I'm the guy who did this patch, many years ago - it was for Wine on Linux, originally. Yes, this was reverse-engineered using IDA. I don't actually know what exactly the patched code does; it just seemed to be the source of the error message after debugging it. It's some kind of rendering loop that goes out of bounds sometimes, presumably having to do with partially rendered tiles at the edge of the map.

We have actually noticed that after applying the patch, structures at the top of the screen aren't rendered properly anymore when moving down. They just kind of collapse into themselves and are fixed by moving it back up again.

I looked at the code you removed, but can't quite figure out what it does unfortunately.

Hey me from the past, I just wanted to tell you I started the game again in 2022 and finished it this time. The middle part of the campaign was a real hump to overcome because all those maps had three layers, but after those it really gets breezier.