Handle members who are existing hierarchy members

When adding a new member record for a user who is
already an active member of the hierarchy, they should
be added in active state too

Changelog: changed
EE: true

ee/app/models/ee/member.rb

@@ -148,6 +148,7 @@ module EE
 
     def set_membership_activation
       return unless group
+      return if user && ::Member.in_hierarchy(group.root_ancestor).with_user(user).with_state(:active).limit(1).any?
 
       self.state = ::Member::STATE_AWAITING if group.user_cap_reached?
     end

ee/spec/factories/group_members.rb

@@ -7,5 +7,11 @@ FactoryBot.modify do
         member.wait
       end
     end
+
+    trait :active do
+      after(:create) do |member|
+        member.activate
+      end
+    end
   end
 end

ee/spec/factories/project_members.rb

@@ -7,5 +7,11 @@ FactoryBot.modify do
         member.wait
       end
     end
+
+    trait :active do
+      after(:create) do |member|
+        member.activate
+      end
+    end
   end
 end

ee/spec/models/member_spec.rb

@@ -164,6 +164,7 @@ RSpec.describe Member, type: :model do
              namespace_settings: create(:namespace_settings, new_user_signups_cap: 1))
     end
 
+    let_it_be(:subgroup) { create(:group, parent: group) }
     let_it_be(:project, refind: true) { create(:project, namespace: group)}
     let_it_be(:user) { create(:user) }
 
@@ -220,8 +221,6 @@ RSpec.describe Member, type: :model do
         end
 
         it 'sets the group member to awaiting when added to a subgroup' do
-          subgroup = create(:group, parent: group)
-
           subgroup.add_developer(user)
 
           expect(user.group_members.last).to be_awaiting
@@ -232,6 +231,24 @@ RSpec.describe Member, type: :model do
 
           expect(user.project_members.last).to be_awaiting
         end
+
+        context 'when the user is already an active group member' do
+          it 'sets the group member to active' do
+            create(:group_member, :active, group: group, user: user)
+            subgroup.add_owner(user)
+
+            expect(user.group_members.last).to be_active
+          end
+        end
+
+        context 'when the user is already an active project member' do
+          it 'sets the group member to active' do
+            create(:project_member, :active, project: project, user: user)
+            subgroup.add_owner(user)
+
+            expect(user.group_members.last).to be_active
+          end
+        end
       end
     end