Re: [Emacs-diffs] emacs-25 d7084f2: Fix todo-mode use of minibuffer completion keymap (bug#23695).

[Stefan Monnier]

>>> -  (let ((map minibuffer-local-completion-map))
>>> -    (define-key map " " nil)
>>> +  (let ((minibuffer-local-completion-map
>>> +         (copy-keymap minibuffer-local-completion-map)))
>>> +    (define-key minibuffer-local-completion-map " " 'self-insert-command)
>> Why bind it to `self-insert-command` rather than to nil?
> Is that a general recommendation,
> e.g. to make the `?' key insert `?' in the minibuffer also bind it to
> nil?

The question is: do you want to hide the "SPC is completion" binding, or
do you want to force SPC to insert a space.

> I guess that answers the question.)

Right, IMO what we want here is to hide the "SPC is completion" binding.
Also, the old code used nil (as can be seen in the chunk of patch still
quoted above).

> Are you saying it is generally better to use the latter?

Yes, it's more efficient.

> If so, when is it better to use the former?

Never.  Copying is a bad idea.


        Stefan