It is set correctly on the only path that uses it, but the
compiler can't know that.

This probably needs more work, but it's a start.

KaiGai Kohei

Laurenz Albe, somewhat modified by me.

Per a request from Greg Smith.

This entails adjusting pgbench to use getopt_long() rather
than getopt().

On balance, the need to cover this case changes my mind in favor of pushing
all error-message generation duties into the two fe-secure.c routines.
So do it that way.

In many cases, pqsecure_read/pqsecure_write set up useful error messages,
which were then overwritten with useless ones by their callers.  Fix this
by defining the responsibility to set an error message to be entirely that
of the lower-level function when using SSL.

Back-patch to 8.3; the code is too different in 8.2 to be worth the
trouble.

This disables an entirely unnecessary "sanity check" that causes failures
in nonblocking mode, because OpenSSL complains if we move or compact the
write buffer.  The only actual requirement is that we not modify pending
data once we've attempted to send it, which we don't.  Per testing and
research by Martin Pihlak, though this fix is a lot simpler than his patch.

I put the same change into the backend, although it's less clear whether
it's necessary there.  We do use nonblock mode in some situations in
streaming replication, so seems best to keep the same behavior in the
backend as in libpq.

Back-patch to all supported releases.

creating and removing a file because access() doesn't work on that
platform.

Backpatch to 9.1 where this check was added.

Also change "switch" to "arg" because "switch" is a bit of a sloppy
term.  So the environment variable is called
PSQL_EDITOR_LINENUMBER_ARG.  Set "+" as hardcoded default value on
Unix (since "vi" is the hardcoded default editor), so many users won't
have to configure this at all.  Move the documentation around a bit to
centralize the editor configuration under environment variables,
rather than repeating bits of it under every backslash command that
invokes an editor.

The original implementation simply did nothing when replacing an existing
object during CREATE EXTENSION.  The folly of this was exposed by a report
from Marc Munro: if the existing object belongs to another extension, we
are left in an inconsistent state.  We should insist that the object does
not belong to another extension, and then add it to the current extension
if not already a member.

I broke this in commit 5da79169, which
was obviously insufficiently well tested.  Add some regression tests
in the hope of making future slip-ups more likely to be noticed.

writes for logging.

PQsetvalue unnecessarily duplicated the logic in pqAddTuple, and didn't
duplicate it exactly either --- pqAddTuple does not care what is in the
tuple-pointer array positions beyond the last valid entry, whereas the
code in PQsetvalue assumed such positions would contain NULL.  This led
to possible crashes if PQsetvalue was applied to a PGresult that had
previously been enlarged with pqAddTuple, for instance one built from a
server query.  Fix by relying on pqAddTuple instead of duplicating logic,
and not assuming anything about the contents of res->tuples[res->ntups].

Back-patch to 8.4, where PQsetvalue was introduced.

Andrew Chernow

Previously, xpath() simply returned an empty array if the expression did
not yield a node set.  This is useless for expressions that return scalars,
such as one with name() at the top level.  Arrange to return the scalar
value as a single-element xml array, instead.  (String values will be
suitably escaped.)

This change will also cause xpath_exists() to return true, not false,
for such expressions.

Florian Pflug, reviewed by Radoslaw Smogura

Without this it's possible for the output to not be legal XML, as
illustrated by the added regression test cases.

NB: this change will need to be called out as an incompatibility in the
9.2 release notes, since it's possible somebody was relying on the old
behavior, even though it's clearly wrong.

Florian Pflug, reviewed by Radoslaw Smogura

Also, double-quote the log file name in all places, to allow (on all
platforms) log file names with spaces.

Back patch to 9.0 and 9.1.

This requires a new shared catalog, pg_shseclabel.

Along the way, fix the security_label regression tests so that they
don't monkey with the labels of any pre-existing objects.  This is
unlikely to matter in practice, since only the label for the "dummy"
provider was being manipulated.  But this way still seems cleaner.

KaiGai Kohei, with fairly extensive hacking by me.

libxml reports some errors (like invalid xmlns attributes) via the error
handler hook, but still returns a success indicator to the library caller.
This causes us to miss some errors that are important to report.  Since the
"generic" error handler hook doesn't know whether the message it's getting
is for an error, warning, or notice, stop using that and instead start
using the "structured" error handler hook, which gets enough information
to be useful.

While at it, arrange to save and restore the error handler hook setting in
each libxml-using function, rather than assuming we can set and forget the
hook.  This should improve the odds of working nicely with third-party
libraries that also use libxml.

In passing, volatile-ize some local variables that get modified within
PG_TRY blocks.  I noticed this while testing with an older gcc version
than I'd previously tried to compile xml.c with.

Florian Pflug and Tom Lane, with extensive review/testing by Noah Misch

KaiGai Kohei, based on feedback from Yeb Havinga, with some
corrections by me.

This is a bit more consistent with the way pg_description is
documented, and also include a useful cross-link.

Noah Misch diagnosed the buildfarm problems in the isolation tests
partly as failure to differentiate backends properly; the old code was
using backend IDs, which is not good enough because a new backend might
use an already used ID.  Use PIDs instead.

Also, the code was purposely careless about other concurrent activity,
because it isn't expected; and in fact, it doesn't affect the vast
majority of the time.  However, it can be observed that autovacuum can
block tables for long enough to cause sporadic failures.  The new code
accounts for that by ignoring locks held by processes not explicitly
declared in our spec file.

Author: Noah Misch

The previous value of 20ms is dangerously close to the time actually
spent just waiting for the deadlock to happen, so on occasion it causes
the test to fail simply because the other session didn't get to run
early enough, not managing to cause the deadlock that needs to be
detected.  With this new value, it's expected that most machines on
normal load will be able to pass the test.

Author: Noah Misch

These new files allow the new FK tests on isolationtester to pass on the
serializable and repeatable read isolation levels (which are untested
by the buildfarm).

Author: Kevin Grittner
Reviewed by Noah Misch

Subtransaction locks now released en masse at main commit, rather than
repeatedly re-scanning for locks as we ascend the nested transaction tree.
Split transaction state TBLOCK_SUBEND into two states, TBLOCK_SUBCOMMIT
and TBLOCK_SUBRELEASE to allow the commit path to be optimised using
the existing code in ResourceOwnerRelease() which appears to have been
intended for this usage, judging from comments therein.

1. In GetLockStatusData, avoid initializing instance before we've ensured
that the array is large enough.  Otherwise, if repalloc moves the block
around, we're hosed.

2. Add the word "Relation" to the name of some identifiers, to avoid
assuming that the fast-path mechanism will only ever apply to relations
(though these particular parts certainly will).  Some of the macros
could possibly use similar treatment, but the names are getting awfully
long already.

3. Add a missing word to comment in AtPrepare_Locks().

Reported by Peter Eisentraut.

Fujii Masao

gcc -Wextra complains that the other way around is obsolescent, and
this was the only place where it was written in this order.

Standby servers can now have WALSender processes, which can work with
either WALReceiver or archive_commands to pass data. Fully updated
docs, including new conceptual terms of sending server, upstream and
downstream servers. WALSenders terminated when promote to master.

Fujii Masao, review, rework and doc rewrite by Simon Riggs

This is more SQL-spec-compliant, more easily extensible, and better
performing than the old method of inventing special variables.

Pavel Stehule, reviewed by Shigeru Hanada and David Wheeler

Noah Misch.  Review and minor cosmetic changes by me.

Patch originally by Akira Kurosawa <kurosawa-akira@mxc.nes.nec.co.jp>.

When an AccessShareLock, RowShareLock, or RowExclusiveLock is requested
on an unshared database relation, and we can verify that no conflicting
locks can possibly be present, record the lock in a per-backend queue,
stored within the PGPROC, rather than in the primary lock table.  This
eliminates a great deal of contention on the lock manager LWLocks.

This patch also refactors the interface between GetLockStatusData() and
pg_lock_status() to be a bit more abstract, so that we don't rely so
heavily on the lock manager's internal representation details.  The new
fast path lock structures don't have a LOCK or PROCLOCK structure to
return, so we mustn't depend on that for purposes of listing outstanding
locks.

Review by Jeff Davis.