Sorry I commented too quickly below after first tryout. After couple of
boots and tryouts it did finally succeed after longer wait time and now
after testing some 5 times I have managed to log with different user after
loging out. it is slow, but it will get there. So certainly I see good
progress, looks better now.

ti 29. toukok. 2018 klo 22.47 Heikki Moisander (<email address hidden>)
kirjoitti:

> heikki@ThinkPad-X301:~$ apt-cache policy gdm3
> gdm3:
>   Asennettu: 3.28.2-0ubuntu1.1
>   Ehdokas:   3.28.2-0ubuntu1.1
>   Versiotaulukko:
>  *** 3.28.2-0ubuntu1.1 500
>         500 http://fi.archive.ubuntu.com/ubuntu bionic-proposed/main
> amd64 Packages
>         100 /var/lib/dpkg/status
>      3.28.0-0ubuntu1 500
>         500 http://fi.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
>
> I seem to have fixed version now. It does not work for me any different
> from the previous version. Nothing happens while trying to change user or
> log in with different user account. After trying I can get back to login
> screen but then only way to login is boot.
>
> ti 29. toukok. 2018 klo 17.31 Łukasz Zemczak (<email address hidden>)
> kirjoitti:
>
>> Hello Chris, or anyone else affected,
>>
>> Accepted gdm3 into bionic-proposed. The package will build now and be
>> available at https://launchpad.net/ubuntu/+source/gdm3/3.28.2-0ubuntu1.1
>> in a few hours, and then in the -proposed repository.
>>
>> Please help us by testing this new package.  See
>> https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
>> to enable and use -proposed.Your feedback will aid us getting this
>> update out to other Ubuntu users.
>>
>> If this package fixes the bug for you, please add a comment to this bug,
>> mentioning the version of the package you tested and change the tag from
>> verification-needed-bionic to verification-done-bionic. If it does not
>> fix the bug for you, please add a comment stating that, and change the
>> tag to verification-failed-bionic. In either case, without details of
>> your testing we will not be able to proceed.
>>
>> Further information regarding the verification process can be found at
>> https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
>> advance!
>>
>> ** Changed in: gdm3 (Ubuntu Bionic)
>>        Status: In Progress => Fix Committed
>>
>> ** Tags removed: verification-failed-bionic
>> ** Tags added: verification-needed-bionic
>>
>> --
>> You received this bug notification because you are subscribed to a
>> duplicate bug report (1768619).
>> https://bugs.launchpad.net/bugs/1766137
>>
>> Title:
>>   [regression] Password accepted but login fails (blank purple screen
>>   and mouse pointer only)
>>
>> Status in gdm:
>>   Fix Released
>> Status in Release Notes for Ubuntu:
>>   Fix Released
>> Status in gdm3 package in Ubuntu:
>>   In Progress
>> Status in gnome-shell package in Ubuntu:
>>   Invalid
>> Status in gdm3 source package in Bionic:
>>   Fix Committed
>> Status in gnome-shell source package in Bionic:
>>   Invalid
>>
>> Bug description:
>>   [ Description ]
>>
>>   Due to a refcounting bug, a GDBusConnection was getting disposed when
>>   it was still required. The symptom of this was that you couldn't log
>>   in on the second attempt if you'd got your password wrong on the first
>>   attempt. All you'd see is a blank purple screen and mouse pointer
>>   only.
>>
>>   [ Test case ]
>>
>>   1. Boot to GDM
>>   2. Click your username
>>   3. Type the wrong password a couple of times, pressing enter after each
>> time
>>   4. Type the right password
>>
>>   If the bug is happening, after 4. the system hangs at a blank screen
>>   with the mouse cursor. If you then switch to a VT or otherwise connect
>>   to the machine, you can examine the journal and you'll see a
>>   G_IS_DBUS_CONNECTION failure.
>>
>>   [ Fix ]
>>
>>   Marco and I worked upstream on this fix. We found out that there was a
>>   problem like this-
>>
>>   The GdmClient has a shared GDBusConnection for its operations. The
>>   first time  someone calls for it, it is created and stored in the
>>   object's private structure. Subsequent calls return *a new reference*
>>   to this same object. It turned out that the asynchronous method to get
>>   the connection was accidentally unreferencing its object before giving
>>   it to the caller if it was returning an already-existing connection.
>>
>>   For this to work properly, we need to nullify the pointer we stored
>>   when the connection goes away, so we know when to make a new one.
>>   There were some cases where we didn't add the weak references required
>>   to do that. Those are also fixed.
>>
>>   [ Regression potential ]
>>
>>   Now we share connections more than we did before. We also more
>>   carefully track when to clear our object. If we got this wrong, we
>>   might end up leaking the connection or dropping it in even more cases.
>>
>>   [ Original report ]
>>
>>   WORKAROUND: After typing an incorrect password, click Cancel, then
>>   click your name, then enter your password again.
>>
>>   ---
>>
>>   Trying to log into my session (Gnome, Xorg), if I enter the wrong
>>   password before entering it correctly, the session doesn't load and I
>>   get a purple screen, a mouse cursor, and an invisible but clickable
>>   menu in the top right. If I enter it correctly the first time, there
>>   is no problem.
>>
>>   I've replicated this from a fresh boot, after logging out and after
>>   'sudo service gdm restart' from the Ctrl-Alt-F4 console.
>>
>>   This is a fresh install, and didn't occur when I was using a previous
>>   install of 18.04 (until Friday).
>>
>>   ProblemType: Bug
>>   DistroRelease: Ubuntu 18.04
>>   Package: gdm3 3.28.0-0ubuntu1
>>   ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15
>>   Uname: Linux 4.15.0-15-generic x86_64
>>   ApportVersion: 2.20.9-0ubuntu6
>>   Architecture: amd64
>>   CurrentDesktop: ubuntu:GNOME
>>   Date: Sun Apr 22 20:31:13 2018
>>   InstallationDate: Installed on 2018-04-22 (0 days ago)
>>   InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64
>> (20180421.1)
>>   SourcePackage: gdm3
>>   UpgradeStatus: No upgrade log present (probably fresh install)
>>
>> To manage notifications about this bug go to:
>> https://bugs.launchpad.net/gdm/+bug/1766137/+subscriptions
>>
>