Guest users must not be able to search for other users

[PVince81]

Steps to reproduce

1. Setup NC 22 with Talk 12.0.0
2. Enable the guests app
3. Add "spreed" the to guest app's allow list
4. Create a user "Bob"
5. Create a folder "guests"
6. Share the folder "guests" by inviting a new guest "[email protected]" (make sure to have mailhog configured to receive the email)
7. Login as "[email protected]" after setting a password
8. Open the Talk app
9. In the search bar on the left sidebar, type "Bob"
10. Click on "Bob"

Expected behaviour

Bob does not appear in the search results.

Actual behaviour

Bob appears and Alice was able to initiate a one to one conversation.

Talk app

Talk app version: 12.0.0 from git stable22 (edb5f45d98283adad59d45e20e68f73b98d17596)

Server configuration

Nextcloud Version: stable 22 (57a4ef9da8831c02b13d4d5772197185adc0220a)

Analysis

This is a regression from NC 21.
Executing the same steps using stable21 from server and stable21.1 from the Talk app works as expected.

[PVince81]

the search is using the autocomplete API:

https://vvortex.local/ocs/v2.php/core/autocomplete/get?search=bob&itemType=call&itemId=new&shareTypes[]=0&shareTypes[]=1&shareTypes[]=7

[PVince81]

I went back to around 11.0.0-rc.1 (e754b751b) but the API still returns the user. So the regression is likely on server, not in the talk app.

[PVince81]

a bisect on the server points at nextcloud/server@4b1576e from nextcloud/server#24295

[PVince81]

Revert PR here: nextcloud/server#27715