In purchase line, delivery_date shows planned_date / effective_date of related moves if those exist, otherways it shows the purchase delivery_date. But in case that delivery_date was edited (actually we change delivery_date_store) it is not shown the planned_date / effective_date of related moves but the delivery_date_store.
I think this is confusing to the user: Depending on whether the delivery_date was edited or not, he will see the expected date or the move effective_date.
That is not what I see in the code. If you think there is a change to do in the code please fill a bugs with a review.
It is pointless (and even impossible) to discuss such detail in a general forum.
Thank you for the reply. I’ll fill a bug: Issue 10394: If delivery_date is edited it doesn't show effective_date but delivery_date_store - Tryton issue tracker