kwin in ppa:kubuntu-ppa/backports hangs just after login when launching a random application.

[Ｖ字龍(Vdragon)]

Upstream bug report
Bug 317052 – ppa:kubuntu-ppa/backports : QXIMInputContext on QGraphicsView locks in _xcb_conn_wait
https://bugs.kde.org/show_bug.cgi?id=317052

System: Ubuntu 12.10 x86 32bit with ppa:kubuntu-ppa/backports enabled

How to reproduce
---------------------------------
1. Login to KDE
2. Launch any application (e.g. Dolphin)
3. Wait 5 sec.

Symptoms
---------------------------------
* The whole screen hangs, only mouse cursur is movable.
* It still able to switch to diffrent terminals
* kwin --replace and any GUI application will hang if executed after this hang until the original kwin is killed

Workaround
---------------------------------
1. switch to TTY terminal and login
2. send SIGKILL signal to terminate kwin (SIGTERM is not sufficient)
    pkill --signal SIGKILL kwin
3. run another terminal emulator in TTY terminal
    env DISPLAY=:0 konsole
4. Switch back to X terminal, execute following command in the Konsole window
     kwin &
5. redo 1~4 if the problem persists.

Other details
----------------------------------
* It seems that this issue is not related to graphic hardware...
* ppa-purge the kubuntu-ppa/backports to downgrade everything back to quantal-updates seems to solve this issue too.

[Ｖ字龍(Vdragon) (vdragon)]

Here's a screenshot when the terminal hangs.

[Ｖ字龍(Vdragon) (vdragon)]

Hi,
same as the upstream report I decided to close this bug because I can't reproduce it lately, It may probably be a random issue from Ubuntu/Kubuntu.