Add tab-completion for ALTER TABLE ALTER CONSTRAINT in psql.

Back-patch to 9.4 where ALTER TABLE ALTER CONSTRAINT was added.

Michael Paquier, bug reported by Andrey Lizenko.
Improve typcache: cache negative lookup results, add invalidation logic.

Previously, if the typcache had for example tried and failed to find a hash
opclass for a given data type, it would nonetheless repeat the unsuccessful
catalog lookup each time it was asked again.  This can lead to a
significant amount of useless bufmgr traffic, as in a recent report from
Scott Marlowe.  Like the catalog caches, typcache should be able to cache
negative results.  This patch arranges that by making use of separate flag
bits to remember whether a particular item has been looked up, rather than
treating a zero OID as an indicator that no lookup has been done.

Also, install a credible invalidation mechanism, namely watching for inval
events in pg_opclass.  The sole advantage of the lack of negative caching
was that the code would cope if operators or opclasses got added for a type
mid-session; to preserve that behavior we have to be able to invalidate
stale lookup results.  Updates in pg_opclass should be pretty rare in
production systems, so it seems sufficient to just invalidate all the
dependent data whenever one happens.

Adding proper invalidation also means that this code will now react sanely
if an opclass is dropped mid-session.  Arguably, that's a back-patchable
bug fix, but in view of the lack of complaints from the field I'll refrain
from back-patching.  (Probably, in most cases where an opclass is dropped,
the data type itself is dropped soon after, so that this misfeasance has
no bad consequences.)
Improve performance of OverrideSearchPathMatchesCurrent().

This function was initially coded on the assumption that it would not be
performance-critical, but that turns out to be wrong in workloads that
are heavily dependent on the speed of plpgsql functions.  Speed it up by
hard-coding the comparison rules, thereby avoiding palloc/pfree traffic
from creating and immediately freeing an OverrideSearchPath object.
Per report from Scott Marlowe.
Add bms_next_member(), and use it where appropriate.

This patch adds a way of iterating through the members of a bitmapset
nondestructively, unlike the old way with bms_first_member().  While
bms_next_member() is very slightly slower than bms_first_member()
(at least for typical-size bitmapsets), eliminating the need to palloc
and pfree a temporary copy of the target bitmapset is a significant win.
So this method should be preferred in all cases where a temporary copy
would be necessary.

Tom Lane, with suggestions from Dean Rasheed and David Rowley
Add bms_get_singleton_member(), and use it where appropriate.

This patch adds a function that replaces a bms_membership() test followed
by a bms_singleton_member() call, performing both the test and the
extraction of a singleton set's member in one scan of the bitmapset.
The performance advantage over the old way is probably minimal in current
usage, but it seems worthwhile on notational grounds anyway.

David Rowley
Update transaction README for persistent multixacts

Multixacts are now maintained during recovery, but the README didn't get
the memo.  Backpatch to 9.3, where the divergence was introduced.
Fix BRIN operator family definitions

The original definitions were leaving no room for cross-type operators,
so queries that compared a column of one type against something of a
different type were not taking advantage of the index.  Fix by making
the opfamilies more like the ones for Btree, and include a few
cross-type operator classes.

Catalog version bumped.

Per complaints from Hubert Lubaczewski, Mark Wong, Heikki Linnakangas.
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