- if (strcasecmp (u->buf, "ipv4") == 0) {
- protocol = AF_INET;
- } else if (strcasecmp (u->buf, "ipv6") == 0) {
- protocol = AF_INET6;
- } else if (strcasecmp (u->buf, "any") == 0) {
- protocol = AF_UNSPEC;
+ if (u->buf && strcasecmp (u->buf, "ipv4") == 0) {
+ protocol = AVAHI_PROTO_INET;
+ } else if (u->buf && strcasecmp (u->buf, "ipv6") == 0) {
+ protocol = AVAHI_PROTO_INET6;
+ } else if (u->buf && strcasecmp (u->buf, "any") == 0) {
+ protocol = AVAHI_PROTO_UNSPEC;