(Server) Using /locate in customized worlds on a structure that is very far away or doesn't exist freezes the game

The bug

Using /locate on a non-existent or very far away structure freezes the game. The game, however, unfreezes when a structure is found. It's best to reproduce in customized worlds with many biomes scattered in small patches.

How to reproduce

1. Download the Forest Biomes worldgen
2. Import it to a new MC world
3. Open it to LAN
4. Use /locate mansion
   → Game freezes