Re: Fix for fragile code in ltree/crc32.c

On Wed, 2026-08-19 at 10:44 +0300, Heikki Linnakangas wrote:
> Looking at pg_strfold() (and other similar functions), there's no
> indication that there's an upper bound on the destination size like
> this. Does UNICODE_CASEMAP_BUFSZ work for all collation providers and
> locales? How about adding a comment in pg_strfold() and friends about
> that?

Attached two patches. The first one is the same and backpatches through
18. The second defines some new macros and uses those, which is a
better place to document the limits, and I'll only commit that one to
master.

Along with the Case Mapping Complexities comment I'm adding here:

https://www.postgresql.org/message-id/fe35594a54923c94142390dabb365b737c581f2a.camel@j-davis.com

(which will be backpatched to 18), I think that should be sufficient,
but I could add another note there about the byte limits if you think
it would be worthwhile.

Regards,
Jeff Davis