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
Branch
------
REL_16_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/4c9397c374d9cf567837682fe2672df421209921
Modified Files
--------------
src/test/perl/PostgreSQL/Test/BackgroundPsql.pm | 75 ++++++++++++++++++++-----
1 file changed, 60 insertions(+), 15 deletions(-)
