The set_value() function of x2many fields is asynchronous. When a record is
loaded, the invisibility changers (IC) are evaluated once set_value() has been
performed on every fields. As set_value() didn't return its deferred, the IC where
evaluated with wrong values. It produced in particular the following bug:
Go to Customers > Agrolait (the Contacts tab is displayed), switch to next record,
which is the first contact of Agrolait. The Contacts tab is still displayed,
whereas it should not (the invisible condition being is_company == false and
child_ids == [], i.e. there is no contact).
Also call this._super() in set_value() of AbstractManyField instead of
duplicating the function of its parent.
Aaron Bohy
3bb35d68b6