Inconsistent error codes returned on lack of access for EXPLAIN UPDATE with view

CREATE DATABASE privtest_db;

CREATE TABLE privtest_db.t1 (a INT);

CREATE TABLE privtest_db.t2 (a INT);

INSERT INTO privtest_db.t2 VALUES (1), (2), (3);

CREATE VIEW privtest_db.v1 (a) AS SELECT a FROM privtest_db.t1;

GRANT ALL    ON privtest_db.t1 TO 'privtest'@'localhost';

GRANT ALL    ON privtest_db.t2 TO 'privtest'@'localhost';

GRANT SELECT ON privtest_db.v1 TO 'privtest'@'localhost';

connect(con1,localhost,privtest,,);

USE privtest_db;

# Single-table UPDATE, multi-table DELETE, multi-table UPDATE all return

# the same ER_TABLEACCESS_DENIED_ERROR

# because there is no UPDATE/DELETE grants on v1

--error ER_TABLEACCESS_DENIED_ERROR

UPDATE v1 SET v1.a = v1.a + 1 WHERE v1.a = 2;

--error ER_TABLEACCESS_DENIED_ERROR

DELETE v1 FROM v1, t2 WHERE v1.a = t2.a;

--error ER_TABLEACCESS_DENIED_ERROR

UPDATE v1, t2 SET v1.a = v1.a + 1 WHERE v1.a = t2.a;

# But for EXPLAIN, it's different:

# Single-table UPDATE and multi-table DELETE both return ER_TABLEACCESS_DENIED_ERROR

# while the multi-table UPDATE returns ER_VIEW_NO_EXPLAIN

--error ER_TABLEACCESS_DENIED_ERROR

EXPLAIN UPDATE v1 SET v1.a = v1.a + 1 WHERE v1.a = 2;

--error ER_TABLEACCESS_DENIED_ERROR

EXPLAIN DELETE v1 FROM v1, t2 WHERE v1.a = t2.a;

--error ER_TABLEACCESS_DENIED_ERROR

EXPLAIN UPDATE v1, t2 SET v1.a = v1.a + 1 WHERE v1.a = t2.a;