chromium/third_party/blink/web_tests/dom/node/default-namespace-empty-argument.html

<p>Test for a <href="https://bugs.webkit.org/show_bug.cgi?id=30992">bug 30992</a>: Node.isDefaultNamespace doesn't convert empty strings to null.</p>
<p>Should say PASS:</p>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

document.write((document.implementation.createDocument(null, 'root', null).isDefaultNamespace('')) ? "PASS" : "FAIL");
</script>