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_esp *espinfo = (struct ipt_esp *)(*match)->data;	switch (c) {	case '1':		if (*flags & ESP_SPI)			exit_error(PARAMETER_PROBLEM,				   "Only one `--spi' allowed");		if (check_inverse(optarg, &invert))			optind++;		parse_esp_spis(argv[optind-1], espinfo->spis);		if (invert)			espinfo->invflags |= IPT_ESP_INV_SPI;		*flags |= ESP_SPI;		break;	default:		return 0;	}	return 1;}