Message-ID: <9e6f15bbd30f8d64027ee32551bdcaed9506fc9f.camel@cybertec.at>
Subject: Re: BUG #19341: REPLACE() fails to match final character when using
 nondeterministic ICU collation
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Heikki Linnakangas <hlinnaka@iki.fi>, adam.warland@infor.com,
	pgsql-bugs@lists.postgresql.org
Date: Tue, 02 Dec 2025 18:45:47 +0100
In-Reply-To: <6387cb3e-aec8-41a0-acef-bacdbfb435db@iki.fi>
References: <19341-1d9a22915edfec58@postgresql.org>
	 <60b467ac47d5c6bbb9c21c3bdfecce8e5de60cda.camel@cybertec.at>
	 <6935ea1e-cfb1-400b-9057-3d43b55d621a@iki.fi>
	 <6387cb3e-aec8-41a0-acef-bacdbfb435db@iki.fi>
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On Tue, 2025-12-02 at 19:29 +0200, Heikki Linnakangas wrote:
> I added a simple test for this, and I think this is still not quite=20
> right. I added the following to collate.icu.utf test:
>=20
> +-- Test for match at the end of the string.  (We had a bug on that
> +-- once)
> +SELECT a, b, replace(b COLLATE ignore_accents, 'te', 'ma') FROM test4nfd=
;
> + a |  b   | replace
> +---+------+---------
> + 1 | cote | coma
> + 2 | co=CC=82te | coma
> + 3 | cote=CC=81 | coma
> + 4 | co=CC=82te=CC=81 | coma
> +(4 rows)
> +
>=20
> In the added test query, the accents on the 'o' are stripped, which=20
> doesn't look correct.

I am not sure if that is OK or not (after all, it's an accent
insensitive collation, so "coma" and "co=CC=82ma" should be the same).

But it seems unrelated to the bug report at hand.

Yours,
Laurenz Albe