Index: trac/Ticket.py
===================================================================
--- trac/Ticket.py	(revision 1056)
+++ trac/Ticket.py	(working copy)
@@ -448,9 +448,7 @@
 
         if preview:
             # Use user supplied values
-            for field in Ticket.std_fields:
-                if self.args.has_key(field) and field != 'reporter':
-                    ticket[field] = self.args.get(field)
+            ticket.populate(self.args)
             self.req.hdf.setValue('ticket.action', action)
             reporter_id = self.args.get('author')
             comment = self.args.get('comment')