Don't blow up in tree view on empty repo

app/controllers/projects_controller.rb

@@ -5,7 +5,7 @@ class ProjectsController < Projects::ApplicationController
   before_action :project, except: [:new, :create]
   before_action :repository, except: [:new, :create]
   before_action :assign_ref_vars, only: [:show], if: :repo_exists?
-  before_action :tree, only: [:show], if: :project_view_files?
+  before_action :tree, only: [:show], if: [:repo_exists?, :project_view_files?]
 
   # Authorize
   before_action :authorize_admin_project!, only: [:edit, :update, :housekeeping, :download_export, :export, :remove_export, :generate_new_export]

spec/controllers/projects_controller_spec.rb

@@ -43,6 +43,26 @@ describe ProjectsController do
       end
     end
 
+    context "project with empty repo" do
+      let(:empty_project) { create(:project_empty_repo, :public) }
+
+      before { sign_in(user) }
+
+      User.project_views.keys.each do |project_view|
+        context "with #{project_view} view set" do
+          before do
+            user.update_attributes(project_view: project_view)
+
+            get :show, namespace_id: empty_project.namespace.path, id: empty_project.path
+          end
+
+          it "renders the empty project view" do
+            expect(response).to render_template('empty')
+          end
+        end
+      end
+    end
+
     context "rendering default project view" do
       render_views