diff options
author | Jian Liang <jianliang79@gmail.com> | 2013-12-14 10:59:35 +0800 |
---|---|---|
committer | The Qt Project <gerrit-noreply@qt-project.org> | 2013-12-24 02:56:41 +0100 |
commit | 8fcab70408628f730860d3861a06fc519d069f5e (patch) | |
tree | eb0aa24e05cd717cecaa5f22bb932142e0e7de27 /tests/auto | |
parent | 0e1ce36ae67de940b2d499ec7f23e520dce0f112 (diff) |
Avoid crash due to accessing deleted QWidgetWindow object
Change childWidget->windowHandle() to childWidget->internalWinId() in
q_createNativeChildrenAndSetParent() to determine whether should we call
childWidget->winId().
This is because in some circumstances Qt will crash due to accessing
deleted QWidgetWindow object if we use windowHandle(). Think about the
following scenario:
1) create a widget A without parent and add two child widgets B and C to A
2) create a native widget D as the child of B, note that when we set
Qt::WA_NativeWindow attribute to it, its QWidgetWindow will be created
which means its windowHandle() is not null.
3) create a top level widget E as the child of C and show it. This will
make Qt call createWinId() to A and then
q_createNativeChildrenAndSetParent() will be called to create A's native
children recursively and finally make D's QWidgetWindow object become a
child of A's QWidgetWindow object. Please note here that B will not become
a native widget just because at that moment windowHandle() of D is not
null and Qt will not call winId() to its parent B
4) Set A's parent to another widget which has been shown, setParent_sys()
will be called to A and then Qt will call destroy() to A. in destroy() Qt
will try to call destroy() to its children recursively with a condition that
the child has Qt::WA_NativeWindow been set. But D's parent B is not a native
widget right now so B and D is not destroyed. Qt will then deleted the
QWidgetWindow object of A, since E's QWidgetWindow object is a child of
A's QWidgetWindow object, it will also be deleted. Now E hold a deleted
pointer of QWidgetWindow object. This is the source of crash later.
Task-number: QTBUG-35600
Change-Id: I97a20a68e626ee62b15bb4eae580e26f8948923b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Diffstat (limited to 'tests/auto')
-rw-r--r-- | tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp b/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp index 1bbbfd610e..d6b7fc20ed 100644 --- a/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp +++ b/tests/auto/widgets/kernel/qwidget_window/tst_qwidget_window.cpp @@ -94,6 +94,8 @@ private slots: #ifndef QT_NO_DRAGANDDROP void tst_dnd(); #endif + + void tst_qtbug35600(); }; void tst_QWidget_window::initTestCase() @@ -568,5 +570,33 @@ void tst_QWidget_window::tst_dnd() } #endif +void tst_QWidget_window::tst_qtbug35600() +{ + QWidget w; + w.show(); + + QWidget *wA = new QWidget; + QHBoxLayout *layoutA = new QHBoxLayout; + + QWidget *wB = new QWidget; + layoutA->addWidget(wB); + + QWidget *wC = new QWidget; + layoutA->addWidget(wC); + + wA->setLayout(layoutA); + + QWidget *wD = new QWidget; + wD->setAttribute(Qt::WA_NativeWindow); + wD->setParent(wB); + + QWidget *wE = new QWidget(wC, Qt::Tool | Qt::FramelessWindowHint | Qt::WindowTransparentForInput); + wE->show(); + + wA->setParent(&w); + + // QTBUG-35600: program may crash here or on exit +} + QTEST_MAIN(tst_QWidget_window) #include "tst_qwidget_window.moc" |