- fixed: Non-actor classes never called InitializeDefaults to set up their special variables.

- fixed: DThinkerIterator and DBlockThingsIterator did not have a default constructor that was safe to call from an out-of-game context.

src/dobjtype.cpp

@@ -3193,6 +3193,8 @@ void PClass::Derive(PClass *newclass, FName name)
 //==========================================================================
 
 void PClass::InitializeDefaults()
+{
+	if (IsKindOf(RUNTIME_CLASS(PClassActor)))
 	{
 		assert(Defaults == NULL);
 		Defaults = (BYTE *)M_Malloc(Size);
@@ -3223,6 +3225,7 @@ void PClass::InitializeDefaults()
 		{
 			memset(Defaults + sizeof(DObject), 0, Size - sizeof(DObject));
 		}
+	}
 
 	if (bRuntimeClass)
 	{

src/dthinker.cpp

@@ -710,8 +710,12 @@ class DThinkerIterator : public DObject, public FThinkerIterator
 {
 	DECLARE_CLASS(DThinkerIterator, DObject)
 
+	DThinkerIterator()
+	{
+	}
+
 public:
-	DThinkerIterator(PClass *cls = nullptr, int statnum = MAX_STATNUM + 1)
+	DThinkerIterator(PClass *cls, int statnum = MAX_STATNUM + 1)
 		: FThinkerIterator(cls, statnum)
 	{
 	}

src/dthinker.h

@@ -125,6 +125,9 @@ public:
 	FThinkerIterator (const PClass *type, int statnum, DThinker *prev);
 	DThinker *Next (bool exact = false);
 	void Reinit ();
+
+protected:
+	FThinkerIterator() {}
 };
 
 template <class T> class TThinkerIterator : public FThinkerIterator

src/p_maputl.cpp

@@ -1177,6 +1177,11 @@ class DBlockThingsIterator : public DObject, public FMultiBlockThingsIterator
 {
 	DECLARE_CLASS(DBlockThingsIterator, DObject);
 	FPortalGroupArray check;
+protected:
+	DBlockThingsIterator()
+		:FMultiBlockThingsIterator(check)
+	{
+	}
 public:
 	FMultiBlockThingsIterator::CheckResult cres;
 
@@ -1186,7 +1191,7 @@ public:
 		return FMultiBlockThingsIterator::Next(&cres);
 	}
 
-	DBlockThingsIterator(AActor *origin = nullptr, double checkradius = -1, bool ignorerestricted = false)
+	DBlockThingsIterator(AActor *origin, double checkradius = -1, bool ignorerestricted = false)
 		: FMultiBlockThingsIterator(check, origin, checkradius, ignorerestricted)
 	{
 		cres.thing = nullptr;

src/p_maputl.h

@@ -327,6 +327,8 @@ class FMultiBlockThingsIterator
 
 	void startIteratorForGroup(int group);
 
+protected:
+	FMultiBlockThingsIterator(FPortalGroupArray &check) : checklist(check) {}
 public:
 
 	struct CheckResult

src/scripting/zscript/zcc_compile.cpp

@@ -1874,7 +1874,14 @@ void ZCCCompiler::InitDefaults()
 		if (!c->Type()->IsDescendantOf(RUNTIME_CLASS(AActor)))
 		{
 			if (c->Defaults.Size()) Error(c->cls, "%s: Non-actor classes may not have defaults", c->Type()->TypeName.GetChars());
-			if (c->Type()->ParentClass) c->Type()->ParentClass->DeriveData(c->Type());
+			if (c->Type()->ParentClass)
+			{
+				auto ti = static_cast<PClassActor *>(c->Type());
+				FString mename = ti->TypeName.GetChars();
+
+				ti->InitializeDefaults();
+				ti->ParentClass->DeriveData(ti);
+			}
 		}
 		else
 		{