Removing a user's password effectively locks them out of admin privileges

[David D Lowe]

Steps to reproduce this bug:

- Log in with a user who has admin privileges
- Open User Accounts from System Settings
- Click "Unlock" and authenticate yourself
- Click on the "Password" field.
- Set "Action" to "Log in without a password"
- Click on "Change"

(Same steps with screenshots can be found in this answer: http://askubuntu.com/a/281093/2355 )

This successfully sets the user's password to empty. However, it does not ensure that sudoers includes a NOPASSWD directive, so the user now can longer use sudo, gksu, pkexec or PolicyKit to authenticate themself to gain admin rights.

What I expected to happen:

This functionality should be disabled for users with admin rights, or the sudoers file should be modified as appropriate, and PolicyKit made to work for users without a password.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: gnome-control-center 1:3.4.2-0ubuntu19.1
ProcVersionSignature: Ubuntu 3.5.0-26.42-generic 3.5.7.6
Uname: Linux 3.5.0-26-generic i686
ApportVersion: 2.6.1-0ubuntu10
Architecture: i386
Date: Sat Apr 13 20:59:29 2013
MarkForUpload: True
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to quantal on 2012-10-18 (176 days ago)
usr_lib_gnome-control-center:
 activity-log-manager-control-center 0.9.4-0ubuntu4.2
 deja-dup 24.0-0ubuntu2
 gnome-control-center-signon 0.0.18-0ubuntu1
 indicator-datetime 12.10.2-0ubuntu3.1