Block inventory duplication

By using a piston to push a chest (or any other block with inventory) you can duplicate any item.
Steps to duplicate
1.) Access any block with inventory
2.) Have a piston push said block, this can be done with another player or a redstone delay
3.) Within about 1/2 a second before the block is pushed, take out the desired item to be duplicated
You should now have the item in your inventory and the blocks inventory, this can also be used to destroy items by repeating the steps but inserting the item before pushed. This bug is devistating as it can be done in survival with no cheats as well as working with items such as shulker boxes filled with items.