Changes with nginx 0.6.22 19 Dec 2007v0.6.22

    *) Change: now all ngx_http_perl_module methods return values copied to
       perl's allocated memory.

    *) Bugfix: if nginx was built with ngx_http_perl_module, the perl
       before 5.8.6 was used, and perl supported threads, then during
       reconfiguration the master process aborted; bug appeared in
       0.5.9.
       Thanks to Boris Zhmurov.

    *) Bugfix: the ngx_http_perl_module methods may get invalid values of
       the regex captures.

    *) Bugfix: a segmentation fault occurred in worker process, if the
       $r->has_request_body() method was called for a request whose small
       request body was already received.

    *) Bugfix: large_client_header_buffers did not freed before going to
       keep-alive state.
       Thanks to Olexander Shtepa.

    *) Bugfix: the last address was missed in the $upstream_addr variable;
       bug appeared in 0.6.18.

    *) Bugfix: the "fastcgi_catch_stderr" directive did return error code;
       now it returns 502 code, that can be rerouted to a next server using
       the "fastcgi_next_upstream invalid_header" directive.

    *) Bugfix: a segmentation fault occurred in master process if the
       "fastcgi_catch_stderr" directive was used; bug appeared in
       0.6.10.
       Thanks to Manlio Perillo.

14 files changed, 242 insertions, 115 deletions

diff --git a/src/core/nginx.c b/src/core/nginx.c
index 579ee161b..ee636825b 100644
--- a/src/core/nginx.c
+++ b/src/core/nginx.c
@@ -273,9 +273,11 @@ main(int argc, char *const *argv)
         return 1;
     }
 
-    /* ngx_crc32_init() requires ngx_cacheline_size set in ngx_os_init() */
+    /*
+     * ngx_crc32_table_init() requires ngx_cacheline_size set in ngx_os_init()
+     */
 
-    if (ngx_crc32_init() != NGX_OK) {
+    if (ngx_crc32_table_init() != NGX_OK) {
         return 1;
     }
 
@@ -756,12 +758,6 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
 {
     ngx_core_conf_t  *ccf = conf;
 
-#if !(NGX_WIN32)
-    ngx_str_t       lock_file;
-    struct group   *grp;
-    struct passwd  *pwd;
-#endif
-
     ngx_conf_init_value(ccf->daemon, 1);
     ngx_conf_init_value(ccf->master, 1);
     ngx_conf_init_msec_value(ccf->timer_resolution, 0);
@@ -794,6 +790,8 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
 #if !(NGX_WIN32)
 
     if (ccf->user == (uid_t) NGX_CONF_UNSET_UINT && geteuid() == 0) {
+        struct group   *grp;
+        struct passwd  *pwd;
 
         ngx_set_errno(0);
         pwd = getpwnam(NGX_USER);
@@ -846,6 +844,9 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
         return NGX_CONF_ERROR;
     }
 
+    {
+    ngx_str_t  lock_file;
+
     lock_file = cycle->old_cycle->lock_file;
 
     if (lock_file.len) {
@@ -879,6 +880,7 @@ ngx_core_module_init_conf(ngx_cycle_t *cycle, void *conf)
                               ccf->lock_file.len),
                    ".accept", sizeof(".accept"));
     }
+    }
 
 #endif
 
diff --git a/src/core/nginx.h b/src/core/nginx.h
index 3221a75c6..bae7d8339 100644
--- a/src/core/nginx.h
+++ b/src/core/nginx.h
@@ -8,7 +8,7 @@
 #define _NGINX_H_INCLUDED_
 
 
-#define NGINX_VERSION      "0.6.21"
+#define NGINX_VERSION      "0.6.22"
 #define NGINX_VER          "nginx/" NGINX_VERSION
 
 #define NGINX_VAR          "NGINX"
diff --git a/src/core/ngx_conf_file.c b/src/core/ngx_conf_file.c
index 6084abb4b..f00cf019b 100644
--- a/src/core/ngx_conf_file.c
+++ b/src/core/ngx_conf_file.c
@@ -934,7 +934,7 @@ ngx_conf_set_str_array_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     a = (ngx_array_t **) (p + cmd->offset);
 
-    if (*a == NULL) {
+    if (*a == NGX_CONF_UNSET_PTR) {
         *a = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t));
         if (*a == NULL) {
             return NGX_CONF_ERROR;
diff --git a/src/core/ngx_crc32.c b/src/core/ngx_crc32.c
index 64b02ac7a..624510cee 100644
--- a/src/core/ngx_crc32.c
+++ b/src/core/ngx_crc32.c
@@ -102,7 +102,7 @@ uint32_t *ngx_crc32_table_short = ngx_crc32_table16;
 
 
 ngx_int_t
-ngx_crc32_init(void)
+ngx_crc32_table_init(void)
 {
     void  *p;
 
diff --git a/src/core/ngx_crc32.h b/src/core/ngx_crc32.h
index 7d5279d36..4435e4517 100644
--- a/src/core/ngx_crc32.h
+++ b/src/core/ngx_crc32.h
@@ -49,7 +49,30 @@ ngx_crc32_long(u_char *p, size_t len)
 }
 
 
-ngx_int_t ngx_crc32_init(void);
+#define ngx_crc32_init(crc)                                                   \
+    crc = 0xffffffff
+
+
+static ngx_inline void
+ngx_crc32_update(uint32_t *crc, u_char *p, size_t len)
+{
+    uint32_t  c;
+
+    c = *crc;
+
+    while (len--) {
+        c = ngx_crc32_table256[(c ^ *p++) & 0xff] ^ (c >> 8);
+    }
+
+    *crc = c;
+}
+
+
+#define ngx_crc32_final(crc)                                                  \
+    crc ^= 0xffffffff
+
+
+ngx_int_t ngx_crc32_table_init(void);
 
 
 #endif /* _NGX_CRC32_H_INCLUDED_ */
diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index f900a2824..edcb6b5b0 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -42,20 +42,21 @@ static ngx_str_t  error_log = ngx_null_string;
 ngx_cycle_t *
 ngx_init_cycle(ngx_cycle_t *old_cycle)
 {
-    void               *rv;
-    u_char             *lock_file;
-    ngx_uint_t          i, n;
-    ngx_log_t          *log;
-    ngx_conf_t          conf;
-    ngx_pool_t         *pool;
-    ngx_cycle_t        *cycle, **old;
-    ngx_shm_zone_t     *shm_zone, *oshm_zone;
-    ngx_slab_pool_t    *shpool;
-    ngx_list_part_t    *part, *opart;
-    ngx_open_file_t    *file;
-    ngx_listening_t    *ls, *nls;
-    ngx_core_conf_t    *ccf, *old_ccf;
-    ngx_core_module_t  *module;
+    void                *rv;
+    char               **senv, **env;
+    u_char              *lock_file;
+    ngx_uint_t           i, n;
+    ngx_log_t           *log;
+    ngx_conf_t           conf;
+    ngx_pool_t          *pool;
+    ngx_cycle_t         *cycle, **old;
+    ngx_shm_zone_t      *shm_zone, *oshm_zone;
+    ngx_slab_pool_t     *shpool;
+    ngx_list_part_t     *part, *opart;
+    ngx_open_file_t     *file;
+    ngx_listening_t     *ls, *nls;
+    ngx_core_conf_t     *ccf, *old_ccf;
+    ngx_core_module_t   *module;
 
     log = old_cycle->log;
 
@@ -187,6 +188,9 @@ ngx_init_cycle(ngx_cycle_t *old_cycle)
     }
 
 
+    senv = environ;
+
+
     ngx_memzero(&conf, sizeof(ngx_conf_t));
     /* STUB: init array ? */
     conf.args = ngx_array_create(pool, 10, sizeof(ngx_str_t));
@@ -694,9 +698,20 @@ old_shm_zone_done:
 
     if (ngx_process == NGX_PROCESS_MASTER || ngx_is_init_cycle(old_cycle)) {
 
+        /*
+         * perl_destruct() frees environ if it is not the same as it was at
+         * perl_construct() time.  So we have saved an previous cycle
+         * environment before ngx_conf_parse() where it will be changed.
+         */
+
+        env = environ;
+        environ = senv;
+
         ngx_destroy_pool(old_cycle->pool);
         cycle->old_cycle = NULL;
 
+        environ = env;
+
         return cycle;
     }
 
@@ -938,9 +953,6 @@ ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user)
     ngx_uint_t        i;
     ngx_list_part_t  *part;
     ngx_open_file_t  *file;
-#if !(NGX_WIN32)
-    ngx_file_info_t   fi;
-#endif
 
     part = &cycle->open_files.part;
     file = part->elts;
@@ -996,6 +1008,7 @@ ngx_reopen_files(ngx_cycle_t *cycle, ngx_uid_t user)
         }
 #else
         if (user != (ngx_uid_t) NGX_CONF_UNSET_UINT) {
+            ngx_file_info_t  fi;
 
             if (ngx_file_info((const char *) file[i].name.data, &fi) == -1) {
                 ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
diff --git a/src/core/ngx_file.c b/src/core/ngx_file.c
index f85578623..b6b15ca5f 100644
--- a/src/core/ngx_file.c
+++ b/src/core/ngx_file.c
@@ -61,16 +61,19 @@ ngx_create_temp_file(ngx_file_t *file, ngx_path_t *path, ngx_pool_t *pool,
 
     n = (uint32_t) ngx_next_temp_number(0);
 
+    cln = ngx_pool_cleanup_add(pool, sizeof(ngx_pool_cleanup_file_t));
+    if (cln == NULL) {
+        return NGX_ERROR;
+    }
+
     for ( ;; ) {
         (void) ngx_sprintf(file->name.data + path->name.len + 1 + path->len,
                            "%010uD%Z", n);
 
-        ngx_create_hashed_filename(file, path);
+        ngx_create_hashed_filename(path, file->name.data, file->name.len);
 
-        cln = ngx_pool_cleanup_add(pool, sizeof(ngx_pool_cleanup_file_t));
-        if (cln == NULL) {
-            return NGX_ERROR;
-        }
+        ngx_log_debug1(NGX_LOG_DEBUG_CORE, file->log, 0,
+                       "hashed path: %s", file->name.data);
 
         file->fd = ngx_open_tempfile(file->name.data, persistent, access);
 
@@ -117,31 +120,27 @@ ngx_create_temp_file(ngx_file_t *file, ngx_path_t *path, ngx_pool_t *pool,
 
 
 void
-ngx_create_hashed_filename(ngx_file_t *file, ngx_path_t *path)
+ngx_create_hashed_filename(ngx_path_t *path, u_char *file, size_t len)
 {
-    size_t      name, pos, level;
-    ngx_uint_t  i;
+    size_t      i, level;
+    ngx_uint_t  n;
 
-    name = file->name.len;
-    pos = path->name.len + 1;
+    i = path->name.len + 1;
 
-    file->name.data[path->name.len + path->len]  = '/';
+    file[path->name.len + path->len]  = '/';
 
-    for (i = 0; i < 3; i++) {
-        level = path->level[i];
+    for (n = 0; n < 3; n++) {
+        level = path->level[n];
 
         if (level == 0) {
             break;
         }
 
-        name -= level;
-        file->name.data[pos - 1] = '/';
-        ngx_memcpy(&file->name.data[pos], &file->name.data[name], level);
-        pos += level + 1;
+        len -= level;
+        file[i - 1] = '/';
+        ngx_memcpy(&file[i], &file[len], level);
+        i += level + 1;
     }
-
-    ngx_log_debug1(NGX_LOG_DEBUG_CORE, file->log, 0,
-                   "hashed path: %s", file->name.data);
 }
 
 
@@ -425,9 +424,6 @@ ngx_create_pathes(ngx_cycle_t *cycle, ngx_uid_t user)
     ngx_err_t         err;
     ngx_uint_t        i;
     ngx_path_t      **path;
-#if !(NGX_WIN32)
-    ngx_file_info_t   fi;
-#endif
 
     path = cycle->pathes.elts;
     for (i = 0; i < cycle->pathes.nelts; i++) {
@@ -447,6 +443,8 @@ ngx_create_pathes(ngx_cycle_t *cycle, ngx_uid_t user)
         }
 
 #if !(NGX_WIN32)
+        {
+        ngx_file_info_t   fi;
 
         if (ngx_file_info((const char *) path[i]->name.data, &fi) == -1) {
             ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
@@ -474,7 +472,7 @@ ngx_create_pathes(ngx_cycle_t *cycle, ngx_uid_t user)
                 return NGX_ERROR;
             }
         }
-
+        }
 #endif
     }
 
@@ -483,6 +481,107 @@ ngx_create_pathes(ngx_cycle_t *cycle, ngx_uid_t user)
 
 
 ngx_int_t
+ngx_create_path_and_rename_file(ngx_str_t *src, ngx_str_t *to,
+    ngx_uint_t access, ngx_uint_t full_path, ngx_uint_t delete, ngx_log_t *log)
+{
+    ngx_err_t  err;
+
+#if !(NGX_WIN32)
+
+    if (ngx_change_file_access(src->data, access) == NGX_FILE_ERROR) {
+        ngx_log_error(NGX_LOG_CRIT, log, ngx_errno,
+                      ngx_change_file_access_n " \"%s\" failed", src->data);
+        err = 0;
+        goto failed;
+    }
+
+#endif
+
+    if (ngx_rename_file(src->data, to->data) != NGX_FILE_ERROR) {
+        return NGX_OK;
+    }
+
+    err = ngx_errno;
+
+    if (err == NGX_ENOENT) {
+
+        if (!full_path) {
+            goto failed;
+        }
+
+        err = ngx_create_full_path(to->data, ngx_dir_access(access));
+
+        if (err) {
+            ngx_log_error(NGX_LOG_CRIT, log, err,
+                          ngx_create_dir_n " \"%s\" failed", to->data);
+            err = 0;
+            goto failed;
+        }
+
+        if (ngx_rename_file(src->data, to->data) != NGX_FILE_ERROR) {
+            return NGX_OK;
+        }
+
+        err = ngx_errno;
+        goto failed;
+    }
+
+#if (NGX_WIN32)
+
+    if (err == NGX_EEXIST) {
+        if (ngx_win32_rename_file(src, to, log) == NGX_OK) {
+
+            if (ngx_rename_file(src->data, to->data) != NGX_FILE_ERROR) {
+                return NGX_OK;
+            }
+
+            err = ngx_errno;
+
+        } else {
+            err = 0;
+        }
+    }
+
+#endif
+
+failed:
+
+    if (delete) {
+        if (ngx_delete_file(src->data) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_CRIT, log, ngx_errno,
+                          ngx_delete_file_n " \"%s\" failed", src->data);
+        }
+    }
+
+    if (err) {
+        ngx_log_error(NGX_LOG_CRIT, log, err,
+                      ngx_rename_file_n " \"%s\" to \"%s\" failed",
+                      src->data, to->data);
+    }
+
+    return NGX_ERROR;
+}
+
+
+/*
+ * ctx->init_handler() - see ctx->alloc
+ * ctx->file_handler() - file handler
+ * ctx->pre_tree_handler() - handler is called before entering directory
+ * ctx->post_tree_handler() - handler is called after leaving directory
+ * ctx->spec_handler() - special (socket, FIFO, etc.) file handler
+ *
+ * ctx->data - some data structure, it may be the same on all levels, or
+ *     reallocated if ctx->alloc is nonzero
+ *
+ * ctx->alloc - a size of data structure that is allocated at every level
+ *     and is initilialized by ctx->init_handler()
+ *
+ * ctx->log - a log
+ *
+ * on fatal (memory) error handler must return NGX_ABORT to stop walking tree
+ */
+
+ngx_int_t
 ngx_walk_tree(ngx_tree_ctx_t *ctx, ngx_str_t *tree)
 {
     void       *data, *prev;
diff --git a/src/core/ngx_file.h b/src/core/ngx_file.h
index 063b0fb83..61089ff34 100644
--- a/src/core/ngx_file.h
+++ b/src/core/ngx_file.h
@@ -84,11 +84,13 @@ ssize_t ngx_write_chain_to_temp_file(ngx_temp_file_t *tf, ngx_chain_t *chain);
 ngx_int_t ngx_create_temp_file(ngx_file_t *file, ngx_path_t *path,
     ngx_pool_t *pool, ngx_uint_t persistent, ngx_uint_t clean,
     ngx_uint_t access);
-void ngx_create_hashed_filename(ngx_file_t *file, ngx_path_t *path);
+void ngx_create_hashed_filename(ngx_path_t *path, u_char *file, size_t len);
 ngx_int_t ngx_create_path(ngx_file_t *file, ngx_path_t *path);
 ngx_err_t ngx_create_full_path(u_char *dir, ngx_uint_t access);
 ngx_int_t ngx_add_path(ngx_conf_t *cf, ngx_path_t **slot);
 ngx_int_t ngx_create_pathes(ngx_cycle_t *cycle, ngx_uid_t user);
+ngx_int_t ngx_create_path_and_rename_file(ngx_str_t *src, ngx_str_t *to,
+    ngx_uint_t access, ngx_uint_t full_path, ngx_uint_t delete, ngx_log_t *log);
 ngx_int_t ngx_walk_tree(ngx_tree_ctx_t *ctx, ngx_str_t *tree);
 
 void ngx_init_temp_number(void);
diff --git a/src/core/ngx_open_file_cache.c b/src/core/ngx_open_file_cache.c
index dab98b3ff..d518f4b96 100644
--- a/src/core/ngx_open_file_cache.c
+++ b/src/core/ngx_open_file_cache.c
@@ -53,11 +53,8 @@ ngx_open_file_cache_init(ngx_pool_t *pool, ngx_uint_t max, time_t inactive)
         return NULL;
     }
 
-    ngx_rbtree_sentinel_init(sentinel);
-
-    cache->rbtree.root = sentinel;
-    cache->rbtree.sentinel = sentinel;
-    cache->rbtree.insert = ngx_open_file_cache_rbtree_insert_value;
+    ngx_rbtree_init(&cache->rbtree, sentinel,
+                    ngx_open_file_cache_rbtree_insert_value);
 
     cache->current = 0;
     cache->max = max;
diff --git a/src/core/ngx_palloc.c b/src/core/ngx_palloc.c
index 978fc30f0..4cf7e8a4b 100644
--- a/src/core/ngx_palloc.c
+++ b/src/core/ngx_palloc.c
@@ -40,6 +40,8 @@ ngx_destroy_pool(ngx_pool_t *pool)
 
     for (c = pool->cleanup; c; c = c->next) {
         if (c->handler) {
+            ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, pool->log, 0,
+                           "run cleanup: %p", c);
             c->handler(c->data);
         }
     }
@@ -245,8 +247,8 @@ ngx_pool_cleanup_file(void *data)
 {
     ngx_pool_cleanup_file_t  *c = data;
 
-    ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, c->log, 0, "run cleanup: %p, fd:%d",
-                   c, c->fd);
+    ngx_log_debug1(NGX_LOG_DEBUG_ALLOC, c->log, 0, "file cleanup: fd:%d",
+                   c->fd);
 
     if (ngx_close_file(c->fd) == NGX_FILE_ERROR) {
         ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
@@ -262,8 +264,8 @@ ngx_pool_delete_file(void *data)
 
     ngx_err_t  err;
 
-    ngx_log_debug3(NGX_LOG_DEBUG_ALLOC, c->log, 0, "run cleanup: %p, fd:%d %s",
-                   c, c->fd, c->name);
+    ngx_log_debug2(NGX_LOG_DEBUG_ALLOC, c->log, 0, "file cleanup: fd:%d %s",
+                   c->fd, c->name);
 
     if (ngx_delete_file(c->name) == NGX_FILE_ERROR) {
         err = ngx_errno;
diff --git a/src/core/ngx_rbtree.c b/src/core/ngx_rbtree.c
index 0a5753cdf..7d240fe81 100644
--- a/src/core/ngx_rbtree.c
+++ b/src/core/ngx_rbtree.c
@@ -97,28 +97,20 @@ void
 ngx_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node,
     ngx_rbtree_node_t *sentinel)
 {
-    for ( ;; ) {
-
-        if (node->key < temp->key) {
-
-            if (temp->left == sentinel) {
-                temp->left = node;
-                break;
-            }
-
-            temp = temp->left;
+    ngx_rbtree_node_t  **p;
 
-        } else {
+    for ( ;; ) {
 
-            if (temp->right == sentinel) {
-                temp->right = node;
-                break;
-            }
+        p = (node->key < temp->key) ? &temp->left : &temp->right;
 
-            temp = temp->right;
+        if (*p == sentinel) {
+            break;
         }
+
+        temp = *p;
     }
 
+    *p = node;
     node->parent = temp;
     node->left = sentinel;
     node->right = sentinel;
@@ -130,6 +122,8 @@ void
 ngx_rbtree_insert_timer_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node,
     ngx_rbtree_node_t *sentinel)
 {
+    ngx_rbtree_node_t  **p;
+
     for ( ;; ) {
 
         /*
@@ -139,29 +133,20 @@ ngx_rbtree_insert_timer_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node,
          * The comparison takes into account that overflow.
          */
 
-        if ((ngx_rbtree_key_int_t) node->key - (ngx_rbtree_key_int_t) temp->key
-            < 0)
-        {
-            /*  node->key < temp->key */
-
-            if (temp->left == sentinel) {
-                temp->left = node;
-                break;
-            }
-
-            temp = temp->left;
+        /*  node->key < temp->key */
 
-        } else {
-
-            if (temp->right == sentinel) {
-                temp->right = node;
-                break;
-            }
+        p = ((ngx_rbtree_key_int_t) node->key - (ngx_rbtree_key_int_t) temp->key
+              < 0)
+            ? &temp->left : &temp->right;
 
-            temp = temp->right;
+        if (*p == sentinel) {
+            break;
         }
+
+        temp = *p;
     }
 
+    *p = node;
     node->parent = temp;
     node->left = sentinel;
     node->right = sentinel;
diff --git a/src/core/ngx_resolver.c b/src/core/ngx_resolver.c
index ab4dcdabc..be0121e2e 100644
--- a/src/core/ngx_resolver.c
+++ b/src/core/ngx_resolver.c
@@ -67,9 +67,9 @@ static void ngx_resolver_read_response(ngx_event_t *rev);
 static void ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf,
     size_t n);
 static void ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t n,
-    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan, ngx_uint_t i);
+    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan, ngx_uint_t ans);
 static void ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
-    ngx_uint_t ident, ngx_uint_t code);
+    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan);
 static ngx_resolver_node_t *ngx_resolver_lookup_name(ngx_resolver_t *r,
     ngx_str_t *name, uint32_t hash);
 static ngx_resolver_node_t *ngx_resolver_lookup_addr(ngx_resolver_t *r,
@@ -884,11 +884,6 @@ ngx_resolver_process_response(ngx_resolver_t *r, u_char *buf, size_t n)
         goto done;
     }
 
-    if (code == 0 && nan == 0) {
-        err = "no answers in DNS response";
-        goto done;
-    }
-
     i = sizeof(ngx_resolver_query_t);
 
     while (i < (ngx_uint_t) n) {
@@ -934,13 +929,13 @@ found:
     case NGX_RESOLVE_A:
 
         ngx_resolver_process_a(r, buf, n, ident, code, nan,
-                              i + sizeof(ngx_resolver_qs_t));
+                               i + sizeof(ngx_resolver_qs_t));
 
         break;
 
     case NGX_RESOLVE_PTR:
 
-        ngx_resolver_process_ptr(r, buf, n, ident, code);
+        ngx_resolver_process_ptr(r, buf, n, ident, code, nan);
 
         break;
 
@@ -1006,6 +1001,10 @@ ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t last,
         goto failed;
     }
 
+    if (code == 0 && nan == 0) {
+        code = 3; /* NXDOMAIN */
+    }
+
     if (code) {
         next = rn->waiting;
         rn->waiting = NULL;
@@ -1204,6 +1203,8 @@ ngx_resolver_process_a(ngx_resolver_t *r, u_char *buf, size_t last,
         ngx_log_debug1(NGX_LOG_DEBUG_CORE, r->log, 0,
                        "resolver cname:\"%V\"", &name);
 
+        ngx_queue_remove(&rn->queue);
+
         rn->cnlen = (u_short) name.len;
         rn->u.cname = name.data;
         rn->valid = ngx_time() + r->valid;
@@ -1250,7 +1251,7 @@ failed:
 
 static void
 ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
-    ngx_uint_t ident, ngx_uint_t code)
+    ngx_uint_t ident, ngx_uint_t code, ngx_uint_t nan)
 {
     char                 *err;
     size_t                len;
@@ -1307,6 +1308,10 @@ ngx_resolver_process_ptr(ngx_resolver_t *r, u_char *buf, size_t n,
         goto failed;
     }
 
+    if (code == 0 && nan == 0) {
+        code = 3; /* NXDOMAIN */
+    }
+
     if (code) {
         next = rn->waiting;
         rn->waiting = NULL;
diff --git a/src/core/ngx_string.c b/src/core/ngx_string.c
index 2eaffd60d..f878c559f 100644
--- a/src/core/ngx_string.c
+++ b/src/core/ngx_string.c
@@ -816,18 +816,17 @@ ngx_hextoi(u_char *line, size_t n)
 }
 
 
-void
-ngx_md5_text(u_char *text, u_char *md5)
+u_char *
+ngx_hex_dump(u_char *dst, u_char *src, size_t len)
 {
-    int            i;
     static u_char  hex[] = "0123456789abcdef";
 
-    for (i = 0; i < 16; i++) {
-        *text++ = hex[md5[i] >> 4];
-        *text++ = hex[md5[i] & 0xf];
+    while (len--) {
+        *dst++ = hex[*src >> 4];
+        *dst++ = hex[*src++ & 0xf];
     }
 
-    *text = '\0';
+    return dst;
 }
 
 
diff --git a/src/core/ngx_string.h b/src/core/ngx_string.h
index 1bca791bf..4fe5cb604 100644
--- a/src/core/ngx_string.h
+++ b/src/core/ngx_string.h
@@ -141,7 +141,7 @@ off_t ngx_atoof(u_char *line, size_t n);
 time_t ngx_atotm(u_char *line, size_t n);
 ngx_int_t ngx_hextoi(u_char *line, size_t n);
 
-void ngx_md5_text(u_char *text, u_char *md5);
+u_char *ngx_hex_dump(u_char *dst, u_char *src, size_t len);
 
 
 #define ngx_base64_encoded_length(len)  (((len + 2) / 3) * 4)