Resync techQueue if techQueueLength mismatch

NebulaModel/Packets/GameHistory/GameHistoryResearchUpdatePacket.cs

@@ -4,16 +4,18 @@ public class GameHistoryResearchUpdatePacket
 {
     public GameHistoryResearchUpdatePacket() { }
 
-    public GameHistoryResearchUpdatePacket(int techId, long hashUploaded, long hashNeeded, int techHashedFor10Frames)
+    public GameHistoryResearchUpdatePacket(int techId, long hashUploaded, long hashNeeded, int techHashedFor10Frames, int techQueueLength)
     {
         TechId = techId;
         HashUploaded = hashUploaded;
         HashNeeded = hashNeeded;
         TechHashedFor10Frames = techHashedFor10Frames;
+        TechQueueLength = (ushort)techQueueLength;
     }
 
     public int TechId { get; set; }
     public long HashUploaded { get; set; }
     public long HashNeeded { get; set; }
     public int TechHashedFor10Frames { get; set; }
+    public ushort TechQueueLength { get; set; }
 }

NebulaModel/Packets/GameHistory/GameHistoryTechQueueSyncRequest.cs

@@ -0,0 +1,13 @@
+namespace NebulaModel.Packets.GameHistory;
+
+public class GameHistoryTechQueueSyncRequest
+{
+    public GameHistoryTechQueueSyncRequest() { }
+
+    public GameHistoryTechQueueSyncRequest(int[] techQueue)
+    {
+        TechQueue = techQueue;
+    }
+
+    public int[] TechQueue { get; set; }
+}

NebulaNetwork/PacketProcessors/GameHistory/GameHistoryResearchUpdateProcessor.cs

@@ -1,5 +1,6 @@
 #region
 
+using System;
 using NebulaAPI.Packets;
 using NebulaModel.Logger;
 using NebulaModel.Networking;
@@ -29,5 +30,11 @@ protected override void ProcessPacket(GameHistoryResearchUpdatePacket packet, Ne
         state.hashNeeded = packet.HashNeeded;
         data.techStates[data.currentTech] = state;
         Multiplayer.Session.Statistics.TechHashedFor10Frames = packet.TechHashedFor10Frames;
+
+        if (packet.TechQueueLength != GameMain.history.techQueueLength)
+        {
+            // TechQueue length mismatch. Ask from server to get a full queue to stay in sync
+            conn.SendPacket(new GameHistoryTechQueueSyncRequest([]));
+        }
     }
 }

NebulaNetwork/PacketProcessors/GameHistory/GameHistoryTechQueueSyncProcessor.cs

@@ -0,0 +1,42 @@
+#region
+
+using NebulaAPI.GameState;
+using NebulaAPI.Packets;
+using NebulaModel.Networking;
+using NebulaModel.Packets;
+using NebulaModel.Packets.GameHistory;
+using NebulaWorld;
+
+#endregion
+
+namespace NebulaNetwork.PacketProcessors.GameHistory;
+
+[RegisterPacketProcessor]
+internal class GameHistoryTechQueueSyncProcessor : PacketProcessor<GameHistoryTechQueueSyncRequest>
+{
+    protected override void ProcessPacket(GameHistoryTechQueueSyncRequest packet, NebulaConnection conn)
+    {
+        if (IsHost)
+        {
+            packet.TechQueue = GameMain.history.techQueue;
+            conn.SendPacket(packet);
+        }
+        else
+        {
+            using (Multiplayer.Session.History.IsIncomingRequest.On())
+            {
+                var length = GameMain.history.techQueue.Length;
+                for (var i = 0; i < length; i++)
+                {
+                    // Clear the original queue by dequeue for compatibility
+                    GameMain.history.DequeueTech();
+                }
+                for (var i = 0; i < packet.TechQueue.Length; i++)
+                {
+                    if (packet.TechQueue[i] == 0) return;
+                    GameMain.history.EnqueueTech(packet.TechQueue[i]);
+                }
+            }
+        }
+    }
+}

NebulaNetwork/Server.cs

@@ -418,7 +418,7 @@ public void Update()
             {
                 var state = GameMain.data.history.techStates[GameMain.data.history.currentTech];
                 SendPacket(new GameHistoryResearchUpdatePacket(GameMain.data.history.currentTech, state.hashUploaded,
-                    state.hashNeeded, GameMain.statistics.techHashedFor10Frames));
+                    state.hashNeeded, GameMain.statistics.techHashedFor10Frames, GameMain.data.history.techQueueLength));
             }
         }