<html class="reftest-wait">
<head>

<style>
 colgroup#s { width: 200px; }
</style>

<script>
function boom()
{
  document.body.offsetHeight;

  var last = document.getElementById("last");
  var parent = last.parentNode;

  var colgroup = document.createElement("colgroup");
  colgroup.setAttribute("id", "s");
  parent.insertBefore(colgroup, last);

  var newtbody = document.createElement("tbody");
  var newrow = document.createElement("tr");
  var newcell = document.createElement("td");
  newcell.appendChild(document.createTextNode("cell 1,1"));
  newrow.appendChild(newcell);
  newcell = document.createElement("td");
  newcell.appendChild(document.createTextNode("cell 1,2"));
  newrow.appendChild(newcell);
  newtbody.appendChild(newrow);
  parent.insertBefore(newtbody, last);

  document.body.offsetHeight;
  document.documentElement.className = "";
}
</script>

</head>
<body onload="boom();">
<table border="1">
<colgroup></colgroup>
<tbody id="last"><tr><td>cell 2,1</td><td>cell 2,2</td></tr></tbody>
</table>
</body>
</html>