25 seconds delay when org.Xfce.FileManager isn't available
The problem is in main_window.c:g_dbus_proxy_new_for_bus_sync:859. I have no idea how D-Bus works but can't we use a better-known, generic bus name and object path here? Thunar also owns org.freedesktop.FileManager1, so perhaps we could use that here. In theory, this should fix the delay and allow Ristretto to function with any file manager that adheres to the D-Bus spec.