bug#23093: 25.0.92; Change for the worse: minibuffer completion window splits below rather that right

[martin rudalics]

> In Emacs 24 when using completion in the minibuffer, when the frame is
> sufficiently wide it is split vertically (into side-by-side windows)
> with the completions in the window on the right.
>
> There seems to have been an (undocumented?) behaviour change -- now when
> using completion in the minibuffer the frame seems always to be split
> horizontally (into above-and-below windows) with the completions in the
> lower window.
>
> This change does not seem to me to be an improvement, as now far fewer
> of the available completions are visible at once.

Customizing ‘temp-buffer-max-height’ would fix that.

> I suppose whether a "portrait" or "landscape" completions window is
> better probably depends on the number and length of the completions and
> also on the user's frame size, so presumably the splitting behaviour
> should be a user option.

It is.  Please customize ‘display-buffer-alist’ for the buffer named
*Completions*.

> As long as the option is available and documented, I have no opinion on
> the default, although it would seem more compatible to make it default
> to the old behaviour.

martin