-make sure instance placeholder works with duplicate(), fixes #3378

scene/main/instance_placeholder.cpp

@@ -14,11 +14,24 @@ bool InstancePlaceholder::_set(const StringName& p_name, const Variant& p_value)
 
 bool InstancePlaceholder::_get(const StringName& p_name,Variant &r_ret) const{
 
+	for (const List<PropSet>::Element *E=stored_values.front();E;E=E->next()) {
+		if (E->get().name==p_name) {
+			r_ret=E->get().value;
+			return true;
+		}
+	}
 	return false;
 }
 void InstancePlaceholder::_get_property_list( List<PropertyInfo> *p_list) const{
 
+	for (const List<PropSet>::Element *E=stored_values.front();E;E=E->next()) {
+		PropertyInfo pi;
+		pi.name=E->get().name;
+		pi.type=E->get().value.get_type();
+		pi.usage=PROPERTY_USAGE_STORAGE;
 
+		p_list->push_back(pi);
+	}
 }
 
 

scene/main/node.cpp

@@ -33,6 +33,7 @@
 #include "scene/resources/packed_scene.h"
 #include "io/resource_loader.h"
 #include "viewport.h"
+#include "instance_placeholder.h"
 
 VARIANT_ENUM_CAST(Node::PauseMode);
 
@@ -1471,7 +1472,14 @@ Node *Node::duplicate(bool p_use_instancing) const {
 
 	bool instanced=false;
 
-	if (p_use_instancing && get_filename()!=String()) {
+	if (cast_to<InstancePlaceholder>()) {
+
+		const InstancePlaceholder *ip = cast_to<const InstancePlaceholder>();
+		InstancePlaceholder *nip = memnew( InstancePlaceholder );
+		nip->set_instance_path( ip->get_instance_path() );
+		node=nip;
+
+	} else if (p_use_instancing && get_filename()!=String()) {
 
 		Ref<PackedScene> res = ResourceLoader::load(get_filename());
 		ERR_FAIL_COND_V(res.is_null(),NULL);