Re: Stop frames stealing eachothers' minibuffers!

[Gregory Heytings]

> > > > > (i) Have two frames open displaying buffers.
> > > > > (ii) On frame F1 do C-x b.  This leaves a minibuffer open there.
> > > > > (iii) Move to F2.
> > > > > (iv) Do C-x 8 RET <enter some character>.
> > > > > F1's minibuffer is now on F2.  This is bad.
> > >
> > > But I see the same with Emacs 27.  After moving to F2, the minibuffer 
> > > of F1 appears there.
> >
> > Are you sure?  You see the minibuffer moving from frame F1 to frame F2, 
> > without doing anything?  With Emacs 27?  I have Emacs 27.1, and do not 
> > see this, neither with graphical nor with terminal Emacs.
>
> Why "moving"?  The active minibuffer is already on F2 because after 
> (iii) I am on F2 and answered the C-x 8 prompt there.  With Emacs 27 
> built two days ago.

Yes, and this is precisely the "bad" behavior Alan would like to fix.

With Emacs 28 (-Q), the active minibuffer is moved from frame F1 to frame 
F2 at step (iii), _before_ you answer the C-x 8 RET. That is, the active 
minibuffer is moved from frame F1 to frame F2 whenever you switch from 
frame F1 to frame F2.

With Emacs 21-27, this happens only at step (iv), _after_ you hit C-x 8 
RET.  That is, the active minibuffer is moved from frame F1 to frame F2 
only when you activate a new minibuffer on frame F2.