#include <QApplication>
#include <QTextLayout>

int textHeightForWidth(int width)
{
    int height = 0;
    QTextLayout tl("Foo bar und so");
    tl.beginLayout();
    while (true) {
        QTextLine line = tl.createLine();
        if (!line.isValid())
            break;
        line.setLineWidth(width);
        height += line.height();
    }
    tl.endLayout();
    return height;
}

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    qDebug() << textHeightForWidth(50);
    qDebug() << textHeightForWidth(-1); // Proceeds with Qt < 6.5, Freezes with Qt 6.5
    return 0;
}