Comment # 3 on bug 1206739 from Mark Gray

Okay... How about this fix for /etc/profile.d/openssh-dbus.sh

if test -n "$SSH_CONNECTION" -a -n "$DISPLAY"
 then
     export SAVE_DBUS_SESSION_BUS_ADDRESS=$DBUS_SESSION_BUS_ADDRESS
     unset DBUS_SESSION_BUS_ADDRESS
     dbus-update-activation-environment --systemd --all
     DBUS_SESSION_BUS_ADDRESS=$SAVE_DBUS_SESSION_BUS_ADDRESS
     unset SAVE_DBUS_SESSION_BUS_ADDRESS
fi

Seems to work for both the local X11 user and the ssh -X user (why am I the
only one complaining about this? Perhaps I should have waited until someone
else noticed the problem. Oh well...)