autotest: add test for MAV_CMD_DO_LAND_START

Tools/autotest/arducopter.py

@@ -10308,6 +10308,44 @@ def MAV_CMD_NAV_VTOL_LAND(self):
             command(mavutil.mavlink.MAV_CMD_NAV_LAND)
             self.wait_mode('LAND')
 
+    def start_flying_simple_rehome_mission(self, items):
+        '''uploads items, changes mode to auto, waits ready to arm and arms
+        vehicle.  If the first item it a takeoff you can expect the
+        vehicle to fly after this method returns
+        '''
+
+        self.upload_simple_relhome_mission(items)
+
+        self.set_parameter("AUTO_OPTIONS", 3)
+        self.change_mode('AUTO')
+        self.wait_ready_to_arm()
+
+        self.arm_vehicle()
+
+    def _MAV_CMD_DO_LAND_START(self, run_cmd):
+        alt = 5
+        self.start_flying_simple_rehome_mission([
+            (mavutil.mavlink.MAV_CMD_NAV_TAKEOFF, 0, 0, alt),
+            (mavutil.mavlink.MAV_CMD_NAV_WAYPOINT, 200, 0, alt),
+            (mavutil.mavlink.MAV_CMD_NAV_LAND, 0, 0, 0),
+            (mavutil.mavlink.MAV_CMD_DO_LAND_START, 0, 0, alt),
+            (mavutil.mavlink.MAV_CMD_NAV_WAYPOINT, 200, 2000, alt),
+            (mavutil.mavlink.MAV_CMD_NAV_LAND, 0, 0, 0),
+        ])
+
+        self.wait_current_waypoint(2)
+        run_cmd(mavutil.mavlink.MAV_CMD_DO_LAND_START)
+        self.wait_current_waypoint(5)
+        # we pretend to be in RTL mode while doing this:
+        self.wait_mode("AUTO_RTL")
+        self.do_RTL()
+
+    def MAV_CMD_DO_LAND_START(self):
+        '''test handling of mavlink-received MAV_CMD_DO_LAND_START command'''
+        self._MAV_CMD_DO_LAND_START(self.run_cmd)
+        self.zero_throttle()
+        self._MAV_CMD_DO_LAND_START(self.run_cmd_int)
+
     def tests2b(self):  # this block currently around 9.5mins here
         '''return list of all tests'''
         ret = ([
@@ -10373,6 +10411,7 @@ def tests2b(self):  # this block currently around 9.5mins here
             self.SafetySwitch,
             self.BrakeZ,
             self.MAV_CMD_DO_FLIGHTTERMINATION,
+            self.MAV_CMD_DO_LAND_START,
         ])
         return ret