<!DOCTYPE HTML>
<html>
<head>
<!-- Test appends -->
<style>
body > div { border:1px solid black; margin:1em;
             font-family:sans-serif; letter-spacing:2px; }
#d2:after { content:"Kitty"; }
#d3:after { content:"ty"; }
</style>
<script>function flush() { document.body.offsetHeight; }</script>
</head>
<body>
  <div id="d1"><span>Hello</span> <script>flush();</script><span>Kitty</span></div>
  <div id="d2"><script>flush();</script><span>Hello</span> </div>
  <div id="d3"><span>Hello</span> <script>flush();</script><span>Kit</span></div>
  <div id="d4"><span>Hello</span><script>flush();</script> <span>Kitty</span></div>
</body>
</html>