bug#34873: 27.0.50; Creating unibyte string in emacs modules

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: lg.zevlg@gmail.com,  34873@debbugs.gnu.org
> Date: Wed, 26 Aug 2020 12:43:59 +0200
> 
> In what way are unibyte strings slippery slopes?  They're a standard
> part of the Emacs type vocabulary.

They produce incorrect display of non-ASCII characters, for starters.
They also produce unexpected effects when concatenated with multibyte
strings.  They are in general something to avoid because of these and
other subtleties, since many Lisp programmers are unaware of them, and
can easily fall into one of these pitfalls.

In this case AFAIR the request was to use unibyte strings for binary
data, i.e. stuff that is not a string at all, which is one more reason
not to base the implementation on unibyte strings.