Pairing with Self in Tournaments

This seems to appear at random in some tournaments, where a player is paired with him/herself in a tournament. How does the win/loss affect the player and the final standing in the tournaments over all? Could more functionality be given to tournament directors to manually pair or adjust/remove games from setup?

https://online-go.com/tournament/4192

This happens when a player joins the tournament twice, I’m still trying to solve that problem in all cases.