BUG #14879: Bug connected with table structure modification and trigger function query plan invalidation

The following bug has been logged on the website:

Bug reference: 14879
Logged by: Konstantin Evteev
Email address: konst583(at)gmail(dot)com
PostgreSQL version: 9.4.12
Operating system: Debian GNU/Linux 8 (jessie)
Description:

There is a bug connected with table structure modification and trigger
function query plan invalidation:

1) 1st session - create table:
create table test(test_id int, new_test_id bigint)

2) 1st session - create func and trigger after insert or update

CREATE OR REPLACE FUNCTION test_trg_func()
RETURNS trigger AS
$BODY$

begin

NEW.new_test_id = NEW.test_id;
return NEW;

end;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;

CREATE TRIGGER test_trg
BEFORE INSERT OR UPDATE
ON test
FOR EACH ROW
EXECUTE PROCEDURE test_trg_func();

3) 1st session
insert into test (test_id) values (5)

4) 2nd session(another session) alter table :

alter table test rename column test_id to old_test_id;
alter table test rename column new_test_id to test_id;
alter table test rename column old_test_id to new_test_id;

5) 1st session:

insert into test (test_id) values (5)

ERROR: type of parameter 15 (bigint) does not match that when preparing the
plan (integer)
CONTEXT: PL/pgSQL function test_trg_func() line 5 at assignment

********** Error **********

ERROR: type of parameter 15 (bigint) does not match that when preparing the
plan (integer)
SQL state: 42804
Context: PL/pgSQL function test_trg_func() line 5 at assignment

-----------------------------------------

Workaround - recreate trg_func to invalidate plan