Fix writing m3u file

app/musicmuster.py

@@ -1829,15 +1829,16 @@ class Window(QMainWindow):
             # Required directive on first line
             f.write("#EXTM3U\n")
             for playlistrow in repository.get_playlist_rows(playlist_id):
-                f.write(
-                    "#EXTINF:"
-                    f"{int(playlistrow.duration / 1000)},"
-                    f"{playlistrow.title} - "
-                    f"{playlistrow.artist}"
-                    "\n"
-                    f"{playlistrow.path}"
-                    "\n"
-                )
+                if playlistrow.track:
+                    f.write(
+                        "#EXTINF:"
+                        f"{int(playlistrow.track.duration / 1000)},"
+                        f"{playlistrow.track.title} - "
+                        f"{playlistrow.track.artist}"
+                        "\n"
+                        f"{playlistrow.track.path}"
+                        "\n"
+                    )
 
     def fade(self, checked: bool = False) -> None:
         """Fade currently playing track"""