Create the beginnings of internals documentation for the regex code.

Create src/backend/regex/README to hold an implementation overview of
the regex package, and fill it in with some preliminary notes about
the code's DFA/NFA processing and colormap management.  Much more to
do there of course.

Also, improve some code comments around the colormap and cvec code.
No functional changes except to add one missing assert.
Add caching of ctype.h/wctype.h results in regc_locale.c.

While this doesn't save a huge amount of runtime, it still seems worth
doing, especially since I realized that the data copying I did in my first
draft was quite unnecessary.  In this version, once we have the results
cached, getting them back for re-use is really very cheap.

Also, remove the hard-wired limitation to not consider wctype.h results for
character codes above 255.  It turns out that we can't push the limit as
far up as I'd originally hoped, because the regex colormap code is not
efficient enough to cope very well with character classes containing many
thousand letters, which a Unicode locale is entirely capable of producing.
Still, we can push it up to U+7FF (which I chose as the limit of 2-byte
UTF8 characters), which will at least make Eastern Europeans happy pending
a better solution.  Thus, this commit resolves the specific complaint in
bug #6457, but not the more general issue that letters of non-western
alphabets are mostly not recognized as matching [[:alpha:]].
Fix regex back-references that are directly quantified with *.

The syntax "\n*", that is a backref with a * quantifier directly applied
to it, has never worked correctly in Spencer's library.  This has been an
open bug in the Tcl bug tracker since 2005:
https://sourceforge.net/tracker/index.php?func=detail&aid=1115587&group_id=10894&atid=110894

The core of the problem is in parseqatom(), which first changes "\n*" to
"\n+|" and then applies repeat() to the NFA representing the backref atom.
repeat() thinks that any arc leading into its "rp" argument is part of the
sub-NFA to be repeated.  Unfortunately, since parseqatom() already created
the arc that was intended to represent the empty bypass around "\n+", this
arc gets moved too, so that it now leads into the state loop created by
repeat().  Thus, what was supposed to be an "empty" bypass gets turned into
something that represents zero or more repetitions of the NFA representing
the backref atom.  In the original example, in place of
	^([bc])\1*$
we now have something that acts like
	^([bc])(\1+|[bc]*)$
At runtime, the branch involving the actual backref fails, as it's supposed
to, but then the other branch succeeds anyway.

We could no doubt fix this by some rearrangement of the operations in
parseqatom(), but that code is plenty ugly already, and what's more the
whole business of converting "x*" to "x+|" probably needs to go away to fix
another problem I'll mention in a moment.  Instead, this patch suppresses
the *-conversion when the target is a simple backref atom, leaving the case
of m == 0 to be handled at runtime.  This makes the patch in regcomp.c a
one-liner, at the cost of having to tweak cbrdissect() a little.  In the
event I went a bit further than that and rewrote cbrdissect() to check all
the string-length-related conditions before it starts comparing characters.
It seems a bit stupid to possibly iterate through many copies of an
n-character backreference, only to fail at the end because the target
string's length isn't a multiple of n --- we could have found that out
before starting.  The existing coding could only be a win if integer
division is hugely expensive compared to character comparison, but I don't
know of any modern machine where that might be true.

This does not fix all the problems with quantified back-references.  In
particular, the code is still broken for back-references that appear within
a larger expression that is quantified (so that direct insertion of the
quantification limits into the BACKREF node doesn't apply).  I think fixing
that will take some major surgery on the NFA code, specifically introducing
an explicit iteration node type instead of trying to transform iteration
into concatenation of modified regexps.

Back-patch to all supported branches.  In HEAD, also add a regression test
case for this.  (It may seem a bit silly to create a regression test file
for just one test case; but I'm expecting that we will soon import a whole
bunch of regex regression tests from Tcl, so might as well create the
infrastructure now.)
Fix a couple of cases of JSON output.

First, as noted by Itagaki Takahiro, a datum of type JSON doesn't
need to be escaped. Second, ensure that numeric output not in
the form of a legal JSON number is quoted and escaped.
Don't reject threaded Python on FreeBSD.

According to Chris Rees, this has worked for awhile, and the current
FreeBSD port is removing the test anyway.
pg_regress: Add application name setting

Set the PGAPPNAME environment variable in pg_regress so that it
identifies itself as such instead of "psql".
Fix typo, noticed by Will Crawford.
Avoid double close of file handle in syslogger on win32

This causes an exception when running under a debugger or in particular
when running on a debug version of Windows.

Patch from MauMau
Cosmetic cleanup for commit a760893dbda9934e287789d54bbd3c4ca3914ce0.

Mostly, fixing overlooked comments.
Don't clear btpo_cycleid during _bt_vacuum_one_page.

When "vacuuming" a single btree page by removing LP_DEAD tuples, we are not
actually within a vacuum operation, but rather in an ordinary insertion
process that could well be running concurrently with a vacuum.  So clearing
the cycleid is incorrect, and could cause the concurrent vacuum to miss
removing tuples that it needs to remove.  This is a longstanding bug
introduced by commit e6284649b9e30372b3990107a082bc7520325676 of
2006-07-25.  I believe it explains Maxim Boguk's recent report of index
corruption, and probably some other previously unexplained reports.

In 9.0 and up this is a one-line fix; before that we need to introduce a
flag to tell _bt_delitems what to do.
REASSIGN OWNED: Support foreign data wrappers and servers

This was overlooked when implementing those kinds of objects, in commit
cae565e503c42a0942ca1771665243b4453c5770.

Per report from Pawel Casperek.
Add parameters for controlling locations of server-side SSL files

This allows changing the location of the files that were previously
hard-coded to server.crt, server.key, root.crt, root.crl.

server.crt and server.key continue to be the default settings and are
thus required to be present by default if SSL is enabled.  But the
settings for the server-side CA and CRL are now empty by default, and
if they are set, the files are required to be present.  This replaces
the previous behavior of ignoring the functionality if the files were
not found.
Draft release notes for 9.1.3, 9.0.7, 8.4.11, 8.3.18.
Improve wording of pg_upgrade logfile option:

  -l, --logfile=FILENAME        log internal activity to file\n\
Fix typo in comment.

Sandro Santilli
Make EXPLAIN (BUFFERS) track blocks dirtied, as well as those written.

Also expose the new counters through pg_stat_statements.

Patch by me.  Review by Fujii Masao and Greg Smith.
Don't install hstore--1.0.sql any more.

Since the current version is 1.1, the 1.0 file isn't really needed.  We do
need the 1.0--1.1 upgrade file, so people on 1.0 can upgrade.

Per recent discussion on pgsql-hackers.
Fix build without OpenSSL

This is a fixup for commit a445cb92ef5b3a31313ebce30e18cc1d6e0bdecb.
Remove inappropriate quotes

And adjust wording for consistency.
Allow MinGW builds to use standardly-named OpenSSL libraries.

In the Fedora variant of MinGW, the openssl libraries have their normal
names, not libeay32 and libssleay32.  Adjust configure probes to allow
that, per bug #6486.

Tomasz Ostrowski