Adding/Removing an external monitor causes maximized windows to move to another workspace

I guess the hot plug events for adding and removing external monitors are a really complicated issue. In my case, I have two monitors connected to my computer. Turning them off causes a hot plug event saying that first one and then the other have gone away. Turning them on again causes windows to turn up in different places as they were before, which is of course not the expected behavior.

Moving the window when un-maximazing is obviously wrong, but my point is that the solution as to what to do when monitors appear or go away is not trivial at all.

I'm running precise and I've applied the changes available at the unity SRU ppa.

This bug is still present with the currently available latest updates.

Behaviour:
When having two monitors, if a window is maximized in the right monitor and this monitor is turned off, the window moves to the left [correct, expected].
  If it's unmaximized, it moves to the workspace to the right or to the left, depending on which workspace it is [incorrect].
  If while still maximized, the monitor comes back, it stays on the right. [unexpected, at least for me]

--
Regards,
Marga

A little update.
If I add second display, maximize application to it and window has "Visible on all workspaces" set, after removing second display window is moved to current workspace, active display maximized, but when I un-maximize the window, it's gone. I cant get it back to work with it, no matter how I try - clicking in unity launcher just switches desktops, wmctrl can't move the window and there is no possibility for me get that window in any visible area anymore. Only solution to it is - right click in unity launcher and choose "Quit".

In addition to the problem that all full screen windows show up on the current workspace after resuming from standby or changing the monitor setup (adding/removing monitor), I also have problems with switching off monitors in general.

I have a dual monitor setup and switching the monitors off causes some trouble. All is fine, if you switch them on again before the screen saver is activated. After the screen saver is activated only the primary output of the graphics adapter is activated. The second monitor is not even available anymore until I detect it with the nvidia-settings-manager.

I've been looking at this and have a working solution, but I have to make some compromises on the geometry of restoring the maximized window. Since the monitor that got removed may have had a much larger resolution than the current monitor, I think it's best to restore the window to the top left of the workspace since it's conceivable that it could restore somewhere far to the right and/or far to the bottom and still wouldn't look right. Also, if the restored window is still larger than the screen even with the window positioned at the top left, then the window will be shrunk to fit the screen.

This bug was fixed in the package compiz - 1:0.9.11+14.04.20140328-0ubuntu1

---------------
compiz (1:0.9.11+14.04.20140328-0ubuntu1) trusty; urgency=low

  [ Chris Townsend ]
  * Fix issue where having a maximized window on a second monitor, then
    that monitor gets removed which moves the maximized window to the
    main monitor, then restoring the maximized window would place it on
    a different viewport. It should stay on the same viewport. (LP:
    #1171878)
 -- Ubuntu daily release <email address hidden> Fri, 28 Mar 2014 10:44:36 +0000

I still observe the problem with

$ apt-cache policy compiz
compiz:
  Installed: 1:0.9.11+14.04.20140328-0ubuntu1
  Candidate: 1:0.9.11+14.04.20140328-0ubuntu1

Example:
4 workspaces, external monitor plugged in. Applications are maximized to primary monitors in workspaces 2 and 3. Current worspace is workspace 1. When disconnecting the external monitor, those maximized applications move from workspaces 2 and 3 to workspace 1.

Expected behavior: maximized applications should remain on their original workspaces.

@cometdog,

This bug is specifically about unmaximizing a window once it moves to a different screen when unplugging a monitor. The issue you describe is indeed a bug, but should be tracked in a different bug. I'll see if a bug has already been reported for the issue you describe. If not, then I'll make one:)

@cometdog
https://bugs.launchpad.net/compiz/+bug/1304531

I don' t quite get why 763148 can be seen as fixed without fixing maximized windows bug.

@khadgaray patches appears to fix this behavior on precise.

Attached is the debdiff for the proposed Compiz SRU that fixes this. Also, a branch is linked to this bug for the same fix.

Hello Eduards, or anyone else affected,

Accepted compiz into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/compiz/1:0.9.7.12-0ubuntu4 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed 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 https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

After install compiz from propose, all problems with multi monitor support (which was described here) was solved for me.

Now it is working perfectly.

Thanks you!

The verification of the Stable Release Update for compiz 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.

This bug was fixed in the package compiz - 1:0.9.7.12-0ubuntu4

---------------
compiz (1:0.9.7.12-0ubuntu4) precise; urgency=low

  * debian/patches/fix_external_monitor_hotplug.patch
    - Cherry-pick fixes upstream for window mismanagement when adding
      and/or removing an external monitor. (LP: #763148) (LP: #1171878)
 -- Chris Townsend <email address hidden> Mon, 07 Jul 2014 15:15:43 -0400