Ubiquity not powering off with "ubiquity ubiquity/poweroff boolean true" in preseed file

[KDEUSER56]

What I did:

1.) Downloaded official Ubuntu 14.04 Desktop iso
2.) Placed the preseed file in the iso and changed the kernel boot command line to
       "file=/cdrom/preseed/install.seed boot=casper noninteractive noprompt initrd=/casper/initrd.lz quiet splash --"
3.) Let the installer run

What happens: After the installation is finished, the live session is started
What should happen: After the installation is finished, the system should power off.

Poweroff works when I work around the following way:

ubiquity ubiquity/success_command string sudo poweroff;

Note: Poweroff does neither work with

ubiquity ubiquity/poweroff string true

[KDEUSER56 (kdeuser56)]

Still true for both trusty and latest utopic. Please have a look at it, despite being a minor issue, it should still be fixed.

[Simon Quigley (tsimonq2)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. It would help us a lot if you could test it on a currently supported Ubuntu version. If you test it and it is still an issue, kindly upload the updated logs by running only once:
apport-collect https://api.launchpad.net/1.0/bugs/1329417

and any other logs that are relevant for this particular issue.

[Launchpad Janitor (janitor)]

[Expired for ubiquity (Ubuntu) because there has been no activity for 60 days.]

[Christopher Malau (trishmapow)]

Still an issue on 20.04.6, noninteractive and poweroff do not work together.