From 5b5b542f2f98e3113b06dcfc6de60103734362c6 Mon Sep 17 00:00:00 2001
From: Conrad Hoffmann <ch@bitfehler.net>
Date: Thu, 1 Feb 2024 14:05:49 +0100
Subject: [PATCH] caldav: fix match on open time ranges

Matches on open time ranges (i.e. no end date) were not properly
handled, as `end` is simply the zero time, which confuses the
`.Before()` and `.After()` logic employed here.

This commit fixes that by adding the appropriate `.IsZero()` checks and
also adds a test case.

The current behavior unfortunately broke compatibility with DAVx5, which
by default queries only events less than 90 days ago (by using an open
time range).
---
 caldav/match.go      | 11 ++++-------
 caldav/match_test.go | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/caldav/match.go b/caldav/match.go
index 948b33c..459a663 100644
--- a/caldav/match.go
+++ b/caldav/match.go
@@ -138,7 +138,6 @@ func matchCompTimeRange(start, end time.Time, comp *ical.Component) (bool, error
 		return len(rset.Between(start, end, true)) > 0, nil
 	}
 
-	// TODO handle "infinity" values in query
 	// TODO handle more than just events
 	if comp.Name != ical.CompEvent {
 		return false, nil
@@ -155,15 +154,15 @@ func matchCompTimeRange(start, end time.Time, comp *ical.Component) (bool, error
 	}
 
 	// Event starts in time range
-	if eventStart.After(start) && eventStart.Before(end) {
+	if eventStart.After(start) && (end.IsZero() || eventStart.Before(end)) {
 		return true, nil
 	}
 	// Event ends in time range
-	if eventEnd.After(start) && eventEnd.Before(end) {
+	if eventEnd.After(start) && (end.IsZero() || eventEnd.Before(end)) {
 		return true, nil
 	}
 	// Event covers entire time range plus some
-	if eventStart.Before(start) && eventEnd.After(end) {
+	if eventStart.Before(start) && (!end.IsZero() && eventEnd.After(end)) {
 		return true, nil
 	}
 	return false, nil
@@ -172,13 +171,11 @@ func matchCompTimeRange(start, end time.Time, comp *ical.Component) (bool, error
 func matchPropTimeRange(start, end time.Time, field *ical.Prop) (bool, error) {
 	// See https://datatracker.ietf.org/doc/html/rfc4791#section-9.9
 
-	// TODO handle "infinity" values in query
-
 	ptime, err := field.DateTime(start.Location())
 	if err != nil {
 		return false, err
 	}
-	if ptime.After(start) && ptime.Before(end) {
+	if ptime.After(start) && (end.IsZero() || ptime.Before(end)) {
 		return true, nil
 	}
 	return false, nil
diff --git a/caldav/match_test.go b/caldav/match_test.go
index 73114bb..79e5095 100644
--- a/caldav/match_test.go
+++ b/caldav/match_test.go
@@ -209,6 +209,23 @@ END:VCALENDAR`)
 			addrs: []CalendarObject{event1, event2, event3, todo1},
 			want:  []CalendarObject{event2, event3},
 		},
+		{
+			// https://datatracker.ietf.org/doc/html/rfc4791#section-7.8.1
+			name: "events in open time range (no end date)",
+			query: &CalendarQuery{
+				CompFilter: CompFilter{
+					Name: "VCALENDAR",
+					Comps: []CompFilter{
+						CompFilter{
+							Name:  "VEVENT",
+							Start: toDate(t, "20060104T000000Z"),
+						},
+					},
+				},
+			},
+			addrs: []CalendarObject{event1, event2, event3, todo1},
+			want:  []CalendarObject{event2, event3},
+		},
 		{
 			// https://datatracker.ietf.org/doc/html/rfc4791#section-7.8.6
 			name: "events by UID",