qt applications have render update delay in gnome when compiz is enabled

[Andrew Manson (real_ate)]

Its a bit of a strange bug, i think it might be related to the fact that i installed KDE 4.2 using the method discribed at http://www.kubuntu.org/news/kde-4.2 i.e. adding the custom reporatories.

The best way to describe this bug is by giving an example.

Open LYX ( which uses the Qt libraries ) and open a file. Everything looks grand if you use the up and down arrows to navagate, it gets the hint to redisplay, but if you use the middle mouse button nothing moves! Well actually you can see the the blinking Text Cursor has moved to where it is expected to be by moving the middle mouse button but the rest of the text hasn't moved at all!

To get the rest of the text to move you need to click into the text area before anything changes.

And as the title of this bug says this only ever happens when compiz is turned on! If i go to System > Preferences > appearance > Visual Effects and set the effects to "NONE" then the problem has gone away. But of course i can't use any of the useful compiz stuff then in gnome ;)

I've tried to disable the Window Decoration in Compiz cos i thought that would help but it leaves all of my windows without a title bar and it is impossible to do anything with.

Anyone able to lend a hand in figuring out what exactly is wrong with this?

Oh and i'm using Ubuntu 8.10 btw

[Jonathan Thomas (echidnaman)]

It could be either a compiz issue or a video driver issue, but I don't think it would be a KDE issue if it happens with pure Qt apps.

[Michael (michaeljt)]

This is probably not a Qt bug - I see this with the title bars of all my windows (Ubuntu-Gnome), which are not always updated correctly. It is best seen in Firefox, where when I switch tabs a few times the title bar often reflects the last tab to be selected, not the current one. It is also noticeable as strange artefacts in the title bars of other applications. Is is most noticeable though in VirtualBox, which is a Qt application and shows this update problems throughout it's selector window.

It also seems to be related to the graphic drivers in use (I am using NVidia proprietary as I need Compiz and Nouveau isn't there yet :( ). Other people have tested VirtualBox with compiz and other video drivers without issues.

[polarapfel (tobias-weisserth-eu)]

I can confirm this bug on a Dell Latitude D630 with the proprietary Nvidia driver on Ubuntu 9.04 "Jaunty". In Gnome with visual effects enabled, Qt applications like KeePassX or the git client cola do not update their windows correctly and basically become unusable. If I disable visual effects in Gnome, each Qt application behaves correctly.

[Bryce Harrington (bryce)]

Hi real-ate,

Thank you for taking the time to report this bug and helping to make Ubuntu better. You reported this bug a while ago and there hasn't been any activity in it recently. We were wondering is this still an issue for you? Can you try with the latest development release of Ubuntu? (ISO CD images are available from http://cdimage.ubuntu.com/releases/)

If it remains an issue, could you also attach a new /var/log/Xorg.0.log?
Thanks in advance.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Bryce Harrington (bryce)]

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.