Paper/patches/server/1032-Don-t-fire-sync-events-during-worldgen.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Thu, 23 Nov 2023 10:33:25 -0800
Subject: [PATCH] Don't fire sync events during worldgen

Fixes EntityPotionEffectEvent
Fixes EntityPoseChangeEvent

Asynchronous chunk generation provides an opportunity for things
to happen async that previously fired synchronous-only events. This
patch is for mitigating those issues by various methods.

Also fixes correctly marking/clearing the entity generation flag.
This patch sets the generation flag anytime an entity is created
via StructureTemplate before loading from NBT to catch uses of
the flag during the loading logic. This patch clears the generation
flag from an entity when added to a ServerLevel for the situation
where generation happened directly to a ServerLevel and the
entity still has the flag set.

diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index ad4a987c1de4265f9f0d6a8769aaed95d0a66786..a1fd04399ef61d0257d1e4a6bb627e4a1b7a7ceb 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -1681,6 +1681,7 @@ public class ServerLevel extends Level implements WorldGenLevel {
     // CraftBukkit start
     private boolean addEntity(Entity entity, CreatureSpawnEvent.SpawnReason spawnReason) {
         org.spigotmc.AsyncCatcher.catchOp("entity add"); // Spigot
+        entity.generation = false; // Paper - Don't fire sync event during generation; Reset flag if it was added during a ServerLevel generation process
         // Paper start
         if (entity.valid) {
             MinecraftServer.LOGGER.error("Attempted Double World add on " + entity, new Throwable());
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index aef714923ff1e9d476aacd9bfaa80f85dc84890b..d77faa799de1b7cc23adb91d82a45a05532532f1 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -713,7 +713,11 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, S
         if (pose == this.getPose()) {
             return;
         }
-        this.level.getCraftServer().getPluginManager().callEvent(new EntityPoseChangeEvent(this.getBukkitEntity(), Pose.values()[pose.ordinal()]));
+        // Paper start - Don't fire sync event during generation
+        if (!this.generation) {
+            this.level.getCraftServer().getPluginManager().callEvent(new EntityPoseChangeEvent(this.getBukkitEntity(), Pose.values()[pose.ordinal()]));
+        }
+        // Paper end - Don't fire sync event during generation
         // CraftBukkit end
         this.entityData.set(Entity.DATA_POSE, pose);
     }
diff --git a/src/main/java/net/minecraft/world/entity/EntityType.java b/src/main/java/net/minecraft/world/entity/EntityType.java
index 940b8d0b89d7e55c938aefbe80ee71b0db3dacb8..abb2a02e0fc1deedb0ad76aec64f74ce355129cc 100644
--- a/src/main/java/net/minecraft/world/entity/EntityType.java
+++ b/src/main/java/net/minecraft/world/entity/EntityType.java
@@ -588,9 +588,15 @@ public class EntityType<T extends Entity> implements FeatureElement, EntityTypeT
     }
 
     public static Optional<Entity> create(CompoundTag nbt, Level world) {
+        // Paper start - Don't fire sync event during generation
+        return create(nbt, world, false);
+    }
+    public static Optional<Entity> create(CompoundTag nbt, Level world, boolean generation) {
+        // Paper end - Don't fire sync event during generation
         return Util.ifElse(EntityType.by(nbt).map((entitytypes) -> {
             return entitytypes.create(world);
         }), (entity) -> {
+            if (generation) entity.generation = true; // Paper - Don't fire sync event during generation
             entity.load(nbt);
         }, () -> {
             EntityType.LOGGER.warn("Skipping Entity with id {}", nbt.getString("id"));
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index c30ae7d8b5ee601db30111054c74ce60625d8203..7204fc4d535fb7cf5579aa51148e6a1262f3124d 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -1133,6 +1133,11 @@ public abstract class LivingEntity extends Entity implements Attackable {
     }
 
     public boolean addEffect(MobEffectInstance mobeffect, @Nullable Entity entity, EntityPotionEffectEvent.Cause cause) {
+        // Paper start - Don't fire sync event during generation
+        return this.addEffect(mobeffect, entity, cause, true);
+    }
+    public boolean addEffect(MobEffectInstance mobeffect, @Nullable Entity entity, EntityPotionEffectEvent.Cause cause, boolean fireEvent) {
+        // Paper end - Don't fire sync event during generation
         // org.spigotmc.AsyncCatcher.catchOp("effect add"); // Spigot // Paper - move to API
         if (this.isTickingEffects) {
             this.effectsToProcess.add(new ProcessableEffect(mobeffect, cause));
@@ -1152,10 +1157,13 @@ public abstract class LivingEntity extends Entity implements Attackable {
                 override = new MobEffectInstance(mobeffect1).update(mobeffect);
             }
 
+            if (fireEvent) { // Paper - Don't fire sync event during generation
             EntityPotionEffectEvent event = CraftEventFactory.callEntityPotionEffectChangeEvent(this, mobeffect1, mobeffect, cause, override);
+            override = event.isOverride(); // Paper - Don't fire sync event during generation
             if (event.isCancelled()) {
                 return false;
             }
+            } // Paper - Don't fire sync event during generation
             // CraftBukkit end
 
             if (mobeffect1 == null) {
@@ -1163,7 +1171,7 @@ public abstract class LivingEntity extends Entity implements Attackable {
                 this.onEffectAdded(mobeffect, entity);
                 flag = true;
                 // CraftBukkit start
-            } else if (event.isOverride()) {
+            } else if (override) { // Paper - Don't fire sync event during generation
                 mobeffect1.update(mobeffect);
                 this.onEffectUpdated(mobeffect1, true, entity);
                 // CraftBukkit end
diff --git a/src/main/java/net/minecraft/world/entity/monster/Spider.java b/src/main/java/net/minecraft/world/entity/monster/Spider.java
index 5a9f4a022c8e7a0804543335bfe91e1328d040e6..8094c133f9e934c98eee09738220bacd87a0a364 100644
--- a/src/main/java/net/minecraft/world/entity/monster/Spider.java
+++ b/src/main/java/net/minecraft/world/entity/monster/Spider.java
@@ -182,7 +182,7 @@ public class Spider extends Monster {
             MobEffect mobeffectlist = entityspider_groupdataspider.effect;
 
             if (mobeffectlist != null) {
-                this.addEffect(new MobEffectInstance(mobeffectlist, -1), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.SPIDER_SPAWN); // CraftBukkit
+                this.addEffect(new MobEffectInstance(mobeffectlist, -1), null, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.SPIDER_SPAWN, world instanceof net.minecraft.server.level.ServerLevel); // CraftBukkit // Paper - Don't fire sync event during generation; only if this is happening in a ServerLevel
             }
         }
 
diff --git a/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java b/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
index 52c389472e013e658344496218689465350bf8a3..8c4d434bffa640a17d6870080f79cd0e492c7537 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/structure/templatesystem/StructureTemplate.java
@@ -518,7 +518,7 @@ public class StructureTemplate {
     private static Optional<Entity> createEntityIgnoreException(ServerLevelAccessor world, CompoundTag nbt) {
         // CraftBukkit start
         // try {
-            return EntityType.create(nbt, world.getLevel());
+            return EntityType.create(nbt, world.getLevel(), true); // Paper - Don't fire sync event during generation
         // } catch (Exception exception) {
             // return Optional.empty();
         // }
diff --git a/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java b/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
index a650411e3fa7e2a045ac55502c77028be348acf1..86a20c91beff6b27e6ec886e49ba902b216106f2 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
@@ -93,15 +93,17 @@ public abstract class DelegatedGeneratorAccess implements WorldGenLevel {
         return this.handle.getLevel();
     }
 
-    @Override
-    public void addFreshEntityWithPassengers(Entity arg0, CreatureSpawnEvent.SpawnReason arg1) {
-        this.handle.addFreshEntityWithPassengers(arg0, arg1);
-    }
-
-    @Override
-    public void addFreshEntityWithPassengers(Entity entity) {
-        this.handle.addFreshEntityWithPassengers(entity);
-    }
+    // Paper start - Don't fire sync event during generation; don't override these methods so all entities are run through addFreshEntity
+    // @Override
+    // public void addFreshEntityWithPassengers(Entity arg0, CreatureSpawnEvent.SpawnReason arg1) {
+    //     this.handle.addFreshEntityWithPassengers(arg0, arg1);
+    // }
+    //
+    // @Override
+    // public void addFreshEntityWithPassengers(Entity entity) {
+    //     this.handle.addFreshEntityWithPassengers(entity);
+    // }
+    // Paper end - Don't fire sync event during generation; don't override these methods
 
     @Override
     public ServerLevel getMinecraftWorld() {
diff --git a/src/main/java/org/bukkit/craftbukkit/util/TransformerGeneratorAccess.java b/src/main/java/org/bukkit/craftbukkit/util/TransformerGeneratorAccess.java
index b4b297945fb601701aac845d09e88fb74b09c3fa..7482dfe64458320d44089c0778591694202e9f70 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/TransformerGeneratorAccess.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/TransformerGeneratorAccess.java
@@ -39,21 +39,23 @@ public class TransformerGeneratorAccess extends DelegatedGeneratorAccess {
         return super.addFreshEntity(arg0, arg1);
     }
 
-    @Override
-    public void addFreshEntityWithPassengers(Entity entity) {
-        if (this.structureTransformer != null && !this.structureTransformer.transformEntity(entity)) {
-            return;
-        }
-        super.addFreshEntityWithPassengers(entity);
-    }
-
-    @Override
-    public void addFreshEntityWithPassengers(Entity arg0, SpawnReason arg1) {
-        if (this.structureTransformer != null && !this.structureTransformer.transformEntity(arg0)) {
-            return;
-        }
-        super.addFreshEntityWithPassengers(arg0, arg1);
-    }
+    // Paper start - Don't fire sync event during generation; don't override these methods so all entities are run through addFreshEntity
+    // @Override
+    // public void addFreshEntityWithPassengers(Entity entity) {
+    //     if (this.structureTransformer != null && !this.structureTransformer.transformEntity(entity)) {
+    //         return;
+    //     }
+    //     super.addFreshEntityWithPassengers(entity);
+    // }
+    //
+    // @Override
+    // public void addFreshEntityWithPassengers(Entity arg0, SpawnReason arg1) {
+    //     if (this.structureTransformer != null && !this.structureTransformer.transformEntity(arg0)) {
+    //         return;
+    //     }
+    //     super.addFreshEntityWithPassengers(arg0, arg1);
+    // }
+    // Paper end - Don't fire sync event during generation; don't override these methods
 
     public boolean setCraftBlock(BlockPos position, CraftBlockState craftBlockState, int i, int j) {
         if (this.structureTransformer != null) {