kcalendarcore/0001-ICalFormat-don-t-shift-all-day-invite-dates-to-UTC.patch

From e73b2e4863c589a8b152327ff7c45831d1d1b052 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Vr=C3=A1til?= <dvratil@kde.org>
Date: Fri, 13 Oct 2023 17:50:08 +0200
Subject: [PATCH] ICalFormat: don't shift all-day invite dates to UTC

When generating scheduling message for an event, the ICalFormat
checks whether the event is recurrent and if not it shifts the
start and end datetimes to UTC timezone (since recurring events
need TZ information for proper calculations across DSTs and TZs).

However if the event is an all-day event with start and end datetimes
in local time (e.g. Europe/Prague), this shift effectively moves
the start and end datetimes from midnight to -2 hours previous day.
Later on when writing the DTSTART and DTEND properties, the code
omits the time (since it's an all-day event) and only writes out
DATEs, but now the scheduling message is actually shifted one day
back!

This change extends the check in ICalFormat to also avoid shifting
dates to UTC when the event is an all-day event, since in this case
the timezone information is dropped anyway.

BUG: 421400
FIXED-IN: 5.112.0
(cherry picked from commit 921e04f64921e86288e57144c82dab2a1a0679b5)
---
 autotests/testicalformat.cpp | 24 ++++++++++++++++++++++++
 autotests/testicalformat.h   |  1 +
 src/icalformat.cpp           |  2 +-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/autotests/testicalformat.cpp b/autotests/testicalformat.cpp
index c8f3fddb3..54ba2c3cd 100644
--- a/autotests/testicalformat.cpp
+++ b/autotests/testicalformat.cpp
@@ -542,4 +542,28 @@ void ICalFormatTest::testNonTextCustomProperties()
     QCOMPARE(event->nonKDECustomProperty("X-APPLE-STRUCTURED-LOCATION"), QLatin1String("geo:52.063921,5.128511"));
 }
 
+void ICalFormatTest::testAllDaySchedulingMessage()
+{
+    auto event = KCalendarCore::Event::Ptr::create();
+    event->setSummary(QStringLiteral("All Day Event"));
+    event->setDtStart(QDateTime(QDate(2023, 10, 13), QTime(0, 0, 0), QTimeZone("Europe/Prague")));
+    event->setDtEnd(QDateTime(QDate(2023, 10, 15), QTime(0, 0, 0), QTimeZone("Europe/Prague")));
+    event->setOrganizer(Person(QStringLiteral("Dan"), QStringLiteral("dvratil@example.com")));
+    event->addAttendee(Attendee(QStringLiteral("Konqi"), QStringLiteral("konqi@example.com")));
+    event->setAllDay(true);
+
+    ICalFormat format;
+    auto calendar = MemoryCalendar::Ptr::create(QTimeZone::utc());
+    const auto itipString = format.createScheduleMessage(event, KCalendarCore::iTIPRequest);
+    QVERIFY(!itipString.isEmpty());
+
+    auto scheduleMsg = format.parseScheduleMessage(calendar, itipString);
+    QVERIFY(scheduleMsg->error().isEmpty());
+
+    auto parsedEvent = scheduleMsg->event().staticCast<KCalendarCore::Event>();
+    QVERIFY(parsedEvent);
+    QCOMPARE(parsedEvent->dtStart().date(), event->dtStart().date());
+    QCOMPARE(parsedEvent->dtEnd().date(), event->dtEnd().date());
+}
+
 #include "moc_testicalformat.cpp"
diff --git a/autotests/testicalformat.h b/autotests/testicalformat.h
index 14d86a56c..7c0423459 100644
--- a/autotests/testicalformat.h
+++ b/autotests/testicalformat.h
@@ -32,6 +32,7 @@ private Q_SLOTS:
     void testUidGenerationUniqueness();
     void testIcalFormat();
     void testNonTextCustomProperties();
+    void testAllDaySchedulingMessage();
 };
 
 #endif
diff --git a/src/icalformat.cpp b/src/icalformat.cpp
index 71fd91a19..72a35a0ad 100644
--- a/src/icalformat.cpp
+++ b/src/icalformat.cpp
@@ -436,7 +436,7 @@ QString ICalFormat::createScheduleMessage(const IncidenceBase::Ptr &incidence, i
 
         // Recurring events need timezone information to allow proper calculations
         // across timezones with different DST.
-        const bool useUtcTimes = !i->recurs();
+        const bool useUtcTimes = !i->recurs() && !i->allDay();
 
         const bool hasSchedulingId = (i->schedulingID() != i->uid());
 
-- 
2.42.0