test: Check if someone broke file sharing with Talk

[nickvergessen]

• Suspicious failing tests from fix(hpb-service): Support HPB service accounts without expiration #15698

Talk integration tests started failing

  Scenario: get room for file no longer shared
    Given user "participant1" shares "welcome.txt" with user "participant2" with OCS 100
    And user "participant2" accepts last share
    And user "participant1" deletes last share
    When user "participant1" gets the room for path "welcome.txt" with 404 (v1)

I bisected:

$ git bisect bad
39e2e70084c7aa3899c1c32816321769cb2f4d8f is the first bad commit
commit 39e2e70084c7aa3899c1c32816321769cb2f4d8f (HEAD)
Author: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>
Date:   Fri Aug 1 13:05:54 2025 +0200

    feat(mounts): optimize load of mounts by filtering on database side
    
    Signed-off-by: Benjamin Gaussorgues <benjamin.gaussorgues@nextcloud.com>

 lib/private/Files/Config/UserMountCache.php | 68 ++++++++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 44 insertions(+), 24 deletions(-)

nextcloud/server#54197

---

I logged the accesslist here:

spreed/lib/Files/Util.php

Lines 39 to 62 in 956a1ab

	if (!isset($this->accessLists[$fileId])) {
	$nodes = $this->rootFolder->getById((int)$fileId);
	if (empty($nodes)) {
	return [];
	}
	$node = array_shift($nodes);
	$accessList = $this->shareManager->getAccessList($node);
	if (!$node->getStorage()->instanceOfStorage(SharedStorage::class)) {
	// The file is not a shared file,
	// let's check the accesslist for mount points of groupfolders and external storages
	$mountsForFile = $this->userMountCache->getMountsForFileId($fileId);
	$affectedUserIds = array_map(function (ICachedMountInfo $mount) {
	return $mount->getUser()->getUID();
	}, $mountsForFile);
	$accessList['users'] = array_unique(array_merge($affectedUserIds, $accessList['users']));
	}
	$this->accessLists[$fileId] = $accessList['users'];
	}
	return $this->accessLists[$fileId];

It seems it returns the user even though the share was deleted:

{"message":"[{\"users\":[\"participant1\",\"participant2\"],\"remote\":false,\"public\":false,\"mail\":[],\"email\":[]}]"}

If I add a PROPFIND from particiapnt2 before getting the room it fails the request correctly with 404 as it is no longer shared with anyone:
90eda64

---

I assume correct that this is intended right?
It's basically a proof that the caching is working. Unfortunately this also means that you'd receive activity and other things until your filesystem was setup again?

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not possible
• 📘 API documentation in docs/ has been updated or is not required
• 🔖 Capability is added or not needed

[nickvergessen]

• Same bug is now triggered by [stable31] fix: cast fileid to string in getMountsForFileId server#54744 on stable31, so backporting

[nickvergessen]

/backport to stable31