Bug#838050: GDM3-only behaviour; Wayland not totally broken; bad tablets break even that

[Andrew Chadwick]

Reported upstream as a gnome-shell bug initially at
https://bugzilla.gnome.org/show_bug.cgi?id=771628


I can confirm that downgrading mutter and its support files and libs
fixes the problem. In a picture such as

gnome-shell    3.21.91-2
gnome-session  3.20.2-1
libwacom2      0.22-1   <<< ***OR 0.19-1, doesn't matter!
xserver-xorg   1:7.7+16
xwayland       2:1.18.4-1
mutter         3.21.92-1   <<< *** gnome-shell segfaults

Downgrading mutter (& its lib and -common package) to 3.21.91 fixes
the segfaults, in both Xorg and Xwayland.

mutter         3.21.91-2   <<< +++ no segfaults, all tablets OK

Quick workaround for people having problems right now:

# apt-get install mutter=3.21.91-2 mutter-common=3.21.91-2 libmutter0i=3.21.91-2
# apt-mark hold mutter mutter-common libmutter0i