Ticket #22430: 22430.patch

src/wp-includes/functions.php

@@ -4457 +4457 @@
  * @since 2.2.0
  */
 function wp_ob_end_flush_all() {
+        $start = (int) ini_get('zlib.output_compression');
         $levels = ob_get_level();
-        for ( $i = 0; $i < $levels; $i++ ) {
+        for ( $i = $start; $i < $levels; $i++ ) {
                 ob_end_flush();
         }
 }