diff --git a/dom/tests/mochitest/bugs/mochitest.ini b/dom/tests/mochitest/bugs/mochitest.ini
index dce49b928d61..973829916f37 100644
--- a/dom/tests/mochitest/bugs/mochitest.ini
+++ b/dom/tests/mochitest/bugs/mochitest.ini
@@ -76,7 +76,6 @@ skip-if = (buildapp == 'b2g' && (toolkit != 'gonk' || debug))
 [test_bug404748.html]
 [test_bug406375.html]
 skip-if = buildapp == 'mulet' || buildapp == 'b2g' || toolkit == 'android'
-[test_bug411103.html]
 [test_bug414291.html]
 tags = openwindow
 [test_bug427744.html]
diff --git a/dom/tests/mochitest/bugs/test_bug411103.html b/dom/tests/mochitest/bugs/test_bug411103.html
deleted file mode 100644
index 3830cf03322e..000000000000
--- a/dom/tests/mochitest/bugs/test_bug411103.html
+++ /dev/null
@@ -1,188 +0,0 @@
-<!DOCTYPE html>
-<html>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=411103
--->
-<head>
-  <title>Test for Bug 411103</title>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=411103">Mozilla Bug 411103</a>
-<p id="display"></p>
-<div id="content" style="display: none"></div>
-
-<!-- XML's createElement and createElementNS aren't HTML's, of course -->
-<iframe src="data:application/xml,%3Cfoo%3EXML%3C/foo%3E" name="xmlWindow"></iframe>
-
-<!-- for good measure... -->
-<iframe src="data:application/xhtml+xml,%3Chtml%20xmlns=%22http://www.w3.org/1999/xhtml%22%3E%3Cbody%3E%3Cp%3EXHTML%3C/p%3E%3C/body%3E%3C/html%3E"
-        name="xhtmlWindow"></iframe>
-
-<pre id="test">
-<script class="testbody" type="text/javascript">
-
-SimpleTest.waitForExplicitFinish();
-
-/** Test for Bug 411103 **/
-var allNSTests =
-  [
-   { args: [undefined, undefined] },
-   { args: [null, undefined] },
-   { args: [undefined, null] },
-   { args: [null, null] },
-   { args: [null, ""], code: 5 },
-   { args: ["", null] },
-   { args: ["", ""], code: 5 },
-   { args: [null, "<div>"], code: 5 },
-   { args: [null, "0div"], code: 5 },
-   { args: [null, "di v"], code: 5 },
-   { args: [null, "di<v"], code: 5 },
-   { args: [null, "-div"], code: 5 },
-   { args: [null, ".div"], code: 5 },
-   { args: ["http://example.com/", "<div>"], code: 5 },
-   { args: ["http://example.com/", "0div"], code: 5 },
-   { args: ["http://example.com/", "di<v"], code: 5 },
-   { args: ["http://example.com/", "-div"], code: 5 },
-   { args: ["http://example.com/", ".div"], code: 5 },
-   { args: [null, ":div"], code: 14 },
-   { args: [null, "div:"], code: 14 },
-   { args: ["http://example.com/", ":div"], code: 14 },
-   { args: ["http://example.com/", "div:"], code: 14 },
-   { args: [null, "d:iv"], code: 14 },
-   { args: [null, "a:b:c"], code: 14, message: "valid XML name, invalid QName" },
-   { args: ["http://example.com/", "a:b:c"], code: 14, message: "valid XML name, invalid QName" },
-   { args: [null, "a::c"], code: 14, message: "valid XML name, invalid QName" },
-   { args: ["http://example.com/", "a::c"], code: 14, message: "valid XML name, invalid QName" },
-   { args: ["http://example.com/", "a:0"], code: 5, message: "valid XML name, not a valid QName" },
-   { args: ["http://example.com/", "0:a"], code: 5, message: "0 at start makes it not a valid XML name" },
-   { args: ["http://example.com/", "a:_"] },
-   { args: ["http://example.com/", "a:\u0BC6"], code: 14,
-     message: "non-ASCII character after colon is CombiningChar, which is " +
-              "NCNameChar but not (Letter | \"_\") so invalid at start of " +
-              "NCName (but still a valid XML name, hence not 5)" },
-   { args: ["http://example.com/", "\u0BC6:a"], code: 14,
-     message: "non-ASCII character after colon is CombiningChar, which is " +
-              "NCNameChar but not (Letter | \"_\") so invalid at start of " +
-              "NCName (Gecko chooses to throw 14 here, but either is valid " +
-              "as this is both an invalid XML name and an invalid QName)" },
-   { args: ["http://example.com/", "a:a\u0BC6"] },
-   { args: ["http://example.com/", "a\u0BC6:a"] },
-   { args: ["http://example.com/", "xml:test"], code: 14, message: "binding xml prefix wrong" },
-   { args: ["http://example.com/", "xmlns:test"], code: 14, message: "binding xmlns prefix wrong" },
-   { args: ["http://www.w3.org/2000/xmlns/", "x:test"], code: 14, message: "binding namespace namespace to wrong prefix" },
-   { args: ["http://www.w3.org/2000/xmlns/", "xmlns:test"] },
-   { args: ["http://www.w3.org/XML/1998/namespace", "xml:test"] },
-   { args: ["http://www.w3.org/XML/1998/namespace", "x:test"] },
-  ];
-
-var allNoNSTests =
-  [
-   { args: [undefined] },
-   { args: [null] },
-   { args: [""], code: 5 },
-   { args: ["<div>"], code: 5 },
-   { args: ["0div"], code: 5 },
-   { args: ["di v"], code: 5 },
-   { args: ["di<v"], code: 5 },
-   { args: ["-div"], code: 5 },
-   { args: [".div"], code: 5 },
-   { args: [":"], message: "valid XML name, invalid QName" },
-   { args: [":div"], message: "valid XML name, invalid QName" },
-   { args: ["div:"], message: "valid XML name, invalid QName" },
-   { args: ["d:iv"] },
-   { args: ["a:b:c"], message: "valid XML name, invalid QName" },
-   { args: ["a::c"], message: "valid XML name, invalid QName" },
-   { args: ["a::c:"], message: "valid XML name, invalid QName" },
-   { args: ["a:0"], message: "valid XML name, not a valid QName" },
-   { args: ["0:a"], code: 5, message: "0 at start makes it not a valid XML name" },
-   { args: ["a:_"] },
-   { args: ["a:\u0BC6"],
-     message: "non-ASCII character after colon is CombiningChar, which is " +
-              "valid in pre-namespace XML" },
-   { args: ["\u0BC6:a"], code: 5, message: "not a valid start character" },
-   { args: ["a:a\u0BC6"] },
-   { args: ["a\u0BC6:a"] },
-   { args: ["xml:test"] },
-   { args: ["xmlns:test"] },
-   { args: ["x:test"] },
-   { args: ["xmlns:test"] },
-  ];
-
-function sourceify(v)
-{
-  switch (typeof v)
-  {
-    case "undefined":
-      return v;
-
-    case "string":
-      return '"' + v.replace('"', '\\"') + '"';
-
-    default:
-      return String(v);
-  }
-}
-
-function sourceifyArgs(args)
-{
-  var copy = new Array(args.length);
-  for (var i = 0, sz = args.length; i < sz; i++)
-    copy[i] = sourceify(args[i]);
-
-  return copy.join(", ");
-}
-
-function runTests(tests, methodName, document)
-{
-  for (var i = 0, sz = tests.length; i < sz; i++)
-  {
-    var test = tests[i];
-  
-    var argStr = sourceifyArgs(test.args);
-    try
-    {
-      document[methodName].apply(document, test.args);
-      var msg = "expected no exception for " +
-                "document." + methodName + "(" + argStr + ")";
-      if ("message" in test)
-        msg += "; " + test.message;
-      ok(!("code" in test), msg);
-    }
-    catch (e)
-    {
-      msg = "exception code for document." + methodName + "(" + argStr + ")";
-      if ("message" in test)
-        msg += "; " + test.message;
-      is(e.code, test.code || "no exception", msg);
-    }
-  }
-}
-
-
-function run()
-{
-  // HTML document
-  runTests(allNSTests, "createElementNS", document);
-  runTests(allNoNSTests, "createElement", document);
-
-  // XML document
-  var xmlDocument = window.frames.xmlWindow.document;
-  runTests(allNSTests, "createElementNS", xmlDocument);
-  runTests(allNoNSTests, "createElement", xmlDocument);
-
-  // XHTML document, for good measure
-  var xhtmlDocument = window.frames.xhtmlWindow.document;
-  runTests(allNSTests, "createElementNS", xhtmlDocument);
-  runTests(allNoNSTests, "createElement", xhtmlDocument);
-
-  SimpleTest.finish();
-}
-
-window.addEventListener("load", run, false);
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/parser/expat/lib/moz_extensions.c b/parser/expat/lib/moz_extensions.c
index f5b0f6539c57..37b9e7f71e71 100644
--- a/parser/expat/lib/moz_extensions.c
+++ b/parser/expat/lib/moz_extensions.c
@@ -45,18 +45,15 @@ int MOZ_XMLCheckQName(const char* ptr, const char* end, int ns_aware,
       nmstrt = ns_aware; /* e.g. "a:0" should be valid if !ns_aware */
       break;
     case BT_NONASCII:
-      if (nmstrt && !IS_NMSTRT_CHAR_MINBPC(ptr)) {
-        /* If this is a valid name character and we're namespace-aware, the
-           QName is malformed.  Otherwise, this character's invalid at the
-           start of a name (or, if we're namespace-aware, at the start of a
-           localpart). */
-        return (IS_NAME_CHAR_MINBPC(ptr) && ns_aware) ?
-               MOZ_EXPAT_MALFORMED :
-               MOZ_EXPAT_INVALID_CHARACTER;
-      }
-      if (!IS_NAME_CHAR_MINBPC(ptr)) {
+      if (!IS_NAME_CHAR_MINBPC(ptr) ||
+          (nmstrt && !*colon && !IS_NMSTRT_CHAR_MINBPC(ptr))) {
         return MOZ_EXPAT_INVALID_CHARACTER;
       }
+      if (nmstrt && *colon && !IS_NMSTRT_CHAR_MINBPC(ptr)) {
+        /* If a non-starting character like a number is right after the colon,
+           this is a namespace error, not invalid character */
+        return MOZ_EXPAT_MALFORMED;
+      }
       nmstrt = 0;
       break;
     case BT_NMSTRT:
diff --git a/testing/web-platform/meta/dom/nodes/DOMImplementation-createDocument.html.ini b/testing/web-platform/meta/dom/nodes/DOMImplementation-createDocument.html.ini
index b540807ecb1f..6f2dc3f4dc14 100644
--- a/testing/web-platform/meta/dom/nodes/DOMImplementation-createDocument.html.ini
+++ b/testing/web-platform/meta/dom/nodes/DOMImplementation-createDocument.html.ini
@@ -1,30 +1,18 @@
 [DOMImplementation-createDocument.html]
   type: testharness
-  [createDocument test 6: null,"̀foo",null,"INVALID_CHARACTER_ERR"]
-    expected: FAIL
-    bug: 1298818
-
-  [createDocument test 172: metadata for null,null,DocumentType node]
-    expected: FAIL
-    bug: 520969
-
-  [createDocument test 172: null,null,DocumentType node,null]
-    expected: FAIL
-    bug: 520969
-
-  [createDocument test 185: null,"",DocumentType node]
-    expected: FAIL
-    bug: 520969
-
-  [createDocument test: null,"̀foo",null,"INVALID_CHARACTER_ERR"]
+  [createDocument test: "http://example.com/","a:0",null,"NAMESPACE_ERR"]
     expected: FAIL
+    bug: https://github.com/whatwg/dom/issues/319
 
   [createDocument test: null,null,DocumentType node <!DOCTYPE html>,null]
     expected: FAIL
+    bug: 520969
 
-  [createDocument test 170: metadata for null,null,DocumentType node <!DOCTYPE html>]
+  [createDocument test 195: metadata for null,null,DocumentType node <!DOCTYPE html>]
     expected: FAIL
+    bug: 520969
 
   [createDocument test: null,"",DocumentType node <!DOCTYPE html -//W3C//DTD XHTML 1.0 Transitional//EN http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd>]
     expected: FAIL
+    bug: 520969
 
diff --git a/testing/web-platform/meta/dom/nodes/Document-createElementNS.html.ini b/testing/web-platform/meta/dom/nodes/Document-createElementNS.html.ini
index 59d6e19151cd..0a772835fb21 100644
--- a/testing/web-platform/meta/dom/nodes/Document-createElementNS.html.ini
+++ b/testing/web-platform/meta/dom/nodes/Document-createElementNS.html.ini
@@ -1,8 +1,14 @@
 [Document-createElementNS.html]
   type: testharness
-  [createElementNS test 6: null,"̀foo","INVALID_CHARACTER_ERR"]
+  [createElementNS test in HTML document: "http://example.com/","a:0","NAMESPACE_ERR"]
+    bug: https://github.com/whatwg/dom/issues/319
     expected: FAIL
 
-  [createElementNS test: null,"̀foo","INVALID_CHARACTER_ERR"]
+  [createElementNS test in XML document: "http://example.com/","a:0","NAMESPACE_ERR"]
+    bug: https://github.com/whatwg/dom/issues/319
+    expected: FAIL
+
+  [createElementNS test in XHTML document: "http://example.com/","a:0","NAMESPACE_ERR"]
+    bug: https://github.com/whatwg/dom/issues/319
     expected: FAIL
 
diff --git a/testing/web-platform/tests/common/dummy.xhtml b/testing/web-platform/tests/common/dummy.xhtml
new file mode 100644
index 000000000000..5b208d744505
--- /dev/null
+++ b/testing/web-platform/tests/common/dummy.xhtml
@@ -0,0 +1,2 @@
+<!DOCTYPE html>
+<html><head><title>Dummy XHTML document</title></head><body /></html>
diff --git a/testing/web-platform/tests/common/dummy.xml b/testing/web-platform/tests/common/dummy.xml
new file mode 100644
index 000000000000..4a60c3035fcc
--- /dev/null
+++ b/testing/web-platform/tests/common/dummy.xml
@@ -0,0 +1 @@
+<foo>Dummy XML document</foo>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElement.html b/testing/web-platform/tests/dom/nodes/Document-createElement.html
index 59fa02d83f56..bacaff0f6a00 100644
--- a/testing/web-platform/tests/dom/nodes/Document-createElement.html
+++ b/testing/web-platform/tests/dom/nodes/Document-createElement.html
@@ -9,6 +9,8 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <div id="log"></div>
+<iframe src="/common/dummy.xml"></iframe>
+<iframe src="/common/dummy.xhtml"></iframe>
 <script>
 function toASCIIUppercase(str) {
   var diff = "a".charCodeAt(0) - "A".charCodeAt(0);
@@ -22,64 +24,134 @@ function toASCIIUppercase(str) {
   }
   return res;
 }
-test(function() {
-  var HTMLNS = "http://www.w3.org/1999/xhtml",
-      valid = [
-        //[input, localName],
-        [undefined, "undefined"],
-        [null, "null"],
-        ["foo", "foo"],
-        ["f1oo", "f1oo"],
-        ["foo1", "foo1"],
-        ["f\u0300oo", "f\u0300oo"],
-        ["foo\u0300", "foo\u0300"],
-        [":foo", ":foo"],
-        ["f:oo", "f:oo"],
-        ["foo:", "foo:"],
-        ["xml", "xml"],
-        ["xmlns", "xmlns"],
-        ["xmlfoo", "xmlfoo"],
-        ["xml:foo", "xml:foo"],
-        ["xmlns:foo", "xmlns:foo"],
-        ["xmlfoo:bar", "xmlfoo:bar"],
-        ["svg", "svg"],
-        ["math", "math"],
-        ["FOO", "foo"],
-        ["mar\u212a", "mar\u212a"],
-        ["\u0130nput", "\u0130nput"],
-        ["\u0131nput", "\u0131nput"]
-     ],
-     invalid = [
-       "",
-       "1foo",
-       "\u0300foo",
-       "}foo",
-       "f}oo",
-       "foo}",
-       "\ufffffoo",
-       "f\uffffoo",
-       "foo\uffff",
-       "<foo",
-       "foo>",
-       "<foo>",
-       "f<oo"
-     ]
+function toASCIILowercase(str) {
+  var diff = "a".charCodeAt(0) - "A".charCodeAt(0);
+  var res = "";
+  for (var i = 0; i < str.length; ++i) {
+    if ("A" <= str[i] && str[i] <= "Z") {
+      res += String.fromCharCode(str.charCodeAt(i) + diff);
+    } else {
+      res += str[i];
+    }
+  }
+  return res;
+}
+var HTMLNS = "http://www.w3.org/1999/xhtml",
+    valid = [
+      undefined,
+      null,
+      "foo",
+      "f1oo",
+      "foo1",
+      "f\u0BC6",
+      "foo\u0BC6",
+      ":",
+      ":foo",
+      "f:oo",
+      "foo:",
+      "f:o:o",
+      "f::oo",
+      "f::oo:",
+      "foo:0",
+      "foo:_",
+      // combining char after :, invalid QName but valid Name
+      "foo:\u0BC6",
+      "foo:foo\u0BC6",
+      "foo\u0BC6:foo",
+      "xml",
+      "xmlns",
+      "xmlfoo",
+      "xml:foo",
+      "xmlns:foo",
+      "xmlfoo:bar",
+      "svg",
+      "math",
+      "FOO",
+      // Test that non-ASCII chars don't get uppercased/lowercased
+      "mar\u212a",
+      "\u0130nput",
+      "\u0131nput",
+    ],
+    invalid = [
+      "",
+      "1foo",
+      "1:foo",
+      "fo o",
+      "\u0BC6foo",
+      "}foo",
+      "f}oo",
+      "foo}",
+      "\ufffffoo",
+      "f\uffffoo",
+      "foo\uffff",
+      "<foo",
+      "foo>",
+      "<foo>",
+      "f<oo",
+      "-foo",
+      ".foo",
+      "\u0BC6",
+    ]
 
-  valid.forEach(function(t) {
-    test(function() {
-      var elt = document.createElement(t[0])
-      assert_true(elt instanceof Element)
-      assert_true(elt instanceof Node)
-      assert_equals(elt.localName, t[1])
-      assert_equals(elt.tagName, toASCIIUppercase(t[1]))
-      assert_equals(elt.prefix, null)
-      assert_equals(elt.namespaceURI, HTMLNS)
-    }, "createElement(" + format_value(t[0]) + ")");
+var xmlIframe = document.querySelector('[src="/common/dummy.xml"]');
+var xhtmlIframe = document.querySelector('[src="/common/dummy.xhtml"]');
+
+function getWin(desc) {
+  if (desc == "HTML document") {
+    return window;
+  }
+  if (desc == "XML document") {
+    assert_equals(xmlIframe.contentDocument.documentElement.textContent,
+                  "Dummy XML document", "XML document didn't load");
+    return xmlIframe.contentWindow;
+  }
+  if (desc == "XHTML document") {
+    assert_equals(xhtmlIframe.contentDocument.documentElement.textContent,
+                  "Dummy XHTML document", "XHTML document didn't load");
+    return xhtmlIframe.contentWindow;
+  }
+}
+
+
+valid.forEach(function(t) {
+  ["HTML document", "XML document", "XHTML document"].forEach(function(desc) {
+    async_test(function(testObj) {
+      window.addEventListener("load", function() {
+        testObj.step(function() {
+          var win = getWin(desc);
+          var doc = win.document;
+          var elt = doc.createElement(t)
+          assert_true(elt instanceof win.Element, "instanceof Element")
+          assert_true(elt instanceof win.Node, "instanceof Node")
+          assert_equals(elt.localName,
+                        desc == "HTML document" ? toASCIILowercase(String(t))
+                                                : String(t),
+                        "localName")
+          assert_equals(elt.tagName,
+                        desc == "HTML document" ? toASCIIUppercase(String(t))
+                                                : String(t),
+                        "tagName")
+          assert_equals(elt.prefix, null, "prefix")
+          assert_equals(elt.namespaceURI,
+                        desc == "XML document" ? null : HTMLNS, "namespaceURI")
+        });
+        testObj.done();
+      });
+    }, "createElement(" + format_value(t) + ") in " + desc);
   });
-  invalid.forEach(function(arg) {
-    test(function() {
-      assert_throws("INVALID_CHARACTER_ERR", function() { document.createElement(arg) })
-    }, "createElement(" + format_value(arg) + ")");
+});
+invalid.forEach(function(arg) {
+  ["HTML document", "XML document", "XHTML document"].forEach(function(desc) {
+    async_test(function(testObj) {
+      window.addEventListener("load", function() {
+        testObj.step(function() {
+          var doc = getWin(desc).document;
+          assert_throws("InvalidCharacterError",
+                        function() { doc.createElement(arg) })
+        });
+        testObj.done();
+      });
+    }, "createElement(" + format_value(arg) + ") in " + desc);
   });
-})
+});
 </script>
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElementNS.html b/testing/web-platform/tests/dom/nodes/Document-createElementNS.html
index 75005a09e2ed..68341bcd44f2 100644
--- a/testing/web-platform/tests/dom/nodes/Document-createElementNS.html
+++ b/testing/web-platform/tests/dom/nodes/Document-createElementNS.html
@@ -6,59 +6,87 @@
 <script src="/resources/testharnessreport.js"></script>
 <script src="Document-createElementNS.js"></script>
 <div id="log"></div>
+<iframe src="/common/dummy.xml"></iframe>
+<iframe src="/common/dummy.xhtml"></iframe>
 <script>
-test(function() {
-  var tests = createElementNS_tests.concat([
-    /* Arrays with three elements:
-     *   the namespace argument
-     *   the qualifiedName argument
-     *   the expected exception, or null if none
-     */
-    ["", "", "INVALID_CHARACTER_ERR"],
-    [null, null, null],
-    [null, "", "INVALID_CHARACTER_ERR"],
-    [undefined, null, null],
-    [undefined, "", "INVALID_CHARACTER_ERR"],
-    ["http://example.com/", null, null],
-    ["http://example.com/", "", "INVALID_CHARACTER_ERR"],
-    ["/", null, null],
-    ["/", "", "INVALID_CHARACTER_ERR"],
-    ["http://www.w3.org/XML/1998/namespace", null, null],
-    ["http://www.w3.org/XML/1998/namespace", "", "INVALID_CHARACTER_ERR"],
-    ["http://www.w3.org/2000/xmlns/", null, "NAMESPACE_ERR"],
-    ["http://www.w3.org/2000/xmlns/", "", "INVALID_CHARACTER_ERR"],
-    ["foo:", null, null],
-    ["foo:", "", "INVALID_CHARACTER_ERR"],
-  ])
+var tests = createElementNS_tests.concat([
+  /* Arrays with three elements:
+   *   the namespace argument
+   *   the qualifiedName argument
+   *   the expected exception, or null if none
+   */
+  ["", "", "INVALID_CHARACTER_ERR"],
+  [null, null, null],
+  [null, "", "INVALID_CHARACTER_ERR"],
+  [undefined, null, null],
+  [undefined, "", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", null, null],
+  ["http://example.com/", "", "INVALID_CHARACTER_ERR"],
+  ["/", null, null],
+  ["/", "", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/XML/1998/namespace", null, null],
+  ["http://www.w3.org/XML/1998/namespace", "", "INVALID_CHARACTER_ERR"],
+  ["http://www.w3.org/2000/xmlns/", null, "NAMESPACE_ERR"],
+  ["http://www.w3.org/2000/xmlns/", "", "INVALID_CHARACTER_ERR"],
+  ["foo:", null, null],
+  ["foo:", "", "INVALID_CHARACTER_ERR"],
+])
 
-  tests.forEach(function(t, i) {
-    test(function() {
-      var namespace = t[0], qualifiedName = t[1], expected = t[2]
-      if (expected != null) {
-        assert_throws(expected, function() { document.createElementNS(namespace, qualifiedName) })
-      } else {
-        var element = document.createElementNS(namespace, qualifiedName)
-        assert_not_equals(element, null)
-        assert_equals(element.nodeType, Node.ELEMENT_NODE)
-        assert_equals(element.nodeType, element.ELEMENT_NODE)
-        assert_equals(element.nodeValue, null)
-        assert_equals(element.ownerDocument, document)
-        var qualified = String(qualifiedName), names = []
-        if (qualified.indexOf(":") >= 0) {
-          names = qualified.split(":", 2)
-        } else {
-          names = [null, qualified]
+var xmlIframe = document.querySelector('[src="/common/dummy.xml"]');
+var xhtmlIframe = document.querySelector('[src="/common/dummy.xhtml"]');
+
+function runTest(t, i, desc) {
+  async_test(function(testObj) {
+    window.addEventListener("load", function() {
+      testObj.step(function() {
+        var doc;
+        if (desc == "HTML document") {
+          doc = document;
+        } else if (desc == "XML document") {
+          doc = xmlIframe.contentDocument;
+          // Make sure we're testing the right document
+          assert_equals(doc.documentElement.textContent, "Dummy XML document");
+        } else if (desc == "XHTML document") {
+          doc = xhtmlIframe.contentDocument;
+          assert_equals(doc.documentElement.textContent, "Dummy XHTML document");
         }
-        assert_equals(element.prefix, names[0])
-        assert_equals(element.localName, names[1])
-        assert_equals(element.tagName, qualified)
-        assert_equals(element.nodeName, qualified)
-        assert_equals(element.namespaceURI, namespace === undefined ? null : namespace)
-      }
-    }, "createElementNS test: " + t.map(format_value))
-  })
+        var namespace = t[0], qualifiedName = t[1], expected = t[2]
+        if (expected != null) {
+          assert_throws(expected, function() { doc.createElementNS(namespace, qualifiedName) })
+        } else {
+          var element = doc.createElementNS(namespace, qualifiedName)
+          assert_not_equals(element, null)
+          assert_equals(element.nodeType, Node.ELEMENT_NODE)
+          assert_equals(element.nodeType, element.ELEMENT_NODE)
+          assert_equals(element.nodeValue, null)
+          assert_equals(element.ownerDocument, doc)
+          var qualified = String(qualifiedName), names = []
+          if (qualified.indexOf(":") >= 0) {
+            names = qualified.split(":", 2)
+          } else {
+            names = [null, qualified]
+          }
+          assert_equals(element.prefix, names[0])
+          assert_equals(element.localName, names[1])
+          assert_equals(element.tagName, qualified)
+          assert_equals(element.nodeName, qualified)
+          assert_equals(element.namespaceURI,
+                        namespace === undefined || namespace === "" ? null
+                                                                    : namespace)
+        }
+      });
+      testObj.done();
+    });
+  }, "createElementNS test in " + desc + ": " + t.map(format_value))
+}
+
+tests.forEach(function(t, i) {
+  runTest(t, i, "HTML document")
+  runTest(t, i, "XML document")
+  runTest(t, i, "XHTML document")
 })
 
+
 test(function() {
   var HTMLNS = "http://www.w3.org/1999/xhtml";
   var element = document.createElementNS(HTMLNS, "span");
diff --git a/testing/web-platform/tests/dom/nodes/Document-createElementNS.js b/testing/web-platform/tests/dom/nodes/Document-createElementNS.js
index e5d3047ad662..b390712aa17b 100644
--- a/testing/web-platform/tests/dom/nodes/Document-createElementNS.js
+++ b/testing/web-platform/tests/dom/nodes/Document-createElementNS.js
@@ -4,12 +4,13 @@ var createElementNS_tests = [
    *   the qualifiedName argument
    *   the expected exception, or null if none
    */
+  [null, null, null],
   [null, undefined, null],
   [null, "foo", null],
   [null, "1foo", "INVALID_CHARACTER_ERR"],
   [null, "f1oo", null],
   [null, "foo1", null],
-  [null, "\u0300foo", "INVALID_CHARACTER_ERR"],
+  [null, "\u0BC6foo", "INVALID_CHARACTER_ERR"],
   [null, "}foo", "INVALID_CHARACTER_ERR"],
   [null, "f}oo", "INVALID_CHARACTER_ERR"],
   [null, "foo}", "INVALID_CHARACTER_ERR"],
@@ -21,9 +22,13 @@ var createElementNS_tests = [
   [null, "<foo>", "INVALID_CHARACTER_ERR"],
   [null, "f<oo", "INVALID_CHARACTER_ERR"],
   [null, "^^", "INVALID_CHARACTER_ERR"],
+  [null, "fo o", "INVALID_CHARACTER_ERR"],
+  [null, "-foo", "INVALID_CHARACTER_ERR"],
+  [null, ".foo", "INVALID_CHARACTER_ERR"],
   [null, ":foo", "NAMESPACE_ERR"],
   [null, "f:oo", "NAMESPACE_ERR"],
   [null, "foo:", "NAMESPACE_ERR"],
+  [null, "f:o:o", "NAMESPACE_ERR"],
   [null, ":", "NAMESPACE_ERR"],
   [null, "xml", null],
   [null, "xmlns", "NAMESPACE_ERR"],
@@ -32,9 +37,11 @@ var createElementNS_tests = [
   [null, "xmlns:foo", "NAMESPACE_ERR"],
   [null, "xmlfoo:bar", "NAMESPACE_ERR"],
   [null, "null:xml", "NAMESPACE_ERR"],
+  ["", null, null],
   ["", ":foo", "NAMESPACE_ERR"],
   ["", "f:oo", "NAMESPACE_ERR"],
   ["", "foo:", "NAMESPACE_ERR"],
+  [undefined, null, null],
   [undefined, undefined, null],
   [undefined, "foo", null],
   [undefined, "1foo", "INVALID_CHARACTER_ERR"],
@@ -43,6 +50,7 @@ var createElementNS_tests = [
   [undefined, ":foo", "NAMESPACE_ERR"],
   [undefined, "f:oo", "NAMESPACE_ERR"],
   [undefined, "foo:", "NAMESPACE_ERR"],
+  [undefined, "f::oo", "NAMESPACE_ERR"],
   [undefined, "xml", null],
   [undefined, "xmlns", "NAMESPACE_ERR"],
   [undefined, "xmlfoo", null],
@@ -51,11 +59,28 @@ var createElementNS_tests = [
   [undefined, "xmlfoo:bar", "NAMESPACE_ERR"],
   ["http://example.com/", "foo", null],
   ["http://example.com/", "1foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "<foo>", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "fo<o", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "-foo", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", ".foo", "INVALID_CHARACTER_ERR"],
   ["http://example.com/", "f1oo", null],
   ["http://example.com/", "foo1", null],
   ["http://example.com/", ":foo", "NAMESPACE_ERR"],
   ["http://example.com/", "f:oo", null],
+  ["http://example.com/", "f:o:o", "NAMESPACE_ERR"],
   ["http://example.com/", "foo:", "NAMESPACE_ERR"],
+  ["http://example.com/", "f::oo", "NAMESPACE_ERR"],
+  ["http://example.com/", "a:0", "NAMESPACE_ERR"],
+  ["http://example.com/", "0:a", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:_", null],
+  ["http://example.com/", "a:\u0BC6", "NAMESPACE_ERR"],
+  ["http://example.com/", "\u0BC6:a", "INVALID_CHARACTER_ERR"],
+  ["http://example.com/", "a:a\u0BC6", null],
+  ["http://example.com/", "a\u0BC6:a", null],
+  ["http://example.com/", "xml:test", "NAMESPACE_ERR"],
+  ["http://example.com/", "xmlns:test", "NAMESPACE_ERR"],
+  ["http://example.com/", "test:xmlns", null],
+  ["http://example.com/", "xmlns", "NAMESPACE_ERR"],
   ["http://example.com/", "_:_", null],
   ["http://example.com/", "_:h0", null],
   ["http://example.com/", "_:test", null],
