bug#24759: 25.1.50; electric-quote-mode

[Eli Zaretskii <eliz@gnu.org>]

> From: Dani Moncayo <dmoncayo@gmail.com>
> Date: Sat, 22 Oct 2016 10:16:35 +0200
> Cc: Paul Eggert <eggert@cs.ucla.edu>, 24759@debbugs.gnu.org
> 
> > And if electric-quote-mode wants to be more user-friendly, it could
> > ask, upon the first insertion of any electric quote character into a
> > buffer, whether the user would like to her buffer-file-coding-system
> > switched to UTF-8.
> 
> I'd like such a feature, but I'd rather make it general (not specific
> to electric-quote-mode).  That is, whenever a buffer gets a character
> (whether typed, yanked, electrically inserted, ...) which is not
> representable in the current buffer-file-coding-system, Emacs could
> offer the user to switch the coding system to UTF-8 (or another one
> which can represent all the characters currently present in the
> buffer), like happens when the buffer is about to be saved to a file.

IMO, this would be too annoying and detrimental to performance in many
cases.  I think you underestimate how much 'insert' is used in Emacs,
without the user knowing anything about that.  In most such cases, the
buffer into which the character is entered will never be saved to any
file.

My proposal was specifically for the case where keyboard input caused
these characters be inserted after conversion by electric-quote-mode,
which hopefully restricts the applicable use cases to those where the
user is typing at the keyboard.