Fixed bug 1958 - Cocoa SwapWindow doesn't swap the specified window

Ryan C. Gordon

We have this in Cocoa_GL_SwapWindow()...

    /* FIXME: Do we need to get the context for the window? */
    [[NSOpenGLContext currentContext] flushBuffer];

...which means if the current GL context is not the one in (window), we swap a different one than requested.

Right now, we don't store information about which context is assigned to which window, and the OS doesn't give you a way to retrieve it from an NSView. We would have to track this per-window during SDL_GL_MakeCurrent() (and SDL_GL_CreateContext) calls.