bug#15302: calendar + diary + holidy => stacktrace.

[Jambunathan K]

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Case I: Stacktrace


1. .emacs for this bug

(setq debug-on-error t)
(custom-set-variables
 '(calendar-date-style (quote european))
 '(calendar-holidays
   (quote
    ((holiday-fixed 1 1 "New Year's Day")
     (holiday-fixed 1 26  "Republic Day")
     (holiday-fixed 8 15 "Independence Day")
     (holiday-fixed 10 2 "Gandhi Jayanthi")
     (holiday-fixed 12 25 "Christmas")
     (indian-holidays))))
 '(calendar-mark-diary-entries-flag t)
 '(calendar-mark-holidays-flag t)
 '(calendar-setup nil)
 '(calendar-today-visible-hook (quote (calendar-mark-today)))
 '(calendar-view-diary-initially-flag t)
 '(calendar-view-holidays-initially-flag t)
 '(diary-display-function (quote diary-fancy-display))
 '(diary-file "/home/kjambunathan/data/jambu.diary")
 '(diary-file-name-prefix nil)
 '(diary-file-name-prefix-function (quote file-name-base))
 '(diary-list-include-blanks t)
 '(diary-number-of-entries 7))

(add-hook 'diary-list-entries-hook 'diary-include-other-diary-files)
(add-hook 'diary-mark-entries-hook 'diary-mark-included-diary-files)

(defun indian-holidays ()
  '(;; ((1 14 2013) "Pongal")
    ;; ((1 15 2013) "Thiruvallar Day")
    ;; ((1 16 2013) "Uzhavar Thirunal")
    ;; ((1 25 2013) "Milad-Un Nabi")
    ;; ((3 29 2013) "Good Friday")
    ;; ((4 1 2013) "Annual Closing of Accounts")
    ;; ((4 11 2013) "Telugu New Year's Day")
    ;; ((4 14 2013) "Tamil New Year's Day")
    ;; ((4 24 2013) "Mahavir Jayanthi")
    ((5 1 2013) "May Day")              ; Comment this to avoid stacktrace
    ((8 9 2013) "Ramzan")
    ((8 28 2013) "Krishna Jayanthi")
    ((9 9 2013) "Vinayaka Chaturthi")
    ((9 30 2013) "Half-Yearly Closing of Accounts")
    ((10 13 2013) "Ayudha Puja")
    ((10 14 2013) "Vijaya Dasami")
    ((10 16 2013) "Bakrid")
    ((11 2 2013) "Deepavali")
    ((11 14 2013) "Muharram")))

2. Ensure that the `diary-file' exists but is empty.
3. ~/src/emacs/trunk/src/emacs --debug-init -Q -l ~/.emacs
4. M-x calendar
5. See the following stacktrace.

Debugger entered--Lisp error: (wrong-type-argument wholenump -60)
  move-to-column(-60)
  calendar-cursor-to-visible-date((5 1 2013))
  calendar-mark-visible-date((5 1 2013) holiday)
  calendar-mark-holidays()
  calendar-generate-window(9 2013)
  calendar-basic-setup(nil)
  calendar(nil)
  call-interactively(calendar record nil)
  command-execute(calendar record)
  execute-extended-command(nil "calendar")
  call-interactively(execute-extended-command nil nil)
  command-execute(execute-extended-command)

Note that the holidays include the May Day which is "outside" the
currently displayed months of Aug, Sep, Oct.  (This bug is filed on 8
Sep 2013)

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Case II: Wrong fontification


1. Modify the .emacs so that May Day holiday is commented out.
2. M-x calendar
3. Note that the holidays are displayed fine.
4. Note that the fontification is wrong.  i.e., the holiday face
   stretches beyond the calendar dates to the right edge of the window.

calendar-wrong-fontification.png
Description: PNG image

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Case III: Feature request


It is painful to create Indian Holidays within Emacs calendar.

1. Indian dates follow European style.  But the diary's canonical format
   is American.  =>  Cognitive Dissonance.

2. Indian holidays, except for state holidays cannot be algorithmically
   specified.  (Like N-th Sunday of M-th Month of C-th Calendar are
   something like that).  So, they fall on different English months and
   dates.  I don't think Emacs supports traditional Indian calendars.
   (I believe there are many of these with regional variations.)

   So I would much prefer that there be an easy way to create holiday
   entries right from the 3-month calendar by hand.

   I am thinking of something like ...

   A cross between holiday-fixed (holiday-fixed currently doesn't take
   an Year) and `i a' (for inserting anniversaries).  

   I would also appreciate if there be a way to add a reminder to the
   holiday entries.  If we need to go home for Deepavali, then we need
   to make our railway bookings atleast 3 months (IIRC) in advance
   because of holiday rush.