The crash is mutter issue #4871, a regression from !5057, and
!5375 ("wayland/touch: Do not crash on empty focus surface") carries
the same NULL check as our patch. Say so in the overlay and the
patch, so it is clear when the patch can go.
Assisted-by: Claude:opus-5
gnome-shell keeps segfaulting in libmutter, and with the PAM core
limit at 0 systemd-coredump threw every dump away, so there was no
backtrace to work from. Raise the limit to unlimited; dumps land
root-owned in /var/lib/systemd/coredump, readable only by their
owner. Enable nixseparatedebuginfod2 so gdb/coredumpctl can fetch
symbols for store paths on demand.
The user manager inherits the limit at its first login, so it takes
a reboot (or a full logout) to apply.
Assisted-by: Claude:opus-5
