Option 'taglets/taglet/tagletpath' ignored when pointing to a JAR

The tagletpath property used in a taglets/taglet element seems to be completely ignored, despite being documented. It looks as if this never worked before. It is also utterly untested. There is an old bug MJAVADOC-231, but whatever that was meant to fix, it seems to be unrelated to this one. If I have a local JAR unavailable on Maven Central sitting in a libraries folder, I cannot use it in any other way than to contrive to put a copy into my local Maven repository and use tagletArtifact instead of taglets/taglet/tagletpath.

I noticed this, when trying to help someone asking a question on the Maven users mailing list. In his sample repository, an effort to convert the Xalan Ant Build to Maven, the commit to check out is is 6daf2890. Just run mvn -DskipTests=true site.