[FIX] models: during setup, reset properties memoized on model classes

This is necessary, because a model's class is kept when applying model
extensions.

openerp/addons/test_inherit/models.py

@@ -140,3 +140,7 @@ class Parent2(models.AbstractModel):
 
     def stuff(self):
         return super(Parent2, self).stuff() + 'P2'
+
+    @api.constrains('foo')
+    def _check_foo(self):
+        pass

openerp/addons/test_inherit/tests/test_inherit.py

@@ -116,3 +116,7 @@ class TestInherit(common.TransactionCase):
         # check method overriding
         self.assertEqual(parent.stuff(), 'P1P2')
         self.assertEqual(child.stuff(), 'P1P2C1')
+
+        # check properties memoized on model
+        self.assertEqual(len(parent._constraint_methods), 1)
+        self.assertEqual(len(child._constraint_methods), 1)

openerp/models.py

@@ -782,6 +782,10 @@ class BaseModel(object):
         for (key, _, msg) in cls._sql_constraints:
             cls.pool._sql_error[cls._table + '_' + key] = msg
 
+        # reset properties memoized on cls
+        cls._constraint_methods = BaseModel._constraint_methods
+        cls._onchange_methods = BaseModel._onchange_methods
+
     @property
     def _constraint_methods(self):
         """ Return a list of methods implementing Python constraints. """