<!DOCTYPE html>
<html class="reftest-wait">
<head>
  <meta charset="UTF-8">
  <!-- This testcase ensures that we correctly re-evaluate the percent height
       on the purple flex item "itemA", in response to the height of its flex
       container being dynamically changed. -->
  <style>
    #flex {
      display: inline-flex;
      flex-direction: column;
      border: 1px solid black;
      max-width: 50px;
      height: 60px;
    }
    #itemA {
      background: purple;
      height: 50%;
      flex: none;
    }
    #itemB {
      background: lightblue;
      flex: none;
    }
  </style>
  <script>
    function tweak() {
      document.getElementById("flex").style.height = "150px";
      document.documentElement.removeAttribute("class");
    }
    window.addEventListener("MozReftestInvalidate", tweak, false);
  </script>
</head>
<body>
  <div id="flex">
    <div id="itemA">A</div>
    <div id="itemB">BB</div>
  </div>
</body>
</html>