### 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
}
			} break;
			case WINDOW_MOVE_DOWN: {
				if (tab_container->get_current_tab() < tab_container->get_tab_count() - 1) {
					tab_container->move_child(current, tab_container->get_current_tab() + 1);
					tab_container->set_current_tab(tab_container->get_current_tab());
					_update_script_names();
				}
			} break;
			default: {
				if (p_option >= WINDOW_SELECT_BASE) {
					_go_to_tab(p_option - WINDOW_SELECT_BASE);
					_update_script_names();
				}
			}
		}
	} else {
		EditorHelp *help = Object::cast_to<EditorHelp>(tab_container->get_current_tab_control());
		if (help) {
			switch (p_option) {
				case HELP_SEARCH_FIND: {
					help->popup_search();
				} break;
				case HELP_SEARCH_FIND_NEXT: {
					help->search_again();
				} break;
				case HELP_SEARCH_FIND_PREVIOUS: {
					help->search_again(true);
				} break;
				case FILE_CLOSE: {