id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,uname,nginx_version 1204,"""gzip_vary"" will add a duplicate Vary header if a PHP page also adds a Vary header",RichardBradley@…,,"I have a PHP app served by nginx, and I'd like to enable gzip output compression. I have turned on the ""gzip"" and ""gzip_vary"" settings: {{{ /etc/nginx/nginx.conf: gzip on; /etc/nginx/nginx.conf: gzip_vary on; /etc/nginx/nginx.conf: gzip_disable ""msie6""; }}} My PHP app already adds a Vary header. == Observed Behaviour == Unfortunately this causes `nginx` to add a duplicate Vary header: {{{ HTTP/1.1 200 OK Server: nginx Content-Type: text/html; charset=UTF-8 Transfer-Encoding: chunked Connection: keep-alive Vary: Accept-Encoding Cache-Control: max-age=300, public Vary: Accept-Encoding,X-Cookie-ckps_language Content-language: en-GB Date: Mon, 13 Feb 2017 15:20:39 GMT }}} == Expected Behaviour == I believe that `nginx` should merge the ""Vary"" header added by `gzip_vary` with any `Vary` headers produced by hosted apps. == Previous reports of this bug == See also: * http://serverfault.com/questions/821310/nginx-gzip-vary-header-together-with-existing-vary-headers * https://forum.nginx.org/read.php?2,240322,240322#msg-240322 ",defect,closed,major,,nginx-core,1.10.x,duplicate,"gzip,gzip_vary",,"Linux ip-10-56-38-16.eu-west-1.compute.internal 2.6.32-642.13.1.el6.x86_64 #1 SMP Wed Jan 11 20:56:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux ","nginx version: nginx/1.10.2 built by gcc 4.4.7 20120313 (Red Hat 4.4.7-17) (GCC) built with OpenSSL 1.0.1e-fips 11 Feb 2013 TLS SNI support enabled configure arguments: --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/lib64/nginx/modules --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/tmp/client_body --http-proxy-temp-path=/var/lib/nginx/tmp/proxy --http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi --http-uwsgi-temp-path=/var/lib/nginx/tmp/uwsgi --http-scgi-temp-path=/var/lib/nginx/tmp/scgi --pid-path=/var/run/nginx.pid --lock-path=/var/lock/subsys/nginx --user=nginx --group=nginx --with-file-aio --with-ipv6 --with-http_ssl_module --with-http_v2_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module=dynamic --with-http_image_filter_module=dynamic --with-http_geoip_module=dynamic --with-http_sub_module --with-http_dav_module --with-http_flv_module --with-http_mp4_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_random_index_module --with-http_secure_link_module --with-http_degradation_module --with-http_slice_module --with-http_stub_status_module --with-http_perl_module=dynamic --with-mail=dynamic --with-mail_ssl_module --with-pcre --with-pcre-jit --with-stream=dynamic --with-stream_ssl_module --with-debug --with-cc-opt='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic' --with-ld-opt=' -Wl,-E'"