Paper/patches/server-unmapped/0279-Improve-death-events.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Phoenix616 <mail@moep.tv>
Date: Tue, 21 Aug 2018 01:39:35 +0100
Subject: [PATCH] Improve death events

This adds the ability to cancel the death events and to modify the sound
an entity makes when dying. (In cases were no sound should it will be
called with shouldPlaySound set to false allowing unsilencing of silent
entities)

It makes handling of entity deaths a lot nicer as you no longer need
to listen on the damage event and calculate if the entity dies yourself
to cancel the death which has the benefit of also receiving the dropped
items and experience which is otherwise only properly possible by using
internal code.

diff --git a/src/main/java/net/minecraft/server/level/EntityPlayer.java b/src/main/java/net/minecraft/server/level/EntityPlayer.java
index b581a6d3ec06498a4c6db92eb50c5d2b28038131..ae9e0f55ddc194aaef1e57e81863569d9bc7b8f3 100644
--- a/src/main/java/net/minecraft/server/level/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/level/EntityPlayer.java
@@ -214,6 +214,10 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     public int ping;
     public boolean viewingCredits;
     private int containerUpdateDelay; // Paper
+    // Paper start - cancellable death event
+    public boolean queueHealthUpdatePacket = false;
+    public net.minecraft.network.protocol.game.PacketPlayOutUpdateHealth queuedHealthUpdatePacket;
+    // Paper end
 
     // CraftBukkit start
     public String displayName;
@@ -717,6 +721,15 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
         IChatBaseComponent defaultMessage = this.getCombatTracker().getDeathMessage();
 
         org.bukkit.event.entity.PlayerDeathEvent event = CraftEventFactory.callPlayerDeathEvent(this, loot, PaperAdventure.asAdventure(defaultMessage), defaultMessage.getString(), keepInventory); // Paper - Adventure
+        // Paper start - cancellable death event
+        if (event.isCancelled()) {
+            // make compatible with plugins that might have already set the health in an event listener
+            if (this.getHealth() <= 0) {
+                this.setHealth((float) event.getReviveHealth());
+            }
+            return;
+        }
+        // Paper end
 
         // SPIGOT-943 - only call if they have an inventory open
         if (this.activeContainer != this.defaultContainer) {
@@ -863,8 +876,17 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
                         }
                     }
                 }
-
-                return super.damageEntity(damagesource, f);
+                // Paper start - cancellable death events
+                //return super.damageEntity(damagesource, f);
+                this.queueHealthUpdatePacket = true;
+                boolean damaged = super.damageEntity(damagesource, f);
+                this.queueHealthUpdatePacket = false;
+                if (this.queuedHealthUpdatePacket != null) {
+                    this.playerConnection.sendPacket(this.queuedHealthUpdatePacket);
+                    this.queuedHealthUpdatePacket = null;
+                }
+                return damaged;
+                // Paper end
             }
         }
     }
diff --git a/src/main/java/net/minecraft/world/damagesource/CombatTracker.java b/src/main/java/net/minecraft/world/damagesource/CombatTracker.java
index f6f79ed9c38206cc6a4feb5504e854a476868aec..7d2b947b3c2b255c01241f2c4a6d7377a0a7c671 100644
--- a/src/main/java/net/minecraft/world/damagesource/CombatTracker.java
+++ b/src/main/java/net/minecraft/world/damagesource/CombatTracker.java
@@ -203,6 +203,7 @@ public class CombatTracker {
         this.h = null;
     }
 
+    public final void reset() { this.g(); } // Paper - OBFHELPER
     public void g() {
         int i = this.f ? 300 : 100;
 
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 37497d7ff04b84d4758997970dbdbf88b40d0493..28390d3830ed9f3f5d97ab38913e6c40f9943a70 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -1538,6 +1538,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
     }
     // CraftBukkit end
 
+    public final void runKillTrigger(Entity entity, int kills, DamageSource damageSource) { this.a(entity, kills, damageSource); } // Paper - OBFHELPER
     public void a(Entity entity, int i, DamageSource damagesource) {
         if (entity instanceof EntityPlayer) {
             CriterionTriggers.c.a((EntityPlayer) entity, this, damagesource);
@@ -2442,6 +2443,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, ne
         this.fallDistance = 0.0F;
     }
 
+    public final void onKill(WorldServer worldserver, EntityLiving entityLiving) { this.a(worldserver, entityLiving); } // Paper - OBFHELPER
     public void a(WorldServer worldserver, EntityLiving entityliving) {}
 
     protected void l(double d0, double d1, double d2) {
diff --git a/src/main/java/net/minecraft/world/entity/EntityLiving.java b/src/main/java/net/minecraft/world/entity/EntityLiving.java
index bfbfdeffe668ac3363ffdab2c5cb7b19217f55ea..e20acbd904f12e9036cb0565d6aa9a3f63008d43 100644
--- a/src/main/java/net/minecraft/world/entity/EntityLiving.java
+++ b/src/main/java/net/minecraft/world/entity/EntityLiving.java
@@ -189,7 +189,7 @@ public abstract class EntityLiving extends Entity {
     protected float aL;
     protected float aM;
     protected float aN;
-    protected int aO;
+    protected int aO;protected int getKillCount() { return this.aO; } // Paper - OBFHELPER
     public float lastDamage;
     protected boolean jumping;
     public float aR;
@@ -233,6 +233,7 @@ public abstract class EntityLiving extends Entity {
     public Set<UUID> collidableExemptions = new HashSet<>();
     public boolean canPickUpLoot;
     public org.bukkit.craftbukkit.entity.CraftLivingEntity getBukkitLivingEntity() { return (org.bukkit.craftbukkit.entity.CraftLivingEntity) super.getBukkitEntity(); } // Paper
+    public boolean silentDeath = false; // Paper - mark entity as dying silently for cancellable death event
 
     @Override
     public float getBukkitYaw() {
@@ -1348,13 +1349,17 @@ public abstract class EntityLiving extends Entity {
             if (knockbackCancelled) this.world.broadcastEntityEffect(this, (byte) 2); // Paper - Disable explosion knockback
             if (this.dl()) {
                 if (!this.f(damagesource)) {
-                    SoundEffect soundeffect = this.getSoundDeath();
+                    // Paper start - moved into CraftEventFactory event caller for cancellable death event
+                    //SoundEffect soundeffect = this.getSoundDeath();
 
-                    if (flag1 && soundeffect != null) {
-                        this.playSound(soundeffect, this.getSoundVolume(), this.dH());
-                    }
+//                    if (flag1 && soundeffect != null) {
+//                        this.playSound(soundeffect, this.getSoundVolume(), this.dH());
+//                    }
+                    this.silentDeath = !flag1; // mark entity as dying silently
+                    // Paper end
 
                     this.die(damagesource);
+                    this.silentDeath = false; // Paper - cancellable death event - reset to default
                 }
             } else if (flag1) {
                 this.c(damagesource);
@@ -1493,6 +1498,7 @@ public abstract class EntityLiving extends Entity {
             Entity entity = damagesource.getEntity();
             EntityLiving entityliving = this.getKillingEntity();
 
+            /* // Paper - move down to make death event cancellable - this is the runKillTrigger below
             if (this.aO >= 0 && entityliving != null) {
                 entityliving.a(this, this.aO, damagesource);
             }
@@ -1500,20 +1506,40 @@ public abstract class EntityLiving extends Entity {
             if (this.isSleeping()) {
                 this.entityWakeup();
             }
+            */ // Paper
 
             this.killed = true;
-            this.getCombatTracker().g();
+            // this.getCombatTracker().g(); // Paper - moved into if below as .reset()
             if (this.world instanceof WorldServer) {
                 if (entity != null) {
-                    entity.a((WorldServer) this.world, this);
+                    // entity.a((WorldServer) this.world, this); // Paper - move below into if for onKill
                 }
 
-                this.d(damagesource);
+                // Paper start
+                org.bukkit.event.entity.EntityDeathEvent deathEvent = this.d(damagesource);
+                if (deathEvent == null || !deathEvent.isCancelled()) {
+                    if (this.getKillCount() >= 0 && entityliving != null) {
+                        entityliving.runKillTrigger(this, this.getKillCount(), damagesource);
+                    }
+                    if (this.isSleeping()) {
+                        this.entityWakeup();
+                    }
+                    this.getCombatTracker().reset();
+                    if (entity != null) {
+                        entity.onKill((WorldServer) this.world, this);
+                    }
+                } else {
+                    this.killed = false;
+                    this.setHealth((float) deathEvent.getReviveHealth());
+                }
+                // Paper end
                 this.f(entityliving);
             }
 
+            if (this.killed) { // Paper
             this.world.broadcastEntityEffect(this, (byte) 3);
             this.setPose(EntityPose.DYING);
+            } // Paper
         }
     }
 
@@ -1521,7 +1547,7 @@ public abstract class EntityLiving extends Entity {
         if (!this.world.isClientSide) {
             boolean flag = false;
 
-            if (entityliving instanceof EntityWither) {
+            if (this.killed && entityliving instanceof EntityWither) { // Paper
                 if (this.world.getGameRules().getBoolean(GameRules.MOB_GRIEFING)) {
                     BlockPosition blockposition = this.getChunkCoordinates();
                     IBlockData iblockdata = Blocks.WITHER_ROSE.getBlockData();
@@ -1549,7 +1575,8 @@ public abstract class EntityLiving extends Entity {
         }
     }
 
-    protected void d(DamageSource damagesource) {
+    protected org.bukkit.event.entity.EntityDeathEvent processDeath(DamageSource damagesource) { return d(damagesource); } // Paper - OBFHELPER
+    protected org.bukkit.event.entity.EntityDeathEvent d(DamageSource damagesource) { // Paper
         Entity entity = damagesource.getEntity();
         int i;
 
@@ -1567,15 +1594,18 @@ public abstract class EntityLiving extends Entity {
             this.dropDeathLoot(damagesource, i, flag);
         }
         // CraftBukkit start - Call death event
-        CraftEventFactory.callEntityDeathEvent(this, this.drops);
+        org.bukkit.event.entity.EntityDeathEvent deathEvent = CraftEventFactory.callEntityDeathEvent(this, this.drops); // Paper
+        this.postDeathDropItems(deathEvent); // Paper
         this.drops = new ArrayList<>();
         // CraftBukkit end
 
         // this.dropInventory();// CraftBukkit - moved up
         this.dropExperience();
+        return deathEvent; // Paper
     }
 
     protected void dropInventory() {}
+    protected void postDeathDropItems(org.bukkit.event.entity.EntityDeathEvent event) {} // Paper - method for post death logic that cannot be ran before the event is potentially cancelled
 
     // CraftBukkit start
     public int getExpReward() {
@@ -1660,6 +1690,7 @@ public abstract class EntityLiving extends Entity {
         return SoundEffects.ENTITY_GENERIC_HURT;
     }
 
+    public final SoundEffect getDeathSoundEffect() { return this.getSoundDeath(); } // Paper - OBFHELPER
     @Nullable
     protected SoundEffect getSoundDeath() {
         return SoundEffects.ENTITY_GENERIC_DEATH;
@@ -2196,10 +2227,12 @@ public abstract class EntityLiving extends Entity {
 
     }
 
+    public final float getDeathSoundVolume() { return this.getSoundVolume(); } // Paper - OBFHELPER
     protected float getSoundVolume() {
         return 1.0F;
     }
 
+    public float getSoundPitch() { return dH();} // Paper - OBFHELPER
     protected float dH() {
         return this.isBaby() ? (this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.5F : (this.random.nextFloat() - this.random.nextFloat()) * 0.2F + 1.0F;
     }
diff --git a/src/main/java/net/minecraft/world/entity/animal/EntityFox.java b/src/main/java/net/minecraft/world/entity/animal/EntityFox.java
index 77de0706aaa32b565cb1e14754e93a1c4a6e15bd..b7fa24318ef43918b6b10ff4ea8acb960527296e 100644
--- a/src/main/java/net/minecraft/world/entity/animal/EntityFox.java
+++ b/src/main/java/net/minecraft/world/entity/animal/EntityFox.java
@@ -647,15 +647,25 @@ public class EntityFox extends EntityAnimal {
     }
 
     @Override
-    protected void d(DamageSource damagesource) {
-        ItemStack itemstack = this.getEquipment(EnumItemSlot.MAINHAND);
+    protected org.bukkit.event.entity.EntityDeathEvent d(DamageSource damagesource) { // Paper
+        ItemStack itemstack = this.getEquipment(EnumItemSlot.MAINHAND).cloneItemStack(); // Paper
+
+        // Paper start - Cancellable death event
+        org.bukkit.event.entity.EntityDeathEvent deathEvent = super.d(damagesource);
+
+        // Below is code to drop
+
+        if (deathEvent == null || deathEvent.isCancelled()) {
+            return deathEvent;
+        }
+        // Paper end
 
         if (!itemstack.isEmpty()) {
             this.a(itemstack);
             this.setSlot(EnumItemSlot.MAINHAND, ItemStack.b);
         }
 
-        super.d(damagesource);
+        return deathEvent; // Paper
     }
 
     public static boolean a(EntityFox entityfox, EntityLiving entityliving) {
diff --git a/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseChestedAbstract.java b/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseChestedAbstract.java
index aa12a0c9f30cd2b8a6de75ff9822843da808ae64..3daa1780a332128bd472fa80039112f3ca9bc4e9 100644
--- a/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseChestedAbstract.java
+++ b/src/main/java/net/minecraft/world/entity/animal/horse/EntityHorseChestedAbstract.java
@@ -68,11 +68,19 @@ public abstract class EntityHorseChestedAbstract extends EntityHorseAbstract {
                 this.a((IMaterial) Blocks.CHEST);
             }
 
-            this.setCarryingChest(false);
+            //this.setCarryingChest(false); // Paper - moved to post death logic
         }
 
     }
 
+    // Paper start
+    protected void postDeathDropItems(org.bukkit.event.entity.EntityDeathEvent event) {
+        if (this.isCarryingChest() && (event == null || !event.isCancelled())) {
+            this.setCarryingChest(false);
+        }
+    }
+    // Paper end
+
     @Override
     public void saveData(NBTTagCompound nbttagcompound) {
         super.saveData(nbttagcompound);
diff --git a/src/main/java/net/minecraft/world/entity/decoration/EntityArmorStand.java b/src/main/java/net/minecraft/world/entity/decoration/EntityArmorStand.java
index 8d35240405d7f7245f3c7b0b611973d58fa4384f..69361caebf0d3caa5195b519a16691705ac5e16a 100644
--- a/src/main/java/net/minecraft/world/entity/decoration/EntityArmorStand.java
+++ b/src/main/java/net/minecraft/world/entity/decoration/EntityArmorStand.java
@@ -746,7 +746,8 @@ public class EntityArmorStand extends EntityLiving {
 
     @Override
     public void killEntity() {
-        org.bukkit.craftbukkit.event.CraftEventFactory.callEntityDeathEvent(this, drops); // CraftBukkit - call event
+        org.bukkit.event.entity.EntityDeathEvent event = org.bukkit.craftbukkit.event.CraftEventFactory.callEntityDeathEvent(this, drops); // CraftBukkit - call event // Paper - make cancellable
+        if (event.isCancelled()) return; // Paper - make cancellable
         this.die();
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index a13867ff6d188e7633a91f1e1600116286ac0cd4..6c5075ef2420131aa21b403623a5dfa485ee73e5 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1839,7 +1839,15 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     }
 
     public void sendHealthUpdate() {
-        getHandle().playerConnection.sendPacket(new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel()));
+        // Paper start - cancellable death event
+        //getHandle().playerConnection.sendPacket(new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel()));
+        PacketPlayOutUpdateHealth packet = new PacketPlayOutUpdateHealth(getScaledHealth(), getHandle().getFoodData().getFoodLevel(), getHandle().getFoodData().getSaturationLevel());
+        if (this.getHandle().queueHealthUpdatePacket) {
+            this.getHandle().queuedHealthUpdatePacket = packet;
+        } else {
+            this.getHandle().playerConnection.sendPacket(packet);
+        }
+        // Paper end
     }
 
     public void injectScaledMaxHealth(Collection<AttributeModifiable> collection, boolean force) {
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index 338b319910d12cf62ab9c5977257ad1ccec5544a..b7ebd2e3e919d09ee99997f2358cc0c399d5041b 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -18,6 +18,8 @@ import net.minecraft.network.protocol.game.PacketPlayInCloseWindow;
 import net.minecraft.resources.MinecraftKey;
 import net.minecraft.server.level.EntityPlayer;
 import net.minecraft.server.level.WorldServer;
+import net.minecraft.sounds.SoundCategory;
+import net.minecraft.sounds.SoundEffect;
 import net.minecraft.util.Unit;
 import net.minecraft.world.EnumHand;
 import net.minecraft.world.IInventory;
@@ -805,9 +807,16 @@ public class CraftEventFactory {
     public static EntityDeathEvent callEntityDeathEvent(EntityLiving victim, List<org.bukkit.inventory.ItemStack> drops) {
         CraftLivingEntity entity = (CraftLivingEntity) victim.getBukkitEntity();
         EntityDeathEvent event = new EntityDeathEvent(entity, drops, victim.getExpReward());
+        populateFields(victim, event); // Paper - make cancellable
         CraftWorld world = (CraftWorld) entity.getWorld();
         Bukkit.getServer().getPluginManager().callEvent(event);
 
+        // Paper start - make cancellable
+        if (event.isCancelled()) {
+            return event;
+        }
+        playDeathSound(victim, event);
+        // Paper end
         victim.expToDrop = event.getDroppedExp();
 
         for (org.bukkit.inventory.ItemStack stack : event.getDrops()) {
@@ -823,8 +832,15 @@ public class CraftEventFactory {
         CraftPlayer entity = victim.getBukkitEntity();
         PlayerDeathEvent event = new PlayerDeathEvent(entity, drops, victim.getExpReward(), 0, deathMessage, stringDeathMessage); // Paper - Adventure
         event.setKeepInventory(keepInventory);
+        populateFields(victim, event); // Paper - make cancellable
         org.bukkit.World world = entity.getWorld();
         Bukkit.getServer().getPluginManager().callEvent(event);
+        // Paper start - make cancellable
+        if (event.isCancelled()) {
+            return event;
+        }
+        playDeathSound(victim, event);
+        // Paper end
 
         victim.keepLevel = event.getKeepLevel();
         victim.newLevel = event.getNewLevel();
@@ -841,6 +857,31 @@ public class CraftEventFactory {
         return event;
     }
 
+    // Paper start - helper methods for making death event cancellable
+    // Add information to death event
+    private static void populateFields(EntityLiving victim, EntityDeathEvent event) {
+        event.setReviveHealth(event.getEntity().getAttribute(org.bukkit.attribute.Attribute.GENERIC_MAX_HEALTH).getValue());
+        event.setShouldPlayDeathSound(!victim.silentDeath && !victim.isSilent());
+        SoundEffect soundEffect = victim.getDeathSoundEffect();
+        event.setDeathSound(soundEffect != null ? org.bukkit.craftbukkit.CraftSound.getBukkit(soundEffect) : null);
+        event.setDeathSoundCategory(org.bukkit.SoundCategory.valueOf(victim.getSoundCategory().name()));
+        event.setDeathSoundVolume(victim.getDeathSoundVolume());
+        event.setDeathSoundPitch(victim.getSoundPitch());
+    }
+
+    // Play death sound manually
+    private static void playDeathSound(EntityLiving victim, EntityDeathEvent event) {
+        if (event.shouldPlayDeathSound() && event.getDeathSound() != null && event.getDeathSoundCategory() != null) {
+            EntityHuman source = victim instanceof EntityHuman ? (EntityHuman) victim : null;
+            double x = event.getEntity().getLocation().getX();
+            double y = event.getEntity().getLocation().getY();
+            double z = event.getEntity().getLocation().getZ();
+            SoundEffect soundEffect = org.bukkit.craftbukkit.CraftSound.getSoundEffect(event.getDeathSound());
+            SoundCategory soundCategory = SoundCategory.valueOf(event.getDeathSoundCategory().name());
+            victim.world.playSound(source, x, y, z, soundEffect, soundCategory, event.getDeathSoundVolume(), event.getDeathSoundPitch());
+        }
+    }
+    // Paper end
     /**
      * Server methods
      */