function l() may generate class="active active" in some cases

Some modules, for whatever reason, may set a link as class="active" (in the $attributes argument). But function l() may append ' active' if the url path is equal to current. Here's the code from function l():

  if ($path == $_GET['q']) {
    if (isset($attributes['class'])) {
      $attributes['class'] .= ' active';
    }
    else {
      $attributes['class'] = 'active';
    }
  }

Here's a possible solution to illustrate what I mean:

  if ($path == $_GET['q']) {
    if (isset($attributes['class']) && $attributes['class'] != 'active') {
      $attributes['class'] .= ' active';
    }
    else {
      $attributes['class'] = 'active';
    }
  }