[8.0][regression] Problem with computed integer fields

[ludwiktrammer]

An regression exists introduced in commit f2e4a10 (on November 3th).

I've got a model with a computed integer field:

class Foo(models.Model):
    _name = 'my.foo'

    # ...
    age = fields.Integer(compute='compute_age')

    @api.one
    def compute_age(self):
        self.age = 25  # simplified example ;)

When I try to display objects of this model in kanban view (grouped by an entirely different field) I get the following error:

File "/[snip]/odoo/openerp/models.py", line 2101, in read_group
    if getattr(self._fields[f].base_field.column, '_classic_write')
AttributeError: 'NoneType' object has no attribute '_classic_write'

The problem didn't exist before commit f2e4a10. It seems that this is the change that causes the problem.

[yvaucher]

I confirm this with Float field as well. It impacts fields which are automatically added as summed in tree view.

A workaround is to override read_group:

@api.model
def read_group(self, domain, fields, groupby, offset=0, limit=None,
               orderby=False, lazy=True):
    """ Remove computed Float fields from read_group to avoid
    AttributeError: 'NoneType' object has no attribute '_classic_write'
    due to odoo/odoo#3972
    """
    remove_fields = ('computed_field', )
    keep_fields = [f for f in fields if not f in remove_fields]
    _super = super(PurchaseOrderLine, self)
    return _super.read_group(domain, stored_fields, groupby=groupby,
                             offset=offset, limit=limit,
                             orderby=orderby, lazy=lazy)

[mart-e]

Indeed an inssue with non-stored integer (or float) that could not be aggreated.
It was fixed at 33c8aae