3 files changed, 41 insertions, 11 deletions
diff --git a/railties/lib/rails/rack/debugger.rb b/railties/lib/rails/rack/debugger.rb
index 902361ce77..f7b77bcb3b 100644
--- a/railties/lib/rails/rack/debugger.rb
+++ b/railties/lib/rails/rack/debugger.rb
@@ -12,8 +12,8 @@ module Rails
         ::Debugger.settings[:autoeval] = true if ::Debugger.respond_to?(:settings)
         puts "=> Debugger enabled"
       rescue LoadError
-        puts "You're missing the 'debugger' gem. Add it to your Gemfile, bundle, and try again."
-        exit
+        puts "You're missing the 'debugger' gem. Add it to your Gemfile, bundle it and try again."
+        exit(1)
       end
 
       def call(env)
diff --git a/railties/lib/rails/rack/log_tailer.rb b/railties/lib/rails/rack/log_tailer.rb
index 18f22e8089..46517713c9 100644
--- a/railties/lib/rails/rack/log_tailer.rb
+++ b/railties/lib/rails/rack/log_tailer.rb
@@ -1,13 +1,17 @@
+require 'active_support/deprecation'
+
 module Rails
   module Rack
     class LogTailer
       def initialize(app, log = nil)
+        ActiveSupport::Deprecation.warn('LogTailer is deprecated and will be removed on Rails 5.')
+
         @app = app
 
         path = Pathname.new(log || "#{::File.expand_path(Rails.root)}/log/#{Rails.env}.log").cleanpath
 
         @cursor = @file = nil
-        if ::File.exists?(path)
+        if ::File.exist?(path)
           @cursor = ::File.size(path)
           @file = ::File.open(path, 'r')
         end
diff --git a/railties/lib/rails/rack/logger.rb b/railties/lib/rails/rack/logger.rb
index 7be2333981..9962e6d943 100644
--- a/railties/lib/rails/rack/logger.rb
+++ b/railties/lib/rails/rack/logger.rb
@@ -1,19 +1,23 @@
 require 'active_support/core_ext/time/conversions'
 require 'active_support/core_ext/object/blank'
+require 'active_support/log_subscriber'
+require 'action_dispatch/http/request'
+require 'rack/body_proxy'
 
 module Rails
   module Rack
     # Sets log tags, logs the request, calls the app, and flushes the logs.
     class Logger < ActiveSupport::LogSubscriber
       def initialize(app, taggers = nil)
-        @app, @taggers = app, taggers || []
+        @app          = app
+        @taggers      = taggers || []
       end
 
       def call(env)
         request = ActionDispatch::Request.new(env)
 
-        if Rails.logger.respond_to?(:tagged)
-          Rails.logger.tagged(compute_tags(request)) { call_app(request, env) }
+        if logger.respond_to?(:tagged)
+          logger.tagged(compute_tags(request)) { call_app(request, env) }
         else
           call_app(request, env)
         end
@@ -23,13 +27,20 @@ module Rails
 
       def call_app(request, env)
         # Put some space between requests in development logs.
-        if Rails.env.development?
-          Rails.logger.debug ''
-          Rails.logger.debug ''
+        if development?
+          logger.debug ''
+          logger.debug ''
         end
 
-        Rails.logger.info started_request_message(request)
-        @app.call(env)
+        instrumenter = ActiveSupport::Notifications.instrumenter
+        instrumenter.start 'request.action_dispatch', request: request
+        logger.info { started_request_message(request) }
+        resp = @app.call(env)
+        resp[2] = ::Rack::BodyProxy.new(resp[2]) { finish(request) }
+        resp
+      rescue Exception
+        finish(request)
+        raise
       ensure
         ActiveSupport::LogSubscriber.flush_all!
       end
@@ -55,6 +66,21 @@ module Rails
           end
         end
       end
+
+      private
+
+      def finish(request)
+        instrumenter = ActiveSupport::Notifications.instrumenter
+        instrumenter.finish 'request.action_dispatch', request: request
+      end
+
+      def development?
+        Rails.env.development?
+      end
+
+      def logger
+        Rails.logger
+      end
     end
   end
 end