Test case for PLyMapping_ToTuple issue

crashtest.sql

CREATE OR REPLACE PROCEDURAL LANGUAGE plpythonu;
CREATE TABLE foo (
    id integer not null primary key,
    value integer not null
);
CREATE FUNCTION get_foo() RETURNS SETOF foo
    LANGUAGE plpythonu
    AS $$
r = plpy.execute("select * from foo limit 1 FOR UPDATE")
if len(r) == 0:
        return
id = r[0]['id']
r = plpy.execute("update foo SET value = value + 1 WHERE id = %s RETURNING *" % id)
yield r[0]
$$;
COPY foo (id, value) FROM stdin;
1	1
\.
select * from get_foo();
alter table foo drop column value;
alter table foo add column value int;
update foo set value=1;
select * from get_foo();