Footnote back links with --id-prefix

[frabjous]

Is this broken in v2.0.6?

I'm getting this behavior:

Running:

$ echo 'This.^[Has a footnote.]' | pandoc --id-prefix='foo'

I get:

<p>This.<a href="#foofn1" class="footnote-ref" id="foofnref1"><sup>1</sup></a></p>
<section class="footnotes">
<hr />
<ol>
<li id="foofn1"><p>Has a footnote.<a href="#foofoofnref1" class="footnote-back">↩</a></p></li>
</ol>
</section>

Notice the double "foofoo" in the "back link", which breaks it.