Add loc with query string (get parameters) into drupal xml sitemap link

How to reproduce:

    $xmllink = array(
      'id' => 1,
      'type' => 'custom',
      'subtype' => 'custom1',
      'status' => 1,
      'changefreq' => 86400*7,
      'lastmod' => time(),
      'priority' => 0.8,
      'loc' => 'node?page=2',
      'access' => 1,
      'language' => LANGUAGE_NONE,
    );
    xmlsitemap_link_save($xmllink);

And after this we will see in sitemap.xml:

<url><loc>http://example.com/node%3Fpage%3D2</loc><lastmod>2013-02-13T18:47Z</lastmod><changefreq>weekly</changefreq><priority>0.8</priority></url>

I have solve this problem for me via this patch for function xmlsitemap_generate_chunk(stdClass $sitemap, XMLSitemapWriter $writer, $chunk) {

        'xmlsitemap_link' => $link,
        'xmlsitemap_sitemap' => $sitemap,
      );
+     if(strpos($link['loc'],'?')) {
+       list($link['loc'],$loc_query)=explode('?',$link['loc']);
+     } else {
+       $loc_query=NULL;
+     }
      // @todo Add a separate hook_xmlsitemap_link_url_alter() here?
      $link_url = url($link['loc'], $link_options + $url_options);
+     
+     if($loc_query)
+       $link_url .= '?'.$loc_query;
  
      // Skip this link if it was a duplicate of the last one.
      // @todo Figure out a way to do this before generation so we can report

@Ari Linn, thanks for the hint, your version is more simple and works well. Here is updated patch with your version of solution. Please re-test it and commit to head.