Application: kontact (5.15.3 (20.08.3))

Qt Version: 5.15.2
Frameworks Version: 5.75.0
Operating System: Linux 5.9.15-200.fc33.x86_64 x86_64
Windowing system: Wayland
Distribution: "Fedora release 33 (Thirty Three)"

-- Information about the crash:
- What I was doing when the application crashed:
Syncing th email.
open Kmail open a thread it will say 'Retriving Folder Contents' and will show the mail thread. On clicking another thread it will again say 'Retriving Folder Contents' and if we click the already displayed mailmit will again show 'Retriving Folder .....'. It takes considerable time for retriving the folder contents and some times crashes..

The crash can be reproduced sometimes.

-- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault

[KCrash Handler]
#4  0x00007f17f9371d0e in KMReaderMainWin::~KMReaderMainWin() () from /lib64/libkmailprivate.so.5
#5  0x00007f17f9371e2d in KMReaderMainWin::~KMReaderMainWin() () from /lib64/libkmailprivate.so.5
#6  0x00007f18aa0adb21 in QObject::event(QEvent*) () from /lib64/libQt5Core.so.5
#7  0x00007f18ab33b08d in KXmlGuiWindow::event(QEvent*) () from /lib64/libKF5XmlGui.so.5
#8  0x00007f18aab1aec3 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /lib64/libQt5Widgets.so.5
#9  0x00007f18aa085bd8 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /lib64/libQt5Core.so.5
#10 0x00007f18aa0888c7 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /lib64/libQt5Core.so.5
#11 0x00007f18aa0d2c27 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQt5Core.so.5
#12 0x00007f18a0c9096f in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#13 0x00007f18a0ce2758 in g_main_context_iterate.constprop () from /lib64/libglib-2.0.so.0
#14 0x00007f18a0c8dd43 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#15 0x00007f18aa0d26f3 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#16 0x00007f18aa08457b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /lib64/libQt5Core.so.5
#17 0x00007f18aa08c1b4 in QCoreApplication::exec() () from /lib64/libQt5Core.so.5
#18 0x0000559c4e1ce58c in main ()
[Inferior 1 (process 4346) detached]

Possible duplicates by query: bug 430790, bug 430722, bug 430698, bug 430623, bug 430543.

Reported using DrKonqi