[FIX] stock_account: correct forecast report total amount and currency

Steps:
- Go to Settings > Companies > Manage Companies
- Create a company (1) with a different currency than the one you're in
- Go to inventory > Products > Products > Create a product (2)
  - Storable Product
  - Cost: 10
- Click Update Quantity
- Create a new quantity line with 1 in On Hand Quantity
- Switch to company (1)
- Go to Inventory > Products > Products > Edit product (2)
  - Storable Product
  - Cost: 15
- Click Update Quantity
- Create a new quantity line with 1 in On Hand Quantity
- Go back to the product
- Click the "Forecasted" smart button

Bug:
Traceback here:
https://github.com/odoo/odoo/blob/47bfdf0592a5dd93870ca1a9da326351d70087bb/addons/stock_account/report/report_stock_forecasted.py#L17
ValueError: Expected singleton: res.currency(2, 1)

Explanation:
The amount is the sum of the `stock.valuation.layer`s of a product
across all companies and these companies may have different currencies.

This commit scopes the computation of the amount inside the company of
the current warehouse.

Also the `stock.quant` values displayed in the "On Hand" report are not
correct for the other companies when displaying their data by selecting
all the checkboxes in the global company dropdown.
This commit also fixes the amounts in the On Hand view by using the
standard price per company and attributing the correct currency to the
`stock.quant`.

opw:2444593

closes odoo#65267

X-original-commit: 67d975b
Signed-off-by: backspac <backspac@users.noreply.github.com>

addons/stock_account/models/stock_quant.py

@@ -20,8 +20,8 @@ def _compute_value(self):
         average cost is the same for all location and the valuation field is
         a estimation more than a real value).
         """
-        self.currency_id = self.env.company.currency_id
         for quant in self:
+            quant.currency_id = quant.company_id.currency_id
             # If the user didn't enter a location yet while enconding a quant.
             if not quant.location_id:
                 quant.value = 0
@@ -36,10 +36,10 @@ def _compute_value(self):
                 if float_is_zero(quantity, precision_rounding=quant.product_id.uom_id.rounding):
                     quant.value = 0.0
                     continue
-                average_cost = quant.product_id.value_svl / quantity
+                average_cost = quant.product_id.with_company(quant.company_id).value_svl / quantity
                 quant.value = quant.quantity * average_cost
             else:
-                quant.value = quant.quantity * quant.product_id.standard_price
+                quant.value = quant.quantity * quant.product_id.with_company(quant.company_id).standard_price
 
     @api.model
     def read_group(self, domain, fields, groupby, offset=0, limit=None, orderby=False, lazy=True):

addons/stock_account/report/report_stock_forecasted.py

@@ -12,9 +12,16 @@ def _compute_draft_quantity_count(self, product_template_ids, product_variant_id
         """ Overrides to computes the valuations of the stock. """
         res = super()._compute_draft_quantity_count(product_template_ids, product_variant_ids, wh_location_ids)
         domain = self._product_domain(product_template_ids, product_variant_ids)
-        svl = self.env['stock.valuation.layer'].search(domain)
+        company = self.env['stock.location'].browse(wh_location_ids).mapped('company_id')
+        svl = self.env['stock.valuation.layer'].search(domain + [('company_id', '=', company.id)])
         currency = svl.currency_id or self.env.company.currency_id
-        value = float_repr(sum(svl.mapped('value')), precision_digits=currency.decimal_places)
+        quantity = sum(svl.filtered(lambda layer: layer.stock_move_id.location_dest_id.id in wh_location_ids).mapped('quantity'))
+        if quantity:
+            total_quantity = sum(svl.mapped('quantity'))
+            value = sum(svl.mapped('value')) * (quantity / total_quantity)
+        else:
+            value = 0
+        value = float_repr(value, precision_digits=currency.decimal_places)
         if currency.position == 'after':
             value = '%s %s' % (value, currency.symbol)
         else: