.expect( 4 );
+
+	var target = $( "#resizable1" )
+		.resizable( { aspectRatio: 1 } )
+		.resizable( "option", "aspectRatio", false );
+
+	var handle = ".ui-resizable-e";
+
+	testHelper.drag( handle, 80 );
+
+	assert.equal( target.width(), 180, "compare width - size change" );
+	assert.equal( target.height(), 100, "compare height - no size change" );
+
+	target.resizable( "option", "aspectRatio", 2 );
+
+	testHelper.drag( handle, -40 );
+
+	assert.equal( target.width(), 140, "compare width - size change" );
+	assert.equal( target.height(), 70, "compare height - size change in proper relation" );
+} );
+
 QUnit.test( "containment", function( assert ) {
 	assert.expect( 4 );
 

ui/widgets/resizable.js

@@ -226,6 +226,9 @@ $.widget( "ui.resizable", $.ui.mouse, {
 			this._removeHandles();
 			this._setupHandles();
 			break;
+		case "aspectRatio":
+			this._aspectRatio = !!value;
+			break;
 		default:
 			break;
 		}