gboolean
thunar_file_is_desktop_file (const ThunarFile *file)
{
  const gchar         *content_type;
  const gchar * const *data_dirs;
  guint                i;
  gchar               *path;
  gboolean             is_desktop_file = FALSE;

  _thunar_return_val_if_fail (THUNAR_IS_FILE (file), FALSE);

  if (G_UNLIKELY (file->info == NULL || file->gfile == NULL))
    return FALSE;

  /* only allow desktop files with the correct extension */
  if (!g_str_has_suffix (thunar_file_get_basename (file), ".desktop"))
    return FALSE:

  content_type = g_file_info_get_content_type (file->info);
  if (content_type != NULL
      && g_content_type_equals (content_type, "application/x-desktop"))
    {
      /* if the desktop file has the +x flag, we can safely execute it everywhere */
      if (g_file_info_get_attribute_boolean (file->info, G_FILE_ATTRIBUTE_ACCESS_CAN_EXECUTE))
        return TRUE;

      path = g_file_get_path (file->gfile);
      if (G_UNLIKELY (path == NULL))
        return FALSE;

      /* look if the file is in one of the system data dirs */
      data_dirs = g_get_system_data_dirs ();
      for (i = 0; data_dirs[i] != NULL; i++)
        if (g_str_has_prefix (path, data_dirs[i]))
          {
            is_desktop_file = TRUE;
            break;
          }

      /* user's data dir is also ok */
      if (is_desktop_file == FALSE
          && g_str_has_prefix (path, g_get_user_data_dir ()))
        is_desktop_file = TRUE;

      /* cleanup */
      g_free (path);
    }

  return is_desktop_file;
}