Prefer Rails.logger over RAILS_DEFAULT_LOGGER

actionpack/lib/action_controller/failsafe.rb

@@ -42,8 +42,8 @@ module ActionController
       end
 
       def failsafe_logger
-        if defined?(::RAILS_DEFAULT_LOGGER) && !::RAILS_DEFAULT_LOGGER.nil?
-          ::RAILS_DEFAULT_LOGGER
+        if defined? Rails && Rails.logger
+          Rails.logger
         else
           Logger.new($stderr)
         end

activesupport/lib/active_support/dependencies.rb

@@ -559,9 +559,9 @@ module ActiveSupport #:nodoc:
       # Old style environment.rb referenced this method directly.  Please note, it doesn't
       # actually *do* anything any more.
       def self.root(*args)
-        if defined?(RAILS_DEFAULT_LOGGER)
-          RAILS_DEFAULT_LOGGER.warn "Your environment.rb uses the old syntax, it may not continue to work in future releases."
-          RAILS_DEFAULT_LOGGER.warn "For upgrade instructions please see: http://manuals.rubyonrails.com/read/book/19"
+        if defined? Rails && Rails.logger
+          Rails.logger.warn "Your environment.rb uses the old syntax, it may not continue to work in future releases."
+          Rails.logger.warn "For upgrade instructions please see: http://manuals.rubyonrails.com/read/book/19"
         end
       end
     end

activesupport/lib/active_support/deprecation.rb

@@ -13,7 +13,7 @@ module ActiveSupport
                          $stderr.puts callstack.join("\n  ") if debug
                        },
       'development' => Proc.new { |message, callstack|
-                         logger = defined?(::RAILS_DEFAULT_LOGGER) ? ::RAILS_DEFAULT_LOGGER : Logger.new($stderr)
+                         logger = defined? Rails ? Rails.logger : Logger.new($stderr)
                          logger.warn message
                          logger.debug callstack.join("\n  ") if debug
                        }

railties/lib/commands/runner.rb

@@ -48,5 +48,7 @@ begin
     eval(code_or_file)
   end
 ensure
-  RAILS_DEFAULT_LOGGER.flush if RAILS_DEFAULT_LOGGER
+  if defined? Rails
+    Rails.logger.flush if Rails.logger.respond_to?(:flush)
+  end
 end