BDS CompressedBiomeDefinitionListSerializer_v582 deserialize/serialize error

[romanalexander]

Somewhere around protocol 729 the CompressedBiomeDefinitionList packet got changed(?) and won't byte-for-byte serialize correctly, causing vanilla BDS to disconnect. Observed on client v1.21.30

Reproduce:
On latest head try to connect through BDS via ProxyPass with packet reserializing
Client will disconnect with Broken Packet unless you bypass deserializer for CompressedBiomeDefinitionList

[Kaooot]

I'm not aware of any changes to CompressedBiomeDefinitionListPacket in v729 and it worked fine for me when I used the latest ProxyPass version with changed codec for v729.

[romanalexander]

I just retested on b315ef6 this still occurs. On BDS 1.21.30.25, client version 1.21.30

Flat world won't send any compressed biome data, only a vanilla singleplayer world will.

[Alemiz112]

I was able to repro this. Will investigate soon.

[romanalexander]

attached is the state of the bytebuffer bidirectionally packetlog.zip
the serialized data is much larger than what BDS sends