Not really, maybe I did not explain myself correctly:

- If the moduledir starts with a slash, it is an absolute path, and 
therefore we don't change anything, to avoid breaking backwards 
compatibility.
- If the moduledir does not start with a slash, it is a relative path 
and therefore $basedir needs to be appended, whether the relative path 
is simple, or composed by various subdirectories.

Hope this clarifies it... or what kind of validation were you talking about?