postgresql/src
Tom Lane bc7885b7f5 Work around portability issue with newer versions of mktime().
Recent glibc versions have made mktime() fail if tm_isdst is
inconsistent with the prevailing timezone; in particular it fails for
tm_isdst = 1 when the zone is UTC.  (This seems wildly inconsistent
with the POSIX-mandated treatment of "incorrect" values for the other
fields of struct tm, so if you ask me it's a bug, but I bet they'll
say it's intentional.)  This has been observed to cause cosmetic
problems when pg_restore'ing an archive created in a different
timezone.

To fix, do mktime() using the field values from the archive, and if
that fails try again with tm_isdst = -1.  This will give a result
that's off by the UTC-offset difference from the original zone, but
that was true before, too.  It's not terribly critical since we don't
do anything with the result except possibly print it.  (Someday we
should flush this entire bit of logic and record a standard-format
timestamp in the archive instead.  That's not okay for a back-patched
bug fix, though.)

Also, guard our only other use of mktime() by having initdb's
build_time_t() set tm_isdst = -1 not 0.  This case could only have
an issue in zones that are DST year-round; but I think some do exist,
or could in future.

Per report from Wells Oliver.  Back-patch to all supported
versions, since any of them might need to run with a newer glibc.

Discussion: https://postgr.es/m/CAOC+FBWDhDHO7G-i1_n_hjRzCnUeFO+H-Czi1y10mFhRWpBrew@mail.gmail.com
2021-06-13 14:32:42 -04:00
..
backend Ensure pg_filenode_relation(0, 0) returns NULL. 2021-06-12 13:29:24 -04:00
bin Work around portability issue with newer versions of mktime(). 2021-06-13 14:32:42 -04:00
common Fix incautious handling of possibly-miscoded strings in client code. 2021-06-07 14:15:25 -04:00
fe_utils Fix incautious handling of possibly-miscoded strings in client code. 2021-06-07 14:15:25 -04:00
include Remove unnecessary declaration in win32_port.h 2021-06-08 13:40:03 +09:00
interfaces Fix incautious handling of possibly-miscoded strings in client code. 2021-06-07 14:15:25 -04:00
makefiles Remove libpq.rc, use win32ver.rc for libpq 2020-01-15 15:06:12 +01:00
pl Force NO SCROLL for plpgsql's implicit cursors. 2021-06-08 18:40:06 -04:00
port Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00
template Further tweaking of PG_SYSROOT heuristics for macOS. 2021-01-20 12:07:31 -05:00
test Further tweaks to stuck_on_old_timeline recovery test 2021-06-13 07:19:34 -04:00
timezone Update time zone data files to tzdata release 2021a. 2021-01-24 16:29:47 -05:00
tools Add fallback implementation for setenv() 2021-06-01 09:27:25 +09:00
tutorial tutorial: land height is "elevation", not "altitude" 2021-03-10 20:25:18 -05:00
.gitignore
DEVELOPERS
Makefile Fix partial-build problems introduced by having more generated headers. 2018-04-09 16:42:10 -04:00
Makefile.global.in Update Unicode data to Unicode 13.0.0 and CLDR 37 2020-04-24 09:52:59 +02:00
Makefile.shlib Add PostgreSQL home page to --help output 2020-02-28 13:12:21 +01:00
nls-global.mk NLS: Fix backend gettext triggers 2019-09-23 09:04:20 +02:00