From 12e62c6742d6e13fdeba26c0211c52ed38baf898 Mon Sep 17 00:00:00 2001
From: Stephen Hodgson <hodgson.designs@gmail.com>
Date: Mon, 28 Sep 2020 14:29:16 -0400
Subject: [PATCH] Fixed issues around errors when starting and stopping
 playmode in editor (#668)

* Fixed issues around errors when starting and stopping playmode in editor

* updated sdk checkout
---
 .../BaseMixedRealitySpatialMeshObserver.cs             | 10 +++++-----
 Runtime/Services/MixedRealityToolkit.cs                | 10 +---------
 .../MixedRealitySpatialAwarenessSystem.cs              |  9 +++------
 3 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/Runtime/Providers/SpatialObservers/BaseMixedRealitySpatialMeshObserver.cs b/Runtime/Providers/SpatialObservers/BaseMixedRealitySpatialMeshObserver.cs
index 9f6b323a8..adc5189d9 100644
--- a/Runtime/Providers/SpatialObservers/BaseMixedRealitySpatialMeshObserver.cs
+++ b/Runtime/Providers/SpatialObservers/BaseMixedRealitySpatialMeshObserver.cs
@@ -134,10 +134,8 @@ public override void Disable()
             // Disable any spatial meshes we might have.
             foreach (var meshObject in spatialMeshObjects.Values)
             {
-                if (meshObject.GameObject != null)
-                {
-                    meshObject.GameObject.SetActive(false);
-                }
+                Debug.Assert(meshObject.GameObject != null);
+                meshObject.GameObject.SetActive(false);
             }
         }
 
@@ -152,7 +150,7 @@ public override void Destroy()
                 meshObject.GameObject.Destroy();
             }
 
-            spatialMeshObjects.Clear();
+            Debug.Assert(spatialMeshObjects.Count == 0);
 
             lock (spatialMeshObjectPool)
             {
@@ -161,6 +159,8 @@ public override void Destroy()
                     var meshObject = spatialMeshObjectPool.Pop();
                     meshObject.GameObject.Destroy();
                 }
+
+                Debug.Assert(spatialMeshObjectPool.Count == 0);
             }
         }
 
diff --git a/Runtime/Services/MixedRealityToolkit.cs b/Runtime/Services/MixedRealityToolkit.cs
index d1e3953aa..522f27917 100644
--- a/Runtime/Services/MixedRealityToolkit.cs
+++ b/Runtime/Services/MixedRealityToolkit.cs
@@ -673,15 +673,7 @@ private void Awake()
 
             if (IsInitialized && instance != this)
             {
-                if (Application.isEditor)
-                {
-                    DestroyImmediate(gameObject);
-                }
-                else
-                {
-                    Destroy(gameObject);
-                }
-
+                gameObject.Destroy();
                 Debug.LogWarning($"Trying to instantiate a second instance of the {nameof(MixedRealityToolkit)}. Additional Instance was destroyed");
             }
             else if (!IsInitialized)
diff --git a/Runtime/Services/SpatialAwarenessSystem/MixedRealitySpatialAwarenessSystem.cs b/Runtime/Services/SpatialAwarenessSystem/MixedRealitySpatialAwarenessSystem.cs
index 1174e2945..1ce2625f3 100644
--- a/Runtime/Services/SpatialAwarenessSystem/MixedRealitySpatialAwarenessSystem.cs
+++ b/Runtime/Services/SpatialAwarenessSystem/MixedRealitySpatialAwarenessSystem.cs
@@ -202,25 +202,22 @@ public override void Destroy()
             if (spatialAwarenessParent != null)
             {
                 spatialAwarenessParent.transform.DetachChildren();
+                spatialAwarenessParent.Destroy();
             }
 
-            spatialAwarenessParent.Destroy();
-
             // Detach the mesh objects (they are to be cleaned up by the observer) and cleanup the parent
             if (meshParent != null)
             {
                 meshParent.transform.DetachChildren();
+                meshParent.Destroy();
             }
 
-            meshParent.Destroy();
-
             // Detach the surface objects (they are to be cleaned up by the observer) and cleanup the parent
             if (surfaceParent != null)
             {
                 surfaceParent.transform.DetachChildren();
+                surfaceParent.Destroy();
             }
-
-            surfaceParent.Destroy();
         }
 
         #region Mesh Events