nginx 0.7.45 *) Change: now the "proxy_cache" and the "proxy_cache_valid" can be set on different levels. *) Change: the "clean_time" parameter of the "proxy_cache_path" directive is canceled. *) Feature: the "max_size" parameter of the "proxy_cache_path" directive. *) Feature: the ngx_http_fastcgi_module preliminary cache support. *) Feature: now on shared memory allocation errors directive and zone names are logged. *) Bugfix: the directive "add_header last-modified ''" did not delete a "Last-Modified" response header line; the bug had appeared in 0.7.44. *) Bugfix: a relative path in the "auth_basic_user_file" directive given without variables did not work; the bug had appeared in 0.7.44. Thanks to Jerome Loyet. *) Bugfix: in an "alias" directive given using variables without references to captures of regular expressions; the bug had appeared in 0.7.42.

--- a/src/http/modules/ngx_http_headers_filter_module.c
+++ b/src/http/modules/ngx_http_headers_filter_module.c
@@ -608,6 +608,11 @@ ngx_http_headers_add(ngx_conf_t *cf, ngx
         break;
     }
 
+    if (value[2].len == 0) {
+        ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t));
+        return NGX_CONF_OK;
+    }
+
     ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
 
     ccv.cf = cf;