From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Wed, 21 Dec 2022 10:38:41 -0800
Subject: [PATCH] Fix spawn-animals and spawn-monsters settings


diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index d9cd497bc1b654030ff1a597f038b6a881df9f6b..b8ad61d7a0fb4bda02a561b284fcbf19ee3b0e0c 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -649,18 +649,12 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         if (!nbt.isEmpty()) {
             // CraftBukkit start - these are spawned serialized (DefinedStructure) and we don't call an add event below at the moment due to ordering complexities
             world.addWorldGenChunkEntities(EntityType.loadEntitiesRecursive(nbt, world).filter((entity) -> {
-                boolean needsRemoval = false;
-                net.minecraft.server.dedicated.DedicatedServer server = world.getCraftServer().getServer();
-                if (!server.areNpcsEnabled() && entity instanceof net.minecraft.world.entity.npc.Npc) {
+                if (world.shouldDiscardEntityInWorld(entity)) { // Paper - this needs to be per-world & simplified
                     entity.discard();
-                    needsRemoval = true;
-                }
-                if (!server.isSpawningAnimals() && (entity instanceof net.minecraft.world.entity.animal.Animal || entity instanceof net.minecraft.world.entity.animal.WaterAnimal)) {
-                    entity.discard();
-                    needsRemoval = true;
+                    return false; // Paper
                 }
                 checkDupeUUID(world, entity); // Paper
-                return !needsRemoval;
+                return true; // Paper
             }), position); // Paper - rewrite chunk system
             // CraftBukkit end
         }
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index b78a9628a88f2a495ef6de74446a02a14d41a1f6..fd190f19f11ec9253b715abd7971d0e551013486 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -970,6 +970,11 @@ public class ServerLevel extends Level implements WorldGenLevel {
     private boolean shouldDiscardEntity(Entity entity) {
         return !this.server.isSpawningAnimals() && (entity instanceof Animal || entity instanceof WaterAnimal) ? true : !this.server.areNpcsEnabled() && entity instanceof Npc;
     }
+    // Paper start - per world version of above method
+    public boolean shouldDiscardEntityInWorld(Entity entity) {
+        return !this.getChunkSource().spawnFriendlies && (entity instanceof Animal || entity instanceof WaterAnimal) ? true : !this.server.areNpcsEnabled() && entity instanceof Npc; // TODO per-world npc setting in paper configs
+    }
+    // Paper end
 
     private void wakeUpAllPlayers() {
         this.sleepStatus.removeAllSleepers();
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index f67ec3f5f4b7e2f678609f2387cc8afa2adce161..7bbbedb718ebc9029029714de892bd838929c6f0 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -673,17 +673,15 @@ public class CraftEventFactory {
         return event;
     }
 
-    public static boolean doEntityAddEventCalling(Level world, Entity entity, SpawnReason spawnReason) {
+    public static boolean doEntityAddEventCalling(ServerLevel world, Entity entity, SpawnReason spawnReason) { // Paper
         if (entity == null) return false;
 
         org.bukkit.event.Cancellable event = null;
         if (entity instanceof net.minecraft.world.entity.LivingEntity && !(entity instanceof ServerPlayer)) {
-            boolean isAnimal = entity instanceof Animal || entity instanceof WaterAnimal || entity instanceof AbstractGolem;
-            boolean isMonster = entity instanceof Monster || entity instanceof Ghast || entity instanceof Slime;
-            boolean isNpc = entity instanceof Npc;
+            // Paper - this was wrong in several different ways
 
             if (spawnReason != SpawnReason.CUSTOM) {
-                if (isAnimal && !world.getWorld().getAllowAnimals() || isMonster && !world.getWorld().getAllowMonsters() || isNpc && !world.getCraftServer().getServer().areNpcsEnabled()) {
+                if (world.shouldDiscardEntityInWorld(entity)) { // Paper - this was wrong in several different ways
                     entity.discard();
                     return false;
                 }