Uniquifies path slug creation for trial group name

ee/app/controllers/trials_controller.rb

@@ -91,7 +91,7 @@ class TrialsController < ApplicationController
 
   def create_group
     name = sanitize(params[:new_group_name])
-    group = Groups::CreateService.new(current_user, name: name, path: name.parameterize).execute
+    group = Groups::CreateService.new(current_user, name: name, path: Namespace.clean_path(name.parameterize)).execute
 
     params[:namespace_id] = group.id if group.persisted?
 

ee/changelogs/unreleased/42774-new-trial-creation-fails-if-group-url-is-already-taken.yml

+---
+title: Uniquifies path slug creation from trial new group name
+merge_request: 22147
+author:
+type: added

ee/spec/features/trials/select_namespace_spec.rb

@@ -64,16 +64,21 @@ describe 'Trial Select Namespace', :js do
       context 'enters an existing group name' do
         let!(:namespace) { create(:namespace, owner_id: user.id, path: 'gitlab') }
 
-        it 'shows validation error' do
+        before do
+          expect_any_instance_of(GitlabSubscriptions::ApplyTrialService).to receive(:execute) do
+            { success: true }
+          end
+        end
+
+        it 'proceeds to the next step with a unique url' do
           fill_in 'New Group Name', with: namespace.path
 
           click_button 'Start your free trial'
 
           wait_for_requests
 
-          expect(page).to have_selector('.flash-text')
-          expect(find('.flash-alert')).to have_text('Group URL has already been taken')
-          expect(current_path).to eq(apply_trials_path)
+          expect(page).not_to have_css('flash-container')
+          expect(current_path).to eq('/gitlab1')
         end
       end