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

--- a/net/minecraft/world/entity/EntityInsentient.java
+++ b/net/minecraft/world/entity/EntityInsentient.java
@@ -89,6 +89,20 @@
 import net.minecraft.world.level.storage.loot.parameters.LootContextParameters;
 import net.minecraft.world.phys.AxisAlignedBB;
 
+// CraftBukkit start
+import net.minecraft.server.level.EntityPlayer;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+import org.bukkit.craftbukkit.entity.CraftLivingEntity;
+import org.bukkit.event.entity.CreatureSpawnEvent;
+import org.bukkit.event.entity.EntityCombustByEntityEvent;
+import org.bukkit.event.entity.EntityRemoveEvent;
+import org.bukkit.event.entity.EntityTargetLivingEntityEvent;
+import org.bukkit.event.entity.EntityTargetEvent;
+import org.bukkit.event.entity.EntityTransformEvent;
+import org.bukkit.event.entity.EntityUnleashEvent;
+import org.bukkit.event.entity.EntityUnleashEvent.UnleashReason;
+// CraftBukkit end
+
 public abstract class EntityInsentient extends EntityLiving implements EquipmentUser, Targeting {
 
     private static final DataWatcherObject<Byte> DATA_MOB_FLAGS_ID = DataWatcher.defineId(EntityInsentient.class, DataWatcherRegistry.BYTE);
@@ -138,6 +152,8 @@
     private BlockPosition restrictCenter;
     private float restrictRadius;
 
+    public boolean aware = true; // CraftBukkit
+
     protected EntityInsentient(EntityTypes<? extends EntityInsentient> entitytypes, World world) {
         super(entitytypes, world);
         this.handItems = NonNullList.withSize(2, ItemStack.EMPTY);
@@ -165,6 +181,12 @@
 
     }
 
+    // CraftBukkit start
+    public void setPersistenceRequired(boolean persistenceRequired) {
+        this.persistenceRequired = persistenceRequired;
+    }
+    // CraftBukkit end
+
     protected void registerGoals() {}
 
     public static AttributeProvider.Builder createMobAttributes() {
@@ -269,11 +291,42 @@
 
     @Nullable
     protected final EntityLiving getTargetFromBrain() {
-        return (EntityLiving) this.getBrain().getMemory(MemoryModuleType.ATTACK_TARGET).orElse((Object) null);
+        return (EntityLiving) this.getBrain().getMemory(MemoryModuleType.ATTACK_TARGET).orElse(null); // CraftBukkit - decompile error
     }
 
     public void setTarget(@Nullable EntityLiving entityliving) {
+        // CraftBukkit start - fire event
+        setTarget(entityliving, EntityTargetEvent.TargetReason.UNKNOWN, true);
+    }
+
+    public boolean setTarget(EntityLiving entityliving, EntityTargetEvent.TargetReason reason, boolean fireEvent) {
+        if (getTarget() == entityliving) return false;
+        if (fireEvent) {
+            if (reason == EntityTargetEvent.TargetReason.UNKNOWN && getTarget() != null && entityliving == null) {
+                reason = getTarget().isAlive() ? EntityTargetEvent.TargetReason.FORGOT_TARGET : EntityTargetEvent.TargetReason.TARGET_DIED;
+            }
+            if (reason == EntityTargetEvent.TargetReason.UNKNOWN) {
+                this.level().getCraftServer().getLogger().log(java.util.logging.Level.WARNING, "Unknown target reason, please report on the issue tracker", new Exception());
+            }
+            CraftLivingEntity ctarget = null;
+            if (entityliving != null) {
+                ctarget = (CraftLivingEntity) entityliving.getBukkitEntity();
+            }
+            EntityTargetLivingEntityEvent event = new EntityTargetLivingEntityEvent(this.getBukkitEntity(), ctarget, reason);
+            this.level().getCraftServer().getPluginManager().callEvent(event);
+            if (event.isCancelled()) {
+                return false;
+            }
+
+            if (event.getTarget() != null) {
+                entityliving = ((CraftLivingEntity) event.getTarget()).getHandle();
+            } else {
+                entityliving = null;
+            }
+        }
         this.target = entityliving;
+        return true;
+        // CraftBukkit end
     }
 
     @Override
@@ -412,6 +465,12 @@
         return null;
     }
 
+    // CraftBukkit start - Add delegate method
+    public SoundEffect getAmbientSound0() {
+        return getAmbientSound();
+    }
+    // CraftBukkit end
+
     @Override
     public void addAdditionalSaveData(NBTTagCompound nbttagcompound) {
         super.addAdditionalSaveData(nbttagcompound);
@@ -486,7 +545,10 @@
             }
         }
 
-        if (either != null) {
+        // CraftBukkit start - SPIGOT-7487: Don't save (and possible drop) leash, when the holder was removed by a plugin
+        Entity leashHolder = this.leashHolder;
+        if (either != null && (leashHolder == null || !leashHolder.pluginRemoved)) {
+            // CraftBukkit end
             nbttagcompound.put("leash", (NBTBase) either.map((uuid) -> {
                 NBTTagCompound nbttagcompound1 = new NBTTagCompound();
 
@@ -507,16 +569,26 @@
             nbttagcompound.putBoolean("NoAI", this.isNoAi());
         }
 
+        nbttagcompound.putBoolean("Bukkit.Aware", this.aware); // CraftBukkit
     }
 
     @Override
     public void readAdditionalSaveData(NBTTagCompound nbttagcompound) {
         super.readAdditionalSaveData(nbttagcompound);
+
+        // CraftBukkit start - If looting or persistence is false only use it if it was set after we started using it
         if (nbttagcompound.contains("CanPickUpLoot", 1)) {
-            this.setCanPickUpLoot(nbttagcompound.getBoolean("CanPickUpLoot"));
+            boolean data = nbttagcompound.getBoolean("CanPickUpLoot");
+            if (isLevelAtLeast(nbttagcompound, 1) || data) {
+                this.setCanPickUpLoot(data);
+            }
         }
 
-        this.persistenceRequired = nbttagcompound.getBoolean("PersistenceRequired");
+        boolean data = nbttagcompound.getBoolean("PersistenceRequired");
+        if (isLevelAtLeast(nbttagcompound, 1) || data) {
+            this.persistenceRequired = data;
+        }
+        // CraftBukkit end
         NBTTagList nbttaglist;
         NBTTagCompound nbttagcompound1;
         int i;
@@ -565,7 +637,7 @@
         if (nbttagcompound.contains("leash", 10)) {
             this.delayedLeashInfo = Either.left(nbttagcompound.getCompound("leash").getUUID("UUID"));
         } else if (nbttagcompound.contains("leash", 11)) {
-            this.delayedLeashInfo = (Either) GameProfileSerializer.readBlockPos(nbttagcompound, "leash").map(Either::right).orElse((Object) null);
+            this.delayedLeashInfo = (Either) GameProfileSerializer.readBlockPos(nbttagcompound, "leash").map(Either::right).orElse(null); // CraftBukkit - decompile error
         } else {
             this.delayedLeashInfo = null;
         }
@@ -577,6 +649,11 @@
         }
 
         this.setNoAi(nbttagcompound.getBoolean("NoAI"));
+        // CraftBukkit start
+        if (nbttagcompound.contains("Bukkit.Aware")) {
+            this.aware = nbttagcompound.getBoolean("Bukkit.Aware");
+        }
+        // CraftBukkit end
     }
 
     @Override
@@ -651,20 +728,26 @@
 
     protected void pickUpItem(EntityItem entityitem) {
         ItemStack itemstack = entityitem.getItem();
-        ItemStack itemstack1 = this.equipItemIfPossible(itemstack.copy());
+        ItemStack itemstack1 = this.equipItemIfPossible(itemstack.copy(), entityitem); // CraftBukkit - add item
 
         if (!itemstack1.isEmpty()) {
             this.onItemPickup(entityitem);
             this.take(entityitem, itemstack1.getCount());
             itemstack.shrink(itemstack1.getCount());
             if (itemstack.isEmpty()) {
-                entityitem.discard();
+                entityitem.discard(EntityRemoveEvent.Cause.PICKUP); // CraftBukkit - add Bukkit remove cause
             }
         }
 
     }
 
     public ItemStack equipItemIfPossible(ItemStack itemstack) {
+        // CraftBukkit start - add item
+        return this.equipItemIfPossible(itemstack, null);
+    }
+
+    public ItemStack equipItemIfPossible(ItemStack itemstack, EntityItem entityitem) {
+        // CraftBukkit end
         EnumItemSlot enumitemslot = getEquipmentSlotForItem(itemstack);
         ItemStack itemstack1 = this.getItemBySlot(enumitemslot);
         boolean flag = this.canReplaceCurrentItem(itemstack, itemstack1);
@@ -675,11 +758,19 @@
             flag = itemstack1.isEmpty();
         }
 
-        if (flag && this.canHoldItem(itemstack)) {
+        // CraftBukkit start
+        boolean canPickup = flag && this.canHoldItem(itemstack);
+        if (entityitem != null) {
+            canPickup = !org.bukkit.craftbukkit.event.CraftEventFactory.callEntityPickupItemEvent(this, entityitem, 0, !canPickup).isCancelled();
+        }
+        if (canPickup) {
+            // CraftBukkit end
             double d0 = (double) this.getEquipmentDropChance(enumitemslot);
 
             if (!itemstack1.isEmpty() && (double) Math.max(this.random.nextFloat() - 0.1F, 0.0F) < d0) {
+                this.forceDrops = true; // CraftBukkit
                 this.spawnAtLocation(itemstack1);
+                this.forceDrops = false; // CraftBukkit
             }
 
             if (enumitemslot.isArmor() && itemstack.getCount() > 1) {
@@ -813,7 +904,7 @@
     @Override
     public void checkDespawn() {
         if (this.level().getDifficulty() == EnumDifficulty.PEACEFUL && this.shouldDespawnInPeaceful()) {
-            this.discard();
+            this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
         } else if (!this.isPersistenceRequired() && !this.requiresCustomPersistence()) {
             EntityHuman entityhuman = this.level().getNearestPlayer(this, -1.0D);
 
@@ -823,14 +914,14 @@
                 int j = i * i;
 
                 if (d0 > (double) j && this.removeWhenFarAway(d0)) {
-                    this.discard();
+                    this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
                 }
 
                 int k = this.getType().getCategory().getNoDespawnDistance();
                 int l = k * k;
 
                 if (this.noActionTime > 600 && this.random.nextInt(800) == 0 && d0 > (double) l && this.removeWhenFarAway(d0)) {
-                    this.discard();
+                    this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
                 } else if (d0 < (double) l) {
                     this.noActionTime = 0;
                 }
@@ -844,6 +935,7 @@
     @Override
     protected final void serverAiStep() {
         ++this.noActionTime;
+        if (!this.aware) return; // CraftBukkit
         GameProfilerFiller gameprofilerfiller = this.level().getProfiler();
 
         gameprofilerfiller.push("sensing");
@@ -1311,6 +1403,12 @@
         if (!this.isAlive()) {
             return EnumInteractionResult.PASS;
         } else if (this.getLeashHolder() == entityhuman) {
+            // CraftBukkit start - fire PlayerUnleashEntityEvent
+            if (CraftEventFactory.callPlayerUnleashEntityEvent(this, entityhuman, enumhand).isCancelled()) {
+                ((EntityPlayer) entityhuman).connection.send(new PacketPlayOutAttachEntity(this, this.getLeashHolder()));
+                return EnumInteractionResult.PASS;
+            }
+            // CraftBukkit end
             this.dropLeash(true, !entityhuman.hasInfiniteMaterials());
             this.gameEvent(GameEvent.ENTITY_INTERACT, entityhuman);
             return EnumInteractionResult.sidedSuccess(this.level().isClientSide);
@@ -1336,6 +1434,13 @@
         ItemStack itemstack = entityhuman.getItemInHand(enumhand);
 
         if (itemstack.is(Items.LEAD) && this.canBeLeashed(entityhuman)) {
+            // CraftBukkit start - fire PlayerLeashEntityEvent
+            if (CraftEventFactory.callPlayerLeashEntityEvent(this, entityhuman, entityhuman, enumhand).isCancelled()) {
+                ((EntityPlayer) entityhuman).resendItemInHands(); // SPIGOT-7615: Resend to fix client desync with used item
+                ((EntityPlayer) entityhuman).connection.send(new PacketPlayOutAttachEntity(this, this.getLeashHolder()));
+                return EnumInteractionResult.PASS;
+            }
+            // CraftBukkit end
             this.setLeashedTo(entityhuman, true);
             itemstack.shrink(1);
             return EnumInteractionResult.sidedSuccess(this.level().isClientSide);
@@ -1351,7 +1456,7 @@
             if (itemstack.getItem() instanceof ItemMonsterEgg) {
                 if (this.level() instanceof WorldServer) {
                     ItemMonsterEgg itemmonsteregg = (ItemMonsterEgg) itemstack.getItem();
-                    Optional<EntityInsentient> optional = itemmonsteregg.spawnOffspringFromSpawnEgg(entityhuman, this, this.getType(), (WorldServer) this.level(), this.position(), itemstack);
+                    Optional<EntityInsentient> optional = itemmonsteregg.spawnOffspringFromSpawnEgg(entityhuman, this, (EntityTypes<? extends EntityInsentient>) this.getType(), (WorldServer) this.level(), this.position(), itemstack); // CraftBukkit - decompile error
 
                     optional.ifPresent((entityinsentient) -> {
                         this.onOffspringSpawnedFromEgg(entityhuman, entityinsentient);
@@ -1401,12 +1506,19 @@
         return this.restrictRadius != -1.0F;
     }
 
+    // CraftBukkit start
     @Nullable
     public <T extends EntityInsentient> T convertTo(EntityTypes<T> entitytypes, boolean flag) {
+        return this.convertTo(entitytypes, flag, EntityTransformEvent.TransformReason.UNKNOWN, CreatureSpawnEvent.SpawnReason.DEFAULT);
+    }
+
+    @Nullable
+    public <T extends EntityInsentient> T convertTo(EntityTypes<T> entitytypes, boolean flag, EntityTransformEvent.TransformReason transformReason, CreatureSpawnEvent.SpawnReason spawnReason) {
+        // CraftBukkit end
         if (this.isRemoved()) {
             return null;
         } else {
-            T t0 = (EntityInsentient) entitytypes.create(this.level());
+            T t0 = entitytypes.create(this.level()); // CraftBukkit - decompile error
 
             if (t0 == null) {
                 return null;
@@ -1440,7 +1552,12 @@
                     }
                 }
 
-                this.level().addFreshEntity(t0);
+                // CraftBukkit start
+                if (CraftEventFactory.callEntityTransformEvent(this, t0, transformReason).isCancelled()) {
+                    return null;
+                }
+                this.level().addFreshEntity(t0, spawnReason);
+                // CraftBukkit end
                 if (this.isPassenger()) {
                     Entity entity = this.getVehicle();
 
@@ -1448,7 +1565,7 @@
                     t0.startRiding(entity, true);
                 }
 
-                this.discard();
+                this.discard(EntityRemoveEvent.Cause.TRANSFORMATION); // CraftBukkit - add Bukkit remove cause
                 return t0;
             }
         }
@@ -1461,7 +1578,8 @@
 
         if (this.leashHolder != null) {
             if (!this.isAlive() || !this.leashHolder.isAlive()) {
-                this.dropLeash(true, true);
+                this.level().getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), (!this.isAlive()) ? UnleashReason.PLAYER_UNLEASH : UnleashReason.HOLDER_GONE)); // CraftBukkit
+                this.dropLeash(true, !this.leashHolder.pluginRemoved);// CraftBukkit - SPIGOT-7487: Don't drop leash, when the holder was removed by a plugin
             }
 
         }
@@ -1473,7 +1591,9 @@
             this.delayedLeashInfo = null;
             this.clearRestriction();
             if (!this.level().isClientSide && flag1) {
+                this.forceDrops = true; // CraftBukkit
                 this.spawnAtLocation((IMaterial) Items.LEAD);
+                this.forceDrops = false; // CraftBukkit
             }
 
             if (!this.level().isClientSide && flag && this.level() instanceof WorldServer) {
@@ -1527,6 +1647,7 @@
         boolean flag1 = super.startRiding(entity, flag);
 
         if (flag1 && this.isLeashed()) {
+            this.level().getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), UnleashReason.UNKNOWN)); // CraftBukkit
             this.dropLeash(true, true);
         }
 
@@ -1555,7 +1676,9 @@
                 }
 
                 if (this.tickCount > 100) {
+                    this.forceDrops = true; // CraftBukkit
                     this.spawnAtLocation((IMaterial) Items.LEAD);
+                    this.forceDrops = false; // CraftBukkit
                     this.delayedLeashInfo = null;
                 }
             }
@@ -1638,14 +1761,21 @@
         int i = EnchantmentManager.getFireAspect(this);
 
         if (i > 0) {
-            entity.igniteForSeconds(i * 4);
+            // CraftBukkit start - Call a combust event when somebody hits with a fire enchanted item
+            EntityCombustByEntityEvent combustEvent = new EntityCombustByEntityEvent(this.getBukkitEntity(), entity.getBukkitEntity(), i * 4);
+            org.bukkit.Bukkit.getPluginManager().callEvent(combustEvent);
+
+            if (!combustEvent.isCancelled()) {
+                entity.igniteForSeconds(combustEvent.getDuration(), false);
+            }
+            // CraftBukkit end
         }
 
         boolean flag = entity.hurt(this.damageSources().mobAttack(this), f);
 
         if (flag) {
             if (f1 > 0.0F && entity instanceof EntityLiving) {
-                ((EntityLiving) entity).knockback((double) (f1 * 0.5F), (double) MathHelper.sin(this.getYRot() * 0.017453292F), (double) (-MathHelper.cos(this.getYRot() * 0.017453292F)));
+                ((EntityLiving) entity).knockback((double) (f1 * 0.5F), (double) MathHelper.sin(this.getYRot() * 0.017453292F), (double) (-MathHelper.cos(this.getYRot())) * 0.017453292F, this, org.bukkit.event.entity.EntityKnockbackEvent.KnockbackCause.ENTITY_ATTACK); // CraftBukkit
                 this.setDeltaMovement(this.getDeltaMovement().multiply(0.6D, 1.0D, 0.6D));
             }
 
@@ -1695,6 +1825,7 @@
     @Override
     protected void removeAfterChangingDimensions() {
         super.removeAfterChangingDimensions();
+        this.level().getCraftServer().getPluginManager().callEvent(new EntityUnleashEvent(this.getBukkitEntity(), UnleashReason.UNKNOWN)); // CraftBukkit
         this.dropLeash(true, false);
         this.getAllSlots().forEach((itemstack) -> {
             if (!itemstack.isEmpty()) {