Null path retrieved from path redirect, leading to global flush

In expire.module, you've got:

    // Path redirects
    if (module_exists('path_redirect')) {
      $path_redirects = expire_path_redirect_load(array('redirect' => $path));
      if (isset($path_redirects)) {
        foreach ($path_redirects as $path_redirect) {
          $expire[] = $path_redirect['path'];
        }
      }
    }

I'm suggesting:

    // Path redirects
    if (module_exists('path_redirect')) {
      $path_redirects = expire_path_redirect_load(array('redirect' => $path));
      if (isset($path_redirects)) {
        foreach ($path_redirects as $path_redirect) {
          if (!empty($path_redirect['redirect'])) {
            $expire[] = $path_redirect['redirect'];
          }
        }
      }
    }

There's no column in the path_redirect table named 'path'. The column that you want is 'redirect'. If a result is returned from expire_path_redirect_load(), $expire[] would be set to NULL, which results in a global flush.