merge revision(s) 62244,62246,62301,62302,62303,62422,62436,62452: [Backport #14481]

	Merge RubyGems-2.7.5 from upstream.

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

	test_gem_util.rb: fix broken test

	* test/rubygems/test_gem_util.rb: no guarantee that tmpdir is
	  always underneath the root directory at all.

	test_gem_commands_setup_command.rb: BUNDLER_VERS

	* test/rubygems/test_gem_commands_setup_command.rb: run bundled
	  gem command, instead of installed one.

	no need to set bundled bundler unless Gem::USE_BUNDLER_FOR_GEMDEPS


	revert r62302 and force to define the version constant


	Merge RubyGems 2.7.6 from upstream.

	  It fixed some security vulnerabilities.

	  http://blog.rubygems.org/2018/02/15/2.7.6-released.html

	fix regexp literal warning.

	test/rubygems/test_gem_server.rb: eliminate duplicated character class warning.
	[Bug #14481]

	Remove unnecessary `[]`s

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@62837 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

25 files changed, 143 insertions, 64 deletions

diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index 0475ced164..2762bfcb88 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -10,7 +10,7 @@ require 'rbconfig'
 require 'thread'
 
 module Gem
-  VERSION = "2.7.3"
+  VERSION = "2.7.6"
 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/owner_command.rb b/lib/rubygems/commands/owner_command.rb
index 8e2271657a..637b5bdc4d 100644
--- a/lib/rubygems/commands/owner_command.rb
+++ b/lib/rubygems/commands/owner_command.rb
@@ -64,7 +64,7 @@ permission to.
     end
 
     with_response response do |resp|
-      owners = YAML.load resp.body
+      owners = Gem::SafeYAML.load resp.body
 
       say "Owners for gem: #{name}"
       owners.each do |owner|
diff --git a/lib/rubygems/commands/setup_command.rb b/lib/rubygems/commands/setup_command.rb
index 5d1414d102..ee6ce88eae 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
+    specs_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)
+    bundler_bin_dir = 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..b924122827 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
@@ -378,9 +378,9 @@ EOM
             File.dirname destination
           end
 
-        FileUtils.mkdir_p mkdir, mkdir_options
+        mkdir_p_safe mkdir, mkdir_options, destination_dir, entry.full_name
 
-        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?
@@ -416,20 +416,35 @@ EOM
     raise Gem::Package::PathError.new(filename, destination_dir) if
       filename.start_with? '/'
 
-    destination_dir = File.realpath destination_dir if
-      File.respond_to? :realpath
+    destination_dir = realpath destination_dir
     destination_dir = File.expand_path destination_dir
 
     destination = File.join destination_dir, filename
     destination = File.expand_path destination
 
     raise Gem::Package::PathError.new(destination, destination_dir) unless
-      destination.start_with? destination_dir
+      destination.start_with? destination_dir + '/'
 
     destination.untaint
     destination
   end
 
+  def mkdir_p_safe mkdir, mkdir_options, destination_dir, file_name
+    destination_dir = realpath File.expand_path(destination_dir)
+    parts = mkdir.split(File::SEPARATOR)
+    parts.reduce do |path, basename|
+      path = realpath path  unless path == ""
+      path = File.expand_path(path + File::SEPARATOR + basename)
+      lstat = File.lstat path rescue nil
+      if !lstat || !lstat.directory?
+        unless path.start_with? destination_dir and (FileUtils.mkdir path, mkdir_options rescue false)
+          raise Gem::Package::PathError.new(file_name, destination_dir)
+        end
+      end
+      path
+    end
+  end
+
   ##
   # Loads a Gem::Specification from the TarEntry +entry+
 
@@ -603,6 +618,10 @@ EOM
       raise Gem::Package::FormatError.new \
               'package content (data.tar.gz) is missing', @gem
     end
+
+    if duplicates = @files.group_by {|f| f }.select {|k,v| v.size > 1 }.map(&:first) and duplicates.any?
+      raise Gem::Security::Exception, "duplicate files in the package: (#{duplicates.map(&:inspect).join(', ')})"
+    end
   end
 
   ##
@@ -616,6 +635,16 @@ EOM
     raise Gem::Package::FormatError.new(e.message, entry.full_name)
   end
 
+  if File.respond_to? :realpath
+    def realpath file
+      File.realpath file
+    end
+  else
+    def realpath file
+      file
+    end
+  end
+
 end
 
 require 'rubygems/package/digest_io'
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/package/tar_header.rb b/lib/rubygems/package/tar_header.rb
index c54bd14d57..d557357114 100644
--- a/lib/rubygems/package/tar_header.rb
+++ b/lib/rubygems/package/tar_header.rb
@@ -104,25 +104,30 @@ class Gem::Package::TarHeader
     fields = header.unpack UNPACK_FORMAT
 
     new :name     => fields.shift,
-        :mode     => fields.shift.oct,
-        :uid      => fields.shift.oct,
-        :gid      => fields.shift.oct,
-        :size     => fields.shift.oct,
-        :mtime    => fields.shift.oct,
-        :checksum => fields.shift.oct,
+        :mode     => strict_oct(fields.shift),
+        :uid      => strict_oct(fields.shift),
+        :gid      => strict_oct(fields.shift),
+        :size     => strict_oct(fields.shift),
+        :mtime    => strict_oct(fields.shift),
+        :checksum => strict_oct(fields.shift),
         :typeflag => fields.shift,
         :linkname => fields.shift,
         :magic    => fields.shift,
-        :version  => fields.shift.oct,
+        :version  => strict_oct(fields.shift),
         :uname    => fields.shift,
         :gname    => fields.shift,
-        :devmajor => fields.shift.oct,
-        :devminor => fields.shift.oct,
+        :devmajor => strict_oct(fields.shift),
+        :devminor => strict_oct(fields.shift),
         :prefix   => fields.shift,
 
         :empty => empty
   end
 
+  def self.strict_oct(str)
+    return str.oct if str =~ /\A[0-7]*\z/
+    raise ArgumentError, "#{str.inspect} is not an octal string"
+  end
+
   ##
   # Creates a new TarHeader using +vals+
 
diff --git a/lib/rubygems/package/tar_writer.rb b/lib/rubygems/package/tar_writer.rb
index f68b8d4c5e..390f7851a3 100644
--- a/lib/rubygems/package/tar_writer.rb
+++ b/lib/rubygems/package/tar_writer.rb
@@ -196,6 +196,8 @@ class Gem::Package::TarWriter
       digest_name == signer.digest_name
     end
 
+    raise "no #{signer.digest_name} in #{digests.values.compact}" unless signature_digest
+
     if signer.key then
       signature = signer.sign signature_digest.digest
 
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/server.rb b/lib/rubygems/server.rb
index 93b3af36f8..62c3dfe9cf 100644
--- a/lib/rubygems/server.rb
+++ b/lib/rubygems/server.rb
@@ -623,6 +623,18 @@ div.method-source-code pre { color: #ffdead; overflow: hidden; }
       executables = nil if executables.empty?
       executables.last["is_last"] = true if executables
 
+      # Pre-process spec homepage for safety reasons
+      begin
+        homepage_uri = URI.parse(spec.homepage)
+        if [URI::HTTP, URI::HTTPS].member? homepage_uri.class
+          homepage_uri = spec.homepage
+        else
+          homepage_uri = "."
+        end
+      rescue URI::InvalidURIError
+        homepage_uri = "."
+      end
+
       specs << {
         "authors"             => spec.authors.sort.join(", "),
         "date"                => spec.date.to_s,
@@ -632,7 +644,7 @@ div.method-source-code pre { color: #ffdead; overflow: hidden; }
         "only_one_executable" => (executables && executables.size == 1),
         "full_name"           => spec.full_name,
         "has_deps"            => !deps.empty?,
-        "homepage"            => spec.homepage,
+        "homepage"            => homepage_uri,
         "name"                => spec.name,
         "rdoc_installed"      => Gem::RDoc.new(spec).rdoc_installed?,
         "ri_installed"        => Gem::RDoc.new(spec).ri_installed?,
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/specification.rb b/lib/rubygems/specification.rb
index efc08c4738..2560324b7a 100644
--- a/lib/rubygems/specification.rb
+++ b/lib/rubygems/specification.rb
@@ -15,6 +15,7 @@ require 'rubygems/basic_specification'
 require 'rubygems/stub_specification'
 require 'rubygems/util/list'
 require 'stringio'
+require 'uri'
 
 ##
 # The Specification class contains the information for a Gem.  Typically
@@ -2822,10 +2823,16 @@ http://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard li
       raise Gem::InvalidSpecificationException, "#{lazy} is not a summary"
     end
 
-    if homepage and not homepage.empty? and
-       homepage !~ /\A[a-z][a-z\d+.-]*:/i then
-      raise Gem::InvalidSpecificationException,
-            "\"#{homepage}\" is not a URI"
+    # Make sure a homepage is valid HTTP/HTTPS URI
+    if homepage and not homepage.empty?
+      begin
+        homepage_uri = URI.parse(homepage)
+        unless [URI::HTTP, URI::HTTPS].member? homepage_uri.class
+          raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
+        end
+      rescue URI::InvalidURIError
+        raise Gem::InvalidSpecificationException, "\"#{homepage}\" is not a valid HTTP URI"
+      end
     end
 
     # Warnings
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