Subject: bug#51062: Customizable window resizing

From: Juri Linkov <[email-masked]>
Date: Tue, 04 Jan 2022 10:33:48 +0200

>>> You mean to run 'shrink-window-if-larger-than-buffer' from that hook
>>> unless the user removed it?
>>
>> The problem is that the argument of this function should be a buffer,
>> not a window as in 'shrink-window-if-larger-than-buffer'.
>> This is why bug#52855 proposed to add a new function
>>
>>    shrink-buffer-if-larger-than-buffer
>>
>> But not sure if this should be added to window.el,
>> or better to leave in vc.el with the name vc-shrink-buffer?
>
> "shrink-buffer-if-larger-than-buffer"?  Maybe this should become
> 'shrink-buffer-window-if-larger-than-buffer' then.

Should such a function be added to window.el?

> With the usual problem what to do when there are two windows showing
> that buffer.

It's understandable why vc-diff-internal and vc-diff-finish
use get-buffer-window to get a window:

vc-diff-internal:
      (pop-to-buffer (current-buffer))
      (let ((buf (current-buffer)))
        (vc-run-delayed (vc-diff-finish buf ...

vc-diff-finish:
  (let ((window (get-buffer-window buffer t)))
        (with-current-buffer buffer
          ...
          (when window
            (shrink-window-if-larger-than-buffer window))))

This is needed to handle the case when the window was deleted
before the vc command finished.

But why vc-log-internal-common doesn't so the same?

vc-log-internal-common:
    (pop-to-buffer buffer)
    (vc-run-delayed
      ...
      (shrink-window-if-larger-than-buffer)

So I posted a patch in bug#52855 to use the same function
that relies on get-buffer-window in both cases.

But it seems you propose to remember the window with e.g.

  (setq window (pop-to-buffer (current-buffer)))

then to use it in:

  (run-hook-with-args 'vc-diff-finish-functions window)

where the defalut value of 'vc-diff-finish-functions' is:

  '(shrink-window-if-larger-than-buffer)

Then 'shrink-buffer-window-if-larger-than-buffer' is not needed.