Do not allow approve if author is committer

This commit fixes the case when author is a committer
If merge request approvals are disabled for an author
then Approve button should be hidden for the author

ee/app/models/approval_state.rb

@@ -140,8 +140,8 @@ class ApprovalState
     return false if approvals.where(user: user).any?
     # At this point, follow self-approval rules. Otherwise authors must
     # have been in the list of unactioned_approvers to have been approved.
-    return committers_can_approve? if merge_request.committers.include?(user)
-    return authors_can_approve? if merge_request.author == user
+    return false if !authors_can_approve? && merge_request.author == user
+    return false if !committers_can_approve? && merge_request.committers.include?(user)
 
     true
   end

ee/changelogs/unreleased/id-fix-approve-button-visibility.yml

+---
+title: Fix preventing approval of merge requests by an author
+merge_request: 11263
+author:
+type: fixed

ee/spec/models/approval_state_spec.rb

@@ -608,10 +608,10 @@ describe ApprovalState do
               expect(subject.can_approve?(user)).to be_truthy
             end
 
-            it 'allows the user to approve the MR if not within the approvers list' do
+            it 'does not allow the user to approve the MR if not within the approvers list' do
               allow(subject).to receive(:approvers).and_return([])
 
-              expect(subject.can_approve?(user)).to be_truthy
+              expect(subject.can_approve?(user)).to be_falsey
             end
           end
         end