Ticket #12915: formfield_callback_inheritance_v2.diff

django/forms/models.py

@@ -179 +179 @@
 
 class ModelFormMetaclass(type):
     def __new__(cls, name, bases, attrs):
-        formfield_callback = attrs.pop('formfield_callback',
-                lambda f: f.formfield())
+        if 'formfield_callback' in attrs:
+            attrs['formfield_callback'] = staticmethod(attrs['formfield_callback'])
         try:
             parents = [b for b in bases if issubclass(b, ModelForm)]
         except NameError:
@@ -198 +198 @@
         if opts.model:
             # If a model is defined, extract form fields from it.
             fields = fields_for_model(opts.model, opts.fields,
-                                      opts.exclude, formfield_callback)
+                                      opts.exclude, getattr(new_class, 'formfield_callback', lambda f: f.formfield()))
             # Override default model fields with any custom declared ones
             # (plus, include all the other declared fields).
             fields.update(declared_fields)