From ad2c4f712acd7b7bd10e4dae9181cd3edf98b9ca Mon Sep 17 00:00:00 2001
From: Paul Sauve <paul@burngames.net>
Date: Sun, 14 Jul 2019 21:05:03 -0500
Subject: [PATCH] Do less work if we have a custom Bukkit generator

If the Bukkit generator already has a spawn, use it immediately instead
of spending time generating one that we won't use

diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index 6220af6b4..f1ad7be75 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -663,12 +663,6 @@ public class WorldServer extends World {
         } else if (this.worldData.getType() == WorldType.DEBUG_ALL_BLOCK_STATES) {
             this.worldData.setSpawn(BlockPosition.ZERO.up());
         } else {
-            WorldChunkManager worldchunkmanager = this.chunkProvider.getChunkGenerator().getWorldChunkManager();
-            List<BiomeBase> list = worldchunkmanager.a();
-            Random random = new Random(this.getSeed());
-            BlockPosition blockposition = worldchunkmanager.a(0, 0, 256, list, random);
-            ChunkCoordIntPair chunkcoordintpair = blockposition == null ? new ChunkCoordIntPair(0, 0) : new ChunkCoordIntPair(blockposition);
-
             // CraftBukkit start
             if (this.generator != null) {
                 Random rand = new Random(this.getSeed());
@@ -685,6 +679,14 @@ public class WorldServer extends World {
             }
             // CraftBukkit end
 
+            // Paper start - this is useless if craftbukkit returns early
+            WorldChunkManager worldchunkmanager = this.chunkProvider.getChunkGenerator().getWorldChunkManager();
+            List<BiomeBase> list = worldchunkmanager.a();
+            Random random = new Random(this.getSeed());
+            BlockPosition blockposition = worldchunkmanager.a(0, 0, 256, list, random);
+            ChunkCoordIntPair chunkcoordintpair = blockposition == null ? new ChunkCoordIntPair(0, 0) : new ChunkCoordIntPair(blockposition);
+            // Paper end
+
             if (blockposition == null) {
                 WorldServer.LOGGER.warn("Unable to find spawn biome");
             }
-- 
2.23.0