Door closing sound: fix AI stuck between stations and lock doors when opening

src/Devices/DoorClosingSound.cs

@@ -118,11 +118,18 @@ namespace OpenbveFcmbTrainPlugin
                         // Use departure time - door closing sound duration
                         AiTriggerDoorClosingSound |= CurrentTime.Seconds >= route.CurrentStation.DepartureTime - DoorClosingSoundDuration;
                     }
-                    // TODO: AI gets stuck if doors open between stations, check distance to stop point
                 }
                 else
                 {
-                    AiTriggerDoorClosingSound = false;
+                    // The doors have been opened between stations
+                    if (route.CurrentStation.StopPosition - route.CurrentStation.BackwardTolerance > train.State.Location)
+                    {
+                        AiTriggerDoorClosingSound = true;
+                    }
+                    else
+                    {
+                        AiTriggerDoorClosingSound = false;
+                    }
                 }
             }
             else
@@ -166,6 +173,10 @@ namespace OpenbveFcmbTrainPlugin
             {
                 DoorOpenTime = CurrentTime;
             }
+
+            // Set door closing counter to value higher than maximum where doors are allowed to close
+            // This effectively locks the doors when they open
+            DoorClosingSoundCounter = DoorClosingSoundDuration + DoorClosingSoundTimeout;
         }
 
         /// <summary>Is called when the device should perform the AI.</summary>