Revert "Add libpq function PQhostaddr()."

This reverts commit 9f80f4835a55a1cbffcda5d23a617917f3286c14.  The
function returned the raw value of a connection parameter, a task served
by PQconninfo().  The next commit will reimplement the psql \conninfo
change that way.  Back-patch to 9.4, where that commit first appeared.
Reimplement 9f80f4835a55a1cbffcda5d23a617917f3286c14 with PQconninfo().

Apart from ignoring "hostaddr" set to the empty string, this behaves
identically to its predecessor.  Back-patch to 9.4, where the original
commit first appeared.

Reviewed by Fujii Masao.
Remove PQhostaddr() from 9.4 release notes.

Back-patch to 9.4, like the feature's removal.
Move test modules from contrib to src/test/modules

This is advance preparation for introducing even more test modules; the
easy solution is to add them to contrib, but that's bloated enough that
it seems a good time to think of something different.

Moved modules are dummy_seclabel, test_shm_mq, test_parser and
worker_spi.

(test_decoding was also a candidate, but there was too much opposition
to moving that one.  We can always reconsider later.)
Fix minor bugs in commit 30bf4689a96cd283af33edcdd6b7210df3f20cd8 et al.

Coverity complained that the "else" added to fillPGconn() was unreachable,
which it was.  Remove the dead code.  In passing, rearrange the tests so as
not to bother trying to fetch values for options that can't be assigned.

Pre-9.3 did not have that issue, but it did have a "return" that should be
"goto oom_error" to ensure that a suitable error message gets filled in.
Add a #define for the inet overlaps operator.

Extracted from pending inet selectivity patch.  The rest of it isn't
quite ready to commit, but we might as well push this part so the patch
doesn't have to track the moving target of pg_operator.h.
Fix missing space in documentation

Ian Barwick
Put SSL_pending() call behind the new internal SSL API.

It seems likely that any SSL implementation will need a similar call, not
just OpenSSL.
Fix hstore_to_json_loose's detection of valid JSON number values.

We expose a function IsValidJsonNumber that internally calls the lexer
for json numbers. That allows us to use the same test everywhere,
instead of inventing a broken test for hstore conversions. The new
function is also used in datum_to_json, replacing the code that is now
moved to the new function.

Backpatch to 9.3 where hstore_to_json_loose was introduced.
Move security_label test

Rather than have the core security_label regression test depend on the
dummy_seclabel module, have that part of the test be executed by
dummy_seclabel itself directly.  This simplifies the testing rig a bit;
in particular it should silence the problems from the MSVC buildfarm
phylum, which haven't yet gotten taught how to install src/test/modules.
Guard against bad "dscale" values in numeric_recv().

We were not checking to see if the supplied dscale was valid for the given
digit array when receiving binary-format numeric values.  While dscale can
validly be more than the number of nonzero fractional digits, it shouldn't
be less; that case causes fractional digits to be hidden on display even
though they're there and participate in arithmetic.

Bug #12053 from Tommaso Sala indicates that there's at least one broken
client library out there that sometimes supplies an incorrect dscale value,
leading to strange behavior.  This suggests that simply throwing an error
might not be the best response; it would lead to failures in applications
that might seem to be working fine today.  What seems the least risky fix
is to truncate away any digits that would be hidden by dscale.  This
preserves the existing behavior in terms of what will be printed for the
transmitted value, while preventing subsequent arithmetic from producing
results inconsistent with that.

In passing, throw a specific error for the case of dscale being outside
the range that will fit into a numeric's header.  Before you got "value
overflows numeric format", which is a bit misleading.

Back-patch to all supported branches.
dummy_seclabel: add sql/, expected/, and .gitignores

Michael Paquier
pageinspect/BRIN: minor tweaks

Michael Paquier

Double-dash additions suggested by Peter Geoghegan
Minor cleanup of function declarations for BRIN.

Get rid of PG_FUNCTION_INFO_V1() macros, which are quite inappropriate
for built-in functions (possibly leftovers from testing as a loadable
module?).  Also, fix gratuitous inconsistency between SQL-level and
C-level names of the minmax support functions.
Fix JSON aggregates to work properly when final function is re-executed.

Davide S. reported that json_agg() sometimes produced multiple trailing
right brackets.  This turns out to be because json_agg_finalfn() attaches
the final right bracket, and was doing so by modifying the aggregate state
in-place.  That's verboten, though unfortunately it seems there's no way
for nodeAgg.c to check for such mistakes.

Fix that back to 9.3 where the broken code was introduced.  In 9.4 and
HEAD, likewise fix json_object_agg(), which had copied the erroneous logic.
Make some cosmetic cleanups as well.
Don't skip SQL backends in logical decoding for visibility computation.

The logical decoding patchset introduced PROC_IN_LOGICAL_DECODING flag
PGXACT flag, that allows such backends to be skipped when computing
the xmin horizon/snapshots. That's fine and sensible for walsenders
streaming out logical changes, but not at all fine for SQL backends
doing logical decoding. If the latter set that flag any change they
have performed outside of logical decoding will not be regarded as
visible - which e.g. can lead to that change being vacuumed away.

Note that not setting the flag for SQL backends isn't particularly
bothersome - the SQL backend doesn't do streaming, so it only runs for
a limited amount of time.

Per buildfarm member 'tick' and Alvaro.

Backpatch to 9.4, where logical decoding was introduced.
Improve error messages for malformed array input strings.

Make the error messages issued by array_in() uniformly follow the style
	ERROR: malformed array literal: "actual input string"
	DETAIL: specific complaint here
and rewrite many of the specific complaints to be clearer.

The immediate motivation for doing this is a complaint from Josh Berkus
that json_to_record() produced an unintelligible error message when
dealing with an array item, because it tries to feed the JSON-format
array value to array_in().  Really it ought to be smart enough to
perform JSON-to-Postgres array conversion, but that's a future feature
not a bug fix.  In the meantime, this change is something we agreed
we could back-patch into 9.4, and it should help de-confuse things a bit.
Install kludges to fix check-world for src/test/modules

check-world failed in a completely clean tree, because src/test/modules
fail to build unless errcodes.h is generated first.  To fix this,
install a dependency in src/test/modules' Makefile so that the necessary
file is generated.  Even with this, running "make check" within
individual module subdirs will still fail because the dependency is not
considered there, but this case is less interesting and would be messier
to fix.

check-world still failed with the above fix in place, this time because
dummy_seclabel used LOAD to load the dynamic library, which doesn't work
because the @libdir@ (expanded by the makefile) is expanded to the final
install path, not the temporary installation directory used by make
check.  To fix, tweak things so that CREATE EXTENSION can be used
instead, which solves the problem because the library path is expanded
by the backend, which is aware of the true libdir.
Fix whitespace
Fix typos