Bug 361513

Application: plasmashell (5.4.2)

Qt Version: 5.4.2
Operating System: Linux 4.2.0-35-generic x86_64
Distribution: Ubuntu 15.10

-- Information about the crash:
- What I was doing when the application crashed:

Switching windows from Chromium to something else (I forget).  A few minutes prior I had disconnected my laptop from HDMI (nothing unusual happened while I was watching a video with it).

- Unusual behavior I noticed:

The screen momentarily turned all black.  Nothing looked strange after it lit up again.

-- Backtrace:
Application: Plasma (plasmashell), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f1064ec3800 (LWP 1944))]

Thread 8 (Thread 0x7f106281f700 (LWP 1946)):
#0  0x00007f107198688d in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f10759cdbd2 in poll (__timeout=-1, __nfds=1, __fds=0x7f106281ecc0) at /usr/include/x86_64-linux-gnu/bits/poll2.h:46
#2  _xcb_conn_wait (c=c@entry=0x2071200, cond=cond@entry=0x2071240, vector=vector@entry=0x0, count=count@entry=0x0) at ../../src/xcb_conn.c:459
#3  0x00007f10759cf74f in xcb_wait_for_event (c=0x2071200) at ../../src/xcb_in.c:623
#4  0x00007f1064b69a39 in QXcbEventReader::run (this=0x207b600) at qxcbconnection.cpp:1105
#5  0x00007f10720792be in QThreadPrivate::start (arg=0x207b600) at thread/qthread_unix.cpp:337
#6  0x00007f10711686aa in start_thread (arg=0x7f106281f700) at pthread_create.c:333
#7  0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 7 (Thread 0x7f1056011700 (LWP 1953)):
#0  0x00007f106e732884 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f106e73311b in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f10722b029b in QEventDispatcherGlib::processEvents (this=0x7f10500008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7f1056010da0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f10720743d4 in QThread::exec (this=this@entry=0x223f890) at thread/qthread.cpp:503
#6  0x00007f107489cf85 in QQmlThreadPrivate::run (this=0x223f890) at qml/ftw/qqmlthread.cpp:141
#7  0x00007f10720792be in QThreadPrivate::start (arg=0x223f890) at thread/qthread_unix.cpp:337
#8  0x00007f10711686aa in start_thread (arg=0x7f1056011700) at pthread_create.c:333
#9  0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 6 (Thread 0x7f104a11e700 (LWP 2002)):
#0  0x00007f106e777869 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f106e732789 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f106e73311b in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f10722b029b in QEventDispatcherGlib::processEvents (this=0x7f10440008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7f104a11dda0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f10720743d4 in QThread::exec (this=this@entry=0x2473000) at thread/qthread.cpp:503
#7  0x00007f107489cf85 in QQmlThreadPrivate::run (this=0x2473000) at qml/ftw/qqmlthread.cpp:141
#8  0x00007f10720792be in QThreadPrivate::start (arg=0x2473000) at thread/qthread_unix.cpp:337
#9  0x00007f10711686aa in start_thread (arg=0x7f104a11e700) at pthread_create.c:333
#10 0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 5 (Thread 0x7f10437fe700 (LWP 2012)):
#0  0x00007f107198244d in read () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f106e7764e0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f106e732cd4 in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f106e733190 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f10722b029b in QEventDispatcherGlib::processEvents (this=0x7f10340008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#6  0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7f10437fdda0, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#7  0x00007f10720743d4 in QThread::exec (this=this@entry=0x2785110) at thread/qthread.cpp:503
#8  0x00007f107489cf85 in QQmlThreadPrivate::run (this=0x2785110) at qml/ftw/qqmlthread.cpp:141
#9  0x00007f10720792be in QThreadPrivate::start (arg=0x2785110) at thread/qthread_unix.cpp:337
#10 0x00007f10711686aa in start_thread (arg=0x7f10437fe700) at pthread_create.c:333
#11 0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f1041ef0700 (LWP 2100)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1  0x00007f1076c28114 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#2  0x00007f1076c28159 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Script.so.5
#3  0x00007f10711686aa in start_thread (arg=0x7f1041ef0700) at pthread_create.c:333
#4  0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f103b443700 (LWP 2118)):
#0  0x00007f107198688d in poll () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f106e7331ec in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f10722b029b in QEventDispatcherGlib::processEvents (this=0x7f0fb00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#4  0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7f103b442d50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#5  0x00007f10720743d4 in QThread::exec (this=this@entry=0x2a23320) at thread/qthread.cpp:503
#6  0x00007f1075218ef6 in QQuickPixmapReader::run (this=0x2a23320) at util/qquickpixmapcache.cpp:797
#7  0x00007f10720792be in QThreadPrivate::start (arg=0x2a23320) at thread/qthread_unix.cpp:337
#8  0x00007f10711686aa in start_thread (arg=0x7f103b443700) at pthread_create.c:333
#9  0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f0fa545f700 (LWP 2623)):
#0  0x00007f106e777884 in g_mutex_unlock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1  0x00007f106e732770 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f106e73311b in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f10722b029b in QEventDispatcherGlib::processEvents (this=0x7f0fa00008c0, flags=...) at kernel/qeventdispatcher_glib.cpp:420
#5  0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7f0fa545ed80, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#6  0x00007f10720743d4 in QThread::exec (this=<optimized out>) at thread/qthread.cpp:503
#7  0x00007f0fa645c8f7 in KCupsConnection::run() () from /usr/lib/x86_64-linux-gnu/libkcupslib.so
#8  0x00007f10720792be in QThreadPrivate::start (arg=0x4f260a0) at thread/qthread_unix.cpp:337
#9  0x00007f10711686aa in start_thread (arg=0x7f0fa545f700) at pthread_create.c:333
#10 0x00007f1071991e9d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f1064ec3800 (LWP 1944)):
[KCrash Handler]
#6  0x000000000000002f in ?? ()
#7  0x00007f1074808b41 in QQmlEnginePrivate::cache (obj=0x63780f0, this=0x2782fd0) at qml/qqmlengine_p.h:430
#8  QQmlData::ensurePropertyCache (engine=0x276f470, object=object@entry=0x63780f0) at qml/qqmlengine.cpp:1748
#9  0x00007f10747e272f in QV4::QObjectWrapper::create (engine=engine@entry=0x278bc50, object=object@entry=0x63780f0) at jsruntime/qv4qobjectwrapper.cpp:669
#10 0x00007f10747e33f3 in QV4::QObjectWrapper::wrap (engine=0x278bc50, object=0x63780f0) at jsruntime/qv4qobjectwrapper.cpp:603
#11 0x00007f107489ef9c in QV8Engine::fromVariant (this=this@entry=0x278bbe0, variant=...) at qml/v8/qv8engine.cpp:404
#12 0x00007f1074890347 in QV4::QmlContextWrapper::get (m=<optimized out>, name=<optimized out>, hasProperty=0x7ffe57569680) at qml/qqmlcontextwrapper.cpp:234
#13 0x00007f107477bc4a in QV4::Object::get (hasProperty=0x7ffe57569680, name=0x7f10427ceda0, this=<optimized out>) at jsruntime/qv4object_p.h:252
#14 QV4::ExecutionContext::getProperty (this=0x7ffe57569770, name=0x7f10427ceda0) at jsruntime/qv4context.cpp:379
#15 0x00007f104012292e in ?? ()
#16 0x00007f0fae7ddf80 in __bss_start () from /usr/lib/x86_64-linux-gnu/libtaskmanager.so.5
#17 0x0000000001000006 in ?? ()
#18 0x0000000001000006 in ?? ()
#19 0x00007f0fae5a05de in QHash<unsigned long long, QHashDummyValue>::contains (akey=@0x7ffe575696f8: 16777222, this=0x7f10427fe070) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qhash.h:901
#20 QSet<unsigned long long>::contains (value=@0x7ffe575696f8: 16777222, this=0x7f10427fe070) at /usr/include/x86_64-linux-gnu/qt5/QtCore/qset.h:94
#21 TaskManager::Task::hasTransient (this=<optimized out>, w=16777222) at ../../libtaskmanager/task.cpp:330
#22 0x00007f10427cf6a0 in ?? ()
#23 0x00007f1048a35000 in ?? ()
#24 0x00007f10747a76d6 in QV4::SimpleScriptFunction::call (that=0x7f10427fe0d0, callData=<optimized out>) at jsruntime/qv4functionobject.cpp:512
#25 0x00007f1074883c98 in QV4::Object::call (d=0x7f1074883c98 <QQmlJavaScriptExpression::evaluate(QQmlContextData*, QV4::ValueRef, QV4::CallData*, bool*)+648>, this=<optimized out>) at ../../include/QtQml/5.4.2/QtQml/private/../../../../../src/qml/jsruntime/qv4object_p.h:278
#26 QQmlJavaScriptExpression::evaluate (this=this@entry=0x42ff560, context=<optimized out>, function=function@entry=..., callData=callData@entry=0x7f10427fe008, isUndefined=isUndefined@entry=0x0) at qml/qqmljavascriptexpression.cpp:158
#27 0x00007f10748287d6 in QQmlBoundSignalExpression::evaluate (this=<optimized out>, a=a@entry=0x0) at qml/qqmlboundsignal.cpp:281
#28 0x00007f107482901b in QQmlBoundSignal_callback (e=0x42ccef8, a=0x0) at qml/qqmlboundsignal.cpp:408
#29 0x00007f1074867507 in QQmlNotifier::emitNotify (endpoint=0x42ccef8, a=a@entry=0x0) at qml/qqmlnotifier.cpp:73
#30 0x00007f10748070fc in QQmlData::signalEmitted (object=0x42cdb60, index=3, a=0x0) at qml/qqmlengine.cpp:722
#31 0x00007f1072289090 in QMetaObject::activate (sender=0x42cdb60, signalOffset=<optimized out>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3603
#32 0x00007f1072289f87 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7f10749e2920 <QQmlTimer::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3582
#33 0x00007f107490b1e0 in QQmlTimer::triggered (this=<optimized out>) at .moc/moc_qqmltimer_p.cpp:250
#34 0x00007f10748fadca in QQmlTimer::event (this=0x42cdb60, e=<optimized out>) at types/qqmltimer.cpp:334
#35 0x00007f1072d36b8c in QApplicationPrivate::notify_helper (this=this@entry=0x2064810, receiver=receiver@entry=0x42cdb60, e=e@entry=0x62200c0) at kernel/qapplication.cpp:3720
#36 0x00007f1072d3c230 in QApplication::notify (this=0x7ffe5756a310, receiver=0x42cdb60, e=0x62200c0) at kernel/qapplication.cpp:3503
#37 0x00007f1072258f1b in QCoreApplication::notifyInternal (this=0x7ffe5756a310, receiver=0x42cdb60, event=event@entry=0x62200c0) at kernel/qcoreapplication.cpp:935
#38 0x00007f107225b057 in QCoreApplication::sendEvent (event=0x62200c0, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:228
#39 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x2059d70) at kernel/qcoreapplication.cpp:1552
#40 0x00007f107225b588 in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1410
#41 0x00007f10722afe73 in postEventSourceDispatch (s=0x2056b60) at kernel/qeventdispatcher_glib.cpp:271
#42 0x00007f106e732ff7 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#43 0x00007f106e733250 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#44 0x00007f106e7332fc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#45 0x00007f10722b027f in QEventDispatcherGlib::processEvents (this=0x210a5b0, flags=...) at kernel/qeventdispatcher_glib.cpp:418
#46 0x00007f107225675a in QEventLoop::exec (this=this@entry=0x7ffe5756a190, flags=..., flags@entry=...) at kernel/qeventloop.cpp:204
#47 0x00007f107225e2cc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1188
#48 0x00007f107257300c in QGuiApplication::exec () at kernel/qguiapplication.cpp:1510
#49 0x00007f1072d33025 in QApplication::exec () at kernel/qapplication.cpp:2956
#50 0x00000000004322c3 in main (argc=2, argv=<optimized out>) at ../../shell/main.cpp:176

Reported using DrKonqi