The Shutdown command don't work on xfce version 4.12.1 See message https://forum.xfce.org/viewtopic.php?id=11601 It's the same on OpenBSD and NetBSD. I try to send Shutdown via DBus and have same result, only Logout. dbus-send --type=method_call --dest=org.xfce.SessionManager /org/xfce/SessionManager org.xfce.Session.Manager.Shutdown boolean:false So I had a Stop.desktop file with Exec=pkexec /usr/local/lib/xfce4/session/xfsm-shutdown-helper --shutdown and i can shutdown without su to root.
It works fine if you start your session within consolekit, cf https://cvsweb.openbsd.org/cgi-bin/cvsweb/ports/meta/xfce/pkg/README-main?rev=1.13&content-type=text/x-cvsweb-markup It will also change/improve in 4.14, see https://bugzilla.xfce.org/show_bug.cgi?id=14722
Like I say in the forum, it works fine with consolekit2. But xfce came with org.xfce.session.policy. pkg_info consolekit2 give nothing about xfce : Required by: polkit-qt5-0.112.0p7 So, I think xfce can work without it and use org.xfce.session.policy. The same thing appear in OpenBSD, Netbsd and Debian-Linux, so i think it's a bug. If the xfce team want we use consolekit2 : - consolekit2 must been required by xfce. - org.xfce.session.policy must been removed. It's a pity to do that because only shutdown don't work.