[O] org-caldav problem: void-function url-http-options

[Julien Cubizolles]

Since a few days (maybe an emacs update) I get this error message
whenever I run org-caldav-sync. 

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (void-function url-http-options)
  url-http-options("https://www.google.com/calendar/dav/address@hidden/events/";)
  
url-dav-supported-p("https://www.google.com/calendar/dav/address@hidden/events/";)
  (or (and (boundp (quote url-dav-patched-version)) url-dav-patched-version) 
(url-dav-supported-p (org-caldav-events-url)))
  (if (or (and (boundp (quote url-dav-patched-version)) 
url-dav-patched-version) (url-dav-supported-p (org-caldav-events-url))) nil 
(error "You have to either use Emacs from bzr, or the patched `url-dav' package 
from the org-caldav repository."))
  org-caldav-sync()
  call-interactively(org-caldav-sync record nil)
  command-execute(org-caldav-sync record)
  execute-extended-command(nil "org-caldav-sync")
  call-interactively(execute-extended-command nil nil)
--8<---------------cut here---------------end--------------->8---

I've been digging around a bit and url-http-options is defined in
url-http.el which is present on my system
(/usr/share/emacs/24.3.50/lisp/url/url-http.el.gz) so I don't understand
why it isn't found (assuming that void-function message actually means
it can't find the definition of the function).

Everything was working fine with org-caldav before and I was very happy
with it. Thanks a lot to its developper.

Julien.