Javadoc plugin with Javadoc 8: error fetching URLs

Running a few of my projects under Java 8, I found that the
maven-javadoc-plugin won't accept <link> configuration items that work
under Javadoc 6.

For example, I have this:

<link>http://mvel.codehaus.org/javadoc/2.0</link>

With Javadoc 8 installed, whatever the maven-javadoc-plugin is doing to
feed this URL to javadoc isn't working and I get:

[WARNING] javadoc: warning - Error fetching URL:
http://mvel.codehaus.org/javadoc/2.0

This works fine using Javadoc 6.

Is this a known issue, or should I file a bug?

Best,
Laird