Clarified use of nua_refer().

darcs-hash:20051028080138-65a35-6a1d6f66ff2d87ed37ad9bc8ae419967321d39fd.gz

libsofia-sip-ua/nua/nua.c

@@ -1150,9 +1150,11 @@ void nua_terminate(nua_handle_t *nh, tag_type_t tag, tag_value_t value, ...)
 /** Transfer a call. 
  * 
  * Send a REFER request asking the recipient to transfer the call. The REFER
- * request also establishes a subscription to the "refer" event. The event
- * id parameter can be determined by the CSeq number from the SIP response
- * returned with the nua_r_refer event.
+ * request also establishes a subscription to the "refer" event. The "refer"
+ * event will have an "id" parameter, which has the value of CSeq number in
+ * the REFER request. After initiating the REFER request, the nua engine
+ * sends application a nua_r_refer event with status 100 and tag
+ * SIPTAG_EVENT() containing a matching event header.
  *
  * @param nh              Pointer to operation handle
  * @param tag, value, ... List of tagged parameters

libsofia-sip-ua/nua/nua_stack.c

@@ -6115,6 +6115,10 @@ ua_refer(nua_t *nua, nua_handle_t *nh, nua_event_t e, tagi_t const *tags)
     return UA_EVENT1(e, NUA_500_ERROR);
   }
 
+  /*
+   * We send a 100 trying event so that application gets a event 
+   * it can use to match NOTIFYs with its REFER
+   */
   ua_event(nua, nh, NULL, e, SIP_100_TRYING, 
 	   NUTAG_REFER_EVENT(event),
 	   TAG_END());