anchor.diff:  
     extraConfig =
       ''
  +      ${optionalString config.enableUploads ''
  +        Alias ${config.urlPrefix}/images ${config.uploadDir}
  +
  +        <Directory ${config.uploadDir}>
  +            Order allow,deny
  +            Allow from all
  +            Options -Indexes
  +        </Directory>
  +      ''}
  +      
         Alias ${config.urlPrefix} ${mediawikiRoot}
   
         <Directory ${mediawikiRoot}>
  
positive.code:           $wgArticlePath = "${config.articleUrlPrefix}/$1";
          ''}
  
          ${config.extraConfig}
        ?>
      '';
  
negative.code:         e.g. http://server/wiki/Page.  Leave empty to use the main URL
          prefix, e.g. http://server/w/index.php?title=Page.
        '';
      };
  
      enableUploads = mkOption {
        default = false;
        description = "Whether to enable file uploads.";
      };
  
      uploadDir = mkOption {
        default = throw "You must specify `uploadDir'.";
        example = "/data/mediawiki-upload";
        description = "The directory that stores uploaded files.";
      };
  
      extraConfig = mkOption {
  