*) introduce ngx_strchr()
*) test server_name for '/': it's common configuration error when
   trailing ';' is omitted and a next directive is treated as server_name
diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 49eed1b..7fa0ba3 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -2614,6 +2614,12 @@
             return NGX_CONF_ERROR;
         }
 
+        if (ngx_strchr(value[i].data, '/')) {
+            ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
+                               "server name \"%V\" has strange symbols",
+                               &value[i]);
+        }
+
         sn = ngx_array_push(&cscf->server_names);
         if (sn == NULL) {
             return NGX_CONF_ERROR;