manual merge of pull request stleary#18

XMLTest.java

@@ -321,4 +321,20 @@ public void shouldHandleIllegalJSONNodeNames()
 
         assertEquals(expected, result);
     }
+
+    @Test
+    public void shouldHandleNullNodeValue()
+    {
+        JSONObject inputJSON = new JSONObject();
+        inputJSON.put("nullValue", JSONObject.NULL);
+        // This is a possible preferred result
+        String expectedXML = "<nullValue/>";
+        String actualXML = "<nullValue>null</nullValue>";
+        /**
+         * This is the current behavior. JSONObject.NULL is emitted as 
+         * the string, "null".
+         */
+        String resultXML = XML.toString(inputJSON);
+        assertEquals(actualXML, resultXML);
+    }
 }