From 1a0baa3f36e8dd6992f19172a6b267300c7f6be9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tom=20Mittelst=C3=A4dt?= <1358-github@monster-box.de>
Date: Wed, 2 Sep 2026 07:32:26 +0200
Subject: [PATCH] Filter cancelled events out of remote_calendar (#180949)

Co-authored-by: 1358 <1583407+1358@users.noreply.github.com>
---
 .../components/remote_calendar/calendar.py    |  24 +++-
 .../remote_calendar/test_calendar.py          | 106 ++++++++++++++++++
 2 files changed, 127 insertions(+), 3 deletions(-)

diff --git a/homeassistant/components/remote_calendar/calendar.py b/homeassistant/components/remote_calendar/calendar.py
index 7273bf345e8d..30cdd57e303b 100644
--- a/homeassistant/components/remote_calendar/calendar.py
+++ b/homeassistant/components/remote_calendar/calendar.py
@@ -4,7 +4,7 @@ from datetime import datetime, timedelta
 import logging
 from typing import override
 
-from ical.event import Event
+from ical.event import Event, EventStatus
 from ical.timeline import Timeline, materialize_timeline
 
 from homeassistant.components.calendar import CalendarEntity, CalendarEvent
@@ -67,7 +67,11 @@ class RemoteCalendarEntity(
         if self._timeline is None:
             return None
         now = dt_util.now()
-        events = self._timeline.active_after(now)
+        events = (
+            event
+            for event in self._timeline.active_after(now)
+            if not _is_cancelled(event)
+        )
         if event := next(events, None):
             return _get_calendar_event(event)
         return None
@@ -84,7 +88,11 @@ class RemoteCalendarEntity(
                 start_date,
                 end_date,
             )
-            return [_get_calendar_event(event) for event in events]
+            return [
+                _get_calendar_event(event)
+                for event in events
+                if not _is_cancelled(event)
+            ]
 
         return await self.hass.async_add_executor_job(events_in_range)
 
@@ -132,6 +140,16 @@ class RemoteCalendarEntity(
         self.async_write_ha_state()
 
 
+def _is_cancelled(event: Event) -> bool:
+    """Return whether an event has been called off.
+
+    rfc5545 keeps a cancelled event in the calendar rather than deleting it, so
+    a remote calendar can serve one. A calendar entity does not return such
+    events.
+    """
+    return event.status == EventStatus.CANCELLED
+
+
 def _get_calendar_event(event: Event) -> CalendarEvent:
     """Return a CalendarEvent from an API event."""
 
diff --git a/tests/components/remote_calendar/test_calendar.py b/tests/components/remote_calendar/test_calendar.py
index 2cc9b8adac18..954b43e67b7c 100644
--- a/tests/components/remote_calendar/test_calendar.py
+++ b/tests/components/remote_calendar/test_calendar.py
@@ -213,6 +213,112 @@ async def test_api_date_event(
     assert len(events) == 1
 
 
+CANCELLED_EVENT_ICS = textwrap.dedent(
+    """\
+    BEGIN:VCALENDAR
+    VERSION:2.0
+    BEGIN:VEVENT
+    SUMMARY:Festival International de Jazz de Montreal
+    LOCATION:Montreal
+    DTSTART:20070628
+    DTEND:20070709
+    STATUS:CANCELLED
+    END:VEVENT
+    END:VCALENDAR
+    """
+)
+
+
+@respx.mock
+async def test_cancelled_event_is_not_returned(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    get_events: GetEventsFn,
+) -> None:
+    """Test that an event called off is not returned by the API."""
+    respx.get(CALENDER_URL).mock(
+        return_value=Response(status_code=200, text=CANCELLED_EVENT_ICS)
+    )
+    await setup_integration(hass, config_entry)
+
+    events = await get_events("2007-06-28T00:00:00Z", "2007-07-10T00:00:00Z")
+
+    assert events == []
+
+
+@pytest.mark.freeze_time(datetime(2007, 6, 28, 12))
+@respx.mock
+async def test_cancelled_event_does_not_turn_the_entity_on(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+) -> None:
+    """Test that an event called off is not picked up as the current event.
+
+    The event would be active at this time were it not cancelled, so this
+    covers the state path rather than the API one.
+    """
+    respx.get(CALENDER_URL).mock(
+        return_value=Response(status_code=200, text=CANCELLED_EVENT_ICS)
+    )
+    await setup_integration(hass, config_entry)
+
+    state = hass.states.get(TEST_ENTITY)
+    assert state
+    assert state.state == STATE_OFF
+
+
+CANCELLED_OCCURRENCE_ICS = textwrap.dedent(
+    """\
+    BEGIN:VCALENDAR
+    VERSION:2.0
+    BEGIN:VEVENT
+    SUMMARY:Daily series
+    UID:daily-series
+    DTSTART;VALUE=DATE:20261002
+    DTEND;VALUE=DATE:20261003
+    RRULE:FREQ=DAILY;COUNT=5
+    STATUS:CONFIRMED
+    END:VEVENT
+    BEGIN:VEVENT
+    SUMMARY:Daily series
+    UID:daily-series
+    RECURRENCE-ID;VALUE=DATE:20261003
+    DTSTART;VALUE=DATE:20261003
+    DTEND;VALUE=DATE:20261004
+    STATUS:CANCELLED
+    END:VEVENT
+    END:VCALENDAR
+    """
+)
+
+
+@respx.mock
+async def test_cancelled_occurrence_of_a_series_is_not_returned(
+    hass: HomeAssistant,
+    config_entry: MockConfigEntry,
+    get_events: GetEventsFn,
+) -> None:
+    """Test that only the cancelled occurrence of a recurring series is dropped.
+
+    The filtering has to happen after the series is expanded: dropping the
+    cancelled VEVENT before expansion would remove the override, and the RRULE
+    would then produce that day as an ordinary event again.
+    """
+    respx.get(CALENDER_URL).mock(
+        return_value=Response(status_code=200, text=CANCELLED_OCCURRENCE_ICS)
+    )
+    await setup_integration(hass, config_entry)
+
+    events = await get_events("2026-10-01T00:00:00Z", "2026-10-08T00:00:00Z")
+
+    assert [event["start"] for event in events] == [
+        {"date": "2026-10-02"},
+        {"date": "2026-10-04"},
+        {"date": "2026-10-05"},
+        {"date": "2026-10-06"},
+    ]
+
+
 @pytest.mark.freeze_time(datetime(2007, 6, 28, 12))
 @respx.mock
 async def test_active_event(