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):


addons/stock_account/models/stock.py
valued_move_lines = move.move_line_ids.filtered(lambda ml: ml.location_id._should_be_valued() and not ml.location_dest_id._should_be_valued() and not ml.owner_id)
        valued_quantity = 0
        for valued_move_line in valued_move_lines:
            valued_quantity += valued_move_line.product_uom_id._compute_quantity(valued_move_line.qty_done, move.product_id.uom_id)
        qty_to_take_on_candidates = quantity or valued_quantity
        candidates = move.product_id._get_fifo_candidates_in_move()
        new_standard_price = 0
        tmp_value = 0  
        for candidate in candidates:
            new_standard_price = candidate.price_unit
            if candidate.remaining_qty <= qty_to_take_on_candidates:
                qty_taken_on_candidate = candidate.remaining_qty
            else:
                qty_taken_on_candidate = qty_to_take_on_candidates
            
            
            
            candidate_price_unit = candidate.remaining_value / candidate.remaining_qty
            value_taken_on_candidate = qty_taken_on_candidate * candidate_price_unit
            candidate_vals = {
                'remaining_qty': candidate.remaining_qty - qty_taken_on_candidate,
                'remaining_value': candidate.remaining_value - value_taken_on_candidate,
            }
            candidate.write(candidate_vals)
            qty_to_take_on_candidates -= qty_taken_on_candidate
            tmp_value += value_taken_on_candidate
            if qty_to_take_on_candidates == 0:
                break