fix: Fix reconnect failure after leaving host session

Minecraft.Client/Common/Network/GameNetworkManager.cpp

@@ -1396,7 +1396,19 @@ void CGameNetworkManager::CreateSocket( INetworkPlayer *pNetworkPlayer, bool loc
 	Minecraft *pMinecraft = Minecraft::GetInstance();
 
 	Socket *socket = NULL;
-	shared_ptr<MultiplayerLocalPlayer> mpPlayer = pMinecraft->localplayers[pNetworkPlayer->GetUserIndex()];
+	int localUserIndex = -1;
+	shared_ptr<MultiplayerLocalPlayer> mpPlayer;
+	if (localPlayer)
+	{
+		localUserIndex = pNetworkPlayer->GetUserIndex();
+#ifdef _WINDOWS64
+		// Win64 client local user is always the primary pad, not the network small-id slot.
+		if (!g_NetworkManager.IsHost())
+			localUserIndex = ProfileManager.GetPrimaryPad();
+#endif
+		if (localUserIndex >= 0 && localUserIndex < XUSER_MAX_COUNT)
+			mpPlayer = pMinecraft->localplayers[localUserIndex];
+	}
 	if( localPlayer && mpPlayer != NULL && mpPlayer->connection != NULL)
 	{
 		// If we already have a MultiplayerLocalPlayer here then we are doing a session type change
@@ -1425,7 +1437,14 @@ void CGameNetworkManager::CreateSocket( INetworkPlayer *pNetworkPlayer, bool loc
 		// the player in to the game server
 		if( localPlayer && g_NetworkManager.IsInGameplay() )
 		{
-			int idx = pNetworkPlayer->GetUserIndex();
+			int idx = localUserIndex;
+			if (idx < 0 || idx >= XUSER_MAX_COUNT)
+				idx = ProfileManager.GetPrimaryPad();
+			if (idx < 0 || idx >= XUSER_MAX_COUNT)
+			{
+				app.DebugPrintf("CreateSocket: invalid local user index %d\n", idx);
+				return;
+			}
 			app.DebugPrintf("Creating new client connection for idx: %d\n", idx);
 
 			ClientConnection *connection;

Minecraft.Client/Common/Network/PlatformNetworkManagerStub.cpp

@@ -270,25 +270,44 @@ void CPlatformNetworkManagerStub::DoWork()
 	// Keep LAN search ticking whenever the join menu callback is active, even if QNet state
 	// is not idle due to prior connection attempts.
 	TickSearch();
-	if (_iQNetStubState == QNET_STATE_GAME_PLAY && m_pIQNet->IsHost())
+	if (m_pIQNet->IsHost())
 	{
 		BYTE disconnectedSmallId;
 		while (WinsockNetLayer::PopDisconnectedSmallId(&disconnectedSmallId))
 		{
-			IQNetPlayer *qnetPlayer = m_pIQNet->GetPlayerBySmallId(disconnectedSmallId);
+			if (disconnectedSmallId == 0 || disconnectedSmallId >= MINECRAFT_NET_MAX_PLAYERS)
-			if (qnetPlayer != NULL && qnetPlayer->m_smallId == disconnectedSmallId)
+				continue;
+
+			app.DebugPrintf("Win64 LAN: Processing disconnected smallId=%d\n", disconnectedSmallId);
+
+			IQNetPlayer *qnetPlayer = &IQNet::m_player[disconnectedSmallId];
+			if (qnetPlayer->m_smallId == disconnectedSmallId)
 			{
-				NotifyPlayerLeaving(qnetPlayer);
+				if (qnetPlayer->GetCustomDataValue() != 0)
+				{
+					NotifyPlayerLeaving(qnetPlayer);
+				}
+				else
+				{
+					app.DebugPrintf("Win64 LAN: smallId=%d had no active network player object\n", disconnectedSmallId);
+				}
 				qnetPlayer->m_smallId = 0;
 				qnetPlayer->m_isRemote = false;
 				qnetPlayer->m_isHostPlayer = false;
 				qnetPlayer->m_gamertag[0] = 0;
 				qnetPlayer->SetCustomDataValue(0);
-				WinsockNetLayer::PushFreeSmallId(disconnectedSmallId);
-				if (IQNet::s_playerCount > 1)
-					IQNet::s_playerCount--;
 			}
+			WinsockNetLayer::PushFreeSmallId(disconnectedSmallId);
 		}
+
+		// Keep player-count in sync with active remote slots.
+		DWORD highestUsedIndex = 0;
+		for (DWORD i = 1; i < MINECRAFT_NET_MAX_PLAYERS; i++)
+		{
+			if (IQNet::m_player[i].GetCustomDataValue() != 0)
+				highestUsedIndex = i;
+		}
+		IQNet::s_playerCount = highestUsedIndex + 1;
 	}
 #endif
 }

Minecraft.Client/Windows64/Network/WinsockNetLayer.cpp

@@ -397,11 +397,12 @@ bool WinsockNetLayer::SendToSmallId(BYTE targetSmallId, const void *data, int da
 SOCKET WinsockNetLayer::GetSocketForSmallId(BYTE smallId)
 {
 	EnterCriticalSection(&s_connectionsLock);
-	for (size_t i = 0; i < s_connections.size(); i++)
+	for (size_t i = s_connections.size(); i > 0; i--)
 	{
-		if (s_connections[i].smallId == smallId && s_connections[i].active)
+		Win64RemoteConnection &conn = s_connections[i - 1];
+		if (conn.smallId == smallId && conn.active && conn.tcpSocket != INVALID_SOCKET)
 		{
-			SOCKET sock = s_connections[i].tcpSocket;
+			SOCKET sock = conn.tcpSocket;
 			LeaveCriticalSection(&s_connectionsLock);
 			return sock;
 		}
@@ -492,9 +493,26 @@ DWORD WINAPI WinsockNetLayer::AcceptThreadProc(LPVOID param)
 		{
 			app.DebugPrintf("Failed to send small ID to client\n");
 			closesocket(clientSocket);
+			PushFreeSmallId(assignedSmallId);
 			continue;
 		}
 
+		// If an old slot for this smallId somehow remains, retire it before reusing the id.
+		EnterCriticalSection(&s_connectionsLock);
+		for (size_t i = 0; i < s_connections.size(); i++)
+		{
+			if (s_connections[i].smallId == assignedSmallId)
+			{
+				s_connections[i].active = false;
+				if (s_connections[i].tcpSocket != INVALID_SOCKET)
+				{
+					closesocket(s_connections[i].tcpSocket);
+					s_connections[i].tcpSocket = INVALID_SOCKET;
+				}
+			}
+		}
+		LeaveCriticalSection(&s_connectionsLock);
+
 		Win64RemoteConnection conn;
 		conn.tcpSocket = clientSocket;
 		conn.smallId = assignedSmallId;
@@ -574,18 +592,21 @@ DWORD WINAPI WinsockNetLayer::RecvThreadProc(LPVOID param)
 	delete[] recvBuf;
 
 	EnterCriticalSection(&s_connectionsLock);
-	for (size_t i = 0; i < s_connections.size(); i++)
+	if (connIdx < (DWORD)s_connections.size())
 	{
-		if (s_connections[i].smallId == clientSmallId)
+		s_connections[connIdx].active = false;
+		if (s_connections[connIdx].tcpSocket != INVALID_SOCKET)
 		{
-			s_connections[i].active = false;
+			closesocket(s_connections[connIdx].tcpSocket);
-			closesocket(s_connections[i].tcpSocket);
+			s_connections[connIdx].tcpSocket = INVALID_SOCKET;
-			s_connections[i].tcpSocket = INVALID_SOCKET;
-			break;
 		}
 	}
 	LeaveCriticalSection(&s_connectionsLock);
 
+	// Return this id immediately so rapid reconnect attempts don't exhaust the id pool
+	// while the game thread catches up with disconnect processing.
+	PushFreeSmallId(clientSmallId);
+
 	EnterCriticalSection(&s_disconnectLock);
 	s_disconnectedSmallIds.push_back(clientSmallId);
 	LeaveCriticalSection(&s_disconnectLock);
@@ -609,8 +630,21 @@ bool WinsockNetLayer::PopDisconnectedSmallId(BYTE *outSmallId)
 
 void WinsockNetLayer::PushFreeSmallId(BYTE smallId)
 {
+	if (smallId == 0 || smallId >= MINECRAFT_NET_MAX_PLAYERS)
+		return;
+
 	EnterCriticalSection(&s_freeSmallIdLock);
-	s_freeSmallIds.push_back(smallId);
+	bool found = false;
+	for (size_t i = 0; i < s_freeSmallIds.size(); i++)
+	{
+		if (s_freeSmallIds[i] == smallId)
+		{
+			found = true;
+			break;
+		}
+	}
+	if (!found)
+		s_freeSmallIds.push_back(smallId);
 	LeaveCriticalSection(&s_freeSmallIdLock);
 }