The Tor Browser / file revision

 /*

  * Any copyright is dedicated to the Public Domain.

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

  */

 var BUGNUMBER = 501739;

 var summary =

   "String.prototype.match behavior with zero-length matches involving " +

   "forward lookahead";

 print(BUGNUMBER + ": " + summary);

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

  * BEGIN TEST *

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

 var r = /(?=x)/g;

 var res = "aaaaaaaaaxaaaaaaaaax".match(r);

 assertEq(res.length, 2);

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

 if (typeof reportCompare === "function")

   reportCompare(true, true);

 print("Tests complete");