rem: sigc::bind(sigc::ptr_fun(&do_view_changelog), ver));
add: sigc::bind(sigc::ptr_fun(&do_view_changelog), pkgname, curverstr));
context: void view_changelog(pkgCache::VerIterator ver){  bool in_debian=false;  // TODO: add a configurable association between origins and changelog URLs.  for(pkgCache::VerFileIterator vf=ver.FileList();      !vf.end() && !in_debian; ++vf)    if(!vf.File().end() && vf.File().Origin()!=NULL &&       strcmp(vf.File().Origin(), "Debian")==0)      in_debian=true;  if(!in_debian)    {      show_message(_("You can only view changelogs of official Debian packages."),		   NULL, get_style("Error"));      return;    }  download_manager *manager = get_changelog(ver,					    sigc::bind(sigc::ptr_fun(&do_view_changelog), ver));  if(manager != NULL)    (new ui_download_manager(manager, true, false,			     _("Downloading Changelog"),			     _(""),			     _("Download Changelog")))->start();}