# File lib/sass/tree/visitors/perform.rb, line 214
  def visit_import(node)
    if path = node.css_import?
      return Sass::Tree::CssImportNode.resolved("url(#{path})")
    end
    file = node.imported_file
    handle_import_loop!(node) if @stack.any? {|e| e[:filename] == file.options[:filename]}

    @stack.push(:filename => node.filename, :line => node.line)
    root = file.to_tree
    Sass::Tree::Visitors::CheckNesting.visit(root)
    node.children = root.children.map {|c| visit(c)}.flatten
    node
  rescue Sass::SyntaxError => e
    e.modify_backtrace(:filename => node.imported_file.options[:filename])
    e.add_backtrace(:filename => node.filename, :line => node.line)
    raise e
  ensure
    @stack.pop unless path
  end