When a vector layer is exported to an OWSContext document, we throw an exception when the layer contains no features, and the geometries are to be exported inside of an InlineGeometry-element. This commit fixes this behaviour by exporting sth. like this in such cases: <Layer name="vector" hidden="0">i <ows:Title xmlns:ows="http://www.opengis.net/ows"/> <InlineGeometry/> </Layer>