xlink:show="new" support omits link element

<para><link xlink:href="my.mp3" xlink:show="new">Audio</link></para>

... generates XHTML link output with the wrong target value:

  <p><a class="ulink" href="my.mp3" target="_top">Audio</a></p>

Changing the element from link to phrase works:
  <para><phrase xlink:href="my.mp3" xlink:show="new">Audio</phrase></para>

Resulting in the target I expect: