Made the pattern in the first regex an utf-8 pattern, otherwise it could fail

lib/hashtag.php

@@ -1,7 +1,7 @@
 <?php
 
 function hashtag($str,$ucfirst=true) {
-	$str=preg_replace('#^\W*(.*)\W*$#','$1',$str);
+	$str=preg_replace('#^\W*(.*)\W*$#u','$1',$str);
 	$str=preg_split('#\W+#u',$str);
 	$c=count($str);
 	if ($c>1) {