Bug 344591

Summary: Systemsettings crashes when leaving kscreen kcm
Product: [Plasma] KScreen Reporter: Lukas Schneiderbauer <lukas.schneiderbauer>
Component: kcmAssignee: Daniel Vrátil <dvratil>
Status: RESOLVED DUPLICATE    
Severity: normal CC: davispuh, waltercool
Priority: NOR    
Version: 5.2.1   
Target Milestone: ---   
Platform: Gentoo Packages   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Lukas Schneiderbauer 2015-02-26 11:50:29 UTC 
KDE Systemsettings crashes when leaving kscreen kcm in plasma 5.2.1.

Reproducible: Always

Steps to Reproduce:
1. Start systemsettings
2. click "Display and Monitor"
3. click the "back" button
results in a silent crash. 



It even doesn't ask me if I want to restart systemsettings as it does normally.

opening via systemsettings via terminal produces following output:
kf5.kservice.sycoca: Trying to open ksycoca from "/home/lukas/.cache/ksycoca5"
LOAD
kscreen: launcherDataAvailable: "org.kde.KScreen.Backend.XRandR"
kscreen: Launcher finished with exit code 1 , status 0
kscreen: Service for requested backend already running
fname "/usr/share/plasma/desktoptheme/default/metadata.desktop"
fname "/usr/share/plasma/desktoptheme/default/metadata.desktop"
Segmentation fault

Sorry, I didn't know how to produce more debug output. Maybe you could tell me if needed.
Comment 1 Daniel Vrátil 2015-03-05 12:49:04 UTC 
Please follow the guidelines in here [0], and try to get a full backtrace through GDB.

[0] https://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports
Comment 2 Lukas Schneiderbauer 2015-03-09 14:00:49 UTC 
Program received signal SIGSEGV, Segmentation fault.
QQuickWindow::maybeUpdate (this=0x31) at items/qquickwindow.cpp:2890
2890    items/qquickwindow.cpp: No such file or directory.

#0  0x00007fffda796cce in QQuickItemPrivate::addToDirtyList (this=0xe9e550) at items/qquickitem.cpp:5634
#1  0x00007fffda796d78 in QQuickItemPrivate::dirty (this=0xe9e550, type=<optimized out>) at items/qquickitem.cpp:5618
#2  0x00007fffda7a0de5 in QQuickItem::qt_static_metacall (_o=0xe9e550, _c=15328464, _id=2, _a=0x7fffc8134bb0) at .moc/moc_qquickitem.cpp:595
#3  0x00007ffff4ec8dfa in QObject::event (this=this@entry=0xe9e4d0, e=e@entry=0x7fffc816d600) at kernel/qobject.cpp:1245
#4  0x00007fffda79f97b in QQuickItem::event (this=0xe9e4d0, ev=0x7fffc816d600) at items/qquickitem.cpp:7305
#5  0x00007ffff631252c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#6  0x00007ffff6317920 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQt5Widgets.so.5
#7  0x00007ffff4e984cb in QCoreApplication::notifyInternal (this=0x7fffffffdab0, receiver=0xe9e4d0, event=event@entry=0x7fffc816d600)
    at kernel/qcoreapplication.cpp:935
#8  0x00007ffff4e9a56b in sendEvent (event=0x7fffc816d600, receiver=<optimized out>) at kernel/qcoreapplication.h:228
#9  QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x663460) at kernel/qcoreapplication.cpp:1552
#10 0x00007ffff4e9ab78 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#11 0x00007ffff4eefae3 in postEventSourceDispatch (s=0x6a80d0) at kernel/qeventdispatcher_glib.cpp:271
#12 0x00007ffff05d590d in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#13 0x00007ffff05d5bf8 in ?? () from /usr/lib64/libglib-2.0.so.0
#14 0x00007ffff05d5cac in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#15 0x00007ffff4eefed7 in QEventDispatcherGlib::processEvents (this=0x6b3b00, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#16 0x00007ffff4e95d22 in QEventLoop::exec (this=this@entry=0x7fffffffd990, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#17 0x00007ffff4e9d8fc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#18 0x000000000040f42c in main ()

Do you also need the libglib-2.0.so.0 backtrace?
Comment 3 Daniel Vrátil 2015-03-18 10:39:35 UTC 
Hmm, this actually looks like a Qt bug to me. What version of Qt 5 are you running?
Comment 4 Lukas Schneiderbauer 2015-03-18 11:10:45 UTC 
(In reply to Daniel Vrátil from comment #3)
> Hmm, this actually looks like a Qt bug to me. What version of Qt 5 are you
> running?

It says: version 5.4.1 is installed.
Comment 5 Daniel Vrátil 2015-03-18 14:43:19 UTC 
Thanks. I believe this is caused by a regression in Qt 5.4.0 which should be fixed in 5.4.2 (QTBUG-43376).

Marking as invalid, since it's not KScreen fault :) Please reopen if you run into this in Qt 5.4.2 or 5.5 (once they are released).
Comment 6 Dāvis 2015-07-09 02:05:43 UTC 
Still crashes even with Qt 5.4.2

QQuickItemPrivate::addToDirtyList() () from /usr/lib/libQt5Quick.so.5
QQuickItemPrivate::dirty(QQuickItemPrivate::DirtyType) () from /usr/lib/libQt5Quick.so.5
Comment 7 Lukas Schneiderbauer 2015-11-02 20:06:37 UTC 
Still crashes with Qt 5.5.1.
Comment 8 Pablo Cholaky 2015-11-04 18:16:22 UTC 
I can reproduce that with Qt 5.5.1, Frameworks 15.08

#0  0x00007ffff3a3b62e in QQuickItemPrivate::addToDirtyList (this=0xbd34a0) at items/qquickitem.cpp:5633
#1  0x00007ffff3a3b6d8 in QQuickItemPrivate::dirty (this=0xbd34a0, type=<optimized out>) at items/qquickitem.cpp:5617
#2  0x00007ffff3a3befe in QQuickItem::update (this=<optimized out>) at items/qquickitem.cpp:4088
#3  0x00007ffff3a47fbd in QQuickItem::qt_static_metacall (_o=<optimized out>, _c=<optimized out>, _id=<optimized out>, _a=<optimized out>) at .moc/moc_qquickitem.cpp:597
#4  0x00007ffff4f2f31a in QObject::event (this=this@entry=0xbd38f0, e=e@entry=0x7fffd0079ae0) at kernel/qobject.cpp:1239
#5  0x00007ffff3a439db in QQuickItem::event (this=0xbd38f0, ev=0x7fffd0079ae0) at items/qquickitem.cpp:7317
#6  0x00007ffff62cc79c in QApplicationPrivate::notify_helper (this=this@entry=0x62a900, receiver=receiver@entry=0xbd38f0, e=e@entry=0x7fffd0079ae0) at kernel/qapplication.cpp:3716
#7  0x00007ffff62d1c88 in QApplication::notify (this=0x7fffffffd9d0, receiver=0xbd38f0, e=0x7fffd0079ae0) at kernel/qapplication.cpp:3499
#8  0x00007ffff4f064ad in QCoreApplication::notifyInternal (this=0x7fffffffd9d0, receiver=0xbd38f0, event=event@entry=0x7fffd0079ae0) at kernel/qcoreapplication.cpp:965
#9  0x00007ffff4f09243 in QCoreApplication::sendEvent (event=0x7fffd0079ae0, receiver=<optimized out>) at kernel/qcoreapplication.h:224
#10 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x629b40) at kernel/qcoreapplication.cpp:1593
#11 0x00007ffff4f09808 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1451
#12 0x00007ffff4f53593 in postEventSourceDispatch (s=0x796ed0) at kernel/qeventdispatcher_glib.cpp:271
#13 0x00007ffff188baed in g_main_dispatch (context=0x7fffe40016f0) at /var/tmp/portage/dev-libs/glib-2.44.1-r1/work/glib-2.44.1/glib/gmain.c:3122
#14 g_main_context_dispatch (context=context@entry=0x7fffe40016f0) at /var/tmp/portage/dev-libs/glib-2.44.1-r1/work/glib-2.44.1/glib/gmain.c:3737
#15 0x00007ffff188bdd0 in g_main_context_iterate (context=context@entry=0x7fffe40016f0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>)
    at /var/tmp/portage/dev-libs/glib-2.44.1-r1/work/glib-2.44.1/glib/gmain.c:3808
#16 0x00007ffff188be7c in g_main_context_iteration (context=0x7fffe40016f0, may_block=1) at /var/tmp/portage/dev-libs/glib-2.44.1-r1/work/glib-2.44.1/glib/gmain.c:3869
#17 0x00007ffff4f53607 in QEventDispatcherGlib::processEvents (this=0x792720, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#18 0x00007ffff4f0510a in QEventLoop::exec (this=this@entry=0x7fffffffd8b0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#19 0x00007ffff4f0c3ec in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1229
#20 0x00007ffff5de445c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1527
#21 0x00007ffff62c83e5 in QApplication::exec () at kernel/qapplication.cpp:2976
#22 0x000000000040f5bb in main (argc=1, argv=<optimized out>) at /var/tmp/portage/kde-plasma/systemsettings-5.4.2/work/systemsettings-5.4.2/app/main.cpp:55
Comment 9 Christoph Feck 2015-12-03 20:12:46 UTC 

*** This bug has been marked as a duplicate of bug 344651 ***