Re: completion-regexp-list and case-fold-search

[Richard Stallman]

      Whether something is a valid completion for
    the minibuffer completion functions has nothing to do with whether the
    user prefers _interactive regexp searches_ to be case-sensitive or
    not.  Hence, `case-fold-search' should be bound around all calls to
    `{try,test}-completion' and `all-completions'.

I agree.

    2.  More radically, make `{try,test}-completion' and `all-completions'
        _themselves_ bind `case-fold-search' to the value of
        `completion-ignore-case', thereby effectively making the
        case-sensitivity of `completion-regexp-list' entirely determined
        by `completion-ignore-case'.

I think that is the correct fix.

    1.  Make all the basic minibuffer completion functions bind
        `case-fold-search' to the value of `completion-ignore-case' around
        all calls to `{try,test}-completion' and `all-completions', as
        `partial-completion-mode' already does.

That would be incorrect, since it would distort the behavior
of many user commands in the minibuffer.

    Do we want to go for (1) or (2)?  With (1) we are absolutely certain
    that we do not break any code that was not already broken.  (Because
    all we do is make both values of `partial-completion-mode' consistent.)

Are you saying that partial-completion-mode does something analogous
to #1?  If so, I think that is a bug, and we should replace that
with something analogous to #2.

Would you like to do that?