The first patch is unchanged (it adjusts y-or-n-p so that the prompt's
text properties are preserved), the second patch uses the new
(literal …) feature from rx and adds a test case for
dired--isolated-char-p[1].

Quoting my previous email:

> Some things I wonder about:
> 
> 1. About read--propertize-prompt…
> 
>     1. Should the function return a copy of its argument instead of
>        propertizing it directly?
> 
>     2. Is it properly named?  Does it fit in subr.el?  I placed it there
>        because I figured other users of read-char in subr.el could use
>        it, e.g. read-char-choice.
> 
> 2. dired-aux.el already contains some logic to detect isolated
>    characters; I could not think of a way to re-use it, so I added my
>    own functions to find *non*-isolated characters.  I added unit tests
>    for these new functions; still, there may be some redundancy there.

Thank you for your time.


[1] (should-not (dired--isolated-char-p "foo `bar`?" 9))