This appears related at least to 140_backport_default_internet_apps.patch which stops even loading the XML files from /usr/share/gnome-control-center/default-apps (why does firefox ship an XML file there?)
This appears related at least to 140_backport_ default_ internet_ apps.patch which stops even loading the XML files from /usr/share/ gnome-control- center/ default- apps (why does firefox ship an XML file there?)