The return value of conf_path() should be named $conf_path

#1: rename-conf_path-1960764-1.patch queued for re-testing.

Oops, I think this needs a reroll already following #1949724: Allow simpletest child sites to additionally load a test-specific settings.php to allow testing anonymous and configless updates.

The new hunk will need to be updated too:

  // Check for a simpletest override.                                           
  if ($simpletest_conf_path = _drupal_simpletest_conf_path()) {
    $conf = $simpletest_conf_path;
    return $conf;
  }

Here's the whole function with the latest patch applied:

function conf_path($require_settings = TRUE, $reset = FALSE) {
  $conf_path = &drupal_static(__FUNCTION__, '');

  if ($conf_path && !$reset) {
    return $conf_path;
  }

  // Check for a simpletest override.
  if ($simpletest_conf_path = _drupal_simpletest_conf_path()) {
    $conf_path = $simpletest_conf_path;
    return $conf_path;
  }

  // Otherwise, use the normal $conf_path.
  $script_name = $_SERVER['SCRIPT_NAME'];
  if (!$script_name) {
    $script_name = $_SERVER['SCRIPT_FILENAME'];
  }
  $http_host = $_SERVER['HTTP_HOST'];
  $conf_path = find_conf_path($http_host, $script_name, $require_settings);
  return $conf_path;
}

Thanks @foopang!