Re: Backport Unicode updates?

[Carlos O'Donell <carlos@redhat.com>]

On 1/22/23 09:39, Florian Weimer wrote:
> * Naïm Favier via Libc-stable:
> 
>> It would be nice to backport Unicode updates (and more generally
>> changes to locale data, I guess) to release branches, so that
>> distributions can include them more quickly. See
>> https://github.com/weechat/weechat/issues/79,
>> https://github.com/NixOS/nixpkgs/issues/202548 for more context.
>>
>> For example, could the Unicode 15 support in 7fe6734d28 be
>> backported to the stable 2.36 (and maybe 2.35) branches without
>> breaking anything?
> 
> Changes to collation order and case conversion have broken on-disk
> data structures in the past (such as B-tree indices for PostgreSQL).
> So it's not risk-free.
 
Correct, it would be my preference not to backport Unicode updates into official
release branches because of this risk. Likewise there are other risks in the more
general case when updating locale data including: translated name length changes
breaking UX layouts, custom collation changes (same issue as Unicode updates),
and the addition of nl_item constants for nl_langinfo breaking on-disk compiled
locale ABI (like we saw with %OB/%Ob and static binaries).

We have, as an upstream, set the expectation is that this level of change only
happens at the major version boundaries.

-- 
Cheers,
Carlos.