Merge RubyGems-2.7.5 from upstream.

  Please see its details: http://blog.rubygems.org/2018/02/06/2.7.5-released.html

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62244 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

50 files changed, 251 insertions, 174 deletions

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 0475ced164..f368226d47 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -10,7 +10,7 @@ require 'rbconfig'
 require 'thread'
 
 module Gem
-  VERSION = "2.7.3"
+  VERSION = "2.7.5"
 end
 
 # Must be first since it unloads the prelude from 1.9.2
@@ -161,7 +161,7 @@ module Gem
   # these are defined in Ruby 1.8.7, hence the need for this convoluted setup.
 
   READ_BINARY_ERRORS = begin
-    read_binary_errors = [Errno::EACCES, Errno::EROFS]
+    read_binary_errors = [Errno::EACCES, Errno::EROFS, Errno::ENOSYS]
     read_binary_errors << Errno::ENOTSUP if Errno.const_defined?(:ENOTSUP)
     read_binary_errors
   end.freeze
@@ -171,7 +171,7 @@ module Gem
   # these are defined in Ruby 1.8.7.
 
   WRITE_BINARY_ERRORS = begin
-    write_binary_errors = []
+    write_binary_errors = [Errno::ENOSYS]
     write_binary_errors << Errno::ENOTSUP if Errno.const_defined?(:ENOTSUP)
     write_binary_errors
   end.freeze
@@ -871,19 +871,19 @@ An Array (#{env.inspect}) was passed in from #{caller[3]}
   # Safely read a file in binary mode on all platforms.
 
   def self.read_binary(path)
-    open path, 'rb+' do |f|
+    File.open path, 'rb+' do |f|
       f.flock(File::LOCK_EX)
       f.read
     end
   rescue *READ_BINARY_ERRORS
-    open path, 'rb' do |f|
+    File.open path, 'rb' do |f|
       f.read
     end
   rescue Errno::ENOLCK # NFS
     if Thread.main != Thread.current
       raise
     else
-      open path, 'rb' do |f|
+      File.open path, 'rb' do |f|
         f.read
       end
     end
diff --git a/lib/rubygems/commands/generate_index_command.rb b/lib/rubygems/commands/generate_index_command.rb
index 01f1f88405..0b677b73a9 100644
--- a/lib/rubygems/commands/generate_index_command.rb
+++ b/lib/rubygems/commands/generate_index_command.rb
@@ -68,7 +68,7 @@ Marshal::MINOR_VERSION constants.  It is used to ensure compatibility.
 
     if not File.exist?(options[:directory]) or
        not File.directory?(options[:directory]) then
-      alert_error "unknown directory name #{directory}."
+      alert_error "unknown directory name #{options[:directory]}."
       terminate_interaction 1
     else
       indexer = Gem::Indexer.new options.delete(:directory), options
diff --git a/lib/rubygems/commands/setup_command.rb b/lib/rubygems/commands/setup_command.rb
index 5d1414d102..6966cde01a 100644
--- a/lib/rubygems/commands/setup_command.rb
+++ b/lib/rubygems/commands/setup_command.rb
@@ -350,7 +350,9 @@ By default, this RubyGems will install gem as:
   def install_default_bundler_gem
     return unless Gem::USE_BUNDLER_FOR_GEMDEPS
 
-    mkdir_p Gem::Specification.default_specifications_dir
+    specs_dir = Gem::Specification.default_specifications_dir
+    File.join(options[:destdir], specs_dir) unless Gem.win_platform?
+    mkdir_p specs_dir
 
     # Workaround for non-git environment.
     gemspec = File.open('bundler/bundler.gemspec', 'rb'){|f| f.read.gsub(/`git ls-files -z`/, "''") }
@@ -359,23 +361,36 @@ By default, this RubyGems will install gem as:
     bundler_spec = Gem::Specification.load("bundler/bundler.gemspec")
     bundler_spec.files = Dir.chdir("bundler") { Dir["{*.md,{lib,exe,man}/**/*}"] }
     bundler_spec.executables -= %w[bundler bundle_ruby]
-    Dir.entries(Gem::Specification.default_specifications_dir).
+
+    # Remove bundler-*.gemspec in default specification directory.
+    Dir.entries(specs_dir).
       select {|gs| gs.start_with?("bundler-") }.
-      each {|gs| File.delete(File.join(Gem::Specification.default_specifications_dir, gs)) }
+      each {|gs| File.delete(File.join(specs_dir, gs)) }
 
-    default_spec_path = File.join(Gem::Specification.default_specifications_dir, "#{bundler_spec.full_name}.gemspec")
+    default_spec_path = File.join(specs_dir, "#{bundler_spec.full_name}.gemspec")
     Gem.write_binary(default_spec_path, bundler_spec.to_ruby)
 
     bundler_spec = Gem::Specification.load(default_spec_path)
 
+    # Remove gemspec that was same version of vendored bundler.
+    normal_gemspec = File.join(Gem.default_dir, "specifications", "bundler-#{bundler_spec.version}.gemspec")
+    if File.file? normal_gemspec
+      File.delete normal_gemspec
+    end
+
+    # Remove gem files that were same version of vendored bundler.
     if File.directory? bundler_spec.gems_dir
       Dir.entries(bundler_spec.gems_dir).
-        select {|default_gem| File.basename(default_gem).match(/^bundler-#{Gem::Version::VERSION_PATTERN}$/) }.
+        select {|default_gem| File.basename(default_gem) == "bundler-#{bundler_spec.version}" }.
         each {|default_gem| rm_r File.join(bundler_spec.gems_dir, default_gem) }
     end
 
-    mkdir_p bundler_spec.bin_dir
-    bundler_spec.executables.each {|e| cp File.join("bundler", bundler_spec.bindir, e), File.join(bundler_spec.bin_dir, e) }
+    bundler_bin_dir = File.join(Gem.default_dir, 'gems', bundler_spec.full_name, bundler_spec.bindir)
+    File.join(options[:destdir], bundler_bin_dir) unless Gem.win_platform?
+    mkdir_p bundler_bin_dir
+    bundler_spec.executables.each do |e|
+      cp File.join("bundler", bundler_spec.bindir, e), File.join(bundler_bin_dir, e)
+    end
 
     if Gem.win_platform?
       require 'rubygems/installer'
diff --git a/lib/rubygems/commands/unpack_command.rb b/lib/rubygems/commands/unpack_command.rb
index eb7f550673..b873f20d28 100644
--- a/lib/rubygems/commands/unpack_command.rb
+++ b/lib/rubygems/commands/unpack_command.rb
@@ -94,7 +94,7 @@ command help for an example.
 
         spec_file = File.basename spec.spec_file
 
-        open spec_file, 'w' do |io|
+        File.open spec_file, 'w' do |io|
           io.write metadata
         end
       else
@@ -176,7 +176,7 @@ command help for an example.
 
     metadata = nil
 
-    open path, Gem.binary_mode do |io|
+    File.open path, Gem.binary_mode do |io|
       tar = Gem::Package::TarReader.new io
       tar.each_entry do |entry|
         case entry.full_name
diff --git a/lib/rubygems/config_file.rb b/lib/rubygems/config_file.rb
index a4efed0f5a..c0d19dbfc2 100644
--- a/lib/rubygems/config_file.rb
+++ b/lib/rubygems/config_file.rb
@@ -458,7 +458,7 @@ if you believe they were disclosed to a third party.
 
   # Writes out this config file, replacing its source.
   def write
-    open config_file_name, 'w' do |io|
+    File.open config_file_name, 'w' do |io|
       io.write to_yaml
     end
   end
diff --git a/lib/rubygems/ext/builder.rb b/lib/rubygems/ext/builder.rb
index a1619c97d7..eb9db199d5 100644
--- a/lib/rubygems/ext/builder.rb
+++ b/lib/rubygems/ext/builder.rb
@@ -212,7 +212,7 @@ EOF
 
     FileUtils.mkdir_p @spec.extension_dir
 
-    open destination, 'wb' do |io| io.puts output end
+    File.open destination, 'wb' do |io| io.puts output end
 
     destination
   end
diff --git a/lib/rubygems/indexer.rb b/lib/rubygems/indexer.rb
index 871cc09d8d..3ea994414b 100644
--- a/lib/rubygems/indexer.rb
+++ b/lib/rubygems/indexer.rb
@@ -2,6 +2,7 @@
 require 'rubygems'
 require 'rubygems/package'
 require 'time'
+require 'tmpdir'
 
 begin
   gem 'builder'
@@ -64,7 +65,7 @@ class Gem::Indexer
     @build_modern = options[:build_modern]
 
     @dest_directory = directory
-    @directory = File.join(Dir.tmpdir, "gem_generate_index_#{$$}")
+    @directory = Dir.mktmpdir 'gem_generate_index'
 
     marshal_name = "Marshal.#{Gem.marshal_version}"
 
@@ -123,7 +124,7 @@ class Gem::Indexer
         marshal_name = File.join @quick_marshal_dir, spec_file_name
 
         marshal_zipped = Gem.deflate Marshal.dump(spec)
-        open marshal_name, 'wb' do |io| io.write marshal_zipped end
+        File.open marshal_name, 'wb' do |io| io.write marshal_zipped end
 
         files << marshal_name
 
@@ -261,7 +262,7 @@ class Gem::Indexer
 
     zipped = Gem.deflate data
 
-    open "#{filename}.#{extension}", 'wb' do |io|
+    File.open "#{filename}.#{extension}", 'wb' do |io|
       io.write zipped
     end
   end
@@ -427,7 +428,7 @@ class Gem::Indexer
 
     specs_index = compact_specs specs_index.uniq.sort
 
-    open dest, 'wb' do |io|
+    File.open dest, 'wb' do |io|
       Marshal.dump specs_index, io
     end
   end
diff --git a/lib/rubygems/installer.rb b/lib/rubygems/installer.rb
index 0cbca0791b..ee5fedeb64 100644
--- a/lib/rubygems/installer.rb
+++ b/lib/rubygems/installer.rb
@@ -206,7 +206,7 @@ class Gem::Installer
     ruby_executable = false
     existing = nil
 
-    open generated_bin, 'rb' do |io|
+    File.open generated_bin, 'rb' do |io|
       next unless io.gets =~ /^#!/ # shebang
       io.gets # blankline
 
@@ -427,7 +427,7 @@ class Gem::Installer
   # specifications directory.
 
   def write_spec
-    open spec_file, 'w' do |file|
+    File.open spec_file, 'w' do |file|
       spec.installed_by_version = Gem.rubygems_version
 
       file.puts spec.to_ruby_for_cache
@@ -464,7 +464,12 @@ class Gem::Installer
   def generate_bin # :nodoc:
     return if spec.executables.nil? or spec.executables.empty?
 
-    Dir.mkdir @bin_dir unless File.exist? @bin_dir
+    begin
+      Dir.mkdir @bin_dir
+    rescue SystemCallError
+      raise unless File.directory? @bin_dir
+    end
+
     raise Gem::FilePermissionError.new(@bin_dir) unless File.writable? @bin_dir
 
     spec.executables.each do |filename|
@@ -863,7 +868,7 @@ TEXT
 
     build_info_file = File.join build_info_dir, "#{spec.full_name}.info"
 
-    open build_info_file, 'w' do |io|
+    File.open build_info_file, 'w' do |io|
       @build_args.each do |arg|
         io.puts arg
       end
diff --git a/lib/rubygems/package.rb b/lib/rubygems/package.rb
index 77811ed5ec..3ac5662b68 100644
--- a/lib/rubygems/package.rb
+++ b/lib/rubygems/package.rb
@@ -219,7 +219,7 @@ class Gem::Package
       next unless stat.file?
 
       tar.add_file_simple file, stat.mode, stat.size do |dst_io|
-        open file, 'rb' do |src_io|
+        File.open file, 'rb' do |src_io|
           dst_io.write src_io.read 16384 until src_io.eof?
         end
       end
@@ -380,7 +380,7 @@ EOM
 
         FileUtils.mkdir_p mkdir, mkdir_options
 
-        open destination, 'wb' do |out|
+        File.open destination, 'wb' do |out|
           out.write entry.read
           FileUtils.chmod entry.header.mode, destination
         end if entry.file?
diff --git a/lib/rubygems/package/file_source.rb b/lib/rubygems/package/file_source.rb
index 1a4dc4c824..ecc3a68677 100644
--- a/lib/rubygems/package/file_source.rb
+++ b/lib/rubygems/package/file_source.rb
@@ -23,11 +23,11 @@ class Gem::Package::FileSource < Gem::Package::Source # :nodoc: all
   end
 
   def with_write_io &block
-    open path, 'wb', &block
+    File.open path, 'wb', &block
   end
 
   def with_read_io &block
-    open path, 'rb', &block
+    File.open path, 'rb', &block
   end
 
 end
diff --git a/lib/rubygems/package/old.rb b/lib/rubygems/package/old.rb
index f6e6e67c38..322d682ca8 100644
--- a/lib/rubygems/package/old.rb
+++ b/lib/rubygems/package/old.rb
@@ -80,7 +80,7 @@ class Gem::Package::Old < Gem::Package
 
         FileUtils.mkdir_p File.dirname destination
 
-        open destination, 'wb', entry['mode'] do |out|
+        File.open destination, 'wb', entry['mode'] do |out|
           out.write file_data
         end
 
diff --git a/lib/rubygems/request_set/lockfile.rb b/lib/rubygems/request_set/lockfile.rb
index 7f6eadb939..76ad17d486 100644
--- a/lib/rubygems/request_set/lockfile.rb
+++ b/lib/rubygems/request_set/lockfile.rb
@@ -223,7 +223,7 @@ class Gem::RequestSet::Lockfile
   def write
     content = to_s
 
-    open "#{@gem_deps_file}.lock", 'w' do |io|
+    File.open "#{@gem_deps_file}.lock", 'w' do |io|
       io.write content
     end
   end
diff --git a/lib/rubygems/security.rb b/lib/rubygems/security.rb
index 4690dd9230..236577c5a3 100644
--- a/lib/rubygems/security.rb
+++ b/lib/rubygems/security.rb
@@ -578,7 +578,7 @@ module Gem::Security
   def self.write pemmable, path, permissions = 0600, passphrase = nil, cipher = KEY_CIPHER
     path = File.expand_path path
 
-    open path, 'wb', permissions do |io|
+    File.open path, 'wb', permissions do |io|
       if passphrase and cipher
         io.write pemmable.to_pem cipher, passphrase
       else
diff --git a/lib/rubygems/security/trust_dir.rb b/lib/rubygems/security/trust_dir.rb
index bf44975cc6..849cf3cd3e 100644
--- a/lib/rubygems/security/trust_dir.rb
+++ b/lib/rubygems/security/trust_dir.rb
@@ -93,7 +93,7 @@ class Gem::Security::TrustDir
 
     destination = cert_path certificate
 
-    open destination, 'wb', @permissions[:trusted_cert] do |io|
+    File.open destination, 'wb', @permissions[:trusted_cert] do |io|
       io.write certificate.to_pem
     end
   end
diff --git a/lib/rubygems/source.rb b/lib/rubygems/source.rb
index bd84c217a7..b28b850660 100644
--- a/lib/rubygems/source.rb
+++ b/lib/rubygems/source.rb
@@ -160,7 +160,7 @@ class Gem::Source
     if update_cache? then
       FileUtils.mkdir_p cache_dir
 
-      open local_spec, 'wb' do |io|
+      File.open local_spec, 'wb' do |io|
         io.write spec
       end
     end
diff --git a/lib/rubygems/stub_specification.rb b/lib/rubygems/stub_specification.rb
index 8337375ab4..ae2effbc84 100644
--- a/lib/rubygems/stub_specification.rb
+++ b/lib/rubygems/stub_specification.rb
@@ -113,6 +113,8 @@ class Gem::StubSpecification < Gem::BasicSpecification
     unless @data
       begin
         saved_lineno = $.
+
+        # TODO It should be use `File.open`, but bundler-1.16.1 example expects Kernel#open.
         open loaded_from, OPEN_MODE do |file|
           begin
             file.readline # discard encoding line
diff --git a/lib/rubygems/test_case.rb b/lib/rubygems/test_case.rb
index f7f216e5e3..39aa4fc9a7 100644
--- a/lib/rubygems/test_case.rb
+++ b/lib/rubygems/test_case.rb
@@ -488,7 +488,7 @@ class Gem::TestCase < MiniTest::Unit::TestCase
 
     gemspec = "#{name}.gemspec"
 
-    open File.join(directory, gemspec), 'w' do |io|
+    File.open File.join(directory, gemspec), 'w' do |io|
       io.write git_spec.to_ruby
     end
 
@@ -592,7 +592,7 @@ class Gem::TestCase < MiniTest::Unit::TestCase
   # Reads a Marshal file at +path+
 
   def read_cache(path)
-    open path.dup.untaint, 'rb' do |io|
+    File.open path.dup.untaint, 'rb' do |io|
       Marshal.load io.read
     end
   end
@@ -612,7 +612,7 @@ class Gem::TestCase < MiniTest::Unit::TestCase
     dir = File.dirname path
     FileUtils.mkdir_p dir unless File.directory? dir
 
-    open path, 'wb' do |io|
+    File.open path, 'wb' do |io|
       yield io if block_given?
     end
 
@@ -727,7 +727,7 @@ class Gem::TestCase < MiniTest::Unit::TestCase
     install_default_specs(*specs)
 
     specs.each do |spec|
-      open spec.loaded_from, 'w' do |io|
+      File.open spec.loaded_from, 'w' do |io|
         io.write spec.to_ruby_for_cache
       end
     end
@@ -1363,7 +1363,7 @@ Also, a list:
       yield specification if block_given?
     end
 
-    open File.join(directory, "#{name}.gemspec"), 'w' do |io|
+    File.open File.join(directory, "#{name}.gemspec"), 'w' do |io|
       io.write vendor_spec.to_ruby
     end
 
diff --git a/lib/rubygems/test_utilities.rb b/lib/rubygems/test_utilities.rb
index 686916ea02..83c9d2d0fe 100644
--- a/lib/rubygems/test_utilities.rb
+++ b/lib/rubygems/test_utilities.rb
@@ -346,7 +346,7 @@ class Gem::TestCase::SpecFetcherSetup
   end
 
   def write_spec spec # :nodoc:
-    open spec.spec_file, 'w' do |io|
+    File.open spec.spec_file, 'w' do |io|
       io.write spec.to_ruby_for_cache
     end
   end
diff --git a/lib/rubygems/util.rb b/lib/rubygems/util.rb
index 2de45c900b..6c75910004 100644
--- a/lib/rubygems/util.rb
+++ b/lib/rubygems/util.rb
@@ -114,7 +114,8 @@ module Gem::Util
 
     here = File.expand_path directory
     loop do
-      Dir.chdir here, &block
+      Dir.chdir here, &block rescue Errno::EACCES
+
       new_here = File.expand_path('..', here)
       return if new_here == here # toplevel
       here = new_here
diff --git a/lib/rubygems/validator.rb b/lib/rubygems/validator.rb
index 83448229bb..6842e4fa9c 100644
--- a/lib/rubygems/validator.rb
+++ b/lib/rubygems/validator.rb
@@ -34,7 +34,7 @@ class Gem::Validator
   # gem_path:: [String] Path to gem file
 
   def verify_gem_file(gem_path)
-    open gem_path, Gem.binary_mode do |file|
+    File.open gem_path, Gem.binary_mode do |file|
       gem_data = file.read
       verify_gem gem_data
     end
@@ -109,7 +109,7 @@ class Gem::Validator
 
         good, gone, unreadable = nil, nil, nil, nil
 
-        open gem_path, Gem.binary_mode do |file|
+        File.open gem_path, Gem.binary_mode do |file|
           package = Gem::Package.new gem_path
 
           good, gone = package.contents.partition { |file_name|
@@ -134,7 +134,7 @@ class Gem::Validator
 
               source = File.join gem_directory, entry['path']
 
-              open source, Gem.binary_mode do |f|
+              File.open source, Gem.binary_mode do |f|
                 unless f.read == data then
                   errors[gem_name][entry['path']] = "Modified from original"
                 end
diff --git a/test/rubygems/test_gem.rb b/test/rubygems/test_gem.rb
index bd4c91d96d..183771f0f3 100644
--- a/test/rubygems/test_gem.rb
+++ b/test/rubygems/test_gem.rb
@@ -463,7 +463,7 @@ class TestGem < Gem::TestCase
     assert File.directory?(util_cache_dir)
   end
 
-  unless win_platform? || Process.uid == 0 then # only for FS that support write protection
+  unless win_platform? || Process.uid.zero? then # only for FS that support write protection
     def test_self_ensure_gem_directories_write_protected
       gemdir = File.join @tempdir, "egd"
       FileUtils.rm_r gemdir rescue nil
@@ -775,7 +775,7 @@ class TestGem < Gem::TestCase
   end
 
   def test_self_read_binary
-    open 'test', 'w' do |io|
+    File.open 'test', 'w' do |io|
       io.write "\xCF\x80"
     end
 
@@ -1642,7 +1642,7 @@ class TestGem < Gem::TestCase
     spec = Gem::Specification.find { |s| s == spec }
     refute spec.activated?
 
-    open gem_deps_file, 'w' do |io|
+    File.open gem_deps_file, 'w' do |io|
       io.write 'gem "a"'
     end
 
@@ -1661,7 +1661,7 @@ class TestGem < Gem::TestCase
 
     refute spec.activated?
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.write 'gem "a"'
     end
 
@@ -1705,7 +1705,7 @@ class TestGem < Gem::TestCase
 
     refute spec.activated?
 
-    open 'Gemfile', 'w' do |io|
+    File.open 'Gemfile', 'w' do |io|
       io.write 'gem "a"'
     end
 
@@ -1734,7 +1734,7 @@ class TestGem < Gem::TestCase
 
     refute spec.activated?
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.write 'gem "a"'
     end
 
@@ -1749,7 +1749,7 @@ class TestGem < Gem::TestCase
     skip 'Insecure operation - read' if RUBY_VERSION <= "1.8.7"
     rubygems_gemdeps, ENV['RUBYGEMS_GEMDEPS'] = ENV['RUBYGEMS_GEMDEPS'], 'x'
 
-    open 'x', 'w' do |io|
+    File.open 'x', 'w' do |io|
       io.write 'gem "a"'
     end
 
@@ -1790,7 +1790,7 @@ You may need to `gem install -g` to install missing gems
     spec = Gem::Specification.find { |s| s == spec }
     refute spec.activated?
 
-    open 'x', 'w' do |io|
+    File.open 'x', 'w' do |io|
       io.write 'gem "a"'
     end
 
diff --git a/test/rubygems/test_gem_commands_cleanup_command.rb b/test/rubygems/test_gem_commands_cleanup_command.rb
index a222659ead..60d208fcc0 100644
--- a/test/rubygems/test_gem_commands_cleanup_command.rb
+++ b/test/rubygems/test_gem_commands_cleanup_command.rb
@@ -158,7 +158,7 @@ class TestGemCommandsCleanupCommand < Gem::TestCase
     assert_path_exists @a_1_1.gem_dir
   ensure
     FileUtils.chmod 0755, @gemhome
-  end unless win_platform? || Process.uid == 0
+  end unless win_platform? || Process.uid.zero?
 
   def test_execute_dry_run
     @cmd.options[:args] = %w[a]
diff --git a/test/rubygems/test_gem_commands_install_command.rb b/test/rubygems/test_gem_commands_install_command.rb
index fefc5c7059..822d40e3f3 100644
--- a/test/rubygems/test_gem_commands_install_command.rb
+++ b/test/rubygems/test_gem_commands_install_command.rb
@@ -131,7 +131,7 @@ class TestGemCommandsInstallCommand < Gem::TestCase
 
   def test_execute_no_user_install
     skip 'skipped on MS Windows (chmod has no effect)' if win_platform?
-    skip 'skipped in root privilege' if Process.uid == 0
+    skip 'skipped in root privilege' if Process.uid.zero?
 
     specs = spec_fetcher do |fetcher|
       fetcher.gem 'a', 2
diff --git a/test/rubygems/test_gem_commands_push_command.rb b/test/rubygems/test_gem_commands_push_command.rb
index b888a741f0..1c5dbfe23e 100644
--- a/test/rubygems/test_gem_commands_push_command.rb
+++ b/test/rubygems/test_gem_commands_push_command.rb
@@ -132,7 +132,7 @@ class TestGemCommandsPushCommand < Gem::TestCase
     }
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
     Gem.configuration.load_api_keys
@@ -166,7 +166,7 @@ class TestGemCommandsPushCommand < Gem::TestCase
     }
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
     Gem.configuration.load_api_keys
@@ -193,7 +193,7 @@ class TestGemCommandsPushCommand < Gem::TestCase
     }
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
     Gem.configuration.load_api_keys
@@ -235,7 +235,7 @@ class TestGemCommandsPushCommand < Gem::TestCase
     }
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
     Gem.configuration.load_api_keys
@@ -266,7 +266,7 @@ class TestGemCommandsPushCommand < Gem::TestCase
     }
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
     Gem.configuration.load_api_keys
diff --git a/test/rubygems/test_gem_commands_setup_command.rb b/test/rubygems/test_gem_commands_setup_command.rb
index 2136edb1be..9fdf428501 100644
--- a/test/rubygems/test_gem_commands_setup_command.rb
+++ b/test/rubygems/test_gem_commands_setup_command.rb
@@ -6,6 +6,8 @@ require 'rubygems/commands/setup_command'
 
 class TestGemCommandsSetupCommand < Gem::TestCase
 
+  BUNDLER_VERS = `gem list -e bundler`[/([^() ]+)\)\Z/, 1] || "1.16.1"
+
   def setup
     super
 
@@ -16,27 +18,27 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     FileUtils.mkdir_p 'bin'
     FileUtils.mkdir_p 'lib/rubygems/ssl_certs/rubygems.org'
 
-    open 'bin/gem',                   'w' do |io| io.puts '# gem'          end
-    open 'lib/rubygems.rb',           'w' do |io| io.puts '# rubygems.rb'  end
-    open 'lib/rubygems/test_case.rb', 'w' do |io| io.puts '# test_case.rb' end
-    open 'lib/rubygems/ssl_certs/rubygems.org/foo.pem', 'w' do |io| io.puts 'PEM'       end
+    File.open 'bin/gem',                   'w' do |io| io.puts '# gem'          end
+    File.open 'lib/rubygems.rb',           'w' do |io| io.puts '# rubygems.rb'  end
+    File.open 'lib/rubygems/test_case.rb', 'w' do |io| io.puts '# test_case.rb' end
+    File.open 'lib/rubygems/ssl_certs/rubygems.org/foo.pem', 'w' do |io| io.puts 'PEM'       end
 
     FileUtils.mkdir_p 'bundler/exe'
     FileUtils.mkdir_p 'bundler/lib/bundler'
 
-    open 'bundler/exe/bundle',        'w' do |io| io.puts '# bundle'       end
-    open 'bundler/lib/bundler.rb',    'w' do |io| io.puts '# bundler.rb'   end
-    open 'bundler/lib/bundler/b.rb',  'w' do |io| io.puts '# b.rb'         end
+    File.open 'bundler/exe/bundle',        'w' do |io| io.puts '# bundle'       end
+    File.open 'bundler/lib/bundler.rb',    'w' do |io| io.puts '# bundler.rb'   end
+    File.open 'bundler/lib/bundler/b.rb',  'w' do |io| io.puts '# b.rb'         end
 
     FileUtils.mkdir_p 'default/gems'
 
     gemspec = Gem::Specification.new
     gemspec.name = "bundler"
-    gemspec.version = "1.16.0"
+    gemspec.version = BUNDLER_VERS
     gemspec.bindir = "exe"
     gemspec.executables = ["bundle"]
 
-    open 'bundler/bundler.gemspec',   'w' do |io|
+    File.open 'bundler/bundler.gemspec',   'w' do |io|
       io.puts gemspec.to_ruby
     end
 
@@ -46,6 +48,11 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     end
 
     FileUtils.mkdir_p File.join(Gem.default_dir, "specifications")
+
+    open(File.join(Gem.default_dir, "specifications", "bundler-#{BUNDLER_VERS}.gemspec"), 'w') do |io|
+      io.puts "# bundler-#{BUNDLER_VERS}"
+    end
+
     open(File.join(Gem.default_dir, "specifications", "bundler-audit-1.0.0.gemspec"), 'w') do |io|
       io.puts '# bundler-audit'
     end
@@ -134,13 +141,25 @@ class TestGemCommandsSetupCommand < Gem::TestCase
 
     default_dir = Gem::Specification.default_specifications_dir
 
+    # expect to remove other versions of bundler gemspecs on default specification directory.
     refute_path_exists File.join(default_dir, "bundler-1.15.4.gemspec")
-    refute_path_exists 'default/gems/bundler-1.15.4'
-
-    assert_path_exists File.join(default_dir, "bundler-1.16.0.gemspec")
-    assert_path_exists 'default/gems/bundler-1.16.0'
+    assert_path_exists File.join(default_dir, "bundler-#{BUNDLER_VERS}.gemspec")
 
+    # expect to not remove bundler-* gemspecs.
     assert_path_exists File.join(Gem.default_dir, "specifications", "bundler-audit-1.0.0.gemspec")
+
+    # expect to remove normal gem that was same version. because it's promoted default gems.
+    refute_path_exists File.join(Gem.default_dir, "specifications", "bundler-#{BUNDLER_VERS}.gemspec")
+
+    # expect to install default gems. It location was `site_ruby` directory on real world.
+    assert_path_exists "default/gems/bundler-#{BUNDLER_VERS}"
+
+    # expect to not remove other versions of bundler on `site_ruby`
+    assert_path_exists 'default/gems/bundler-1.15.4'
+
+    # TODO: We need to assert to remove same version of bundler on gem_dir directory(It's not site_ruby dir)
+
+    # expect to not remove bundler-* direcotyr.
     assert_path_exists 'default/gems/bundler-audit-1.0.0'
   end if Gem::USE_BUNDLER_FOR_GEMDEPS
 
@@ -162,14 +181,14 @@ class TestGemCommandsSetupCommand < Gem::TestCase
     FileUtils.mkdir_p lib_rubygems_defaults
     FileUtils.mkdir_p lib_bundler
 
-    open securerandom_rb,    'w' do |io| io.puts '# securerandom.rb'     end
+    File.open securerandom_rb,    'w' do |io| io.puts '# securerandom.rb'     end
 
-    open old_builder_rb,     'w' do |io| io.puts '# builder.rb'          end
-    open old_format_rb,      'w' do |io| io.puts '# format.rb'           end
-    open old_bundler_c_rb,   'w' do |io| io.puts '# c.rb'                end
+    File.open old_builder_rb,     'w' do |io| io.puts '# builder.rb'          end
+    File.open old_format_rb,      'w' do |io| io.puts '# format.rb'           end
+    File.open old_bundler_c_rb,   'w' do |io| io.puts '# c.rb'                end
 
-    open engine_defaults_rb, 'w' do |io| io.puts '# jruby.rb'            end
-    open os_defaults_rb,     'w' do |io| io.puts '# operating_system.rb' end
+    File.open engine_defaults_rb, 'w' do |io| io.puts '# jruby.rb'            end
+    File.open os_defaults_rb,     'w' do |io| io.puts '# operating_system.rb' end
 
     @cmd.remove_old_lib_files lib
 
@@ -191,7 +210,7 @@ class TestGemCommandsSetupCommand < Gem::TestCase
 
     @cmd.options[:previous_version] = Gem::Version.new '2.0.2'
 
-    open 'History.txt', 'w' do |io|
+    File.open 'History.txt', 'w' do |io|
       io.puts <<-History_txt
 # coding: UTF-8
 
diff --git a/test/rubygems/test_gem_commands_uninstall_command.rb b/test/rubygems/test_gem_commands_uninstall_command.rb
index 2097ca7d43..2fdff706e7 100644
--- a/test/rubygems/test_gem_commands_uninstall_command.rb
+++ b/test/rubygems/test_gem_commands_uninstall_command.rb
@@ -92,7 +92,7 @@ class TestGemCommandsUninstallCommand < Gem::InstallerTestCase
     # Evil hack to prevent false removal success
     FileUtils.rm_f @executable
 
-    open @executable, "wb+" do |f| f.puts "binary" end
+    File.open @executable, "wb+" do |f| f.puts "binary" end
 
     @cmd.options[:executables] = true
     @cmd.options[:args] = [@spec.name]
@@ -204,7 +204,7 @@ class TestGemCommandsUninstallCommand < Gem::InstallerTestCase
     end
 
     assert Gem::Specification.find_all_by_name('dep_x').length > 0
-    assert Gem::Specification.find_all_by_name('x').length == 0
+    assert Gem::Specification.find_all_by_name('x').length.zero?
   end
 
   def test_execute_all
diff --git a/test/rubygems/test_gem_dependency_installer.rb b/test/rubygems/test_gem_dependency_installer.rb
index e55cc75682..3d76291668 100644
--- a/test/rubygems/test_gem_dependency_installer.rb
+++ b/test/rubygems/test_gem_dependency_installer.rb
@@ -424,7 +424,7 @@ class TestGemDependencyInstaller < Gem::TestCase
     extconf_rb = File.join @gemhome, 'gems', 'e-1', 'extconf.rb'
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |io|
+    File.open extconf_rb, 'w' do |io|
       io.write <<-EXTCONF_RB
         require 'mkmf'
         create_makefile 'e'
diff --git a/test/rubygems/test_gem_doctor.rb b/test/rubygems/test_gem_doctor.rb
index 39b8a11692..8db65d70ce 100644
--- a/test/rubygems/test_gem_doctor.rb
+++ b/test/rubygems/test_gem_doctor.rb
@@ -24,7 +24,7 @@ class TestGemDoctor < Gem::TestCase
 
     FileUtils.rm b.spec_file
 
-    open c.spec_file, 'w' do |io|
+    File.open c.spec_file, 'w' do |io|
       io.write 'this will raise an exception when evaluated.'
     end
 
@@ -77,7 +77,7 @@ Removed directory gems/c-2
 
     FileUtils.rm b.spec_file
 
-    open c.spec_file, 'w' do |io|
+    File.open c.spec_file, 'w' do |io|
       io.write 'this will raise an exception when evaluated.'
     end
 
diff --git a/test/rubygems/test_gem_ext_builder.rb b/test/rubygems/test_gem_ext_builder.rb
index d142ef28da..3dabd3e350 100644
--- a/test/rubygems/test_gem_ext_builder.rb
+++ b/test/rubygems/test_gem_ext_builder.rb
@@ -32,7 +32,7 @@ class TestGemExtBuilder < Gem::TestCase
     results = []
 
     Dir.chdir @ext do
-      open 'Makefile', 'w' do |io|
+      File.open 'Makefile', 'w' do |io|
         io.puts <<-MAKEFILE
 all:
 \t@#{Gem.ruby} -e "puts %Q{all: \#{ENV['DESTDIR']}}"
@@ -72,7 +72,7 @@ install:
     results = []
 
     Dir.chdir @ext do
-      open 'Makefile', 'w' do |io|
+      File.open 'Makefile', 'w' do |io|
         io.puts <<-MAKEFILE
 all:
 \t@#{Gem.ruby} -e "puts %Q{all: \#{ENV['DESTDIR']}}"
@@ -107,7 +107,7 @@ install:
 
     extconf_rb = File.join ext_dir, 'extconf.rb'
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
         require 'mkmf'
 
@@ -168,7 +168,7 @@ install:
 
     extconf_rb = File.join ext_dir, 'extconf.rb'
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
         require 'mkmf'
 
@@ -290,7 +290,7 @@ install:
 
     FileUtils.mkdir_p @spec.gem_dir
 
-    open File.join(@spec.gem_dir, "extconf.rb"), "w" do |f|
+    File.open File.join(@spec.gem_dir, "extconf.rb"), "w" do |f|
       f.write <<-'RUBY'
         puts "IN EXTCONF"
         extconf_args = File.join File.dirname(__FILE__), 'extconf_args'
@@ -323,7 +323,7 @@ install:
 
     build_info_file = File.join build_info_dir, "#{@spec.full_name}.info"
 
-    open build_info_file, 'w' do |io|
+    File.open build_info_file, 'w' do |io|
       io.puts '--with-foo-dir=/nonexistent'
     end
 
diff --git a/test/rubygems/test_gem_gemcutter_utilities.rb b/test/rubygems/test_gem_gemcutter_utilities.rb
index c3f9a7ea18..286d59a787 100644
--- a/test/rubygems/test_gem_gemcutter_utilities.rb
+++ b/test/rubygems/test_gem_gemcutter_utilities.rb
@@ -31,7 +31,7 @@ class TestGemGemcutterUtilities < Gem::TestCase
 
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
 
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
 
@@ -46,7 +46,7 @@ class TestGemGemcutterUtilities < Gem::TestCase
     keys = { :rubygems_api_key => 'KEY' }
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
 
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
 
@@ -59,7 +59,7 @@ class TestGemGemcutterUtilities < Gem::TestCase
     keys = { :rubygems_api_key => 'KEY', :other => 'OTHER' }
     FileUtils.mkdir_p File.dirname Gem.configuration.credentials_path
 
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write keys.to_yaml
     end
 
@@ -163,7 +163,7 @@ class TestGemGemcutterUtilities < Gem::TestCase
     other_api_key = 'f46dbb18bb6a9c97cdc61b5b85c186a17403cdcbf'
 
     FileUtils.mkdir_p File.dirname(Gem.configuration.credentials_path)
-    open Gem.configuration.credentials_path, 'w' do |f|
+    File.open Gem.configuration.credentials_path, 'w' do |f|
       f.write Hash[:other_api_key, other_api_key].to_yaml
     end
     util_sign_in [api_key, 200, 'OK']
diff --git a/test/rubygems/test_gem_indexer.rb b/test/rubygems/test_gem_indexer.rb
index a4a966e8de..5a9075e676 100644
--- a/test/rubygems/test_gem_indexer.rb
+++ b/test/rubygems/test_gem_indexer.rb
@@ -39,8 +39,7 @@ class TestGemIndexer < Gem::TestCase
 
   def test_initialize
     assert_equal @tempdir, @indexer.dest_directory
-    assert_equal File.join(Dir.tmpdir, "gem_generate_index_#{$$}"),
-                 @indexer.directory
+    assert_match %r{#{Dir.mktmpdir('gem_generate_index').match(/.*-/)}}, @indexer.directory
 
     indexer = Gem::Indexer.new @tempdir
     assert indexer.build_modern
diff --git a/test/rubygems/test_gem_install_update_options.rb b/test/rubygems/test_gem_install_update_options.rb
index 69a2b61041..371e408d27 100644
--- a/test/rubygems/test_gem_install_update_options.rb
+++ b/test/rubygems/test_gem_install_update_options.rb
@@ -141,7 +141,7 @@ class TestGemInstallUpdateOptions < Gem::InstallerTestCase
   def test_user_install_disabled_read_only
     if win_platform?
       skip('test_user_install_disabled_read_only test skipped on MS Windows')
-    elsif Process.uid == 0
+    elsif Process.uid.zero?
       skip('test_user_install_disabled_read_only test skipped in root privilege')
     else
       @cmd.handle_options %w[--no-user-install]
diff --git a/test/rubygems/test_gem_installer.rb b/test/rubygems/test_gem_installer.rb
index 63acc3d130..93b0482407 100644
--- a/test/rubygems/test_gem_installer.rb
+++ b/test/rubygems/test_gem_installer.rb
@@ -140,7 +140,7 @@ end
       s.require_path = 'lib'
     end
 
-    open File.join(util_inst_bindir, 'executable'), 'w' do |io|
+    File.open File.join(util_inst_bindir, 'executable'), 'w' do |io|
      io.write <<-EXEC
 #!/usr/local/bin/ruby
 #
@@ -437,7 +437,7 @@ gem 'other', version
 
     if win_platform?
       skip('test_generate_bin_script_no_perms skipped on MS Windows')
-    elsif Process.uid == 0
+    elsif Process.uid.zero?
       skip('test_generate_bin_script_no_perms skipped in root privilege')
     else
       FileUtils.chmod 0000, util_inst_bindir
@@ -531,7 +531,7 @@ gem 'other', version
 
     if win_platform?
       skip('test_generate_bin_symlink_no_perms skipped on MS Windows')
-    elsif Process.uid == 0
+    elsif Process.uid.zero?
       skip('test_user_install_disabled_read_only test skipped in root privilege')
     else
       FileUtils.chmod 0000, util_inst_bindir
diff --git a/test/rubygems/test_gem_package.rb b/test/rubygems/test_gem_package.rb
index cec1981c4c..936df60522 100644
--- a/test/rubygems/test_gem_package.rb
+++ b/test/rubygems/test_gem_package.rb
@@ -24,7 +24,7 @@ class TestGemPackage < Gem::Package::TarTestCase
   end
 
   def test_class_new_old_format
-    open 'old_format.gem', 'wb' do |io|
+    File.open 'old_format.gem', 'wb' do |io|
       io.write SIMPLE_GEM
     end
 
@@ -45,7 +45,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -110,8 +110,8 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir_p 'lib/empty'
 
-    open 'lib/code.rb',  'w' do |io| io.write '# lib/code.rb'  end
-    open 'lib/extra.rb', 'w' do |io| io.write '# lib/extra.rb' end
+    File.open 'lib/code.rb',  'w' do |io| io.write '# lib/code.rb'  end
+    File.open 'lib/extra.rb', 'w' do |io| io.write '# lib/extra.rb' end
 
     package = Gem::Package.new 'bogus.gem'
     package.spec = spec
@@ -140,7 +140,7 @@ class TestGemPackage < Gem::Package::TarTestCase
     spec.files = %w[lib/code.rb lib/code_sym.rb]
 
     FileUtils.mkdir_p 'lib'
-    open 'lib/code.rb',  'w' do |io| io.write '# lib/code.rb'  end
+    File.open 'lib/code.rb',  'w' do |io| io.write '# lib/code.rb'  end
 
     # NOTE: 'code.rb' is correct, because it's relative to lib/code_sym.rb
     File.symlink('code.rb', 'lib/code_sym.rb')
@@ -179,7 +179,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -218,7 +218,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -261,7 +261,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -311,7 +311,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -348,7 +348,7 @@ class TestGemPackage < Gem::Package::TarTestCase
 
     FileUtils.mkdir 'lib'
 
-    open 'lib/code.rb', 'w' do |io|
+    File.open 'lib/code.rb', 'w' do |io|
       io.write '# lib/code.rb'
     end
 
@@ -408,7 +408,7 @@ class TestGemPackage < Gem::Package::TarTestCase
       end
     end
 
-    open 'empty.gem', 'wb' do |io|
+    File.open 'empty.gem', 'wb' do |io|
       io.write gem.string
     end
 
@@ -620,7 +620,7 @@ class TestGemPackage < Gem::Package::TarTestCase
       end
     end
 
-    open 'mismatch.gem', 'wb' do |io|
+    File.open 'mismatch.gem', 'wb' do |io|
       io.write gem.string
     end
 
@@ -670,7 +670,7 @@ class TestGemPackage < Gem::Package::TarTestCase
       end
     end
 
-    open 'data_checksum_missing.gem', 'wb' do |io|
+    File.open 'data_checksum_missing.gem', 'wb' do |io|
       io.write gem.string
     end
 
@@ -773,7 +773,7 @@ class TestGemPackage < Gem::Package::TarTestCase
     FileUtils.mkdir 'lib'
     FileUtils.touch 'lib/code.rb'
 
-    open @gem, 'wb' do |gem_io|
+    File.open @gem, 'wb' do |gem_io|
       Gem::Package::TarWriter.new gem_io do |gem|
         build.add_metadata gem
         build.add_contents gem
@@ -804,7 +804,7 @@ class TestGemPackage < Gem::Package::TarTestCase
   end
 
   def test_verify_truncate
-    open 'bad.gem', 'wb' do |io|
+    File.open 'bad.gem', 'wb' do |io|
       io.write File.read(@gem, 1024) # don't care about newlines
     end
 
diff --git a/test/rubygems/test_gem_package_old.rb b/test/rubygems/test_gem_package_old.rb
index c15475b0c7..604981b3c1 100644
--- a/test/rubygems/test_gem_package_old.rb
+++ b/test/rubygems/test_gem_package_old.rb
@@ -7,7 +7,7 @@ class TestGemPackageOld < Gem::TestCase
   def setup
     super
 
-    open 'old_format.gem', 'wb' do |io|
+    File.open 'old_format.gem', 'wb' do |io|
       io.write SIMPLE_GEM
     end
 
diff --git a/test/rubygems/test_gem_rdoc.rb b/test/rubygems/test_gem_rdoc.rb
index 3961a8e3f9..0355883cb3 100644
--- a/test/rubygems/test_gem_rdoc.rb
+++ b/test/rubygems/test_gem_rdoc.rb
@@ -223,7 +223,7 @@ class TestGemRDoc < Gem::TestCase
 
   def test_remove_unwritable
     skip 'chmod not supported' if Gem.win_platform?
-    skip 'skipped in root privilege' if Process.uid == 0
+    skip 'skipped in root privilege' if Process.uid.zero?
     FileUtils.mkdir_p @a.base_dir
     FileUtils.chmod 0, @a.base_dir
 
@@ -252,7 +252,7 @@ class TestGemRDoc < Gem::TestCase
 
   def test_setup_unwritable
     skip 'chmod not supported' if Gem.win_platform?
-    skip 'skipped in root privilege' if Process.uid == 0
+    skip 'skipped in root privilege' if Process.uid.zero?
     FileUtils.mkdir_p @a.doc_dir
     FileUtils.chmod 0, @a.doc_dir
 
diff --git a/test/rubygems/test_gem_remote_fetcher.rb b/test/rubygems/test_gem_remote_fetcher.rb
index fc51b06f1b..20e34e84e1 100644
--- a/test/rubygems/test_gem_remote_fetcher.rb
+++ b/test/rubygems/test_gem_remote_fetcher.rb
@@ -431,7 +431,7 @@ PeIQQkFng2VVot/WAQbv3ePqWq07g1BBcwIBAg==
     assert File.exist?(a1_cache_gem)
   end
 
-  unless win_platform? || Process.uid == 0 # File.chmod doesn't work
+  unless win_platform? || Process.uid.zero? # File.chmod doesn't work
     def test_download_local_read_only
       FileUtils.mv @a1_gem, @tempdir
       local_path = File.join @tempdir, @a1.file_name
diff --git a/test/rubygems/test_gem_request_set.rb b/test/rubygems/test_gem_request_set.rb
index 3a48827481..5dc6c1518d 100644
--- a/test/rubygems/test_gem_request_set.rb
+++ b/test/rubygems/test_gem_request_set.rb
@@ -52,7 +52,7 @@ class TestGemRequestSet < Gem::TestCase
     rs = Gem::RequestSet.new
     installed = []
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts 'gem "a"'
       io.flush
 
@@ -78,7 +78,7 @@ class TestGemRequestSet < Gem::TestCase
 
     rs = Gem::RequestSet.new
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts 'gem "a"'
       io.flush
 
@@ -104,7 +104,7 @@ Gems to install:
     rs = Gem::RequestSet.new
     installed = []
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts 'gem "a"'
     end
 
@@ -128,7 +128,7 @@ Gems to install:
 
     rs = Gem::RequestSet.new
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts 'gem "a"'
       io.flush
 
@@ -150,7 +150,7 @@ Gems to install:
     rs = Gem::RequestSet.new
     installed = []
 
-    open 'gem.deps.rb.lock', 'w' do |io|
+    File.open 'gem.deps.rb.lock', 'w' do |io|
       io.puts <<-LOCKFILE
 GEM
   remote: #{@gem_repo}
@@ -167,7 +167,7 @@ DEPENDENCIES
       LOCKFILE
     end
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts 'gem "b"'
     end
 
@@ -190,7 +190,7 @@ DEPENDENCIES
     rs = Gem::RequestSet.new
     installed = []
 
-    open 'gem.deps.rb', 'w' do |io|
+    File.open 'gem.deps.rb', 'w' do |io|
       io.puts <<-GEM_DEPS
 gem "a"
 ruby "0"
diff --git a/test/rubygems/test_gem_request_set_lockfile.rb b/test/rubygems/test_gem_request_set_lockfile.rb
index 908f97303e..7460b7efad 100644
--- a/test/rubygems/test_gem_request_set_lockfile.rb
+++ b/test/rubygems/test_gem_request_set_lockfile.rb
@@ -31,7 +31,7 @@ class TestGemRequestSetLockfile < Gem::TestCase
   def write_lockfile lockfile
     @lock_file = File.expand_path "#{@gem_deps_file}.lock"
 
-    open @lock_file, 'w' do |io|
+    File.open @lock_file, 'w' do |io|
       io.write lockfile
     end
   end
@@ -387,7 +387,7 @@ DEPENDENCIES
           s.add_dependency 'c', '~> 1.0'
         end
 
-        open 'b.gemspec', 'w' do |io|
+        File.open 'b.gemspec', 'w' do |io|
           io.write b.to_ruby
         end
 
@@ -400,7 +400,7 @@ DEPENDENCIES
       Dir.chdir 'c' do
         c = Gem::Specification.new 'c', 1
 
-        open 'c.gemspec', 'w' do |io|
+        File.open 'c.gemspec', 'w' do |io|
           io.write c.to_ruby
         end
 
@@ -455,7 +455,7 @@ DEPENDENCIES
 
     gem_deps_lock_file = "#{@gem_deps_file}.lock"
 
-    open gem_deps_lock_file, 'w' do |io|
+    File.open gem_deps_lock_file, 'w' do |io|
       io.write 'hello'
     end
 
diff --git a/test/rubygems/test_gem_request_set_lockfile_parser.rb b/test/rubygems/test_gem_request_set_lockfile_parser.rb
index 9946c522d9..f3517da43a 100644
--- a/test/rubygems/test_gem_request_set_lockfile_parser.rb
+++ b/test/rubygems/test_gem_request_set_lockfile_parser.rb
@@ -536,7 +536,7 @@ DEPENDENCIES
   end
 
   def write_lockfile lockfile
-    open @lock_file, 'w' do |io|
+    File.open @lock_file, 'w' do |io|
       io.write lockfile
     end
   end
diff --git a/test/rubygems/test_gem_request_set_lockfile_tokenizer.rb b/test/rubygems/test_gem_request_set_lockfile_tokenizer.rb
index ab506a14e6..f4aba6d94a 100644
--- a/test/rubygems/test_gem_request_set_lockfile_tokenizer.rb
+++ b/test/rubygems/test_gem_request_set_lockfile_tokenizer.rb
@@ -295,7 +295,7 @@ GEM
   end
 
   def write_lockfile lockfile
-    open @lock_file, 'w' do |io|
+    File.open @lock_file, 'w' do |io|
       io.write lockfile
     end
   end
diff --git a/test/rubygems/test_gem_resolver_git_specification.rb b/test/rubygems/test_gem_resolver_git_specification.rb
index 9e8e2c5715..211757eb20 100644
--- a/test/rubygems/test_gem_resolver_git_specification.rb
+++ b/test/rubygems/test_gem_resolver_git_specification.rb
@@ -70,7 +70,7 @@ class TestGemResolverGitSpecification < Gem::TestCase
     Dir.chdir 'git/a' do
       FileUtils.mkdir_p 'ext/lib'
 
-      open 'ext/extconf.rb', 'w' do |io|
+      File.open 'ext/extconf.rb', 'w' do |io|
         io.puts 'require "mkmf"'
         io.puts 'create_makefile "a"'
       end
diff --git a/test/rubygems/test_gem_server.rb b/test/rubygems/test_gem_server.rb
index 6fe02e480f..b5c025e694 100644
--- a/test/rubygems/test_gem_server.rb
+++ b/test/rubygems/test_gem_server.rb
@@ -100,7 +100,7 @@ class TestGemServer < Gem::TestCase
     specs_dir = File.join dir, 'specifications'
     FileUtils.mkdir_p specs_dir
 
-    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+    File.open File.join(specs_dir, spec.spec_name), 'w' do |io|
       io.write spec.to_ruby
     end
 
@@ -198,7 +198,7 @@ class TestGemServer < Gem::TestCase
 
     FileUtils.mkdir_p specs_dir
 
-    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+    File.open File.join(specs_dir, spec.spec_name), 'w' do |io|
       io.write spec.to_ruby
     end
 
@@ -339,7 +339,7 @@ class TestGemServer < Gem::TestCase
     specs_dir = File.join dir, 'specifications'
     FileUtils.mkdir_p specs_dir
 
-    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+    File.open File.join(specs_dir, spec.spec_name), 'w' do |io|
       io.write spec.to_ruby
     end
 
@@ -378,7 +378,7 @@ class TestGemServer < Gem::TestCase
     specs_dir = File.join dir, 'specifications'
     FileUtils.mkdir_p specs_dir
 
-    open File.join(specs_dir, spec.spec_name), 'w' do |io|
+    File.open File.join(specs_dir, spec.spec_name), 'w' do |io|
       io.write spec.to_ruby
     end
 
diff --git a/test/rubygems/test_gem_source.rb b/test/rubygems/test_gem_source.rb
index 4a93e222f8..8805a9b404 100644
--- a/test/rubygems/test_gem_source.rb
+++ b/test/rubygems/test_gem_source.rb
@@ -110,7 +110,7 @@ class TestGemSource < Gem::TestCase
 
     cache_file = File.join cache_dir, a1.spec_name
 
-    open cache_file, 'wb' do |io|
+    File.open cache_file, 'wb' do |io|
       Marshal.dump a1, io
     end
 
@@ -163,7 +163,7 @@ class TestGemSource < Gem::TestCase
 
     cache_file = File.join cache_dir, "latest_specs.#{Gem.marshal_version}"
 
-    open cache_file, 'wb' do |io|
+    File.open cache_file, 'wb' do |io|
       Marshal.dump latest_specs, io
     end
 
@@ -187,7 +187,7 @@ class TestGemSource < Gem::TestCase
 
     cache_file = File.join cache_dir, "latest_specs.#{Gem.marshal_version}"
 
-    open cache_file, 'wb' do |io|
+    File.open cache_file, 'wb' do |io|
       # Setup invalid data in the cache:
       io.write Marshal.dump(latest_specs)[0, 10]
     end
diff --git a/test/rubygems/test_gem_source_git.rb b/test/rubygems/test_gem_source_git.rb
index 0e13a11e7e..8f5d3ee745 100644
--- a/test/rubygems/test_gem_source_git.rb
+++ b/test/rubygems/test_gem_source_git.rb
@@ -229,7 +229,7 @@ class TestGemSourceGit < Gem::TestCase
       Dir.chdir 'b' do
         b = Gem::Specification.new 'b', 1
 
-        open 'b.gemspec', 'w' do |io|
+        File.open 'b.gemspec', 'w' do |io|
           io.write b.to_ruby
         end
 
diff --git a/test/rubygems/test_gem_specification.rb b/test/rubygems/test_gem_specification.rb
index 7bfeb48d3c..b1087c9f59 100644
--- a/test/rubygems/test_gem_specification.rb
+++ b/test/rubygems/test_gem_specification.rb
@@ -922,7 +922,7 @@ dependencies: []
   end
 
   def test_self_load_relative
-    open 'a-2.gemspec', 'w' do |io|
+    File.open 'a-2.gemspec', 'w' do |io|
       io.write @a2.to_ruby_for_cache
     end
 
@@ -1114,7 +1114,7 @@ dependencies: []
   end
 
   def test_self_remove_spec_removed
-    open @a1.spec_file, 'w' do |io|
+    File.open @a1.spec_file, 'w' do |io|
       io.write @a1.to_ruby
     end
 
@@ -1366,13 +1366,13 @@ dependencies: []
 
     assert_empty @ext.build_args
 
-    open @ext.build_info_file, 'w' do |io|
+    File.open @ext.build_info_file, 'w' do |io|
       io.puts
     end
 
     assert_empty @ext.build_args
 
-    open @ext.build_info_file, 'w' do |io|
+    File.open @ext.build_info_file, 'w' do |io|
       io.puts '--with-foo-dir=wherever'
     end
 
@@ -1388,9 +1388,9 @@ dependencies: []
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
@@ -1438,9 +1438,9 @@ dependencies: []
     extconf_rb = File.join spec.gem_dir, spec.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
         end
@@ -1464,7 +1464,7 @@ dependencies: []
 
   def test_build_extensions_extensions_dir_unwritable
     skip 'chmod not supported' if Gem.win_platform?
-    skip 'skipped in root privilege' if Process.uid == 0
+    skip 'skipped in root privilege' if Process.uid.zero?
 
     ext_spec
 
@@ -1473,9 +1473,9 @@ dependencies: []
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
@@ -1490,7 +1490,7 @@ dependencies: []
     @ext.build_extensions
     refute_path_exists @ext.extension_dir
   ensure
-    unless ($DEBUG or win_platform? or Process.uid == 0) then
+    unless ($DEBUG or win_platform? or Process.uid.zero?) then
       FileUtils.chmod 0755, File.join(@ext.base_dir, 'extensions')
       FileUtils.chmod 0755, @ext.base_dir
     end
@@ -1506,9 +1506,9 @@ dependencies: []
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
@@ -1555,9 +1555,9 @@ dependencies: []
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
@@ -3422,9 +3422,9 @@ end
     extconf_rb = File.join @ext.gem_dir, @ext.extensions.first
     FileUtils.mkdir_p File.dirname extconf_rb
 
-    open extconf_rb, 'w' do |f|
+    File.open extconf_rb, 'w' do |f|
       f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
diff --git a/test/rubygems/test_gem_stub_specification.rb b/test/rubygems/test_gem_stub_specification.rb
index 43680265c7..f9a3a236c0 100644
--- a/test/rubygems/test_gem_stub_specification.rb
+++ b/test/rubygems/test_gem_stub_specification.rb
@@ -127,9 +127,9 @@ class TestStubSpecification < Gem::TestCase
       extconf_rb = File.join s.gem_dir, s.extensions.first
       FileUtils.mkdir_p File.dirname extconf_rb
 
-      open extconf_rb, 'w' do |f|
+      File.open extconf_rb, 'w' do |f|
         f.write <<-'RUBY'
-        open 'Makefile', 'w' do |f|
+        File.open 'Makefile', 'w' do |f|
           f.puts "clean:\n\techo clean"
           f.puts "default:\n\techo built"
           f.puts "install:\n\techo installed"
@@ -149,7 +149,7 @@ class TestStubSpecification < Gem::TestCase
     spec = new_default_spec 'default', 1
     spec.extensions << 'extconf.rb'
 
-    open spec.loaded_from, 'w' do |io|
+    File.open spec.loaded_from, 'w' do |io|
       io.write spec.to_ruby_for_cache
     end
 
@@ -198,7 +198,7 @@ class TestStubSpecification < Gem::TestCase
 
   def stub_with_version
     spec = File.join @gemhome, 'specifications', 'stub_e-2.gemspec'
-    open spec, 'w' do |io|
+    File.open spec, 'w' do |io|
       io.write <<-STUB
 # -*- encoding: utf-8 -*-
 # stub: stub_v 2 ruby lib
@@ -221,7 +221,7 @@ end
 
   def stub_without_version
     spec = File.join @gemhome, 'specifications', 'stub-2.gemspec'
-    open spec, 'w' do |io|
+    File.open spec, 'w' do |io|
       io.write <<-STUB
 # -*- encoding: utf-8 -*-
 # stub: stub_v ruby lib
@@ -245,7 +245,7 @@ end
 
   def stub_with_extension
     spec = File.join @gemhome, 'specifications', 'stub_e-2.gemspec'
-    open spec, 'w' do |io|
+    File.open spec, 'w' do |io|
       io.write <<-STUB
 # -*- encoding: utf-8 -*-
 # stub: stub_e 2 ruby lib
@@ -271,7 +271,7 @@ end
 
   def stub_without_extension
     spec = File.join @gemhome, 'specifications', 'stub-2.gemspec'
-    open spec, 'w' do |io|
+    File.open spec, 'w' do |io|
       io.write <<-STUB
 # -*- encoding: utf-8 -*-
 # stub: stub 2 ruby lib
diff --git a/test/rubygems/test_gem_util.rb b/test/rubygems/test_gem_util.rb
index dc85d25586..80dbff4b9e 100644
--- a/test/rubygems/test_gem_util.rb
+++ b/test/rubygems/test_gem_util.rb
@@ -5,7 +5,7 @@ require 'rubygems/util'
 class TestGemUtil < Gem::TestCase
 
   def test_class_popen
-    skip "MJIT executes process and it's caught by Process.wait(-1)" if RubyVM::MJIT.enabled?
+    skip "MJIT executes process and it's caught by Process.wait(-1)" if defined?(RubyVM::MJIT) && RubyVM::MJIT.enabled?
     assert_equal "0\n", Gem::Util.popen(Gem.ruby, '-e', 'p 0')
 
     assert_raises Errno::ECHILD do
@@ -30,6 +30,28 @@ class TestGemUtil < Gem::TestCase
     loop { break if enum.next.nil? } # exhaust the enumerator
   end
 
+  def test_traverse_parents_does_not_crash_on_permissions_error
+    skip 'skipped on MS Windows (chmod has no effect)' if win_platform?
+
+    FileUtils.mkdir_p 'd/e/f'
+    # remove 'execute' permission from "e" directory and make it
+    # impossible to cd into it and its children
+    FileUtils.chmod(0666, 'd/e')
+
+    paths = Gem::Util.traverse_parents('d/e/f').to_a
+
+    assert_equal File.join(@tempdir, 'd'), paths[0]
+    assert_equal @tempdir, paths[1]
+    # File.expand_path with macOS returns `/private` prefix.
+    if RUBY_PLATFORM !~ /darwin/
+      assert_equal Dir.tmpdir, paths[2]
+      assert_equal '/', paths[3]
+    end
+  ensure
+    # restore default permissions, allow the directory to be removed
+    FileUtils.chmod(0775, 'd/e') unless win_platform?
+  end
+
   def test_linked_list_find
     list = [1,2,3,4,5].inject(Gem::List.new(0)) { |m,o|
       Gem::List.new o, m
diff --git a/test/rubygems/test_gem_version.rb b/test/rubygems/test_gem_version.rb
index 56c818663e..792ad5f084 100644
--- a/test/rubygems/test_gem_version.rb
+++ b/test/rubygems/test_gem_version.rb
@@ -2,6 +2,8 @@
 require 'rubygems/test_case'
 require "rubygems/version"
 
+require "minitest/benchmark"
+
 class TestGemVersion < Gem::TestCase
 
   class V < ::Gem::Version
@@ -102,6 +104,15 @@ class TestGemVersion < Gem::TestCase
     end
   end
 
+  def bench_anchored_version_pattern
+    assert_performance_linear 0.5 do |count|
+      version_string = count.times.map {|i| "0" * i.succ }.join(".") << "."
+      version_string =~ Gem::Version::ANCHORED_VERSION_PATTERN
+    end
+  rescue RegexpError
+    skip "It fails to allocate the memory for regex pattern of Gem::Version::ANCHORED_VERSION_PATTERN"
+  end
+
   def test_empty_version
     ["", "   ", " "].each do |empty|
       assert_equal "0", Gem::Version.new(empty).version
diff --git a/test/rubygems/test_require.rb b/test/rubygems/test_require.rb
index a106fc21a6..e292ce226d 100644
--- a/test/rubygems/test_require.rb
+++ b/test/rubygems/test_require.rb
@@ -70,10 +70,12 @@ class TestGemRequire < Gem::TestCase
 
   def create_sync_thread
     Thread.new do
-      yield
-    ensure
-      FILE_ENTERED_LATCH.release
-      FILE_EXIT_LATCH.await
+      begin
+        yield
+      ensure
+        FILE_ENTERED_LATCH.release
+        FILE_EXIT_LATCH.await
+      end
     end
   end
 
@@ -100,8 +102,8 @@ class TestGemRequire < Gem::TestCase
     assert t1.join, "thread 1 should exit"
     assert t2.join, "thread 2 should exit"
   ensure
-    Object.send :remove_const, :FILE_ENTERED_LATCH
-    Object.send :remove_const, :FILE_EXIT_LATCH
+    Object.send :remove_const, :FILE_ENTERED_LATCH if Object.const_defined? :FILE_ENTERED_LATCH
+    Object.send :remove_const, :FILE_EXIT_LATCH if Object.const_defined? :FILE_EXIT_LATCH
   end
 
   def test_require_is_not_lazy_with_exact_req