Add PrefabHandler shutdown

Author: EmandM

com.unity.netcode.gameobjects/Runtime/Core/NetworkManager.cs

@@ -1593,8 +1593,9 @@ internal void ShutdownInternal()
             // Completely reset the NetworkClient
             ConnectionManager.LocalClient = new NetworkClient();
 
-            // This cleans up the internal prefabs list
+            // Clean up the internal prefabs data
             NetworkConfig?.Prefabs?.Shutdown();
+            PrefabHandler.Shutdown();
 
             // Reset the configuration hash for next session in the event
             // that the prefab list changes

com.unity.netcode.gameobjects/Runtime/Core/NetworkObject.cs

@@ -3247,6 +3247,7 @@ internal static NetworkObject AddSceneObject(in SceneObject sceneObject, FastBuf
                 var bufferSerializer = new BufferSerializer<BufferSerializerReader>(new BufferSerializerReader(reader));
                 networkObject.SynchronizeNetworkBehaviours(ref bufferSerializer, networkManager.LocalClientId);
 
+                // Ensure that the buffer is completely reset
                 if (reader.Position != endOfSynchronizationData)
                 {
                     Debug.LogWarning($"[Size mismatch] Expected: {endOfSynchronizationData} Currently At: {reader.Position}!");

com.unity.netcode.gameobjects/Runtime/Spawning/NetworkPrefabHandler.cs

@@ -283,27 +283,21 @@ internal uint GetSourceGlobalObjectIdHash(uint networkPrefabHash)
         internal NetworkObject HandleNetworkPrefabSpawn(uint networkPrefabAssetHash, ulong ownerClientId, Vector3 position, Quaternion rotation, byte[] instantiationData = null)
         {
             NetworkObject networkObjectInstance = null;
-            var needsInstantiation = true;
             if (instantiationData != null)
             {
                 if (m_PrefabAssetToPrefabHandlerWithData.TryGetValue(networkPrefabAssetHash, out var prefabInstanceHandler))
                 {
-                    needsInstantiation = false;
                     networkObjectInstance = prefabInstanceHandler.Instantiate(ownerClientId, position, rotation, instantiationData);
                 }
                 else
                 {
                     Debug.LogError($"[InstantiationData] Failed instantiate with data: no compatible data handler found for object hash {networkPrefabAssetHash}. Instantiation data will be dropped.");
+                    return null;
                 }
             }
-
-            // Fallback to default handler
-            if (needsInstantiation)
+            else if (m_PrefabAssetToPrefabHandler.TryGetValue(networkPrefabAssetHash, out var prefabInstanceHandler))
             {
-                if (m_PrefabAssetToPrefabHandler.TryGetValue(networkPrefabAssetHash, out var prefabInstanceHandler))
-                {
-                    networkObjectInstance = prefabInstanceHandler.Instantiate(ownerClientId, position, rotation);
-                }
+                networkObjectInstance = prefabInstanceHandler.Instantiate(ownerClientId, position, rotation);
             }
 
             // Now we must make sure this alternate PrefabAsset spawned in place of the prefab asset with the networkPrefabAssetHash (GlobalObjectIdHash)
@@ -466,5 +460,10 @@ internal void Initialize(NetworkManager networkManager)
         {
             m_NetworkManager = networkManager;
         }
+
+        internal void Shutdown()
+        {
+            m_PrefabInstanceToPrefabAsset.Clear();
+        }
     }
 }