ActionMailer preview routes get clobbered by a globbing route

[GBH]

rails/actionmailer/lib/action_mailer/railtie.rb

Line 44 in b47d8de

app.routes.append do

I think it should be prepend and not append.

If application has a globbing route like

get '*path', to: 'foo#bar'

preview routes become inaccessible

[jcutrell]

Perhaps the correct fix would be:

if options.show_previews
          app.routes.append do
            get '/rails/mailers'         => "rails/mailers#index"
          end
          app.routes.prepend do
            get '/rails/mailers/*path'   => "rails/mailers#preview"
          end
        end

But that feels wrong too.

[GBH]

Anything you add with append will not be accessible if app has globing route.
*path basically means everything. Nothing gets past this.

I made pull request with the fix there.