Merge pull request #393 from Csantucci/Fix-join-split

Bug fix for https://bugs.launchpad.net/or/+bug/1922480 Wrong subpath selected after join and split

Author: Csantucci

Source/Orts.Simulation/Simulation/Physics/Train.cs

@@ -6791,14 +6791,12 @@ public virtual bool CheckRouteActions(float elapsedClockSeconds)
                 if (positionNowBack == PresentPosition[0].TCSectionIndex && directionNowBack != PresentPosition[0].TCDirection)
                 {
                     ReverseFormation(IsActualPlayerTrain);
-                    // active subpath must be incremented in parallel in incorporated train if present
-                    if (IncorporatedTrainNo >= 0) IncrementSubpath(Simulator.TrainDictionary[IncorporatedTrainNo]);
+                    TryIncrementSubpath();
                 }
                 else if (positionNow == PresentPosition[1].TCSectionIndex && directionNow != PresentPosition[1].TCDirection)
                 {
                     ReverseFormation(IsActualPlayerTrain);
-                    // active subpath must be incremented in parallel in incorporated train if present
-                    if (IncorporatedTrainNo >= 0) IncrementSubpath(Simulator.TrainDictionary[IncorporatedTrainNo]);
+                    TryIncrementSubpath();
                 }
             }
 
@@ -11611,6 +11609,23 @@ public void TemporarilyRemoveFromTrack()
             activeActions.Clear();
         }
 
+        //================================================================================================//
+        //
+        // Checks if it has to go to next active subpath
+        //
+        private void TryIncrementSubpath()
+        {
+            // active subpath must be incremented in parallel in incorporated train if present; not just after incorporation
+            if (IncorporatedTrainNo >= 0)
+            {
+                var incorporatedTrain = Simulator.TrainDictionary[IncorporatedTrainNo];
+                if (incorporatedTrain.PresentPosition[0].TCSectionIndex != PresentPosition[1].TCSectionIndex && incorporatedTrain.PresentPosition[1].TCSectionIndex != PresentPosition[1].TCSectionIndex)
+                    IncrementSubpath(incorporatedTrain);
+                incorporatedTrain.PresentPosition[0].TCSectionIndex = -1;
+                incorporatedTrain.PresentPosition[1].TCSectionIndex = -1;
+            }
+        }
+
         //================================================================================================//
         //
         // Goes to next active subpath