[Bug]: Already cached mounts are added over and over

[sorbaugh]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

A setup of the FS will add some mounts to oc_mounts again even though they are already present.
Found in #50157.

Steps to reproduce

1. Place debugger at

   server/lib/private/Files/Config/UserMountCache.php

   Line 97 in 13f2306

   $this->connection->beginTransaction();

2. Observe the home mount being added every time the FS is setup.

Expected behavior

Only fire the events when necessary

Nextcloud Server version

master

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

No response