Files can not be deleted by the retention job if the file is not deletable in the user mount point

[danxuliu]

The retention job only takes into account the first node of the first mount point of a file to be deleted. If that node is not deletable the retention job will fail to delete it, even if it would be deletable when using a node from another mount point.

Moreover, in some cases the retention job may not be able to delete a file even if there is a single mount point if the file is not deletable in that mount point (for example, if it is in a group folder without delete permissions). -> Extracted to #142

Steps to reproduce

• As an admin, create users user0 and user1
• Log in as user0
• Open the Files app
• Create a folder
• Share the folder with user1
• Remove delete permissions from the share
• Open the folder
• Upload an old file (a file with an mtime from months or years ago)
• Add a tag deleteTest to that file
• Log out
• Log in as user1 (so the mount point for the shared folder is created)
• Log out
• As an admin, create user user2
• Transfer ownership of files from user0 to user2 with occ files:transfer-ownership user0 user2
• Delete user0 with occ user:delete user0 (so the mount point for the shared folder becomes the first one for the file)
• Log in as user1
• Do NOT log out (so the shared storage for the shared folder is kept "alive"; this needs to be done after the share was transferred)
• As an admin, open the Flow admin settings
• Create a new retention job to delete files with tag deleteTest and a modification time older than 10 days
• Set debug level for Nextcloud logs with occ config:system:set loglevel --type integer --value 0
• Wait patiently until the retention job runs or force its execution with occ background-job:execute --force-execute XXX (requires Add a command to show info about a background job and force-execute it server#27217)
  • The following SQL query can be used to find out the job ID; if there is more than one retention job look for the matching tag ID in the arguments: SELECT id, argument FROM oc_jobs WHERE class LIKE "%Files_Retention%"

Expected behaviour

The file is deleted.

Actual behaviour

The file is not deleted. Nextcloud logs show a NotPermittedException when trying to delete the file with the retention job.