The following crashes the parser:
for x in; do
0
done
This is because grub_script_arglist_to_argv() doesn't consider the
possibility that arglist is NULL. Catch that explicitly.
This avoids a NULL pointer dereference.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>