This is a backport of 70291a3c66e. Originally it was only applied to master,
but I (Andres) am planning to fix a few bugs in BackgroundPsql that are harder
to fix in the backbranches with the old behavior. It's also generally good for
test infrastructure to behave similarly across branches, to avoid pain during
backpatching. 70291a3c66e changes the behavior in some cases, but after
discussing it, we are ok with that, it seems unlikely that there are
out-of-core tests relying on the prior behavior.
Discussion: https://postgr.es/m/ilcctzb5ju2gulvnadjmhgatnkxsdpac652byb2u3d3wqziyvx@fbuqcglker46
Michael's original commit message:
A newline is not added at the end of an empty query result, causing the
banner of the hardcoded \echo to not be discarded. This would reflect
on scripts that expect an empty result by showing the "QUERY_SEPARATOR"
in the output returned back to the caller, which was confusing.
This commit changes BackgroundPsql::query() so as empty results are able
to work correctly, making the first newline before the banner optional,
bringing more flexibility.
Note that this change affects 037_invalid_database.pl, where three
queries generated an empty result, with the script relying on the data
from the hardcoded banner to exist in the expected output. These
queries are changed to use query_safe(), leading to a simpler script.
The author has also proposed a test in a different patch where empty
results would exist when using BackgroundPsql.
Author: Jacob Champion
Reviewed-by: Andrew Dunstan, Michael Paquier
Discussion: https://postgr.es/m/CAOYmi+=60deN20WDyCoHCiecgivJxr=98s7s7-C8SkXwrCfHXg@mail.gmail.com
Absorb upstream bug fix (their commit
e322673a841d9abd69994ae8cd20e191090b6ef4), which prevents a null
pointer dereference crash if SN_create_env() gets a malloc failure
at just the wrong point.
Thanks to Maksim Korotkov for discovering the null-pointer
bug and submitting the fix to upstream snowball.
Reported-by: Maksim Korotkov <m.korotkov@postgrespro.ru>
Author: Maksim Korotkov <m.korotkov@postgrespro.ru>
Discussion: https://postgr.es/m/1d1a46-67ab1000-21-80c451@83151435
Backpatch-through: 13
When considering a local buffer, the GetBufferDescriptor() call in
BufferGetLSNAtomic() would be retrieving a shared buffer with a bad
buffer ID. Since the code checks whether the buffer is shared before
using the retrieved BufferDesc, this issue did not lead to any
malfunction. Nonetheless this seems like trouble waiting to happen,
so fix it by ensuring that GetBufferDescriptor() is only called when
we know the buffer is shared.
Author: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Discussion: https://postgr.es/m/CAHewXNku-o46-9cmUgyv6LkSZ25doDrWq32p=oz9kfD8ovVJMg@mail.gmail.com
Backpatch-through: 13
In try_partitionwise_join, we try to break down the join between two
partitioned relations into joins between matching partitions. To
achieve this, we iterate through each pair of partitions from the two
joining relations and create child join relations for them. To reduce
memory accumulation during each iteration, one step we take is freeing
the SpecialJoinInfos created for the child joins.
A child join's SpecialJoinInfo is a copy of the parent join's
SpecialJoinInfo, with some members being translated copies of their
counterparts in the parent. However, when freeing the bitmapset
members in a child join's SpecialJoinInfo, we failed to check whether
they were translated copies. As a result, we inadvertently freed the
members that were still in use by the parent SpecialJoinInfo, leading
to crashes when those freed members were accessed.
To fix, check if each member of the child join's SpecialJoinInfo is a
translated copy and free it only if that's the case. This requires
passing the parent join's SpecialJoinInfo as a parameter to
free_child_join_sjinfo.
Back-patch to v17 where this bug crept in.
Bug: #18806
Reported-by: 孟令彬 <m_lingbin@126.com>
Diagnosed-by: Tender Wang <tndrwang@gmail.com>
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/18806-d70b0c9fdf63dcbf@postgresql.org
Backpatch-through: 17
Coverity complained that we weren't doing that, and it's right.
This fix just makes fmtIdEnc() honor the general convention that OOM
causes a PQExpBuffer to become marked "broken", without any immediate
error. In the pretty-unlikely case that we actually did hit OOM here,
the end result would be to return an empty string to the caller,
probably resulting in invalid SQL syntax in an issued command (if
nothing else went wrong, which is even more unlikely). It's tempting
to throw an "out of memory" error if the buffer becomes broken, but
there's not a lot of point in doing that only here and not in hundreds
of other PQExpBuffer-using places in pg_dump and similar callers.
The whole issue could do with some non-time-crunched redesign, perhaps.
This is a followup to the fixes for CVE-2025-1094, and should be
included if cherry-picking those fixes.
Instead of dropping the trailing byte(s) of an invalid or incomplete
multibyte character, replace only the first byte with a known-invalid
sequence, and process the rest normally. This seems less likely to
confuse incautious callers than the behavior adopted in 5dc1e42b4.
While we're at it, adjust PQescapeStringInternal to produce at most
one bleat about invalid multibyte characters per string. This
matches the behavior of PQescapeInternal, and avoids the risk of
producing tons of repetitive junk if a long string is simply given
in the wrong encoding.
This is a followup to the fixes for CVE-2025-1094, and should be
included if cherry-picking those fixes.
Author: Andres Freund <andres@anarazel.de>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Reported-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://postgr.es/m/20250215012712.45@rfd.leadboat.com
Backpatch-through: 13
In 5dc1e42b4fa I fixed bugs in various escape functions, unfortunately as part
of that I introduced a new bug in PQescapeLiteral()/PQescapeIdentifier(). The
bug is that I made PQescapeInternal() just use strlen(), rather than taking
the specified input length into account.
That's bad, because it can lead to including input that wasn't intended to be
included (in case len is shorter than null termination of the string) and
because it can lead to reading invalid memory if the input string is not null
terminated.
Expand test_escape to this kind of bug:
a) for escape functions with length support, append data that should not be
escaped and check that it is not
b) add valgrind requests to detect access of bytes that should not be touched
Author: Tom Lane <tgl@sss.pgh.pa.us>
Author: Andres Freund <andres@anarazel.de
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/Z64jD3u46gObCo1p@pryzbyj2023
Backpatch: 13
Commit 27cc7cd2bc8a accidentally placed the assertion ensuring
that the pointer isn't NULL after it had already been accessed.
Fix by moving the pointer dereferencing to after the assertion.
Backpatch to all supported branches.
Author: Dmitry Koval <d.koval@postgrespro.ru>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/1618848d-cdc7-414b-9c03-08cf4bef4408@postgrespro.ru
Backpatch-through: 13
When an UPDATE trigger referencing a new table and a DELETE trigger
referencing an old table are both present, MakeTransitionCaptureState()
returns an inconsistent result for UPDATE commands in its set of flags
and tuplestores holding the TransitionCaptureState for transition
tables.
As proved by the test added here, this issue causes a crash in v14 and
earlier versions (down to 11, actually, older versions do not support
triggers on partitioned tables) during cross-partition updates on a
partitioned table. v15 and newer versions are safe thanks to
7103ebb7aae8.
This commit fixes the function so that it returns a consistent state
by using portions of the changes made in commit 7103ebb7aae8 for v13 and
v14. v15 and newer versions are slightly tweaked to match with the
older versions, mainly for consistency across branches.
Author: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20250207.150238.968446820828052276.horikyota.ntt@gmail.com
Backpatch-through: 13
The phase of the test waiting for a restartpoint to complete was not
working as intended, due to a log_contains() call incorrectly
written.
The problem reported by the author could be simply reproduced by
removing the injection_points_wakeup() call: the test succeeds rather
than waiting for the restartpoint completion. In most cases, the
restartpoint completion is fast enough that the test offered the wanted
coverage. On slow machines, it could have become unreliable.
Oversight in 6782709df81f.
Author: Nitin Jadhav
Discussion: https://postgr.es/m/CAMm1aWa_6u+o52r7h7G6pX-oWD0Qraf0ee17Ma50qxGS0B_Rzg@mail.gmail.com
Backpatch-through: 17
The correct function documented to free the memory allocated for the
result returned by PQescapeIdentifier() and PQescapeLiteral() is
PQfreemem(). pg_createsubscriber.c relied on pg_free() instead, which
is not incorrect as both do a free() internally, but inconsistent with
the documentation.
While on it, this commit fixes a small memory leak introduced by
4867f8a555ce, as the code of pg_createsubscriber makes this effort.
Author: Ranier Vilela
Reviewed-by: Euler Taveira
Discussion: https://postgr.es/m/CAEudQAp=AW5dJXrGLbC_aZg_9nOo=42W7uLDRONFQE-gcgnkgQ@mail.gmail.com
Backpatch-through: 17
We need to tell fmtId() what encoding to assume, but this function
doesn't know that. Fortunately we can fix that without changing the
function's API, because we can just use SQL_ASCII. That's because
database names in connection requests are effectively binary not text:
no encoding-aware processing will happen on them.
This fixes XversionUpgrade failures seen in the buildfarm. The
alternative of having pg_upgrade use setFmtEncoding() is unappetizing,
given that it's connecting to multiple databases that may have
different encodings.
Andres Freund, Noah Misch, Tom Lane
Security: CVE-2025-1094
On machines where char is unsigned this could lead to option parsing looping
endlessly. It's also too narrow a type on other hardware.
Found via Tom Lane's monitoring of the buildfarm.
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Security: CVE-2025-1094
Backpatch-through: 13
As highlighted by the prior commit, writing correct escape functions is less
trivial than one might hope.
This test module tries to verify that different escaping functions behave
reasonably. It e.g. tests:
- Invalidly encoded input to an escape function leads to invalidly encoded
output
- Trailing incomplete multi-byte characters are handled sensibly
- Escaped strings are parsed as single statement by psql's parser (which
derives from the backend parser)
There are further tests that would be good to add. But even in the current
state it was rather useful for writing the fix in the prior commit.
Reviewed-by: Noah Misch <noah@leadboat.com>
Backpatch-through: 13
Security: CVE-2025-1094
Previously invalidly encoded input to various escaping functions could lead to
the escaped string getting incorrectly parsed by psql. To be safe, escaping
functions need to ensure that neither invalid nor incomplete multi-byte
characters can be used to "escape" from being quoted.
Functions which can report errors now return an error in more cases than
before. Functions that cannot report errors now replace invalid input bytes
with a byte sequence that cannot be used to escape the quotes and that is
guaranteed to error out when a query is sent to the server.
The following functions are fixed by this commit:
- PQescapeLiteral()
- PQescapeIdentifier()
- PQescapeString()
- PQescapeStringConn()
- fmtId()
- appendStringLiteral()
Reported-by: Stephen Fewer <stephen_fewer@rapid7.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 13
Security: CVE-2025-1094
This commit adds fmtIdEnc() and fmtQualifiedIdEnc(), which allow to specify
the encoding as an explicit argument. Additionally setFmtEncoding() is
provided, which defines the encoding when no explicit encoding is provided, to
avoid breaking all code using fmtId().
All users of fmtId()/fmtQualifiedId() are either converted to the explicit
version or a call to setFmtEncoding() has been added.
This commit does not yet utilize the now well-defined encoding, that will
happen in a subsequent commit.
Reviewed-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Backpatch-through: 13
Security: CVE-2025-1094
There are cases where we cannot / do not want to error out for invalidly
encoded input. In such cases it can be useful to replace e.g. an incomplete
multi-byte characters with bytes that will trigger an error when getting
validated as part of a larger string.
Unfortunately, until now, for some encoding no such sequence existed. For
those encodings this commit removes one previously accepted input combination
- we consider that to be ok, as the chosen bytes are outside of the valid
ranges for the encodings, we just previously failed to detect that.
As we cannot add a new field to pg_wchar_table without breaking ABI, this is
implemented "in-line" in the newly added function.
Author: Noah Misch <noah@leadboat.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Backpatch-through: 13
Security: CVE-2025-1094
Commit af35fe501 caused "pgbench -i" to emit a '\r' character
for each data row loaded (when stderr is a terminal).
That's effectively invisible on-screen, but it causes the
connected terminal program to consume a lot of cycles.
It's even worse if you're connected over ssh, as the data
then has to pass through the ssh tunnel.
Simplest fix is to move the added logic inside the if-tests
that check whether to print a progress line. We could do
it another way that avoids duplicating these few lines,
but on the whole this seems the most transparent way to
write it.
Like the previous commit, back-patch to all supported versions.
Reported-by: Andres Freund <andres@anarazel.de>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/4k4drkh7bcmdezq6zbkhp25mnrzpswqi2o75d5uv2eeg3aq6q7@b7kqdmzzwzgb
Backpatch-through: 13
Try to make it absolutely plain that we don't retain the
originally specified time zone, only the UTC timestamp.
While at it, make glossary entries for "UTC" and "GMT".
Author: Robert Treat <rob@xzilla.net>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/173796426022.1064.9135167366862649513@wrigleys.postgresql.org
Backpatch-through: 13
Before OpenSSL 1.1.0 the legacy names ssleay32 and libeay32 were
still used on Windows, and while we have support for this auto-
conf the meson buildsystem only used the new names on all plat-
forms. This adds support for the old name scheme when building
on Windows.
This patch only applies to 17 and 16 as master no longer support
OpenSSL 1.0.2.
Author: Darek Ślusarczyk <dslusarczyk@splunk.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CAN55FZ1Nk8wqY=mTrN78H026TuGV50h2H6uq1PwxhTauPYi3ug@mail.gmail.com
Backpatch-through: 16
Previously, if a backend that attached to a shared tree attempted to
start iteration, it resulted in a crash. This commit resolves the
issue by ensuring iter_context is created in RT_ATTACH().
This fix applies only to v17, where radixtree.h was introduced. In the
master branch, this issue was separately resolved by 960013f2a1, which
eliminated the iter_context entirely.
Reviewed-by: John Naylor
Discussion: https://postgr.es/m/CAD21AoBB2U47V=F+wQRB1bERov_of5=BOZGaybjaV8FLQyqG3Q@mail.gmail.com
Two links in the isn module documentation were pointing to tools
which had been moved, resulting in 404 error responses. Update
to the new URLs for the tools. The link to the Sequoia 2000 page
in the history section was no longer working, and since the page
is no longer available online update our link to point at the
paper instead which is on a stable URL.
These links exist in all versions of the documentation so backpatch
to all supported branches.
Author: Daniel Gustafsson <daniel@yesql.se>
Reported-by: charukiewicz@protonmail.com
Discussion: https://postgr.es/m/173679670185.705.8565555804465055355@wrigleys.postgresql.org
Backpatch-through: 13
Meson 1.7 stopped building all the dependencies of tests as part of the
default build target. But it does breaks CI because we only built the default
target before running the test, and ran the tests with --no-rebuild.
The simplest fix would be to remove --no-rebuild from MTEST_ARGS, but it seems
better to explicitly build the test dependencies, so compiler warnings /
errors are visible as part of the build step.
Discussion: https://postgr.es/m/CAGECzQSvM3iSDmjF+=Kof5an6jN8UbkP_4cKKT9w6GZavmb5yQ@mail.gmail.com
Backpatch: 16-, where meson was added
The missing dependency was, e.g., visible when doing
ninja clean && ninja meson-test-prereq && meson test --no-rebuild --suite setup --suite libpq
This is a bit more complicated than other related fixes, because until now
libpq's tests depended on 'frontend_code', which includes a dependency on
fe_utils, which in turns on libpq. That in turn required
src/interfaces/libpq/test to be entered from the top-level, not from
libpq/meson.build. Because of that the test definitions in libpq/meson.build
could not declare a dependency on the binaries defined in
libpq/test/meson.build.
To fix this, this commit creates frontend_no_fe_utils_code, which allows us to
recurse into libpq/test from withing libpq/meson.build.
Apply this to all branches with meson support, as part of an effort to fix
incorrect test dependencies that can lead to test failures.
Discussion: https://postgr.es/m/CAGECzQSvM3iSDmjF+=Kof5an6jN8UbkP_4cKKT9w6GZavmb5yQ@mail.gmail.com
Discussion: https://postgr.es/m/bdba588f-69a9-4f3e-9b95-62d07210a32e@eisentraut.org
Backpatch: 16-, where meson support was added
This is required to ensure correct test dependencies, previously
the test binaries would not necessarily be built.
The missing dependency was, e.g., visible when doing
ninja clean && ninja meson-test-prereq && m test --no-rebuild --suite setup --suite test_json_parser
Apply this to all branches with meson support, as part of an effort to fix
incorrect test dependencies that can lead to test failures.
Author: Peter Eisentraut <peter@eisentraut.org>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CAGECzQSvM3iSDmjF+=Kof5an6jN8UbkP_4cKKT9w6GZavmb5yQ@mail.gmail.com
Discussion: https://postgr.es/m/bdba588f-69a9-4f3e-9b95-62d07210a32e@eisentraut.org
Backpatch: 17-, where test_json_parser was added
The missing dependency was, e.g., visible when doing
ninja clean && ninja meson-test-prereq && meson test --no-rebuild --suite setup --suite cube
because meson (and thus its internal meson-test-prereq target) did not know
about a lot of the required targets.
Previously tmp_install did not actually depend on the relevant files being
built. That was mostly not visible, because "meson test" currently uses the
'default' targets as a test's dependency if no dependency is specified.
However, there are plans to narrow that on the meson side, to make it quicker
to run tests.
Apply this to all branches with meson support, as part of an effort to fix
incorrect test dependencies that can lead to test failures.
Discussion: https://postgr.es/m/CAGECzQSvM3iSDmjF+=Kof5an6jN8UbkP_4cKKT9w6GZavmb5yQ@mail.gmail.com
Discussion: https://postgr.es/m/bdba588f-69a9-4f3e-9b95-62d07210a32e@eisentraut.org
Backpatch: 16-, where meson support was added
Protect against malformed timestamps. Also protect against negative WalSegSz
as it triggers division by zero:
((0x100000000UL) / (WalSegSz)) can turn into zero in
XLogFileName(xlogfilename, ControlFile->checkPointCopy.ThisTimeLineID,
segno, WalSegSz);
because if WalSegSz is -1 then by arithmetic rules in C we get
0x100000000UL / 0xFFFFFFFFFFFFFFFFUL == 0.
Author: Ilyasov Ian <ianilyasov@outlook.com>
Author: Anton Voloshin <a.voloshin@postgrespro.ru>
Backpatch-through: 13
A few of the version checks in vacuum_one_database() do not call
PQfinish() before exiting. This precedent was unintentionally
established in commit 00d1e88d36, and while it's probably not too
problematic, it seems better to properly close the connection.
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/Z6JAwqN1I8ljTuXp%40nathan
Backpatch-through: 13
logging_collector was only mentioning stderr and csvlog, and forgot
about jsonlog. Oversight in dc686681e079, that has added support for
jsonlog in log_destination.
While on it, the description in the GUC table is tweaked to be more
consistent with the documentation and postgresql.conf.sample.
Author: Umar Hayat
Reviewed-by: Ashutosh Bapat, Tom Lane
Discussion: https://postgr.es/m/CAD68Dp1K_vBYqBEukHw=1jF7e76t8aszGZTFL2ugi=H7r=a7MA@mail.gmail.com
Backpatch-through: 13
Use <function> rather than <structname> in the <title> to be consistent
with how other functions in this module are documented. Also suffix the
function name with () for consistency.
Backpatch to v17 where pg_buffercache_evict was introduced.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/CAExHW5uKWH8CuZc9NCb8XxSQc6uzvACV0cScebm54kF763ERAw@mail.gmail.com
Backpatch-through: 17
smgrDoPendingSyncs had two distinct risks of integer overflow while
deciding which way to ensure durability of a newly-created relation.
First, it accumulated the total size of all forks in a variable of
type BlockNumber (uint32). While we restrict an individual fork's
size to fit in that, I don't believe there's such a restriction on
all of them added together. Second, it proceeded to multiply the
sum by BLCKSZ, which most certainly could overflow a uint32.
(The exact expression is total_blocks * BLCKSZ / 1024. The
compiler might choose to optimize that to total_blocks * 8,
which is not at quite as much risk of overflow as a literal
reading would be, but it's still wrong.)
If an overflow did occur it could lead to a poor choice to
shove a very large relation into WAL instead of fsync'ing it.
This wouldn't be fatal, but it could be inefficient.
Change total_blocks to uint64 which should be plenty, and
rearrange the comparison calculation to be overflow-safe.
I noticed this while looking for ramifications of the proposed
change in MAX_KILOBYTES. It's not entirely clear to me why
wal_skip_threshold is limited to MAX_KILOBYTES in the
first place, but in any case this code is unsafe regardless
of the range of wal_skip_threshold.
Oversight in c6b92041d which introduced wal_skip_threshold,
so back-patch to v13.
Discussion: https://postgr.es/m/1a01f0-66ec2d80-3b-68487680@27595217
Backpatch-through: 13
If a column is omitted in an INSERT, and there's no column default,
the code in preptlist.c generates a NULL Const to be inserted.
Furthermore, if the column is of a domain type, we wrap the Const
in CoerceToDomain, so as to throw a run-time error if the domain
has a NOT NULL constraint. That's fine as far as it goes, but
there are two problems:
1. We're being sloppy about the type/typmod that the Const is
labeled with. It really should have the domain's base type/typmod,
since it's the input to CoerceToDomain not the output. This can
result in coerce_to_domain inserting a useless length-coercion
function (useless because it's being applied to a null). The
coercion would typically get const-folded away later, but it'd
be better not to create it in the first place.
2. We're not applying expression preprocessing (specifically,
eval_const_expressions) to the resulting expression tree.
The planner's primary expression-preprocessing pass already happened,
so that means the length coercion step and CoerceToDomain node miss
preprocessing altogether.
This is at the least inefficient, since it means the length coercion
and CoerceToDomain will actually be executed for each inserted row,
though they could be const-folded away in most cases. Worse, it
seems possible that missing preprocessing for the length coercion
could result in an invalid plan (for example, due to failing to
perform default-function-argument insertion). I'm not aware of
any live bug of that sort with core datatypes, and it might be
unreachable for extension types as well because of restrictions of
CREATE CAST, but I'm not entirely convinced that it's unreachable.
Hence, it seems worth back-patching the fix (although I only went
back to v14, as the patch doesn't apply cleanly at all in v13).
There are several places in the rewriter that are building null
domain constants the same way as preptlist.c. While those are
before the planner and hence don't have any reachable bug, they're
still applying a length coercion that will be const-folded away
later, uselessly wasting cycles. Hence, make a utility routine
that all of these places can call to do it right.
Making this code more careful about the typmod assigned to the
generated NULL constant has visible but cosmetic effects on some
of the plans shown in contrib/postgres_fdw's regression tests.
Discussion: https://postgr.es/m/1865579.1738113656@sss.pgh.pa.us
Backpatch-through: 14
