fset_root_window 1081 src/frame.c      fset_root_window (f, root_window);
fset_root_window 2277 src/frame.c      fset_root_window (f, Qnil);
fset_root_window 2495 src/window.c       fset_root_window (XFRAME (o->frame), new);
fset_root_window 7350 src/window.c         fset_root_window (f, data->root_window);