Ticket #4271: 4271.diff

django/newforms/forms.py

@@ -57 +57 @@
     # class, not to the Form class.
     def __init__(self, data=None, auto_id='id_%s', prefix=None, initial=None):
         self.is_bound = data is not None
-        self.data = data or {}
+        if data:
+            self.data = data.copy()
+        else:
+            self.data = {}
         self.auto_id = auto_id
         self.prefix = prefix
         self.initial = initial or {}