Re: Garbled display of UTF-8 encoded mails

[Sven Joachim <svenjoac@gmx.de>]

On 2010-11-24 11:19 +0100, Sven Joachim wrote:

> However, this contains a change in semantics that is not mentioned and
> might have been unintended.  The old version of mm-enable-multibyte for
> Emacs was (set-buffer-multibyte 'to), whereas the new one is
> (set-buffer-multibyte t), and this seems to be what causes all my
> problems.  Reverting the change in master:
>
> diff --git a/lisp/mm-util.el b/lisp/mm-util.el
> index 67b41e0..700c1a6 100644
> --- a/lisp/mm-util.el
> +++ b/lisp/mm-util.el
> @@ -903,7 +903,7 @@ mail with multiple parts is preferred to sending a Unicode one.")
>        "Set the multibyte flag of the current buffer.
>  Only do this if the default value of `enable-multibyte-characters' is
>  non-nil.  This is a no-op in XEmacs."
> -      (set-buffer-multibyte t)))
> +      (set-buffer-multibyte 'to)))
>  
>    (if (featurep 'xemacs)
>        (defalias 'mm-disable-multibyte 'ignore)
>
> solves the issue for me.

BTW, I found an old commit which did the same change, but the ChangeLog
entry is not especially informative what exactly the problems were:

,----
| $ git show 302ab06a28aec7e405145417bdcbf324246ea192
| commit 302ab06a28aec7e405145417bdcbf324246ea192
| Author: Simon Josefsson <jas@extundo.com>
| Date:   Sun Nov 30 16:59:35 2003 +0000
| 
|     (mm-enable-multibyte): Call set-buffer-multibyte with
|     'to argument.  Fixes something or other in Emacs 22, and is
|     backwards compatible.  From Kenichi Handa <handa@m17n.org>.
| 
| diff --git a/lisp/ChangeLog b/lisp/ChangeLog
| index 6e37dbe..8d55cf2 100644
| --- a/lisp/ChangeLog
| +++ b/lisp/ChangeLog
| @@ -1,5 +1,9 @@
|  2003-11-30  Simon Josefsson  <jas@extundo.com>
|  
| +	* mm-util.el (mm-enable-multibyte): Call set-buffer-multibyte with
| +	'to argument.  Fixes something or other in Emacs 22, and is
| +	backwards compatible.  From Kenichi Handa <handa@m17n.org>.
| +
|  	* gnus-agent.el (gnus-agent-expire-unagentized-dirs): Custom fix.
|  
|  2003-11-30  Lars Magne Ingebrigtsen  <larsi@gnus.org>
| diff --git a/lisp/mm-util.el b/lisp/mm-util.el
| index eef5c04..cbd85b1 100644
| --- a/lisp/mm-util.el
| +++ b/lisp/mm-util.el
| @@ -413,7 +413,7 @@ used as the line break code type of the coding system."
|  	"Set the multibyte flag of the current buffer.
|  Only do this if the default value of `enable-multibyte-characters' is
|  non-nil.  This is a no-op in XEmacs."
| -	(set-buffer-multibyte t))
| +	(set-buffer-multibyte 'to))
|      (defalias 'mm-enable-multibyte 'ignore))
|  
|    (if mm-emacs-mule
| 
`----

I haven't been able to find a mailinglist thread which describes this in
greater detail.

Sven