From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Mon, 19 Sep 2022 00:13:02 +0100
Subject: [PATCH] Mitigate effects of WorldCreator#keepSpawnLoaded ret type
 change

TODO: Remove in 1.21?

diff --git a/src/main/java/org/bukkit/craftbukkit/util/Commodore.java b/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
index d7495ea25713e959d106764054ce6642af497035..7131ae1fdfd7ac22f8178ff4d6265b4b6c14acb8 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/Commodore.java
@@ -460,6 +460,12 @@ public class Commodore
                             super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CB_PACKAGE + "/advancement/CraftAdvancement", "getDisplay0", desc, false);
                             return;
                         }
+                        if (owner.equals("org/bukkit/WorldCreator") && name.equals("keepSpawnLoaded") && desc.equals("(Lnet/kyori/adventure/util/TriState;)V")) {
+                            super.visitMethodInsn(opcode, owner, name, "(Lnet/kyori/adventure/util/TriState;)Lorg/bukkit/WorldCreator;", itf);
+                            // new method has a return, so, make sure we pop it
+                            super.visitInsn(Opcodes.POP);
+                            return;
+                        }
                         // Paper end
 
                         // Paper start - ItemFactory#getSpawnEgg (paper had original method that returned ItemStack, upstream added identical but returned Material)