RE: Mix of completing-read and read-string

[Drew Adams]

>>   (let ((minibuffer-local-completion-map
>>          minibuffer-local-completion-map))
>
> (copy-keymap minibuffer-local-completion-map) would be safer, eh?


This is probably the best approach; it is used in Emacs sources:

(let ((minibuffer-local-completion-map
       (let ((map  (make-sparse-keymap)))
         (set-keymap-parent map minibuffer-local-completion-map)
         (define-key map " " 'self-insert-command)
         (define-key map "?" 'self-insert-command)
         map)))
  (completing-read ...))