formula mb string functions

application/Espo/Core/Formula/Functions/StringGroup/ContainsType.php

@@ -48,6 +48,6 @@ class ContainsType extends \Espo\Core\Formula\Functions\Base
             return false;
         }
 
-        return strpos($string, $needle) !== false;
+        return mb_strpos($string, $needle) !== false;
     }
 }

application/Espo/Core/Formula/Functions/StringGroup/LowerCaseType.php

@@ -53,6 +53,6 @@ class LowerCaseType extends \Espo\Core\Formula\Functions\Base
             $value = strval($value);
         }
 
-        return strtolower($value);
+        return mb_strtolower($value);
     }
 }

application/Espo/Core/Formula/Functions/StringGroup/SubstringType.php

@@ -1,4 +1,4 @@
-<?php
+<?php
 /************************************************************************
  * This file is part of EspoCRM.
  *
@@ -52,9 +52,9 @@ class SubstringType extends \Espo\Core\Formula\Functions\Base
 
         if (count($item->value) > 2) {
             $length = $this->evaluate($item->value[2]);
-            return substr($string, $start, $length);
+            return mb_substr($string, $start, $length);
         } else {
-            return substr($string, $start);
+            return mb_substr($string, $start);
         }
     }
 }

application/Espo/Core/Formula/Functions/StringGroup/UpperCaseType.php

@@ -53,6 +53,6 @@ class UpperCaseType extends \Espo\Core\Formula\Functions\Base
             $value = strval($value);
         }
 
-        return strtoupper($value);
+        return mb_strtoupper($value);
     }
 }