Putative fix to crash in IPv4 DHCP, introduced whilst

generalising the DHCP option filter code:
don't match options against context tag  when
context->netid.net == NULL, since there's no tag then.

src/dhcp-common.c

@@ -102,7 +102,7 @@ struct dhcp_netid *option_filter(struct dhcp_netid *tags, struct dhcp_netid *con
     }
 
   /* now flag options which are valid, including the context tags,
-     otherwise valid options are inhibited if we found a higher priotity one above */
+     otherwise valid options are inhibited if we found a higher priority one above */
   if (context_tags)
     {
       struct dhcp_netid *last_tag;

src/lease.c

@@ -504,10 +504,9 @@ u64 lease_find_max_addr6(struct dhcp_context *context)
   if (!(context->flags & (CONTEXT_STATIC | CONTEXT_PROXY)))
     for (lease = leases; lease; lease = lease->next)
       {
-#ifdef HAVE_DHCP6
 	if (!(lease->flags & (LEASE_TA | LEASE_NA)))
 	  continue;
-#endif
+
 	if (is_same_net6((struct in6_addr *)lease->hwaddr, &context->start6, 64) &&
 	    addr6part((struct in6_addr *)lease->hwaddr) > addr6part(&context->start6) &&
 	    addr6part((struct in6_addr *)lease->hwaddr) <= addr6part(&context->end6) &&

src/rfc2131.c

@@ -2095,7 +2095,8 @@ static void do_options(struct dhcp_context *context,
   struct dhcp_netid_list *id_list;
 
   /* filter options based on tags, those we want get DHOPT_TAGOK bit set */
-  tagif = option_filter(netid, &context->netid, config_opts);
+  context->netid.next = NULL;
+  tagif = option_filter(netid, context->netid.net ? &context->netid : NULL, config_opts);
 	
   /* logging */
   if (option_bool(OPT_LOG_OPTS) && req_options)