Feature request: Improve allowed values for generate series

Hello Pgsql-hackers,

Seems I fall into corner case:

test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-09', INTERVAL '00:00:00' );
ERROR: step size cannot equal zero

But:
test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-10', INTERVAL '1 day' );
generate_series
------------------------
2020-11-09 00:00:00+02
2020-11-10 00:00:00+02
(2 rows)

Here we start at 2020-11-09, add interval of one day and finish at 2020-11-10
Done! series is generated.

In first case I expect that I start at 2020-11-09, add interval of zero and finish at 2020-11-09
Everything is consistent.

test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-09', INTERVAL '00:00:00' );
generate_series
------------------------
2020-11-09 00:00:00+02
(1 row)

So I feature request to allow zero size step for cases when start point is equest to finish

What do you think?

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Best regards,
Eugen Konkov