palemoon-dev/platform/layout/reftests/xul/inactive-fixed-bg-bug1272525.xul

<?xml version="1.0"?>
<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
  <!-- Test that a fixed background layer inside an inactive layer tree
       is clipped correctly. Here, the inactive layer tree is created by
       the SVGEffects display item built for the clip-path on the outer div.
       The bug only reproduces in XUL because fixed backgrounds are only
       layerized if their animated geometry root is the root frame, but
       in HTML there's always an enclosing HTML scroll frame. -->
  <style xmlns="http://www.w3.org/1999/xhtml"><![CDATA[
    #inner {
      width: 100px;
      height: 100px;
      background: linear-gradient(red, blue) no-repeat fixed;
      background-size: 800px 800px;
    }

    #outer {
      margin: 50px 50px 0;
      width: 100px;
      height: 200px;
      clip-path: url(#path);
      position: fixed;
    }
  ]]></style>
  <div xmlns="http://www.w3.org/1999/xhtml" id="outer">
    <div xmlns="http://www.w3.org/1999/xhtml" id="inner"></div>
  </div>

  <svg xmlns="http://www.w3.org/2000/svg" height="0">
    <defs>
      <clipPath id="path" clipPathUnits="objectBoundingBox">
        <polygon points="0.25,0.25 0.25,0.75 0.75,0.75 0.75,0.25"/>
      </clipPath>
    </defs>
  </svg>
</window>