Previously, ExecInitModifyTable relied on ExecInitJunkFilter,
and thence ExecCleanTypeFromTL, to build the target descriptor from
the query tlist.  While we just checked (in ExecCheckPlanOutput)
that the tlist produces compatible output, this is not a great
substitute for the relation's actual tuple descriptor that's
available from the relcache.  For one thing, dropped columns will
not be correctly marked attisdropped; it's a bit surprising that
we've gotten away with that this long.  But the real reason for
being concerned with this is that using the table's descriptor means
that the slot will have correct attrmissing data, allowing us to
revert the klugy fix of commit ba9f18ab.  (This commit undoes
that one's changes in trigger.c, but keeps the new test case.)
Thus we can solve the bogus-trigger-tuple problem with fewer cycles
rather than more.

No back-patch, since this doesn't fix any additional bug, and it
seems somewhat more likely to have unforeseen side effects than
ba9f18ab's narrow fix.

Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org

These are old enough that they'll cause more confusion and distraction
to new readers, than they could help anyone upgrade from very old
servers.

Discussion: https://www.postgresql.org/message-id/fd93f1c5-7818-a02c-01e5-1075ac0d4def%40iki.fi

This is useful for checks of relation pages without having to load the
pages into the shared buffers, and two cases can make use of that: page
verification in base backups and the online, lock-safe, flavor.

Compatibility is kept with past versions using a macro that calls the
new extended routine with the set of options compatible with the
original version.

Extracted from a larger patch by the same author.

Author: Anastasia Lubennikova
Reviewed-by: Michael Paquier, Julien Rouhaud
Discussion: https://postgr.es/m/608f3476-0598-2514-2c03-e05c7d2b0cbd@postgrespro.ru

If the old row has any "missing" attributes that are supposed to
be retrieved from an associated tuple descriptor, the wrong things
happened because the trigger result is shoved directly into an
executor slot that lacks the missing-attribute data.  Notably,
CHECK-constraint verification would incorrectly see those columns
as NULL, and so would RETURNING-list evaluation.

Band-aid around this by forcibly expanding the tuple before passing
it to the trigger function.  (IMO it was a fundamental misdesign to
put the missing-attribute data into tuple constraints, which so
much of the system considers to be optional.  But we're probably
stuck with that now, and will have to continue to apply band-aids
as we find other places with similar issues.)

Back-patch to v12.  v11 would also have the issue, except that
commit 920311ab1 already applied a similar band-aid.  That forced
expansion in more cases than seem really necessary, though, so
this isn't a directly equivalent fix.

Amit Langote, with some cosmetic changes by me

Discussion: https://postgr.es/m/16644-5da7ef98a7ac4545@postgresql.org

Author: Zhijie Hou
Discussion: https://postgr.es/m/14cd74ea00204cc8a7ea5d738ac82cd1@G08CNEXMBPEKD05.g08.fujitsu.local
Backpatch-through: 12, where the mistake was introduced

We must not set the "done" flag until after we've executed the
initialization function.  Otherwise, other threads can fall through
the initial unlocked test before initialization is really complete.

This has been seen to cause rare failures of ecpg's thread/descriptor
test, and it could presumably cause other sorts of misbehavior in
threaded ECPG-using applications, since ecpglib relies on
pthread_once() in several places.

Diagnosis and patch by me, based on investigation by Alexander Lakhin.
Back-patch to all supported branches (the bug dates to 2007).

Discussion: https://postgr.es/m/16685-d6cd241872c101d3@postgresql.org

genhtml has been generating the following warning with this new code:
WARNING: function data mismatch at /path/src/common/unicode_norm.c:102

HTML coverage reports care about the uniqueness of functions defined in
source files, ignoring any assumptions around CFLAGS.  783f0cc6
introduced a duplicated definition of get_code_entry(), leading to a
warning and potentially some incorrect data generated in the reports.
This refactors the code so as the code has only one function
declaration, fixing the warning.

Oversight in 783f0cc6.

Reported-by: Tom Lane
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/207789.1603469272@sss.pgh.pa.us

This completes both the FORCE and NO FORCE options, NO INHERIT needing a
small adjustment.

Author: Li Japin
Discussion: https://postgr.es/m/15B10F9F-5847-4F5E-BD66-8E25AA473C95@hotmail.com

verify_heapam() wasn't being careful to sanity-check tuple line
pointers before using them, resulting in SIGBUS on alignment-picky
architectures.  Fix that, add some more test coverage.

Mark Dilger, some tweaking by me

Discussion: https://postgr.es/m/30B8E99A-2D9C-48D4-A55C-741C9D5F1563@enterprisedb.com

Instead of immediately PQfinish'ing a dead connection, save it aside
so that we can still extract its parameters for \connect attempts.
(This works because PQconninfo doesn't care whether the PGconn is in
CONNECTION_BAD state.)  This allows developers to reconnect with
just \c after a database crash and restart.

It's tempting to use the same approach instead of closing the old
connection after a failed non-interactive \connect command.  However,
that would not be very safe: consider a script containing
	\c db1 user1 live_server
	\c db2 user2 dead_server
	\c db3
The script would be expecting to connect to db3 at dead_server, but
if we re-use parameters from the first connection then it might
successfully connect to db3 at live_server.  This'd defeat the goal
of not letting a script accidentally execute commands against the
wrong database.

Discussion: https://postgr.es/m/38464.1603394584@sss.pgh.pa.us

The tests added by commit 866e24d4 failed on big-endian machines
due to lack of attention to endianness considerations.  Fix that.

While here, improve a few small cosmetic things, such as running
it through perltidy.

Mark Dilger

Discussion: https://postgr.es/m/30B8E99A-2D9C-48D4-A55C-741C9D5F1563@enterprisedb.com

The ExplainCloseGroup arguments for incremental sort usage data
didn't match the corresponding ExplainOpenGroup.  This only matters
for XML-format output, which is probably why we'd not noticed.

Daniel Gustafsson, per bug #16683 from Frits Jalvingh

Discussion: https://postgr.es/m/16683-8005033324ad34e9@postgresql.org

The order of AuthenticationGSSContinue and AuthenticationSSPI was
swapped, based on the other Authentication* protocol messages being
listed in subcode order.

The behavioural change in the -t/--table option happened around 15 years
ago and there seems little point in keeping it around.

Author: Ian Barwick
Discussion: https://www.postgresql.org/message-id/CAB8KJ%3Dh-XALik4M7gv-pX48%3D%2BSPWexfaYwa%2ByTnPwD3DxceXrg%40mail.gmail.com

Thinko in commit 1375422c. EvalPlanQualStart() was mistakenly
resetting the parent EState's es_result_relations, when it should
initialize the field in the child EPQ EState it just created.

That was clearly wrong, but it didn't cause any ill effects, because
es_result_relations is currently not used after the ExecInit* phase.

Author: Amit Langote
Discussion: https://www.postgresql.org/message-id/CA%2BHiwqFEuq8AAAmxXsTDVZ1r38cHbfYuiPQx_%3DYyKe2DC-6q4A%40mail.gmail.com

This replaces the existing binary search with two perfect hash functions
for the composition and the decomposition in the backend code, at the
cost of slightly-larger binaries there (35kB in libpgcommon_srv.a).  Per
the measurements done, this improves the speed of the recomposition and
decomposition by up to 30~40 times for the NFC and NFKC conversions,
while all other operations get at least 40% faster.  This is not as
"good" as what libicu has, but it closes the gap a lot as per the
feedback from Daniel Verite.

The decomposition table remains the same, getting used for the binary
search in the frontend code, where we care more about the size of the
libraries like libpq over performance as this gets involved only in code
paths related to the SCRAM authentication.  In consequence, note that
the perfect hash function for the recomposition needs to use a new
inverse lookup array back to to the existing decomposition table.

The size of all frontend deliverables remains unchanged, even with
--enable-debug, including libpq.

Author: John Naylor
Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/CAFBsxsHUuMFCt6-pU+oG-F1==CmEp8wR+O+bRouXWu6i8kXuqA@mail.gmail.com

DST law changes in Palestine, with a whopping 120 hours' notice.
Also some historical corrections for Palestine.

There's no functional change at all here, but I'm curious to see
whether this change successfully shuts up Coverity's warning about
a useless strcmp(), which appeared with the previous update.

Discussion: http://mm.icann.org/pipermail/tz/2020-October/029370.html

ECPG's PREPARE ... FROM and EXECUTE IMMEDIATE can optionally take
the target query as a simple literal, rather than the more usual
string-variable reference.  This was previously documented as
being a C string literal, but that's a lie in one critical respect:
you can't write a data double quote as \" in such literals.  That's
because the lexer is in SQL mode at this point, so it'll parse
double-quoted strings as SQL identifiers, within which backslash
is not special, so \" ends the literal.

I looked into making this work as documented, but getting the lexer
to switch behaviors at just the right point is somewhere between
very difficult and impossible.  It's not really worth the trouble,
because these cases are next to useless: if you have a fixed SQL
statement to execute or prepare, you might as well write it as
a direct EXEC SQL, saving the messiness of converting it into
a string literal and gaining the opportunity for compile-time
SQL syntax checking.

Instead, let's just document (and test) the workaround of writing
a double quote as an octal escape (\042) in such cases.

There's no code behavioral change here, so in principle this could
be back-patched, but it's such a niche case I doubt it's worth
the trouble.

Per report from 1250kv.

Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us

If you write the literal 'abc''def' in an EXEC SQL command, that will
come out the other end as 'abc'def', triggering a syntax error in the
backend.  Likewise, "abc""def" is reduced to "abc"def" which is wrong
syntax for a quoted identifier.

The cause is that the lexer thinks it should emit just one quote
mark, whereas what it really should do is keep the string as-is.

Add some docs and test cases, too.

Although this seems clearly a bug, I fear users wouldn't appreciate
changing it in minor releases.  Some may well be working around it
by applying an extra doubling of affected quotes, as for example
sql/dyntest.pgc has been doing.

Per investigation of a report from 1250kv, although this isn't
exactly what he/she was on about.

Discussion: https://postgr.es/m/673825.1603223178@sss.pgh.pa.us

Mark Dilger, with a couple of stray semicolons removed by me.

Discussion: http://postgr.es/m/2A7DA1A8-C4AA-43DF-A985-3CA52F4DC775@enterprisedb.com

The check for whether to complain about not having an old connection
to get parameters from was seriously out of date: it had not been
rethought when we invented connstrings, nor when we invented the
-reuse-previous option.  Replace it with a check that throws an
error if reuse-previous is active and we lack an old connection to
reuse.  While that doesn't move the goalposts very far in terms of
easing reconnection after a server crash, at least it's consistent.

If the user specifies a connstring plus additional parameters
(which is invalid per the documentation), the extra parameters were
silently ignored.  That seems like it could be really confusing,
so let's throw a syntax error instead.

Teach the connstring code path to re-use the old connection's password
in the same cases as the old-style-syntax code path would, ie if we
are reusing parameters and the values of username, host/hostaddr, and
port are not being changed.  Document this behavior, too, since it was
unmentioned before.  Also simplify the implementation a bit, giving
rise to two new and useful properties: if there's a "password=xxx" in
the connstring, we'll use it not ignore it, and by default (i.e.,
except with --no-password) we will prompt for a password if the
re-used password or connstring password doesn't work.  The previous
code just failed if the re-used password didn't work.

Given the paucity of field complaints about these issues, I don't
think that they rise to the level of back-patchable bug fixes,
and in any case they might represent undesirable behavior changes
in minor releases.  So no back-patch.

Discussion: https://postgr.es/m/235210.1603321144@sss.pgh.pa.us

Mark Dilger, reviewed by Peter Geoghegan, Andres Freund, Álvaro Herrera,
Michael Paquier, Amul Sul, and by me. Some last-minute cosmetic
revisions by me.

Discussion: http://postgr.es/m/12ED3DA8-25F0-4B68-937D-D907CFBF08E7@enterprisedb.com

There is a handful of places where we called list_delete_ptr() to remove
some element from a List.  In many of these places we know, or with very
little additional effort know the index of the ListCell that we need to
remove.

Here we change all of those places to instead either use one of;
list_delete_nth_cell(), foreach_delete_current() or list_delete_last().
Each of these saves from having to iterate over the list to search for the
element to remove by its pointer value.

There are some small performance gains to be had by doing this, but in the
general case, none of these lists are likely to be very large, so the
lookup was probably never that expensive anyway.  However, some of the
calls are in fairly hot code paths, e.g process_equivalence().  So any
small gains there are useful.

Author: Zhijie Hou and David Rowley
Discussion: https://postgr.es/m/b3517353ec7c4f87aa560678fbb1034b@G08CNEXMBPEKD05.g08.fujitsu.local

psql's \connect claims to be able to re-use previous connection
parameters, but in fact it only re-uses the database name, user name,
host name (and possibly hostaddr, depending on version), and port.
This is problematic for assorted use cases.  Notably, pg_dump[all]
emits "\connect databasename" commands which we would like to have
re-use all other parameters.  If such a script is loaded in a psql run
that initially had "-d connstring" with some non-default parameters,
those other parameters would be lost, potentially causing connection
failure.  (Thus, this is the same kind of bug addressed in commits
a45bc8a4 and 8e5793ab, although the details are much different.)

To fix, redesign do_connect() so that it pulls out all properties
of the old PGconn using PQconninfo(), and then replaces individual
properties in that array.  In the case where we don't wish to re-use
anything, get libpq's default settings using PQconndefaults() and
replace entries in that, so that we don't need different code paths
for the two cases.

This does result in an additional behavioral change for cases where
the original connection parameters allowed multiple hosts, say
"psql -h host1,host2", and the \connect request allows re-use of the
host setting.  Because the previous coding relied on PQhost(), it
would only permit reconnection to the same host originally selected.
Although one can think of scenarios where that's a good thing, there
are others where it is not.  Moreover, that behavior doesn't seem to
meet the principle of least surprise, nor was it documented; nor is
it even clear it was intended, since that coding long pre-dates the
addition of multi-host support to libpq.  Hence, this patch is content
to drop it and re-use the host list as given.

Per Peter Eisentraut's comments on bug #16604.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/16604-933f4b8791227b15@postgresql.org

Should cause tests to be a bit faster

Theoretically one could go into src/test/thread and build/run this
program there.  In practice, that hasn't worked since 96bf88d5,
and probably much longer on some platforms (likely including just
the sort of hoary leftovers where this test might be of interest).
While it wouldn't be too hard to repair the breakage, the fact that
nobody has noticed for two years shows that there is zero usefulness
in maintaining this build pathway.  Let's get rid of it and decree
that thread_test.c is *only* meant to be built/used in configure.

Given that decision, it makes sense to put thread_test.c under config/
and get rid of src/test/thread altogether, so that's what I did.

In passing, update src/test/README, which had been ignored by some
not-so-recent additions of subdirectories.

Discussion: https://postgr.es/m/227659.1603041612@sss.pgh.pa.us

Commit 8dace66e added #ifdefs for a
number of errno symbols because they were not present on Windows.
Later, commit 125ad539 added
replacement #defines for some of those symbols.  So some of the
changes from the first commit are made dead code by the second commit
and can now be removed.

Discussion: https://www.postgresql.org/message-id/flat/6dee8574-b0ad-fc49-9c8c-2edc796f0033@2ndquadrant.com

After de8feb1f, some warnings remained
that were only visible when using GCC on Windows.  Fix those as well.

Note that the ecpg test source files don't use the full pg_config.h,
so we can't use pg_funcptr_t there but have to do it the long way.

80f8eb79 has added to the normalization quick check headers some code
generated by PerfectHash.pm that is incompatible with the settings of
gitattributes for this repository, as whitespaces followed a set of tabs
for the first element of a line in the table.  Instead of adding a new
exception to gitattributes, rework the format generated so as a right
padding with spaces is used instead of a left padding.  This keeps the
table generated in a readable shape with its set of columns, making
unnecessary an update of gitattributes.

Reported-by: Peter Eisentraut
Author: John Naylor
Discussion: https://postgr.es/m/d601b3b5-a3c7-5457-2f84-3d6513d690fc@2ndquadrant.com

More precisely, correctly handle the ONLY flag indicating not to
recurse.  This was implemented in 86f57594 by recursing in
trigger.c, but that's the wrong place; use ATSimpleRecursion instead,
which behaves properly.  However, because legacy inheritance has never
recursed in that situation, make sure to do that only for new-style
partitioning.

I noticed this problem while testing a fix for another bug in the
vicinity.

This has been wrong all along, so backpatch to 11.

Discussion: https://postgr.es/m/20201016235925.GA29829@alvherre.pgsql

Change the attribute 'name' to 'slot_name' in pg_stat_replication_slots
view to make it clear and that way we will be consistent with the other
places like pg_stat_wal_receiver view where we display the same attribute.

In the passing, fix the typo in one of the macros in the related code.

Bump the catversion as we have modified the name in the catalog as well.

Reported-by: Noriyoshi Shinoda
Author: Noriyoshi Shinoda
Reviewed-by: Sawada  Masahiko and Amit Kapila
Discussion: https://postgr.es/m/CA+fd4k5_pPAYRTDrO2PbtTOe0eHQpBvuqmCr8ic39uTNmR49Eg@mail.gmail.com

When told to process all databases, clusterdb, reindexdb, and vacuumdb
would reconnect by replacing their --maintenance-db parameter with the
name of the target database.  If that parameter is a connstring (which
has been allowed for a long time, though we failed to document that
before this patch), we'd lose any other options it might specify, for
example SSL or GSS parameters, possibly resulting in failure to connect.
Thus, this is the same bug as commit a45bc8a4 fixed in pg_dump and
pg_restore.  We can fix it in the same way, by using libpq's rules for
handling multiple "dbname" parameters to add the target database name
separately.  I chose to apply the same refactoring approach as in that
patch, with a struct to handle the command line parameters that need to
be passed through to connectDatabase.  (Maybe someday we can unify the
very similar functions here and in pg_dump/pg_restore.)

Per Peter Eisentraut's comments on bug #16604.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/16604-933f4b8791227b15@postgresql.org

Since commit 913bbd88, check_sql_fn_retval() can either insert type
coercion steps in-line in the Query that produces the SQL function's
results, or generate a new top-level Query to perform the coercions,
if modifying the Query's output in-place wouldn't be safe.  However,
it appears that the latter case has never actually worked, because
the code tried to inject the new Query back into the query list it was
passed ... which is not the list that will be used for later processing
when we execute the SQL function "normally" (without inlining it).
So we ended up with no coercion happening at run-time, leading to
wrong results or crashes depending on the datatypes involved.

While the regression tests look like they cover this area well enough,
through a huge bit of bad luck all the test cases that exercise the
separate-Query path were checking either inline-able cases (which
accidentally didn't have the bug) or cases that are no-ops at runtime
(e.g., varchar to text), so that the failure to perform the coercion
wasn't obvious.  The fact that the cases that don't work weren't
allowed at all before v13 probably contributed to not noticing the
problem sooner, too.

To fix, get rid of the separate "flat" list of Query nodes and instead
pass the real two-level list that is going to be used later.  I chose
to make the same change in check_sql_fn_statements(), although that has
no actual bug, just so that we don't need that data structure at all.

This is an API change, as evidenced by the adjustments needed to
callers outside functions.c.  That's a bit scary to be doing in a
released branch, but so far as I can tell from a quick search,
there are no outside callers of these functions (and they are
sufficiently specific to our semantics for SQL-language functions that
it's not apparent why any extension would need to call them).  In any
case, v13 already changed the API of check_sql_fn_retval() compared to
prior branches.

Per report from pinker.  Back-patch to v13 where this code came in.

Discussion: https://postgr.es/m/1603050466566-0.post@n3.nabble.com

- Misc grammar and punctuation fixes.

- Stylistic cleanup: use spaces between function arguments and JSON fields
  in examples. For example "foo(a,b)" -> "foo(a, b)". Add semicolon after
  last END in a few PL/pgSQL examples that were missing them.

- Make sentence that talked about "..." and ".." operators more clear,
  by avoiding to end the sentence with "..". That makes it look the same
  as "..."

- Fix syntax description for HAVING: HAVING conditions cannot be repeated

Patch by Justin Pryzby, per Yaroslav Schekin's report. Backpatch to all
supported versions, to the extent that the patch applies easily.

Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com

ALTER SEQUENCE RESTART was made transactional in commit 3d79013b.
Backpatch to v10, where that was introduced.

Patch by Justin Pryzby, per Yaroslav Schekin's report.

Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com

The output for this query changed in commit 4e2477b7b8. Backport to 9.6
like that commit.

Patch by Justin Pryzby, per Yaroslav Schekin's report.

Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com

Commit 028350f6 changed its behavior from "at most" to "exactly", but
forgot to update the documentation. Backpatch to 9.6.

Patch by Justin Pryzby, per Yaroslav Schekin's report.

Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com

Author: Daniel Gustafsson <daniel@yesql.se>
Discussion: https://postgr.es/m/A05874AE-8771-4C61-A24E-0B6249B8F3C2@yesql.se