Private group configured as approvers in project settings is not added as approvers in merge request when the user that create the merge request can't see the group
Summary
In gitlab 11.1 and earlier, when a user create a merge request, all users in group configured as approvers in project configuration were added as approvers in merge request independently of user that create the merge request. Since gitlab 11.2, when the user which create the merge request can't see one of the group configured in project configuration, members of this group are not added as approvers in merge request, all other group visible for the user are still added. Adminstrator user are not impacted by this behaviour, i guess that's because they can see all users and groups even if they aren't being shared explecitly.
Steps to reproduce
Create a project.
Create a private group A containing user A.
Create a private group B containing user B (user must not be a gitlab administrator).
Set required approvals to 1 in project configuration.
Add group A as approvers in project configuration.
Create a merge request with user B.
What is the current bug behavior?
The created merge request not contains user A as approver
What is the expected correct behavior?
The created merge request contains user A as approver