compositor: check viewport dst size validity

wp_viewporter requires the destination size to be always in integers,
even when it is implicit from source rectangle. Emit appropriate
protocol errors.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
1 file changed