[FIX] stock_account: standard price update move done

When you change the quantity done of a done move of a product valuated
by standard price in perpetual valuation, the price used to update
create the corrective journal entry is the price unit of the move
instead of the standard price.

This behaviour leads to iconsistancy like having a empty stock and still
have a valuation on the stock valuation account.

To fix this issue, we check if we are working in standard price and use
the standard price of the product instead of the move unit price.

addons/stock_account/models/stock.py

@@ -72,7 +72,10 @@ class StockMoveLine(models.Model):
                 }
                 move_id.write(move_vals)
                 if move_id.product_id.valuation == 'real_time':
-                    move_id.with_context(force_valuation_amount=qty_difference*move_id.price_unit)._account_entry_move()
+                    if move_id.product_id.cost_method == 'standard':
+                        move_id.with_context(force_valuation_amount=qty_difference * move_id.product_id.standard_price)._account_entry_move()
+                    else:
+                        move_id.with_context(force_valuation_amount=qty_difference*move_id.price_unit)._account_entry_move()
         return super(StockMoveLine, self).write(vals)