autotest: add test for quadplane stickmixing

Tools/autotest/quadplane.py

@@ -406,6 +406,18 @@ class AutoTestQuadPlane(AutoTest):
             "CPUFailsafe": "servo channel values not scaled like ArduPlane",
         }
 
+    def test_pilot_yaw(self):
+        self.takeoff(10, mode="QLOITER")
+        self.set_parameter("STICK_MIXING", 0)
+        self.set_rc(4, 1700)
+        for mode in "QLOITER", "QHOVER":
+            self.wait_heading(45)
+            self.wait_heading(90)
+            self.wait_heading(180)
+            self.wait_heading(275)
+        self.set_rc(4, 1500)
+        self.do_RTL()
+
     def CPUFailsafe(self):
         '''In lockup Plane should copy RC inputs to RC outputs'''
         self.plane_CPUFailsafe()
@@ -450,6 +462,10 @@ class AutoTestQuadPlane(AutoTest):
         ret.extend([
             ("TestMotorMask", "Test output_motor_mask", self.test_motor_mask),
 
+            ("PilotYaw",
+             "Test pilot yaw in various modes",
+             self.test_pilot_yaw),
+
             ("ParameterChecks",
              "Test Arming Parameter Checks",
              self.test_parameter_checks),