Bug 364067

A discussion came up with VDR experts (hey, these guys are also very experienced) when I was trying to configure my Video Disk Recorder PC also to be useable as a Desktop PC using KDE.  The idea is to have the PC being controlled by VDR and the user. To avoid that the PCs gets shut down by the desktop when a recording is active by VDR, the VDR process should set an inhibitor that is avoiding the shutdown and the Desktop is recognizing this, not requesting a shutdown. Logind / system-dbus provide the needed infrastructure with inhibitors for that.  The todays behaviour is, that the user will be prompted for a password in both cases. While this is ok when the shutdown was triggered by the user, an inactivity timeout should not open a popup. There I would expect that the desktop waits until the inhibitor has been closed.


Reproducible: Always

Steps to Reproduce:
1. Set an inhibitor from another user. I used the added python program for that.
2. Wait until the the desktop wants to suspend due to inactivity. Configure PowerDevil accordingly. 


Actual Results:  
A dialog pops up asking for confirmation even that there is likely no user as the session timed out and a suspend is triggered.

Expected Results:  
Power Devil should wait until the inhibitor has been removed. Then a shutdown should beeing triggered. As an alternative there should be an timeout for the password prompt a retry to suspend after some time.

This is the program I used to set the inhibitor. Run it from another user and then try to suspend the machine from the session user. In any case the sleep will be rejected.  

#!/usr/bin/python3

import dbus
import logging
import time

bus = dbus.SystemBus()

def inhibit(what='sleep', who='First Base',
            why="left field", mode="block"):
    try:
        a = bus.get_object('org.freedesktop.login1',
                                '/org/freedesktop/login1')
        interface = 'org.freedesktop.login1.Manager'
        print("Inhibitor opened: what = {}, mode = {}".format(what, mode))
        fd = a.Inhibit(what, who, why, mode, dbus_interface=interface)
        return fd
    except Exception as error:
        logging.exception(error)
        logging.warning("could not set inhibitor lock")

if __name__ == '__main__':
    my_inhibitor_fd = inhibit()
    #input('press any key to exit inhibitor')
    inhibitTime = 1200
    print("Suspend inhibitor will be active for {} seconds".format(inhibitTime))
    time.sleep(inhibitTime)