<!DOCTYPE html>
<html>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=1221421
-->
<head>
  <meta charset="utf-8">
  <title>Test for Bug 1221421</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
  <script type="text/javascript">

  var x = document.documentElement.style;
  x.__proto__ = [1, 2, 3];

  var res = 0;
  for (var h = 0; h < 5000; ++h) {
    res += x.length;
  }
  is(res, 15000, "length getter should return array length");

  </script>
</head>

<body>
  <a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1221421">Mozilla Bug 1221421</a>
</body>
</html>
