Respond 404 when unauthorized user imports members

app/controllers/projects/project_members_controller.rb

@@ -100,7 +100,7 @@ class Projects::ProjectMembersController < Projects::ApplicationController
       status = @project.team.import(source_project, current_user)
       notice = status ? "Successfully imported" : "Import failed"
     else
-      notice = 'Import failed - source project not found!'
+      return render_404
     end
 
     redirect_to(namespace_project_project_members_path(project.namespace, project),

spec/controllers/projects/project_members_controller_spec.rb

@@ -41,8 +41,8 @@ describe Projects::ProjectMembersController do
         expect(project.team_members).to_not include member
       end
 
-      it 'pretends that source projects does not exist' do
-        expect(response).to set_flash.to /source project not found/
+      it 'responds with not found' do
+        expect(response.status).to eq 404
       end
     end
   end