The gamma controls no longer work on (io)Quake based games with Mesa drivers. This regression occurred in 7.4 commit:
Maarten says it "should be driver ABI compatible", but it breaks Mesa's own drivers. I have observed this broken behavior with the Mesa software renderer, a Geforce 650 with Mesa 10.5 and 10.6, and ATI X1800 with Mesa 10.5 and 10.6. Ironically, the proprietary drivers have hacked around this bug, so they're not affected. Nouveau's default gamma is so dark that OpenArena is unplayable with my GTX 650.
A sample of downstream bug reports from game engines/frameworks affected:
It should be possible for a game to control it's own gamma and not force the user to change system-wide settings every time they want to play. How can we fix this issue? Implement the same work-around as the proprietary drivers or revert/fix the commit that's causing this problem?
*** This bug has been marked as a duplicate of bug 27222 ***