if user has set presence_id, don't override it

src/mod/endpoints/mod_sofia/mod_sofia.c

@@ -4358,9 +4358,12 @@ static switch_call_cause_t sofia_outgoing_channel(switch_core_session_t *session
 	if (tech_pvt->local_url) {
 		switch_channel_set_variable(nchannel, "sip_local_url", tech_pvt->local_url);
 		if (profile->pres_type) {
+			const char *presence_id = switch_channel_get_variable(nchannel, "presence_id");
+			if (zstr(presence_id)) {
 				switch_channel_set_variable(nchannel, "presence_id", tech_pvt->local_url);
 			}
 		}
+	}
 	switch_channel_set_variable(nchannel, "sip_destination_url", tech_pvt->dest);
 #if 0
 	dest_num = switch_core_session_strdup(nsession, dest);

src/mod/endpoints/mod_sofia/sofia.c

@@ -7501,14 +7501,16 @@ void sofia_handle_sip_i_invite(nua_t *nua, sofia_profile_t *profile, nua_handle_
 	}
 
 	if (profile->pres_type) {
+		const char *presence_id = switch_channel_get_variable(channel, "presence_id");
+		if (zstr(presence_id)) {
 			const char *user = switch_str_nil(sip->sip_from->a_url->url_user);
 			const char *host = switch_str_nil(sip->sip_from->a_url->url_host);
-
 			char *tmp = switch_mprintf("%s@%s", user, host);
 			switch_assert(tmp);
 			switch_channel_set_variable(channel, "presence_id", tmp);
 			free(tmp);
 		}
+	}
 
 
 	if (sip->sip_request->rq_url->url_params) {