Return conflict error in label API when title is taken by group label

app/models/project.rb

@@ -1062,10 +1062,6 @@ class Project < ActiveRecord::Base
     forks.count
   end
-  def find_label(name)
-    labels.find_by(name: name)
-  end
-
   def origin_merge_requests
     merge_requests.where(source_project_id: self.id)
   end

lib/api/labels.rb

@@ -29,8 +29,8 @@ module API
         required_attributes! [:name, :color]
         attrs = attributes_for_keys [:name, :color, :description]
-        label = user_project.find_label(attrs[:name])
+        label = available_labels.find_by(title: attrs[:name])
         conflict!('Label already exists') if label
         label = user_project.labels.create(attrs)
@@ -54,7 +54,7 @@ module API
         authorize! :admin_label, user_project
         required_attributes! [:name]
-        label = user_project.find_label(params[:name])
+        label = user_project.labels.find_by(title: params[:name])
         not_found!('Label') unless label
         label.destroy
@@ -75,7 +75,7 @@ module API
         authorize! :admin_label, user_project
         required_attributes! [:name]
-        label = user_project.find_label(params[:name])
+        label = user_project.labels.find_by(title: params[:name])
         not_found!('Label not found') unless label
         attrs = attributes_for_keys [:new_name, :color, :description]

spec/requests/api/labels_spec.rb

@@ -83,7 +83,20 @@ describe API::API, api: true  do
       expect(json_response['message']['title']).to eq(['is invalid'])
     end
-    it 'returns 409 if label already exists' do
+    it 'returns 409 if label already exists in group' do
+      group = create(:group)
+      group_label = create(:group_label, group: group)
+      project.update(group: group)
+
+      post api("/projects/#{project.id}/labels", user),
+           name: group_label.name,
+           color: '#FFAABB'
+
+      expect(response).to have_http_status(409)
+      expect(json_response['message']).to eq('Label already exists')
+    end
+
+    it 'returns 409 if label already exists in project' do
       post api("/projects/#{project.id}/labels", user),
            name: 'label1',
            color: '#FFAABB'