Prevent dropping Resource to the same resource picker

editor/editor_node.cpp

@@ -5324,7 +5324,7 @@ bool EditorNode::is_distraction_free_mode_enabled() const {
 	return distraction_free->is_pressed();
 }
 
-Variant EditorNode::drag_resource(const Ref<Resource> &p_res, Control *p_from) {
+Dictionary EditorNode::drag_resource(const Ref<Resource> &p_res, Control *p_from) {
 	Control *drag_control = memnew(Control);
 	TextureRect *drag_preview = memnew(TextureRect);
 	Label *label = memnew(Label);
@@ -5364,7 +5364,7 @@ Variant EditorNode::drag_resource(const Ref<Resource> &p_res, Control *p_from) {
 	return drag_data;
 }
 
-Variant EditorNode::drag_files_and_dirs(const Vector<String> &p_paths, Control *p_from) {
+Dictionary EditorNode::drag_files_and_dirs(const Vector<String> &p_paths, Control *p_from) {
 	bool has_folder = false;
 	bool has_file = false;
 	for (int i = 0; i < p_paths.size(); i++) {

editor/editor_node.h

@@ -870,8 +870,8 @@ public:
 
 	bool is_exiting() const { return exiting; }
 
-	Variant drag_resource(const Ref<Resource> &p_res, Control *p_from);
-	Variant drag_files_and_dirs(const Vector<String> &p_paths, Control *p_from);
+	Dictionary drag_resource(const Ref<Resource> &p_res, Control *p_from);
+	Dictionary drag_files_and_dirs(const Vector<String> &p_paths, Control *p_from);
 
 	void add_tool_menu_item(const String &p_name, const Callable &p_callback);
 	void add_tool_submenu_item(const String &p_name, PopupMenu *p_submenu);

editor/editor_resource_picker.cpp

@@ -615,6 +615,13 @@ void EditorResourcePicker::_get_allowed_types(bool p_with_convert, HashSet<Strin
 }
 
 bool EditorResourcePicker::_is_drop_valid(const Dictionary &p_drag_data) const {
+	{
+		const ObjectID source_picker = p_drag_data.get("source_picker", ObjectID());
+		if (source_picker == get_instance_id()) {
+			return false;
+		}
+	}
+
 	if (base_type.is_empty()) {
 		return true;
 	}
@@ -670,7 +677,9 @@ bool EditorResourcePicker::_is_type_valid(const String &p_type_name, const HashS
 
 Variant EditorResourcePicker::get_drag_data_fw(const Point2 &p_point, Control *p_from) {
 	if (edited_resource.is_valid()) {
-		return EditorNode::get_singleton()->drag_resource(edited_resource, p_from);
+		Dictionary drag_data = EditorNode::get_singleton()->drag_resource(edited_resource, p_from);
+		drag_data["source_picker"] = get_instance_id();
+		return drag_data;
 	}
 
 	return Variant();