Created attachment 1758259 [details]
Trace of drkonqi crash

Description of problem:

I was using a Fedora 34 KDE Plasma installation with Plasma 5.21.0 on Wayland. drkonqi segmentation faulted in QTextEngine::itemize at text/qtextengine.cpp:2081 in qt5-qtbase-5.15.2-13.fc34.x86_64 when trying to enter a description in its "Information about the crash" box of crashes in RKWard https://bugzilla.redhat.com/show_bug.cgi?id=1929503 and System Settings https://bugzilla.redhat.com/show_bug.cgi?id=1930440 The trace of the crashing thread had 96112 frames, so I'll just list the top and bottom 50 in this description and attach the full trace. The trace looked like the same 10 or so functions were repeatedly called a few thousand times. A stack overflow or exhaustion might have happened due to reaching the stack size limit.

Core was generated by `/usr/libexec/drkonqi -platform wayland --appname systemsettings5 --apppath /usr'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007fa7899683ee in QTextEngine::itemize (this=0x555a6eb9de40) at text/qtextengine.cpp:2081
2081    {
[Current thread is 1 (Thread 0x7fa78a71edc0 (LWP 7358))]

(gdb) bt
#0  0x00007fa7899683ee in QTextEngine::itemize (this=0x555a6eb9de40) at text/qtextengine.cpp:2081
#1  0x00007fa789970e70 in QTextLayout::beginLayout (this=this@entry=0x555a6ef18e20)
    at text/qtextlayout.cpp:659
#2  0x00007fa7899b3201 in QTextDocumentLayoutPrivate::layoutBlock (this=this@entry=0x555a6eeb55e0, 
    bl=..., blockPosition=blockPosition@entry=50, blockFormat=..., 
    layoutStruct=layoutStruct@entry=0x7ffcf77899a0, layoutFrom=layoutFrom@entry=50, layoutTo=51, 
    previousBlockFormat=0x7ffcf7789810) at text/qtextdocumentlayout.cpp:3500
#3  0x00007fa7899b48ed in QTextDocumentLayoutPrivate::layoutFlow (this=this@entry=0x555a6eeb55e0, 
    it=..., layoutStruct=layoutStruct@entry=0x7ffcf77899a0, layoutFrom=layoutFrom@entry=50, 
    layoutTo=layoutTo@entry=51, width=..., width@entry=...) at text/qtextdocumentlayout.cpp:3305
#4  0x00007fa7899baedb in QTextDocumentLayoutPrivate::layoutFrame (this=this@entry=0x555a6eeb55e0, 
    f=f@entry=0x555a6ef18fe0, layoutFrom=layoutFrom@entry=50, layoutTo=layoutTo@entry=51, 
    frameWidth=..., frameWidth@entry=..., frameHeight=..., parentY=...)
    at text/qtextdocumentlayout.cpp:3046
#5  0x00007fa7899bb571 in QTextDocumentLayoutPrivate::layoutFrame (this=this@entry=0x555a6eeb55e0, 
    f=f@entry=0x555a6ef18fe0, layoutFrom=layoutFrom@entry=50, layoutTo=layoutTo@entry=51, 
    parentY=..., parentY@entry=...) at text/qtextdocumentlayout.cpp:2936
#6  0x00007fa7899bbb18 in QTextDocumentLayout::doLayout (this=this@entry=0x555a6ef0f750, 
    from=from@entry=50, oldLength=oldLength@entry=1, length=length@entry=1)
    at ../../include/QtGui/5.15.2/QtGui/private/../../../../../src/gui/painting/qfixed_p.h:66
#7  0x00007fa7899bc5bd in QTextDocumentLayout::documentChanged (this=0x555a6ef0f750, from=50, 
    oldLength=1, length=1) at text/qtextdocumentlayout.cpp:3817
#8  0x00007fa789998bc5 in QTextDocumentPrivate::finishEdit (this=0x555a6ef16ac0)
    at text/qtextdocument_p.cpp:1221
#9  0x00007fa789999089 in QTextDocumentPrivate::endEditBlock (this=<optimized out>)
--Type <RET> for more, q to quit, c to continue without paging--c
    at text/qtextdocument_p.cpp:1203
#10 0x00007fa78a226321 in QWidgetTextControlPrivate::inputMethodEvent (this=<optimized out>, e=<optimized out>) at widgets/qwidgettextcontrol.cpp:2137
#11 0x00007fa78a21d52e in QWidgetTextControl::processEvent (this=this@entry=0x555a6ef16880, e=e@entry=0x7ffcf778a000, coordinateOffset=..., contextWidget=contextWidget@entry=0x555a6ef12640) at widgets/qwidgettextcontrol.cpp:998
#12 0x00007fa78a1fe2dd in QTextEditPrivate::sendControlEvent (e=0x7ffcf778a000, this=0x555a6edc53d0) at widgets/qtextedit_p.h:103
#13 QTextEdit::inputMethodEvent (this=0x555a6ef12500, e=0x7ffcf778a000) at widgets/qtextedit.cpp:1803
#14 0x00007fa78a07685e in QWidget::event (this=this@entry=0x555a6ef12500, event=event@entry=0x7ffcf778a000) at kernel/qwidget.cpp:9019
#15 0x00007fa78a11fcd2 in QFrame::event (this=0x555a6ef12500, e=0x7ffcf778a000) at widgets/qframe.cpp:550
#16 0x00007fa78a035e73 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555a6ef12500, e=0x7ffcf778a000) at kernel/qapplication.cpp:3632
#17 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef12500, event=0x7ffcf778a000) at kernel/qcoreapplication.cpp:1063
#18 0x00007fa787da71f8 in QtWaylandClient::QWaylandTextInput::commit (this=0x555a6ea48f50) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:94
#19 QtWaylandClient::QWaylandInputContext::commit (this=<optimized out>) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:425
#20 0x00007fa78a070a3d in QWidget::setFocus (reason=Qt::OtherFocusReason, this=<optimized out>) at kernel/qwidget.cpp:6326
#21 QWidget::setFocus (this=0x555a6ef10250, reason=reason@entry=Qt::OtherFocusReason) at kernel/qwidget.cpp:6284
#22 0x0000555a6dea93b5 in QWidget::setFocus (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtWidgets/qwidget.h:420
#23 BugzillaInformationPage::checkTexts (this=0x555a6ef0b410) at /usr/src/debug/plasma-drkonqi-5.21.0-1.fc34.x86_64/src/bugzillaintegration/reportassistantpages_bugzilla.cpp:416
#24 0x00007fa78949f4b0 in QtPrivate::QSlotObjectBase::call (a=0x7ffcf778a1f0, r=<optimized out>, this=0x555a6ef2b0e0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#25 doActivate<false> (sender=0x555a6ef12500, signal_index=7, argv=0x7ffcf778a1f0) at kernel/qobject.cpp:3886
#26 0x00007fa78949f4fd in doActivate<false> (sender=0x555a6ef16880, signal_index=3, argv=0x7ffcf778a2c0) at kernel/qobject.cpp:3898
#27 0x00007fa78a228db3 in QWidgetTextControl::qt_metacall (this=0x555a6ef16880, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7ffcf778a3c0) at .moc/moc_qwidgettextcontrol_p.cpp:489
#28 0x00007fa78949f282 in doActivate<false> (sender=0x555a6ef16aa0, signal_index=4, argv=0x7ffcf778a3c0) at kernel/qobject.cpp:3912
#29 0x00007fa7894999e7 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fa789d3c3c0 <QTextDocument::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x0) at kernel/qobject.cpp:3946
#30 0x00007fa789c2a157 in QTextDocument::contentsChanged (this=<optimized out>) at .moc/moc_qtextdocument.cpp:427
#31 0x00007fa789998cdc in QTextDocumentPrivate::finishEdit (this=0x555a6ef16ac0) at text/qtextdocument_p.cpp:1247
#32 0x00007fa789999089 in QTextDocumentPrivate::endEditBlock (this=<optimized out>) at text/qtextdocument_p.cpp:1203
#33 0x00007fa78a226321 in QWidgetTextControlPrivate::inputMethodEvent (this=<optimized out>, e=<optimized out>) at widgets/qwidgettextcontrol.cpp:2137
#34 0x00007fa78a21d52e in QWidgetTextControl::processEvent (this=this@entry=0x555a6ef16880, e=e@entry=0x7ffcf778a7d0, coordinateOffset=..., contextWidget=contextWidget@entry=0x555a6ef12640) at widgets/qwidgettextcontrol.cpp:998
#35 0x00007fa78a1fe2dd in QTextEditPrivate::sendControlEvent (e=0x7ffcf778a7d0, this=0x555a6edc53d0) at widgets/qtextedit_p.h:103
#36 QTextEdit::inputMethodEvent (this=0x555a6ef12500, e=0x7ffcf778a7d0) at widgets/qtextedit.cpp:1803
#37 0x00007fa78a07685e in QWidget::event (this=this@entry=0x555a6ef12500, event=event@entry=0x7ffcf778a7d0) at kernel/qwidget.cpp:9019
#38 0x00007fa78a11fcd2 in QFrame::event (this=0x555a6ef12500, e=0x7ffcf778a7d0) at widgets/qframe.cpp:550
#39 0x00007fa78a035e73 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555a6ef12500, e=0x7ffcf778a7d0) at kernel/qapplication.cpp:3632
#40 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef12500, event=0x7ffcf778a7d0) at kernel/qcoreapplication.cpp:1063
#41 0x00007fa787da71f8 in QtWaylandClient::QWaylandTextInput::commit (this=0x555a6ea48f50) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:94
#42 QtWaylandClient::QWaylandInputContext::commit (this=<optimized out>) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:425
#43 0x00007fa78a070a3d in QWidget::setFocus (reason=Qt::OtherFocusReason, this=<optimized out>) at kernel/qwidget.cpp:6326
#44 QWidget::setFocus (this=0x555a6ef10250, reason=reason@entry=Qt::OtherFocusReason) at kernel/qwidget.cpp:6284
#45 0x0000555a6dea93b5 in QWidget::setFocus (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtWidgets/qwidget.h:420
#46 BugzillaInformationPage::checkTexts (this=0x555a6ef0b410) at /usr/src/debug/plasma-drkonqi-5.21.0-1.fc34.x86_64/src/bugzillaintegration/reportassistantpages_bugzilla.cpp:416
#47 0x00007fa78949f4b0 in QtPrivate::QSlotObjectBase::call (a=0x7ffcf778a9c0, r=<optimized out>, this=0x555a6ef2b0e0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#48 doActivate<false> (sender=0x555a6ef12500, signal_index=7, argv=0x7ffcf778a9c0) at kernel/qobject.cpp:3886
#49 0x00007fa78949f4fd in doActivate<false> (sender=0x555a6ef16880, signal_index=3, argv=0x7ffcf778aa90) at kernel/qobject.cpp:3898

... 

#96061 QTextEdit::inputMethodEvent (this=0x555a6ef12500, e=0x7ffcf7f81100) at widgets/qtextedit.cpp:1803
#96062 0x00007fa78a07685e in QWidget::event (this=this@entry=0x555a6ef12500, event=event@entry=0x7ffcf7f81100) at kernel/qwidget.cpp:9019
#96063 0x00007fa78a11fcd2 in QFrame::event (this=0x555a6ef12500, e=0x7ffcf7f81100) at widgets/qframe.cpp:550
#96064 0x00007fa78a035e73 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555a6ef12500, e=0x7ffcf7f81100) at kernel/qapplication.cpp:3632
#96065 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef12500, event=0x7ffcf7f81100) at kernel/qcoreapplication.cpp:1063
#96066 0x00007fa787da71f8 in QtWaylandClient::QWaylandTextInput::commit (this=0x555a6ea48f50) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:94
#96067 QtWaylandClient::QWaylandInputContext::commit (this=<optimized out>) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:425
#96068 0x00007fa78a070a3d in QWidget::setFocus (reason=Qt::OtherFocusReason, this=<optimized out>) at kernel/qwidget.cpp:6326
#96069 QWidget::setFocus (this=0x555a6ef10250, reason=reason@entry=Qt::OtherFocusReason) at kernel/qwidget.cpp:6284
#96070 0x0000555a6dea93b5 in QWidget::setFocus (this=<optimized out>, this=<optimized out>) at /usr/include/qt5/QtWidgets/qwidget.h:420
#96071 BugzillaInformationPage::checkTexts (this=0x555a6ef0b410) at /usr/src/debug/plasma-drkonqi-5.21.0-1.fc34.x86_64/src/bugzillaintegration/reportassistantpages_bugzilla.cpp:416
#96072 0x00007fa78949f4b0 in QtPrivate::QSlotObjectBase::call (a=0x7ffcf7f812f0, r=<optimized out>, this=0x555a6ef2b0e0) at ../../include/QtCore/../../src/corelib/kernel/qobjectdefs_impl.h:398
#96073 doActivate<false> (sender=0x555a6ef12500, signal_index=7, argv=0x7ffcf7f812f0) at kernel/qobject.cpp:3886
#96074 0x00007fa78949f4fd in doActivate<false> (sender=0x555a6ef16880, signal_index=3, argv=0x7ffcf7f813c0) at kernel/qobject.cpp:3898
#96075 0x00007fa78a228db3 in QWidgetTextControl::qt_metacall (this=0x555a6ef16880, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7ffcf7f814c0) at .moc/moc_qwidgettextcontrol_p.cpp:489
#96076 0x00007fa78949f282 in doActivate<false> (sender=0x555a6ef16aa0, signal_index=4, argv=0x7ffcf7f814c0) at kernel/qobject.cpp:3912
#96077 0x00007fa7894999e7 in QMetaObject::activate (sender=<optimized out>, m=m@entry=0x7fa789d3c3c0 <QTextDocument::staticMetaObject>, local_signal_index=local_signal_index@entry=1, argv=argv@entry=0x0) at kernel/qobject.cpp:3946
#96078 0x00007fa789c2a157 in QTextDocument::contentsChanged (this=<optimized out>) at .moc/moc_qtextdocument.cpp:427
#96079 0x00007fa789998cdc in QTextDocumentPrivate::finishEdit (this=0x555a6ef16ac0) at text/qtextdocument_p.cpp:1247
#96080 0x00007fa789999089 in QTextDocumentPrivate::endEditBlock (this=<optimized out>) at text/qtextdocument_p.cpp:1203
#96081 0x00007fa78a226321 in QWidgetTextControlPrivate::inputMethodEvent (this=<optimized out>, e=<optimized out>) at widgets/qwidgettextcontrol.cpp:2137
#96082 0x00007fa78a21d52e in QWidgetTextControl::processEvent (this=this@entry=0x555a6ef16880, e=e@entry=0x7ffcf7f818d0, coordinateOffset=..., contextWidget=contextWidget@entry=0x555a6ef12640) at widgets/qwidgettextcontrol.cpp:998
#96083 0x00007fa78a1fe2dd in QTextEditPrivate::sendControlEvent (e=0x7ffcf7f818d0, this=0x555a6edc53d0) at widgets/qtextedit_p.h:103
#96084 QTextEdit::inputMethodEvent (this=0x555a6ef12500, e=0x7ffcf7f818d0) at widgets/qtextedit.cpp:1803
#96085 0x00007fa78a07685e in QWidget::event (this=this@entry=0x555a6ef12500, event=event@entry=0x7ffcf7f818d0) at kernel/qwidget.cpp:9019
#96086 0x00007fa78a11fcd2 in QFrame::event (this=0x555a6ef12500, e=0x7ffcf7f818d0) at widgets/qframe.cpp:550
#96087 0x00007fa78a035e73 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555a6ef12500, e=0x7ffcf7f818d0) at kernel/qapplication.cpp:3632
#96088 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef12500, event=0x7ffcf7f818d0) at kernel/qcoreapplication.cpp:1063
#96089 0x00007fa787da71f8 in QtWaylandClient::QWaylandTextInput::commit (this=0x555a6ea48f50) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:94
#96090 QtWaylandClient::QWaylandInputContext::commit (this=<optimized out>) at /usr/src/debug/qt5-qtwayland-5.15.2-4.fc34.x86_64/src/client/qwaylandinputcontext.cpp:425
#96091 0x00007fa78a070a3d in QWidget::setFocus (reason=Qt::MouseFocusReason, this=<optimized out>) at kernel/qwidget.cpp:6326
#96092 QWidget::setFocus (this=this@entry=0x555a6ef10250, reason=reason@entry=Qt::MouseFocusReason) at kernel/qwidget.cpp:6284
#96093 0x00007fa78a03688d in QApplicationPrivate::giveFocusAccordingToFocusPolicy (widget=widget@entry=0x555a6ef10250, event=event@entry=0x7ffcf7f81e40, localPos=...) at kernel/qapplication.cpp:4095
#96094 0x00007fa78a03e80d in QApplication::notify (this=0x7ffcf7f82630, receiver=0x555a6ef10250, e=0x7ffcf7f81e40) at kernel/qapplication.cpp:3039
#96095 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef10250, event=0x7ffcf7f81e40) at kernel/qcoreapplication.cpp:1063
#96096 0x00007fa78a03be6a in QApplicationPrivate::sendMouseEvent (receiver=receiver@entry=0x555a6ef10250, event=event@entry=0x7ffcf7f81e40, alienWidget=alienWidget@entry=0x555a6ef10250, nativeWidget=0x555a6ee2a240, buttonDown=buttonDown@entry=0x7fa78a572330 <qt_button_down>, lastMouseReceiver=..., spontaneous=true, onlyDispatchEnterLeave=false) at kernel/qapplication.cpp:2614
#96097 0x00007fa78a08ee05 in QWidgetWindow::handleMouseEvent (this=0x555a6ef99b70, event=0x7ffcf7f820f0) at kernel/qwidgetwindow.cpp:683
#96098 0x00007fa78a0921fe in QWidgetWindow::event (this=0x555a6ef99b70, event=0x7ffcf7f820f0) at kernel/qwidgetwindow.cpp:300
#96099 0x00007fa78a035e73 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555a6ef99b70, e=0x7ffcf7f820f0) at kernel/qapplication.cpp:3632
#96100 0x00007fa78946ef48 in QCoreApplication::notifyInternal2 (receiver=0x555a6ef99b70, event=0x7ffcf7f820f0) at kernel/qcoreapplication.cpp:1063
#96101 0x00007fa7898afad8 in QGuiApplicationPrivate::processMouseEvent (e=0x555a6f249f70) at kernel/qguiapplication.cpp:2275
#96102 0x00007fa7898915cc in QWindowSystemInterface::sendWindowSystemEvents (flags=...) at kernel/qwindowsysteminterface.cpp:1169
#96103 0x00007fa787dc6014 in userEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /lib64/libQt5WaylandClient.so.5
#96104 0x00007fa787ead0bf in g_main_dispatch (context=0x555a6ea708b0) at ../glib/gmain.c:3337
#96105 g_main_context_dispatch (context=0x555a6ea708b0) at ../glib/gmain.c:4055
#96106 0x00007fa787f00358 in g_main_context_iterate.constprop.0 (context=context@entry=0x555a6ea708b0, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4131
#96107 0x00007fa787eaa9b3 in g_main_context_iteration (context=0x555a6ea708b0, may_block=1) at ../glib/gmain.c:4196
#96108 0x00007fa7894bb6f8 in QEventDispatcherGlib::processEvents (this=0x555a6ea68c80, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#96109 0x00007fa78946d9b2 in QEventLoop::exec (this=this@entry=0x7ffcf7f82420, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#96110 0x00007fa789475544 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#96111 0x0000555a6de7b921 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/plasma-drkonqi-5.21.0-1.fc34.x86_64/src/main.cpp:224

The pointer layoutData was null in QTextEngine::itemize so layoutData->items.size() at line 2083 might've been a null pointer dereference.

(gdb) l
2076        if (specialData && specialData->preeditPosition != -1)
2077            layoutData->string.insert(specialData->preeditPosition, specialData->preeditText);
2078    }
2079
2080    void QTextEngine::itemize() const
2081    {
2082        validate();
2083        if (layoutData->items.size())
2084            return;
2085
(gdb) p layoutData
$2 = (QTextEngine::LayoutData *) 0x0


Version-Release number of selected component (if applicable):
plasma-drkonqi-5.21.0-1.fc34.x86_64
kf5-plasma-5.79.0-2.fc34.x86_64
qt5-qtbase-5.15.2-13.fc34.x86_64


How reproducible:
drkonqi crashed in this way 4 of 4 times I tried to enter a description of what I was doing at the time of the crash.

Steps to Reproduce:
1. Boot a Fedora 34 KDE Plasma installation updated to 2021-2-19.
2. Log in to Plasma 5.21.0 on Wayland
3. Start System Settings 
4. search for Activities in the search box. 
5. select Activities in the side bar
6. select Privacy in the Activities screen. 
7. set Keep history: 1 month 
8. set Remember opened documents: Do not remember. 
9. select the Clear History box 
10. select Forget Everything
11. Click Report Bug in the drkonqi notification
12. Click Report Bug in drkonqi 
13. select Next
14. select Yes for Do you remember what you were doing prior to the crash?
15. select What I was doing when the application "System Settings" crashed
16. select Next
17. select Next
18. enter a valid email address and password for the KDE Bugzilla
19. select Login
20. select Next
21. select There are no real duplicates
22. click in the Information about the crash box
23. enter text in the Information about the crash box

Actual results:
drkonqi segmentation faulted in QTextEngine::itemize when trying to enter information about crashes

Expected results:
No crashes would happen. The report could be submitted to KDE Bugzilla normally.

Additional info:
https://bugs.kde.org/show_bug.cgi?id=429136 had a similar trace and description.