Description:
------------
flush function output for html body in some times.it disappear at begin and end of html body.

exsample code:
<?php
define('XML_RPC', TRUE);
$XMLRPCVersion="1.0";
flush();
exit;

....more code
?>
it display:
0

<?php
define('XML_RPC', TRUE);
$XMLRPCVersion="1.0";
ob_flush();
exit;

....more code
?>
it display nothing

compare with to http headers i found that:

"Content-Length: 0"
exist when use ob_flush but not exist in flush
so i add this in my php codes like this
<?php
define('XML_RPC', TRUE);
$XMLRPCVersion="1.0";
header("Content-Length: 0");
flush();
exit;

....more code
?>
now all thing is work will!
i download php source code an compare flush with ob_flush.
in ob_flush:

	if (send_buffer) {
		if (just_flush) { /* if flush is called prior to proper end, ensure presence of NUL */
			final_buffer[final_buffer_length] = '\0';
		}
		OG(php_body_write)(final_buffer, final_buffer_length TSRMLS_CC);
	} 

in flush:
	if (sapi_module.flush) {
		sapi_module.flush(SG(server_context));
		return SUCCESS;
	} else {
		return FAILURE;
	}

i can't understand well with this codes but i think maybe some buffer is not zeromemory befor used.