Paper/nms-patches/DispenserRegistry.patch

--- a/net/minecraft/server/DispenserRegistry.java
+++ b/net/minecraft/server/DispenserRegistry.java
@@ -7,6 +7,11 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
+import org.bukkit.event.block.BlockDispenseEvent;
+// CraftBukkit end
+
 public class DispenserRegistry {
 
     public static final PrintStream a = System.out;
@@ -69,7 +74,7 @@
         BlockDispenser.REGISTRY.a(Items.SPLASH_POTION, new IDispenseBehavior() {
             public ItemStack a(ISourceBlock isourceblock, final ItemStack itemstack) {
                 return (new DispenseBehaviorProjectile() {
-                    protected IProjectile a(World world, IPosition iposition, ItemStack itemstack) {
+                    protected IProjectile a(World world, IPosition iposition, ItemStack itemstack1) { // CraftBukkit - decompile issue
                         return new EntityPotion(world, iposition.getX(), iposition.getY(), iposition.getZ(), itemstack1.cloneItemStack());
                     }
 
@@ -86,7 +91,7 @@
         BlockDispenser.REGISTRY.a(Items.LINGERING_POTION, new IDispenseBehavior() {
             public ItemStack a(ISourceBlock isourceblock, final ItemStack itemstack) {
                 return (new DispenseBehaviorProjectile() {
-                    protected IProjectile a(World world, IPosition iposition, ItemStack itemstack) {
+                    protected IProjectile a(World world, IPosition iposition, ItemStack itemstack1) { // CraftBukkit - decompile issue
                         return new EntityPotion(world, iposition.getX(), iposition.getY(), iposition.getZ(), itemstack1.cloneItemStack());
                     }
 
@@ -106,14 +111,46 @@
                 double d0 = isourceblock.getX() + (double) enumdirection.getAdjacentX();
                 double d1 = (double) ((float) (isourceblock.getBlockPosition().getY() + enumdirection.getAdjacentY()) + 0.2F);
                 double d2 = isourceblock.getZ() + (double) enumdirection.getAdjacentZ();
-                Entity entity = ItemMonsterEgg.a(isourceblock.getWorld(), ItemMonsterEgg.h(itemstack), d0, d1, d2);
+                // Entity entity = ItemMonsterEgg.a(isourceblock.getWorld(), ItemMonsterEgg.h(itemstack), d0, d1, d2);
+
+                // CraftBukkit start
+                World world = isourceblock.getWorld();
+                ItemStack itemstack1 = itemstack.cloneAndSubtract(1);
+                org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack1);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(d0, d1, d2));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    itemstack.add(1);
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    itemstack.add(1);
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+
+                itemstack1 = CraftItemStack.asNMSCopy(event.getItem());
+
+                Entity entity = ItemMonsterEgg.spawnCreature(isourceblock.getWorld(), ItemMonsterEgg.h(itemstack), event.getVelocity().getX(), event.getVelocity().getY(), event.getVelocity().getZ(), org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DISPENSE_EGG);
 
                 if (entity instanceof EntityLiving && itemstack.hasName()) {
                     entity.setCustomName(itemstack.getName());
                 }
 
                 ItemMonsterEgg.a(isourceblock.getWorld(), (EntityHuman) null, itemstack, entity);
-                itemstack.subtract(1);
+                // itemstack.subtract(1);// Handled during event processing
+                // CraftBukkit end
                 return itemstack;
             }
         });
@@ -123,10 +160,39 @@
                 double d0 = isourceblock.getX() + (double) enumdirection.getAdjacentX();
                 double d1 = (double) ((float) isourceblock.getBlockPosition().getY() + 0.2F);
                 double d2 = isourceblock.getZ() + (double) enumdirection.getAdjacentZ();
-                EntityFireworks entityfireworks = new EntityFireworks(isourceblock.getWorld(), d0, d1, d2, itemstack);
+                // CraftBukkit start
+                World world = isourceblock.getWorld();
+                ItemStack itemstack1 = itemstack.cloneAndSubtract(1);
+                org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack1);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(d0, d1, d2));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    itemstack.add(1);
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    itemstack.add(1);
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+
+                itemstack1 = CraftItemStack.asNMSCopy(event.getItem());
+                EntityFireworks entityfireworks = new EntityFireworks(isourceblock.getWorld(), event.getVelocity().getX(), event.getVelocity().getY(), event.getVelocity().getZ(), itemstack1);
 
                 isourceblock.getWorld().addEntity(entityfireworks);
-                itemstack.subtract(1);
+                // itemstack.subtract(1); // Handled during event processing
+                // CraftBukkit end
                 return itemstack;
             }
 
@@ -147,8 +213,38 @@
                 double d4 = random.nextGaussian() * 0.05D + (double) enumdirection.getAdjacentY();
                 double d5 = random.nextGaussian() * 0.05D + (double) enumdirection.getAdjacentZ();
 
-                world.addEntity(new EntitySmallFireball(world, d0, d1, d2, d3, d4, d5));
-                itemstack.subtract(1);
+                // CraftBukkit start
+                ItemStack itemstack1 = itemstack.cloneAndSubtract(1);
+                org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack1);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(d3, d4, d5));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    itemstack.add(1);
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    itemstack.add(1);
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+
+                EntitySmallFireball fireball = new EntitySmallFireball(world, d0, d1, d2, event.getVelocity().getX(), event.getVelocity().getY(), event.getVelocity().getZ());
+                fireball.projectileSource = new org.bukkit.craftbukkit.projectiles.CraftBlockProjectileSource((TileEntityDispenser) isourceblock.getTileEntity());
+
+                world.addEntity(fireball);
+                // itemstack.subtract(1); // Handled during event processing
+                // CraftBukkit end
                 return itemstack;
             }
 
@@ -169,7 +265,53 @@
                 ItemBucket itembucket = (ItemBucket) itemstack.getItem();
                 BlockPosition blockposition = isourceblock.getBlockPosition().shift((EnumDirection) isourceblock.e().get(BlockDispenser.FACING));
 
-                return itembucket.a((EntityHuman) null, isourceblock.getWorld(), blockposition) ? new ItemStack(Items.BUCKET) : this.b.a(isourceblock, itemstack);
+                // CraftBukkit start
+                World world = isourceblock.getWorld();
+                int x = blockposition.getX();
+                int y = blockposition.getY();
+                int z = blockposition.getZ();
+                if (world.isEmpty(blockposition) || !world.getType(blockposition).getMaterial().isBuildable()) {
+                    org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                    CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+                    BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(x, y, z));
+                    if (!BlockDispenser.eventFired) {
+                        world.getServer().getPluginManager().callEvent(event);
+                    }
+
+                    if (event.isCancelled()) {
+                        return itemstack;
+                    }
+
+                    if (!event.getItem().equals(craftItem)) {
+                        // Chain to handler for new item
+                        ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                        IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                        if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                            idispensebehavior.a(isourceblock, eventStack);
+                            return itemstack;
+                        }
+                    }
+
+                    itembucket = (ItemBucket) CraftItemStack.asNMSCopy(event.getItem()).getItem();
+                }
+                // CraftBukkit end
+
+                if (itembucket.a((EntityHuman) null, isourceblock.getWorld(), blockposition)) {
+                    // CraftBukkit start - Handle stacked buckets
+                    Item item = Items.BUCKET;
+                    itemstack.subtract(1);
+                    if (itemstack.isEmpty()) {
+                        itemstack.setItem(Items.BUCKET);
+                        itemstack.setCount(1);
+                    } else if (((TileEntityDispenser) isourceblock.getTileEntity()).addItem(new ItemStack(item)) < 0) {
+                        this.b.a(isourceblock, new ItemStack(item));
+                    }
+                    // CraftBukkit end
+                    return itemstack;
+                } else {
+                    return this.b.a(isourceblock, itemstack);
+                }
             }
         };
 
@@ -196,6 +338,30 @@
                     item = Items.LAVA_BUCKET;
                 }
 
+                // CraftBukkit start
+                org.bukkit.block.Block bukkitBlock = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(bukkitBlock, craftItem.clone(), new org.bukkit.util.Vector(blockposition.getX(), blockposition.getY(), blockposition.getZ()));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+                // CraftBukkit end
+
                 world.setAir(blockposition);
                 itemstack.subtract(1);
                 if (itemstack.isEmpty()) {
@@ -213,14 +379,42 @@
             protected ItemStack b(ISourceBlock isourceblock, ItemStack itemstack) {
                 World world = isourceblock.getWorld();
 
+                // CraftBukkit start
+                org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(0, 0, 0));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+                // CraftBukkit end
+
                 this.b = true;
                 BlockPosition blockposition = isourceblock.getBlockPosition().shift((EnumDirection) isourceblock.e().get(BlockDispenser.FACING));
 
                 if (world.isEmpty(blockposition)) {
-                    world.setTypeUpdate(blockposition, Blocks.FIRE.getBlockData());
-                    if (itemstack.isDamaged(1, world.random)) {
-                        itemstack.setCount(0);
+                    // CraftBukkit start - Ignition by dispensing flint and steel
+                    if (!org.bukkit.craftbukkit.event.CraftEventFactory.callBlockIgniteEvent(world, blockposition.getX(), blockposition.getY(), blockposition.getZ(), isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ()).isCancelled()) {
+                        world.setTypeUpdate(blockposition, Blocks.FIRE.getBlockData());
+                        if (itemstack.isDamaged(1, world.random)) {
+                            itemstack.setCount(0);
+                        }
                     }
+                    // CraftBukkit end
                 } else if (world.getType(blockposition).getBlock() == Blocks.TNT) {
                     Blocks.TNT.postBreak(world, blockposition, Blocks.TNT.getBlockData().set(BlockTNT.EXPLODE, Boolean.valueOf(true)));
                     world.setAir(blockposition);
@@ -238,6 +432,30 @@
                     World world = isourceblock.getWorld();
                     BlockPosition blockposition = isourceblock.getBlockPosition().shift((EnumDirection) isourceblock.e().get(BlockDispenser.FACING));
 
+                    // CraftBukkit start
+                    org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                    CraftItemStack craftItem = CraftItemStack.asNewCraftStack(itemstack.getItem());
+
+                    BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(0, 0, 0));
+                    if (!BlockDispenser.eventFired) {
+                        world.getServer().getPluginManager().callEvent(event);
+                    }
+
+                    if (event.isCancelled()) {
+                        return itemstack;
+                    }
+
+                    if (!event.getItem().equals(craftItem)) {
+                        // Chain to handler for new item
+                        ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                        IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                        if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                            idispensebehavior.a(isourceblock, eventStack);
+                            return itemstack;
+                        }
+                    }
+                    // CraftBukkit end
+
                     if (ItemDye.a(itemstack, world, blockposition)) {
                         if (!world.isClientSide) {
                             world.triggerEffect(2005, blockposition, 0);
@@ -256,11 +474,40 @@
             protected ItemStack b(ISourceBlock isourceblock, ItemStack itemstack) {
                 World world = isourceblock.getWorld();
                 BlockPosition blockposition = isourceblock.getBlockPosition().shift((EnumDirection) isourceblock.e().get(BlockDispenser.FACING));
-                EntityTNTPrimed entitytntprimed = new EntityTNTPrimed(world, (double) blockposition.getX() + 0.5D, (double) blockposition.getY(), (double) blockposition.getZ() + 0.5D, (EntityLiving) null);
+                // EntityTNTPrimed entitytntprimed = new EntityTNTPrimed(world, (double) blockposition.getX() + 0.5D, (double) blockposition.getY(), (double) blockposition.getZ() + 0.5D, (EntityLiving) null);
+
+                // CraftBukkit start
+                ItemStack itemstack1 = itemstack.cloneAndSubtract(1);
+                org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack1);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector((double) blockposition.getX() + 0.5D, (double) blockposition.getY(), (double) blockposition.getZ() + 0.5D));
+                if (!BlockDispenser.eventFired) {
+                   world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    itemstack.add(1);
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    itemstack.add(1);
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+
+                EntityTNTPrimed entitytntprimed = new EntityTNTPrimed(world, event.getVelocity().getX(), event.getVelocity().getY(), event.getVelocity().getZ(), (EntityLiving) null);
+                // CraftBukkit end
 
                 world.addEntity(entitytntprimed);
                 world.a((EntityHuman) null, entitytntprimed.locX, entitytntprimed.locY, entitytntprimed.locZ, SoundEffects.gV, SoundCategory.BLOCKS, 1.0F, 1.0F);
-                itemstack.subtract(1);
+                // itemstack.subtract(1); // CraftBukkit - handled above
                 return itemstack;
             }
         });
@@ -271,6 +518,30 @@
                 BlockPosition blockposition = isourceblock.getBlockPosition().shift(enumdirection);
                 BlockSkull blockskull = Blocks.SKULL;
 
+                // CraftBukkit start
+                org.bukkit.block.Block bukkitBlock = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(bukkitBlock, craftItem.clone(), new org.bukkit.util.Vector(blockposition.getX(), blockposition.getY(), blockposition.getZ()));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+                // CraftBukkit end
+
                 this.b = true;
                 if (world.isEmpty(blockposition) && blockskull.b(world, blockposition, itemstack)) {
                     if (!world.isClientSide) {
@@ -319,6 +590,30 @@
                 BlockPosition blockposition = isourceblock.getBlockPosition().shift((EnumDirection) isourceblock.e().get(BlockDispenser.FACING));
                 BlockPumpkin blockpumpkin = (BlockPumpkin) Blocks.PUMPKIN;
 
+                // CraftBukkit start
+                org.bukkit.block.Block bukkitBlock = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+                CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+                BlockDispenseEvent event = new BlockDispenseEvent(bukkitBlock, craftItem.clone(), new org.bukkit.util.Vector(blockposition.getX(), blockposition.getY(), blockposition.getZ()));
+                if (!BlockDispenser.eventFired) {
+                    world.getServer().getPluginManager().callEvent(event);
+                }
+
+                if (event.isCancelled()) {
+                    return itemstack;
+                }
+
+                if (!event.getItem().equals(craftItem)) {
+                    // Chain to handler for new item
+                    ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                    IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                    if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                        idispensebehavior.a(isourceblock, eventStack);
+                        return itemstack;
+                    }
+                }
+                // CraftBukkit end
+
                 this.b = true;
                 if (world.isEmpty(blockposition) && blockpumpkin.b(world, blockposition)) {
                     if (!world.isClientSide) {
@@ -388,6 +683,30 @@
             EnumDirection enumdirection = (EnumDirection) isourceblock.e().get(BlockDispenser.FACING);
             BlockPosition blockposition = isourceblock.getBlockPosition().shift(enumdirection);
 
+            // CraftBukkit start
+            org.bukkit.block.Block bukkitBlock = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+            CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack);
+
+            BlockDispenseEvent event = new BlockDispenseEvent(bukkitBlock, craftItem.clone(), new org.bukkit.util.Vector(blockposition.getX(), blockposition.getY(), blockposition.getZ()));
+            if (!BlockDispenser.eventFired) {
+                world.getServer().getPluginManager().callEvent(event);
+            }
+
+            if (event.isCancelled()) {
+                return itemstack;
+            }
+
+            if (!event.getItem().equals(craftItem)) {
+                // Chain to handler for new item
+                ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                    idispensebehavior.a(isourceblock, eventStack);
+                    return itemstack;
+                }
+            }
+            // CraftBukkit end
+
             this.b = world.a(block, blockposition, false, EnumDirection.DOWN, (Entity) null);
             if (this.b) {
                 EnumDirection enumdirection1 = world.isEmpty(blockposition.down()) ? enumdirection : EnumDirection.UP;
@@ -456,12 +775,40 @@
                 d3 = 0.0D;
             }
 
-            EntityBoat entityboat = new EntityBoat(world, d0, d1 + d3, d2);
+            // EntityBoat entityboat = new EntityBoat(world, d0, d1 + d3, d2);
+            // CraftBukkit start
+            ItemStack itemstack1 = itemstack.cloneAndSubtract(1);
+            org.bukkit.block.Block block = world.getWorld().getBlockAt(isourceblock.getBlockPosition().getX(), isourceblock.getBlockPosition().getY(), isourceblock.getBlockPosition().getZ());
+            CraftItemStack craftItem = CraftItemStack.asCraftMirror(itemstack1);
+
+            BlockDispenseEvent event = new BlockDispenseEvent(block, craftItem.clone(), new org.bukkit.util.Vector(d0, d1 + d3, d2));
+            if (!BlockDispenser.eventFired) {
+                world.getServer().getPluginManager().callEvent(event);
+            }
+
+            if (event.isCancelled()) {
+                itemstack.add(1);
+                return itemstack;
+            }
+
+            if (!event.getItem().equals(craftItem)) {
+                itemstack.add(1);
+                // Chain to handler for new item
+                ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+                IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.REGISTRY.get(eventStack.getItem());
+                if (idispensebehavior != IDispenseBehavior.NONE && idispensebehavior != this) {
+                    idispensebehavior.a(isourceblock, eventStack);
+                    return itemstack;
+                }
+            }
+
+            EntityBoat entityboat = new EntityBoat(world, event.getVelocity().getX(), event.getVelocity().getY(), event.getVelocity().getZ());
+            // CraftBukkit end
 
             entityboat.setType(this.c);
             entityboat.yaw = enumdirection.l();
-            world.addEntity(entityboat);
-            itemstack.subtract(1);
+            if (!world.addEntity(entityboat)) itemstack.add(1); // CraftBukkit
+            // itemstack.subtract(1); // CraftBukkit - handled during event processing
             return itemstack;
         }