From c224ec2f23ac9dbd8f4bb1d52b3918fee0418a84 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Thu, 21 May 2020 15:17:31 +0200
Subject: [PATCH 1/9] Add deck:transfer-ownership command

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 appinfo/info.xml                  |  1 +
 lib/Command/TransferOwnership.php | 63 +++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)
 create mode 100644 lib/Command/TransferOwnership.php

diff --git a/appinfo/info.xml b/appinfo/info.xml
index 05755a365..a40f79e99 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -50,6 +50,7 @@
     </repair-steps>
     <commands>
         <command>OCA\Deck\Command\UserExport</command>
+        <command>OCA\Deck\Command\TransferOwnership</command>
     </commands>
     <activity>
         <settings>
diff --git a/lib/Command/TransferOwnership.php b/lib/Command/TransferOwnership.php
new file mode 100644
index 000000000..e7b242efb
--- /dev/null
+++ b/lib/Command/TransferOwnership.php
@@ -0,0 +1,63 @@
+<?php
+declare(strict_types=1);
+
+namespace OCA\Deck\Command;
+
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+final class TransferOwnership extends Command {
+
+	protected function configure() {
+		$this
+			->setName('deck:transfer-ownership')
+			->setDescription('Change owner of deck entities')
+			->addArgument(
+				'owner',
+				InputArgument::REQUIRED,
+				'Owner uid'
+			)
+            ->addArgument(
+                'newOwner',
+                InputArgument::REQUIRED,
+                'New owner uid'
+            );
+	}
+
+	protected function execute(InputInterface $input, OutputInterface $output) {
+		$owner = $input->getArgument('owner');
+		$newOwner = $input->getArgument('newOwner');
+        $db = \OC::$server->getDatabaseConnection();
+
+        $output->writeln("Transfer deck entities from $owner to $newOwner");
+        $params = [
+            'owner' => $owner,
+            'newOwner' => $newOwner
+        ];
+
+        $output->writeln('update oc_deck_assigned_users');
+        $stmt = $db->prepare('UPDATE `oc_deck_assigned_users` SET `participant` = :newOwner WHERE `participant` = :owner');
+        $stmt->execute($params);
+
+        $output->writeln('update oc_deck_attachment');
+        $stmt = $db->prepare('UPDATE `oc_deck_attachment` SET `created_by` = :newOwner WHERE `created_by` = :owner');
+        $stmt->execute($params);
+
+        $output->writeln('update oc_deck_boards');
+        $stmt = $db->prepare('UPDATE `oc_deck_boards` SET `owner` = :newOwner WHERE `owner` = :owner');
+        $stmt->execute($params);
+
+        $output->writeln('update oc_deck_board_acl');
+        $stmt = $db->prepare('UPDATE `oc_deck_board_acl` SET `participant` = :newOwner WHERE `participant` = :owner');
+        $stmt->execute($params);
+
+        $output->writeln('update oc_deck_cards');
+        $stmt = $db->prepare('UPDATE `oc_deck_cards` SET `owner` = :newOwner WHERE `owner` = :owner');
+        $stmt->execute($params);
+
+        $output->writeln("Transfer deck entities from $owner to $newOwner completed");
+    }
+
+}

From d1d864145c3d90f79fcf11608a2cf6eead301717 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Mon, 25 May 2020 09:46:57 +0200
Subject: [PATCH 2/9] Update docs

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 docs/User_documentation_en.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/docs/User_documentation_en.md b/docs/User_documentation_en.md
index 75b0e57a5..40f137d5c 100644
--- a/docs/User_documentation_en.md
+++ b/docs/User_documentation_en.md
@@ -14,6 +14,7 @@ Overall, Deck is easy to use. You can create boards, add users, share the Deck,
 3. [Handle cards options](#3-handle-cards-options)
 4. [Archive old tasks](#4-archive-old-tasks)
 5. [Manage your board](#5-manage-your-board)
+6. [New owner for the deck entities](#6-new-owner-for-the-deck-entities)
 
 ### 1. Create my first board
 In this example, we're going to create a board and share it with an other nextcloud user.
@@ -67,3 +68,6 @@ The **sharing tab** allows you to add users or even groups to your boards.
 **Deleted objects** allows you to return previously deleted stacks or cards.  
 The **Timeline** allows you to see everything that happened in your boards. Everything!
 
+### 6. New owner for the deck entities
+You can transfer ownership of boards, cards, etc to a new user, using `occ` command `deck:transfer-ownership`  
+`$ php occ deck:transfer-ownership owner newOwner`

From bdc50a7cb3f380ff1d915733675eb993ab742405 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Thu, 4 Jun 2020 15:41:32 +0200
Subject: [PATCH 3/9] Move code to BoardService

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 lib/Command/TransferOwnership.php | 52 +++++++++++--------------------
 lib/Db/AclMapper.php              | 17 ++++++++++
 lib/Db/AssignedUsersMapper.php    | 16 ++++++++++
 lib/Db/BoardMapper.php            | 16 ++++++++++
 lib/Db/CardMapper.php             | 16 ++++++++++
 lib/Service/BoardService.php      | 17 ++++++++++
 6 files changed, 101 insertions(+), 33 deletions(-)

diff --git a/lib/Command/TransferOwnership.php b/lib/Command/TransferOwnership.php
index e7b242efb..e2a7c67ce 100644
--- a/lib/Command/TransferOwnership.php
+++ b/lib/Command/TransferOwnership.php
@@ -1,8 +1,8 @@
 <?php
-declare(strict_types=1);
 
 namespace OCA\Deck\Command;
 
+use OCA\Deck\Service\BoardService;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Input\InputArgument;
 use Symfony\Component\Console\Input\InputInterface;
@@ -10,6 +10,15 @@
 
 final class TransferOwnership extends Command {
 
+	protected $boardService;
+
+	public function __construct(BoardService $boardService)
+	{
+		parent::__construct();
+
+		$this->boardService = $boardService;
+	}
+
 	protected function configure() {
 		$this
 			->setName('deck:transfer-ownership')
@@ -19,45 +28,22 @@ protected function configure() {
 				InputArgument::REQUIRED,
 				'Owner uid'
 			)
-            ->addArgument(
-                'newOwner',
-                InputArgument::REQUIRED,
-                'New owner uid'
-            );
+			->addArgument(
+				'newOwner',
+				InputArgument::REQUIRED,
+				'New owner uid'
+			);
 	}
 
 	protected function execute(InputInterface $input, OutputInterface $output) {
 		$owner = $input->getArgument('owner');
 		$newOwner = $input->getArgument('newOwner');
-        $db = \OC::$server->getDatabaseConnection();
 
-        $output->writeln("Transfer deck entities from $owner to $newOwner");
-        $params = [
-            'owner' => $owner,
-            'newOwner' => $newOwner
-        ];
+		$output->writeln("Transfer deck entities from $owner to $newOwner");
 
-        $output->writeln('update oc_deck_assigned_users');
-        $stmt = $db->prepare('UPDATE `oc_deck_assigned_users` SET `participant` = :newOwner WHERE `participant` = :owner');
-        $stmt->execute($params);
+		$this->boardService->transferOwnership($owner, $newOwner);
 
-        $output->writeln('update oc_deck_attachment');
-        $stmt = $db->prepare('UPDATE `oc_deck_attachment` SET `created_by` = :newOwner WHERE `created_by` = :owner');
-        $stmt->execute($params);
-
-        $output->writeln('update oc_deck_boards');
-        $stmt = $db->prepare('UPDATE `oc_deck_boards` SET `owner` = :newOwner WHERE `owner` = :owner');
-        $stmt->execute($params);
-
-        $output->writeln('update oc_deck_board_acl');
-        $stmt = $db->prepare('UPDATE `oc_deck_board_acl` SET `participant` = :newOwner WHERE `participant` = :owner');
-        $stmt->execute($params);
-
-        $output->writeln('update oc_deck_cards');
-        $stmt = $db->prepare('UPDATE `oc_deck_cards` SET `owner` = :newOwner WHERE `owner` = :owner');
-        $stmt->execute($params);
-
-        $output->writeln("Transfer deck entities from $owner to $newOwner completed");
-    }
+		$output->writeln("Transfer deck entities from $owner to $newOwner completed");
+	}
 
 }
diff --git a/lib/Db/AclMapper.php b/lib/Db/AclMapper.php
index e0ed3c838..848678250 100644
--- a/lib/Db/AclMapper.php
+++ b/lib/Db/AclMapper.php
@@ -51,4 +51,21 @@ public function findByParticipant($type, $participant) {
 		$sql = 'SELECT * from *PREFIX*deck_board_acl WHERE type = ? AND participant = ?';
 		return $this->findEntities($sql, [$type, $participant]);
 	}
+
+	/**
+	 * @param $ownerId
+	 * @param $newOwnerId
+	 * @return void
+	 */
+	public function transferOwnership($ownerId, $newOwnerId)
+	{
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId,
+			'type' => Acl::PERMISSION_TYPE_USER
+		];
+		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner AND `type` = :type";
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+	}
 }
diff --git a/lib/Db/AssignedUsersMapper.php b/lib/Db/AssignedUsersMapper.php
index bd18f46cd..49abb972b 100644
--- a/lib/Db/AssignedUsersMapper.php
+++ b/lib/Db/AssignedUsersMapper.php
@@ -114,4 +114,20 @@ private function getOrigin(AssignedUsers $assignment) {
 		}
 		return null;
 	}
+
+	/**
+	 * @param $ownerId
+	 * @param $newOwnerId
+	 * @return void
+	 */
+	public function transferOwnership($ownerId, $newOwnerId)
+	{
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId
+		];
+		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner";
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+	}
 }
diff --git a/lib/Db/BoardMapper.php b/lib/Db/BoardMapper.php
index 43e070a6b..5e1f06c61 100644
--- a/lib/Db/BoardMapper.php
+++ b/lib/Db/BoardMapper.php
@@ -261,4 +261,20 @@ public function mapOwner(Board &$board) {
 			return null;
 		});
 	}
+
+    /**
+     * @param $ownerId
+     * @param $newOwnerId
+     * @return void
+     */
+    public function transferOwnership($ownerId, $newOwnerId)
+    {
+        $params = [
+            'owner' => $ownerId,
+            'newOwner' => $newOwnerId
+        ];
+        $sql = "UPDATE `{$this->tableName}` SET `owner` = :newOwner WHERE `owner` = :owner";
+        $stmt = $this->execute($sql, $params);
+        $stmt->closeCursor();
+    }
 }
diff --git a/lib/Db/CardMapper.php b/lib/Db/CardMapper.php
index ad2c97724..dcb524bac 100644
--- a/lib/Db/CardMapper.php
+++ b/lib/Db/CardMapper.php
@@ -205,4 +205,20 @@ public function mapOwner(Card &$card) {
 			return null;
 		});
 	}
+
+	/**
+	 * @param $ownerId
+	 * @param $newOwnerId
+	 * @return void
+	 */
+	public function transferOwnership($ownerId, $newOwnerId)
+	{
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId
+		];
+		$sql = "UPDATE `{$this->tableName}`  SET `owner` = :newOwner WHERE `owner` = :owner";
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+	}
 }
diff --git a/lib/Service/BoardService.php b/lib/Service/BoardService.php
index 868164b91..598c661ef 100644
--- a/lib/Service/BoardService.php
+++ b/lib/Service/BoardService.php
@@ -29,6 +29,7 @@
 use OCA\Deck\Db\Acl;
 use OCA\Deck\Db\AclMapper;
 use OCA\Deck\Db\AssignedUsersMapper;
+use OCA\Deck\Db\CardMapper;
 use OCA\Deck\Db\ChangeHelper;
 use OCA\Deck\Db\IPermissionMapper;
 use OCA\Deck\Db\Label;
@@ -63,6 +64,7 @@ class BoardService {
 	/** @var EventDispatcherInterface */
 	private $eventDispatcher;
 	private $changeHelper;
+	private $cardMapper;
 
 	public function __construct(
 		BoardMapper $boardMapper,
@@ -73,6 +75,7 @@ public function __construct(
 		PermissionService $permissionService,
 		NotificationHelper $notificationHelper,
 		AssignedUsersMapper $assignedUsersMapper,
+		CardMapper $cardMapper,
 		IUserManager $userManager,
 		IGroupManager $groupManager,
 		ActivityManager $activityManager,
@@ -94,6 +97,7 @@ public function __construct(
 		$this->eventDispatcher = $eventDispatcher;
 		$this->changeHelper = $changeHelper;
 		$this->userId = $userId;
+		$this->cardMapper = $cardMapper;
 	}
 
 	/**
@@ -669,6 +673,19 @@ public function clone($id, $userId) {
 		return $newBoard;
 	}
 
+	/**
+	 * @param $ownerId
+	 * @param $newOwnerId
+	 * @return void
+	 */
+	public function transferOwnership($owner, $newOwner)
+	{
+		$this->boardMapper->transferOwnership($owner, $newOwner);
+		$this->assignedUsersMapper->transferOwnership($owner, $newOwner);
+		$this->aclMapper->transferOwnership($owner, $newOwner);
+		$this->cardMapper->transferOwnership($owner, $newOwner);
+	}
+
 	private function enrichWithStacks($board, $since = -1) {
 		$stacks = $this->stackMapper->findAll($board->getId(), null, null, $since);
 

From 3b6b5ee83d73875c72cc720d887544c093a97c95 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Sun, 7 Jun 2020 16:11:36 +0200
Subject: [PATCH 4/9] Add tests

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 .../database/TransferOwnershipTest.php        | 144 ++++++++++++++++++
 1 file changed, 144 insertions(+)
 create mode 100644 tests/integration/database/TransferOwnershipTest.php

diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
new file mode 100644
index 000000000..132a79202
--- /dev/null
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -0,0 +1,144 @@
+<?php
+
+namespace OCA\Deck\Service;
+
+use OCA\Deck\Db\Acl;
+use OCA\Deck\Db\AssignedUsersMapper;
+use OCA\Deck\Db\Board;
+
+/**
+ * @group DB
+ * @coversDefaultClass OCA\Deck\Service\BoardService
+ */
+class AssignedUsersMapperTest extends \Test\TestCase {
+	private const TEST_OWNER = 'test-share-user1';
+	private const TEST_NEW_OWNER = 'target';
+	private const TEST_GROUP = 'test-share-user1';
+
+	/** @var BoardService */
+	protected $boardService;
+	/** @var CardService */
+	protected $cardService;
+	/** @var StackService */
+	protected $stackService;
+	/** @var AssignedUsersMapper */
+	protected $assignedUsersMapper;
+	/** @var AssignmentService */
+	private $assignmentService;
+    /** @var Board */
+    private $board;
+    private $cards;
+    private $stacks;
+
+    public static function setUpBeforeClass(): void {
+		parent::setUpBeforeClass();
+
+		$backend = new \Test\Util\User\Dummy();
+		\OC_User::useBackend($backend);
+		\OC::$server->getUserManager()->registerBackend($backend);
+		$backend->createUser(self::TEST_OWNER, self::TEST_OWNER);
+		$backend->createUser(self::TEST_NEW_OWNER, self::TEST_NEW_OWNER);
+		// create group
+		$groupBackend = new \Test\Util\Group\Dummy();
+		$groupBackend->createGroup(self::TEST_GROUP);
+		$groupBackend->addToGroup(self::TEST_OWNER, self::TEST_GROUP);
+		\OC::$server->getGroupManager()->addBackend($groupBackend);
+	}
+
+	public function setUp(): void {
+		parent::setUp();
+		\OC::$server->getUserSession()->login(self::TEST_OWNER, self::TEST_OWNER);
+		$this->boardService = \OC::$server->query(BoardService::class);
+		$this->stackService = \OC::$server->query(StackService::class);
+		$this->cardService = \OC::$server->query(CardService::class);
+		$this->assignmentService = \OC::$server->query(AssignmentService::class);
+		$this->assignedUsersMapper = \OC::$server->query(AssignedUsersMapper::class);
+		$this->createBoardWithExampleData();
+	}
+
+	public function createBoardWithExampleData() {
+		$stacks = [];
+		$board = $this->boardService->create('Test', self::TEST_OWNER, '000000');
+		$id = $board->getId();
+        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_OWNER, true, true, true);
+        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
+		$stacks[] = $this->stackService->create('Stack A', $id, 1);
+		$stacks[] = $this->stackService->create('Stack B', $id, 1);
+		$stacks[] = $this->stackService->create('Stack C', $id, 1);
+		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
+		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
+        $this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
+        $this->board = $board;
+		$this->cards = $cards;
+		$this->stacks = $stacks;
+	}
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferBoardOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $boardOwner = $board->getOwner();
+        $this->assertEquals(self::TEST_NEW_OWNER, $boardOwner);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferACLOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isTargetInAcl = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_NEW_OWNER && $item->getType() === Acl::PERMISSION_TYPE_USER;
+        });
+        $this->assertTrue($isTargetInAcl);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testNoTransferAclOwnershipIfGroupType()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isGroupInAcl = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_GROUP && $item->getType() === Acl::PERMISSION_TYPE_GROUP;
+        });
+        $this->assertTrue($isGroupInAcl);
+    }
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTransferCardOwnership()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $card = $this->cardService->find($this->cards[0]->getId());
+        $cardOwner = $card->getOwner();
+        $this->assertEquals(self::TEST_NEW_OWNER, $cardOwner);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testReassignCardToNewOwner()
+    {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+        $participantsUIDs = [];
+        foreach ($assignedUsers as $user) {
+            $participantsUIDs[] = $user->getParticipant();
+        }
+        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
+        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+    }
+
+	public function tearDown(): void {
+		$this->boardService->deleteForce($this->board->getId());
+		parent::tearDown();
+	}
+}

From d8ceb8cf6767c6c89d148e98fb951c3ba4c9335c Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Sun, 7 Jun 2020 16:18:38 +0200
Subject: [PATCH 5/9] Fix code style

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 lib/Command/TransferOwnership.php             |   5 +-
 lib/Db/AclMapper.php                          |   3 +-
 lib/Db/AssignedUsersMapper.php                |   3 +-
 lib/Db/BoardMapper.php                        |  29 ++--
 lib/Db/CardMapper.php                         |   3 +-
 lib/Service/BoardService.php                  |   3 +-
 .../database/TransferOwnershipTest.php        | 133 +++++++++---------
 7 files changed, 83 insertions(+), 96 deletions(-)

diff --git a/lib/Command/TransferOwnership.php b/lib/Command/TransferOwnership.php
index e2a7c67ce..c3175477e 100644
--- a/lib/Command/TransferOwnership.php
+++ b/lib/Command/TransferOwnership.php
@@ -9,11 +9,9 @@
 use Symfony\Component\Console\Output\OutputInterface;
 
 final class TransferOwnership extends Command {
-
 	protected $boardService;
 
-	public function __construct(BoardService $boardService)
-	{
+	public function __construct(BoardService $boardService) {
 		parent::__construct();
 
 		$this->boardService = $boardService;
@@ -45,5 +43,4 @@ protected function execute(InputInterface $input, OutputInterface $output) {
 
 		$output->writeln("Transfer deck entities from $owner to $newOwner completed");
 	}
-
 }
diff --git a/lib/Db/AclMapper.php b/lib/Db/AclMapper.php
index 848678250..f74af1142 100644
--- a/lib/Db/AclMapper.php
+++ b/lib/Db/AclMapper.php
@@ -57,8 +57,7 @@ public function findByParticipant($type, $participant) {
 	 * @param $newOwnerId
 	 * @return void
 	 */
-	public function transferOwnership($ownerId, $newOwnerId)
-	{
+	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
 			'owner' => $ownerId,
 			'newOwner' => $newOwnerId,
diff --git a/lib/Db/AssignedUsersMapper.php b/lib/Db/AssignedUsersMapper.php
index 49abb972b..b8d4c76f0 100644
--- a/lib/Db/AssignedUsersMapper.php
+++ b/lib/Db/AssignedUsersMapper.php
@@ -120,8 +120,7 @@ private function getOrigin(AssignedUsers $assignment) {
 	 * @param $newOwnerId
 	 * @return void
 	 */
-	public function transferOwnership($ownerId, $newOwnerId)
-	{
+	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
 			'owner' => $ownerId,
 			'newOwner' => $newOwnerId
diff --git a/lib/Db/BoardMapper.php b/lib/Db/BoardMapper.php
index 5e1f06c61..7d07de92b 100644
--- a/lib/Db/BoardMapper.php
+++ b/lib/Db/BoardMapper.php
@@ -262,19 +262,18 @@ public function mapOwner(Board &$board) {
 		});
 	}
 
-    /**
-     * @param $ownerId
-     * @param $newOwnerId
-     * @return void
-     */
-    public function transferOwnership($ownerId, $newOwnerId)
-    {
-        $params = [
-            'owner' => $ownerId,
-            'newOwner' => $newOwnerId
-        ];
-        $sql = "UPDATE `{$this->tableName}` SET `owner` = :newOwner WHERE `owner` = :owner";
-        $stmt = $this->execute($sql, $params);
-        $stmt->closeCursor();
-    }
+	/**
+	 * @param $ownerId
+	 * @param $newOwnerId
+	 * @return void
+	 */
+	public function transferOwnership($ownerId, $newOwnerId) {
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId
+		];
+		$sql = "UPDATE `{$this->tableName}` SET `owner` = :newOwner WHERE `owner` = :owner";
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+	}
 }
diff --git a/lib/Db/CardMapper.php b/lib/Db/CardMapper.php
index dcb524bac..2ec63dcc1 100644
--- a/lib/Db/CardMapper.php
+++ b/lib/Db/CardMapper.php
@@ -211,8 +211,7 @@ public function mapOwner(Card &$card) {
 	 * @param $newOwnerId
 	 * @return void
 	 */
-	public function transferOwnership($ownerId, $newOwnerId)
-	{
+	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
 			'owner' => $ownerId,
 			'newOwner' => $newOwnerId
diff --git a/lib/Service/BoardService.php b/lib/Service/BoardService.php
index 598c661ef..a4c5adfe8 100644
--- a/lib/Service/BoardService.php
+++ b/lib/Service/BoardService.php
@@ -678,8 +678,7 @@ public function clone($id, $userId) {
 	 * @param $newOwnerId
 	 * @return void
 	 */
-	public function transferOwnership($owner, $newOwner)
-	{
+	public function transferOwnership($owner, $newOwner) {
 		$this->boardMapper->transferOwnership($owner, $newOwner);
 		$this->assignedUsersMapper->transferOwnership($owner, $newOwner);
 		$this->aclMapper->transferOwnership($owner, $newOwner);
diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
index 132a79202..0a8132532 100644
--- a/tests/integration/database/TransferOwnershipTest.php
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -25,12 +25,12 @@ class AssignedUsersMapperTest extends \Test\TestCase {
 	protected $assignedUsersMapper;
 	/** @var AssignmentService */
 	private $assignmentService;
-    /** @var Board */
-    private $board;
-    private $cards;
-    private $stacks;
+	/** @var Board */
+	private $board;
+	private $cards;
+	private $stacks;
 
-    public static function setUpBeforeClass(): void {
+	public static function setUpBeforeClass(): void {
 		parent::setUpBeforeClass();
 
 		$backend = new \Test\Util\User\Dummy();
@@ -60,82 +60,77 @@ public function createBoardWithExampleData() {
 		$stacks = [];
 		$board = $this->boardService->create('Test', self::TEST_OWNER, '000000');
 		$id = $board->getId();
-        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_OWNER, true, true, true);
-        $this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
+		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_OWNER, true, true, true);
+		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
 		$stacks[] = $this->stackService->create('Stack A', $id, 1);
 		$stacks[] = $this->stackService->create('Stack B', $id, 1);
 		$stacks[] = $this->stackService->create('Stack C', $id, 1);
 		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
 		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
-        $this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
-        $this->board = $board;
+		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
+		$this->board = $board;
 		$this->cards = $cards;
 		$this->stacks = $stacks;
 	}
 
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testTransferBoardOwnership()
-    {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $board = $this->boardService->find($this->board->getId());
-        $boardOwner = $board->getOwner();
-        $this->assertEquals(self::TEST_NEW_OWNER, $boardOwner);
-    }
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testTransferBoardOwnership() {
+		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$board = $this->boardService->find($this->board->getId());
+		$boardOwner = $board->getOwner();
+		$this->assertEquals(self::TEST_NEW_OWNER, $boardOwner);
+	}
 
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testTransferACLOwnership()
-    {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $board = $this->boardService->find($this->board->getId());
-        $acl = $board->getAcl();
-        $isTargetInAcl = (bool)array_filter($acl, function ($item) {
-            return $item->getParticipant() === self::TEST_NEW_OWNER && $item->getType() === Acl::PERMISSION_TYPE_USER;
-        });
-        $this->assertTrue($isTargetInAcl);
-    }
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testTransferACLOwnership() {
+		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$board = $this->boardService->find($this->board->getId());
+		$acl = $board->getAcl();
+		$isTargetInAcl = (bool)array_filter($acl, function ($item) {
+			return $item->getParticipant() === self::TEST_NEW_OWNER && $item->getType() === Acl::PERMISSION_TYPE_USER;
+		});
+		$this->assertTrue($isTargetInAcl);
+	}
 
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testNoTransferAclOwnershipIfGroupType()
-    {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $board = $this->boardService->find($this->board->getId());
-        $acl = $board->getAcl();
-        $isGroupInAcl = (bool)array_filter($acl, function ($item) {
-            return $item->getParticipant() === self::TEST_GROUP && $item->getType() === Acl::PERMISSION_TYPE_GROUP;
-        });
-        $this->assertTrue($isGroupInAcl);
-    }
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testTransferCardOwnership()
-    {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $card = $this->cardService->find($this->cards[0]->getId());
-        $cardOwner = $card->getOwner();
-        $this->assertEquals(self::TEST_NEW_OWNER, $cardOwner);
-    }
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testNoTransferAclOwnershipIfGroupType() {
+		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$board = $this->boardService->find($this->board->getId());
+		$acl = $board->getAcl();
+		$isGroupInAcl = (bool)array_filter($acl, function ($item) {
+			return $item->getParticipant() === self::TEST_GROUP && $item->getType() === Acl::PERMISSION_TYPE_GROUP;
+		});
+		$this->assertTrue($isGroupInAcl);
+	}
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testTransferCardOwnership() {
+		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$card = $this->cardService->find($this->cards[0]->getId());
+		$cardOwner = $card->getOwner();
+		$this->assertEquals(self::TEST_NEW_OWNER, $cardOwner);
+	}
 
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testReassignCardToNewOwner()
-    {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
-        $participantsUIDs = [];
-        foreach ($assignedUsers as $user) {
-            $participantsUIDs[] = $user->getParticipant();
-        }
-        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
-        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
-    }
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testReassignCardToNewOwner() {
+		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+		$participantsUIDs = [];
+		foreach ($assignedUsers as $user) {
+			$participantsUIDs[] = $user->getParticipant();
+		}
+		$this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
+		$this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+	}
 
 	public function tearDown(): void {
 		$this->boardService->deleteForce($this->board->getId());

From 4d48b1dda17c6df3c73697d9755b6e60882b6285 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Mon, 8 Jun 2020 14:06:50 +0200
Subject: [PATCH 6/9] Fix wrong class name

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 .../database/TransferOwnershipTest.php          | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
index 0a8132532..e49e409b4 100644
--- a/tests/integration/database/TransferOwnershipTest.php
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -10,7 +10,7 @@
  * @group DB
  * @coversDefaultClass OCA\Deck\Service\BoardService
  */
-class AssignedUsersMapperTest extends \Test\TestCase {
+class TransferOwnershipTest extends \Test\TestCase {
 	private const TEST_OWNER = 'test-share-user1';
 	private const TEST_NEW_OWNER = 'target';
 	private const TEST_GROUP = 'test-share-user1';
@@ -132,6 +132,21 @@ public function testReassignCardToNewOwner() {
 		$this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
 	}
 
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testReassignCardToNewParticipantOnlyIfParticipantHasUserType() {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+        $this->assignmentService->ass($cards[0]->getId(), self::TEST_OWNER);
+        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+        $participantsUIDs = [];
+        foreach ($assignedUsers as $user) {
+            $participantsUIDs[] = $user->getParticipant();
+        }
+        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
+        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+    }
+
 	public function tearDown(): void {
 		$this->boardService->deleteForce($this->board->getId());
 		parent::tearDown();

From caac805e75839dc4fbe8357bea2d7c0517cac273 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Tue, 9 Jun 2020 05:21:24 +0200
Subject: [PATCH 7/9] Check type before transfer card participants ownership

Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>

temp
---
 Makefile                                      |  3 +--
 lib/Db/AssignedUsersMapper.php                |  5 +++--
 tests/integration/config/behat.yml            |  4 ++--
 .../database/TransferOwnershipTest.php        | 21 ++++++++++++++++++-
 tests/integration/run.sh                      |  2 +-
 tests/unit/Service/BoardServiceTest.php       |  5 +++++
 6 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/Makefile b/Makefile
index 54930c6b6..8d428a7d3 100644
--- a/Makefile
+++ b/Makefile
@@ -50,8 +50,7 @@ ifeq (, $(shell which phpunit 2> /dev/null))
 	php $(build_tools_directory)/phpunit.phar -c tests/phpunit.xml --coverage-clover build/php-unit.coverage.xml
 	php $(build_tools_directory)/phpunit.phar -c tests/phpunit.integration.xml --coverage-clover build/php-integration.coverage.xml
 else
-	phpunit -c tests/phpunit.xml --coverage-clover build/php-unit.coverage.xml
-	phpunit -c tests/phpunit.integration.xml --coverage-clover build/php-integration.coverage.xml
+	phpunit -c tests/phpunit.integration.xml --testsuite=integration-database --coverage-clover build/php-integration.coverage.xml
 endif
 
 test-integration:
diff --git a/lib/Db/AssignedUsersMapper.php b/lib/Db/AssignedUsersMapper.php
index b8d4c76f0..136ab760e 100644
--- a/lib/Db/AssignedUsersMapper.php
+++ b/lib/Db/AssignedUsersMapper.php
@@ -123,9 +123,10 @@ private function getOrigin(AssignedUsers $assignment) {
 	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
 			'owner' => $ownerId,
-			'newOwner' => $newOwnerId
+			'newOwner' => $newOwnerId,
+            'type' => AssignedUsers::TYPE_USER
 		];
-		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner";
+		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner AND `type`= :type";
 		$stmt = $this->execute($sql, $params);
 		$stmt->closeCursor();
 	}
diff --git a/tests/integration/config/behat.yml b/tests/integration/config/behat.yml
index f557adde8..5006985ec 100644
--- a/tests/integration/config/behat.yml
+++ b/tests/integration/config/behat.yml
@@ -5,8 +5,8 @@ default:
         - '%paths.base%/../features/'
       contexts:
         - FeatureContext:
-            baseUrl:  http://localhost:8080/index.php/ocs/
+            baseUrl:  http://localhost:9090/index.php/ocs/
             admin:
               - admin
               - admin
-            regular_user_password: 123456
\ No newline at end of file
+            regular_user_password: 123456
diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
index e49e409b4..aff664640 100644
--- a/tests/integration/database/TransferOwnershipTest.php
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -13,6 +13,8 @@
 class TransferOwnershipTest extends \Test\TestCase {
 	private const TEST_OWNER = 'test-share-user1';
 	private const TEST_NEW_OWNER = 'target';
+	private const TEST_NEW_OWNER_PARTICIPANT = 'target-participant';
+	private const TEST_NEW_OWNER_IN_ACL = 'target-in-acl';
 	private const TEST_GROUP = 'test-share-user1';
 
 	/** @var BoardService */
@@ -38,6 +40,7 @@ public static function setUpBeforeClass(): void {
 		\OC::$server->getUserManager()->registerBackend($backend);
 		$backend->createUser(self::TEST_OWNER, self::TEST_OWNER);
 		$backend->createUser(self::TEST_NEW_OWNER, self::TEST_NEW_OWNER);
+		$backend->createUser(self::TEST_NEW_OWNER_PARTICIPANT, self::TEST_NEW_OWNER_PARTICIPANT);
 		// create group
 		$groupBackend = new \Test\Util\Group\Dummy();
 		$groupBackend->createGroup(self::TEST_GROUP);
@@ -68,6 +71,7 @@ public function createBoardWithExampleData() {
 		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
 		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
 		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
+		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_NEW_OWNER_PARTICIPANT);
 		$this->board = $board;
 		$this->cards = $cards;
 		$this->stacks = $stacks;
@@ -137,7 +141,22 @@ public function testReassignCardToNewOwner() {
      */
     public function testReassignCardToNewParticipantOnlyIfParticipantHasUserType() {
         $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $this->assignmentService->ass($cards[0]->getId(), self::TEST_OWNER);
+        $this->assignmentService->ass($this->cards[0]->getId(), self::TEST_OWNER);
+        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+        $participantsUIDs = [];
+        foreach ($assignedUsers as $user) {
+            $participantsUIDs[] = $user->getParticipant();
+        }
+        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
+        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTargetAlreadyParticipantOfTransferedCard() {
+        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER_PARTICIPANT);
+        $this->assignmentService->assignUser($this->cards[0]->getId(), self::TEST_OWNER);
         $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
         $participantsUIDs = [];
         foreach ($assignedUsers as $user) {
diff --git a/tests/integration/run.sh b/tests/integration/run.sh
index 63a733723..17ad85028 100755
--- a/tests/integration/run.sh
+++ b/tests/integration/run.sh
@@ -28,7 +28,7 @@ composer dump-autoload
 if [ -z "$EXECUTOR_NUMBER" ]; then
     EXECUTOR_NUMBER=0
 fi
-PORT=$((8080 + $EXECUTOR_NUMBER))
+PORT=$((9090 + $EXECUTOR_NUMBER))
 echo $PORT
 php -S localhost:$PORT -t $OC_PATH &
 PHPPID=$!
diff --git a/tests/unit/Service/BoardServiceTest.php b/tests/unit/Service/BoardServiceTest.php
index 6553a6245..4f181c533 100644
--- a/tests/unit/Service/BoardServiceTest.php
+++ b/tests/unit/Service/BoardServiceTest.php
@@ -31,6 +31,7 @@
 use OCA\Deck\Db\AssignedUsersMapper;
 use OCA\Deck\Db\Board;
 use OCA\Deck\Db\BoardMapper;
+use OCA\Deck\Db\CardMapper;
 use OCA\Deck\Db\ChangeHelper;
 use OCA\Deck\Db\LabelMapper;
 use OCA\Deck\Db\StackMapper;
@@ -56,6 +57,8 @@ class BoardServiceTest extends TestCase {
 	private $boardMapper;
 	/** @var StackMapper */
 	private $stackMapper;
+    /** @var CardMapper */
+    private $cardMapper;
 	/** @var PermissionService */
 	private $permissionService;
 	/** @var NotificationHelper */
@@ -80,6 +83,7 @@ public function setUp(): void {
 		$this->aclMapper = $this->createMock(AclMapper::class);
 		$this->boardMapper = $this->createMock(BoardMapper::class);
 		$this->stackMapper = $this->createMock(StackMapper::class);
+		$this->cardMapper = $this->createMock(CardMapper::class);
 		$this->labelMapper = $this->createMock(LabelMapper::class);
 		$this->permissionService = $this->createMock(PermissionService::class);
 		$this->notificationHelper = $this->createMock(NotificationHelper::class);
@@ -99,6 +103,7 @@ public function setUp(): void {
 			$this->permissionService,
 			$this->notificationHelper,
 			$this->assignedUsersMapper,
+			$this->cardMapper,
 			$this->userManager,
 			$this->groupManager,
 			$this->activityManager,

From 0b85ccc82085fa093eff72d1bcd3dafadb22bf32 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Sat, 18 Jul 2020 07:40:47 +0300
Subject: [PATCH 8/9] Transfer deck ownership even if target user already
 participant of a board

https://github.com/nextcloud/deck/pull/1955#issuecomment-640392715
Signed-off-by: Sergey Shliakhov <husband.sergey@gmail.com>
---
 lib/Db/AclMapper.php                          |  36 ++++--
 lib/Db/AssignedUsersMapper.php                |   9 +-
 lib/Service/BoardService.php                  |   6 +-
 .../database/TransferOwnershipTest.php        | 115 +++++++++++-------
 4 files changed, 113 insertions(+), 53 deletions(-)

diff --git a/lib/Db/AclMapper.php b/lib/Db/AclMapper.php
index f74af1142..0ac14fd84 100644
--- a/lib/Db/AclMapper.php
+++ b/lib/Db/AclMapper.php
@@ -58,13 +58,33 @@ public function findByParticipant($type, $participant) {
 	 * @return void
 	 */
 	public function transferOwnership($ownerId, $newOwnerId) {
-		$params = [
-			'owner' => $ownerId,
-			'newOwner' => $newOwnerId,
-			'type' => Acl::PERMISSION_TYPE_USER
-		];
-		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner AND `type` = :type";
-		$stmt = $this->execute($sql, $params);
-		$stmt->closeCursor();
+        $params = [
+            'owner' => $ownerId,
+            'newOwner' => $newOwnerId,
+            'type' => Acl::PERMISSION_TYPE_USER
+        ];
+		//We want preserve permissions from both users
+        $sql = "UPDATE `{$this->tableName}` AS `source` 
+                    LEFT JOIN `{$this->tableName}` AS `target` 
+                    ON `target`.`participant` = :newOwner AND `target`.`type` = :type 
+                    SET `source`.`permission_edit` =(`source`.`permission_edit` || `target`.`permission_edit`), 
+                        `source`.`permission_share` =(`source`.`permission_share` || `target`.`permission_share`), 
+                        `source`.`permission_manage` =(`source`.`permission_manage` || `target`.`permission_manage`) 
+                    WHERE `source`.`participant` = :owner AND `source`.`type` = :type";
+        $stmt = $this->execute($sql, $params);
+        $stmt->closeCursor();
+        //We can't transfer acl if target already in acl
+        $sql = "DELETE FROM `{$this->tableName}` 
+                    WHERE `participant` = :newOwner 
+                        AND `type` = :type 
+                        AND EXISTS (SELECT `id` FROM (SELECT `id` FROM `{$this->tableName}` 
+                                    WHERE `participant` = :owner AND `type` = :type) as tmp)";
+        $stmt = $this->execute($sql, $params);
+        $stmt->closeCursor();
+        //Now we can transfer without errors
+        $sqlUpdate = "UPDATE `{$this->tableName}`  
+                        SET `participant` = :newOwner WHERE `participant` = :owner AND `type` = :type";
+        $stmt = $this->execute($sqlUpdate, $params);
+        $stmt->closeCursor();
 	}
 }
diff --git a/lib/Db/AssignedUsersMapper.php b/lib/Db/AssignedUsersMapper.php
index 136ab760e..df90236dc 100644
--- a/lib/Db/AssignedUsersMapper.php
+++ b/lib/Db/AssignedUsersMapper.php
@@ -122,10 +122,17 @@ private function getOrigin(AssignedUsers $assignment) {
 	 */
 	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
-			'owner' => $ownerId,
 			'newOwner' => $newOwnerId,
             'type' => AssignedUsers::TYPE_USER
 		];
+        $sql = "DELETE FROM `{$this->tableName}`  WHERE `participant` = :newOwner AND `type`= :type";
+        $stmt = $this->execute($sql, $params);
+        $stmt->closeCursor();
+        $params = [
+            'owner' => $ownerId,
+            'newOwner' => $newOwnerId,
+            'type' => AssignedUsers::TYPE_USER
+        ];
 		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner AND `type`= :type";
 		$stmt = $this->execute($sql, $params);
 		$stmt->closeCursor();
diff --git a/lib/Service/BoardService.php b/lib/Service/BoardService.php
index a4c5adfe8..fa5613182 100644
--- a/lib/Service/BoardService.php
+++ b/lib/Service/BoardService.php
@@ -680,9 +680,9 @@ public function clone($id, $userId) {
 	 */
 	public function transferOwnership($owner, $newOwner) {
 		$this->boardMapper->transferOwnership($owner, $newOwner);
-		$this->assignedUsersMapper->transferOwnership($owner, $newOwner);
-		$this->aclMapper->transferOwnership($owner, $newOwner);
-		$this->cardMapper->transferOwnership($owner, $newOwner);
+        $this->aclMapper->transferOwnership($owner, $newOwner);
+        $this->assignedUsersMapper->transferOwnership($owner, $newOwner);
+        $this->cardMapper->transferOwnership($owner, $newOwner);
 	}
 
 	private function enrichWithStacks($board, $since = -1) {
diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
index aff664640..459615860 100644
--- a/tests/integration/database/TransferOwnershipTest.php
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -3,6 +3,7 @@
 namespace OCA\Deck\Service;
 
 use OCA\Deck\Db\Acl;
+use OCA\Deck\Db\AssignedUsers;
 use OCA\Deck\Db\AssignedUsersMapper;
 use OCA\Deck\Db\Board;
 
@@ -11,10 +12,9 @@
  * @coversDefaultClass OCA\Deck\Service\BoardService
  */
 class TransferOwnershipTest extends \Test\TestCase {
-	private const TEST_OWNER = 'test-share-user1';
-	private const TEST_NEW_OWNER = 'target';
-	private const TEST_NEW_OWNER_PARTICIPANT = 'target-participant';
-	private const TEST_NEW_OWNER_IN_ACL = 'target-in-acl';
+	private const TEST_USER_1 = 'test-share-user1';
+	private const TEST_USER_2 = 'test-user2';
+	private const TEST_USER_3 = 'test-user3';
 	private const TEST_GROUP = 'test-share-user1';
 
 	/** @var BoardService */
@@ -38,19 +38,19 @@ public static function setUpBeforeClass(): void {
 		$backend = new \Test\Util\User\Dummy();
 		\OC_User::useBackend($backend);
 		\OC::$server->getUserManager()->registerBackend($backend);
-		$backend->createUser(self::TEST_OWNER, self::TEST_OWNER);
-		$backend->createUser(self::TEST_NEW_OWNER, self::TEST_NEW_OWNER);
-		$backend->createUser(self::TEST_NEW_OWNER_PARTICIPANT, self::TEST_NEW_OWNER_PARTICIPANT);
+		$backend->createUser(self::TEST_USER_1, self::TEST_USER_1);
+		$backend->createUser(self::TEST_USER_2, self::TEST_USER_2);
+		$backend->createUser(self::TEST_USER_3, self::TEST_USER_3);
 		// create group
 		$groupBackend = new \Test\Util\Group\Dummy();
 		$groupBackend->createGroup(self::TEST_GROUP);
-		$groupBackend->addToGroup(self::TEST_OWNER, self::TEST_GROUP);
+		$groupBackend->addToGroup(self::TEST_USER_1, self::TEST_GROUP);
 		\OC::$server->getGroupManager()->addBackend($groupBackend);
 	}
 
 	public function setUp(): void {
 		parent::setUp();
-		\OC::$server->getUserSession()->login(self::TEST_OWNER, self::TEST_OWNER);
+		\OC::$server->getUserSession()->login(self::TEST_USER_1, self::TEST_USER_1);
 		$this->boardService = \OC::$server->query(BoardService::class);
 		$this->stackService = \OC::$server->query(StackService::class);
 		$this->cardService = \OC::$server->query(CardService::class);
@@ -61,17 +61,17 @@ public function setUp(): void {
 
 	public function createBoardWithExampleData() {
 		$stacks = [];
-		$board = $this->boardService->create('Test', self::TEST_OWNER, '000000');
+		$board = $this->boardService->create('Test', self::TEST_USER_1, '000000');
 		$id = $board->getId();
-		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_OWNER, true, true, true);
+		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_USER_1, true, true, true);
 		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
-		$stacks[] = $this->stackService->create('Stack A', $id, 1);
+		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_USER_3, false, true, false);
+        $stacks[] = $this->stackService->create('Stack A', $id, 1);
 		$stacks[] = $this->stackService->create('Stack B', $id, 1);
 		$stacks[] = $this->stackService->create('Stack C', $id, 1);
-		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
-		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_OWNER);
-		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_OWNER);
-		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_NEW_OWNER_PARTICIPANT);
+		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_USER_1);
+		$cards[] = $this->cardService->create('Card 2', $stacks[0]->getId(), 'text', 0, self::TEST_USER_1);
+		$this->assignmentService->assignUser($cards[0]->getId(), self::TEST_USER_1);
 		$this->board = $board;
 		$this->cards = $cards;
 		$this->stacks = $stacks;
@@ -81,21 +81,21 @@ public function createBoardWithExampleData() {
 	 * @covers ::transferOwnership
 	 */
 	public function testTransferBoardOwnership() {
-		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
 		$board = $this->boardService->find($this->board->getId());
 		$boardOwner = $board->getOwner();
-		$this->assertEquals(self::TEST_NEW_OWNER, $boardOwner);
+		$this->assertEquals(self::TEST_USER_2, $boardOwner);
 	}
 
 	/**
 	 * @covers ::transferOwnership
 	 */
 	public function testTransferACLOwnership() {
-		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
 		$board = $this->boardService->find($this->board->getId());
 		$acl = $board->getAcl();
 		$isTargetInAcl = (bool)array_filter($acl, function ($item) {
-			return $item->getParticipant() === self::TEST_NEW_OWNER && $item->getType() === Acl::PERMISSION_TYPE_USER;
+			return $item->getParticipant() === self::TEST_USER_2 && $item->getType() === Acl::PERMISSION_TYPE_USER;
 		});
 		$this->assertTrue($isTargetInAcl);
 	}
@@ -104,7 +104,7 @@ public function testTransferACLOwnership() {
 	 * @covers ::transferOwnership
 	 */
 	public function testNoTransferAclOwnershipIfGroupType() {
-		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
 		$board = $this->boardService->find($this->board->getId());
 		$acl = $board->getAcl();
 		$isGroupInAcl = (bool)array_filter($acl, function ($item) {
@@ -116,54 +116,87 @@ public function testNoTransferAclOwnershipIfGroupType() {
 	 * @covers ::transferOwnership
 	 */
 	public function testTransferCardOwnership() {
-		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
 		$card = $this->cardService->find($this->cards[0]->getId());
 		$cardOwner = $card->getOwner();
-		$this->assertEquals(self::TEST_NEW_OWNER, $cardOwner);
+		$this->assertEquals(self::TEST_USER_2, $cardOwner);
 	}
 
 	/**
 	 * @covers ::transferOwnership
 	 */
 	public function testReassignCardToNewOwner() {
-		$this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
 		$assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
 		$participantsUIDs = [];
 		foreach ($assignedUsers as $user) {
 			$participantsUIDs[] = $user->getParticipant();
 		}
-		$this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
-		$this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+		$this->assertContains(self::TEST_USER_2, $participantsUIDs);
+		$this->assertNotContains(self::TEST_USER_1, $participantsUIDs);
 	}
 
     /**
      * @covers ::transferOwnership
      */
     public function testReassignCardToNewParticipantOnlyIfParticipantHasUserType() {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER);
-        $this->assignmentService->ass($this->cards[0]->getId(), self::TEST_OWNER);
-        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
+        $this->assignmentService->assignUser($this->cards[1]->getId(), self::TEST_USER_1, AssignedUsers::TYPE_GROUP);
+        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
+        $assignedUsers = $this->assignedUsersMapper->find($this->cards[1]->getId());
         $participantsUIDs = [];
         foreach ($assignedUsers as $user) {
             $participantsUIDs[] = $user->getParticipant();
         }
-        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
-        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+        $this->assertContains(self::TEST_USER_1, $participantsUIDs);
+        $this->assertNotContains(self::TEST_USER_2, $participantsUIDs);
     }
 
     /**
      * @covers ::transferOwnership
      */
-    public function testTargetAlreadyParticipantOfTransferedCard() {
-        $this->boardService->transferOwnership(self::TEST_OWNER, self::TEST_NEW_OWNER_PARTICIPANT);
-        $this->assignmentService->assignUser($this->cards[0]->getId(), self::TEST_OWNER);
-        $assignedUsers = $this->assignedUsersMapper->find($this->cards[0]->getId());
-        $participantsUIDs = [];
-        foreach ($assignedUsers as $user) {
-            $participantsUIDs[] = $user->getParticipant();
-        }
-        $this->assertContains(self::TEST_NEW_OWNER, $participantsUIDs);
-        $this->assertNotContains(self::TEST_OWNER, $participantsUIDs);
+    public function testTargetAlreadyParticipantOfBoard() {
+        $this->expectNotToPerformAssertions();
+        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testDontRemoveTargetFromAcl() {
+        $this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isOwnerInAcl = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_USER_3 && $item->getType() === Acl::PERMISSION_TYPE_USER;
+        });
+        $this->assertTrue($isOwnerInAcl);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testMergePermissions() {
+        $this->boardService->addAcl($this->board->getId(), Acl::PERMISSION_TYPE_USER, self::TEST_USER_2, true, false, true);
+        $this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
+        $board = $this->boardService->find($this->board->getId());
+        $acl = $board->getAcl();
+        $isMerged = (bool)array_filter($acl, function ($item) {
+            return $item->getParticipant() === self::TEST_USER_1
+                && $item->getType() === Acl::PERMISSION_TYPE_USER
+                && $item->getPermission(Acl::PERMISSION_EDIT)
+                && $item->getPermission(Acl::PERMISSION_SHARE)
+                && $item->getPermission(Acl::PERMISSION_MANAGE);
+        });
+        $this->assertTrue($isMerged);
+    }
+
+    /**
+     * @covers ::transferOwnership
+     */
+    public function testTargetAlreadyParticipantOfCard() {
+        $this->expectNotToPerformAssertions();
+        $this->assignmentService->assignUser($this->cards[0]->getId(), self::TEST_USER_3, AssignedUsers::TYPE_USER);
+        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
     }
 
 	public function tearDown(): void {

From 1535c4a208ca61ddc2d13c940af4c5fd7d63c117 Mon Sep 17 00:00:00 2001
From: Sergey Shliakhov <husband.sergey@gmail.com>
Date: Sat, 18 Jul 2020 09:02:28 +0300
Subject: [PATCH 9/9] Fix coding styles

---
 lib/Db/AclMapper.php                          |  32 ++---
 lib/Db/AssignedUsersMapper.php                |  18 +--
 lib/Service/BoardService.php                  |   6 +-
 .../database/TransferOwnershipTest.php        | 126 +++++++++---------
 tests/unit/Service/BoardServiceTest.php       |   4 +-
 5 files changed, 93 insertions(+), 93 deletions(-)

diff --git a/lib/Db/AclMapper.php b/lib/Db/AclMapper.php
index 0ac14fd84..6e9ddb6aa 100644
--- a/lib/Db/AclMapper.php
+++ b/lib/Db/AclMapper.php
@@ -58,33 +58,33 @@ public function findByParticipant($type, $participant) {
 	 * @return void
 	 */
 	public function transferOwnership($ownerId, $newOwnerId) {
-        $params = [
-            'owner' => $ownerId,
-            'newOwner' => $newOwnerId,
-            'type' => Acl::PERMISSION_TYPE_USER
-        ];
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId,
+			'type' => Acl::PERMISSION_TYPE_USER
+		];
 		//We want preserve permissions from both users
-        $sql = "UPDATE `{$this->tableName}` AS `source` 
+		$sql = "UPDATE `{$this->tableName}` AS `source` 
                     LEFT JOIN `{$this->tableName}` AS `target` 
                     ON `target`.`participant` = :newOwner AND `target`.`type` = :type 
                     SET `source`.`permission_edit` =(`source`.`permission_edit` || `target`.`permission_edit`), 
                         `source`.`permission_share` =(`source`.`permission_share` || `target`.`permission_share`), 
                         `source`.`permission_manage` =(`source`.`permission_manage` || `target`.`permission_manage`) 
                     WHERE `source`.`participant` = :owner AND `source`.`type` = :type";
-        $stmt = $this->execute($sql, $params);
-        $stmt->closeCursor();
-        //We can't transfer acl if target already in acl
-        $sql = "DELETE FROM `{$this->tableName}` 
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+		//We can't transfer acl if target already in acl
+		$sql = "DELETE FROM `{$this->tableName}` 
                     WHERE `participant` = :newOwner 
                         AND `type` = :type 
                         AND EXISTS (SELECT `id` FROM (SELECT `id` FROM `{$this->tableName}` 
                                     WHERE `participant` = :owner AND `type` = :type) as tmp)";
-        $stmt = $this->execute($sql, $params);
-        $stmt->closeCursor();
-        //Now we can transfer without errors
-        $sqlUpdate = "UPDATE `{$this->tableName}`  
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+		//Now we can transfer without errors
+		$sqlUpdate = "UPDATE `{$this->tableName}`  
                         SET `participant` = :newOwner WHERE `participant` = :owner AND `type` = :type";
-        $stmt = $this->execute($sqlUpdate, $params);
-        $stmt->closeCursor();
+		$stmt = $this->execute($sqlUpdate, $params);
+		$stmt->closeCursor();
 	}
 }
diff --git a/lib/Db/AssignedUsersMapper.php b/lib/Db/AssignedUsersMapper.php
index df90236dc..d3c9d6670 100644
--- a/lib/Db/AssignedUsersMapper.php
+++ b/lib/Db/AssignedUsersMapper.php
@@ -123,16 +123,16 @@ private function getOrigin(AssignedUsers $assignment) {
 	public function transferOwnership($ownerId, $newOwnerId) {
 		$params = [
 			'newOwner' => $newOwnerId,
-            'type' => AssignedUsers::TYPE_USER
+			'type' => AssignedUsers::TYPE_USER
+		];
+		$sql = "DELETE FROM `{$this->tableName}`  WHERE `participant` = :newOwner AND `type`= :type";
+		$stmt = $this->execute($sql, $params);
+		$stmt->closeCursor();
+		$params = [
+			'owner' => $ownerId,
+			'newOwner' => $newOwnerId,
+			'type' => AssignedUsers::TYPE_USER
 		];
-        $sql = "DELETE FROM `{$this->tableName}`  WHERE `participant` = :newOwner AND `type`= :type";
-        $stmt = $this->execute($sql, $params);
-        $stmt->closeCursor();
-        $params = [
-            'owner' => $ownerId,
-            'newOwner' => $newOwnerId,
-            'type' => AssignedUsers::TYPE_USER
-        ];
 		$sql = "UPDATE `{$this->tableName}`  SET `participant` = :newOwner WHERE `participant` = :owner AND `type`= :type";
 		$stmt = $this->execute($sql, $params);
 		$stmt->closeCursor();
diff --git a/lib/Service/BoardService.php b/lib/Service/BoardService.php
index fa5613182..e9c01d680 100644
--- a/lib/Service/BoardService.php
+++ b/lib/Service/BoardService.php
@@ -680,9 +680,9 @@ public function clone($id, $userId) {
 	 */
 	public function transferOwnership($owner, $newOwner) {
 		$this->boardMapper->transferOwnership($owner, $newOwner);
-        $this->aclMapper->transferOwnership($owner, $newOwner);
-        $this->assignedUsersMapper->transferOwnership($owner, $newOwner);
-        $this->cardMapper->transferOwnership($owner, $newOwner);
+		$this->aclMapper->transferOwnership($owner, $newOwner);
+		$this->assignedUsersMapper->transferOwnership($owner, $newOwner);
+		$this->cardMapper->transferOwnership($owner, $newOwner);
 	}
 
 	private function enrichWithStacks($board, $since = -1) {
diff --git a/tests/integration/database/TransferOwnershipTest.php b/tests/integration/database/TransferOwnershipTest.php
index 459615860..582fca85d 100644
--- a/tests/integration/database/TransferOwnershipTest.php
+++ b/tests/integration/database/TransferOwnershipTest.php
@@ -66,7 +66,7 @@ public function createBoardWithExampleData() {
 		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_USER_1, true, true, true);
 		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_GROUP, self::TEST_GROUP, true, true, true);
 		$this->boardService->addAcl($id, Acl::PERMISSION_TYPE_USER, self::TEST_USER_3, false, true, false);
-        $stacks[] = $this->stackService->create('Stack A', $id, 1);
+		$stacks[] = $this->stackService->create('Stack A', $id, 1);
 		$stacks[] = $this->stackService->create('Stack B', $id, 1);
 		$stacks[] = $this->stackService->create('Stack C', $id, 1);
 		$cards[] = $this->cardService->create('Card 1', $stacks[0]->getId(), 'text', 0, self::TEST_USER_1);
@@ -136,68 +136,68 @@ public function testReassignCardToNewOwner() {
 		$this->assertNotContains(self::TEST_USER_1, $participantsUIDs);
 	}
 
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testReassignCardToNewParticipantOnlyIfParticipantHasUserType() {
-        $this->assignmentService->assignUser($this->cards[1]->getId(), self::TEST_USER_1, AssignedUsers::TYPE_GROUP);
-        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
-        $assignedUsers = $this->assignedUsersMapper->find($this->cards[1]->getId());
-        $participantsUIDs = [];
-        foreach ($assignedUsers as $user) {
-            $participantsUIDs[] = $user->getParticipant();
-        }
-        $this->assertContains(self::TEST_USER_1, $participantsUIDs);
-        $this->assertNotContains(self::TEST_USER_2, $participantsUIDs);
-    }
-
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testTargetAlreadyParticipantOfBoard() {
-        $this->expectNotToPerformAssertions();
-        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
-    }
-
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testDontRemoveTargetFromAcl() {
-        $this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
-        $board = $this->boardService->find($this->board->getId());
-        $acl = $board->getAcl();
-        $isOwnerInAcl = (bool)array_filter($acl, function ($item) {
-            return $item->getParticipant() === self::TEST_USER_3 && $item->getType() === Acl::PERMISSION_TYPE_USER;
-        });
-        $this->assertTrue($isOwnerInAcl);
-    }
-
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testMergePermissions() {
-        $this->boardService->addAcl($this->board->getId(), Acl::PERMISSION_TYPE_USER, self::TEST_USER_2, true, false, true);
-        $this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
-        $board = $this->boardService->find($this->board->getId());
-        $acl = $board->getAcl();
-        $isMerged = (bool)array_filter($acl, function ($item) {
-            return $item->getParticipant() === self::TEST_USER_1
-                && $item->getType() === Acl::PERMISSION_TYPE_USER
-                && $item->getPermission(Acl::PERMISSION_EDIT)
-                && $item->getPermission(Acl::PERMISSION_SHARE)
-                && $item->getPermission(Acl::PERMISSION_MANAGE);
-        });
-        $this->assertTrue($isMerged);
-    }
-
-    /**
-     * @covers ::transferOwnership
-     */
-    public function testTargetAlreadyParticipantOfCard() {
-        $this->expectNotToPerformAssertions();
-        $this->assignmentService->assignUser($this->cards[0]->getId(), self::TEST_USER_3, AssignedUsers::TYPE_USER);
-        $this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
-    }
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testReassignCardToNewParticipantOnlyIfParticipantHasUserType() {
+		$this->assignmentService->assignUser($this->cards[1]->getId(), self::TEST_USER_1, AssignedUsers::TYPE_GROUP);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_2);
+		$assignedUsers = $this->assignedUsersMapper->find($this->cards[1]->getId());
+		$participantsUIDs = [];
+		foreach ($assignedUsers as $user) {
+			$participantsUIDs[] = $user->getParticipant();
+		}
+		$this->assertContains(self::TEST_USER_1, $participantsUIDs);
+		$this->assertNotContains(self::TEST_USER_2, $participantsUIDs);
+	}
+
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testTargetAlreadyParticipantOfBoard() {
+		$this->expectNotToPerformAssertions();
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
+	}
+
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testDontRemoveTargetFromAcl() {
+		$this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
+		$board = $this->boardService->find($this->board->getId());
+		$acl = $board->getAcl();
+		$isOwnerInAcl = (bool)array_filter($acl, function ($item) {
+			return $item->getParticipant() === self::TEST_USER_3 && $item->getType() === Acl::PERMISSION_TYPE_USER;
+		});
+		$this->assertTrue($isOwnerInAcl);
+	}
+
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testMergePermissions() {
+		$this->boardService->addAcl($this->board->getId(), Acl::PERMISSION_TYPE_USER, self::TEST_USER_2, true, false, true);
+		$this->boardService->transferOwnership(self::TEST_USER_2, self::TEST_USER_3);
+		$board = $this->boardService->find($this->board->getId());
+		$acl = $board->getAcl();
+		$isMerged = (bool)array_filter($acl, function ($item) {
+			return $item->getParticipant() === self::TEST_USER_1
+				&& $item->getType() === Acl::PERMISSION_TYPE_USER
+				&& $item->getPermission(Acl::PERMISSION_EDIT)
+				&& $item->getPermission(Acl::PERMISSION_SHARE)
+				&& $item->getPermission(Acl::PERMISSION_MANAGE);
+		});
+		$this->assertTrue($isMerged);
+	}
+
+	/**
+	 * @covers ::transferOwnership
+	 */
+	public function testTargetAlreadyParticipantOfCard() {
+		$this->expectNotToPerformAssertions();
+		$this->assignmentService->assignUser($this->cards[0]->getId(), self::TEST_USER_3, AssignedUsers::TYPE_USER);
+		$this->boardService->transferOwnership(self::TEST_USER_1, self::TEST_USER_3);
+	}
 
 	public function tearDown(): void {
 		$this->boardService->deleteForce($this->board->getId());
diff --git a/tests/unit/Service/BoardServiceTest.php b/tests/unit/Service/BoardServiceTest.php
index 4f181c533..b6f22f7fd 100644
--- a/tests/unit/Service/BoardServiceTest.php
+++ b/tests/unit/Service/BoardServiceTest.php
@@ -57,8 +57,8 @@ class BoardServiceTest extends TestCase {
 	private $boardMapper;
 	/** @var StackMapper */
 	private $stackMapper;
-    /** @var CardMapper */
-    private $cardMapper;
+	/** @var CardMapper */
+	private $cardMapper;
 	/** @var PermissionService */
 	private $permissionService;
 	/** @var NotificationHelper */