68542ae1ef
This reverts commit 47e339b46e80f01c2a4d020dbef7341e5a02b7eb. The approach that was used to reduce the amount of work we do on RR events to the necessary minimum is flawed. It assumes that, when the first event we see where the retrieved XRRScreenResources.timestamp is bigger than the previous, we already have all the data we need to rebuild our view of the world. That isn't true however, because the X server sends RRScreenChangeNotify events for every step of the configuration change, i.e. it lacks an atomic reconfiguration API. In particular, if the X screen size is one of the changes, when we rebuild our state and emit monitors-changed, the X screen size might still be the previous one and since we stop updating ourselves until another reconfiguration happens (noticed by looking at XRRScreenResources.timestamp) we end up with the wrong idea of the X screen size. https://bugzilla.gnome.org/show_bug.cgi?id=738630