Cancel unknown block entities in BlockRewriter#registerBlockEntityData (ViaVersion#4466)

Author: FlorianMichael

common/src/main/java/com/viaversion/viaversion/rewriter/BlockRewriter.java

@@ -268,7 +268,12 @@ public void registerBlockEntityData(C packetType, @Nullable BiConsumer<UserConne
             final int blockEntityId = wrapper.read(Types.VAR_INT);
             final Mappings mappings = protocol.getMappingData().getBlockEntityMappings();
             if (mappings != null) {
-                wrapper.write(Types.VAR_INT, mappings.getNewIdOrDefault(blockEntityId, blockEntityId));
+                final int mappedBlockEntityId = mappings.getNewId(blockEntityId);
+                if (mappedBlockEntityId == -1) {
+                    wrapper.cancel();
+                    return;
+                }
+                wrapper.write(Types.VAR_INT, mappedBlockEntityId);
             } else {
                 wrapper.write(Types.VAR_INT, blockEntityId);
             }

common/src/main/java/com/viaversion/viaversion/util/SerializerVersion.java

@@ -50,7 +50,7 @@ public enum SerializerVersion {
     V1_20_3(TextComponentCodec.V1_20_3, SNbt.V1_14),
     V1_20_5(TextComponentCodec.V1_20_5, SNbt.V1_14),
     V1_21_4(TextComponentCodec.V1_21_4, SNbt.V1_14),
-    V1_21_5(TextComponentCodec.V1_21_5, SNbt.V1_21_5);
+    V1_21_5(TextComponentCodec.V1_21_5, null/*Currently not needed and also not implemented 100% in MCStructs*/);
 
     final TextComponentSerializer jsonSerializer;
     final SNbt<? extends Tag> sNbt;