note 112999 added to function.mb-encode-mimeheader

I found a bug-like behaviour of "mb_encode_mimeheader()" in PHP 5.3.5. Changelog says nothing about this now on Aug 16 2013. <?php echo mb_encode_mimeheader("123", "UTF-8", "B").'<BR>'; // 123 (No problem) echo mb_encode_mimeheader("=", "UTF-8", "B").'<BR>'; // =?UTF-8?B?PQ==?= echo mb_encode_mimeheader("?", "UTF-8", "B").'<BR>'; // =?UTF-8?B?PW==?= echo mb_encode_mimeheader("_", "UTF-8", "B").'<BR>'; // =?UTF-8?B?XW==?= Also with "Q", echo mb_encode_mimeheader("=", "UTF-8", "Q").'<BR>'; // =?UTF-8?Q?=3D=?= ?> Ascii letters (0x20(space) - 0x7E(~)) are No problem whereas '='(3D), '?'(3F), '_'(5F)' are exceptions. ---- Server IP: 49.212.134.217 Probable Submitter: 101.141.138.209 ---- Manual Page -- http://php.net/manual/en/function.mb-encode-mimeheader.php Edit -- https://master.php.net/note/edit/112999 Del: integrated -- https://master.php.net/note/delete/112999/integrated Del: useless -- https://master.php.net/note/delete/112999/useless Del: bad code -- https://master.php.net/note/delete/112999/bad+code Del: spam -- https://master.php.net/note/delete/112999/spam Del: non-english -- https://master.php.net/note/delete/112999/non-english Del: in docs -- https://master.php.net/note/delete/112999/in+docs Del: other reasons-- https://master.php.net/note/delete/112999 Reject -- https://master.php.net/note/reject/112999 Search -- https://master.php.net/manage/user-notes.php