From 41832ce7e4a40eb8600fe473859a0548b3312d7b Mon Sep 17 00:00:00 2001
From: DerFrZocker <derrieple@gmail.com>
Date: Sat, 18 Dec 2021 11:33:22 +1100
Subject: [PATCH] SPIGOT-6843: Wrong PLAINS biome during custom chunk
 generation

---
 .../craftbukkit/generator/CustomChunkGenerator.java   | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
index d65f33a31..a05514870 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
@@ -186,6 +186,17 @@ public class CustomChunkGenerator extends InternalChunkGenerator {
             }
             ChunkSection section = sections[sec];
 
+            // SPIGOT-6843: Copy biomes over to new section.
+            // Not the most performant way, but has a small footprint and developer should move to the new api anyway
+            ChunkSection oldSection = csect[sec];
+            for (int biomeX = 0; biomeX < 4; biomeX++) {
+                for (int biomeY = 0; biomeY < 4; biomeY++) {
+                    for (int biomeZ = 0; biomeZ < 4; biomeZ++) {
+                        section.setBiome(biomeX, biomeY, biomeZ, oldSection.getNoiseBiome(biomeX, biomeY, biomeZ));
+                    }
+                }
+            }
+
             csect[sec] = section;
         }