Reworked multi headers to use linked lists. Multi headers are now using linked lists instead of arrays. Notably, the following fields were changed: r->headers_in.cookies (renamed to r->headers_in.cookie), r->headers_in.x_forwarded_for, r->headers_out.cache_control, r->headers_out.link, u->headers_in.cache_control u->headers_in.cookies (renamed to u->headers_in.set_cookie). The r->headers_in.cookies and u->headers_in.cookies fields were renamed to r->headers_in.cookie and u->headers_in.set_cookie to match header names. The ngx_http_parse_multi_header_lines() and ngx_http_parse_set_cookie_lines() functions were changed accordingly. With this change, multi headers are now essentially equivalent to normal headers, and following changes will further make them equivalent.

--- a/src/http/ngx_http_core_module.h
+++ b/src/http/ngx_http_core_module.h
@@ -529,7 +529,7 @@ ngx_int_t ngx_http_set_disable_symlinks(
     ngx_http_core_loc_conf_t *clcf, ngx_str_t *path, ngx_open_file_info_t *of);
 
 ngx_int_t ngx_http_get_forwarded_addr(ngx_http_request_t *r, ngx_addr_t *addr,
-    ngx_array_t *headers, ngx_str_t *value, ngx_array_t *proxies,
+    ngx_table_elt_t *headers, ngx_str_t *value, ngx_array_t *proxies,
     int recursive);
 
 ngx_int_t ngx_http_link_multi_headers(ngx_http_request_t *r);