PostgreSQL 10.19 commit log

commit   : 477008d10fb5a024038ed23f0beba901f1f47ae2    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 17:05:38 -0500    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 17:05:38 -0500    

commit   : 3eadebaa975d8a0af444b8ecc4a84854cdd7920a    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 14:02:16 -0500    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 14:02:16 -0500    

Security: CVE-2021-23214, CVE-2021-23222  

commit   : e65d9c8cd15a86207f1da387a9c917c93c14ea11    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 11:14:56 -0500    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 11:14:56 -0500    

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  

commit   : 9ae0f1112954989e955b4b29e4580216eccfcee4    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 11:01:43 -0500    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 8 Nov 2021 11:01:43 -0500    

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  

commit   : c3bda112ebe20fe47da44ae644a77a1aef5083bf    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 8 Nov 2021 09:17:24 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 8 Nov 2021 09:17:24 -0300    

Introduced in 1d97d3d0867f.  
  
Co-authored-by: Alexander Lakhin <exclusion@gmail.com>  
Discussion: https://postgr.es/m/83641f59-d566-b33e-ef21-a272a98675aa@gmail.com  

commit   : 992d0c3a9cc0e421b75ca6b7776c7c910b6d42f1    
  
author   : Peter Eisentraut <peter@eisentraut.org>    
date     : Mon, 8 Nov 2021 10:09:21 +0100    
  
committer: Peter Eisentraut <peter@eisentraut.org>    
date     : Mon, 8 Nov 2021 10:09:21 +0100    

Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git  
Source-Git-Hash: 3f8ccab66ae01c89727b0284ac600ae6648c1adf  

commit   : fdbad0043345c3a7eddda7698b52fcc7ba121500    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 7 Nov 2021 14:21:51 -0500    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 7 Nov 2021 14:21:51 -0500    

commit   : 774d00573966e40104337fd14153973a79abc5ce    
  
author   : Alexander Korotkov <akorotkov@postgresql.org>    
date     : Sat, 6 Nov 2021 18:31:21 +0300    
  
committer: Alexander Korotkov <akorotkov@postgresql.org>    
date     : Sat, 6 Nov 2021 18:31:21 +0300    

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  

commit   : 58b600f64bfb80ca6daf6d9f27af9c3105e13500    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Fri, 5 Nov 2021 12:29:34 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Fri, 5 Nov 2021 12:29:34 -0300    

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  

commit   : 245799d39c378b03021304c69cae9dd79f0937e3    
  
author   : Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Wed, 3 Nov 2021 19:38:17 +0200    
  
committer: Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Wed, 3 Nov 2021 19:38:17 +0200    

Previous commit added a test to 'largeobject', but neglected the  
alternative expected output file 'largeobject_1.source'. Per failure  
on buildfarm animal 'hamerkop'.  
  
Discussion: https://www.postgresql.org/message-id/DBA08346-9962-4706-92D1-230EE5201C10@yesql.se  

commit   : 7b55bb892a0b3bf5c2e44873d091508eea8bba45    
  
author   : Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Wed, 3 Nov 2021 11:09:08 +0200    
  
committer: Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Wed, 3 Nov 2021 11:09:08 +0200    

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  

commit   : 656312c2ac328aa8af20b4c5f0fab1f7f7202b2f    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 1 Nov 2021 13:07:23 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 1 Nov 2021 13:07:23 -0300    

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>  

commit   : d87d5f8d8d3ae35c15c44ddb26bbc2b916f2bc12    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 31 Oct 2021 19:13:48 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 31 Oct 2021 19:13:48 -0400    

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  

commit   : d0fe211ce4768e1195ab27e7109c0cb22c39a9e2    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 29 Oct 2021 11:38:18 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 29 Oct 2021 11:38:18 -0400    

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.  

commit   : 1d2a7b51509f8b3453d2b04e530ecb7e72c7fe41    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Thu, 28 Oct 2021 09:26:29 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Thu, 28 Oct 2021 09:26:29 +0900    

Reported-by: Anton Voloshin  
Discussion: https://postgr.es/m/15a86d4e-a237-1acd-18a2-fd69730f1ab9@postgrespro.ru  
Backpatch-through: 10  

commit   : 0275314e4f017ee3f84e9b77637388610a4417c1    
  
author   : Magnus Hagander <magnus@hagander.net>    
date     : Wed, 27 Oct 2021 16:20:02 +0200    
  
committer: Magnus Hagander <magnus@hagander.net>    
date     : Wed, 27 Oct 2021 16:20:02 +0200    

Make this more clear both in the help message and docs.  
  
Reviewed-By: Michael Paquier  
Backpatch-through: 9.6  
Discussion: https://postgr.es/m/CABUevEw6Je0WUFTLhPKOk4+BoBuDrE-fKw3N4ckqgDBMFu4paA@mail.gmail.com  

commit   : 560124a37c2f6ef8db606f74eda442b48e3f9601    
  
author   : Noah Misch <noah@leadboat.com>    
date     : Sat, 23 Oct 2021 18:36:38 -0700    
  
committer: Noah Misch <noah@leadboat.com>    
date     : Sat, 23 Oct 2021 18:36:38 -0700    

The purpose of commit 8a54e12a38d1545d249f1402f66c8cde2837d97c 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  

commit   : db86746fd11e6d453e53b1550a46d325e3574aa7    
  
author   : Noah Misch <noah@leadboat.com>    
date     : Sat, 23 Oct 2021 18:36:38 -0700    
  
committer: Noah Misch <noah@leadboat.com>    
date     : Sat, 23 Oct 2021 18:36:38 -0700    

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  

commit   : 438d467a5241532278896dc53c709b26431b4225    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Sat, 23 Oct 2021 14:43:55 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Sat, 23 Oct 2021 14:43:55 +0900    

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  

commit   : 10f9faf6d87393e3599e6892576d902d4ea07143    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 22 Oct 2021 15:22:26 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 22 Oct 2021 15:22:26 -0400    

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  

commit   : 13e52d7c553327c41620a678720477079c8a5802    
  
author   : Amit Kapila <akapila@postgresql.org>    
date     : Thu, 21 Oct 2021 10:12:59 +0530    
  
committer: Amit Kapila <akapila@postgresql.org>    
date     : Thu, 21 Oct 2021 10:12:59 +0530    

This was originally done in commit 5e77625b26 for 15 only, as a  
troubleshooting aid but multiple people showed interest in back-patching  
this.  
  
Author: Jeremy Schneider  
Reviewed-by: Amit Kapila  
Backpatch-through: 9.6  
Discussion: https://postgr.es/m/808ed65b-994c-915a-361c-577f088b837f@amazon.com  

commit   : 922e3c3b72d847bc9010b19a1f31875e6be49577    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Wed, 20 Oct 2021 16:49:10 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Wed, 20 Oct 2021 16:49:10 +0900    

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   : 9681c8fd5fd03f9abe830049575c156534f4f587    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 19 Oct 2021 11:35:15 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 19 Oct 2021 11:35:15 -0400    

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  

commit   : 4fda03b671a6849972d0a66b4af5518cd2a97a70    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 19 Oct 2021 12:59:54 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 19 Oct 2021 12:59:54 +0200    

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  

commit   : abdf81a20ba2ddc06a0ebdd58ee8747306fb2004    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 19 Oct 2021 12:59:50 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 19 Oct 2021 12:59:50 +0200    

Make sure that the string parsing is limited by the size of the  
destination buffer.  
  
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 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: 9.6  

commit   : d36bdc4e9d3ecfc47d2db4fe4cc84eb5baa0cf9c    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 18 Oct 2021 19:08:25 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 18 Oct 2021 19:08:25 -0300    

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  

commit   : d1a6a08dfafc249d5df294e8c56b1b52b61e47df    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Mon, 18 Oct 2021 11:57:02 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Mon, 18 Oct 2021 11:57:02 +0900    

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  

commit   : 2e2a232831c7f7c886827c6305b6a9553de4b3b4    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 16 Oct 2021 12:23:57 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 16 Oct 2021 12:23:57 -0400    

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  

commit   : 9364f64a2a73cc5e0c85a8f09f8f6461809b4fcb    
  
author   : Jeff Davis <jdavis@postgresql.org>    
date     : Thu, 14 Oct 2021 12:25:48 -0700    
  
committer: Jeff Davis <jdavis@postgresql.org>    
date     : Thu, 14 Oct 2021 12:25:48 -0700    

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  

commit   : 41cce2326135c05d6db311ad894703c3080be33c    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Wed, 13 Oct 2021 18:49:27 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Wed, 13 Oct 2021 18:49:27 -0300    

The test code added with ff9f111bce24 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  

commit   : eb55dcbeed6657c507293d4386023aad4030dbe3    
  
author   : Etsuro Fujita <efujita@postgresql.org>    
date     : Wed, 13 Oct 2021 19:00:08 +0900    
  
committer: Etsuro Fujita <efujita@postgresql.org>    
date     : Wed, 13 Oct 2021 19:00:08 +0900    

The comments were misplaced when adding postgres_fdw.  Fix that by  
moving the comments to more appropriate functions.  
  
Author: Etsuro Fujita  
Backpatch-through: 9.6  
Discussion: https://postgr.es/m/CAPmGK164sAXQtC46mDFyu6d-T25Mzvh5qaRNkit06VMmecYnOA%40mail.gmail.com  

commit   : 2e33fbda1263533518614c3930cca4b8eb21bd26    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 6 Oct 2021 15:50:24 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 6 Oct 2021 15:50:24 -0400    

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  

commit   : 4853baaaca4a3469247027f7dc86b516e35f7c0a    
  
author   : Dean Rasheed <dean.a.rasheed@gmail.com>    
date     : Wed, 6 Oct 2021 13:23:13 +0100    
  
committer: Dean Rasheed <dean.a.rasheed@gmail.com>    
date     : Wed, 6 Oct 2021 13:23:13 +0100    

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  

commit   : 129ac7d349116ac6ddd89d5e55d05f42adf473d2    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 5 Oct 2021 10:24:15 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 5 Oct 2021 10:24:15 -0400    

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  

commit   : 9cb9c91460c424bb5b856e3e09b59e55854a0293    
  
author   : Bruce Momjian <bruce@momjian.us>    
date     : Mon, 4 Oct 2021 17:21:09 -0400    
  
committer: Bruce Momjian <bruce@momjian.us>    
date     : Mon, 4 Oct 2021 17:21:09 -0400    

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 only (missed in previous commit)  

commit   : d5fa3c086eaba8de4af289e6f0059afa05f8e1f5    
  
author   : Andres Freund <andres@anarazel.de>    
date     : Mon, 4 Oct 2021 13:28:06 -0700    
  
committer: Andres Freund <andres@anarazel.de>    
date     : Mon, 4 Oct 2021 13:28:06 -0700    

3c5b0685b921 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 3c5b0685b921  

commit   : cd24791425882a76e890743728f381b7f764cf29    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 4 Oct 2021 14:52:17 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 4 Oct 2021 14:52:17 -0400    

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  

commit   : 8a6a1fe07e062911f6bbcb395b673931cada1ccd    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Mon, 4 Oct 2021 14:06:03 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Mon, 4 Oct 2021 14:06:03 +0900    

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  

commit   : e323630cdd3cf7a0a2579f20f8808a33be4391e6    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 2 Oct 2021 16:05:42 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 2 Oct 2021 16:05:42 -0400    

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  

commit   : cb0799db0d8e4e3aaf897b311a39b562bcb31118    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 2 Oct 2021 16:05:10 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 2 Oct 2021 16:05:10 -0400    

The original intent seems to have been to sort case-insensitively  
by the Windows zone name, but various changes over the years did  
not get that memo.  This commit just moves a few entries to  
restore exact alphabetic order, to ease comparison to the outputs  
of processing scripts.  
  
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  

commit   : f951ea3a2a830f93b623862ad22ec889883b3adc    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 1 Oct 2021 14:59:35 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 1 Oct 2021 14:59:35 -0400    

get_variable_range() would incautiously believe that statistics  
containing only an MCV list are sufficient to derive a range estimate.  
That's okay for an enum-like column that contains only MCVs, but  
otherwise the estimate could be pretty bad.  Make it report that the  
range is indeterminate unless the MCVs plus nullfrac account for  
the whole table.  
  
I don't think this needs a dedicated test case, since a quick code  
coverage check verifies that the existing regression tests traverse  
all the alternatives.  There is room to doubt that a future-proof  
test case could be built anyway, given that the submitted example  
accidentally doesn't fail before v11.  
  
Per bug #17207 from Simon Perepelitsa.  Back-patch to v10.  
In principle this has been broken all along, but I'm hesitant to  
make such changes in 9.6, since if anyone is unhappy with 9.6.24's  
behavior there will be no second chance to fix it.  
  
Discussion: https://postgr.es/m/17207-5265aefa79e333b4@postgresql.org  

commit   : d30d8257ec749dd9b5b449dd4b79831481e3634e    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 30 Sep 2021 16:23:10 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 30 Sep 2021 16:23:10 -0400    

Computing related timestamps by subtracting "N days" is sensitive  
to the prevailing timezone, since we interpret that as "same local  
time on the N'th prior day".  Even though the intervals in question  
are only two to four days, through remarkable bad luck they managed  
to cross the end of Ramadan in 2014, causing the test's output to  
change if timezone is set to Africa/Casablanca.  (Maybe in other  
Muslim areas as well; I didn't check.)  There's absolutely no reason  
for this test to exercise interval subtraction, so just get rid of  
that and use plain timestamptz constants representing the intended  
values.  
  
Per report from Andres Freund.  Back-patch to v10 where this test  
script came in.  
  
Discussion: https://postgr.es/m/20210930183641.7lh4jhvpipvromca@alap3.anarazel.de  

commit   : d9fe2cc7dd3e063eecfa88239a8aeea84641b335    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Wed, 29 Sep 2021 11:21:51 -0300    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Wed, 29 Sep 2021 11:21:51 -0300    

Physical replication always ships WAL segment files to replicas once  
they are complete.  This is a problem if one WAL record is split across  
a segment boundary and the primary server crashes before writing down  
the segment with the next portion of the WAL record: WAL writing after  
crash recovery would happily resume at the point where the broken record  
started, overwriting that record ... but any standby or backup may have  
already received a copy of that segment, and they are not rewinding.  
This causes standbys to stop following the primary after the latter  
crashes:  
  LOG:  invalid contrecord length 7262 at A8/D9FFFBC8  
because the standby is still trying to read the continuation record  
(contrecord) for the original long WAL record, but it is not there and  
it will never be.  A workaround is to stop the replica, delete the WAL  
file, and restart it -- at which point a fresh copy is brought over from  
the primary.  But that's pretty labor intensive, and I bet many users  
would just give up and re-clone the standby instead.  
  
A fix for this problem was already attempted in commit 515e3d84a0b5, but  
it only addressed the case for the scenario of WAL archiving, so  
streaming replication would still be a problem (as well as other things  
such as taking a filesystem-level backup while the server is down after  
having crashed), and it had performance scalability problems too; so it  
had to be reverted.  
  
This commit fixes the problem using an approach suggested by Andres  
Freund, whereby the initial portion(s) of the split-up WAL record are  
kept, and a special type of WAL record is written where the contrecord  
was lost, so that WAL replay in the replica knows to skip the broken  
parts.  With this approach, we can continue to stream/archive segment  
files as soon as they are complete, and replay of the broken records  
will proceed across the crash point without a hitch.  
  
Because a new type of WAL record is added, users should be careful to  
upgrade standbys first, primaries later. Otherwise they risk the standby  
being unable to start if the primary happens to write such a record.  
  
A new TAP test that exercises this is added, but the portability of it  
is yet to be seen.  
  
This has been wrong since the introduction of physical replication, so  
backpatch all the way back.  In stable branches, keep the new  
XLogReaderState members at the end of the struct, to avoid an ABI  
break.  
  
Author: Álvaro Herrera <alvherre@alvh.no-ip.org>  
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>  
Reviewed-by: Nathan Bossart <bossartn@amazon.com>  
Discussion: https://postgr.es/m/202108232252.dh7uxf6oxwcy@alvherre.pgsql  

commit   : 2ddf1c1be6c87ece5428ce94c2ca86bb1ffe0dc0    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Sun, 26 Sep 2021 19:18:37 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Sun, 26 Sep 2021 19:18:37 +0900    

Author: Justin Pryzby  
Discussion: https://postgr.es/m/20210924215827.GS831@telsasoft.com  
Backpatch-through: 9.6  

commit   : 1d7e8e772453a4edd99b3954a9f3707ce5a2176a    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 25 Sep 2021 10:53:55 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 25 Sep 2021 10:53:55 -0400    

Be a little more vocal about the risks of remote collations not  
matching local ones.  Actually fixing these risks seems hard,  
and I've given up on the idea that it might be back-patchable.  
So the best we can do for the back branches is add documentation.  
  
Per discussion of bug #16583 from Jiří Fejfar.  
  
Discussion: https://postgr.es/m/2438715.1632510693@sss.pgh.pa.us  

commit   : eb643536b9f16d58e17f21a226dd63be61e44011    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:27:28 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:27:28 +0200    

OpenSSL 3 introduced the concept of providers to support modularization,  
and moved the outdated ciphers to the new legacy provider. In case it's  
not loaded in the users openssl.cnf file there will be a lot of regress  
test failures, so add alternative outputs covering those.  
  
Also document the need to load the legacy provider in order to use older  
ciphers with OpenSSL-enabled pgcrypto.  
  
This will be backpatched to all supported version once there is sufficient  
testing in the buildfarm of OpenSSL 3.  
  
Reviewed-by: Michael Paquier  
Discussion: https://postgr.es/m/FEF81714-D479-4512-839B-C769D2605F8A@yesql.se  
Backpatch-through: 9.6  

commit   : e802b594e7946d7fea9302f2231943c36255e084    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:27:20 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:27:20 +0200    

The PX layer in pgcrypto is handling digest padding on its own uniformly  
for all backend implementations. Starting with OpenSSL 3.0.0, DecryptUpdate  
doesn't flush the last block in case padding is enabled so explicitly  
disable it as we don't use it.  
  
This will be backpatched to all supported version once there is sufficient  
testing in the buildfarm of OpenSSL 3.  
  
Reviewed-by: Peter Eisentraut, Michael Paquier  
Discussion: https://postgr.es/m/FEF81714-D479-4512-839B-C769D2605F8A@yesql.se  
Backpatch-through: 9.6  

commit   : 841075a65cdc2d034dd8a473f25c5f584c8856d7    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:25:48 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Sat, 25 Sep 2021 11:25:48 +0200    

This has previously not been a problem (that anyone ever reported),  
but in future OpenSSL versions (3.0.0), where legacy ciphers are/can  
be disabled, this is the place where this is reported.  So we need to  
catch the error here, otherwise the higher-level functions would  
return garbage.  The nearby encryption code already handled errors  
similarly.  
  
Author: Peter Eisentraut <peter@eisentraut.org>  
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>  
Discussion: https://www.postgresql.org/message-id/9e9c431c-0adc-7a6d-9b1a-915de1ba3fe7@enterprisedb.com  
Backpatch-through: 9.6  

commit   : 1d1d13bc72aa2d0344520bd2f302262ce2064364    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Sat, 25 Sep 2021 15:12:11 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Sat, 25 Sep 2021 15:12:11 +0900    

Index vacuums may happen multiple times depending on the number of dead  
tuples stored, as of maintenance_work_mem for a manual VACUUM.  For  
autovacuum, this is controlled by autovacuum_work_mem instead, if set.  
The documentation mentioned the former, but not the latter in the  
context of autovacuum.  
  
Reported-by: Nikolai Berkoff  
Author: Laurenz Albe, Euler Taveira  
Discussion: https://postgr.es/m/161545365522.10134.12195402324485546870@wrigleys.postgresql.org  
Backpatch-through: 9.6  

commit   : ed3474b43490405a528f22671539c3983070f00e    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Sat, 25 Sep 2021 14:48:25 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Sat, 25 Sep 2021 14:48:25 +0900    

Reported-by: rir  
Discussion: https://postgr.es/m/20210924183658.3syyitp3yuxjv2fp@localhost  
Backpatch-through: 9.6  

commit   : d77e085afd52e9023075288ba95cf3280e273c2d    
  
author   : Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 21 Sep 2021 01:13:11 +0200    
  
committer: Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 21 Sep 2021 01:13:11 +0200    

Calculating degree of a functional dependency may allocate a lot of  
memory - we have released mot of the explicitly allocated memory, but  
e.g. detoasted varlena values were left behind. That may be an issue,  
because we consider a lot of dependencies (all combinations), and the  
detoasting may happen for each one again.  
  
Fixed by calling dependency_degree() in a dedicated context, and  
resetting it after each call. We only need the calculated dependency  
degree, so we don't need to copy anything.  
  
Backpatch to PostgreSQL 10, where extended statistics were introduced.  
  
Backpatch-through: 10  
Discussion: https://www.postgresql.org/message-id/20210915200928.GP831%40telsasoft.com  

commit   : 3aac99068cd7abe9d6fbc8c0faa361d75f7d0bfc    
  
author   : Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 21 Sep 2021 01:14:11 +0200    
  
committer: Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 21 Sep 2021 01:14:11 +0200    

Until now, all extended statistics on a given relation were built in the  
same memory context, without resetting. Some of the memory was released  
explicitly, but not all of it - for example memory allocated while  
detoasting values is hard to free. This is how it worked since extended  
statistics were introduced in PostgreSQL 10, but adding support for  
extended stats on expressions made the issue somewhat worse as it  
increases the number of statistics to build.  
  
Fixed by adding a memory context which gets reset after building each  
statistics object (all the statistics kinds included in it). Resetting  
it after building each statistics kind would be even better, but it  
would require more invasive changes and copying of results, making it  
harder to backpatch.  
  
Backpatch to PostgreSQL 10, where extended statistics were introduced.  
  
Author: Justin Pryzby  
Reported-by: Justin Pryzby  
Reviewed-by: Tomas Vondra  
Backpatch-through: 10  
Discussion: https://www.postgresql.org/message-id/20210915200928.GP831%40telsasoft.com  

commit   : 782480fe757f9bbce8d6224585a02172c2c408bb    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Wed, 22 Sep 2021 08:43:45 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Wed, 22 Sep 2021 08:43:45 +0900    

Contrary to the output of native perl, Msys perl generates outputs with  
CRLFs characters.  There are already places in the TAP code where CRLFs  
(\r\n) are automatically converted to LF (\n) on Msys, but we missed a  
couple of places when running commands and using their output for  
comparison, that would lead to failures.  
  
This problem has been found thanks to the test added in 5adb067 using  
TestLib::command_checks_all(), but after a closer look more code paths  
were missing a filter.  
  
This is backpatched all the way down to prevent any surprises if a new  
test is introduced in stable branches.  
  
Reviewed-by: Andrew Dunstan, Álvaro Herrera  
Discussion: https://postgr.es/m/1252480.1631829409@sss.pgh.pa.us  
Backpatch-through: 9.6  

commit   : 923b7efc259818688979f38ba88cba0d0d41ba10    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 20 Sep 2021 11:48:52 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 20 Sep 2021 11:48:52 -0400    

Casting a value that's already of a type with a specific typmod  
to an unspecified typmod doesn't do anything so far as run-time  
behavior is concerned.  However, it really ought to change the  
exposed type of the expression to match.  Up to now,  
coerce_type_typmod hasn't bothered with that, which creates gotchas  
in contexts such as recursive unions.  If for example one side of  
the union is numeric(18,3), but it needs to be plain numeric to  
match the other side, there's no direct way to express that.  
  
This is easy enough to fix, by inserting a RelabelType to update the  
exposed type of the expression.  However, it's a bit nervous-making  
to change this behavior, because it's stood for a really long time.  
But no complaints have emerged about 14beta3, so go ahead and  
back-patch.  
  
Back-patch of 5c056b0c2 into previous supported branches.  
  
Discussion: https://postgr.es/m/CABNQVagu3bZGqiTjb31a8D5Od3fUMs7Oh3gmZMQZVHZ=uWWWfQ@mail.gmail.com  
Discussion: https://postgr.es/m/1488389.1631984807@sss.pgh.pa.us  

commit   : 61fb2b98f9df8bd770747b641d26615dc2d15cf8    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 19 Sep 2021 11:36:53 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sun, 19 Sep 2021 11:36:53 -0400    

"PGcon" should be "PGconn".  Noted by D. Frey.  
  
Discussion: https://postgr.es/m/163191739352.4680.16994248583642672629@wrigleys.postgresql.org  

commit   : 639d731acc2b6a998e262a29d5a4a6f5b3340952    
  
author   : Fujii Masao <fujii@postgresql.org>    
date     : Thu, 16 Sep 2021 13:07:29 +0900    
  
committer: Fujii Masao <fujii@postgresql.org>    
date     : Thu, 16 Sep 2021 13:07:29 +0900    

ProcArrayGroupClearXid function has a parameter named "proc",  
but the same name was used for its local variables. This commit fixes  
this variable shadowing, to improve code readability.  
  
Back-patch to all supported versions, to make future back-patching  
easy though this patch is classified as refactoring only.  
  
Reported-by: Ranier Vilela  
Author: Ranier Vilela, Aleksander Alekseev  
https://postgr.es/m/CAEudQAqyoTZC670xWi6w-Oe2_Bk1bfu2JzXz6xRfiOUzm7xbyQ@mail.gmail.com  

commit   : fe70ec9078a5f20a2bd21687ba31cb351147a113    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 13 Sep 2021 12:42:04 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 13 Sep 2021 12:42:04 -0400    

Ordinarily, using EXIT this way would draw "control reached end of  
function without RETURN".  However, if the function is one where we  
don't require an explicit RETURN (such as a DO block), that should  
not happen.  It did anyway, because add_dummy_return() neglected to  
account for the case.  
  
Per report from Herwig Goemans.  Back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/868ae948-e3ca-c7ec-95a6-83cfc08ef750@gmail.com  

commit   : 83a3737a63a52a006c3f1290cda25acbda3607fa    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Mon, 13 Sep 2021 13:24:47 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Mon, 13 Sep 2021 13:24:47 +0900    

An out-of-memory failure happening when allocating the structures to  
store the connection parameter keywords and values would mess up with  
the set of connections saved, as on failure the pthread mutex would  
still be hold with the new connection object listed but free()'d.  
  
Rather than just unlocking the mutex, which would leave the static list  
of connections into an inconsistent state, move the allocation for the  
structures of the connection parameters before beginning the test  
manipulation.  This ensures that the list of connections and the  
connection mutex remain consistent all the time in this code path.  
  
This error is unlikely going to happen, but this could mess up badly  
with ECPG clients in surprising ways, so backpatch all the way down.  
  
Reported-by: ryancaicse  
Discussion: https://postgr.es/m/17186-b4cfd8f0eb4d1dee@postgresql.org  
Backpatch-through: 9.6  

commit   : daac97eb0b9f680916561ae636ce554fbeec8bd5    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 11 Sep 2021 15:19:31 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 11 Sep 2021 15:19:31 -0400    

If search_start is greater than the length of the string, we should just  
return REG_NOMATCH immediately.  (Note that the equality case should  
*not* be rejected, since the pattern might be able to match zero  
characters.)  This guards various internal assumptions that the min of a  
range of string positions is not more than the max.  Violation of those  
assumptions could allow an attempt to fetch string[search_start-1],  
possibly causing a crash.  
  
Jaime Casanova pointed out that this situation is reachable with the  
new regexp_xxx functions that accept a user-specified start position.  
I don't believe it's reachable via any in-core call site in v14 and  
below.  However, extensions could possibly call pg_regexec with an  
out-of-range search_start, so let's back-patch the fix anyway.  
  
Discussion: https://postgr.es/m/20210911180357.GA6870@ahch-to  

commit   : ca1dd6234049bd5f9c06c45b0bffc867120eaac3    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 9 Sep 2021 11:45:48 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 9 Sep 2021 11:45:48 -0400    

We don't allow relations to exceed 2^32-1 blocks, because block  
numbers are 32 bits and the last possible block number is reserved  
to mean InvalidBlockNumber.  There is a check for this in mdextend,  
but that's really way too late, because the smgr API requires us to  
create a buffer for the block-to-be-added, and we do not want to  
have any buffer with blocknum InvalidBlockNumber.  (Such a case  
can trigger assertions in bufmgr.c, plus I think it might confuse  
ReadBuffer's logic for data-past-EOF later on.)  So put the check  
into ReadBuffer.  
  
Per report from Christoph Berg.  It's been like this forever,  
so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/YTn1iTkUYBZfcODk@msg.credativ.de  

commit   : f77489046d172b3111d4d588479fc4e7444ec36b    
  
author   : Fujii Masao <fujii@postgresql.org>    
date     : Thu, 9 Sep 2021 23:59:40 +0900    
  
committer: Fujii Masao <fujii@postgresql.org>    
date     : Thu, 9 Sep 2021 23:59:40 +0900    

Previously, walreceiver always closed the currently-opened WAL segment  
and created its archive notification file, after it finished writing  
the current segment up and received any WAL data that should be  
written into the next segment. If walreceiver exited just before  
any WAL data in the next segment arrived at standby, it did not  
create the archive notification file of the current segment  
even though that's known completed. This behavior could cause  
WAL archiving of the segment to be delayed until subsequent  
restartpoints or checkpoints created its notification file.  
  
To fix the issue, this commit changes walreceiver so that it creates  
an archive notification file of a current WAL segment immediately  
if that's known completed before receiving next WAL data.  
  
Back-patch to all supported branches.  
  
Reported-by: Kyotaro Horiguchi  
Author: Fujii Masao  
Reviewed-by: Kyotaro Horiguchi  
Discussion: https://postgr.es/m/20200630.165503.1465894182551545886.horikyota.ntt@gmail.com  

commit   : 97b62cc480c8b9e0c14c5a94165ddcaad232f335    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 8 Sep 2021 15:09:43 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 8 Sep 2021 15:09:43 -0400    

Coverity complained that one caller of getFormattedTypeName() failed  
to free the returned string.  Which is true, but rather than fixing  
that one, let's get rid of this tedious and error-prone requirement.  
Now that getFormattedTypeName() caches its result, strdup'ing that  
result and expecting the caller to free it accomplishes little except  
to waste cycles.  We do create a leak in the case where getTypes didn't  
make a TypeInfo for the type, but that basically shouldn't ever happen.  
  
Back-patch, as commit 6c450a861 was.  This isn't a particularly  
interesting bug fix, but the API change seems like a hazard for  
future back-patching activity if we don't back-patch it.  

commit   : 9de082399cfec5814b2a696f751577ed927920fc    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 8 Sep 2021 12:05:43 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 8 Sep 2021 12:05:43 -0400    

If we copy data-modifying CTEs from the original query to a replacement  
query (from a DO INSTEAD rule), we must set hasModifyingCTE properly  
in the replacement query.  Failure to do this can cause various  
unpleasantness, such as unsafe usage of parallel plans.  The code also  
neglected to propagate hasRecursive, though that's only cosmetic at  
the moment.  
  
A difficulty arises if the rule action is an INSERT...SELECT.  We  
attach the original query's RTEs and CTEs to the sub-SELECT Query, but  
data-modifying CTEs are only allowed to appear in the topmost Query.  
For the moment, throw an error in such cases.  It would probably be  
possible to avoid this error by attaching the CTEs to the top INSERT  
Query instead; but that would require a bunch of new code to adjust  
ctelevelsup references.  Given the narrowness of the use-case, and  
the need to back-patch this fix, it does not seem worth the trouble  
for now.  We can revisit this if we get field complaints.  
  
Per report from Greg Nancarrow.  Back-patch to all supported branches.  
(The test case added here does not fail before v10, but there are  
plenty of places checking top-level hasModifyingCTE in 9.6, so I have  
no doubt that this code change is necessary there too.)  
  
Greg Nancarrow and Tom Lane  
  
Discussion: https://postgr.es/m/CAJcOf-f68DT=26YAMz_i0+Au3TcLO5oiHY5=fL6Sfuits6r+_w@mail.gmail.com  
Discussion: https://postgr.es/m/CAJcOf-fAdj=nDKMsRhQzndm-O13NY4dL6xGcEvdX5Xvbbi0V7g@mail.gmail.com  

commit   : 28cde380c1c02754bc0eebb88e9ec9c4de91a8fb    
  
author   : Amit Kapila <akapila@postgresql.org>    
date     : Wed, 8 Sep 2021 11:23:01 +0530    
  
committer: Amit Kapila <akapila@postgresql.org>    
date     : Wed, 8 Sep 2021 11:23:01 +0530    

Updates/Deletes on a relation were allowed even without replica identity  
after we define the publication for all tables. This would later lead to  
an error on subscribers. The reason was that for such publications we were  
not invalidating the relcache and the publication information for  
relations was not getting rebuilt. Similarly, we were not invalidating the  
relcache after dropping of such publications which will prohibit  
Updates/Deletes without replica identity even without any publication.  
  
Author: Vignesh C and Hou Zhijie  
Reviewed-by: Hou Zhijie, Kyotaro Horiguchi, Amit Kapila  
Backpatch-through: 10, where it was introduced  
Discussion: https://postgr.es/m/CALDaNm0pF6zeWqCA8TCe2sDuwFAy8fCqba=nHampCKag-qLixg@mail.gmail.com  

commit   : b28c862a6c11c5f9fc77687124747d551b7c74a1    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 6 Sep 2021 11:29:52 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 6 Sep 2021 11:29:52 -0400    

timetz_zone() delivered completely wrong answers if the zone was  
specified by a dynamic TZ abbreviation, because it failed to account  
for the difference between the POSIX conventions for field values in  
struct pg_tm and the conventions used in PG-specific datetime code.  
  
As a stopgap fix, just adjust the tm_year and tm_mon fields to match  
PG conventions.  This is fixed in a different way in HEAD (388e71af8)  
but I don't want to back-patch the change of reference point.  
  
Discussion: https://postgr.es/m/CAJ7c6TOMG8zSNEZtCn5SPe+cCk3Lfxb71ZaQwT2F4T7PJ_t=KA@mail.gmail.com  

commit   : 70354dd560c7cdf4bf32653e9687051bf8abcb0e    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 4 Sep 2021 16:29:08 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Sat, 4 Sep 2021 16:29:08 -0400    

Attempting to make hashfloat4() look as much as possible like  
hashfloat8(), I'd figured I could replace NaNs with get_float4_nan()  
before widening to float8.  However, results from protosciurus  
and topminnow show that on some platforms that produces a different  
bit-pattern from get_float8_nan(), breaking the intent of ce773f230.  
Rearrange so that we use the result of get_float8_nan() for all NaN  
cases.  As before, back-patch.  

commit   : 9aaf7dbff36f76f1836a7327f5d1804061891724    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Sat, 4 Sep 2021 12:14:30 -0400    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Sat, 4 Sep 2021 12:14:30 -0400    

This reverts commit 515e3d84a0b5 and equivalent commits in back  
branches.  This solution to the problem has a number of problems, so  
we'll try again with a different approach.  
  
Per note from Andres Freund  
  
Discussion: https://postgr.es/m/20210831042949.52eqp5xwbxgrfank@alap3.anarazel.de  

commit   : 6e2f4581781b5bc509012ac9e0718deb707635b2    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 3 Sep 2021 21:04:45 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 3 Sep 2021 21:04:45 -0400    

Replace fixed-length command buffers with psprintf() calls.  We didn't  
have anything as convenient as psprintf() when this code was written,  
but now that we do, there's little reason for the limitation to  
stand.  Removing it eliminates some corner cases where (for example)  
starting the postmaster with a whole lot of options fails.  
  
Most individual file names that pg_ctl deals with are still restricted  
to MAXPGPATH, but we've seldom had complaints about that limitation  
so long as it only applies to one filename.  
  
Back-patch to all supported branches.  
  
Phil Krylov  
  
Discussion: https://postgr.es/m/567e199c6b97ee19deee600311515b86@krylov.eu  

commit   : 5d7c6b6c8b4a9e03a16b5c2f5106e1fc5bff9681    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 3 Sep 2021 16:38:55 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 3 Sep 2021 16:38:55 -0400    

Previously this was allowed, but the collation effectively vanished  
into the ether because of the way lookup_collation() works: you could  
not use the collation, nor even drop it.  Seems better to give an  
error up front than to leave the user wondering why it doesn't work.  
  
(Because this test is in DefineCollation not CreateCollation, it does  
not prevent pg_import_system_collations from creating ICU collations,  
regardless of the initially-chosen encoding.)  
  
Per bug #17170 from Andrew Bille.  Back-patch to v10 where ICU support  
was added.  
  
Discussion: https://postgr.es/m/17170-95845cf3f0a9c36d@postgresql.org  

commit   : 2bb20e34c11fe1b11f84307a8bb683e865fbbf6d    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 2 Sep 2021 17:24:42 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 2 Sep 2021 17:24:42 -0400    

The IEEE 754 standard allows a wide variety of bit patterns for NaNs,  
of which at least two ("NaN" and "-NaN") are pretty easy to produce  
from SQL on most machines.  This is problematic because our btree  
comparison functions deem all NaNs to be equal, but our float hash  
functions know nothing about NaNs and will happily produce varying  
hash codes for them.  That causes unexpected results from queries  
that hash a column containing different NaN values.  It could also  
produce unexpected lookup failures when using a hash index on a  
float column, i.e. "WHERE x = 'NaN'" will not find all the rows  
it should.  
  
To fix, special-case NaN in the float hash functions, not too much  
unlike the existing special case that forces zero and minus zero  
to hash the same.  I arranged for the most vanilla sort of NaN  
(that coming from the C99 NAN constant) to still have the same  
hash code as before, to reduce the risk to existing hash indexes.  
  
I dithered about whether to back-patch this into stable branches,  
but ultimately decided to do so.  It's a clear improvement for  
queries that hash internally.  If there is anybody who has -NaN  
in a hash index, they'd be well advised to re-index after applying  
this patch ... but the misbehavior if they don't will not be much  
worse than the misbehavior they had before.  
  
Per bug #17172 from Ma Liangzhu.  
  
Discussion: https://postgr.es/m/17172-7505bea9e04e230f@postgresql.org  

commit   : 86dc1e0406822fee319db3e84a7ef3838e1480a8    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Thu, 2 Sep 2021 11:36:16 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Thu, 2 Sep 2021 11:36:16 +0900    

This makes the documentation more accurate grammatically.  
  
Author: Elena Indrupskaya  
Discussion: https://postgr.es/m/1c994b3d-951e-59bb-1ac2-7b9221c0e4cf@postgrespro.ru  
Backpatch-through: 9.6  

commit   : 387093e432253784f49cb0c129c882bb310b9d9b    
  
author   : Amit Kapila <akapila@postgresql.org>    
date     : Wed, 1 Sep 2021 09:46:03 +0530    
  
committer: Amit Kapila <akapila@postgresql.org>    
date     : Wed, 1 Sep 2021 09:46:03 +0530    

The check to test whether the subscription workers were restarting after a  
change in the subscription was failing. The reason was that the test was  
assuming the walsender started before it reaches the 'streaming' state and  
the walsender was exiting due to an error before that. Now, the walsender  
was erroring out before reaching the 'streaming' state because it tries to  
acquire the slot before the previous walsender has exited.  
  
In passing, improve the die messages so that it is easier to investigate  
the failures in the future if any.  
  
Reported-by: Michael Paquier, as per buildfarm  
Author: Ajin Cherian  
Reviewed-by: Masahiko Sawada, Amit Kapila  
Backpatch-through: 10, where this test was introduced  
Discussion: https://postgr.es/m/YRnhFxa9bo73wfpV@paquier.xyz  

commit   : ba8f1a0be5833338ddbf1cea3427f6baace3f4c8    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 31 Aug 2021 15:04:05 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 31 Aug 2021 15:04:05 -0400    

For no particularly good reason, getPolicies() queried pg_policy  
separately for each table.  We can collect all the policies in  
a single query instead, and attach them to the correct TableInfo  
objects using findTableByOid() lookups.  On the regression  
database, this reduces the number of queries substantially, and  
provides a visible savings even when running against a local  
server.  
  
Per complaint from Hubert Depesz Lubaczewski.  Since this is such  
a simple fix and can have a visible performance benefit, back-patch  
to all supported branches.  
  
Discussion: https://postgr.es/m/20210826084430.GA26282@depesz.com  

commit   : 0e7bdc722c65045d85161c6ae0125743ae93d185    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 31 Aug 2021 13:53:33 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 31 Aug 2021 13:53:33 -0400    

There's long been a "TODO: there might be some value in caching  
the results" annotation on pg_dump's getFormattedTypeName function;  
but we hadn't gotten around to checking what it was costing us to  
repetitively look up type names.  It turns out that when dumping the  
current regression database, about 10% of the total number of queries  
issued are duplicative format_type() queries.  However, Hubert Depesz  
Lubaczewski reported a not-unusual case where these account for over  
half of the queries issued by pg_dump.  Individually these queries  
aren't expensive, but when network lag is a factor, they add up to a  
problem.  We can very easily add some caching to getFormattedTypeName  
to solve it.  
  
Since this is such a simple fix and can have a visible performance  
benefit, back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/20210826084430.GA26282@depesz.com  

commit   : 6963e723f1dde295397a6a31b36775da7de8357b    
  
author   : Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 31 Aug 2021 19:21:29 +0200    
  
committer: Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 31 Aug 2021 19:21:29 +0200    

Commit 5be8ce82e8 added a new role to the stats_ext regression suite,  
but the role name did not start with regress_ causing failures when  
running with ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS. Fixed by  
renaming the role to start with the expected regress_ prefix.  
  
Backpatch-through: 10, same as the new regression test  
Discussion: https://postgr.es/m/1F238937-7CC2-4703-A1B1-6DC225B8978A%40enterprisedb.com  

commit   : bfb732c0e849705a04c7c07800edf7f407742f9f    
  
author   : Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 31 Aug 2021 18:03:05 +0200    
  
committer: Tomas Vondra <tomas.vondra@postgresql.org>    
date     : Tue, 31 Aug 2021 18:03:05 +0200    

When an ownership check on extended statistics object failed, the code  
was calling aclcheck_error_type to report the failure, which is clearly  
wrong, resulting in cache lookup errors. Fix by calling aclcheck_error.  
  
This issue exists since the introduction of extended statistics, so  
backpatch all the way back to PostgreSQL 10. It went unnoticed because  
there were no tests triggering the error, so add one.  
  
Reported-by: Mark Dilger  
Backpatch-through: 10, where extended stats were introduced  
Discussion: https://postgr.es/m/1F238937-7CC2-4703-A1B1-6DC225B8978A%40enterprisedb.com  

commit   : 02797ffa9a31db63a6cd499c67700c0de4863e4c    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 30 Aug 2021 16:29:12 -0400    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 30 Aug 2021 16:29:12 -0400    

Most data-corruption reports mention the location of the problem, but  
this one failed to.  Add it.  
  
Backpatch all the way back.  In 12 and older, also assign the  
ERRCODE_DATA_CORRUPTED error code as was done in commit fd6ec93bf890 for  
13 and later.  
  
Discussion: https://postgr.es/m/202108191637.oqyzrdtnheir@alvherre.pgsql  

commit   : 16cad4be32a44b9d05c594d1f53a60ea6e0f58b6    
  
author   : Amit Kapila <akapila@postgresql.org>    
date     : Mon, 30 Aug 2021 10:00:03 +0530    
  
committer: Amit Kapila <akapila@postgresql.org>    
date     : Mon, 30 Aug 2021 10:00:03 +0530    

ERRCODE_CONFIGURATION_LIMIT_EXCEEDED was used for checksum failure, use  
ERRCODE_DATA_CORRUPTED instead.  
  
Reported-by: Tatsuhito Kasahara  
Author: Tatsuhito Kasahara  
Backpatch-through: 9.6, where it was introduced  
Discussion: https://postgr.es/m/CAP0=ZVLHtYffs8SOWcFJWrBGoRzT9QQbk+_aP+E5AHLNXiOorA@mail.gmail.com  

commit   : f11c1bb17099834a3640a750b263e08f5e6f8135    
  
author   : Noah Misch <noah@leadboat.com>    
date     : Fri, 27 Aug 2021 23:33:23 -0700    
  
committer: Noah Misch <noah@leadboat.com>    
date     : Fri, 27 Aug 2021 23:33:23 -0700    

If the system crashed between CREATE TABLESPACE and the next checkpoint,  
the result could be some files in the tablespace unexpectedly containing  
no rows.  Affected files would be those for which the system did not  
write WAL; see the wal_skip_threshold documentation.  Before v13, a  
different set of conditions governed the writing of WAL; see v12's  
<sect2 id="populate-pitr">.  (The v12 conditions were broader in some  
ways and narrower in others.)  Users may want to audit non-default  
tablespaces for unexpected short files.  The bug could have truncated an  
index without affecting the associated table, and reindexing the index  
would fix that particular problem.  
  
This fixes the bug by making create_tablespace_directories() more like  
TablespaceCreateDbspace().  create_tablespace_directories() was  
recursively removing tablespace contents, reasoning that WAL redo would  
recreate everything removed that way.  That assumption holds for other  
wal_level values.  Under wal_level=minimal, the old approach could  
delete files for which no other copy existed.  Back-patch to 9.6 (all  
supported versions).  
  
Reviewed by Robert Haas and Prabhat Sahu.  Reported by Robert Haas.  
  
Discussion: https://postgr.es/m/CA+TgmoaLO9ncuwvr2nN-J4VEP5XyAcy=zKiHxQzBbFRxxGxm0w@mail.gmail.com  

commit   : 6a787c83c48a4d87d5aaa57776015ab77934d0ce    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 27 Aug 2021 19:42:42 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 27 Aug 2021 19:42:42 -0400    

Somehow, spgist overlooked the need to call pgstat_count_index_scan().  
Hence, pg_stat_all_indexes.idx_scan and equivalent columns never  
became nonzero for an SP-GiST index, although the related per-tuple  
counters worked fine.  
  
This fix works a bit differently from other index AMs, in that the  
counter increment occurs in spgrescan not spggettuple/spggetbitmap.  
It looks like this won't make the user-visible semantics noticeably  
different, so I won't go to the trouble of introducing an is-this-  
the-first-call flag just to make the counter bumps happen in the  
same places.  
  
Per bug #17163 from Christian Quest.  Back-patch to all supported  
versions.  
  
Discussion: https://postgr.es/m/17163-b8c5cc88322a5e92@postgresql.org  

commit   : 7c8f2c77108dd569f7fba3b42ca4e9f2452647ab    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Fri, 27 Aug 2021 22:50:19 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Fri, 27 Aug 2021 22:50:19 +0200    

Author: Dave Cramer <davecramer@gmail.com>  
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>  
Discussion: https://postgr.es/m/CADK3HHLZmqAQZ2ByPDQQ9yhGqax36kksq6sDkV0yYzsxw6ipvQ@mail.gmail.com  

commit   : 96f6ef9fe451aa07d0b9b744f41482e52bdd1b8a    
  
author   : Robert Haas <rhaas@postgresql.org>    
date     : Wed, 25 Aug 2021 08:32:04 -0400    
  
committer: Robert Haas <rhaas@postgresql.org>    
date     : Wed, 25 Aug 2021 08:32:04 -0400    

Pengchengliu reported an assertion failure in a parallel woker while  
performing a parallel scan using an overflowed snapshot. The proximate  
cause is that TransactionXmin was set to an incorrect value.  The  
underlying cause is incorrect snapshot handling in parallel.c.  
  
In particular, InitializeParallelDSM() was unconditionally calling  
GetTransactionSnapshot(), because I (rhaas) mistakenly thought that  
was always retrieving an existing snapshot whereas, at isolation  
levels less than REPEATABLE READ, it's actually taking a new one. So  
instead do this only at higher isolation levels where there actually  
is a single snapshot for the whole transaction.  
  
By itself, this is not a sufficient fix, because we still need to  
guarantee that TransactionXmin gets set properly in the workers. The  
easiest way to do that seems to be to install the leader's active  
snapshot as the transaction snapshot if the leader did not serialize a  
transaction snapshot. This doesn't affect the results of future  
GetTrasnactionSnapshot() calls since those have to take a new snapshot  
anyway; what we care about is the side effect of setting TransactionXmin.  
  
Report by Pengchengliu. Patch by Greg Nancarrow, except for some comment  
text which I supplied.  
  
Discussion: https://postgr.es/m/002f01d748ac$eaa781a0$bff684e0$@tju.edu.cn  

commit   : edc6d3a9806fc330e6c8fd603b0455c1693b10eb    
  
author   : Fujii Masao <fujii@postgresql.org>    
date     : Wed, 25 Aug 2021 11:43:56 +0900    
  
committer: Fujii Masao <fujii@postgresql.org>    
date     : Wed, 25 Aug 2021 11:43:56 +0900    

The distance in phrase operator must be an integer value between zero  
and MAXENTRYPOS inclusive. But previously the error message about  
its valid value included the information about its upper limit  
but not lower limit (i.e., zero). This commit improves the error message  
so that it also includes the information about its lower limit.  
  
Back-patch to v9.6 where full-text phrase search was supported.  
  
Author: Kyotaro Horiguchi  
Reviewed-by: Fujii Masao  
Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com  

commit   : 062c4c791937b3ee82d280a6a24d8c53f13c568e    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 24 Aug 2021 16:37:27 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 24 Aug 2021 16:37:27 -0400    

Regexps like "(.){0}...\1" drew an "invalid backreference number".  
That's not unreasonable on its face, since the capture group will  
never be matched if it's iterated zero times.  However, other engines  
such as Perl's don't complain about this, nor do we throw an error for  
related cases such as "(.)|\1", even though that backref can never  
succeed either.  Also, if the zero-iterations case happens at runtime  
rather than compile time --- say, "(x)*...\1" when there's no "x" to  
be found --- that's not an error, we just deem the backref to not  
match.  Making this even less defensible, no error was thrown for  
nested cases such as "((.)){0}...\2"; and to add insult to injury,  
those cases could result in assertion failures instead.  (It seems  
that nothing especially bad happened in non-assert builds, though.)  
  
Let's just fix it so that no error is thrown and instead the backref  
is deemed to never match, so that compile-time detection of no  
iterations behaves the same as run-time detection.  
  
Per report from Mark Dilger.  This appears to be an aboriginal error  
in Spencer's library, so back-patch to all supported versions.  
  
Pre-v14, it turns out to also be necessary to back-patch one aspect of  
commits cb76fbd7e/00116dee5, namely to create capture-node subREs with  
the begin/end states of their subexpressions, not the current lp/rp  
of the outer parseqatom invocation.  Otherwise delsub complains that  
we're trying to disconnect a state from itself.  This is a bit scary  
but code examination shows that it's safe: in the pre-v14 code, if we  
want to wrap iteration around the subexpression, the first thing we do  
is overwrite the atom's begin/end fields with new states.  So the  
bogus values didn't survive long enough to be used for anything, except  
if no iteration is required, in which case it doesn't matter.  
  
Discussion: https://postgr.es/m/A099E4A8-4377-4C64-A98C-3DEDDC075502@enterprisedb.com  

commit   : df87b7c441b1bf2c85f9a753e7750590c19da506    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 23 Aug 2021 17:41:07 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Mon, 23 Aug 2021 17:41:07 -0400    

The recursion in cdissect() was careless about clearing match data  
for capturing parentheses after rejecting a partial match.  This  
could allow a later back-reference to succeed when by rights it  
should fail for lack of a defined referent.  
  
To fix, think a little more rigorously about what the contract  
between different levels of cdissect's recursion needs to be.  
With the right spec, we can fix this using fewer rather than more  
resets of the match data; the key decision being that a failed  
sub-match is now explicitly responsible for clearing any matches  
it may have set.  
  
There are enough other cross-checks and optimizations in the code  
that it's not especially easy to exhibit this problem; usually, the  
match will fail as-expected.  Plus, regexps that are even potentially  
vulnerable are most likely user errors, since there's just not much  
point in writing a back-ref that doesn't always have a referent.  
These facts perhaps explain why the issue hasn't been detected,  
even though it's almost certainly a couple of decades old.  
  
Discussion: https://postgr.es/m/151435.1629733387@sss.pgh.pa.us  

commit   : 03c371d3c177ac05d22b25793ddebea7de9437ed    
  
author   : Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 23 Aug 2021 15:50:35 -0400    
  
committer: Alvaro Herrera <alvherre@alvh.no-ip.org>    
date     : Mon, 23 Aug 2021 15:50:35 -0400    

WAL records may span multiple segments, but XLogWrite() does not  
wait for the entire record to be written out to disk before  
creating archive status files.  Instead, as soon as the last WAL page of  
the segment is written, the archive status file is created, and the  
archiver may process it.  If PostgreSQL crashes before it is able to  
write and flush the rest of the record (in the next WAL segment), the  
wrong version of the first segment file lingers in the archive, which  
causes operations such as point-in-time restores to fail.  
  
To fix this, keep track of records that span across segments and ensure  
that segments are only marked ready-for-archival once such records have  
been completely written to disk.  
  
This has always been wrong, so backpatch all the way back.  
  
Author: Nathan Bossart <bossartn@amazon.com>  
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>  
Reviewed-by: Ryo Matsumura <matsumura.ryo@fujitsu.com>  
Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>  
Discussion: https://postgr.es/m/CBDDFA01-6E40-46BB-9F98-9340F4379505@amazon.com  

commit   : e0f2acf26062c6279b738738ae48e15bb5408c94    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 20 Aug 2021 14:19:04 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 20 Aug 2021 14:19:04 -0400    

After detecting a sub-match "dissect" failure (i.e., a backref match  
failure) in the i'th sub-match of an iteration node, we should proceed  
by adjusting the attempted length of the i'th submatch.  As coded,  
though, these functions changed the attempted length of the *last*  
sub-match, and only after exhausting all possibilities for that would  
they back up to adjust the next-to-last sub-match, and then the  
second-from-last, etc; all of which is wasted effort, since only  
changing the start or length of the i'th sub-match can possibly make  
it succeed.  This oversight creates the possibility for exponentially  
bad performance.  Fortunately the problem is masked in most cases by  
optimizations or constraints applied elsewhere; which explains why  
we'd not noticed it before.  But it is possible to reach the problem  
with fairly simple, if contrived, regexps.  
  
Oversight in my commit 173e29aa5.  That's pretty ancient now,  
so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/1808998.1629412269@sss.pgh.pa.us  

commit   : 2739a281060f0da5c71fd6601b00c95970de1e80    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 19 Aug 2021 12:12:36 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Thu, 19 Aug 2021 12:12:36 -0400    

transformLockingClause neglected to exclude the pseudo-RTEs for  
OLD/NEW when processing a rule's query.  This led to odd errors  
or even crashes later on.  This bug is very ancient, but it's  
not terribly surprising that nobody noticed, since the use-case  
for SELECT FOR UPDATE in a non-view rule is somewhere between  
thin and non-existent.  Still, crashing is not OK.  
  
Per bug #17151 from Zhiyong Wu.  Thanks to Masahiko Sawada  
for analysis of the problem.  
  
Discussion: https://postgr.es/m/17151-c03a3e6e4ec9aadb@postgresql.org  

commit   : 82ad7ecb428096d88394d0ee046ff950b73dff93    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 18 Aug 2021 18:12:51 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Wed, 18 Aug 2021 18:12:51 -0400    

Recursion into the FILTER clause was mis-implemented, such that a  
relevant Var or Aggref at the very top of the FILTER clause would  
be ignored.  (Of course, that'd have to be a plain boolean Var or  
boolean-returning aggregate.)  The consequence would be  
mis-identification of the correct semantic level of the aggregate,  
which could lead to not-per-spec query behavior.  If the FILTER  
expression is an aggregate, this could also lead to failure to issue  
an expected "aggregate function calls cannot be nested" error, which  
would likely result in a core dump later on, since the planner and  
executor aren't expecting such cases to appear.  
  
The root cause is that commit b560ec1b0 blindly copied some code  
that assumed it's recursing into a List, and thus didn't examine the  
top-level node.  To forestall questions about why this call doesn't  
look like the others, as well as possible future copy-and-paste  
mistakes, let's change all three check_agg_arguments_walker calls in  
check_agg_arguments, even though only the one for the filter clause  
is really broken.  
  
Per bug #17152 from Zhiyong Wu.  This has been wrong since we  
implemented FILTER, so back-patch to all supported versions.  
(Testing suggests that pre-v11 branches manage to avoid crashing  
in the bad-Aggref case, thanks to "redundant" checks in ExecInitAgg.  
But I'm not sure how thorough that protection is, and anyway the  
wrong-behavior issue remains, so fix 9.6 and 10 too.)  
  
Discussion: https://postgr.es/m/17152-c7f906cc1a88e61b@postgresql.org  

commit   : ef7e24ff7fc38ef460e3113f1e1cb73b232693c2    
  
author   : Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 17 Aug 2021 14:27:37 +0200    
  
committer: Daniel Gustafsson <dgustafsson@postgresql.org>    
date     : Tue, 17 Aug 2021 14:27:37 +0200    

In OpenSSL there are two types of BIO's (I/O abstractions):  
source/sink and filters. A source/sink BIO is a source and/or  
sink of data, ie one acting on a socket or a file. A filter  
BIO takes a stream of input from another BIO and transforms it.  
In order for BIO_find_type() to be able to traverse the chain  
of BIO's and correctly find all BIO's of a certain type they  
shall have the type bit set accordingly, source/sink BIO's  
(what PostgreSQL implements) use BIO_TYPE_SOURCE_SINK and  
filter BIO's use BIO_TYPE_FILTER. In addition to these, file  
descriptor based BIO's should have the descriptor bit set,  
BIO_TYPE_DESCRIPTOR.  
  
The PostgreSQL implementation didn't set the type bits, which  
went unnoticed for a long time as it's only really relevant  
for code auditing the OpenSSL installation, or doing similar  
tasks. It is required by the API though, so this fixes it.  
  
Backpatch through 9.6 as this has been wrong for a long time.  
  
Author: Itamar Gafni  
Discussion: https://postgr.es/m/SN6PR06MB39665EC10C34BB20956AE4578AF39@SN6PR06MB3966.namprd06.prod.outlook.com  
Backpatch-through: 9.6  

commit   : 7d6d1555926ae6c5b24016a3399b5cdf73fe712f    
  
author   : Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Tue, 17 Aug 2021 10:00:06 +0300    
  
committer: Heikki Linnakangas <heikki.linnakangas@iki.fi>    
date     : Tue, 17 Aug 2021 10:00:06 +0300    

The backslash sequences, including \123 and \x12 escapes, are interpreted  
after encoding conversion. The docs failed to mention that.  
  
Backpatch to all supported versions.  
  
Reported-by: Andreas Grob  
Discussion: https://www.postgresql.org/message-id/17142-9181542ca1df75ab%40postgresql.org  

commit   : 024fd44e0566fe2db264aaa3c6d45d0dfdd30b60    
  
author   : Michael Paquier <michael@paquier.xyz>    
date     : Mon, 16 Aug 2021 12:12:02 +0900    
  
committer: Michael Paquier <michael@paquier.xyz>    
date     : Mon, 16 Aug 2021 12:12:02 +0900    

This commit ensures that the wait interval in the replay delay loop  
waiting for an amount of time defined by recovery_min_apply_delay is  
correctly handled on reload, recalculating the delay if this GUC value  
is updated, based on the timestamp of the commit record being replayed.  
  
The previous behavior would be problematic for example with replay  
still waiting even if the delay got reduced or just cancelled.  If the  
apply delay was increased to a larger value, the wait would have just  
respected the old value set, finishing earlier.  
  
Author: Soumyadeep Chakraborty, Ashwin Agrawal  
Reviewed-by: Kyotaro Horiguchi, Michael Paquier  
Discussion: https://postgr.es/m/CAE-ML+93zfr-HLN8OuxF0BjpWJ17O5dv1eMvSE5jsj9jpnAXZA@mail.gmail.com  
Backpatch-through: 9.6  

commit   : 7915a9515cfb867d34c45f564daf70888274929f    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 13 Aug 2021 13:58:47 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Fri, 13 Aug 2021 13:58:47 -0400    

Like the ARM case, just use gcc's __sync_lock_test_and_set();  
that will compile into AMOSWAP.W.AQ which does what we need.  
  
At some point it might be worth doing some work on atomic ops  
for RISC-V, but this should be enough for a creditable port.  
  
Back-patch to all supported branches, just in case somebody  
wants to try them on RISC-V.  
  
Marek Szuba  
  
Discussion: https://postgr.es/m/dea97b6d-f55f-1f6d-9109-504aa7dfa421@gentoo.org  

commit   : 4874886b4c03f807e11f013352cf103cc7bfd345    
  
author   : David Rowley <drowley@postgresql.org>    
date     : Fri, 13 Aug 2021 16:44:18 +1200    
  
committer: David Rowley <drowley@postgresql.org>    
date     : Fri, 13 Aug 2021 16:44:18 +1200    

This fixes a bug in simplehash.h which caused an incorrect size mask to be  
used when the hash table grew to SH_MAX_SIZE (2^32).  The code was  
incorrectly setting the size mask to 0 when the hash tables reached the  
maximum possible number of buckets.  This would result always trying to  
use the 0th bucket causing an  infinite loop of trying to grow the hash  
table due to there being too many collisions.  
  
Seemingly it's not that common for simplehash tables to ever grow this big  
as this bug dates back to v10 and nobody seems to have noticed it before.  
However, probably the most likely place that people would notice it would  
be doing a large in-memory Hash Aggregate with something close to at least  
2^31 groups.  
  
After this fix, the code now works correctly with up to within 98% of 2^32  
groups and will fail with the following error when trying to insert any  
more items into the hash table:  
  
ERROR:  hash table size exceeded  
  
However, the work_mem (or hash_mem_multiplier in newer versions) settings  
will generally cause Hash Aggregates to spill to disk long before reaching  
that many groups.  The minimal test case I did took a work_mem setting of  
over 192GB to hit the bug.  
  
simplehash hash tables are used in a few other places such as Bitmap Index  
Scans, however, again the size that the hash table can become there is  
also limited to work_mem and it would take a relation of around 16TB  
(2^31) pages and a very large work_mem setting to hit this.  With smaller  
work_mem values the table would become lossy and never grow large enough  
to hit the problem.  
  
Author: Yura Sokolov  
Reviewed-by: David Rowley, Ranier Vilela  
Discussion: https://postgr.es/m/b1f7f32737c3438136f64b26f4852b96@postgrespro.ru  
Backpatch-through: 10, where simplehash.h was added  

commit   : d49e228a664dd868b6a034e730e99b4f510869a6    
  
author   : Thomas Munro <tmunro@postgresql.org>    
date     : Fri, 13 Aug 2021 10:38:22 +1200    
  
committer: Thomas Munro <tmunro@postgresql.org>    
date     : Fri, 13 Aug 2021 10:38:22 +1200    

It's hard to disable ASLR on current macOS releases, for testing with  
-DEXEC_BACKEND.  You could already set the environment variable  
PG_SHMEM_ADDR to something not likely to collide with mappings created  
earlier in process startup.  Let's also provide a default value that  
works on current releases and architectures, for developer convenience.  
  
As noted in the pre-existing comment, this is a horrible hack, but  
-DEXEC_BACKEND is only used by Unix-based PostgreSQL developers for  
testing some otherwise Windows-only code paths, so it seems excusable.  
  
Back-patch to all supported branches.  
  
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>  
Discussion: https://postgr.es/m/20210806032944.m4tz7j2w47mant26%40alap3.anarazel.de  

commit   : 843d2879aaefd870c978107e4c69b6681db49ca3    
  
author   : Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 10 Aug 2021 18:10:30 -0400    
  
committer: Tom Lane <tgl@sss.pgh.pa.us>    
date     : Tue, 10 Aug 2021 18:10:30 -0400    

As a result of confusion about whether the "char" type is signed or  
unsigned, scans for index searches like "col < 'x'" or "col <= 'x'"  
would start at the middle of the index not the left end, thus missing  
many or all of the entries they should find.  Fortunately, this  
is not a symptom of index corruption.  It's only the search logic  
that is broken, and we can fix it without unpleasant side-effects.  
  
Per report from Jason Kim.  This has been wrong since btree_gin's  
beginning, so back-patch to all supported branches.  
  
Discussion: https://postgr.es/m/20210810001649.htnltbh7c63re42p@jasonk.me