Index: django/db/models/fields/__init__.py
===================================================================
--- django/db/models/fields/__init__.py	(wersja 5036)
+++ django/db/models/fields/__init__.py	(kopia robocza)
@@ -286,7 +286,11 @@
         field's data.
         """
         if rel:
-            return new_data.get(self.name, [self.get_default()])[0]
+            new_data_getted = new_data.get(self.name, self.get_default())
+            if isinstance(new_data_getted, list):
+                return new_data_getted[0]
+            else:
+                return new_data_getted
         val = new_data.get(self.name, self.get_default())
         if not self.empty_strings_allowed and val == '' and self.null:
             val = None