Can I relicense source ports that mix Doom Source License and GPL to pure GPLv3?

[Spleen]

Specifically, most of it is GPLv3 but a couple files are DSL. I've bugged Maes about it a couple years ago, and I wonder if I should bug him again, or if it's okay to just swap out the licenses myself.

MochaDoom is a great project and I was thinking of doing things to its code just for kicks, but I'm concerned about the license for a couple files in particular. If I start messing around with it now and putting that stuff on github, would it be complicated to sort it out later?

:~/mochadoom$ grep -EIRin 'doom source code license'
src/f/EndLevel.java:11:// only under the terms of the DOOM Source Code License as
src/f/EndLevel.java:16:// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
src/v/BufferedRenderer32.java:17:// only under the terms of the DOOM Source Code License as
src/v/BufferedRenderer32.java:22:// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
src/v/BufferedRenderer16.java:17:// only under the terms of the DOOM Source Code License as
src/v/BufferedRenderer16.java:22:// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
src/v/GammaTables.java:11://only under the terms of the DOOM Source Code License as
src/v/GammaTables.java:16://FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
src/w/WadLoader.java:9:// only under the terms of the DOOM Source Code License as
src/w/WadLoader.java:14:// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License

[Gez]

Code that comes directly from Doom can be relicensed, code new to Mocha and put under the DSL, well, you'll have to get Maes' okay.

[Spleen]

Thanks Gez.

I send Maes another PM, this time with a list of the 5 files. If that turns out to be not enough, I can send some sed or awk commands or something, that will just swap the license right in there.

[Spleen]

Hooray, Maes finally swapped the Doom Source License with the GPL. Now I can make a MochaDoom fork! Thank you Maes!!!!