Save the current script when adding a new method via signal connection

This makes it possible for external editors to pick up the changes.
Most modern editors should reload the file automatically,
but some older/lightweight editors may ask the user instead
(or only warn after trying to save in the external editor).

This closes #41283.

(cherry picked from commit 0ade6866014b9d4bf8469b4fe06e6a7ef9e82592)

editor/plugins/script_editor_plugin.cpp

@@ -551,7 +551,7 @@ void ScriptEditor::_close_tab(int p_idx, bool p_save, bool p_history_back) {
 		if (p_save) {
 			// Do not try to save internal scripts
 			if (!script.is_valid() || !(script->get_path() == "" || script->get_path().find("local://") != -1 || script->get_path().find("::") != -1)) {
-				_menu_option(FILE_SAVE);
+				_save_current_script();
 			}
 		}
 
@@ -948,6 +948,39 @@ bool ScriptEditor::is_scripts_panel_toggled() {
 	return list_split->is_visible();
 }
 
+void ScriptEditor::_save_current_script() {
+	ScriptEditorBase *current = _get_current_editor();
+
+	if (_test_script_times_on_disk()) {
+		return;
+	}
+
+	if (trim_trailing_whitespace_on_save) {
+		current->trim_trailing_whitespace();
+	}
+
+	current->insert_final_newline();
+
+	if (convert_indent_on_save) {
+		if (use_space_indentation) {
+			current->convert_indent_to_spaces();
+		} else {
+			current->convert_indent_to_tabs();
+		}
+	}
+
+	RES resource = current->get_edited_resource();
+	Ref<TextFile> text_file = resource;
+
+	if (text_file != nullptr) {
+		current->apply_code();
+		_save_text_file(text_file, text_file->get_path());
+		return;
+	}
+
+	editor->save_resource(resource);
+}
+
 void ScriptEditor::_menu_option(int p_option) {
 	ScriptEditorBase *current = _get_current_editor();
 	switch (p_option) {
@@ -1089,33 +1122,7 @@ void ScriptEditor::_menu_option(int p_option) {
 	if (current) {
 		switch (p_option) {
 			case FILE_SAVE: {
-				if (_test_script_times_on_disk()) {
-					return;
-				}
-
-				if (trim_trailing_whitespace_on_save) {
-					current->trim_trailing_whitespace();
-				}
-
-				current->insert_final_newline();
-
-				if (convert_indent_on_save) {
-					if (use_space_indentation) {
-						current->convert_indent_to_spaces();
-					} else {
-						current->convert_indent_to_tabs();
-					}
-				}
-
-				RES resource = current->get_edited_resource();
-				Ref<TextFile> text_file = resource;
-				if (text_file != nullptr) {
-					current->apply_code();
-					_save_text_file(text_file, text_file->get_path());
-					break;
-				}
-				editor->save_resource(resource);
-
+				_save_current_script();
 			} break;
 			case FILE_SAVE_AS: {
 				if (trim_trailing_whitespace_on_save) {
@@ -2284,6 +2291,9 @@ void ScriptEditor::_add_callback(Object *p_obj, const String &p_function, const
 
 		script_list->select(script_list->find_metadata(i));
 
+		// Save the current script so the changes can be picked up by an external editor.
+		_save_current_script();
+
 		break;
 	}
 }

editor/plugins/script_editor_plugin.h

@@ -276,6 +276,7 @@ class ScriptEditor : public PanelContainer {
 
 	String _get_debug_tooltip(const String &p_text, Node *_se);
 
+	void _save_current_script();
 	void _resave_scripts(const String &p_str);
 	void _reload_scripts();