NullPointerException on empty polygon object

[mgmax]

The following file results in
java.lang.NullPointerException: Cannot invoke "com.kitfox.svg.SVGDiagram.getRoot()" because the return value of "com.kitfox.svg.SVGUniverse.getDiagram(java.net.URI)" is null

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
   version="1.1"
   viewBox="0 0 595.4 842.4">
    <polygon points=""/>
</svg>

(minimized from a real-world example)