* Added a new method FlowId.isValidFlowId()
* Use the above method to fix a bug inside the FlowManager.addFlow()

Bug found by: Jono
diff --git a/src/main/java/net/onrc/onos/ofcontroller/util/FlowPath.java b/src/main/java/net/onrc/onos/ofcontroller/util/FlowPath.java
index a720fc6..ab3edb1 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/util/FlowPath.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/util/FlowPath.java
@@ -6,6 +6,7 @@
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowEntry;
 import net.onrc.onos.ofcontroller.core.INetMapTopologyObjects.IFlowPath;
 
+import org.codehaus.jackson.annotate.JsonIgnore;
 import org.codehaus.jackson.annotate.JsonProperty;
 
 /**
@@ -210,6 +211,18 @@
     }
 
     /**
+     * Test whether the Flow ID is valid.
+     *
+     * @return true if the Flow ID is valid, otherwise false.
+     */
+    @JsonIgnore
+    public boolean isValidFlowId() {
+	if (this.flowId == null)
+	    return false;
+	return (this.flowId.isValid());
+    }
+
+    /**
      * Get the Caller ID of the flow path installer.
      *
      * @return the Caller ID of the flow path installer.