Fix biomes

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/packets/WorldPackets.java

@@ -171,6 +171,15 @@ public class WorldPackets {
                             }
                         }
 
+                        // Rewrite biome id 255 to plains
+                        if (chunk.isBiomeData()) {
+                            for (int i = 0; i < 256; i++) {
+                                int data = chunk.getBiomeData()[i] & 0xFF;
+                                if (data == 255)
+                                    chunk.getBiomeData()[i] = 1;
+                            }
+                        }
+
                         // Rewrite BlockEntities to normal blocks
                         BlockEntityProvider provider = Via.getManager().getProviders().get(BlockEntityProvider.class);
                         for (CompoundTag tag : chunk.getBlockEntities()) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/types/Chunk1_13Type.java

@@ -101,7 +101,7 @@ public class Chunk1_13Type extends PartialType<Chunk, ClientWorld> {
         // Write biome data
         if (chunk.isBiomeData()) {
             for (byte value : chunk.getBiomeData()) {
-                output.writeInt(0); // This is a temporary workaround, we'll look into fixing this soon :)
+                output.writeInt(value & 0xFF); // This is a temporary workaround, we'll look into fixing this soon :)
             }
         }