[FIX] stock_account: product_price_update_before_done

When updating several moves for the same product, each time a write was done,
the move.product_id.standard_price was not updated due to "with_context(force_company=move.company_id.id)"
before write. Making a with_context before write changes the environment of the write, this why the cache
was not updated.

opw:709329

addons/stock_account/models/stock.py

@@ -184,6 +184,7 @@ class StockMove(models.Model):
     def product_price_update_before_done(self):
         tmpl_dict = defaultdict(lambda: 0.0)
         # adapt standard price on incomming moves if the product cost_method is 'average'
+        std_price_update = {}
         for move in self.filtered(lambda move: move.location_id.usage == 'supplier' and move.product_id.cost_method == 'average'):
             product_tot_qty_available = move.product_id.qty_available + tmpl_dict[move.product_id.id]
 
@@ -192,12 +193,13 @@ class StockMove(models.Model):
                 new_std_price = move.get_price_unit()
             else:
                 # Get the standard price
-                amount_unit = move.product_id.standard_price
+                amount_unit = std_price_update.get(move.product_id.id) or move.product_id.standard_price
                 new_std_price = ((amount_unit * product_tot_qty_available) + (move.get_price_unit() * move.product_qty)) / (product_tot_qty_available + move.product_qty)
 
             tmpl_dict[move.product_id.id] += move.product_qty
             # Write the standard price, as SUPERUSER_ID because a warehouse manager may not have the right to write on products
             move.product_id.with_context(force_company=move.company_id.id).write({'standard_price': new_std_price})
+            std_price_update[move.product_id.id] = new_std_price
 
     @api.multi
     def product_price_update_after_done(self):