You store something force shut down Minecraft then reopen then you have the same amount in the Hot bar and the storage block.
I found it by accident and I thought you guys (Mojang) might want to know.
How to reproduce.
First get a storage block (chest, barrels, etc.
Put items you want to duplicate
Use the command Ctrl + Shift + Esc
Close Minecraft
Go back in and a crash or error will pop up
Go back to the same world
Then you should have a duplicate of the same Item.
Why you should fix it because this might affect how survival games or stuff like that. If people use this then that is basically cheating.
Thank you for your report!
We're tracking this issue in MC-63, so this ticket is being resolved and linked as a duplicate.
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