Fix broken DNSMASQ_USER<x> envvars in script with more than one class.

src/lease.c

@@ -1110,10 +1110,14 @@ int do_script_run(time_t now)
 }
 
 #ifdef HAVE_SCRIPT
+/* delim == -1 -> delim = 0, but embeded 0s, creating extra records, are OK. */
 void lease_add_extradata(struct dhcp_lease *lease, unsigned char *data, unsigned int len, int delim)
 {
   unsigned int i;
   
+  if (delim == -1)
+    delim = 0;
+  else
     /* check for embeded NULLs */
     for (i = 0; i < len; i++)
       if (data[i] == 0)

src/rfc2131.c

@@ -1308,7 +1308,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		      /* If the user-class option started as counted strings, the first byte will be zero. */
 		      if (len != 0 && ucp[0] == 0)
 			ucp++, len--;
-		      lease_add_extradata(lease, ucp, len, 0);
+		      lease_add_extradata(lease, ucp, len, -1);
 		    }
 		}
 #endif