This is returned as an integer, which we deal with as an unsigned integer. Deal with it as an integer all along, and skip safely negative values. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1920>
This now lives in the core, and will get updated from events in the UI thread. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1403>