// Copyright 2015 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. function Bar() { } function Baz() { } Baz.prototype = { __proto__: new Bar() } var x = new Baz(); function foo(y) { return y instanceof Bar; } assertTrue(foo(x)); Baz.prototype.__proto__ = null; assertFalse(foo(x));