ItemStack itemstack = null;
Slot slot = (Slot) inventorySlots.get(slotnumber);
if (slot != null && slot.getHasStack())
{
ItemStack itemstack1 = slot.getStack();
itemstack = itemstack1.copy();
if (inventoryTileEntity.isItemValidForSlot(0, itemstack1))
{
if (slotnumber == 1 || slotnumber == 0)
{
if (!mergeItemStack(itemstack1, 3, 38, false))