<!DOCTYPE html>

<html>
<head>
  <style type="text/css">
    .container {
        height: 50px;
        width: 200px;
        margin: 30px;
        -webkit-box-shadow: 0 0 40px black;
    }
    
    .clipper {
      margin-top: 100px;
      height: 50px;
      width: 200px;
      margin: 30px;
      overflow: hidden;
      border: 1px solid black;
    }
    
    .inner {
      height: 30px;
      width: 100%;
      margin-top: -40px;
      -webkit-box-shadow: 0 0 40px black;
      border: 1px solid blue;
    }
  </style>
</head>
<body>
  <!-- First shadowed box sets up a cached buffer. -->
  <div class="container"></div>

  <!-- Second clipped box tests the bug. -->
  <!-- There should not be a band of the shadow color inside this box. -->
  <div class="clipper">
    <div class="inner">
    </div>
  </div>

</body>
</html>