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

[Stefan Monnier]

> So, while I agreed that #1 should probably be fixed, and even
> suggested how to do that in the least risky way, actually doing that
> is not a priority, IMO, not until we have a very grave problem caused
> by it.

FWIW, I think it's important to fix the insert-file-contents case.
It breaks syntax-ppss, for example, although for various reasons of how
syntax-ppss is implemented and used, this happens to rarely show up.
[ So, yes, it's not top priority, but it should still be fixed.  ]

>> #1 breaks the entire b-c-f model --- "hey, I'm about to modify the
>> buffer, so throw away caches" ---- and can lead to anything with a
>> cache flush in b-c-f (like syntax-ppss) not properly discarding
>> out-of-date buffer information.
> That single case of #1 is revert-buffer, which conceptually throws
> away the entire buffer and replaces it with what's on disk.  That it
> actually keeps portions of the buffer is an optimization, but the
> concept still stands.  So I don't see how it breaks the entire model,
> at least not in practice.

The optimization is beside the point: not calling b-c-f in some corner
case breaks the entire model because a user such as syntax-ppss relies
on b-c-f to know when to flush its cache, so if you don't call it when
the buffer is modified, the cache ends up stale.


        Stefan