Fixed clients who leave a server and re-join becoming desynced and not being kicked by the server.

The clients didn't reset their ChatMessage.LastID, which caused an exception to be thrown when clamping the chatmsg ID server-side, preventing the server from updating the lastRecvEntityEventID of the client later in the method. The server wouldn't kick the client, because ServerEntityEventManager wouldn't handle cases where a client is waiting for an event that doesn't exist anymore.

Subsurface/Source/Networking/GameClient.cs

@@ -99,6 +99,7 @@ namespace Barotrauma.Networking
 
             otherClients = new List<Client>();
 
+            ChatMessage.LastID = 0;
             GameMain.NetLobbyScreen = new NetLobbyScreen();
         }
 

Subsurface/Source/Networking/GameServer.cs

@@ -713,7 +713,8 @@ namespace Barotrauma.Networking
                             DebugConsole.ThrowError("client.lastRecvEntityEventID > lastEntityEventID");                        
 #endif
                                                 
-                        c.lastRecvChatMsgID = NetIdUtils.Clamp(c.lastRecvChatMsgID, lastRecvChatMsgID, c.lastChatMsgQueueID);
+                        if (NetIdUtils.IdMoreRecent(lastRecvChatMsgID, c.lastRecvChatMsgID)) c.lastRecvChatMsgID = lastRecvChatMsgID;
+                        if (NetIdUtils.IdMoreRecent(c.lastRecvChatMsgID, c.lastChatMsgQueueID)) c.lastRecvChatMsgID = c.lastChatMsgQueueID;
 
                         if (NetIdUtils.IdMoreRecent(lastRecvEntitySpawnID, c.lastRecvEntitySpawnID)) c.lastRecvEntitySpawnID = lastRecvEntitySpawnID;
                         if (NetIdUtils.IdMoreRecent(c.lastRecvEntitySpawnID, lastEntitySpawnID)) c.lastRecvEntitySpawnID = lastEntitySpawnID;

Subsurface/Source/Networking/NetEntityEvent/ServerEntityEventManager.cs

@@ -73,7 +73,10 @@ namespace Barotrauma.Networking
             var newEvent = new ServerEntityEvent(entity, (UInt16)(ID + 1));
             if (extraData != null) newEvent.SetData(extraData);
             
-            events.RemoveAll(e => NetIdUtils.IdMoreRecent((UInt16)(lastSentToAll+1),e.ID)); //remove events that have been sent to all clients, they are redundant now
+            //remove events that have been sent to all clients, they are redundant now
+            //keep at least one event in the list (lastSentToAll == e.ID) so we can use it to keep track of the latest ID
+            events.RemoveAll(e => NetIdUtils.IdMoreRecent(lastSentToAll, e.ID)); 
+            
             for (int i = events.Count - 1; i >= 0; i--)
             {
                 //we already have an identical event that's waiting to be sent
@@ -139,6 +142,14 @@ namespace Barotrauma.Networking
 
                     if (toKick != null) toKick.ForEach(c => server.DisconnectClient(c, "", "You have been disconnected because of excessive desync"));
                 }
+
+                if (events.Count > 0)
+                {
+                    //the client is waiting for an event that we don't have anymore
+                    //(the ID they're expecting is smaller than the ID of the first event in our list)
+                    List<Client> toKick = inGameClients.FindAll(c => NetIdUtils.IdMoreRecent(events[0].ID, (UInt16)(c.lastRecvEntityEventID+1)));
+                    if (toKick != null) toKick.ForEach(c => server.DisconnectClient(c, "", "You have been disconnected because of excessive desync"));
+                }
             }
             
             var timedOutClients = clients.FindAll(c => c.inGame && c.NeedsMidRoundSync && Timing.TotalTime > c.MidRoundSyncTimeOut);