commander: require home position for MISSION, fallback to LOITER

src/modules/commander/commander.cpp

@@ -1718,6 +1718,13 @@ set_main_state_rc(struct vehicle_status_s *status, struct manual_control_setpoin
 			}
 
             print_reject_mode(status, "AUTO_MISSION");
+
+            // fallback to LOITER if home position not set
+            res = main_state_transition(status, MAIN_STATE_AUTO_LOITER);
+
+            if (res != TRANSITION_DENIED) {
+                break;  // changed successfully or already in this state
+            }
 		}
 
         // fallback to POSCTL

src/modules/commander/state_machine_helper.cpp

@@ -271,7 +271,6 @@ main_state_transition(struct vehicle_status_s *status, main_state_t new_main_sta
 		}
 		break;
 
-	case MAIN_STATE_AUTO_MISSION:
 	case MAIN_STATE_AUTO_LOITER:
 		/* need global position estimate */
 		if (status->condition_global_position_valid) {
@@ -279,6 +278,7 @@ main_state_transition(struct vehicle_status_s *status, main_state_t new_main_sta
 		}
 		break;
 
+	case MAIN_STATE_AUTO_MISSION:
 	case MAIN_STATE_AUTO_RTL:
 		/* need global position and home position */
 		if (status->condition_global_position_valid && status->condition_home_position_valid) {