Re: BUG #17362: Error "could not find block containing chunk" when using index with icu collation on CentOS 7

On 11.01.22 23:19, Peter Geoghegan wrote:
> On Tue, Jan 11, 2022 at 3:16 AM PG Bug reporting form
> <noreply(at)postgresql(dot)org> wrote:
>> When I query a table containing certain Unicode data, using an index that
>> has certain collation, I get error message "could not find block containing
>> chunk". This is fully reproducible on CentOS 7 using the official RPM. (I
>> could not reproduce this on Oracle Linux 8, though):
>
> It looks like you're probably not using utf8 as your database
> encoding, based on the stacktrace -- even though I would expect that
> on your ICU version. What does "show server_encoding;" show you when
> run from psql?
>
> My guess is that you can temporarily work around the bug (which looks
> like a bug in our !HAVE_UCOL_STRCOLLUTF8 ICU support) by making sure
> to use UTF-8 as the server encoding.

It looks like the reporter's system is rhel7, which does not have
HAVE_UCOL_STRCOLLUTF8, so it will use the other code independent of the
encoding.

There could very well be some subtle memory counting bug or similar in
icu_to_uchar() perhaps. Needs more analysis.