do not run regex for empty host name since regex always fails in this case,

the bug had been introduced in r2196

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 3ae6ddb2844bd7de18e64ba71a0a618e62d88a61..a0c4ea3b8f13942fbe057005ef02fecaab41941a 100644 (file)
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -1688,7 +1688,7 @@ ngx_http_find_virtual_server(ngx_http_request_t *r, u_char *host, size_t len)
 
 #if (NGX_PCRE)
 
-    if (r->virtual_names->nregex) {
+    if (len && r->virtual_names->nregex) {
         size_t                   ncaptures;
         ngx_int_t                n;
         ngx_uint_t               i;