<!DOCTYPE html>
<html>
  <head>
    <title>Test context-fill-opacity works with context-fill</title>
    <style>

img {
  width: 100px;
  height: 100px;
  -moz-context-properties: fill, fill-opacity;
  fill: blue;
  fill-opacity: 0.5;
}

    </style>
  </head>
  <body>
    <img src="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg'><rect width='100%' height='100%' fill='context-fill' fill-opacity='context-fill-opacity'/></svg>">
  </body>
</html>