window_system_available 6428 src/fileio.c         && window_system_available (SELECTED_FRAME ()))
window_system_available  137 src/frame.c      if (window_system_available (f))
window_system_available 6759 src/w32fns.c     if (window_system_available (NULL))
window_system_available 9352 src/xfns.c           && window_system_available (SELECTED_FRAME ())