Merge branch '17106'

* 17106:
  add lib to $LOAD_PATH on application inhertence. fixes #17106
  add a test for #17106

2 files changed, 23 insertions, 0 deletions

diff --git a/railties/test/application/configuration_test.rb b/railties/test/application/configuration_test.rb
index 0eddf644d9..2b6eb3624a 100644
--- a/railties/test/application/configuration_test.rb
+++ b/railties/test/application/configuration_test.rb
@@ -59,6 +59,20 @@ module ApplicationTests
       end
     end
 
+    test "lib dir is on LOAD_PATH during config" do
+      app_file 'lib/my_logger.rb', <<-RUBY
+        require "logger"
+        class MyLogger < ::Logger
+        end
+      RUBY
+      add_to_top_of_config <<-RUBY
+        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
       add_to_config <<-RUBY
         config.active_record.migration_error    = :page_load
diff --git a/railties/test/isolation/abstract_unit.rb b/railties/test/isolation/abstract_unit.rb
index 40469e31d7..bf2992005b 100644
--- a/railties/test/isolation/abstract_unit.rb
+++ b/railties/test/isolation/abstract_unit.rb
@@ -231,6 +231,15 @@ module TestHelpers
       end
     end
 
+    def add_to_top_of_config(str)
+      environment = File.read("#{app_path}/config/application.rb")
+      if environment =~ /(Rails::Application\s*)/
+        File.open("#{app_path}/config/application.rb", 'w') do |f|
+          f.puts $` + $1 + "\n#{str}\n" + $'
+        end
+      end
+    end
+
     def add_to_config(str)
       environment = File.read("#{app_path}/config/application.rb")
       if environment =~ /(\n\s*end\s*end\s*)\Z/