bug#35507: Gnus mojibakifies UTF-8 text/x-patch attachments from Thunderbird

[Eli Zaretskii <eliz@gnu.org>]

> From: Andy Moreton <andrewjmoreton@gmail.com>
> Date: Thu, 02 May 2019 16:43:31 +0100
> 
> > So yes, I think Noam is right, and 'undecided' is a better alternative here.
> 
> That is arguing for the existing code, which does not work correctly.

No, the existing code simply uses the undecoded string.

What I argue for is to do this:

diff --git a/lisp/gnus/mm-view.el b/lisp/gnus/mm-view.el
index 1e1d264b99..173ebfab48 100644
--- a/lisp/gnus/mm-view.el
+++ b/lisp/gnus/mm-view.el
@@ -475,7 +475,7 @@ mm-display-inline-fontify
 		    (charset
 		     (mm-decode-string text charset))
 		    (t
-		     text)))
+		     (mm-decode-string text 'undecided))))
       (let ((font-lock-verbose nil)     ; font-lock is a bit too verbose.
 	    (enable-local-variables nil))
         ;; We used to set font-lock-mode-hook to nil to avoid enabling

> I am disinclined to look any further at this, as nobody else appears to
> be running the existing code before commenting, or testing the proposed
> patch.

Please don't be offended, there's no intent to offend you here.  Your
efforts are greatly appreciated.  We are just discussing a small
change to what you were proposing, see above.

Or are you saying that using undecided as above doesn't do the job?

(Sorry, I don't use Gnus, so to be able to reproduce the problem and
test a proposed solution I need detailed instructions, I cannot easily
do it myself without investing an inordinate amount of time.)