Crash in KDDockWidgets::DockWidgetInstantiator::isFocusedChanged

[msarehn]

Sometimes, although not reliably, KDDockWidgets (QtQuick backend) crashes when closing a DockWidget.

We've already had similar crashes before with 2.0. We've bumped to 2.1-dev because it includes b7db57c (Do not emit isFocusedChanged in a delayed manner) which improves the situation a little bit, but does not get rid of the crashes completely.

FWIW, we do have a commercial license for KDDW.

Details

Version: 2.1-dev commit 497f65f

Backtrace

Thread 1 "coreui" received signal SIGSEGV, Segmentation fault.
0x00007ffff2824dc1 in QObjectPrivate::maybeSignalConnected(unsigned int) const () from /opt/qt6/lib/libQt6Core.so.6
(gdb) bt
#0  0x00007ffff2824dc1 in QObjectPrivate::maybeSignalConnected(unsigned int) const () from /opt/qt6/lib/libQt6Core.so.6
#1  0x00007ffff2834ca8 in void doActivate<false>(QObject*, int, void**) () from /opt/qt6/lib/libQt6Core.so.6
#2  0x00007ffff6eb4f6e in KDDockWidgets::DockWidgetInstantiator::isFocusedChanged (this=0x5555563e7230, _t1=false)
    at /home/arehn/src/build-dcf-ecosystem-Menlo_Qt6_6_6_0-Debug/coreui/3rdparty/KDDockWidgets/src/kddockwidgets_autogen/5PJCAAPZ7B/moc_DockWidgetInstantiator.cpp:812
#3  0x00007ffff737b772 in KDDockWidgets::DockWidgetInstantiator::<lambda(bool)>::operator()(bool) const (__closure=0x555556251ea0, is=false)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtquick/DockWidgetInstantiator.cpp:228
#4  0x00007ffff73809b5 in std::_Function_handler<void(bool), KDDockWidgets::DockWidgetInstantiator::componentComplete()::<lambda(bool)> >::_M_invoke(const std::_Any_data &, bool &&) (__functor=..., __args#0=@0x7fffffffc524: false) at /usr/include/c++/9/bits/std_function.h:300
#5  0x00007ffff6f0ed38 in std::function<void (bool)>::operator()(bool) const (this=0x555556251ea0, __args#0=false)
    at /usr/include/c++/9/bits/std_function.h:688
#6  0x00007ffff6f0e4cd in KDBindings::Signal<bool>::Impl::emit (this=0x5555562519b0, p#0=false)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/3rdparty/kdbindings/signal.h:301
#7  0x00007ffff6f0e00b in KDBindings::Signal<bool>::emit (this=0x55555624d940, p#0=false)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/3rdparty/kdbindings/signal.h:494
#8  0x00007ffff7085b1d in KDDockWidgets::DockRegistry::setFocusedDockWidget (this=0x5555556b1bc0, dw=0x0)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/DockRegistry.cpp:123
#9  0x00007ffff70857db in KDDockWidgets::DockRegistry::onFocusedViewChanged (this=0x5555556b1bc0, view=
    std::shared_ptr<class KDDockWidgets::Core::View> (use count 3, weak count 1) = {...})
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/DockRegistry.cpp:111
#10 0x00007ffff70c1743 in std::__invoke_impl<void, void (KDDockWidgets::DockRegistry::*&)(std::shared_ptr<KDDockWidgets::Core::View>), KDDockWidgets::DockRegistry*&, std::shared_ptr<KDDockWidgets::Core::View> > (__f=
    @0x5555556b1e30: (void (KDDockWidgets::DockRegistry::*)(class KDDockWidgets::DockRegistry * const, class std::shared_ptr<KDDockWidgets::Core::View>)) 0x7ffff708547a <KDDockWidgets::DockRegistry::onFocusedViewChanged(std::shared_ptr<KDDockWidgets::Core::View>)>,
    __t=@0x5555556b1e40: 0x5555556b1bc0) at /usr/include/c++/9/bits/invoke.h:73
#11 0x00007ffff70b9bed in std::__invoke<void (KDDockWidgets::DockRegistry::*&)(std::shared_ptr<KDDockWidgets::Core::View>), KDDockWidgets::DockRegistry*&, std::shared_ptr<KDDockWidgets::Core::View> > (__fn=
    @0x5555556b1e30: (void (KDDockWidgets::DockRegistry::*)(class KDDockWidgets::DockRegistry * const, class std::shared_ptr<KDDockWidgets::Core::View>)) 0x7ffff708547a <KDDockWidgets::DockRegistry::onFocusedViewChanged(std::shared_ptr<KDDockWidgets::Core::View>)>)
    at /usr/include/c++/9/bits/invoke.h:95
#12 0x00007ffff70affcf in std::_Bind<void (KDDockWidgets::DockRegistry::*(KDDockWidgets::DockRegistry*, KDBindings::Private::placeholder<1>))(std::shared_ptr<KDDockWidgets::Core::View>)>::__call<void, std::shared_ptr<KDDockWidgets::Core::View>&&, 0ul, 1ul>(std::tuple<std::shared_ptr<KDDockWidgets::Core::View>&&>&&, std::_Index_tuple<0ul, 1ul>) (this=0x5555556b1e30, __args=...) at /usr/include/c++/9/functional:400
#13 0x00007ffff70a584b in std::_Bind<void (KDDockWidgets::DockRegistry::*(KDDockWidgets::DockRegistry*, KDBindings::Private::placeholder<1>))(std::shared_ptr<KDDockWidgets::Core::View>)>::operator()<std::shared_ptr<KDDockWidgets::Core::View>, void>(std::shared_ptr<KDDockWidgets::Core::View>&&) (this=0x5555556b1e30) at /usr/include/c++/9/functional:484
#14 0x00007ffff709ec5a in std::_Function_handler<void (std::shared_ptr<KDDockWidgets::Core::View>), std::_Bind<void (KDDockWidgets::DockRegistry::*(KDDockWidgets::DockRegistry*, KDBindings::Private::placeholder<1>))(std::shared_ptr<KDDockWidgets::Core::View>)> >::_M_invoke(std::_Any_data const&, std::shared_ptr<KDDockWidgets::Core::View>&&) (__functor=..., __args#0=...) at /usr/include/c++/9/bits/std_function.h:300
#15 0x00007ffff72a7bf5 in std::function<void (std::shared_ptr<KDDockWidgets::Core::View>)>::operator()(std::shared_ptr<KDDockWidgets::Core::View>) const (this=0x555555ba67e8, __args#0=std::shared_ptr<class KDDockWidgets::Core::View> (empty) = {...})
    at /usr/include/c++/9/bits/std_function.h:688
--Type <RET> for more, q to quit, c to continue without paging--
#16 0x00007ffff72a78e2 in KDBindings::Signal<std::shared_ptr<KDDockWidgets::Core::View> >::Impl::emit (this=0x5555556b1dd0,
    p#0=std::shared_ptr<class KDDockWidgets::Core::View> (use count 3, weak count 1) = {...})
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/3rdparty/kdbindings/signal.h:301
#17 0x00007ffff72a74e9 in KDBindings::Signal<std::shared_ptr<KDDockWidgets::Core::View> >::emit (this=0x5555556b1920,
    p#0=std::shared_ptr<class KDDockWidgets::Core::View> (use count 3, weak count 1) = {...})
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/3rdparty/kdbindings/signal.h:494
#18 0x00007ffff736d313 in KDDockWidgets::QtQuick::Platform::<lambda(QObject*)>::operator()(QObject *) const (__closure=0x5555556b50a0,
    obj=0x5555556f1680) at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtquick/Platform.cpp:90
#19 0x00007ffff736f715 in QtPrivate::FunctorCall<QtPrivate::IndexesList<0>, QtPrivate::List<QObject*>, void, KDDockWidgets::QtQuick::Platform::init()::<lambda(QObject*)> >::call(KDDockWidgets::QtQuick::Platform::<lambda(QObject*)> &, void **) (f=..., arg=0x7fffffffcb40)
    at /opt/qt6/include/QtCore/qobjectdefs_impl.h:137
#20 0x00007ffff736f64b in QtPrivate::Functor<KDDockWidgets::QtQuick::Platform::init()::<lambda(QObject*)>, 1>::call<QtPrivate::List<QObject*>, void>(KDDockWidgets::QtQuick::Platform::<lambda(QObject*)> &, void *, void **) (f=..., arg=0x7fffffffcb40)
    at /opt/qt6/include/QtCore/qobjectdefs_impl.h:339
#21 0x00007ffff736f5b6 in QtPrivate::QCallableObject<KDDockWidgets::QtQuick::Platform::init()::<lambda(QObject*)>, QtPrivate::List<QObject*>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=1, this_=0x5555556b5090, r=0x5555555b10d0, a=0x7fffffffcb40,
    ret=0x0) at /opt/qt6/include/QtCore/qobjectdefs_impl.h:522
#22 0x00007ffff2834df3 in void doActivate<false>(QObject*, int, void**) () from /opt/qt6/lib/libQt6Core.so.6
#23 0x00007ffff2f2feb6 in QGuiApplication::focusObjectChanged(QObject*) () from /opt/qt6/lib/libQt6Gui.so.6
#24 0x00007ffff2f397d2 in QGuiApplication::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /opt/qt6/lib/libQt6Gui.so.6
#25 0x00007ffff2835177 in void doActivate<false>(QObject*, int, void**) () from /opt/qt6/lib/libQt6Core.so.6
#26 0x00007ffff2f92b96 in QWindow::focusObjectChanged(QObject*) () from /opt/qt6/lib/libQt6Gui.so.6
#27 0x00007ffff1e09ab6 in QQuickDeliveryAgentPrivate::clearFocusInScope(QQuickItem*, QQuickItem*, Qt::FocusReason, QFlags<QQuickDeliveryAgentPrivate::FocusOption>) () from /opt/qt6/lib/libQt6Quick.so.6
#28 0x00007ffff1c66463 in QQuickItem::setParentItem(QQuickItem*) () from /opt/qt6/lib/libQt6Quick.so.6
#29 0x00007ffff1c67343 in QQuickItem::~QQuickItem() () from /opt/qt6/lib/libQt6Quick.so.6
#30 0x00007ffff6ef3cf7 in KDDockWidgets::QtQuick::View::~View (this=0x555556280d10, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtquick/views/View.h:67
#31 0x00007ffff739a654 in KDDockWidgets::QtQuick::Group::~Group (this=0x555556280d10, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtquick/views/Group.cpp:66
#32 0x00007ffff739a6c4 in KDDockWidgets::QtQuick::Group::~Group (this=0x555556280d10, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtquick/views/Group.cpp:75
#33 0x00007ffff71fc62d in KDDockWidgets::Core::View::Private::free (this=0x5555563e43c0)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/View.cpp:100
#34 0x00007ffff71ef037 in KDDockWidgets::Core::Controller::~Controller (this=0x555555ba2fa0, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/Controller.cpp:37
#35 0x00007ffff7142fcc in KDDockWidgets::Core::Group::~Group (this=0x555555ba2fa0, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/Group.cpp:117
#36 0x00007ffff7143024 in KDDockWidgets::Core::Group::~Group (this=0x555555ba2fa0, __in_chrg=<optimized out>)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/Group.cpp:134
#37 0x00007ffff740abb3 in KDDockWidgets::Core::DelayedDelete::call (this=0x55555637fe40)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/core/DelayedCall.cpp:41
--Type <RET> for more, q to quit, c to continue without paging--
#38 0x00007ffff73ef037 in KDDockWidgets::QtCommon::Platform_qt::<lambda()>::operator()(void) const (__closure=0x5555560e2760)
    at /home/arehn/src/dcf-ecosystem/coreui/3rdparty/KDDockWidgets/src/qtcommon/Platform.cpp:330
#39 0x00007ffff73efbe2 in QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, KDDockWidgets::QtCommon::Platform_qt::runDelayed(int, KDDockWidgets::Core::DelayedCall*)::<lambda()> >::call(KDDockWidgets::QtCommon::Platform_qt::<lambda()> &, void **) (f=...,
    arg=0x555556bd72b8) at /opt/qt6/include/QtCore/qobjectdefs_impl.h:137
#40 0x00007ffff73efb8f in QtPrivate::Functor<KDDockWidgets::QtCommon::Platform_qt::runDelayed(int, KDDockWidgets::Core::DelayedCall*)::<lambda()>, 0>::call<QtPrivate::List<>, void>(KDDockWidgets::QtCommon::Platform_qt::<lambda()> &, void *, void **) (f=..., arg=0x555556bd72b8)
    at /opt/qt6/include/QtCore/qobjectdefs_impl.h:339
#41 0x00007ffff73efafa in QtPrivate::QCallableObject<KDDockWidgets::QtCommon::Platform_qt::runDelayed(int, KDDockWidgets::Core::DelayedCall*)::<lambda()>, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase *, QObject *, void **, bool *) (which=1, this_=0x5555560e2750,
    r=0x5555555b10d0, a=0x555556bd72b8, ret=0x0) at /opt/qt6/include/QtCore/qobjectdefs_impl.h:522
#42 0x00007ffff282696b in QObject::event(QEvent*) () from /opt/qt6/lib/libQt6Core.so.6
#43 0x00007ffff2f3cf13 in QGuiApplication::event(QEvent*) () from /opt/qt6/lib/libQt6Gui.so.6
#44 0x00007ffff27d645a in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /opt/qt6/lib/libQt6Core.so.6
#45 0x00007ffff27d9e35 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /opt/qt6/lib/libQt6Core.so.6
#46 0x00007ffff2a8e2e7 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () from /opt/qt6/lib/libQt6Core.so.6
#47 0x00007ffff00b317d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#48 0x00007ffff00b3400 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#49 0x00007ffff00b34a3 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#50 0x00007ffff2a8dbe8 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /opt/qt6/lib/libQt6Core.so.6
#51 0x00007ffff27e1e03 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /opt/qt6/lib/libQt6Core.so.6
#52 0x00007ffff27de3f6 in QCoreApplication::exec() () from /opt/qt6/lib/libQt6Core.so.6
#53 0x00007ffff6d62253 in guimain (args=...) at /home/arehn/src/dcf-ecosystem/coreui/src/coreui-shared.cpp:370
#54 0x0000555555563c50 in main (argc=4, argv=0x7fffffffe1a8) at /home/arehn/src/dcf-ecosystem/coreui/src/main.cpp:40

[iamsergio]

Hi,

Is it repro with the example ./bin/qtquick_dockwidgets ?
Which flags are you passing to Config::setFlags() ?

[msarehn]

Is it repro with the example ./bin/qtquick_dockwidgets ?

Nope.

Which flags are you passing to Config::setFlags() ?

None, we don't call this. Its at the default.

[iamsergio]

@msarehn I can't reproduce, but I understand why it happened. Should be fixed, please test latest 2.1 branch

[msarehn]

@iamsergio that was quick, thanks! I was going through the code and arrived at the same solution the very moment you've pushed the fix.

Works as intendend, doesn't crash anymore 👍