prevent float to int cast deprecation warning in truncate modifier

Fixes #699

CHANGELOG.md

@@ -7,7 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Fixed
--  PHP 8.1 deprecation notices in demo/plugins/cacheresource.pdo.php [#706](https://github.com/smarty-php/smarty/issues/706)
+- PHP 8.1 deprecation notices in demo/plugins/cacheresource.pdo.php [#706](https://github.com/smarty-php/smarty/issues/706)
+- PHP 8.1 deprecation notices in truncate modifier [#699](https://github.com/smarty-php/smarty/issues/699)
 
 ## [4.1.0] - 2022-02-06
 

libs/plugins/modifier.truncate.php

@@ -42,8 +42,8 @@ function smarty_modifier_truncate($string, $length = 80, $etc = '...', $break_wo
             if (!$middle) {
                 return mb_substr($string, 0, $length, Smarty::$_CHARSET) . $etc;
             }
-            return mb_substr($string, 0, $length / 2, Smarty::$_CHARSET) . $etc .
-                   mb_substr($string, -$length / 2, $length, Smarty::$_CHARSET);
+            return mb_substr($string, 0, intval($length / 2), Smarty::$_CHARSET) . $etc .
+                   mb_substr($string, -intval($length / 2), $length, Smarty::$_CHARSET);
         }
         return $string;
     }
@@ -56,7 +56,7 @@ function smarty_modifier_truncate($string, $length = 80, $etc = '...', $break_wo
         if (!$middle) {
             return substr($string, 0, $length) . $etc;
         }
-        return substr($string, 0, $length / 2) . $etc . substr($string, -$length / 2);
+        return substr($string, 0, intval($length / 2)) . $etc . substr($string, -intval($length / 2));
     }
     return $string;
 }