Use internal URL alias doesn't redirect properly

When entering an internal URL alias into field URL Address, the URL is not resolved; it redirects to the absolute URL.
For instance I enter topics/test (URL alias pointing to internal path taxonomy/term/1) into the URL Address field. Redirects to http://topics/test; I except though that it recognizes the alias as internal path and handles the redirection appropriately.

I tracked it down to the line of code when validating the Drupal path in function _simpleads_validate_url(); drupal_valid_path() handles only internal paths. So the correct code is:

if (drupal_valid_path(drupal_get_normal_path($url))) { ... }

Instead of:

if (drupal_valid_path($url)) { ... }