Fixed #26534 -- Fixed boolean form fields has_changed() with hidden input.

django/forms/fields.py

@@ -720,12 +720,9 @@ class BooleanField(Field):
             raise ValidationError(self.error_messages['required'], code='required')
 
     def has_changed(self, initial, data):
-        # Sometimes data or initial could be None or '' which should be the
-        # same thing as False.
-        if initial == 'False':
-            # show_hidden_initial may have transformed False to 'False'
-            initial = False
-        return bool(initial) != bool(data)
+        # Sometimes data or initial may be a string equivalent of a boolean
+        # so we should run it through to_python first to get a boolean value
+        return self.to_python(initial) != self.to_python(data)
 
 
 class NullBooleanField(BooleanField):
@@ -754,14 +751,6 @@ class NullBooleanField(BooleanField):
     def validate(self, value):
         pass
 
-    def has_changed(self, initial, data):
-        # 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 CallableChoiceIterator(object):
     def __init__(self, choices_func):

tests/forms_tests/field_tests/test_booleanfield.py

@@ -54,3 +54,8 @@ class BooleanFieldTest(SimpleTestCase):
         self.assertTrue(f.has_changed(True, ''))
         # Initial value may have mutated to a string due to show_hidden_initial (#19537)
         self.assertTrue(f.has_changed('False', 'on'))
+        # HiddenInput widget sends string values for boolean but doesn't clean them in value_from_datadict
+        self.assertFalse(f.has_changed(False, 'False'))
+        self.assertFalse(f.has_changed(True, 'True'))
+        self.assertTrue(f.has_changed(False, 'True'))
+        self.assertTrue(f.has_changed(True, 'False'))

tests/forms_tests/field_tests/test_nullbooleanfield.py

@@ -67,3 +67,10 @@ class NullBooleanFieldTest(FormFieldAssertionsMixin, SimpleTestCase):
         self.assertTrue(f.has_changed(True, False))
         self.assertTrue(f.has_changed(True, None))
         self.assertTrue(f.has_changed(True, False))
+        # HiddenInput widget sends string values for boolean but doesn't clean them in value_from_datadict
+        self.assertFalse(f.has_changed(False, 'False'))
+        self.assertFalse(f.has_changed(True, 'True'))
+        self.assertFalse(f.has_changed(None, ''))
+        self.assertTrue(f.has_changed(False, 'True'))
+        self.assertTrue(f.has_changed(True, 'False'))
+        self.assertTrue(f.has_changed(None, 'False'))