[soc2009/model-validation] remove lazily translated strings for pickling of db fields

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2009/model-validation@11399 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/__init__.py

@@ -112,6 +112,35 @@ class Field(object):
         messages.update(error_messages or {})
         self.error_messages = messages
 
+    def __getstate__(self):
+        """
+        Pickling support.
+        """
+        from django.utils.functional import Promise
+        obj_dict = self.__dict__.copy()
+        items = []
+        translated_keys = []
+        for k, v in self.error_messages.items():
+            if isinstance(v, Promise):
+                args = getattr(v, '_proxy____args', None)
+                if args:
+                    translated_keys.append(k)
+                    v = args[0]
+            items.append((k,v))
+        obj_dict['_translated_keys'] = translated_keys
+        obj_dict['error_messages'] = dict(items)
+        return obj_dict
+
+    def __setstate__(self, obj_dict):
+        """
+        Unpickling support.
+        """
+        translated_keys = obj_dict.pop('_translated_keys')
+        self.__dict__.update(obj_dict)
+        for k in translated_keys:
+            self.error_messages[k] = _(self.error_messages[k])
+
+
     def __cmp__(self, other):
         # This is needed because bisect does not take a comparison function.
         return cmp(self.creation_counter, other.creation_counter)