<!DOCTYPE html>
<html>
<script>
if (window.testRunner)
    testRunner.dumpAsText();
</script>
<body>
<p>This test shouldn't crash.</p>
<p><math><mroot><mrow><mroot><mrow><mroot><mrow><mroot><mrow><mroot><mrow><mroot><mrow><mroot><mrow id="insertion-point"></mrow></mroot></mrow></mroot></mrow></mroot></mrow></mroot></mrow></mroot></mrow></mroot></mrow></mroot></math></p></body></html>
<script>
var elem = document.getElementById("insertion-point"); 
var parent = elem.parentNode;
var wbr = document.createElement("wbr");
parent.insertBefore(wbr, elem);
</script>