The Tor Browser / file revision

 /*

  * Any copyright is dedicated to the Public Domain.

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

  * Contributor: Jason Orendorff

  */

 // This test appeared in bug 497789 comment 78.

 var a = {x: 'a'},

     b1 = Object.create(a),

     c1 = Object.create(b1),

     b2 = Object.create(a),

     c2 = Object.create(b2);

 b2.x = 'b';  // foreshadowing a.x

 var s = '';

 for each (var obj in [c1, c2])

     s += obj.x;

 assertEq(s, 'ab');

 reportCompare(0, 0, "Property cache soundness: objects with the same shape but different prototypes.");