Bug 314243

We need a backtrace, please have a look at http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports

Created attachment 76860 [details]
Backlog

I added the backlog of the crash as attachment.

Backtrace from attachment (please always paste backtraces in comments, else those are not searchable):

Thread 1 (Thread 0x7fc6d4272780 (LWP 8487)):
[KCrash Handler]
#6  isSignalConnected (signal_index=3, this=0x10) at kernel/qobject_p.h:234
#7  QMetaObject::activate (sender=0x1db9020, m=<optimized out>, local_signal_index=0, argv=0x7fff857be4d0) at kernel/qobject.cpp:3456
#8  0x00007fc6d31bd23f in ProgressBar::cancelled (this=this@entry=0x1db9020, _t1=_t1@entry=0x1db9020) at ./ProgressBar.moc:115
#9  0x00007fc6d31bd36b in ProgressBar::cancel (this=0x1db9020) at ../../src/statusbar/ProgressBar.cpp:99
#10 0x00007fc6d31be8b8 in CompoundProgressBar::cancelAll (this=0x1ab0c50) at ../../src/statusbar/CompoundProgressBar.cpp:245
#11 0x00007fc6d14dbf5f in QMetaObject::activate (sender=0x1ab15b0, m=<optimized out>, local_signal_index=<optimized out>, argv=0x7fff857be6f0) at kernel/qobject.cpp:3547
#12 0x00007fc6d2512422 in QAbstractButton::clicked (this=<optimized out>, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:220
#13 0x00007fc6d2265d2e in QAbstractButtonPrivate::emitClicked (this=this@entry=0x1ab15e0) at widgets/qabstractbutton.cpp:548
#14 0x00007fc6d2266560 in QAbstractButtonPrivate::click (this=this@entry=0x1ab15e0) at widgets/qabstractbutton.cpp:541
#15 0x00007fc6d22667cc in QAbstractButton::mouseReleaseEvent (this=0x1ab15b0, e=0x7fff857befa0) at widgets/qabstractbutton.cpp:1123
#16 0x00007fc6d232099a in QToolButton::mouseReleaseEvent (this=<optimized out>, e=<optimized out>) at widgets/qtoolbutton.cpp:718
#17 0x00007fc6d1ef7850 in QWidget::event (this=0x1ab15b0, event=0x7fff857befa0) at kernel/qwidget.cpp:8371
#18 0x00007fc6d1ea7e9c in QApplicationPrivate::notify_helper (this=this@entry=0xe27630, receiver=receiver@entry=0x1ab15b0, e=e@entry=0x7fff857befa0) at kernel/qapplication.cpp:4562
#19 0x00007fc6d1eacb6b in QApplication::notify (this=<optimized out>, receiver=0x1ab15b0, e=0x7fff857befa0) at kernel/qapplication.cpp:4105
#20 0x00007fc6d3c81636 in KApplication::notify (this=0x7fff857c1ed0, receiver=0x1ab15b0, event=0x7fff857befa0) at ../../kdeui/kernel/kapplication.cpp:311
#21 0x00007fc6d14c656e in QCoreApplication::notifyInternal (this=0x7fff857c1ed0, receiver=0x1ab15b0, event=0x7fff857befa0) at kernel/qcoreapplication.cpp:915
#22 0x00007fc6d1ea8cd3 in sendEvent (event=<optimized out>, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#23 QApplicationPrivate::sendMouseEvent (receiver=0x1ab15b0, event=0x7fff857befa0, alienWidget=0x1ab15b0, nativeWidget=0x1aafa20, buttonDown=0x7fc6d2984308 <qt_button_down>, lastMouseReceiver=..., spontaneous=true) at kernel/qapplication.cpp:3173
#24 0x00007fc6d1f26554 in QETWidget::translateMouseEvent (this=this@entry=0x1aafa20, event=event@entry=0x7fff857bf720) at kernel/qapplication_x11.cpp:4622
#25 0x00007fc6d1f2544f in QApplication::x11ProcessEvent (this=0x7fff857c1ed0, event=0x7fff857bf720) at kernel/qapplication_x11.cpp:3737
#26 0x00007fc6d1f4cfa2 in x11EventSourceDispatch (s=0xe23100, callback=0x0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#27 0x00007fc6cb5b2ab5 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#28 0x00007fc6cb5b2de8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007fc6cb5b2ea4 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007fc6d14f4bf6 in QEventDispatcherGlib::processEvents (this=0xcb3ad0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#31 0x00007fc6d1f4cc1e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#32 0x00007fc6d14c52bf in QEventLoop::processEvents (this=this@entry=0x7fff857bfaf0, flags=...) at kernel/qeventloop.cpp:149
#33 0x00007fc6d14c5548 in QEventLoop::exec (this=0x7fff857bfaf0, flags=...) at kernel/qeventloop.cpp:204
#34 0x00007fc6d14ca708 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1187
#35 0x000000000040909a in main (argc=2, argv=0x7fff857c2038) at ../../src/main.cpp:329

Is this reproducible? It clearly is not an Amarok bug, looks more like a Qt problem. Which KDE and Qt versions do you use?

I can reproduce it every time.
I am using KDE 4.10 RC3 (from Kbuntu PPA) and Qt 4.8.2 from Ubuntu's repos.

And you always get the same backtrace? Because the one you posted doesn't show anything on the Amarok side

You have to wait a while and then press abort, but I can reproduce it here.

Last debug output:

amarok:     BEGIN: void ProgressBar::cancel() 
amarok:       cancelling operation:  "Generating playlist..." 
amarok:       BEGIN: virtual void Dynamic::BiasedPlaylist::requestAbort() 
amarok:       END__: virtual void Dynamic::BiasedPlaylist::requestAbort() [Took: 0s] 
KCrash: Application 'amarok' crashing...

Maybe something is deleted in requestAbort that shouldn't.

Git commit 95e694452be6c040bb8040f39b260c97b214f1c0 by Ralf Engels.
Committed on 06/02/2013 at 01:02.
Pushed by rengels into branch 'master'.

Fix crashed when dynamic playlist based on last.fm is aborted

Since the bias solver runs in a different thread care must be taken
for signals.
FIXED-IN: 2.8

M  +3    -3    src/browsers/BrowserMessageArea.cpp

http://commits.kde.org/amarok/95e694452be6c040bb8040f39b260c97b214f1c0