Some of the Unicode/*.map files had identification comments added to them,
evidently by hand.  Others did not.  Modify the generating scripts to
produce these comments automatically, and update the generated files that
lacked them.

This is just minor cleanup as a by-product of trying to verify that the
*.map files can indeed be reproduced from authoritative data.  There are a
depressingly large number that fail to reproduce from the claimed sources.
I have not touched those in this commit, except for the JIS 2004-related
files which required only a single comment update to match.

Since this only affects comments, no need to consider a back-patch.

Previously, if no host information had been specified at connection time,
PQhost() would return NULL (unless you are on Windows, in which case you
got "localhost").  This is an unhelpful definition for a couple of reasons:
it can cause corner-case crashes in applications (cf commit c5ef8ce5),
and there's no well-defined way for applications to find out the socket
directory path that's actually in use.  As an example of the latter
problem, psql substituted DEFAULT_PGSOCKET_DIR for NULL in a couple of
places, but this is subtly wrong because it's conceivable that psql is
using a libpq shared library that was built with a different setting.

Hence, change PQhost() to return DEFAULT_PGSOCKET_DIR when appropriate,
and strip out the now-dead substitutions in psql.  (There is still one
remaining reference to DEFAULT_PGSOCKET_DIR in psql, in prompt.c, which
I don't see a nice way to get rid of.  But it only controls a prompt
abbreviation decision, so it seems noncritical.)

Also update the docs for PQhost, which had never previously mentioned
the possibility of a socket directory path being returned.  In passing
fix the outright-incorrect code comment about PGconn.pgunixsocket.

Attached is a patch for being able to do COPY (query) without a CTE.

Author: Marko Tiikkaja
Review: Michael Paquier

Failure to initially palloc the comboCids array, or to realloc it bigger
when needed, left combocid's data structures in an inconsistent state that
would cause trouble if the top transaction continues to execute.  Noted
while examining a user complaint about the amount of memory used for this.
(There's not much we can do about that, but it does point up that repalloc
failure has a non-negligible chance of occurring here.)

In HEAD/9.5, also avoid possible invocation of memcpy() with a null pointer
in SerializeComboCIDState; cf commit 13bba022.

PQhost() can return NULL in non-error situations, namely when a Unix-socket
connection has been selected by default.  That behavior is a tad debatable
perhaps, but for the moment we should make sure that psql copes with it.
Unfortunately, do_connect() failed to: it could pass a NULL pointer to
strcmp(), resulting in crashes on most platforms.  This was reported as a
security issue by ChenQin of Topsec Security Team, but the consensus of
the security list is that it's just a garden-variety bug with no security
implications.

For paranoia's sake, I made the keep_password test not trust PQuser or
PQport either, even though I believe those will never return NULL given
a valid PGconn.

Back-patch to all supported branches.

The integer overflow situation in div_var_fast() is a great deal more
complicated than the pre-existing comments would suggest.  Moreover, the
comments were also flat out incorrect as to the precise statement of the
maxdiv loop invariant.  Upon clarifying that, it becomes apparent that the
way in which we updated maxdiv after a carry propagation pass was overly
slow, complex, and conservative: we can just reset it to one, which is much
easier and also reduces the number of times carry propagation occurs.
Fix that and improve the relevant comments.

Since this is mostly a comment fix, with only a rather marginal performance
boost, no need for back-patch.

Tom Lane and Dean Rasheed

Now pageinspect can show data stored in the heap tuple.

Nikolay Shaplov

Also fix getErrorText() to return the right error string on failure.
This behavior now matches that of other operating systems.

Report by Noah Misch

Backpatch through 9.1

Per http://www.postgresql.org/message-id/flat/564C4CE6.9000509@postgrespro.ru
Pavel Luzanov <p.luzanov@postgrespro.ru>

from Michael Paquier

The POSIX standard for tar headers requires archive member sizes to be
printed in octal with at most 11 digits, limiting the representable file
size to 8GB.  However, GNU tar and apparently most other modern tars
support a convention in which oversized values can be stored in base-256,
allowing any practical file to be a tar member.  Adopt this convention
to remove two limitations:
* pg_dump with -Ft output format failed if the contents of any one table
exceeded 8GB.
* pg_basebackup failed if the data directory contained any file exceeding
8GB.  (This would be a fatal problem for installations configured with a
table segment size of 8GB or more, and it has also been seen to fail when
large core dump files exist in the data directory.)

File sizes under 8GB are still printed in octal, so that no compatibility
issues are created except in cases that would have failed entirely before.

In addition, this patch fixes several bugs in the same area:

* In 9.3 and later, we'd defined tarCreateHeader's file-size argument as
size_t, which meant that on 32-bit machines it would write a corrupt tar
header for file sizes between 4GB and 8GB, even though no error was raised.
This broke both "pg_dump -Ft" and pg_basebackup for such cases.

* pg_restore from a tar archive would fail on tables of size between 4GB
and 8GB, on machines where either "size_t" or "unsigned long" is 32 bits.
This happened even with an archive file not affected by the previous bug.

* pg_basebackup would fail if there were files of size between 4GB and 8GB,
even on 64-bit machines.

* In 9.3 and later, "pg_basebackup -Ft" failed entirely, for any file size,
on 64-bit big-endian machines.

In view of these potential data-loss bugs, back-patch to all supported
branches, even though removal of the documented 8GB limit might otherwise
be considered a new feature rather than a bug fix.

The previous way of reconstructing check constraints was to do a separate
"ALTER TABLE ONLY tab ADD CONSTRAINT" for each table in an inheritance
hierarchy.  However, that way has no hope of reconstructing the check
constraints' own inheritance properties correctly, as pointed out in
bug #13779 from Jan Dirk Zijlstra.  What we should do instead is to do
a regular "ALTER TABLE", allowing recursion, at the topmost table that
has a particular constraint, and then suppress the work queue entries
for inherited instances of the constraint.

Annoyingly, we'd tried to fix this behavior before, in commit 5ed6546c,
but we failed to notice that it wasn't reconstructing the pg_constraint
field values correctly.

As long as I'm touching pg_get_constraintdef_worker anyway, tweak it to
always schema-qualify the target table name; this seems like useful backup
to the protections installed by commit 5f173040.

In HEAD/9.5, get rid of get_constraint_relation_oids, which is now unused.
(I could alternatively have modified it to also return conislocal, but that
seemed like a pretty single-purpose API, so let's not pretend it has some
other use.)  It's unused in the back branches as well, but I left it in
place just in case some third-party code has decided to use it.

In HEAD/9.5, also rename pg_get_constraintdef_string to
pg_get_constraintdef_command, as the previous name did nothing to explain
what that entry point did differently from others (and its comment was
equally useless).  Again, that change doesn't seem like material for
back-patching.

I did a bit of re-pgindenting in tablecmds.c in HEAD/9.5, as well.

Otherwise, back-patch to all supported branches.

The previous coding attempts to destroy the DSM in this case, but
child nodes might have stored data there and still be holding onto
pointers in this case.  So don't do that.

Also, free the reader array instead of leaking it.

Extracted from two different patch versions both by Amit Kapila.

Amit Langote

Reported by Andres Freund.

Some versions of Perl export a macro named HS_KEY.  This creates a
conflict in contrib/hstore_plperl against hstore's macro of the same
name.  The most future-proof solution seems to be to rename our macro;
I chose HSTORE_KEY.  For consistency, rename HS_VAL and related macros
similarly.

Back-patch to 9.5.  contrib/hstore_plperl doesn't exist before that
so there is no need to worry about the conflict in older releases.

Per reports from Marco Atzeri and Mike Blackwell.

Silly mistake in my commit 09cecdf2, reported by Erik Rijkers.

The fact that the buildfarm didn't find this implies that we are not
testing Perl builds that lack MULTIPLICITY, which is a bit disturbing
from a coverage standpoint.  Until today I'd have said nobody cared
about such configurations anymore; but maybe not.

This was already true for CREATE EXTENSION, but historically has not
been true for other object types.  Therefore, this is a backward
incompatibility.  Per discussion on pgsql-hackers, everyone seems to
agree that the new behavior is better.

Marti Raudsepp, reviewed by Haribabu Kommi and myself

The target is now named 'bincheck' rather than 'tapcheck' so that it
reflects what is checked instead of the test mechanism. Some of the
logic is improved, making it easier to add further sets of TAP based
tests in future. Also, the environment setting logic is imrpoved.

As discussed on -hackers a couple of months ago.

KaiGai Kohei

At least one of the names was, due to a function renaming late in the
development of ON CONFLICT, wrong. Since including function names in
error messages is against the message style guide anyway, remove them
from the messages.

Discussion: CAM3SWZT8paz=usgMVHm0XOETkQvzjRtAUthATnmaHQQY0obnGw@mail.gmail.com
Backpatch: 9.5, where ON CONFLICT was introduced

Author: Peter Geoghegan and Andres Freund
Discussion: CAM3SWZScpWzQ-7EJC77vwqzZ1GO8GNmURQ1QqDQ3wRn7AbW1Cg@mail.gmail.com
Backpatch: 9.5, where ON CONFLICT was introduced

Per buildfarm member anchovy, 2.6.0 exists in the wild now.
Hopefully it works with Postgres; if not, we'll have to do something
about that, but in any case claiming it's "too old" is pretty silly.

Remote expressions now also matter to make_foreignscan()

Noted by Etsuro Fujita.

Amit Kapila, per design ideas from me.

When I wrote this code originally, the intention was to recompute the
remapinfo only when the tupledesc changes.  This presumably only
happens once per query, but I copied the design pattern from other
DestReceivers.  However, due to a silly oversight on my part,
tqueue->tupledesc never got set, leading to recomputation for every
tuple.

This should improve the performance of parallel scans that return a
significant number of tuples.

Report by Amit Kapila; patch by me, reviewed by him.

div_var_fast() postpones propagating carries in the same way as mul_var(),
so it has the same corner-case overflow risk we fixed in 246693e5,
namely that the size of the carries has to be accounted for when setting
the threshold for executing a carry propagation step.  We've not devised
a test case illustrating the brokenness, but the required fix seems clear
enough.  Like the previous fix, back-patch to all active branches.

Dean Rasheed

from Euler Taveira

Prior to commit 0709b7ee, access to
variables within a spinlock-protected critical section had to be done
through a volatile pointer, but that should no longer be necessary.

Review by Andres Freund

Since commit 11e13185, ruleutils.c has
attempted to ensure that each RTE in a query or plan tree has a unique
alias name.  However, the code that was added for this could be quite slow,
even as bad as O(N^3) if N identical RTE names must be replaced, as noted
by Jeff Janes.  Improve matters by building a transient hash table within
set_rtable_names.  The hash table in itself reduces the cost of detecting a
duplicate from O(N) to O(1), and we can save another factor of N by storing
the number of de-duplicated names already created for each entry, so that
we don't have to re-try names already created.  This way is probably a bit
slower overall for small range tables, but almost by definition, such cases
should not be a performance problem.

In principle the same problem applies to the column-name-de-duplication
code; but in practice that seems to be less of a problem, first because
N is limited since we don't support extremely wide tables, and second
because duplicate column names within an RTE are fairly rare, so that in
practice the cost is more like O(N^2) not O(N^3).  It would be very much
messier to fix the column-name code, so for now I've left that alone.

An independent problem in the same area was that the de-duplication code
paid no attention to the identifier length limit, and would happily produce
identifiers that were longer than NAMEDATALEN and wouldn't be unique after
truncation to NAMEDATALEN.  This could result in dump/reload failures, or
perhaps even views that silently behaved differently than before.  We can
fix that by shortening the base name as needed.  Fix it for both the
relation and column name cases.

In passing, check for interrupts in set_rtable_names, just in case it's
still slow enough to be an issue.

Back-patch to 9.3 where this code was introduced.

Amit Kapila

Normally ruleutils prints a whole-row Var as "foo.*".  We already knew that
that doesn't work at top level of a SELECT list, because the parser would
treat the "*" as a directive to expand the reference into separate columns,
not a whole-row Var.  However, Joshua Yanovski points out in bug #13776
that the same thing happens at top level of a ROW() construct; and some
nosing around in the parser shows that the same is true in VALUES().
Hence, apply the same workaround already devised for the SELECT-list case,
namely to add a forced cast to the appropriate rowtype in these cases.
(The alternative of just printing "foo" was rejected because it is
difficult to avoid ambiguity against plain columns named "foo".)

Back-patch to all supported branches.