--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/libcalendaring/lib/Sabre/VObject/StringUtil.php	Sat Jan 13 08:57:56 2018 -0500
@@ -0,0 +1,61 @@
+<?php
+
+namespace Sabre\VObject;
+
+/**
+ * Useful utilities for working with various strings.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class StringUtil {
+
+    /**
+     * Returns true or false depending on if a string is valid UTF-8
+     *
+     * @param string $str
+     * @return bool
+     */
+    static function isUTF8($str) {
+
+        // First check.. mb_check_encoding
+        if (!mb_check_encoding($str, 'UTF-8')) {
+            return false;
+        }
+
+        // Control characters
+        if (preg_match('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', $str)) {
+            return false;
+        }
+
+        return true;
+
+    }
+
+    /**
+     * This method tries its best to convert the input string to UTF-8.
+     *
+     * Currently only ISO-5991-1 input and UTF-8 input is supported, but this
+     * may be expanded upon if we receive other examples.
+     *
+     * @param string $str
+     * @return string
+     */
+    static function convertToUTF8($str) {
+
+        $encoding = mb_detect_encoding($str , array('UTF-8','ISO-8859-1'), true);
+
+        if ($encoding === 'ISO-8859-1') {
+            $newStr = utf8_encode($str);
+        } else {
+            $newStr = $str;
+        }
+
+        // Removing any control characters
+        return (preg_replace('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', '', $newStr));
+
+    }
+
+}
+