> > in cases where he's made major modifications to code already in > > MAME. If the code wasn't properly licensed to begin with, then he has no legal > rights > > to it. > > I might be wrong, but from balrog's explanations of the legal aspects of the problem, > if Haze has rewritten the code using the former version just for reference, then he > has full right on the new code (even if it is nice to still give credit to the > persons who did previous work)
This would be correct if he completely rewrote it. But in many cases, he's modified code, but enough of the original remains that he couldn't claim exclusive copyright over it.
Haze did, in some past posts, make some additional arguments about the ethics of rewriting someone's code to get around licensing issues. I didn't find these particularly compelling. If the old code is merely used as reference, giving credit should be sufficient.