fix: preserve link shares on ownership transfer

apps/files/lib/Service/OwnershipTransferService.php

@@ -20,6 +20,7 @@
 use OCA\GroupFolders\Mount\GroupMountPoint;
 use OCP\Console\IOutput;
 use OCP\Console\Verbosity;
+use OCP\DB\QueryBuilder\IQueryBuilder;
 use OCP\Encryption\IManager as IEncryptionManager;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\IHomeMountProvider;
@@ -29,6 +30,7 @@
 use OCP\Files\IRootFolder;
 use OCP\Files\Mount\IMountManager;
 use OCP\Files\NotFoundException;
+use OCP\IDBConnection;
 use OCP\IUser;
 use OCP\IUserManager;
 use OCP\L10N\IFactory;
@@ -55,6 +57,7 @@ public function __construct(
 		private IFactory $l10nFactory,
 		private IRootFolder $rootFolder,
 		private IEventDispatcher $eventDispatcher,
+		private IDBConnection $connection,
 	) {
 	}
 
@@ -524,6 +527,8 @@ private function restoreShares(
 					if ($shareMountPoint) {
 						$this->mountManager->removeMount($shareMountPoint->getMountPoint());
 					}
+
+					$this->promoteLinkShares($share);
 					$this->shareManager->deleteShare($share);
 				} else {
 					if ($share->getShareOwner() === $sourceUid) {
@@ -604,11 +609,13 @@ private function transferIncomingShares(
 				$shareTarget = $finalShareTarget . $shareTarget;
 				if ($share->getShareType() === IShare::TYPE_USER
 					&& $share->getSharedBy() === $destinationUid) {
+					$this->promoteLinkShares($share);
 					$this->shareManager->deleteShare($share);
 				} elseif (isset($destinationShares[$share->getNodeId()])) {
 					$destinationShare = $destinationShares[$share->getNodeId()];
 					// Keep the share which has the most permissions and discard the other one.
 					if ($destinationShare->getPermissions() < $share->getPermissions()) {
+						$this->promoteLinkShares($destinationShare);
 						$this->shareManager->deleteShare($destinationShare);
 						$share->setSharedWith($destinationUid);
 						// trigger refetching of the node so that the new owner and mountpoint are taken into account
@@ -628,8 +635,10 @@ private function transferIncomingShares(
 						$this->mountManager->moveMount($oldMountPoint, $newMountPoint);
 						continue;
 					}
+					$this->promoteLinkShares($share);
 					$this->shareManager->deleteShare($share);
 				} elseif ($share->getShareOwner() === $destinationUid) {
+					$this->promoteLinkShares($share);
 					$this->shareManager->deleteShare($share);
 				} else {
 					$share->setSharedWith($destinationUid);
@@ -661,6 +670,19 @@ private function transferIncomingShares(
 		$output->writeln('');
 	}
 
+	/**
+	 * Links or email shares need to be promoted before the original share
+	 * is dropped, as the deletion is cascaded.
+	 */
+	private function promoteLinkShares(IShare $share): void {
+		$qb = $this->connection->getQueryBuilder();
+		$qb->update('share')
+			->set('parent', $qb->createNamedParameter(null, IQueryBuilder::PARAM_NULL))
+			->where($qb->expr()->eq('parent', $qb->createNamedParameter($share->getId())))
+			->andWhere($qb->expr()->in('share_type', $qb->createNamedParameter([IShare::TYPE_LINK, IShare::TYPE_EMAIL], IQueryBuilder::PARAM_INT_ARRAY)))
+			->executeStatement();
+	}
+
 	private function getShareMountPoint(string $uid, string $target): string {
 		return '/' . $uid . '/files/' . trim($target, '/') . '/';
 	}

build/integration/features/bootstrap/CommandLine.php

@@ -10,47 +10,7 @@
 require __DIR__ . '/autoload.php';
 
 trait CommandLine {
-	/** @var int return code of last command */
-	private int $lastCode = 0;
-	/** @var string stdout of last command */
-	private string $lastStdOut = '';
-	/** @var string stderr of last command */
-	private string $lastStdErr = '';
-	protected string $ocPath = '../..';
-
-	/**
-	 * Invokes an OCC command
-	 *
-	 * @param string[] $args OCC command, the part behind "occ". For example: "files:transfer-ownership"
-	 * @return int exit code
-	 */
-	public function runOcc(array $args = [], string $inputString = ''): int {
-		$args = array_map(function ($arg) {
-			return escapeshellarg($arg);
-		}, $args);
-		$args[] = '--no-ansi';
-		$args = implode(' ', $args);
-
-		$descriptor = [
-			0 => ['pipe', 'r'],
-			1 => ['pipe', 'w'],
-			2 => ['pipe', 'w'],
-		];
-		$process = proc_open('php console.php ' . $args, $descriptor, $pipes, $this->ocPath);
-		if ($inputString !== '') {
-			fwrite($pipes[0], $inputString . "\n");
-			fclose($pipes[0]);
-		}
-		$this->lastStdOut = stream_get_contents($pipes[1]);
-		$this->lastStdErr = stream_get_contents($pipes[2]);
-		$this->lastCode = proc_close($process);
-
-		// Clean opcode cache
-		$client = new GuzzleHttp\Client();
-		$client->request('GET', 'http://localhost:8080/apps/testing/clean_opcode_cache.php');
-
-		return $this->lastCode;
-	}
+	use OccRunner;
 
 	/**
 	 * @Given /^invoking occ with "([^"]*)"$/

build/integration/features/bootstrap/FeatureContext.php

@@ -17,6 +17,7 @@
  */
 class FeatureContext implements Context, SnippetAcceptingContext {
 	use AppConfiguration;
+	use OccRunner;
 	use ContactsMenu;
 	use ExternalStorage;
 	use Search;

build/integration/features/bootstrap/Mail.php

@@ -5,7 +5,7 @@
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
 trait Mail {
-	// CommandLine trait is expected to be used in the class that uses this
+	// OccRunner trait is expected to be used in the class that uses this
 	// trait.
 
 	/**
@@ -23,7 +23,7 @@ public function killDummyMailServer() {
 
 		exec('kill ' . $this->fakeSmtpServerPid);
 
-		$this->invokingTheCommand('config:system:delete mail_smtpport');
+		$this->runOcc(['config:system:delete', 'mail_smtpport']);
 	}
 
 	/**
@@ -32,7 +32,7 @@ public function killDummyMailServer() {
 	public function dummyMailServerIsListening() {
 		// Default smtpport (25) is restricted for regular users, so the
 		// FakeSMTP uses 2525 instead.
-		$this->invokingTheCommand('config:system:set mail_smtpport --value=2525 --type integer');
+		$this->runOcc(explode(' ', 'config:system:set mail_smtpport --value=2525 --type integer'));
 
 		$this->fakeSmtpServerPid = exec('php features/bootstrap/FakeSMTPHelper.php >/dev/null 2>&1 & echo $!');
 	}

build/integration/features/bootstrap/OccRunner.php

@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+require __DIR__ . '/autoload.php';
+
+/**
+ * Plumbing for running occ commands in behat tests, which does not include
+ * the behat step definitions for command line tests.
+ */
+trait OccRunner {
+	/** @var int return code of last command */
+	private int $lastCode = 0;
+	/** @var string stdout of last command */
+	private string $lastStdOut = '';
+	/** @var string stderr of last command */
+	private string $lastStdErr = '';
+	protected string $ocPath = '../..';
+
+	/**
+	 * Invokes an OCC command
+	 *
+	 * @param string[] $args OCC command, the part behind "occ". For example: "files:transfer-ownership"
+	 * @return int exit code
+	 */
+	public function runOcc(array $args = [], string $inputString = ''): int {
+		$args = array_map(function ($arg) {
+			return escapeshellarg($arg);
+		}, $args);
+		$args[] = '--no-ansi';
+		$args = implode(' ', $args);
+
+		$descriptor = [
+			0 => ['pipe', 'r'],
+			1 => ['pipe', 'w'],
+			2 => ['pipe', 'w'],
+		];
+		$process = proc_open('php console.php ' . $args, $descriptor, $pipes, $this->ocPath);
+		if ($inputString !== '') {
+			fwrite($pipes[0], $inputString . "\n");
+			fclose($pipes[0]);
+		}
+		$this->lastStdOut = stream_get_contents($pipes[1]);
+		$this->lastStdErr = stream_get_contents($pipes[2]);
+		$this->lastCode = proc_close($process);
+
+		// Clean opcode cache
+		$client = new GuzzleHttp\Client();
+		$client->request('GET', 'http://localhost:8080/apps/testing/clean_opcode_cache.php');
+
+		return $this->lastCode;
+	}
+}

build/integration/files_features/transfer-ownership.feature

@@ -252,6 +252,71 @@ Feature: transfer-ownership
 			| uid_file_owner | user3 |
 			| share_with | group1 |
 
+	Scenario: transferring ownership of folder shared with transfer recipient who created a link share
+		Given user "user0" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user0" is shared with user "user1" with permissions 31
+		And user "user1" accepts last share
+		And as "user1" creating a share with
+			| path | test/somefile.txt |
+			| shareType | 3 |
+		And the OCS status code should be "100"
+		When transferring ownership from "user0" to "user1"
+		And the command was successful
+		Then last link share can be downloaded
+
+	Scenario: transferring ownership of folder shared with transfer recipient who created a mail share
+		Given dummy mail server is listening
+		And user "user0" exists
+		And user "user1" exists
+		And User "user0" created a folder "/test"
+		And User "user0" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user0" is shared with user "user1" with permissions 31
+		And user "user1" accepts last share
+		And as "user1" creating a share with
+			| path | test/somefile.txt |
+			| shareType | 4 |
+			| shareWith | dumy@test.com |
+		And the OCS status code should be "100"
+		When transferring ownership from "user0" to "user1"
+		And the command was successful
+		Then last share can be downloaded
+
+	Scenario: transferring ownership of folder owned by transfer recipient with a link share created by the source
+		Given user "user0" exists
+		And user "user1" exists
+		And user "user2" exists
+		And User "user1" created a folder "/test"
+		And User "user1" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user1" is shared with user "user2" with permissions 31
+		And user "user2" accepts last share
+		And folder "/test" of user "user2" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And as "user0" creating a share with
+			| path | test/somefile.txt |
+			| shareType | 3 |
+		And the OCS status code should be "100"
+		When transferring ownership from "user0" to "user1"
+		And the command was successful
+		Then last link share can be downloaded
+
+	Scenario: transferring ownership of folder shared directly by transfer recipient with a link share created by the source
+		Given user "user0" exists
+		And user "user1" exists
+		And User "user1" created a folder "/test"
+		And User "user1" uploads file "data/textfile.txt" to "/test/somefile.txt"
+		And folder "/test" of user "user1" is shared with user "user0" with permissions 31
+		And user "user0" accepts last share
+		And as "user0" creating a share with
+			| path | test/somefile.txt |
+			| shareType | 3 |
+		And the OCS status code should be "100"
+		When transferring ownership from "user0" to "user1"
+		And the command was successful
+		Then last link share can be downloaded
+
 	Scenario: transferring ownership transfers received shares
 		Given user "user0" exists
 		And user "user1" exists