Created attachment 319934 [details]
In Icculus Quake II, the mouse behavior is exactly opposite from normal both vertically and horizontally. Y-axis reversal would of course be easy to fix by just activating "invert mouse" in the game, but seeing that there is little reason why anyone would prefer to look right when moving the mouse left or vice versa, there is no toggle for that. And yet, that's exactly what it does, and I haven't been able to find any setting to change it. The inversion is on *both* axes.
The bug sounds very similar to me to bug #162592 in another game, Warsow, which was fixed by applying some sort of patch to fix the way the game interprets data from the DGA mouse extension in X11. I don't know what would have to be done to replicate that bugfix in Icculus Quake II. The users reporting the Warsow bug are seeing exactly the same behavior as I'm seeing in Quake II though.
This behavior shows up in the regular GLX clients "quake2" and "quake2-max". I don't know whether the SDL clients "sdlquake2" and sdlquake2-max" have the issue or not because they have distorted sound issues (irrelevant for this bug report) on my system that have been making me not use them. The regular non-SDL clients would be perfect if the mouse action wasn't backwards.