Comment 7 for bug 1060259

In fact, my previous comment was wrong, the merge proposal doesn't work : here is the bug scenario with the code of the merge proposal :
You have a picking with 3 products :
1) you do a partial delivery of 1 product -> the generated invoice is OK and has 1 product.
2) you deliver the last 2 products -> you get an error message "This picking list does not require invoicing."

When you look at the code and the exact behavior of the 2 pickings, you understand that, at step 2, the "active_id" variable in the do_partial() function of stock_invoice_directly/wizard/stock_invoice.py contains the ID the "done" picking with 1 products, and not the ID of the picking with 2 products.