Description:
------------
Hello, I've got "Zero Sized Reply" when I try to replace a long string with PCRE.

Test script:
---------------
<?php
$strtest='';
for($i=0; $i<1024; $i++)$strtest.=chr(rand(1, 254));
$strtest.='B';
for($i=0; $i<1024*512; $i++)$strtest.=chr(rand(1, 254));
$strtest.='signature';
for($i=0; $i<1024; $i++)$strtest.=chr(rand(1, 254));

preg_replace('/b(?:.(?!signature))*.(sig.+)/sim', 'null${1}', $strtest);
?>

Expected result:
----------------
blank page

Actual result:
--------------
ERROR
The requested URL could not be retrieved

While trying to retrieve the URL: *******

The following error was encountered: 
Zero Sized Reply 

Squid did not receive any data for this request. 

Your cache administrator is *******.
Generated Tue, 05 Oct 2010 05:28:19 GMT by ******* (squid/2.7.STABLE3)