<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>background on body should fill the viewport even when it has bogus siblings</title>
  <style>
   html { background-color:transparent; background-image:none; }
   body { background-color:yellow; color:navy; }
  </style>
  <script>
   window.onload = function() {
     var newElm = document.createElementNS("urn:foo:bogus", "body");
     document.documentElement.insertBefore(newElm, document.getElementsByTagName("body")[0]);
     document.getElementsByTagName("p")[0].firstChild.data = "The entire viewport should be yellow.";
   }
  </script>
 </head>
 <body>
  <p>FAIL (script didn't run)</p>
 </body>
</html>