The Dupe Glitch Which must be fixed

When you load a new world and place a chest and the click save and exit and then you load back in to the world and place some items in the chest and without closing the chest you hit ctrl>shift.Esc and then if you close the Open JDK the game crashes and when you load back in you have the item in the chest and also in your inventory.      

                                                                                           I think it needs to be fixed or the entire fun of the game will be messsed up.                    Thank You