minor improvements

* when a train in shunting mode is directed to an occupied block, the train there is moved to the parking list of that block
* some null pointer checks

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>de.srsoftware</groupId>
 	<artifactId>web4rail</artifactId>
-	<version>1.4.28</version>
+	<version>1.4.29</version>
 	<name>Web4Rail</name>
 	<packaging>jar</packaging>
 	<description>Java Model Railway Control</description>

src/main/java/de/srsoftware/web4rail/Route.java

@@ -401,6 +401,7 @@ public class Route extends BaseClass {
 	}
 	
 	private void freeIgnoring(Vector<Tile> skipTiles) {
+		if (isNull(context)) return;
 		Train train = context.train();
 		Vector<Tile> reversedPath = reverse(path());
 		if (isSet(skipTiles)) reversedPath.removeAll(skipTiles);

src/main/java/de/srsoftware/web4rail/moving/Train.java

@@ -432,10 +432,11 @@ public class Train extends BaseClass implements Comparable<Train> {
 	}
 
 	
-	public void dropTrace(boolean dropStuck) {
+	public Train dropTrace(boolean dropStuck) {
 		while (!trace.isEmpty()) trace.stream().findFirst().get().free(this);
 		trace.clear();
 		if (dropStuck) stuckTrace = null;
+		return this;
 	}
 	
 	private BrakeProcess endBrake() {
@@ -453,7 +454,6 @@ public class Train extends BaseClass implements Comparable<Train> {
 		direction = endedRoute.endDirection; // muss vor der Auswertung des Destination-Tags stehen!				
 		Block endBlock = endedRoute.endBlock();
 		Block startBlock = endedRoute.startBlock();
-		shunting = false;
 		if (endBlock == destination) {
 			destination = null;
 			
@@ -504,6 +504,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 		if ((!autopilot) || isNull(nextPreparedRoute) || (isSet(waitTime) && waitTime > 0)) setSpeed(0);
 		route = null;
 		endBlock.setTrain(this);
+		shunting = false; // wird in setTrain verwendet, muss also danach stehen
 		currentBlock = endBlock;
 		trace.add(endBlock);
 		if (!trace.contains(startBlock)) startBlock.dropTrain(this);

src/main/java/de/srsoftware/web4rail/threads/BrakeProcess.java

@@ -85,6 +85,7 @@ public class BrakeProcess extends BaseClass implements Runnable{
 		updateDistance();
 		LOG.debug("updateTime(): start speed was {} {}.",startSpeed,BaseClass.speedUnit);
 		Integer newTimeStep = timeStep;
+		if (isNull(newTimeStep)) return;
 		long calculated;
 		int step = 32*newTimeStep;			
 		for (int i=0; i<20; i++) {

src/main/java/de/srsoftware/web4rail/tiles/Block.java

@@ -453,6 +453,15 @@ public abstract class Block extends StretchableTile{
 		internalContacts.remove(blockContact);
 	}
 	
+	@Override
+	public boolean setTrain(Train newTrain) {
+		if (isDisabled()) return false;
+		if (isNull(newTrain)) return false;
+		Train occupyingTrain = occupyingTrain();
+		if (isSet(occupyingTrain) && newTrain != occupyingTrain && newTrain.isShunting()) parkedTrains.add(occupyingTrain.dropTrace(false));
+		return super.setTrain(newTrain);
+	}
+	
 	public abstract List<Connector> startPoints();
 
 	@Override

src/main/java/de/srsoftware/web4rail/tiles/Tile.java

@@ -465,10 +465,10 @@ public abstract class Tile extends BaseClass implements Comparable<Tile> {
 		if (isNull(newTrain)) return false;		
 		if (isSet(reservingTrain) && newTrain != reservingTrain) return false;
 		if (isSet(lockingTrain)   && newTrain != lockingTrain)   return false;
-		if (isSet(occupyingTrain) && newTrain != occupyingTrain) return false;
+		if (isSet(occupyingTrain) && (newTrain != occupyingTrain) && !newTrain.isShunting()) return false;
+		reservingTrain = lockingTrain = null;
 		if (occupyingTrain == newTrain) return true;
 		occupyingTrain = newTrain;
-		reservingTrain = lockingTrain = null;
 		plan.place(this);
 		return true;
 	}