Incorrect drawing QPainter::drawPolygon (drawPolyline) if drawing primitive that exceeds drawing area.

Example.

{ QPixmap Buffer(100, 100); QPainter painter; painter.begin(&Buffer); painter.setPen(QPen(Qt::red)); painter.setBrush(QBrush(Qt::yellow)); QPolygon poly; poly << QPoint(200,-100) << QPoint(200,200) << QPoint(-1,200) << QPoint(-1,-100) << QPoint(200,-100); painter.drawPolygon(poly); // or drawPolyline(poly) Buffer.save("c:/1.png", "PNG"); }

The result pixmap must contain yellow rectangle without any outline.
But there is a DIAGONAL red line.

Note 1.
  Using QPainterPath with the same data makes correct drawing.
  QPainterPath path;
  path.addPolygon(poly);
  painter.drawPath(path);

Note 2.
  Changing X coordinate -1 to any other number (-2, -1000, etc) makes correct drawing.