Fix inaccurate description of tablespace.

Currently we don't need to update the pg_tablespace catalog
after redefining the symbolic links to the tablespaces
because pg_tablespace.spclocation column was removed in
PostgreSQL 9.2.

Back patch to 9.2 where pg_tablespace.spclocation was removed.

Ian Barwick, with minor change by me.
Fix typo in comment.

Hitoshi Harada
Fix regexp_matches() handling of zero-length matches.

We'd find the same match twice if it was of zero length and not immediately
adjacent to the previous match.  replace_text_regexp() got similar cases
right, so adjust this search logic to match that.  Note that even though
the regexp_split_to_xxx() functions share this code, they did not display
equivalent misbehavior, because the second match would be considered
degenerate and ignored.

Jeevan Chalke, with some cosmetic changes by me.
pg_dump/pg_dumpall:  remove unnecessary SQL trailing semicolons
Patch by Ian Lawrence Barwick
Fix a couple of inconsequential typos in new header
Fix mis-indented lines

Per Coverity
Allow a context to be passed in for error handling

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.
Add locking around SSL_context usage in libpq

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.
Remove SnapshotNow and HeapTupleSatisfiesNow.

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.
Assorted bgworker-related comment fixes.

Per gripes by Amit Kapila.
Improve comments for IncrementalMaintenance DML enabling functions.

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

Per complaint from Andres Freund, although using different comment
text.
Improve handling of pthread_mutex_lock error case

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
pg_test_fsync: expand ops/sec display
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.
Fix typo in comment.

Etsuro Fujita
Fix crash in error report of invalid tuple lock

My tweak of these error messages in commit c359a1b082 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.
Fix old visibility bug in HeapTupleSatisfiesDirty

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 3f7fbf85dc5b42, 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
Make sure float4in/float8in accept all standard spellings of "infinity".

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.
Various cleanups for REFRESH MATERIALIZED VIEW CONCURRENTLY.

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.
Simplify query_planner's API by having it return the top-level RelOptInfo.

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.
pgtest:  allow passing parameters, e.g. -s/--silent
Previously only -n was recognized.