Re: setenv -> locale-coding-system cannot handle ASCII?!

[Richard Stallman]

    What a character in a unibyte buffer represents depends on a
    context.  It may be a character represented by a single
    byte, or a raw byte not yet decoded, or a byte constituing a
    multibyte form of the different character.

    On the other hand, a character in a unibyte string always
    represents a raw byte.  Emacs coerces it into a character
    represented by that single byte when a unibyte string is
    concatenated with a multibyte string, or it is inserted in a
    multibyte buffer.
    ------------------------------------------------------------

    But, I'm not sure such a change is really necessary.  Are
    you sure that the change doesn't break the current usage of
    unibyte strings?

To me this seems like a limitation, not an improvement.  If you cut a
string out of a unibyte buffer, its contents have the same kind of
meaning as the unibyte buffers's contents.

Practically speaking, to implement this would seem to mean
removing features, but which features?

Meanwhile, I wonder whether there is any difference between
handing unibyte text inserted from a unibyte string
and unibyte text inserted from a unibyte buffer with
insert-buffer-substring.  I would expect and hope they
work the same.