Exception when trying to use a custom form schema from an extension

[amercader]

Both with the package and group controllers, when overriding the default _db_to_form_schema method (which does nothing) from an extension, you get an exception because the context is not passed to the validators.

File '/home/adria/dev/envs/iati/src/ckan/ckan/controllers/group.py', line 140 in edit
  old_data, errors = validate(old_data, schema)
File '/home/adria/dev/envs/iati/src/ckan/ckan/lib/navl/dictization_functions.py', line 215 in validate
  converted_data, errors = _validate(flattened, schema, context)
File '/home/adria/dev/envs/iati/src/ckan/ckan/lib/navl/dictization_functions.py', line 270 in _validate
  convert(converter, key, converted_data, errors, context)
File '/home/adria/dev/envs/iati/src/ckan/ckan/lib/navl/dictization_functions.py', line 178 in convert
  converter(key, converted_data, errors, context)
File '/home/adria/dev/envs/iati/src/ckan/ckan/logic/validators.py', line 108 in group_name_validator
  model = context['model']
KeyError: 'model'

[amercader]

Reopening, because another change is needed to support custom schemas

[amercader]

Fixed in eca1edce3a0f