<!doctype html>
<svg style="position: absolute; width: 0; height: 0">
  <defs>
    <pattern id="rect" width="100" height="100">
      <rect fill="red" width="100" height="100" />
    </pattern>
  </defs>
</svg>
<div id="host"></div>
<script>
  // Test references from a <svg:use> subtree.
  host.attachShadow({ mode: "open" }).innerHTML = `
    <svg width="100" height="100">
      <defs>
        <pattern id="rect" width="100" height="100">
          <rect fill="red" width="100" height="100" />
        </pattern>
        <symbol id="useme">
          <pattern id="rect" width="100" height="100">
            <rect fill="lime" width="100" height="100" />
          </pattern>
          <rect fill="url(#rect)" width="100" height="100" />
        </symbol>
      </defs>
      <use href="#useme" />
    </svg>
  `;
</script>