Capsule QML element will change the length if it is not at least two times the radius

Capsule QML element will change the length if it is not at least two times the radius. The problem is that this means it will lose the user defined length even if it was set at the same time as the radius setting. What should happen is that it should warn about the length being incorrect instead of changing it directly as this would fit more in the convention as to what Qt usually does in this instance.