The fb layer of X can't deal with strides that are not a multiple of
4, so when Xephyr allocates its own framebuffer it should make sure to
align it.
This fixes crashes and rendering corruption when Xephyr runs in a
depth that is different from the host X server and its screen size is
not a multiple of 4 / depth. (This is particularly easy to trigger if
you use the -resizeable option).
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Soren Sandmann <ssp@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>