Never ending folder loop and file lock - federated sharing

Owncloud versions used

User A: owncloud 10.11.0 prealpha (git)
User B: owncloud 10.11.0 prealpha (git) / 10.10 / 10.09

User A on ownCloud server1, User B on another ownCloud server2.

Steps to reproduce

1. Create a folder ‘f1’ in User A side.
2. Create a folder ‘f2’ in User B side.
3. Share f1 with B and f2 with A.
4. Move f2 inside f1 at A.
5. Move f1 inside f2 at B.
6. Open f1 and try navigating as deep as you can.
7. This results to a never ending loop. (Issue 1)
8. Try deleting any of these. Files are locked and cannot be deleted now.
9. Unshare these folders f1 and f2 from User A and B side respectively.
10. Both folders f1 and f2 are now empty.
11. Try deleting them again, they won't be deleted.

Expected behaviour

• Owncloud detects the never ending loop and stops me from moving the folder.
• Owncloud lets me delete folder f1 and f2 after being unshared.

Actual behaviour

• The folders can be moved inside another shared folder easily.
• Even after unsharing and deleting everything inside the folder, the folder can not be deleted.

Server configuration

Operating system: ubuntu 20.04

Web server: apache2

Database: MySQL

PHP version: 7.4.3

ownCloud version: 10.11.0 prealpha (git)

Updated from an older ownCloud or fresh install: fresh

Where did you install ownCloud from: github

PS: This is an existing issue in older version as well. The same issue occurs between two servers running on v10.10 as well.

Start by reproducing the folder moves between two federated ownCloud servers using the listed steps, then trace the sharing and folder move/deletion paths involved. Done means the server prevents the circular move and permits f1 and f2 to be deleted after they are unshared; no source file or test is named in the issue.