[SOLVED] QT bug in QStyleSheetStyle() found!

mkae

This is a bug which I am hunting after since quite a while: When clicking on the Authors tab in an About dialog box a QT application would crash.

This has been first described here in "this thread":http://developer.qt.nokia.com/forums/viewthread/6725 .

Here are links with the complete bug history on Linux and MacOSX:

Linux distros running QT with KDE 4.6.3 Gentoo and KDE 4.7.0 Archlinux on "b.k.o":https://bugs.kde.org/show_bug.cgi?id=278157
Mac OS X with KDE 4.6.x up to KDE 4.7.0 on "b.k.o":https://bugs.kde.org/show_bug.cgi?id=276066 and "MacPort's trac":http://trac.macports.org/ticket/28410

Since "I had already filed a bug at QTbug":https://bugreports.qt.nokia.com/browse/QTBUG-19872 , I'll update that as well.

Here is Cristian Onet's final analysis:

@New crash information added by DrKonqi

kmymoney (4.5.96-svn1241546) on KDE Platform 4.7.40 (4.7.40 (KDE 4.8 >=
200110623) using Qt 4.7.1

From the stack trace it is clear that the code from
KAboutApplicationPersonListDelegate::paint
style->drawPrimitive(QStyle::PE_Widget, &option, painter, 0);
causes a crash in Qt when a custom stylesheet is used by the application.
This is because in static QWidget *containerWidget(const QWidget *w) from
qstylesheetstyle.cpp w is used without checking if it's 0. Although this is
Qt's fault not KDE's.

-- Backtrace (Reduced):
#6 0x00007f6002a931c8 in QScopedPointer<QObjectData,
QScopedPointerDeleter<QObjectData> >::operator-> (this=0x8) at
/home/kde-devel/qt4/include/QtCore/qscopedpointer.h:112
#7 0x00007f6002a92f96 in QObject::parent (this=0x0) at
/home/kde-devel/qt4/include/QtCore/qobject.h:250
#8 0x00007f6002aa7e76 in QWidget::parentWidget (this=0x0) at
/home/kde-devel/qt4/include/QtGui/qwidget.h:1022
#9 0x00007f6002ee78e8 in containerWidget (w=0x0) at
/home/kde-devel/kdesrc/qt-copy/src/gui/styles/qstylesheetstyle.cpp:2380
#10 0x00007f6002ef5e68 in QStyleSheetStyle::drawPrimitive (this=0xd8e470,
pe=QStyle::PE_Widget, opt=0x7fff605e8a70, p=0x7fff605e8c00, w=0x0) at
/home/kde-devel/kdesrc/qt-copy/src/gui/styles/qstylesheetstyle.cpp:4252@

giesbert

Hi mkae,

can you please use a more describing header? this is quite general.

mkae

Thanks for the hint, Gerolf! :-)

giesbert

I am sure, it's not a standard Qt dialog, right?
Because I know no authors tab in an about dialog... :-)

mkae

Well, it's a dialog created with the KDE framework.

mkae

Marked as resolved. See here: http://developer.qt.nokia.com/forums/viewthread/6725