Bug 298352

With the latest qt-at-spi plugin up till v3.1, I stumbled across a segfault when closing KDE apps' about dialog.

qt-4.8.0-7.fc16.x86_64
qt-at-spi-0.3.1-1.fc16.x86_64
kdelibs-4.7.4-1.fc16.x86_64

Filed here on request of Frederik Gladhorn, should be assigned to him.





Reproducible: Always

Steps to Reproduce:
1. Open Kwrite, Kate, Konqueror etc.
2. Go Help->About (Appname)
3. Close the dialog
Actual Results:  
Segfault occurs, only with QT_ACCESSIBILITY set to 1. This does seem to be different problem then https://bugs.kde.org/show_bug.cgi?id=284005


Here's what goes out in stderr at that time:
FIXME: handle dialog end.
kwrite(23025) KWidgetItemDelegateEventListener::eventFilter: User of KWidgetItemDelegate should not delete widgets created by createItemWidgets!
kwrite(23025) KWidgetItemDelegateEventListener::eventFilter: User of KWidgetItemDelegate should not delete widgets created by createItemWidgets!
kwrite(23025) KWidgetItemDelegateEventListener::eventFilter: User of KWidgetItemDelegate should not delete widgets created by createItemWidgets!
... (repeats great number of times)

KCrash: Application 'kwrite' crashing...
KCrash: Attempting to start /usr/libexec/kde4/drkonqi from kdeinit
sock_file=/home/vhumpa/.kde/socket-vhumpa/kdeinit4__1

Here goes backtrace taken from KCrash (with available debuginfos installed):

Application: Kate (kate), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
82	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[Current thread is 1 (Thread 0x7f61c284f840 (LWP 603))]

Thread 3 (Thread 0x7f61b50d4700 (LWP 605)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:165
#1  0x00000036da984e62 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0x36dac7e240) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#2  0x00000036da984e99 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=<optimized out>) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#3  0x00000037b1e07d90 in start_thread (arg=0x7f61b50d4700) at pthread_create.c:309
#4  0x00000037b16f0f5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 2 (Thread 0x7f61b3452700 (LWP 607)):
#0  0x00000037b16ea403 in select () at ../sysdeps/unix/syscall-template.S:82
#1  0x00000036d29563cf in QProcessManager::run (this=0x36d2cce040) at io/qprocess_unix.cpp:244
#2  0x00000036d287bb6b in QThreadPrivate::start (arg=0x36d2cce040) at thread/qthread_unix.cpp:298
#3  0x00000037b1e07d90 in start_thread (arg=0x7f61b3452700) at pthread_create.c:309
#4  0x00000037b16f0f5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

Thread 1 (Thread 0x7f61c284f840 (LWP 603)):
[KCrash Handler]
#6  0x0000000000000130 in ?? ()
#7  0x00000036d298c564 in QObject::disconnect (sender=0x13509f0, signal=0x159a299 "rowsInserted(QModelIndex,int,int)", receiver=0x1354750, method=0x1599539 "_k_slotRowsInserted(QModelIndex,int,int)") at kernel/qobject.cpp:2891
#8  0x00000031fda2fd16 in eventFilter (event=0x7fffd90e93a0, watched=0x1352590, this=0x13538a0) at /usr/src/debug/kdelibs-4.7.4/kdeui/itemviews/kwidgetitemdelegate.cpp:243
#9  KWidgetItemDelegatePrivate::eventFilter (this=0x13538a0, watched=0x1352590, event=0x7fffd90e93a0) at /usr/src/debug/kdelibs-4.7.4/kdeui/itemviews/kwidgetitemdelegate.cpp:226
#10 0x00000036d29791d8 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<optimized out>, receiver=0x1352590, event=0x7fffd90e93a0) at kernel/qcoreapplication.cpp:986
#11 0x00000036d2fc995f in notify_helper (e=0x7fffd90e93a0, receiver=0x1352590, this=0xa367d0) at kernel/qapplication.cpp:4546
#12 QApplicationPrivate::notify_helper (this=0xa367d0, receiver=0x1352590, e=0x7fffd90e93a0) at kernel/qapplication.cpp:4522
#13 0x00000036d2fce813 in QApplication::notify (this=0x7fffd90ea410, receiver=0x1352590, e=0x7fffd90e93a0) at kernel/qapplication.cpp:4411
#14 0x00000031fda50766 in KApplication::notify (this=0x7fffd90ea410, receiver=0x1352590, event=0x7fffd90e93a0) at /usr/src/debug/kdelibs-4.7.4/kdeui/kernel/kapplication.cpp:311
#15 0x00000036d297904c in QCoreApplication::notifyInternal (this=0x7fffd90ea410, receiver=0x1352590, event=0x7fffd90e93a0) at kernel/qcoreapplication.cpp:876
#16 0x00000036d34d991d in sendEvent (event=0x7fffd90e93a0, receiver=0x1352590) at ../../src/corelib/kernel/qcoreapplication.h:231
#17 QAccessible::queryAccessibleInterface (object=0x1352590) at accessible/qaccessible.cpp:588
#18 0x00000036d34df66d in QAccessible::updateAccessibility (o=<optimized out>, who=0, reason=QAccessible::ObjectDestroyed) at accessible/qaccessible_unix.cpp:102
#19 0x00000036d301467f in QWidget::~QWidget (this=0x1352590, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1678
#20 0x00000036d3014949 in QWidget::~QWidget (this=0x1352590, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1699
#21 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x1352080) at kernel/qobject.cpp:1908
#22 0x00000036d3014670 in QWidget::~QWidget (this=0x1351760, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#23 0x00000031fd9cafbe in ~KAboutApplicationPersonListView (this=0x1351760, __in_chrg=<optimized out>) at /usr/src/debug/kdelibs-4.7.4/kdeui/dialogs/kaboutapplicationpersonlistview_p.h:26
#24 KDEPrivate::KAboutApplicationPersonListView::~KAboutApplicationPersonListView (this=0x1351760, __in_chrg=<optimized out>) at /usr/src/debug/kdelibs-4.7.4/kdeui/dialogs/kaboutapplicationpersonlistview_p.h:26
#25 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x13505e0) at kernel/qobject.cpp:1908
#26 0x00000036d3014670 in QWidget::~QWidget (this=0x1224d40, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#27 0x00000036d3014949 in QWidget::~QWidget (this=0x1224d40, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1699
#28 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x1224910) at kernel/qobject.cpp:1908
#29 0x00000036d3014670 in QWidget::~QWidget (this=0x12248e0, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#30 0x00000036d342cc39 in QStackedWidget::~QStackedWidget (this=0x12248e0, __in_chrg=<optimized out>) at widgets/qstackedwidget.cpp:193
#31 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x12246a0) at kernel/qobject.cpp:1908
#32 0x00000036d3014670 in QWidget::~QWidget (this=0x115e7d0, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#33 0x00000036d3438659 in QTabWidget::~QTabWidget (this=0x115e7d0, __in_chrg=<optimized out>) at widgets/qtabwidget.cpp:367
#34 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x13568f0) at kernel/qobject.cpp:1908
#35 0x00000036d3014670 in QWidget::~QWidget (this=0x1356570, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#36 0x00000036d3014949 in QWidget::~QWidget (this=0x1356570, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1699
#37 0x00000036d298b395 in QObjectPrivate::deleteChildren (this=0x11b10d0) at kernel/qobject.cpp:1908
#38 0x00000036d3014670 in QWidget::~QWidget (this=0x103af20, __in_chrg=<optimized out>) at kernel/qwidget.cpp:1675
#39 0x00000031fd9beb79 in KAboutApplicationDialog::~KAboutApplicationDialog (this=0x103af20, __in_chrg=<optimized out>) at /usr/src/debug/kdelibs-4.7.4/kdeui/dialogs/kaboutapplicationdialog.cpp:306
#40 0x00000031fdafc38e in KHelpMenu::timerExpired (this=0xec6840) at /usr/src/debug/kdelibs-4.7.4/kdeui/widgets/khelpmenu.cpp:347
#41 0x00000036d2991f16 in QObject::event (this=0xec6840, e=<optimized out>) at kernel/qobject.cpp:1195
#42 0x00000036d2fc9994 in notify_helper (e=0x14d31d0, receiver=0xec6840, this=0xa367d0) at kernel/qapplication.cpp:4550
#43 QApplicationPrivate::notify_helper (this=0xa367d0, receiver=0xec6840, e=0x14d31d0) at kernel/qapplication.cpp:4522
#44 0x00000036d2fce813 in QApplication::notify (this=0x7fffd90ea410, receiver=0xec6840, e=0x14d31d0) at kernel/qapplication.cpp:4411
#45 0x00000031fda50766 in KApplication::notify (this=0x7fffd90ea410, receiver=0xec6840, event=0x14d31d0) at /usr/src/debug/kdelibs-4.7.4/kdeui/kernel/kapplication.cpp:311
#46 0x00000036d297904c in QCoreApplication::notifyInternal (this=0x7fffd90ea410, receiver=0xec6840, event=0x14d31d0) at kernel/qcoreapplication.cpp:876
#47 0x00000036d297cada in sendEvent (event=0x14d31d0, receiver=0xec6840) at kernel/qcoreapplication.h:231
#48 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x9f64b0) at kernel/qcoreapplication.cpp:1500
#49 0x00000036d29a7933 in sendPostedEvents () at kernel/qcoreapplication.h:236
#50 postEventSourceDispatch (s=0xa33e70) at kernel/qeventdispatcher_glib.cpp:279
#51 0x00000037b3244acd in g_main_dispatch (context=0xa329e0) at gmain.c:2441
#52 g_main_context_dispatch (context=0xa329e0) at gmain.c:3011
#53 0x00000037b32452c8 in g_main_context_iterate (context=0xa329e0, block=<optimized out>, dispatch=1, self=<optimized out>) at gmain.c:3089
#54 0x00000037b324549c in g_main_context_iteration (context=0xa329e0, may_block=1) at gmain.c:3152
#55 0x00000036d29a7d5f in QEventDispatcherGlib::processEvents (this=0x9f7970, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#56 0x00000036d306c66e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:207
#57 0x00000036d2978182 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#58 0x00000036d29783d7 in QEventLoop::exec (this=0x7fffd90ea350, flags=...) at kernel/qeventloop.cpp:204
#59 0x00000036d297cdd5 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1148
#60 0x000000320060608d in kdemain () from /usr/lib64/libkdeinit4_kate.so
#61 0x00000037b162169d in __libc_start_main (main=0x400730, argc=1, ubp_av=0x7fffd90eb948, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffd90eb938) at libc-start.c:226
#62 0x0000000000400761 in _start ()