[Bug]: Mountpoints of Collectives app no longer initialized on all requests

[mejo-]

⚠️ 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 (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

Starting today, the Nextcloud server master branch broke mountpoint initialization of the Collectives app. When requesting the pages of a collective from the Collectives app backend, the folder that is supposed to hold the mountpoints for all collectives is empty instead.

The second get in this line throws a NotFoundException, because the mountpoints for the users collectives are not mounted yet: https://gitlab.com/collectivecloud/collectives/-/blob/main/lib/Service/PageService.php#L71

I'm updating the Nextcloud server code almost daily, so I suppose that some change within the last days broke this.

After a hint by @CarlSchwan, I tried adding 'Mountprovider::class' as extra argument to the parent::_constructor() call in CollectiveMountpoint, which indeed seems to fix the issue for me.

@PVince81 @icewind1991

Steps to reproduce

1. Checkout latest Nextcloud server master branch.
2. Install Collectives app.
3. Create a collective and try to browse its pages. An error message will be shown that the pages list could not be fetched.

Expected behavior

The mountpoints for the users collectives should be mounted during the requests to the Collectives app API.

Installation method

Manual installation

Operating system

No response

PHP engine version

PHP 7.4

Web server

Nginx

Database engine version

MariaDB

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

No response

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

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

Configuration report

No response

List of activated Apps

...

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

[PVince81]

we merge #31773 on Monday, so perhaps this could be related

[PVince81]

@icewind1991 any update ? did any recent PR fix this ?

[icewind1991]

#31901 fixes the handling of mounts with the Mountprovider::class added to the parent::constructor call.

[PVince81]

@mejo- the PR is merged, please try again with master