DUPLICATING ITEMS!!!1.8/1.9 (tested by me)

hi!
I was searching 4 glitches on youtube and i found this cool glitch
i tried it in singleplayer and it works fine on 1.8 and 1.9
watch the video with some attention coz its a little bit confusing but it works perfect and you can get how much items u want

This is for the 1.8 pre release -_-

anyone tried this?

yes xD sorry coz when i posted this i was tired but i will correct it =D