55xfce4-session

cat /etc/X11/Xsession.d/55xfce4-session
# For Xfce, we add a directory to XDG_DATA_DIRS
# to allow the admin to set, for example, defaults.list properly
BASESTARTUP=$(basename "$STARTUP" | cut -d\  -f1)
if [ "$BASESTARTUP" = x-session-manager ]; then
    BASESTARTUP=$(basename $(readlink /etc/alternatives/x-session-manager))
fi
case "$BASESTARTUP" in
  xfce4-session|startxfce4)
    # We prepend /usr/share/xfce4 since its defaults.list actually points
    # to /etc so it is configurable.
    if [ -z "$XDG_DATA_DIRS" ]; then
      XDG_DATA_DIRS=/usr/share/xfce4:/usr/local/share/:/usr/share/
    else
      XDG_DATA_DIRS=/usr/share/xfce4:"$XDG_DATA_DIRS"
    fi
    export XDG_DATA_DIRS
    if [ -n "$DBUS_SESSION_BUS_ADDRESS" ] && \
      command -v dbus-update-activation-environment >/dev/null; then
        dbus-update-activation-environment --verbose --systemd XDG_DATA_DIRS
    fi
    ;;
esac