getRoute() method must provide the complete route from source port to...

getRoute() method must provide the complete route from source port to destination port even when the route involves only one switch.  getRoute() must also not provide route from same switch-port to itself.

src/main/java/net/floodlightcontroller/topology/TopologyInstance.java

 package net.floodlightcontroller.topology;
 
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -602,19 +603,31 @@ public class TopologyInstance {
 
     protected Route getRoute(long srcId, short srcPort,
                              long dstId, short dstPort) {
+
+
+        // Return null the route source and desitnation are the
+        // same switchports.
+        if (srcId == dstId && srcPort == dstPort)
+            return null;
+
+        List<NodePortTuple> nptList;
         NodePortTuple npt;
         Route r = getRoute(srcId, dstId);
         if (r == null && srcId != dstId) return null;
 
-        RouteId id = new RouteId(srcId, dstId);
-
-        List<NodePortTuple> nptList= r.getPath();
+        if (r != null) {
+            nptList= r.getPath();
+        } else {
+            nptList = new ArrayList<NodePortTuple>();
+        }
         npt = new NodePortTuple(srcId, srcPort);
         nptList.add(0, npt); // add src port to the front
         npt = new NodePortTuple(dstId, dstPort);
         nptList.add(npt); // add dst port to the end
 
-        return new Route(id, nptList);
+        RouteId id = new RouteId(srcId, dstId);
+        r = new Route(id, nptList);
+        return r;
     }
 
     protected Route getRoute(long srcId, long dstId) {