From 9f3d07e339e728e0bd57d3bfcfdfab498cab5198 Mon Sep 17 00:00:00 2001
From: SebastianKrupinski <krupinskis05@gmail.com>
Date: Wed, 17 Jul 2024 15:26:05 -0400
Subject: [PATCH] fix(caldav): Throw 403 Forbidden Error instead of 500
 Internal Server Error

Signed-off-by: SebastianKrupinski <krupinskis05@gmail.com>
---
 apps/dav/lib/CalDAV/CalDavBackend.php | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 58deffc1536eb..79e1025c5ee49 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -98,6 +98,7 @@
 use Sabre\VObject\Property;
 use Sabre\VObject\Reader;
 use Sabre\VObject\Recur\EventIterator;
+use Sabre\VObject\Recur\NoInstancesException;
 use function array_column;
 use function array_map;
 use function array_merge;
@@ -3020,7 +3021,15 @@ public function getDenormalizedData(string $calendarData): array {
 					$lastOccurrence = $firstOccurrence;
 				}
 			} else {
-				$it = new EventIterator($vEvents);
+				try {
+					$it = new EventIterator($vEvents);
+				} catch (NoInstancesException $e) {
+					$this->logger->debug('Caught no instance exception for calendar data. This usually indicates invalid calendar data.', [
+						'app' => 'dav',
+						'exception' => $e,
+					]);
+					throw new Forbidden($e->getMessage());
+				}
 				$maxDate = new DateTime(self::MAX_DATE);
 				$firstOccurrence = $it->getDtStart()->getTimestamp();
 				if ($it->isInfinite()) {