Qt is crashing when showing this tooltip. Why?

kalos

My Qt application keeps on crashing when "this tooltip":http://www.qtcentre.org/attachment.php?attachmentid=4996&d=1280131546 is shown

To reproduce the problem just set a widget tooltip in the following way:

@QFile file ( "tooltip.txt" ) ;
file.open(QIODevice::ReadOnly);
QTextStream stream(&file);
QString tooltipText = stream.readAll();
file.close();

myWidget->setToolTip(tooltipText);@

I'm using the latest version of Qt (4.6.3) on Windows
I'm going to submit a bugreport, but in the meanwhile can anyone suggest me a solution to fix this crash problem?

Thanks in advance for your help

sabrog

It's strange, because with root rights i don't get crash and have Plastique style on widget. But without root rights i have Windows Classic style (Ubuntu) and crash with this errors:

<pre>
0x005354a3 in (anonymous namespace)::LineBreakHelper::adjustRightBearing (this=0xbfffdf18,
maxGlyphs=2147483647) at /var/tmp/qt-src/src/gui/text/qtextlayout.cpp:1692
</pre>

Something wrong here:

@ inline void adjustRightBearing()
{
if (currentPosition <= 0)
return;

        qreal rb;
        fontEngine->getGlyphBearings(currentGlyph(), 0, &amp;rb);
        rightBearing = qMin(QFixed(), QFixed::fromReal(rb));
    }@

kalos

For me too it is crashing in that function, and precisely when currentGlyph() is called.

tobias.hunger

Does it crash when using other styles (run the application with @appname -style STYLENAME@)? That would narrow the issue down to the style used:-)

Please consider filing a "bugreport":http://bugreports.qt.nokia.com/ providing as much information as possible.

kalos

where can I find the list of styles strings I can launch the application with?

tobias.hunger

That is indeed a bit tricky:-) The following piece of code dumps the names:

@#include <QtGui/QStyleFactory>
#include <QtCore/QtDebug>

int main(int, char *)
{
QStyleFactory *sf = new QStyleFactory;
qDebug() << sf->keys();
delete sf;
}
@

kalos

Thanks Tobias for the trick.

Well I tested the application against the following styles:

Windows
WindowsXP
Motif
CDE
Plastique
Cleanlooks

It crashes only with WindowsXP and Cleanlooks styles

tobias.hunger

Good... Please report a bug against those styles then.