Merge pull request #748 in VECTO/vecto-sim from...

Merge pull request #748 in VECTO/vecto-sim from ~EMQUARIMA/vecto-sim:bugfix/VECTO-931-at-error-in-vecto-version-3.3.2.1519 to develop

* commit 'f3a10008':
  AT shift strategy: avoid emergency upshift from TC to locked if acc in locked gear is less than 0
  avoid null-reference execption

VectoCore/VectoCore/Models/SimulationComponent/Impl/ATShiftStrategy.cs

@@ -194,7 +194,8 @@ namespace TUGraz.VectoCore.Models.SimulationComponent.Impl
 					nextInAngularSpeed = outAngularVelocity * ModelData.Gears[gear + 1].Ratio;
 					nextInTorque = outTorque / ModelData.Gears[gear + 1].Ratio;
 				}
-				if (!IsBelowDownShiftCurve(gear + 1, nextInTorque, nextInAngularSpeed)) {
+				var acc = EstimateAccelerationForGear(gear + 1, outAngularVelocity);
+				if ((acc > 0 || _gearbox.TCLocked) && !IsBelowDownShiftCurve(gear + 1, nextInTorque, nextInAngularSpeed)) {
 					Log.Debug("engine speed would be above max speed / rated speed - shift up");
 					Upshift(absTime, gear);
 					return true;

VectoCore/VectoCore/Models/SimulationComponent/Impl/TorqueConverter.cs

@@ -271,6 +271,9 @@ namespace TUGraz.VectoCore.Models.SimulationComponent.Impl
 					absTime, dt, outAngularVelocity, engineSpeed,
 					x => x.DeltaFullLoad.IsSmaller(0),
 					x => VectoMath.Abs(DataBus.EngineSpeed - x.EngineSpeed).Value());
+				if (tqOperatingPoint == null) {
+					return null;
+				}
 				tqOperatingPoint.Creeping = true;
 				return tqOperatingPoint;
 			}