merge r2903, r2911, r2912, r3002:

fix various failures handling

src/core/ngx_cycle.c

@@ -216,7 +216,7 @@ ngx_init_cycle(ngx_cycle_t *old_cycle)
 
         if (module->create_conf) {
             rv = module->create_conf(cycle);
-            if (rv == NGX_CONF_ERROR) {
+            if (rv == NULL) {
                 ngx_destroy_pool(pool);
                 return NULL;
             }

src/core/ngx_output_chain.c

@@ -314,12 +314,11 @@ ngx_output_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
 
 #endif
 
+        cl->next = NULL;
         *ll = cl;
         ll = &cl->next;
     }
 
-    *ll = NULL;
-
     return NGX_OK;
 }
 

src/event/modules/ngx_devpoll_module.c

@@ -550,7 +550,7 @@ ngx_devpoll_create_conf(ngx_cycle_t *cycle)
 
     dpcf = ngx_palloc(cycle->pool, sizeof(ngx_devpoll_conf_t));
     if (dpcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     dpcf->changes = NGX_CONF_UNSET;

src/event/modules/ngx_epoll_module.c

@@ -552,7 +552,7 @@ ngx_epoll_create_conf(ngx_cycle_t *cycle)
 
     epcf = ngx_palloc(cycle->pool, sizeof(ngx_epoll_conf_t));
     if (epcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     epcf->events = NGX_CONF_UNSET;

src/event/modules/ngx_eventport_module.c

@@ -581,7 +581,7 @@ ngx_eventport_create_conf(ngx_cycle_t *cycle)
 
     epcf = ngx_palloc(cycle->pool, sizeof(ngx_eventport_conf_t));
     if (epcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     epcf->events = NGX_CONF_UNSET;

src/event/modules/ngx_kqueue_module.c

@@ -768,7 +768,7 @@ ngx_kqueue_create_conf(ngx_cycle_t *cycle)
 
     kcf = ngx_palloc(cycle->pool, sizeof(ngx_kqueue_conf_t));
     if (kcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     kcf->changes = NGX_CONF_UNSET;

src/event/modules/ngx_rtsig_module.c

@@ -691,7 +691,7 @@ ngx_rtsig_create_conf(ngx_cycle_t *cycle)
 
     rtscf = ngx_palloc(cycle->pool, sizeof(ngx_rtsig_conf_t));
     if (rtscf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     rtscf->signo = NGX_CONF_UNSET;

src/event/ngx_event.c

@@ -1113,7 +1113,7 @@ ngx_event_create_conf(ngx_cycle_t *cycle)
 
     ecf = ngx_palloc(cycle->pool, sizeof(ngx_event_conf_t));
     if (ecf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     ecf->connections = NGX_CONF_UNSET_UINT;
@@ -1128,7 +1128,7 @@ ngx_event_create_conf(ngx_cycle_t *cycle)
     if (ngx_array_init(&ecf->debug_connection, cycle->pool, 4,
                        sizeof(ngx_event_debug_t)) == NGX_ERROR)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
 #endif

src/event/ngx_event_openssl.c

@@ -2115,7 +2115,7 @@ ngx_openssl_create_conf(ngx_cycle_t *cycle)
 
     oscf = ngx_pcalloc(cycle->pool, sizeof(ngx_openssl_conf_t));
     if (oscf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_access_module.c

@@ -201,7 +201,7 @@ ngx_http_access_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_access_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return conf;

src/http/modules/ngx_http_addition_filter_module.c

@@ -212,7 +212,7 @@ ngx_http_addition_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_addition_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_auth_basic_module.c

@@ -372,7 +372,7 @@ ngx_http_auth_basic_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_basic_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return conf;

src/http/modules/ngx_http_autoindex_module.c

@@ -632,7 +632,7 @@ ngx_http_autoindex_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_palloc(cf->pool, sizeof(ngx_http_autoindex_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->enable = NGX_CONF_UNSET;

src/http/modules/ngx_http_browser_module.c

@@ -423,7 +423,7 @@ ngx_http_browser_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_browser_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_charset_filter_module.c

@@ -1488,27 +1488,27 @@ ngx_http_charset_create_main_conf(ngx_conf_t *cf)
 
     mcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_charset_main_conf_t));
     if (mcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&mcf->charsets, cf->pool, 2, sizeof(ngx_http_charset_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&mcf->tables, cf->pool, 1,
                        sizeof(ngx_http_charset_tables_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&mcf->recodes, cf->pool, 2,
                        sizeof(ngx_http_charset_recode_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return mcf;
@@ -1522,7 +1522,7 @@ ngx_http_charset_create_loc_conf(ngx_conf_t *cf)
 
     lcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_charset_loc_conf_t));
     if (lcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_dav_module.c

@@ -1154,7 +1154,7 @@ ngx_http_dav_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_dav_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_fastcgi_module.c

@@ -1836,7 +1836,7 @@ ngx_http_fastcgi_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_fastcgi_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_gzip_filter_module.c

@@ -1069,7 +1069,7 @@ ngx_http_gzip_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_gzip_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_gzip_static_module.c

@@ -251,7 +251,7 @@ ngx_http_gzip_static_create_conf(ngx_conf_t *cf)
 
     conf = ngx_palloc(cf->pool, sizeof(ngx_http_gzip_static_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->enable = NGX_CONF_UNSET;

src/http/modules/ngx_http_headers_filter_module.c

@@ -421,7 +421,7 @@ ngx_http_headers_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_headers_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_image_filter_module.c

@@ -948,7 +948,7 @@ ngx_http_image_filter_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_image_filter_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->filter = NGX_CONF_UNSET_UINT;

src/http/modules/ngx_http_index_module.c

@@ -366,7 +366,7 @@ ngx_http_index_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_palloc(cf->pool, sizeof(ngx_http_index_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->indices = NULL;

src/http/modules/ngx_http_limit_req_module.c

@@ -522,7 +522,7 @@ ngx_http_limit_req_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_req_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_limit_zone_module.c

@@ -381,7 +381,7 @@ ngx_http_limit_zone_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_zone_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_log_module.c

@@ -714,18 +714,18 @@ ngx_http_log_create_main_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_log_main_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&conf->formats, cf->pool, 4, sizeof(ngx_http_log_fmt_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     fmt = ngx_array_push(&conf->formats);
     if (fmt == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     fmt->name.len = sizeof("combined") - 1;
@@ -735,7 +735,7 @@ ngx_http_log_create_main_conf(ngx_conf_t *cf)
 
     fmt->ops = ngx_array_create(cf->pool, 16, sizeof(ngx_http_log_op_t));
     if (fmt->ops == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return conf;
@@ -749,7 +749,7 @@ ngx_http_log_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_log_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->open_file_cache = NGX_CONF_UNSET_PTR;

src/http/modules/ngx_http_map_module.c

@@ -160,7 +160,7 @@ ngx_http_map_create_conf(ngx_conf_t *cf)
 
     mcf = ngx_palloc(cf->pool, sizeof(ngx_http_map_conf_t));
     if (mcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     mcf->hash_max_size = NGX_CONF_UNSET_UINT;

src/http/modules/ngx_http_memcached_module.c

@@ -513,7 +513,7 @@ ngx_http_memcached_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_memcached_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_proxy_module.c

@@ -1884,7 +1884,7 @@ ngx_http_proxy_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_proxy_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_random_index_module.c

@@ -280,7 +280,7 @@ ngx_http_random_index_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_palloc(cf->pool, sizeof(ngx_http_random_index_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->enable = NGX_CONF_UNSET;

src/http/modules/ngx_http_realip_module.c

@@ -360,7 +360,7 @@ ngx_http_realip_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_realip_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_referer_module.c

@@ -221,7 +221,7 @@ ngx_http_referer_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_referer_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
 #if (NGX_PCRE)

src/http/modules/ngx_http_rewrite_module.c

@@ -220,7 +220,7 @@ ngx_http_rewrite_create_loc_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_rewrite_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     conf->stack_size = NGX_CONF_UNSET_UINT;
@@ -568,7 +568,7 @@ ngx_http_rewrite_if(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     if_code = ngx_array_push_n(lcf->codes, sizeof(ngx_http_script_if_code_t));
     if (if_code == NULL) {
-        return NULL;
+        return NGX_CONF_ERROR;
     }
 
     if_code->code = ngx_http_script_if_code;

src/http/modules/ngx_http_secure_link_module.c

@@ -152,7 +152,7 @@ ngx_http_secure_link_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_secure_link_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_ssi_filter_module.c

@@ -2689,14 +2689,14 @@ ngx_http_ssi_create_main_conf(ngx_conf_t *cf)
 
     smcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_ssi_main_conf_t));
     if (smcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     smcf->commands.pool = cf->pool;
     smcf->commands.temp_pool = cf->temp_pool;
 
     if (ngx_hash_keys_array_init(&smcf->commands, NGX_HASH_SMALL) != NGX_OK) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return smcf;
@@ -2736,7 +2736,7 @@ ngx_http_ssi_create_loc_conf(ngx_conf_t *cf)
 
     slcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_ssi_loc_conf_t));
     if (slcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_ssl_module.c

@@ -302,7 +302,7 @@ ngx_http_ssl_create_srv_conf(ngx_conf_t *cf)
 
     sscf = ngx_pcalloc(cf->pool, sizeof(ngx_http_ssl_srv_conf_t));
     if (sscf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_sub_filter_module.c

@@ -638,7 +638,7 @@ ngx_http_sub_create_conf(ngx_conf_t *cf)
 
     slcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_sub_loc_conf_t));
     if (slcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_userid_filter_module.c

@@ -570,7 +570,7 @@ ngx_http_userid_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_userid_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/ngx_http_xslt_filter_module.c

@@ -1172,7 +1172,7 @@ ngx_http_xslt_filter_create_main_conf(ngx_conf_t *cf)
 
     conf = ngx_palloc(cf->pool, sizeof(ngx_http_xslt_filter_main_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&conf->dtd_files, cf->pool, 1,
@@ -1200,7 +1200,7 @@ ngx_http_xslt_filter_create_conf(ngx_conf_t *cf)
 
     conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_xslt_filter_loc_conf_t));
     if (conf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/modules/perl/ngx_http_perl_module.c

@@ -784,7 +784,7 @@ ngx_http_perl_create_main_conf(ngx_conf_t *cf)
 
     pmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_perl_main_conf_t));
     if (pmcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&pmcf->requires, cf->pool, 1, sizeof(u_char *))
@@ -869,7 +869,7 @@ ngx_http_perl_create_loc_conf(ngx_conf_t *cf)
 
     plcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_perl_loc_conf_t));
     if (plcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/ngx_http_core_module.c

@@ -2699,14 +2699,14 @@ ngx_http_core_create_main_conf(ngx_conf_t *cf)
 
     cmcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_core_main_conf_t));
     if (cmcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&cmcf->servers, cf->pool, 4,
                        sizeof(ngx_http_core_srv_conf_t *))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     cmcf->server_names_hash_max_size = NGX_CONF_UNSET_UINT;
@@ -2758,7 +2758,7 @@ ngx_http_core_create_srv_conf(ngx_conf_t *cf)
 
     cscf = ngx_pcalloc(cf->pool, sizeof(ngx_http_core_srv_conf_t));
     if (cscf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*
@@ -2771,14 +2771,14 @@ ngx_http_core_create_srv_conf(ngx_conf_t *cf)
                        sizeof(ngx_http_listen_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&cscf->server_names, cf->temp_pool, 4,
                        sizeof(ngx_http_server_name_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     cscf->connection_pool_size = NGX_CONF_UNSET_SIZE;
@@ -2889,7 +2889,7 @@ ngx_http_core_create_loc_conf(ngx_conf_t *cf)
 
     lcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_core_loc_conf_t));
     if (lcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*

src/http/ngx_http_request.c

@@ -451,13 +451,15 @@ ngx_http_init_request(ngx_event_t *rev)
                       sizeof(ngx_table_elt_t))
         != NGX_OK)
     {
-        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        ngx_destroy_pool(r->pool);
+        ngx_http_close_connection(c);
         return;
     }
 
     r->ctx = ngx_pcalloc(r->pool, sizeof(void *) * ngx_http_max_module);
     if (r->ctx == NULL) {
-        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        ngx_destroy_pool(r->pool);
+        ngx_http_close_connection(c);
         return;
     }
 
@@ -466,7 +468,8 @@ ngx_http_init_request(ngx_event_t *rev)
     r->variables = ngx_pcalloc(r->pool, cmcf->variables.nelts
                                         * sizeof(ngx_http_variable_value_t));
     if (r->variables == NULL) {
-        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
+        ngx_destroy_pool(r->pool);
+        ngx_http_close_connection(c);
         return;
     }
 

src/http/ngx_http_script.c

@@ -561,7 +561,7 @@ ngx_http_script_add_code(ngx_array_t *codes, size_t size, void *code)
 
     new = ngx_array_push_n(codes, size);
     if (new == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (code) {

src/http/ngx_http_upstream.c

@@ -4274,7 +4274,7 @@ ngx_http_upstream_create_main_conf(ngx_conf_t *cf)
                        sizeof(ngx_http_upstream_srv_conf_t *))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return umcf;

src/mail/ngx_mail_auth_http_module.c

@@ -1302,7 +1302,7 @@ ngx_mail_auth_http_create_conf(ngx_conf_t *cf)
 
     ahcf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_auth_http_conf_t));
     if (ahcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     ahcf->timeout = NGX_CONF_UNSET_MSEC;

src/mail/ngx_mail_core_module.c

@@ -120,20 +120,20 @@ ngx_mail_core_create_main_conf(ngx_conf_t *cf)
 
     cmcf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_core_main_conf_t));
     if (cmcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&cmcf->servers, cf->pool, 4,
                        sizeof(ngx_mail_core_srv_conf_t *))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     if (ngx_array_init(&cmcf->listen, cf->pool, 4, sizeof(ngx_mail_listen_t))
         != NGX_OK)
     {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     return cmcf;

src/mail/ngx_mail_proxy_module.c

@@ -1061,7 +1061,7 @@ ngx_mail_proxy_create_conf(ngx_conf_t *cf)
 
     pcf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_proxy_conf_t));
     if (pcf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     pcf->enable = NGX_CONF_UNSET;

src/mail/ngx_mail_ssl_module.c

@@ -166,7 +166,7 @@ ngx_mail_ssl_create_conf(ngx_conf_t *cf)
 
     scf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_ssl_conf_t));
     if (scf == NULL) {
-        return NGX_CONF_ERROR;
+        return NULL;
     }
 
     /*