Problem with quadratic Bezier curve

A quadratic Bezier curve is not drown correctly with a combination of points and pen width. The issue can be reproduced with the Painter Paths Example by adding there the code below and modifying the penWidthSpinBox range to 0, 200 (penWidthSpinBox->setRange(0, 200); ).

QPainterPath bezierProblemPath;
bezierProblemPath.moveTo(29.5, 45.5);
bezierProblemPath.quadTo(31.5, 41, 32, 39);

QPainterPath bezierPath;
bezierPath.moveTo(29, 45);
bezierPath.quadTo(31, 41, 32, 39);

renderAreas.push_back(new RenderArea(bezierProblemPath));
renderAreas.push_back(new RenderArea(bezierPath));

When this modified example is run and the font size is set to 45, the curves will be as shown in the screenshot. The issue can be seen with the path on the left, the one on the right is drawn correctly.