Only track new constant definitions when we're reloading dependencies

activesupport/lib/active_support/dependencies.rb

@@ -138,14 +138,22 @@ def require_association(file_name)
       end
 
       def load_with_new_constant_marking(file, *extras) #:nodoc:
-        Dependencies.new_constants_in(Object) { load_without_new_constant_marking(file, *extras) }
+        if Dependencies.load?
+          Dependencies.new_constants_in(Object) { load_without_new_constant_marking(file, *extras) }
+        else
+          load_without_new_constant_marking(file, *extras)
+        end
       rescue Exception => exception  # errors from loading file
         exception.blame_file! file
         raise
       end
 
       def require(file, *extras) #:nodoc:
-        Dependencies.new_constants_in(Object) { super }
+        if Dependencies.load?
+          Dependencies.new_constants_in(Object) { super }
+        else
+          super
+        end
       rescue Exception => exception  # errors from required file
         exception.blame_file! file
         raise

activesupport/test/dependencies_test.rb

@@ -694,27 +694,27 @@ def test_autoload_doesnt_shadow_error_when_mechanism_not_set_to_load
     with_loading 'autoloading_fixtures' do
       ActiveSupport::Dependencies.mechanism = :require
       2.times do
-        assert_raise(NameError) {"RaisesNameError".constantize}
+        assert_raise(NameError) { assert_equal 123, ::RaisesNameError::FooBarBaz }
       end
     end
   end
 
   def test_autoload_doesnt_shadow_name_error
     with_loading 'autoloading_fixtures' do
-      assert !defined?(::RaisesNameError), "::RaisesNameError is defined but it hasn't been referenced yet!"
+      Object.send(:remove_const, :RaisesNameError) if defined?(::RaisesNameError)
       2.times do
         begin
-          ::RaisesNameError.object_id
+          ::RaisesNameError::FooBarBaz.object_id
           flunk 'should have raised NameError when autoloaded file referenced FooBarBaz'
         rescue NameError => e
           assert_equal 'uninitialized constant RaisesNameError::FooBarBaz', e.message
         end
         assert !defined?(::RaisesNameError), "::RaisesNameError is defined but it should have failed!"
       end
 
-      assert !defined?(RaisesNameError)
+      assert !defined?(::RaisesNameError)
       2.times do
-        assert_raise(NameError) { RaisesNameError }
+        assert_raise(NameError) { ::RaisesNameError }
         assert !defined?(::RaisesNameError), "::RaisesNameError is defined but it should have failed!"
       end
     end