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

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.

Per Coverity Scan

PGTYPEStimestamp_defmt_scan() was declared twice inside different .c
files, with slightly different prototypes.  Move it into a header file
and correct the prototype.

There are cases where the day of year value in struct tm is used, but it never
got calculated. Problem found by Coverity scan.

The returned error message already includes a newline, but the callers
were adding their own when printing it out.

mm_strdup() is provided to check errors from strdup(), but some places
were failing to use it.

On Unix-ish platforms, EWOULDBLOCK may be the same as EAGAIN, which is
*not* a success return, at least not on Linux.  We need to treat it as a
failure to avoid giving a misleading error message.  Per the Single Unix
Spec, only EINPROGRESS and EINTR returns indicate that the connection
attempt is in progress.

On Windows, on the other hand, EWOULDBLOCK (WSAEWOULDBLOCK) is the expected
case.  We must accept EINPROGRESS as well because Cygwin will return that,
and it doesn't seem worth distinguishing Cygwin from native Windows here.
It's not very clear whether EINTR can occur on Windows, but let's leave
that part of the logic alone in the absence of concrete trouble reports.

Also, remove the test for errno == 0, effectively reverting commit
da9501bd, which AFAICS was just a thinko;
or at best it might have been a workaround for a platform-specific bug,
which we can hope is gone now thirteen years later.  In any case, since
libpq makes no effort to reset errno to zero before calling connect(),
it seems unlikely that that test has ever reliably done anything useful.

Andres Freund and Tom Lane

Let the hacking begin ...

A few more minor spelling corrections, no functional changes.

Thom Brown

Make slightly better decisions about indentation than what pgindent
is capable of.  Mostly breaking out long function calls into one
line per argument, with a few other minor adjustments.

No functional changes- all whitespace.
pgindent ran cleanly (didn't change anything) after.
Passes all regressions.

This is the first run of the Perl-based pgindent script.  Also update
pgindent instructions.

Previously, libpq and the backend had opposite ideas about whether
it was necessary for the client to send a CopyDone message after
receiving an ErrorResponse, making it impossible to cleanly exit
COPY BOTH mode.  Fix libpq so that works correctly, adopting the
backend's notion that an ErrorResponse kills the copy in both
directions.

Adjust receivelog.c to avoid a degradation in the quality of the
resulting error messages.  libpqwalreceiver.c is already doing
the right thing, so no adjustment needed there.

Add an explicit statement to the documentation explaining how
this part of the protocol is supposed to work, in the hopes of
avoiding future confusion in this area.

Since the consequences of all this confusion are very limited,
especially in the back-branches where no client ever attempts
to exit COPY BOTH mode without closing the connection entirely,
no back-patch.

There's probably no real bug here at present, so not backpatching.
But it seems good to make these bits consistent with the rest of
libpq, so as to avoid future surprises.

Patch by me.  Review by Tom Lane.

In most cases, these were just references to the SQL standard in
general.  In a few cases, a contrast was made between SQL92 and later
standards -- those have been kept unchanged.

Only adjusted the user-exposed messages and documentation,  not all
source code comments.

This reverts commit 3780fc67.

HP-UX didn't like it.  There would probably be a way to fix that, but
since the net effect of all of this is zero because ecpg ends up using
libpq anyway, it's not worth bothering further.

This will hopefully be easier to use than pg_config for users who are
already used to the pkg-config interface.  It also works better for
multi-arch installations.

reviewed by Tom Lane

It doesn't actually use libpq.  But we need to keep libpq in the
CPPFLAGS for building, because compatlib uses ecpglib.h which uses
libpq-fe.h, but we don't need to refer to libpq for linking.

reviewed by Tom Lane

In some parallel make situations, the install-headers target could be
called before the installation directories are created by installdirs,
causing the installation to fail.  Fix that by making install-headers
depend on installdirs.

We need this in non-ENABLE_THREAD_SAFETY builds, and also to satisfy
the exports.txt entry; while it might be a good idea to remove the
latter, I'm hesitant to do so except in the context of an intentional
ABI break.  At least we don't have a separately maintained source file
for it anymore.

We had two copies of this function in the backend and libpq, which was
already pretty bogus, but it turns out that we need it in some other
programs that don't use libpq (such as pg_test_fsync).  So put it where
it probably should have been all along.  The signal-mask-initialization
support in src/backend/libpq/pqsignal.c stays where it is, though, since
we only need that in the backend.

I fixed this code back in commit 841b4a2d, but didn't think carefully
enough about the behavior near zero, which meant it improperly rejected
1999-12-31 24:00:00.  Per report from Magnus Hagander.

This includes backend "COPY TO/FROM PROGRAM '...'" syntax, and corresponding
psql \copy syntax. Like with reading/writing files, the backend version is
superuser-only, and in the psql version, the program is run in the client.

In the passing, the psql \copy STDIN/STDOUT syntax is subtly changed: if you
the stdin/stdout is quoted, it's now interpreted as a filename. For example,
"\copy foo from 'stdin'" now reads from a file called 'stdin', not from
standard input. Before this, there was no way to specify a filename called
stdin, stdout, pstdin or pstdout.

This creates a new function in pgport, wait_result_to_str(), which can
be used to convert the exit status of a process, as returned by wait(3),
to a human-readable string.

Etsuro Fujita, reviewed by Amit Kapila.

The backend grammar treats STDIN and STDOUT completely interchangeable, so
that the above accepted. Arguably that was a mistake the backend grammar,
but it's not ecpg's business to second guess that.

This patch addresses the problem that applications currently have to
extract object names from possibly-localized textual error messages,
if they want to know for example which index caused a UNIQUE_VIOLATION
failure.  It adds new error message fields to the wire protocol, which
can carry the name of a table, table column, data type, or constraint
associated with the error.  (Since the protocol spec has always instructed
clients to ignore unrecognized field types, this should not create any
compatibility problem.)

Support for providing these new fields has been added to just a limited set
of error reports (mainly, those in the "integrity constraint violation"
SQLSTATE class), but we will doubtless add them to more calls in future.

Pavel Stehule, reviewed and extensively revised by Peter Geoghegan, with
additional hacking by Tom Lane.

Bug reported and fixed by Chen Huajun <chenhj@cn.fujitsu.com>.

New command-line utility to test whether a server is ready to
accept connections.

Phil Sorber, reviewed by Michael Paquier and Peter Eisentraut

This bug goes back to the original Postgres95 sources.  Its significance
to modern PG versions is marginal, since we have not used PQprintTuples()
internally in a very long time, and it doesn't seem to have ever been
documented either.  Still, it *is* exposed to client apps, so somebody
out there might possibly be using it.

Xi Wang

This is now used by ecpg tests, and not clobbered by pg_upgrade
tests. This change won't affect anything that doesn't set this
environment variable, but will enable the buildfarm to control
exactly what port regression test installs will be running on,
and thus to detect possible rogue postmasters more easily.

Backpatch to release 9.2 where EXTRA_REGRESS_OPTS was first used.

Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.

Before this patch, streaming replication would refuse to start replicating
if the timeline in the primary doesn't exactly match the standby. The
situation where it doesn't match is when you have a master, and two
standbys, and you promote one of the standbys to become new master.
Promoting bumps up the timeline ID, and after that bump, the other standby
would refuse to continue.

There's significantly more timeline related logic in streaming replication
now. First of all, when a standby connects to primary, it will ask the
primary for any timeline history files that are missing from the standby.
The missing files are sent using a new replication command TIMELINE_HISTORY,
and stored in standby's pg_xlog directory. Using the timeline history files,
the standby can follow the latest timeline present in the primary
(recovery_target_timeline='latest'), just as it can follow new timelines
appearing in an archive directory.

START_REPLICATION now takes a TIMELINE parameter, to specify exactly which
timeline to stream WAL from. This allows the standby to request the primary
to send over WAL that precedes the promotion. The replication protocol is
changed slightly (in a backwards-compatible way although there's little hope
of streaming replication working across major versions anyway), to allow
replication to stop when the end of timeline reached, putting the walsender
back into accepting a replication command.

Many thanks to Amit Kapila for testing and reviewing various versions of
this patch.

Patch done by Jiang Guiqing <jianggq@cn.fujitsu.com>.