[IMP]pms: qty to invoice to 0 if total amount is 0

pms/models/folio_sale_line.py

@@ -506,7 +506,7 @@ class FolioSaleLine(models.Model):
             "Product Unit of Measure"
         )
         for line in self:
-            if line.state == "draft":
+            if line.state == "draft" or line.price_total == 0.0:
                 line.invoice_status = "no"
             # REVIEW: if qty_to_invoice < 0 (invoice qty > sale qty),
             # why status to_invoice?? this behavior is copied from sale order
@@ -625,7 +625,7 @@ class FolioSaleLine(models.Model):
         Otherwise, the quantity delivered is used.
         """
         for line in self:
-            if line.folio_id.state not in ["draft"]:
+            if line.folio_id.state not in ["draft"] and line.price_total > 0.0:
                 line.qty_to_invoice = line.product_uom_qty - line.qty_invoiced
             else:
                 line.qty_to_invoice = 0

pms/models/pms_folio.py

@@ -814,9 +814,10 @@ class PmsFolio(models.Model):
         - to_invoice: if any SO line is 'to_invoice', the whole SO is 'to_invoice'
         - invoiced: if all SO lines are invoiced, the SO is invoiced.
         """
-        unconfirmed_orders = self.filtered(lambda so: so.state in ["draft"])
+        unconfirmed_orders = self.filtered(lambda folio: folio.state in ["draft"])
         unconfirmed_orders.invoice_status = "no"
-        confirmed_orders = self - unconfirmed_orders
+        zero_orders = self.filtered(lambda folio: folio.amount_total == 0)
+        confirmed_orders = self - unconfirmed_orders - zero_orders
         if not confirmed_orders:
             return
         line_invoice_status_all = [