setAttributeNS-empty-namespace.html

<body>
<p>Test that setAttributeNS("", ...) creates an attribute in null namespace. Per DOM 3 Core,</p>
<pre>In programming languages where empty strings can be differentiated from null, empty strings, when given as a namespace URI, are converted to null.</pre>
<script>
if (window.testRunner)
    testRunner.dumpAsText();

document.body.setAttributeNS("", "a", "b");
var attrNamespace = document.body.getAttributeNodeNS("", "a").namespaceURI;
document.write(attrNamespace === null ? "PASS" : ("FAIL: '" + attrNamespace + "'"));
</script>
</body>

chromium/third_party/blink/web_tests/fast/dom/setAttributeNS-empty-namespace.html