Merged in f5soh/librepilot/LP-569_PosHold_YawControl (pull request #485)

LP-569 Ignore YawControl while using PosHold, AutoTakeOff and AutoCruize

Approved-by: Lalanne Laurent <f5soh@free.fr>
Approved-by: Alessio Morale <alessiomorale@gmail.com>
Approved-by: Philippe Renon <philippe_renon@yahoo.fr>
Approved-by: Paul Jewell <paul@teulu.org>

Author: f5soh

flight/modules/PathFollower/vtolflycontroller.cpp

@@ -274,7 +274,9 @@ int8_t VtolFlyController::UpdateStabilizationDesired(bool yaw_attitude, float ya
     }
 #endif // if 0
 
-    if (yaw_attitude) {
+    // Yaw Attitude will be disabled without velocity requested.
+    // PositionHold, AutoTakeoff or AutoCruise still using manual Yaw.
+    if (yaw_attitude && ((fabsf(pathDesired->StartingVelocity) > 0.0f) && (fabsf(pathDesired->EndingVelocity) > 0.0f))) {
         stabDesired.StabilizationMode.Yaw = STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE;
         stabDesired.Yaw = yaw_direction;
     } else {