Confirmation token mentioned twice in GET request, but only once in the URL?

Question

I'm facing a strange bug when I follow confirmation link from devise email. The link is correct:

.../ru/users/confirmation?confirmation_token=yDNePwDTbxBzy5PqZE1e

However in server log I get:

Started GET "/ru/users/confirmation?confirmation_token=yDNePwDTbxBzy5PqZE1e?confirmation_token=yDNePwDTbxBzy5PqZE1e"

As you see it is mentioned twice. For this reason I can't confirm the email.

The strangest thing is that it works in webrick, and I only see this issue in production (which happen to be nginx + passenger).

It might be the problem with my setup. I'm using Rails v4, and Devise v3. I re-wrote default devise confirmation#edit controller, and a couple of others, since I wanted to implement "sign-up by email" strategy, and also use ldap_authenticatable model instead of database_authenticatable. I also patched ldap_authenticatable to support multiple LDAPs. But even so -- can you point me where I should look to dig into my issue?

Edit

Middleware: production environment is 4 entries shorter:

• production

    $ RAILS_ENV=production bundle exec rake middleware 
    use Rack::Sendfile 
    use Rack::Lock 
    use Rack::Runtime 
    use Rack::MethodOverride 
    use ActionDispatch::RequestId 
    use Rails::Rack::Logger 
    use ActionDispatch::ShowExceptions 
    use ActionDispatch::DebugExceptions 
    use ActionDispatch::RemoteIp 
    use ActionDispatch::Callbacks 
    use ActiveRecord::ConnectionAdapters::ConnectionManagement 
    use ActiveRecord::QueryCache 
    use ActionDispatch::Cookies 
    use ActionDispatch::Session::CookieStore 
    use ActionDispatch::Flash
    use ActionDispatch::ParamsParser
    use Rack::Head
    use Rack::ConditionalGet
    use Rack::ETag
    use Warden::Manager
    run Login::Application.routes
  

• development:

    $ RAILS_ENV=development bundle exec rake middleware
    use Rack::Sendfile
  + use ActionDispatch::Static
    use Rack::Lock
    use Rack::Runtime
    use Rack::MethodOverride
    use ActionDispatch::RequestId
    use Rails::Rack::Logger
    use ActionDispatch::ShowExceptions
  + use WebConsole::Middleware
    use ActionDispatch::DebugExceptions
    use ActionDispatch::RemoteIp
  + use ActionDispatch::Reloader
    use ActionDispatch::Callbacks
  + use ActiveRecord::Migration::CheckPending
    use ActiveRecord::ConnectionAdapters::ConnectionManagement
    use ActiveRecord::QueryCache
    use ActionDispatch::Cookies
    use ActionDispatch::Session::CookieStore
    use ActionDispatch::Flash
    use ActionDispatch::ParamsParser
    use Rack::Head
    use Rack::ConditionalGet
    use Rack::ETag
    use Warden::Manager
    run Login::Application.routes
  

Edit 2

I found out what was the reason: the link in the email was http. If I change that to https -- it works. So one just have to add

 config.action_mailer.default_url_options = {:protocol => 'https'}

in config/environments/production.rb and it works (on web-server restart). source