LayoutTests/fast/table/anonymous-colgroup-simple.html

<table><tbody id="tbody"><col id="col">
<script>
if (window.testRunner)
    testRunner.dumpAsText();
document.body.offsetHeight;
tbody.prepend(col);
document.body.offsetHeight;
col.before("or assert.");
document.body.offsetHeight;
tbody.prepend(col);
document.body.offsetHeight;
col.before("Pass if no crash ");
</script>