Horton

Re: libpq async duplicate error results

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Fabien COELHO <coelho@cri.ensmp.fr>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-02-17T01:11:09Z
Lists: pgsql-hackers 
Hi,

On 2022-02-16 18:51:37 -0500, Tom Lane wrote:
> This seems workable, and you'll notice it fixes the duplicated text
> in the test case Andres was worried about.

Cool.

I find it mildly scary that we didn't have any other tests verifying the libpq
side of connection termination. Seems like we we maybe should add a few more?
Some simple cases we can do via isolationtester. But some others would
probably require a C test program to be robust...


> +	/* Also, do nothing if the argument is OOM_result */
> +	if (res == unconstify(PGresult *, &OOM_result))
> +		return;

Wouldn't it make more sense to make res const, rather than unconstifying
&OOM_result?


Greetings,

Andres Freund

Commits

  1. libpq: drop pending pipelined commands in pqDropConnection().

  2. Adjust interaction of libpq pipeline mode with errorMessage resets.

  3. Rearrange libpq's error reporting to avoid duplicated error text.

  4. In libpq, always append new error messages to conn->errorMessage.