PostgreSQL 9.2.17 commit log

commit   : e9dca8ce147f32d7d64a9e64f9d8339310ad6535    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 9 May 2016 16:56:07 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 9 May 2016 16:56:07 -0400    

commit   : 3ad64ae4dadc56b756cb50845963c13ceb85d33f    
  
author   : Peter Eisentraut <[email protected]>    
date     : Mon, 9 May 2016 10:09:45 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Mon, 9 May 2016 10:09:45 -0400    

Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git  
Source-Git-Hash: 32e77ddc0a1641ccc73056a7c2113264ba2942ff  

commit   : fded76698ee89322e93ae66bdf5cee7e0b64aa4a    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 7 May 2016 17:26:24 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 7 May 2016 17:26:24 -0400    

commit   : e3a493ac08b7b0fb9de85a002aeff69e4f8fba43    
  
author   : Peter Eisentraut <[email protected]>    
date     : Fri, 8 Apr 2016 13:48:14 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Fri, 8 Apr 2016 13:48:14 -0400    

OpenSSL has an unfortunate tendency to mix per-session state error  
handling with per-thread error handling.  This can cause problems when  
programs that link to libpq with OpenSSL enabled have some other use of  
OpenSSL; without care, one caller of OpenSSL may cause problems for the  
other caller.  Backend code might similarly be affected, for example  
when a third party extension independently uses OpenSSL without taking  
the appropriate precautions.  
  
To fix, don't trust other users of OpenSSL to clear the per-thread error  
queue.  Instead, clear the entire per-thread queue ahead of certain I/O  
operations when it appears that there might be trouble (these I/O  
operations mostly need to call SSL_get_error() to check for success,  
which relies on the queue being empty).  This is slightly aggressive,  
but it's pretty clear that the other callers have a very dubious claim  
to ownership of the per-thread queue.  Do this is both frontend and  
backend code.  
  
Finally, be more careful about clearing our own error queue, so as to  
not cause these problems ourself.  It's possibly that control previously  
did not always reach SSLerrmessage(), where ERR_get_error() was supposed  
to be called to clear the queue's earliest code.  Make sure  
ERR_get_error() is always called, so as to spare other users of OpenSSL  
the possibility of similar problems caused by libpq (as opposed to  
problems caused by a third party OpenSSL library like PHP's OpenSSL  
extension).  Again, do this is both frontend and backend code.  
  
See bug #12799 and https://bugs.php.net/bug.php?id=68276  
  
Based on patches by Dave Vitek and Peter Eisentraut.  
  
From: Peter Geoghegan <[email protected]>  

commit   : 11247dd99a6502799a3cb5fdbe1f5c2354862b1b    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 6 May 2016 12:09:20 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 6 May 2016 12:09:20 -0400    

to_timestamp() handles the TH/th format codes by advancing over two input  
characters, whatever those are.  It failed to notice whether there were  
two characters available to be skipped, making it possible to advance  
the pointer past the end of the input string and keep on parsing.  
A similar risk existed in the handling of "Y,YYY" format: it would advance  
over three characters after the "," whether or not three characters were  
available.  
  
In principle this might be exploitable to disclose contents of server  
memory.  But the security team concluded that it would be very hard to use  
that way, because the parsing loop would stop upon hitting any zero byte,  
and TH/th format codes can't be consecutive --- they have to follow some  
other format code, which would have to match whatever data is there.  
So it seems impractical to examine memory very much beyond the end of the  
input string via this bug; and the input string will always be in local  
memory not in disk buffers, making it unlikely that anything very  
interesting is close to it in a predictable way.  So this doesn't quite  
rise to the level of needing a CVE.  
  
Thanks to Wolf Roediger for reporting this bug.  

commit   : 29d154e3687bc27d89ca88a9f184ce4f436b25bd    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 5 May 2016 20:08:58 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 5 May 2016 20:08:58 -0400    

DST law changes in Russia (Magadan, Tomsk regions) and Venezuela.  
Historical corrections for Russia.  There are new zone names Europe/Kirov  
and Asia/Tomsk reflecting the fact that these regions now have different  
time zone histories from adjacent regions.  

commit   : dabd745f3d2a265dff2b6c7621a2959c236c633b    
  
author   : Peter Eisentraut <[email protected]>    
date     : Wed, 4 May 2016 14:07:00 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Wed, 4 May 2016 14:07:00 -0400    

From: Alexander Law <[email protected]>  

commit   : a1b572bdc78469b7e6a22be1b73e0904383564d6    
  
author   : Peter Eisentraut <[email protected]>    
date     : Tue, 3 May 2016 21:06:25 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Tue, 3 May 2016 21:06:25 -0400    

From: Alexander Law <[email protected]>  

commit   : 28e02b8fde7356fb917e36a20d9ddeb19aded53a    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 2 May 2016 11:18:11 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 2 May 2016 11:18:11 -0400    

awk's equality-comparison operator is "==" not "=".  We got this right  
in many places, but not in configure's checks for supported version  
numbers of flex and perl.  It hadn't been noticed because unsupported  
versions are so old as to be basically extinct in the wild, and because  
the only consequence is whether or not a WARNING flies by during  
configure.  
  
Daniel Gustafsson noted the problem with respect to the test for flex,  
I found the other by reviewing other awk calls.  

commit   : 7ee15c05d2fbe7a9dde07867aead93583fbd14ce    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Mon, 2 May 2016 10:07:49 +0300    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Mon, 2 May 2016 10:07:49 +0300    

CHECK_PAGE_OFFSET_RANGE() has been unused forever.  
CHECK_RELATION_BLOCK_RANGE() has been unused in pgstatindex.c ever since  
bt_page_stats() and bt_page_items() functions were moved from pgstattuple  
to pageinspect module. It still exists in pageinspect/btreefuncs.c.  
  
Daniel Gustafsson  

commit   : f02cb8c9a06ef13bf31432dcc72db1e8b931ded6    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 29 Apr 2016 20:19:38 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 29 Apr 2016 20:19:38 -0400    

Given a three-or-more-way equivalence class, such as X.Y = Y.Y = Z.Z,  
it was possible for the planner to omit one of the quals needed to  
enforce that all members of the equivalence class are actually equal.  
This only happened in the case of a parameterized join node for two  
of the relations, that is a plan tree like  
  
	Nested Loop  
	  ->  Scan X  
	  ->  Nested Loop  
	    ->  Scan Y  
	    ->  Scan Z  
	          Filter: Z.Z = X.X  
  
The eclass machinery normally expects to apply X.X = Y.Y when those  
two relations are joined, but in this shape of plan tree they aren't  
joined until the top node --- and, if the lower nested loop is marked  
as parameterized by X, the top node will assume that the relevant eclass  
condition(s) got pushed down into the lower node.  On the other hand,  
the scan of Z assumes that it's only responsible for constraining Z.Z  
to match any one of the other eclass members.  So one or another of  
the required quals sometimes fell between the cracks, depending on  
whether consideration of the eclass in get_joinrel_parampathinfo()  
for the lower nested loop chanced to generate X.X = Y.Y or X.X = Z.Z  
as the appropriate constraint there.  If it generated the latter,  
it'd erroneously suppose that the Z scan would take care of matters.  
To fix, force X.X = Y.Y to be generated and applied at that join node  
when this case occurs.  
  
This is *extremely* hard to hit in practice, because various planner  
behaviors conspire to mask the problem; starting with the fact that the  
planner doesn't really like to generate a parameterized plan of the  
above shape.  (It might have been impossible to hit it before we  
tweaked things to allow this plan shape for star-schema cases.)  Many  
thanks to Alexander Kirkouski for submitting a reproducible test case.  
  
The bug can be demonstrated in all branches back to 9.2 where parameterized  
paths were introduced, so back-patch that far.  

commit   : c563d97c6bfd63e4d533bf01d0074d3a47e7a12c    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 28 Apr 2016 11:50:58 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 28 Apr 2016 11:50:58 -0400    

Commit 23a41573c attempted to fix the DatumGetBool macro to ignore bits  
in a Datum that are to the left of the actual bool value.  But it did that  
by casting the Datum to bool; and on compilers that use C99 semantics for  
bool, that ends up being a whole-word test, not a 1-byte test.  This seems  
to be the true explanation for contrib/seg failing in VS2015.  To fix, use  
GET_1_BYTE() explicitly.  I think in the previous patch, I'd had some idea  
of not having to commit to bool being exactly 1 byte wide, but regardless  
of what the compiler's bool is, boolean columns and Datums are certainly  
1 byte wide.  
  
The previous fix was (eventually) back-patched into all active versions,  
so do likewise with this one.  

commit   : 0f54912837ec3f1dc352627b18dca3d7d54fc787    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 23 Apr 2016 16:53:15 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 23 Apr 2016 16:53:15 -0400    

NetBSD has seen fit to invent a libc function named strtoi(), which  
conflicts with the long-established static functions of the same name in  
datetime.c and ecpg's interval.c.  While muttering darkly about intrusions  
on application namespace, we'll rename our functions to avoid the conflict.  
  
Back-patch to all supported branches, since this would affect attempts  
to build any of them on recent NetBSD.  
  
Thomas Munro  

commit   : ad2d32b57e7b38d52dd2505efa19a28b19b773cb    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 20:05:58 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 20:05:58 -0400    

Given a left join containing a full join in its righthand side, with  
the left join's joinclause referencing only one side of the full join  
(in a non-strict fashion, so that the full join doesn't get simplified),  
the planner could fail with "failed to build any N-way joins" or related  
errors.  This happened because the full join was seen as overlapping the  
left join's RHS, and then recent changes within join_is_legal() caused  
that function to conclude that the full join couldn't validly be formed.  
Rather than try to rejigger join_is_legal() yet more to allow this,  
I think it's better to fix initsplan.c so that the required join order  
is explicit in the SpecialJoinInfo data structure.  The previous coding  
there essentially ignored full joins, relying on the fact that we don't  
flatten them in the joinlist data structure to preserve their ordering.  
That's sufficient to prevent a wrong plan from being formed, but as this  
example shows, it's not sufficient to ensure that the right plan will  
be formed.  We need to work a bit harder to ensure that the right plan  
looks sane according to the SpecialJoinInfos.  
  
Per bug #14105 from Vojtech Rylko.  This was apparently induced by  
commit 8703059c6 (though now that I've seen it, I wonder whether there  
are related cases that could have failed before that); so back-patch  
to all active branches.  Unfortunately, that patch also went into 9.0,  
so this bug is a regression that won't be fixed in that branch.  

commit   : b5ebc513d199d184d85e405022cec4d2f7e98563    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 16:58:47 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 16:58:47 -0400    

The coverage was rather lean for cases that bind() or listen() might  
return.  Add entries for everything that there's a direct equivalent  
for in the set of Unix errnos that elog.c has heard of.  

commit   : d1e4ede7ab4c1b5984fcb634360cca34e77562a5    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 16:16:19 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 16:16:19 -0400    

There's no longer a need for the MSVC-version-specific code stanza that  
forcibly redefines errno code symbols, because since commit 73838b52 we're  
unconditionally redefining them in the stanza before this one anyway.  
Now it's merely confusing and ugly, so get rid of it; and improve the  
comment that explains what's going on here.  
  
Although this is just cosmetic, back-patch anyway since I'm intending  
to back-patch some less-cosmetic changes in this same hunk of code.  

commit   : 6848827b43dc654ec609b7922d48f348d5ebc6b3    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 15:44:18 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 15:44:18 -0400    

Fix Windows builds to report something useful rather than "could not bind  
IPv4 socket: No error" when bind() fails.  
  
Back-patch of commits d1b7d4877b9a71f4 and 22989a8e34168f57.  
  
Discussion: <[email protected]>  

commit   : c7c145e4fb8f38c2c6b7a3b239e4c33f1aa0ae87    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 14:20:18 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 21 Apr 2016 14:20:18 -0400    

When we shoehorned "x op ANY (array)" into the SQL syntax, we created a  
fundamental ambiguity as to the proper treatment of a sub-SELECT on the  
righthand side: perhaps what's meant is to compare x against each row of  
the sub-SELECT's result, or perhaps the sub-SELECT is meant as a scalar  
sub-SELECT that delivers a single array value whose members should be  
compared against x.  The grammar resolves it as the former case whenever  
the RHS is a select_with_parens, making the latter case hard to reach ---  
but you can get at it, with tricks such as attaching a no-op cast to the  
sub-SELECT.  Parse analysis would throw away the no-op cast, leaving a  
parsetree with an EXPR_SUBLINK SubLink directly under a ScalarArrayOpExpr.  
ruleutils.c was not clued in on this fine point, and would naively emit  
"x op ANY ((SELECT ...))", which would be parsed as the first alternative,  
typically leading to errors like "operator does not exist: text = text[]"  
during dump/reload of a view or rule containing such a construct.  To fix,  
emit a no-op cast when dumping such a parsetree.  This might well be  
exactly what the user wrote to get the construct accepted in the first  
place; and even if she got there with some other dodge, it is a valid  
representation of the parsetree.  
  
Per report from Karl Czajkowski.  He mentioned only a case involving  
RLS policies, but actually the problem is very old, so back-patch to  
all supported branches.  
  
Report: <[email protected]>  

commit   : 1b22368ff7a8eb7cdee987c417c26bf524995e33    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 20 Apr 2016 23:48:13 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 20 Apr 2016 23:48:13 -0400    

In commit 2ffa86962077c588 we made pg_ctl recognize an environment variable  
PGCTLTIMEOUT to set the default timeout for starting and stopping the  
postmaster.  However, pg_regress uses pg_ctl only for the "stop" end of  
that; it has bespoke code for starting the postmaster, and that code has  
historically had a hard-wired 60-second timeout.  Further buildfarm  
experience says it'd be a good idea if that timeout were also controlled  
by PGCTLTIMEOUT, so let's make it so.  Like the previous patch, back-patch  
to all active branches.  
  
Discussion: <[email protected]>  

commit   : b24f7e2800be7a5d9c29677b8ef35f61c925d0d4    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 18 Apr 2016 13:33:07 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 18 Apr 2016 13:33:07 -0400    

Per discussion, there doesn't seem to be much value in having  
NUM_SPINLOCK_SEMAPHORES set to 1024: under any scenario where you are  
running more than a few backends concurrently, you really had better have a  
real spinlock implementation if you want tolerable performance.  And 1024  
semaphores is a sizable fraction of the system-wide SysV semaphore limit  
on many platforms.  Therefore, reduce this setting's default value to 128  
to make it less likely to cause out-of-semaphores problems.  

commit   : 37f30b2510525155f4f1f94288a015163689cc69    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 18 Apr 2016 13:19:52 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 18 Apr 2016 13:19:52 -0400    

My back-patch of the 9.4-era commit 44cd47c1d49655c5 into 9.2 and 9.3 fixed  
HPPA builds as expected, but it broke --disable-spinlocks builds, because  
the dummy spinlock is initialized before the underlying semaphore  
infrastructure is alive.  In 9.4 and up this works because of commit  
daa7527afc227443, which decoupled initialization of an slock_t variable  
from access to the actual system semaphore object.  The best solution  
seems to be to back-port that patch, which should be a net win anyway  
because it improves the usability of --disable-spinlocks builds in the  
older branches; and it's been out long enough now to not be worrisome  
from a stability perspective.  

commit   : 9008922bf727ba4337ed26b5c07df7f1d5f1548b    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 16 Apr 2016 10:41:57 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 16 Apr 2016 10:41:57 -0400    

Back-patch 9.4-era commit 44cd47c1d49655c5 into 9.2 and 9.3.  As with  
my back-patches of yesterday, this was not seen as necessary at the time  
because we didn't expect barrier.h to need to work before 9.4, but  
commit 37de8de9e33606a0 invalidated that theory.  
  
Per an attempt to run gaur and pademelon over old branches they've  
not been run on since ~2013.  

commit   : 56aa0f142d8e450bc0f94bb39b50f16aff3296df    
  
author   : Peter Eisentraut <[email protected]>    
date     : Fri, 15 Apr 2016 20:44:10 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Fri, 15 Apr 2016 20:44:10 -0400    

From: Alexander Law <[email protected]>  

commit   : d7dbc882d3deecee3c00cfe9fd50eb0903c5651a    
  
author   : Tom Lane <[email protected]>    
date     : Fri, 15 Apr 2016 16:49:48 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Fri, 15 Apr 2016 16:49:48 -0400    

We weren't particularly maintaining barrier.h before 9.4, because nothing  
was using it in those branches.  Well, nothing until commit 37de8de9e got  
back-patched.  That broke 9.2 and 9.3 for some non-mainstream platforms  
that we haven't been testing in the buildfarm, including icc on ia64,  
HPPA, and Alpha.  
  
This commit effectively back-patches commits e5592c61a, 89779bf2c,  
and 747ca6697, though I did it just by copying the file (less copyright  
date updates) rather than by cherry-picking those commits.  
  
Per an attempt to run gaur and pademelon over old branches they've  
not been run on since ~2013.  

commit   : b54508596dc4202d581873a8841c72fcf3bae7a6    
  
author   : Andres Freund <[email protected]>    
date     : Thu, 14 Apr 2016 18:54:06 -0700    
  
committer: Andres Freund <[email protected]>    
date     : Thu, 14 Apr 2016 18:54:06 -0700    

These aren't valid C89. Found thanks to gcc's -Wc90-c99-compat. These  
exist in differing places in most supported branches.  

commit   : 6bb42d520436a37c9873e64f144547779bb9886b    
  
author   : Tom Lane <[email protected]>    
date     : Wed, 13 Apr 2016 18:57:52 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Wed, 13 Apr 2016 18:57:52 -0400    

As reported by Michael Feld, pg_upgrade'ing an installation having  
extensions with operator families that contain just a single operator class  
failed to reproduce the extension membership of those operator families.  
This caused no immediate ill effects, but would create problems when later  
trying to do a plain dump and restore, because the seemingly-not-part-of-  
the-extension operator families would appear separately in the pg_dump  
output, and then would conflict with the families created by loading the  
extension.  This has been broken ever since extensions were introduced,  
and many of the standard contrib extensions are affected, so it's a bit  
astonishing nobody complained before.  
  
The cause of the problem is a perhaps-ill-considered decision to omit  
such operator families from pg_dump's output on the grounds that the  
CREATE OPERATOR CLASS commands could recreate them, and having explicit  
CREATE OPERATOR FAMILY commands would impede loading the dump script into  
pre-8.3 servers.  Whatever the merits of that decision when 8.3 was being  
written, it looks like a poor tradeoff now.  We can fix the pg_upgrade  
problem simply by removing that code, so that the operator families are  
dumped explicitly (and then will be properly made to be part of their  
extensions).  
  
Although this fixes the behavior of future pg_upgrade runs, it does nothing  
to clean up existing installations that may have improperly-linked operator  
families.  Given the small number of complaints to date, maybe we don't  
need to worry about providing an automated solution for that; anyone who  
needs to clean it up can do so with manual "ALTER EXTENSION ADD OPERATOR  
FAMILY" commands, or even just ignore the duplicate-opfamily errors they  
get during a pg_restore.  In any case we need this fix.  
  
Back-patch to all supported branches.  
  
Discussion: <[email protected]>  

commit   : 9422b61d1312f69a70ae2d8a3cc17a87aa50e5a9    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 11 Apr 2016 18:17:03 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 11 Apr 2016 18:17:03 -0400    

It turns out that those PyErr_Clear() calls I removed from plpy_elog.c  
in 7e3bb080387f4143 et al were not quite as random as they appeared: they  
mask a Python 2.3.x bug.  (Specifically, it turns out that PyType_Ready()  
can fail if the error indicator is set on entry, and PLy_traceback's fetch  
of frame.f_code may be the first operation in a session that requires the  
"frame" type to be readied.  Ick.)  Put back the clear call, but in a more  
centralized place closer to what it's protecting, and this time with a  
comment warning what it's really for.  
  
Per buildfarm member prairiedog.  Although prairiedog was only failing  
on HEAD, it seems clearly possible for this to occur in older branches  
as well, so back-patch to 9.2 the same as the previous patch.  

commit   : e1f08ba1cc8ce31be75ec694e229daaa002adc6a    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 10 Apr 2016 23:15:55 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 10 Apr 2016 23:15:55 -0400    

PLy_elog() could attempt to access strings that Python had already freed,  
because the strings that PLy_get_spi_error_data() returns are simply  
pointers into storage associated with the error "val" PyObject.  That's  
fine at the instant PLy_get_spi_error_data() returns them, but just after  
that PLy_traceback() intentionally releases the only refcount on that  
object, allowing it to be freed --- so that the strings we pass to  
ereport() are dangling pointers.  
  
In principle this could result in garbage output or a coredump.  In  
practice, I think the risk is pretty low, because there are no Python  
operations between where we decrement that refcount and where we use the  
strings (and copy them into PG storage), and thus no reason for Python  
to recycle the storage.  Still, it's clearly hazardous, and it leads to  
Valgrind complaints when running under a Valgrind that hasn't been  
lobotomized to ignore Python memory allocations.  
  
The code was a mess anyway: we fetched the error data out of Python  
(clearing Python's error indicator) with PyErr_Fetch, examined it, pushed  
it back into Python with PyErr_Restore (re-setting the error indicator),  
then immediately pulled it back out with another PyErr_Fetch.  Just to  
confuse matters even more, there were some gratuitous-and-yet-hazardous  
PyErr_Clear calls in the "examine" step, and we didn't get around to doing  
PyErr_NormalizeException until after the second PyErr_Fetch, making it even  
less clear which object was being manipulated where and whether we still  
had a refcount on it.  (If PyErr_NormalizeException did substitute a  
different "val" object, it's possible that the problem could manifest for  
real, because then we'd be doing assorted Python stuff with no refcount  
on the object we have string pointers into.)  
  
So, rearrange all that into some semblance of sanity, and don't decrement  
the refcount on the Python error objects until the end of PLy_elog().  
In HEAD, I failed to resist the temptation to reformat some messy bits  
from 5c3c3cd0a3046339 along the way.  
  
Back-patch as far as 9.2, because the code is substantially the same  
that far back.  I believe that 9.1 has the bug as well; but the code  
around it is rather different and I don't want to take a chance on  
breaking something for what seems a low-probability problem.  

commit   : d1eee9ba85be978c5b137d657dc8e3fd7bc2cebd    
  
author   : Teodor Sigaev <[email protected]>    
date     : Fri, 8 Apr 2016 21:26:12 +0300    
  
committer: Teodor Sigaev <[email protected]>    
date     : Fri, 8 Apr 2016 21:26:12 +0300    

Found during investigation of failure of skink buildfarm member and its  
valgrind report.  
  
Backpatch to all supported branches  

commit   : 9e77d0e3cf83b3a207d68a81738d7d6f0b60fe34    
  
author   : Andrew Dunstan <[email protected]>    
date     : Fri, 8 Apr 2016 12:25:10 -0400    
  
committer: Andrew Dunstan <[email protected]>    
date     : Fri, 8 Apr 2016 12:25:10 -0400    

Most of what is produced by the detailed verbosity level is of no  
interest at all, so switch to the normal level for more usable output.  
  
Christian Ullrich  
  
Backpatch to all live branches  

commit   : 209880ba7da708ab8df74dc47b9fad0665807f64    
  
author   : Alvaro Herrera <[email protected]>    
date     : Tue, 5 Apr 2016 19:03:42 -0300    
  
committer: Alvaro Herrera <[email protected]>    
date     : Tue, 5 Apr 2016 19:03:42 -0300    

Commit b8a91d9d1c put the description of the new IF EXISTS clause in the  
wrong place -- move it where it belongs.  
  
Backpatch to 9.2.  

commit   : 5496c75de7140e0fedf2fba70bd2df08743d6a64    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 4 Apr 2016 11:13:17 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 4 Apr 2016 11:13:17 -0400    

The first iteration of the signal-checking loop would compute sigmask(0)  
which expands to 1<<(-1) which is undefined behavior according to the  
C standard.  The lack of field reports of trouble suggest that it  
evaluates to 0 on all existing Windows compilers, but that's hardly  
something to rely on.  Since signal 0 isn't a queueable signal anyway,  
we can just make the loop iterate from 1 instead, and save a few cycles  
as well as avoiding the undefined behavior.  
  
In passing, avoid evaluating the volatile expression UNBLOCKED_SIGNAL_QUEUE  
twice in a row; there's no reason to waste cycles like that.  
  
Noted by Aleksander Alekseev, though this isn't his proposed fix.  
Back-patch to all supported branches.  

commit   : e19b7f7c8bfb41899bdfa386049a0e2490ea6a79    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 29 Mar 2016 21:38:15 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 29 Mar 2016 21:38:15 -0400    

The server hasn't paid attention to the TZ environment variable since  
commit ca4af308c32d03db, but that commit missed removing this documentation  
reference, as did commit d883b916a947a3c6 which added the reference where  
it now belongs (initdb).  
  
Back-patch to 9.2 where the behavior changed.  Also back-patch  
d883b916a947a3c6 as needed.  
  
Matthew Somerville  

commit   : b4b06931ed22e9a38442b16676aaf16ace92bf8d    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 29 Mar 2016 11:54:58 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 29 Mar 2016 11:54:58 -0400    

Whenever this function is used with the FORMAT_MESSAGE_FROM_SYSTEM flag,  
it's good practice to include FORMAT_MESSAGE_IGNORE_INSERTS as well.  
Otherwise, if the message contains any %n insertion markers, the function  
will try to fetch argument strings to substitute --- which we are not  
passing, possibly leading to a crash.  This is exactly analogous to the  
rule about not giving printf() a format string you're not in control of.  
  
Noted and patched by Christian Ullrich.  
Back-patch to all supported branches.