[POLL] [BUG] Inverse behavior from \ <space> [9.6.4 (release_9.6.4-1-g76cf21 @ /Users/johnw/.emacs.d/lisp/org-mode/lisp/)]

[Ihor Radchenko <yantar92@posteo.net>]

"John Wiegley" <johnw@gnu.org> writes:

> When I type ‘\ c’, the agenda view limits to my (c)all tags. This is what I
> expected to see.
>
> When I type ‘\ <space>’, however, it limits to every tag *but* the empty tag.
> This is the opposite of what I expect to see.

Confirmed.

In `org-agenda-filter-by-tag',

((or (eq char ?\s)
	  (setq a (rassoc char alist))
	  (and tag (setq a (cons tag nil))))
      (org-agenda-filter-show-all-tag)
      (setq tag (car a))
      (setq org-agenda-tag-filter
	    (cons (concat (if exclude "-" "+") tag)
		  (if accumulate current nil)))
      (org-agenda-filter-apply org-agenda-tag-filter 'tag expand))

"\ <space>" will call

(org-agenda-filter-make-matcher '("+") 'tag nil) ; => (and (or tags))

which matches entries with tags, not the entries without tags.

But <space> is actually not documented, so I am not sure if it is a bug.
I can see logic with <space> being "any tag" (it appears alongside other
tag shortcuts), and I can see logic with <space> being "no tag"
(consistent with `org-set-tags-command').

Changing the current behaviour will be a breaking change.

I am inclined to change the current behaviour and document it, unless
there are objections.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
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