diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma/Number/15.7.4.2-2-n.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma/Number/15.7.4.2-2-n.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+/**
+   File Name:          15.7.4.2-2-n.js
+   ECMA Section:       15.7.4.2.1 Number.prototype.toString()
+   Description:
+   If the radix is the number 10 or not supplied, then this number value is
+   given as an argument to the ToString operator; the resulting string value
+   is returned.
+
+   If the radix is supplied and is an integer from 2 to 36, but not 10, the
+   result is a string, the choice of which is implementation dependent.
+
+   The toString function is not generic; it generates a runtime error if its
+   this value is not a Number object. Therefore it cannot be transferred to
+   other kinds of objects for use as a method.
+
+   Author:             christine@netscape.com
+   Date:               16 september 1997
+*/
+var SECTION = "15.7.4.2-2-n";
+var VERSION = "ECMA_1";
+startTest();
+
+writeHeaderToLog( SECTION + " Number.prototype.toString()");
+
+DESCRIPTION = "o = new Object(); o.toString = Number.prototype.toString; o.toString()";
+EXPECTED = "error";
+
+new TestCase(SECTION, 
+	     "o = new Object(); o.toString = Number.prototype.toString; o.toString()", 
+	     "error",   
+	     eval("o = new Object(); o.toString = Number.prototype.toString; o.toString()") );
+
+//    new TestCase(SECTION,  "o = new String(); o.toString = Number.prototype.toString; o.toString()",  "error",    eval("o = new String(); o.toString = Number.prototype.toString; o.toString()") );
+//    new TestCase(SECTION,  "o = 3; o.toString = Number.prototype.toString; o.toString()",             "error",    eval("o = 3; o.toString = Number.prototype.toString; o.toString()") );
+
+test();