The problem is: I found this fix by trial and error, someone who knows the code should verify that the fix is correct. For example, I don't know whether 0 is always represented as list (0 0) at this point (given how many different settings there are...) and whether it is the correct code place to handle this case. TIA, Michael. In GNU Emacs 31.0.50 (build 15, x86_64-pc-linux-gnu, cairo version 1.16.0) of 2024-07-02 built on drachen Repository revision: 7b256c6118326a76e81cc004576c78ba5a475ffd Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12101007 System Description: Debian GNU/Linux 12 (bookworm) Configured using: 'configure --with-x-toolkit=no --with-native-compilation=no' Configured features: CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG LCMS2 LIBSELINUX LIBSYSTEMD LIBXML2 MODULES NOTIFY INOTIFY OLDXMENU PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF WEBP X11 XDBE XIM XINPUT2 XPM ZLIB Important settings: value of $LC_ALL: de_DE.utf8 value of $LC_COLLATE: C value of $LC_TIME: C value of $LANG: de_DE.utf8 locale-coding-system: utf-8-unix