Make name and message non-enumerable on Error object (this is a partial fix for issue 1215)

test/mjsunit/error-constructors.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 41 matching lines @@
 // dont-delete. This is not specified, but allowing overwriting the
 // name property with a getter can leaks error objects from different
 // script tags in the same context in a browser setting. We therefore
 // disallow changes to the name property on error objects.
 assertEquals("ReferenceError", ReferenceError.prototype.name);
 delete ReferenceError.prototype.name;
 assertEquals("ReferenceError", ReferenceError.prototype.name);
 ReferenceError.prototype.name = "not a reference error";
 assertEquals("ReferenceError", ReferenceError.prototype.name);
 
+// Check that message and name are not enumerable on Error objects.
+var desc = Object.getOwnPropertyDescriptor(Error.prototype, 'name');
+assertFalse(desc['enumerable']);
+desc = Object.getOwnPropertyDescriptor(Error.prototype, 'message');
+assertFalse(desc['enumerable']);
+
+var e = new Error("foobar");
+desc = Object.getOwnPropertyDescriptor(e, 'message');
+assertFalse(desc['enumerable']);
+desc = Object.getOwnPropertyDescriptor(e, 'arguments');
+assertFalse(desc['enumerable']);
+desc = Object.getOwnPropertyDescriptor(e, 'type');
+assertFalse(desc['enumerable']);
+desc = Object.getOwnPropertyDescriptor(e, 'stack');
+assertFalse(desc['enumerable']);
+
+// name is not tested above, but in addition we should have no enumerable
+// properties, so we simply assert that.
+for (var v in e) {
+  assertUnreachable();
+}