Integrity error on many2many when using inheritance by prototyping

[Karel Marissens]

Simple case:
Model A defines a many2many field to model X.
Model B inherits from model A but defines a new name (thus: inheritance by prototyping).

When creating an object of model B, an integrity error occurs. When looking in the console, this is the underlying error:

2013-08-02 12:01:43,125 6440 ERROR test01 openerp.sql_db: bad query: insert into model_a_model_x_rel (model_a_id,model_x_id) values (37, 6)
Traceback (most recent call last):
  File "C:\...\openerp-server\openerp\sql_db.py", line 226, in execute
    res = self._obj.execute(query, params)
IntegrityError: insert or update on table "model_a_model_x_rel" violates foreign key constraint "model_a_model_x_rel_model_a_id_fkey"
DETAIL: Key (model_a_id)=(37) is not present in table "model_a".

By doing the inheritance by prototyping, the definition of the many2many field is copied from model a to model b. Thus, the many2many in model b defines the same relational table for storing the relation. Since model b is another table altogether, this doesn't work.

A workaround is to do an overwrite of the many2many in model b to define another relational table, but shouldn't this happen automatically? The same problem could possibly happen with one2many fields (not tested).