From d021dd20f15b86bd8b002fd87f5ef7b62e8f1e10 Mon Sep 17 00:00:00 2001
From: Bob Weinand <bobwei9@hotmail.com>
Date: Thu, 7 Jul 2016 16:07:00 +0200
Subject: [PATCH] Fix broken hostname validation to match RFC 1123 2.1

Fixes #34
---
 lib/DefaultResolver.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/DefaultResolver.php b/lib/DefaultResolver.php
index 699138e..044ef11 100644
--- a/lib/DefaultResolver.php
+++ b/lib/DefaultResolver.php
@@ -84,7 +84,9 @@ class DefaultResolver implements Resolver {
     }
 
     private function isValidHostName($name) {
-        $pattern = "/^(?:[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9]){0,1})(?:\\.[a-z0-9][a-z0-9-]{0,61}[a-z0-9])*$/i";
+        $pattern = <<<'REGEX'
+/^(?<name>[a-z0-9]([a-z0-9-]*[a-z0-9])?)(\.(?&name))*$/i
+REGEX;
 
         return !isset($name[253]) && \preg_match($pattern, $name);
     }