Pathologic do not correct transform #anchor url

That would be a great feature. The problem is that input filters don't have access to much context outside of the piece of text they are filtering, and thus can't know if the text is part of a node, block, or some other thing, or if that thing has its own URL. So when the filter runs, there's no certain way to determine what the path of the thing that the text belongs to is so it can be added to the link.

So it's a great idea, but not currently possible. =[

Changing to a feature request and keeping it open just in case there's a way to do it some day.

correct code