From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pasi Eronen <pe@iki.fi>
cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>,
        Peter Geoghegan <pg@bowt.ie>,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #17362: Error "could not find block containing chunk" when
 using index with icu collation on CentOS 7
In-reply-to: 
 <CAGtiUvnysMFJqv0NLtJKu-ww1QBid76nV7TBqKn=rGDQQ1VFow@mail.gmail.com>
References: <17362-63967721ee562fa7@postgresql.org>
 <CAH2-Wz=K4AZqQentZ0VgYjk3RpRA8n6oVrt2Cv0b977dA4qrDQ@mail.gmail.com>
 <3869d444-2f89-f157-318d-a71ed712dcb7@enterprisedb.com>
 <efd06d12-549b-8490-54f4-e43f7fb1d2cc@enterprisedb.com>
 <CAGtiUvnysMFJqv0NLtJKu-ww1QBid76nV7TBqKn=rGDQQ1VFow@mail.gmail.com>
Comments: In-reply-to Pasi Eronen <pe@iki.fi>
	message dated "Wed, 02 Feb 2022 16:39:29 +0200"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <14516.1643824167.1@sss.pgh.pa.us>
Date: Wed, 02 Feb 2022 12:49:27 -0500
Message-ID: <14517.1643824167@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/14517.1643824167%40sss.pgh.pa.us>
Precedence: bulk

Pasi Eronen <pe@iki.fi> writes:
> In varlena.c, ssup_extra->buf1 and buf2 are initialized to 1024-byte
> buffers, allocated from the ssup->ssup_cxt memory context.  That
> strange-looking test string in my bug report just happens to be 1044
> bytes, so a larger buffer is needed at some point.

> If growing the buffer happens in "varstrfastcmp_locale", it uses
> MemoryContextAlloc(ssup->ssup_cxt, ...). But if growing the buffer
> happens in "varstr_abbrev_convert", it just calls "palloc" - and
> apparently the current memory context is not ssup_cxt at this point
> (at least according to debugging printf's I added).

> Might this be causing the problem?

Indeed.  The whole thing seems flat-out wrong to me: repalloc
would be shorter, safer, and more idiomatic.

			regards, tom lane