Player dying in Nether portal is teleported after death

The bug

When a player dies while standing in a Nether portal, they are teleported to the other dimension after their death, i.e. while seeing the death screen.

How to reproduce

1. Build a Nether portal
2. Step into lava and start taking damage
3. Move into the portal while still taking damage and only having little health left
   You are teleported to the other dimension while seeing the death screen