bug#7962: 23.2; capitalize / ISO 8859 / UNIBYTE / utf-8 backward compatibility

[Eli Zaretskii]

> Date: Fri, 04 Feb 2011 09:22:14 +0100
> From: Emmanuel Bigler <Emmanuel.Bigler@ens2m.fr>
> 
> Le 04/02/2011 09:09, Emmanuel Bigler a écrit :
> > Now the last test is to enter fresh letters in 2-byte, capitalize them,
> > do not switch bak to unibyet display, save the file, exits emacs,  and
> > see what happens when re-loaded/displayed as unibyte.
> 
> 
> I just did this test.
> 
> After loading the old unibyte file, toggling 2-byte display on, I 
> entered freshly typed letters with a diacritic sign. Did not toggle back 
> to unibyte, and saved buffer - killed emacs.
> Re-loaded emacs <myfile> ; note that in my .emacs I have nothing to 
> force emacs to be unibyte.

If there's nothing in your .emacs to force Emacs to be unibyte, then
what do you mean by "loading the old unibyte file"?  What exactly do
you type to do that?

Btw, perhaps it is better that you use "emacs -Q" for these
experiments, until we figure out what's wrong with editing these files
in multibyte mode.

> However,  new letters added at the end of the file in the previous 
> 2-byte session show as 2-byte in unibyte displayed

What do you mean by "unibyte display"?  How did you manage to force
Emacs to display the text as unibyte?  It does not do that by default.

> and were stored as 2-byte when stores under the "2-byte display"
> setting. Nothing but normal, after all.

No, this isn't "normal".

Your procedure for using multibyte Emacs is incorrect.  I will suggest
the correct procedure once I understand how you force the buffer that
visits a file be unibyte.  There should be no problems with editing
buffers with ISO-8859-1 text in multibyte mode.