Horton

Re: UCT (Re: pgsql: Update time zone data files to tzdata release 2019a.)

Andrew Gierth <andrew@tao11.riddles.org.uk>

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From: Andrew Gierth <andrew@tao11.riddles.org.uk>
To: Stephen Frost <sfrost@snowman.net>
Cc: Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Christoph Berg <myon@debian.org>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2019-06-20T19:19:24Z
Lists: pgsql-hackers 
>>>>> "Stephen" == Stephen Frost <sfrost@snowman.net> writes:

 Stephen> In the situation that started this discussion, a change had
 Stephen> already been made and it was only later realized that it
 Stephen> caused a regression.

Just to keep the facts straight:

The regression was introduced by importing tzdb 2019a (in late April)
into the previous round of point releases; the change in UTC behaviour
was not mentioned in the commit and presumably didn't show up on
anyone's radar until there were field complaints (which didn't reach our
mailing lists until Jun 4 as far as I know).

Tom's "fix" of backpatching 23bd3cec6 (which happened on Friday 14th)
addressed only a subset of cases, as far as I know working only on Linux
(the historical convention has always been for /etc/localtime to be a
copy of a zonefile, not a symlink to one). I only decided to write (and
if need be commit) my own followup fix after confirming that the bug was
unfixed in a default FreeBSD install when set to UTC, and there was a
good chance that a number of other less-popular platforms were affected
too.

 Stephen> Piling on to that, the regression was entwined with other
 Stephen> important changes that we wanted to include in the release.

I'm not sure what you're referring to here?

-- 
Andrew (irc:RhodiumToad)

Commits

  1. Tweak our special-case logic for the IANA "Factory" timezone.

  2. Avoid choosing "localtime" or "posixrules" as TimeZone during initdb.

  3. Prefer timezone name "UTC" over alternative spellings.

  4. Attempt to identify system timezone by reading /etc/localtime symlink.

  5. Update time zone data files to tzdata release 2019a.