Leaders give wrong rendering with overflow-wrap: break-word

[liZe]

<style>
  ol {
    font-family: Liberation Sans;
    overflow-wrap: break-word;
    width: 14em;
  }
  a::after {
    content: leader(".") "12345";
  }
</style>

<ol id="toc">
  <li><a href="#chapter3">The Last Chapter Very Long</a></li>
</ol>

Related to unicode-org/core-spec#521.