fix edge case that causes crash when unregistering (#247)

.gitignore

@@ -281,3 +281,5 @@ images/test_text.png
 
 src/mod/codecs/mod_amrwb/test/test_amrwb
 src/mod/endpoints/mod_sofia/test/sipp-based-tests
+
+DEBBUILD/

src/mod/endpoints/mod_sofia/sofia.c

@@ -1515,14 +1515,6 @@ static void our_sofia_event_callback(nua_event_t event,
 
 	if (sofia_private && sofia_private != &mod_sofia_globals.destroy_private && sofia_private != &mod_sofia_globals.keep_private) {
 		if (!zstr(sofia_private->gateway_name)) {
-			if (event == nua_r_unregister && status != 401 && status != 407) {
-				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Destroy handle after unregister for gateway %s.\n", sofia_private->gateway_name);
-				sofia_private_free(sofia_private);
-				nua_handle_bind(nh, NULL);
-				nua_handle_destroy(nh);
-				nh = NULL;
-				return;
-			}
 			if (!(gateway = sofia_reg_find_gateway(sofia_private->gateway_name))) {
 				return;
 			}
@@ -1633,6 +1625,14 @@ static void our_sofia_event_callback(nua_event_t event,
 		}
 	}
 
+	if (event == nua_r_unregister && status != 401 && status != 407 && status >= 200) {
+		if (gateway) {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Mark gateway %s for destruction after unregister. Status %d.\n", sofia_private->gateway_name, status);
+			gateway->destroy = 1;
+		}
+		goto done;
+	}
+
 	if (sofia_test_pflag(profile, PFLAG_AUTH_ALL) && tech_pvt && tech_pvt->key && sip && (event < nua_r_set_params || event > nua_r_authenticate)) {
 		sip_authorization_t const *authorization = NULL;
 

src/mod/endpoints/mod_sofia/sofia_reg.c

@@ -461,6 +461,22 @@ void sofia_reg_check_gateway(sofia_profile_t *profile, time_t now)
 			user_via = NULL;
 		}
 
+		if(ostate == REG_STATE_DOWN && gateway_ptr->destroy) {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Destroy sofia_private and nua_handler for gateway %s\n", gateway_ptr->name);
+
+			if (gateway_ptr->sofia_private) {
+				sofia_private_free(gateway_ptr->sofia_private);
+			}
+
+			if (gateway_ptr->nh) {
+				nua_handle_bind(gateway_ptr->nh, NULL);
+				nua_handle_destroy(gateway_ptr->nh);
+				gateway_ptr->nh = NULL;
+			}
+
+			gateway_ptr->destroy = 0;
+		}
+
 		switch (ostate) {
 		case REG_STATE_DOWN:
 		case REG_STATE_NOREG: