How a 20 year old bug in GTA San Andreas surfaced in Windows 11 24H2

The trouble is that if some weirdness happens because of the edit, you've got to handle it even if you say it would be reasonable to assume that it's outside of being supported. Maybe you spend a bit more time defensive coding around what inputs it reads from the file, maybe a certain proportion of users doing the save edit see bugs in an apparently unrelated part of the game and seek support (and their bug report might not be complete with all the details), developers spend time to chase down what went wrong, maybe they bad-mouth it on forums which affects sales - there's going to be some cost to handling all of that.

One of the anecdotes from Titan Quest developed by Iron Lore is that their copy protection had multiple checks, crackers removed the early checks to get the game running but later 'tripwires' as you progress through the game remained and the game appeared to crash. So the game earned a reputation for being buggy for something no normal user would hit running the game as intended.

You both are correct.

But also keep in mind in 2004 the legality of many open source projects was not really tested very well in court. Pretty sure that was right around the time one of the bigger linux distros was throwing its weight around and suing people. So you want to ship on PS2 and XBOX and PC and GameCube. Can you use that lib from inside windows? Not really. Can you build/vs buy? Buy means you need the code and probably will have to port it to PS2/GameCube yourself. Can you use that opensource lib? Probably, but legal is still dragging its feet, and you get to port it to PS2. Meanwhile your devs need a library 3 weeks ago and have hacked something together from an older codebase that your company owns and it works and means you can hit your gold master date.

Would you do that now? No. You would grab one of the multitudes of decent libs out there and make sure you are following the terms correctly. Back then? Yeah I can totally see it happening. Open source was semi legally grey/opaque to many corporations. They were scared to death of losing control of their secret sauce code and getting sued.

Definitely similar to a drug addiction, speaking from firsthand experience with both. GTA has been harder to give up than cocaine was.

My takeaway, speaking as someone who leans towards functional programming and immutability, is "this is yet another example of a mutability problem that could never happen in a functional context"

(so, for example, this bug would have never been created by Rust unless it was deeply misused)

Once this category of error is raised to your attention, you start to notice it more and more.

A little piece of technology made sense in the original context, but then it got moved to a different context without realizing that move broke the contract. Specifically in this case a flying boat became an airplane.

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I recently worked a bug that feels very similar:

A linux cups printer would not print to the selected tray, instead it always requested manual feed.

Ok. Try a bunch of command line options, same issue.

Ok. Make the selection directly in the PPD (postscript printer definition) file. Same issue.

Ok! Decompile the PXL file. Wrong tray is set in pxl file... why?

Check Debug2 log level for cups - Wrong MediaPosition is being sent to ghostscript (which compiles the printer options into the print job) by a cups filter... why?

Cups filter is translating the MediaPosition from the PPD file... because the philosophy of cups is to do what the user intended. The intention inferred from MediaPosition in the PPD file (postscript printer definition) is that the MediaPosition corresponds to the PWG (Printer Working Group) MediaPosition, NOT the vendor MediaPosition (or local equivalent - in this case MediaSource).

AHA!! My PPD file had been copied from a previous generation of server, from a time when that cups filter did NOT translate the MediaPosition, so the VENDOR MediaSource numbers were used. Historically, this makes sense. The vendor tray number is set in the vendor ppd file because cups didn't know how to translate that.

Fast forward to a new execution context, and cups filters have gotten better at translating user intention, now it's translating a number that doesn't need to be translated, and silently selecting the wrong tray.

TLDR; There is no such thing as a printer command, only printer suggestions.