Fix(Core): fix truncated CSV export (#556)

Author: stonebuzz

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fix truncated CSV export
 - Fix injection for `groups_id` and `groups_id_tech` fields
 - Fix missing `purge` action
 - Fix user fields nullability to prevent SQL errors during injection

inc/modelcsv.class.php

@@ -127,7 +127,7 @@ public function showSample(PluginDatainjectionModel $model)
         );
         header('Content-Type: text/comma-separated-values');
         header('Content-Transfer-Encoding: UTF-8');
-        header('Content-Length: ' . mb_strlen($sample, 'UTF-8'));
+        header('Content-Length: ' . strlen($sample));
         header('Pragma: no-cache');
         header('Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
         header('Expires: 0');