[1.12.2] Checking if player inventory is empty is inconsistent

[That_Martin_Guy]

I'm creating a block that,when activated, will hurt the player if his inventory is empty, and if it isn't put a random item in the inventory into an itemstack list. It only sometimes does the intended behaviour, though, and I can't really tell when it does so.

 

Block.onBlockActivated code:

 

            List<ItemStack> lostItems = playerIn.getCapability(Capabilities.LOST_ITEMS_CAPABILITY, null).getLostItems();

            if(!lostItems.isEmpty())
            {
                Random random = new Random();

                if(playerIn.inventory.isEmpty())
                {
                    playerIn.attackEntityFrom(new HoleDamageSource(), 19.0f);
                }
                else
                {
                    int itemIndex = random.nextInt(playerIn.inventory.getSizeInventory());

                    while(playerIn.inventory.getStackInSlot(itemIndex).isEmpty())
                    {
                        itemIndex = random.nextInt(playerIn.inventory.getSizeInventory());
                    }

                    playerIn.inventory.removeStackFromSlot(itemIndex);
                    lostItems.add(playerIn.inventory.getStackInSlot(itemIndex));
                }
            }
            else
            {
                playerIn.sendMessage(new TextComponentString("You reach in but find nothing inside"));
            }
            return true;

 

EDIT: To clarify, sometimes it adds AIR items to the list when the inventory is empty (even though it shouldn't), but other times it hurts the player.

Edited March 3, 2018 by That_Martin_Guy

[loordgek]

29 minutes ago, That_Martin_Guy said:

sometimes it adds AIR items

that is is intended, use NonNullList instead of list

[That_Martin_Guy]

I rewrote the method three times without figuring out the answer was this simple... Thanks!