[MC-80246] Duplicating items in Singleplayer using Open to LAN feature

This is a duplication glitch found way back in Minecraft 1.4. I thought it might be funny to see if it still works, and it does.

The explaination can be found on my Imgur: http://imgur.com/a/YAgr5

The glitch has been done with an OptiFine installation, but is also doable without.

EDIT: Because there is some confusion, I've recorded myself performing it: https://www.youtube.com/watch?v=ee116NWSCu4 (Didn't havce much time to edit it, sorry)

Have a great day! -MegaXLR

Linked issues

marcono1234 2015-05-11T15:43:51Z

Can you please add the way how to reproduce this here as well. And by the way I don't really understand your explanation. For example

Login in Singleplayer with player 2 and You'll see the items are still there

won't work before

Start a LAN world (doesn't matter which account you choose) and your items won't disappear

Confirmed for 1.9.1 pre-3 and probably all versions in between.

Duplicate of MC-697.