comparison core/lib/Drupal/Core/Asset/JsOptimizer.php @ 17:129ea1e6d783

Update, including to Drupal core 8.6.10

 
     // If a BOM is found, convert the file to UTF-8, then use substr() to
     // remove the BOM from the result.
     $data = file_get_contents($js_asset['data']);
     if ($encoding = (Unicode::encodingFromBOM($data))) {
-      $data = Unicode::substr(Unicode::convertToUtf8($data, $encoding), 1);
+      $data = mb_substr(Unicode::convertToUtf8($data, $encoding), 1);
     }
     // If no BOM is found, check for the charset attribute.
     elseif (isset($js_asset['attributes']['charset'])) {
       $data = Unicode::convertToUtf8($data, $js_asset['attributes']['charset']);
     }