xml:base not respected on <content> elements

[pabo]

It appears that the xml:base attribute is only respected on the <feed> and <entry> elements. At least one atom feed I consume puts the xml base on <content> elements within <entry>'s

Example feed

<feed xmlns="http://www.w3.org/2005/Atom">
  <title>kottke.org</title>
  <link rel="alternate" type="text/html" href="http://kottke.org/"/>
  <link rel="self" type="application/atom+xml" href="http://feeds.kottke.org/main"/>
  ...
  <entry>
    ...
    <content type="html" xml:lang="en" xml:base="https://kottke.org/">
      ...
    </content>
  </entry>
</feed>

This has the effect of relative URLs within the content resolving incorrectly - in this case with base url of http://feeds.kottke.org/ instead of https://kottke.org/.

I don't know why the feed puts the base where it does, since it seems to always be static at the feed level. But is this a common enough thing to add support for here?