BUG #2539: PL/PgSQL doesn't disallow COPY commands on compile, even though it disallows them.

The following bug has been logged online:

Bug reference: 2539
Logged by: David Fetter
Email address: david(at)fetter(dot)org
PostgreSQL version: All
Operating system: Linux and OSX that I've tested
Description: PL/PgSQL doesn't disallow COPY commands on compile, even
though it disallows them.
Details:

Here's a repro:

davidfetter=> SHOW check_function_bodies ;
check_function_bodies
-----------------------
on
(1 row)

davidfetter=> CREATE OR REPLACE FUNCTION bad_func()
RETURNS VOID
LANGUAGE plpgsql
AS $$
BEGIN
CREATE TEMPORARY TABLE bad(i INTEGER) ON COMMIT DROP;
INSERT INTO bad
SELECT s.i FROM generate_series(1,10) AS s(i);
COPY bad TO stdout;
END;
$$;
CREATE FUNCTION
davidfetter=> select bad_func();
ERROR: SPI_execute_plan failed executing query "COPY bad TO stdout":
SPI_ERROR_COPY
CONTEXT: PL/pgSQL function "bad_func" line 5 at SQL statement