xwayland: Do not round non-standard modes

Currently, Xwayland uses libxcvt to generate the mode info and then
passes that to RRModeGet() to generate a RRMode.

However, libxcvt may round down the width to match the horizontal
granularity (8), and that's a problem when the Wayland compositor is
running a non-standard size (like, e.g. running nested with a custom
size) because XRandR would report a width smaller than the actual size.

To avoid that, check whether the CVT computed size differs from the
expected size, and fallback to a simpler computation not doing any
rounding if that's the case.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1540
Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>

0 files changed, 0 insertions, 0 deletions