nginx 1.3.10 *) Change: domain names specified in configuration file are now resolved to IPv6 addresses as well as IPv4 ones. *) Change: now if the "include" directive with mask is used on Unix systems, included files are sorted in alphabetical order. *) Change: the "add_header" directive adds headers to 201 responses. *) Feature: the "geo" directive now supports IPv6 addresses in CIDR notation. *) Feature: the "flush" and "gzip" parameters of the "access_log" directive. *) Feature: variables support in the "auth_basic" directive. *) Bugfix: nginx could not be built with the ngx_http_perl_module in some cases. *) Bugfix: a segmentation fault might occur in a worker process if the ngx_http_xslt_module was used. *) Bugfix: nginx could not be built on MacOSX in some cases. Thanks to Piotr Sikora. *) Bugfix: the "limit_rate" directive with high rates might result in truncated responses on 32-bit platforms. Thanks to Alexey Antropov. *) Bugfix: a segmentation fault might occur in a worker process if the "if" directive was used. Thanks to Piotr Sikora. *) Bugfix: a "100 Continue" response was issued with "413 Request Entity Too Large" responses. *) Bugfix: the "image_filter", "image_filter_jpeg_quality" and "image_filter_sharpen" directives might be inherited incorrectly. Thanks to Ian Babrou. *) Bugfix: "crypt_r() failed" errors might appear if the "auth_basic" directive was used on Linux. *) Bugfix: in backup servers handling. Thanks to Thomas Chen. *) Bugfix: proxied HEAD requests might return incorrect response if the "gzip" directive was used.

--- a/src/http/ngx_http_script.c
+++ b/src/http/ngx_http_script.c
@@ -114,11 +114,6 @@ ngx_http_compile_complex_value(ngx_http_
 
     v = ccv->value;
 
-    if (v->len == 0) {
-        ngx_conf_log_error(NGX_LOG_EMERG, ccv->cf, 0, "empty parameter");
-        return NGX_ERROR;
-    }
-
     nv = 0;
     nc = 0;
 
@@ -133,8 +128,9 @@ ngx_http_compile_complex_value(ngx_http_
         }
     }
 
-    if (v->data[0] != '$' && (ccv->conf_prefix || ccv->root_prefix)) {
-
+    if ((v->len == 0 || v->data[0] != '$')
+        && (ccv->conf_prefix || ccv->root_prefix))
+    {
         if (ngx_conf_full_name(ccv->cf->cycle, v, ccv->conf_prefix) != NGX_OK) {
             return NGX_ERROR;
         }