Roster requests to bare JID of the user are not responded

If I include a 'to' attribute in a roster request, which is the bare JID of the connected resource, like:

I don't get a response. According to RFC 6120 the server should treat that as if there weren't a 'to' attribute, right?

This is due to this code in IQRosterHandler.java, which returns null:

I also don't understand the comment and the else part.