RGB Curves node creates "super white"

The RGB Curves node seems to display a strange behaviour, it can apparently create a “super white” output. I didn’t notice this “super white” until I tried to use the "multiply blending option in the mix node, the whites of the image resulted in lighter areas on the underlying image when this is not supposed to happen with the multiply blending mode. When I connected the image without the RGB Curves node the multiply blending behaved as expected.

So my question is this, is there a way to clip the white to 1.0 or whatever is nescecary to get the normal image input behaviour back?

this should work: http://screencast.com/t/IfydtlmlE
split out and limit the channels, then recombine.

I already found a solution that requires less nodes. All you need to do is add an extra point in your curve, to get it extending on the edge of the “clipped” region (see image).


But thank you for your effort, your solution might come in handy in the future.