When using nested groups without a memberof overlay, then fetchListOfGroups is called from getGroupsByMember without applying the group filter.
In some setups, the "unfiltered" result is then written back to the group mapping table. That might cause random "An administrator removed you from group" activities.
I was unable to replicate it locally, but we got the feedback that the random activities stopped with the patch applied.
Ref: https://github.com/nextcloud/server/issues/42195
Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>
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