pg_dump:  make argument combination error exit code consistent

Per report from Pavel Golub
docs:  to_timestamp and to_date do minimal range checking

Initial patch from Steve Crawford
C comment update: relfilenode is only unique with a tablespace

Report from Antonin Houska
Don't reject ROW_MARK_REFERENCE rowmarks for materialized views.

We should allow this so that matviews can be referenced in UPDATE/DELETE
statements in READ COMMITTED isolation level.  The requirement for that
is that a re-fetch by TID will see the same row version the query saw
earlier, which is true of matviews, so there's no reason for the
restriction.  Per bug #9398.

Michael Paquier, after a suggestion by me
Send keepalives from walsender even when busy sending WAL.

If walsender doesn't hear from the client for the time specified by
wal_sender_timeout, it will conclude the connection or client is dead, and
disconnect. When half of wal_sender_timeout has elapsed, it sends a ping
to the client, leaving it the remainig half of wal_sender_timeout to
respond. However, it only checked if half of wal_sender_timeout had elapsed
when it was about to sleep, so if it was busy sending WAL to the client for
long enough, it would not send the ping request in time. Then the client
would not know it needs to send a reply, and the walsender will disconnect
even though the client is still alive. Fix that.

Andres Freund, reviewed by Robert Haas, and some further changes by me.
Backpatch to 9.3. Earlier versions relied on the client to send the
keepalives on its own, and hence didn't have this problem.
isdigit() needs an unsigned char argument.

Per the C standard, the routine should be passed an int, with a value that's
representable as an unsigned char or EOF. Passing a signed char is wrong,
because a negative value is not representable as an unsigned char.
Unfortunately no compiler warns about that.
Avoid getting more than AccessShareLock when deparsing a query.

In make_ruledef and get_query_def, we have long used AcquireRewriteLocks
to ensure that the querytree we are about to deparse is up-to-date and
the schemas of the underlying relations aren't changing.  Howwever, that
function thinks the query is about to be executed, so it acquires locks
that are stronger than necessary for the purpose of deparsing.  Thus for
example, if pg_dump asks to deparse a rule that includes "INSERT INTO t",
we'd acquire RowExclusiveLock on t.  That results in interference with
concurrent transactions that might for example ask for ShareLock on t.
Since pg_dump is documented as being purely read-only, this is unexpected.
(Worse, it used to actually be read-only; this behavior dates back only
to 8.1, cf commit ba4200246.)

Fix this by adding a parameter to AcquireRewriteLocks to tell it whether
we want the "real" execution locks or only AccessShareLock.

Report, diagnosis, and patch by Dean Rasheed.  Back-patch to all supported
branches.
Fix name of syslog_ident GUC in docs.

Michael Paquier
Avoid memcpy() with same source and destination address.

The behavior of that is undefined, although unlikely to lead to problems in
practice.

Found by running regression tests with Valgrind.
Fix dangling smgr_owner pointer when a fake relcache entry is freed.

A fake relcache entry can "own" a SmgrRelation object, like a regular
relcache entry. But when it was free'd, the owner field in SmgrRelation
was not cleared, so it was left pointing to free'd memory.

Amazingly this apparently hasn't caused crashes in practice, or we would've
heard about it earlier. Andres found this with Valgrind.

Report and fix by Andres Freund, with minor modifications by me. Backpatch
to all supported versions.
fix ReplicationSlotsCountDBSlots for dropping unrelated databases

YAMAMOTO Takashi
release notes:  add item missed in 9.2.5 release

Item is "Prevent errors in WAL replay due to references to uninitialized
empty pages".

Report and text by Andres Freund

Backpatch through 9.2.
Fix contrib/postgres_fdw to handle multiple join conditions properly.

The previous coding supposed that it could consider just a single join
condition in any one parameterized path for the foreign table.  But in
reality, the parameterized-path machinery forces all join clauses that are
"movable to" the foreign table to be evaluated at that node; including
clauses that we might not consider safe to send across.  Such cases would
result in an Assert failure in an assert-enabled build, and otherwise in
sending an unsafe clause to the foreign server, which might result in
errors or silently-wrong answers.  A lesser problem was that the
cost/rowcount estimates generated for the parameterized path failed to
account for any additional join quals that get assigned to the scan.

To fix, rewrite postgresGetForeignPaths so that it correctly collects all
the movable quals for any one outer relation when generating parameterized
paths; we'll now generate just one path per outer relation not one per join
qual.  Also fix bogus assumptions in postgresGetForeignPlan and
estimate_path_cost_size that only safe-to-send join quals will be
presented.

Based on complaint from Etsuro Fujita that the path costs were being
miscalculated, though this is significantly different from his proposed
patch.
Remove unportable use of anonymous unions from reorderbuffer.h.

In b89e151054a I had assumed it was ok to use anonymous unions as
struct members, but while a longstanding extension in many compilers,
it's only been standardized in C11.

To fix, remove one of the anonymous unions which tried to hide some
implementation specific enum values and give the other a name. The
latter unfortunately requires changes in output plugins, but since the
feature has only been added a few days ago...

Andres Freund
docs:  improve TABLE command by showing supported clauses

Initial patch by Colin 't Hart
doc: improve server's keepalive description

Use superior libpq keepalive description for the server-level
parameters.

Per report by Tatsuo Ishii and Marko Tiikkaja
pg_upgrade: document delete problems with tablespaces inside the cluster directory

Per report by Marc Mamin
docs:  small adjustements to recent SELECT and pg_upgrade improvements
pg_ctl:  improve handling of invalid data directory

Return '4' and report a meaningful error message when a non-existent or
invalid data directory is passed.  Previously, pg_ctl would just report
the server was not running.

Patch by me and Amit Kapila
Report from Peter Eisentraut
C comments: improve description of relfilenode uniqueness

Report by Antonin Houska