Paper/Spigot-Server-Patches/0280-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/CombatTracker.java b/src/main/java/net/minecraft/server/CombatTracker.java
index 0790d45e3c8ac68c280b9378d93061b48b045639..a8054a599e3eb502e7bbce903b5683987f95fb66 100644
--- a/src/main/java/net/minecraft/server/CombatTracker.java
+++ b/src/main/java/net/minecraft/server/CombatTracker.java
@@ -192,6 +192,7 @@ 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/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index b2cccdc9f2f243cd3fb1283ade0280b2acb0f772..4923fe299e7f057d5d70d346e83e746185eafdd3 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1452,6 +1452,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
     // 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);
@@ -2351,6 +2352,7 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
         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/server/EntityArmorStand.java b/src/main/java/net/minecraft/server/EntityArmorStand.java
index 4e6f195965af2108631f373a3a2987826e4317de..01c0ec114cf913e54058a2f5298807dbb83d1cf4 100644
--- a/src/main/java/net/minecraft/server/EntityArmorStand.java
+++ b/src/main/java/net/minecraft/server/EntityArmorStand.java
@@ -704,7 +704,8 @@ 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 a7bbf21e9736a0da38f95d93b013097b1e745306..56c119e8d11c5ffb1f90ac4249bce434b3e78884 100644
--- a/src/main/java/net/minecraft/server/EntityFox.java
+++ b/src/main/java/net/minecraft/server/EntityFox.java
@@ -577,15 +577,25 @@ 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/server/EntityHorseChestedAbstract.java b/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
index 09d076db37507b17797635df232a568752c97584..3bcebb89c9f9a5243d1d215a47d7d5e64d2529b2 100644
--- a/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
+++ b/src/main/java/net/minecraft/server/EntityHorseChestedAbstract.java
@@ -50,11 +50,19 @@ 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/server/EntityLiving.java b/src/main/java/net/minecraft/server/EntityLiving.java
index 99dac0a315c29dd394ea3e8049da89c62ace65cc..81e41ec85160eeef833824821d797db9b3d38b40 100644
--- a/src/main/java/net/minecraft/server/EntityLiving.java
+++ b/src/main/java/net/minecraft/server/EntityLiving.java
@@ -96,7 +96,7 @@ 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;
@@ -140,6 +140,7 @@ 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() {
@@ -1249,13 +1250,17 @@ 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);
@@ -1394,6 +1399,7 @@ 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);
             }
@@ -1401,20 +1407,40 @@ 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
         }
     }
 
@@ -1422,7 +1448,7 @@ 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();
@@ -1443,7 +1469,8 @@ 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;
 
@@ -1461,15 +1488,18 @@ 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() {
@@ -1554,6 +1584,7 @@ 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;
@@ -2084,10 +2115,12 @@ 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/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index dd3ae707776626d54894d19d5b0968256104c4dd..08e2e911d726e9d306f5fcc7755ab89f94959aa3 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -84,6 +84,10 @@ 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;
@@ -586,6 +590,15 @@ 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) {
@@ -737,8 +750,17 @@ 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 9a2e6bedfc50fba10f37c01d825f80415bfb69d3..a4afe638515471159d505a5e402a934206d8c1f5 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftSound.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftSound.java
@@ -1003,6 +1003,22 @@ 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 982b8a7028385d38ff0bd88aabd94801ae258037..6c3b9df31e9c44f7171cf08014561e4b095133b1 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -1784,7 +1784,15 @@ 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 1c806c97bf77cb3a71086d51110605b147bdbfbf..2222d3fdb9920f5662d42c0303bd05a4a07483c7 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -791,9 +791,16 @@ 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()) {
@@ -809,8 +816,15 @@ 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();
@@ -827,6 +841,31 @@ 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.playSound(source, x, y, z, soundEffect, soundCategory, event.getDeathSoundVolume(), event.getDeathSoundPitch());
+        }
+    }
+    // Paper end
     /**
      * Server methods
      */