fix: deactivated child NetworkBehaviour exceptions [NCCBUG-138] (Unity-Technologies#2096)

Author: NoelStephensUnity

com.unity.netcode.gameobjects/CHANGELOG.md

@@ -11,7 +11,10 @@ Additional documentation and release notes are available at [Multiplayer Documen
 
 - When using `UnityTransport`, _reliable_ payloads are now allowed to exceed the configured 'Max Payload Size'. Unreliable payloads remain bounded by this setting. (#2081)
 
+
 ### Fixed
+
+- Fixed issue when attempting to spawn a parent `GameObject`, with `NetworkObject` component attached, that has one or more child `GameObject`s, that are inactive in the hierarchy, with `NetworkBehaviour` components it will no longer attempt to spawn the associated NetworkBehaviour(s) or invoke ownership changed notifications but will log a warning message. (#2096)
 - Fixed issue where `NetworkObject.NetworkHide` was despawning and destroying, as opposed to only despawning, in-scene placed `NetworkObject`s. (#2086)
 - Fixed issue where `NetworkAnimator` would not synchronize a looping animation for late joining clients if it was at the very end of its loop. (#2076)
 - Fixed issue where `NetworkAnimator` was not removing its subscription from `OnClientConnectedCallback` when despawned during the shutdown sequence. (#2074)

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

@@ -553,7 +553,14 @@ internal void InvokeBehaviourOnGainedOwnership()
 
             for (int i = 0; i < ChildNetworkBehaviours.Count; i++)
             {
-                ChildNetworkBehaviours[i].InternalOnGainedOwnership();
+                if (ChildNetworkBehaviours[i].gameObject.activeInHierarchy)
+                {
+                    ChildNetworkBehaviours[i].InternalOnGainedOwnership();
+                }
+                else
+                {
+                    Debug.LogWarning($"{ChildNetworkBehaviours[i].gameObject.name} is disabled! Netcode for GameObjects does not support disabled NetworkBehaviours! The {ChildNetworkBehaviours[i].GetType().Name} component was skipped during ownership assignment!");
+                }
             }
         }
 
@@ -805,7 +812,14 @@ internal void InvokeBehaviourNetworkSpawn()
 
             for (int i = 0; i < ChildNetworkBehaviours.Count; i++)
             {
-                ChildNetworkBehaviours[i].InternalOnNetworkSpawn();
+                if (ChildNetworkBehaviours[i].gameObject.activeInHierarchy)
+                {
+                    ChildNetworkBehaviours[i].InternalOnNetworkSpawn();
+                }
+                else
+                {
+                    Debug.LogWarning($"{ChildNetworkBehaviours[i].gameObject.name} is disabled! Netcode for GameObjects does not support spawning disabled NetworkBehaviours! The {ChildNetworkBehaviours[i].GetType().Name} component was skipped during spawn!");
+                }
             }
         }
 

com.unity.netcode.gameobjects/Tests/Runtime/NetworkBehaviourGenericTests.cs

@@ -2,6 +2,7 @@
 using UnityEngine;
 using UnityEngine.TestTools;
 using Unity.Netcode.TestHelpers.Runtime;
+using Unity.Netcode.Components;
 
 namespace Unity.Netcode.RuntimeTests
 {
@@ -23,6 +24,46 @@ public class SimpleNetworkBehaviour : NetworkBehaviour
         {
         }
 
+        protected override IEnumerator OnSetup()
+        {
+            m_AllowServerToStart = false;
+            return base.OnSetup();
+        }
+
+        /// <summary>
+        /// This validates the fix for when a child GameObject with a NetworkBehaviour
+        /// is deleted while the parent GameObject with a NetworkObject is spawned and
+        /// is not deleted until a later time would cause an exception due to the
+        /// NetworkBehaviour not being removed from the NetworkObject.ChildNetworkBehaviours
+        /// list.
+        /// </summary>
+        [UnityTest]
+        public IEnumerator ValidatedDisableddNetworkBehaviourWarning()
+        {
+            m_AllowServerToStart = true;
+
+            yield return s_DefaultWaitForTick;
+
+            // Now just start the Host
+            yield return StartServerAndClients();
+
+            var parentObject = new GameObject();
+            var childObject = new GameObject();
+            childObject.name = "ChildObject";
+            childObject.transform.parent = parentObject.transform;
+            var parentNetworkObject = parentObject.AddComponent<NetworkObject>();
+            var childBehaviour = childObject.AddComponent<NetworkTransform>();
+
+            // Set the child object to be inactive in the hierarchy
+            childObject.SetActive(false);
+
+            LogAssert.Expect(LogType.Warning, $"{childObject.name} is disabled! Netcode for GameObjects does not support disabled NetworkBehaviours! The {childBehaviour.GetType().Name} component was skipped during ownership assignment!");
+            LogAssert.Expect(LogType.Warning, $"{childObject.name} is disabled! Netcode for GameObjects does not support spawning disabled NetworkBehaviours! The {childBehaviour.GetType().Name} component was skipped during spawn!");
+
+            parentNetworkObject.Spawn();
+            yield return s_DefaultWaitForTick;
+        }
+
         /// <summary>
         /// This test validates a fix to NetworkBehaviour.NetworkObject when
         /// the NetworkManager.LogLevel is set to Developer