According to the xdg-shell v6 protocol a positioner object is only
complete if both the size and its anchor rectangle are set. Ensure the
weston clients do this and let weston be more strict on checking if a
client has done so.
This also fixes weston-terminal popups not showing up on gnome-shell
3.22.
Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>