Make Nginx ignore the content-length header from PHP-FPM - nginx

Question

I have PHP FPM + Nginx setup. One of my PHP applications sets an invalid content length header, so I'm trying to ignore it using fastcgi_hide_header, but it doesn't work. It works for headers other than Content-Length, so I assume there is a problem with that in particular.
What is the correct way of doing this? I cannot modify the PHP application to fix the source of the problem.
server {
listen 8000 default_server;
root /var/www;
index index.php index.html index.htm;
rewrite_log on;
# Make site accessible from http://localhost/
server_name localhost;
location / {
try_files $uri $uri/ /index.php;
}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
location ~ [^/]\.php(/|$) {
fastcgi_split_path_info ^(.+?\.php)(/.*)$;
# NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
# With php5-cgi alone:
fastcgi_hide_header X-Fake-Header;
fastcgi_hide_header Content-Length;
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}
}
Output if I remove the code in PHP that sets the headers (this is the desired output):
< HTTP/1.1 200 OK
* Server nginx/1.4.1 (Ubuntu) is not blacklisted
< Server: nginx/1.4.1 (Ubuntu)
< Date: Thu, 13 Feb 2014 01:58:07 GMT
< Content-Type: text/html
< Transfer-Encoding: chunked
< Connection: keep-alive
< X-Powered-By: PHP/5.5.3-1ubuntu2.1
If I leave the code in, but use the above nginx config, I get this:
< HTTP/1.1 200 OK
* Server nginx/1.4.1 (Ubuntu) is not blacklisted
< Server: nginx/1.4.1 (Ubuntu)
< Date: Thu, 13 Feb 2014 01:59:09 GMT
< Content-Type: text/html
< Content-Length: 6
< Connection: keep-alive
< X-Powered-By: PHP/5.5.3-1ubuntu2.1

Answer 1

I ended up having to user the HttpHeadersMore module in Nginx (if you're on Ubuntu, this is included with nginx-extras but not nginx-full).
With the module installed, I just added the following to my Nginx configuration:
more_clear_headers Content-Length;
This worked as expected.