#1250 Decorate can create a multipart message with no part headers

[Mark Sapiro]

If the message to be decorated is a single part message with no Content-* headers and the message body contains non-us-ascii characters (note that this is not a valid message), Decorate.process() will convert the message to multipart/mixed with a text/plain part for the original body and additional text/plain part(s) for msg_header and/or msg_footer.

The problem is the part that corresponds to the original message body has no part headers which confuses some mail readers.

This is fixed in bzr for 2.1.11.