Re: Stop frames stealing eachothers' minibuffers!

[Alan Mackenzie]

Hello, Martin.

On Sat, Nov 21, 2020 at 10:02:15 +0100, martin rudalics wrote:
>  >> (setq default-frame-alist '((minibuffer . nil)))

>  >> (defun foo ()
>  >>     (interactive)
>  >>     (read-from-minibuffer "...?")
>  >>     (insert (format "%s" (selected-frame))))

>  >> insert (foo) into *scratch* and type C-x C-e.  After answering the
>  >> prompt this gets me #<frame *Minibuf-1* 0x36132d8>.  Do the same with
>  >> Emacs 27 and it will get you the *scratch* frame.

>  > Yes, I see this (except for the Emacs 27 bit which I haven't tried,
>  > yet).

>  > However, if I type (frame-list) into *scratch* and do C-x C-e I get only
>  > one frame in the list, and it has the same address in the #<frame ...>
>  > output as the " *Minibuf-1* 0xxxx" output.

> You have to _load_ the

> (setq default-frame-alist '((minibuffer . nil)))

> part, it won't work after your default initial frame has been already
> set up.  Run Emacs via something like

> emacs -Q --load ~/foo.el

> to see the effect ....

OK, I've got it now.

[ .... ]

> But indeed, with Emacs -Q executing 'foo' defined as

> (defun foo ()
>    (interactive)
>    (read-from-minibuffer "...?")
>    (insert (format "window: %s .. frame: %s" (selected-window) 
> (selected-frame))))

> reveals another aspect broken by your change.  The values reported by
> 'selected-window' and 'select-frame' do not match up any more (unless
> our masochistic way of printing frame names hides an important detail).

I'll look at that later.  I'll look at the other things below [snipped]
later, too.  I'm a bit short of time today.

[ .... ]

Here's a quick and dirty patch to minibuf.c which appears to fix the bug,
but I haven't given it much testing yet:



diff --git a/src/minibuf.c b/src/minibuf.c
index 464e3018f7..5312dc9805 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -508,7 +508,14 @@ read_minibuf (Lisp_Object map, Lisp_Object initial, 
Lisp_Object prompt,
   mini_frame = WINDOW_FRAME (XWINDOW (minibuf_window));
   if (!EQ (mini_frame, selected_frame))
     record_unwind_protect (restore_window_configuration,
-                          Fcons (Qt,
+                          Fcons (
+                                  /* If we're at top minibuffer level in a
+                                     minibuffer-only frame, arrange for the
+                                     frame later to be switched back.  */
+                                  (FRAME_MINIBUF_ONLY_P (XFRAME (mini_frame))
+                                   && minibuf_level <= 1)
+                                  ? Qnil
+                                  : Qt,
                                   Fcurrent_window_configuration (mini_frame)));
 
   /* If the minibuffer is on an iconified or invisible frame,


> martin

-- 
Alan Mackenzie (Nuremberg, Germany).