bug#29116: 24.5; Parsing dates from VCAL

bug#29116: 24.5; Parsing dates from VCAL

[Vegard Vesterheim]

I received an email containing a VCAL attachment which Gnus is unable to
render, the error in the minibuffer says:

  Wrong type argument: char-or-string-p, nil

The VCAL-attachment contains this:

    DTSTART;VALUE=DATE:20171208

The spec for DTSTART states that the value type for DTSTART can be
either DATE-TIME or DATE, so this seems like a valid format, so I am
inclined to think that this is a bug in emacs.

Here is the backtrace (parameters removed 
  timezone-make-arpa-date(2000 0 0 "01:00:00" (3600 "CET"))
  timezone-make-date-arpa-standard("20171208" nil nil)
  gnus-icalendar-event--decode-datefield(...)
  gnus-icalendar-event-from-ical(...)
  gnus-icalendar-event-from-buffer(...)
  gnus-icalendar-event-from-handle(...)
  gnus-icalendar-mm-inline(...)
  mm-display-inline(...)
  mm-display-part(...)
  gnus-mime-display-alternative(...)
  gnus-mime-display-part(..)
  gnus-display-mime()
  gnus-article-prepare-display()
  gnus-article-prepare(94599 nil)
  gnus-summary-display-article(94599)
  gnus-summary-next-article(nil)

Looking at the backtrace it seems that the problem is related to parsing
the date string: "20171208".

bug#29116: 24.5; Parsing dates from VCAL

[Robert Pluim]

Vegard Vesterheim <vegard.vesterheim@uninett.no> writes:

> I received an email containing a VCAL attachment which Gnus is unable to
> render, the error in the minibuffer says:
>
>   Wrong type argument: char-or-string-p, nil
>
> The VCAL-attachment contains this:
>
>     DTSTART;VALUE=DATE:20171208
>
> The spec for DTSTART states that the value type for DTSTART can be
> either DATE-TIME or DATE, so this seems like a valid format, so I am
> inclined to think that this is a bug in emacs.

Yes, it's allowed, but annoying.

> Here is the backtrace (parameters removed 
>   timezone-make-arpa-date(2000 0 0 "01:00:00" (3600 "CET"))
>   timezone-make-date-arpa-standard("20171208" nil nil)
>   gnus-icalendar-event--decode-datefield(...)
>   gnus-icalendar-event-from-ical(...)
>   gnus-icalendar-event-from-buffer(...)
>   gnus-icalendar-event-from-handle(...)
>   gnus-icalendar-mm-inline(...)
>   mm-display-inline(...)
>   mm-display-part(...)
>   gnus-mime-display-alternative(...)
>   gnus-mime-display-part(..)
>   gnus-display-mime()
>   gnus-article-prepare-display()
>   gnus-article-prepare(94599 nil)
>   gnus-summary-display-article(94599)
>   gnus-summary-next-article(nil)
>
> Looking at the backtrace it seems that the problem is related to parsing
> the date string: "20171208".

timezone-parse-date assumes that the time-of-day is present in the
string to be parsed, which is not the case here. Looking at the code
icalendar should set the time to "00000" in that case. Would you have
a complete example VCAL file?

Thanks

Robert

bug#29116: 24.5; Parsing dates from VCAL

[Vegard Vesterheim]

[-- Attachment #1: Type: text/plain, Size: 500 bytes --]

On Sun, 05 Nov 2017 11:19:08 +0100 Robert Pluim <rpluim@gmail.com> wrote:

> Vegard Vesterheim <vegard.vesterheim@uninett.no> writes:
>> Looking at the backtrace it seems that the problem is related to parsing
>> the date string: "20171208".
>
> timezone-parse-date assumes that the time-of-day is present in the
> string to be parsed, which is not the case here. Looking at the code
> icalendar should set the time to "00000" in that case. Would you have
> a complete example VCAL file?

Attached:


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: cal.ical --]
[-- Type: text/x-vcalendar, Size: 1264 bytes --]

BEGIN:VCALENDAR
METHOD:REQUEST
PRODID:Microsoft Exchange Server 2010
VERSION:2.0
BEGIN:VTIMEZONE
TZID:W. Europe Standard Time
BEGIN:STANDARD
DTSTART:16010101T030000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=10
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:16010101T020000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;INTERVAL=1;BYDAY=-1SU;BYMONTH=3
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=NEEDS-ACTION;RSVP=TRUE;CN=Vegard Ves
 terheim:MAILTO:vegard.vesterheim@uninett.no
DESCRIPTION;LANGUAGE=en-US:Meeting description
 SUMMARY;LANGUAGE=en-US:Re-certification
DTSTART;VALUE=DATE:20171208
DTEND;VALUE=DATE:20171209
UID:040000008200E00074C5B7101A82E00800000000434E72372153D301000000000000000
 010000000B8E13E691E414545A6B9D006B49136EC
CLASS:PUBLIC
PRIORITY:5
DTSTAMP:20171101T145345Z
TRANSP:OPAQUE
STATUS:CONFIRMED
SEQUENCE:0
LOCATION;LANGUAGE=en-US:UNINETT 5.etg Perl [vbro.no/Perl] (260.502)
X-MICROSOFT-CDO-APPT-SEQUENCE:0
X-MICROSOFT-CDO-OWNERAPPTID:2115701571
X-MICROSOFT-CDO-BUSYSTATUS:TENTATIVE
X-MICROSOFT-CDO-INTENDEDSTATUS:BUSY
X-MICROSOFT-CDO-ALLDAYEVENT:TRUE
X-MICROSOFT-CDO-IMPORTANCE:1
X-MICROSOFT-CDO-INSTTYPE:0
X-MICROSOFT-DISALLOW-COUNTER:FALSE
END:VEVENT
END:VCALENDAR

[-- Attachment #3: Type: text/plain, Size: 680 bytes --]


My naive workaraound for this bug was to modify the function
gnus-icalendar-event--decode-datafile:

(defun gnus-icalendar-event--decode-datefield (ical field)
  (let* ((date (icalendar--get-event-property ical field))
         (date-props (icalendar--get-event-property-attributes ical field))
         (tz (plist-get date-props 'TZID)))

    ;; VVWASHERE-start, fix bug in parsing DATE
    (and (eq (car date-props) 'VALUE)
         (string= (car (cdr date-props)) "DATE")
         (setq date (concat date "T00:00")))
    ;; VVWASHERE-end, fix bug in parsing DATE
    
    (cdr date-props)
    (date-to-time (timezone-make-date-arpa-standard date nil tz))))


-- 
- Vegard V -

bug#29116: 24.5; Parsing dates from VCAL

[Robert Pluim]

Vegard Vesterheim <vegard.vesterheim@uninett.no> writes:

> On Sun, 05 Nov 2017 11:19:08 +0100 Robert Pluim <rpluim@gmail.com> wrote:
>
>> Vegard Vesterheim <vegard.vesterheim@uninett.no> writes:
>>> Looking at the backtrace it seems that the problem is related to parsing
>>> the date string: "20171208".
>>
>> timezone-parse-date assumes that the time-of-day is present in the
>> string to be parsed, which is not the case here. Looking at the code
>> icalendar should set the time to "00000" in that case. Would you have
>> a complete example VCAL file?
>
> Attached:
>

Thanks for that.

> My naive workaraound for this bug was to modify the function
> gnus-icalendar-event--decode-datafile:
>
> (defun gnus-icalendar-event--decode-datefield (ical field)
>   (let* ((date (icalendar--get-event-property ical field))
>          (date-props (icalendar--get-event-property-attributes ical field))
>          (tz (plist-get date-props 'TZID)))
>
>     ;; VVWASHERE-start, fix bug in parsing DATE
>     (and (eq (car date-props) 'VALUE)
>          (string= (car (cdr date-props)) "DATE")
>          (setq date (concat date "T00:00")))
>     ;; VVWASHERE-end, fix bug in parsing DATE
>

I thought the spec called for T000000, but if it's working for you,
then leave well enough alone.

>     (cdr date-props)
>     (date-to-time (timezone-make-date-arpa-standard date nil tz))))

Duh, I've been looking at the wrong branch. This looks like it was
fixed by 417cf67485, which is available in the 25.1 release or later.

Robert

bug#29116: 24.5; Parsing dates from VCAL

[Vegard Vesterheim]

On Mon, 06 Nov 2017 11:01:32 +0100 Robert Pluim <rpluim@gmail.com> wrote:

> Duh, I've been looking at the wrong branch. This looks like it was
> fixed by 417cf67485, which is available in the 25.1 release or later.

Thanks for looking into this. Case closed.

For now, I guess I'll just wrap my workaround with a
  (if version< emacs-version "25.1")

-- 
- Vegard V -

bug#29116: 24.5; Parsing dates from VCAL

[Robert Pluim]

Vegard Vesterheim <vegard.vesterheim@uninett.no> writes:

> On Mon, 06 Nov 2017 11:01:32 +0100 Robert Pluim <rpluim@gmail.com> wrote:
>
>> Duh, I've been looking at the wrong branch. This looks like it was
>> fixed by 417cf67485, which is available in the 25.1 release or later.
>
> Thanks for looking into this. Case closed.
>

Closing, thanks.

Robert