id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
22430,wp_ob_end_flush_all bug when zlib.output_compression = On,Matthias Reuter,,"When zlib.output_compression is set to On, the function wp_ob_end_flush_all throws the following error:

{{{
Notice: ob_end_flush() [ref.outcontrol]: failed to delete buffer zlib output compression in /wp-includes/functions.php on line 2683
}}}

You can see this error e.g. when opening /wp-login.php in browser.

Critical Issue related to this bug: it also affects usage of /wp-admin/customize.php - the preview results in a blank page. Seems that the error avoids ajax snippets from getting loaded succesfully.

Hotfix is replacing in /wp-includes/functions.php

{{{
function wp_ob_end_flush_all() {
	$levels = ob_get_level();
	for ($i=0; $i<$levels; $i++)
		ob_end_flush();
}
}}}

with

{{{
function wp_ob_end_flush_all() {
	//$levels = ob_get_level();
	//for ($i=0; $i<$levels; $i++)
	//	ob_end_flush();
}
}}}

This issue occurs in all browsers (ie,ff,opera, etc) with both latest versions of WordPress, 3.4.2 and latest nightly build on a LAMP system with PHP Version 5.3.10-1~dotdeb.0.

PHP zlib settings:

{{{
Directive	Local Value	Master Value
zlib.output_compression	On	Off
zlib.output_compression_level	5	-1
zlib.output_handler	no value	no value
}}}
",defect (bug),closed,normal,,General,2.8,major,duplicate,,