Oh, don’t get me wrong, I fully agree. Undefined behavior is terrible UX and a huge security risk.

Undefined behavior was kind of okay when RAM and storage were measured in kilobytes and adding checks for this stuff was noticeably expensive. That time has passed, though, and modern developers have no business thinking like that, even ones working on low-level languages.

I should’ve phrased my comment differently.

Yeah, that’s basically the kind of logic you use when designing a low-level programming language: If we didn’t define what happens here then anything that happens is correct behavior and it’s up to the user to avoid it.

Of course applying that logic to a GUI application intended for a comparatively nontechnical audience is utter madness.

That one’s easy. Is the crash part of the program’s design?

If not: It’s an implementation bug, the program is not behaving as intended.

If yes: It’s a design bug, crashes shouldn’t be intended behavior.