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Subject: Re: SERVICEFILE shows wrong file after servicefile fallback
From: Chao Li <li.evan.chao@gmail.com>
In-Reply-To: <aiEDZBg0Vwh0TClB@paquier.xyz>
Date: Thu, 4 Jun 2026 13:47:04 +0800
Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>,
 tfoertsch123@gmail.com,
 kanbayashi.dev@gmail.com
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References: <59DD1652-4EB5-449B-8DE3-959F06561A96@gmail.com>
 <aiEDZBg0Vwh0TClB@paquier.xyz>
To: Michael Paquier <michael@paquier.xyz>
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> On Jun 4, 2026, at 12:47, Michael Paquier <michael@paquier.xyz> wrote:
>=20
> On Tue, Jun 02, 2026 at 09:42:23PM +0800, Chao Li wrote:
>> While testing =E2=80=9Cpsql: Add variable SERVICEFILE=E2=80=9D, I =
found a small
>> issue where SERVICEFILE may show the wrong value.
>>=20
>> While tracing the code, I noticed there is a fallback path. If the
>> service file specified in the connection string does not contain the
>> requested service, libpq falls back to pg_service.conf. So I tested
>> the following case:
>=20
> Right, as of the default file in PGSYSCONFDIR.  This qualifies as an
> open item for v19.
>=20
>> I think the bug was actually introduced by the previous commit
>> 092f3c63efc6. In parseServiceFile(), if the service file has already
>> been set in the connection options, it refuses to update the value,
>> so the fallback service file is not synced to the connection
>> options. Then SERVICEFILE is read from the connection options, which
>> still contain the original file specified on the command line. So,
>> SERVICEFILE just makes the bug visible.
>=20
> Yep, it looks like you are right here.  It does not make sense to show
> in SERVICEFILE the file that has been skipped in favor of the second
> default in PGSYSCONFDIR.  We need to show the latter.  An \echo of=20
> SERVICEFILE is an interesting way to show your point.  Why not.
>=20
> Thanks for the report, will fix.
> --
> Michael

Thanks for confirming. I just added it to the Open Item list.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/