[stable25] fix: catch ManuallyLockedException and use app context

apps/files_versions/lib/Storage.php

@@ -436,24 +436,26 @@ private static function copyFileContents($view, $path1, $path2) {
 		$view->lockFile($path1, ILockingProvider::LOCK_EXCLUSIVE);
 		$view->lockFile($path2, ILockingProvider::LOCK_EXCLUSIVE);
 
-		// TODO add a proper way of overwriting a file while maintaining file ids
-		if ($storage1->instanceOfStorage('\OC\Files\ObjectStore\ObjectStoreStorage') || $storage2->instanceOfStorage('\OC\Files\ObjectStore\ObjectStoreStorage')) {
-			$source = $storage1->fopen($internalPath1, 'r');
-			$target = $storage2->fopen($internalPath2, 'w');
-			[, $result] = \OC_Helper::streamCopy($source, $target);
-			fclose($source);
-			fclose($target);
-
-			if ($result !== false) {
-				$storage1->unlink($internalPath1);
+		try {
+			// TODO add a proper way of overwriting a file while maintaining file ids
+			if ($storage1->instanceOfStorage('\OC\Files\ObjectStore\ObjectStoreStorage') || $storage2->instanceOfStorage('\OC\Files\ObjectStore\ObjectStoreStorage')) {
+				$source = $storage1->fopen($internalPath1, 'r');
+				$target = $storage2->fopen($internalPath2, 'w');
+				[, $result] = \OC_Helper::streamCopy($source, $target);
+				fclose($source);
+				fclose($target);
+
+				if ($result !== false) {
+					$storage1->unlink($internalPath1);
+				}
+			} else {
+				$result = $storage2->moveFromStorage($storage1, $internalPath1, $internalPath2);
 			}
-		} else {
-			$result = $storage2->moveFromStorage($storage1, $internalPath1, $internalPath2);
+		} finally {
+			$view->unlockFile($path1, ILockingProvider::LOCK_EXCLUSIVE);
+			$view->unlockFile($path2, ILockingProvider::LOCK_EXCLUSIVE);
 		}
 
-		$view->unlockFile($path1, ILockingProvider::LOCK_EXCLUSIVE);
-		$view->unlockFile($path2, ILockingProvider::LOCK_EXCLUSIVE);
-
 		return ($result !== false);
 	}
 

apps/files_versions/lib/Versions/VersionManager.php

@@ -27,8 +27,13 @@
 
 use OCP\Files\File;
 use OCP\Files\FileInfo;
+use OCP\Files\IRootFolder;
+use OCP\Files\Lock\ILock;
+use OCP\Files\Lock\ILockManager;
+use OCP\Files\Lock\LockContext;
 use OCP\Files\Storage\IStorage;
 use OCP\IUser;
+use OCP\Lock\ManuallyLockedException;
 
 class VersionManager implements IVersionManager {
 	/** @var (IVersionBackend[])[] */
@@ -94,7 +99,7 @@ public function createVersion(IUser $user, FileInfo $file) {
 
 	public function rollback(IVersion $version) {
 		$backend = $version->getBackend();
-		return $backend->rollback($version);
+		return self::handleAppLocks(fn(): ?bool => $backend->rollback($version));
 	}
 
 	public function read(IVersion $version) {
@@ -110,4 +115,48 @@ public function getVersionFile(IUser $user, FileInfo $sourceFile, $revision): Fi
 	public function useBackendForStorage(IStorage $storage): bool {
 		return false;
 	}
+
+	/**
+	 * Catch ManuallyLockedException and retry in app context if possible.
+	 *
+	 * Allow users to go back to old versions via the versions tab in the sidebar
+	 * even when the file is opened in the viewer next to it.
+	 *
+	 * Context: If a file is currently opened for editing
+	 * the files_lock app will throw ManuallyLockedExceptions.
+	 * This prevented the user from rolling an opened file back to a previous version.
+	 *
+	 * Text and Richdocuments can handle changes of open files.
+	 * So we execute the rollback under their lock context
+	 * to let them handle the conflict.
+	 *
+	 * @param callable $callback function to run with app locks handled
+	 * @return bool|null
+	 * @throws ManuallyLockedException
+	 *
+	 */
+	private static function handleAppLocks(callable $callback): ?bool {
+			try {
+					return $callback();
+			} catch (ManuallyLockedException $e) {
+					$owner = (string) $e->getOwner();
+					$appsThatHandleUpdates = array("text", "richdocuments");
+					if (!in_array($owner, $appsThatHandleUpdates)) {
+							throw $e;
+					}
+					// The LockWrapper in the files_lock app only compares the lock type and owner
+					// when checking the lock against the current scope.
+					// So we do not need to get the actual node here
+					// and use the root node instead.
+					$root = \OC::$server->get(IRootFolder::class);
+					$lockContext = new LockContext($root, ILock::TYPE_APP, $owner);
+					$lockManager = \OC::$server->get(ILockManager::class);
+					$result = null;
+					$lockManager->runInScope($lockContext, function() use ($callback, &$result) {
+							$result = $callback();
+					});
+					return $result;
+			}
+	}
+
 }