We've seen intermittent failures in this test on slower buildfarm
machines, which I think can be explained by assuming that autovacuum
emitted some additional WAL. Disable autovacuum to stabilize it.
In passing, use stringwise not numeric comparison to compare
WAL file names. Doesn't matter at present, but they are
hex strings not decimal ...
Discussion: https://postgr.es/m/1372189.1636499287@sss.pgh.pa.us
libpq collects up to a bufferload of data whenever it reads data from
the socket. When SSL or GSS encryption is requested during startup,
any additional data received with the server's yes-or-no reply
remained in the buffer, and would be treated as already-decrypted data
once the encryption handshake completed. Thus, a man-in-the-middle
with the ability to inject data into the TCP connection could stuff
some cleartext data into the start of a supposedly encryption-protected
database session.
This could probably be abused to inject faked responses to the
client's first few queries, although other details of libpq's behavior
make that harder than it sounds. A different line of attack is to
exfiltrate the client's password, or other sensitive data that might
be sent early in the session. That has been shown to be possible with
a server vulnerable to CVE-2021-23214.
To fix, throw a protocol-violation error if the internal buffer
is not empty after the encryption handshake.
Our thanks to Jacob Champion for reporting this problem.
Security: CVE-2021-23222
The server collects up to a bufferload of data whenever it reads data
from the client socket. When SSL or GSS encryption is requested
during startup, any additional data received with the initial
request message remained in the buffer, and would be treated as
already-decrypted data once the encryption handshake completed.
Thus, a man-in-the-middle with the ability to inject data into the
TCP connection could stuff some cleartext data into the start of
a supposedly encryption-protected database session.
This could be abused to send faked SQL commands to the server,
although that would only work if the server did not demand any
authentication data. (However, a server relying on SSL certificate
authentication might well not do so.)
To fix, throw a protocol-violation error if the internal buffer
is not empty after the encryption handshake.
Our thanks to Jacob Champion for reporting this problem.
Security: CVE-2021-23214
Currently, lastOverflowedXid is never reset. It's just adjusted on new
transactions known to be overflowed. But if there are no overflowed
transactions for a long time, snapshots could be mistakenly marked as
suboverflowed due to wraparound.
This commit fixes this issue by resetting lastOverflowedXid when needed
altogether with KnownAssignedXids.
Backpatch to all supported versions.
Reported-by: Stan Hu
Discussion: https://postgr.es/m/CAMBWrQ%3DFp5UAsU_nATY7EMY7NHczG4-DTDU%3DmCvBQZAQ6wa2xQ%40mail.gmail.com
Author: Kyotaro Horiguchi, Alexander Korotkov
Reviewed-by: Stan Hu, Simon Riggs, Nikolay Samokhvalov, Andrey Borodin, Dmitry Dolgov
When a role being dropped contains is referenced by catalog objects that
are concurrently also being dropped, a crash can result while trying to
construct the string that describes the objects. Suppress that by
ignoring objects whose descriptions are returned as NULL.
The majority of relevant codesites were already cautious about this
already; we had just missed a couple.
This is an old bug, so backpatch all the way back.
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/17126-21887f04508cb5c8@postgresql.org
If lo_export() fails to open the target file or to write to it, it leaks
the created LargeObjectDesc and its snapshot in the top-transaction
context and resource owner. That's pretty harmless, it's a small leak
after all, but it gives the user a "Snapshot reference leak" warning.
Fix by using a short-lived memory context and no resource owner for
transient LargeObjectDescs that are opened and closed within one function
call. The leak is easiest to reproduce with lo_export() on a directory
that doesn't exist, but in principle the other lo_* functions could also
fail.
Backpatch to all supported versions.
Reported-by: Andrew B
Reviewed-by: Alvaro Herrera
Discussion: https://www.postgresql.org/message-id/32bf767a-2d65-71c4-f170-122f416bab7e@iki.fi
Failing to do so results in inability of logical decoding to process the
WAL stream. Handle it by doing nothing.
Backpatch all the way back.
Reported-by: Petr Jelínek <petr.jelinek@enterprisedb.com>
Windows fails on a request to read() more than INT_MAX bytes,
and perhaps other platforms could have similar issues. Let's
adjust this code to read at most 1GB per call.
(One would not have thought the file could get that big, but now
we have a field report of trouble, so it can. We likely ought to
add some mechanism to limit the size of the query-texts file
separately from the size of the hash table. That is not this
patch, though.)
Per bug #17254 from Yusuke Egashira. It's been like this for
awhile, so back-patch to all supported branches.
Discussion: https://postgr.es/m/17254-a926c89dc03375c2@postgresql.org
DST law changes in Fiji, Jordan, Palestine, and Samoa. Historical
corrections for Barbados, Cook Islands, Guyana, Niue, Portugal, and
Tonga.
Also, the Pacific/Enderbury zone has been renamed to Pacific/Kanton.
The following zones have been merged into nearby, more-populous zones
whose clocks have agreed since 1970: Africa/Accra, America/Atikokan,
America/Blanc-Sablon, America/Creston, America/Curacao,
America/Nassau, America/Port_of_Spain, Antarctica/DumontDUrville,
and Antarctica/Syowa.
Commits fdd965d07 and 3cd9c3b92 tested CREATE INDEX CONCURRENTLY by
launching two separate pgbench runs concurrently. This was needed so
that only a single client thread would run CREATE INDEX CONCURRENTLY,
avoiding deadlock between two CICs. However, there's a better way,
which is to use an advisory lock to prevent concurrent CICs. That's
better in part because the test code is shorter and more readable, but
mostly because it automatically scales things to launch an appropriate
number of CICs relative to the number of INSERT transactions.
As committed, typically half to three-quarters of the CIC transactions
were pointless because the INSERT transactions had already stopped.
In passing, remove background_pgbench, which was added to support
these tests and isn't needed anymore. We can always put it back
if we find a use for it later.
Back-patch to v12; older pgbench versions lack the
conditional-execution features needed for this method.
Tom Lane and Andrey Borodin
Discussion: https://postgr.es/m/139687.1635277318@sss.pgh.pa.us
The purpose of commit 8a54e12a38 was to
fix this, and it sufficed when the PREPARE TRANSACTION completed before
the CIC looked for lock conflicts. Otherwise, things still broke. As
before, in a cluster having used CIC while having enabled prepared
transactions, queries that use the resulting index can silently fail to
find rows. It may be necessary to reindex to recover from past
occurrences; REINDEX CONCURRENTLY suffices. Fix this for future index
builds by making CIC wait for arbitrarily-recent prepared transactions
and for ordinary transactions that may yet PREPARE TRANSACTION. As part
of that, have PREPARE TRANSACTION transfer locks to its dummy PGPROC
before it calls ProcArrayClearTransaction(). Back-patch to 9.6 (all
supported versions).
Andrey Borodin, reviewed (in earlier versions) by Andres Freund.
Discussion: https://postgr.es/m/01824242-AA92-4FE9-9BA7-AEBAFFEA3D0C@yandex-team.ru
CIC and REINDEX CONCURRENTLY assume backends see their catalog changes
no later than each backend's next transaction start. That failed to
hold when a backend absorbed a relevant invalidation in the middle of
running RelationBuildDesc() on the CIC index. Queries that use the
resulting index can silently fail to find rows. Fix this for future
index builds by making RelationBuildDesc() loop until it finishes
without accepting a relevant invalidation. It may be necessary to
reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices.
Back-patch to 9.6 (all supported versions).
Noah Misch and Andrey Borodin, reviewed (in earlier versions) by Andres
Freund.
Discussion: https://postgr.es/m/20210730022548.GA1940096@gust.leadboat.com
The documentation was imprecise about the starting LSN used for WAL
streaming if nothing can be found in the local archive directory
defined with the pg_receivewal command, so be more talkative on this
matter.
Extracted from a larger patch by the same author.
Author: Ronan Dunklau, Michael Paquier
Discussion: https://postgr.es/m/18708360.4lzOvYHigE@aivenronan
Backpatch-through: 10
Non-global default privilege entries should be dumped as-is,
not made relative to the default ACL for their object type.
This would typically only matter if one had revoked some
on-by-default privileges in a global entry, and then wanted
to grant them again in a non-global entry.
Per report from Boris Korzun. This is an old bug, so back-patch
to all supported branches.
Neil Chen, test case by Masahiko Sawada
Discussion: https://postgr.es/m/111621616618184@mail.yandex.ru
Discussion: https://postgr.es/m/CAA3qoJnr2+1dVJObNtfec=qW4Z0nz=A9+r5bZKoTSy5RDjskMw@mail.gmail.com
The build scripts of Visual Studio would fail to detect properly a 3.0.0
build as the check on the second digit was failing. This is adjusted
where needed, allowing the builds to complete. Note that the MSIs of
OpenSSL mentioned in the documentation have not changed any library
names for Win32 and Win64, making this change straight-forward.
Reported-by: htalaco, via github
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/YW5XKYkq6k7OtrFq@paquier.xyz
Backpatch-through: 9.6
Commit 1b5d797cd4 intended to relax the lock level used to rename
indexes, but inadvertently allowed *any* relation to be renamed with a
lowered lock level, as long as the command is spelled ALTER INDEX.
That's undesirable for other relation types, so retry the operation with
the higher lock if the relation turns out not to be an index.
After this fix, ALTER INDEX <sometable> RENAME will require access
exclusive lock, which it didn't before.
Author: Nathan Bossart <bossartn@amazon.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reported-by: Onder Kalaci <onderk@microsoft.com>
Discussion: https://postgr.es/m/PH0PR21MB1328189E2821CDEC646F8178D8AE9@PH0PR21MB1328.namprd21.prod.outlook.com
ldapsearch's deprecated -h/-p arguments were removed, need to use -H now -
which has been around for over 20 years.
As perltidy insists on reflowing the parameters anyway, change order and
"phrasing" to yield a less confusing layout (per suggestion from Tom Lane).
Discussion: https://postgr.es/m/20211009233850.wvr6apcrw2ai6cnj@alap3.anarazel.de
Backpatch: 11-, where the tests were added.
An update such as "UPDATE ... SET fld[n].subfld = whatever"
failed if the array elements were domains rather than plain
composites. That's because isAssignmentIndirectionExpr()
failed to cope with the CoerceToDomain node that would appear
in the expression tree in this case. The result would typically
be a crash, and even if we accidentally didn't crash, we'd not
correctly preserve other fields of the same array element.
Per report from Onder Kalaci. Back-patch to v11 where arrays of
domains came in.
Discussion: https://postgr.es/m/PH0PR21MB132823A46AA36F0685B7A29AD8BD9@PH0PR21MB1328.namprd21.prod.outlook.com
I think when I added this assertion (in commit 8f889b108), I was only
thinking of the use of transformExpressionList at top level of INSERT
and VALUES. But it's also called by transformRowExpr(), which can
certainly occur in an UPDATE targetlist, so it's inappropriate to
suppose that p_multiassign_exprs must be empty. Besides, since the
input is not expected to contain ResTargets, there's no reason it
should contain MultiAssignRefs either. Hence this code need not
be concerned about the state of p_multiassign_exprs, and we should
just drop the assertion.
Per bug #17236 from ocean_li_996. It's been wrong for years,
so back-patch to all supported branches.
Discussion: https://postgr.es/m/17236-3210de9bcba1d7ca@postgresql.org
If the blob TOC file cannot be parsed, the error message was failing
to print the filename as the variable holding it was shadowed by the
destination buffer for parsing. When the filename fails to parse,
the error will print an empty string:
./pg_restore -d foo -F d dump
pg_restore: error: invalid line in large object TOC file "": ..
..instead of the intended error message:
./pg_restore -d foo -F d dump
pg_restore: error: invalid line in large object TOC file "dump/blobs.toc": ..
Fix by renaming both variables as the shared name was too generic to
store either and still convey what the variable held.
Backpatch all the way down to 9.6.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/A2B151F5-B32B-4F2C-BA4A-6870856D9BDE@yesql.se
Backpatch-through: 9.6
Make sure that the string parsing is limited by the size of the
destination buffer.
In pg_basebackup the available values sent from the server
is limited to two characters so there was no risk of overflow.
In pg_dump the buffer is bounded by MAXPGPATH, and thus the limit
must be inserted via preprocessor expansion and the buffer increased
by one to account for the terminator. There is no risk of overflow
here, since in this case, the buffer scanned is smaller than the
destination buffer.
Backpatch the pg_basebackup fix to 11 where it was introduced, and
the pg_dump fix all the way down to 9.6.
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/B14D3D7B-F98C-4E20-9459-C122C67647FB@yesql.se
Backpatch-through: 11 and 9.6
Failing to do that, any direct inserts/updates of those partitions
would fail to enforce the correct constraint, that is, one that
considers the new partition constraint of their parent table.
Backpatch to 10.
Reported by: Hou Zhijie <houzj.fnst@fujitsu.com>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Nitin Jadhav <nitinjadhavpostgres@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Discussion: https://postgr.es/m/OS3PR01MB5718DA1C4609A25186D1FBF194089%40OS3PR01MB5718.jpnprd01.prod.outlook.com
During a replication slot creation, an ERROR generated in the same
transaction as the one creating a to-be-exported snapshot would have
left the backend in an inconsistent state, as the associated static
export snapshot state was not being reset on transaction abort, but only
on the follow-up command received by the WAL sender that created this
snapshot on replication slot creation. This would trigger inconsistency
failures if this session tried to export again a snapshot, like during
the creation of a replication slot.
Note that a snapshot export cannot happen in a transaction block, so
there is no need to worry resetting this state for subtransaction
aborts. Also, this inconsistent state would very unlikely show up to
users. For example, one case where this could happen is an
out-of-memory error when building the initial snapshot to-be-exported.
Dilip found this problem while poking at a different patch, that caused
an error in this code path for reasons unrelated to HEAD.
Author: Dilip Kumar
Reviewed-by: Michael Paquier, Zhihong Yu
Discussion: https://postgr.es/m/CAFiTN-s0zA1Kj0ozGHwkYkHwa5U0zUE94RSc_g81WrpcETB5=w@mail.gmail.com
Backpatch-through: 9.6
It was clearly the intent to do so all along, but the original coding
fat-fingered this by checking the wrong array element. We fixed it
in passing in 403a3d91c, but that later got reverted, and we forgot
to keep this bug fix.
Most of the time this'd be relatively harmless, since once we lock
any of the partitioned table's leaf partitions, that would suffice
to prevent major DDL on the partitioned table itself. However, a
childless partitioned table would get dumped with no relevant lock
whatsoever, possibly allowing dump failure or inconsistent output.
Unlike 403a3d91c, there are no versioning concerns, since every server
version that has partitioned tables will allow you to lock one.
Back-patch to v10 where partitioned tables were introduced.
Discussion: https://postgr.es/m/1018205.1634346327@sss.pgh.pa.us
An extension may want to call GetSecurityLabel() on a shared object
before the shared relcaches are fully initialized. For instance, a
ClientAuthentication_hook might want to retrieve the security label on
a role.
Discussion: https://postgr.es/m/ecb7af0b26e3be1d96d291c8453a86f1f82d9061.camel@j-davis.com
Backpatch-through: 9.6
The test code added with ff9f111bce fails under valgrind, and probably
other slow cases too, because if (say) autovacuum runs in between and
produces WAL of its own, the large INSERT fails to account for that in
the LSN calculations. Rewrite to use a DO loop.
Per complaint from Andres Freund
Backpatch to all branches.
Discussion: https://postgr.es/m/20211013180338.5guyqzpkcisqugrl@alap3.anarazel.de
This fixes a set of issues that cause different breakages or annoyances
when using pg_upgrade's test.sh to do upgrades across different major
versions:
- test.sh is completely broken when using v14 as new version because of
the removal of testtablespace/ as Makefile rule. Older versions of
pg_regress don't support --make-tablespacedir, blocking the creation of
the tablespace. In order to fix that, it is simple enough to create
those directories in the script itself, but only do that when an old
version is involved. This fix is needed on HEAD and REL_14_STABLE.
- The script would fail when using PG <= v11 as old version because of
WITH OIDS relations not supported in v12. In order to fix this, this
steals a method from the buildfarm that uses a DO block to change all
the relations marked as WITH OIDS, allowing pg_upgrade to pass. This is
more portable than using ALTER TABLE queries on the relations causing
issues. This is fixed down to v12, and authored originally by Andrew
Dunstan.
- Not using --extra-float-digits=0 with v11 as old version causes
a lot of diffs in the dumps, making the whole unreadable. This gets
only done when using v11 as old version. This is fixed down to v12.
The buildfarm code uses that already.
Note that the addition of --wal-segsize and --allow-group-access breaks
the script when using v10 or older at initdb time as these got added in
11. 10 would be EOL'd next year and nobody has complained about those
problems yet, so nothing is done about that. This means that this
commit fixes upgrade tests using test.sh with v11 as minimum older
version, up to HEAD, and that it is enough to apply this change down to
12. The old and new dumps still generate diffs, still require manual
checks, and more could be done to reduce the noise, but this allows the
tests to run with a rather minimal amount of them.
I have tested this commit and test.sh with v11 as minimum across all the
branches where this is applied. Note that this commit has no impact on
the normal pg_upgrade test run with a simple "make check".
Author: Justin Pryzby, Andrew Dunstan, Michael Paquier
Discussion: https://postgr.es/m/20201206180248.GI24052@telsasoft.com
Backpatch-through: 12
Incrementing the level of the call stack reported is useful for
debugging purposes as it allows to control which part of the test is
exactly failing, especially if a test is structured with subroutines
that call routines from Test::More.
This adds more incrementations of $Test::Builder::Level where debugging
gets improved (for example it does not make sense for some paths like
pg_rewind where long subroutines are used).
A note is added to src/test/perl/README about that, based on a
suggestion from Andrew Dunstan and a wording coming from both of us.
Usage of Test::Builder::Level has spread in 12, so a backpatch down to
this version is done.
Reviewed-by: Andrew Dunstan, Peter Eisentraut, Daniel Gustafsson
Discussion: https://postgr.es/m/YV1CCFwgM1RV1LeS@paquier.xyz
Backpatch-through: 12
Commit c7b7311f6 adjusted conversion_error_callback to always use
information from the query's rangetable, to avoid doing catalog lookups
in an already-failed transaction. However, as a result of the utterly
inadequate documentation for make_tuple_from_result_row, I failed to
realize that fsstate could be NULL in some contexts. That led to a
crash if we got a conversion error in such a context. Fix by falling
back to the previous coding when fsstate is NULL. Improve the
commentary, too.
Per report from Andrey Borodin. Back-patch to 9.6, like the previous
patch.
Discussion: https://postgr.es/m/08916396-55E4-4D68-AB3A-BD6066F9E5C0@yandex-team.ru
This fixes a loss of precision that occurs when the first input is
very close to 1, so that its logarithm is very small.
Formerly, during the initial low-precision calculation to estimate the
result weight, the logarithm was computed to a local rscale that was
capped to NUMERIC_MAX_DISPLAY_SCALE (1000). However, the base may be
as close as 1e-16383 to 1, hence its logarithm may be as small as
1e-16383, and so the local rscale needs to be allowed to exceed 16383,
otherwise all precision is lost, leading to a poor choice of rscale
for the full-precision calculation.
Fix this by removing the cap on the local rscale during the initial
low-precision calculation, as we already do in the full-precision
calculation. This doesn't change the fact that the initial calculation
is a low-precision approximation, computing the logarithm to around 8
significant digits, which is very fast, especially when the base is
very close to 1.
Patch by me, reviewed by Alvaro Herrera.
Discussion: https://postgr.es/m/CAEZATCV-Ceu%2BHpRMf416yUe4KKFv%3DtdgXQAe5-7S9tD%3D5E-T1g%40mail.gmail.com
queries.sgml failed to mention the rather important point that
INTERSECT binds more tightly than UNION or EXCEPT. I thought
it could also use more discussion of the role of parentheses
in these constructs.
Per gripe from Christopher Painter-Wakefield.
Discussion: https://postgr.es/m/163338891727.12510.3939775743980651160@wrigleys.postgresql.org
The old URL was HTTP 404 and the git link didn't build. Also update two
other ICU links. If we ever get a good link we will add it back.
Reported-by: Anton Voloshin
Author: Laurenz Albe
Backpatch-through: 10
3c5b0685b9 used setFilePointer() to set the position of the filehandle, but
passed the wrong filehandle, always leaving the position at 0. Instead of just
fixing that, remove use of setFilePointer(), we have a perl fd at this point,
so we can just use perl's seek().
Additionally, the perl filehandle wasn't closed, just the windows filehandle.
Reviewed-By: Andrew Dunstan <andrew@dunslane.net>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20211003173038.64mmhgxctfqn7wl6@alap3.anarazel.de
Backpatch: 9.6-, like 3c5b0685b9
Per discussion, let's just follow CLDR's default zone mappings
faithfully. There are two changes here that are clear improvements:
* Mapping "Greenwich Standard Time" to Atlantic/Reykjavik is actually
a better fit than using London, because Iceland hasn't observed DST
since 1968, so this is more nearly what people might expect.
* Since the "Samoa" zone is specified to be UTC+13:00, we must map
it to Pacific/Apia not Pacific/Samoa; the latter refers to American
Samoa which is now on the other side of the date line.
The rest of these changes look like they're choosing the most populous
IANA zone as representative. Whatever the details, we're just going
to say "if you don't like this mapping, complain to CLDR".
Discussion: https://postgr.es/m/3266414.1633045628@sss.pgh.pa.us
Some specific logic is done at the end of recovery when involving 2PC
transactions:
1) Call RecoverPreparedTransactions(), to recover the state of 2PC
transactions into memory (re-acquire locks, etc.).
2) ShutdownRecoveryTransactionEnvironment(), to move back to normal
operations, mainly cleaning up recovery locks and KnownAssignedXids
(including any 2PC transaction tracked previously).
3) Switch XLogCtl->SharedRecoveryState to RECOVERY_STATE_DONE, which is
the tipping point for any process calling RecoveryInProgress() to check
if the cluster is still in recovery or not.
Any snapshot taken between steps 2) and 3) would be empty, causing any
transaction relying on a snapshot at this point to potentially corrupt
data as there could still be some 2PC transactions to track, with
RecentXmin moving backwards on successive calls to GetSnapshotData() in
the same transaction.
As SharedRecoveryState is the point to take into account to know if it
is safe to discard KnownAssignedXids, this commit moves step 2) after
step 3), so as we can never finish with empty snapshots.
This exists since the introduction of hot standby, so backpatch all the
way down. The window with incorrect snapshots is extremely small, but I
have seen it when running 023_pitr_prepared_xact.pl, as did buildfarm
member fairywren. Thomas Munro also found it independently. Special
thanks to Andres Freund for taking the time to analyze this issue.
Reported-by: Thomas Munro, Michael Paquier
Analyzed-by: Andres Freund
Discussion: https://postgr.es/m/20210422203603.fdnh3fu2mmfp2iov@alap3.anarazel.de
Backpatch-through: 9.6
This corrects a bunch of entries in win32_tzmap[], and adds a few
new ones, based on the CLDR project's windowsZones.xml file.
Non-cosmetic changes fall into four main categories:
* Flat-out errors:
US/Aleutan doesn't exist
America/Salvador doesn't exist
Asia/Baku is wrong for Yerevan
Asia/Dhaka (Bangladesh) is wrong for Astana (Kazakhstan)
Europe/Bucharest is wrong for Chisinau
America/Mexico_City is wrong for Chetumal
America/Buenos_Aires is wrong for Cayenne
America/Caracas has its own zone, so poor fit for La Paz
US/Eastern is wrong for Haiti
US/Eastern is wrong for Indiana (East)
Asia/Karachi is wrong for Tashkent
Etc/UTC+12 doesn't exist
Signs of Etc/GMT zones were backwards
* Judgment calls:
(These changes follow CLDR's choices, except for the first one)
Use Europe/London for "Greenwich Standard Time", since that seems much
more likely than Africa/Casablanca to be what people will think that
zone name means. CLDR has Atlantic/Reykjavik here, but that's no better.
Asia/Shanghai seems a better fit than Hong Kong for "China Standard
Time".
Europe/Sarajevo is now a link to Belgrade, ie "Central Europe Standard
Time"; so use Warsaw for "Central European Standard Time".
America/Sao_Paulo seems more representative than Araguaina for
"E. South America Standard Time".
Africa/Johannesburg seems more representative than Harare for
"South Africa Standard Time".
* New Windows zone names:
"Israel Standard Time"
"Kaliningrad Standard Time"
"Russia Time Zone N" for various N
"Singapore Standard Time"
"South Sudan Standard Time"
"W. Central Africa Standard Time"
"West Bank Standard Time"
"Yukon Standard Time"
Some of these replace older spellings, but I kept the older spellings
too in case our code runs on a machine with the older data.
* Replace aliases (tzdb Links) with underlying city-named zones:
(This tracks tzdb's longstanding practice, and reduces inconsistency
with the rest of the entries, as well as with CLDR.)
US/Alaska
Asia/Kuwait
Asia/Muscat
Canada/Atlantic
Australia/Canberra
Canada/Saskatchewan
US/Central
US/Eastern
US/Hawaii
US/Mountain
Canada/Newfoundland
US/Pacific
Back-patch to all supported branches, as is our usual practice for
time zone data updates.
Discussion: https://postgr.es/m/3266414.1633045628@sss.pgh.pa.us