Index: source/network/NetFileTransfer.h
===================================================================
--- source/network/NetFileTransfer.h
+++ source/network/NetFileTransfer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2016 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -86,6 +86,10 @@
 	 */
 	Status HandleMessageReceive(const CNetMessage* message);
 
+	Status OnFileTransferResponse(const CNetMessage* message);
+	Status OnFileTransferData(const CNetMessage* message);
+	Status OnFileTransferAck(const CNetMessage* message);
+
 	/**
 	 * Registers a file-receiving task.
 	 */
Index: source/network/NetFileTransfer.cpp
===================================================================
--- source/network/NetFileTransfer.cpp
+++ source/network/NetFileTransfer.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2016 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -27,104 +27,115 @@
 Status CNetFileTransferer::HandleMessageReceive(const CNetMessage* message)
 {
 	if (message->GetType() == NMT_FILE_TRANSFER_RESPONSE)
-	{
-		CFileTransferResponseMessage* respMessage = (CFileTransferResponseMessage*)message;
-
-		if (m_FileReceiveTasks.find(respMessage->m_RequestID) == m_FileReceiveTasks.end())
-		{
-			LOGERROR("Net transfer: Unsolicited file transfer response (id=%d)", (int)respMessage->m_RequestID);
-			return ERR::FAIL;
-		}
+		return OnFileTransferResponse(message);
 
-		if (respMessage->m_Length == 0 || respMessage->m_Length > MAX_FILE_TRANSFER_SIZE)
-		{
-			LOGERROR("Net transfer: Invalid size for file transfer response (length=%d)", (int)respMessage->m_Length);
-			return ERR::FAIL;
-		}
+	if (message->GetType() == NMT_FILE_TRANSFER_DATA)
+		return OnFileTransferData(message);
 
-		shared_ptr<CNetFileReceiveTask> task = m_FileReceiveTasks[respMessage->m_RequestID];
+	if (message->GetType() == NMT_FILE_TRANSFER_ACK)
+		return OnFileTransferAck(message);
 
-		task->m_Length = respMessage->m_Length;
-		task->m_Buffer.reserve(respMessage->m_Length);
+	return INFO::SKIPPED;
+}
 
-		LOGMESSAGERENDER("Downloading data over network (%d KB) - please wait...", (int)(task->m_Length/1024));
-		m_LastProgressReportTime = timer_Time();
+Status CNetFileTransferer::OnFileTransferResponse(const CNetMessage* message)
+{
+	CFileTransferResponseMessage* respMessage = (CFileTransferResponseMessage*)message;
 
-		return INFO::OK;
+	if (m_FileReceiveTasks.find(respMessage->m_RequestID) == m_FileReceiveTasks.end())
+	{
+		LOGERROR("Net transfer: Unsolicited file transfer response (id=%d)", (int)respMessage->m_RequestID);
+		return ERR::FAIL;
 	}
-	else if (message->GetType() == NMT_FILE_TRANSFER_DATA)
+
+	if (respMessage->m_Length == 0 || respMessage->m_Length > MAX_FILE_TRANSFER_SIZE)
 	{
-		CFileTransferDataMessage* dataMessage = (CFileTransferDataMessage*)message;
+		LOGERROR("Net transfer: Invalid size for file transfer response (length=%d)", (int)respMessage->m_Length);
+		return ERR::FAIL;
+	}
 
-		if (m_FileReceiveTasks.find(dataMessage->m_RequestID) == m_FileReceiveTasks.end())
-		{
-			LOGERROR("Net transfer: Unsolicited file transfer data (id=%d)", (int)dataMessage->m_RequestID);
-			return ERR::FAIL;
-		}
+	shared_ptr<CNetFileReceiveTask> task = m_FileReceiveTasks[respMessage->m_RequestID];
 
-		shared_ptr<CNetFileReceiveTask> task = m_FileReceiveTasks[dataMessage->m_RequestID];
+	task->m_Length = respMessage->m_Length;
+	task->m_Buffer.reserve(respMessage->m_Length);
 
-		task->m_Buffer += dataMessage->m_Data;
+	LOGMESSAGERENDER("Downloading data over network (%d KB) - please wait...", (int)(task->m_Length/1024));
+	m_LastProgressReportTime = timer_Time();
 
-		if (task->m_Buffer.size() > task->m_Length)
-		{
-			LOGERROR("Net transfer: Invalid size for file transfer data (length=%d actual=%d)", (int)task->m_Length, (int)task->m_Buffer.size());
-			return ERR::FAIL;
-		}
+	return INFO::OK;
+}
 
-		CFileTransferAckMessage ackMessage;
-		ackMessage.m_RequestID = task->m_RequestID;
-		ackMessage.m_NumPackets = 1; // TODO: would be nice to send a single ack for multiple packets at once
-		m_Session->SendMessage(&ackMessage);
+Status CNetFileTransferer::OnFileTransferData(const CNetMessage* message)
+{
+	CFileTransferDataMessage* dataMessage = (CFileTransferDataMessage*)message;
 
-		if (task->m_Buffer.size() == task->m_Length)
-		{
-			LOGMESSAGERENDER("Download completed");
+	if (m_FileReceiveTasks.find(dataMessage->m_RequestID) == m_FileReceiveTasks.end())
+	{
+		LOGERROR("Net transfer: Unsolicited file transfer data (id=%d)", (int)dataMessage->m_RequestID);
+		return ERR::FAIL;
+	}
 
-			task->OnComplete();
-			m_FileReceiveTasks.erase(dataMessage->m_RequestID);
-			return INFO::OK;
-		}
+	shared_ptr<CNetFileReceiveTask> task = m_FileReceiveTasks[dataMessage->m_RequestID];
 
-		// TODO: should report progress using proper GUI
+	task->m_Buffer += dataMessage->m_Data;
 
-		// Report the download status occassionally
-		double t = timer_Time();
-		if (t > m_LastProgressReportTime + 0.5)
-		{
-			LOGMESSAGERENDER("Downloading data: %.1f%% of %d KB", 100.f*task->m_Buffer.size()/task->m_Length, (int)(task->m_Length/1024));
-			m_LastProgressReportTime = t;
-		}
+	if (task->m_Buffer.size() > task->m_Length)
+	{
+		LOGERROR("Net transfer: Invalid size for file transfer data (length=%d actual=%d)", (int)task->m_Length, (int)task->m_Buffer.size());
+		return ERR::FAIL;
+	}
+
+	CFileTransferAckMessage ackMessage;
+	ackMessage.m_RequestID = task->m_RequestID;
+	ackMessage.m_NumPackets = 1; // TODO: would be nice to send a single ack for multiple packets at once
+	m_Session->SendMessage(&ackMessage);
+
+	if (task->m_Buffer.size() == task->m_Length)
+	{
+		LOGMESSAGERENDER("Download completed");
 
+		task->OnComplete();
+		m_FileReceiveTasks.erase(dataMessage->m_RequestID);
 		return INFO::OK;
 	}
-	else if (message->GetType() == NMT_FILE_TRANSFER_ACK)
+
+	// TODO: should report progress using proper GUI
+
+	// Report the download status occassionally
+	double t = timer_Time();
+	if (t > m_LastProgressReportTime + 0.5)
 	{
-		CFileTransferAckMessage* ackMessage = (CFileTransferAckMessage*)message;
+		LOGMESSAGERENDER("Downloading data: %.1f%% of %d KB", 100.f*task->m_Buffer.size()/task->m_Length, (int)(task->m_Length/1024));
+		m_LastProgressReportTime = t;
+	}
 
-		if (m_FileSendTasks.find(ackMessage->m_RequestID) == m_FileSendTasks.end())
-		{
-			LOGERROR("Net transfer: Unsolicited file transfer ack (id=%d)", (int)ackMessage->m_RequestID);
-			return ERR::FAIL;
-		}
+	return INFO::OK;
+}
 
-		CNetFileSendTask& task = m_FileSendTasks[ackMessage->m_RequestID];
+Status CNetFileTransferer::OnFileTransferAck(const CNetMessage* message)
+{
+	CFileTransferAckMessage* ackMessage = (CFileTransferAckMessage*)message;
 
-		if (ackMessage->m_NumPackets > task.packetsInFlight)
-		{
-			LOGERROR("Net transfer: Invalid num packets for file transfer ack (num=%d inflight=%d)",
-				(int)ackMessage->m_NumPackets, (int)task.packetsInFlight);
-			return ERR::FAIL;
-		}
+	if (m_FileSendTasks.find(ackMessage->m_RequestID) == m_FileSendTasks.end())
+	{
+		LOGERROR("Net transfer: Unsolicited file transfer ack (id=%d)", (int)ackMessage->m_RequestID);
+		return ERR::FAIL;
+	}
 
-		task.packetsInFlight -= ackMessage->m_NumPackets;
+	CNetFileSendTask& task = m_FileSendTasks[ackMessage->m_RequestID];
 
-		return INFO::OK;
+	if (ackMessage->m_NumPackets > task.packetsInFlight)
+	{
+		LOGERROR("Net transfer: Invalid num packets for file transfer ack (num=%d inflight=%d)",
+			(int)ackMessage->m_NumPackets, (int)task.packetsInFlight);
+		return ERR::FAIL;
 	}
 
-	return INFO::SKIPPED;
-}
+	task.packetsInFlight -= ackMessage->m_NumPackets;
 
+	return INFO::OK;
+
+}
 
 void CNetFileTransferer::StartTask(const shared_ptr<CNetFileReceiveTask>& task)
 {