Bug 321855

Application: plasma-desktop (4.10.90)
KDE Platform Version: 4.10.90
Qt Version: 4.8.4
Operating System: Linux 3.10.0-1-generic i686
Distribution: Ubuntu Saucy Salamander (development branch)

-- Information about the crash:
- What I was doing when the application crashed:
Not exactly sure what I did precisely, though it happened during the startup sequence with ksplash still on the right screen (left was usable already). My plasmarc's are available if wished so, it consists of three panels:

- two panels, auto hiding with icon task manager, pager and show desktop plasmoid.
- top-bar panel with "window menu bar", "Quick access", Kate sessions, systray and clock.
- Desktop has the py-cashew plasmoid.

- Unusual behavior I noticed:
It crashed upon startup and auto-recovered, that's when I generated the BT.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0xb1218740 (LWP 2551))]

Thread 4 (Thread 0xabd93b40 (LWP 2552)):
#0  0xb76ec424 in __kernel_vsyscall ()
#1  0xb20c684b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i386-linux-gnu/libpthread.so.0
#2  0xb759ed7c in pthread_cond_wait () from /lib/i386-linux-gnu/libc.so.6
#3  0xb30c6642 in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#4  0xb30c668f in ?? () from /usr/lib/i386-linux-gnu/libQtScript.so.4
#5  0xb20c2d78 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#6  0xb75913de in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 3 (Thread 0xa38ffb40 (LWP 2555)):
#0  0xb76ec424 in __kernel_vsyscall ()
#1  0xb7581dcb in poll () from /lib/i386-linux-gnu/libc.so.6
#2  0xb1fbc7cb in g_poll () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0xb1fad808 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0xb1fad948 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0xb5fffabf in QEventDispatcherGlib::processEvents (this=0xa2f00468, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#6  0xb5fcebc3 in QEventLoop::processEvents (this=this@entry=0xa38ff228, flags=...) at kernel/qeventloop.cpp:149
#7  0xb5fceee9 in QEventLoop::exec (this=this@entry=0xa38ff228, flags=...) at kernel/qeventloop.cpp:204
#8  0xb5ebdefd in QThread::exec (this=this@entry=0x9f30988) at thread/qthread.cpp:542
#9  0xb5faefc4 in QInotifyFileSystemWatcherEngine::run (this=0x9f30988) at io/qfilesystemwatcher_inotify.cpp:256
#10 0xb5ec07ef in QThreadPrivate::start (arg=0x9f30988) at thread/qthread_unix.cpp:338
#11 0xb20c2d78 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#12 0xb75913de in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 2 (Thread 0xa2effb40 (LWP 2556)):
#0  0xb5ea0cb0 in ___tls_get_addr@plt () from /usr/lib/i386-linux-gnu/libQtCore.so.4
#1  0xb5ebf473 in get_thread_data () at thread/qthread_unix.cpp:182
#2  QThreadData::current () at thread/qthread_unix.cpp:208
#3  0xb5fff9c9 in postEventSourcePrepare (s=0xa2500db0, timeout=0xa2eff0bc) at kernel/qeventdispatcher_glib.cpp:256
#4  0xb1facde3 in g_main_context_prepare () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0xb1fad6ff in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#6  0xb1fad948 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#7  0xb5fffabf in QEventDispatcherGlib::processEvents (this=0xa2500468, flags=...) at kernel/qeventdispatcher_glib.cpp:426
#8  0xb5fcebc3 in QEventLoop::processEvents (this=this@entry=0xa2eff228, flags=...) at kernel/qeventloop.cpp:149
#9  0xb5fceee9 in QEventLoop::exec (this=this@entry=0xa2eff228, flags=...) at kernel/qeventloop.cpp:204
#10 0xb5ebdefd in QThread::exec (this=this@entry=0x9fb50e8) at thread/qthread.cpp:542
#11 0xb5faefc4 in QInotifyFileSystemWatcherEngine::run (this=0x9fb50e8) at io/qfilesystemwatcher_inotify.cpp:256
#12 0xb5ec07ef in QThreadPrivate::start (arg=0x9fb50e8) at thread/qthread_unix.cpp:338
#13 0xb20c2d78 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#14 0xb75913de in clone () from /lib/i386-linux-gnu/libc.so.6

Thread 1 (Thread 0xb1218740 (LWP 2551)):
[KCrash Handler]
#7  0xb67cc464 in GeneralId () from /usr/lib/libkdeui.so.5
#8  0xae7032c0 in agiName (i=i@entry=0xb55e4f8) at ../../../applets/icontasks/taskgroupitem.cpp:1260
#9  0xae705465 in TaskGroupItem::matchingItem (this=0xa164f28, from=from@entry=0xb41b1a0) at ../../../applets/icontasks/taskgroupitem.cpp:1278
#10 0xae7008ac in AbstractTaskItem::paint (this=0xb465ac8, painter=0xbfdad564, option=0x920df70) at ../../../applets/icontasks/abstracttaskitem.cpp:1232
#11 0xb5b4f232 in _q_paintItem (item=item@entry=0xb465ad0, painter=painter@entry=0xbfdad564, option=option@entry=0x920df70, widget=widget@entry=0x9d88d48, useWindowOpacity=useWindowOpacity@entry=true, painterStateProtection=painterStateProtection@entry=true) at graphicsview/qgraphicsscene.cpp:4335
#12 0xb5b60beb in QGraphicsScenePrivate::drawItemHelper (this=0x920de20, item=item@entry=0xb465ad0, painter=0xbfdad564, option=0x920df70, widget=0x9d88d48, painterStateProtection=true) at graphicsview/qgraphicsscene.cpp:4431
#13 0xb5b63a03 in QGraphicsScenePrivate::draw (this=0x920de20, item=0xb465ad0, painter=0xbfdad564, viewTransform=0xbfdad5e0, transformPtr=transformPtr@entry=0xbfdacb50, exposedRegion=0x9d8b064, widget=0x9d88d48, opacity=1, effectTransform=0x0, wasDirtyParentSceneTransform=false, drawItem=true) at graphicsview/qgraphicsscene.cpp:4966
#14 0xb5b64185 in QGraphicsScenePrivate::drawSubtreeRecursive (this=0x920de20, item=0xb465ad0, painter=0xbfdad564, viewTransform=0xbfdad5e0, exposedRegion=0x9d8b064, widget=0x9d88d48, parentOpacity=1, effectTransform=0x0) at graphicsview/qgraphicsscene.cpp:4857
#15 0xb5b63664 in QGraphicsScenePrivate::draw (this=0x920de20, item=0xa164f30, painter=0xbfdad564, viewTransform=0xbfdad5e0, transformPtr=transformPtr@entry=0xbfdacde0, exposedRegion=0x9d8b064, widget=0x9d88d48, opacity=1, effectTransform=0x0, wasDirtyParentSceneTransform=false, drawItem=true) at graphicsview/qgraphicsscene.cpp:4996
#16 0xb5b64185 in QGraphicsScenePrivate::drawSubtreeRecursive (this=0x920de20, item=0xa164f30, painter=0xbfdad564, viewTransform=0xbfdad5e0, exposedRegion=0x9d8b064, widget=0x9d88d48, parentOpacity=1, effectTransform=0x0) at graphicsview/qgraphicsscene.cpp:4857
#17 0xb5b63664 in QGraphicsScenePrivate::draw (this=0x920de20, item=0x95f97a0, painter=0xbfdad564, viewTransform=0xbfdad5e0, transformPtr=transformPtr@entry=0xbfdad070, exposedRegion=0x9d8b064, widget=0x9d88d48, opacity=1, effectTransform=0x0, wasDirtyParentSceneTransform=false, drawItem=true) at graphicsview/qgraphicsscene.cpp:4996
#18 0xb5b64185 in QGraphicsScenePrivate::drawSubtreeRecursive (this=0x920de20, item=0x95f97a0, painter=0xbfdad564, viewTransform=0xbfdad5e0, exposedRegion=0x9d8b064, widget=0x9d88d48, parentOpacity=1, effectTransform=0x0) at graphicsview/qgraphicsscene.cpp:4857
#19 0xb5b63664 in QGraphicsScenePrivate::draw (this=0x920de20, item=0x9644cf8, painter=0xbfdad564, viewTransform=0xbfdad5e0, transformPtr=transformPtr@entry=0xbfdad300, exposedRegion=0x9d8b064, widget=0x9d88d48, opacity=1, effectTransform=0x0, wasDirtyParentSceneTransform=false, drawItem=true) at graphicsview/qgraphicsscene.cpp:4996
#20 0xb5b64185 in QGraphicsScenePrivate::drawSubtreeRecursive (this=this@entry=0x920de20, item=0x9644cf8, painter=0xbfdad564, viewTransform=0xbfdad5e0, exposedRegion=0x9d8b064, widget=0x9d88d48, parentOpacity=parentOpacity@entry=1, effectTransform=effectTransform@entry=0x0) at graphicsview/qgraphicsscene.cpp:4857
#21 0xb5b648ee in QGraphicsScenePrivate::drawItems (this=0x920de20, painter=0xbfdad564, viewTransform=0xbfdad5e0, exposedRegion=0x9d8b064, widget=0x9d88d48) at graphicsview/qgraphicsscene.cpp:4739
#22 0xb5b85564 in QGraphicsView::paintEvent (this=<optimized out>, event=<optimized out>) at graphicsview/qgraphicsview.cpp:3471
#23 0xb5539535 in QWidget::event (this=this@entry=0xa2aaf38, event=event@entry=0xbfdadb38) at kernel/qwidget.cpp:8532
#24 0xb593eb3c in QFrame::event (this=this@entry=0xa2aaf38, e=e@entry=0xbfdadb38) at widgets/qframe.cpp:557
#25 0xb59cceb8 in QAbstractScrollArea::viewportEvent (this=this@entry=0xa2aaf38, e=e@entry=0xbfdadb38) at widgets/qabstractscrollarea.cpp:1043
#26 0xb5b84277 in QGraphicsView::viewportEvent (this=<optimized out>, event=<optimized out>) at graphicsview/qgraphicsview.cpp:2866
#27 0xb59cd136 in viewportEvent (event=0xbfdadb38, this=<optimized out>) at widgets/qabstractscrollarea_p.h:100
#28 QAbstractScrollAreaFilter::eventFilter (this=0x9fc5298, o=0x9d88d48, e=0xbfdadb38) at widgets/qabstractscrollarea_p.h:116
#29 0xb5fd021e in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=this@entry=0x9189fb8, receiver=receiver@entry=0x9d88d48, event=event@entry=0xbfdadb38) at kernel/qcoreapplication.cpp:1056
#30 0xb54dfd31 in QApplicationPrivate::notify_helper (this=0x9189fb8, receiver=0x9d88d48, e=0xbfdadb38) at kernel/qapplication.cpp:4563
#31 0xb54e6833 in QApplication::notify (this=0x91689c0, receiver=receiver@entry=0x9d88d48, e=e@entry=0xbfdadb38) at kernel/qapplication.cpp:4353
#32 0xb6641e24 in KApplication::notify (this=0x91689c0, receiver=0x9d88d48, event=0xbfdadb38) at ../../kdeui/kernel/kapplication.cpp:311
#33 0xb5fd00aa in QCoreApplication::notifyInternal (this=0x91689c0, receiver=0x9d88d48, event=0xbfdadb38) at kernel/qcoreapplication.cpp:946
#34 0xb5533261 in sendSpontaneousEvent (event=0xbfdadb38, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:234
#35 QWidgetPrivate::drawWidget (this=0x9da9470, pdev=0xa5893e8, rgn=..., offset=..., flags=4, sharedPainter=0x0, backingStore=0x9db0ec0) at kernel/qwidget.cpp:5598
#36 0xb5533d61 in QWidgetPrivate::paintSiblingsRecursive (this=this@entry=0x9d8ad18, pdev=0xa5893e8, siblings=..., index=<optimized out>, rgn=..., offset=..., flags=4, sharedPainter=0x0, backingStore=0x9db0ec0) at kernel/qwidget.cpp:5807
#37 0xb5532dfa in QWidgetPrivate::drawWidget (this=0x9d8ad18, pdev=0xa5893e8, rgn=..., offset=..., flags=flags@entry=5, sharedPainter=sharedPainter@entry=0x0, backingStore=backingStore@entry=0x9db0ec0) at kernel/qwidget.cpp:5651
#38 0xb571faed in QWidgetBackingStore::sync (this=0x9db0ec0) at painting/qbackingstore.cpp:1373
#39 0xb55277bb in QWidgetPrivate::syncBackingStore (this=this@entry=0x9d8ad18) at kernel/qwidget.cpp:1896
#40 0xb5538f7c in QWidget::event (this=this@entry=0xa2aaf38, event=event@entry=0xb5c4ff8) at kernel/qwidget.cpp:8679
#41 0xb593eb3c in QFrame::event (this=this@entry=0xa2aaf38, e=0xb5c4ff8) at widgets/qframe.cpp:557
#42 0xb59ccd7f in QAbstractScrollArea::event (this=this@entry=0xa2aaf38, e=e@entry=0xb5c4ff8) at widgets/qabstractscrollarea.cpp:996
#43 0xb5b8409c in QGraphicsView::event (this=0xa2aaf38, event=0xb5c4ff8) at graphicsview/qgraphicsview.cpp:2740
#44 0xb54dfd54 in QApplicationPrivate::notify_helper (this=0x9189fb8, receiver=0xa2aaf38, e=0xb5c4ff8) at kernel/qapplication.cpp:4567
#45 0xb54e6833 in QApplication::notify (this=0x91689c0, receiver=receiver@entry=0xa2aaf38, e=e@entry=0xb5c4ff8) at kernel/qapplication.cpp:4353
#46 0xb6641e24 in KApplication::notify (this=0x91689c0, receiver=0xa2aaf38, event=0xb5c4ff8) at ../../kdeui/kernel/kapplication.cpp:311
#47 0xb5fd00aa in QCoreApplication::notifyInternal (this=0x91689c0, receiver=receiver@entry=0xa2aaf38, event=event@entry=0xb5c4ff8) at kernel/qcoreapplication.cpp:946
#48 0xb5fd388d in sendEvent (event=0xb5c4ff8, receiver=0xa2aaf38) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#49 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0xa2aaf38, event_type=event_type@entry=77, data=0x911e130) at kernel/qcoreapplication.cpp:1570
#50 0xb5fd3d9c in QCoreApplication::sendPostedEvents (receiver=0xa2aaf38, event_type=event_type@entry=77) at kernel/qcoreapplication.cpp:1463
#51 0xb5b5818e in dispatchPendingUpdateRequests (this=0x9d8ad18) at ../../include/QtGui/private/../../../src/gui/graphicsview/qgraphicsview_p.h:200
#52 QGraphicsScenePrivate::_q_processDirtyItems (this=0x920de20) at graphicsview/qgraphicsscene.cpp:515
#53 0xb5b5b93b in QGraphicsScene::qt_static_metacall (_o=0xb6869220 <vtable for (anonymous namespace)::DelayedWindowEvent+8>, _id=190178552, _a=0xb333b50, _c=<optimized out>) at .moc/release-shared/moc_qgraphicsscene.cpp:107
#54 0xb5fe195a in QMetaCallEvent::placeMetaCall (this=0xb5cf850, object=0x91ee580) at kernel/qobject.cpp:524
#55 0xb5fe976b in QObject::event (this=this@entry=0x91ee580, e=e@entry=0xb5cf850) at kernel/qobject.cpp:1194
#56 0xb5b69e0f in QGraphicsScene::event (this=0x91ee580, event=0xb5cf850) at graphicsview/qgraphicsscene.cpp:3565
#57 0xb54dfd54 in QApplicationPrivate::notify_helper (this=0x9189fb8, receiver=0x91ee580, e=0xb5cf850) at kernel/qapplication.cpp:4567
#58 0xb54e6833 in QApplication::notify (this=0x91689c0, receiver=receiver@entry=0x91ee580, e=e@entry=0xb5cf850) at kernel/qapplication.cpp:4353
#59 0xb6641e24 in KApplication::notify (this=0x91689c0, receiver=0x91ee580, event=0xb5cf850) at ../../kdeui/kernel/kapplication.cpp:311
#60 0xb5fd00aa in QCoreApplication::notifyInternal (this=0x91689c0, receiver=receiver@entry=0x91ee580, event=event@entry=0xb5cf850) at kernel/qcoreapplication.cpp:946
#61 0xb5fd388d in sendEvent (event=0xb5cf850, receiver=0x91ee580) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#62 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x911e130) at kernel/qcoreapplication.cpp:1570
#63 0xb5fd3d9c in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1463
#64 0xb600014e in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#65 postEventSourceDispatch (s=0x9189c60) at kernel/qeventdispatcher_glib.cpp:279
#66 0xb1fad4de in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#67 0xb1fad888 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#68 0xb1fad948 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#69 0xb5fffa9f in QEventDispatcherGlib::processEvents (this=this@entry=0x911eea8, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#70 0xb559497e in QGuiEventDispatcherGlib::processEvents (this=0x911eea8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#71 0xb5fd3ded in QCoreApplication::processEvents (flags=...) at kernel/qcoreapplication.cpp:1133
#72 0xb2145a9c in ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-qt.so.2
#73 0xb2148d30 in DBusMenuImporter::slotMenuAboutToShow() () from /usr/lib/i386-linux-gnu/libdbusmenu-qt.so.2
#74 0xb214cbb0 in ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-qt.so.2
#75 0xb5fe51a7 in QMetaObject::activate (sender=sender@entry=0xb5cae88, m=m@entry=0xb5e3fb94 <QMenu::staticMetaObject>, local_signal_index=local_signal_index@entry=0, argv=argv@entry=0x0) at kernel/qobject.cpp:3539
#76 0xb597da75 in QMenu::aboutToShow (this=0xb5cae88) at .moc/release-shared/moc_qmenu.cpp:165
#77 0xb5984918 in QMenu::qt_static_metacall (_o=<optimized out>, _id=<optimized out>, _a=0xbfdaecb4, _c=<optimized out>) at .moc/release-shared/moc_qmenu.cpp:74
#78 0xb5fd8b84 in QMetaMethod::invoke (this=this@entry=0xbfdaedd4, object=0xb5cae88, connectionType=<optimized out>, returnValue=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., val7=..., val8=..., val9=...) at kernel/qmetaobject.cpp:1664
#79 0xb5fdb163 in QMetaObject::invokeMethod (obj=0xb5cae88, member=0xb2154120 "aboutToShow", type=Qt::AutoConnection, ret=..., val0=..., val1=..., val2=..., val3=..., val4=..., val5=..., val6=..., val7=..., val8=..., val9=...) at kernel/qmetaobject.cpp:1179
#80 0xb214643f in DBusMenuImporter::updateMenu() () from /usr/lib/i386-linux-gnu/libdbusmenu-qt.so.2
#81 0xb214cb88 in ?? () from /usr/lib/i386-linux-gnu/libdbusmenu-qt.so.2
#82 0xb5fe195a in QMetaCallEvent::placeMetaCall (this=0xb5c1da8, object=0xb5cf630) at kernel/qobject.cpp:524
#83 0xb5fe976b in QObject::event (this=0xb5cf630, e=0xb5c1da8) at kernel/qobject.cpp:1194
#84 0xb54dfd54 in QApplicationPrivate::notify_helper (this=0x9189fb8, receiver=0xb5cf630, e=0xb5c1da8) at kernel/qapplication.cpp:4567
#85 0xb54e6833 in QApplication::notify (this=0x91689c0, receiver=receiver@entry=0xb5cf630, e=e@entry=0xb5c1da8) at kernel/qapplication.cpp:4353
#86 0xb6641e24 in KApplication::notify (this=0x91689c0, receiver=0xb5cf630, event=0xb5c1da8) at ../../kdeui/kernel/kapplication.cpp:311
#87 0xb5fd00aa in QCoreApplication::notifyInternal (this=0x91689c0, receiver=receiver@entry=0xb5cf630, event=event@entry=0xb5c1da8) at kernel/qcoreapplication.cpp:946
#88 0xb5fd388d in sendEvent (event=0xb5c1da8, receiver=0xb5cf630) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:231
#89 QCoreApplicationPrivate::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0, data=0x911e130) at kernel/qcoreapplication.cpp:1570
#90 0xb5fd3d9c in QCoreApplication::sendPostedEvents (receiver=receiver@entry=0x0, event_type=event_type@entry=0) at kernel/qcoreapplication.cpp:1463
#91 0xb600014e in sendPostedEvents () at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:236
#92 postEventSourceDispatch (s=0x9189c60) at kernel/qeventdispatcher_glib.cpp:279
#93 0xb1fad4de in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#94 0xb1fad888 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#95 0xb1fad948 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#96 0xb5fffa9f in QEventDispatcherGlib::processEvents (this=this@entry=0x911eea8, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#97 0xb559497e in QGuiEventDispatcherGlib::processEvents (this=0x911eea8, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#98 0xb5fcebc3 in QEventLoop::processEvents (this=this@entry=0xbfdaf648, flags=...) at kernel/qeventloop.cpp:149
#99 0xb5fceee9 in QEventLoop::exec (this=this@entry=0xbfdaf648, flags=...) at kernel/qeventloop.cpp:204
#100 0xb5fd4a7e in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1218
#101 0xb54ddf84 in QApplication::exec () at kernel/qapplication.cpp:3828
#102 0xb76aa927 in kdemain (argc=1, argv=0xbfdaf7e4) at ../../../../plasma/desktop/shell/main.cpp:126
#103 0x0804855b in main (argc=1, argv=0xbfdaf7e4) at plasma-desktop_dummy.cpp:3

Reported using DrKonqi