Bug#586685: (no subject)

[Frank Mertens]

I faced the same issue of broken ssh scripts.
My solution was to put the following into /etc/gdm3/PostLogin/Default:

#!/bin/sh
if [ ! -e $HOME/.Xauthority ]; then
         touch $HOME/.Xauthority
         chmod 600 $HOME/.Xauthority
         chown $USER.$USER $HOME/.Xauthority
fi
cat $XAUTHORITY > $HOME/.Xauthority
exit 0