// Copyright 2016 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. // Flags: --allow-natives-syntax function F() {} var f = new F function foo(x) { return x instanceof F }; %PrepareFunctionForOptimization(foo); %OptimizeFunctionOnNextCall(foo); assertFalse(foo(1)); var proto = Object.getPrototypeOf(F); Object.setPrototypeOf(F, null); F[Symbol.hasInstance] = function(v) { return true }; Object.setPrototypeOf(F, proto); assertTrue(foo(1));