Created attachment 1079121 [details] bt of konversation when it was locked up qt5-qtbase-5.5.0-15.fc22.x86_64 plasma-workspace-5.4.1-3.fc22.x86_64 libxcb-1.11-8.fc22.x86_64 libX11-1.6.3-1.fc22.x86_64 konversation-1.6-1.fc22.x86_64 When returning to my desk after an extended period, konversation is locked up when the system is unlocked. The cause appears to be the powering on of the monitors - my monitors are physically powered off for "reasons" when I leave the desk, and the time stamps in konversation appear to stop at the approximate time the monitors are repowered. The interesting data point is that konversation is the only application locked up. The plasmashell is working fine, the notification panel, konsole, and dolphin windows I have open all operate as normal. Konversation is the only application locked up. The backtrace is attached to this bz, and rdieter was able to trace it back to a Freedesktop bug as a possible root cause. Related bugs are at bugs.kde.org (338999) and bugreports.qt.io (42738)
<nod>, according to the aforementioned bugs, this is a libX11 issue, triaging there. According to a commenter on the freedesktop.org, they think it stems from this upstream commit, http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=83e1ba59c48c79f8b0a7e7aa0b9c9cfd84fa403d "The commit unlocks the display when an application-defined error handler is invoked, but re-locking the display requires re-syncing the sequence numbers which requires a remote call. The commit author couldn't remember why the display lock was held while the error function was called - I guess the sequence number re-sync was the reason. Reverting the commit fixes the problem." We'll probably want a confirmation of this or deeper investigation before coming up with a plan to address this.
Test libX11 build available in this copr, https://copr.fedoraproject.org/coprs/rdieter/libxcb/ with the aforementioned commit reverted
Fedora 22 changed to end-of-life (EOL) status on 2016-07-19. Fedora 22 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.