2 files changed, 28 insertions, 5 deletions

diff --git a/src/ClientHandle.cpp b/src/ClientHandle.cpp
index 10920496d..c774a92c2 100644
--- a/src/ClientHandle.cpp
+++ b/src/ClientHandle.cpp
@@ -1824,10 +1824,7 @@ void cClientHandle::SendData(const char * a_Data, size_t a_Size)
 	}
 
 	cCSLock Lock(m_CSOutgoingData);
-	if (m_Link != nullptr)
-	{
-		m_Link->Send(a_Data, a_Size);
-	}
+	m_OutgoingData.append(a_Data, a_Size);
 }
 
 
@@ -1888,6 +1885,17 @@ void cClientHandle::Tick(float a_Dt)
 	{
 		m_Protocol->DataReceived(IncomingData.data(), IncomingData.size());
 	}
+
+	// Send any queued outgoing data:
+	AString OutgoingData;
+	{
+		cCSLock Lock(m_CSOutgoingData);
+		std::swap(OutgoingData, m_OutgoingData);
+	}
+	if ((m_Link != nullptr) && !OutgoingData.empty())
+	{
+		m_Link->Send(OutgoingData.data(), OutgoingData.size());
+	}
 	
 	m_TicksSinceLastPacket += 1;
 	if (m_TicksSinceLastPacket > 600)  // 30 seconds time-out
@@ -1976,6 +1984,17 @@ void cClientHandle::ServerTick(float a_Dt)
 		m_Protocol->DataReceived(IncomingData.data(), IncomingData.size());
 	}
 	
+	// Send any queued outgoing data:
+	AString OutgoingData;
+	{
+		cCSLock Lock(m_CSOutgoingData);
+		std::swap(OutgoingData, m_OutgoingData);
+	}
+	if ((m_Link != nullptr) && !OutgoingData.empty())
+	{
+		m_Link->Send(OutgoingData.data(), OutgoingData.size());
+	}
+	
 	if (m_State == csAuthenticated)
 	{
 		StreamNextChunk();
diff --git a/src/ClientHandle.h b/src/ClientHandle.h
index f5b7faede..8129d6a50 100644
--- a/src/ClientHandle.h
+++ b/src/ClientHandle.h
@@ -376,9 +376,13 @@ private:
 	Protected by m_CSIncomingData. */
 	AString m_IncomingData;
 
-	/** Protects data going out through m_Link against multi-threaded sending. */
+	/** Protects m_OutgoingData against multithreaded access. */
 	cCriticalSection m_CSOutgoingData;
 
+	/** Buffer for storing outgoing data from any thread; will get sent in Tick() (to prevent deadlocks).
+	Protected by m_CSOutgoingData. */
+	AString m_OutgoingData;
+
 	Vector3d m_ConfirmPosition;
 
 	cPlayer * m_Player;