Re: Stop frames stealing eachothers' minibuffers!

[Gregory Heytings via "Emacs development discussions." <emacs-devel@gnu.org>]

>
> Thanks.  To elaborate on an earlier problem I mentioned which, as I 
> found out, happens already with Emacs 27 at the least.  I'd be just 
> interested if you can reproduce it on your system.  Start with
>
> emacs -Q --eval "(setq default-frame-alist '((minibuffer . nil)))"
>
> Now in the minibuffer window type C-h f and at the prompt type setq RET. 
> This pops up a help window on the normal frame explaining 'setq' and 
> 'Type "q" in help window to delete it.' appears in the minibuffer 
> window.  Here, sometimes the normal frame is selected, sometimes the 
> minibuffer frame remains selected.  It might be a timing issue since 
> sometimes I see the cursor flicker at the end of the 'Type "q" ...' text 
> before it moves to the normal frame, provided it moves there.
>
> The strange thing that happens is when I now type "q" in the help 
> window.  Here the minibuffer window gets selected and ready to receive 
> input but no cursor is shown in it.  Do you see that?  Anyone else?
>

I can confirm this behavior.  It does not happen with Emacs 23 to 25, and 
happens with Emacs 26 to 28.  Except that:

"Now in the minibuffer window type C-h f and..." is (in my case at least) 
"Select the miniwindow frame, type C-h f, and..."

I did not see the "sometimes the normal frame is selected, sometimes the 
minibuffer frame remains selected", in my case at least the miniwindow 
frame remains selected in all cases.  Which means that I need to click in 
the *Help* buffer before typing "q".

"Here the minibuffer window gets selected and ready to receive input but 
no cursor is shown in it." is (in my case at least) "The minibuffer gets 
selected and ready to receive input but no cursor is shown in it AND the 
miniwindow frame is not raised (put above the main frame by the window 
manager)".

Another strange thing is that at that point a number of keys are bound to 
something, as if something like "C-x 5" was always pressed:

"b" says "Switch to buffer in other frame"
"f" says "Find file in other frame:"
"m" opens "mail"
"i" opens "info"
"n" creates a new frame

But it is not the "C-x 5" keymap, because "d" or "r" for example are not 
bound, and "n" is not bound in "C-x 5".