Item duplication method with barrels

Steps to Reproduce:
1. Place a barrel
2. Set both your render and simulation distance to 32
3. Set your maximum framerate to 10 FPS
4. Put any item(s) you want in the barrel
5. Close the game via task manager
6. Start Minecraft again
7. Join back into your world
8. Open the barrel again and look in your player inventory

What actually happened was...:
The items got duplicated. You will still have the items in your player inventory but they are also in the barrel inventory

What I expected to happen was...:
The items should not be in your player inventory anymore