"0 approvals required" when project shared with group

Summary

When project is shared with specific members ("Members with access to >project<"), these members are possible approvers. Thus when MR requires 2 approvals, and project is shared with 5 people, everything is fine. If the project is shared with 1 person only, then 2 approvals get cut to 1 (because there's only 1 possible approver).

However, when the project is shared with a group ("Groups with access to >project<"), then group members aren't considered as possible approvers - no matter how many people are in the group, merge requests always require 0 approvals, because members included via group aren't considered as potential reviewers. This is inconsistent with the behaviour described above.

Steps to reproduce

Share the project with a group of more than 1 person. Create a merge request with at least 2 approvals required. Merge request requires 0 approvals. Add a person from the group directly - merge request now requires 1 approval (and more when including more people).

What is the current bug behavior?

Members of the groups with which the project is shared aren't considered as potential reviewers.

What is the expected correct behavior?

All members with whom the project is shared are considered as potential reviewers.

Happens on Gitlab EE (gitlab.com) v. 9.1.1-ee 43c23ff4