Paper/Spigot-Server-Patches/0300-Improve-death-events.patch

From 11a05d88ac3b775120ee4c8319d2c249400e45f2 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/CombatTracker.java b/src/main/java/net/minecraft/server/CombatTracker.java
index 84c3ea9d00..f563a7b630 100644
--- a/src/main/java/net/minecraft/server/CombatTracker.java
+++ b/src/main/java/net/minecraft/server/CombatTracker.java
@@ -175,6 +175,7 @@ public class CombatTracker {
         this.h = null;
     }
 
+    public void reset() { this.g(); } // Paper - OBFHELPER
     public void g() {
         int i = this.f ? 300 : 100;
 
diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 7811beb807..f9b097fd6f 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1517,6 +1517,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         return false;
     }
 
+    public 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);
@@ -2410,6 +2411,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         this.fallDistance = 0.0F;
     }
 
+    public void onKill(EntityLiving entityLiving) { this.b(entityLiving); } // Paper - OBFHELPER
     public void b(EntityLiving entityliving) {}
 
     protected void i(double d0, double d1, double d2) {
diff --git a/src/main/java/net/minecraft/server/EntityArmorStand.java b/src/main/java/net/minecraft/server/EntityArmorStand.java
index 627925e3ba..e516db2701 100644
--- a/src/main/java/net/minecraft/server/EntityArmorStand.java
+++ b/src/main/java/net/minecraft/server/EntityArmorStand.java
@@ -683,7 +683,8 @@ 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/net/minecraft/server/EntityFox.java b/src/main/java/net/minecraft/server/EntityFox.java
index 85231309fd..1da2f013fc 100644
--- a/src/main/java/net/minecraft/server/EntityFox.java
+++ b/src/main/java/net/minecraft/server/EntityFox.java
@@ -597,15 +597,25 @@ 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.a);
         }
 
-        super.d(damagesource);
+        return deathEvent; // Paper
     }
 
     public static boolean a(EntityFox entityfox, EntityLiving entityliving) {
diff --git a/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java b/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
index 2483cfd28a..2a988366cd 100644
--- a/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
+++ b/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
@@ -55,11 +55,19 @@ 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 b(NBTTagCompound nbttagcompound) {
         super.b(nbttagcompound);
diff --git a/src/main/java/net/minecraft/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
index b09712ca91..1e53af2cce 100644
--- a/src/main/java/net/minecraft/server/EntityLiving.java
+++ b/src/main/java/net/minecraft/server/EntityLiving.java
@@ -85,7 +85,7 @@ public abstract class EntityLiving extends Entity {
     protected float aV;
     protected float aW;
     protected float aX;
-    protected int aY;
+    protected int aY; protected int getKillCount() { return this.aY; } // Paper - OBFHELPER
     public float lastDamage;
     protected boolean jumping;
     public float bb;
@@ -128,6 +128,7 @@ public abstract class EntityLiving extends Entity {
     public boolean collides = true;
     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() {
@@ -1185,13 +1186,17 @@ public abstract class EntityLiving extends Entity {
 
             if (this.getHealth() <= 0.0F) {
                 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.a(soundeffect, this.getSoundVolume(), this.cV());
-                    }
+                    //if (flag1 && soundeffect != null) {
+                    //    this.a(soundeffect, this.getSoundVolume(), this.cV());
+                    //}
+                    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);
@@ -1329,6 +1334,7 @@ public abstract class EntityLiving extends Entity {
             Entity entity = damagesource.getEntity();
             EntityLiving entityliving = this.getKillingEntity();
 
+            /* // Paper - move down to make death event cancellable
             if (this.aY >= 0 && entityliving != null) {
                 entityliving.a(this, this.aY, damagesource);
             }
@@ -1340,14 +1346,32 @@ public abstract class EntityLiving extends Entity {
             if (this.isSleeping()) {
                 this.dy();
             }
+            */ // Paper
 
             this.killed = true;
-            this.getCombatTracker().g();
+            //this.getCombatTracker().g();
             if (!this.world.isClientSide) {
-                this.d(damagesource);
+                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 (entity != null) {
+                        entity.onKill(this);
+                    }
+                    if (this.isSleeping()) {
+                        this.dy();
+                    }
+                    this.getCombatTracker().reset();
+                } else {
+                    this.killed = false;
+                    this.setHealth((float) deathEvent.getReviveHealth());
+                }
+                // Paper end
+
                 boolean flag = false;
 
-                if (entityliving instanceof EntityWither) {
+                if (this.killed && entityliving instanceof EntityWither) {
                     if (this.world.getGameRules().getBoolean(GameRules.MOB_GRIEFING)) {
                         BlockPosition blockposition = new BlockPosition(this.locX, this.locY, this.locZ);
                         IBlockData iblockdata = Blocks.WITHER_ROSE.getBlockData();
@@ -1366,12 +1390,15 @@ public abstract class EntityLiving extends Entity {
                 }
             }
 
+            if (this.killed) { // Paper
             this.world.broadcastEntityEffect(this, (byte) 3);
             this.setPose(EntityPose.DYING);
+            } // Paper
         }
     }
 
-    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;
 
@@ -1384,21 +1411,24 @@ public abstract class EntityLiving extends Entity {
         boolean flag = this.lastDamageByPlayerTime > 0;
 
         this.cF(); // CraftBukkit - from below // PAIL
+        org.bukkit.event.entity.EntityDeathEvent deathEvent; // Paper
         if (this.isDropExperience() && this.world.getGameRules().getBoolean(GameRules.DO_MOB_LOOT)) {
             this.a(damagesource, flag);
             this.dropDeathLoot(damagesource, i, flag);
             // CraftBukkit start - Call death event
-            CraftEventFactory.callEntityDeathEvent(this, this.drops);
-            this.drops = new ArrayList<org.bukkit.inventory.ItemStack>();
+            deathEvent = CraftEventFactory.callEntityDeathEvent(this, this.drops); // Paper
         } else {
-            CraftEventFactory.callEntityDeathEvent(this);
+            deathEvent = CraftEventFactory.callEntityDeathEvent(this); // Paper
             // CraftBukkit end
         }
+        this.postDeathDropItems(deathEvent); // Paper
+        this.drops = new ArrayList<>(); // Paper
 
-        // this.cF();// CraftBukkit - moved up
+        return deathEvent; // Paper
     }
 
     protected void cF() {}
+    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
 
     protected void dropDeathLoot(DamageSource damagesource, int i, boolean flag) {}
 
@@ -1449,6 +1479,7 @@ 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;
@@ -1898,10 +1929,12 @@ 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 cV();} // Paper - OBFHELPER
     protected float cV() {
         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/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index dcd48d8b3d..d7bc6e3297 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -75,6 +75,10 @@ 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.server.PacketPlayOutUpdateHealth queuedHealthUpdatePacket;
+    // Paper end
 
     // CraftBukkit start
     public String displayName;
@@ -533,6 +537,15 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
 
         String deathmessage = defaultMessage.getString();
         org.bukkit.event.entity.PlayerDeathEvent event = CraftEventFactory.callPlayerDeathEvent(this, loot, deathmessage, keepInventory);
+        // 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) {
@@ -686,8 +699,17 @@ 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/org/bukkit/craftbukkit/CraftSound.java b/src/main/java/org/bukkit/craftbukkit/CraftSound.java
index 73cb64e09d..9f317ff2e8 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftSound.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftSound.java
@@ -806,6 +806,22 @@ public enum CraftSound {
     WEATHER_RAIN_ABOVE("weather.rain.above");
     private final String minecraftKey;
 
+    // Paper start - cancellable death event
+    public static CraftSound getBySoundEffect(final SoundEffect effect) {
+        MinecraftKey key = IRegistry.SOUND_EVENT.getKey(effect);
+        Preconditions.checkArgument(key != null, "Key for sound effect %s not found?", effect.toString());
+
+        return valueOf(key.getKey().replace('.', '_').toUpperCase(java.util.Locale.ENGLISH));
+    }
+
+    public static Sound getSoundByEffect(final SoundEffect effect) {
+        return Sound.valueOf(getBySoundEffect(effect).name());
+    }
+
+    public static SoundEffect getSoundEffect(final Sound sound) {
+        return getSoundEffect(getSound(sound));
+    }
+    // Paper end
     CraftSound(String minecraftKey) {
         this.minecraftKey = minecraftKey;
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 2c99a1e9df..e9458dc65f 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1722,7 +1722,15 @@ 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<AttributeInstance> 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 5309a4e304..4074100c44 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -736,9 +736,16 @@ 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()) {
@@ -754,8 +761,15 @@ public class CraftEventFactory {
         CraftPlayer entity = victim.getBukkitEntity();
         PlayerDeathEvent event = new PlayerDeathEvent(entity, drops, victim.getExpReward(), 0, deathMessage);
         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();
@@ -772,6 +786,31 @@ 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());
+        net.minecraft.server.SoundEffect soundEffect = victim.getDeathSoundEffect();
+        event.setDeathSound(soundEffect != null ? org.bukkit.craftbukkit.CraftSound.getSoundByEffect(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();
+            net.minecraft.server.SoundEffect soundEffect = org.bukkit.craftbukkit.CraftSound.getSoundEffect(event.getDeathSound());
+            net.minecraft.server.SoundCategory soundCategory = net.minecraft.server.SoundCategory.valueOf(event.getDeathSoundCategory().name());
+            victim.world.sendSoundEffect(source, x, y, z, soundEffect, soundCategory, event.getDeathSoundVolume(), event.getDeathSoundPitch());
+        }
+    }
+    // Paper end
     /**
      * Server methods
      */
-- 
2.22.0