From f1c693669ccbbb301121ce3768ef6e647fce5b95 Mon Sep 17 00:00:00 2001
From: Alex <a.ovcharov@gmail.com>
Date: Tue, 20 Jun 2023 10:19:11 +0300
Subject: [PATCH 1/2] fixed issue: Undefined index: plusminus #467

https://github.com/sabre-io/vobject/issues/467
---
 lib/DateTimeParser.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/DateTimeParser.php b/lib/DateTimeParser.php
index 4a71931a2..5ce9f207a 100644
--- a/lib/DateTimeParser.php
+++ b/lib/DateTimeParser.php
@@ -93,7 +93,7 @@ public static function parseDuration(string $duration): \DateInterval
 
         $invert = false;
 
-        if ('-' === $matches['plusminus']) {
+        if (isset($matches['plusminus']) && '-' === $matches['plusminus']) {
             $invert = true;
         }
 

From e4d7c4eac1601ac6fa9a0fe15dfe8b692823c8d0 Mon Sep 17 00:00:00 2001
From: Phil Davis <phil@jankaritech.com>
Date: Thu, 9 Nov 2023 17:42:59 +0545
Subject: [PATCH 2/2] Add unit test for parsing a zero duration

---
 tests/VObject/DateTimeParserTest.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/VObject/DateTimeParserTest.php b/tests/VObject/DateTimeParserTest.php
index b1e7f7cd1..cdf0fe990 100644
--- a/tests/VObject/DateTimeParserTest.php
+++ b/tests/VObject/DateTimeParserTest.php
@@ -34,6 +34,12 @@ public function testParseICalendarDurationDateInterval(): void
         self::assertEquals($expected, DateTimeParser::parseDuration('-PT3M'));
     }
 
+    public function testParseDurationZero(): void
+    {
+        $expected = new \DateInterval('PT0S');
+        self::assertEquals($expected, DateTimeParser::parseDuration('P'));
+    }
+
     public function testParseICalendarDurationFail(): void
     {
         $this->expectException(InvalidDataException::class);