Re: BUG #16939: Plural interval for negative singular

On Tue, Mar 23, 2021 at 05:21:30AM +0000, PG Bug reporting form wrote:
> The following bug has been logged on the website:
>
> Bug reference: 16939
> Logged by: Max Neverov
> Email address: neverov(dot)max(at)gmail(dot)com
> PostgreSQL version: 13.2
> Operating system: alpine
> Description:
>
> Execute the query:
> postgres=# set intervalstyle='postgres';
> SET
> postgres=# select interval '-1 year -1 day';
> interval
> ------------------
> -1 years -1 days
> (1 row)
>
> Expected output:
> -1 year -1 day
>
> The code
> (https://github.com/postgres/postgres/blob/master/src/backend/utils/adt/datetime.c#L4193)
> pluralizes a time unit if the value is not 1, should check both -1 and 1.
>

Wow, interesting. Seems there were a few places in the code that
handled this properly, and several that didn't. The attached patch
fixes these and updates the regression tests. I will apply this for PG
14 in the next few days. This is too likely to break something to
backpatch. Thanks for the report.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

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