gio: Error out when we cannot modify a GAppInfo

g_desktop_app_info_set_as_default_for_type() and
g_desktop_app_info_set_as_last_used_for_type () require the
application's ID, but depending on how the GAppInfo was created,
we might not be have one, and would thus silently fail to set
the default application, or last used application.

https://bugzilla.gnome.org/show_bug.cgi?id=657445
1 file changed