Rework skull dropping. Fixes BUKKIT-2930 and BUKKIT-2820

Skulls need their tile entity in order to create an item correctly when
broken unlike every other block. Instead of sprinkling special cases all
over the code just override dropNaturally for skulls to read from their
tile entity and make sure everything that wants to drop them calls this
method before removing the block. There is only one case where this wasn't
already true so we end up with much less special casing.

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

@@ -78,8 +78,21 @@ public class BlockSkull extends BlockContainer {
         return i;
     }
 
-    // CraftBukkit - drop the item like every other block
-    // public void dropNaturally(World world, int i, int j, int k, int l, float f, int i1) {}
+    // CraftBukkit start - special case dropping so we can get info from the tile entity
+    public void dropNaturally(World world, int i, int j, int k, int l, float f, int i1) {
+        if (world.random.nextFloat() < f) {
+            ItemStack itemstack = new ItemStack(Item.SKULL.id, 1, this.getDropData(world, i, j, k));
+            TileEntitySkull tileentityskull = (TileEntitySkull) world.getTileEntity(i, j, k);
+
+            if (tileentityskull.getSkullType() == 3 && tileentityskull.getExtraType() != null && tileentityskull.getExtraType().length() > 0) {
+                itemstack.setTag(new NBTTagCompound());
+                itemstack.getTag().setString("SkullOwner", tileentityskull.getExtraType());
+            }
+
+            this.b(world, i, j, k, itemstack);
+        }
+    }
+    // CraftBukkit end
 
     public void a(World world, int i, int j, int k, int l, EntityHuman entityhuman) {
         if (entityhuman.abilities.canInstantlyBuild) {
@@ -92,7 +105,7 @@ public class BlockSkull extends BlockContainer {
 
     public void remove(World world, int i, int j, int k, int l, int i1) {
         if (!world.isStatic) {
-            /* CraftBukkit start - don't special code dropping the item
+            /* CraftBukkit start - drop item in code above, not here
             if ((i1 & 8) == 0) {
                 ItemStack itemstack = new ItemStack(Item.SKULL.id, 1, this.getDropData(world, i, j, k));
                 TileEntitySkull tileentityskull = (TileEntitySkull) world.getTileEntity(i, j, k);

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

@@ -264,18 +264,13 @@ public class Explosion {
 
                 // CraftBukkit - stop explosions from putting out fire
                 if (l > 0 && l != Block.FIRE.id) {
-                    // CraftBukkit start - special case skulls, add yield
-                    int data = this.world.getData(i, j, k);
-                    if (l == Block.SKULL.id) {
-                        data = Block.SKULL.getDropData(this.world, i, j, k);
-                    }
-
                     Block block = Block.byId[l];
 
                     if (block.a(this)) {
-                        block.dropNaturally(this.world, i, j, k, data, event.getYield(), 0);
+                        // CraftBukkit
+                        block.dropNaturally(this.world, i, j, k, this.world.getData(i, j, k), event.getYield(), 0);
                     }
-                    // CraftBukkit end
+
                     if (this.world.setRawTypeIdAndData(i, j, k, 0, 0, this.world.isStatic)) {
                         this.world.applyPhysics(i, j, k, 0);
                     }

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

@@ -290,9 +290,11 @@ public class ItemInWorldManager {
             int l = this.world.getTypeId(i, j, k);
             if (Block.byId[l] == null) return false; // CraftBukkit - a plugin set block to air without cancelling
             int i1 = this.world.getData(i, j, k);
+
             // CraftBukkit start - special case skulls, their item data comes from a tile entity
-            if (l == Block.SKULL.id) {
-                i1 = Block.SKULL.getDropData(world, i, j, k);
+            if (l == Block.SKULL.id && !this.isCreative()) {
+                Block.SKULL.dropNaturally(world, i, j, k, i1, 1.0F, 0);
+                return this.d(i, j, k);
             }
             // CraftBukkit end
 

src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -1084,11 +1084,7 @@ public class CraftWorld implements World {
         int blockY = block.getY();
         int blockZ = block.getZ();
         // following code is lifted from Explosion.a(boolean), and modified
-        int data = block.getData();
-        if (blockId == net.minecraft.server.Block.SKULL.id) {
-            data = net.minecraft.server.Block.SKULL.getDropData(this.world, blockX, blockY, blockZ);
-        }
-        net.minecraft.server.Block.byId[blockId].dropNaturally(this.world, blockX, blockY, blockZ, data, yield, 0);
+        net.minecraft.server.Block.byId[blockId].dropNaturally(this.world, blockX, blockY, blockZ, block.getData(), yield, 0);
         block.setType(org.bukkit.Material.AIR);
         // not sure what this does, seems to have something to do with the 'base' material of a block.
         // For example, WOODEN_STAIRS does something with WOOD in this method

src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java

@@ -348,10 +348,6 @@ public class CraftBlock implements Block {
         boolean result = false;
 
         if (block != null) {
-            if (block.id == net.minecraft.server.Block.SKULL.id) {
-                data = (byte) block.getDropData(chunk.getHandle().world, x, y, z);
-            }
-
             block.dropNaturally(chunk.getHandle().world, x, y, z, data, 1.0F, 0);
             result = true;
         }