Screen locking issue - account with no password set

[Captain Zlog]

Have an account with no password set. When computer resumes from suspend state, where user with no pasword is logged in, system now request password and will not unlock screen.

Expected action is to automatically unlock screen without asking for a password.

Workaround is to get the 'Switch Account' screen up and select the same user and then click "Log In" - no password requested this time. Same action occurs if Ctl-Alt-L pressed when logged in as this user.

This was working fine under Ubuntu 14.04 but now performs incorrectly since upgrade to 14.10 (not a fresh install). Installed version of gnome-scrrensaver is 3.6.1-0ubuntu14

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: gnome-screensaver 3.6.1-0ubuntu14
ProcVersionSignature: Ubuntu 3.16.0-23.31-generic 3.16.4
Uname: Linux 3.16.0-23-generic x86_64
ApportVersion: 2.14.7-0ubuntu8
Architecture: amd64
CurrentDesktop: Unity
Date: Mon Oct 27 12:52:07 2014
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GsettingsGnomeSession:
 org.gnome.desktop.session session-name 'ubuntu'
 org.gnome.desktop.session idle-delay uint32 300
InstallationDate: Installed on 2013-06-11 (502 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424)
SourcePackage: gnome-screensaver
Symptom: security
Title: Screen locking issue
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Luca Chiodini (l-chiodini)]

This also affects Ubuntu 14.10 with a fresh install.

[Captain Zlog (graham-n)]

Been doing some more investigation on this problem. Looked in System Settings->Security & Privacy and found on the Security tab that both "Waking from suspend" and "Returning from blank screen" were both checked, indicating password required in both cases. Unchecked both items and the problem has now gone away - functionality is now as expected. Not sure if these items were checked under 14.04 and just ignored when resuming from suspend or whether the upgrade to 14.10 actually set these items. Bug can now be closed.

[Luca Chiodini (l-chiodini)]

Captain analysis is correct, but this is a bug anyway.
You cannot ask for a non-existent password.
This is a problem in a multi-user system, where different policies may be applied to different users. For example, user A is password-protected while user B is not. Options above are enabled. With current behaviour, user B can't log in.