I finally got myself to start working on the pjpdns stuff and the cdb vs tinycdb question resolved itself pretty soon as far as pjpdns is concerned. Some functions and their arguments (cdb_findnext, cdb_findstart, etc.) have changed in tinycdb due to which pjpdns would not link against it as is. I would have to patch it to get it working.
Of course, being a lazy bum, I took the easy route and linked against my fork of cdb, which worked. Here is my fork of pjpdns with the changes. There are still some things that can be trimmed out in pjpdns as a result of this. There's also the entire "unlicensed code" thing I need to sort out since a lot of code in the original cdb does not have any license.
There are also a bunch of other changes I made to pjpdns, which included removing some auto-generated cruft from the repository and adding a bit of autotools candy so that any future autotools related changes don't result in git-log spam.
PJP had given a presentation some weeks ago on what would probably end up being pjpdns. One of the problems pointed on on his review request for inclusion of djbdns into Fedora was that it included code for cdb, which exists as a separate package and hence should be dynamically linked to instead. Someone even pointed out that (s)he had autotoolized cdb but did not respond to any further requests for more information.
I figured it was something I could do, so I went ahead and ported cdb to gnu-autotools. Here is my cdb fork. There is still some code which is unused, but I haven't really bothered to update in much since the time I found tinycdb, which seems to be maintained too. So my next project is to try and get djbdns to either use tinycdb or if that fails, my cdb fork.
I wonder how I can license the cdb fork though (if I decide to distribute it at some point). A lot of code is unlicensed, which is why (according to wikipedia) the tinycdb fork was written in the first place.
Oh, and let it be recorded officially and publicly that if pjpdns goes live, it was me who misread djbdns during the beginning of the presentation as pjpdns. Yes, that is my desperate attempt at being relevant to something completely unrelated :D