Fix issue when running from CLI

Author: ornicar

lib/phpUserAgentStringParser.php

@@ -18,10 +18,10 @@ class phpUserAgentStringParser
    */
   public function parse($userAgentString = null)
   {
-    // use current user agetn string as default
+    // use current user agent string as default
     if(!$userAgentString)
     {
-      $userAgentString = $_SERVER['HTTP_USER_AGENT'];
+      $userAgentString = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : null;
     }
 
     // parse quickly (with medium accuracy)
@@ -51,6 +51,11 @@ protected function doParse($userAgentString)
       'operating_system'  => null
     );
 
+    if(empty($userAgent['string']))
+    {
+      return $userAgent;
+    }
+
     // build regex that matches phrases for known browsers
     // (e.g. "Firefox/2.0" or "MSIE 6.0" (This only matches the major and minor
     // version numbers.  E.g. "2.0.0.6" is parsed as simply "2.0"