<!DOCTYPE html>
<body>
<a>
    <p>
        <b>
            <u id="test"/>
            <keygen form="test"/>
        </b>
</a>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

document.body.innerText = `This tests removing a subtree containing a form associated element with two non-form elements with matching ID.
The test passses if WebKit doesn't hit a debug assertion.

PASS.`;
</script>