From: Manu <manuelreyesbravo@gmail.com>
To: pgsql-bugs@lists.postgresql.org
Cc: Srinath Reddy Sadipiralla <srinath2133@gmail.com>,
 Amit Langote <amitlangote09@gmail.com>, chaitanyyachoudhary@gmail.com
Subject: Re: BUG #19695: JSON_VALUE ... RETURNING jsonb returns NULL for later
 evaluation once one evaluation returns NULL
Date: Wed, 23 Sep 2026 17:12:34 -0300
Message-ID: <179019435414.699921.11893679831783704384@gmail.com>
In-Reply-To: 
 <CAFC+b6p8Oo3_pLXPa=DVXx1XDQJ09b2W3U3WKPtkQYyh0z0z-A@mail.gmail.com>
References: 
 <CAFC+b6p8Oo3_pLXPa=DVXx1XDQJ09b2W3U3WKPtkQYyh0z0z-A@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: 
 <https://www.postgresql.org/message-id/179019435414.699921.11893679831783704384%40gmail.com>
Precedence: bulk

Hi Srinath,

I tested your v1 on master, REL_18_STABLE and REL_17_STABLE, together
with Andrey's v2 for #19621 [1], which touches the same function.  Both
apply cleanly on all three branches, build without warnings, and the
main regression suite passes.  On all three,
JSON_VALUE(x, '$' RETURNING jsonb) over '1', 'null', '2' now returns
1, NULL, 2 (it was 1, NULL, NULL).

The fix looks right to me: that branch fills val_string but never
cleared the resnull left by an earlier row.

A small thing: git apply warns about trailing whitespace on four lines
of the new test in sqljson_queryfuncs.sql.

[1]
https://postgr.es/m/CAB8bMitawD=3DERVLwYuDXvMT_OJqf+qAKx=3D3GEH6V_WHT7jnq7A@m=
ail.gmail.com

Regards,
Manu