Re: [O] "S:" prefix when syncing via CalDAV

[John Morrissey]

On Sun, Jul 23, 2017 at 01:38:23PM +0200, Nicolas Goaziou wrote:
> John Morrissey <address@hidden> writes:
> 
> > I'm syncing to Nextcloud via CalDAV with org-mode 9.0.3 and the latest
> > org-caldav.
> >
> > Events are sometimes synced (and modified in the .org file) with the
> > prefix "S:". The symptoms are exactly like:
> >
> >   https://github.com/dengste/org-caldav/issues/33#issuecomment-74551937
> >
> >   "The SCHEDULED time gets converted to an active timestamp and a
> >   freshly created property drawer with a new id is inserted above that
> >   newly created active timestamp."
> >
> > It looks like this prefix is being prepended by org-icalendar-entry in
> > ox-icalendar, but I don't know enough about Lisp or org internals to
> > debug much further.
> >
> > Here are my org-{icalendar,caldav} settings:
> >
> >   (setq org-icalendar-alarm-time 30)
> >   (setq org-icalendar-use-deadline '(event-if-todo event-if-not-todo 
> > todo-due)
> >         org-icalendar-use-scheduled '(event-if-todo event-if-not-todo 
> > todo-start))
> >   (setq org-export-exclude-category (list "dummy"))
> >
> >   (setq org-caldav-inbox (expand-file-name "~/org/caldav-inbox.org"))
> >   (setq org-caldav-files org-agenda-files)
> >   (setq org-caldav-show-sync-results nil)
> >   (setq org-caldav-resume-aborted 'never)
> >
> > Is there some configuration I need to change to stop this behavior?
> 
> Since "org-caldav.el" is not distributed with Org mode, I need to
> understand what part of the problem is specifically related to
> "ox-icalendar.el".
> 
> Could you show an example demonstrating why the generated ".ics" file is
> not correct, and what should be done instead?

Hi Nicolas, the behavior I'm observing isn't so much that the .ics is
incorrect. Instead, it's what happens to the corresponding item in the
org file.

For example, an entry that looks like:

* TODO do a thing
  SCHEDULED: <2017-07-24 Mon>
  :PROPERTIES:
  :ID:       03fe6016-6373-450f-aa31-e8403a573c49
  :END:

turns into:

* TODO S: call european motorsports
  :PROPERTIES:
  :ID:       ca7ecc02-0c67-4c22-ad6c-9c06e6d19e9a
  :END:
  <2017-07-24 Mon>
  :PROPERTIES:
  :ID:       03fe6016-6373-450f-aa31-e8403a573c49
  :END:

"S:" is prepended, the scheduled timestamp is replaced by an active
timestamp, and an additional properties drawer is created with a different
ID. This happens with deadline items, too.

This usually happens around the time of the scheduled/deadline timestamp, so
an item can sync just fine until sometime around the scheduled date, then
this transformation happens. It doesn't seem to happen at any fixed point
relative to the scheduled/deadline timestamp. Sometimes several CalDAV syncs
will happen on the day of the timestamp before one sync finally triggers(?)
the transformation. Does that make sense?

I don't know much Lisp or org internals, so I'm not entirely sure where this
is happening. The only reference point I could find in the code is in
ox-icalendar where it inserts the "S:" prefix, which happens concurrently
with the other org item transformations I mentioned above.

-john