Re: BUG #16939: Plural interval for negative singular

On Tue, Apr 27, 2021 at 10:44:15PM -0700, Noah Misch wrote:
> On Tue, Apr 27, 2021 at 04:10:19PM -0400, Bruce Momjian wrote:
> > Yes, I found the same like you did.  Are you saying we should remove the
> > abs() calls here so we are consistent?
> 
> No, I advise just reverting 5da9868.  The output funcs should keep doing what
> they did in v13, inconsistency and all.
> 
> I was asking the above question to see which of singular or plural was more
> common before $SUBJECT's commit.  I count two examples of singular and seven
> examples of plural (one in EVALUATE_MESSAGE_PLURAL(), six modified in commit
> 5da9868).  Given that, ...
> 
> On Mon, Apr 26, 2021 at 01:06:16PM -0400, Bruce Momjian wrote:
> > Well, we should then add a comment that this is inconsistent but should
> > not be changed.
> 
> ... adding comments to the two places that use abs() to achieve singular "-1"
> sounds fine.

OK, first, I never realized that saying -1 plural was valid.  Second,
the two places you showed are actually using abs() properly since
negative values are shown with an "ago" suffix, not a negative sign:

	SET intervalstyle = postgres_verbose;

	SELECT '2020-01-01 01:03:00'::timestamptz - '2020-01-01 02:02:01'::timestamptz;
	      ?column?
	---------------------
	 @ 59 mins 1 sec ago
	(1 row)

Attached is a patch which reverts 9ee7d533da and 5da9868ed9, and adds a
comment about the "ago" usage.  The good news is that we were already
consistent in using plural -1.  :-)

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.