duped glitch

hello i have found a a duping glitch that was completely unintended to find and how this had happened is while i was walking around i had accidently opened my inv super fast and was like clicking to so i clicked on a item and that item had been grabbed super quickly out of my inv then when that happened it glitched and i was holding the item on my mouse with the inv closed so i clicked and i dropped it then i rushed to pick it up and all the sudden i noticed that i had 2 shovel's