From d2e005c39dc3adfe5e6f6b1ade096f3cfa4b8c84 Mon Sep 17 00:00:00 2001
From: Ruslan Ermilov <ru@nginx.com>
Date: Tue, 22 May 2012 13:12:14 +0000
Subject: [PATCH] Fixed potential null pointer dereference in
 ngx_resolver_create(). While here, improved error message.

---
 src/core/ngx_resolver.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index edc43dce2..54bd384e8 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -175,7 +175,12 @@ ngx_resolver_create(ngx_conf_t *cf, ngx_str_t *names, ngx_uint_t n)
         u.port = 53;
 
         if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) {
-            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%V: %s", &u.host, u.err);
+            if (u.err) {
+                ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                                   "%s in resolver \"%V\"",
+                                   u.err, &u.host);
+            }
+
             return NULL;
         }