Core/Misc: Fixed thread-unsafe access to list of objects that should be spawned in a cell

Port From (https://github.com/TrinityCore/TrinityCore/commit/7b6589c1ecc159f6949c5535785fba79a04b2c4a)

Source/Game/Entities/Transport.cs

@@ -591,18 +591,22 @@ namespace Game.Entities
         void LoadStaticPassengers()
         {
             uint mapId = (uint)GetGoInfo().MoTransport.SpawnMap;
+            if (mapId == 0)
+                return;
+
             var cells = Global.ObjectMgr.GetMapObjectGuids(mapId, GetMap().GetDifficultyID());
             if (cells == null)
                 return;
-            foreach (var cell in cells)
-            {
-                // Creatures on transport
-                foreach (var npc in cell.Value.creatures)
-                    CreateNPCPassenger(npc, Global.ObjectMgr.GetCreatureData(npc));
 
+            foreach (var (_, guids) in cells)
+            {
                 // GameObjects on transport
-                foreach (var go in cell.Value.gameobjects)
+                foreach (var spawnId in guids.gameobjects)
-                    CreateGOPassenger(go, Global.ObjectMgr.GetGameObjectData(go));
+                    CreateGOPassenger(spawnId, Global.ObjectMgr.GetGameObjectData(spawnId));
+
+                // Creatures on transport
+                foreach (var spawnId in guids.creatures)
+                    CreateNPCPassenger(spawnId, Global.ObjectMgr.GetCreatureData(spawnId));
             }
         }
 

Source/Game/Garrisons/Garrisons.cs

@@ -738,20 +738,24 @@ namespace Game.Garrisons
 
                 if (go.GetGoType() == GameObjectTypes.GarrisonBuilding && go.GetGoInfo().GarrisonBuilding.SpawnMap != 0)
                 {
-                    foreach (var cellGuids in Global.ObjectMgr.GetMapObjectGuids((uint)go.GetGoInfo().GarrisonBuilding.SpawnMap, map.GetDifficultyID()))
+                    var cells = Global.ObjectMgr.GetMapObjectGuids((uint)go.GetGoInfo().GarrisonBuilding.SpawnMap, map.GetDifficultyID());
+                    if (cells != null)
                     {
-                        foreach (var spawnId in cellGuids.Value.creatures)
+                        foreach (var (_, guids) in cells)
                         {
-                            Creature spawn = BuildingSpawnHelper<Creature>(go, spawnId, map);
+                            foreach (var spawnId in guids.creatures)
-                            if (spawn != null)
+                            {
-                                BuildingInfo.Spawns.Add(spawn.GetGUID());
+                                Creature spawn = BuildingSpawnHelper<Creature>(go, spawnId, map);
-                        }
+                                if (spawn != null)
+                                    BuildingInfo.Spawns.Add(spawn.GetGUID());
+                            }
 
-                        foreach (var spawnId in cellGuids.Value.gameobjects)
+                            foreach (var spawnId in guids.gameobjects)
-                        {
+                            {
-                            GameObject spawn = BuildingSpawnHelper<GameObject>(go, spawnId, map);
+                                GameObject spawn = BuildingSpawnHelper<GameObject>(go, spawnId, map);
-                            if (spawn != null)
+                                if (spawn != null)
-                                BuildingInfo.Spawns.Add(spawn.GetGUID());
+                                    BuildingInfo.Spawns.Add(spawn.GetGUID());
+                            }
                         }
                     }
                 }

Source/Game/Globals/ObjectManager.cs

@@ -10376,16 +10376,15 @@ namespace Game
         {
             var key = (mapid, difficulty);
 
-            if (mapObjectGuidsStore.ContainsKey(key) && mapObjectGuidsStore[key].ContainsKey(cellid))
+            if (mapObjectGuidsStore.ContainsKey(key) && mapObjectGuidsStore[key].TryGetValue(cellid, out CellObjectGuids guids))
-                return mapObjectGuidsStore[key][cellid];
+                return guids;
 
             return null;
         }
 
         public Dictionary<uint, CellObjectGuids> GetMapObjectGuids(uint mapid, Difficulty difficulty)
         {
-            var key = (mapid, difficulty);
+            return mapObjectGuidsStore.LookupByKey((mapid, difficulty));
-            return mapObjectGuidsStore.LookupByKey(key);
         }
 
         public PageText GetPageText(uint pageEntry)

Source/Game/Maps/ObjectGridLoader.cs

@@ -101,20 +101,16 @@ namespace Game.Maps
         {
             CellCoord cellCoord = i_cell.GetCellCoord();
             CellObjectGuids cellguids = Global.ObjectMgr.GetCellObjectGuids(i_map.GetId(), i_map.GetDifficultyID(), cellCoord.GetId());
-            if (cellguids == null)
+            if (cellguids != null)
-                return;
+                LoadHelper<GameObject>(cellguids.gameobjects, cellCoord, ref i_gameObjects, i_map);
-
-            LoadHelper<GameObject>(cellguids.gameobjects, cellCoord, ref i_gameObjects, i_map);
         }
 
         public override void Visit(IList<Creature> objs)
         {
             CellCoord cellCoord = i_cell.GetCellCoord();
             CellObjectGuids cellguids = Global.ObjectMgr.GetCellObjectGuids(i_map.GetId(), i_map.GetDifficultyID(), cellCoord.GetId());
-            if (cellguids == null)
+            if (cellguids != null)
-                return;
+                LoadHelper<Creature>(cellguids.creatures, cellCoord, ref i_creatures, i_map);
-
-            LoadHelper<Creature>(cellguids.creatures, cellCoord, ref i_creatures, i_map);
         }
 
         public override void Visit(IList<AreaTrigger> objs)
@@ -221,7 +217,7 @@ namespace Game.Maps
         {
             // stop any fights at grid de-activation and remove dynobjects/areatriggers created at cast by creatures
             for (var i = 0; i < objs.Count; ++i)
-            {  
+            {
                 Creature creature = objs[i];
                 creature.RemoveAllDynObjects();
                 creature.RemoveAllAreaTriggers();
@@ -274,7 +270,7 @@ namespace Game.Maps
 
                 obj.SetDestroyedObject(true);
                 obj.CleanupsBeforeDelete();
-            }       
+            }
         }
     }