### 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 (String(d["type"]) == "files") {
		Vector<String> files = d["files"];
		if (files.size() == 0) {
			return false; 
		}
		for (int i = 0; i < files.size(); i++) {
			String file = files[i];
			if (file.is_empty() || !FileAccess::exists(file)) {
				continue;
			}
			if (ResourceLoader::exists(file, "Script")) {
				Ref<Script> scr = ResourceLoader::load(file);
				if (scr.is_valid()) {
					return true;
				}
			}
			if (textfile_extensions.has(file.get_extension())) {
				Error err;
				Ref<TextFile> text_file = _load_text_file(file, &err);
				if (text_file.is_valid() && err == OK) {
					return true;
				}
			}
		}
		return false;
	}
	return false;
}
void ScriptEditor::drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) {