a298943fac
The default ZoomRegion is created at startup and only updated if it is active when the monitor setup changes. Thus when reactivating the magnifier after a display change, the viewport used is still the one that been computed with the old screen geometry values. Move screen update code inside a function and call it both when activating the zoom region and when the monitor changes during a zoom session. Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1120