Minecraft sometimes renders the item held in the world joined before instead of the current world.

Reproduce:
1. join a world/server
2. put an item in your hand
3. leave world/server
4. join another world (no server)
5. move the window in the background before join finished
6. wait until world loaded and the Esc screen is schown
7. move window back in the foreground

Result:
The item selected in the last world is shown. When that was air no item is shown. When entering the game completely the switch item animation is played.

Expected:
Shown the item that is held in te current world.