unit test for FS#2173

_test/tests/inc/utf8_strtolower.test.php

+<?php
+// use no mbstring help here
+if(!defined('UTF8_NOMBSTRING')) define('UTF8_NOMBSTRING',1);
+
+class utf8_strtolower_test extends DokuWikiTest {
+
+    function test_givens(){
+        $data = array(
+            'Αρχιτεκτονική Μελέτη' => 'αρχιτεκτονική μελέτη', // FS#2173
+        );
+
+        foreach($data as $input => $expected) {
+            $this->assertEquals($expected, utf8_strtolower($input));
+        }
+
+        // just make sure our data was correct
+        if(function_exists('mb_strtolower')) {
+            foreach($data as $input => $expected) {
+                $this->assertEquals($expected, mb_strtolower($input, 'utf-8'));
+            }
+        }
+    }
+}
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