Inconsistent QPainter behaviour

Running the test code below will show that the behavior of flat rects varies for Arcs and Ellipses.

For flat arcs, QPainter draws what appears to be a line which is the correct behavior. This is because the bounding rect for a flat rect is actually the flat rect adjusted in each coordinate direction by line width / 2.0. Therefore, the bounding rect is non-flat and accommodates the "mathematical" line exactly as it would be painted on a device. This also coincides with the definition of bounding rect painting behaviour
in QGraphicsItem.

For flat ellipses, QPainter does not draw what appears to be a line which is incorrect behavior.

Test code:
//---------------------------------------------------------
#include <QtGui>

class MyWidget : public QWidget
{
void paintEvent(QPaintEvent * event)

{ QPainter painter(this); QRect rect1(10, 10, 100, 100); painter.drawArc(rect1, 0, 180 * 16); QRect rect2(10, 70, 100, 0); painter.drawArc(rect2, 0, 180 * 16); QRect rect3(10, 80, 100, 100); painter.drawEllipse(rect3); QRect rect4(10, 190, 100, 0); painter.drawEllipse(rect4); }

};

int main(int argc, char * argv[])
{
QApplication app(argc, argv);
MyWidget widget;
widget.setGeometry(0, 0, 120, 200);
widget.show();
return app.exec();
}
//---------------------------------------------------------