bug#59486: completion-auto-wrap disobeyed by vertical navigation

[Juri Linkov]

> I don't really understand the difference between minibuffer-previous-* and
> minibuffer-previous-line-* commands (the available documentation is minimal
> and doesn't explain this difference), so it's hard to suggest an alternative.

minibuffer-previous-* are intended to navigate the completion list
horizontally while the minibuffer is active, and minibuffer-previous-line-*
vertically.

> But one immediate alternative is to use <LEFT> and <RIGHT> for
> the minibuffer-previous-* family, like previous-completion does.

<LEFT> and <RIGHT> are useful to move point in the minibuffer.
But do you think it would be okay to use <LEFT> and <RIGHT>
for navigation of completions from the minibuffer after
adding a new user option, when is non-nil (disabled by default)?