<!DOCTYPE html>
<html>
  <head>
  </head>
  <body>
    <!--    
        https://bugs.webkit.org/show_bug.cgi?id=76664
        The 'a' should be in a red box that sits on the bottom left of an enclosing yellow box.
    -->
    <style>
    .caption1 { background-color:yellow; width: 40px; display: inline-block;}
    .fl { float: left; background-color:red;}
    </style>
    <div class="caption1">caption1<div class="fl">a</div></div>
  </body>
</html>