mavlink: don't miss mission current updates

When a mission is finished we need to make sure to send the mission
current message and not drop it. Otherwise, MAVSDK tests might not get
the update that the mission has been finished.

src/modules/mavlink/mavlink_mission.cpp

@@ -503,6 +503,8 @@ MavlinkMissionManager::send()
 	if (_mission_result_sub.update()) {
 		const mission_result_s &mission_result = _mission_result_sub.get();
 
+		bool send_current = false;
+
 		if (_current_seq != mission_result.seq_current) {
 
 			_current_seq = mission_result.seq_current;
@@ -511,7 +513,7 @@ MavlinkMissionManager::send()
 
 			if (mission_result.seq_total > 0) {
 				if (mission_result.seq_current < mission_result.seq_total) {
-					send_mission_current(_current_seq);
+					send_current = true;
 
 				} else {
 					_mavlink.send_statustext_critical("ERROR: wp index out of bounds\t");
@@ -521,6 +523,16 @@ MavlinkMissionManager::send()
 			}
 		}
 
+		// Send MISSION_CURRENT when finished state changes (to notify MISSION_STATE_COMPLETE)
+		if (_last_finished != mission_result.finished) {
+			_last_finished = mission_result.finished;
+			send_current = true;
+		}
+
+		if (send_current) {
+			send_mission_current(_current_seq);
+		}
+
 		if (_last_reached != mission_result.seq_reached) {
 
 			_last_reached = mission_result.seq_reached;

src/modules/mavlink/mavlink_mission.h

@@ -132,6 +132,7 @@ private:
 	static int32_t		_current_seq;				///< Current item sequence in active mission
 
 	int32_t			_last_reached{-1};			///< Last reached waypoint in active mission (-1 means nothing reached)
+	bool			_last_finished{false};			///< Last mission finished state
 
 	dm_item_t		_transfer_dataman_id{DM_KEY_WAYPOINTS_OFFBOARD_1};	///< Dataman storage ID for current transmission