### 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
}
		}
	}
	if (current) {
		switch (p_option) {
			case FILE_SAVE: {
				save_current_script();
			} break;
			case FILE_SAVE_AS: {
				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();
					}
				}
				Ref<Resource> resource = current->get_edited_resource();
				Ref<TextFile> text_file = resource;
				Ref<Script> scr = resource;
				if (text_file != nullptr) {
					file_dialog->set_file_mode(EditorFileDialog::FILE_MODE_SAVE_FILE);
					file_dialog->set_access(EditorFileDialog::ACCESS_FILESYSTEM);
					file_dialog_option = FILE_SAVE_AS;
					List<String> extensions;
					ResourceLoader::get_recognized_extensions_for_type("Script", &extensions);
					file_dialog->clear_filters();