From a0e47543d6dea49cd08daffcb97033e5c6e43139 Mon Sep 17 00:00:00 2001
From: Pavlin Radoslavov <pavlin@onlab.us>
Date: Fri, 17 Oct 2014 19:22:17 -0700
Subject: [PATCH] Bug fix: don't generate topology events with "null" reasons.

Approved by: Yuta
---
 .../onlab/onos/net/topology/impl/DefaultTopologyProvider.java  | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/core/net/src/main/java/org/onlab/onos/net/topology/impl/DefaultTopologyProvider.java b/core/net/src/main/java/org/onlab/onos/net/topology/impl/DefaultTopologyProvider.java
index 7ee6ddd0f9..9631c66e26 100644
--- a/core/net/src/main/java/org/onlab/onos/net/topology/impl/DefaultTopologyProvider.java
+++ b/core/net/src/main/java/org/onlab/onos/net/topology/impl/DefaultTopologyProvider.java
@@ -23,6 +23,7 @@ import org.onlab.onos.net.topology.TopologyProviderRegistry;
 import org.onlab.onos.net.topology.TopologyProviderService;
 import org.slf4j.Logger;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Timer;
 import java.util.concurrent.ExecutorService;
@@ -88,7 +89,7 @@ public class DefaultTopologyProvider extends AbstractProvider
         linkService.addListener(linkListener);
 
         isStarted = true;
-        triggerTopologyBuild(null);
+        triggerTopologyBuild(Collections.<Event>emptyList());
         log.info("Started");
     }