From: Tom Lane <tgl@sss.pgh.pa.us>
To: Erik Wienhold <ewie@ewie.name>
cc: Michal Bartak <maxym.srpl@gmail.com>, pgsql-hackers@lists.postgresql.org
Subject: Re: CASE control block broken by a single line comment
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Comments: In-reply-to Erik Wienhold <ewie@ewie.name>
	message dated "Sat, 06 Apr 2024 23:14:23 +0200"
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Date: Sun, 07 Apr 2024 00:33:12 -0400
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Erik Wienhold <ewie@ewie.name> writes:
> On 2024-04-06 20:14 +0200, Michal Bartak wrote:
>> The issue described bellow exists in postgresql ver 16.2 (found in some
>> previous major versions)

> Can confirm also on master.

I'm sure it's been there a while :-(

> I'm surprised that the comment is not skipped by the scanner at this
> point.  Maybe because the parser just reads the raw expression between
> WHEN and THEN with plpgsql_append_source_text via read_sql_construct.

> How about the attached patch?  It's a workaround by simply adding a line
> feed character between the raw expression and the closing parenthesis.

I don't have time to look into this on this deadline weekend, but
what's bothering me about this report is the worry that we've made
the same mistake elsewhere, or will do so in future.  I suspect
it'd be much more robust if we could remove the comment from the
expr->query string.  No idea how hard that is.

			regards, tom lane