Stop the build asploding on 1.8.7

activerecord/lib/active_record/attribute_methods/read.rb

@@ -105,6 +105,8 @@ module ActiveRecord
       # Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
       # "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
       def read_attribute(attr_name)
+        return unless attr_name
+
         attr_name = attr_name.to_s
         methods   = self.class.generated_external_attribute_methods
 

activerecord/test/cases/attribute_methods_test.rb

@@ -707,6 +707,10 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     Topic.undefine_attribute_methods
   end
 
+  def test_read_attribute_with_nil_should_not_asplode
+    assert_equal nil, Topic.new.read_attribute(nil)
+  end
+
   private
   def cached_columns
     @cached_columns ||= time_related_columns_on_topic.map(&:name)