QTransform::type() doesn't always return correct transformation type

#include <QTransform>
#include <QDebug>

int main(int argc, char *argv[])
{
    QTransform t1;
    t1.scale(10,10);
    qDebug() << "type 1: " << t1.type(); // Good.

    QTransform t2 = t1.inverted();
    qDebug() << "type 2: " << t2.type(); // Good.

    QTransform t3 = t1.adjoint() / t1.determinant();
    // This prints 0(TxNone), but I don't think that is
    // the right answer. Then all of the map() functions
    // treat the transform as the identity matrix.
    qDebug() << "type 3: " << t3.type(); // Bad.
    qDebug() << "(t2 == t3): " << (t2 == t3);

    return 0;
}