Details
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Bug
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Resolution: Cannot Reproduce
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P2: Important
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None
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5.2.1, 5.3.2, 5.4.2, 5.5.0
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None
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Mageia Linux Cauldron x86_64
Description
This program crashes due to failed assert:
import QtQuick 2.2 import QtQuick.Window 2.1 import QtQuick.Controls 1.1 Window { id: main property string text: "Test text" visible: true Loader { id: categoryLoader anchors.centerIn: parent sourceComponent: labelComponent Component { id: labelComponent Row { spacing: 10 Label { anchors.verticalCenter: parent.verticalCenter text: main.text } Button { anchors.verticalCenter: parent.verticalCenter text: "Edit" onClicked: categoryLoader.sourceComponent = editorComponent } } } Component { id: editorComponent TextField { text: main.text onEditingFinished: { main.text = text categoryLoader.sourceComponent = labelComponent } } } } }
To reproduce, click on "Edit" button, change some text and press Enter.
I cannot reproduce it with official Qt binaries, only if I compile Qt on my own and only if I configure Qt with -debug or -developer-build. With -release the program works fine.
Stack trace:
0 raise 0x7ffff54c8627 1 abort 0x7ffff54c9dba 2 qt_message_fatal qlogging.cpp 1575 0x7ffff65c42f2 3 QMessageLogger::fatal qlogging.cpp 777 0x7ffff65c0a5e 4 qt_assert qglobal.cpp 2967 0x7ffff65b9cd6 5 QQuickItemPrivate::removeChild qquickitem.cpp 2735 0x7ffff7a6f149 6 QQuickItem::setParentItem qquickitem.cpp 2513 0x7ffff7a6e4f0 7 QQuickLoaderPrivate::clear qquickloader.cpp 110 0x7ffff7b6a016 8 QQuickLoader::setSourceComponent qquickloader.cpp 463 0x7ffff7b6a810 9 QQuickLoader::qt_static_metacall moc_qquickloader_p.cpp 250 0x7ffff7b6c0b6 10 QQuickLoader::qt_metacall moc_qquickloader_p.cpp 301 0x7ffff7b6c24d 11 QMetaObject::metacall qmetaobject.cpp 296 0x7ffff68075ff 12 QQmlPropertyPrivate::write qqmlproperty.cpp 1329 0x7ffff6e38de1 13 QV4::QObjectWrapper::setProperty qv4qobjectwrapper.cpp 556 0x7ffff6de1ba3 14 QV4::QObjectWrapper::setQmlProperty qv4qobjectwrapper.cpp 443 0x7ffff6de08ce 15 QV4::QObjectWrapper::put qv4qobjectwrapper.cpp 708 0x7ffff6de2641 16 QV4::Object::put qv4object_p.h 280 0x7ffff6cb950d 17 QV4::Runtime::setProperty qv4runtime.cpp 567 0x7ffff6e00972 18 QV4::Moth::VME::run qv4vme_moth.cpp 496 0x7ffff6deedfb 19 QV4::Moth::VME::exec qv4vme_moth.cpp 925 0x7ffff6df2e02 20 QV4::ScriptFunction::call qv4functionobject.cpp 458 0x7ffff6d7cc6d 21 QV4::Object::call qv4object_p.h 302 0x7ffff6cb95da 22 QQmlJavaScriptExpression::evaluate qqmljavascriptexpression.cpp 158 0x7ffff6eb753c 23 QQmlBoundSignalExpression::evaluate qqmlboundsignal.cpp 281 0x7ffff6e4b0c7 24 QQmlBoundSignal_callback qqmlboundsignal.cpp 408 0x7ffff6e4b710 25 QQmlNotifier::emitNotify qqmlnotifier.cpp 73 0x7ffff6e96ca7 26 QQmlData::signalEmitted qqmlengine.cpp 751 0x7ffff6e1fb4c 27 QMetaObject::activate qobject.cpp 3604 0x7ffff683c828 28 QQmlVMEMetaObject::activate qqmlvmemetaobject.cpp 1325 0x7ffff6e1c062 29 QQmlVMEMetaObject::metaCall qqmlvmemetaobject.cpp 914 0x7ffff6e1a052 30 QAbstractDynamicMetaObject::metaCall qobject_p.h 421 0x7ffff6bddea4 31 QMetaObject::metacall qmetaobject.cpp 294 0x7ffff68075df 32 QQmlObjectOrGadget::metacall qqmlpropertycache.cpp 1689 0x7ffff6e90b54 33 CallMethod qv4qobjectwrapper.cpp 1178 0x7ffff6de3de6 34 CallPrecise qv4qobjectwrapper.cpp 1413 0x7ffff6de47bf 35 QV4::QObjectMethod::callInternal qv4qobjectwrapper.cpp 1898 0x7ffff6de6f5f 36 QV4::QObjectMethod::call qv4qobjectwrapper.cpp 1833 0x7ffff6de6951 37 QV4::Object::call qv4object_p.h 302 0x7ffff6cb95da 38 QV4::Runtime::callProperty qv4runtime.cpp 974 0x7ffff6e0327e 39 QV4::Moth::VME::run qv4vme_moth.cpp 556 0x7ffff6def56d 40 QV4::Moth::VME::exec qv4vme_moth.cpp 925 0x7ffff6df2e02 41 QV4::ScriptFunction::call qv4functionobject.cpp 458 0x7ffff6d7cc6d 42 QV4::Object::call qv4object_p.h 302 0x7ffff6cb95da 43 QQmlJavaScriptExpression::evaluate qqmljavascriptexpression.cpp 158 0x7ffff6eb753c 44 QQmlBoundSignalExpression::evaluate qqmlboundsignal.cpp 281 0x7ffff6e4b0c7 45 QQmlBoundSignal_callback qqmlboundsignal.cpp 408 0x7ffff6e4b710 46 QQmlNotifier::emitNotify qqmlnotifier.cpp 73 0x7ffff6e96ca7 47 QQmlData::signalEmitted qqmlengine.cpp 751 0x7ffff6e1fb4c 48 QMetaObject::activate qobject.cpp 3604 0x7ffff683c828 49 QMetaObject::activate qobject.cpp 3583 0x7ffff683c62e 50 QQuickTextInput::editingFinished moc_qquicktextinput_p.cpp 1156 0x7ffff7c1cc65 51 QQuickTextInputPrivate::processKeyEvent qquicktextinput.cpp 4270 0x7ffff7b05db9 52 QQuickTextInput::keyPressEvent qquicktextinput.cpp 1522 0x7ffff7afb110 53 QQuickItemPrivate::deliverKeyEvent qquickitem.cpp 4649 0x7ffff7a7413b 54 QQuickItem::event qquickitem.cpp 7251 0x7ffff7a7a43c 55 QQuickTextInput::event qquicktextinput.cpp 1730 0x7ffff7afbd2f 56 QCoreApplicationPrivate::notify_helper qcoreapplication.cpp 1093 0x7ffff67fed2a 57 QCoreApplication::notify qcoreapplication.cpp 1038 0x7ffff67fea0c 58 QGuiApplication::notify qguiapplication.cpp 1537 0x7ffff727cf3e 59 QCoreApplication::notifyInternal qcoreapplication.cpp 965 0x7ffff67fe916 60 QCoreApplication::sendEvent qcoreapplication.h 224 0x7ffff7a7e7dd 61 QQuickWindow::sendEvent qquickwindow.cpp 2594 0x7ffff7a973eb 62 QQuickWindowPrivate::deliverKeyEvent qquickwindow.cpp 1443 0x7ffff7a9075a 63 QQuickWindow::keyPressEvent qquickwindow.cpp 1421 0x7ffff7a90673 64 QWindow::event qwindow.cpp 1989 0x7ffff728d8c9 65 QQuickWindow::event qquickwindow.cpp 1414 0x7ffff7a9063e 66 QCoreApplicationPrivate::notify_helper qcoreapplication.cpp 1093 0x7ffff67fed2a 67 QCoreApplication::notify qcoreapplication.cpp 1038 0x7ffff67fea0c 68 QGuiApplication::notify qguiapplication.cpp 1537 0x7ffff727cf3e 69 QCoreApplication::notifyInternal qcoreapplication.cpp 965 0x7ffff67fe916 70 QCoreApplication::sendSpontaneousEvent qcoreapplication.h 227 0x7ffff72848f9 71 QGuiApplicationPrivate::processKeyEvent qguiapplication.cpp 1899 0x7ffff727e356 72 QGuiApplicationPrivate::processWindowSystemEvent qguiapplication.cpp 1588 0x7ffff727d0dc 73 QWindowSystemInterface::sendWindowSystemEvents qwindowsysteminterface.cpp 608 0x7ffff72658b1 74 userEventSourceDispatch qeventdispatcher_glib.cpp 70 0x7fffe9d6f510 75 g_main_context_dispatch 0x7ffff3b370bd 76 g_main_context_iterate.isra 0x7ffff3b37368 77 g_main_context_iteration 0x7ffff3b3740c 78 QEventDispatcherGlib::processEvents qeventdispatcher_glib.cpp 418 0x7ffff6874381 79 QPAEventDispatcherGlib::processEvents qeventdispatcher_glib.cpp 115 0x7fffe9d6f732 80 QEventLoop::processEvents qeventloop.cpp 128 0x7ffff67fb516 81 QEventLoop::exec qeventloop.cpp 204 0x7ffff67fb7ef 82 QCoreApplication::exec qcoreapplication.cpp 1229 0x7ffff67feff0 83 QGuiApplication::exec qguiapplication.cpp 1528 0x7ffff727ceee 84 main main.cpp 11 0x400e97
Doing some research, I found possible source of the problem.
In QQuickLoaderPrivate::clear() it calls item->setParentItem(0). In QQuickItem::setParentItem() it calls clearFocusInScope() for QQuickWindowPrivate and maybe in other thread the loader object is changed and it has new item property. When setParentItem() continues execution, it tries to remove oneself from parent's children list using pointer to parent. But the pointer now leads to a different item which has different children list and this fails assert.
Possible fix:
--- src/quick/items/qquickitem.cpp
+++ src/quick/items/qquickitem.cpp
@@ -2510,7 +2510,9 @@ void QQuickItem::setParentItem(QQuickItem *parentItem)
}
const bool wasVisible = isVisible();
- op->removeChild(this);
+ if (op->childItems.contains(this)) {
+ op->removeChild(this);
+ }
if (wasVisible) {
emit oldParentItem->visibleChildrenChanged();
}
This looks more like a hack, so may be it should be fixed in a different way.