Ticket #11860: nullbooleanselect_patch.diff

django/forms/widgets.py

@@ -452 +452 @@
                 False: False}.get(value, None)
 
     def _has_changed(self, initial, data):
-        # Sometimes data or initial could be None or u'' which should be the
-        # same thing as False.
-        return bool(initial) != bool(data)
+        # For a NullBooleanSelect, None (unknown) and False (No)
+        # are not the same
+        if initial is not None:
+            initial = bool(initial)
+        if data is not None:
+            data = bool(data)
+        return initial != data
 
 class SelectMultiple(Select):
     def render(self, name, value, attrs=None, choices=()):

tests/regressiontests/forms/widgets.py

@@ -532 +532 @@
 <option value="2">Yes</option>
 <option value="3" selected="selected">No</option>
 </select>
+>>> w._has_changed(False, None)
+True
+>>> w._has_changed(None, False)
+True
+>>> w._has_changed(None, None)
+False
+>>> w._has_changed(False, False)
+False
+>>> w._has_changed(True, False)
+True
+>>> w._has_changed(True, None)
+True
+>>> w._has_changed(True, True)
+False
 
 """ + \
 r""" # [This concatenation is to keep the string below the jython's 32K limit].