Test namespace prefix for element equality

components/script/dom/node.rs

@@ -2368,8 +2368,8 @@ impl<'a> NodeMethods for &'a Node {
         fn is_equal_element(node: &Node, other: &Node) -> bool {
             let element: &Element = ElementCast::to_ref(node).unwrap();
             let other_element: &Element = ElementCast::to_ref(other).unwrap();
-            // FIXME: namespace prefix
             (*element.namespace() == *other_element.namespace()) &&
+            (*element.prefix() == *other_element.prefix()) &&
             (*element.local_name() == *other_element.local_name()) &&
             (element.attrs().len() == other_element.attrs().len())
         }

tests/wpt/metadata/dom/nodes/Node-isEqualNode.xhtml.ini

@@ -1,3 +1,6 @@
 [Node-isEqualNode.xhtml]
   type: testharness
-  disabled: xml
+  expected: TIMEOUT
+  [isEqualNode should return true when only the internal subsets of DocumentTypes differ.]
+    expected: NOTRUN
+

tests/wpt/web-platform-tests/dom/nodes/Node-isEqualNode.xhtml

@@ -33,6 +33,30 @@ test(function() {
   assert_true(a.isEqualNode(b))
 }, "isEqualNode should return true when the attributes are in a different order")
 
+test(function() {
+  var a = document.createElementNS("ns", "prefix:foo")
+  var b = document.createElementNS("ns", "prefix:foo")
+  assert_true(a.isEqualNode(b))
+}, "isEqualNode should return true if elements have same namespace, prefix, and local name")
+
+test(function() {
+  var a = document.createElementNS("ns1", "prefix:foo")
+  var b = document.createElementNS("ns2", "prefix:foo")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different namespace")
+
+test(function() {
+  var a = document.createElementNS("ns", "prefix1:foo")
+  var b = document.createElementNS("ns", "prefix2:foo")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different prefix")
+
+test(function() {
+  var a = document.createElementNS("ns", "prefix:foo1")
+  var b = document.createElementNS("ns", "prefix:foo2")
+  assert_false(a.isEqualNode(b))
+}, "isEqualNode should return false if elements have different local name")
+
 test(function() {
   var a = document.createElement("foo")
   a.setAttributeNS("ns", "x:a", "bar")