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
""" Accounting Valuation Entries """
        self.ensure_one()
        if self.product_id.type != 'product':
            
            return False
        if self.restrict_partner_id:
            
            return False
        location_from = self.location_id
        location_to = self.location_dest_id
        company_from = self._is_out() and self.mapped('move_line_ids.location_id.company_id') or False
        company_to = self._is_in() and self.mapped('move_line_ids.location_dest_id.company_id') or False
        
        
        if self._is_in():
            journal_id, acc_src, acc_dest, acc_valuation = self._get_accounting_data_for_valuation()
            if location_from and location_from.usage == 'customer':  
                self.with_context(force_company=company_to.id)._create_account_move_line(acc_dest, acc_valuation, journal_id)
            else:
                self.with_context(force_company=company_to.id)._create_account_move_line(acc_src, acc_valuation, journal_id)
        
        if self._is_out():