Re: BUG #19406: substring(text) fails on valid UTF-8 toasted value in PostgreSQL 15.16

From: Noah Misch <noah(at)leadboat(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Thomas Munro <thomas(dot)munro(at)gmail(dot)com>, ranvis(at)gmail(dot)com, pgsql-bugs(at)lists(dot)postgresql(dot)org
Subject: Re: BUG #19406: substring(text) fails on valid UTF-8 toasted value in PostgreSQL 15.16
Date: 2026-02-17 04:20:43
Message-ID: 20260217042043.99.noahmisch@microsoft.com
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

On Mon, Feb 16, 2026 at 01:21:45PM -0500, Tom Lane wrote:
> Noah Misch <noah(at)leadboat(dot)com> writes:
> > Pushed as commit 9f4fd11
>
> Various BF animals are complaining
>
> varlena.c: In function 'text_substring':
> varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> int32 E; /* end position, exclusive */
> ^
>
> and I've also seen that locally depending on which gcc version and -O
> level I'm using. Could we silence that?
>
>
> bollworm | 2026-02-16 09:32:03 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> camel | 2026-02-16 09:32:30 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> chimaera | 2026-02-16 11:40:29 | /home/debian/20-chimaera/buildroot/HEAD/pgsql.build/../pgsql/src/backend/utils/adt/varlena.c:739:5: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> comma | 2026-02-16 14:55:48 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> conchuela | 2026-02-16 15:20:01 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> flea | 2026-02-16 09:31:52 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> krait | 2026-02-16 09:50:17 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> pipit | 2026-02-15 02:36:02 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> urocryon | 2026-02-15 01:45:07 | varlena.c:739:5: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> wireworm | 2026-02-16 15:20:49 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
> ziege | 2026-02-15 01:18:25 | varlena.c:590:9: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]

Thanks. I've pushed commit 8cef93d.

In response to

Browse pgsql-bugs by date

  From Date Subject
Next Message PG Bug reporting form 2026-02-17 11:19:36 BUG #19412: Wrong query result with not null constraint
Previous Message Richard Guo 2026-02-17 01:55:30 Re: BUG #19405: Assertion in eval_windowaggregates() fails due to integer overflow