Prevent nbt copy when placing a block

src/main/java/net/minestom/server/instance/DynamicChunk.java

@@ -55,8 +55,7 @@ public class DynamicChunk extends Chunk {
         final int index = ChunkUtils.getBlockIndex(x, y, z);
         // Handler
         final BlockHandler handler = block.handler();
-        final NBTCompound nbt = block.nbt();
+        if (handler != null || block.hasNbt()) {
-        if (handler != null || nbt != null) {
             this.entries.put(index, block);
         } else {
             this.entries.remove(index);

src/main/java/net/minestom/server/instance/block/Block.java

@@ -97,6 +97,9 @@ public interface Block extends ProtocolObject, TagReadable, BlockConstants {
         return getTag(Tag.NBT);
     }
 
+    @Contract(pure = true)
+    boolean hasNbt();
+
     /**
      * Returns the block handler.
      *

src/main/java/net/minestom/server/instance/block/BlockImpl.java

@@ -65,6 +65,11 @@ class BlockImpl implements Block {
         return new BlockImpl(registry, properties, nbt, handler);
     }
 
+    @Override
+    public boolean hasNbt() {
+        return nbt != null && nbt.getSize() > 0;
+    }
+
     @Override
     public @Nullable BlockHandler handler() {
         return handler;