<svg xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<clipPath id="myclip">
<rect x="0" y="0" width="200" height="200" style="transform: scale(.5)"/>
<!-- second rect causes masking -->
<rect x="0" y="0" width="200" height="200" style="transform: scale(.5)"/>
</clipPath>
</defs>
<g clip-path="url(#myclip)">
<rect x="0" y="0" width="200" height="200" fill="red"/>
<rect x="0" y="0" width="100" height="100" fill="green"/>
</g>
</svg>