Windows move in workspaces after a window resize event

[Jon]

I run Ubuntu 14.04 LTS as a VirtualBox guest (both with VB 4.3.x and 5.x) using the default desktop. If I toggle the size of the screen (using Host-Right-Ctrl-F) from maximised to not maximised and then back again, the workspaces behave incorrectly. The same happens also if I save and restore a VirtualBox session from disk.

Here is what goes wrong:

- Maximised windows move between Workspaces
- When activating the Workspaces viewer, maximised windows cannot be dragged to the Workspace they should be on - they appear to drag, and then "snap back" to their present (wrong) location
- Unmaximising and re-maximising a window fixes the problem for that window only

I have written a script to toggle the maximisation status of all windows, which resolves the problem.

It is probably of note that this bug only affects maximised windows - if a window is not maximised then it remains on the correct workspace, and can
be moved to any other without my 'reset' hack.

I don't think the Workspace grid size makes any difference - I've had this happen with 3x2 and 3x3 arrangements.

I have installed a brand new Ubuntu guest using the "ubuntu-14.04.2-desktop-amd64.iso" image and cannot reproduce the problem. It is perhaps the case that the problematic machine was installed using the "ubuntu-14.04-desktop-amd64.iso" image (I don't know if that would matter).

[Jon (jonpad)]

System info:

lsb_release -rd
Description: Ubuntu 14.04.3 LTS
Release: 14.04

unity --version
unity 7.2.5

Interestingly, I ran apport to get some system information, and I get this message:

> Your system is providing 3D via software rendering rather than hardware rendering. This is a compatibility mode which should display 3D graphics properly but the performance may be very poor. If the problem you're reporting is related to graphics performance, your real question may be why X didn't use hardware acceleration for your system.

3D acceleration is indeed turned on for this VM, and Workspaces animation is very snappy, so as far as I've been aware it +has+ been using hardware acceleration. I don't know if this is relevant, but adding it anyway.

Let me know if you need any logs.

[Jon (jonpad)]

Here is the script I'm currently using to rescue stuck windows - activating them has the nice side-effect of bringing them back to their original Workspace as well.

#!/bin/bash
#
# Resets all Windows after triggering Ubuntu/VirtualBox windowing bug
#
# @todo Filter out windows we don't need, using grep

for window in `wmctrl -l | cut -d " " -f 1`; do
    # Debugging
    #echo $window

    # Looks like doing just one axis doesn't work
    wmctrl -i -r $window -b toggle,maximized_vert,maximized_horz
    wmctrl -i -r $window -b toggle,maximized_vert,maximized_horz

    # Activate them as well
    wmctrl -R $window
done

[Launchpad Janitor (janitor)]

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

[Tom Inglis (tominglis)]

I can confirm this issue, but on a regular desktop installation of 14.04.4, not a virtualised instance.

I think that this bug is related:

https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1295267