Spawning at world origin when alt+f4 pressed during world generation

When creating a new world, (that is while the loading screen is shown) you can press alt+f4 to schedule a Minecraft termination after the world was created. However, even thought the world is fully created, the player position is not set, resulting in a spawn at 0, 0, 0.

Steps to reproduce:
1. In the main menu, click "Singleplayer"
2. Click "Create new world"

3. Click "Create new world"
4. While the world is being created, press alt+f4 and wait for Minecraft to close
5. Launch Minecraft again and enter the world