Bug 379465

Summary:	kwin_x11 crashes after mpv is set to fullscreen
Product:	[Plasma] kwin	Reporter:	Nicolas F. <kdebugs>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	crash	CC:	muesli
Priority:	NOR	Keywords:	drkonqi
Version First Reported In:	5.9.5
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Nicolas F. 2017-05-03 06:50:10 UTC

Application: kwin_x11 (5.9.5)

Qt Version: 5.8.0
Frameworks Version: 5.33.0
Operating System: Linux 4.10.13-1-ARCH x86_64
Distribution: "Arch Linux"

-- Information about the crash:
- What I was doing when the application crashed:
I set mpv to fullscreen by hitting F in mpv. Upon trying to exit fullscreen by hitting F again, I noticed that it's not working, and discovered that the issue is that kwin crashed.

- Unusual behavior I noticed:
When restarting kwin_x11 from the terminal, I noticed that the terminal it was restarted in did not get any window decorations. Other windows however are fine.

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Aborted
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fc83d2c9840 (LWP 25014))]

Thread 5 (Thread 0x7fc801a4f700 (LWP 25023)):
#0  0x00007fc835f63756 in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007fc8392da234 in  () at /usr/lib/libQt5Script.so.5
#2  0x00007fc8392da279 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007fc835f5d2e7 in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007fc83cd2154f in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7fc80d0df700 (LWP 25021)):
#0  0x00007fc83cd1776b in ppoll () at /usr/lib/libc.so.6
#1  0x00007fc83a39b329 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007fc83a39c99a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007fc83a3498ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fc83a16ba73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007fc83a1706d8 in  () at /usr/lib/libQt5Core.so.5
#6  0x00007fc835f5d2e7 in start_thread () at /usr/lib/libpthread.so.0
#7  0x00007fc83cd2154f in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7fc8218b0700 (LWP 25017)):
#0  0x00007fc83cd1776b in ppoll () at /usr/lib/libc.so.6
#1  0x00007fc83a39b329 in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007fc83a39c99a in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007fc83a3498ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007fc83a16ba73 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007fc833e2e125 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007fc83a1706d8 in  () at /usr/lib/libQt5Core.so.5
#7  0x00007fc835f5d2e7 in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007fc83cd2154f in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7fc823a00700 (LWP 25016)):
#0  0x00007fc83cd1767d in poll () at /usr/lib/libc.so.6
#1  0x00007fc83be308e0 in  () at /usr/lib/libxcb.so.1
#2  0x00007fc83be32679 in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007fc824adc239 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007fc83a1706d8 in  () at /usr/lib/libQt5Core.so.5
#5  0x00007fc835f5d2e7 in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007fc83cd2154f in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7fc83d2c9840 (LWP 25014)):
[KCrash Handler]
#6  0x00007fc83cc68a10 in raise () at /usr/lib/libc.so.6
#7  0x00007fc83cc6a13a in abort () at /usr/lib/libc.so.6
#8  0x00007fc83a156e21 in  () at /usr/lib/libQt5Core.so.5
#9  0x00007fc83a16ad04 in QThread::~QThread() () at /usr/lib/libQt5Core.so.5
#10 0x00007fc83a16adf9 in QThread::~QThread() () at /usr/lib/libQt5Core.so.5
#11 0x00007fc83a375441 in QObjectPrivate::deleteChildren() () at /usr/lib/libQt5Core.so.5
#12 0x00007fc83a37ed9f in QObject::~QObject() () at /usr/lib/libQt5Core.so.5
#13 0x00007fc820e8cc69 in KWin::X11StandalonePlatform::~X11StandalonePlatform() () at /usr/lib/qt/plugins/org.kde.kwin.platforms/KWinX11Platform.so
#14 0x00007fc83a375441 in QObjectPrivate::deleteChildren() () at /usr/lib/libQt5Core.so.5
#15 0x00007fc83a37ed9f in QObject::~QObject() () at /usr/lib/libQt5Core.so.5
#16 0x00007fc83a34cf86 in QCoreApplication::~QCoreApplication() () at /usr/lib/libQt5Core.so.5
#17 0x00007fc83b02ddc1 in QApplication::~QApplication() () at /usr/lib/libQt5Widgets.so.5
#18 0x00007fc83cfe0834 in  () at /usr/lib/libkdeinit5_kwin_x11.so
#19 0x00007fc83cfe23e0 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#20 0x00007fc83cc55511 in __libc_start_main () at /usr/lib/libc.so.6
#21 0x000000000040069a in _start ()

Reported using DrKonqi

Comment 1 Martin Flöser 2017-05-03 15:07:01 UTC

As always for arch users the backtrace is completely useless as it's missing debug symbols. Nothing we can do.

Comment 2 Nicolas F. 2017-05-12 02:04:42 UTC

Then DrKonqi should probably not give this backtrace a 3 out of 3 star rating.

I'm personally not going to try and reproduce this again with debug symbols. Building Qt with debug symbols is going to take me way too long, and the crash happens so rarely that it's hard to reproduce in the first place.

Comment 3 Martin Flöser 2017-05-12 04:57:01 UTC

Without the backtrace we cannot investigate -> wontfix.

Comment 4 Nicolas F. 2017-05-12 16:12:23 UTC

I've discovered that the qutebrowser people host an Arch Linux repository with prebuilt qt5 debug packages. I've installed qt5-base-debug from there and built kwin with build type RelWithDebInfo. I hope the crash happens again so that I can supply you with a useful backtrace.

Comment 5 Christian Muehlhaeuser 2017-09-02 20:57:04 UTC

I can reliably reproduce this every time mpv goes fullscreen. I'm on Arch as well though.