Paper/patches/server/0854-Prevent-entity-loading-causing-async-lookups.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Sun, 6 Mar 2022 11:09:09 -0500
Subject: [PATCH] Prevent entity loading causing async lookups


diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 8770c02b6ba1d1dcb7b5fa3ac7f006a7097234f5..0bc808ac268dce5a170e7e55666885b8c2c09164 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -788,6 +788,7 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource {
 
     public void baseTick() {
         this.level.getProfiler().push("entityBaseTick");
+        if (firstTick && this instanceof net.minecraft.world.entity.NeutralMob neutralMob) neutralMob.tickInitialPersistentAnger(level); // Paper - Update last hurt when ticking
         this.feetBlockState = null;
         if (this.isPassenger() && this.getVehicle().isRemoved()) {
             this.stopRiding();
diff --git a/src/main/java/net/minecraft/world/entity/NeutralMob.java b/src/main/java/net/minecraft/world/entity/NeutralMob.java
index dedf76de5d6f46b9626ca4a98cfffe125b90dd0c..7dac62b6370dae3ad6d098857c3136d5acf2bd74 100644
--- a/src/main/java/net/minecraft/world/entity/NeutralMob.java
+++ b/src/main/java/net/minecraft/world/entity/NeutralMob.java
@@ -42,18 +42,11 @@ public interface NeutralMob {
                 UUID uuid = nbt.getUUID("AngryAt");
 
                 this.setPersistentAngerTarget(uuid);
-                Entity entity = ((ServerLevel) world).getEntity(uuid);
-
-                if (entity != null) {
-                    if (entity instanceof Mob) {
-                        this.setLastHurtByMob((Mob) entity);
-                    }
-
-                    if (entity.getType() == EntityType.PLAYER) {
-                        this.setLastHurtByPlayer((Player) entity);
-                    }
-
-                }
+                // Paper - Moved diff to separate method
+                // If this entity already survived its first tick, e.g. is loaded and ticked in sync, actively
+                // tick the initial persistent anger.
+                // If not, let the first tick on the baseTick call the method later down the line.
+                if (this instanceof Entity entity && !entity.firstTick) this.tickInitialPersistentAnger(world);
             }
         }
     }
@@ -127,4 +120,26 @@ public interface NeutralMob {
 
     @Nullable
     LivingEntity getTarget();
+
+    // Paper start - Update last hurt when ticking
+    default void tickInitialPersistentAnger(Level level) {
+        UUID target = getPersistentAngerTarget();
+        if (target == null) {
+            return;
+        }
+
+        Entity entity = ((ServerLevel) level).getEntity(target);
+
+        if (entity != null) {
+            if (entity instanceof Mob) {
+                this.setLastHurtByMob((Mob) entity);
+            }
+
+            if (entity.getType() == EntityType.PLAYER) {
+                this.setLastHurtByPlayer((Player) entity);
+            }
+
+        }
+    }
+    // Paper end
 }