improve hash creation warning message

This improves the wording of commit 84aa8ba128a08e6fdebb2497c7a79ebf18093e12.

Report by Kevin Grittner
Remove dead InRecovery check.

With the new B-tree incomplete split handling in 9.4, _bt_insert_parent is
never called in recovery.
pg_upgrade:  adjust C comments
Add 'ignore_nulls' option to row_to_json

Provide an option to skip NULL values in a row when generating a JSON
object from that row with row_to_json.  This can reduce the size of the
JSON object in cases where columns are NULL without really reducing the
information in the JSON object.

This also makes row_to_json into a single function with default values,
rather than having multiple functions.  In passing, change array_to_json
to also be a single function with default values (we don't add an
'ignore_nulls' option yet- it's not clear that there is a sensible
use-case there, and it hasn't been asked for in any case).

Pavel Stehule
Fix vacuumdb --analyze-in-stages --all order

When running vacuumdb --analyze-in-stages --all, it needs to run the
first stage across all databases before the second one, instead of
running all stages in a database before processing the next one.

Also respect the --quiet option with --analyze-in-stages.
Fix JSON regression tests.

Commit 95d737ff45a38809130a2c633d9e6bc26c825036 neglected to update
expected/json_1.out.  Per buildfarm.
Fix power_var_int() for large integer exponents.

The code for raising a NUMERIC value to an integer power wasn't very
careful about large powers.  It got an outright wrong answer for an
exponent of INT_MIN, due to failure to consider overflow of the Abs(exp)
operation; which is fixable by using an unsigned rather than signed
exponent value after that point.  Also, even though the number of
iterations of the power-computation loop is pretty limited, it's easy for
the repeated squarings to result in ridiculously enormous intermediate
values, which can take unreasonable amounts of time/memory to process,
or even overflow the internal "weight" field and so produce a wrong answer.
We can forestall misbehaviors of that sort by bailing out as soon as the
weight value exceeds what will fit in int16, since then the final answer
must overflow (if exp > 0) or underflow (if exp < 0) the packed numeric
format.

Per off-list report from Pavel Stehule.  Back-patch to all supported
branches.
Fix GIN data page split ratio calculation.

The code that tried to split a page at 75/25 ratio, when appending to the
end of an index, was buggy in two ways. First, there was a silly typo that
caused it to just fill the left page as full as possible. But the logic as
it was intended wasn't correct either, and would actually have given a ratio
closer to 60/40 than 75/25.

Gaetano Mendola spotted the typo. Backpatch to 9.4, where this code was added.
Support Subject Alternative Names in SSL server certificates.

This patch makes libpq check the server's hostname against DNS names listed
in the X509 subjectAltName extension field in the server certificate. This
allows the same certificate to be used for multiple domain names. If there
are no SANs in the certificate, the Common Name field is used, like before
this patch. If both are given, the Common Name is ignored. That is a bit
surprising, but that's the behavior mandated by the relevant RFCs, and it's
also what the common web browsers do.

This also adds a libpq_ngettext helper macro to allow plural messages to be
translated in libpq. Apparently this happened to be the first plural message
in libpq, so it was not needed before.

Alexey Klyukin, with some kibitzing by me.
Handle border = 3 in expanded mode

In psql, expanded mode was not being displayed correctly when using
the normal ascii or unicode linestyles and border set to '3'.  Now,
per the documentation, border '3' is really only sensible for HTML
and LaTeX formats, however, that's no excuse for ascii/unicode to
break in that case, and provisions had been made for psql to cleanly
handle this case (and it did, in non-expanded mode).

This was broken when ascii/unicode was initially added a good five
years ago because print_aligned_vertical_line wasn't passed in the
border setting being used by print_aligned_vertical but instead was
given the whole printTableContent.  There really isn't a good reason
for vertical_line to have the entire printTableContent structure, so
just pass in the printTextFormat and border setting (similar to how
this is handled in horizontal_line).

Pointed out by Pavel Stehule, fix by me.

Back-patch to all currently-supported versions.
Add unicode_{column|header|border}_style to psql

With the unicode linestyle, this adds support to control if the
column, header, or border style should be single or double line
unicode characters.  The default remains 'single'.

In passing, clean up the border documentation and address some
minor formatting/spelling issues.

Pavel Stehule, with some additional changes by me.
Add GUC to enable logging of replication commands.

Previously replication commands like IDENTIFY_COMMAND were not logged
even when log_statements is set to all. Some users who want to audit
all types of statements were not satisfied with this situation. To
address the problem, this commit adds new GUC log_replication_commands.
If it's enabled, all replication commands are logged in the server log.

There are many ways to allow us to enable that logging. For example,
we can extend log_statement so that replication commands are logged
when it's set to all. But per discussion in the community, we reached
the consensus to add separate GUC for that.

Reviewed by Ian Barwick, Robert Haas and Heikki Linnakangas.
Change NTUP_PER_BUCKET to 1 to improve hash join lookup speed.

Since this makes the bucket headers use ~10x as much memory, properly
account for that memory when we figure out whether everything fits
in work_mem.  This might result in some cases that previously used
only a single batch getting split into multiple batches, but it's
unclear as yet whether we need defenses against that case, and if so,
what the shape of those defenses should be.

It's worth noting that even in these edge cases, users should still be
no worse off than they would have been last week, because commit
45f6240a8fa9d35548eb2ef23dba2c11540aa02a saved a big pile of memory
on exactly the same workloads.

Tomas Vondra, reviewed and somewhat revised by me.
More formatting.c variable renaming, for clarity
Revert f68dc5d86b9f287f80f4417f5a24d876eb13771d

Renaming will have to be more comprehensive, so I need approval.
pg_ctl: Add tests for behavior with nonexistent data directory

This behavior was made more precise in commit
11d205e2bd66cefe0b7d69c02e831cd055cbb5bb.
Run missing documentation tools through "missing"

Instead of just erroring out when a tool is missing, wrap the call with
the "missing" script that we are already using for bison, flex, and
perl, so that the users get a useful error message.
Invent PGC_SU_BACKEND and mark log_connections/log_disconnections that way.

This new GUC context option allows GUC parameters to have the combined
properties of PGC_BACKEND and PGC_SUSET, ie, they don't change after
session start and non-superusers can't change them.  This is a more
appropriate choice for log_connections and log_disconnections than their
previous context of PGC_BACKEND, because we don't want non-superusers
to be able to affect whether their sessions get logged.

Note: the behavior for log_connections is still a bit odd, in that when
a superuser attempts to set it from PGOPTIONS, the setting takes effect
but it's too late to enable or suppress connection startup logging.
It's debatable whether that's worth fixing, and in any case there is
a reasonable argument for PGC_SU_BACKEND to exist.

In passing, re-pgindent the files touched by this commit.

Fujii Masao, reviewed by Joe Conway and Amit Kapila
Fix pointer type in size passed to memset.

Pointers are all the same size, so it makes no practical difference, but
let's be tidy.

Found by Coverity, noted off-list by Tom Lane.