Fix of rbtree lookup on hash collisions.

Previous code incorrectly assumed that nodes with identical keys are linked
together.  This might not be true after tree rebalance.

Patch by Lanshun Zhou.

1 files changed, 6 insertions, 11 deletions

diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index 5c516175e..2e3047135 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -1689,20 +1689,15 @@ ngx_resolver_lookup_name(ngx_resolver_t *r, ngx_str_t *name, uint32_t hash)
 
         /* hash == node->key */
 
-        do {
-            rn = (ngx_resolver_node_t *) node;
-
-            rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen);
-
-            if (rc == 0) {
-                return rn;
-            }
+        rn = (ngx_resolver_node_t *) node;
 
-            node = (rc < 0) ? node->left : node->right;
+        rc = ngx_memn2cmp(name->data, rn->name, name->len, rn->nlen);
 
-        } while (node != sentinel && hash == node->key);
+        if (rc == 0) {
+            return rn;
+        }
 
-        break;
+        node = (rc < 0) ? node->left : node->right;
     }
 
     /* not found */