Make sure multiline string is not accepted by the regexp

activesupport/lib/active_support/configurable.rb

@@ -107,7 +107,7 @@ module ActiveSupport
         options = names.extract_options!
 
         names.each do |name|
-          raise NameError.new('invalid config attribute name') unless name =~ /\A[_A-Za-z]\w*\Z/
+          raise NameError.new('invalid config attribute name') unless name =~ /\A[_A-Za-z]\w*\z/
 
           reader, reader_line = "def #{name}; config.#{name}; end", __LINE__
           writer, writer_line = "def #{name}=(value); config.#{name} = value; end", __LINE__

activesupport/test/configurable_test.rb

@@ -95,10 +95,18 @@ class ConfigurableActiveSupport < ActiveSupport::TestCase
         config_accessor "invalid attribute name"
       end
     end
+
     assert_raises NameError do
       Class.new do
         include ActiveSupport::Configurable
-        config_accessor "invalid attribute\nname"
+        config_accessor "invalid\nattribute"
+      end
+    end
+
+    assert_raises NameError do
+      Class.new do
+        include ActiveSupport::Configurable
+        config_accessor "invalid\n"
       end
     end
   end