Do not consider purchase as done when invoice or shipment state are none

If there are still line to invoice or to receive, the purchase should not be
done.

Closes #12594

modules/purchase/purchase.py

@@ -827,11 +827,13 @@ class Purchase(
 
     def is_done(self):
         return ((self.invoice_state == 'paid'
-                or self.invoice_state == 'none')
+                or (self.invoice_state == 'none'
+                    and all(not l.quantity
+                        for l in self.lines if l.type == 'line')))
             and (self.shipment_state == 'received'
-                or self.shipment_state == 'none'
-                or all(l.product.type == 'service'
-                    for l in self.lines if l.product)))
+                or (self.shipment_state == 'none'
+                    and all(l.product.type == 'service'
+                        for l in self.lines if l.product))))
 
     @classmethod
     def delete(cls, purchases):

modules/purchase/tests/scenario_purchase_manual_invoice.rst

@@ -68,7 +68,7 @@ Purchase with manual invoice method::
     >>> purchase.click('quote')
     >>> purchase.click('confirm')
     >>> purchase.state
-    'done'
+    'processing'
     >>> purchase.invoice_state
     'none'
     >>> len(purchase.invoices)