The Tor Browser / file revision

 /*

  * Any copyright is dedicated to the Public Domain.

  * http://creativecommons.org/licenses/publicdomain/

  * Contributor:

  *   Jeff Walden <jwalden+code@mit.edu>

  */

 //-----------------------------------------------------------------------------

 var BUGNUMBER = 880591;

 var summary =

   "Assertion redefining length property of a frozen dictionary-mode array";

 print(BUGNUMBER + ": " + summary);

 /**************

  * BEGIN TEST *

  **************/

 function convertToDictionaryMode(arr)

 {

   Object.defineProperty(arr, 0, { configurable: true });

   Object.defineProperty(arr, 1, { configurable: true });

   delete arr[0];

 }

 var arr = [];

 convertToDictionaryMode(arr);

 Object.freeze(arr);

 Object.defineProperty(arr, "length", {});

 /******************************************************************************/

 if (typeof reportCompare === "function")

   reportCompare(true, true);

 print("Tests complete");