Incomplete page by nginx -> fcgi -> php-fpm with keepalive

[Ondra42]

I have problem somewhere between nginx and php-fpm. When I use keep-alive
connection for fastgcgi php-fpm, there is often problem with loading page.
Page not completely loaded. I tried to debug using wireshark, and see that
php-fpm send to nginx coplete reply, but nginx to client sent incoplete
page. Size of incomplete page is defined by chunk size. For test, download
http://kinohled.cz/bugreport.tar.gz and run ./showBug.sh . You will se:

Run Nginx on port 9876
Run php-fpm on port 6789
Correct size of answer is 16172;
keepalive on,  size:  8002
keepalive off, size: 16172
 Next test (1 of 5)-
...

Tested on Debian Squeeze and many version of Nginx/PHP-FPM . Error shows on
default Nginx/PHP-FPM version by Debian Squeeze by dotdeb.org .

nginx/1.2.6
PHP 5.3.21-1~dotdeb.0

On Nginx error log:

upstream sent unsupported FastCGI protocol version: 0 while reading
upstream

Any suggestion ?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,235764,235764#msg-235764