[FIX] stock_account: In stock valuation report, if all products real …

…price, don't do the product history price query

addons/stock_account/wizard/stock_valuation_history.py

@@ -65,8 +65,10 @@ def read_group(self, cr, uid, domain, fields, groupby, offset=0, limit=None, con
             products_rec = self.pool['product.product'].read(cr, uid, product_ids, ['cost_method', 'product_tmpl_id'], context=context)
             products_dict = dict((product['id'], product) for product in products_rec)
             cost_method_product_tmpl_ids = list(set(product['product_tmpl_id'][0] for product in products_rec if product['cost_method'] != 'real'))
-            cr.execute('SELECT DISTINCT ON (product_template_id, company_id) product_template_id, company_id, cost FROM product_price_history WHERE product_template_id in %s AND datetime <= %s ORDER BY product_template_id, company_id, datetime DESC', (tuple(cost_method_product_tmpl_ids), date))
-            histories = cr.dictfetchall()
+            histories = []
+            if cost_method_product_tmpl_ids:
+                cr.execute('SELECT DISTINCT ON (product_template_id, company_id) product_template_id, company_id, cost FROM product_price_history WHERE product_template_id in %s AND datetime <= %s ORDER BY product_template_id, company_id, datetime DESC', (tuple(cost_method_product_tmpl_ids), date))
+                histories = cr.dictfetchall()
             histories_dict = {}
             for history in histories:
                 histories_dict[(history['product_template_id'], history['company_id'])] = history['cost']