Enable accessing a branch from within Jira dev panel

config/routes/project.rb

@@ -477,12 +477,15 @@ constraints(ProjectUrlConstrainer.new) do
     end
   end
 
+  # EE-specific
   scope path: '/-/jira', as: :jira do
     scope path: '*namespace_id', namespace_id: Gitlab::PathRegex.full_namespace_route_regex do
       resources :projects, path: '/', constraints: { id: Gitlab::PathRegex.project_route_regex }, only: :show
 
       scope path: ':project_id', constraints: { project_id: Gitlab::PathRegex.project_route_regex }, module: :projects do
         resources :commit, only: :show, constraints: { id: /\h{7,40}/ }
+
+        get 'tree/*id', to: 'tree#show', as: nil
       end
     end
   end