Program: 156030
Project: 156030
Buggy source:
@Override protected Object decode(Channel channel,SocketAddress remoteAddress,Object msg) throws Exception {
  ChannelBuffer buf=(ChannelBuffer)msg;
  buf.skipBytes(2);
  buf.readShort();
  ChannelBuffer id=buf.readBytes(7);
  int command=buf.readUnsignedShort();
  ChannelBuffer response;
  if (channel != null) {
    if (command == MSG_LOGIN) {
      response=ChannelBuffers.wrappedBuffer(new byte[]{0x01});
      sendResponse(channel,remoteAddress,id,MSG_LOGIN_RESPONSE,response);
    }
 else     if (command == MSG_HEARTBEAT) {
      response=ChannelBuffers.wrappedBuffer(new byte[]{0x01});
      sendResponse(channel,remoteAddress,id,MSG_HEARTBEAT,response);
    }
 else     if (command == MSG_SERVER) {
      response=ChannelBuffers.copiedBuffer(getServer(channel),StandardCharsets.US_ASCII);
      sendResponse(channel,remoteAddress,id,MSG_SERVER,response);
    }
  }
  Position position=new Position();
  position.setProtocol(getProtocolName());
  if (command == MSG_ALARM) {
    position.set(Position.KEY_ALARM,decodeAlarm(buf.readUnsignedByte()));
  }
 else   if (command == MSG_POSITION_LOGGED) {
    buf.skipBytes(6);
  }
  DeviceSession deviceSession=identify(id,channel,remoteAddress);
  if (deviceSession == null) {
    return null;
  }
  position.setDeviceId(deviceSession.getDeviceId());
  if (command == MSG_RFID) {
    for (int i=0; i < 15; i++) {
      long rfid=buf.readUnsignedInt();
      if (rfid != 0) {
        String card=String.format("String_Node_Str",rfid);
        position.set("String_Node_Str" + (i + 1),card);
        position.set(Position.KEY_RFID,card);
      }
    }
  }
  String sentence=buf.toString(buf.readerIndex(),buf.readableBytes() - 4,StandardCharsets.US_ASCII);
  if (command == MSG_POSITION || command == MSG_POSITION_LOGGED || command == MSG_ALARM) {
    return decodeRegular(position,sentence);
  }
 else   if (command == MSG_RFID) {
    return decodeRfid(position,sentence);
  }
 else   if (command == MSG_OBD_RT) {
    return decodeObd(position,sentence);
  }
  return null;
}

Fixed version (ground truth):
@Override protected Object decode(Channel channel,SocketAddress remoteAddress,Object msg) throws Exception {
  ChannelBuffer buf=(ChannelBuffer)msg;
  buf.skipBytes(2);
  buf.readShort();
  ChannelBuffer id=buf.readBytes(7);
  int command=buf.readUnsignedShort();
  ChannelBuffer response;
  if (channel != null) {
    if (command == MSG_LOGIN) {
      response=ChannelBuffers.wrappedBuffer(new byte[]{0x01});
      sendResponse(channel,remoteAddress,id,MSG_LOGIN_RESPONSE,response);
      return null;
    }
 else     if (command == MSG_HEARTBEAT) {
      response=ChannelBuffers.wrappedBuffer(new byte[]{0x01});
      sendResponse(channel,remoteAddress,id,MSG_HEARTBEAT,response);
      return null;
    }
 else     if (command == MSG_SERVER) {
      response=ChannelBuffers.copiedBuffer(getServer(channel),StandardCharsets.US_ASCII);
      sendResponse(channel,remoteAddress,id,MSG_SERVER,response);
      return null;
    }
  }
  Position position=new Position();
  position.setProtocol(getProtocolName());
  if (command == MSG_ALARM) {
    position.set(Position.KEY_ALARM,decodeAlarm(buf.readUnsignedByte()));
  }
 else   if (command == MSG_POSITION_LOGGED) {
    buf.skipBytes(6);
  }
  DeviceSession deviceSession=identify(id,channel,remoteAddress);
  if (deviceSession == null) {
    return null;
  }
  position.setDeviceId(deviceSession.getDeviceId());
  if (command == MSG_RFID) {
    for (int i=0; i < 15; i++) {
      long rfid=buf.readUnsignedInt();
      if (rfid != 0) {
        String card=String.format("String_Node_Str",rfid);
        position.set("String_Node_Str" + (i + 1),card);
        position.set(Position.KEY_RFID,card);
      }
    }
  }
  String sentence=buf.toString(buf.readerIndex(),buf.readableBytes() - 4,StandardCharsets.US_ASCII);
  if (command == MSG_POSITION || command == MSG_POSITION_LOGGED || command == MSG_ALARM) {
    return decodeRegular(position,sentence);
  }
 else   if (command == MSG_RFID) {
    return decodeRfid(position,sentence);
  }
 else   if (command == MSG_OBD_RT) {
    return decodeObd(position,sentence);
  }
  return null;
}