Commit aa1047a3 originally added this as:
+ // this is from the DarkPlaces engine, reduces to 3x3. Original code
+ // released under GPL2 or any later version.
According to Rudolf Polzer, the original author (a certain LH) was
actually asked whether it would be ok to put this code under LGPL, and
the author gave his agreement. This code is not from id Software either
(on which large parts of DarkPlaces is based on), which is the main
reason why DarkPlaces is under GPL.
So this note is just confusing, and always has been LGPL. Fix it.