A. Normal - 2013-12-15

You're right about bool_swab and bool_opengl_swap, these variable are aliased. bool_opengl_swap is kept for compatibility with older configurations.

Now about fullscreen flickering, apparently SDL has trouble with double buffering under Mac OS X, and it seems it's not a new issue:

http://lists.libsdl.org/pipermail/sdl-libsdl.org/2002-December/032375.html

Can you confirm that bool_doublebuffer=true works fine in OpenGL mode?