Andres Freund bb2bf22761 tests: BackgroundPsql: Fix potential for lost errors on windows
This addresses various corner cases in BackgroundPsql:

- On windows stdout and stderr may arrive out of order, leading to errors not
  being reported, or attributed to the wrong statement.

  To fix, emit the "query-separation banner" on both stdout and stderr and
  wait for both.

- Very occasionally the "query-separation banner" would not get removed, because
  we waited until the banner arrived, but then replaced the banner plus
  newline.

  To fix, wait for banner and newline.

- For interactive psql replacing $banner\n is not sufficient, interactive psql
  outputs \r\n.

- For interactive psql, where commands are echoed to stdout, the \echo
  command, rather than its output, would be matched.

  This would sometimes lead to output from the prior query, or wait_connect(),
  being returned in the next command.

  This also affected wait_connect(), leading to sometimes sending queries to
  psql before the connection actually was established.

While debugging these issues I also found that it's hard to know whether a
query separation banner was attributed to the right query. Make that easier by
counting the queries each BackgroundPsql instance has emitted and include the
number in the banner.

Also emit psql stdout/stderr in query() and wait_connect() as Test::More
notes, without that it's rather hard to debug some issues in CI and buildfarm.

As this can cause issues not just to-be-added tests, but also existing ones,
backpatch the fix to all supported versions.

Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/wmovm6xcbwh7twdtymxuboaoarbvwj2haasd3sikzlb3dkgz76@n45rzycluzft
Backpatch-through: 13
2025-02-19 10:46:49 -05:00
2019-12-18 09:13:13 +01:00
2025-02-17 16:17:13 -05:00
2025-02-17 16:17:13 -05:00
2025-01-01 11:21:54 -05:00
2020-02-10 20:47:50 +01:00
2020-02-10 20:47:50 +01:00
2020-02-10 20:47:50 +01:00

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

PostgreSQL has many language interfaces, many of which are listed here:

	https://www.postgresql.org/download/

See the file INSTALL for instructions on how to build and install
PostgreSQL.  That file also lists supported operating systems and
hardware platforms and contains information regarding any other
software packages that are required to build or run the PostgreSQL
system.  Copyright and license information can be found in the
file COPYRIGHT.  A comprehensive documentation set is included in this
distribution; it can be read as described in the installation
instructions.

The latest version of this software may be obtained at
https://www.postgresql.org/download/.  For more information look at our
web site located at https://www.postgresql.org/.
Description
he World's Most Advanced Open Source Relational Database.
Readme 735 MiB
Languages
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