Deleting a game version with authorExt breaks gameprofilelinks

[dfabulich]

MariaDB [ifdb]> select gpl.* from gameprofilelinks gpl
join games on games.id = gameid where authorExt is null;
+------------------+------------------+---------------------+
| gameid           | userid           | moddate             |
+------------------+------------------+---------------------+
| 2t1ulhzlz82ycbj7 | sizbae6ix4ge9pa2 | 2010-08-30 13:56:30 |
| 08cvrv46idil7fth | rtwk8n84r3mail9i | 2018-09-03 09:24:10 |
| mt9zy6fqpkwishtq | y5hnu94znl7tnryk | 2024-09-01 17:59:26 |
+------------------+------------------+---------------------+

In each case, the game lists no profile links, but the user profile links to that game.

• Michael Baltes links to Welcome to the Universe, but it doesn't link back.
• Tommaso Caldarola links to Uno zombie a Deadville, but it doesn't link back. (It seems like it should, though…?)
• Produções do Assombro links to Barbarossa, but it doesn't link back.

[dfabulich]

One way to reproduce this is to delete a game version, like this.

1. In a Docker test environment, login as ifdbadmin, and create a new game listing, title "test" author "test"
2. Edit the game listing, change the author to Jeremy Freese {9k1wi1rc7qphxchl}. Now when you click the profile link next to Freese's name, it will take you to his profile page, which will link to your test listing.
3. Return to the test listing, click View Update History in the footer, and click "Delete Version", rolling back to the initial version where the author is "test".

Expected: The "test" game should now be removed from Jeremy Freese's profile
Actual: The "test" game remains on Jeremy Freese's profile

[dfabulich]

In the case of Welcome to the Universe, I think this one may be kinda my fault!

When I was running my IFComp importer, I believe I made a mistake with copying and pasting some TUIDs around, and accidentally transmogrified Welcome to the Universe into the wrong game entirely. (I can't remember what game it was now. There's not even a way to prove that this ever happened, because I was only able to delete my bogus change. #1207)

I went in and deleted my bogus version, but that must have triggered this bug.

[dfabulich]

I ran this in production; the bogus backlinks are gone for now, but this bug remains.

delete from gameprofilelinks where gameid in 
select gameid from gameprofilelinks
join games on games.id = gameid where authorExt is null);

(I also went in and manually linked Uno zombie a Deadville to Tommaso Caldarola.)