fix(dav): exclude trashed calendar objects from reminder processing

The getRemindersToProcess() query joined calendarobjects without filtering out soft-deleted (trashed) objects. This caused reminders to continue firing for events the user had already deleted, since deletion moves objects to the trashbin rather than removing them from the calendarobjects table.

Add a deleted_at IS NULL condition to the calendarobjects join so
trashed objects are excluded from reminder processing.

Additionally:
- Remove unnecessary GROUP BY (joins are on primary keys with no aggregate functions, so no duplicate rows are possible)
- Add $stmt->free() to release database cursors after fetching
- Clean up redundant docblocks and fix typos
- Extract column list for readability

Fixes: #53497

Signed-off-by: Josh <josh.t.richards@gmail.com>

Author: joshtrichards

apps/dav/lib/CalDAV/Reminder/Backend.php

@@ -3,92 +3,89 @@
 declare(strict_types=1);
 
 /**
- * SPDX-FileCopyrightText: 2019 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2019-2026 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 namespace OCA\DAV\CalDAV\Reminder;
 
 use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\IDBConnection;
 
-/**
- * Class Backend
- *
- * @package OCA\DAV\CalDAV\Reminder
- */
 class Backend {
-
-	/**
-	 * Backend constructor.
-	 *
-	 * @param IDBConnection $db
-	 * @param ITimeFactory $timeFactory
-	 */
 	public function __construct(
 		protected IDBConnection $db,
 		protected ITimeFactory $timeFactory,
 	) {
 	}
 
 	/**
-	 * Get all reminders with a notification date before now
-	 *
-	 * @return array
-	 * @throws \Exception
+	 * Get all reminders with a notification date before now,
+	 * excluding objects that have been moved to the trashbin.
 	 */
-	public function getRemindersToProcess():array {
+	public function getRemindersToProcess(): array {
 		$query = $this->db->getQueryBuilder();
-		$query->select(['cr.id', 'cr.calendar_id','cr.object_id','cr.is_recurring','cr.uid','cr.recurrence_id','cr.is_recurrence_exception','cr.event_hash','cr.alarm_hash','cr.type','cr.is_relative','cr.notification_date','cr.is_repeat_based','co.calendardata', 'c.displayname', 'c.principaluri'])
+
+		$columns = [
+			'cr.id',
+			'cr.calendar_id',
+			'cr.object_id',
+			'cr.is_recurring',
+			'cr.uid',
+			'cr.recurrence_id',
+			'cr.is_recurrence_exception',
+			'cr.event_hash',
+			'cr.alarm_hash',
+			'cr.type',
+			'cr.is_relative',
+			'cr.notification_date',
+			'cr.is_repeat_based',
+			'co.calendardata',
+			'c.displayname',
+			'c.principaluri',
+		];
+
+		$query->select($columns)
 			->from('calendar_reminders', 'cr')
-			->where($query->expr()->lte('cr.notification_date', $query->createNamedParameter($this->timeFactory->getTime())))
-			->join('cr', 'calendarobjects', 'co', $query->expr()->eq('cr.object_id', 'co.id'))
-			->join('cr', 'calendars', 'c', $query->expr()->eq('cr.calendar_id', 'c.id'))
-			->groupBy('cr.event_hash', 'cr.notification_date', 'cr.type', 'cr.id', 'cr.calendar_id', 'cr.object_id', 'cr.is_recurring', 'cr.uid', 'cr.recurrence_id', 'cr.is_recurrence_exception', 'cr.alarm_hash', 'cr.is_relative', 'cr.is_repeat_based', 'co.calendardata', 'c.displayname', 'c.principaluri');
+			->where($query->expr()->lte(
+				'cr.notification_date',
+				$query->createNamedParameter($this->timeFactory->getTime())
+			))
+			->join('cr', 'calendarobjects', 'co', $query->expr()->andX(
+				$query->expr()->eq('cr.object_id', 'co.id'),
+				$query->expr()->isNull('co.deleted_at')
+			))
+			->join('cr', 'calendars', 'c', $query->expr()->eq('cr.calendar_id', 'c.id'));
+
 		$stmt = $query->executeQuery();
+		$rows = $stmt->fetchAllAssociative();
+		$stmt->free();
 
-		return array_map(
-			[$this, 'fixRowTyping'],
-			$stmt->fetchAllAssociative()
-		);
+		return array_map([$this, 'fixRowTyping'], $rows);
 	}
 
 	/**
-	 * Get all scheduled reminders for an event
-	 *
-	 * @param int $objectId
-	 * @return array
+	 * Get all scheduled reminders for an event.
 	 */
-	public function getAllScheduledRemindersForEvent(int $objectId):array {
+	public function getAllScheduledRemindersForEvent(int $objectId): array {
 		$query = $this->db->getQueryBuilder();
 		$query->select('*')
 			->from('calendar_reminders')
 			->where($query->expr()->eq('object_id', $query->createNamedParameter($objectId)));
+
 		$stmt = $query->executeQuery();
+		$rows = $stmt->fetchAllAssociative();
+		$stmt->free();
 
-		return array_map(
-			[$this, 'fixRowTyping'],
-			$stmt->fetchAllAssociative()
-		);
+		return array_map([$this, 'fixRowTyping'], $rows);
 	}
 
 	/**
-	 * Insert a new reminder into the database
+	 * Insert a new reminder into the database.
 	 *
-	 * @param int $calendarId
-	 * @param int $objectId
-	 * @param string $uid
-	 * @param bool $isRecurring
-	 * @param int $recurrenceId
-	 * @param bool $isRecurrenceException
-	 * @param string $eventHash
-	 * @param string $alarmHash
-	 * @param string $type
-	 * @param bool $isRelative
-	 * @param int $notificationDate
-	 * @param bool $isRepeatBased
 	 * @return int The insert id
 	 */
-	public function insertReminder(int $calendarId,
+	public function insertReminder(
+		int $calendarId,
 		int $objectId,
 		string $uid,
 		bool $isRecurring,
@@ -99,7 +96,8 @@ public function insertReminder(int $calendarId,
 		string $type,
 		bool $isRelative,
 		int $notificationDate,
-		bool $isRepeatBased):int {
+		bool $isRepeatBased,
+	): int {
 		$query = $this->db->getQueryBuilder();
 		$query->insert('calendar_reminders')
 			->values([
@@ -122,13 +120,12 @@ public function insertReminder(int $calendarId,
 	}
 
 	/**
-	 * Sets a new notificationDate on an existing reminder
-	 *
-	 * @param int $reminderId
-	 * @param int $newNotificationDate
+	 * Set a new notification date on an existing reminder.
 	 */
-	public function updateReminder(int $reminderId,
-		int $newNotificationDate):void {
+	public function updateReminder(
+		int $reminderId,
+		int $newNotificationDate
+	): void {
 		$query = $this->db->getQueryBuilder();
 		$query->update('calendar_reminders')
 			->set('notification_date', $query->createNamedParameter($newNotificationDate))
@@ -137,12 +134,9 @@ public function updateReminder(int $reminderId,
 	}
 
 	/**
-	 * Remove a reminder by it's id
-	 *
-	 * @param integer $reminderId
-	 * @return void
+	 * Remove a reminder by its id.
 	 */
-	public function removeReminder(int $reminderId):void {
+	public function removeReminder(int $reminderId): void {
 		$query = $this->db->getQueryBuilder();
 
 		$query->delete('calendar_reminders')
@@ -151,11 +145,9 @@ public function removeReminder(int $reminderId):void {
 	}
 
 	/**
-	 * Cleans reminders in database
-	 *
-	 * @param int $objectId
+	 * Remove all reminders for a calendar object.
 	 */
-	public function cleanRemindersForEvent(int $objectId):void {
+	public function cleanRemindersForEvent(int $objectId): void {
 		$query = $this->db->getQueryBuilder();
 
 		$query->delete('calendar_reminders')
@@ -164,23 +156,16 @@ public function cleanRemindersForEvent(int $objectId):void {
 	}
 
 	/**
-	 * Remove all reminders for a calendar
-	 *
-	 * @param int $calendarId
-	 * @return void
+	 * Remove all reminders for a calendar.
 	 */
-	public function cleanRemindersForCalendar(int $calendarId):void {
+	public function cleanRemindersForCalendar(int $calendarId): void {
 		$query = $this->db->getQueryBuilder();
 
 		$query->delete('calendar_reminders')
 			->where($query->expr()->eq('calendar_id', $query->createNamedParameter($calendarId)))
 			->executeStatement();
 	}
 
-	/**
-	 * @param array $row
-	 * @return array
-	 */
 	private function fixRowTyping(array $row): array {
 		$row['id'] = (int)$row['id'];
 		$row['calendar_id'] = (int)$row['calendar_id'];