Improve EntityTargetLivingEntityEvent for 1.16 mobs

CraftBukkit has a bug in their implementation and is incorrectly handling forget
Also adds more target reasons for why it forgot target.

Fixes #4042

2 files changed, 59 insertions, 39 deletions

diff --git a/Spigot-Server-Patches/0532-Improve-EntityTargetLivingEntityEvent-for-1.16-mobs.patch b/Spigot-Server-Patches/0532-Improve-EntityTargetLivingEntityEvent-for-1.16-mobs.patch
new file mode 100644
index 0000000000..b7c5a49bd4
--- /dev/null
+++ b/Spigot-Server-Patches/0532-Improve-EntityTargetLivingEntityEvent-for-1.16-mobs.patch
@@ -0,0 +1,59 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jake Potrebic <[email protected]>
+Date: Fri, 3 Jul 2020 15:03:33 -0700
+Subject: [PATCH] Improve EntityTargetLivingEntityEvent for 1.16 mobs
+
+CraftBukkit has a bug in their implementation and is incorrectly handling forget
+Also adds more target reasons for why it forgot target.
+
+diff --git a/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java b/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
+index 254a4afeed2148fc1a8d698c90ba0b98eda01687..51203fd30bfee57ef8d52d0360a64a7e1d6c65a3 100644
+--- a/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
++++ b/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
+@@ -26,15 +26,15 @@ public class BehaviorAttackTargetForget<E extends EntityInsentient> extends Beha
+ 
+     protected void a(WorldServer worldserver, E e0, long i) {
+         if (a((EntityLiving) e0)) {
+-            this.d(e0);
++            this.d(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.FORGOT_TARGET); // Paper
+         } else if (this.c(e0)) {
+-            this.d(e0);
++            this.d(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_DIED); // Paper
+         } else if (this.a(e0)) {
+-            this.d(e0);
++            this.d(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_OTHER_LEVEL); // Paper
+         } else if (!IEntitySelector.f.test(this.b(e0))) {
+-            this.d(e0);
++            this.d(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_INVALID); // Paper
+         } else if (this.b.test(this.b(e0))) {
+-            this.d(e0);
++            this.d(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_INVALID); // Paper
+         }
+     }
+ 
+@@ -58,17 +58,20 @@ public class BehaviorAttackTargetForget<E extends EntityInsentient> extends Beha
+         return optional.isPresent() && !((EntityLiving) optional.get()).isAlive();
+     }
+ 
+-    private void d(E e0) {
++    private void d(E e0, EntityTargetEvent.TargetReason reason) {
+         // CraftBukkit start
+-        EntityLiving old = e0.getBehaviorController().getMemory(MemoryModuleType.ATTACK_TARGET).orElse(null);
+-        EntityTargetEvent event = CraftEventFactory.callEntityTargetLivingEvent(e0, old, (old != null && !old.isAlive()) ? EntityTargetEvent.TargetReason.TARGET_DIED : EntityTargetEvent.TargetReason.FORGOT_TARGET);
++        // Paper start - fix this event
++        //EntityLiving old = e0.getBehaviorController().getMemory(MemoryModuleType.ATTACK_TARGET).orElse(null);
++        EntityTargetEvent event = CraftEventFactory.callEntityTargetLivingEvent(e0, null, reason);
+         if (event.isCancelled()) {
+             return;
+         }
+-        if (event.getTarget() != null) {
++        // comment out, bad logic - bad
++        /*if (event.getTarget() != null) {
+             e0.getBehaviorController().setMemory(MemoryModuleType.ATTACK_TARGET, ((CraftLivingEntity) event.getTarget()).getHandle());
+             return;
+-        }
++        }*/
++        // Paper end
+         // CraftBukkit end
+         e0.getBehaviorController().removeMemory(MemoryModuleType.ATTACK_TARGET);
+     }
diff --git a/Spigot-Server-Patches/0532-added-EntityTargetLivingEntityEvent-to-1.16-mobs.patch b/Spigot-Server-Patches/0532-added-EntityTargetLivingEntityEvent-to-1.16-mobs.patch
deleted file mode 100644
index 2fc8f4b530..0000000000
--- a/Spigot-Server-Patches/0532-added-EntityTargetLivingEntityEvent-to-1.16-mobs.patch
+++ /dev/null
@@ -1,39 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Jake Potrebic <[email protected]>
-Date: Fri, 3 Jul 2020 15:03:33 -0700
-Subject: [PATCH] added EntityTargetLivingEntityEvent to 1.16 mobs
-
-1.16 added a different behavior system for the new mobs
-
-diff --git a/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java b/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
-index 254a4afeed2148fc1a8d698c90ba0b98eda01687..643e996b87acd95d6fecf9a3883a0744f4d223a9 100644
---- a/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
-+++ b/src/main/java/net/minecraft/server/BehaviorAttackTargetForget.java
-@@ -26,15 +26,22 @@ public class BehaviorAttackTargetForget<E extends EntityInsentient> extends Beha
- 
-     protected void a(WorldServer worldserver, E e0, long i) {
-         if (a((EntityLiving) e0)) {
--            this.d(e0);
-+            handleEvent(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.FORGOT_TARGET); // Paper
-         } else if (this.c(e0)) {
--            this.d(e0);
-+            handleEvent(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_DIED); // Paper
-         } else if (this.a(e0)) {
--            this.d(e0);
-+            handleEvent(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_OTHER_LEVEL); // Paper
-         } else if (!IEntitySelector.f.test(this.b(e0))) {
--            this.d(e0);
-+            handleEvent(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_INVALID); // Paper
-         } else if (this.b.test(this.b(e0))) {
--            this.d(e0);
-+            handleEvent(e0, org.bukkit.event.entity.EntityTargetEvent.TargetReason.TARGET_INVALID); // Paper
-+        }
-+    }
-+    // Paper start
-+    private void handleEvent(E entity, org.bukkit.event.entity.EntityTargetEvent.TargetReason reason) {
-+        org.bukkit.event.entity.EntityTargetLivingEntityEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callEntityTargetLivingEvent(entity, null, reason);
-+        if (!event.isCancelled()) {
-+            this.d(entity);
-         }
-     }
-