PL/pgSQL caught exceptions leak memory?

Caught exceptions in PL/pgSQL appear to leak memory -- is that
expected? Here's a contrived test case:

CREATE FUNCTION foo(n integer) RETURNS void AS $$
BEGIN
FOR i IN 1 .. n LOOP
BEGIN
RAISE EXCEPTION 'test';
EXCEPTION
WHEN OTHERS THEN
NULL;
END;
END LOOP;
END;
$$ LANGUAGE plpgsql VOLATILE STRICT;

SELECT foo(200000);

If you watch the backend with top you should see the process size
grow by around 500-600 (512?) bytes per exception caught (you might
need to use more iterations on a fast system to see the effect).

--
Michael Fuhr