Revert "opengl32: Return a NULL pointer for functions requiring unsupported or disabled extensions.".

[Alexandre Julliard]

Sebastian Lackner <sebastian at fds-team.de> writes:

> @Alexandre: Just to make sure I tested it in practice, and it indeed solves
> the bug. It would be acceptable but 1.8, but wouldn't solve
> https://bugs.winehq.org/show_bug.cgi?id=39563 for example. I am aware that
> its technically not a Wine bug, but it could still be solved by being less
> strict with extension filtering. Both MESA and NVIDIA return valid valid
> function pointers in this case.

Actually I would argue that it is a Wine bug. If you can get a valid
function on Windows even when the extension is missing, you should get
one on Wine. Conversely, if you get a NULL pointer on Windows for a
missing function, you should get NULL on Wine too.

This means that we have a responsibility to properly remap functions and
extensions between the Windows and the Unix side. We can't simply
forward to the Unix driver and hope that it happens to follow the
Windows semantics.

-- 
Alexandre Julliard
julliard at winehq.org