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
doc: remove extra whitespace in SGML markup
Correct copy/pasto in comment for REPLICA IDENTITY
Teach on_exit_reset() to discard pending cleanups for dsm.

If a postmaster child invokes fork() and then calls on_exit_reset, that
should be sufficient to let it exit() without breaking anything, but
dynamic shared memory broke that by not updating on_exit_reset() to
discard callbacks registered with dynamic shared memory segments.

Per investigation of a complaint from Tom Lane.
Allow logical decoding via the walsender interface.

In order for this to work, walsenders need the optional ability to
connect to a database, so the "replication" keyword now allows true
or false, for backward-compatibility, and the new value "database"
(which causes the "dbname" parameter to be respected).

walsender needs to loop not only when idle but also when sending
decoded data to the user and when waiting for more xlog data to decode.
This means that there are now three separate loops inside walsender.c;
although some refactoring has been done here, this is still a bit ugly.

Andres Freund, with contributions from Álvaro Herrera, and further
review by me.
Allow dynamic shared memory segments to be kept until shutdown.

Amit Kapila, reviewed by Kyotaro Horiguchi, with some further
changes by me.
Fix tracking of psql script line numbers during \copy from another place.

Commit 08146775acd8bfe0fcc509c71857abb928697171 changed do_copy() to
temporarily scribble on pset.cur_cmd_source.  That was a mighty ugly bit of
code in any case, but in particular it broke handleCopyIn's ability to tell
whether it was reading from the current script source file (in which case
pset.lineno should be incremented for each line of COPY data), or from
someplace else (in which case it shouldn't).  The former case still worked,
the latter not so much.  The visible effect was that line numbers reported
for errors in a script file would be wrong if there were an earlier \copy
that was reading anything other than inline-in-the-script-file data.

To fix, introduce another pset field that holds the file do_copy wants the
COPY code to use.  This is a little bit ugly, but less so than passing the
file down explicitly through several layers that aren't COPY-specific.

Extracted from a larger patch by Kumar Rajeev Rastogi; that patch also
changes printing of COPY command tags, which is not a bug fix and shouldn't
get back-patched.  This particular idea was from a suggestion by Amit
Khandekar, if I'm reading the thread correctly.

Back-patch to 9.2 where the faulty code was introduced.