ellipse negative rx,ry

Hello,

The specs say that for ellipse (and other shapes) that negative rx,ry is an
error, but wouldn't it be useful to allow this, for example when animating
these values?

And I don't think that a value of zero should result in no rendering, e.g if
rx=0 it should be rendered as a vertical line.. I think..

??

--
Sigurd Lerstad