Merge branch 'dz-fix-group-with-dot' into 'master'

Fix 404 when group path has dot in the name

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23401

See merge request !6919

config/routes/group.rb

 require 'constraints/group_url_constrainer'
 
 constraints(GroupUrlConstrainer.new) do
-  scope(path: ':id', as: :group, controller: :groups) do
+  scope(path: ':id',
+        as: :group,
+        constraints: { id: /[a-zA-Z.0-9_\-]+(?<!\.atom)/ },
+        controller: :groups) do
     get '/', action: :show
     patch '/', action: :update
     put '/', action: :update

spec/routing/routing_spec.rb

@@ -270,6 +270,12 @@ describe "Groups", "routing" do
 
     expect(get('/1')).to route_to('groups#show', id: '1')
   end
+
+  it "also display group#show with dot in the path" do
+    allow(Group).to receive(:find_by_path).and_return(true)
+
+    expect(get('/group.with.dot')).to route_to('groups#show', id: 'group.with.dot')
+  end
 end
 
 describe HealthCheckController, 'routing' do