Refactor code to be more efficient.

src/main/java/net/minecraft/server/Block.java

@@ -164,7 +164,7 @@ public class Block {
     public final Material material;
     public float frictionFactor;
     private String name;
-    public ArrayList<ItemStack> dropList = new ArrayList<ItemStack>(1); // CraftBukkit
+    public final ArrayList<ItemStack> dropList = new ArrayList<ItemStack>(1); // CraftBukkit
 
     protected Block(int i, Material material) {
         this.bR = true;
@@ -362,7 +362,7 @@ public class Block {
 
     protected void a(World world, int i, int j, int k, ItemStack itemstack) {
         // CraftBukkit start - the logic of this function is moved into finishDrop
-        // This is such a hackish change it's rediculous.
+        // This is such a hackish change it's ridiculous.
         this.dropList.add(itemstack);
     }
 
@@ -550,6 +550,7 @@ public class Block {
         this.dropList.clear();
     }
 
+    // Blocks that have different drops in certain situations need to override this. IE: Sheers on BlockLeaves
     public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         // CraftBukkit end
         if (this.h() && EnchantmentManager.hasSilkTouchEnchantment(entityhuman.inventory)) {
@@ -563,7 +564,8 @@ public class Block {
 
             this.dropNaturally(world, i, j, k, l, 1.0F, i1); // CraftBukkit
         }
-        return this.dropList; // CraftBukkit
+
+        return this.dropList;
     }
 
     protected boolean h() {

src/main/java/net/minecraft/server/BlockDeadBush.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 
 public class BlockDeadBush extends BlockFlower {
@@ -38,13 +37,13 @@ public class BlockDeadBush extends BlockFlower {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         if (!world.isStatic && entityhuman.U() != null && entityhuman.U().id == Item.SHEARS.id) {
             this.a(world, i, j, k, new ItemStack(Block.DEAD_BUSH, 1, l));
-            return this.dropList;
         } else {
             return super.calculateDrops(world, entityhuman, i, j, k, l);
         }
+        return this.dropList;
     }
     // CraftBukkit end
 }

src/main/java/net/minecraft/server/BlockLeaves.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 
 import org.bukkit.event.block.LeavesDecayEvent; // CraftBukkit
@@ -173,13 +172,13 @@ public class BlockLeaves extends BlockTransparant {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         if (!world.isStatic && entityhuman.U() != null && entityhuman.U().id == Item.SHEARS.id) {
             this.a(world, i, j, k, new ItemStack(Block.LEAVES.id, 1, l & 3));
-            return this.dropList;
         } else {
             return super.calculateDrops(world, entityhuman, i, j, k, l);
         }
+        return this.dropList;
     }
     // CraftBukkit end
 

src/main/java/net/minecraft/server/BlockLongGrass.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 
 public class BlockLongGrass extends BlockFlower {
@@ -38,13 +37,13 @@ public class BlockLongGrass extends BlockFlower {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         if (!world.isStatic && entityhuman.U() != null && entityhuman.U().id == Item.SHEARS.id) {
             this.a(world, i, j, k, new ItemStack(Block.LONG_GRASS, 1, l));
-            return this.dropList;
         } else {
             return super.calculateDrops(world, entityhuman, i, j, k, l);
         }
+        return this.dropList;
     }
     // CraftBukkit end
 }

src/main/java/net/minecraft/server/BlockPistonExtension.java

@@ -14,7 +14,7 @@ public class BlockPistonExtension extends Block {
     }
 
     // CraftBukkit start - Support getDrops() in BlockBreakEvent
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int d) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int d) {
         super.calculateDrops(world, entityhuman, i, j, k, d);
         int l = world.getData(i, j, k) & 0x7;
         if (l > 5 || l < 0) return this.dropList;

src/main/java/net/minecraft/server/BlockSnow.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 import org.bukkit.craftbukkit.event.CraftEventFactory;
 
@@ -74,7 +73,7 @@ public class BlockSnow extends Block {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         this.a(world, i, j, k, new ItemStack(Item.SNOW_BALL.id, 1, 1));
         return this.dropList;
     }

src/main/java/net/minecraft/server/BlockTNT.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 
 public class BlockTNT extends Block {
@@ -57,7 +56,7 @@ public class BlockTNT extends Block {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         if ((l & 1) == 0) {
             this.a(world, i, j, k, new ItemStack(Block.TNT.id, 1, 0));
         }

src/main/java/net/minecraft/server/BlockVine.java

@@ -1,6 +1,5 @@
 package net.minecraft.server;
 
-import java.util.ArrayList; // CraftBukkit
 import java.util.Random;
 
 public class BlockVine extends Block {
@@ -298,13 +297,13 @@ public class BlockVine extends Block {
     }
 
     // CraftBukkit start - Calculate drops
-    public ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
+    public java.util.ArrayList<ItemStack> calculateDrops(World world, EntityHuman entityhuman, int i, int j, int k, int l) {
         if (!world.isStatic && entityhuman.U() != null && entityhuman.U().id == Item.SHEARS.id) {
             this.a(world, i, j, k, new ItemStack(Block.VINE, 1, 0));
-            return this.dropList;
         } else {
             return super.calculateDrops(world, entityhuman, i, j, k, l);
         }
+        return this.dropList;
     }
     // CraftBukkit end
 }

src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java

@@ -1,8 +1,6 @@
 package org.bukkit.craftbukkit.event;
 
 import java.net.InetAddress;
-import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
@@ -18,7 +16,6 @@ import net.minecraft.server.EntityItem;
 import net.minecraft.server.EntityLiving;
 import net.minecraft.server.EntityPlayer;
 import net.minecraft.server.EntityPotion;
-import net.minecraft.server.IInventory;
 import net.minecraft.server.InventoryCrafting;
 import net.minecraft.server.Item;
 import net.minecraft.server.ItemStack;
@@ -512,12 +509,13 @@ public class CraftEventFactory {
         return event;
     }
 
+    private static final List<org.bukkit.inventory.ItemStack> drops = new java.util.ArrayList<org.bukkit.inventory.ItemStack>();
+
     public static boolean callBlockBreakEvent(World world, int x, int y, int z, int id, int data, boolean creative, EntityHuman player) {
         net.minecraft.server.Block blockType = net.minecraft.server.Block.byId[id];
         if (blockType == null) { // Illegal block ID
             return true;
         }
-        Block block = world.getWorld().getBlockAt(x, y, z);
 
         // Tell client the block is gone immediately then process events
         if (world.getTileEntity(x, y, z) == null) {
@@ -528,10 +526,12 @@ public class CraftEventFactory {
             ((EntityPlayer) player).netServerHandler.sendPacket(packet);
         }
 
-        List<ItemStack> calculatedDrops = blockType.calculateDrops(world, player, x, y, z, data);
+        Block block = world.getWorld().getBlockAt(x, y, z);
-        List<org.bukkit.inventory.ItemStack> drops = new ArrayList<org.bukkit.inventory.ItemStack>(calculatedDrops.size());
+        List<ItemStack> toDrop = blockType.calculateDrops(world, player, x, y, z, data);
+        drops.clear();
+
         if (!creative && player.b(blockType)) {
-            for (ItemStack stack : calculatedDrops) {
+            for (ItemStack stack : toDrop) {
                 drops.add(new CraftItemStack(stack));
             }
         }
@@ -540,17 +540,16 @@ public class CraftEventFactory {
         world.getServer().getPluginManager().callEvent(event);
 
         if (event.isCancelled()) {
-            blockType.dropList.clear();
+            toDrop.clear();
             // Let the client know the block still exists
             ((EntityPlayer) player).netServerHandler.sendPacket(new Packet53BlockChange(x, y, z, world));
             return true;
         }
 
-        ArrayList<ItemStack> toDrop = new ArrayList<ItemStack>(drops.size());
+        toDrop.clear();
         for (org.bukkit.inventory.ItemStack stack : drops) {
             toDrop.add(CraftItemStack.createNMSItemStack(stack));
         }
-        blockType.dropList = toDrop;
 
         return false; // Event not cancelled
     }