backporting fixes from modus

Author: dfb

Source/UnrealEnginePython/Private/FMModule.cpp

@@ -227,7 +227,7 @@ static PyObject *create_subclass(PyObject *self, PyObject *args)
                 if (!pyInst)
                 {
                     LERROR("failed to instantiate python class");
-                    PyErr_Format(PyExc_Exception, "Failed to instantiate python clsas");
+                    PyErr_Format(PyExc_Exception, "Failed to instantiate python class");
                     return;
                 }
                 pyObj->py_proxy = pyInst; // pyInst's ref is now owned by py_proxy. TODO: who decref's this later?

Source/UnrealEnginePython/Private/UEPyModule.cpp

@@ -1181,12 +1181,10 @@ static void ue_pyobject_dealloc(ue_PyUObject *self)
 #if defined(UEPY_MEMORY_DEBUG)
 	UE_LOG(LogPython, Warning, TEXT("Destroying ue_PyUObject %p mapped to UObject %p"), self, self->ue_object);
 #endif
-    FUnrealEnginePythonHouseKeeper *housekeeper = FUnrealEnginePythonHouseKeeper::Get();
 	if (self->owned)
 	{
-		housekeeper->UntrackUObject(self->ue_object);
+        FUnrealEnginePythonHouseKeeper::Get()->UntrackUObject(self->ue_object);
 	}
-    housekeeper->UnregisterPyUObject(self->ue_object);
 
 	if (self->auto_rooted && (self->ue_object && self->ue_object->IsValidLowLevel() && self->ue_object->IsRooted()))
 	{
@@ -1329,7 +1327,9 @@ static int ue_PyUObject_setattro(ue_PyUObject *self, PyObject *attr_name, PyObje
 		{
 #if WITH_EDITOR
             if (!self->creating)
-			self->ue_object->PreEditChange(u_property);
+            {
+			    self->ue_object->PreEditChange(u_property);
+            }
 #endif
 			if (ue_py_convert_pyobject(value, u_property, (uint8*)self->ue_object, 0))
 			{
@@ -1874,10 +1874,7 @@ ue_PyUObject *ue_get_python_uobject(UObject *ue_obj)
 		ue_py_object->py_dict = PyDict_New();
 		ue_py_object->owned = 0;
 
-        FUnrealEnginePythonHouseKeeper *housekeeper = FUnrealEnginePythonHouseKeeper::Get();
-        housekeeper->RegisterPyUObject(ue_obj, ue_py_object);
-        Py_INCREF(ue_py_object); // this is needed only because the following decrefs it
-        housekeeper->TrackUObject(ue_obj);
+        FUnrealEnginePythonHouseKeeper::Get()->RegisterPyUObject(ue_obj, ue_py_object);
 
 #if defined(UEPY_MEMORY_DEBUG)
 		UE_LOG(LogPython, Warning, TEXT("CREATED UPyObject at %p for %p %s"), ue_py_object, ue_obj, *ue_obj->GetName());

Source/UnrealEnginePython/Public/FMPythonClass.cpp

@@ -20,3 +20,15 @@ void UFMPythonClass::CallPyConstructor(ue_PyUObject *self)
 }
 
 
+UObject* UFMPythonClass::CreateDefaultObject()
+{
+    bool savedLoad = GIsInitialLoad;
+
+    // this is a total hack but be need to go around the default
+    // package loading logic when loading default objects
+    GIsInitialLoad = false;
+    UObject *ret = Super::CreateDefaultObject();
+    GIsInitialLoad = savedLoad;
+
+    return ret;
+}

Source/UnrealEnginePython/Public/FMPythonClass.h

@@ -22,6 +22,9 @@ class UFMPythonClass : public UClass
     // true while we're creating this class (including the stuff in Python)
     bool creating;
 
+protected:
+    virtual UObject* CreateDefaultObject() override;
+
 private:
 
 	PyObject * py_constructor;

Source/UnrealEnginePython/Public/PythonHouseKeeper.h

@@ -167,7 +167,6 @@ class FUnrealEnginePythonHouseKeeper : public FGCObject
 	{
 		uint32 Garbaged = 0;
 		TArray<UObject *> BrokenList;
-        TArray<ue_PyUObject *> needDecRef;
 		for (auto &UObjectPyItem : UObjectPyMapping)
 		{
 			UObject *Object = UObjectPyItem.Key;
@@ -183,26 +182,14 @@ class FUnrealEnginePythonHouseKeeper : public FGCObject
 				BrokenList.Add(Object);
 				Garbaged++;
 		}
-			else if (Tracker.PyUObject->ob_base.ob_refcnt == 1)
-			{	// the tracker is the only thing keeping this alive, so release the last reference
-#if defined(UEPY_MEMORY_DEBUG)
-				UE_LOG(LogPython, Warning, TEXT("Auto-decrefing UObject at %p %s"), Object, *Object->GetName());
-#endif
-                needDecRef.Add(Tracker.PyUObject);
-            }
 			else
 			{
 #if defined(UEPY_MEMORY_DEBUG)
-				UE_LOG(LogPython, Error, TEXT("UObject at %p %s is in use, py ref count %d"), Object, *Object->GetName(), Tracker.PyUObject->ob_base.ob_refcnt);
+				UE_LOG(LogPython, Error, TEXT("UObject at %p %s is in use"), Object, *Object->GetName());
 #endif
 	}
 		}
 
-        for (ue_PyUObject *py_obj : needDecRef)
-        {
-            Py_DECREF(py_obj); // on the next GC run, this object will dealloc and unregister itself
-        }
-
 		for (UObject *Object : BrokenList)
 		{
 			FPythonUOjectTracker &Tracker = UObjectPyMapping[Object];