PaperMC/paper-server/nms-patches/net/minecraft/world/entity/EntityLiving.patch

--- a/net/minecraft/world/entity/EntityLiving.java
+++ b/net/minecraft/world/entity/EntityLiving.java
@@ -119,6 +119,30 @@
 import net.minecraft.world.scores.ScoreboardTeam;
 import org.apache.logging.log4j.Logger;
 
+// CraftBukkit start
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
+import com.google.common.base.Function;
+import net.minecraft.nbt.NBTTagFloat;
+import net.minecraft.nbt.NBTTagInt;
+import net.minecraft.world.entity.animal.EntityAnimal;
+import org.bukkit.Location;
+import org.bukkit.craftbukkit.attribute.CraftAttributeMap;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.entity.Player;
+import org.bukkit.event.entity.ArrowBodyCountChangeEvent;
+import org.bukkit.event.entity.EntityDamageEvent;
+import org.bukkit.event.entity.EntityDamageEvent.DamageModifier;
+import org.bukkit.event.entity.EntityPotionEffectEvent;
+import org.bukkit.event.entity.EntityRegainHealthEvent;
+import org.bukkit.event.entity.EntityResurrectEvent;
+import org.bukkit.event.entity.EntityTeleportEvent;
+import org.bukkit.event.player.PlayerItemConsumeEvent;
+// CraftBukkit end
+
 public abstract class EntityLiving extends Entity {
 
     private static final UUID SPEED_MODIFIER_SPRINTING_UUID = UUID.fromString("662A6B8D-DA3E-4C1C-8813-96EA6097278D");
@@ -227,6 +251,21 @@
     private float swimAmount;
     private float swimAmountO;
     protected BehaviorController<?> brain;
+    // CraftBukkit start
+    public int expToDrop;
+    public int maxAirTicks = 300;
+    public boolean forceDrops;
+    public ArrayList<org.bukkit.inventory.ItemStack> drops = new ArrayList<org.bukkit.inventory.ItemStack>();
+    public final org.bukkit.craftbukkit.attribute.CraftAttributeMap craftAttributes;
+    public boolean collides = true;
+    public Set<UUID> collidableExemptions = new HashSet<>();
+    public boolean bukkitPickUpLoot;
+
+    @Override
+    public float getBukkitYaw() {
+        return getHeadRotation();
+    }
+    // CraftBukkit end
 
     protected EntityLiving(EntityTypes<? extends EntityLiving> entitytypes, World world) {
         super(entitytypes, world);
@@ -239,7 +278,9 @@
         this.useItem = ItemStack.EMPTY;
         this.lastClimbablePos = Optional.empty();
         this.attributes = new AttributeMapBase(AttributeDefaults.a(entitytypes));
-        this.setHealth(this.getMaxHealth());
+        this.craftAttributes = new CraftAttributeMap(attributes); // CraftBukkit
+        // CraftBukkit - setHealth(getMaxHealth()) inlined and simplified to skip the instanceof check for EntityPlayer, as getBukkitEntity() is not initialized in constructor
+        this.entityData.set(EntityLiving.DATA_HEALTH_ID, (float) this.getAttributeInstance(GenericAttributes.MAX_HEALTH).getValue());
         this.blocksBuilding = true;
         this.rotA = (float) ((Math.random() + 1.0D) * 0.009999999776482582D);
         this.ah();
@@ -306,7 +347,13 @@
                 double d1 = Math.min((double) (0.2F + f / 15.0F), 2.5D);
                 int i = (int) (150.0D * d1);
 
-                ((WorldServer) this.level).a(new ParticleParamBlock(Particles.BLOCK, iblockdata), this.locX(), this.locY(), this.locZ(), i, 0.0D, 0.0D, 0.0D, 0.15000000596046448D);
+                // CraftBukkit start - visiblity api
+                if (this instanceof EntityPlayer) {
+                    ((WorldServer) this.level).sendParticles((EntityPlayer) this, new ParticleParamBlock(Particles.BLOCK, iblockdata), this.locX(), this.locY(), this.locZ(), i, 0.0D, 0.0D, 0.0D, 0.15000000596046448D, false);
+                } else {
+                    ((WorldServer) this.level).a(new ParticleParamBlock(Particles.BLOCK, iblockdata), this.locX(), this.locY(), this.locZ(), i, 0.0D, 0.0D, 0.0D, 0.15000000596046448D);
+                }
+                // CraftBukkit end
             }
         }
 
@@ -566,7 +613,7 @@
 
     protected void dB() {
         ++this.deathTime;
-        if (this.deathTime == 20 && !this.level.isClientSide()) {
+        if (this.deathTime >= 20 && !this.isRemoved() && !this.level.isClientSide()) { // CraftBukkit - (this.deathTicks == 20) -> (this.deathTicks >= 20 && !this.dead)
             this.level.broadcastEntityEffect(this, (byte) 60);
             this.a(Entity.RemovalReason.KILLED);
         }
@@ -658,9 +705,15 @@
     }
 
     protected void playEquipSound(ItemStack itemstack) {
+        // CraftBukkit start
+        this.playEquipSound(itemstack, false);
+    }
+
+    protected void playEquipSound(ItemStack itemstack, boolean silent) {
         SoundEffect soundeffect = itemstack.M();
 
-        if (!itemstack.isEmpty() && soundeffect != null && !this.isSpectator()) {
+        if (!itemstack.isEmpty() && soundeffect != null && !this.isSpectator() && !silent) {
+            // CraftBukkit end
             this.a(GameEvent.EQUIP);
             this.playSound(soundeffect, 1.0F, 1.0F);
         }
@@ -722,6 +775,17 @@
             }
         }
 
+        // CraftBukkit start
+        if (nbttagcompound.hasKey("Bukkit.MaxHealth")) {
+            NBTBase nbtbase = nbttagcompound.get("Bukkit.MaxHealth");
+            if (nbtbase.getTypeId() == 5) {
+                this.getAttributeInstance(GenericAttributes.MAX_HEALTH).setValue(((NBTTagFloat) nbtbase).asDouble());
+            } else if (nbtbase.getTypeId() == 3) {
+                this.getAttributeInstance(GenericAttributes.MAX_HEALTH).setValue(((NBTTagInt) nbtbase).asDouble());
+            }
+        }
+        // CraftBukkit end
+
         if (nbttagcompound.hasKeyOfType("Health", 99)) {
             this.setHealth(nbttagcompound.getFloat("Health"));
         }
@@ -759,9 +823,32 @@
 
     }
 
+    // CraftBukkit start
+    private boolean isTickingEffects = false;
+    private List<ProcessableEffect> effectsToProcess = Lists.newArrayList();
+
+    private static class ProcessableEffect {
+
+        private MobEffectList type;
+        private MobEffect effect;
+        private final EntityPotionEffectEvent.Cause cause;
+
+        private ProcessableEffect(MobEffect effect, EntityPotionEffectEvent.Cause cause) {
+            this.effect = effect;
+            this.cause = cause;
+        }
+
+        private ProcessableEffect(MobEffectList type, EntityPotionEffectEvent.Cause cause) {
+            this.type = type;
+            this.cause = cause;
+        }
+    }
+    // CraftBukkit end
+
     protected void tickPotionEffects() {
         Iterator iterator = this.activeEffects.keySet().iterator();
 
+        isTickingEffects = true; // CraftBukkit
         try {
             while (iterator.hasNext()) {
                 MobEffectList mobeffectlist = (MobEffectList) iterator.next();
@@ -771,6 +858,12 @@
                     this.a(mobeffect, true, (Entity) null);
                 })) {
                     if (!this.level.isClientSide) {
+                        // CraftBukkit start
+                        EntityPotionEffectEvent event = CraftEventFactory.callEntityPotionEffectChangeEvent(this, mobeffect, null, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.EXPIRATION);
+                        if (event.isCancelled()) {
+                            continue;
+                        }
+                        // CraftBukkit end
                         iterator.remove();
                         this.a(mobeffect);
                     }
@@ -781,6 +874,17 @@
         } catch (ConcurrentModificationException concurrentmodificationexception) {
             ;
         }
+        // CraftBukkit start
+        isTickingEffects = false;
+        for (ProcessableEffect e : effectsToProcess) {
+            if (e.effect != null) {
+                addEffect(e.effect, e.cause);
+            } else {
+                removeEffect(e.type, e.cause);
+            }
+        }
+        effectsToProcess.clear();
+        // CraftBukkit end
 
         if (this.effectsDirty) {
             if (!this.level.isClientSide) {
@@ -907,7 +1011,13 @@
         this.entityData.set(EntityLiving.DATA_EFFECT_COLOR_ID, 0);
     }
 
+    // CraftBukkit start
     public boolean removeAllEffects() {
+        return removeAllEffects(org.bukkit.event.entity.EntityPotionEffectEvent.Cause.UNKNOWN);
+    }
+
+    public boolean removeAllEffects(EntityPotionEffectEvent.Cause cause) {
+        // CraftBukkit end
         if (this.level.isClientSide) {
             return false;
         } else {
@@ -916,7 +1026,14 @@
             boolean flag;
 
             for (flag = false; iterator.hasNext(); flag = true) {
-                this.a((MobEffect) iterator.next());
+                // CraftBukkit start
+                MobEffect effect = (MobEffect) iterator.next();
+                EntityPotionEffectEvent event = CraftEventFactory.callEntityPotionEffectChangeEvent(this, effect, null, cause, EntityPotionEffectEvent.Action.CLEARED);
+                if (event.isCancelled()) {
+                    continue;
+                }
+                this.a(effect);
+                // CraftBukkit end
                 iterator.remove();
             }
 
@@ -945,18 +1062,48 @@
         return this.addEffect(mobeffect, (Entity) null);
     }
 
+    // CraftBukkit start
+    public boolean addEffect(MobEffect mobeffect, EntityPotionEffectEvent.Cause cause) {
+        return this.addEffect(mobeffect, (Entity) null, cause);
+    }
+
     public boolean addEffect(MobEffect mobeffect, @Nullable Entity entity) {
+        return this.addEffect(mobeffect, entity, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.UNKNOWN);
+    }
+
+    public boolean addEffect(MobEffect mobeffect, @Nullable Entity entity, EntityPotionEffectEvent.Cause cause) {
+        if (isTickingEffects) {
+            effectsToProcess.add(new ProcessableEffect(mobeffect, cause));
+            return true;
+        }
+        // CraftBukkit end
+
         if (!this.c(mobeffect)) {
             return false;
         } else {
             MobEffect mobeffect1 = (MobEffect) this.activeEffects.get(mobeffect.getMobEffect());
 
+            // CraftBukkit start
+            boolean override = false;
+            if (mobeffect1 != null) {
+                override = new MobEffect(mobeffect1).b(mobeffect);
+            }
+
+            EntityPotionEffectEvent event = CraftEventFactory.callEntityPotionEffectChangeEvent(this, mobeffect1, mobeffect, cause, override);
+            if (event.isCancelled()) {
+                return false;
+            }
+            // CraftBukkit end
+
             if (mobeffect1 == null) {
                 this.activeEffects.put(mobeffect.getMobEffect(), mobeffect);
                 this.a(mobeffect, entity);
                 return true;
-            } else if (mobeffect1.b(mobeffect)) {
+                // CraftBukkit start
+            } else if (event.isOverride()) {
+                mobeffect1.b(mobeffect);
                 this.a(mobeffect1, true, entity);
+                // CraftBukkit end
                 return true;
             } else {
                 return false;
@@ -993,13 +1140,39 @@
         return this.getMonsterType() == EnumMonsterType.UNDEAD;
     }
 
+    // CraftBukkit start
     @Nullable
     public MobEffect c(@Nullable MobEffectList mobeffectlist) {
+        return c(mobeffectlist, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.UNKNOWN);
+    }
+
+    @Nullable
+    public MobEffect c(@Nullable MobEffectList mobeffectlist, EntityPotionEffectEvent.Cause cause) {
+        if (isTickingEffects) {
+            effectsToProcess.add(new ProcessableEffect(mobeffectlist, cause));
+            return null;
+        }
+
+        MobEffect effect = this.activeEffects.get(mobeffectlist);
+        if (effect == null) {
+            return null;
+        }
+
+        EntityPotionEffectEvent event = CraftEventFactory.callEntityPotionEffectChangeEvent(this, effect, null, cause);
+        if (event.isCancelled()) {
+            return null;
+        }
+
         return (MobEffect) this.activeEffects.remove(mobeffectlist);
     }
 
     public boolean removeEffect(MobEffectList mobeffectlist) {
-        MobEffect mobeffect = this.c(mobeffectlist);
+        return removeEffect(mobeffectlist, org.bukkit.event.entity.EntityPotionEffectEvent.Cause.UNKNOWN);
+    }
+
+    public boolean removeEffect(MobEffectList mobeffectlist, EntityPotionEffectEvent.Cause cause) {
+        MobEffect mobeffect = this.c(mobeffectlist, cause);
+        // CraftBukkit end
 
         if (mobeffect != null) {
             this.a(mobeffect);
@@ -1036,20 +1209,55 @@
 
     }
 
+    // CraftBukkit start - Delegate so we can handle providing a reason for health being regained
     public void heal(float f) {
+        heal(f, EntityRegainHealthEvent.RegainReason.CUSTOM);
+    }
+
+    public void heal(float f, EntityRegainHealthEvent.RegainReason regainReason) {
         float f1 = this.getHealth();
 
         if (f1 > 0.0F) {
-            this.setHealth(f1 + f);
+            EntityRegainHealthEvent event = new EntityRegainHealthEvent(this.getBukkitEntity(), f, regainReason);
+            // Suppress during worldgen
+            if (this.valid) {
+                this.level.getCraftServer().getPluginManager().callEvent(event);
+            }
+
+            if (!event.isCancelled()) {
+                this.setHealth((float) (this.getHealth() + event.getAmount()));
+            }
+            // CraftBukkit end
         }
 
     }
 
     public float getHealth() {
+        // CraftBukkit start - Use unscaled health
+        if (this instanceof EntityPlayer) {
+            return (float) ((EntityPlayer) this).getBukkitEntity().getHealth();
+        }
+        // CraftBukkit end
         return (Float) this.entityData.get(EntityLiving.DATA_HEALTH_ID);
     }
 
     public void setHealth(float f) {
+        // CraftBukkit start - Handle scaled health
+        if (this instanceof EntityPlayer) {
+            org.bukkit.craftbukkit.entity.CraftPlayer player = ((EntityPlayer) this).getBukkitEntity();
+            // Squeeze
+            if (f < 0.0F) {
+                player.setRealHealth(0.0D);
+            } else if (f > player.getMaxHealth()) {
+                player.setRealHealth(player.getMaxHealth());
+            } else {
+                player.setRealHealth(f);
+            }
+
+            player.updateScaledHealth(false);
+            return;
+        }
+        // CraftBukkit end
         this.entityData.set(EntityLiving.DATA_HEALTH_ID, MathHelper.a(f, 0.0F, this.getMaxHealth()));
     }
 
@@ -1063,7 +1271,7 @@
             return false;
         } else if (this.level.isClientSide) {
             return false;
-        } else if (this.dV()) {
+        } else if (this.isRemoved() || this.dead || this.getHealth() <= 0.0F) { // CraftBukkit - Don't allow entities that got set to dead/killed elsewhere to get damaged and die
             return false;
         } else if (damagesource.isFire() && this.hasEffect(MobEffects.FIRE_RESISTANCE)) {
             return false;
@@ -1074,10 +1282,11 @@
 
             this.noActionTime = 0;
             float f1 = f;
-            boolean flag = false;
+            boolean flag = f > 0.0F && this.applyBlockingModifier(damagesource); // Copied from below
             float f2 = 0.0F;
 
-            if (f > 0.0F && this.applyBlockingModifier(damagesource)) {
+            // CraftBukkit - Moved into damageEntity0(DamageSource, float)
+            if (false && f > 0.0F && this.applyBlockingModifier(damagesource)) {
                 this.damageShield(f);
                 f2 = f;
                 f = 0.0F;
@@ -1095,27 +1304,47 @@
             this.animationSpeed = 1.5F;
             boolean flag1 = true;
 
-            if ((float) this.invulnerableTime > 10.0F) {
+            if ((float) this.invulnerableTime > (float) this.invulnerableDuration / 2.0F) { // CraftBukkit - restore use of maxNoDamageTicks
                 if (f <= this.lastHurt) {
+                    this.forceExplosionKnockback = true; // CraftBukkit - SPIGOT-949 - for vanilla consistency, cooldown does not prevent explosion knockback
                     return false;
                 }
 
-                this.damageEntity0(damagesource, f - this.lastHurt);
+                // CraftBukkit start
+                if (!this.damageEntity0(damagesource, f - this.lastHurt)) {
+                    return false;
+                }
+                // CraftBukkit end
                 this.lastHurt = f;
                 flag1 = false;
             } else {
+                // CraftBukkit start
+                if (!this.damageEntity0(damagesource, f)) {
+                    return false;
+                }
                 this.lastHurt = f;
-                this.invulnerableTime = 20;
-                this.damageEntity0(damagesource, f);
+                this.invulnerableTime = this.invulnerableDuration; // CraftBukkit - restore use of maxNoDamageTicks
+                // this.damageEntity0(damagesource, f);
+                // CraftBukkit end
                 this.hurtDuration = 10;
                 this.hurtTime = this.hurtDuration;
             }
 
-            if (damagesource.g() && !this.getEquipment(EnumItemSlot.HEAD).isEmpty()) {
+            // CraftBukkit - Moved into damageEntity0(DamageSource, float)
+            if (false && damagesource.g() && !this.getEquipment(EnumItemSlot.HEAD).isEmpty()) {
                 this.damageHelmet(damagesource, f);
                 f *= 0.75F;
             }
 
+            // CraftBukkit start
+            if (this instanceof EntityAnimal) {
+                ((EntityAnimal) this).resetLove();
+                if (this instanceof EntityTameableAnimal) {
+                    ((EntityTameableAnimal) this).setWillSit(false);
+                }
+            }
+            // CraftBukkit end
+
             this.hurtDir = 0.0F;
             Entity entity1 = damagesource.getEntity();
 
@@ -1238,19 +1467,29 @@
             EnumHand[] aenumhand = EnumHand.values();
             int i = aenumhand.length;
 
+            // CraftBukkit start
+            ItemStack itemstack1 = ItemStack.EMPTY;
             for (int j = 0; j < i; ++j) {
                 EnumHand enumhand = aenumhand[j];
-                ItemStack itemstack1 = this.b(enumhand);
+                itemstack1 = this.b(enumhand);
 
                 if (itemstack1.a(Items.TOTEM_OF_UNDYING)) {
                     itemstack = itemstack1.cloneItemStack();
-                    itemstack1.subtract(1);
+                    // itemstack1.subtract(1); // CraftBukkit
                     break;
                 }
             }
 
-            if (itemstack != null) {
-                if (this instanceof EntityPlayer) {
+            EntityResurrectEvent event = new EntityResurrectEvent((LivingEntity) this.getBukkitEntity());
+            event.setCancelled(itemstack == null);
+            this.level.getCraftServer().getPluginManager().callEvent(event);
+
+            if (!event.isCancelled()) {
+                if (!itemstack1.isEmpty()) {
+                    itemstack1.subtract(1);
+                }
+                if (itemstack != null && this instanceof EntityPlayer) {
+                    // CraftBukkit end
                     EntityPlayer entityplayer = (EntityPlayer) this;
 
                     entityplayer.b(StatisticList.ITEM_USED.b(Items.TOTEM_OF_UNDYING));
@@ -1258,14 +1497,16 @@
                 }
 
                 this.setHealth(1.0F);
-                this.removeAllEffects();
-                this.addEffect(new MobEffect(MobEffects.REGENERATION, 900, 1));
-                this.addEffect(new MobEffect(MobEffects.ABSORPTION, 100, 1));
-                this.addEffect(new MobEffect(MobEffects.FIRE_RESISTANCE, 800, 0));
+                // CraftBukkit start
+                this.removeAllEffects(org.bukkit.event.entity.EntityPotionEffectEvent.Cause.TOTEM);
+                this.addEffect(new MobEffect(MobEffects.REGENERATION, 900, 1), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.TOTEM);
+                this.addEffect(new MobEffect(MobEffects.ABSORPTION, 100, 1), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.TOTEM);
+                this.addEffect(new MobEffect(MobEffects.FIRE_RESISTANCE, 800, 0), org.bukkit.event.entity.EntityPotionEffectEvent.Cause.TOTEM);
+                // CraftBukkit end
                 this.level.broadcastEntityEffect(this, (byte) 35);
             }
 
-            return itemstack != null;
+            return !event.isCancelled();
         }
     }
 
@@ -1370,14 +1611,22 @@
                     IBlockData iblockdata = Blocks.WITHER_ROSE.getBlockData();
 
                     if (this.level.getType(blockposition).isAir() && iblockdata.canPlace(this.level, blockposition)) {
-                        this.level.setTypeAndData(blockposition, iblockdata, 3);
-                        flag = true;
+                        // CraftBukkit start - call EntityBlockFormEvent for Wither Rose
+                        flag = org.bukkit.craftbukkit.event.CraftEventFactory.handleBlockFormEvent(this.level, blockposition, iblockdata, 3, this);
+                        // CraftBukkit end
                     }
                 }
 
                 if (!flag) {
                     EntityItem entityitem = new EntityItem(this.level, this.locX(), this.locY(), this.locZ(), new ItemStack(Items.WITHER_ROSE));
 
+                    // CraftBukkit start
+                    org.bukkit.event.entity.EntityDropItemEvent event = new org.bukkit.event.entity.EntityDropItemEvent(this.getBukkitEntity(), (org.bukkit.entity.Item) entityitem.getBukkitEntity());
+                    CraftEventFactory.callEvent(event);
+                    if (event.isCancelled()) {
+                        return;
+                    }
+                    // CraftBukkit end
                     this.level.addEntity(entityitem);
                 }
             }
@@ -1397,21 +1646,40 @@
 
         boolean flag = this.lastHurtByPlayerTime > 0;
 
+        this.dropInventory(); // CraftBukkit - from below
         if (this.dD() && this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBLOOT)) {
             this.a(damagesource, flag);
             this.dropDeathLoot(damagesource, i, flag);
         }
+        // CraftBukkit start - Call death event
+        CraftEventFactory.callEntityDeathEvent(this, this.drops);
+        this.drops = new ArrayList<>();
+        // CraftBukkit end
 
-        this.dropInventory();
+        // this.dropInventory();// CraftBukkit - moved up
         this.dropExperience();
     }
 
     protected void dropInventory() {}
 
-    protected void dropExperience() {
+    // CraftBukkit start
+    public int getExpReward() {
         if (this.level instanceof WorldServer && (this.alwaysGivesExp() || this.lastHurtByPlayerTime > 0 && this.isDropExperience() && this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBLOOT))) {
-            EntityExperienceOrb.a((WorldServer) this.level, this.getPositionVector(), this.getExpValue(this.lastHurtByPlayer));
+            int i = this.getExpValue(this.lastHurtByPlayer);
+            return i;
+        } else {
+            return 0;
+        }
+    }
+    // CraftBukkit end
+
+    protected void dropExperience() {
+        // CraftBukkit start - Update getExpReward() above if the removed if() changes!
+        if (true) {
+            EntityExperienceOrb.a((WorldServer) this.level, this.getPositionVector(), this.expToDrop);
+            this.expToDrop = 0;
         }
+        // CraftBukkit end
 
     }
 
@@ -1527,9 +1795,14 @@
         int i = this.d(f, f1);
 
         if (i > 0) {
+            // CraftBukkit start
+            if (!this.damageEntity(damagesource, (float) i)) {
+                return true;
+            }
+            // CraftBukkit end
             this.playSound(this.getSoundFall(i), 1.0F, 1.0F);
             this.playBlockStepSound();
-            this.damageEntity(damagesource, (float) i);
+            // this.damageEntity(damagesource, (float) i); // CraftBukkit - moved up
             return true;
         } else {
             return flag;
@@ -1578,7 +1851,7 @@
 
     protected float applyArmorModifier(DamageSource damagesource, float f) {
         if (!damagesource.ignoresArmor()) {
-            this.damageArmor(damagesource, f);
+            // this.damageArmor(damagesource, f); // CraftBukkit - Moved into damageEntity0(DamageSource, float)
             f = CombatMath.a(f, (float) this.getArmorStrength(), (float) this.b(GenericAttributes.ARMOR_TOUGHNESS));
         }
 
@@ -1591,7 +1864,8 @@
         } else {
             int i;
 
-            if (this.hasEffect(MobEffects.DAMAGE_RESISTANCE) && damagesource != DamageSource.OUT_OF_WORLD) {
+            // CraftBukkit - Moved to damageEntity0(DamageSource, float)
+            if (false && this.hasEffect(MobEffects.DAMAGE_RESISTANCE) && damagesource != DamageSource.OUT_OF_WORLD) {
                 i = (this.getEffect(MobEffects.DAMAGE_RESISTANCE).getAmplifier() + 1) * 5;
                 int j = 25 - i;
                 float f1 = f * (float) j;
@@ -1622,29 +1896,172 @@
         }
     }
 
-    protected void damageEntity0(DamageSource damagesource, float f) {
-        if (!this.isInvulnerable(damagesource)) {
-            f = this.applyArmorModifier(damagesource, f);
-            f = this.applyMagicModifier(damagesource, f);
-            float f1 = f;
+    // CraftBukkit start
+    protected boolean damageEntity0(final DamageSource damagesource, float f) { // void -> boolean, add final
+       if (!this.isInvulnerable(damagesource)) {
+            final boolean human = this instanceof EntityHuman;
+            float originalDamage = f;
+            Function<Double, Double> hardHat = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    if (damagesource.g() && !EntityLiving.this.getEquipment(EnumItemSlot.HEAD).isEmpty()) {
+                        return -(f - (f * 0.75F));
+
+                    }
+                    return -0.0;
+                }
+            };
+            float hardHatModifier = hardHat.apply((double) f).floatValue();
+            f += hardHatModifier;
+
+            Function<Double, Double> blocking = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    return -((EntityLiving.this.applyBlockingModifier(damagesource)) ? f : 0.0);
+                }
+            };
+            float blockingModifier = blocking.apply((double) f).floatValue();
+            f += blockingModifier;
+
+            Function<Double, Double> armor = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    return -(f - EntityLiving.this.applyArmorModifier(damagesource, f.floatValue()));
+                }
+            };
+            float armorModifier = armor.apply((double) f).floatValue();
+            f += armorModifier;
+
+            Function<Double, Double> resistance = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    if (!damagesource.isStarvation() && EntityLiving.this.hasEffect(MobEffects.DAMAGE_RESISTANCE) && damagesource != DamageSource.OUT_OF_WORLD) {
+                        int i = (EntityLiving.this.getEffect(MobEffects.DAMAGE_RESISTANCE).getAmplifier() + 1) * 5;
+                        int j = 25 - i;
+                        float f1 = f.floatValue() * (float) j;
+                        return -(f - (f1 / 25.0F));
+                    }
+                    return -0.0;
+                }
+            };
+            float resistanceModifier = resistance.apply((double) f).floatValue();
+            f += resistanceModifier;
+
+            Function<Double, Double> magic = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    return -(f - EntityLiving.this.applyMagicModifier(damagesource, f.floatValue()));
+                }
+            };
+            float magicModifier = magic.apply((double) f).floatValue();
+            f += magicModifier;
+
+            Function<Double, Double> absorption = new Function<Double, Double>() {
+                @Override
+                public Double apply(Double f) {
+                    return -(Math.max(f - Math.max(f - EntityLiving.this.getAbsorptionHearts(), 0.0F), 0.0F));
+                }
+            };
+            float absorptionModifier = absorption.apply((double) f).floatValue();
+
+            EntityDamageEvent event = CraftEventFactory.handleLivingEntityDamageEvent(this, damagesource, originalDamage, hardHatModifier, blockingModifier, armorModifier, resistanceModifier, magicModifier, absorptionModifier, hardHat, blocking, armor, resistance, magic, absorption);
+            if (damagesource.getEntity() instanceof EntityHuman) {
+                ((EntityHuman) damagesource.getEntity()).resetAttackCooldown(); // Moved from EntityHuman in order to make the cooldown reset get called after the damage event is fired
+            }
+            if (event.isCancelled()) {
+                return false;
+            }
 
-            f = Math.max(f - this.getAbsorptionHearts(), 0.0F);
-            this.setAbsorptionHearts(this.getAbsorptionHearts() - (f1 - f));
-            float f2 = f1 - f;
+            f = (float) event.getFinalDamage();
 
+            // Resistance
+            if (event.getDamage(DamageModifier.RESISTANCE) < 0) {
+                float f3 = (float) -event.getDamage(DamageModifier.RESISTANCE);
+                if (f3 > 0.0F && f3 < 3.4028235E37F) {
+                    if (this instanceof EntityPlayer) {
+                        ((EntityPlayer) this).a(StatisticList.DAMAGE_RESISTED, Math.round(f3 * 10.0F));
+                    } else if (damagesource.getEntity() instanceof EntityPlayer) {
+                        ((EntityPlayer) damagesource.getEntity()).a(StatisticList.DAMAGE_DEALT_RESISTED, Math.round(f3 * 10.0F));
+                    }
+                }
+            }
+
+            // Apply damage to helmet
+            if (damagesource.g() && !this.getEquipment(EnumItemSlot.HEAD).isEmpty()) {
+                this.damageHelmet(damagesource, f);
+            }
+
+            // Apply damage to armor
+            if (!damagesource.ignoresArmor()) {
+                float armorDamage = (float) (event.getDamage() + event.getDamage(DamageModifier.BLOCKING) + event.getDamage(DamageModifier.HARD_HAT));
+                this.damageArmor(damagesource, armorDamage);
+            }
+
+            // Apply blocking code // PAIL: steal from above
+            if (event.getDamage(DamageModifier.BLOCKING) < 0) {
+                this.level.broadcastEntityEffect(this, (byte) 29); // SPIGOT-4635 - shield damage sound
+                this.damageShield((float) -event.getDamage(DamageModifier.BLOCKING));
+                Entity entity = damagesource.k();
+
+                if (entity instanceof EntityLiving) {
+                    this.shieldBlock((EntityLiving) entity);
+                }
+            }
+
+            absorptionModifier = (float) -event.getDamage(DamageModifier.ABSORPTION);
+            this.setAbsorptionHearts(Math.max(this.getAbsorptionHearts() - absorptionModifier, 0.0F));
+            float f2 = absorptionModifier;
+
+            if (f2 > 0.0F && f2 < 3.4028235E37F && this instanceof EntityHuman) {
+                ((EntityHuman) this).a(StatisticList.DAMAGE_ABSORBED, Math.round(f2 * 10.0F));
+            }
             if (f2 > 0.0F && f2 < 3.4028235E37F && damagesource.getEntity() instanceof EntityPlayer) {
                 ((EntityPlayer) damagesource.getEntity()).a(StatisticList.DAMAGE_DEALT_ABSORBED, Math.round(f2 * 10.0F));
             }
 
-            if (f != 0.0F) {
+            if (f > 0 || !human) {
+                if (human) {
+                    // PAIL: Be sure to drag all this code from the EntityHuman subclass each update.
+                    ((EntityHuman) this).applyExhaustion(damagesource.getExhaustionCost(), org.bukkit.event.entity.EntityExhaustionEvent.ExhaustionReason.DAMAGED); // CraftBukkit - EntityExhaustionEvent
+                    if (f < 3.4028235E37F) {
+                        ((EntityHuman) this).a(StatisticList.DAMAGE_TAKEN, Math.round(f * 10.0F));
+                    }
+                }
+                // CraftBukkit end
                 float f3 = this.getHealth();
 
                 this.setHealth(f3 - f);
                 this.getCombatTracker().trackDamage(damagesource, f3, f);
-                this.setAbsorptionHearts(this.getAbsorptionHearts() - f);
+                // CraftBukkit start
+                if (!human) {
+                    this.setAbsorptionHearts(this.getAbsorptionHearts() - f);
+                }
                 this.a(GameEvent.ENTITY_DAMAGED, damagesource.getEntity());
+
+                return true;
+            } else {
+                // Duplicate triggers if blocking
+                if (event.getDamage(DamageModifier.BLOCKING) < 0) {
+                    if (this instanceof EntityPlayer) {
+                        CriterionTriggers.ENTITY_HURT_PLAYER.a((EntityPlayer) this, damagesource, f, originalDamage, true);
+                        f2 = (float) -event.getDamage(DamageModifier.BLOCKING);
+                        if (f2 > 0.0F && f2 < 3.4028235E37F) {
+                            ((EntityPlayer) this).a(StatisticList.DAMAGE_BLOCKED_BY_SHIELD, Math.round(originalDamage * 10.0F));
+                        }
+                    }
+
+                    if (damagesource.getEntity() instanceof EntityPlayer) {
+                        CriterionTriggers.PLAYER_HURT_ENTITY.a((EntityPlayer) damagesource.getEntity(), this, damagesource, f, originalDamage, true);
+                    }
+
+                    return false;
+                } else {
+                    return originalDamage > 0;
+                }
+                // CraftBukkit end
             }
         }
+        return false; // CraftBukkit
     }
 
     public CombatTracker getCombatTracker() {
@@ -1665,8 +2082,18 @@
     }
 
     public final void setArrowCount(int i) {
-        this.entityData.set(EntityLiving.DATA_ARROW_COUNT_ID, i);
+        // CraftBukkit start
+        setArrowCount(i, false);
+    }
+
+    public final void setArrowCount(int i, boolean flag) {
+        ArrowBodyCountChangeEvent event = CraftEventFactory.callArrowBodyCountChangeEvent(this, getArrowCount(), i, flag);
+        if (event.isCancelled()) {
+            return;
+        }
+        this.entityData.set(EntityLiving.DATA_ARROW_COUNT_ID, event.getNewAmount());
     }
+    // CraftBukkit end
 
     public final int eh() {
         return (Integer) this.entityData.get(EntityLiving.DATA_STINGER_COUNT_ID);
@@ -1962,6 +2389,12 @@
 
     public abstract ItemStack getEquipment(EnumItemSlot enumitemslot);
 
+    // CraftBukkit start
+    public void setSlot(EnumItemSlot enumitemslot, ItemStack itemstack, boolean silent) {
+        this.setSlot(enumitemslot, itemstack);
+    }
+    // CraftBukkit end
+
     @Override
     public abstract void setSlot(EnumItemSlot enumitemslot, ItemStack itemstack);
 
@@ -2205,6 +2638,7 @@
                 }
 
                 if (this.onGround && !this.level.isClientSide) {
+                    if (getFlag(7) && !CraftEventFactory.callToggleGlideEvent(this, false).isCancelled()) // CraftBukkit
                     this.setFlag(7, false);
                 }
             } else {
@@ -2735,6 +3169,7 @@
         }
 
         if (!this.level.isClientSide) {
+            if (flag != this.getFlag(7) && !CraftEventFactory.callToggleGlideEvent(this, flag).isCancelled()) // CraftBukkit
             this.setFlag(7, flag);
         }
 
@@ -2902,14 +3337,21 @@
 
     @Override
     public boolean isInteractable() {
-        return !this.isRemoved();
+        return !this.isRemoved() && this.collides; // CraftBukkit
     }
 
     @Override
     public boolean isCollidable() {
-        return this.isAlive() && !this.isSpectator() && !this.isClimbing();
+        return this.isAlive() && !this.isSpectator() && !this.isClimbing() && this.collides; // CraftBukkit
     }
 
+    // CraftBukkit start - collidable API
+    @Override
+    public boolean canCollideWithBukkit(Entity entity) {
+        return isCollidable() && this.collides != this.collidableExemptions.contains(entity.getUniqueID());
+    }
+    // CraftBukkit end
+
     @Override
     protected void velocityChanged() {
         this.hurtMarked = this.random.nextDouble() >= this.b(GenericAttributes.KNOCKBACK_RESISTANCE);
@@ -3107,7 +3549,25 @@
         } else {
             if (!this.useItem.isEmpty() && this.isHandRaised()) {
                 this.b(this.useItem, 16);
-                ItemStack itemstack = this.useItem.a(this.level, this);
+                // CraftBukkit start - fire PlayerItemConsumeEvent
+                ItemStack itemstack;
+                if (this instanceof EntityPlayer) {
+                    org.bukkit.inventory.ItemStack craftItem = CraftItemStack.asBukkitCopy(this.useItem);
+                    PlayerItemConsumeEvent event = new PlayerItemConsumeEvent((Player) this.getBukkitEntity(), craftItem);
+                    level.getCraftServer().getPluginManager().callEvent(event);
+
+                    if (event.isCancelled()) {
+                        // Update client
+                        ((EntityPlayer) this).getBukkitEntity().updateInventory();
+                        ((EntityPlayer) this).getBukkitEntity().updateScaledHealth();
+                        return;
+                    }
+
+                    itemstack = (craftItem.equals(event.getItem())) ? this.useItem.a(this.level, this) : CraftItemStack.asNMSCopy(event.getItem()).a(level, this);
+                } else {
+                    itemstack = this.useItem.a(this.level, this);
+                }
+                // CraftBukkit end
 
                 if (itemstack != this.useItem) {
                     this.a(enumhand, itemstack);
@@ -3179,6 +3639,12 @@
     }
 
     public boolean a(double d0, double d1, double d2, boolean flag) {
+        // CraftBukkit start
+        return safeTeleport(d0, d1, d2, flag, org.bukkit.event.player.PlayerTeleportEvent.TeleportCause.UNKNOWN).orElse(false);
+    }
+
+    public Optional<Boolean> safeTeleport(double d0, double d1, double d2, boolean flag, org.bukkit.event.player.PlayerTeleportEvent.TeleportCause cause) {
+        // CraftBukkit end
         double d3 = this.locX();
         double d4 = this.locY();
         double d5 = this.locZ();
@@ -3203,16 +3669,41 @@
             }
 
             if (flag2) {
-                this.enderTeleportTo(d0, d6, d2);
+                // CraftBukkit start - Teleport event
+                // this.enderTeleportTo(d0, d6, d2);
+
+                // first set position, to check if the place to teleport is valid
+                this.setPosition(d0, d6, d2);
                 if (world.getCubes(this) && !world.containsLiquid(this.getBoundingBox())) {
                     flag1 = true;
                 }
+                // now revert and call event if the teleport place is valid
+                this.setPosition(d3, d4, d5);
+
+                if (flag1) {
+                    if (!(this instanceof EntityPlayer)) {
+                        EntityTeleportEvent teleport = new EntityTeleportEvent(this.getBukkitEntity(), new Location(this.level.getWorld(), d3, d4, d5), new Location(this.level.getWorld(), d0, d6, d2));
+                        this.level.getCraftServer().getPluginManager().callEvent(teleport);
+                        if (!teleport.isCancelled()) {
+                            Location to = teleport.getTo();
+                            this.enderTeleportTo(to.getX(), to.getY(), to.getZ());
+                        } else {
+                            return Optional.empty();
+                        }
+                    } else {
+                        // player teleport event is called in the underlining code
+                        if (((EntityPlayer) this).connection.a(d0, d6, d2, this.getYRot(), this.getXRot(), java.util.Collections.emptySet(), false, cause)) {
+                            return Optional.empty();
+                        }
+                    }
+                }
+                // CraftBukkit end
             }
         }
 
         if (!flag1) {
-            this.enderTeleportTo(d3, d4, d5);
-            return false;
+            // this.enderTeleportTo(d3, d4, d5); // CraftBukkit - already set the location back
+            return Optional.of(false); // CraftBukkit
         } else {
             if (flag) {
                 world.broadcastEntityEffect(this, (byte) 46);
@@ -3222,7 +3713,7 @@
                 ((EntityCreature) this).getNavigation().o();
             }
 
-            return true;
+            return Optional.of(true); // CraftBukkit
         }
     }
 
@@ -3305,7 +3796,7 @@
     }
 
     public void entityWakeup() {
-        Optional optional = this.getBedPosition();
+        Optional<BlockPosition> optional = this.getBedPosition(); // CraftBukkit - decompile error
         World world = this.level;
 
         java.util.Objects.requireNonNull(this.level);
@@ -3337,7 +3828,7 @@
 
     @Nullable
     public EnumDirection eX() {
-        BlockPosition blockposition = (BlockPosition) this.getBedPosition().orElse((Object) null);
+        BlockPosition blockposition = (BlockPosition) this.getBedPosition().orElse(null); // CraftBukkit - decompile error
 
         return blockposition != null ? BlockBed.a((IBlockAccess) this.level, blockposition) : null;
     }
@@ -3386,7 +3877,7 @@
                 Pair<MobEffect, Float> pair = (Pair) iterator.next();
 
                 if (!world.isClientSide && pair.getFirst() != null && world.random.nextFloat() < (Float) pair.getSecond()) {
-                    entityliving.addEffect(new MobEffect((MobEffect) pair.getFirst()));
+                    entityliving.addEffect(new MobEffect((MobEffect) pair.getFirst()), EntityPotionEffectEvent.Cause.FOOD); // CraftBukkit
                 }
             }
         }