diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/extensions/regress-431428.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/extensions/regress-431428.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+// |reftest| require-or(debugMode,skip)
+/* -*- 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/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 431428;
+var summary = 'Do not crash with for..in, trap';
+var actual = 'No Crash';
+var expect = 'No Crash';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+function test()
+{
+  enterFunc ('test');
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+ 
+  function f() { 
+    for ( var a in [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]) { }
+  }
+
+  if (typeof trap == 'function' && typeof setDebug == 'function')
+  {
+    setDebug(true);
+    "" + f;
+    trap(f, 0, "");
+    "" + f;
+  }
+
+  reportCompare(expect, actual, summary);
+
+  exitFunc ('test');
+}