[PATCH 19 of 20] Auth request: multiple WWW-Authenticate headers (ticket #485)

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1650492343 -10800
#      Thu Apr 21 01:05:43 2022 +0300
# Node ID 2c0188329c7d848c891feb7635fff77941449814
# Parent  fa9751ffe7723a11159c158078e454671e81cb87
Auth request: multiple WWW-Authenticate headers (ticket #485).

When using auth_request with an upstream server which returns 401
(Unauthorized), multiple WWW-Authenticate headers from the upstream server
response are now properly copied to the response.

diff --git a/src/http/modules/ngx_http_auth_request_module.c b/src/http/modules/ngx_http_auth_request_module.c
--- a/src/http/modules/ngx_http_auth_request_module.c
+++ b/src/http/modules/ngx_http_auth_request_module.c
@@ -101,7 +101,7 @@ ngx_module_t  ngx_http_auth_request_modu
 static ngx_int_t
 ngx_http_auth_request_handler(ngx_http_request_t *r)
 {
-    ngx_table_elt_t               *h, *ho;
+    ngx_table_elt_t               *h, *ho, **ph;
     ngx_http_request_t            *sr;
     ngx_http_post_subrequest_t    *ps;
     ngx_http_auth_request_ctx_t   *ctx;
@@ -147,7 +147,9 @@ ngx_http_auth_request_handler(ngx_http_r
                 h = sr->upstream->headers_in.www_authenticate;
             }
 
-            if (h) {
+            ph = &r->headers_out.www_authenticate;
+
+            while (h) {
                 ho = ngx_list_push(&r->headers_out.headers);
                 if (ho == NULL) {
                     return NGX_ERROR;
@@ -156,7 +158,10 @@ ngx_http_auth_request_handler(ngx_http_r
                 *ho = *h;
                 ho->next = NULL;
 
-                r->headers_out.www_authenticate = ho;
+                *ph = ho;
+                ph = &ho->next;
+
+                h = h->next;
             }
 
             return ctx->status;