Bug in iCalendar export

[Nick Dokos <nicholas.dokos@hp.com>]

There seems to be a bug somewhere in org-export-icalendar code where the
*ical-tmp* buffer seems to get deleted prematurely, but  I can't figure out
where exactly, so I'm hoping that a) it's reproducible and b) somebody will
see what's wrong.

Versions:
---------

emacs: GNU Emacs 22.1.50.2 (i686-pc-linux-gnu, GTK+ Version 2.10.11) of 2007-11-23 on gamaville.dokosmarshall.org
org: Org-mode version 6.04b

Sample org file:
----------------

I just cut and pasted from the org manual:

---------------------------------------------------------------------------
* Birthdays and similar stuff
#+CATEGORY: Holiday
%%(org-calendar-holiday)   ; special function for holiday names
#+CATEGORY: Ann
%%(diary-anniversary 14  5 1956) Arthur Dent is %d years old
%%(diary-anniversary  2 10 1869) Mahatma Gandhi would be %d years old
---------------------------------------------------------------------------

Then I do M-x org-export-icalendar-this-file (or C-c C-e i) and I get the following
backtrace:

---------------------------------------------------------------------------
Debugger entered--Lisp error: (error "Selecting deleted buffer")
  set-buffer(#<killed buffer>)
  (save-current-buffer (set-buffer sexp-buffer) (insert sexp "\n"))
  (with-current-buffer sexp-buffer (insert sexp "\n"))
  (catch :skip (org-agenda-skip) (setq b (match-beginning 0)) (goto-char (1- ...)) (forward-sexp 1) (end-of-line 1) (setq sexp (buffer-substring b ...)) (with-current-buffer sexp-buffer (insert sexp "\n")) (princ (org-diary-to-ical-string sexp-buffer)))
  (while (re-search-forward "^&?%%(" nil t) (catch :skip (org-agenda-skip) (setq b ...) (goto-char ...) (forward-sexp 1) (end-of-line 1) (setq sexp ...) (with-current-buffer sexp-buffer ...) (princ ...)))
  (progn (goto-char (point-min)) (while (re-search-forward "^&?%%(" nil t) (catch :skip ... ... ... ... ... ... ... ...)))
  (if (and org-icalendar-include-sexps (condition-case nil ... ...) (fboundp ...)) (progn (goto-char ...) (while ... ...)))
  (when (and org-icalendar-include-sexps (condition-case nil ... ...) (fboundp ...)) (goto-char (point-min)) (while (re-search-forward "^&?%%(" nil t) (catch :skip ... ... ... ... ... ... ... ...)))
  (save-excursion (goto-char (point-min)) (while (re-search-forward re1 nil t) (catch :skip ... ... ... ... ... ... ... ... ... ... ... ...)) (when (and org-icalendar-include-sexps ... ...) (goto-char ...) (while ... ...)) (when org-icalendar-include-todo (setq prefix "TODO-") (goto-char ...) (while ... ...)))
  (let ((re1 ...) (re2 ...) (dts ...) hd ts ts2 state status (inc t) pos b sexp rrule scheduledp deadlinep prefix tmp pri category entry location summary desc uid (sexp-buffer ...)) (org-refresh-category-properties) (save-excursion (goto-char ...) (while ... ...) (when ... ... ...) (when org-icalendar-include-todo ... ... ...)))
  org-print-icalendar-entries(nil)
  (let ((standard-output ical-buffer)) (if combine (and ... ... ...) (org-start-icalendar-file category)) (org-print-icalendar-entries combine) (when (or ... ...) (org-finish-icalendar-file) (set-buffer ical-buffer) (save-buffer) (run-hooks ...) (and ... ... ...)))
  (catch (quote nextfile) (org-check-agenda-file file) (set-buffer (org-get-agenda-file-buffer file)) (unless combine (setq ical-file ...) (setq ical-buffer ...) (with-current-buffer ical-buffer ...)) (setq category (or org-category ...)) (if (symbolp category) (setq category ...)) (let (...) (if combine ... ...) (org-print-icalendar-entries combine) (when ... ... ... ... ... ...)))
  (while (setq file (pop files)) (catch (quote nextfile) (org-check-agenda-file file) (set-buffer ...) (unless combine ... ... ...) (setq category ...) (if ... ...) (let ... ... ... ...)))
  (let* ((dir ...) file ical-file ical-buffer category started org-agenda-new-buffers) (and (get-buffer "*ical-tmp*") (kill-buffer "*ical-tmp*")) (when combine (setq ical-file ... ical-buffer ...) (set-buffer ical-buffer) (erase-buffer)) (while (setq file ...) (catch ... ... ... ... ... ... ...)) (org-release-buffers org-agenda-new-buffers))
  (save-excursion (org-prepare-agenda-buffers files) (let* (... file ical-file ical-buffer category started org-agenda-new-buffers) (and ... ...) (when combine ... ... ...) (while ... ...) (org-release-buffers org-agenda-new-buffers)))
  org-export-icalendar(nil "/home/nick/lib/org/ical.org")
  org-export-icalendar-this-file()
  call-interactively(org-export-icalendar-this-file)
  (if (and bg (nth 2 ass)) (let (...) (set-process-sentinel p ...) (message "Background process \"%s\": started" p)) (call-interactively (nth 1 ass)))
  (let* ((bg ...) (help "[t]   insert the export option template\n[v]   limit export to visible part of outline tree\n\n[a] export as ASCII\n\n[h] export as HTML\n[H] export as HTML to temporary buffer\n[R] export region as HTML\n[b] export as HTML and browse immediately\n[x] export as XOXO\n\n[l] export as LaTeX\n[L] export as LaTeX to temporary buffer\n\n[i] export current file as iCalendar file\n[I] export all agenda files as iCalendar files\n[c] export agenda files into combined iCalendar file\n\n[F] publish current file\n[P] publish current project\n[X] publish... (project will be prompted for)\n[A] publish all projects") (cmds ...) r1 r2 ass) (save-window-excursion (delete-other-windows) (with-output-to-temp-buffer "*Org Export/Publishing Help*" ...) (message "Select command: ") (set
 q r1 ...)) (setq r2 (if ... ... r1)) (unless (setq ass ...) (error "No command associated with key %c" r1)) (if (and bg ...) (let ... ... ...) (call-interactively ...)))
  org-export(nil)
  call-interactively(org-export)
---------------------------------------------------------------------------


If there is only one %%(...) expression in the file, the export seems to work, but
with more than one, the error gets triggered.

If more information is needed, let me know: I'd be happy to supply it.

Thanks,
Nick