bug#38818: Dired: mention deleting buffers, not just windows

[Pieter van Oostrum]

And, by the way, that message arrived here with the CJK characters in Dan 
Jacobson's name mangled. Whereas the normally are 積丹尼, they now are <some 
unprintable characters>, and message-send-mail crashes on it.

Debugger entered--Lisp error: (cl-assertion-failed ((save-excursion (goto-char 
(point-min)) (not (re-search-forward "[^\0-\377]" nil t))) nil))
  cl--assertion-failed((save-excursion (goto-char (point-min)) (not 
(re-search-forward "[^\0-\377]" nil t))))
  message-send-mail(nil)
  message-send-via-mail(nil)

The raw header is:

To: =?iso-8859-1?Q?=E7=A9=8D=E4=B8=B9=E5=B0=BC?= Dan Jacobson
 <jidanni@jidanni.org>
which translates to unprintable characters, which cause this error.
Normally it would be
From: =?UTF-8?Q?=E7=A9=8D=E4=B8=B9=E5=B0=BC?= Dan Jacobson
so it seems to be a mixup of encodings on RMS's side.

When these unprintable characters re in the message body, you get an error 
message with a choice:

Non-printable characters found.  Continue sending? (delete, replace, send, 
edit, ?):

but when they are in the header it just bails out with an uncomprehensible error
cl--assertion-failed: Assertion failed: (save-excursion (goto-char (point-min)) 
(not (re-search-forward "[^.-ÿ]" nil t)))
which isn't helpful at all.
-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]