Restart equivalent to log out when multiple users are logged in

To reproduce:

1) Log in multiple users via lightdm
2) On one of the users, select the power icon in the upper left and choose Shut Down...
3) Select the Restart button

Observed behavior: the current user is logged out and the console returns to the lightdm log in screen.

Expected behavior: the system warns the user others are logged in and verifies that the user wishes to restart anyway. The computer actually restarts when confirmed.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lightdm 1.2.1-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.2.0-30.48-generic-pae 3.2.27
Uname: Linux 3.2.0-30-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu13
Architecture: i386
Date: Wed Sep 12 20:35:36 2012
ExecutablePath: /usr/sbin/lightdm
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
SourcePackage: lightdm
UpgradeStatus: Upgraded to precise on 2012-05-27 (108 days ago)