Purpur/patches/server/0205-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 214bc2bcbcb88a9a62d2151a62aaa57beadc7da0..6d7a2eece40e5c665d6ec6f21f8a342e350fbec4 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 5e62ecb980199f8dba97703403ef811167a24ec5..0f8e261912feac68bdc8119d7368d8719618e787 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 c6267fa6832596c1c0944cecbbe0e4ed0eb3e0b8..dc26629d7aa1fc82dbc9902c807312cd814e5465 100644
--- a/src/main/java/net/minecraft/world/entity/player/Player.java
+++ b/src/main/java/net/minecraft/world/entity/player/Player.java
@@ -1991,6 +1991,52 @@ 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);