[tannhaeuser]

I get what Nick is trying to do (allow F/OSS to continue receiving security fixes while requiring commercial users to pay), even forwarded his call for help or other support last year. I'm not sure though relicensing MIT code under AGPL is legally sound if your additions are just bug fixes.

[qalmakka]

> I'm not sure though relicensing MIT code under AGPL is legally sound if your additions are just bug fixes.

It is: the original unmodified code is still MIT, but the bits you wrote and thus you hold the copyright for are AGPL. The combination of your bits + old bits is AGPL; some judge may argue your derived work isn't derived enough if you just change a few characters though. Still, I may argue that fixing a bug, no matter how trivial, requires you to perform a creative task, which almost definitely is by itself to be considered enough to go above the threshold required by a derived work.

[eqvinox]

It really doesn't matter until one tries to enforce an AGPL provision. If you do, that's where as you say will be arguments whether one added something substantial enough; basically the AGPL terms can really only be enforced on those additions.