<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<svg xmlns="http://www.w3.org/2000/svg">
  <title>Test 'mask' containing masked content</title>
  <mask id="m1" maskUnits="objectBoundingBox" maskContentUnits="objectBoundingBox">
    <rect width="0.5" height="1" fill="white"/>
  </mask>
  <mask id="m2" maskUnits="objectBoundingBox" maskContentUnits="objectBoundingBox">
    <rect width="1" height="1" fill="white" mask="url(#m1)"/>
  </mask>
  <rect width="100%" height="100%" fill="lime"/>
  <rect width="50" height="100%" fill="red"/>
  <g mask="url(#m2)">
    <rect width="50" height="100%" fill="lime"/>
    <rect x="50" width="50" height="100%" fill="red"/>
  </g>
</svg>