Unity restart broken

[Alin Andrei]

Restarting Unity no longer works properly in Ubuntu 15.04 Vivid Vervet.

Steps to reproduce: press ALT + F2, type Unity and press ENTER.

What should occur: Unity should be restarted without logging out the user.

What actually occurs: the LightDM login screen greeter shows up (so the user is logged out) instead of just restarting Unity.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: unity 7.3.2+15.04.20150330-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-12.12-generic 3.19.3
Uname: Linux 3.19.0-12-generic x86_64
ApportVersion: 2.17-0ubuntu1
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Wed Apr 8 14:50:13 2015
InstallationDate: Installed on 2015-03-11 (28 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150306)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Christian Dannie Storgaard (cybolic)]

As Unity's performance tends to severely diminish over time (sometimes a few hours, sometimes a day or two, in my experience), it is actually necessary to restart Unity, so this bug makes Unity close to unusable for extended sessions.

[Alin Andrei (nilarimogard)]

This bug still occurs in Wily.