Wikimedia Bugzilla is closed!

It looks like the export function doesn't create a right encoding header, so mod_gzip doesn't recognise it as already gziped and gzip it again. The result is a non readable text, because browsers only unzip once.

The produced encoding header looks like this: 
 
 Content-Encoding: , gzip 

At the moment I only found a workaround by commenting some parts in includes/GlobalFunctions.php:

function wfResetOutputBuffers( $resetGzipEncoding=true ) {
        while( $status = ob_get_status() ) {
                if( $status['type'] == 0 /* PHP_OUTPUT_HANDLER_INTERNAL */ ) {
                        echo 'status 0';
                        // Probably from zlib.output_compression or other
                        // PHP-internal setting which can't be removed.
                        //
                        // Give up, and hope the result doesn't break
                        // output behavior.
                        break;
                }
/* Commented because of encoding errors 
               if( !ob_end_clean() ) {
                        // Could not remove output buffer handler; abort now
                        // to avoid getting in some kind of infinite loop.
                        break;
                }

                if( $resetGzipEncoding ) {
                        if( $status['name'] == 'ob_gzhandler' ) {
                                // Reset the 'Content-Encoding' field set by this handler
                                // so we can start fresh.
                                header( 'Content-Encoding:' );
                        }
                }
*/
        }
}