Subject: bug#37555: mml-attach-file ascii, big5

From: 積丹尼 Dan Jacobson <[email-masked]>
Date: Mon, 30 Sep 2019 00:23:32 +0800

I used C-c C-a mml-attach-file and filled in the description with "提案"
and instead of 100% UTF we see ascii and big5 mentioned below.

Content-Type: text/html; charset=utf-8
Content-Disposition: inline; filename=DJ1.html
Content-Transfer-Encoding: 8bit
Content-Description: =?us-ascii?Q?=3D=3Fbig5=3FB=3F0Eg=3D=3F=3D?=

See my https://jidanni.org/comp/configuration

Gnus v5.13
GNU Emacs 26.3 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.11)
 of 2019-09-23, modified by Debian