fix: Don't auto complete nor allow sharing to disabled users

Assisted-by: ClaudeCode:claude-opus-5-5
Signed-off-by: Carl Schwan <carl@carlschwan.eu>

[skip ci]

Author: CarlSchwan

apps/files_sharing/tests/Listener/RestrictInteractionListenerTest.php

@@ -177,7 +177,7 @@ public function testNodeResourceShareActionNoLinkEmailReceiverMissingReadPermiss
 			new RemoteGroupReceiver(''),
 			new RemoteUserReceiver(''),
 			new RoomReceiver(''),
-			new UserReceiver(''),
+			new UserReceiver($this->user->getUID(), $this->user),
 		] as $receiver) {
 			$event = new RestrictInteractionEvent($this->user->getUID(), $this->user, [$resource], new ShareAction(Constants::PERMISSION_ALL & ~Constants::PERMISSION_READ), [$receiver]);
 			$this->assertEquals('File share needs at least read permission.', $event->isInteractionRestricted());

core/Listener/RestrictInteractionListener.php

@@ -55,6 +55,10 @@ public function handle(Event $event): void {
 			}
 
 			foreach ($event->receivers as $receiver) {
+				if ($receiver instanceof UserReceiver && !$receiver->getUser()->isEnabled()) {
+					throw new InteractionRestrictedException('Sharing with a disabled account is not allowed.', $this->l10n->t('Cannot share with a disabled account.'));
+				}
+
 				if ($this->manager->shareWithGroupMembersOnly()) {
 					if ($receiver instanceof UserReceiver) {
 						$groups = array_intersect(

lib/private/Collaboration/Collaborators/MailPlugin.php

@@ -127,7 +127,7 @@ public function search($search, $limit, $offset, ISearchResult $searchResult): b
 
 				if (isset($contact['isLocalSystemBook'])) {
 					$contactUser = $this->userManager->get($contact['UID']);
-					if ($contactUser === null) {
+					if ($contactUser === null || !$contactUser->isEnabled()) {
 						continue;
 					}
 

lib/private/Collaboration/Collaborators/RemotePlugin.php

@@ -73,7 +73,7 @@ public function search($search, $limit, $offset, ISearchResult $searchResult): b
 					}
 
 					$localUser = $this->userManager->get($remoteUser);
-					if ($localUser !== null && $remoteUser !== $this->userId && $cloudId === $localUser->getCloudId()) {
+					if ($localUser !== null && $localUser->isEnabled() && $remoteUser !== $this->userId && $cloudId === $localUser->getCloudId()) {
 						$result['wide'][] = [
 							'label' => $contact['FN'],
 							'uuid' => $contact['UID'],

tests/Core/Listener/RestrictInteractionListenerTest.php

@@ -86,6 +86,21 @@ public function testShareActionDisabledForUser(): void {
 		$this->assertTrue($group->delete());
 	}
 
+	public function testShareActionUserReceiverDisabled(): void {
+		$user2 = Server::get(IUserManager::class)->createUser('user2', 'password');
+		$this->assertNotFalse($user2);
+
+		$event = new RestrictInteractionEvent($this->user->getUID(), $this->user, [], new ShareAction(), [new UserReceiver($user2->getUID(), $user2)]);
+		$this->assertFalse($event->isInteractionRestricted());
+
+		$user2->setEnabled(false);
+
+		$event = new RestrictInteractionEvent($this->user->getUID(), $this->user, [], new ShareAction(), [new UserReceiver($user2->getUID(), $user2)]);
+		$this->assertEquals('Cannot share with a disabled account.', $event->isInteractionRestricted());
+
+		$this->assertTrue($user2->delete());
+	}
+
 	/** @psalm-suppress DeprecatedMethod The configs are not migrated to IAppConfig, so using deprecated IConfig is required for now. */
 	public function testShareActionUserReceiverGroupMembersOnly(): void {
 		$user2 = Server::get(IUserManager::class)->createUser('user2', 'password');

tests/lib/Collaboration/Collaborators/MailPluginTest.php

@@ -58,6 +58,9 @@ protected function setUp(): void {
 				$user
 					->method('getUID')
 					->willReturn($uid);
+				$user
+					->method('isEnabled')
+					->willReturn(!str_starts_with($uid, 'disabled'));
 
 				return $user;
 			});

tests/lib/Share20/ManagerTest.php

@@ -2266,11 +2266,11 @@ public function testUserCreateChecksShareWithGroupMembersOnlySharedGroup(): void
 			->setNode($node)
 			->setPermissions(Constants::PERMISSION_ALL);
 
-		$sharedBy = $this->createMock(IUser::class);
+		$sharedBy = $this->createEnabledUser(true);
 		$sharedBy
 			->method('getUID')
 			->willReturn('sharedBy');
-		$sharedWith = $this->createMock(IUser::class);
+		$sharedWith = $this->createEnabledUser(true);
 
 		$this->groupManager
 			->method('getUserGroupIds')
@@ -2456,8 +2456,8 @@ public function testUserCreateChecksIdenticalPathNotSharedWithUser(): void {
 			->setProviderId('foo')
 			->setId('bar');
 
-		$sharedWith = $this->createMock(IUser::class);
-		$sharedBy = $this->createMock(IUser::class);
+		$sharedWith = $this->createEnabledUser(true);
+		$sharedBy = $this->createEnabledUser(true);
 		$sharedBy
 			->method('getUID')
 			->willReturn('sharedBy');
@@ -3271,15 +3271,17 @@ public function testCanShare($expected, $sharingEnabled, $disabledForUser): void
 			->with('user1')
 			->willReturn($userFolder);
 
-		$user1 = $this->createMock(IUser::class);
+		$user1 = $this->createEnabledUser(true);
 		$user1
 			->method('getUID')
 			->willReturn('user1');
 
 		$this->userManager
 			->method('get')
-			->with('user1')
-			->willReturn($user1);
+			->willReturnMap([
+				['user1', $user1],
+				['user2', $this->createEnabledUser(true)],
+			]);
 
 		$share = $this->manager->newShare()
 			->setShareType(IShare::TYPE_USER)