swiftmailer/swiftmailer — pull request #475 by mimimi5 (2014-05-19 03:52:15+00:00)
Title: #444 fix is wrong

It is iconv that transpose arguments, not mb_convert_encoding.
_convertString encodes $string charset when Swift_Mime_MimePart charset ($this->getCharset()) is not utf-8. So mb_convert_encoding and iconv must convert from utf-8 to $charset.