<!doctype html>
<title>document.implementation.createDocument with current document's DOCTYPE</title>
<body>
FAIL (Script did not run);
<script>
document.body.textContent = "FAIL";
try {
    document.implementation.createDocument(null, null, document.doctype);
    document.body.textContent = "FAIL (no exception)";
}
catch(e) {
    if (e.code === DOMException.WRONG_DOCUMENT_ERR || e.code === DOMException.NOT_SUPPORTED_ERR)
        document.body.textContent = "PASS";
    else
        document.body.textContent = "FAIL (wrong exception: " + e.code + ")";
}
</script>