Re: [ISSUE] links navigation not consistent behavior

[Nick Dokos <ndokos@gmail.com>]

Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:

> Hello,
>
> stardiviner <numbchild@gmail.com> writes:
>
>> For example, I have following Org content:
>>
>> #+begin_src org ,*** TODO Figwheel [0/1]
>>
>> - [ ] https://www.youtube.com/watch?v=yUTxm29fjT4 :: I built a
>>   Figwheel-inspired, hot code reloading experience for Clojure,
>>   with an eye towards #datascience hacking.
>>
>> ,*** TODO Docker ClojureScript [0/3]
>>
>> - [ ] https://www.youtube.com/watch?v=yUTxm29fjT4 #+end_src
>>
>> When my point at beginning of buffer, then press {{{kbd(C-c C-x
>> C-n)}}} , it does not jump to first link, it jump to second link
>> instead. But when I jump backwards with {{{kbd(C-c C-x C-p)}}}
>> works fine.
>
> I rewrote this functions some weeks ago. Please try again on master.
>

I can reproduce the problem with very recent org. I did some debugging
and here are my notes:


,----
| I can reproduce this and traced it to this code:
| 
| ,----
| |     (catch :found
| |       (while (funcall search-fun org-link-any-re nil t)
| | 	(pcase (org-element-lineage (org-element-context) '(link) t) 	;;; <<<<< HERE
| | 	  (`nil nil) (link
| | 	   (goto-char (org-element-property :begin link)) (when
| | 	   (org-invisible-p) (org-show-context)) (throw :found t))))
| `----
| 
| which is a rewrite of org-next-link in commit 4ff8947ea8.
| 
| There is some asymmetry in how forward and backward searches behave:
| 
|  - in the forward case, the search ends up at the end of the first
|    link where `org-element-lineage' returns nil, so the loop repeats;
|    we then end up at the end of the second link where
|    `org-element-lineage' returns the link, we go to the beginning of
|    the link and return.
| 
|  - in the backward case, we end up at the beginning of each link in
|    turn, in which case `org-element-lineage' returns a link, so both
|    links are found.
| 
| So it may be that `org-element-context' should return a structure with
| the link included when called at the end of the first link or it may
| be that the search should back up one char in the forward case, before
| calling org-context.
`----

This may be wrong but I did not have time to continue with it: I hope it's
useful.

-- 
Nick

"There are only two hard problems in computer science: cache
invalidation, naming things, and off-by-one errors." -Martin Fowler