- fixed: The skybox pointer in FSectorPortal must at least be initialized to nullptr when the struct is deserialized, to avoid an access violation if the partially initialized data is used. This can happen when P_SerializeThinkers destroys the original thinkers that were created on map load.

- removed the sector loop for deleting skybox references in ASkyViewpoint::Destroy. Since this only refers to the sectorPortals array it is completely redundant as the following code will clear them just as well.

src/g_shared/a_skies.cpp

@@ -59,13 +59,6 @@ void ASkyViewpoint::BeginPlay ()
 void ASkyViewpoint::Destroy ()
 {
 	// remove all sector references to ourselves.
-	for (int i = 0; i < numsectors; i++)
-	{
-		if (sectors[i].GetPortal(sector_t::floor)->mSkybox == this)
-			sectors[i].ClearPortal(sector_t::floor);
-		if (sectors[i].GetPortal(sector_t::ceiling)->mSkybox == this)
-			sectors[i].ClearPortal(sector_t::ceiling);
-	}
 	for (auto &s : sectorPortals)
 	{
 		if (s.mSkybox == this) s.mSkybox = 0;

src/portal.cpp

@@ -231,6 +231,10 @@ FArchive &operator<< (FArchive &arc, FSectorPortal &port)
 		<< port.mDestination
 		<< port.mDisplacement
 		<< port.mPlaneZ;
+	if (arc.IsLoading())
+	{
+		port.mSkybox = nullptr;
+	}
 	return arc;
 }
 

src/portal.h

@@ -191,7 +191,6 @@ struct FLinePortal
 	double mSinRot;
 	double mCosRot;
 	portnode_t *render_thinglist;
-	void *mRenderData;
 };
 
 extern TArray<FLinePortal> linePortals;
@@ -229,7 +228,6 @@ struct FSectorPortal
 	DVector2 mDisplacement;
 	double mPlaneZ;
 	TObjPtr<AActor> mSkybox;
-	void *mRenderData;
 
 	bool MergeAllowed() const
 	{