Extend "has direct access to file" check also to files in shared folders

Before a file was seen as directly accessible by the user if the user
received the file through a user, group, circle or room share. Now files
that are a descendant of a folder that meets those conditions are seen
as directly accessible by the user too.

Due to this now the rooms for files in a shared folder can be accessed
by any user that has access to the folder; it is no longer needed to
explicitly share the file too with them.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

2 files changed, 23 insertions, 15 deletions

diff --git a/lib/Files/Listener.php b/lib/Files/Listener.php
index 5ee4016a8..7c8427f5e 100644
--- a/lib/Files/Listener.php
+++ b/lib/Files/Listener.php
@@ -36,9 +36,9 @@ use Symfony\Component\EventDispatcher\GenericEvent;
  * specific shared file, for example, when collaboratively editing it. The room
  * is persistent and can be accessed simultaneously by any user with direct
  * access (user, group, circle and room share, but not link share, for example)
- * to that file. The room has no owner, although self joined users become
- * persistent participants automatically when they join until they explicitly
- * leave or no longer have access to the file.
+ * to that file (or to an ancestor). The room has no owner, although self joined
+ * users become persistent participants automatically when they join until they
+ * explicitly leave or no longer have access to the file.
  *
  * These rooms are associated to a "file" object, and their custom behaviour is
  * provided by calling the methods of this class as a response to different room
@@ -84,9 +84,9 @@ class Listener {
 	 * Prevents users from joining if they do not have direct access to the
 	 * file.
 	 *
-	 * A user has direct access to a file if she received the file through a
-	 * user, group, circle or room share (but not through a link share, for
-	 * example), or if she is the owner of such a file.
+	 * A user has direct access to a file if she received the file (or an
+	 * ancestor) through a user, group, circle or room share (but not through a
+	 * link share, for example), or if she is the owner of such a file.
 	 *
 	 * This method should be called before a user joins a room.
 	 *
diff --git a/lib/Files/Util.php b/lib/Files/Util.php
index a6fd32855..e830378c6 100644
--- a/lib/Files/Util.php
+++ b/lib/Files/Util.php
@@ -26,6 +26,7 @@ namespace OCA\Spreed\Files;
 
 use OCP\Files\IRootFolder;
 use OCP\Files\Node;
+use OCP\Files\NotFoundException;
 use OCP\Share\IManager as IShareManager;
 use OCP\Share\IShare;
 
@@ -77,6 +78,8 @@ class Util {
 	 * A user has direct access to a share and, thus, to a file, if she received
 	 * the file through a user, group, circle or room share (but not through a
 	 * public link, for example), or if she is the owner of such a share.
+	 * Note that this includes too files received as a descendant of a folder
+	 * that meets the above conditions.
 	 *
 	 * Only files are taken into account; folders are ignored.
 	 *
@@ -86,16 +89,27 @@ class Util {
 	 */
 	public function getAnyDirectShareOfFileAccessibleByUser(string $fileId, string $userId) {
 		$userFolder = $this->rootFolder->getUserFolder($userId);
-		$fileById = $userFolder->getById($fileId);
-		if (empty($fileById)) {
+		$nodes = $userFolder->getById($fileId);
+		if (empty($nodes)) {
 			return null;
 		}
 
-		foreach ($fileById as $node) {
+		$nodes = array_filter($nodes, function($node) {
+			return $node->getType() === \OCP\Files\FileInfo::TYPE_FILE;
+		});
+
+		while (!empty($nodes)) {
+			$node = array_pop($nodes);
+
 			$share = $this->getAnyDirectShareOfNodeAccessibleByUser($node, $userId);
 			if ($share) {
 				return $share;
 			}
+
+			try {
+				$nodes[] = $node->getParent();
+			} catch (NotFoundException $e) {
+			}
 		}
 
 		return null;
@@ -104,17 +118,11 @@ class Util {
 	/**
 	 * Returns any share of the node that the user has direct access to.
 	 *
-	 * Only files are taken into account; folders are ignored.
-	 *
 	 * @param Node $node
 	 * @param string $userId
 	 * @return IShare|null
 	 */
 	private function getAnyDirectShareOfNodeAccessibleByUser(Node $node, string $userId) {
-		if ($node->getType() === \OCP\Files\FileInfo::TYPE_FOLDER) {
-			return null;
-		}
-
 		$reshares = false;
 		$limit = 1;