User Picture field + Gravatar = problem caused by missing mail field

The views/modules/user/views_handler_field_user_picture.inc file, which handles the user picture field, does not include the users mail field in the query.

I agree that -without the Gravatar module - this is probably useless in most cases... but
1) It is a negligable hit to include mail
2) without the mail field, Gravatar cannot pick-up unique avatars per user (at least not without doing an extra hit per user).

The fix?

class views_handler_field_user_picture extends views_handler_field {
  function construct() {
    parent::construct();
    $this->additional_fields['uid'] = 'uid';
    $this->additional_fields['name'] = 'name';
    $this->additional_fields['mail'] = 'mail';
  }

  function element_type() {
    return 'div';
  }

  function render($values) {
    // Fake an account object.
    $account = new stdClass();
    $account->uid = $values->{$this->aliases['uid']};
    $account->name = $values->{$this->aliases['name']};
    $account->mail = $values->{$this->aliases['mail']};
    $account->picture = $values->{$this->field_alias};

    return theme('user_picture', $account);
  }
}

Basically, add the mail field to the class.