From: Tom Lane <tgl@sss.pgh.pa.us>
To: Masahiko Sawada <sawada.mshk@gmail.com>
cc: "Jonathan S. Katz" <jkatz@postgresql.org>, krking@zju.edu.cn,
        pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17477: A crash bug in transformValuesClause()
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Comments: In-reply-to Masahiko Sawada <sawada.mshk@gmail.com>
	message dated "Tue, 10 May 2022 03:15:04 +0900"
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Date: Mon, 09 May 2022 14:33:38 -0400
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Masahiko Sawada <sawada.mshk@gmail.com> writes:
> On Tue, May 10, 2022 at 2:20 AM Jonathan S. Katz <jkatz@postgresql.org> =
wrote:
>> Confirmed reproducing the crash and that this fixes it. I did a short
>> double-take on the error message:
>> =

>> ERROR:  subquery must return only one column
>> =

>> but it is accurate, given this is what the subquery must do, and zero !=
=3D
>> one.

> Agreed. I've also confirmed that the patch fixes this issue and passed
> the regression tests.

Thanks for checking!  I've pushed the fix now.

When we have a little more time, we might want to look into making
VALUES-with-no-columns be fully supported, that is not a syntax error.
That's not a crasher bug though, so I feel no desire to deal with
it under a release deadline.

			regards, tom lane