[FIX] stock: inventory value

- Go to Inventory > Reports > Inventory Valuation
- Select the pivot view

The top row (containing the Total) has an empty 'Inventory Value'.

This is because there is no domain on the line, so it is skipped.

We fall back on the global domain instead.

opw-1933191

closes #31280

addons/stock/models/stock_quant.py

@@ -110,12 +110,11 @@ def read_group(self, domain, fields, groupby, offset=0, limit=None, orderby=Fals
         res = super(Quant, self).read_group(domain, fields, groupby, offset=offset, limit=limit, orderby=orderby, lazy=lazy)
         if 'inventory_value' in fields:
             for line in res:
-                if '__domain' in line:
-                    lines = self.search(line['__domain'])
-                    inv_value = 0.0
-                    for line2 in lines:
-                        inv_value += line2.inventory_value
-                    line['inventory_value'] = inv_value
+                lines = self.search(line.get('__domain', domain))
+                inv_value = 0.0
+                for line2 in lines:
+                    inv_value += line2.inventory_value
+                line['inventory_value'] = inv_value
         return res
 
     @api.multi