class Sass::Tree::ImportNode

def _cssize(*args)
  super.children
rescue Sass::SyntaxError => e
  e.modify_backtrace(:filename => children.first.filename)
  e.add_backtrace(:filename => @filename, :line => @line)
  raise e
end

def _perform(environment)
  return DirectiveNode.new("@import url(#{full_filename})") if full_filename =~ /\.css$/
  super
end

def cssize(*args)
  super.first
end

def full_filename
  @full_filename ||= import
end

def import
  Sass::Files.find_file_to_import(@imported_filename, import_paths)
rescue Exception => e
  raise SyntaxError.new(e.message, :line => self.line, :filename => @filename)
end

def import_paths
  paths = (@options[:load_paths] || []).dup
  paths.unshift(File.dirname(@options[:filename])) if @options[:filename]
  paths
end

def initialize(imported_filename)
  @imported_filename = imported_filename
  super(nil)
end

def invisible?; to_s.empty?; end

def perform!(environment)
  environment.push_frame(:filename => @filename, :line => @line)
  options = @options.dup
  options.delete(:syntax)
  root = Sass::Files.tree_for(full_filename, options)
  @template = root.template
  self.children = root.children
  self.children = perform_children(environment)
rescue Sass::SyntaxError => e
  e.modify_backtrace(:filename => full_filename)
  e.add_backtrace(:filename => @filename, :line => @line)
  raise e
ensure
  environment.pop_frame
end

def to_sass(tabs = 0, opts = {})
  "#{'  ' * tabs}@import #{@imported_filename}\n"
end

def to_scss(tabs = 0, opts = {})
  "#{'  ' * tabs}@import \"#{@imported_filename}\";\n"
end