#include <QApplication>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QPainter>
#include <QPen>

class MyWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
public:
    MyWidget(QWidget* parent = nullptr) : QOpenGLWidget(parent) { }

protected:
    virtual void initializeGL() override
    {
        initializeOpenGLFunctions();
        glClearColor(1.f, 0.5f, 1.f, 1.f);
    }

    virtual void paintGL() override
    {
        QPainter p(this);

//        p.beginNativePainting();
//        // no need to put anything here to reproduce the bug
//        p.endNativePainting();

        QPen pen(Qt::black, 4);
        p.setPen(pen);

        p.save();
        p.translate(QPointF(800,-12));
        p.rotate(35.7008);
        p.drawEllipse(QPointF(0,0), 245.051, 183.788);
        p.restore();


        // without that last part, the bug does not occur
        pen.setDashPattern({5, 5});
        p.setPen(pen);
        p.drawLine(QPointF(822,-155), QPointF(1220,131));
    }
};


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MyWidget w;
    w.setGeometry(0, 0, 700, 700);
    w.show();
    return a.exec();
}