Application: kdevelop (4.0.2 (using KDevPlatform 1.0.2))
KDE Platform Version: 4.5.5 (KDE 4.5.5)
Qt Version: 4.7.0
Operating System: Linux 2.6.35-31-generic x86_64
Distribution: Ubuntu 10.10

-- Information about the crash:
Open KDevelop.
Do nothing.
Close KDevelop.

Crash.

Everything else about the IDE does seem to work fine, and thanks for it, it's just that for me it's segfaulting on close for some reason. Reproduced 100% of the time.

The crash can be reproduced every time.

-- Backtrace:
Application: KDevelop (kdevelop.bin), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fb7c8b2e760 (LWP 5937))]

Thread 9 (Thread 0x7fb7b817f700 (LWP 5939)):
#0  0x00007fb7c5f7f7f3 in __poll (fds=<value optimized out>, nfds=<value optimized out>, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007fb7bf78b009 in ?? () from /lib/libglib-2.0.so.0
#2  0x00007fb7bf78b7b5 in g_main_loop_run () from /lib/libglib-2.0.so.0
#3  0x00007fb7b88b63c4 in ?? () from /usr/lib/libgio-2.0.so.0
#4  0x00007fb7bf7b07e4 in ?? () from /lib/libglib-2.0.so.0
#5  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#6  0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 8 (Thread 0x7fb7aad0f700 (LWP 5940)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:212
#1  0x00007fb7c728cda2 in wait (this=<value optimized out>, mutex=0x1a29600, time=200000) at thread/qwaitcondition_unix.cpp:86
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x1a29600, time=200000) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7c2996c6e in KDevelop::DUChainPrivate::CleanupThread::run (this=0x1a295e0) at ../../language/duchain/duchain.cpp:286
#4  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x1a295e0) at thread/qthread_unix.cpp:266
#5  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#6  0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 7 (Thread 0x7fb79b806700 (LWP 5974)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x2b12f70, th=0x2af1f40) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x2af1f40) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x2af1f40) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#6  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x2af1f40) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#7  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb79b805e00, parent=0x2b12f70, th=0x2af1f40) at ../../../threadweaver/Weaver/Thread.cpp:87
#8  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x2af1f40) at ../../../threadweaver/Weaver/Thread.cpp:142
#9  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x2af1f40) at thread/qthread_unix.cpp:266
#10 0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#11 0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 6 (Thread 0x7fb7984d2700 (LWP 6053)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x19ab120, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x19ab120, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x19aa5c0, th=0x29e44b0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x19ab240, th=0x29e44b0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x19ab240, th=0x29e44b0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#6  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb7984d1e00, parent=0x19aa5c0, th=0x29e44b0) at ../../../threadweaver/Weaver/Thread.cpp:87
#7  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x29e44b0) at ../../../threadweaver/Weaver/Thread.cpp:142
#8  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x29e44b0) at thread/qthread_unix.cpp:266
#9  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#10 0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 5 (Thread 0x7fb797cd1700 (LWP 6054)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x19ab120, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x19ab120, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x19aa5c0, th=0x7fb7a48c06a0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x19ab240, th=0x7fb7a48c06a0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb797cd0e00, parent=0x19aa5c0, th=0x7fb7a48c06a0) at ../../../threadweaver/Weaver/Thread.cpp:87
#6  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x7fb7a48c06a0) at ../../../threadweaver/Weaver/Thread.cpp:142
#7  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x7fb7a48c06a0) at thread/qthread_unix.cpp:266
#8  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#9  0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#10 0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7fb78f907700 (LWP 6059)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x2b12f70, th=0x3857780) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3857780) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3857780) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#6  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3857780) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#7  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3857780) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#8  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb78f906e00, parent=0x2b12f70, th=0x3857780) at ../../../threadweaver/Weaver/Thread.cpp:87
#9  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x3857780) at ../../../threadweaver/Weaver/Thread.cpp:142
#10 0x00007fb7c728c27e in QThreadPrivate::start (arg=0x3857780) at thread/qthread_unix.cpp:266
#11 0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#12 0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#13 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7fb78f106700 (LWP 6060)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x2b12f70, th=0x3943b80) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3943b80) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb78f105e00, parent=0x2b12f70, th=0x3943b80) at ../../../threadweaver/Weaver/Thread.cpp:87
#6  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x3943b80) at ../../../threadweaver/Weaver/Thread.cpp:142
#7  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x3943b80) at thread/qthread_unix.cpp:266
#8  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#9  0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#10 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fb78e905700 (LWP 6164)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007fb7c728ce3b in wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:88
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x2af1a40, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:160
#3  0x00007fb7bd565524 in ThreadWeaver::WeaverImpl::blockThreadUntilJobsAreBeingAssigned (this=0x2b12f70, th=0x3a387a0) at ../../../threadweaver/Weaver/WeaverImpl.cpp:365
#4  0x00007fb7bd56872b in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3a387a0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:71
#5  0x00007fb7bd568744 in ThreadWeaver::WorkingHardState::applyForWork (this=0x2af1b20, th=0x3a387a0) at ../../../threadweaver/Weaver/WorkingHardState.cpp:74
#6  0x00007fb7bd566c9f in ThreadWeaver::ThreadRunHelper::run (this=0x7fb78e904e00, parent=0x2b12f70, th=0x3a387a0) at ../../../threadweaver/Weaver/Thread.cpp:87
#7  0x00007fb7bd5671f8 in ThreadWeaver::Thread::run (this=0x3a387a0) at ../../../threadweaver/Weaver/Thread.cpp:142
#8  0x00007fb7c728c27e in QThreadPrivate::start (arg=0x3a387a0) at thread/qthread_unix.cpp:266
#9  0x00007fb7c5c8f971 in start_thread (arg=<value optimized out>) at pthread_create.c:304
#10 0x00007fb7c5f8bf3d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fb7c8b2e760 (LWP 5937)):
[KCrash Handler]
#6  0x00007fb7c7ffef45 in ProvidersModel::data (this=<value optimized out>, index=<value optimized out>, role=<value optimized out>) at ../../shell/documentationview.cpp:51
#7  0x00007fb7c6ad684c in QComboBoxPrivate::itemText (this=0x28eb170, index=...) at widgets/qcombobox.cpp:1270
#8  0x00007fb7c6ad69e6 in QComboBox::currentText (this=<value optimized out>) at widgets/qcombobox.cpp:2039
#9  0x00007fb7c6ad74f6 in QComboBox::initStyleOption (this=0x28eb040, option=0x7fffb60ec4a0) at widgets/qcombobox.cpp:1119
#10 0x00007fb7c6ad9f26 in QComboBoxPrivate::updateViewContainerPaletteAndOpacity (this=0x28eb170) at widgets/qcombobox.cpp:1078
#11 0x00007fb7c6adccb8 in QComboBox::changeEvent (this=0x28eb040, e=0x7fffb60eccf0) at widgets/qcombobox.cpp:2734
#12 0x00007fb7c673c838 in QWidget::event (this=0x28eb040, event=0x7fffb60eccf0) at kernel/qwidget.cpp:8477
#13 0x00007fb7c66e6fdc in QApplicationPrivate::notify_helper (this=0x1652bd0, receiver=0x28eb040, e=0x7fffb60eccf0) at kernel/qapplication.cpp:4396
#14 0x00007fb7c66ecaed in QApplication::notify (this=0x7fffb60ee300, receiver=0x28eb040, e=0x7fffb60eccf0) at kernel/qapplication.cpp:4277
#15 0x00007fb7c78d6586 in KApplication::notify (this=0x7fffb60ee300, receiver=0x28eb040, event=0x7fffb60eccf0) at ../../kdeui/kernel/kapplication.cpp:310
#16 0x00007fb7c737fcdc in QCoreApplication::notifyInternal (this=0x7fffb60ee300, receiver=0x28eb040, event=0x7fffb60eccf0) at kernel/qcoreapplication.cpp:732
#17 0x00007fb7c67389a5 in sendEvent (this=0x28eb170) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#18 QWidgetPrivate::propagatePaletteChange (this=0x28eb170) at kernel/qwidget.cpp:1870
#19 0x00007fb7c6738b63 in QWidgetPrivate::setPalette_helper (this=0x28eb170, palette=...) at kernel/qwidget.cpp:4614
#20 0x00007fb7c6738c09 in QWidgetPrivate::resolvePalette (this=0x28eb170) at kernel/qwidget.cpp:4604
#21 0x00007fb7c67463c7 in QWidget::setParent (this=0x28eb040, parent=0x0, f=) at kernel/qwidget.cpp:10018
#22 0x00007fb7c6746872 in QWidget::setParent (this=0x7fffb60ec3c0, parent=0x22a6678) at kernel/qwidget.cpp:9937
#23 0x00007fb7c67498e0 in QWidgetAction::releaseWidget (this=0x29028e0, widget=0x28eb040) at kernel/qwidgetaction.cpp:207
#24 0x00007fb7c6b8a953 in QToolBarLayout::~QToolBarLayout (this=0x28e88d0, __in_chrg=<value optimized out>) at widgets/qtoolbarlayout.cpp:101
#25 0x00007fb7c6742044 in QWidget::~QWidget (this=0x28e5c50, __in_chrg=<value optimized out>) at kernel/qwidget.cpp:1501
#26 0x00007fb7c79e42ae in KToolBar::~KToolBar (this=0x28e5c50, __in_chrg=<value optimized out>) at ../../kdeui/widgets/ktoolbar.cpp:728
#27 0x00007fb7c7391d5f in QObjectPrivate::deleteChildren (this=0x28e6780) at kernel/qobject.cpp:1957
#28 0x00007fb7c6742168 in QWidget::~QWidget (this=0x28e6410, __in_chrg=<value optimized out>) at kernel/qwidget.cpp:1589
#29 0x00007fb7c7f8db6a in DocumentationView::~DocumentationView (this=0x28e6410, __in_chrg=<value optimized out>) at ../../shell/documentationview.h:32
#30 0x00007fb7c7391d5f in QObjectPrivate::deleteChildren (this=0x3b589a0) at kernel/qobject.cpp:1957
#31 0x00007fb7c6742168 in QWidget::~QWidget (this=0x3b58930, __in_chrg=<value optimized out>) at kernel/qwidget.cpp:1589
#32 0x00007fb7c26c023e in ?? () from /usr/lib/libsublime.so.1
#33 0x00007fb7c7391d5f in QObjectPrivate::deleteChildren (this=0x234f420) at kernel/qobject.cpp:1957
#34 0x00007fb7c6742168 in QWidget::~QWidget (this=0x3a4d840, __in_chrg=<value optimized out>) at kernel/qwidget.cpp:1589
#35 0x00007fb7c26c655b in ?? () from /usr/lib/libsublime.so.1
#36 0x00007fb7c7391d5f in QObjectPrivate::deleteChildren (this=0x18d1dd0) at kernel/qobject.cpp:1957
#37 0x00007fb7c6742168 in QWidget::~QWidget (this=0x18d03e0, __in_chrg=<value optimized out>) at kernel/qwidget.cpp:1589
#38 0x00007fb7c79b5f55 in KMainWindow::~KMainWindow (this=0x18d03e0, __in_chrg=<value optimized out>) at ../../kdeui/widgets/kmainwindow.cpp:473
#39 0x00007fb7c26b2bb9 in Sublime::MainWindow::~MainWindow() () from /usr/lib/libsublime.so.1
#40 0x00007fb7c7f9e3ae in KDevelop::MainWindow::~MainWindow (this=0x18d03e0, __in_chrg=<value optimized out>, __vtt_parm=<value optimized out>) at ../../shell/mainwindow.cpp:128
#41 0x00007fb7c7391c08 in QObject::event (this=0x18d03e0, e=0x22a6678) at kernel/qobject.cpp:1202
#42 0x00007fb7c673c6df in QWidget::event (this=0x18d03e0, event=0x3b828d0) at kernel/qwidget.cpp:8646
#43 0x00007fb7c6b2441b in QMainWindow::event (this=0x18d03e0, event=0x3b828d0) at widgets/qmainwindow.cpp:1417
#44 0x00007fb7c79f3c93 in KXmlGuiWindow::event (this=0x7fffb60ec3c0, ev=0x22a6678) at ../../kdeui/xmlgui/kxmlguiwindow.cpp:132
#45 0x00007fb7c66e6fdc in QApplicationPrivate::notify_helper (this=0x1652bd0, receiver=0x18d03e0, e=0x3b828d0) at kernel/qapplication.cpp:4396
#46 0x00007fb7c66ecaed in QApplication::notify (this=0x7fffb60ee300, receiver=0x18d03e0, e=0x3b828d0) at kernel/qapplication.cpp:4277
#47 0x00007fb7c78d6586 in KApplication::notify (this=0x7fffb60ee300, receiver=0x18d03e0, event=0x3b828d0) at ../../kdeui/kernel/kapplication.cpp:310
#48 0x00007fb7c737fcdc in QCoreApplication::notifyInternal (this=0x7fffb60ee300, receiver=0x18d03e0, event=0x3b828d0) at kernel/qcoreapplication.cpp:732
#49 0x00007fb7c7382c22 in sendEvent (receiver=0x0, event_type=<value optimized out>, data=0xe0d110) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#50 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0xe0d110) at kernel/qcoreapplication.cpp:1373
#51 0x00007fb7c73ac653 in sendPostedEvents (s=0x1656740) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#52 postEventSourceDispatch (s=0x1656740) at kernel/qeventdispatcher_glib.cpp:277
#53 0x00007fb7bf787342 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#54 0x00007fb7bf78b2a8 in ?? () from /lib/libglib-2.0.so.0
#55 0x00007fb7bf78b45c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#56 0x00007fb7c73ac193 in QEventDispatcherGlib::processEvents (this=0xe0c8b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:415
#57 0x00007fb7c6799a4e in QGuiEventDispatcherGlib::processEvents (this=0x7fffb60ec3c0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#58 0x00007fb7c737ea02 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#59 0x00007fb7c737edec in QEventLoop::exec (this=0x7fffb60ee130, flags=) at kernel/qeventloop.cpp:201
#60 0x00007fb7c7382ebb in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1009
#61 0x00000000004085f7 in _start ()

Possible duplicates by query: bug 295161.

Reported using DrKonqi