1. In a QTextLayout, assign a pen for the text's outline and Qt::NoBrush for the text's foreground:

       QTextLayout textLayout("Qt");
       QTextLayout::FormatRange range;
       range.start = 0;
       range.length = 2;
       range.format.setFont(f);
       range.format.setTextOutline(pen);
       range.format.setForeground(Qt::NoBrush);
       textLayout.setFormats(QList<QTextLayout::FormatRange>{range});
   

2. Draw this using a QPainter:

   textLayout.draw(&p, QPoint(0, 200));
   

   Expected: The drawn characters will not be filled, i.e. inside the outline, they will be transparent:
   
   Actual: The drawn characters are filled with the color of the outline's pen:
   

I attached a small project to reproduce the issue. It also draws a rectangle for comparison.

Workaround: Setting the foreground to Qt::transparent draws the expected shape.