Bug 296336

Summary:	KDE 4.7.4 still crashing with NULL classClass object
Product:	[Unmaintained] plasma4	Reporter:	Nick Leverton <nick>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED WORKSFORME
Severity:	crash	CC:	adaptee, nick
Priority:	NOR
Version:	4.7.4
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	New crash information added by DrKonqi

Description Nick Leverton 2012-03-19 10:20:18 UTC

Application: plasma-desktop (0.4)
KDE Platform Version: 4.7.4 (4.7.4)
Qt Version: 4.7.4
Operating System: Linux 3.0.0-16-generic-pae i686
Distribution: Ubuntu 11.10

-- Information about the crash:
I had just plugged in a second monitor and was trying to move windows onto it.  The last thing I think I did was probably to right-click on a taskbar entry although I'm not 100% sure.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0xb1ebeb20 (LWP 3275))]

Thread 3 (Thread 0xa73d4b70 (LWP 3281)):
#0  0xb2ff6dbd in __pthread_mutex_lock (mutex=0xa9b7be4) at pthread_mutex_lock.c:61
#1  0xb76562b4 in pthread_mutex_lock (mutex=0xa9b7be4) at forward.c:182
#2  0xb2ed8eda in g_main_context_acquire (context=0xa9b7be0) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:2528
#3  0xb2eda56d in g_main_context_iterate (context=0xa9b7be0, block=1, dispatch=1, self=<optimized out>) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3033
#4  0xb2edac2a in g_main_context_iteration (context=0xa9b7be0, may_block=1) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3152
#5  0xb648eb37 in QEventDispatcherGlib::processEvents (this=0xa9b74f8, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#6  0xb645f1dd in QEventLoop::processEvents (this=0xa73d42a0, flags=...) at kernel/qeventloop.cpp:149
#7  0xb645f421 in QEventLoop::exec (this=0xa73d42a0, flags=...) at kernel/qeventloop.cpp:201
#8  0xb636290b in QThread::exec (this=0xa98e628) at thread/qthread.cpp:498
#9  0xb643fe2d in QInotifyFileSystemWatcherEngine::run (this=0xa98e628) at io/qfilesystemwatcher_inotify.cpp:248
#10 0xb63657b3 in QThreadPrivate::start (arg=0xa98e628) at thread/qthread_unix.cpp:331
#11 0xb2ff4d31 in start_thread (arg=0xa73d4b70) at pthread_create.c:304
#12 0xb764846e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130
Backtrace stopped: Not enough registers or memory available to unwind further

Thread 2 (Thread 0xa6775b70 (LWP 3282)):
#0  do_gettime (frac=0xa6775010, sec=0xa6775008) at tools/qelapsedtimer_unix.cpp:121
#1  qt_gettime () at tools/qelapsedtimer_unix.cpp:140
#2  0xb648f4b6 in QTimerInfoList::updateCurrentTime (this=0xaba1d4c) at kernel/qeventdispatcher_unix.cpp:339
#3  0xb648f80a in QTimerInfoList::timerWait (this=0xaba1d4c, tm=...) at kernel/qeventdispatcher_unix.cpp:442
#4  0xb648e053 in timerSourcePrepareHelper (src=<optimized out>, timeout=0xa677511c) at kernel/qeventdispatcher_glib.cpp:136
#5  0xb648e0ed in timerSourcePrepare (source=0xaba1d18, timeout=<optimized out>) at kernel/qeventdispatcher_glib.cpp:169
#6  0xb2ed988c in g_main_context_prepare (context=0xaba1488, priority=0xa6775178) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:2762
#7  0xb2eda637 in g_main_context_iterate (context=0xaba1488, block=1, dispatch=1, self=<optimized out>) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3069
#8  0xb2edac2a in g_main_context_iteration (context=0xaba1488, may_block=1) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3152
#9  0xb648eb37 in QEventDispatcherGlib::processEvents (this=0xaba0dc0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#10 0xb645f1dd in QEventLoop::processEvents (this=0xa67752a0, flags=...) at kernel/qeventloop.cpp:149
#11 0xb645f421 in QEventLoop::exec (this=0xa67752a0, flags=...) at kernel/qeventloop.cpp:201
#12 0xb636290b in QThread::exec (this=0xab9f7b0) at thread/qthread.cpp:498
#13 0xb643fe2d in QInotifyFileSystemWatcherEngine::run (this=0xab9f7b0) at io/qfilesystemwatcher_inotify.cpp:248
#14 0xb63657b3 in QThreadPrivate::start (arg=0xab9f7b0) at thread/qthread_unix.cpp:331
#15 0xb2ff4d31 in start_thread (arg=0xa6775b70) at pthread_create.c:304
#16 0xb764846e in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:130
Backtrace stopped: Not enough registers or memory available to unwind further

Thread 1 (Thread 0xb1ebeb20 (LWP 3275)):
[KCrash Handler]
#7  TaskManager::Task::classClass (this=0x0) at ../../../libs/taskmanager/task_x11.cpp:74
#8  0xb0a01789 in TaskManager::ToggleLauncherActionImpl::ToggleLauncherActionImpl (this=0xe88f6e0, parent=0xed16818, item=0xbec2d68, strategy=0xa825be0) at ../../../libs/taskmanager/taskactions.cpp:351
#9  0xb0a01ceb in TaskManager::AdvancedMenu::AdvancedMenu (this=0xed16818, parent=0xbeb16a8, item=0xbec2d68, strategy=0xa825be0) at ../../../libs/taskmanager/taskactions.cpp:295
#10 0xb0a02b4b in TaskManager::BasicMenu::BasicMenu (this=0xbeb16a8, parent=0xbff57ae4, item=0xbec2d68, strategy=0xa825be0, visualizationActions=...) at ../../../libs/taskmanager/taskactions.cpp:440
#11 0xb0a0325b in TaskManager::BasicMenu::BasicMenu (this=0xbff57ae4, parent=0x0, group=0xb845238, strategy=0xa825be0, visualizationActions=...) at ../../../libs/taskmanager/taskactions.cpp:462
#12 0xb09c728f in contextMenuEvent (e=0xbff5808c, this=0xee071d8) at ../../../../../plasma/desktop/applets/tasks/taskgroupitem.cpp:440
#13 TaskGroupItem::contextMenuEvent (this=0xee071d8, e=0xbff5808c) at ../../../../../plasma/desktop/applets/tasks/taskgroupitem.cpp:408
#14 0xb5fed833 in QGraphicsItem::sceneEvent (this=0xee071e0, event=0xbff5808c) at graphicsview/qgraphicsitem.cpp:6700
#15 0xb604a856 in QGraphicsWidget::sceneEvent (this=0xee071d8, event=0xbff5808c) at graphicsview/qgraphicswidget.cpp:1223
#16 0xb6016cce in sendEvent (event=0xbff5808c, item=0xee071e0, this=<optimized out>) at graphicsview/qgraphicsscene.cpp:1217
#17 QGraphicsScenePrivate::sendEvent (this=0x9c0ab30, item=0xee071e0, event=0xbff5808c) at graphicsview/qgraphicsscene.cpp:1193
#18 0xb6017448 in QGraphicsScene::contextMenuEvent (this=0x9c07e18, contextMenuEvent=0xbff5808c) at graphicsview/qgraphicsscene.cpp:3609
#19 0xb6026b0c in QGraphicsScene::event (this=0x9c07e18, event=0xbff5808c) at graphicsview/qgraphicsscene.cpp:3407
#20 0xb598bd84 in notify_helper (e=0xbff5808c, receiver=0x9c07e18, this=0x9b02770) at kernel/qapplication.cpp:4486
#21 QApplicationPrivate::notify_helper (this=0x9b02770, receiver=0x9c07e18, e=0xbff5808c) at kernel/qapplication.cpp:4458
#22 0xb5991133 in QApplication::notify (this=0xbff5808c, receiver=0x9c07e18, e=0xbff5808c) at kernel/qapplication.cpp:3886
#23 0xb6ac5971 in KApplication::notify (this=0x9af96b8, receiver=0x9c07e18, event=0xbff5808c) at ../../kdeui/kernel/kapplication.cpp:311
#24 0xb646019e in QCoreApplication::notifyInternal (this=0x9af96b8, receiver=0x9c07e18, event=0xbff5808c) at kernel/qcoreapplication.cpp:787
#25 0xb603f206 in sendEvent (event=0xbff5807c, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#26 QGraphicsView::contextMenuEvent (this=0xb2e2458, event=0xbff58644) at graphicsview/qgraphicsview.cpp:2890
#27 0xb59e6d53 in QWidget::event (this=0xb2e2458, event=0xbff58644) at kernel/qwidget.cpp:8462
#28 0xb5deb285 in QFrame::event (this=0xb2e2458, e=0xbff58644) at widgets/qframe.cpp:557
#29 0xb5e7d821 in QAbstractScrollArea::viewportEvent (this=0xb2e2458, e=0xbff58644) at widgets/qabstractscrollarea.cpp:1043
#30 0xb6048d04 in QGraphicsView::viewportEvent (this=0xb2e2458, event=0xbff58644) at graphicsview/qgraphicsview.cpp:2864
#31 0xb5e7ff36 in viewportEvent (this=<optimized out>, event=0xbff58644) at widgets/qabstractscrollarea_p.h:100
#32 eventFilter (e=0xbff58644, this=<optimized out>, o=<optimized out>) at widgets/qabstractscrollarea_p.h:116
#33 QAbstractScrollAreaFilter::eventFilter (this=0x9ec9730, o=0xa529d20, e=0xbff58644) at widgets/qabstractscrollarea_p.h:115
#34 0xb6460336 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x9b02770, receiver=0xa529d20, event=0xbff58644) at kernel/qcoreapplication.cpp:902
#35 0xb598bd52 in notify_helper (e=0xbff58644, receiver=0xa529d20, this=0x9b02770) at kernel/qapplication.cpp:4482
#36 QApplicationPrivate::notify_helper (this=0x9b02770, receiver=0xa529d20, e=0xbff58644) at kernel/qapplication.cpp:4458
#37 0xb59917c4 in QApplication::notify (this=0xa529d20, receiver=0xa529d20, e=0xbff58644) at kernel/qapplication.cpp:4126
#38 0xb6ac5971 in KApplication::notify (this=0x9af96b8, receiver=0xa529d20, event=0xbff58644) at ../../kdeui/kernel/kapplication.cpp:311
#39 0xb646019e in QCoreApplication::notifyInternal (this=0x9af96b8, receiver=0xa529d20, event=0xbff58644) at kernel/qcoreapplication.cpp:787
#40 0xb5a19385 in sendSpontaneousEvent (event=0xbff58644, receiver=0xa529d20) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#41 QETWidget::translateMouseEvent (this=0xb2e2458, event=0xbff58a9c) at kernel/qapplication_x11.cpp:4576
#42 0xb5a17e8d in QApplication::x11ProcessEvent (this=0x9af96b8, event=0xbff58a9c) at kernel/qapplication_x11.cpp:3693
#43 0xb5a4428c in x11EventSourceDispatch (s=0x9b058a8, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#44 0xb2eda25f in g_main_dispatch (context=0x9b05b48) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:2441
#45 g_main_context_dispatch (context=0x9b05b48) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3011
#46 0xb2eda990 in g_main_context_iterate (context=0x9b05b48, block=-1292987616, dispatch=1, self=<optimized out>) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3089
#47 0xb2edac2a in g_main_context_iteration (context=0x9b05b48, may_block=1) at /build/buildd/glib2.0-2.30.0/./glib/gmain.c:3152
#48 0xb648eada in QEventDispatcherGlib::processEvents (this=0x9b00de8, flags=...) at kernel/qeventdispatcher_glib.cpp:422
#49 0xb5a43e7a in QGuiEventDispatcherGlib::processEvents (this=0x9b00de8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#50 0xb645f1dd in QEventLoop::processEvents (this=0xbff58da4, flags=...) at kernel/qeventloop.cpp:149
#51 0xb645f421 in QEventLoop::exec (this=0xbff58da4, flags=...) at kernel/qeventloop.cpp:201
#52 0xb646419d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1064
#53 0xb5989924 in QApplication::exec () at kernel/qapplication.cpp:3760
#54 0xb774518b in kdemain (argc=1, argv=0xbff58fa4) at ../../../../plasma/desktop/shell/main.cpp:120
#55 0x0804850b in main (argc=1, argv=0xbff58fa4) at plasma-desktop_dummy.cpp:3

This bug may be a duplicate of or related to bug 277033.

Possible duplicates by query: bug 289013, bug 288256, bug 287915, bug 287329, bug 285858.

Reported using DrKonqi

Comment 1 Nick Leverton 2012-03-26 12:50:36 UTC

Created attachment 69904 [details]
New crash information added by DrKonqi

plasma-desktop (0.4) on KDE Platform 4.7.4 (4.7.4) using Qt 4.7.4

Left-clicked on a taskbar entry (but had right-clicked immediately previously so could be a delayed crash from that).

-- Backtrace (Reduced):
#7  TaskManager::Task::classClass (this=0x0) at ../../../libs/taskmanager/task_x11.cpp:74
#8  0xb09bd789 in TaskManager::ToggleLauncherActionImpl::ToggleLauncherActionImpl (this=0xeb18bd8, parent=0xea6d058, item=0x9f9c108, strategy=0xa8585b8) at ../../../libs/taskmanager/taskactions.cpp:351
#9  0xb09bdceb in TaskManager::AdvancedMenu::AdvancedMenu (this=0xea6d058, parent=0xea6a360, item=0x9f9c108, strategy=0xa8585b8) at ../../../libs/taskmanager/taskactions.cpp:295
#10 0xb09beb4b in TaskManager::BasicMenu::BasicMenu (this=0xea6a360, parent=0xbfc9ae84, item=0x9f9c108, strategy=0xa8585b8, visualizationActions=...) at ../../../libs/taskmanager/taskactions.cpp:440
#11 0xb09bf25b in TaskManager::BasicMenu::BasicMenu (this=0xbfc9ae84, parent=0x0, group=0xb0cad88, strategy=0xa8585b8, visualizationActions=...) at ../../../libs/taskmanager/taskactions.cpp:462

Comment 2 Nick Leverton 2013-02-22 21:05:32 UTC

Just to note that I have not experienced this for some time, certainly not since 4.9 if not earlier.

Comment 3 Jekyll Wu 2013-03-11 10:27:23 UTC

(In reply to comment #2)
> Just to note that I have not experienced this for some time, certainly not
> since 4.9 if not earlier.

OK, since there is no further reports from other users neither, close this report for now with the assumption the issue is really fixed in later versions.