Null check entity type in LegacyEntityRewriter#getObjectTrackerHandler (#935)

common/src/main/java/com/viaversion/viabackwards/api/rewriters/EntityRewriter.java

@@ -140,6 +140,7 @@ public abstract class EntityRewriter<C extends ClientboundPacketType, T extends
         if (entityType == null) {
             return null;
         }
+
         tracker(wrapper.user()).addEntity(wrapper.get(Types.VAR_INT, 0), entityType);
 
         int mappedTypeId = newEntityId(entityType.getId());

common/src/main/java/com/viaversion/viabackwards/api/rewriters/LegacyEntityRewriter.java

@@ -124,7 +124,14 @@ public abstract class LegacyEntityRewriter<C extends ClientboundPacketType, T ex
     }
 
     protected PacketHandler getObjectTrackerHandler() {
-        return wrapper -> addTrackedEntity(wrapper, wrapper.get(Types.VAR_INT, 0), objectTypeFromId(wrapper.get(Types.BYTE, 0)));
+        return wrapper -> {
+            EntityType type = objectTypeFromId(wrapper.get(Types.BYTE, 0));
+            if (type == null) {
+                return;
+            }
+
+            addTrackedEntity(wrapper, wrapper.get(Types.VAR_INT, 0), type);
+        };
     }
 
     protected PacketHandler getTrackerAndDataHandler(Type<List<EntityData>> dataType, EntityType entityType) {

common/src/main/java/com/viaversion/viabackwards/protocol/v1_13to1_12_2/rewriter/EntityPacketRewriter1_13.java

@@ -138,6 +138,7 @@ public class EntityPacketRewriter1_13 extends LegacyEntityRewriter<ClientboundPa
                     if (entityType == null) {
                         return;
                     }
+
                     tracker(wrapper.user()).addEntity(wrapper.get(Types.VAR_INT, 0), entityType);
 
                     int oldId = EntityIdMappings1_12_2.getOldId(type);