Setting the QPen style to Qt::DashLine in the following example will cause the painting of the zoomed
clipped rect to not return.

This issue was reported on X11 and not reproduced on Windows

Example code:

QPen pen( Qt::gray );

pen.setStyle( Qt::DashLine );

QPoint offset(30, 30);
qreal zoom = 30.0;
QRectF rect(0, 0, 100, 100);
QPainter painter(this);
painter.translate( -offset );
painter.setRenderHint( QPainter::Antialiasing );
QRectF clipRect = event->rect().translated( offset );
painter.setClipRect( clipRect );
painter.scale( zoom, zoom );
painter.setPen( pen );
painter.drawRect( rect );