2 files changed, 21 insertions, 0 deletions
diff --git a/scene/resources/packed_scene.cpp b/scene/resources/packed_scene.cpp
index c24186a109..e497a628aa 100644
--- a/scene/resources/packed_scene.cpp
+++ b/scene/resources/packed_scene.cpp
@@ -1046,6 +1046,25 @@ Ref<SceneState> SceneState::get_base_scene_state() const {
 	return Ref<SceneState>();
 }
 
+void SceneState::update_instance_resource(String p_path, Ref<PackedScene> p_packed_scene) {
+	ERR_FAIL_COND(p_packed_scene.is_null());
+
+	for (const NodeData &nd : nodes) {
+		if (nd.instance >= 0) {
+			if (!(nd.instance & FLAG_INSTANCE_IS_PLACEHOLDER)) {
+				int instance_id = nd.instance & FLAG_MASK;
+				Ref<PackedScene> original_packed_scene = variants[instance_id];
+				if (original_packed_scene.is_valid()) {
+					if (original_packed_scene->get_path() == p_path) {
+						variants.remove_at(instance_id);
+						variants.insert(instance_id, p_packed_scene);
+					}
+				}
+			}
+		}
+	}
+}
+
 int SceneState::find_node_by_path(const NodePath &p_node) const {
 	ERR_FAIL_COND_V_MSG(node_path_cache.size() == 0, -1, "This operation requires the node cache to have been built.");
 
diff --git a/scene/resources/packed_scene.h b/scene/resources/packed_scene.h
index ef7363dd44..5c53ffdb45 100644
--- a/scene/resources/packed_scene.h
+++ b/scene/resources/packed_scene.h
@@ -150,6 +150,8 @@ public:
 
 	Ref<SceneState> get_base_scene_state() const;
 
+	void update_instance_resource(String p_path, Ref<PackedScene> p_packed_scene);
+
 	//unbuild API
 
 	int get_node_count() const;