Ticket #3258: savesubset.diff

django/newforms/models.py

@@ -36 +36 @@
     for f in opts.fields + opts.many_to_many:
         if isinstance(f, models.AutoField):
             continue
-        setattr(instance, f.attname, clean_data[f.name])
+        if f.name in clean_data:
+            setattr(instance, f.attname, clean_data[f.name])
     if commit:
         instance.save()
     return instance