Re: Remaining dependency on setlocale()

Jeff Davis <pgsql@j-davis.com>

From: Jeff Davis <pgsql@j-davis.com>
To: Peter Eisentraut <peter@eisentraut.org>, Chao Li <li.evan.chao@gmail.com>
Cc: Thomas Munro <thomas.munro@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org
Date: 2025-12-23T20:09:08Z
Lists: pgsql-hackers

Attachments

On Wed, 2025-12-17 at 11:39 +0100, Peter Eisentraut wrote:
> For Metaphone, I found the reference implementation linked from its 
> Wikipedia page, and it looks like our implementation is pretty
> closely 
> aligned to that.  That reference implementation also contains the 
> C-with-cedilla case explicitly.  The correct fix here would probably
> be 
> to change the implementation to work on wide characters.  But I think
> for the moment you could try a shortcut like, use pg_ascii_toupper(),
> but if the encoding is LATIN1 (or LATIN9 or whichever other encodings
> also contain C-with-cedilla at that code point), then explicitly 
> uppercase that one as well.  This would preserve the existing
> behavior.

Done, attached new patches.

Interestingly, WIN1256 encodes only the SMALL LETTER C WITH CEDILLA. I
think, for the purposes here, we can still consider it to "uppercase"
to \xc7, so that it can still be treated as the same sound. Technically
I think that would be an improvement over the current code in this edge
case, and suggests that case folding would be a better approach than
uppercasing.

Regards,
	Jeff Davis