Better warnings when resources can't be saved. Fixes #26531

core/io/resource_importer.h

@@ -68,6 +68,7 @@ public:
 	virtual Variant get_resource_metadata(const String &p_path) const;
 	virtual bool is_import_valid(const String &p_path) const;
 	virtual void get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types = false);
+	virtual bool is_imported(const String &p_path) const { return recognize_path(p_path); }
 
 	virtual bool can_be_imported(const String &p_path) const;
 	virtual int get_import_order(const String &p_path) const;

core/io/resource_loader.cpp

@@ -633,6 +633,31 @@ bool ResourceLoader::is_import_valid(const String &p_path) {
 	return false; //not found
 }
 
+bool ResourceLoader::is_imported(const String &p_path) {
+
+	String path = _path_remap(p_path);
+
+	String local_path;
+	if (path.is_rel_path())
+		local_path = "res://" + path;
+	else
+		local_path = ProjectSettings::get_singleton()->localize_path(path);
+
+	for (int i = 0; i < loader_count; i++) {
+
+		if (!loader[i]->recognize_path(local_path))
+			continue;
+		/*
+		if (p_type_hint!="" && !loader[i]->handles_type(p_type_hint))
+			continue;
+		*/
+
+		return loader[i]->is_imported(p_path);
+	}
+
+	return false; //not found
+}
+
 void ResourceLoader::get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types) {
 
 	String path = _path_remap(p_path);

core/io/resource_loader.h

@@ -79,6 +79,7 @@ public:
 	virtual void get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types = false);
 	virtual Error rename_dependencies(const String &p_path, const Map<String, String> &p_map);
 	virtual bool is_import_valid(const String &p_path) const { return true; }
+	virtual bool is_imported(const String &p_path) const { return false; }
 	virtual int get_import_order(const String &p_path) const { return 0; }
 
 	virtual ~ResourceFormatLoader() {}
@@ -154,6 +155,7 @@ public:
 	static void get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types = false);
 	static Error rename_dependencies(const String &p_path, const Map<String, String> &p_map);
 	static bool is_import_valid(const String &p_path);
+	static bool is_imported(const String &p_path);
 	static int get_import_order(const String &p_path);
 
 	static void set_timestamp_on_load(bool p_timestamp) { timestamp_on_load = p_timestamp; }

editor/editor_node.cpp

@@ -619,7 +619,11 @@ void EditorNode::save_resource_in_path(const Ref<Resource> &p_resource, const St
 	Error err = ResourceSaver::save(path, p_resource, flg | ResourceSaver::FLAG_REPLACE_SUBRESOURCE_PATHS);
 
 	if (err != OK) {
-		show_accept(TTR("Error saving resource!"), TTR("OK"));
+		if (ResourceLoader::is_imported(p_resource->get_path())) {
+			show_accept(TTR("Imported resources can't be saved."), TTR("OK"));
+		} else {
+			show_accept(TTR("Error saving resource!"), TTR("OK"));
+		}
 		return;
 	}
 
@@ -639,6 +643,18 @@ void EditorNode::save_resource(const Ref<Resource> &p_resource) {
 
 void EditorNode::save_resource_as(const Ref<Resource> &p_resource, const String &p_at_path) {
 
+	{
+		String path = p_resource->get_path();
+		int srpos = path.find("::");
+		if (srpos != -1) {
+			String base = path.substr(0, srpos);
+			if (!get_edited_scene() || get_edited_scene()->get_filename() != base) {
+				show_warning(TTR("This resource can't be saved because it does not belong to the edited scene. Make it unique first."));
+				return;
+			}
+		}
+	}
+
 	file->set_mode(EditorFileDialog::MODE_SAVE_FILE);
 	saving_resource = p_resource;