ignore empty packet buffer

server/channelserver/sys_session.go

@@ -162,11 +162,13 @@ func (s *Session) sendLoop() {
 			pkt = <-s.sendPackets
 			buffer = append(buffer, pkt.data...)
 		}
+		if len(buffer) > 0 {
 			err := s.cryptConn.SendPacket(append(buffer, []byte{0x00, 0x10}...))
 			if err != nil {
 				s.logger.Warn("Failed to send packet")
 			}
 			buffer = buffer[:0]
+		}
 		time.Sleep(100 * time.Millisecond)
 	}
 }