migration problem

I attached a testcase that reproduces all problem that I noticed (previously reported in "serious symfony doctrine:migrate issues - symfony 1.4" on symfony-dev)

There is a problem with an empty ON UPDATE when migrate to version 5

• SQLSTATE[42601]: Syntax error: 7 BŁĄD: błąd składni w lub blisko "ON"
  LINE 1: ... (object_c_id) REFERENCES object_c(id) ON UPDATE ON DELETE ...
  ^. Failing Query: "ALTER TABLE object_b ADD CONSTRAINT object_b_object_c_id_object_c_id FOREIGN KEY (object_c_id) REFERENCES object_c(id) ON UPDATE ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE"

When migrateing from 5 to 3
Failing Query: "DROP INDEX object_b_object_c_id_idx" - this index doesn't exist - should be "object_b_object_c_id"

Also
$this->changeColumn('object_a', 'name', 'string', '2048', array(
));
$this->changeColumn('object_b', 'name', 'string', '2048', array(
));
doesn't work for me