Issues if GLX_SWAP_METHOD_OML is not fully supported

[Fabian Maurer]

Hello,
I have an OpenGL program that tries to use WGL_SWAP_METHOD, but while my 
graphics card supports GLX_OML_swap_method, no pixelformat supports its value 
GLX_SWAP_EXCHANGE_OML.

Is this a graphics driver issue? I'm using the most recent open source mesa 
drivers.
Attached a patch proposal to deal with the issue in wine, but I'm not sure if 
this is the right course of action to take.

Fabian Maurer