bug#46177: 27.1; Display problem with minibuffer overlay when using display property

[Clemens]

> Better in what sense?
>
> If you mean a way that prevents the background of the prompt from
> being applied to the text you display via the overlay, I think the
> best/only way is for the overlay string or display string to specify
> the background color.

Yes, I meant to avoid the issue that the minibuffer prompt face gets
applied to strings defined in the display property. The code I posted
simply removes any strings in the display spec and inlines them, which
seems to work well, too. The problem is not only the background color it 
seems, I would need to completely undo the effects of the minibuffer 
prompt face and I don't know how to do that. But what I'm doing now 
works and if there isn't a better solution I'm fine with using it.

I don't understand the reasons for the current behaviour but please
check out the following which seems not appropriate to me:


(set-face-attribute 'minibuffer-prompt nil :foreground "purple")
(minibuffer-with-setup-hook
    (lambda ()
      (overlay-put
       (make-overlay (point-max) (point-max) nil t t)
       'after-string
       (concat " from"
                   (propertize " world"
                               'display
                               " minibuffer"))))
  (read-string "Hello"))


Even with the " from" string between the string defined in the display 
property gets the prompt face applied.