# Content-type header charset info problem **URL:** \ **Category:** NGINX\ **Created:** [May 10, 2012, 5:52pm UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664 "2012-05-10T17:52:04Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![dubstep](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/cdc98d/32.png) [@dubstep](https://www.ruby-forum.com/u/dubstep)\ **Post date:** [May 10, 2012, 5:52pm UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664/1 "2012-05-10T17:52:04Z")
Hello, I’m trying to add “charset=utf-8” to the Content-Type header. When I don’t use “Accept-Encoding:gzip, deflate”, all is fine. When I add the above request header, the response header excludes the charset info from the Content-Type header. I thoroughly read the documentation and it’s not clear if it’s by design nor why I can’t have both charset info into Content-Type and “Vary: Accept-Encoding, User-Agent” response headers. $ curl -s -D- -o/dev/null -H"Host:www.stripped.com" [http://localhost/](http://localhost/) HTTP/1.1 200 OK Date: Thu, 10 May 2012 15:48:36 GMT Content-Type: text/html; charset=utf-8 Connection: close Server: mycacheserver 1.3.2 Last-Modified: Thu, 10 May 2012 15:45:56 GMT Cache-Control: public, max-age=60 ETag: 21adca4e3bc9e6517b61d7385c2536c7 Expires: Thu, 10 May 2012 15:49:36 GMT Vary: Accept-Encoding, User-Agent Content-Length: 222581 $ curl -s -D- -o/dev/null -H “Accept-Encoding:gzip, deflate” -H"Host:www.stripped.com [http://localhost/](http://localhost/) HTTP/1.1 200 OK Date: Thu, 10 May 2012 15:33:10 GMT Content-Type: text/html Connection: close Server: mycacheserver 1.3.2 Last-Modified: Thu, 10 May 2012 15:32:53 GMT Cache-Control: public, max-age=60 ETag: 7dcd476ac501f1929f2ad8efd1731f6 Expires: Thu, 10 May 2012 15:34:10 GMT Vary: Accept-Encoding, User-Agent Content-Encoding: gzip Content-Length: 39914 Any thougths? Thanks! Posted at Nginx Forum: > **[content-type header charset info problem](https://forum.nginx.org/read.php?2,226248,226248#msg-226248)** > > Hello, I'm trying to add "charset=utf-8" to the Content-Type header. When I don't use "Accept-Encoding:gzip, deflate", all is fine. When I add the above request header, the response header excludes the charset info from the... ---
**Author:** ![djeps](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58956e/32.png) [@djeps](https://www.ruby-forum.com/u/djeps)\ **Post date:** [May 10, 2012, 8:34pm UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664/2 "2012-05-10T20:34:37Z")
Hello! On Thu, May 10, 2012 at 11:51:01AM -0400, djeps wrote: > nor why I can’t have both charset info into Content-Type and "Vary: > ETag: 21adca4e3bc9e6517b61d7385c2536c7 > Server: mycacheserver 1.3.2 > Last-Modified: Thu, 10 May 2012 15:32:53 GMT > Cache-Control: public, max-age=60 > ETag: 7dcd476ac501f1929f2ad8efd1731f6 > Expires: Thu, 10 May 2012 15:34:10 GMT > Vary: Accept-Encoding, User-Agent > Content-Encoding: gzip > Content-Length: 39914 > > Any thougths? This doesn’t looks like nginx is responsible for gzipping here (note: Content-Length header present in gzipped response, which might happen only with gzip\_static, but ETag presense excludes it). So it’s likely the problem is somewhere outside of nginx (if it’s involved at all). Maxim D. ---
**Author:** ![djeps](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58956e/32.png) [@djeps](https://www.ruby-forum.com/u/djeps)\ **Post date:** [May 10, 2012, 10:37pm UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664/3 "2012-05-10T22:37:01Z")
Yes, you’re correct Maxim, I’ve a WURFL-based caching system that handles content compression. If I understand you correctly, the headers nginx receive from the upstream proxied server are sent without avail of the ‘charset utf-8;’ directive in nginx. I was wondering If nginx without third party modules would be able to append the charset portion of the Content-Type header with the correct charset. But then, the answer is no. Thank you. Posted at Nginx Forum: > **[Re: content-type header charset info problem](https://forum.nginx.org/read.php?2,226248,226268#msg-226268)** > > Hello, I'm trying to add "charset=utf-8" to the Content-Type header. When I don't use "Accept-Encoding:gzip, deflate", all is fine. When I add the above request header, the response header excludes the charset info from the... ---
**Author:** ![djeps](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58956e/32.png) [@djeps](https://www.ruby-forum.com/u/djeps)\ **Post date:** [May 11, 2012, 9:10am UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664/4 "2012-05-11T09:10:27Z")
Hello! On Thu, May 10, 2012 at 04:36:46PM -0400, djeps wrote: > Yes, you’re correct Maxim, I’ve a WURFL-based caching system that > handles content compression. > > If I understand you correctly, the headers nginx receive from the > upstream proxied server are sent without avail of the ‘charset utf-8;’ > directive in nginx. > > I was wondering If nginx without third party modules would be able to > append the charset portion of the Content-Type header with the correct > charset. But then, the answer is no. Ah, ok, you are trying to use the “charset” directive to add charset, but it doesn’t work with gzipped content, right? This is indeed looks like a problem: charset module ignores gzipped content, as it assumes it can’t recode it anyway, and it doesn’t check if it really needs to recode anything. This should be fixed to still allow it to set charset if no recode needed. You may try the following patch: — a/src/http/modules/ngx\_http\_charset\_filter\_module.c +++ b/src/http/modules/ngx\_http\_charset\_filter\_module.c @@ -258,6 +258,13 @@ ngx\_http\_charset\_header\_filter(ngx\_http\_ return ngx\_http\_next\_header\_filter(r); } - if (!r-\>ignore\_content\_encoding - ``` && r->headers_out.content_encoding ``` - ``` && r->headers_out.content_encoding->value.len) ``` - { - ``` return ngx_http_next_header_filter(r); ``` - } - if (charset == NGX\_HTTP\_NO\_CHARSET || source\_charset == NGX\_HTTP\_NO\_CHARSET) { @@ -311,13 +318,6 @@ ngx\_http\_destination\_charset(ngx\_http\_re ngx\_http\_charset\_loc\_conf\_t \*mlcf; ngx\_http\_charset\_main\_conf\_t \*mcf; - if (!r-\>ignore\_content\_encoding - ``` && r->headers_out.content_encoding ``` - ``` && r->headers_out.content_encoding->value.len) ``` - { - ``` return NGX_DECLINED; ``` - } - if (r-\>headers\_out.content\_type.len == 0) { return NGX\_DECLINED; } Maxim D. ---
**Author:** ![djeps](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58956e/32.png) [@djeps](https://www.ruby-forum.com/u/djeps)\ **Post date:** [May 11, 2012, 4:10pm UTC](https://www.ruby-forum.com/t/content-type-header-charset-info-problem/219664/5 "2012-05-11T16:10:56Z")
Yes, I’d expect the charset definition in content type header even if the content is gzipped. Reading the RFC2616, there is no mutually excludent rule that prohibits the charset to be declared after gzip encoding. Unfortunately, I’m using nginx 1.0.14 and cannot apply patches to it without having it gone through extensive testing and benchmarks again, we’re changing a very important section of our infrastructure and changes like these are always a hard work. I haven’t had the time to check if this patch is applied to the trunk, or the latest stable version of nginx. If the charset module is already with that patch on 1.2 branch then it will be much easier to start the 1.2.X branch testing and benchmarking by our capacity planning and testing team to homologate that version for our infrastructure. Thank you. Posted at Nginx Forum: > **[Re: content-type header charset info problem](https://forum.nginx.org/read.php?2,226248,226307#msg-226307)** > > Hello, I'm trying to add "charset=utf-8" to the Content-Type header. When I don't use "Accept-Encoding:gzip, deflate", all is fine. When I add the above request header, the response header excludes the charset info from the...