<script>
window.onload = function() {
	var parent = document.getElementById('id_1');
	parent.removeChild(parent.childNodes[0]);
	parent.removeChild(parent.childNodes[0]);
	document.getElementById('id_0').appendChild(document.activeElement);
}
</script>
<template id="id_0"></template>
<select required>
	<optgroup id="id_1">
		<option></option>
	</optgroup>
</select>
The test passes if this does not cause a debug assert.