Extension: The E4X XML constructor can now create XML directly from a Java

DOM node. Previously the implementation would have converted to a String
and attempted to reparse.

js/rhino/xmlimplsrc/org/mozilla/javascript/xmlimpl/XMLLibImpl.java

@@ -422,6 +422,15 @@ public final class XMLLibImpl extends XMLLib implements Serializable {
         }
         //    TODO    Technically we should fail on anything except a String, Number or Boolean
         //            See ECMA357 10.3
+        // Extension: if object is a DOM node, use that to construct the XML
+        // object.
+        if (object instanceof Wrapper) {
+            object = ((Wrapper) object).unwrap();
+        }
+        if (object instanceof org.w3c.dom.Node) {
+            org.w3c.dom.Node node = (org.w3c.dom.Node) object;
+            return newXML(XmlNode.createElementFromNode(node));
+        }
         //    Instead we just blindly cast to a String and let them convert anything.
         String s = ScriptRuntime.toString(object);
         //    TODO    Could this get any uglier?

js/rhino/xmlimplsrc/org/mozilla/javascript/xmlimpl/XmlNode.java

@@ -98,6 +98,12 @@ class XmlNode {
         return createImpl( processor.newDocument().createTextNode(value) );
     }
 
+    static XmlNode createElementFromNode(Node node) {
+        if (node instanceof Document)
+            node = ((Document) node).getDocumentElement();
+        return createImpl(node);
+    }
+
     static XmlNode createElement(XmlProcessor processor, String namespaceUri, String xml) throws org.xml.sax.SAXException {
         return createImpl( processor.toXml(namespaceUri, xml) );
     }