How a 20 year old bug in GTA San Andreas surfaced in Windows 11 24H2
After over two decades, players are now forbidden from flying a seaplane, all thanks to undefined code behavior.
Hasnain says:
Gotta love fun bugs and UB
“This was the most interesting bug I’ve encountered for a while. I initially had a hard time believing that a bug like this would directly tie to a specific OS release, but I was proven completely wrong. At the end of the day, it was a simple bug in San Andreas and this function should have never worked right, and yet, at least on PC it hid itself for two decades.
This is an interesting lesson in compatibility: even changes to the stack layout of the internal implementations can have compatibility implications if an application is bugged and unintentionally relies on a specific behavior. This is also not the first time I encountered issues like this: regular visitors might remember Bully: Scholarship Edition which famously broke on Windows 10, for very similar reasons. Just like in this case, Bully should have never worked properly to begin with, but instead, it got away with making incorrect assumptions for years, before changes in Windows 10 finally made it run out of luck.
Yet again, we are reminded to:
Validate your input data – San Andreas was notoriously bad at this, and ultimately this was the main reason why an incomplete config line remained unnoticed.
Not ignore the compilation warnings – this code most likely threw a warning in the original code that was either ignored or disabled!
In the end, the GTA players are lucky: in many other games, issues like this would’ve remained unfixed and they’d become a folk legend. Thankfully, GTAs are moddable and well understood, so we can act upon problems like this and ensure the game stays functional for many more years to come.”