class Rails::Engine

def self.find_root_with_flag(flag, root_path, default = nil) # :nodoc:
  while root_path && File.directory?(root_path) && !File.exist?("#{root_path}/#{flag}")
    parent = File.dirname(root_path)
    root_path = parent != root_path && parent
  end
  root = File.exist?("#{root_path}/#{flag}") ? root_path : default
  raise "Could not find root path for #{self}" unless root
  Pathname.new File.realpath root
end