Sigh. What about my subsequent example? About walking outside with a bodyguard despite the lack of a guarantee you'd stay safe?

I don't get why you're sighing at me when I'm answering your questions politely. If you don't like my replies feel free to stop asking me questions.

Your example about going outside isn't covered by a technical specification with a long list of guarantees formally agreed between two parties so I don't really see how it's comparable.

The question was about whether the original designer deserves any blame for making a sudden change like that. Not about whether the manufacturer is at fault vs. the user vs. a bunch of other middlemen that weren't in the story. That twist just derailed the discussion, and it's frustrating to discuss something when the other person is so keen to avoid the crux of the question. So much so that you didn't even try to address everything else I wrote.

> The question was about whether the original designer deserves any blame for making a sudden change like that.

I don't believe so - as long as there is a version change and it's documented in the change log, which I aim to do with optimisations I write.

If you're using undocumented apparent behaviour, please check the change log when upgrading, or ask us to document the behaviour. But as already described, we may not be able to guarantee what you want while keeping other things you depend on like performance!