QEasingCurve::operator== returning wrong value

The following code fails:

QEasingCurve curve3;
QEasingCurve curve4;
curve4.setAmplitude(.3);
QVERIFY(curve3 != curve4);

I've attached a possible patch. This is causing trouble in QML because when setting an easing curve on an animation, we first check if it is equal to the existing easing curve, and return immediately if it is. This causes code like the following to skip setting the amplitude.

PropertyAnimation {
    easing.type: Easing.InOutBounce
    easing.amplitude: 5
}