Vendor fileutils since it is now a gem

10 files changed, 1659 insertions, 9 deletions

diff --git a/Rakefile b/Rakefile
index f516673ef1..6f08086731 100644
--- a/Rakefile
+++ b/Rakefile
@@ -340,6 +340,13 @@ begin
     lib.vendor_lib = "lib/bundler/vendor/thor"
   end
 
+  Automatiek::RakeTask.new("fileutils") do |lib|
+    lib.download = { :github => "https://github.com/ruby/fileutils" }
+    lib.namespace = "FileUtils"
+    lib.prefix = "Bundler"
+    lib.vendor_lib = "lib/bundler/vendor/fileutils"
+  end
+
   Automatiek::RakeTask.new("net-http-persistent") do |lib|
     lib.download = { :github => "https://github.com/drbrain/net-http-persistent" }
     lib.namespace = "Net::HTTP::Persistent"
@@ -358,6 +365,7 @@ begin
   end
 rescue LoadError
   namespace :vendor do
+    task(:fileutils) { abort "Install the automatiek gem to be able to vendor gems." }
     task(:molinillo) { abort "Install the automatiek gem to be able to vendor gems." }
     task(:thor) { abort "Install the automatiek gem to be able to vendor gems." }
     task("net-http-persistent") { abort "Install the automatiek gem to be able to vendor gems." }
diff --git a/lib/bundler.rb b/lib/bundler.rb
index c9d8846ce5..4516379411 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -1,9 +1,8 @@
 # frozen_string_literal: true
-require "fileutils"
+require "bundler/vendored_fileutils"
 require "pathname"
 require "rbconfig"
 require "thread"
-require "tmpdir"
 
 require "bundler/errors"
 require "bundler/environment_preserver"
@@ -169,6 +168,7 @@ module Bundler
 
     def tmp_home_path(login, warning)
       login ||= "unknown"
+      require "tmpdir"
       path = Pathname.new(Dir.tmpdir).join("bundler", "home")
       SharedHelpers.filesystem_access(path) do |tmp_home_path|
         unless tmp_home_path.exist?
@@ -229,6 +229,7 @@ module Bundler
     end
 
     def tmp(name = Process.pid.to_s)
+      require "tmpdir"
       Pathname.new(Dir.mktmpdir(["bundler", name]))
     end
 
diff --git a/lib/bundler/compact_index_client/updater.rb b/lib/bundler/compact_index_client/updater.rb
index 5aa480fdcc..adf013de04 100644
--- a/lib/bundler/compact_index_client/updater.rb
+++ b/lib/bundler/compact_index_client/updater.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
-require "fileutils"
+require "bundler/vendored_fileutils"
 require "stringio"
-require "tmpdir"
 require "zlib"
 
 module Bundler
@@ -22,6 +21,7 @@ module Bundler
 
       def initialize(fetcher)
         @fetcher = fetcher
+        require "tmpdir"
       end
 
       def update(local_path, remote_path, retrying = nil)
diff --git a/lib/bundler/source/git.rb b/lib/bundler/source/git.rb
index dc204a2b33..c331af967e 100644
--- a/lib/bundler/source/git.rb
+++ b/lib/bundler/source/git.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require "fileutils"
+require "bundler/vendored_fileutils"
 require "uri"
 require "digest/sha1"
 
diff --git a/lib/bundler/ssl_certs/certificate_manager.rb b/lib/bundler/ssl_certs/certificate_manager.rb
index a5e5d84b64..05de6410be 100644
--- a/lib/bundler/ssl_certs/certificate_manager.rb
+++ b/lib/bundler/ssl_certs/certificate_manager.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require "fileutils"
+require "bundler/vendored_fileutils"
 require "net/https"
 require "openssl"
 
diff --git a/lib/bundler/vendor/fileutils/lib/fileutils.rb b/lib/bundler/vendor/fileutils/lib/fileutils.rb
new file mode 100644
index 0000000000..cc69740845
--- /dev/null
+++ b/lib/bundler/vendor/fileutils/lib/fileutils.rb
@@ -0,0 +1,1638 @@
+# frozen_string_literal: true
+#
+# = fileutils.rb
+#
+# Copyright (c) 2000-2007 Minero Aoki
+#
+# This program is free software.
+# You can distribute/modify this program under the same terms of ruby.
+#
+# == module Bundler::FileUtils
+#
+# Namespace for several file utility methods for copying, moving, removing, etc.
+#
+# === Module Functions
+#
+#   require 'bundler/vendor/fileutils/lib/fileutils'
+#
+#   Bundler::FileUtils.cd(dir, options)
+#   Bundler::FileUtils.cd(dir, options) {|dir| block }
+#   Bundler::FileUtils.pwd()
+#   Bundler::FileUtils.mkdir(dir, options)
+#   Bundler::FileUtils.mkdir(list, options)
+#   Bundler::FileUtils.mkdir_p(dir, options)
+#   Bundler::FileUtils.mkdir_p(list, options)
+#   Bundler::FileUtils.rmdir(dir, options)
+#   Bundler::FileUtils.rmdir(list, options)
+#   Bundler::FileUtils.ln(target, link, options)
+#   Bundler::FileUtils.ln(targets, dir, options)
+#   Bundler::FileUtils.ln_s(target, link, options)
+#   Bundler::FileUtils.ln_s(targets, dir, options)
+#   Bundler::FileUtils.ln_sf(target, link, options)
+#   Bundler::FileUtils.cp(src, dest, options)
+#   Bundler::FileUtils.cp(list, dir, options)
+#   Bundler::FileUtils.cp_r(src, dest, options)
+#   Bundler::FileUtils.cp_r(list, dir, options)
+#   Bundler::FileUtils.mv(src, dest, options)
+#   Bundler::FileUtils.mv(list, dir, options)
+#   Bundler::FileUtils.rm(list, options)
+#   Bundler::FileUtils.rm_r(list, options)
+#   Bundler::FileUtils.rm_rf(list, options)
+#   Bundler::FileUtils.install(src, dest, options)
+#   Bundler::FileUtils.chmod(mode, list, options)
+#   Bundler::FileUtils.chmod_R(mode, list, options)
+#   Bundler::FileUtils.chown(user, group, list, options)
+#   Bundler::FileUtils.chown_R(user, group, list, options)
+#   Bundler::FileUtils.touch(list, options)
+#
+# The <tt>options</tt> parameter is a hash of options, taken from the list
+# <tt>:force</tt>, <tt>:noop</tt>, <tt>:preserve</tt>, and <tt>:verbose</tt>.
+# <tt>:noop</tt> means that no changes are made.  The other three are obvious.
+# Each method documents the options that it honours.
+#
+# All methods that have the concept of a "source" file or directory can take
+# either one file or a list of files in that argument.  See the method
+# documentation for examples.
+#
+# There are some `low level' methods, which do not accept any option:
+#
+#   Bundler::FileUtils.copy_entry(src, dest, preserve = false, dereference = false)
+#   Bundler::FileUtils.copy_file(src, dest, preserve = false, dereference = true)
+#   Bundler::FileUtils.copy_stream(srcstream, deststream)
+#   Bundler::FileUtils.remove_entry(path, force = false)
+#   Bundler::FileUtils.remove_entry_secure(path, force = false)
+#   Bundler::FileUtils.remove_file(path, force = false)
+#   Bundler::FileUtils.compare_file(path_a, path_b)
+#   Bundler::FileUtils.compare_stream(stream_a, stream_b)
+#   Bundler::FileUtils.uptodate?(file, cmp_list)
+#
+# == module Bundler::FileUtils::Verbose
+#
+# This module has all methods of Bundler::FileUtils module, but it outputs messages
+# before acting.  This equates to passing the <tt>:verbose</tt> flag to methods
+# in Bundler::FileUtils.
+#
+# == module Bundler::FileUtils::NoWrite
+#
+# This module has all methods of Bundler::FileUtils module, but never changes
+# files/directories.  This equates to passing the <tt>:noop</tt> flag to methods
+# in Bundler::FileUtils.
+#
+# == module Bundler::FileUtils::DryRun
+#
+# This module has all methods of Bundler::FileUtils module, but never changes
+# files/directories.  This equates to passing the <tt>:noop</tt> and
+# <tt>:verbose</tt> flags to methods in Bundler::FileUtils.
+#
+
+module Bundler::FileUtils
+
+  def self.private_module_function(name)   #:nodoc:
+    module_function name
+    private_class_method name
+  end
+
+  #
+  # Returns the name of the current directory.
+  #
+  def pwd
+    Dir.pwd
+  end
+  module_function :pwd
+
+  alias getwd pwd
+  module_function :getwd
+
+  #
+  # Changes the current directory to the directory +dir+.
+  #
+  # If this method is called with block, resumes to the old
+  # working directory after the block execution finished.
+  #
+  #   Bundler::FileUtils.cd('/', :verbose => true)   # chdir and report it
+  #
+  #   Bundler::FileUtils.cd('/') do  # chdir
+  #     # ...               # do something
+  #   end                   # return to original directory
+  #
+  def cd(dir, verbose: nil, &block) # :yield: dir
+    fu_output_message "cd #{dir}" if verbose
+    Dir.chdir(dir, &block)
+    fu_output_message 'cd -' if verbose and block
+  end
+  module_function :cd
+
+  alias chdir cd
+  module_function :chdir
+
+  #
+  # Returns true if +new+ is newer than all +old_list+.
+  # Non-existent files are older than any file.
+  #
+  #   Bundler::FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \
+  #       system 'make hello.o'
+  #
+  def uptodate?(new, old_list)
+    return false unless File.exist?(new)
+    new_time = File.mtime(new)
+    old_list.each do |old|
+      if File.exist?(old)
+        return false unless new_time > File.mtime(old)
+      end
+    end
+    true
+  end
+  module_function :uptodate?
+
+  def remove_trailing_slash(dir)   #:nodoc:
+    dir == '/' ? dir : dir.chomp(?/)
+  end
+  private_module_function :remove_trailing_slash
+
+  #
+  # Creates one or more directories.
+  #
+  #   Bundler::FileUtils.mkdir 'test'
+  #   Bundler::FileUtils.mkdir %w( tmp data )
+  #   Bundler::FileUtils.mkdir 'notexist', :noop => true  # Does not really create.
+  #   Bundler::FileUtils.mkdir 'tmp', :mode => 0700
+  #
+  def mkdir(list, mode: nil, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message "mkdir #{mode ? ('-m %03o ' % mode) : ''}#{list.join ' '}" if verbose
+    return if noop
+
+    list.each do |dir|
+      fu_mkdir dir, mode
+    end
+  end
+  module_function :mkdir
+
+  #
+  # Creates a directory and all its parent directories.
+  # For example,
+  #
+  #   Bundler::FileUtils.mkdir_p '/usr/local/lib/ruby'
+  #
+  # causes to make following directories, if it does not exist.
+  #
+  # * /usr
+  # * /usr/local
+  # * /usr/local/lib
+  # * /usr/local/lib/ruby
+  #
+  # You can pass several directories at a time in a list.
+  #
+  def mkdir_p(list, mode: nil, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message "mkdir -p #{mode ? ('-m %03o ' % mode) : ''}#{list.join ' '}" if verbose
+    return *list if noop
+
+    list.map {|path| remove_trailing_slash(path)}.each do |path|
+      # optimize for the most common case
+      begin
+        fu_mkdir path, mode
+        next
+      rescue SystemCallError
+        next if File.directory?(path)
+      end
+
+      stack = []
+      until path == stack.last   # dirname("/")=="/", dirname("C:/")=="C:/"
+        stack.push path
+        path = File.dirname(path)
+      end
+      stack.pop                 # root directory should exist
+      stack.reverse_each do |dir|
+        begin
+          fu_mkdir dir, mode
+        rescue SystemCallError
+          raise unless File.directory?(dir)
+        end
+      end
+    end
+
+    return *list
+  end
+  module_function :mkdir_p
+
+  alias mkpath    mkdir_p
+  alias makedirs  mkdir_p
+  module_function :mkpath
+  module_function :makedirs
+
+  def fu_mkdir(path, mode)   #:nodoc:
+    path = remove_trailing_slash(path)
+    if mode
+      Dir.mkdir path, mode
+      File.chmod mode, path
+    else
+      Dir.mkdir path
+    end
+  end
+  private_module_function :fu_mkdir
+
+  #
+  # Removes one or more directories.
+  #
+  #   Bundler::FileUtils.rmdir 'somedir'
+  #   Bundler::FileUtils.rmdir %w(somedir anydir otherdir)
+  #   # Does not really remove directory; outputs message.
+  #   Bundler::FileUtils.rmdir 'somedir', :verbose => true, :noop => true
+  #
+  def rmdir(list, parents: nil, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message "rmdir #{parents ? '-p ' : ''}#{list.join ' '}" if verbose
+    return if noop
+    list.each do |dir|
+      begin
+        Dir.rmdir(dir = remove_trailing_slash(dir))
+        if parents
+          until (parent = File.dirname(dir)) == '.' or parent == dir
+            dir = parent
+            Dir.rmdir(dir)
+          end
+        end
+      rescue Errno::ENOTEMPTY, Errno::EEXIST, Errno::ENOENT
+      end
+    end
+  end
+  module_function :rmdir
+
+  #
+  # :call-seq:
+  #   Bundler::FileUtils.ln(target, link, force: nil, noop: nil, verbose: nil)
+  #   Bundler::FileUtils.ln(target,  dir, force: nil, noop: nil, verbose: nil)
+  #   Bundler::FileUtils.ln(targets, dir, force: nil, noop: nil, verbose: nil)
+  #
+  # In the first form, creates a hard link +link+ which points to +target+.
+  # If +link+ already exists, raises Errno::EEXIST.
+  # But if the :force option is set, overwrites +link+.
+  #
+  #   Bundler::FileUtils.ln 'gcc', 'cc', verbose: true
+  #   Bundler::FileUtils.ln '/usr/bin/emacs21', '/usr/bin/emacs'
+  #
+  # In the second form, creates a link +dir/target+ pointing to +target+.
+  # In the third form, creates several hard links in the directory +dir+,
+  # pointing to each item in +targets+.
+  # If +dir+ is not a directory, raises Errno::ENOTDIR.
+  #
+  #   Bundler::FileUtils.cd '/sbin'
+  #   Bundler::FileUtils.ln %w(cp mv mkdir), '/bin'   # Now /sbin/cp and /bin/cp are linked.
+  #
+  def ln(src, dest, force: nil, noop: nil, verbose: nil)
+    fu_output_message "ln#{force ? ' -f' : ''} #{[src,dest].flatten.join ' '}" if verbose
+    return if noop
+    fu_each_src_dest0(src, dest) do |s,d|
+      remove_file d, true if force
+      File.link s, d
+    end
+  end
+  module_function :ln
+
+  alias link ln
+  module_function :link
+
+  #
+  # :call-seq:
+  #   Bundler::FileUtils.ln_s(target, link, force: nil, noop: nil, verbose: nil)
+  #   Bundler::FileUtils.ln_s(target,  dir, force: nil, noop: nil, verbose: nil)
+  #   Bundler::FileUtils.ln_s(targets, dir, force: nil, noop: nil, verbose: nil)
+  #
+  # In the first form, creates a symbolic link +link+ which points to +target+.
+  # If +link+ already exists, raises Errno::EEXIST.
+  # But if the :force option is set, overwrites +link+.
+  #
+  #   Bundler::FileUtils.ln_s '/usr/bin/ruby', '/usr/local/bin/ruby'
+  #   Bundler::FileUtils.ln_s 'verylongsourcefilename.c', 'c', force: true
+  #
+  # In the second form, creates a link +dir/target+ pointing to +target+.
+  # In the third form, creates several symbolic links in the directory +dir+,
+  # pointing to each item in +targets+.
+  # If +dir+ is not a directory, raises Errno::ENOTDIR.
+  #
+  #   Bundler::FileUtils.ln_s Dir.glob('/bin/*.rb'), '/home/foo/bin'
+  #
+  def ln_s(src, dest, force: nil, noop: nil, verbose: nil)
+    fu_output_message "ln -s#{force ? 'f' : ''} #{[src,dest].flatten.join ' '}" if verbose
+    return if noop
+    fu_each_src_dest0(src, dest) do |s,d|
+      remove_file d, true if force
+      File.symlink s, d
+    end
+  end
+  module_function :ln_s
+
+  alias symlink ln_s
+  module_function :symlink
+
+  #
+  # :call-seq:
+  #   Bundler::FileUtils.ln_sf(*args)
+  #
+  # Same as
+  #
+  #   Bundler::FileUtils.ln_s(*args, force: true)
+  #
+  def ln_sf(src, dest, noop: nil, verbose: nil)
+    ln_s src, dest, force: true, noop: noop, verbose: verbose
+  end
+  module_function :ln_sf
+
+  #
+  # Copies a file content +src+ to +dest+.  If +dest+ is a directory,
+  # copies +src+ to +dest/src+.
+  #
+  # If +src+ is a list of files, then +dest+ must be a directory.
+  #
+  #   Bundler::FileUtils.cp 'eval.c', 'eval.c.org'
+  #   Bundler::FileUtils.cp %w(cgi.rb complex.rb date.rb), '/usr/lib/ruby/1.6'
+  #   Bundler::FileUtils.cp %w(cgi.rb complex.rb date.rb), '/usr/lib/ruby/1.6', :verbose => true
+  #   Bundler::FileUtils.cp 'symlink', 'dest'   # copy content, "dest" is not a symlink
+  #
+  def cp(src, dest, preserve: nil, noop: nil, verbose: nil)
+    fu_output_message "cp#{preserve ? ' -p' : ''} #{[src,dest].flatten.join ' '}" if verbose
+    return if noop
+    fu_each_src_dest(src, dest) do |s, d|
+      copy_file s, d, preserve
+    end
+  end
+  module_function :cp
+
+  alias copy cp
+  module_function :copy
+
+  #
+  # Copies +src+ to +dest+. If +src+ is a directory, this method copies
+  # all its contents recursively. If +dest+ is a directory, copies
+  # +src+ to +dest/src+.
+  #
+  # +src+ can be a list of files.
+  #
+  #   # Installing Ruby library "mylib" under the site_ruby
+  #   Bundler::FileUtils.rm_r site_ruby + '/mylib', :force
+  #   Bundler::FileUtils.cp_r 'lib/', site_ruby + '/mylib'
+  #
+  #   # Examples of copying several files to target directory.
+  #   Bundler::FileUtils.cp_r %w(mail.rb field.rb debug/), site_ruby + '/tmail'
+  #   Bundler::FileUtils.cp_r Dir.glob('*.rb'), '/home/foo/lib/ruby', :noop => true, :verbose => true
+  #
+  #   # If you want to copy all contents of a directory instead of the
+  #   # directory itself, c.f. src/x -> dest/x, src/y -> dest/y,
+  #   # use following code.
+  #   Bundler::FileUtils.cp_r 'src/.', 'dest'     # cp_r('src', 'dest') makes dest/src,
+  #                                      # but this doesn't.
+  #
+  def cp_r(src, dest, preserve: nil, noop: nil, verbose: nil,
+           dereference_root: true, remove_destination: nil)
+    fu_output_message "cp -r#{preserve ? 'p' : ''}#{remove_destination ? ' --remove-destination' : ''} #{[src,dest].flatten.join ' '}" if verbose
+    return if noop
+    fu_each_src_dest(src, dest) do |s, d|
+      copy_entry s, d, preserve, dereference_root, remove_destination
+    end
+  end
+  module_function :cp_r
+
+  #
+  # Copies a file system entry +src+ to +dest+.
+  # If +src+ is a directory, this method copies its contents recursively.
+  # This method preserves file types, c.f. symlink, directory...
+  # (FIFO, device files and etc. are not supported yet)
+  #
+  # Both of +src+ and +dest+ must be a path name.
+  # +src+ must exist, +dest+ must not exist.
+  #
+  # If +preserve+ is true, this method preserves owner, group, and
+  # modified time.  Permissions are copied regardless +preserve+.
+  #
+  # If +dereference_root+ is true, this method dereference tree root.
+  #
+  # If +remove_destination+ is true, this method removes each destination file before copy.
+  #
+  def copy_entry(src, dest, preserve = false, dereference_root = false, remove_destination = false)
+    Entry_.new(src, nil, dereference_root).wrap_traverse(proc do |ent|
+      destent = Entry_.new(dest, ent.rel, false)
+      File.unlink destent.path if remove_destination && File.file?(destent.path)
+      ent.copy destent.path
+    end, proc do |ent|
+      destent = Entry_.new(dest, ent.rel, false)
+      ent.copy_metadata destent.path if preserve
+    end)
+  end
+  module_function :copy_entry
+
+  #
+  # Copies file contents of +src+ to +dest+.
+  # Both of +src+ and +dest+ must be a path name.
+  #
+  def copy_file(src, dest, preserve = false, dereference = true)
+    ent = Entry_.new(src, nil, dereference)
+    ent.copy_file dest
+    ent.copy_metadata dest if preserve
+  end
+  module_function :copy_file
+
+  #
+  # Copies stream +src+ to +dest+.
+  # +src+ must respond to #read(n) and
+  # +dest+ must respond to #write(str).
+  #
+  def copy_stream(src, dest)
+    IO.copy_stream(src, dest)
+  end
+  module_function :copy_stream
+
+  #
+  # Moves file(s) +src+ to +dest+.  If +file+ and +dest+ exist on the different
+  # disk partition, the file is copied then the original file is removed.
+  #
+  #   Bundler::FileUtils.mv 'badname.rb', 'goodname.rb'
+  #   Bundler::FileUtils.mv 'stuff.rb', '/notexist/lib/ruby', :force => true  # no error
+  #
+  #   Bundler::FileUtils.mv %w(junk.txt dust.txt), '/home/foo/.trash/'
+  #   Bundler::FileUtils.mv Dir.glob('test*.rb'), 'test', :noop => true, :verbose => true
+  #
+  def mv(src, dest, force: nil, noop: nil, verbose: nil, secure: nil)
+    fu_output_message "mv#{force ? ' -f' : ''} #{[src,dest].flatten.join ' '}" if verbose
+    return if noop
+    fu_each_src_dest(src, dest) do |s, d|
+      destent = Entry_.new(d, nil, true)
+      begin
+        if destent.exist?
+          if destent.directory?
+            raise Errno::EEXIST, d
+          else
+            destent.remove_file if rename_cannot_overwrite_file?
+          end
+        end
+        begin
+          File.rename s, d
+        rescue Errno::EXDEV
+          copy_entry s, d, true
+          if secure
+            remove_entry_secure s, force
+          else
+            remove_entry s, force
+          end
+        end
+      rescue SystemCallError
+        raise unless force
+      end
+    end
+  end
+  module_function :mv
+
+  alias move mv
+  module_function :move
+
+  def rename_cannot_overwrite_file?   #:nodoc:
+    /emx/ =~ RUBY_PLATFORM
+  end
+  private_module_function :rename_cannot_overwrite_file?
+
+  #
+  # Remove file(s) specified in +list+.  This method cannot remove directories.
+  # All StandardErrors are ignored when the :force option is set.
+  #
+  #   Bundler::FileUtils.rm %w( junk.txt dust.txt )
+  #   Bundler::FileUtils.rm Dir.glob('*.so')
+  #   Bundler::FileUtils.rm 'NotExistFile', :force => true   # never raises exception
+  #
+  def rm(list, force: nil, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message "rm#{force ? ' -f' : ''} #{list.join ' '}" if verbose
+    return if noop
+
+    list.each do |path|
+      remove_file path, force
+    end
+  end
+  module_function :rm
+
+  alias remove rm
+  module_function :remove
+
+  #
+  # Equivalent to
+  #
+  #   Bundler::FileUtils.rm(list, :force => true)
+  #
+  def rm_f(list, noop: nil, verbose: nil)
+    rm list, force: true, noop: noop, verbose: verbose
+  end
+  module_function :rm_f
+
+  alias safe_unlink rm_f
+  module_function :safe_unlink
+
+  #
+  # remove files +list+[0] +list+[1]... If +list+[n] is a directory,
+  # removes its all contents recursively. This method ignores
+  # StandardError when :force option is set.
+  #
+  #   Bundler::FileUtils.rm_r Dir.glob('/tmp/*')
+  #   Bundler::FileUtils.rm_r 'some_dir', :force => true
+  #
+  # WARNING: This method causes local vulnerability
+  # if one of parent directories or removing directory tree are world
+  # writable (including /tmp, whose permission is 1777), and the current
+  # process has strong privilege such as Unix super user (root), and the
+  # system has symbolic link.  For secure removing, read the documentation
+  # of #remove_entry_secure carefully, and set :secure option to true.
+  # Default is :secure=>false.
+  #
+  # NOTE: This method calls #remove_entry_secure if :secure option is set.
+  # See also #remove_entry_secure.
+  #
+  def rm_r(list, force: nil, noop: nil, verbose: nil, secure: nil)
+    list = fu_list(list)
+    fu_output_message "rm -r#{force ? 'f' : ''} #{list.join ' '}" if verbose
+    return if noop
+    list.each do |path|
+      if secure
+        remove_entry_secure path, force
+      else
+        remove_entry path, force
+      end
+    end
+  end
+  module_function :rm_r
+
+  #
+  # Equivalent to
+  #
+  #   Bundler::FileUtils.rm_r(list, :force => true)
+  #
+  # WARNING: This method causes local vulnerability.
+  # Read the documentation of #rm_r first.
+  #
+  def rm_rf(list, noop: nil, verbose: nil, secure: nil)
+    rm_r list, force: true, noop: noop, verbose: verbose, secure: secure
+  end
+  module_function :rm_rf
+
+  alias rmtree rm_rf
+  module_function :rmtree
+
+  #
+  # This method removes a file system entry +path+.  +path+ shall be a
+  # regular file, a directory, or something.  If +path+ is a directory,
+  # remove it recursively.  This method is required to avoid TOCTTOU
+  # (time-of-check-to-time-of-use) local security vulnerability of #rm_r.
+  # #rm_r causes security hole when:
+  #
+  # * Parent directory is world writable (including /tmp).
+  # * Removing directory tree includes world writable directory.
+  # * The system has symbolic link.
+  #
+  # To avoid this security hole, this method applies special preprocess.
+  # If +path+ is a directory, this method chown(2) and chmod(2) all
+  # removing directories.  This requires the current process is the
+  # owner of the removing whole directory tree, or is the super user (root).
+  #
+  # WARNING: You must ensure that *ALL* parent directories cannot be
+  # moved by other untrusted users.  For example, parent directories
+  # should not be owned by untrusted users, and should not be world
+  # writable except when the sticky bit set.
+  #
+  # WARNING: Only the owner of the removing directory tree, or Unix super
+  # user (root) should invoke this method.  Otherwise this method does not
+  # work.
+  #
+  # For details of this security vulnerability, see Perl's case:
+  #
+  # * http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0448
+  # * http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0452
+  #
+  # For fileutils.rb, this vulnerability is reported in [ruby-dev:26100].
+  #
+  def remove_entry_secure(path, force = false)
+    unless fu_have_symlink?
+      remove_entry path, force
+      return
+    end
+    fullpath = File.expand_path(path)
+    st = File.lstat(fullpath)
+    unless st.directory?
+      File.unlink fullpath
+      return
+    end
+    # is a directory.
+    parent_st = File.stat(File.dirname(fullpath))
+    unless parent_st.world_writable?
+      remove_entry path, force
+      return
+    end
+    unless parent_st.sticky?
+      raise ArgumentError, "parent directory is world writable, Bundler::FileUtils#remove_entry_secure does not work; abort: #{path.inspect} (parent directory mode #{'%o' % parent_st.mode})"
+    end
+    # freeze tree root
+    euid = Process.euid
+    File.open(fullpath + '/.') {|f|
+      unless fu_stat_identical_entry?(st, f.stat)
+        # symlink (TOC-to-TOU attack?)
+        File.unlink fullpath
+        return
+      end
+      f.chown euid, -1
+      f.chmod 0700
+      unless fu_stat_identical_entry?(st, File.lstat(fullpath))
+        # TOC-to-TOU attack?
+        File.unlink fullpath
+        return
+      end
+    }
+    # ---- tree root is frozen ----
+    root = Entry_.new(path)
+    root.preorder_traverse do |ent|
+      if ent.directory?
+        ent.chown euid, -1
+        ent.chmod 0700
+      end
+    end
+    root.postorder_traverse do |ent|
+      begin
+        ent.remove
+      rescue
+        raise unless force
+      end
+    end
+  rescue
+    raise unless force
+  end
+  module_function :remove_entry_secure
+
+  def fu_have_symlink?   #:nodoc:
+    File.symlink nil, nil
+  rescue NotImplementedError
+    return false
+  rescue TypeError
+    return true
+  end
+  private_module_function :fu_have_symlink?
+
+  def fu_stat_identical_entry?(a, b)   #:nodoc:
+    a.dev == b.dev and a.ino == b.ino
+  end
+  private_module_function :fu_stat_identical_entry?
+
+  #
+  # This method removes a file system entry +path+.
+  # +path+ might be a regular file, a directory, or something.
+  # If +path+ is a directory, remove it recursively.
+  #
+  # See also #remove_entry_secure.
+  #
+  def remove_entry(path, force = false)
+    Entry_.new(path).postorder_traverse do |ent|
+      begin
+        ent.remove
+      rescue
+        raise unless force
+      end
+    end
+  rescue
+    raise unless force
+  end
+  module_function :remove_entry
+
+  #
+  # Removes a file +path+.
+  # This method ignores StandardError if +force+ is true.
+  #
+  def remove_file(path, force = false)
+    Entry_.new(path).remove_file
+  rescue
+    raise unless force
+  end
+  module_function :remove_file
+
+  #
+  # Removes a directory +dir+ and its contents recursively.
+  # This method ignores StandardError if +force+ is true.
+  #
+  def remove_dir(path, force = false)
+    remove_entry path, force   # FIXME?? check if it is a directory
+  end
+  module_function :remove_dir
+
+  #
+  # Returns true if the contents of a file +a+ and a file +b+ are identical.
+  #
+  #   Bundler::FileUtils.compare_file('somefile', 'somefile')       #=> true
+  #   Bundler::FileUtils.compare_file('/dev/null', '/dev/urandom')  #=> false
+  #
+  def compare_file(a, b)
+    return false unless File.size(a) == File.size(b)
+    File.open(a, 'rb') {|fa|
+      File.open(b, 'rb') {|fb|
+        return compare_stream(fa, fb)
+      }
+    }
+  end
+  module_function :compare_file
+
+  alias identical? compare_file
+  alias cmp compare_file
+  module_function :identical?
+  module_function :cmp
+
+  #
+  # Returns true if the contents of a stream +a+ and +b+ are identical.
+  #
+  def compare_stream(a, b)
+    bsize = fu_stream_blksize(a, b)
+    sa = String.new(capacity: bsize)
+    sb = String.new(capacity: bsize)
+    begin
+      a.read(bsize, sa)
+      b.read(bsize, sb)
+      return true if sa.empty? && sb.empty?
+    end while sa == sb
+    false
+  end
+  module_function :compare_stream
+
+  #
+  # If +src+ is not same as +dest+, copies it and changes the permission
+  # mode to +mode+.  If +dest+ is a directory, destination is +dest+/+src+.
+  # This method removes destination before copy.
+  #
+  #   Bundler::FileUtils.install 'ruby', '/usr/local/bin/ruby', :mode => 0755, :verbose => true
+  #   Bundler::FileUtils.install 'lib.rb', '/usr/local/lib/ruby/site_ruby', :verbose => true
+  #
+  def install(src, dest, mode: nil, owner: nil, group: nil, preserve: nil,
+              noop: nil, verbose: nil)
+    if verbose
+      msg = +"install -c"
+      msg << ' -p' if preserve
+      msg << ' -m ' << mode_to_s(mode) if mode
+      msg << " -o #{owner}" if owner
+      msg << " -g #{group}" if group
+      msg << ' ' << [src,dest].flatten.join(' ')
+      fu_output_message msg
+    end
+    return if noop
+    uid = fu_get_uid(owner)
+    gid = fu_get_gid(group)
+    fu_each_src_dest(src, dest) do |s, d|
+      st = File.stat(s)
+      unless File.exist?(d) and compare_file(s, d)
+        remove_file d, true
+        copy_file s, d
+        File.utime st.atime, st.mtime, d if preserve
+        File.chmod fu_mode(mode, st), d if mode
+        File.chown uid, gid, d if uid or gid
+      end
+    end
+  end
+  module_function :install
+
+  def user_mask(target)  #:nodoc:
+    target.each_char.inject(0) do |mask, chr|
+      case chr
+      when "u"
+        mask | 04700
+      when "g"
+        mask | 02070
+      when "o"
+        mask | 01007
+      when "a"
+        mask | 07777
+      else
+        raise ArgumentError, "invalid `who' symbol in file mode: #{chr}"
+      end
+    end
+  end
+  private_module_function :user_mask
+
+  def apply_mask(mode, user_mask, op, mode_mask)   #:nodoc:
+    case op
+    when '='
+      (mode & ~user_mask) | (user_mask & mode_mask)
+    when '+'
+      mode | (user_mask & mode_mask)
+    when '-'
+      mode & ~(user_mask & mode_mask)
+    end
+  end
+  private_module_function :apply_mask
+
+  def symbolic_modes_to_i(mode_sym, path)  #:nodoc:
+    mode = if File::Stat === path
+             path.mode
+           else
+             File.stat(path).mode
+           end
+    mode_sym.split(/,/).inject(mode & 07777) do |current_mode, clause|
+      target, *actions = clause.split(/([=+-])/)
+      raise ArgumentError, "invalid file mode: #{mode_sym}" if actions.empty?
+      target = 'a' if target.empty?
+      user_mask = user_mask(target)
+      actions.each_slice(2) do |op, perm|
+        need_apply = op == '='
+        mode_mask = (perm || '').each_char.inject(0) do |mask, chr|
+          case chr
+          when "r"
+            mask | 0444
+          when "w"
+            mask | 0222
+          when "x"
+            mask | 0111
+          when "X"
+            if FileTest.directory? path
+              mask | 0111
+            else
+              mask
+            end
+          when "s"
+            mask | 06000
+          when "t"
+            mask | 01000
+          when "u", "g", "o"
+            if mask.nonzero?
+              current_mode = apply_mask(current_mode, user_mask, op, mask)
+            end
+            need_apply = false
+            copy_mask = user_mask(chr)
+            (current_mode & copy_mask) / (copy_mask & 0111) * (user_mask & 0111)
+          else
+            raise ArgumentError, "invalid `perm' symbol in file mode: #{chr}"
+          end
+        end
+
+        if mode_mask.nonzero? || need_apply
+          current_mode = apply_mask(current_mode, user_mask, op, mode_mask)
+        end
+      end
+      current_mode
+    end
+  end
+  private_module_function :symbolic_modes_to_i
+
+  def fu_mode(mode, path)  #:nodoc:
+    mode.is_a?(String) ? symbolic_modes_to_i(mode, path) : mode
+  end
+  private_module_function :fu_mode
+
+  def mode_to_s(mode)  #:nodoc:
+    mode.is_a?(String) ? mode : "%o" % mode
+  end
+  private_module_function :mode_to_s
+
+  #
+  # Changes permission bits on the named files (in +list+) to the bit pattern
+  # represented by +mode+.
+  #
+  # +mode+ is the symbolic and absolute mode can be used.
+  #
+  # Absolute mode is
+  #   Bundler::FileUtils.chmod 0755, 'somecommand'
+  #   Bundler::FileUtils.chmod 0644, %w(my.rb your.rb his.rb her.rb)
+  #   Bundler::FileUtils.chmod 0755, '/usr/bin/ruby', :verbose => true
+  #
+  # Symbolic mode is
+  #   Bundler::FileUtils.chmod "u=wrx,go=rx", 'somecommand'
+  #   Bundler::FileUtils.chmod "u=wr,go=rr", %w(my.rb your.rb his.rb her.rb)
+  #   Bundler::FileUtils.chmod "u=wrx,go=rx", '/usr/bin/ruby', :verbose => true
+  #
+  # "a" :: is user, group, other mask.
+  # "u" :: is user's mask.
+  # "g" :: is group's mask.
+  # "o" :: is other's mask.
+  # "w" :: is write permission.
+  # "r" :: is read permission.
+  # "x" :: is execute permission.
+  # "X" ::
+  #   is execute permission for directories only, must be used in conjunction with "+"
+  # "s" :: is uid, gid.
+  # "t" :: is sticky bit.
+  # "+" :: is added to a class given the specified mode.
+  # "-" :: Is removed from a given class given mode.
+  # "=" :: Is the exact nature of the class will be given a specified mode.
+
+  def chmod(mode, list, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message sprintf('chmod %s %s', mode_to_s(mode), list.join(' ')) if verbose
+    return if noop
+    list.each do |path|
+      Entry_.new(path).chmod(fu_mode(mode, path))
+    end
+  end
+  module_function :chmod
+
+  #
+  # Changes permission bits on the named files (in +list+)
+  # to the bit pattern represented by +mode+.
+  #
+  #   Bundler::FileUtils.chmod_R 0700, "/tmp/app.#{$$}"
+  #   Bundler::FileUtils.chmod_R "u=wrx", "/tmp/app.#{$$}"
+  #
+  def chmod_R(mode, list, noop: nil, verbose: nil, force: nil)
+    list = fu_list(list)
+    fu_output_message sprintf('chmod -R%s %s %s',
+                              (force ? 'f' : ''),
+                              mode_to_s(mode), list.join(' ')) if verbose
+    return if noop
+    list.each do |root|
+      Entry_.new(root).traverse do |ent|
+        begin
+          ent.chmod(fu_mode(mode, ent.path))
+        rescue
+          raise unless force
+        end
+      end
+    end
+  end
+  module_function :chmod_R
+
+  #
+  # Changes owner and group on the named files (in +list+)
+  # to the user +user+ and the group +group+.  +user+ and +group+
+  # may be an ID (Integer/String) or a name (String).
+  # If +user+ or +group+ is nil, this method does not change
+  # the attribute.
+  #
+  #   Bundler::FileUtils.chown 'root', 'staff', '/usr/local/bin/ruby'
+  #   Bundler::FileUtils.chown nil, 'bin', Dir.glob('/usr/bin/*'), :verbose => true
+  #
+  def chown(user, group, list, noop: nil, verbose: nil)
+    list = fu_list(list)
+    fu_output_message sprintf('chown %s %s',
+                              (group ? "#{user}:#{group}" : user || ':'),
+                              list.join(' ')) if verbose
+    return if noop
+    uid = fu_get_uid(user)
+    gid = fu_get_gid(group)
+    list.each do |path|
+      Entry_.new(path).chown uid, gid
+    end
+  end
+  module_function :chown
+
+  #
+  # Changes owner and group on the named files (in +list+)
+  # to the user +user+ and the group +group+ recursively.
+  # +user+ and +group+ may be an ID (Integer/String) or
+  # a name (String).  If +user+ or +group+ is nil, this
+  # method does not change the attribute.
+  #
+  #   Bundler::FileUtils.chown_R 'www', 'www', '/var/www/htdocs'
+  #   Bundler::FileUtils.chown_R 'cvs', 'cvs', '/var/cvs', :verbose => true
+  #
+  def chown_R(user, group, list, noop: nil, verbose: nil, force: nil)
+    list = fu_list(list)
+    fu_output_message sprintf('chown -R%s %s %s',
+                              (force ? 'f' : ''),
+                              (group ? "#{user}:#{group}" : user || ':'),
+                              list.join(' ')) if verbose
+    return if noop
+    uid = fu_get_uid(user)
+    gid = fu_get_gid(group)
+    list.each do |root|
+      Entry_.new(root).traverse do |ent|
+        begin
+          ent.chown uid, gid
+        rescue
+          raise unless force
+        end
+      end
+    end
+  end
+  module_function :chown_R
+
+  begin
+    require 'etc'
+  rescue LoadError # rescue LoadError for miniruby
+  end
+
+  def fu_get_uid(user)   #:nodoc:
+    return nil unless user
+    case user
+    when Integer
+      user
+    when /\A\d+\z/
+      user.to_i
+    else
+      Etc.getpwnam(user) ? Etc.getpwnam(user).uid : nil
+    end
+  end
+  private_module_function :fu_get_uid
+
+  def fu_get_gid(group)   #:nodoc:
+    return nil unless group
+    case group
+    when Integer
+      group
+    when /\A\d+\z/
+      group.to_i
+    else
+      Etc.getgrnam(group) ? Etc.getgrnam(group).gid : nil
+    end
+  end
+  private_module_function :fu_get_gid
+
+  #
+  # Updates modification time (mtime) and access time (atime) of file(s) in
+  # +list+.  Files are created if they don't exist.
+  #
+  #   Bundler::FileUtils.touch 'timestamp'
+  #   Bundler::FileUtils.touch Dir.glob('*.c');  system 'make'
+  #
+  def touch(list, noop: nil, verbose: nil, mtime: nil, nocreate: nil)
+    list = fu_list(list)
+    t = mtime
+    if verbose
+      fu_output_message "touch #{nocreate ? '-c ' : ''}#{t ? t.strftime('-t %Y%m%d%H%M.%S ') : ''}#{list.join ' '}"
+    end
+    return if noop
+    list.each do |path|
+      created = nocreate
+      begin
+        File.utime(t, t, path)
+      rescue Errno::ENOENT
+        raise if created
+        File.open(path, 'a') {
+          ;
+        }
+        created = true
+        retry if t
+      end
+    end
+  end
+  module_function :touch
+
+  private
+
+  module StreamUtils_
+    private
+
+    def fu_windows?
+      /mswin|mingw|bccwin|emx/ =~ RUBY_PLATFORM
+    end
+
+    def fu_copy_stream0(src, dest, blksize = nil)   #:nodoc:
+      IO.copy_stream(src, dest)
+    end
+
+    def fu_stream_blksize(*streams)
+      streams.each do |s|
+        next unless s.respond_to?(:stat)
+        size = fu_blksize(s.stat)
+        return size if size
+      end
+      fu_default_blksize()
+    end
+
+    def fu_blksize(st)
+      s = st.blksize
+      return nil unless s
+      return nil if s == 0
+      s
+    end
+
+    def fu_default_blksize
+      1024
+    end
+  end
+
+  include StreamUtils_
+  extend StreamUtils_
+
+  class Entry_   #:nodoc: internal use only
+    include StreamUtils_
+
+    def initialize(a, b = nil, deref = false)
+      @prefix = @rel = @path = nil
+      if b
+        @prefix = a
+        @rel = b
+      else
+        @path = a
+      end
+      @deref = deref
+      @stat = nil
+      @lstat = nil
+    end
+
+    def inspect
+      "\#<#{self.class} #{path()}>"
+    end
+
+    def path
+      if @path
+        File.path(@path)
+      else
+        join(@prefix, @rel)
+      end
+    end
+
+    def prefix
+      @prefix || @path
+    end
+
+    def rel
+      @rel
+    end
+
+    def dereference?
+      @deref
+    end
+
+    def exist?
+      begin
+        lstat
+        true
+      rescue Errno::ENOENT
+        false
+      end
+    end
+
+    def file?
+      s = lstat!
+      s and s.file?
+    end
+
+    def directory?
+      s = lstat!
+      s and s.directory?
+    end
+
+    def symlink?
+      s = lstat!
+      s and s.symlink?
+    end
+
+    def chardev?
+      s = lstat!
+      s and s.chardev?
+    end
+
+    def blockdev?
+      s = lstat!
+      s and s.blockdev?
+    end
+
+    def socket?
+      s = lstat!
+      s and s.socket?
+    end
+
+    def pipe?
+      s = lstat!
+      s and s.pipe?
+    end
+
+    S_IF_DOOR = 0xD000
+
+    def door?
+      s = lstat!
+      s and (s.mode & 0xF000 == S_IF_DOOR)
+    end
+
+    def entries
+      opts = {}
+      opts[:encoding] = ::Encoding::UTF_8 if fu_windows?
+      Dir.entries(path(), opts)\
+          .reject {|n| n == '.' or n == '..' }\
+          .map {|n| Entry_.new(prefix(), join(rel(), n.untaint)) }
+    end
+
+    def stat
+      return @stat if @stat
+      if lstat() and lstat().symlink?
+        @stat = File.stat(path())
+      else
+        @stat = lstat()
+      end
+      @stat
+    end
+
+    def stat!
+      return @stat if @stat
+      if lstat! and lstat!.symlink?
+        @stat = File.stat(path())
+      else
+        @stat = lstat!
+      end
+      @stat
+    rescue SystemCallError
+      nil
+    end
+
+    def lstat
+      if dereference?
+        @lstat ||= File.stat(path())
+      else
+        @lstat ||= File.lstat(path())
+      end
+    end
+
+    def lstat!
+      lstat()
+    rescue SystemCallError
+      nil
+    end
+
+    def chmod(mode)
+      if symlink?
+        File.lchmod mode, path() if have_lchmod?
+      else
+        File.chmod mode, path()
+      end
+    end
+
+    def chown(uid, gid)
+      if symlink?
+        File.lchown uid, gid, path() if have_lchown?
+      else
+        File.chown uid, gid, path()
+      end
+    end
+
+    def copy(dest)
+      lstat
+      case
+      when file?
+        copy_file dest
+      when directory?
+        if !File.exist?(dest) and descendant_directory?(dest, path)
+          raise ArgumentError, "cannot copy directory %s to itself %s" % [path, dest]
+        end
+        begin
+          Dir.mkdir dest
+        rescue
+          raise unless File.directory?(dest)
+        end
+      when symlink?
+        File.symlink File.readlink(path()), dest
+      when chardev?
+        raise "cannot handle device file" unless File.respond_to?(:mknod)
+        mknod dest, ?c, 0666, lstat().rdev
+      when blockdev?
+        raise "cannot handle device file" unless File.respond_to?(:mknod)
+        mknod dest, ?b, 0666, lstat().rdev
+      when socket?
+        raise "cannot handle socket" unless File.respond_to?(:mknod)
+        mknod dest, nil, lstat().mode, 0
+      when pipe?
+        raise "cannot handle FIFO" unless File.respond_to?(:mkfifo)
+        mkfifo dest, 0666
+      when door?
+        raise "cannot handle door: #{path()}"
+      else
+        raise "unknown file type: #{path()}"
+      end
+    end
+
+    def copy_file(dest)
+      File.open(path()) do |s|
+        File.open(dest, 'wb', s.stat.mode) do |f|
+          IO.copy_stream(s, f)
+        end
+      end
+    end
+
+    def copy_metadata(path)
+      st = lstat()
+      if !st.symlink?
+        File.utime st.atime, st.mtime, path
+      end
+      mode = st.mode
+      begin
+        if st.symlink?
+          begin
+            File.lchown st.uid, st.gid, path
+          rescue NotImplementedError
+          end
+        else
+          File.chown st.uid, st.gid, path
+        end
+      rescue Errno::EPERM, Errno::EACCES
+        # clear setuid/setgid
+        mode &= 01777
+      end
+      if st.symlink?
+        begin
+          File.lchmod mode, path
+        rescue NotImplementedError
+        end
+      else
+        File.chmod mode, path
+      end
+    end
+
+    def remove
+      if directory?
+        remove_dir1
+      else
+        remove_file
+      end
+    end
+
+    def remove_dir1
+      platform_support {
+        Dir.rmdir path().chomp(?/)
+      }
+    end
+
+    def remove_file
+      platform_support {
+        File.unlink path
+      }
+    end
+
+    def platform_support
+      return yield unless fu_windows?
+      first_time_p = true
+      begin
+        yield
+      rescue Errno::ENOENT
+        raise
+      rescue => err
+        if first_time_p
+          first_time_p = false
+          begin
+            File.chmod 0700, path()   # Windows does not have symlink
+            retry
+          rescue SystemCallError
+          end
+        end
+        raise err
+      end
+    end
+
+    def preorder_traverse
+      stack = [self]
+      while ent = stack.pop
+        yield ent
+        stack.concat ent.entries.reverse if ent.directory?
+      end
+    end
+
+    alias traverse preorder_traverse
+
+    def postorder_traverse
+      if directory?
+        entries().each do |ent|
+          ent.postorder_traverse do |e|
+            yield e
+          end
+        end
+      end
+    ensure
+      yield self
+    end
+
+    def wrap_traverse(pre, post)
+      pre.call self
+      if directory?
+        entries.each do |ent|
+          ent.wrap_traverse pre, post
+        end
+      end
+      post.call self
+    end
+
+    private
+
+    $fileutils_rb_have_lchmod = nil
+
+    def have_lchmod?
+      # This is not MT-safe, but it does not matter.
+      if $fileutils_rb_have_lchmod == nil
+        $fileutils_rb_have_lchmod = check_have_lchmod?
+      end
+      $fileutils_rb_have_lchmod
+    end
+
+    def check_have_lchmod?
+      return false unless File.respond_to?(:lchmod)
+      File.lchmod 0
+      return true
+    rescue NotImplementedError
+      return false
+    end
+
+    $fileutils_rb_have_lchown = nil
+
+    def have_lchown?
+      # This is not MT-safe, but it does not matter.
+      if $fileutils_rb_have_lchown == nil
+        $fileutils_rb_have_lchown = check_have_lchown?
+      end
+      $fileutils_rb_have_lchown
+    end
+
+    def check_have_lchown?
+      return false unless File.respond_to?(:lchown)
+      File.lchown nil, nil
+      return true
+    rescue NotImplementedError
+      return false
+    end
+
+    def join(dir, base)
+      return File.path(dir) if not base or base == '.'
+      return File.path(base) if not dir or dir == '.'
+      File.join(dir, base)
+    end
+
+    if File::ALT_SEPARATOR
+      DIRECTORY_TERM = "(?=[/#{Regexp.quote(File::ALT_SEPARATOR)}]|\\z)"
+    else
+      DIRECTORY_TERM = "(?=/|\\z)"
+    end
+    SYSCASE = File::FNM_SYSCASE.nonzero? ? "-i" : ""
+
+    def descendant_directory?(descendant, ascendant)
+      /\A(?#{SYSCASE}:#{Regexp.quote(ascendant)})#{DIRECTORY_TERM}/ =~ File.dirname(descendant)
+    end
+  end   # class Entry_
+
+  def fu_list(arg)   #:nodoc:
+    [arg].flatten.map {|path| File.path(path) }
+  end
+  private_module_function :fu_list
+
+  def fu_each_src_dest(src, dest)   #:nodoc:
+    fu_each_src_dest0(src, dest) do |s, d|
+      raise ArgumentError, "same file: #{s} and #{d}" if fu_same?(s, d)
+      yield s, d
+    end
+  end
+  private_module_function :fu_each_src_dest
+
+  def fu_each_src_dest0(src, dest)   #:nodoc:
+    if tmp = Array.try_convert(src)
+      tmp.each do |s|
+        s = File.path(s)
+        yield s, File.join(dest, File.basename(s))
+      end
+    else
+      src = File.path(src)
+      if File.directory?(dest)
+        yield src, File.join(dest, File.basename(src))
+      else
+        yield src, File.path(dest)
+      end
+    end
+  end
+  private_module_function :fu_each_src_dest0
+
+  def fu_same?(a, b)   #:nodoc:
+    File.identical?(a, b)
+  end
+  private_module_function :fu_same?
+
+  @fileutils_output = $stderr
+  @fileutils_label  = ''
+
+  def fu_output_message(msg)   #:nodoc:
+    @fileutils_output ||= $stderr
+    @fileutils_label  ||= ''
+    @fileutils_output.puts @fileutils_label + msg
+  end
+  private_module_function :fu_output_message
+
+  # This hash table holds command options.
+  OPT_TABLE = {}    #:nodoc: internal use only
+  (private_instance_methods & methods(false)).inject(OPT_TABLE) {|tbl, name|
+    (tbl[name.to_s] = instance_method(name).parameters).map! {|t, n| n if t == :key}.compact!
+    tbl
+  }
+
+  #
+  # Returns an Array of method names which have any options.
+  #
+  #   p Bundler::FileUtils.commands  #=> ["chmod", "cp", "cp_r", "install", ...]
+  #
+  def self.commands
+    OPT_TABLE.keys
+  end
+
+  #
+  # Returns an Array of option names.
+  #
+  #   p Bundler::FileUtils.options  #=> ["noop", "force", "verbose", "preserve", "mode"]
+  #
+  def self.options
+    OPT_TABLE.values.flatten.uniq.map {|sym| sym.to_s }
+  end
+
+  #
+  # Returns true if the method +mid+ have an option +opt+.
+  #
+  #   p Bundler::FileUtils.have_option?(:cp, :noop)     #=> true
+  #   p Bundler::FileUtils.have_option?(:rm, :force)    #=> true
+  #   p Bundler::FileUtils.have_option?(:rm, :preserve) #=> false
+  #
+  def self.have_option?(mid, opt)
+    li = OPT_TABLE[mid.to_s] or raise ArgumentError, "no such method: #{mid}"
+    li.include?(opt)
+  end
+
+  #
+  # Returns an Array of option names of the method +mid+.
+  #
+  #   p Bundler::FileUtils.options_of(:rm)  #=> ["noop", "verbose", "force"]
+  #
+  def self.options_of(mid)
+    OPT_TABLE[mid.to_s].map {|sym| sym.to_s }
+  end
+
+  #
+  # Returns an Array of method names which have the option +opt+.
+  #
+  #   p Bundler::FileUtils.collect_method(:preserve) #=> ["cp", "cp_r", "copy", "install"]
+  #
+  def self.collect_method(opt)
+    OPT_TABLE.keys.select {|m| OPT_TABLE[m].include?(opt) }
+  end
+
+  LOW_METHODS = singleton_methods(false) - collect_method(:noop).map(&:intern)
+  module LowMethods
+    private
+    def _do_nothing(*)end
+    ::Bundler::FileUtils::LOW_METHODS.map {|name| alias_method name, :_do_nothing}
+  end
+
+  METHODS = singleton_methods() - [:private_module_function,
+      :commands, :options, :have_option?, :options_of, :collect_method]
+
+  #
+  # This module has all methods of Bundler::FileUtils module, but it outputs messages
+  # before acting.  This equates to passing the <tt>:verbose</tt> flag to
+  # methods in Bundler::FileUtils.
+  #
+  module Verbose
+    include Bundler::FileUtils
+    @fileutils_output  = $stderr
+    @fileutils_label   = ''
+    names = ::Bundler::FileUtils.collect_method(:verbose)
+    names.each do |name|
+      module_eval(<<-EOS, __FILE__, __LINE__ + 1)
+        def #{name}(*args, **options)
+          super(*args, **options, verbose: true)
+        end
+      EOS
+    end
+    private(*names)
+    extend self
+    class << self
+      public(*::Bundler::FileUtils::METHODS)
+    end
+  end
+
+  #
+  # This module has all methods of Bundler::FileUtils module, but never changes
+  # files/directories.  This equates to passing the <tt>:noop</tt> flag
+  # to methods in Bundler::FileUtils.
+  #
+  module NoWrite
+    include Bundler::FileUtils
+    include LowMethods
+    @fileutils_output  = $stderr
+    @fileutils_label   = ''
+    names = ::Bundler::FileUtils.collect_method(:noop)
+    names.each do |name|
+      module_eval(<<-EOS, __FILE__, __LINE__ + 1)
+        def #{name}(*args, **options)
+          super(*args, **options, noop: true)
+        end
+      EOS
+    end
+    private(*names)
+    extend self
+    class << self
+      public(*::Bundler::FileUtils::METHODS)
+    end
+  end
+
+  #
+  # This module has all methods of Bundler::FileUtils module, but never changes
+  # files/directories, with printing message before acting.
+  # This equates to passing the <tt>:noop</tt> and <tt>:verbose</tt> flag
+  # to methods in Bundler::FileUtils.
+  #
+  module DryRun
+    include Bundler::FileUtils
+    include LowMethods
+    @fileutils_output  = $stderr
+    @fileutils_label   = ''
+    names = ::Bundler::FileUtils.collect_method(:noop)
+    names.each do |name|
+      module_eval(<<-EOS, __FILE__, __LINE__ + 1)
+        def #{name}(*args, **options)
+          super(*args, **options, noop: true, verbose: true)
+        end
+      EOS
+    end
+    private(*names)
+    extend self
+    class << self
+      public(*::Bundler::FileUtils::METHODS)
+    end
+  end
+
+end
diff --git a/lib/bundler/vendored_fileutils.rb b/lib/bundler/vendored_fileutils.rb
new file mode 100644
index 0000000000..aab232f097
--- /dev/null
+++ b/lib/bundler/vendored_fileutils.rb
@@ -0,0 +1,3 @@
+# frozen_string_literal: true
+module Bundler; end
+require "bundler/vendor/fileutils/lib/fileutils"
diff --git a/spec/commands/pristine_spec.rb b/spec/commands/pristine_spec.rb
index 9c3918f51e..e4e8df204f 100644
--- a/spec/commands/pristine_spec.rb
+++ b/spec/commands/pristine_spec.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
-require "fileutils"
+require "bundler/vendored_fileutils"
 
 RSpec.describe "bundle pristine" do
   before :each do
diff --git a/spec/plugins/source/example_spec.rb b/spec/plugins/source/example_spec.rb
index 748f083456..d956a0571b 100644
--- a/spec/plugins/source/example_spec.rb
+++ b/spec/plugins/source/example_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe "real source plugins" do
       build_repo2 do
         build_plugin "bundler-source-mpath" do |s|
           s.write "plugins.rb", <<-RUBY
-            require "fileutils"
+            require "bundler/vendored_fileutils"
             require "bundler-source-mpath"
 
             class MPath < Bundler::Plugin::API
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index ee7777a4bd..5c7fcbffa5 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -3,7 +3,7 @@ $:.unshift File.expand_path("..", __FILE__)
 $:.unshift File.expand_path("../../lib", __FILE__)
 
 require "bundler/psyched_yaml"
-require "fileutils"
+require "bundler/vendored_fileutils"
 require "uri"
 require "digest/sha1"