Fixed #24974 -- Fixed inheritance of formfield_callback for modelform_factory forms.

tests/model_forms/tests.py

@@ -2736,6 +2736,28 @@ class FormFieldCallbackTests(SimpleTestCase):
         with self.assertRaises(TypeError):
             modelform_factory(Person, fields="__all__", formfield_callback='not a function or callable')
 
+    def test_inherit_after_custom_callback(self):
+        def callback(db_field, **kwargs):
+            if isinstance(db_field, models.CharField):
+                return forms.CharField(widget=forms.Textarea)
+            return db_field.formfield(**kwargs)
+
+        class BaseForm(forms.ModelForm):
+            class Meta:
+                model = Person
+                fields = '__all__'
+
+        NewForm = modelform_factory(Person, form=BaseForm, formfield_callback=callback)
+
+        class InheritedForm(NewForm):
+            pass
+
+        for name in NewForm.base_fields.keys():
+            self.assertEqual(
+                type(InheritedForm.base_fields[name].widget),
+                type(NewForm.base_fields[name].widget)
+            )
+
 
 class LocalizedModelFormTest(TestCase):
     def test_model_form_applies_localize_to_some_fields(self):