fix(calendar-sync): honor BYDAY rules and drop cancelled events

The expander ignored BYDAY on monthly and yearly rules and stepped DTSTART's day-of-month instead, so a "2nd Wednesday" series rendered on the 12th of every month, the wrong weekday most months. It now resolves nth-weekday entries (2WE, -1TU), bare weekdays with BYSETPOS, and yearly BYMONTH+BYDAY, so each occurrence lands on the day the rule names.

Nothing read the VEVENT STATUS property, so cancelled events rendered as normal meetings: a cancelled instance of a series reappeared at its original time, and standalone cancelled events stayed on the agenda. parse-event now drops STATUS:CANCELLED events, which also kills cancelled series masters. A cancelled RECURRENCE-ID override removes its occurrence instead of overriding it.

The fixes are coupled: until BYDAY generates the right dates, a cancelled override can't match the occurrence it removes.

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/test-calendar-sync--parse-event.el b/tests/test-calendar-sync--parse-event.el
index 9c343db2..b3f58ba2 100644
--- a/tests/test-calendar-sync--parse-event.el
+++ b/tests/test-calendar-sync--parse-event.el
@@ -78,5 +78,37 @@
   (let ((vevent "BEGIN:VEVENT\nSUMMARY:Orphan\nEND:VEVENT"))
     (should (null (calendar-sync--parse-event vevent)))))
 
+;;; STATUS:CANCELLED Cases
+
+(ert-deftest test-calendar-sync--parse-event-error-cancelled-returns-nil ()
+  "Error: a STATUS:CANCELLED event returns nil -- cancelled events don't render."
+  (let* ((start (test-calendar-sync-time-days-from-now 5 14 0))
+         (vevent (concat "BEGIN:VEVENT\n"
+                         "SUMMARY:Cancelled Meeting\n"
+                         "DTSTART:" (test-calendar-sync-ics-datetime start) "\n"
+                         "STATUS:CANCELLED\n"
+                         "END:VEVENT")))
+    (should (null (calendar-sync--parse-event vevent)))))
+
+(ert-deftest test-calendar-sync--parse-event-boundary-cancelled-case-insensitive ()
+  "Boundary: STATUS value matching is case-insensitive."
+  (let* ((start (test-calendar-sync-time-days-from-now 5 14 0))
+         (vevent (concat "BEGIN:VEVENT\n"
+                         "SUMMARY:Cancelled Meeting\n"
+                         "DTSTART:" (test-calendar-sync-ics-datetime start) "\n"
+                         "STATUS:Cancelled\n"
+                         "END:VEVENT")))
+    (should (null (calendar-sync--parse-event vevent)))))
+
+(ert-deftest test-calendar-sync--parse-event-normal-confirmed-still-parses ()
+  "Normal: STATUS:CONFIRMED events still parse."
+  (let* ((start (test-calendar-sync-time-days-from-now 5 14 0))
+         (vevent (concat "BEGIN:VEVENT\n"
+                         "SUMMARY:Confirmed Meeting\n"
+                         "DTSTART:" (test-calendar-sync-ics-datetime start) "\n"
+                         "STATUS:CONFIRMED\n"
+                         "END:VEVENT")))
+    (should (calendar-sync--parse-event vevent))))
+
 (provide 'test-calendar-sync--parse-event)
 ;;; test-calendar-sync--parse-event.el ends here