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

>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

 >>> Anyway, moving on to the question of what should we do about this,
 >>> I don't really have anything better to offer than back-patching
 >>> 23bd3cec6.

 >> The PG12 behavior seems sane, so +1.

 Tom> OK, I'll make that happen.

This isn't good enough, because it still picks "UCT" on a system with no
/etc/localtime and no TZ variable. Testing on HEAD as of 3da73d683 (on
FreeBSD, but it'll be the same anywhere else):

% ls -l /etc/*time*
ls: /etc/*time*: No such file or directory

% env -u TZ bin/initdb -D data -E UTF8 --no-locale
[...]
selecting default timezone ... UCT

We need to absolutely prefer UTC over UCT if both match.

-- 
Andrew (irc:RhodiumToad)