Stop blocking map view part clicks before there is a camera

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Improved the **FastLoader** patch to reuse the initial GameDatabase directory tree during the second config pass while refreshing files and directories created or modified by `Startup.Instantly` addons. Avoids reparsing unchanged configs and saves several seconds in heavily modded installs.
 
 **Bug Fixes**
+- **BlockMapViewPartClick** : Fixed a `NullReferenceException` thrown from `Part.UpdateMouseOver` on every frame of a scene load into flight. The scene reports itself as flight well before `CameraManager.Instance` exists, and both the patch and stock dereferenced it unconditionally. `Part.UpdateMouseOver` is now skipped until there is a camera manager.
 - **EditorAnimatedPartsShipModified** : Fixed a memory leak ([issue #396](https://github.com/KSPModdingLibs/KSPCommunityFixes/issues/396)) where listeners were not properly cleaned up.
 - **EditorAnimatedPartsShipModified** : This patch is now disabled if DMagic Orbital Science is installed because DMagic Orbital Science has a bug that causes a stack overflow crash if you ever call `DMSoilMoisture.OnStop`, which this patch does.
 

KSPCommunityFixes/BugFixes/BlockMapViewPartClick.cs

@@ -13,7 +13,14 @@ protected override void ApplyPatches()
 
         static bool Part_UpdateMouseOver_Prefix()
         {
-            return !HighLogic.LoadedSceneIsFlight || CameraManager.Instance.currentCameraMode != CameraManager.CameraMode.Map;
+            if (!HighLogic.LoadedSceneIsFlight)
+                return true;
+
+            CameraManager cameraManager = CameraManager.Instance;
+            if (cameraManager.IsNullOrDestroyed())
+                return false;
+
+            return cameraManager.currentCameraMode != CameraManager.CameraMode.Map;
         }
     }
 }