rem: if (check_inverse(optarg, &invert)) optind++;
add: check_inverse(optarg, &invert, &optind, 0);
context: parse(int c, char **argv, int invert, unsigned int *flags,      const struct ipt_entry *entry,      unsigned int *nfcache,      struct ipt_entry_match **match){	struct ipt_ah *ahinfo = (struct ipt_ah *)(*match)->data;	switch (c) {	case '1':		if (*flags & AH_SPI)			exit_error(PARAMETER_PROBLEM,				   "Only one `--spi' allowed");		if (check_inverse(optarg, &invert))			optind++;		parse_ah_spis(argv[optind-1], ahinfo->spis);		if (invert)			ahinfo->invflags |= IPT_AH_INV_SPI;		*flags |= AH_SPI;		break;	default:		return 0;	}	return 1;}