Set widget readonly if there is not field for issue1506

tryton/gui/window/view_form/view/form_gtk/interface.py

@@ -256,7 +256,7 @@ class WidgetInterface(object):
 
     def display(self, record, field):
         if not field:
-            self._readonly_set(self.attrs.get('readonly', False))
+            self._readonly_set(self.attrs.get('readonly', True))
             self.invisible_set(self.attrs.get('invisible', False))
             return
         self._readonly_set(self.attrs.get('readonly',