The bug

When tutorial asks you to open your inventory, while you're in the nether portal waiting to be teleported, if you press E to bring up the inventory, you complete this tutorial even though the inventory itself cannot appear while you're in a nether portal.

How to reproduce

1. Edit options.txt so it has tutorialStep:open_inventory in it
2. Open/create a world in creative, make sure you have a lit nether portal
3. Switch to survival, walk/jump/break blocks to make tutorial notification ("Open your inventory") appear
4. Walk into the portal and press E
   →Tutorial notification will be removed, while inventory hasn't appeared