
For stylus buttons we apply a button mapping, e.g. secondary button -> right. This mapping was previously applied to the clutter event's evdev code only, not the actual clutter button. As a result, gnome-shell would always treat the BTN_STYLUS as middle and BTN_STYLUS2 as right, regardless of the mapping. Move the mapping up so we first adjust our evcode, then proceed with the usual mappings. Note that this temporary breaks the stylus mapping to Back/Forward which will be fixed in a follow-up commit. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3649>