Fix lastReplayedEndRecPtr calculation when starting from shutdown checkpoint.

When entering crash recovery followed by archive recovery, and the latest
checkpoint is a shutdown checkpoint, and there are no more WAL records to
replay before transitioning from crash to archive recovery, we would not
immediately allow read-only connections in hot standby mode even if we
could. That's because when starting from a shutdown checkpoint, we set
lastReplayedEndRecPtr incorrectly to the record before the checkpoint
record, instead of the checkpoint record itself. We don't run the redo
routine of the shutdown checkpoint record, but starting recovery from it
goes through the same motions, so it should be considered as replayed.

Reported by Kyotaro HORIGUCHI. All versions with hot standby are affected,
so backpatch to 9.0.
Do wal_level and hot standby checks when doing crash-then-archive recovery.

CheckRequiredParameterValues() should perform the checks if archive recovery
was requested, even if we are going to perform crash recovery first.

Reported by Kyotaro HORIGUCHI. Backpatch to 9.2, like the crash-then-archive
recovery mode.
Allocate fresh memory for post_opts/exec_path

Instead of having read_post_opts() depend on the memory allocated for
the config file (which is now getting free'd), pg_strdup() for
post_opts and exec_path (similar to how it's being done elsewhere).

Noted by Thom Brown.
pg_upgrade:  improve C comment about what old/new oids match
Remove the correct pgstat file on DROP DATABASE

We were unlinking the permanent file, not the non-permanent one.  But
since the stat collector already unlinks all permanent files on startup,
there was nothing for it to unlink.  The non-permanent file remained in
place, and was copied to the permanent directory on shutdown, so in
effect no file was ever dropped.

Backpatch to 9.3, where the issue was introduced by commit 187492b6c2e8.
Before that, there were no per-database files and thus no file to drop
on DROP DATABASE.

Per report from Thom Brown.

Author: Tomáš Vondra
Remove unused field "evttype".

Apparent oversight in commit 3855968f.
Fix test_decoding regression test outputs.

Commit 6f37c08057685ee3c6c63222dba0dac012760dde removed whitespace
from the SQL file but not the expected-output file, and commit
7e8db2dc420099df3fa73987cf2d2d6d1a609d86 changed the error message
without updating the expected outputs.
Fix some typos introduced by the logical decoding patch.

Erik Rijkers
Add comment that ec_relids excludes "child" EquivalenceClass members.

This was already documented a few lines further down, but the comment
just beside the field declaration could be misleading.  Per gripe
from Kyotaro Horiguchi.
Fix portability issues in recently added make_timestamp/make_interval code.

Explicitly reject infinity/NaN inputs, rather than just assuming that
something else will do it for us.  Per buildfarm.

While at it, make some over-parenthesized and under-legible code
more readable.
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.