Qt4 -> Qt5: QPainter scale

[gavinmagnus]

Hello,
I'm performing some conversion from Qt4 to Qt5. My colleague states, that the code below used to create a rectangle with 1 pixel border, covering nearly whole widget, on Qt 4.8.1

QPainter painter( this );
    painter.scale( width(), height() );
 
    painter.setPen( Qt::green );
    painter.setBrush( Qt::yellow );
    painter.drawRect( QRectF( 0.1, 0.1, 0.8, 0.8 )  );

QPainter painter( this );
    painter.scale( width(), height() );

    painter.setPen( Qt::green );
    painter.setBrush( Qt::yellow );
    painter.drawRect( QRectF( 0.1, 0.1, 0.8, 0.8 )  );

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However, when I run this on Qt 5.3.2, the scale works differently. I receive insanely oversized rectangle with really thick border. In other words it is zooming instead of changing distances between points on axes.

I couldn't find this information in any Qt4->Qt5 migration guide, can someone confirm or deny that anything was changed with scaling method?


EDIT:

Looks like this might be the thing:

// Qt4:
void QPainter::scale(qreal sx, qreal sy)
{
    QMatrix m;
    m.scale(sx, sy);
    setMatrix(m, true); // however this calls setWorldMatrix( m ) anyway
}
 
// Qt5:
void QPainter::scale(qreal sx, qreal sy)
{
    Q_D(QPainter);
    if (!d->engine) {
        qWarning("QPainter::scale: Painter not active");
        return;
    }
 
    d->state->worldMatrix.scale(sx,sy);
    d->state->WxF = true;
    d->updateMatrix();
}

// Qt4:
void QPainter::scale(qreal sx, qreal sy)
{
    QMatrix m;
    m.scale(sx, sy);
    setMatrix(m, true); // however this calls setWorldMatrix( m ) anyway
}

// Qt5:
void QPainter::scale(qreal sx, qreal sy)
{
    Q_D(QPainter);
    if (!d->engine) {
        qWarning("QPainter::scale: Painter not active");
        return;
    }

    d->state->worldMatrix.scale(sx,sy);
    d->state->WxF = true;
    d->updateMatrix();
}

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Is there an easy way to migrate my code?