JSTests/test262/test/built-ins/Object/preventExtensions/15.2.3.10-3-24.js

// Copyright (c) 2012 Ecma International.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
es5id: 15.2.3.10-3-24
description: >
    Object.preventExtensions - [[Extensible]]: false on a prototype
    doesn't prevent adding properties to an instance that inherits
    from that prototype
---*/

        var proto = {};
        var preCheck = Object.isExtensible(proto);
        Object.preventExtensions(proto);

        var ConstructFun = function () { };
        ConstructFun.prototype = proto;
        var child = new ConstructFun();

        child.prop = 10;

assert(preCheck, 'preCheck !== true');
assert(child.hasOwnProperty("prop"), 'child.hasOwnProperty("prop") !== true');