fix: inscene networkobjects get destroyed upon client networkmanager shutting down without connecting (#1809)

Author: NoelStephensUnity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -19,7 +19,7 @@ Additional documentation and release notes are available at [Multiplayer Documen
 - Removed `com.unity.modules.animation`, `com.unity.modules.physics` and `com.unity.modules.physics2d` dependencies from the package (#1812)
 
 ### Fixed
-
+- Fixed in-scene NetworkObjects get destroyed if a client fails to connect and shuts down the NetworkManager. (#1809)
 - Fixed user never being notified in the editor that a NetworkBehaviour requires a NetworkObject to function properly. (#1808)
 - Fixed PlayerObjects and dynamically spawned NetworkObjects not being added to the NetworkClient's OwnedObjects (#1801)
 - Fixed issue where NetworkManager would continue starting even if the NetworkTransport selected failed. (#1780)

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

@@ -740,7 +740,7 @@ internal void DespawnAndDestroyNetworkObjects()
 
                         OnDespawnObject(networkObjects[i], shouldDestroy);
                     }
-                    else
+                    else if (networkObjects[i].IsSceneObject != null && !networkObjects[i].IsSceneObject.Value)
                     {
                         UnityEngine.Object.Destroy(networkObjects[i].gameObject);
                     }

testproject/Assets/Tests/Runtime/SceneObjectsNotDestroyedOnShutdownTest.cs

@@ -0,0 +1,138 @@
+
+using System;
+using System.Collections;
+using System.Linq;
+using NUnit.Framework;
+using UnityEngine;
+using UnityEngine.TestTools;
+using UnityEngine.SceneManagement;
+using Unity.Netcode;
+using Unity.Netcode.TestHelpers.Runtime;
+using Object = UnityEngine.Object;
+
+namespace TestProject.RuntimeTests
+{
+    public class SceneObjectsNotDestroyedOnShutdownTest
+    {
+        private const string k_TestScene = "InSceneNetworkObject";
+        private const string k_SceneObjectName = "InSceneObject";
+        private Scene m_TestScene;
+        private NetworkManager m_ClientNetworkManager;
+        private GameObject m_NetworkManagerGameObject;
+        private WaitForSeconds m_DefaultWaitForTick = new WaitForSeconds(1.0f / 30);
+
+        [SetUp]
+        public void Setup()
+        {
+            m_NetworkManagerGameObject = new GameObject();
+            m_ClientNetworkManager = m_NetworkManagerGameObject.AddComponent<NetworkManager>();
+            m_ClientNetworkManager.NetworkConfig = new NetworkConfig();
+            m_ClientNetworkManager.NetworkConfig.NetworkTransport = m_NetworkManagerGameObject.AddComponent<BlankTestingTransport>();
+            SceneManager.sceneLoaded += SceneManager_sceneLoaded;
+            SceneManager.LoadSceneAsync(k_TestScene, LoadSceneMode.Additive);
+        }
+
+        private void SceneManager_sceneLoaded(Scene scene, LoadSceneMode loadSceneMode)
+        {
+            if (scene.name == k_TestScene)
+            {
+                m_TestScene = scene;
+            }
+        }
+
+        [UnityTest]
+        public IEnumerator SceneObjectsNotDestroyedOnShutdown()
+        {
+            var timeoutHelper = new TimeoutHelper(2);
+
+            // Wait for the scene with the in-scene placed NetworkObject to be loaded.
+            yield return NetcodeIntegrationTest.WaitForConditionOrTimeOut(() => m_TestScene.IsValid() && m_TestScene.isLoaded, timeoutHelper);
+            Assert.False(timeoutHelper.TimedOut, "Timed out waiting for scene to load!");
+
+            var loadedInSceneObject = Object.FindObjectsOfType<NetworkObject>().Where((c) => c.name == k_SceneObjectName).FirstOrDefault();
+
+            Assert.IsNotNull(loadedInSceneObject, $"Failed to find {k_SceneObjectName} before starting client!");
+
+            // Only start the client
+            m_ClientNetworkManager.StartClient();
+
+            // Wait for a tick
+            yield return m_DefaultWaitForTick;
+
+            // Shutdown the client
+            m_ClientNetworkManager.Shutdown();
+
+            // Wait for a tick
+            yield return m_DefaultWaitForTick;
+
+            // Find the same object
+            loadedInSceneObject = Object.FindObjectsOfType<NetworkObject>().Where((c) => c.name == k_SceneObjectName).FirstOrDefault();
+
+            // Verify it still exists
+            Assert.IsNotNull(loadedInSceneObject, $"Failed to find {k_SceneObjectName} after starting client!");
+        }
+
+        [TearDown]
+        public void TearDown()
+        {
+            SceneManager.sceneLoaded -= SceneManager_sceneLoaded;
+
+            if (m_TestScene.IsValid() && m_TestScene.isLoaded)
+            {
+                SceneManager.UnloadSceneAsync(m_TestScene);
+            }
+
+            if (m_NetworkManagerGameObject != null)
+            {
+                Object.DestroyImmediate(m_NetworkManagerGameObject);
+            }
+        }
+
+        internal class BlankTestingTransport : TestingNetworkTransport
+        {
+            public override ulong ServerClientId { get; } = 0;
+            public override void Send(ulong clientId, ArraySegment<byte> payload, NetworkDelivery networkDelivery)
+            {
+            }
+
+            public override NetworkEvent PollEvent(out ulong clientId, out ArraySegment<byte> payload, out float receiveTime)
+            {
+                clientId = 0;
+                payload = new ArraySegment<byte>();
+                receiveTime = 0;
+                return NetworkEvent.Nothing;
+            }
+
+            public override bool StartClient()
+            {
+                return true;
+            }
+
+            public override bool StartServer()
+            {
+                return true;
+            }
+
+            public override void DisconnectRemoteClient(ulong clientId)
+            {
+            }
+
+            public override void DisconnectLocalClient()
+            {
+            }
+
+            public override ulong GetCurrentRtt(ulong clientId)
+            {
+                return 0;
+            }
+
+            public override void Shutdown()
+            {
+            }
+
+            public override void Initialize(NetworkManager networkManager = null)
+            {
+            }
+        }
+    }
+}