This extends the work done in commit 2f5c9d9c to provide a more nearly
complete abstraction layer hiding the details of index updating for catalog
changes.  That commit only invented abstractions for catalog inserts and
updates, leaving nearby code for catalog deletes still calling the
heap-level routines directly.  That seems rather ugly from here, and it
does little to help if we ever want to shift to a storage system in which
indexing work is needed at delete time.

Hence, create a wrapper function CatalogTupleDelete(), and replace calls
of simple_heap_delete() on catalog tuples with it.  There are now very
few direct calls of [simple_]heap_delete remaining in the tree.

Discussion: https://postgr.es/m/462.1485902736@sss.pgh.pa.us

Commit a84069d9 added a new type of
DestReceiver to avoid duplicating the existing code for the SHOW
command, but it turns out we can leverage that new DestReceiver
type in a few more places, saving some code.

Michael Paquier, reviewed by Andres Freund and by me.

Discussion: http://postgr.es/m/CAB7nPqSdFOQC0evc0r1nJeQyGBqjBrR41MC4rcMqUUpoJaZbtQ%40mail.gmail.com
Discussion: http://postgr.es/m/CAB7nPqT2K4XFT1JgqufFBjsOc-NUKXg5qBDucHPMbk6Xi1kYaA@mail.gmail.com

"\set" with no arguments displays all defined variables, but it does so
in the order that they appear in variables.c's list, which previously
was mostly creation order.  That makes the list ugly and hard to find
things in, and it exposes some psql implementation details to users.
(For instance, ordinary variables will move to the bottom of the list
if unset and set again, but variables that have hooks won't.)

Fix that by keeping the list in alphabetical order at all times, which
isn't much more complicated than breaking out of the insertion search
loops once we reach an entry that should be after the one to be inserted.

Discussion: https://postgr.es/m/31785.1485900786@sss.pgh.pa.us

This commit improves on the results of commit 511ae628 in two ways:

1. It restores the historical behavior that "\set FOO" is interpreted
as setting FOO to "on", if FOO is a boolean control variable.  We
already found one test script that was expecting that behavior, and
the psql documentation certainly does nothing to discourage people
from assuming that would work, since it often says just "if FOO is set"
when describing the effects of a boolean variable.  However, now this
case will result in actually setting FOO to "on", not an empty string.

2. It arranges for an "\unset" of a control variable to set the value
back to its default value, rather than becoming apparently undefined.
The control variables are also initialized that way at psql startup.

In combination, these things guarantee that a control variable always
has a displayable value that reflects what psql is actually doing.
That is a pretty substantial usability improvement.

The implementation involves adding a second type of variable hook function
that is able to replace a proposed new value (including NULL) with another
one.  We could alternatively have complicated the API of the assign hook,
but this way seems better since many variables can share the same
substitution hook function.

Also document the actual behavior of these variables more fully,
including covering assorted behaviors that were there before but
never documented.

This patch also includes some minor cleanup that should have been in
511ae628 but was missed.

Patch by me, but it owes a lot to discussions with Daniel Vérité.

Discussion: https://postgr.es/m/9572.1485821620@sss.pgh.pa.us

The rule is that if pg_authid.rolpassword begins with "md5" and has the
right length, it's an MD5 hash, otherwise it's a plaintext password. The
idiom has been to use isMD5() to check for that, but that gets awkward,
when we add new kinds of verifiers, like the verifiers for SCRAM
authentication in the pending SCRAM patch set. Replace isMD5() with a new
get_password_type() function, so that when new verifier types are added, we
don't need to remember to modify every place that currently calls isMD5(),
to also recognize the new kinds of verifiers.

Also, use the new plain_crypt_verify function in passwordcheck, so that it
doesn't need to know about MD5, or in the future, about other kinds of
hashes or password verifiers.

Reviewed by Michael Paquier and Peter Eisentraut.

Discussion: https://www.postgresql.org/message-id/2d07165c-1793-e243-a2a9-e45b624c7580@iki.fi

The "Simplify tape block format" commit ignored the rule that blocks
returned by ltsGetFreeBlock() must be written out in the same order, at
least in the first write pass. To fix, relax that requirement, by making
ltsWriteBlock() to detect if it's about to create a "hole" in the
underlying BufFile, and fill it with zeros instead.

Reported, analysed, and reviewed by Peter Geoghegan.

Discussion: https://www.postgresql.org/message-id/CAM3SWZRWdNtkhiG0GyiX_1mUAypiK3dV6-6542pYe2iEL-foTA@mail.gmail.com

Add missing semicolons in UCS_to_* perl scripts.
For consistency, use "$hashref->{key}" style everywhere.

Kyotaro Horiguchi

Discussion: https://www.postgresql.org/message-id/20170130.153738.139030994.horiguchi.kyotaro@lab.ntt.co.jp

The addition of a TestForOldSnapshot() call here has made the
referent of this comment slightly less clear, so move the comment
to compensate.

Amit Kapila (as part of the parallel index scan patch)

Split the existing CatalogUpdateIndexes into two different routines,
CatalogTupleInsert and CatalogTupleUpdate, which do both the heap
insert/update plus the index update.  This removes over 300 lines of
boilerplate code all over src/backend/catalog/ and src/backend/commands.
The resulting code is much more pleasing to the eye.

Also, by encapsulating what happens in detail during an UPDATE, this
facilitates the upcoming WARM patch, which is going to add a few more
lines to the update case making the boilerplate even more boring.

The original CatalogUpdateIndexes is removed; there was only one use
left, and since it's just three lines, we can as well expand it in place
there.  We could keep it, but WARM is going to break all the UPDATE
out-of-core callsites anyway, so there seems to be no benefit in doing
so.

Author: Pavan Deolasee
Discussion: https://www.postgr.es/m/CABOikdOcFYSZ4vA2gYfs=M2cdXzXX4qGHeEiW3fu9PCfkHLa2A@mail.gmail.com

In commit 23f34fa4, we changed how ACLs were handled to use the new
pg_init_privs catalog and to dump out the ACL commands as REVOKE+GRANT
combinations instead of trying to REVOKE all rights always and then
GRANT back just the ones which were in place.

Unfortunately, the DEFAULT PRIVILEGES system didn't quite get the
correct treatment with this change and ended up (incorrectly) only
including positive GRANTs instead of both the REVOKEs and GRANTs
necessary to preserve the correct privileges.

There are only a couple cases where such REVOKEs are possible because,
generally speaking, there's few rights which exist on objects by
default to be revoked.

Examples of REVOKEs which weren't being correctly preserved are when
privileges are REVOKE'd from the creator/owner, like so:

ALTER DEFAULT PRIVILEGES
  FOR ROLE myrole
  REVOKE SELECT ON TABLES FROM myrole;

or when other default privileges are being revoked, such as EXECUTE
rights granted to public for functions:

ALTER DEFAULT PRIVILEGES
  FOR ROLE myrole
  REVOKE EXECUTE ON FUNCTIONS FROM PUBLIC;

Fix this by correctly working out what the correct REVOKE statements are
(if any) and dump them out, just as we do for everything else.

Noticed while developing additional regression tests for pg_dump, which
will be landing shortly.

Back-patch to 9.6 where the bug was introduced.

The pg_dump TAP tests have gotten pretty far from what perltidy thinks
they should be, so fix that, and in passing use long-form argument names
with arguments passed via "=" in a similar vein to 58da8334.

No functional changes here, just whitespace and changing runs from
"-f" to "--file=", and similar.

As pointed out by Alvaro, we actually use perltidy on the perl scripts
in the source tree, so go back to the results of a perltidy run for the
test_pg_dump TAP script.

To make it look slightly less tragic, I changed most of the independent
arguments into long-form single arguments (eg: -f file.sql changed to be
--file=file.sql) to avoid having them confusingly split across lines due
to perltidy.

Back-patch to 9.6, as the last patch was.

next_token() oddly set its buffer space consumption limit to one before
the last char position in the buffer, not the last as you'd expect.
The reason is there was once an ugly kluge to mark keywords by appending
a newline to them, potentially requiring one more byte.  Commit e5e2fc84
removed that kluge, but failed to notice that the length limit could be
increased.

Also, remove some vestigial handling of newline characters in the buffer.
That was left over from when this function read the file directly using
getc().  Commit 7f49a67f changed it to read from a buffer, from which
tokenize_file had already removed the only possible occurrence of newline,
but did not simplify this function in consequence.

Also, ensure that we don't return with *lineptr set to someplace past the
terminating '\0'; that would be catastrophic if a caller were to ask for
another token from the same line.  This is just latent since no callers
actually do call again after a "false" return; but considering that it was
actually costing us extra code to do it wrong, we might as well make it
bulletproof.

Noted while reviewing pg_hba_file_rules patch.

This view is designed along the same lines as pg_file_settings, to wit
it shows what is currently in the file, not what the postmaster has
loaded as the active settings.  That allows it to be used to pre-vet
edits before issuing SIGHUP.  As with the earlier view, go out of our
way to allow errors in the file to be reflected in the view, to assist
that use-case.

(We might at some point invent a view to show the current active settings,
but this is not that patch; and it's not trivial to do.)

Haribabu Kommi, reviewed by Ashutosh Bapat, Michael Paquier, Simon Riggs,
and myself

Discussion: https://postgr.es/m/CAJrrPGerH4jiwpcXT1-46QXUDmNp2QDrG9+-Tek_xC8APHShYw@mail.gmail.com

Quite a few of our built-in system views were not exercised anywhere
in the regression tests.  This is perhaps not so exciting for the ones
that are simple projections/joins of system catalogs, but for the ones
that are wrappers for set-returning C functions, the omission translates
directly to lack of test coverage for those functions.

In many cases, the reason for the omission is that the view doesn't have
much to do with any specific SQL feature, so there's no natural place to
test it.  To remedy that, invent a new script sysviews.sql that's dedicated
to testing SRF-based views.  Move a couple of tests that did fit this
charter into the new script, and add simple "count(*)" based tests of
other views within the charter.  That's enough to ensure we at least
exercise the main code path through the SRF, although it does little to
prove that the output is sane.

More could be done here, no doubt, and I hope someone will think about
how we can test these views more thoroughly.  But this is a starting
point.

Discussion: https://postgr.es/m/19359.1485723741@sss.pgh.pa.us

Previously, if the user set a special variable such as ECHO to an
unrecognized value, psql would bleat but store the new value anyway, and
then fall back to a default setting for the behavior controlled by the
variable.  This was agreed to be a not particularly good idea.  With
this patch, invalid values result in an error message and no change in
state.

(But this applies only to variables that affect psql's behavior; purely
informational variables such as ENCODING can still be set to random
values.)

To do this, modify the API for psql's assign-hook functions so that they
can return an OK/not OK result, and give them the responsibility for
printing error messages when they reject a value.  Adjust the APIs for
ParseVariableBool and ParseVariableNum to support the new behavior
conveniently.

In passing, document the variable VERSION, which had somehow escaped that.
And improve the quite-inadequate commenting in psql/variables.c.

Daniel Vérité, reviewed by Rahila Syed, some further tweaking by me

Discussion: https://postgr.es/m/7356e741-fa59-4146-a8eb-cf95fd6b21fb@mm

Rename some objects so that sorted output becomes less locale-dependent.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

DST law changes in northern Cyprus (new zone Asia/Famagusta), Russia (new
zone Europe/Saratov), Tonga, Antarctica/Casey.  Historical corrections for
Asia/Aqtau, Asia/Atyrau, Asia/Gaza, Asia/Hebron, Italy, Malta.  Replace
invented zone abbreviation "TOT" for Tonga with numeric UTC offset; but
as in the past, we'll keep accepting "TOT" for input.

Peter Geoghegan

In commit 6c268df1, pg_init_privs was added to track the initial
privileges of catalog objects and extensions.  Unfortunately, that
commit didn't include understanding of ALTER EXTENSION ADD/DROP, which
allows the objects associated with an extension to be changed after the
initial CREATE EXTENSION script has been run.

The result of this meant that ACLs for objects added through
ALTER EXTENSION ADD were not recorded into pg_init_privs and we would
end up including those ACLs in pg_dump when we shouldn't have.

This commit corrects that by making sure to have pg_init_privs updated
when ALTER EXTENSION ADD/DROP is run, recording the permissions as they
are at ALTER EXTENSION ADD time, and removing any if/when ALTER
EXTENSION DROP is called.

This issue was pointed out by Moshe Jacobson as commentary on bug #14456
(which was actually a bug about versions prior to 9.6 not handling
custom ACLs on extensions correctly, an issue now addressed with
pg_init_privs in 9.6).

Back-patch to 9.6 where pg_init_privs was introduced.

The formatting of the perl hashes used in the TAP tests for test_pg_dump
was rather horribly inconsistent and made it more difficult than it
really should have been to add new tests or adjust what tests are for
what runs, etc.

Reformat to clean that all up.

Whitespace-only changes.

Etsuro Fujita

Currently, we only need this logic in order to cost a Bitmap Heap
Scan.  But a pending patch for Parallel Bitmap Heap Scan also uses
it to help figure out how many workers to use for the scan, which
has to be determined prior to costing.  So, move the logic to
a separate function to make that easier.

Dilip Kumar.  The patch series of which this is a part has been
reviewed by Andres Freund, Amit Khendekar, Tushar Ahuja, Rafia
Sabih, Haribabu Kommi, and me; it is not clear from the email
discussion which of those people have looked specifically at this
part.

Discussion: http://postgr.es/m/CAFiTN-v3QYNJEZnnmKCeATuLbN-h9tMVfeEF0+BrouYDqjXgwg@mail.gmail.com

tokenize_file() now returns a single list of TokenizedLine structs,
carrying the same information as before.  We were otherwise going to grow a
fourth list to deal with error messages, and that was getting a bit silly.

Haribabu Kommi, revised a bit by me

Discussion: https://postgr.es/m/CAJrrPGfbgbKsjYp=bgZXhMcgxoaGSoBb9fyjrDoOW_YymXv1Kw@mail.gmail.com

Per discussion with Craig Ringer.

Clean up hastily-composed comment.  Normalize whitespace.

Erik Rijkers and myself

When I wrote commit ab1f0c82, I really missed the castNode() macro that
Peter E. had proposed shortly before.  This back-fills the uses I would
have put it to.  It's probably not all that significant, but there are
more assertions here than there were before, and conceivably they will
help catch any bugs associated with those representation changes.

I left behind a number of usages like "(Query *) copyObject(query_var)".
Those could have been converted as well, but Peter has proposed another
notational improvement that would handle copyObject cases automatically,
so I let that be for now.

This is far from a pervasive conversion, but it's a good starting
point.

Author: Peter Eisentraut, with some minor changes by me
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com

The new function allows to cast from one NodeTag based type to
another, while asserting that the conversion is valid.  This replaces
the common pattern of doing a cast and a Assert(IsA(ptr, type))
close-by.

As this seems likely to be used pervasively, we decided to backpatch
this change the addition of this macro. Otherwise backpatched fixes
are more likely not to work on back-branches.

On branches before 9.6, where we do not yet rely on inline functions
being available, the type assertion is only performed if PG_USE_INLINE
support is detected. The cast obviously is performed regardless.

For the benefit of verifying the macro compiles in the back-branches,
this commit contains a single use of the new macro. On master, a
somewhat larger conversion will be committed separately.

Author: Peter Eisentraut and Andres Freund
Reviewed-By: Tom Lane
Discussion: https://postgr.es/m/c5d387d9-3440-f5e0-f9d4-71d53b9fbe52@2ndquadrant.com
Backpatch: 9.2-

Our current DDL only allows a database name to be specified in COMMENT
ON DATABASE, which Andrew Dunstan reports to make this test fail on the
buildfarm.  Remove the line until we gain a DDL command that allows the
current database to be operated on without having the specify it by
name.

Backpatch to 9.5, where these tests appeared.

Discussion: https://postgr.es/m/e6084b89-07a7-7e57-51ee-d7b8fc9ec864@2ndQuadrant.com

Even though these messages are not used yet, we should keep the list
complete.

The CREATE privilege on databases now also enables creating
publications.

We maintained two separate expected files because log_cnt could be one
of two values.  Rewrite the test so that we only need one file.
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>

Add test cases to object_address.sql to test the new logical replication
related object classes, and fix some small bugs discovered by that.

Hot_standby_feedback could be reset by reload and worked correctly, but if
the server was restarted rather than reloaded the xmin was not reset.
Force reset always if hot_standby_feedback is enabled at startup.

Ants Aasma, Craig Ringer

Reported-by: Ants Aasma

!foo means "the tsvector does not contain foo", and therefore it should
match an empty tsvector.  ts_match_vq() overenthusiastically supposed
that an empty tsvector could never match any query, so it forcibly
returned FALSE, the wrong answer.  Remove the premature optimization.

Our behavior on this point was inconsistent, because while seqscans and
GIST index searches both failed to match empty tsvectors, GIN index
searches would find them, since GIN scans don't rely on ts_match_vq().
That makes this certainly a bug, not a debatable definition disagreement,
so back-patch to all supported branches.

Report and diagnosis by Tom Dunstan (bug #14515); added test cases by me.

Discussion: https://postgr.es/m/20170126025524.1434.97828@wrigleys.postgresql.org