Created attachment 45492 [details]
Clipping doesn't respect objectBoundingBox
SVG Clipping doesn't use objectBoundingBox of object, even on activated clipPathUnits="objectBoundingBox".
SVGRenderBase::prepareToRenderSVGContent in SVGRenderSupprt.cpp gives repaintRectInLocalCoordinates to SVGResourceClipper instead of objectBoundingBox.
repaintRectInLocalCoordinates includes the stroke of the object. You can see the result of this bug on the example. You should see a green rect.
Fixed with r52647.