Remove unnecessary code from define_read_method and add assertion to make sure the underscored version is actually generated

activerecord/lib/active_record/attribute_methods/read.rb

@@ -70,13 +70,10 @@ module ActiveRecord
             if cache_attribute?(attr_name)
               access_code = "@attributes_cache['#{attr_name}'] ||= (#{access_code})"
             end
-            if symbol =~ /^[a-zA-Z_]\w*[!?=]?$/
-              generated_attribute_methods.module_eval("def _#{symbol}; #{access_code}; end; alias #{symbol} _#{symbol}", __FILE__, __LINE__)
-            else
-              generated_attribute_methods.module_eval do
-                define_method("_#{symbol}") { eval(access_code) }
-                alias_method(symbol, "_#{symbol}")
-              end
+
+            generated_attribute_methods.module_eval do
+              define_method("_#{attr_name}") { eval(access_code) }
+              alias_method(attr_name, "_#{attr_name}")
             end
           end
       end

activerecord/test/cases/attribute_methods_test.rb

@@ -77,6 +77,7 @@ class AttributeMethodsTest < ActiveRecord::TestCase
   def test_respond_to?
     topic = Topic.find(1)
     assert_respond_to topic, "title"
+    assert_respond_to topic, "_title"
     assert_respond_to topic, "title?"
     assert_respond_to topic, "title="
     assert_respond_to topic, :title