bf68b79e introduced an unused variable
compiler warning on Cygwin.

Change all the auxiliary error-reporting routines to return void,
now that we no longer need to pretend they are passing something
useful to errfinish().  While this probably doesn't save anything
significant at the machine-code level, it allows detection of some
additional types of mistakes.

Pass the error location details (__FILE__, __LINE__, PG_FUNCNAME_MACRO)
to errfinish not errstart.  This shaves a few cycles off the case where
errstart decides we're not going to emit anything.

Re-implement elog() as a trivial wrapper around ereport(), removing
the separate support infrastructure it used to have.  Aside from
getting rid of some now-surplus code, this means that elog() now
really does have exactly the same semantics as ereport(), in particular
that it can skip evaluation work if the message is not to be emitted.

Andres Freund and Tom Lane

Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com

Now that we require C99, we can depend on __VA_ARGS__ to work, and
revising ereport() to use it has several significant benefits:

* The extra parentheses around the auxiliary function calls are now
optional.  Aside from being a bit less ugly, this removes a common
gotcha for new contributors, because in some cases the compiler errors
you got from forgetting them were unintelligible.

* The auxiliary function calls are now evaluated as a comma expression
list rather than as extra arguments to errfinish().  This means that
compilers can be expected to warn about no-op expressions in the list,
allowing detection of several other common mistakes such as forgetting
to add errmsg(...) when converting an elog() call to ereport().

* Unlike the situation with extra function arguments, comma expressions
are guaranteed to be evaluated left-to-right, so this removes platform
dependency in the order of the auxiliary function calls.  While that
dependency hasn't caused us big problems in the past, this change does
allow dropping some rather shaky assumptions around errcontext() domain
handling.

There's no intention to make wholesale changes of existing ereport
calls, but as proof-of-concept this patch removes the extra parens
from a couple of calls in postgres.c.

While new code can be written either way, code intended to be
back-patched will need to use extra parens for awhile yet.  It seems
worth back-patching this change into v12, so as to reduce the window
where we have to be careful about that by one year.  Hence, this patch
is careful to preserve ABI compatibility; a followup HEAD-only patch
will make some additional simplifications.

Andres Freund and Tom Lane

Discussion: https://postgr.es/m/CA+fd4k6N8EjNvZpM8nme+y+05mz-SM8Z_BgkixzkA34R+ej0Kw@mail.gmail.com

A variable was unused in non-assert builds.  Simplify the code to
avoid the issue.
Reported-by: Erik Rijkers <er@xs4all.nl>

Sloppiness in commit cedffbdb, noted by Erikjan Rijkers.
(It's fairly unfortunate that xmllint doesn't catch this.)

Discussion: https://postgr.es/m/2e3dc9e4bfa4802d2c9f5fe15bde44de@xs4all.nl

This moves the main operations of apply_handle_{insert|update|delete},
that of inserting, updating, deleting a tuple into/from a given
relation, into corresponding
apply_handle_{insert|update|delete}_internal functions.  This allows
performing those operations on relations that are not directly the
targets of replication, which is something a later patch will use for
targeting partitioned tables.

Author: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Rafia Sabih <rafia.pghackers@gmail.com>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/CA+HiwqH=Y85vRK3mOdjEkqFK+E=ST=eQiHdpj43L=_eJMOOznQ@mail.gmail.com

It previously only supported NFKC, for use by SASLprep.  This expands
the API to offer the choice of all four normalization forms.  Right
now, there are no internal users of the forms other than NFKC.
Reviewed-by: Daniel Verite <daniel@manitou-mail.org>
Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Discussion: https://www.postgresql.org/message-id/flat/c1909f27-c269-2ed9-12f8-3ab72c8caf7a@2ndquadrant.com

Author: Justin Pryzby
Discussion: https://postgr.es/m/20200321040750.GD13662@telsasoft.com

Previously if a promotion was triggered while recovery was paused,
the paused state continued. Also recovery could be paused by executing
pg_wal_replay_pause() even while a promotion was ongoing. That is,
recovery pause had higher priority over a standby promotion.
But this behavior was not desirable because most users basically wanted
the recovery to complete as soon as possible and the server to become
the master when they requested a promotion.

This commit changes recovery so that it prefers a promotion over
recovery pause. That is, if a promotion is triggered while recovery
is paused, the paused state ends and a promotion continues. Also
this commit makes recovery pause functions like pg_wal_replay_pause()
throw an error if they are executed while a promotion is ongoing.

Internally, this commit adds new internal function PromoteIsTriggered()
that returns true if a promotion is triggered. Since the name of
this function and the existing function IsPromoteTriggered() are
confusingly similar, the commit changes the name of IsPromoteTriggered()
to IsPromoteSignaled, as more appropriate name.

Author: Fujii Masao
Reviewed-by: Atsushi Torikoshi, Sergei Kornilov
Discussion: https://postgr.es/m/00c194b2-dbbb-2e8a-5b39-13f14048ef0a@oss.nttdata.com

restore_command has only been used until now by the backend, but there
is a pending patch for pg_rewind to make use of that in the frontend.

Author: Alexey Kondratov
Reviewed-by: Andrey Borodin, Andres Freund, Alvaro Herrera, Alexander
Korotkov, Michael Paquier
Discussion: https://postgr.es/m/a3acff50-5a0d-9a2c-b3b2-ee36168955c1@postgrespro.ru

This commit introduces new wait events BackupWaitWalArchive and
RecoveryPause. The former is reported while waiting for the WAL files
required for the backup to be successfully archived. The latter is
reported while waiting for recovery in pause state to be resumed.

Author: Fujii Masao
Reviewed-by: Michael Paquier, Atsushi Torikoshi, Robert Haas
Discussion: https://postgr.es/m/f0651f8c-9c96-9f29-0ff9-80414a15308a@oss.nttdata.com

Discussion: https://postgr.es/m/23196.1584943506@sss.pgh.pa.us

Previously 0 was reported in pg_stat_progress_basebackup.total_backup
if the total backup size was not estimated. Per discussion, our consensus
is that NULL is better choise as the value in total_backup in that case.
So this commit makes pg_stat_progress_basebackup view report NULL
in total_backup column if the estimation is disabled.

Bump catversion.

Author: Fujii Masao
Reviewed-by: Amit Langote, Magnus Hagander, Alvaro Herrera
Discussion: https://postgr.es/m/CABUevExnhOD89zBDuPvfAAh243RzNpwCPEWNLtMYpKHMB8gbAQ@mail.gmail.com

Justin Pryzby raised a couple issues with commit 1f39bce0. Fixed.

Also, tweak the way the size of a hash entry is estimated and the
number of buckets is estimated when calling BuildTupleHashTableExt().

Discussion: https://www.postgresql.org/message-id/20200319064222.GR26184@telsasoft.com

backend_type was added to the CVS log output in commit 70a7b477.

Reported-by: Fabrízio de Royes Mello

Discussion: https://postgr.es/m/CAFcNs+ruvRks3BV1j7yQ-MvxsswmKJa0cVh2yK5Dd-xXVM8wPw@mail.gmail.com

Backpatch-through: master

While #16293 only applied to 11 (and 10 to some degree), it seems best
to add tests to all branches with partitioning support.

Reported-By: Daniel WM
Author: Andres Freund
Bug: #16293
Discussion: https://postgr.es/m/16293-26f5777d10143a66@postgresql.org
Backpatch: 10-

This wasn't stated anywhere, and it's perhaps not that obvious,
since we get questions about it from time to time.  Also undocumented
was that the parser actually translates these into operators.

Discussion: https://postgr.es/m/CAFj8pRBkvZ71BqGKZnBBG4=0cKG+s50Dy+DYmrizUKEpAtdc+w@mail.gmail.com

src/port/getopt_long.c failed on such an argument, always seeing it
as an unrecognized switch.  This is unhelpful; better is to treat such
an item as a non-switch argument.  That behavior is what we find in
GNU's getopt_long(); it's what src/port/getopt.c does; and it is
required by POSIX for getopt(), which getopt_long() ought to be
generally a superset of.  Moreover, it's expected by ecpg, which
intends an argument of "-" to mean "read from stdin".  So fix it.

Also add some documentation about ecpg's behavior in this area, since
that was miserably underdocumented.  I had to reverse-engineer it
from the code.

Per bug #16304 from James Gray.  Back-patch to all supported branches,
since this has been broken forever.

Discussion: https://postgr.es/m/16304-c662b00a1322db7f@postgresql.org

autovacuum_vacuum_scale_factor and autovacuum_analyze_scale_factor have
been documented as "float4", but "floating type" is used in this case
for GUCs and relation options in the documentation.

Author: Atsushi Torikoshi
Discussion: https://postgr.es/m/CACZ0uYFf_p9BpbjLccx3CA=eM1Hk2Te=ULY4iptGLUhL-JxCPA@mail.gmail.com
Backpatch-through: 9.5

This reverts commit b7f64c64, which broke the fallback implementation for
C++.  We have discussed a couple of alternatives to reduce the number of
implementations for those asserts, but nothing allowing to reduce the
number of implementations down to three instead of four, so there is no
benefit in keeping this patch.

Thanks to Tom Lane for the discussion.

Discussion: https://postgr.es/m/20200313115033.GA183471@paquier.xyz

All errors of SQLSTATE class 23 should include the name of an object
associated with the error in separate fields of the error report message.
We do this so that applications need not try to extract them from the
possibly-localized human-readable text of the message.

Reported-by: Chris Bandy
Author: Chris Bandy
Reviewed-by: Amit Kapila and Amit Langote
Discussion: https://postgr.es/m/0aa113a3-3c7f-db48-bcd8-f9290b2269ae@gmail.com

Mixing incorrect bounds in the SSL context leads to confusing error
messages generated by OpenSSL which are hard to act on.  New range
checks are added when both min/max parameters are loaded in the context
of a SSL reload to improve the error reporting.  Note that this does not
make use of the GUC hook machinery contrary to 41aadeeb, as there is no
way to ensure a consistent range check (except if there is a way one day
to define range types for GUC parameters?).  Hence, this patch applies
only to OpenSSL, and uses a logic similar to other parameters to trigger
an error when reloading the SSL context in a session.

Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/20200114035420.GE1515@paquier.xyz

This reverts commit cb2fd7ea.  Per
numerous buildfarm members, it was incompatible with parallel query, and
a test case assumed LP64.  Back-patch to 9.5 (all supported versions).

Discussion: https://postgr.es/m/20200321224920.GB1763544@rfd.leadboat.com

headerscheck and cpluspluscheck should skip the recently-added
cmdtaglist.h header, since (like kwlist.h and some other similarly-
designed headers) it's not meant to be included standalone.

evtcache.h was missing an #include to support its usage of Bitmapset.

typecmds.h was missing an #include to support its usage of ParseState.

The first two of these were evidently oversights in commit 2f966131.
I didn't track down exactly which change broke typecmds.h, but it
must have been some rearrangement in one of its existing inclusions,
because it's referenced ParseState for quite a long time and there
were not complaints from these checking programs before.

Until now, only selected bulk operations (e.g. COPY) did this.  If a
given relfilenode received both a WAL-skipping COPY and a WAL-logged
operation (e.g. INSERT), recovery could lose tuples from the COPY.  See
src/backend/access/transam/README section "Skipping WAL for New
RelFileNode" for the new coding rules.  Maintainers of table access
methods should examine that section.

To maintain data durability, just before commit, we choose between an
fsync of the relfilenode and copying its contents to WAL.  A new GUC,
wal_skip_threshold, guides that choice.  If this change slows a workload
that creates small, permanent relfilenodes under wal_level=minimal, try
adjusting wal_skip_threshold.  Users setting a timeout on COMMIT may
need to adjust that timeout, and log_min_duration_statement analysis
will reflect time consumption moving to COMMIT from commands like COPY.

Internally, this requires a reliable determination of whether
RollbackAndReleaseCurrentSubTransaction() would unlink a relation's
current relfilenode.  Introduce rd_firstRelfilenodeSubid.  Amend the
specification of rd_createSubid such that the field is zero when a new
rel has an old rd_node.  Make relcache.c retain entries for certain
dropped relations until end of transaction.

Back-patch to 9.5 (all supported versions).  This introduces a new WAL
record type, XLOG_GIST_ASSIGN_LSN, without bumping XLOG_PAGE_MAGIC.  As
always, update standby systems before master systems.  This changes
sizeof(RelationData) and sizeof(IndexStmt), breaking binary
compatibility for affected extensions.  (The most recent commit to
affect the same class of extensions was
089e4d405d0f3b94c74a2c6a54357a84a681754b.)

Kyotaro Horiguchi, reviewed (in earlier, similar versions) by Robert
Haas.  Heikki Linnakangas and Michael Paquier implemented earlier
designs that materially clarified the problem.  Reviewed, in earlier
designs, by Andrew Dunstan, Andres Freund, Alvaro Herrera, Tom Lane,
Fujii Masao, and Simon Riggs.  Reported by Martijn van Oosterhout.

Discussion: https://postgr.es/m/20150702220524.GA9392@svana.org

The function assumed forkNum=MAIN_FORKNUM and page_std=true, ignoring
the actual arguments.  Existing callers passed exactly those values, so
there's no live bug.  Back-patch to v12, where the function first
appeared, because another fix needs this.

Discussion: https://postgr.es/m/20191118045434.GA1173436@rfd.leadboat.com

swap_relation_files() calls toast_get_valid_index() to find and lock
this index, just before swapping with the rebuilt TOAST index.  The
latter function releases the lock before returning.  Potential for
mischief is low; a concurrent session can issue ALTER INDEX ... SET
(fillfactor = ...), which is not alarming.  Nonetheless, changing
pg_class.relfilenode without a lock is unconventional.  Back-patch to
9.5 (all supported versions), because another fix needs this.

Discussion: https://postgr.es/m/20191226001521.GA1772687@rfd.leadboat.com

Remove an obsolete comment from AtEOXact_cleanup().  Restore formatting
of a comment in struct RelationData, mangled by the pgindent run in
commit 9af4159f.  Back-patch to 9.5 (all
supported versions), because another fix stacks on this.

This is required as it is no safer for two related processes to perform
clean up in gin indexes at a time than for unrelated processes to do the
same.  After acquiring page locks, we can acquire relation extension lock
but reverse never happens which means these will also not participate in
deadlock.  So, avoid checking wait edges from this lock.

Currently, the parallel mode is strictly read-only, but after this patch
we have the infrastructure to allow parallel inserts and parallel copy.

Author: Dilip Kumar, Amit Kapila
Reviewed-by: Amit Kapila, Kuntal Ghosh and Sawada Masahiko
Discussion: https://postgr.es/m/CAD21AoCmT3cFQUN4aVvzy5chw7DuzXrJCbrjTU05B+Ss=Gn1LA@mail.gmail.com

The current doc query specified an alias in the FROM clause and used in
it the target list, but not in the WHERE clause.

Reported-by: axykon@gmail.com

Discussion: https://postgr.es/m/158316348159.30450.16075357948244298217@wrigleys.postgresql.org

Backpatch-through: 9.5

Noticed by Erik Rijkers before I was able to push the fix.

Author: Luis Carril
Reviewed-by: Tomas Vondra, Daniel Gustafsson, Álvaro Herrera
Discussion: https://postgr.es/m/LEJPR01MB0185A19B2E7C98E5E2A031F5E7F20@LEJPR01MB0185.DEUPRD01.PROD.OUTLOOK.DE

These are disabled by the configure code, so this is just fixing an
inconsistency in the MSVC code.

Backpatch to all live branches.

Errors (for example I/O errors or disk full) while printing out result
tables were completely ignored, which could result in silently
truncated output in scripts, for example.  Fix by adding some basic
error checking and reporting.

Author: Daniel Verite <daniel@manitou-mail.org>
Author: David Zhang <david.zhang@highgo.ca>
Discussion: https://www.postgresql.org/message-id/flat/9a0b3c8d-ee14-4b1d-9d0a-2c993bdabacc@manitou-mail.org

This is required as it is no safer for two related processes to extend the
same relation at a time than for unrelated processes to do the same.  We
don't acquire a heavyweight lock on any other object after relation
extension lock which means such a lock can never participate in the
deadlock cycle.  So, avoid checking wait edges from this lock.

This provides an infrastructure to allow parallel operations like insert,
copy, etc. which were earlier not possible as parallel group members won't
conflict for relation extension lock.

Author: Dilip Kumar, Amit Kapila
Reviewed-by: Amit Kapila, Kuntal Ghosh and Sawada Masahiko
Discussion: https://postgr.es/m/CAD21AoCmT3cFQUN4aVvzy5chw7DuzXrJCbrjTU05B+Ss=Gn1LA@mail.gmail.com

Remove comments that are a throw back to a time when nbtree cared about
write-ordering dependencies.  The comments are similar to those removed
by commit 9ee7414e, among others.

This reverts commit e00912e1.

This patch fixes the error message in get_major_server_version() to be
"could not parse version file", and uses the full file path name, rather
than just the data directory path.

Also, commit 4109bb5d added the cause of the failure to the  "could
not open" error message, and improved quoting.  This patch backpatches
the "could not open" cause to PG 12, where it was first widely used, and
backpatches the quoting fix in that patch to all supported releases.

Reported-by: Tom Lane

Discussion: https://postgr.es/m/87pne2w98h.fsf@wibble.ilmari.org

Author: Dagfinn Ilmari Mannsåker

Backpatch-through: 9.5