PERMISSION_SECURITY="secure local" in /etc/sysconfig/security works for most
things even in desktop usage, but KDE hangs on logout when choosing "shut down"
(german "Herunterfahren").

The fix for this are the following two entries in
/etc/polkit-default-privs.local:

org.freedesktop.login1.power-off   auth_admin_keep:auth_admin_keep:yes
org.freedesktop.login1.reboot      auth_admin_keep:auth_admin_keep:yes

After running /sbin/set_polkit_default_privs I can shut down my computer from
the KDE logout dialog again.

Please consider to add these two for polkit-default-privs.restrictive.
(Without these two lines, the workaround is to logout, and then shutdown from
sddm ;-)


Sidenotes:
- The default in restrictive is "auth_admin_keep", and I guess it's too late 
  in the logout process to show a password dialog, so the logout simply hangs.
- The only other local rules I need to live with "permissions.secure" are
  org.freedesktop.packagekit.system-sources-refresh
                                           auth_admin_keep_always:no:yes
  org.freedesktop.NetworkManager.network-control               no:no:yes
  # mount / umount USB stick
  org.freedesktop.udisks2.filesystem-mount     auth_admin:auth_admin:yes
  org.freedesktop.udisks2.eject-media          auth_admin:auth_admin:yes