Re: Possibly Bug in function org-scan-tags

[Nick Dokos <nicholas.dokos@hp.com>]

bala mayam <balamayam@gmail.com> wrote:

> The patch has error, it does not work for the following example file
> /tmp/example.org
> * DONE s1
> * DONE s2
> * DONE s3
> 
> The below patch works for all the cases
> 
> diff --git a/lisp/org.el b/lisp/org.el
> index 8a1fbd3..93d603f 100644
> --- a/lisp/org.el
> +++ b/lisp/org.el
> @@ -12858,7 +12858,8 @@ only lines with a TODO keyword are included in the outpu
>         ;; Get the correct position from where to continue
>         (if org-map-continue-from
>             (goto-char org-map-continue-from)
> -         (and (= (point) lspos) (end-of-line 1)))))
> +         (and (= (point) lspos) (end-of-line 1)))
> +       (setq org-map-continue-from nil)))
>      (when (and (eq action 'sparse-tree)
>                (not org-sparse-tree-open-archived-trees))
>        (org-hide-archived-subtrees (point-min) (point-max)))
> 

OK, I've looked at it some more and unless I'm mistaken again, I think
you are correct that it is a bug. Here's the structure of the relevant
code in org-scan-tags:

     ...
     (while (re-search-forward re nil t)
	(catch :skip
	   ...
	   (when ...
	      (cond
	         ((eq action 'sparse-tree)
		  ... do the sparse-tree stuff...)

		 ((eq action 'agenda)
		  ... do the agenda stuff ...)

		 ((functionp action)   ; user provided a function - the case here
                  (setq org-map-continue-from nil)
	          (save-excursion
		  	(setq rtn1 (funcall action))
			(push rtn1 rtn)))

		 (t (error "Invalid action")))

	      ... stuff after the cond ...
           ) ; closes the when form
	) ; closes the catch

	;; Get the correct position from where to continue
	(if org-map-continue-from
	    (goto-char org-map-continue-from)
	  (and (= (point) lspos) (end-of-line 1)))
    ) ; closes the while

    ...

So in the case of a user-supplied action, org-map-continue-from is
initialized to nil and then the function is called. The function (as in
your case) may modify org-map-continue-from which is then used at the
end of the while loop (and not reset to nil, as you observed, so next
time around, it will be non-nil even if we don't go through the
user-provided action).

I would fix it by pulling the (setq org-map-continue-from nil) from just
before the calling of the function all the way out to the top of the loop,
instead of adding another one at the end as you did, but that's a minor
point.

Nick