plane: reinstate tailsitter roll limit

ArduPlane/mode_qstabilize.cpp

@@ -26,12 +26,15 @@ void ModeQStabilize::update()
     }
     // set nav_roll and nav_pitch using sticks
     int16_t roll_limit = MIN(plane.roll_limit_cd, plane.quadplane.aparm.angle_max);
-    plane.nav_roll_cd  = (plane.channel_roll->get_control_in() / 4500.0) * roll_limit;
-    plane.nav_roll_cd = constrain_int32(plane.nav_roll_cd, -roll_limit, roll_limit);
     float pitch_input = plane.channel_pitch->norm_input();
     // Scale from normalized input [-1,1] to centidegrees
     if (plane.quadplane.tailsitter_active()) {
-        // For tailsitters, the pitch range is symmetrical: [-Q_ANGLE_MAX,Q_ANGLE_MAX]
+        // separate limit for tailsitter roll, if set
+        if (plane.quadplane.tailsitter.max_roll_angle > 0) {
+            roll_limit = plane.quadplane.tailsitter.max_roll_angle * 100.0f;
+        }
+
+        // angle max for tailsitter pitch
         plane.nav_pitch_cd = pitch_input * plane.quadplane.aparm.angle_max;
     } else {
         // pitch is further constrained by LIM_PITCH_MIN/MAX which may impose
@@ -43,5 +46,8 @@ void ModeQStabilize::update()
         }
         plane.nav_pitch_cd = constrain_int32(plane.nav_pitch_cd, plane.pitch_limit_min_cd, plane.aparm.pitch_limit_max_cd.get());
     }
+
+    plane.nav_roll_cd = (plane.channel_roll->get_control_in() / 4500.0) * roll_limit;
+    plane.nav_roll_cd = constrain_int32(plane.nav_roll_cd, -roll_limit, roll_limit);
 }