Dear Maintainer,

In trixie, configuring onboard to be used as the on-screen keyboard for
lightdm's greeter doesn't work. Lightdm attempts to start it, and a quick ps ax
shows it's running, but it doesn't show up on the login screen. This prevents
using it as a means to login. Which worked fine in bookworm.

In the greeter logs we see that onboard is throwing assertion errors about
screen sizes.

Theoretically, all one has to do to enable during login is set the keyboard
option in the /etc/lightdm/lightdm-gtk-greeter.conf file to "onboard -e". This
works under bookworm, but even specifying a full path (/usr/bin/onboard), and
even giving it absolute screen origin coordinates and a size (the -x / -y and
-s options respectively) fails to make it display with the errors still showing
up in the logs.

It should be noted that this bug only happens when using onboard on the login
screen. Onboard works just fine once the user is actually logged in and the
desired window manager (xfce in my case) is running.

Regards,
Patrick Hibbs