Program: 5774
Project: 5774
Buggy source:
@Override public void onReceived(Iterator<FetchedMessage> messages){
  try {
    if (stopLatch.await(1,TimeUnit.NANOSECONDS)) {
      LOG.debug("String_Node_Str");
      return;
    }
  }
 catch (  InterruptedException e) {
    LOG.error("String_Node_Str",e);
    Thread.currentThread().interrupt();
    return;
  }
  long oldestProcessed=Long.MAX_VALUE;
  List<KafkaLogEvent> events=Lists.newArrayList();
  while (messages.hasNext()) {
    FetchedMessage message=messages.next();
    try {
      GenericRecord genericRecord=serializer.toGenericRecord(message.getPayload());
      ILoggingEvent event=serializer.fromGenericRecord(genericRecord);
      LoggingContext loggingContext=LoggingContextHelper.getLoggingContext(event.getMDCPropertyMap());
      KafkaLogEvent logEvent=new KafkaLogEvent(genericRecord,event,loggingContext,message.getTopicPartition().getPartition(),message.getNextOffset());
      events.add(logEvent);
      if (event.getTimeStamp() < oldestProcessed) {
        oldestProcessed=event.getTimeStamp();
      }
    }
 catch (    Throwable th) {
      LOG.error("String_Node_Str",message.getTopicPartition().getTopic(),message.getTopicPartition().getPartition());
    }
  }
  int count=events.size();
  if (!events.isEmpty()) {
    for (    KafkaLogProcessor processor : kafkaLogProcessors) {
      try {
        processor.process(events.iterator());
      }
 catch (      Throwable th) {
        LOG.error("String_Node_Str",processor.getClass().getSimpleName());
      }
    }
    metricsContext.gauge(delayMetric,System.currentTimeMillis() - oldestProcessed);
    metricsContext.increment(Constants.Metrics.Name.Log.PROCESS_MESSAGES_COUNT,count);
  }
  LOG.trace("String_Node_Str",count);
}

Fixed version (ground truth):
@Override public void onReceived(Iterator<FetchedMessage> messages){
  try {
    if (stopLatch.await(1,TimeUnit.NANOSECONDS)) {
      LOG.debug("String_Node_Str");
      return;
    }
  }
 catch (  InterruptedException e) {
    LOG.error("String_Node_Str",e);
    Thread.currentThread().interrupt();
    return;
  }
  long oldestProcessed=Long.MAX_VALUE;
  List<KafkaLogEvent> events=Lists.newArrayList();
  while (messages.hasNext()) {
    FetchedMessage message=messages.next();
    try {
      GenericRecord genericRecord=serializer.toGenericRecord(message.getPayload());
      ILoggingEvent event=serializer.fromGenericRecord(genericRecord);
      LOG.trace("String_Node_Str",event,partition);
      LoggingContext loggingContext=LoggingContextHelper.getLoggingContext(event.getMDCPropertyMap());
      KafkaLogEvent logEvent=new KafkaLogEvent(genericRecord,event,loggingContext,message.getTopicPartition().getPartition(),message.getNextOffset());
      events.add(logEvent);
      if (event.getTimeStamp() < oldestProcessed) {
        oldestProcessed=event.getTimeStamp();
      }
    }
 catch (    Throwable th) {
      LOG.warn("String_Node_Str",message.getNextOffset(),message.getTopicPartition().getTopic(),message.getTopicPartition().getPartition(),th);
    }
  }
  int count=events.size();
  if (!events.isEmpty()) {
    for (    KafkaLogProcessor processor : kafkaLogProcessors) {
      try {
        processor.process(events.iterator());
      }
 catch (      Throwable th) {
        LOG.warn("String_Node_Str",events.size(),processor.getClass().getSimpleName(),th);
      }
    }
    metricsContext.gauge(delayMetric,System.currentTimeMillis() - oldestProcessed);
    metricsContext.increment(Constants.Metrics.Name.Log.PROCESS_MESSAGES_COUNT,count);
  }
  LOG.trace("String_Node_Str",count);
}