Upstream: simplified Content-Encoding handling. Since introduction of offset handling in ngx_http_upstream_copy_header_line() in revision 573:58475592100c, the ngx_http_upstream_copy_content_encoding() function is no longer needed, as its behaviour is exactly equivalent to ngx_http_upstream_copy_header_line() with appropriate offset. As such, the ngx_http_upstream_copy_content_encoding() function was removed. Further, the u->headers_in.content_encoding field is not used anywhere, so it was removed as well. Further, Content-Encoding handling no longer depends on NGX_HTTP_GZIP, as it can be used even without any gzip handling compiled in (for example, in the charset filter).

--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -285,10 +285,6 @@ typedef struct {
     ngx_table_elt_t                 *transfer_encoding;
     ngx_table_elt_t                 *vary;
 
-#if (NGX_HTTP_GZIP)
-    ngx_table_elt_t                 *content_encoding;
-#endif
-
     ngx_table_elt_t                 *cache_control;
     ngx_table_elt_t                 *set_cookie;