add lib to $LOAD_PATH on application inhertence. fixes #17106

3 files changed, 16 insertions, 9 deletions

diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index bc966e87c6..18d9cb72d6 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -88,6 +88,7 @@ module Rails
       def inherited(base)
         super
         Rails.app_class = base
+        add_lib_to_load_path!(find_root(base.called_from))
       end
 
       def instance
@@ -98,6 +99,10 @@ module Rails
         new(initial_variable_values, &block).run_load_hooks!
       end
 
+      def find_root(from)
+        find_root_with_flag "config.ru", from, Dir.pwd
+      end
+
       # Makes the +new+ method public.
       #
       # Note that Rails::Application inherits from Rails::Engine, which
@@ -129,8 +134,6 @@ module Rails
       # are these actually used?
       @initial_variable_values = initial_variable_values
       @block = block
-
-      add_lib_to_load_path!
     end
 
     # Returns true if the application is initialized.
@@ -313,8 +316,8 @@ module Rails
     # are changing config.root inside your application definition or having a custom
     # Rails application, you will need to add lib to $LOAD_PATH on your own in case
     # you need to load files in lib/ during the application configuration as well.
-    def add_lib_to_load_path! #:nodoc:
-      path = File.join config.root, 'lib'
+    def self.add_lib_to_load_path!(root) #:nodoc:
+      path = File.join root, 'lib'
       if File.exist?(path) && !$LOAD_PATH.include?(path)
         $LOAD_PATH.unshift(path)
       end
@@ -358,7 +361,7 @@ module Rails
     end
 
     def config #:nodoc:
-      @config ||= Application::Configuration.new(find_root_with_flag("config.ru", Dir.pwd))
+      @config ||= Application::Configuration.new(self.class.find_root(self.class.called_from))
     end
 
     def config=(configuration) #:nodoc:
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index dc3da1eb41..d985518fd9 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -364,6 +364,10 @@ module Rails
         super
       end
 
+      def find_root(from)
+        find_root_with_flag "lib", from
+      end
+
       def endpoint(endpoint = nil)
         @endpoint ||= nil
         @endpoint = endpoint if endpoint
@@ -531,7 +535,7 @@ module Rails
 
     # Define the configuration object for the engine.
     def config
-      @config ||= Engine::Configuration.new(find_root_with_flag("lib"))
+      @config ||= Engine::Configuration.new(self.class.find_root(self.class.called_from))
     end
 
     # Load data from db/seeds.rb file. It can be used in to load engines'
@@ -658,8 +662,7 @@ module Rails
       paths["db/migrate"].existent.any?
     end
 
-    def find_root_with_flag(flag, default=nil) #:nodoc:
-      root_path = self.class.called_from
+    def self.find_root_with_flag(flag, root_path, default=nil) #:nodoc:
 
       while root_path && File.directory?(root_path) && !File.exist?("#{root_path}/#{flag}")
         parent = File.dirname(root_path)
diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index 2b9f1d9cc1..2b6eb3624a 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -66,10 +66,11 @@ module ApplicationTests
         end
       RUBY
       add_to_top_of_config <<-RUBY
-        equire 'my_logger'
+        require 'my_logger'
         config.logger = MyLogger.new STDOUT
       RUBY
       require "#{app_path}/config/environment"
+      assert_equal 'MyLogger', Rails.application.config.logger.class.name
     end
 
     test "a renders exception on pending migration" do