Re: Unbalanced change hooks (part 2) [Documentation fix still remaining]

[Phillip Lord]

Eli Zaretskii <address@hidden> writes:
>> Sure, I guess you could argue that current Emacs behavior is consistent with
>> the manual, but it's not what anyone would reasonably expect, and the
>> current behavior is surprising even to people who have been writing elisp
>> for a long time.
>
> Surprising or not, the existing implementation is in use for many
> years, and until now no complaints were presented about it.

Actually, it caused me significant issues several years ago, and I would
have prefered that the hooks were balanced. I'd rather fix things than
complain, but you can consider this a complaint if you will.

> And even now we have a single complaint from a single use case of a
> single package (which meanwhile fixed the problem without any core
> changes). Which is ample evidence that the existing implementation
> does a good job after all.

No, I don't think it is. It might be evidence that people know to seek
alternative solutions instead of using b-c-f and a-c-f.


>> I'm confident that with enough review, the core code could be changed to
>> make b-c-f and a-c-f symmetric without causing weird bugs elsewhere. The
>> necessary refactoring will probably make the logic cleaner as well.
>> 
>> Of course there's a risk that changing b-c-f will itself produce weird side
>> effects, but I have a hard time seeing how any code could actually depend on
>> the current surprising behavior.
>
> That's exactly the nonchalant attitude towards changes in core that
> explains why, after 30-odd years of development, which should have
> given us an asymptotically more and more stable Emacs, we still
> succeed quite regularly to break core code and basic features, while
> "confidently" relying on our mythical abilities to refactor correctly
> without any serious testing coverage.  Never again.

Can I deliberately misinterpret this as saying that you think that the
changes would be fine so long as we add lots of tests at the same time?

Phil