Replication Data Loss in Mirror Maker Bouncing testcase; patched by Jun Rao; reviewed by Joel Koshy, John Fung and Neha Narkhede; kafka-567

git-svn-id: https://svn.apache.org/repos/asf/incubator/kafka/branches/0.8@1397717 13f79535-47bb-0310-9956-ffa450edef68

core/src/main/scala/kafka/producer/async/ProducerSendThread.scala

@@ -93,6 +93,8 @@ class ProducerSendThread[K,V](val threadName: String,
           events = new ListBuffer[ProducerData[K,V]]
         }
     }
+    // send the last batch of events
+    tryToHandle(events)
     if(queue.size > 0)
       throw new IllegalQueueStateException("Invalid queue state! After queue shutdown, %d remaining items in the queue"
         .format(queue.size))