Application: kmail (4.14.7)
KDE Platform Version: 4.14.7
Qt Version: 4.8.6
Operating System: Linux 3.19.5-200.fc21.x86_64 x86_64
Distribution: "Fedora release 21 (Twenty One)"

-- Information about the crash:
- What I was doing when the application crashed:
for a few weeks now kmail does not display mail contents and hangs with a 
"retrieving folder contents". I tried exiting the application and got this crash. If I try to reopen kmail nothing happens because somehow the process is still there and I have to kill it.

The crash can be reproduced sometimes.

-- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f5122810900 (LWP 18168))]

Thread 3 (Thread 0x7f50d314f700 (LWP 18171)):
#0  0x0000003caa60c590 in pthread_cond_wait@@GLIBC_2.3.2 () at /lib64/libpthread.so.0
#1  0x0000003cd2f83c93 in JSC::BlockAllocator::blockFreeingThreadMain() () at /lib64/libQtWebKit.so.4
#2  0x0000003cd3293c16 in WTF::wtfThreadEntryPoint(void*) () at /lib64/libQtWebKit.so.4
#3  0x0000003caa60752a in start_thread () at /lib64/libpthread.so.0
#4  0x0000003caa30022d in clone () at /lib64/libc.so.6

Thread 2 (Thread 0x7f50d2466700 (LWP 18172)):
#0  0x0000003caa2f4c8d in poll () at /lib64/libc.so.6
#1  0x0000003caba49b34 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
#2  0x0000003caba49c4c in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#3  0x0000003cb27b54be in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#4  0x0000003cb2784cc1 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#5  0x0000003cb2785025 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#6  0x0000003cb2679b49 in QThread::exec() () at /lib64/libQtCore.so.4
#7  0x0000003cb267c3af in QThreadPrivate::start(void*) () at /lib64/libQtCore.so.4
#8  0x0000003caa60752a in start_thread () at /lib64/libpthread.so.0
#9  0x0000003caa30022d in clone () at /lib64/libc.so.6

Thread 1 (Thread 0x7f5122810900 (LWP 18168)):
[KCrash Handler]
#6  0x0000000001f4ccb0 in  ()
#7  0x0000003cbed7bf00 in KStatusNotifierItem::setIconByName(QString const&) () at /lib64/libkdeui.so.5
#8  0x0000003ce40b53d0 in KMail::KMSystemTray::updateCount() () at /lib64/libkmailprivate.so.4
#9  0x0000003ce40b4b54 in KMail::KMSystemTray::initListOfCollection() () at /lib64/libkmailprivate.so.4
#10 0x0000003ce40bdebd in KMKernel::toggleSystemTray() () at /lib64/libkmailprivate.so.4
#11 0x0000003ce40ed3ff in KMMainWidget::readConfig() () at /lib64/libkmailprivate.so.4
#12 0x0000003ce40fd1dc in KMMainWidget::KMMainWidget(QWidget*, KXMLGUIClient*, KActionCollection*, KSharedPtr<KSharedConfig>) () at /lib64/libkmailprivate.so.4
#13 0x0000003ce40abc98 in KMMainWin::KMMainWin(QWidget*) () at /lib64/libkmailprivate.so.4
#14 0x0000003ce40bcab7 in KMKernel::openReader(bool) () at /lib64/libkmailprivate.so.4
#15 0x0000003ce40c1184 in KMKernel::action(bool, bool, QString const&, QString const&, QString const&, QString const&, QString const&, KUrl const&, KUrl::List const&, QStringList const&, QString const&, QString const&) () at /lib64/libkmailprivate.so.4
#16 0x0000003ce40c2149 in KMKernel::handleCommandLine(bool) () at /lib64/libkmailprivate.so.4
#17 0x00000000004035ab in KMailApplication::newInstance() ()
#18 0x0000003cbec5622a in KUniqueApplicationAdaptor::newInstance(QByteArray const&, QByteArray const&) () at /lib64/libkdeui.so.5
#19 0x0000003cbec5630d in KUniqueApplicationAdaptor::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) [clone .part.19] () at /lib64/libkdeui.so.5
#20 0x0000003cbec56513 in KUniqueApplicationAdaptor::qt_metacall(QMetaObject::Call, int, void**) () at /lib64/libkdeui.so.5
#21 0x0000003cbc024696 in QDBusConnectionPrivate::deliverCall(QObject*, int, QDBusMessage const&, QList<int> const&, int) () at /lib64/libQtDBus.so.4
#22 0x0000003cbc0258ab in QDBusConnectionPrivate::activateCall(QObject*, int, QDBusMessage const&) () at /lib64/libQtDBus.so.4
#23 0x0000003cbc0262c0 in QDBusConnectionPrivate::activateObject(QDBusConnectionPrivate::ObjectTreeNode&, QDBusMessage const&, int) () at /lib64/libQtDBus.so.4
#24 0x0000003cbc02644b in QDBusActivateObjectEvent::placeMetaCall(QObject*) () at /lib64/libQtDBus.so.4
#25 0x0000003cb279f3d1 in QObject::event(QEvent*) () at /lib64/libQtCore.so.4
#26 0x0000003cb49cd153 in QApplication::event(QEvent*) () at /lib64/libQtGui.so.4
#27 0x0000003cb49c7efc in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#28 0x0000003cb49ce958 in QApplication::notify(QObject*, QEvent*) () at /lib64/libQtGui.so.4
#29 0x0000003cbec4ed3a in KApplication::notify(QObject*, QEvent*) () at /lib64/libkdeui.so.5
#30 0x0000003cb278616d in QCoreApplication::notifyInternal(QObject*, QEvent*) () at /lib64/libQtCore.so.4
#31 0x0000003cb2789431 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /lib64/libQtCore.so.4
#32 0x0000003cb27b532e in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /lib64/libQtCore.so.4
#33 0x0000003caba497fb in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
#34 0x0000003caba49b98 in g_main_context_iterate.isra () at /lib64/libglib-2.0.so.0
#35 0x0000003caba49c4c in g_main_context_iteration () at /lib64/libglib-2.0.so.0
#36 0x0000003cb27b549e in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#37 0x0000003cb4a6b176 in QGuiEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtGui.so.4
#38 0x0000003cb2784cc1 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#39 0x0000003cb2785025 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /lib64/libQtCore.so.4
#40 0x0000003cb278a709 in QCoreApplication::exec() () at /lib64/libQtCore.so.4
#41 0x0000000000402ef2 in main ()

Reported using DrKonqi