Three related problems with Drop Shipping with Anglo Saxon Accounting.

One has been broken since #20080.

Another is caused by the same code.

The third - a fix from #12687 - is being bypassed by current code.



Impacted versions:

11.0, and 10.0 for at least some of this

Steps to reproduce:

Set up a product with
- real time valuation
- standard price
- Anglo Saxon accounting
- drop shipping turned on
- invoicing on delivered quantities

Create a product with a standard price of $40.

Current behavior:

_If I create a sales order and choose to ship from existing stock, then the invoice created after delivery is correct, and it has the correct Anglo Saxon account moves._

- Dr COGS $40
- Cr Output $40

If I create a sales order and choose to drop ship, I can then go to the RFQ, and change the RFQ price to $45, then receive the product, and generate the Vendor Bill.  Everything is correct at this point.  When I go back to the Sales Order and create and validate the invoice, it has the incorrect Anglo Saxon account moves:

- Dr Output $45
- Cr COGS $45

Expected behavior:

The accounting should be the same on the invoice.  The value is wrong, and the debits and credits are reversed.

Also, there should be an additional journal:

- Dr Output $40
- Cr Input $40

Th 3 problems are:

1. It is getting a -ve price unit from _compute_average_price because the stock move is not an outgoing move, but a supplier -> customer move!
2. It is getting the average price from those moves and using it, even if the product is using standard price.
3. The extra move that #12687 created is no longer being generated as the account moves are being bypassed entirely for dropshipping.  Somewhere in the process, we need to move the value from stock_input to stock_output.  This may be a v11 problem only.

Video/Screenshot link (optional):


average_price_unit = 0
        qty_delivered = 0
        invoiced_qty = 0
        for move in moves:
            if move.state != 'done':
                continue
            invoiced_qty += move.product_qty
            if invoiced_qty <= qty_done:
                continue
            qty_to_consider = move.product_qty
            if invoiced_qty - move.product_qty < qty_done:
                qty_to_consider = invoiced_qty - qty_done
            qty_to_consider = min(qty_to_consider, quantity - qty_delivered)
            qty_delivered += qty_to_consider
            average_price_unit = (average_price_unit * (qty_delivered - qty_to_consider) + (-1 * move.price_unit) * qty_to_consider) / qty_delivered
            if qty_delivered == quantity:
                break
        return average_price_unit