Backpatch to 9.3.

Backpatch to 9.3, of course.

Per discussion on pgsql-hackers.

Michael Paquier, slightly modified by me.  Original suggestion
from Amit Kapila.

Register atexit() server shutdown if pg_ctl successfully started the
server, but we can't connect to it.

Backpatch to 9.3.

Pavel Raiskup

Was accidentally allowed, but not documented and lacked support
for rename or drop once created.

Per report from Noah Misch.

Timeline IDs are unsigned ints everywhere, except the replication parser
treated them as signed ints.

Avoid using the term "updatable" in confusing ways.  Suggest a trigger
first, before a rule.

The planner logic that attempted to make a preliminary estimate of the
ph_needed levels for PlaceHolderVars seems to be completely broken by
lateral references.  Fortunately, the potential join order optimization
that this code supported seems to be of relatively little value in
practice; so let's just get rid of it rather than trying to fix it.

Getting rid of this allows fairly substantial simplifications in
placeholder.c, too, so planning in such cases should be a bit faster.

Issue noted while pursuing bugs reported by Jeremy Evans and Antonin
Houska, though this doesn't in itself fix either of their reported cases.
What this does do is prevent an Assert crash in the kind of query
illustrated by the added regression test.  (I'm not sure that the plan for
that query is stable enough across platforms to be usable as a regression
test output ... but we'll soon find out from the buildfarm.)

Back-patch to 9.3.  The problem case can't arise without LATERAL, so
no need to touch older branches.

This syntax is supported by the parser, but is non-standard.

_Not_ backpatched to 9.3 in case we change our minds.

We don't want to prevent an extension which creates a matview from
being installed in pg_catalog.

Issue was raised by Hitoshi Harada.
Backpatched to 9.3.

Update emacs.samples with new configuration snippets that match pgindent
et al. formatting more accurately and follow Emacs Lisp best practices
better.

Add .dir-locals.el with a subset of that configuration for casual
editing and viewing.
Reviewed-by: NDimitri Fontaine <dimitri@2ndQuadrant.fr>
Reviewed-by: NNoah Misch <noah@leadboat.com>

We've seen multiple cases of people looking at the postmaster's original
stderr output to try to diagnose problems, not realizing/remembering that
their logging configuration is set up to send log messages somewhere else.
This seems particularly likely to happen in prepackaged distributions,
since many packagers patch the code to change the factory-standard logging
configuration to something more in line with their platform conventions.

In hopes of reducing confusion, emit a LOG message about this at the point
in startup where we are about to switch log output away from the original
stderr, providing a pointer to where to look instead.  This message will
appear as the last thing in the original stderr output.  (We might later
also try to emit such link messages when logging parameters are changed
on-the-fly; but that case seems to be both noticeably harder to do nicely,
and much less frequently a problem in practice.)

Per discussion, back-patch to 9.3 but not further.

Move item about foreign data wrappers supporting inserts/updates/deletes
to object manipulation.

From Etsuro Fujita

We already use search_path to specify the schema, so there is no need
for pg_dump to schema-qualify the name.  Also remove dead code.

Similar to 2cfb1c6f, the order in which
dictionary elements are printed is not reliable.  This reappeared in the
tests of the string representation of result objects.  Reduce the test
case to one result set column so that there is no question of order.

(Yes, there was no UTC back then, but we compute it that way.)
Backpatch to 9.3.

Backpatch to 9.3.
Per request from Marc Dahn

In PM_WAIT_DEAD_END state, checkpointer process must be dead already.
But an immediate shutdown could make postmaster's state machine
transition to PM_WAIT_DEAD_END state even if checkpointer process is
still running,  and which caused assertion failure. This bug was introduced
in commit 457d6cf0.

This patch ensures that postmaster's state machine doesn't transition to
PM_WAIT_DEAD_END state in an immediate shutdown while checkpointer
process is running.

Previously only -n was recognized.

Formerly, query_planner returned one or possibly two Paths for the topmost
join relation, so that grouping_planner didn't see the join RelOptInfo
(at least not directly; it didn't have any hesitation about examining
cheapest_path->parent, though).  However, correct selection of the Paths
involved a significant amount of coupling between query_planner and
grouping_planner, a problem which has gotten worse over time.  It seems
best to give up on this API choice and instead return the topmost
RelOptInfo explicitly.  Then grouping_planner can pull out the Paths it
wants from the rel's path list.  In this way we can remove all knowledge
of grouping behaviors from query_planner.

The only real benefit of the old way is that in the case of an empty
FROM clause, we never made any RelOptInfos at all, just a Path.  Now
we have to gin up a dummy RelOptInfo to represent the empty FROM clause.
That's not a very big deal though.

While at it, simplify query_planner's API a bit more by having the caller
set up root->tuple_fraction and root->limit_tuples, rather than passing
those values as separate parameters.  Since query_planner no longer does
anything with either value, requiring it to fill the PlannerInfo fields
seemed pretty arbitrary.

This patch just rearranges code; it doesn't (intentionally) change any
behaviors.  Followup patches will do more interesting things.

Open and lock each index before checking definition in RMVC.  The
ExclusiveLock on the related table is not viewed as sufficient to
ensure that no changes are made to the index definition, and
invalidation messages from other backends might have been missed.
Additionally, use RelationGetIndexExpressions() and check for NIL
rather than doing our own loop.

Protect against redefinition of tid and rowvar operators in RMVC.
While working on this, noticed that the fixes for bugs found during
the CF made the UPDATE statement useless, since no rows could
qualify for that treatment any more.  Ripping out code to support
the UPDATE statement simplified the operator cleanups.

Change slightly confusing local field name.

Use meaningful alias names on queries in refresh_by_match_merge().

Per concerns of raised by Andres Freund and comments and
suggestions from Noah Misch.  Some additional issues remain, which
will be addressed separately.

The C99 and POSIX standards require strtod() to accept all these spellings
(case-insensitively): "inf", "+inf", "-inf", "infinity", "+infinity",
"-infinity".  However, pre-C99 systems might accept only some or none of
these, and apparently Windows still doesn't accept "inf".  To avoid
surprising cross-platform behavioral differences, manually check for each
of these spellings if strtod() fails.  We were previously handling just
"infinity" and "-infinity" that way, but since C99 is most of the world
now, it seems likely that applications are expecting all these spellings
to work.

Per bug #8355 from Basil Peace.  It turns out this fix won't actually
resolve his problem, because Python isn't being this careful; but that
doesn't mean we shouldn't be.

If a tuple is locked but not updated by a concurrent transaction,
HeapTupleSatisfiesDirty would return that transaction's Xid in xmax,
causing callers to wait on it, when it is not necessary (in fact, if the
other transaction had used a multixact instead of a plain Xid to mark
the tuple, HeapTupleSatisfiesDirty would have behave differently and
*not* returned the Xmax).

This bug was introduced in commit 3f7fbf85, dated December 1998,
so it's almost 15 years old now.  However, it's hard to see this
misbehave, because before we had NOWAIT the only consequence of this is
that transactions would wait for slightly more time than necessary; so
it's not surprising that this hasn't been reported yet.

Craig Ringer and Andres Freund

My tweak of these error messages in commit c359a1b0 contained the
thinko that a query would always have rowMarks set for a query
containing a locking clause.  Not so: when declaring a cursor, for
instance, rowMarks isn't set at the point we're checking, so we'd be
dereferencing a NULL pointer.

The fix is to pass the lock strength to the function raising the error,
instead of trying to reverse-engineer it.  The result not only is more
robust, but it also seems cleaner overall.

Per report from Robert Haas.

Etsuro Fujita

Expand ops/sec by two digits to maintain alignment on servers with fast
I/O subsystems, e.g. can now display < 10M ops/sec with consistent
alignment.

We should really be reporting a useful error along with returning
a valid return code if pthread_mutex_lock() throws an error for
some reason.  Add that and back-patch to 9.0 as the prior patch.

Pointed out by Alvaro Herrera

Move the static functions after the comment and expand the comment.

Per complaint from Andres Freund, although using different comment
text.

Per gripes by Amit Kapila.

We now use MVCC catalog scans, and, per discussion, have eliminated
all other remaining uses of SnapshotNow, so that we can now get rid of
it.  This will break third-party code which is still using it, which
is intentional, as we want such code to be updated to do things the
new way.

I've been working with Nick Phillips on an issue he ran into when
trying to use threads with SSL client certificates.  As it turns out,
the call in initialize_SSL() to SSL_CTX_use_certificate_chain_file()
will modify our SSL_context without any protection from other threads
also calling that function or being at some other point and trying to
read from SSL_context.

To protect against this, I've written up the attached (based on an
initial patch from Nick and much subsequent discussion) which puts
locks around SSL_CTX_use_certificate_chain_file() and all of the other
users of SSL_context which weren't already protected.

Nick Phillips, much reworked by Stephen Frost

Back-patch to 9.0 where we started loading the cert directly instead of
using a callback.

As pointed out by Tom Lane, we can allow other users of the error
handler callbacks to provide their own memory context by adding
the context to use to ErrorData and using that instead of explicitly
using ErrorContext.

This then allows GetErrorContextStack() to be called from inside
exception handlers, so modify plpgsql to take advantage of that and
add an associated regression test for it.

Per Coverity

Patch by Ian Lawrence Barwick