(address_get_nth): New function. Get Nth subaddress from an address.

@@ -33,6 +33,8 @@ extern address_t address_dup __P ((address_t src));
 /* Set FROM to null, after adding its addresses to TO. */
 extern int address_concatenate __P ((address_t to, address_t* from));
 
+extern int address_get_nth
+        __P ((address_t addr, size_t no, address_t *pret));
 extern int address_get_email
 	__P ((address_t, size_t, char *, size_t, size_t *));
 extern int address_get_local_part

@@ -202,6 +202,16 @@ _address_get_nth (address_t addr, size_t no)
 }
 
 int
+address_get_nth (address_t addr, size_t no, address_t *pret)
+{
+  address_t subaddr = _address_get_nth (addr, no);
+  if (!subaddr)
+    return ENOENT;
+  *pret = address_dup (subaddr);
+  return 0;
+}
+
+int
 address_get_personal (address_t addr, size_t no, char *buf, size_t len,
 		      size_t * n)
 {