Fix array overrun in ecpg's version of ParseDateTime().

The code wrote a value into the caller's field[] array before checking
to see if there was room, which of course is backwards.  Per report from
Michael Paquier.

I fixed the equivalent bug in the backend's version of this code way back
in 630684d3a130bb93, but failed to think about ecpg's copy.  Fortunately
this doesn't look like it would be exploitable for anything worse than a
core dump: an external attacker would have no control over the single word
that gets written.
Fix broken example in PL/pgSQL document.

Back-patch to all supported branches.

Marti Raudsepp, per a report from Marko Tiikkaja
Suppress dead, unportable src/port/crypt.c code.

This file used __int64, which is specific to native Windows, rather than
int64.  Suppress the long-unused union field of this type.  Noticed on
Cygwin x86_64 with -lcrypt not installed.  Back-patch to 9.0 (all
supported versions).
Support timezone abbreviations that sometimes change.

Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
Fix core dump in pg_dump --binary-upgrade on zero-column composite type.

This reverts nearly all of commit 28f6cab61ab8958b1a7dfb019724687d92722538
in favor of just using the typrelid we already have in pg_dump's TypeInfo
struct for the composite type.  As coded, it'd crash if the composite type
had no attributes, since then the query would return no rows.

Back-patch to all supported versions.  It seems to not really be a problem
in 9.0 because that version rejects the syntax "create type t as ()", but
we might as well keep the logic similar in all affected branches.

Report and fix by Rushabh Lathia.
Avoid core dump in _outPathInfo() for Path without a parent RelOptInfo.

Nearly all Paths have parents, but a ResultPath representing an empty FROM
clause does not.  Avoid a core dump in such cases.  I believe this is only
a hazard for debugging usage, not for production, else we'd have heard
about it before.  Nonetheless, back-patch to 9.1 where the troublesome code
was introduced.  Noted while poking at bug #11703.
Declare mkdtemp() only if we're providing it.

Follow our usual style of providing an "extern" for a standard library
function only when we're also providing the implementation.  This avoids
issues when the system headers declare the function slightly differently
than we do, as noted by Caleb Welton.

We might have to go to the extent of probing to see if the system headers
declare the function, but let's not do that until it's demonstrated to be
necessary.

Oversight in commit 9e6b1bf258170e62dac555fc82ff0536dfe01d29.  Back-patch
to all supported branches, as that was.
Fix mishandling of FieldSelect-on-whole-row-Var in nested lateral queries.

If an inline-able SQL function taking a composite argument is used in a
LATERAL subselect, and the composite argument is a lateral reference,
the planner could fail with "variable not found in subplan target list",
as seen in bug #11703 from Karl Bartel.  (The outer function call used in
the bug report and in the committed regression test is not really necessary
to provoke the bug --- you can get it if you manually expand the outer
function into "LATERAL (SELECT inner_function(outer_relation))", too.)

The cause of this is that we generate the reltargetlist for the referenced
relation before doing eval_const_expressions() on the lateral sub-select's
expressions (cf find_lateral_references()), so what's scheduled to be
emitted by the referenced relation is a whole-row Var, not the simplified
single-column Var produced by optimizing the function's FieldSelect on the
whole-row Var.  Then setrefs.c fails to match up that lateral reference to
what's available from the outer scan.

Preserving the FieldSelect optimization in such cases would require either
major planner restructuring (to recursively do expression simplification
on sub-selects much earlier) or some amazingly ugly kluge to change the
reltargetlist of a possibly-already-planned relation.  It seems better
just to skip the optimization when the Var is from an upper query level;
the case is not so common that it's likely anyone will notice a few
wasted cycles.

AFAICT this problem only occurs for uplevel LATERAL references, so
back-patch to 9.3 where LATERAL was added.
Flush unlogged table's buffers when copying or moving databases.

CREATE DATABASE and ALTER DATABASE .. SET TABLESPACE copy the source
database directory on the filesystem level. To ensure the on disk
state is consistent they block out users of the affected database and
force a checkpoint to flush out all data to disk. Unfortunately, up to
now, that checkpoint didn't flush out dirty buffers from unlogged
relations.

That bug means there could be leftover dirty buffers in either the
template database, or the database in its old location. Leading to
problems when accessing relations in an inconsistent state; and to
possible problems during shutdown in the SET TABLESPACE case because
buffers belonging files that don't exist anymore are flushed.

This was reported in bug #10675 by Maxim Boguk.

Fix by Pavan Deolasee, modified somewhat by me. Reviewed by MauMau and
Fujii Masao.

Backpatch to 9.1 where unlogged tables were introduced.
Ensure libpq reports a suitable error message on unexpected socket EOF.

The EOF-detection logic in pqReadData was a bit confused about who should
set up the error message in case the kernel gives us read-ready-but-no-data
rather than ECONNRESET or some other explicit error condition.  Since the
whole point of this situation is that the lower-level functions don't know
there's anything wrong, pqReadData itself must set up the message.  But
keep the assumption that if an errno was reported, a message was set up at
lower levels.

Per bug #11712 from Marko Tiikkaja.  It's been like this for a very long
time, so back-patch to all supported branches.
Prevent the already-archived WAL file from being archived again.

Previously the archive recovery always created .ready file for
the last WAL file of the old timeline at the end of recovery even when
it's restored from the archive and has .done file. That is, there was
the case where the WAL file had both .ready and .done files.
This caused the already-archived WAL file to be archived again.

This commit prevents the archive recovery from creating .ready file
for the last WAL file if it has .done file, in order to prevent it from
being archived again.

This bug was added when cascading replication feature was introduced,
i.e., the commit 5286105800c7d5902f98f32e11b209c471c0c69c.
So, back-patch to 9.2, where cascading replication was added.

Reviewed by Michael Paquier
Improve ispell dictionary's defenses against bad affix files.

Don't crash if an ispell dictionary definition contains flags but not
any compound affixes.  (This isn't a security issue since only superusers
can install affix files, but still it's a bad thing.)

Also, be more careful about detecting whether an affix-file FLAG command
is old-format (ispell) or new-format (myspell/hunspell).  And change the
error message about mixed old-format and new-format commands into something
intelligible.

Per bug #11770 from Emre Hasegeli.  Back-patch to all supported branches.
Make the locale comparison in pg_upgrade more lenient

If the locale names are not equal, try to canonicalize both of them by
passing them to setlocale(). Before, we only canonicalized the old cluster's
locale if upgrading from a 8.4-9.2 server, but we also need to canonicalize
when upgrading from a pre-8.4 server. That was an oversight in the code. But
we should also canonicalize on newer server versions, so that we cope if the
canonical form changes from one release to another. I'm about to do just
that to fix bug #11431, by mapping a locale name that contains non-ASCII
characters to a pure-ASCII alias of the same locale.

This is partial backpatch of commit 33755e8edf149dabfc0ed9b697a84f70b0cca0de
in master. Apply to 9.2, 9.3 and 9.4. The canonicalization code didn't exist
before 9.2. In 9.2 and 9.3, this effectively also back-patches the changes
from commit 58274728fb8e087049df67c0eee903d9743fdeda, to be more lax about
the spelling of the encoding in the locale names.
Work around Windows locale name with non-ASCII character.

Windows has one a locale whose name contains a non-ASCII character:
"Norwegian (Bokmål)" (that's an 'a' with a ring on top). That causes
trouble; when passing it setlocale(), it's not clear what encoding the
argument should be in. Another problem is that the locale name is stored in
pg_database catalog table, and the encoding used there depends on what
server encoding happens to be in use when the database is created. For
example, if you issue the CREATE DATABASE when connected to a UTF-8
database, the locale name is stored in pg_database in UTF-8. As long as all
locale names are pure ASCII, that's not a problem.

To work around that, map the troublesome locale name to a pure-ASCII alias
of the same locale, "norwegian-bokmal".

Now, this doesn't change the existing values that are already in
pg_database and in postgresql.conf. Old clusters will need to be fixed
manually. Instructions for that need to be put in the release notes.

This fixes bug #11431 reported by Alon Siman-Tov. Backpatch to 9.2;
backpatching further would require more work than seems worth it.
Oops, I fumbled the backpatch of pg_upgrade changes.

Somehow I got 9.2 and 9.4 correct, but fumbled 9.3.
Improve planning of btree index scans using ScalarArrayOpExpr quals.

Since we taught btree to handle ScalarArrayOpExpr quals natively (commit
9e8da0f75731aaa7605cf4656c21ea09e84d2eb1), the planner has always included
ScalarArrayOpExpr quals in index conditions if possible.  However, if the
qual is for a non-first index column, this could result in an inferior plan
because we can no longer take advantage of index ordering (cf. commit
807a40c551dd30c8dd5a0b3bd82f5bbb1e7fd285).  It can be better to omit the
ScalarArrayOpExpr qual from the index condition and let it be done as a
filter, so that the output doesn't need to get sorted.  Indeed, this is
true for the query introduced as a test case by the latter commit.

To fix, restructure get_index_paths and build_index_paths so that we
consider paths both with and without ScalarArrayOpExpr quals in non-first
index columns.  Redesign the API of build_index_paths so that it reports
what it found, saving useless second or third calls.

Report and patch by Andrew Gierth (though rather heavily modified by me).
Back-patch to 9.2 where this code was introduced, since the issue can
result in significant performance regressions compared to plans produced
by 9.1 and earlier.
Fix two bugs in tsquery @> operator.

1. The comparison for matching terms used only the CRC to decide if there's
a match. Two different terms with the same CRC gave a match.

2. It assumed that if the second operand has more terms than the first, it's
never a match. That assumption is bogus, because there can be duplicate
terms in either operand.

Rewrite the implementation in a way that doesn't have those bugs.

Backpatch to all supported versions.
Reset error message at PQreset()

If you call PQreset() repeatedly, and the connection cannot be
re-established, the error messages from the failed connection attempts
kept accumulating in the error string.

Fixes bug #11455 reported by Caleb Epstein. Backpatch to all supported
versions.
Avoid corrupting tables when ANALYZE inside a transaction is rolled back.

VACUUM and ANALYZE update the target table's pg_class row in-place, that is
nontransactionally.  This is OK, more or less, for the statistical columns,
which are mostly nontransactional anyhow.  It's not so OK for the DDL hint
flags (relhasindex etc), which might get changed in response to
transactional changes that could still be rolled back.  This isn't a
problem for VACUUM, since it can't be run inside a transaction block nor
in parallel with DDL on the table.  However, we allow ANALYZE inside a
transaction block, so if the transaction had earlier removed the last
index, rule, or trigger from the table, and then we roll back the
transaction after ANALYZE, the table would be left in a corrupted state
with the hint flags not set though they should be.

To fix, suppress the hint-flag updates if we are InTransactionBlock().
This is safe enough because it's always OK to postpone hint maintenance
some more; the worst-case consequence is a few extra searches of pg_index
et al.  There was discussion of instead using a transactional update,
but that would change the behavior in ways that are not all desirable:
in most scenarios we're better off keeping ANALYZE's statistical values
even if the ANALYZE itself rolls back.  In any case we probably don't want
to change this behavior in back branches.

Per bug #11638 from Casey Shobe.  This has been broken for a good long
time, so back-patch to all supported branches.

Tom Lane and Michael Paquier, initial diagnosis by Andres Freund
Test IsInTransactionChain, not IsTransactionBlock, in vac_update_relstats.

As noted by Noah Misch, my initial cut at fixing bug #11638 didn't cover
all cases where ANALYZE might be invoked in an unsafe context.  We need to
test the result of IsInTransactionChain not IsTransactionBlock; which is
notationally a pain because IsInTransactionChain requires an isTopLevel
flag, which would have to be passed down through several levels of callers.
I chose to pass in_outer_xact (ie, the result of IsInTransactionChain)
rather than isTopLevel per se, as that seemed marginally more apropos
for the intermediate functions to know about.