transferStackInSlot

	public ItemStack transferStackInSlot(EntityPlayer player, int i)
    {
        ItemStack itemstack = null;
        Slot slot = (Slot)this.inventorySlots.get(i);
        Item item = null;
        Item item2 = null;

        if (slot != null && slot.getHasStack()) {
            ItemStack itemstack1 = slot.getStack();
            itemstack = itemstack1.copy();

            if (i == 2)
            {
                if (!this.mergeItemStack(itemstack1, 3, 39, true))
                {
                    return null;
                }

                slot.onSlotChange(itemstack1, itemstack);
            }
            else if (i != 1 && i != 0)
            {
                if (IceCreamMakerRecipes.getIceCreamResult(item, item2) != null)
                {
                    if (!this.mergeItemStack(itemstack1, 0, 1, false))
                    {
                        return null;
                    }
                }
                else if (icemaker.hasItemPower(itemstack1))
                {
                    if (!this.mergeItemStack(itemstack1, 2, 2, false))
                    {
                        return null;
                    }
                }
                else if (i >= 3 && i < 30)
                {
                    if (!this.mergeItemStack(itemstack1, 30, 39, false))
                    {
                        return null;
                    }
                }
                else if (i >= 30 && i < 39 && !this.mergeItemStack(itemstack1, 3, 30, false))
                {
                    return null;
                }
            }
            else if (!this.mergeItemStack(itemstack1, 3, 39, false))
            {
                return null;
            }

            if (itemstack1.stackSize == 0)
            {
                slot.putStack((ItemStack)null);
            }
            else
            {
                slot.onSlotChanged();
            }

            if (itemstack1.stackSize == itemstack.stackSize)
            {
                return null;
            }

            slot.onPickupFromSlot(player, itemstack1);
        }

        return itemstack;
    }