MBeanServer#[] crashes in const_defined? when MBean class name contains $ about jmx HOT 5 CLOSED

  module MBeans
    ##
    # Create modules in this namespace for each package in the Java fully
    # qualified name and return the deepest module along with the Java class
    # name back to the caller.
    def self.parent_for(java_class_fqn)
      java_class_fqn.split(".").inject(MBeans) do |parent, segment|
        # const_defined? will crash later if we don't remove $
        segment.gsub!('$', 'Dollar') if segment =~ /\$/
        # Note: We are boned if java class name is lower cased
        return [parent, segment] if segment =~ /^[A-Z]/

        segment.capitalize!
        unless parent.const_defined? segment
          parent.const_set segment, Module.new
        else 
          parent.const_get segment
        end
      end

    end
  end

  def test_that_mbeans_parent_for_handles_classes_with_dollar_sign
    bean_module, class_name = JMX::MBeans.parent_for("evil.dollar.Pre$Middle$Post")
    assert_equal(JMX::MBeans::Evil::Dollar, bean_module)
    assert_equal("PreDollarMiddleDollarPost", class_name)
  end

  def test_mbeans_parent_for
    bean_module, class_name = JMX::MBeans.parent_for("com.example.JavaClass")
    assert_equal(JMX::MBeans::Com::Example, bean_module)
    assert_equal("JavaClass", class_name)
  end