Re: [PATCH v2 iproute2 3/3] bridge: mst: Add get/set support for MST states

Please resolve the following issue.

+static int mst_set(int argc, char **argv)
+{
+	struct {
+		struct nlmsghdr		n;
+		struct ifinfomsg	ifi;
+		char			buf[512];
+	} req = {
+		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+		.n.nlmsg_flags = NLM_F_REQUEST,
+		.n.nlmsg_type = RTM_SETLINK,
+		.ifi.ifi_family = PF_BRIDGE,
+	};
+	char *d = NULL, *m = NULL, *s = NULL, *endptr;
+	struct rtattr *af_spec, *mst, *entry;
+	__u16 msti;
+	__u8 state;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "dev") == 0) {
+			NEXT_ARG();
+			d = *argv;
+		} else if (strcmp(*argv, "msti") == 0) {
+			NEXT_ARG();
+			m = *argv;
+		} else if (strcmp(*argv, "state") == 0) {
+			NEXT_ARG();
+			s = *argv;
+		} else {
+			if (matches(*argv, "help") == 0)
+				usage();
+		}
+		argc--; argv++;
+	}
+
+	if (d == NULL || m == NULL || s == NULL) {
+		fprintf(stderr, "Device, MSTI and state are required arguments.\n");
+		return -1;
+	}
+
+	req.ifi.ifi_index = ll_name_to_index(d);
+	if (!req.ifi.ifi_index)
+		return nodev(d);
+
+	msti = strtol(m, &endptr, 10);
+	if (!(*s != '\0' && *endptr == '\0')) {
+		fprintf(stderr,
+			"Error: invalid MSTI\n");
+		return -1;
+	}
+
+	state = strtol(s, &endptr, 10);
+	if (!(*s != '\0' && *endptr == '\0')) {
+		state = parse_stp_state(s);
+		if (state == -1) {
+			fprintf(stderr,
+				"Error: invalid STP port state\n");
+			return -1;

Building with clang shows this problem.


    CC       mst.o
mst.c:215:13: warning: result of comparison of constant -1 with expression of type '__u8' (aka 'unsigned char') is always false [-Wtautological-constant-out-of-range-compare]
                if (state == -1) {
                    ~~~~~ ^  ~~
1 warning generated.