bug#56613: 29; minibuffer-complete-history throws an error for minibuffer-history-variable=t

[Juri Linkov]

> In order to disable sorting from the side of the completion table, it is
> better to use the completion metadata. This way the sort function will
> also be picked up by all the alternative completion UIs.
>
> (completion-in-region
>  (minibuffer--completion-prompt-end) (point-max)
>  (lambda (str pred action)
>    (if (eq action 'metadata)
>        '(metadata (display-sort-function . identity)
>                   (cycle-sort-function . identity))
>      (complete-with-action action completions str pred))))

Thanks for the suggestion, now fixed as well.

Stefan added this comment in minibuffer-complete-history:

    ;; FIXME: Can we make it work for CRM?

But I can't find a function that would return the
current completion boundaries to use instead of hard-coding
minibuffer--completion-prompt-end and point-max.  Then
completing-read-multiple should set locally such a function
that will use crm-separator and return a cons (BEG . END).