JSTests/test262/test/built-ins/Array/prototype/filter/15.4.4.20-9-b-15.js

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

/*---
esid: sec-array.prototype.filter
es5id: 15.4.4.20-9-b-15
description: >
    Array.prototype.filter - decreasing length of array with prototype
    property causes prototype index property to be visited
---*/

        function callbackfn(val, idx, obj) {
            return true;
        }
        var arr = [0, 1, 2];

            Object.defineProperty(Array.prototype, "2", {
                get: function () {
                    return "prototype";
                },
                configurable: true
            });

            Object.defineProperty(arr, "1", {
                get: function () {
                    arr.length = 2;
                    return 1;
                },
                configurable: true
            });

            var newArr = arr.filter(callbackfn);

assert.sameValue(newArr.length, 3, 'newArr.length');
assert.sameValue(newArr[2], "prototype", 'newArr[2]');