desktop or other past screen contents visible before lockscreen on resume

Bug #1375271 reported by Adam Colligan on 2014-09-29
This bug affects 4 people
Affects Status Importance Assigned to Milestone
GNOME Screensaver
Fix Released
Andrea Azzarone
Fix Released
unity (Ubuntu)
Andrea Azzarone

Bug Description


On resume from suspend, screen contents are displayed for a brief time (perhaps 0.5 to 1 sec) before the lock dialog appears.

These screen contents are not always the desktop or open application beneath the lock screen. On at least one occasion, the screen showed content from a full-screen video that had been playing in Firefox some time before the computer had been suspended: neither the video nor its underlying tab were open anymore, so the image(s) was likely part of a buffer somewhere. (Needless to say, if the wrong full-screen video had been watched, depending on the setting, this could be a quite serious issue for some users).

[Test Case]

Suspend and resume the computer (closing the lid or using the session indicator). Since this problem involves a race condition, it is not reliably reproducable at will.

[Regression Potential]

This fix unmaps windows when a suspend or shutdown event occurs: it is possible that the window(s) do not get remapped when a wake event occurs, or the wake even does not get propagated. This does not appear to occur in practice.

[Other Info]

The Ubuntu 14.04 LTS SRU was cherry-picked from upstream Unity where it has been released in the Ubuntu "Vivid Vervet" development release for a couple of months with no apparent regressions.

Related branches

Adam Colligan (adam-p) wrote :
description: updated
Adam Colligan (adam-p) on 2014-09-29
description: updated
description: updated
Marc Deslauriers (mdeslaur) wrote :

What desktop environment are you using?

information type: Private Security → Public
Adam Colligan (adam-p) wrote :

This is stock Ubuntu Unity. Sorry if the gnome screensaver package was a wrong one to add -- I had thought that it was used for lockscreen in unity, and it was involved in the 2011 report.

Changed in compiz:
status: New → Incomplete
status: Incomplete → New
Adam Colligan (adam-p) wrote :

Let me know if there is any specific testing pattern, video recording, or config information I could provide that might help.

Andrea Azzarone (azzar1) on 2014-10-21
Changed in unity:
importance: Undecided → High
assignee: nobody → Andrea Azzarone (andyrock)
milestone: none → 7.3.1
milestone: 7.3.1 → 7.3.2
no longer affects: compiz
Changed in unity (Ubuntu):
assignee: nobody → Andrea Azzarone (andyrock)
Changed in unity:
importance: High → Medium
status: New → In Progress
Changed in unity (Ubuntu):
status: New → In Progress
Changed in unity (Ubuntu):
importance: Undecided → Medium
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package unity - 7.3.1+15.04.20141128-0ubuntu1

unity (7.3.1+15.04.20141128-0ubuntu1) vivid; urgency=low

  [ Andrea Azzarone ]
  * Unmap all windows during shutdown. (LP: #1370017, #1375271)
  * Make sure GetScreenGeometry returns the correct value. (LP:

  [ Marco Trevisan (Treviño) ]
  * Decorated Window: still paint decorations if on transformated
    windows in different workspaces (LP: #1383468)
  * DecoratedWindow: make sure we always set a _NET_FRAME_EXTENTS for
    windows that requested it
  * UnityScreen: when filtering out windows in spread, make sure we
    unscale them (LP: #1316265)
  * PanelMenuView: ensure that proper window tiles and buttons are shown
    at the right place (LP: #1384958, #1384910, #1385285)
  * PanelService: inject special key events back to the root window when
    a menu is opened
  * PanelService: use gdbus to notfy upstart of service start/stop
 -- Ubuntu daily release <email address hidden> Fri, 28 Nov 2014 12:56:28 +0000

Changed in unity (Ubuntu):
status: In Progress → Fix Released
Changed in unity:
status: In Progress → Fix Committed
Andrea Azzarone (azzar1) on 2014-12-20
Changed in unity:
milestone: 7.3.2 → 7.3.1
Stephen M. Webb (bregma) wrote :

Attached debdiff between trusty-updates and SRU.

Stephen M. Webb (bregma) on 2014-12-29
description: updated
Chris J Arges (arges) wrote :

Accepted unity into trusty-proposed. The package will build now and be available at in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at . Thank you in advance!

Changed in unity (Ubuntu Trusty):
status: New → Fix Committed
tags: added: verification-needed-trusty
Mathew Hodson (mhodson) on 2015-01-18
tags: added: lockscreen
removed: lock
Mathew Hodson (mhodson) on 2015-01-18
tags: added: suspend
Adam Colligan (adam-p) wrote :

A form of this regression has now returned with a vengeance; I'm not sure whether to make it into a new bug report or simply to re-open this one, though.

For the past couple of days, resume-from-suspend behavior has frequently been this:

- the lock screen appears at first to have been completely bypassed, and the session appears restored on wakeup

- the cursor is visible on the screen and moves, but the mouse and keyboard cannot actually interact with any objects on the screen

- using ctrl-alt-F(x) to raise a new terminal, then using ctrl-alt-F7 to return to the x session, bringis back the lock screen. Actually logging in to the other session is not necessary, and everything proceeds normally once the lockscreen is brought up.

Mathew Hodson (mhodson) on 2015-01-27
Changed in gnome-screensaver:
status: New → Invalid

Hi Adam:
I have been using 7.2.4+14.04.20141217-0ubuntu1 for a while now and I'm unable to reproduce the problem you mention in comment #8. However, I'll pay attention and report back if I find any problems!

Also, the updated from -proposed seems to have fixed this bug. The behaviour when suspending/resuming is as smooth as ever for me.

Btw, just in case, I Sandybridge integrated graphics on my laptop.

Hi franglais.125,

If the packages from -proposed resolve this bug then please edit Tags and change verification-needed to verification-done. This is needed to move this version of Unity from -proposed to -main.

Also there are two other bugs that need verification. You can see which ones on this webpage:

Hi Mateusz,

I was just waiting to see if I got the same problem as Adam at all... So far so good. I just don't want Adam's problem to be propagated. Adam: are you filing a new bug report? Is it ok if I tag it as verification-done?

Also, I saw the other two bugs, but I wasn't initally affected by them. I'll see if I find time later today to have a look.

I made some tests but not on real hardware. I used VirtualBox.

I didn't have any of the problems described in this bug report. I checked with a couple of windowed programs and then with Firefox in fullscreen and the last test was with Evince in fullscreen. When I resumed the only thing that displayed was lockscreen (no view of the desktop or it's past contents).

Adam in his comment didn't specify the version of Unity and I assume he isn't using the version from -proposed.

I've been trying pretty hard to reproduce Adam's problem (comment #8), and this bug in general, when running unity from -proposed.

I tried this with fullscreen Firefox, flash, totem, without a single problem. The only case were the contents were visible when resuming was when having a fullscreen pdf in Firefox (using pdf.js), but the contents were only visible for a split second (maybe 0.1s or something like that).

I'll mark this as verification-done.

tags: added: verification-done-trusty
removed: verification-needed-trusty
Adam Colligan (adam-p) wrote :

I'll file a new bug report when I have a bit of time and put the link in a comment here when it's done.

I've realized now that this new bug as I'm seeing it is actually not contingent on Suspend taking place. If I simply go to menu "Lock", I get a black screen. Moving the mouse or otherwise triggering the unlock screen instead gives an image of the Desktop with no interaction possible except moving the cursor. Going to a different TTY and then back brings up the lock screen.

Adam Colligan (adam-p) wrote :

Okay, new bug filed: bug #1416897 ( ).

That report includes a more in-depth description.

There is also a 1-minute video of the bug in action ( ). It gives a synced, side-by-side comparison of what the user sees (cameraphone) versus what the OS thinks is being displayed (SimpleScreenRecorder).

I see, you are actually using 14.10. I'm on 14.04, that's a big difference between our systems.

Good luck with the new bug report! Hopefully it will get fixed soon...

Launchpad Janitor (janitor) wrote :

This bug was fixed in the package unity - 7.2.4+14.04.20141217-0ubuntu1

unity (7.2.4+14.04.20141217-0ubuntu1) trusty; urgency=medium

  [ Andrea Azzarone ]
  * Share lockscreen password between screens (lp: #1308540)
  * Allow a distinct pam config file for greeter and for lock-screen.
    (lp: #1305440)
  * Add an arrow activator in the lockscreen. (lp: #1332509)
  * Make sure GetScreenGeometry returns the correct value (lp: #1374785).
  * unmapped all windows prior to shutdown (lp: #1370017) (lp: #1375271)

  [ Brandon Schaefer ]
  * fix tooltip for the "Show Desktop / Restore Windows" icon in the Alt-Tab
    switcher (lp: #1237132)
  * Use CONFIG instead of CACHE to store the first_run.stamp (lp: #1328677)

  [ Eleni Maria Stea ]
  * LayoutSystem: make sure the exposed open windows are displayed in the
    preserved order (lp: #1349281).

  [ handsome_feng ]
  * added support for getting the distro name from /etc/os-release
    (lp: #1329584)

  [ Iain Lane ]
  * When grabbing keys, try prefixing "XF86" if the key isn't found. GNOME
    gives us unprefixed keys sometimes (lp: #1302885).

  [ Marco Trevisan (Treviño) ]
  * make the Launcher icon count badge width depend on the text value width
    and scaling (lp: #1353070) (lp: #1354498) (lp: #796527) (lp: #1066971)
    (lp: #1361713)
  * DecoratedWindow: make edges independent from borders and properly update
    them on actions change (lp: #1276177), (lp: #1299741), (lp: #1301776),
    (lp: #1324104), (lp: #1364225), (lp: #1373695)
  * Lockscreen: scale the UI elements based on current monitor scaling
    (lp: #1292218)
  * UnityScreen: when filtering out windows in spread, make sure we unscale
    them (lp: #1316265).
  * PanelMenuView: ensure that proper window tiles and buttons are shown at
    the right place (lp: #1384910) (lp: #1384958) (lp: #1385285)
  * SearchBar, ActionButtons, IconRenderer: include the font scaling when
    scaling textual items (lp: #1332947) (lp: #1361751) (lp: #1362162)
    (lp: #1362346).
  * ApplicationLauncherIcon: make sure we close the dash if DnD is accepted
    and the application window is about to be focused (lp: #1350331).
  * SwitcherView: set progress on icon render args (lp: #1361679).
  * LockScreenController: wait for the primary shield to get the grab
    before setting the session locked (lp: #1368427) (lp: #1371764).
  * added decorations to windows in non-focused workspaces (lp: #1383468)

  [ Stephen M. Webb ]
  * updated the unity(1) manpage to match the actual command (lp: #1059275)
  * bumped package version to match upstream

  [ Marco Trevisan (Treviño) ]
  * Preparing for unity 7.2.4
 -- Ubuntu daily release <email address hidden> Wed, 17 Dec 2014 20:52:10 +0000

Changed in unity (Ubuntu Trusty):
status: Fix Committed → Fix Released

The verification of the Stable Release Update for unity has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

Stephen M. Webb (bregma) on 2015-02-11
Changed in unity:
status: Fix Committed → Fix Released
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