bug#30043: 25.3; C-M-e inserts euro character

[Stefan Kangas]

tags 30043 - notabug
reopen 30043
thanks

Tomas Nordin <tomasn@posteo.net> writes:

> >> So I guess you somehow have a keyboard which doesn't fit the new
> >> keyboard input code introduced by Emacs 25, and need to use this
> >> fallback variable to avoid the problem.
> >
> > I believe that was the correct answer, and nothing of the rest of the
> > discussion indicated otherwise.  I'm therefore closing this as notabug.
>
> It seems to me then that the correct answer is that keyboards with
> swedish layout on Windows does not fit the new keyboard input code. I
> see the same on a laptop now with emacs 26.2. It is strange that no-one
> else in this country complains.
>
> Using the work-around with setting w32-use-fallback-wm-chars-method
> solves the problem. But the docstring of that variable suggests that I
> shouldn't have to use it unless debugging something.
>
> I am not going to argue with the closing but I don't think this is
> specific to one specific keyboard. It was reproduced on several
> keyboards on different machines.

Hi Tomas,

Thanks for writing back.  It was not my intention to close a
legitimate bug; reopened it now.  I've been investigating this a bit,
and it seems like this new keyboard handling code was introduced due
to deficiencies in the old one.  See:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=19994
See also the possibly related: https://debbugs.gnu.org/bug=23251

If it's the case that this change breaks M-C-e on all Swedish
keyboards on MS-Windows, perhaps it's worth making sure the users
doesn't have to set w32-use-fallback-wm-chars-method to non-nil.  At
the very least, it makes sense to me that the doc string should be
improved as Tomas suggests, and possibly also that the workaround
should be documented in e.g. etc/PROBLEMS.

Eli, what do you think?  I've also Cc:ed Ilya Zakharevich in the hope
that he will be able to help.

Also: is anyone else seeing this on their Swedish keyboard on
MS-Windows?  And Tomas: Are you seeing the same thing with other key
bindings involving one or more modifiers?

I have a Swedish keyboard but no MS-Windows system, so I can't dig
into this beyond this.  I'm also a bit out of my depth.  Therefore,
I'll have to leave it to someone else to decide how to best proceed
here.

Best regards,
Stefan Kangas