Delete filter does not work

Yes, code is there, but it uses an uninitialized variable $fid in function customfilter_filter_delete_submit:

db_query('DELETE FROM {customfilter_filters} WHERE fid = %d', $fid);

So the rules are deleted but not the filter.

A fix seems to be easy. Here's the code that works for me. Please review it.

function customfilter_filter_delete_submit($form, &$form_state) {
  $fid = $form_state['values']['fid'];
  $rules = customfilter_get_rules($fid);
  
  foreach ($rules as $rule) {
    customfilter_delete_rule($rule['rid']);
  }
  
  db_query('DELETE FROM {customfilter_filters} WHERE fid = %d', $fid);
  
  $form_state['redirect'] = 'admin/settings/filters/customfilter';
}

PS: Your module is great, saved me hours of time.

Ok, I see you have already fixed this in the actual development tree. Installing the lasted version of customfilter-6.x-2.x has fixed the problem, too.