Subject: Re: bug#29422: 27.0.50; Symbol enable-multibyte-characters may not be buffer-local

From: Eli Zaretskii <[email-masked]>
Date: Sat, 25 Nov 2017 09:53:33 +0200

> From: Michael Heerdegen <[email-masked]>
> Date: Sat, 25 Nov 2017 02:22:59 +0100
> Cc: Stefan Monnier <[email-masked]>
> 
> Michael Heerdegen <[email-masked]> writes:
> 
> > Debugger entered--Lisp error: (error "Symbol enable-multibyte-characters may not be buffer-local")
> 
> Apparently has been fixed with d1000fb.

Yes, but signaling "Setting constant" when we actually mean a
read-only symbol is sub-optimal, IMO.  That error is for setting stuff
like nil and t, which enable-multibyte-characters isn't.  It will
confuse users to see this error in that case, I think.

And the ELisp manual clearly states that this error is for "symbols
that evaluate to themselves": nil, t, and keyword symbols.  So now the
implementation contradicts the documentation.

How about inventing a new error symbol for these cases?