Log in without password option breaks the authentication right of the specific user

[Thanasis Naskos]

>>lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04

>>apt-cache policy gnome-control-center
gnome-control-center:
  Installed: 1:3.4.1-0ubuntu1
  Candidate: 1:3.4.1-0ubuntu1
  Version table:
 *** 1:3.4.1-0ubuntu1 0
        500 http://ftp.ntua.gr/pub/linux/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status

>>What you expected to happen
Changing my own user profile to not require a password on log in, should completely remove the existing password..

>>What happened instead
I have changed my own user profile to not require a password and log me in automatically. What happened is, once I'm logged in, I find my password is not accepted when I'm trying to install an application or make changes to user accounts.

This bug is also mentioned in this question of askubuntu: http://askubuntu.com/questions/128213/admin-password-authenticates-to-log-in-but-not-to-install-apps-or-change-user-a/

I've proposed there a solution, which worked for me, but I believe that it is important to report this question as bug to launchpad.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-control-center 1:3.4.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-24.37-generic 3.2.14
Uname: Linux 3.2.0-24-generic x86_64
ApportVersion: 2.0.1-0ubuntu7
Architecture: amd64
Date: Wed May 2 14:46:12 2012
ExecutablePath: /usr/bin/gnome-control-center
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)
XsessionErrors:
 (compiz:2352): GConf-CRITICAL **: gconf_client_add_dir: assertion `gconf_valid_key (dirname, NULL)' failed
 (gnome-settings-daemon:2335): power-plugin-WARNING **: was instructed to play a sound loop with one already playing
usr_lib_gnome-control-center:
 activity-log-manager-control-center 0.9.4-0ubuntu3
 deja-dup 22.0-0ubuntu2
 gnome-bluetooth 3.2.2-0ubuntu5
 indicator-datetime 0.3.94-0ubuntu2

[Sebastien Bacher (seb128)]

thank you for your bug report, how did you enable the "log in without password"?

[Thanasis Naskos (naskoos)]

I've enabled "log in without password" through "User Accounts" panel...
I've unlocked it and click in the dots of password field...
Then in the "Action" filed I've selected "log in without a password"

[Sam Bull (dreamsorcerer)]

This bug should be of high importance. I've just been completely locked out of my system because my account has no password, meaning sudo/gksu doesn't work. Which of course means I can't re-enable the password without hacking it with a LiveCD.

This option should allow the user account to login without entering their password, but should keep the password present for sudo authentication.

[Thanasis Naskos (naskoos)]

I believe that it's now fixed!!! I've tested it in a virtual machine using Ubuntu 12.04 LTS 64-bit and everything works great!! Is there anybody else to confirm it??

[Thanasis Naskos (naskoos)]

No my mistake! I wasn't locked out of my system, but I wasn't able to use any sudo command as it doesn't accept my password!!!
Sam bull is right... low importance is to low!

[Thanasis Naskos (naskoos)]

Come on, this is also affecting Ubuntu 13.04 beta 1.
It's too important guys, I'm trying to convience anyone I know to change from windows to Ubuntu but when the time comes for the question "Oh great OS but can I login without password?" I feel so embarassed to say "no because if you try so you 'll be locked out of your system"....

Most windows users don't use any password to login or give Administration privilleges!

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[C. Marques (caina-figueiredo)]

This bug is mean, I was lucky that the option "Automatic Login" was enabled, otherwise I wouldn't be able to login again as typing the password did nothing, I don't know if it's possible to login as root through the login screen, but I was able to do so through the su command once logged in (automatically). Afterwards 'passwd' solve the problem.