bug#47012: xref copies keymap properties to minibuffer

[Juri Linkov]

>> Sharing regexp history between grep and project-find-regexp would be
>> the most desirable.  How better to achieve this?
>
> Either by using 'grep-regexp-history directly, or with either of the
> options below.
>
>> Some commands already use variable *-history-variable, so adding
>> project-regexp-history-variable wouldn't cause a new precedent.
>
> Could you give an example?

What I tried is C-h v *-history-variable TAB

  minibuffer-history-variable
  query-replace-from-history-variable
  query-replace-to-history-variable
  y-or-n-p-history-variable

Maybe other commands use another suffix (probably not).

> And ideally, we should be also able to answer the question why some
> packages have their own variables, and others have "-variable variables".

I don't know.

> If it's just historical reasons, as it often is, maybe
>
>   (defvar project-regexp-history-variable 'grep-regexp-history)
>
> will be good enough.

This would a good thing to do.

>> Whereas using defalias is something new, maybe it could work too:
>>    (defalias 'grep-regexp-history 'project-regexp-history)
>
> Yup, that's what I meant. It does feel a bit hackish, though.
>
> Another possible approach would be some categories based system, together
> with user customization, like completion-category-overrides, but it's
> probably overkill for this problem.

I agree on both these statements.