Purpur/patches/server/0200-Fix-advancement-triggers-on-entity-death.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: William Blake Galbreath <Blake.Galbreath@GMail.com>
Date: Fri, 28 May 2021 12:24:45 -0500
Subject: [PATCH] Fix advancement triggers on entity death

This fixes PaperMC/Paper#3729 and PaperMC/Paper#4252

Paper changes logical order revolving around making the EntityDeathEvent
cancellable. Reordering this logic has ended up with entity equipment being
cleared _before_ advancement criteria can run, causing things like killing
raid captains not giving the voluntary exile advancement.

This fixes the issue by storing a copy of the equipment in a new field just
before doing the death event logic where the equipment is cleared and then
restoring it back to the entity just before the criterion triggers run and
then finally clearing the equipment again right after the criterion is done.

diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 47d9560f4f092e999488a735f6ef9987d4bab0c0..51b6c005db04ba60a3766bc6072ef311eab53992 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -1661,10 +1661,13 @@ public abstract class LivingEntity extends Entity {
                 }
 
                 // Paper start
+                List<List<ItemStack>> equipmentSnapshotBefore = this.cloneEquipment(); // Purpur
                 org.bukkit.event.entity.EntityDeathEvent deathEvent = this.dropAllDeathLoot(source);
                 if (deathEvent == null || !deathEvent.isCancelled()) {
                     if (this.deathScore >= 0 && entityliving != null) {
+                        this.restoreEquipment(equipmentSnapshotBefore); // Purpur
                         entityliving.awardKillScore(this, this.deathScore, source);
+                        this.clearEquipment(); // Purpur
                     }
 
                     if (this.isSleeping()) {
@@ -2548,6 +2551,12 @@ public abstract class LivingEntity extends Entity {
     @Override
     public abstract void setItemSlot(EquipmentSlot slot, ItemStack stack);
 
+    // Purpur start
+    public abstract List<List<ItemStack>> cloneEquipment();
+    public abstract void restoreEquipment(List<List<ItemStack>> list);
+    public abstract void clearEquipment();
+    // Purpur end
+
     protected void verifyEquippedItem(ItemStack stack) {
         CompoundTag nbttagcompound = stack.getTag();
 
diff --git a/src/main/java/net/minecraft/world/entity/Mob.java b/src/main/java/net/minecraft/world/entity/Mob.java
index 02a227e1239ca3a1d54d746ea14b6ae7b12d1cd0..74e73e52139445dd2090cfd3abdbf22497a7b4da 100644
--- a/src/main/java/net/minecraft/world/entity/Mob.java
+++ b/src/main/java/net/minecraft/world/entity/Mob.java
@@ -1026,6 +1026,41 @@ public abstract class Mob extends LivingEntity {
 
     }
 
+    // Purpur start
+    public List<List<ItemStack>> cloneEquipment() {
+        List<List<ItemStack>> list = new java.util.ArrayList<>();
+        List<ItemStack> handItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.handItems) {
+            handItems.add(item.copy());
+        }
+        list.add(handItems);
+        List<ItemStack> armorItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.armorItems) {
+            armorItems.add(item.copy());
+        }
+        list.add(armorItems);
+        return list;
+    }
+
+    public void restoreEquipment(List<List<ItemStack>> list) {
+        this.handItems.clear();
+        List<ItemStack> handItems = list.get(0);
+        for (int i = 0; i < handItems.size(); i++) {
+            this.handItems.set(i, handItems.get(1));
+        }
+        this.armorItems.clear();
+        List<ItemStack> armorItems = list.get(1);
+        for (int i = 0; i < armorItems.size(); i++) {
+            this.armorItems.set(i, armorItems.get(i));
+        }
+    }
+
+    public void clearEquipment() {
+        this.handItems.clear();
+        this.armorItems.clear();
+    }
+    // Purpur end
+
     @Override
     protected void dropCustomDeathLoot(DamageSource source, int lootingMultiplier, boolean allowDrops) {
         super.dropCustomDeathLoot(source, lootingMultiplier, allowDrops);
diff --git a/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java b/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
index 31454b15a20e0484e21c25ffb80d4d536e2ecc0b..4fd44e58e9b83f45a66562f53710ee647b7e2b1b 100644
--- a/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
+++ b/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
@@ -205,6 +205,41 @@ public class ArmorStand extends LivingEntity {
         this.noTickEquipmentDirty = true; // Paper - Allow equipment to be updated even when tick disabled
     }
 
+    // Purpur start
+    public List<List<ItemStack>> cloneEquipment() {
+        List<List<ItemStack>> list = new java.util.ArrayList<>();
+        List<ItemStack> handItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.handItems) {
+            handItems.add(item.copy());
+        }
+        list.add(handItems);
+        List<ItemStack> armorItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.armorItems) {
+            armorItems.add(item.copy());
+        }
+        list.add(armorItems);
+        return list;
+    }
+
+    public void restoreEquipment(List<List<ItemStack>> list) {
+        this.handItems.clear();
+        List<ItemStack> handItems = list.get(0);
+        for (int i = 0; i < handItems.size(); i++) {
+            this.handItems.set(i, handItems.get(1));
+        }
+        this.armorItems.clear();
+        List<ItemStack> armorItems = list.get(1);
+        for (int i = 0; i < armorItems.size(); i++) {
+            this.armorItems.set(i, armorItems.get(1));
+        }
+    }
+
+    public void clearEquipment() {
+        this.handItems.clear();
+        this.armorItems.clear();
+    }
+    // Purpur end
+
     @Override
     public boolean canTakeItem(ItemStack stack) {
         net.minecraft.world.entity.EquipmentSlot enumitemslot = Mob.getEquipmentSlotForItem(stack);
diff --git a/src/main/java/net/minecraft/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
index 8a06a090993119da256db12671e56720ef74c2e2..0c0d4ec5893f082a8b4071a627a64c7b88fd0067 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -1988,6 +1988,52 @@ public abstract class Player extends LivingEntity {
 
     }
 
+    // Purpur start
+    public List<List<ItemStack>> cloneEquipment() {
+        List<List<ItemStack>> list = new java.util.ArrayList<>();
+        List<ItemStack> invItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.inventory.items) {
+            invItems.add(item.copy());
+        }
+        list.add(invItems);
+        List<ItemStack> armorItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.inventory.armor) {
+            armorItems.add(item.copy());
+        }
+        list.add(armorItems);
+        List<ItemStack> offhandItems = new java.util.ArrayList<>();
+        for (ItemStack item : this.inventory.offhand) {
+            offhandItems.add(item.copy());
+        }
+        list.add(offhandItems);
+        return list;
+    }
+
+    public void restoreEquipment(List<List<ItemStack>> list) {
+        this.inventory.items.clear();
+        List<ItemStack> invItems = list.get(0);
+        for (int i = 0; i < invItems.size(); i++) {
+            this.inventory.items.set(i, invItems.get(1));
+        }
+        this.inventory.armor.clear();
+        List<ItemStack> armorItems = list.get(1);
+        for (int i = 0; i < armorItems.size(); i++) {
+            this.inventory.armor.set(i, armorItems.get(1));
+        }
+        this.inventory.offhand.clear();
+        List<ItemStack> offhandItems = list.get(2);
+        for (int i = 0; i < offhandItems.size(); i++) {
+            this.inventory.offhand.set(i, offhandItems.get(1));
+        }
+    }
+
+    public void clearEquipment() {
+        this.inventory.items.clear();
+        this.inventory.armor.clear();
+        this.inventory.offhand.clear();
+    }
+    // Purpur end
+
     public boolean addItem(ItemStack stack) {
         this.equipEventAndSound(stack);
         return this.inventory.add(stack);