bug#45044: 28.0.50; y-or-n-p-with-timout: allows me to go with the arrow to begin of the minibuffer

[Jean Louis]

* Eli Zaretskii <eliz@gnu.org> [2020-12-05 10:49]:
> > From: Jean Louis <admin@gnu.support>
> > Date: Sat, 05 Dec 2020 00:47:55 +0300
> > 
> > (y-or-n-p-with-timeout "No parent nodes, do you wish to exit? " 2 nil)
> > 
> > It allows me, and it should not, to move cursor with arrow left to begin
> > of the buffer over the words "No parent nodes..."
> 
> Why shouldn't it?

I see that those reading functions allow user to go back. Myself
I did not maybe use for decades arrows or C-b to go back, as I
always used BACKSPACE and I am relying that backspace will not
bring me into impossible situation not to be on read-only text
when I am anyway just asked to enter something, and not to edit
the non-editable prompt.

Thus from experience of using always BACKSPACE and BACKSPACE does
not allow me to move to the read-only prompt comes also the
expectation that arrows or C-b should not move cursor to the
prompt itself as it is not useful to be on prompt as I just want
to enter text.

The minibuffer also does not move cursor to begin of the prompt
when using C-a and when there is all that prevention for cursor
not to move to the prompt then C-b and left arrow makes me
surprised and it appears as unwanted behavior.

Maybe it is wanted. To me it is rather unexpected due to habit. I
expect left arrow not to be able to move onto read-only text.