Subject: bug#55169: Can't combine window-min-height with window-height

From: martin rudalics <[email-masked]>
Date: Fri, 6 May 2022 16:10:15 +0200

>> You mean the value of a 'window-height' entry could also be a
 >>
 >>          • A list whose CAR is a function and whose remaining elements
 >>            are the arguments passed to that function.
 >>
 >> so we'd run
 >>
 >> 	    (ignore-errors (funcall (car height) window (nth 1 height) ...))
 >>
 >> in 'window--display-buffer'?  Which means the caller has to know the
 >> function and which arguments it needs in which order.  Sounds fragile.
 >
 > It is intended only for special handling of 'fit-window-to-buffer'.
 > If 'fit-window-to-buffer' with MIN-HEIGHT will really fix this problem,
 > then details of the entry format could be adapted later.
 > And indeed this works exactly as should with
 >
 > (pop-to-buffer (generate-new-buffer "*edit string*")
 >                   '(display-buffer-below-selected
 >                     (window-height . fit-window-to-buffer)))
 >
 > and an experimental patch:
 >
 > diff --git a/lisp/window.el b/lisp/window.el
 > index 9f78784612..a21cf109a4 100644
 > --- a/lisp/window.el
 > +++ b/lisp/window.el
 > @@ -7336,7 +7336,9 @@ window--display-buffer
 >   	         (window-resize window delta nil 'safe t)))
 >             (setq resize-temp-buffer-window-inhibit 'vertical))
 >            ((functionp height)
 > -	  (ignore-errors (funcall height window))
 > +	  (if (eq height 'fit-window-to-buffer)
 > +              (ignore-errors (funcall height window nil 10))
 > +            (ignore-errors (funcall height window)))
 >             (setq resize-temp-buffer-window-inhibit 'vertical)))
 >   	;; Adjust width of window if asked for.
 >   	(cond

This boils down to what I sketched above: ALIST must supply a list whose
car is 'fit-window-to-buffer' and 'window--display-buffer' supplies the
window used as first argument in its call to 'fit-window-to-buffer' and
the rest of the list as the remaining arguments.

martin