Comment 7 for bug 528320

To be precise (good accouting practice requires this)
"Cancel" of a "done" picking must generate a new picking and all dependant documents (except payments of course) with "negative" qty and value of the original document(s).
For this to happen OpenER absolutely needs to know ALL relations between SO/PO - Picking - Invoice (which currently is not the case)
I know negative values are not allowed everywhere .... hence devit/credit must be reversed ....

These new documents follow the workflow of the original documents and can be reconciled automatically.

A problem persists - how to handle price differences of stock moves after the original move (only if average price is selected)