Fix Entity position tracking

SpigotCore_Main/src/de/steamwar/entity/REntityServer.java

@@ -70,7 +70,7 @@ public class REntityServer implements Listener {
     }
 
     void addEntity(REntity entity) {
-        entities.computeIfAbsent(entityToId(entity), i -> new HashSet<>()).add(entity);
+        addEntityToChunk(entity);
         entity.spawn(packet -> updateEntity(entity, packet));
     }
 
@@ -81,6 +81,7 @@ public class REntityServer implements Listener {
             return;
 
         onMissing(players.get(fromId), players.get(toId), entity::despawn);
+        removeEntityFromChunk(entity);
     }
 
     void postEntityMove(REntity entity, double fromX, double fromZ) {
@@ -89,6 +90,7 @@ public class REntityServer implements Listener {
         if(fromId == toId)
             return;
 
+        addEntityToChunk(entity);
         onMissing(players.get(toId), players.get(fromId), entity::spawn);
     }
 
@@ -100,6 +102,14 @@ public class REntityServer implements Listener {
 
     void removeEntity(REntity entity) {
         entity.despawn(packet -> updateEntity(entity, packet));
+        removeEntityFromChunk(entity);
+    }
+
+    private void addEntityToChunk(REntity entity) {
+        entities.computeIfAbsent(entityToId(entity), i -> new HashSet<>()).add(entity);
+    }
+
+    private void removeEntityFromChunk(REntity entity) {
         long id = entityToId(entity);
         HashSet<REntity> entitiesInChunk = entities.get(id);
         entitiesInChunk.remove(entity);