function download() {
                global $wgOut;
                global $wgRequest;
                global $wgCollectionContentTypeToFilename;

                $collection = CollectionSession::getCollection();

                $tempfile = tmpfile();
                $r = self::mwServeCommand( 'render_status', array(
                        'collection_id' => $wgRequest->getVal( 'collection_id' ),
                        'writer' => $wgRequest->getVal( 'writer' ),
                ) );
                $errorMessage = '';
                $info = false;
                if ( isset( $r['url'] ) ) {
                        self::curlreq( 'GET', $r['url'], array(), $errorMessage, $info, $timeout=false, $toFile=$tempfile );
                        $content_type = $r['content_type'];
                        $content_length = $r['content_length'];
                        $content_disposition = $r['content_disposition'];
                } else {
                        $info = self::mwServeCommand( 'download', array(
                                'collection_id' => $wgRequest->getVal( 'collection_id' ),
                                'writer' => $wgRequest->getVal( 'writer' ),
                        ), $timeout=false, $toFile=$tempfile );
                        $content_type = $info['content_type'];
                        $content_length = $info['download_content_length'];
                        $content_disposition = null;
                }
                if ( !$info ) {
                        $wgOut->showErrorPage( 'coll-download_notfound_title', 'coll-download_notfound_text' );
                        return;
                }
                $filename = $collection["title"].".";
                switch($wgRequest->getVal( 'writer', 'rl' ))
                {
                        case "odf":
                        $filename .= "odt";
                        break;
                        case "xhtml":
                        $filename .= "html";
                        break;
                        case "mwxml":
                        $filename .= "xml";
                        break;
                        default:
                        $filename .= "pdf";
                        break;
                }

                wfResetOutputBuffers();
                header( 'Content-Type: ' . $content_type );
                header( 'Content-Length: ' . $content_length);
                if ( $content_disposition ) {
                        header( 'Content-Disposition: ' . $content_disposition .' name="'.$filename.'"');
                }
                header('Content-Disposition: attachment; filename="'.$filename.'"');

                fseek( $tempfile, 0 );
                fpassthru( $tempfile );
                $wgOut->disable();
    }