Merge branch 2.1-stable into develop
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index 225325d..77c968e 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1089,11 +1089,12 @@
 	 * Validate IP Address
 	 *
 	 * @param	string
+	 * @param	string	'ipv4' or 'ipv6' to validate a specific IP format
 	 * @return	bool
 	 */
-	public function valid_ip($ip)
+	public function valid_ip($ip, $which = '')
 	{
-		return $this->CI->input->valid_ip($ip);
+		return $this->CI->input->valid_ip($ip, $which);
 	}
 
 	// --------------------------------------------------------------------