[FIX] stock_account: stock_history report

* shadowing of "fields" import in the read_group function as it receives
  a "fields" arg. As we have to use fields.Datetime in this method,
  whe choosed to reimport it as "fieldsDatetime" to use it.
* cast not_real_cost_method_products.ids list to tuple, because
  psycopg2 only accept tuple for "IN" condition.

addons/stock_account/report/stock_history.py

@@ -2,6 +2,7 @@
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
 from odoo import api, fields, models, tools
+from odoo.fields import Datetime as fieldsDatetime
 
 
 class StockHistory(models.Model):
@@ -26,7 +27,7 @@ class StockHistory(models.Model):
     def read_group(self, domain, fields, groupby, offset=0, limit=None, orderby=False, lazy=True):
         res = super(StockHistory, self).read_group(domain, fields, groupby, offset=offset, limit=limit, orderby=orderby, lazy=lazy)
         if 'inventory_value' in fields:
-            date = self._context.get('history_date', fields.Datetime.now())
+            date = self._context.get('history_date', fieldsDatetime.now())
             stock_history = self.env['stock.history']
             group_lines = {}
             for line in res:
@@ -40,7 +41,7 @@ class StockHistory(models.Model):
                 self._cr.execute("""SELECT DISTINCT ON (product_id, company_id) product_id, company_id, cost
                     FROM product_price_history
                     WHERE product_id in %s AND datetime <= %s
-                    ORDER BY product_id, company_id, datetime DESC""", (not_real_cost_method_products.ids, date))
+                    ORDER BY product_id, company_id, datetime DESC""", (tuple(not_real_cost_method_products.ids), date))
                 for history in self._cr.dictfetchall():
                     histories_dict[(history['product_id'], history['company_id'])] = history['cost']