fix(test): stabilise flaky DB and quota tests

- Quota::fopen: when free_space() returns SPACE_NOT_COMPUTED the previous
  code skipped wrapping the stream entirely, letting unlimited writes
  through. Now wraps with the full quota as a conservative ceiling, which
  makes testStreamCopyNotEnoughSpace deterministic regardless of whether
  the cache has a valid root-size entry.

- CleanupShareTargetTest::setUp: call getUserFolder()->getDirectoryListing()
  for every test user so their home folders are in the filecache before
  any share operations. tearDown wipes filecache; without this
  getShareById (which JOINs on filecache) throws ShareNotFound
  intermittently on the second createUserShare call.

- DBConfigServiceTest::setUp: remove any mounts left by a previously
  failed test run so testSetMountPoint and testGetAllMounts do not see
  unexpected extra rows.

- StoragesServiceTestCase / CleaningDBConfig: add cleanAll() that removes
  every mount from the DB (not just those tracked by the current instance)
  and call it at the top of setUp so testGetStoragesBackendNotVisible and
  testGetStoragesAuthMechanismNotVisible start with an empty external
  mount table.

Signed-off-by: Anna Larch <anna@nextcloud.com>
AI-Assisted-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: miaulalala

apps/files_external/tests/Service/DBConfigServiceTest.php

@@ -26,6 +26,10 @@ protected function setUp(): void {
 		parent::setUp();
 		$this->connection = Server::get(IDBConnection::class);
 		$this->dbConfig = new DBConfigService($this->connection, Server::get(ICrypto::class));
+		// Remove any mounts left by a previously failed test run
+		foreach ($this->dbConfig->getAllMounts() as $mount) {
+			$this->dbConfig->removeMount($mount['mount_id']);
+		}
 	}
 
 	protected function tearDown(): void {

apps/files_external/tests/Service/StoragesServiceTestCase.php

@@ -50,6 +50,13 @@ public function clean(): void {
 			$this->removeMount($id);
 		}
 	}
+
+	public function cleanAll(): void {
+		foreach ($this->getAllMounts() as $mount) {
+			$this->removeMount($mount['mount_id']);
+		}
+		$this->mountIds = [];
+	}
 }
 
 #[\PHPUnit\Framework\Attributes\Group(name: 'DB')]
@@ -65,6 +72,7 @@ abstract class StoragesServiceTestCase extends \Test\TestCase {
 	protected function setUp(): void {
 		parent::setUp();
 		$this->dbConfig = new CleaningDBConfig(Server::get(IDBConnection::class), Server::get(ICrypto::class));
+		$this->dbConfig->cleanAll(); // Remove any mounts left by previous test runs
 		self::$hookCalls = [];
 		$config = Server::get(IConfig::class);
 		$this->dataDir = $config->getSystemValue(

apps/files_sharing/tests/Repair/CleanupShareTargetTest.php

@@ -27,6 +27,11 @@ class CleanupShareTargetTest extends TestCase {
 	protected function setUp(): void {
 		parent::setUp();
 		$this->cleanupShareTarget = Server::get(CleanupShareTarget::class);
+		// Ensure all test users' home folders are in the filecache before any share
+		// operations, because tearDown wipes filecache and getShareById JOINs on it.
+		foreach ([self::TEST_FILES_SHARING_API_USER1, self::TEST_FILES_SHARING_API_USER2, self::TEST_FILES_SHARING_API_USER3] as $user) {
+			$this->rootFolder->getUserFolder($user)->getDirectoryListing();
+		}
 	}
 
 	private function createUserShare(string $by, string $target = self::TEST_FOLDER_NAME): IShare {

lib/private/Files/Storage/Wrapper/Quota.php

@@ -132,10 +132,12 @@ public function fopen(string $path, string $mode) {
 		}
 
 		$source = $this->getWrapperStorage()->fopen($path, $mode);
-		if ($source && (is_int($free) || is_float($free)) && $free >= 0 && $mode !== 'r' && $mode !== 'rb') {
-			// only apply quota for files, not metadata, trash or others
-			if ($this->shouldApplyQuota($path)) {
+		if ($source && $mode !== 'r' && $mode !== 'rb' && $this->shouldApplyQuota($path)) {
+			if ((is_int($free) || is_float($free)) && $free >= 0) {
 				return \OC\Files\Stream\Quota::wrap($source, $free);
+			} elseif ($free === FileInfo::SPACE_NOT_COMPUTED) {
+				// Used space is unknown; apply full quota as a conservative ceiling
+				return \OC\Files\Stream\Quota::wrap($source, $this->getQuota());
 			}
 		}