<html xmlns="http://www.w3.org/1999/xhtml" style="-moz-binding: url(#foo)">
<head>

<xbl:bindings xmlns:xbl="http://www.mozilla.org/xbl">
<xbl:binding id="foo"><xbl:content><fieldset><xbl:children/></fieldset></xbl:content></xbl:binding>
</xbl:bindings>

<script type="text/javascript">

function boom()
{
  var dE = document.documentElement;
  var leg = document.createElementNS("http://www.w3.org/1999/xhtml", "legend");
  leg.style.cssFloat = "left";
  dE.appendChild(leg);
  document.documentElement.offsetHeight;
  dE.removeChild(leg);
}

</script>

</head>

<body onload="boom();"></body>

</html>