Fix children referencing when updating an entity

NitroxServer/Communication/Packets/Processors/PlayerJoiningMultiplayerSessionProcessor.cs

@@ -107,7 +107,7 @@ private void SetupPlayerEntity(Player player)
             NitroxTransform transform = new(player.Position, player.Rotation, NitroxVector3.One);
 
             PlayerWorldEntity playerEntity = new PlayerWorldEntity(transform, 0, null, false, player.GameObjectId, NitroxTechType.None, null, null, new List<Entity>());
-            entityRegistry.AddEntity(playerEntity);
+            entityRegistry.AddOrUpdate(playerEntity);
             world.WorldEntityManager.TrackEntityInTheWorld(playerEntity);
             playerManager.SendPacketToOtherPlayers(new SpawnEntities(playerEntity), player);
         }

NitroxServer/GameLogic/Entities/EntityRegistry.cs

@@ -68,6 +68,9 @@ public void AddEntity(Entity entity)
             }
         }
 
+        /// <summary>
+        /// Registers or updates an entity and its children.
+        /// </summary>
         public void AddOrUpdate(Entity entity)
         {
             if (!entitiesById.TryAdd(entity.Id, entity))
@@ -96,11 +99,21 @@ public void AddEntities(IEnumerable<Entity> entities)
         /// example a dropped InventoryEntity turns into a WorldEntity but keeps its 
         /// battery inside (already known). 
         /// </summary>
+        /// <remarks>
+        /// Updates entities if they already exist
+        /// </remarks>
         public void AddEntitiesIgnoringDuplicate(IEnumerable<Entity> entities)
         {
             foreach (Entity entity in entities)
             {
-                entitiesById.TryAdd(entity.Id, entity);
+                if (entitiesById.TryGetValue(entity.Id, out Entity currentEntity))
+                {
+                    entitiesById.TryUpdate(entity.Id, entity, currentEntity);
+                }
+                else
+                {
+                    entitiesById.TryAdd(entity.Id, entity);
+                }
                 AddEntitiesIgnoringDuplicate(entity.ChildEntities);
             }
         }
@@ -137,8 +150,6 @@ public void RemoveFromParent(Entity entity)
         {
             if (entity.ParentId != null && TryGetEntityById(entity.ParentId, out Entity parentEntity))
             {
-                // TODO: Either use this solution (to remove duplicated entities also) to avoid wrongly-referenced children
-                // Or try fixing wrongly-referenced children (when entities are overwritten by AddOrUpdate)
                 parentEntity.ChildEntities.RemoveAll(childEntity => childEntity.Id.Equals(entity.Id));
                 entity.ParentId = null;
             }
@@ -198,7 +209,6 @@ public void TransferChildren(NitroxId parentId, NitroxId newParentId, Func<Entit
 
         public void TransferChildren(Entity parent, Entity newParent, Func<Entity, bool> filter = null)
         {
-            Log.Debug($"Moving {parent.ChildEntities.Count} children from {parent.Id} to {newParent.Id}");
             IEnumerable<Entity> childrenToMove = filter != null ?
                 parent.ChildEntities.Where(filter) : parent.ChildEntities;
 

NitroxServer/GameLogic/Entities/WorldEntityManager.cs

@@ -132,8 +132,7 @@ public void AddGlobalRootEntity(GlobalRootEntity entity, bool addToRegistry = tr
                 {
                     if (addToRegistry)
                     {
-                        entityRegistry.AddEntity(entity);
-                        entityRegistry.AddEntitiesIgnoringDuplicate(entity.ChildEntities);
+                        entityRegistry.AddOrUpdate(entity);
                     }
                     globalRootEntitiesById.Add(entity.Id, entity);
                 }
@@ -164,8 +163,7 @@ public Optional<Entity> RemoveGlobalRootEntity(NitroxId entityId, bool removeFro
                             childPlayerEntity.ParentId = null;
 
                             // Make sure the PlayerEntity is correctly registered
-                            globalRootEntitiesById[childPlayerEntity.Id] = childPlayerEntity;
-                            entityRegistry.AddOrUpdate(childPlayerEntity);
+                            UpdateGlobalRootEntity(childPlayerEntity);
                         }
                     }
                     removedEntity = entityRegistry.RemoveEntity(entityId);

NitroxServer/GameLogic/EscapePodManager.cs

@@ -63,8 +63,7 @@ private EscapePodWorldEntity CreateNewEscapePod()
             escapePod.ChildEntities.Add(new PrefabChildEntity(new NitroxId(), "9f16d82b-11f4-4eeb-aedf-f2fa2bfca8e3", new NitroxTechType("Fabricator"), 0, null, escapePod.Id));
             escapePod.ChildEntities.Add(new InventoryEntity(0, new NitroxId(), new NitroxTechType("SmallStorage"), null, escapePod.Id, new List<Entity>()));
 
-            entityRegistry.AddEntity(escapePod);
-            entityRegistry.AddEntities(escapePod.ChildEntities);
+            entityRegistry.AddOrUpdate(escapePod);
 
             return escapePod;
         }

NitroxServer/Serialization/World/WorldPersistence.cs

@@ -194,10 +194,6 @@ public World CreateWorld(PersistedWorldData pWorldData, NitroxGameMode gameMode)
 
             EntityRegistry entityRegistry = NitroxServiceLocator.LocateService<EntityRegistry>();
             entityRegistry.AddEntities(pWorldData.EntityData.Entities);
-            foreach (Entity entity in pWorldData.GlobalRootData.Entities)
-            {
-                Log.Debug($"Adding GlobalRootEntity: {entity.Id} of type: {entity.GetType()}");
-            }
             entityRegistry.AddEntitiesIgnoringDuplicate(pWorldData.GlobalRootData.Entities.OfType<Entity>().ToList());
 
             World world = new()