- Phil Blundell added the CURLOPT_SCOPE option, as well as adjusted the URL

parser to allow numerical IPv6-addresses to be specified with the scope
  given, as per RFC4007 - with a percent letter that itself needs to be URL
  escaped. For example, for an address of fe80::1234%1 the HTTP URL is:
  "http://[fe80::1234%251]/"

lib/urldata.h

@@ -903,6 +903,8 @@ struct connectdata {
      set. */
   char *ip_addr_str;
 
+  unsigned int scope;    /* address scope for IPv6 */
+
   char protostr[16];  /* store the protocol string in this buffer */
   int socktype;  /* SOCK_STREAM or SOCK_DGRAM */
 
@@ -1478,6 +1480,7 @@ struct UserDefined {
   bool proxy_transfer_mode; /* set transfer mode (;type=<a|i>) when doing FTP
                                via an HTTP proxy */
   char *str[STRING_LAST]; /* array of strings, pointing to allocated memory */
+  unsigned int scope;    /* address scope for IPv6 */
 };
 
 struct Names {