Re: bug#17545: 24.4.50; icomplete conflicts with minibuffer default

[Slawomir Nowaczyk <Slawomir.Nowaczyk@hh.se>]

On Sun, 17 May 2015 04:07:07 +0300
Dmitry Gutov <dgutov@yandex.ru> wrote:

> On 05/16/2015 05:23 PM, Stefan Monnier wrote:
> >> It seems the easiest way to resolve this is to always make the default
> >> the first item, even when it's not in the collection passed to
> >> `completing-read'.
> >
> > But if the user hit C-., that should change the default.
> 
> Why? Suppose I've pressed C-. a few times, didn't find what I wanted, typed a few chars (didn't find what I wanted there either), erased them, then resigned to my fate and pressed RET. Why would the end selection be the result of those random C-. presses, rather than the default specified by the caller?

How is emacs to know if the user has "resigned to his fate" or "found
the item he wants"?

> On the other hand, we could even call the complaint that started this bug "working as intended". Because C-j is bound to minibuffer-force-complete-and-exit, and its docstring promises it will use the first of the matches. The default isn't even mentioned (the current implementation is against the spec in this regard).

Current behaviour definitely doesn't agree with the spec. Whether it's
"working as intended" I don't know -- but I definitely don't like it.

> But if we wanted to keep that behavior, we could devise a more direct way for a completing-read-function to tell minibuffer that some input has been performed. (eq (minibuffer-prompt-end) (point-max)) apparently doesn't cut it.

I agree.

> Or rather whether any completions are visible. Because if icomplete-show-matches-on-no-input is non-nil, it would be harder to justify using the default instead of the first completion in minibuffer-force-complete-and-exit, even if the user hasn't made any other input.

FWIW, my current workaround is:
  (define-key icomplete-minibuffer-map (kbd "C-.") (lambda () "" (interactive) (progn (setq minibuffer-default nil) (icomplete-forward-completions))))
This is very ugly, but does what I want it to do.

-- 
 Best wishes,
   Slawomir Nowaczyk
     ( Slawomir.Nowaczyk@hh.se )

A hundred thousand lemmings can't be wrong.  -- famous last words