bug#44108: calc windows should be marked as dedicated

bug#44108: calc windows should be marked as dedicated

[Boruch Baum]

Windows that display calc buffers (ie. the stack buffer and the trail
buffer) are typically small-sized single-use windows, yet they are not
marked as dedicated. The consequence is that functions that perform
`pop-to-buffer' or `display-buffer' can use one of them as targets,
which will always be undesirable. A simple example, the one that
prompted this bug report, is when I was in a calc buffer and issued calc
command "u v" to display a 'units description' buffer. This is a long
and wide buffer, yet was displayed in the short and narrow calc trail
window. I vaguely recall having this also happen in the past with help
buffers, but was only motivated now to submit the report.

The solution is that when the calc and calc trail buffers are created,
they should be marked (set-window-dedicated-p)

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bug#44108: Needs to be performed whenever windows are created

[Boruch Baum]

I need to elaborate on my initial report: people who use calc a lot will
be closing and re-opening windows used for the same calc buffers, so the
(set-window-dedicated-p) operation needs to be done at each window
creation event for calc and calc-trail windows, not at buffer creation
events.

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bug#44108: Patch for this bug

[Boruch Baum]

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Attached.

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diff --git a/calc.el b/calc.el
index 4bebd5f..90dcce6 100644
--- a/calc.el
+++ b/calc.el
@@ -1472,6 +1472,7 @@ commands given here will actually operate on the *Calculator* stack."
       (and (windowp full-display)
            (window-point full-display)
            (select-window full-display))
+      (set-window-dedicated-p nil t)
       (calc-check-defines)
       (when (and calc-said-hello interactive)
         (sit-for 2)
@@ -2136,7 +2137,8 @@ the United States."
               (if calc-trail-window-hook
                   (run-hooks 'calc-trail-window-hook)
                 (let ((w (split-window nil (/ (* (window-width) 2) 3) t)))
-                  (set-window-buffer w calc-trail-buffer)))
+                  (set-window-buffer w calc-trail-buffer)
+                  (set-window-dedicated-p w t)))
               (calc-wrapper
                (setq overlay-arrow-string calc-trail-overlay
                      overlay-arrow-position calc-trail-pointer)

bug#44108: Patch for this bug

[Eli Zaretskii]

> Date: Thu, 22 Oct 2020 03:45:09 -0400
> From: Boruch Baum <boruch_baum@gmx.com>
> 
> diff --git a/calc.el b/calc.el
> index 4bebd5f..90dcce6 100644
> --- a/calc.el
> +++ b/calc.el
> @@ -1472,6 +1472,7 @@ commands given here will actually operate on the *Calculator* stack."
>        (and (windowp full-display)
>             (window-point full-display)
>             (select-window full-display))
> +      (set-window-dedicated-p nil t)
>        (calc-check-defines)
>        (when (and calc-said-hello interactive)
>          (sit-for 2)
> @@ -2136,7 +2137,8 @@ the United States."
>                (if calc-trail-window-hook
>                    (run-hooks 'calc-trail-window-hook)
>                  (let ((w (split-window nil (/ (* (window-width) 2) 3) t)))
> -                  (set-window-buffer w calc-trail-buffer)))
> +                  (set-window-buffer w calc-trail-buffer)
> +                  (set-window-dedicated-p w t)))
>                (calc-wrapper
>                 (setq overlay-arrow-string calc-trail-overlay
>                       overlay-arrow-position calc-trail-pointer)

Thanks.

Would people who routinely use Calc please chime in and comment on
this?  Could this have some adverse consequences in some use cases?
Should we have a user option for controlling this behavior?

bug#44108: Patch for this bug

[Eli Zaretskii]

Ping!  Could someone please chime in?
If no comments are heard, I will push this change conditioned on a new
defcustom, in one week's time.

> Date: Sat, 31 Oct 2020 09:54:16 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 44108@debbugs.gnu.org
> 
> > Date: Thu, 22 Oct 2020 03:45:09 -0400
> > From: Boruch Baum <boruch_baum@gmx.com>
> > 
> > diff --git a/calc.el b/calc.el
> > index 4bebd5f..90dcce6 100644
> > --- a/calc.el
> > +++ b/calc.el
> > @@ -1472,6 +1472,7 @@ commands given here will actually operate on the *Calculator* stack."
> >        (and (windowp full-display)
> >             (window-point full-display)
> >             (select-window full-display))
> > +      (set-window-dedicated-p nil t)
> >        (calc-check-defines)
> >        (when (and calc-said-hello interactive)
> >          (sit-for 2)
> > @@ -2136,7 +2137,8 @@ the United States."
> >                (if calc-trail-window-hook
> >                    (run-hooks 'calc-trail-window-hook)
> >                  (let ((w (split-window nil (/ (* (window-width) 2) 3) t)))
> > -                  (set-window-buffer w calc-trail-buffer)))
> > +                  (set-window-buffer w calc-trail-buffer)
> > +                  (set-window-dedicated-p w t)))
> >                (calc-wrapper
> >                 (setq overlay-arrow-string calc-trail-overlay
> >                       overlay-arrow-position calc-trail-pointer)
> 
> Thanks.
> 
> Would people who routinely use Calc please chime in and comment on
> this?  Could this have some adverse consequences in some use cases?
> Should we have a user option for controlling this behavior?
> 
> 
> 
> 

bug#44108: Patch for this bug

[martin rudalics]

 > Ping!  Could someone please chime in?
 > If no comments are heard, I will push this change conditioned on a new
 > defcustom, in one week's time.

IMHO _any_ use of dedicated windows in Emacs should be optional so a
defcustom is certainly a good idea.

Note that 'display-buffer' already processes a 'dedicated' action alist
entry so if 'calc' used it in this context, the option would already be
available now.

martin

bug#44108: Patch for this bug

[Eli Zaretskii]

> Date: Sat, 07 Nov 2020 10:17:15 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 44108@debbugs.gnu.org
> 
> Ping!  Could someone please chime in?
> If no comments are heard, I will push this change conditioned on a new
> defcustom, in one week's time.

Done.