PaperMC/nms-patches/DispenseBehaviorFireworks.patch

--- ../work/decompile-8eb82bde//net/minecraft/server/DispenseBehaviorFireworks.java	Sat Dec  6 21:12:00 2014
+++ src/main/java/net/minecraft/server/DispenseBehaviorFireworks.java	Sat Dec  6 21:11:47 2014
@@ -1,5 +1,8 @@
 package net.minecraft.server;
 
+import org.bukkit.craftbukkit.inventory.CraftItemStack;
+import org.bukkit.event.block.BlockDispenseEvent;
+
 final class DispenseBehaviorFireworks extends DispenseBehaviorItem {
 
     DispenseBehaviorFireworks() {}
@@ -9,10 +12,38 @@
         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.i(), d0, d1, d2, itemstack);
 
+        // CraftBukkit start
+        World world = isourceblock.i();
+        ItemStack itemstack1 = itemstack.a(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.count++;
+            return itemstack;
+        }
+
+        if (!event.getItem().equals(craftItem)) {
+            itemstack.count++;
+            // Chain to handler for new item
+            ItemStack eventStack = CraftItemStack.asNMSCopy(event.getItem());
+            IDispenseBehavior idispensebehavior = (IDispenseBehavior) BlockDispenser.M.get(eventStack.getItem());
+            if (idispensebehavior != IDispenseBehavior.a && idispensebehavior != this) {
+                idispensebehavior.a(isourceblock, eventStack);
+                return itemstack;
+            }
+        }
+
+        EntityFireworks entityfireworks = new EntityFireworks(isourceblock.i(), d0, d1, d2, itemstack);
         isourceblock.i().addEntity(entityfireworks);
-        itemstack.a(1);
+        // itemstack.a(1); // Handled during event processing
+        // CraftBukkit end
         return itemstack;
     }