* lisp/org-pcomplete.el (org-thing-at-point): Only complete where tags
could be located.
(pcomplete/org-mode/tag): Add paring argument to avoid looking at
other arguments on the same line.
* testing/lisp/test-org-pcomplete.el (test-org-pcomplete/tag): New test.
Reported-by: Alain.Cochard@unistra.fr
<http://lists.gnu.org/r/emacs-orgmode/2018-11/msg00154.html>