Convert amount total for order in page checkout doesn’t work properly [#2610330]

Hi,

I don't know if this problem come from commerce module or from my own code, So I have the following information about the problem:

1-scenario
GIVEN: order in the cart page
WHEN: Change the currency(I use module Multicurrency) then click on button checkout
THEN: an problem occurred, The page checkout opened and the line items converted to the current currency whereas amount total of order doesn’t converted.

2-More details
After debugging the code in the function commerce_cart_order_refresh($order)
This function refresh the line items in case exist changing in their currency or amount or comment and that by invoke rules_invoke_event('commerce_product_calculate_sell_price', $cloned_line_item);
So after refreshed all line items it compare if exist difference between old line_item(that come from order) and the refreshed line_item.
If exist changes it save the order with refreshed line_item else do nothing.

So the problem occurred because it doesn’t exist difference between the old line_item and
refreshed line_item always the both have the current currency with converted amount, thus the order doesn’t update.