DST law changes in Egypt, Mongolia, Palestine.
Historical corrections for Canada and Chile.
Revised zone abbreviation for America/Adak (HST/HDT not HAST/HADT).
For some reason this seems to have been missed when the lists in
src/timezone/tznames/ were first constructed. We can't put it in Default
because of the conflict with US CST, but we should certainly list it among
the alternative entries in Asia.txt. (I checked for other oversights, but
all the other abbreviations that are in current use according to the IANA
files seem to be accounted for.) Noted while responding to bug #12326.
DST law changes in the Turks & Caicos Islands (America/Grand_Turk) and
in Fiji. New zone Pacific/Bougainville for portions of Papua New Guinea.
Historical changes for Korea and Vietnam.
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time. But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation. Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.
To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone. For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time. However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.
The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970. The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.
While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.
This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib. Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.
This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time. We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.
In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
Most zones in the Russian Federation are subtracting one or two hours
as of 2014-10-26. Update the meanings of the abbreviations IRKT, KRAT,
MAGT, MSK, NOVT, OMST, SAKT, VLAT, YAKT, YEKT to match.
The IANA timezone database has adopted abbreviations of the form AxST/AxDT
for all Australian time zones, reflecting what they believe to be current
majority practice Down Under. These names do not conflict with usage
elsewhere (other than ACST for Acre Summer Time, which has been in disuse
since 1994). Accordingly, adopt these names into our "Default" timezone
abbreviation set. The "Australia" abbreviation set now contains only
CST,EAST,EST,SAST,SAT,WST, all of which are thought to be mostly historical
usage. Note that SAST has also been changed to be South Africa Standard
Time in the "Default" abbreviation set.
Add zone abbreviations SRET (Asia/Srednekolymsk) and XJT (Asia/Urumqi),
and use WSST/WSDT for western Samoa.
Also a DST law change in the Turks & Caicos Islands (America/Grand_Turk),
and numerous corrections for historical time zone data.
This updates known_abbrevs.txt to be what it should have been already,
were my -P patch not broken; and updates some tznames/ entries that
missed getting any love in previous timezone data updates because zic
failed to flag the change of abbreviation.
The non-cosmetic updates:
* Remove references to "ADT" as "Arabia Daylight Time", an abbreviation
that's been out of use since 2007; therefore, claiming there is a conflict
with "Atlantic Daylight Time" doesn't seem especially helpful. (We have
left obsolete entries in the files when they didn't conflict with anything,
but that seems like a different situation.)
* Fix entirely incorrect GMT offsets for CKT (Cook Islands), FJT, FJST
(Fiji); we didn't even have them on the proper side of the date line.
(Seems to have been aboriginal errors in our tznames data; there's no
evidence anything actually changed recently.)
* FKST (Falkland Islands Summer Time) is now used all year round, so
don't mark it as a DST abbreviation.
* Update SAKT (Sakhalin) to mean GMT+11 not GMT+10.
In cosmetic changes, I fixed a bunch of wrong (or at least obsolete)
claims about abbreviations not being present in the zic files, and
tried to be consistent about how obsolete abbreviations are labeled.
Note the underlying timezone/data files are still at release 2014e;
this is just trying to get us in sync with what those files actually
say before we go to the next update.
The quick hack I added to zic to dump out currently-in-use timezone
abbreviations turns out to have a nasty bug: within each zone, it was
printing the last "struct ttinfo" to be *defined*, not necessarily the
last one in use. This was mainly a problem in zones that had changed the
meaning of their zone abbreviation (to another GMT offset value) and later
changed it back.
As a result of this error, we'd missed out updating the tznames/ files
for some jurisdictions that have changed their zone abbreviations since
the tznames/ files were originally created. I'll address the missing data
updates in a separate commit.
In support of this, have the MSVC build follow GNU make in preferring
GNUmakefile over Makefile when a directory contains both.
Michael Paquier, reviewed by MauMau.
In commit 631dc390f4, we started to handle
simple numeric timezone offsets via the zic library instead of the old
CTimeZone/HasCTZSet kluge. However, we overlooked the fact that the zic
code will reject UTC offsets exceeding a week (which seems a bit arbitrary,
but not because it's too tight ...). This led to possibly setting
session_timezone to NULL, which results in crashes in most timezone-related
operations as of 9.4, and crashes in a small number of places even before
that. So check for NULL return from pg_tzset_offset() and report an
appropriate error message. Per bug #11014 from Duncan Gillis.
Back-patch to all supported branches, like the previous patch.
(Unfortunately, as of today that no longer includes 8.4.)
Coverity identified a number of places in which it couldn't prove that a
string being copied into a fixed-size buffer would fit. We believe that
most, perhaps all of these are in fact safe, or are copying data that is
coming from a trusted source so that any overrun is not really a security
issue. Nonetheless it seems prudent to forestall any risk by using
strlcpy() and similar functions.
Fixes by Peter Eisentraut and Jozef Mlich based on Coverity reports.
In addition, fix a potential null-pointer-dereference crash in
contrib/chkpass. The crypt(3) function is defined to return NULL on
failure, but chkpass.c didn't check for that before using the result.
The main practical case in which this could be an issue is if libc is
configured to refuse to execute unapproved hashing algorithms (e.g.,
"FIPS mode"). This ideally should've been a separate commit, but
since it touches code adjacent to one of the buffer overrun changes,
I included it in this commit to avoid last-minute merge issues.
This issue was reported by Honza Horak.
Security: CVE-2014-0065 for buffer overruns, CVE-2014-0066 for crypt()
We used to have externs for getopt() and its API variables scattered
all over the place. Now that we find we're going to need to tweak the
variable declarations for Cygwin, it seems like a good idea to have
just one place to tweak.
In this commit, the variables are declared "#ifndef HAVE_GETOPT_H".
That may or may not work everywhere, but we'll soon find out.
Andres Freund
DST law changes in Jordan; historical changes in Cuba.
Also, remove the zones Asia/Riyadh87, Asia/Riyadh88, and Asia/Riyadh89.
Per the upstream announcement:
The files solar87, solar88, and solar89 are no longer distributed.
They were a negative experiment -- that is, a demonstration that
tz data can represent solar time only with some difficulty and error.
Their presence in the distribution caused confusion, as Riyadh
civil time was generally not solar time in those years.
Formerly, when using a SQL-spec timezone setting with a fixed GMT offset
(called a "brute force" timezone in the code), the session_timezone
variable was not updated to match the nominal timezone; rather, all code
was expected to ignore session_timezone if HasCTZSet was true. This is
of course obviously fragile, though a search of the code finds only
timeofday() failing to honor the rule. A bigger problem was that
DetermineTimeZoneOffset() supposed that if its pg_tz parameter was
pointer-equal to session_timezone, then HasCTZSet should override the
parameter. This would cause datetime input containing an explicit zone
name to be treated as referencing the brute-force zone instead, if the
zone name happened to match the session timezone that had prevailed
before installing the brute-force zone setting (as reported in bug #8572).
The same malady could affect AT TIME ZONE operators.
To fix, set up session_timezone so that it matches the brute-force zone
specification, which we can do using the POSIX timezone definition syntax
"<abbrev>offset", and get rid of the bogus lookaside check in
DetermineTimeZoneOffset(). Aside from fixing the erroneous behavior in
datetime parsing and AT TIME ZONE, this will cause the timeofday() function
to print its result in the user-requested time zone rather than some
previously-set zone. It might also affect results in third-party
extensions, if there are any that make use of session_timezone without
considering HasCTZSet, but in all cases the new behavior should be saner
than before.
Back-patch to all supported branches.
Most (all?) of Russia has moved to what's effectively year-round daylight
savings time, so that the "standard" zone names now mean an hour later
than they used to. Update that, notably changing MSK as per recent
complaint from Sergey Konoplev, but also CHOT, GET, IRKT, KGT, KRAT,
MAGT, NOVT, OMST, VLAT, YAKT, YEKT. The corresponding DST abbreviations
are presumably now obsolete, but I left them in place with their old
definitions, just to reduce any possible breakage from this change.
Also add VOLT (Europe/Volgograd), which for some reason we never had
before, as well as MIST (Antarctica/Macquarie), and fix obsolete
definitions of MAWT, TKT, and WST.
Add an option to zic.c to dump out all non-obsolete timezone abbreviations
defined in the Olson database. Comparing this list to its previous state
will clue us in when something happens that we may need to account for in
the tznames/ time zone abbreviation lists. The README file's previous
exhortation to "just grep for differences" was completely useless advice,
in my now-considerable experience; but maybe this will be a bit more
useful. As a starting point I built the same list from the tzdata files
as they existed in 2006, which is committed here as known_abbrevs.txt.
Comparison indeed turned up quite a few changes we had neglected to account
for, which I will commit separately.
This seems to have been invented in 2011 to represent GMT+3, non daylight
savings rules, as now used in Europe/Kaliningrad and Europe/Minsk.
There are no conflicts so might as well add it to the Default list.
Per bug #7804 from Ruslan Izmaylov.
DST law changes in Morocco; Tokelau has relocated to the other side of
the International Date Line; and apparently Olson had Tokelau's GMT
offset wrong by an hour even before that.
There are also a large number of non-significant changes in this update.
Upstream took the opportunity to remove trailing whitespace, and the
SCCS-style version numbers on the individual files are gone too.
Due to rather sloppy thinking (on my part, I'm afraid) about the
appropriate behavior for boundary conditions, pg_next_dst_boundary() gave
undefined, platform-dependent results when the input time is exactly the
last recorded DST transition time for the specified time zone, as a result
of fetching values one past the end of its data arrays.
Change its specification to be that it always finds the next DST boundary
*after* the input time, and adjust code to match that. The sole existing
caller, DetermineTimeZoneOffset, doesn't actually care about this
distinction, since it always uses a probe time earlier than the instant
that it does care about. So it seemed best to me to change the API to make
the result=1 and result=0 cases more consistent, specifically to ensure
that the "before" outputs always describe the state at the given time,
rather than hacking the code to obey the previous API comment exactly.
Per bug #6605 from Sergey Burladyan. Back-patch to all supported versions.
We were doing some amazingly complicated things in order to avoid running
the very expensive identify_system_timezone() procedure during GUC
initialization. But there is an obvious fix for that, which is to do it
once during initdb and have initdb install the system-specific default into
postgresql.conf, as it already does for most other GUC variables that need
system-environment-dependent defaults. This means that the timezone (and
log_timezone) settings no longer have any magic behavior in the server.
Per discussion.
Failure to distinguish these cases is the real cause behind the recent
reports of Windows builds crashing on 'infinity'::timestamp, which was
directly due to failure to establish a value of timezone_abbreviations
in postmaster child processes. The postmaster had the desired value,
but write_one_nondefault_variable() didn't transmit it to backends.
To fix that, invent a new value PGC_S_DYNAMIC_DEFAULT, and be sure to use
that or PGC_S_ENV_VAR (as appropriate) for "default" settings that are
computed during initialization. (We need both because there's at least
one variable that could receive a value from either source.)
This commit also fixes ProcessConfigFile's failure to restore the correct
default value for certain GUC variables if they are set in postgresql.conf
and then removed/commented out of the file. We have to recompute and
reinstall the value for any GUC variable that could have received a value
from PGC_S_DYNAMIC_DEFAULT or PGC_S_ENV_VAR sources, and there were a
number of oversights. (That whole thing is a crock that needs to be
redesigned, but not today.)
However, I intentionally didn't make it work "exactly right" for the cases
of timezone and log_timezone. The exactly right behavior would involve
running select_default_timezone, which we'd have to do independently in
each postgres process, causing the whole database to become entirely
unresponsive for as much as several seconds. That didn't seem like a good
idea, especially since the variable's removal from postgresql.conf might be
just an accidental edit. Instead the behavior is to adopt the previously
active setting as if it were default.
Note that this patch creates an ABI break for extensions that use any of
the PGC_S_XXX constants; they'll need to be recompiled.
Tom Lane