bug#81630: 32.0.50; completions-format 'vertical scrolls the completion window on TAB tapping

I can’t say if it’s correct or not, but it’s fixed for me. Thanks

On another note:  This patches will be applied to emacs 31.1 also?

On 16-08-2026, at 11:29, Stephen Berman <[email protected]<mailto:[email protected]>> wrote:

On Sat, 15 Aug 2026 13:03:00 +0000 lucas jimenez <[email protected]<mailto:[email protected]>> wrote:

Hi.

When setting completions-format to 'vertical

and start TAB tapping the completions window starts scrolling up and
down even though all the candidates can be seen in the window.

To reproduce do:
emacs -Q --eval "(setq completions-format 'vertical)"
`M-x 5x5`  and start tapping TAB key or `M-x minibuffer-`

Workaround: set (completion-auto-select 'second-tab) or
(completion-auto-select t) or just don't tap TAB.

This behaviour isn't noticed with 'horizontal or 'one-column

This happens because when `completions-format' is 'vertical the
*Completions* buffer ends in a newline, and that makes
`(pos-visible-in-window-p (point-max) window)' in the "normal tab" case
in `completion--in-region-1' return nil, resulting in the window being
scrolled.  The attached patch prevents this scrolling for me; can you
confirm?  But I cannot tell if such a change might have undesirable
consequences; maybe Stefan Monnier (added in CC:) can tell.

Steve Berman
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