
The current page is going to be destroyed as part of _onKeyboardGroupsChanged cleanup, however we don't unset its pointer, and thus we'd might try to call a function using an invalidated pointer. So, unset the this._current_page reference when its get destroyed, connecting to destroy signal when setting it and disconnecting when changing page. Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1281 https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/540