window.window_size holds the size of the window in windowed mode. Use
window.geometry for setting the opaque region since that holds the
current size.
if (window->opaque || window->fullscreen) {
region = wl_compositor_create_region(window->display->compositor);
wl_region_add(region, 0, 0,
- window->window_size.width,
- window->window_size.height);
+ window->geometry.width,
+ window->geometry.height);
wl_surface_set_opaque_region(window->surface, region);
wl_region_destroy(region);
}