Re: Remaining dependency on setlocale() - Mailing list pgsql-hackers

From Peter Eisentraut
Subject Re: Remaining dependency on setlocale()
Date
Msg-id 38f3f4a6-e95e-47a7-914f-110dd6191301@eisentraut.org
Whole thread Raw
In response to Re: Remaining dependency on setlocale()  (Jeff Davis <pgsql@j-davis.com>)
List pgsql-hackers
On 29.11.25 21:50, Jeff Davis wrote:
> All fixed, thank you! (I apologize for posting a patch in that state to
> begin with...)
> 
> I also reorganized slightly to separate out the pg_iswcased() API into
> its own patch, and moved the like_support.c changes from the ctype_is_c
> patch (already committed: 1476028225) into the pattern prefixes patch.

I reviewed the v11 patches.  But I wasn't able to apply them locally 
(couldn't find a starting commit where they applied cleanly), so I 
haven't tested them.

Patches 0001 through 0006 seem generally ok, with some small comments:

v11-0003-Fix-inconsistency-between-ltree_strncasecmp-and-.patch

The function comment reads "Check if b has a prefix of a." -- Is that 
the same as "Check if a is a prefix of b."?  The latter might be clearer.


v11-0004-Remove-char_tolower-API.patch

The updated comment reads

+        * For efficiency reasons, in the C locale we don't call lower() 
on the
+        * pattern and text, but instead call SB_lower_char on each 
character.

but the patch removes SB_lower_char().


v11-0006-Use-multibyte-aware-extraction-of-pattern-prefix.patch

Might have a small typo in the commit message:

; and preserve and char-at-a-time logic for bytea.


For the remaining patches I have some more substantial questions.

v11-0007-fuzzystrmatch-use-pg_ascii_toupper.patch

dmetaphone.c has a comment

case '\xc7':        /* C with cedilla */

so the premise that "fuzzystrmatch is designed for ASCII" does not
appear to be correct.  Needs more analysis.

(But apparently it's not multibyte aware at all, so I don't know what to 
do about that.)


v11-0008-downcase_identifier-use-method-table-from-locale.patch

I'm confused here about the name of the function pg_strfold_ident().  In 
general, case "folding" results in an opaque string that is really only 
useful for comparing against other case-folded strings.  But for 
identifiers we are actually interested lower-casing.  I think this 
should be corrected in the API naming.


v11-0009-Control-LC_COLLATE-with-GUC.patch

I know there were some complaints about compatibility with extensions, 
but I don't think anything concrete was presented.  I would like to see 
more evidence that we need this.

Also, recall that we used to have a lc_collate GUC, and in the end 
people got confused that it didn't actually show a meaningful value when 
you used ICU.  So we removed that.  It seems adding this back in would 
create a similar kind of confusion.  So to avoid that, maybe this should 
be called fallback_lc_collate or something like that.

If we were to proceed with this patch, it should have some documentation 
and tests.




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