BUG #13886: When INSERT ON CONFLICT DO UPDATE updates, it returns INSERT rather than UPDATE

The following bug has been logged on the website:

Bug reference:      13886
Logged by:          Randy Westlund
Email address:      rwestlun@gmail.com
PostgreSQL version: 9.5.0
Operating system:   FreeBSD-10.2
Description:

Situation:         When INSERT ON CONFLICT DO UPDATE does an update.

Current behavior:  Postgres returns "INSERT"

Expected behavior: Postgres should return "UPDATE"


Steps:

uvbase=> create table test ( id integer primary key, str text );
CREATE TABLE
uvbase=> insert into test (id, str) values (1, 'insert') on conflict(id) do
update set str = 'update';
INSERT 0 1
uvbase=> select * from test;
 id |  str
----+--------
  1 | insert
(1 row)

uvbase=> insert into test (id, str) values (1, 'insert') on conflict(id) do
update set str = 'update';
INSERT 0 1
uvbase=> select * from test;
 id |  str
----+--------
  1 | update
(1 row)



I believe postgres should be returning "UPDATE" here instead of "INSERT"
because I see no way to know which operation took place.  I believe my only
options at the moment are using a second query or adding a column like
"just_created BOOLEAN DEFAULT true", setting it to false in the UPDATE
clause, and returning it.