From d0f46cb6bbefc38c99ee861255e45a88873a6966 Mon Sep 17 00:00:00 2001
From: Igor Sysoev <igor@sysoev.ru>
Date: Mon, 22 Jun 2009 09:32:03 +0000
Subject: [PATCH] merge r2954:

fix segfault if there is error_page 401, proxy_intercept_errors is on
and backend does not return "WWW-Authenticate" header
---
 src/http/ngx_http_upstream.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 67ae1bc1c..c04e643fb 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -1573,8 +1573,9 @@ ngx_http_upstream_intercept_errors(ngx_http_request_t *r,
 
         if (err_page[i].status == status) {
 
-            if (status == NGX_HTTP_UNAUTHORIZED) {
-
+            if (status == NGX_HTTP_UNAUTHORIZED
+                && u->headers_in.www_authenticate)
+            {
                 h = ngx_list_push(&r->headers_out.headers);
 
                 if (h == NULL) {