RE: winex11.drv: recognize WGL_SWAP_METHOD_ARB wgl pixel format attribute.

[Stefan Dösinger]

> WGL_SWAP_METHOD attribute is not handled. Explicitly skip it in
> ConvertAttribWGLtoGLX and always return WGL_SWAP_UNDEFINED_ARB in
> X11DRV_wglGetPixelFormatAttribivARB, because buffers are always in
> undefined state after swap in GLX.
> There's GLX_OML_swap_method. It is supported on fglrx, and I think it is
> supported on the open source drivers as well