756         sock =  openSocket(env, AF_INET6);

   756 

   757         if (sock < 0 && (*env)->ExceptionOccurred(env)) {

   757         /* User can disable ipv6 expicitly by -Djava.net.preferIPv4Stack=true,

   758             freeif(ifs);

   758          * so we have to call ipv6_available()

   759             return NULL;

   759          */

   760         }

   760         if (ipv6_available()) {

   761 

   761 

   762         ifs = enumIPv6Interfaces(env, sock, ifs);

   762            sock =  openSocket(env, AF_INET6);

   763         close(sock);

   763            if (sock < 0 && (*env)->ExceptionOccurred(env)) {

   764 

   764                freeif(ifs);

   765         if ((*env)->ExceptionOccurred(env)) {

   765                return NULL;

   766             freeif(ifs);

   766            }

   767             return NULL;

   767 

   768         }

   768            ifs = enumIPv6Interfaces(env, sock, ifs);

   769            close(sock);

   770 

   771            if ((*env)->ExceptionOccurred(env)) {

   772               freeif(ifs);

   773               return NULL;

   774            }

   775 

   776        }