Apple, multiple video drivers, and SDL_SysWMinfo

So my default build of SDL generates a video driver for both quartz and
x11. This, however, makes SDL_SysWMinfo a little confused because if x11
is supported, it uses a completely different SDL_SysWMinfo than if it’s
not. This is completely confusing pygame, the python-sdl library, which
caches this info for python use. Is there any way to fix this, other
than, say, hacking around it by adding a null “data” field to the x11
SDL_SysWMinfo to make the structures nominally compatible? There isn’t
a way to query at runtime the window properties, thus working around the
need to use a static structure layout?