<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" onload="runTest()">
<script>
  function runTest() {
    document.getElementById("rect3").setAttribute("fill", "url(" + document.baseURI + "#green)");
  }
</script>
<defs>
  <linearGradient id="green" x1="0%" y1="0%" x2="100%" y2="100%">
    <stop offset="50%" style="stop-color:green"/>
  </linearGradient>
  <linearGradient id="red" x1="0%" y1="0%" x2="100%" y2="100%">
    <stop offset="0%" style="stop-color:rgb(255,0, 0);"/>
  </linearGradient>
</defs>
<rect width="50" height="50" fill="url(../custom/uri-reference-handling.svg#green)"/>
<rect x="60" width="50" height="50" fill="url(http://www.example.org/test#red) green"/>
<rect id="rect3" y="60" width="50" height="50" fill="red"/>
<rect x="60" y="60" width="50" height="50" fill="url(no_fragment_identifier) green"/>
</svg>