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

[martin rudalics <rudalics@gmx.at>]

 > 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