Ticket #18525: 18525.diff

wp-admin/includes/class-wp-upgrader.php

@@ -1239 +1239 @@
         }
 
         function flush_output() {
-                wp_ob_end_flush_all();
-                flush();
+                wp_ob_end_flush_all(true);
         }
 }
 

wp-admin/includes/misc.php

@@ -271 +271 @@
                         $message = $message->get_error_message();
         }
         echo "<p>$message</p>\n";
-        wp_ob_end_flush_all();
-        flush();
+        wp_ob_end_flush_all(true);
 }
 
 function wp_doc_link_parse( $content ) {

wp-includes/functions.php

@@ -3274 +3274 @@
  * Flush all output buffers for PHP 5.2.
  *
  * Make sure all output buffers are flushed before our singletons our destroyed.
- *
+ * Only use $disable_compression for pages that need to be updated continuously, like updating the core,
+ * or installing plugins, etc.
+ * @param bool $disable_compression Turn off zlib / gzip compression, attempt to defeat chunking.
+ * @return void
  * @since 2.2.0
  */
-function wp_ob_end_flush_all() {
-        $levels = ob_get_level();
-        for ($i=0; $i<$levels; $i++)
-                ob_end_flush();
+function wp_ob_end_flush_all($disable_compression = false) {
+
+        // Clean the output buffer
+        while ( @ob_get_flush() );
+
+        if ( $disable_compression ) {
+                /**
+                 * Turn off compression - make sure to flush the buffer BEFORE
+                 * turning off compression, see comment from Sam Yong
+                 * @link http://php.net/manual/en/function.ob-end-clean.php
+                 */
+                if ( !headers_sent() && ini_get('zlib.output_handler') ) {
+                        ini_set('zlib.output_handler', '');
+                        ini_set('zlib.output_compression', 0);
+                }
+
+                // Tell apache to send an uncompressed non-chunked response
+                if ( function_exists('apache_setenv') ) {
+
+                        /**
+                         * Turn off mod_deflate
+                         * @link http://httpd.apache.org/docs/2.2/env.html#no-gzip
+                         */
+                        apache_setenv( 'no-gzip', '1' );
+                }
+
+                // Turn off any default output handlers
+                ini_set('output_handler', '');
+                ini_set('output_buffering', false);
+                ini_set('implicit_flush', true);
+
+                // Pad the output by a 4K block just to make sure that whatever apache/php
+                // considers a "chunk" is sent
+                echo str_repeat(chr(0), 4096);
+                flush();
+        }
 }
 
 /**