Description:
------------
A bogus character (a nul before \r\n)  is returned from 
header('WWW-Authenticate: Basic realm="ABC"');

Which causes mod_fcgi to "internal server error".

It only happens with safemode and pcre-regexp


Reproduce code:
---------------
<?

header("HTTP/1.1 401 Unauthorized");
header("WWW-Authenticate: Basic realm=\"ABC\"");

?>


Expected result:
----------------
"In emacs display" 

Status: 401^M
Content-type: text/html^M
X-Powered-By: PHP/4.3.7^M
WWW-Authenticate: Basic realm="ABC-1000"^M
^M






Actual result:
--------------
Status: 401^M
Content-type: text/html^M
X-Powered-By: PHP/4.3.7^M
WWW-Authenticate: Basic realm="ABC-1000"^@^M
^M

Notice ^@ in output.

Hexdump of last part.
3130 3030 2200 0d0a 0d0a
1000" NULL \r\n\r\n