&& ItemStack.areItemStackTagsEqual(itemstack3, itemstack4)) {
l1 = itemstack3.stackSize;
if (l1 > 0 && l1 + itemstack4.stackSize <= itemstack4.getMaxStackSize()) {
itemstack4.stackSize += l1;
itemstack3 = slot2.decrStackSize(l1);
if (itemstack3.stackSize == 0) {
slot2.putStack((ItemStack) null);
}
slot2.onPickupFromSlot(player, inventoryPlayer.getItemStack());