### Godot version

3.5.1mono

### System information

windows10

### Issue description

Error message
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).
See "Steps to reproduce for details"

### Steps to reproduce

Set an external text editor
Create a script
Drop the script to the built-in text editor like this image:
![image](https://user-images.githubusercontent.com/119792950/209504041-039f2620-5e42-4c0f-8c41-cd24486fb3d2.png)
And got error message:
 scene/main/node.cpp:1362 - Index p_index = 0 is out of bounds (data.children.size() = 0).
 scene/main/node.cpp:397 - Parameter "p_child" is null.
 scene/gui/tab_container.cpp:593 - Index p_current = 0 is out of bounds (get_tab_count() = 0).

### Minimal reproduction project

An empty project
EditorSettings::get_singleton()->set("text_editor/script_list/sort_members_outline_alphabetically", p_alphabetic_sort);
	_update_members_overview();
}
void ScriptEditor::_update_members_overview() {
	members_overview->clear();
	ScriptEditorBase *se = _get_current_editor();
	if (!se) {
		return;
	}
	Vector<String> functions = se->get_functions();
	if (EDITOR_GET("text_editor/script_list/sort_members_outline_alphabetically")) {
		functions.sort();
	}
	for (int i = 0; i < functions.size(); i++) {
		String filter = filter_methods->get_text();
		String name = functions[i].get_slice(":", 0);
		if (filter.is_empty() || filter.is_subsequence_ofn(name)) {
			members_overview->add_item(name);
			members_overview->set_item_metadata(-1, functions[i].get_slice(":", 1).to_int() - 1);
		}
	}
	String path = se->get_edited_resource()->get_path();
	bool built_in = !path.is_resource_file();
	String name = built_in ? path.get_file() : se->get_name();
	filename->set_text(name);
}
void ScriptEditor::_update_help_overview_visibility() {