When a form in the admin has no fields prevent failure.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8698 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/helpers.py

@@ -23,7 +23,10 @@ class AdminForm(object):
         if self.form._meta.fields is not None:
             name = self.form._meta.fields[0]
             return forms.BoundField(self.form, self.form.fields[name], name)
+        try:
             return iter(self.form).next()
+        except StopIteration:
+            return None
 
     def _media(self):
         media = self.form.media