Application: plasma-desktop (4.11.16)
KDE Platform Version: 4.14.5
Qt Version: 4.8.6
Operating System: Linux 4.4.39-desktop-1.mga5 x86_64
Distribution: "Mageia 5"

-- Information about the crash:
- What I was doing when the application crashed:
Nothing - rebooted. The system. KDE complains that it no longer has a system tray.

The crash can be reproduced every time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f0e15eae780 (LWP 9216))]

Thread 6 (Thread 0x7f0de96e9700 (LWP 9217)):
#0  0x00007f0e1476ba28 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f0e149f64d2 in QWaitCondition::wait(QMutex*, unsigned long) () at /lib64/libQtCore.so.4
#2  0x00007f0e149e9e65 in QThreadPoolThread::run() () at /lib64/libQtCore.so.4
#3  0x00007f0e149f5fff in QThreadPrivate::start(void*) () at /lib64/libQtCore.so.4
#4  0x00007f0e147665bd in start_thread () at /lib64/libpthread.so.0
#5  0x00007f0e134de62d in clone () at /lib64/libc.so.6

Thread 5 (Thread 0x7f0de0ee8700 (LWP 9218)):
#0  0x00007f0e1476ba28 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f0e149f64d2 in QWaitCondition::wait(QMutex*, unsigned long) () at /lib64/libQtCore.so.4
#2  0x00007f0e149e9e65 in QThreadPoolThread::run() () at /lib64/libQtCore.so.4
#3  0x00007f0e149f5fff in QThreadPrivate::start(void*) () at /lib64/libQtCore.so.4
#4  0x00007f0e147665bd in start_thread () at /lib64/libpthread.so.0
#5  0x00007f0e134de62d in clone () at /lib64/libc.so.6

Thread 4 (Thread 0x7f0de8ee8700 (LWP 9219)):
#0  0x00007f0e1476ba28 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f0e149f64d2 in QWaitCondition::wait(QMutex*, unsigned long) () at /lib64/libQtCore.so.4
#2  0x00007f0e149e9e65 in QThreadPoolThread::run() () at /lib64/libQtCore.so.4
#3  0x00007f0e149f5fff in QThreadPrivate::start(void*) () at /lib64/libQtCore.so.4
#4  0x00007f0e147665bd in start_thread () at /lib64/libpthread.so.0
#5  0x00007f0e134de62d in clone () at /lib64/libc.so.6

Thread 3 (Thread 0x7f0de3fff700 (LWP 9220)):
#0  0x00007f0e1476ba28 in pthread_cond_timedwait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f0e149f64d2 in QWaitCondition::wait(QMutex*, unsigned long) () at /lib64/libQtCore.so.4
#2  0x00007f0e149e9e65 in QThreadPoolThread::run() () at /lib64/libQtCore.so.4
#3  0x00007f0e149f5fff in QThreadPrivate::start(void*) () at /lib64/libQtCore.so.4
#4  0x00007f0e147665bd in start_thread () at /lib64/libpthread.so.0
#5  0x00007f0e134de62d in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f0dbfea3700 (LWP 9221)):
#0  0x00007f0e1476b67f in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x00007f0e06ca273a in QTWTF::TCMalloc_PageHeap::scavengerThread() () at /lib64/libQtScript.so.4
#2  0x00007f0e06ca2769 in  () at /lib64/libQtScript.so.4
#3  0x00007f0e147665bd in start_thread () at /lib64/libpthread.so.0
#4  0x00007f0e134de62d in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f0e15eae780 (LWP 9216)):
[KCrash Handler]
#5  0x00007f0e095c87f7 in Plasma::DataEngine::connectSource(QString const&, QObject*, unsigned int, Plasma::IntervalAlignment) const () at /usr/lib64/libplasma.so.3
#6  0x00007f0dc66272f6 in SocketSentryApplet::updateSourceConnection(bool) () at /usr/lib64/kde4/socksent-plasma-widget.so
#7  0x00007f0dc6628a31 in SocketSentryApplet::constraintsEvent(QFlags<Plasma::Constraint>) () at /usr/lib64/kde4/socksent-plasma-widget.so
#8  0x00007f0e0959874e in Plasma::Applet::flushPendingConstraintsEvents() [clone .part.149] () at /usr/lib64/libplasma.so.3
#9  0x00007f0dea3ad7c6 in SystemTray::PlasmoidTask::forwardConstraintsEvent(QFlags<Plasma::Constraint>) () at /usr/lib64/kde4/plasma_applet_systemtray.so
#10 0x00007f0dea3ac193 in SystemTray::PlasmoidProtocol::forwardConstraintsEvent(QFlags<Plasma::Constraint>, Plasma::Applet*) () at /usr/lib64/kde4/plasma_applet_systemtray.so
#11 0x00007f0dea3a4559 in SystemTray::Manager::forwardConstraintsEvent(QFlags<Plasma::Constraint>, Plasma::Applet*) () at /usr/lib64/kde4/plasma_applet_systemtray.so
#12 0x00007f0dea3b2f31 in SystemTray::Applet::constraintsEvent(QFlags<Plasma::Constraint>) () at /usr/lib64/kde4/plasma_applet_systemtray.so
#13 0x00007f0e0959874e in Plasma::Applet::flushPendingConstraintsEvents() [clone .part.149] () at /usr/lib64/libplasma.so.3
#14 0x00007f0e095b2608 in Plasma::ContainmentPrivate::initApplets() () at /usr/lib64/libplasma.so.3
#15 0x00007f0e095c28ec in Plasma::CoronaPrivate::importLayout(KConfigBase const&, bool) () at /usr/lib64/libplasma.so.3
#16 0x00007f0e095c38aa in Plasma::Corona::loadLayout(QString const&) () at /usr/lib64/libplasma.so.3
#17 0x00007f0e095c3964 in Plasma::Corona::initializeLayout(QString const&) () at /usr/lib64/libplasma.so.3
#18 0x00007f0dfe073ec7 in PlasmaApp::corona(bool) () at /usr/lib64/libkdeinit4_plasma-desktop.so
#19 0x00007f0dfe07433e in PlasmaApp::setupDesktop() () at /usr/lib64/libkdeinit4_plasma-desktop.so
#20 0x00007f0dfe0796b5 in PlasmaApp::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) [clone .part.83] () at /usr/lib64/libkdeinit4_plasma-desktop.so
#21 0x00007f0e14b0ed61 in QObject::event(QEvent*) () at /lib64/libQtCore.so.4
#22 0x00007f0e13c73713 in QApplication::event(QEvent*) () at /lib64/libQtGui.so.4
#23 0x00007f0e13c6e79c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#24 0x00007f0e13c74e40 in QApplication::notify(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#25 0x00007f0e158bc25a in KApplication::notify(QObject*, QEvent*) () at /lib64/libkdeui.so.5
#26 0x00007f0e14af6cad in QCoreApplication::notifyInternal(QObject*, QEvent*) () at /lib64/libQtCore.so.4
#27 0x00007f0e14af9be1 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib64/libQtCore.so.4
#28 0x00007f0e14b23cae in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /lib64/libQtCore.so.4
#29 0x00007f0e105b8c6d in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
#30 0x00007f0e105b8f18 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
#31 0x00007f0e105b8fbc in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#32 0x00007f0e14b23e1e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#33 0x00007f0e13d0c4f6 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtGui.so.4
#34 0x00007f0e14af5931 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#35 0x00007f0e14af5c45 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#36 0x00007f0e14afae59 in QCoreApplication::exec() () at /lib64/libQtCore.so.4
#37 0x00007f0dfe05b36d in kdemain () at /usr/lib64/libkdeinit4_plasma-desktop.so
#38 0x000000000040819a in launch(int, char const*, char const*, char const*, int, char const*, bool, char const*, bool, char const*) ()
#39 0x0000000000409021 in handle_launcher_request(int, char const*) [clone .isra.15] ()
#40 0x000000000040972a in handle_requests(int) ()
#41 0x0000000000405303 in main ()

Reported using DrKonqi