Merge branch 'master' into truffle-head

jruby · Mar 4, 2016 · 4b05809 · 4b05809
2 parents a7bc9de + f125c8d
commit 4b05809
Showing 171 changed files with 836 additions and 439 deletions.
diff --git a/core/src/main/java/org/jruby/ext/nkf/RubyNKF.java b/core/src/main/java/org/jruby/ext/nkf/RubyNKF.java
diff --git a/core/src/main/java/org/jruby/ir/IRBuilder.java b/core/src/main/java/org/jruby/ir/IRBuilder.java
@@ -1733,7 +1733,12 @@ public Operand buildDAsgn(final DAsgnNode dasgnNode) {
         int depth = dasgnNode.getDepth();
         Variable arg = getLocalVariable(dasgnNode.getName(), depth);
         Operand  value = build(dasgnNode.getValueNode());
+
+        // no use copying a variable to itself
+        if (arg == value) return value;
+
         addInstr(new CopyInstr(arg, value));
+
         return value;
 
         // IMPORTANT: The return value of this method is value, not arg!
@@ -1909,6 +1914,7 @@ protected void receiveNonBlockArgs(final ArgsNode argsNode) {
         // Now for opt args
         if (opt > 0) {
             int optIndex = argsNode.getOptArgIndex();
+            Variable temp = createTemporaryVariable();
             for (int j = 0; j < opt; j++, argIndex++) {
                 // Jump to 'l' if this arg is not null.  If null, fall through and build the default value!
                 Label l = getNewLabel();
@@ -1917,10 +1923,12 @@ protected void receiveNonBlockArgs(final ArgsNode argsNode) {
                 Variable av = getNewLocalVariable(argName, 0);
                 if (scope instanceof IRMethod) addArgumentDescription(ArgumentType.opt, argName);
                 // You need at least required+j+1 incoming args for this opt arg to get an arg at all
-                addInstr(new ReceiveOptArgInstr(av, signature.required(), signature.pre(), j));
-                addInstr(BNEInstr.create(l, av, UndefinedValue.UNDEFINED)); // if 'av' is not undefined, go to default
-                build(n.getValue());
+                addInstr(new ReceiveOptArgInstr(temp, signature.required(), signature.pre(), j));
+                addInstr(BNEInstr.create(l, temp, UndefinedValue.UNDEFINED)); // if 'av' is not undefined, go to default
+                Operand defaultResult = build(n.getValue());
+                addInstr(new CopyInstr(temp, defaultResult));
                 addInstr(new LabelInstr(l));
+                addInstr(new CopyInstr(av, temp));
             }
         }
 
@@ -2752,7 +2760,12 @@ public Operand buildLiteral(LiteralNode literalNode) {
     public Operand buildLocalAsgn(LocalAsgnNode localAsgnNode) {
         Variable var  = getLocalVariable(localAsgnNode.getName(), localAsgnNode.getDepth());
         Operand value = build(localAsgnNode.getValueNode());
+
+        // no use copying a variable to itself
+        if (var == value) return value;
+
         addInstr(new CopyInstr(var, value));
+
         return value;
 
         // IMPORTANT: The return value of this method is value, not var!

diff --git a/lib/ruby/stdlib/gauntlet_rubygems.rb b/lib/ruby/stdlib/gauntlet_rubygems.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'gauntlet'
 

diff --git a/lib/ruby/stdlib/rubygems.rb b/lib/ruby/stdlib/rubygems.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # -*- ruby -*-
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
@@ -9,7 +10,7 @@
 require 'thread'
 
 module Gem
-  VERSION = '2.5.1'
+  VERSION = '2.6.1'
 end
 
 # Must be first since it unloads the prelude from 1.9.2
@@ -173,6 +174,14 @@ module Gem
   @pre_reset_hooks      ||= []
   @post_reset_hooks     ||= []
 
+  def self.env_requirement(gem_name)
+    @env_requirements_by_name ||= {}
+    @env_requirements_by_name[gem_name] ||= begin
+      req = ENV["GEM_REQUIREMENT_#{gem_name.upcase}"] || '>= 0'.freeze
+      Gem::Requirement.create(req)
+    end
+  end
+
   ##
   # Try to activate a gem containing +path+. Returns true if
   # activation succeeded or wasn't needed because it was already
@@ -191,8 +200,13 @@ def self.try_activate path
 
     begin
       spec.activate
-    rescue Gem::LoadError # this could fail due to gem dep collisions, go lax
-      Gem::Specification.find_by_name(spec.name).activate
+    rescue Gem::LoadError => e # this could fail due to gem dep collisions, go lax
+      spec_by_name = Gem::Specification.find_by_name(spec.name)
+      if spec_by_name.nil?
+        raise e
+      else
+        spec_by_name.activate
+      end
     end
 
     return true
@@ -238,7 +252,7 @@ def self.bin_path(name, exec_name = nil, *requirements)
     specs = dep.matching_specs(true)
 
     raise Gem::GemNotFoundException,
-          "can't find gem #{name} (#{requirements})" if specs.empty?
+          "can't find gem #{dep}" if specs.empty?
 
     specs = specs.find_all { |spec|
       spec.executables.include? exec_name
@@ -325,16 +339,38 @@ def self.deflate(data)
   # lookup files.
 
   def self.paths
-    @paths ||= Gem::PathSupport.new
+    @paths ||= Gem::PathSupport.new(ENV)
   end
 
   # Initialize the filesystem paths to use from +env+.
   # +env+ is a hash-like object (typically ENV) that
   # is queried for 'GEM_HOME', 'GEM_PATH', and 'GEM_SPEC_CACHE'
+  # Keys for the +env+ hash should be Strings, and values of the hash should
+  # be Strings or +nil+.
 
   def self.paths=(env)
     clear_paths
-    @paths = Gem::PathSupport.new env
+    target = {}
+    env.each_pair do |k,v|
+      case k
+      when 'GEM_HOME', 'GEM_PATH', 'GEM_SPEC_CACHE'
+        case v
+        when nil, String
+          target[k] = v
+        when Array
+          unless Gem::Deprecate.skip
+            warn <<-eowarn
+Array values in the parameter are deprecated. Please use a String or nil.
+An Array was passed in from #{caller[3]}
+            eowarn
+          end
+          target[k] = v.join File::PATH_SEPARATOR
+        end
+      else
+        target[k] = v
+      end
+    end
+    @paths = Gem::PathSupport.new ENV.to_hash.merge(target)
     Gem::Specification.dirs = @paths.path
   end
 
@@ -429,7 +465,9 @@ def self.find_files(glob, check_load_path=true)
 
     files = find_files_from_load_path glob if check_load_path
 
-    files.concat Gem::Specification.stubs.map { |spec|
+    gem_specifications = @gemdeps ? Gem.loaded_specs.values : Gem::Specification.stubs
+
+    files.concat gem_specifications.map { |spec|
       spec.matches_for_glob("#{glob}#{Gem.suffix_pattern}")
     }.flatten
 
@@ -938,9 +976,11 @@ def self.ui
   # by the unit tests to provide environment isolation.
 
   def self.use_paths(home, *paths)
-    paths = nil if paths == [nil]
-    paths = paths.first if Array === Array(paths).first
-    self.paths = { "GEM_HOME" => home, "GEM_PATH" => paths }
+    paths.flatten!
+    paths.compact!
+    hash = { "GEM_HOME" => home, "GEM_PATH" => paths.empty? ? home : paths.join(File::PATH_SEPARATOR) }
+    hash.delete_if { |_, v| v.nil? }
+    self.paths = hash
   end
 
   ##

diff --git a/lib/ruby/stdlib/rubygems/available_set.rb b/lib/ruby/stdlib/rubygems/available_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class Gem::AvailableSet
 
   include Enumerable

diff --git a/lib/ruby/stdlib/rubygems/basic_specification.rb b/lib/ruby/stdlib/rubygems/basic_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # BasicSpecification is an abstract class which implements some common code
 # used by both Specification and StubSpecification.
@@ -94,7 +95,7 @@ def extension_dir
   # Returns path to the extensions directory.
 
   def extensions_dir
-    @extensions_dir ||= Gem.default_ext_dir_for(base_dir) ||
+    Gem.default_ext_dir_for(base_dir) ||
       File.join(base_dir, 'extensions', Gem::Platform.local.to_s,
                 Gem.extension_api_version)
   end
@@ -124,9 +125,9 @@ def full_gem_path
 
   def full_name
     if platform == Gem::Platform::RUBY or platform.nil? then
-      "#{name}-#{version}".untaint
+      "#{name}-#{version}".dup.untaint
     else
-      "#{name}-#{version}-#{platform}".untaint
+      "#{name}-#{version}-#{platform}".dup.untaint
     end
   end
 
@@ -195,7 +196,6 @@ def gems_dir
 
   def internal_init # :nodoc:
     @extension_dir = nil
-    @extensions_dir = nil
     @full_gem_path         = nil
     @gem_dir               = nil
     @ignored = nil
@@ -281,7 +281,7 @@ def lib_dirs_glob
              self.require_paths.first
            end
 
-    "#{self.full_gem_path}/#{dirs}".untaint
+    "#{self.full_gem_path}/#{dirs}".dup.untaint
   end
 
   ##
@@ -325,4 +325,3 @@ def have_file? file, suffixes
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/command.rb b/lib/ruby/stdlib/rubygems/command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -153,7 +154,7 @@ def execute
 
   def show_lookup_failure(gem_name, version, errors, domain)
     if errors and !errors.empty?
-      msg = "Could not find a valid gem '#{gem_name}' (#{version}), here is why:\n"
+      msg = "Could not find a valid gem '#{gem_name}' (#{version}), here is why:\n".dup
       errors.each { |x| msg << "          #{x.wordy}\n" }
       alert_error msg
     else
@@ -299,6 +300,8 @@ def invoke_with_build_args(args, build_args)
 
     options[:build_args] = build_args
 
+    self.ui = Gem::SilentUI.new if options[:silent]
+
     if options[:help] then
       show_help
     elsif @when_invoked then
@@ -519,10 +522,15 @@ def wrap(text, width) # :doc:
     end
   end
 
-  add_common_option('-q', '--quiet', 'Silence commands') do |value, options|
+  add_common_option('-q', '--quiet', 'Silence command progress meter') do |value, options|
     Gem.configuration.verbose = false
   end
 
+  add_common_option("--silent",
+                    "Silence rubygems output") do |value, options|
+    options[:silent] = true
+  end
+
   # Backtrace and config-file are added so they show up in the help
   # commands.  Both options are actually handled before the other
   # options get parsed.
@@ -539,6 +547,11 @@ def wrap(text, width) # :doc:
                     'Turn on Ruby debugging') do
   end
 
+  add_common_option('--norc',
+                    'Avoid loading any .gemrc file') do
+  end
+
+
   # :stopdoc:
 
   HELP = <<-HELP
@@ -579,4 +592,3 @@ def wrap(text, width) # :doc:
 
 module Gem::Commands
 end
-
diff --git a/lib/ruby/stdlib/rubygems/command_manager.rb b/lib/ruby/stdlib/rubygems/command_manager.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/commands/build_command.rb b/lib/ruby/stdlib/rubygems/commands/build_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/package'
 
@@ -41,6 +42,10 @@ def usage # :nodoc:
   def execute
     gemspec = get_one_gem_name
 
+    unless File.exist? gemspec
+      gemspec += '.gemspec' if File.exist? gemspec + '.gemspec'
+    end
+
     if File.exist? gemspec then
       spec = Gem::Specification.load gemspec
 

diff --git a/lib/ruby/stdlib/rubygems/commands/cert_command.rb b/lib/ruby/stdlib/rubygems/commands/cert_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/security'
 begin

diff --git a/lib/ruby/stdlib/rubygems/commands/check_command.rb b/lib/ruby/stdlib/rubygems/commands/check_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/version_option'
 require 'rubygems/validator'

diff --git a/lib/ruby/stdlib/rubygems/commands/cleanup_command.rb b/lib/ruby/stdlib/rubygems/commands/cleanup_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/dependency_list'
 require 'rubygems/uninstaller'
@@ -75,6 +76,9 @@ def execute
   end
 
   def clean_gems
+    @original_home = Gem.dir
+    @original_path = Gem.path
+
     get_primary_gems
     get_candidate_gems
     get_gems_to_cleanup
@@ -86,9 +90,6 @@ def clean_gems
 
     deps = deplist.strongly_connected_components.flatten
 
-    @original_home = Gem.dir
-    @original_path = Gem.path
-
     deps.reverse_each do |spec|
       uninstall_dep spec
     end
@@ -107,6 +108,7 @@ def get_candidate_gems
   end
 
   def get_gems_to_cleanup
+
     gems_to_cleanup = @candidate_gems.select { |spec|
       @primary_gems[spec.name].version != spec.version
     }
@@ -115,6 +117,10 @@ def get_gems_to_cleanup
       spec.default_gem?
     }
 
+    gems_to_cleanup = gems_to_cleanup.select { |spec|
+      spec.base_dir == @original_home
+    }
+
     @default_gems += default_gems
     @default_gems.uniq!
     @gems_to_cleanup = gems_to_cleanup.uniq

diff --git a/lib/ruby/stdlib/rubygems/commands/contents_command.rb b/lib/ruby/stdlib/rubygems/commands/contents_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'English'
 require 'rubygems/command'
 require 'rubygems/version_option'

diff --git a/lib/ruby/stdlib/rubygems/commands/dependency_command.rb b/lib/ruby/stdlib/rubygems/commands/dependency_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/version_option'
@@ -99,7 +100,7 @@ def display_pipe specs # :nodoc:
   end
 
   def display_readable specs, reverse # :nodoc:
-    response = ''
+    response = String.new
 
     specs.each do |spec|
       response << print_dependencies(spec)
@@ -152,7 +153,7 @@ def ensure_specs specs # :nodoc:
   end
 
   def print_dependencies(spec, level = 0) # :nodoc:
-    response = ''
+    response = String.new
     response << '  ' * level + "Gem #{spec.full_name}\n"
     unless spec.dependencies.empty? then
       spec.dependencies.sort_by { |dep| dep.name }.each do |dep|

diff --git a/lib/ruby/stdlib/rubygems/commands/environment_command.rb b/lib/ruby/stdlib/rubygems/commands/environment_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Commands::EnvironmentCommand < Gem::Command
@@ -71,7 +72,7 @@ def usage # :nodoc:
   end
 
   def execute
-    out = ''
+    out = String.new
     arg = options[:args][0]
     out <<
       case arg
@@ -103,7 +104,7 @@ def add_path out, path
   end
 
   def show_environment # :nodoc:
-    out = "RubyGems Environment:\n"
+    out = "RubyGems Environment:\n".dup
 
     out << "  - RUBYGEMS VERSION: #{Gem::VERSION}\n"
 
@@ -157,4 +158,3 @@ def show_environment # :nodoc:
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/commands/fetch_command.rb b/lib/ruby/stdlib/rubygems/commands/fetch_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/version_option'

diff --git a/lib/ruby/stdlib/rubygems/commands/generate_index_command.rb b/lib/ruby/stdlib/rubygems/commands/generate_index_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/indexer'
 

diff --git a/lib/ruby/stdlib/rubygems/commands/help_command.rb b/lib/ruby/stdlib/rubygems/commands/help_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Commands::HelpCommand < Gem::Command

diff --git a/lib/ruby/stdlib/rubygems/commands/install_command.rb b/lib/ruby/stdlib/rubygems/commands/install_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/install_update_options'
 require 'rubygems/dependency_installer'
@@ -185,6 +186,7 @@ def check_version # :nodoc:
   end
 
   def execute
+
     if options.include? :gemdeps then
       install_from_gemdeps
       return # not reached

diff --git a/lib/ruby/stdlib/rubygems/commands/list_command.rb b/lib/ruby/stdlib/rubygems/commands/list_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/commands/query_command'
 

diff --git a/lib/ruby/stdlib/rubygems/commands/lock_command.rb b/lib/ruby/stdlib/rubygems/commands/lock_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Commands::LockCommand < Gem::Command

diff --git a/lib/ruby/stdlib/rubygems/commands/mirror_command.rb b/lib/ruby/stdlib/rubygems/commands/mirror_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 unless defined? Gem::Commands::MirrorCommand

diff --git a/lib/ruby/stdlib/rubygems/commands/open_command.rb b/lib/ruby/stdlib/rubygems/commands/open_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'English'
 require 'rubygems/command'
 require 'rubygems/version_option'
@@ -14,6 +15,10 @@ def initialize
                "Opens gem sources in EDITOR") do |editor, options|
       options[:editor] = editor || get_env_editor
     end
+    add_option('-v', '--version VERSION', String,
+               "Opens specific gem version") do |version|
+      options[:version]  = version
+    end
   end
 
   def arguments # :nodoc:

diff --git a/lib/ruby/stdlib/rubygems/commands/outdated_command.rb b/lib/ruby/stdlib/rubygems/commands/outdated_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/spec_fetcher'

diff --git a/lib/ruby/stdlib/rubygems/commands/owner_command.rb b/lib/ruby/stdlib/rubygems/commands/owner_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/gemcutter_utilities'

diff --git a/lib/ruby/stdlib/rubygems/commands/pristine_command.rb b/lib/ruby/stdlib/rubygems/commands/pristine_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/package'
 require 'rubygems/installer'

diff --git a/lib/ruby/stdlib/rubygems/commands/push_command.rb b/lib/ruby/stdlib/rubygems/commands/push_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/gemcutter_utilities'
@@ -75,13 +76,17 @@ def send_gem name
       @host = gem_data.spec.metadata['default_gem_server']
     end
 
-    # Always include this, even if it's nil
-    args << @host
+    push_host = nil
 
     if gem_data.spec.metadata.has_key?('allowed_push_host')
-      args << gem_data.spec.metadata['allowed_push_host']
+      push_host = gem_data.spec.metadata['allowed_push_host']
     end
 
+    @host ||= push_host
+
+    # Always include @host, even if it's nil
+    args += [ @host, push_host ]
+
     say "Pushing gem to #{@host || Gem.host}..."
 
     response = rubygems_api_request(*args) do |request|

diff --git a/lib/ruby/stdlib/rubygems/commands/query_command.rb b/lib/ruby/stdlib/rubygems/commands/query_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/spec_fetcher'
@@ -49,6 +50,12 @@ def initialize(name = 'query',
       options[:all] = value
     end
 
+    add_option('-e', '--exact',
+               'Name of gem(s) to query on matches the',
+               'provided STRING') do |value, options|
+      options[:exact] = value
+    end
+
     add_option(      '--[no-]prerelease',
                'Display prerelease versions') do |value, options|
       options[:prerelease] = value
@@ -78,7 +85,8 @@ def execute
     elsif !options[:name].source.empty?
       name = Array(options[:name])
     else
-      name = options[:args].to_a.map{|arg| /#{arg}/i }
+      args = options[:args].to_a
+      name = options[:exact] ? args : args.map{|arg| /#{arg}/i }
     end
 
     prerelease = options[:prerelease]
@@ -161,7 +169,7 @@ def show_gems name, prerelease
                :latest
              end
 
-      if name.source.empty?
+      if name.respond_to?(:source) && name.source.empty?
         spec_tuples = fetcher.detect(type) { true }
       else
         spec_tuples = fetcher.detect(type) do |name_tuple|
@@ -276,7 +284,7 @@ def make_entry entry_tuples, platforms
   end
 
   def spec_authors entry, spec
-    authors = "Author#{spec.authors.length > 1 ? 's' : ''}: "
+    authors = "Author#{spec.authors.length > 1 ? 's' : ''}: ".dup
     authors << spec.authors.join(', ')
     entry << format_text(authors, 68, 4)
   end
@@ -290,7 +298,7 @@ def spec_homepage entry, spec
   def spec_license entry, spec
     return if spec.license.nil? or spec.license.empty?
 
-    licenses = "License#{spec.licenses.length > 1 ? 's' : ''}: "
+    licenses = "License#{spec.licenses.length > 1 ? 's' : ''}: ".dup
     licenses << spec.licenses.join(', ')
     entry << "\n" << format_text(licenses, 68, 4)
   end
@@ -340,4 +348,3 @@ def spec_summary entry, spec
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/commands/rdoc_command.rb b/lib/ruby/stdlib/rubygems/commands/rdoc_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/version_option'
 require 'rubygems/rdoc'

diff --git a/lib/ruby/stdlib/rubygems/commands/search_command.rb b/lib/ruby/stdlib/rubygems/commands/search_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/commands/query_command'
 

diff --git a/lib/ruby/stdlib/rubygems/commands/server_command.rb b/lib/ruby/stdlib/rubygems/commands/server_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/server'
 

diff --git a/lib/ruby/stdlib/rubygems/commands/setup_command.rb b/lib/ruby/stdlib/rubygems/commands/setup_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 ##

diff --git a/lib/ruby/stdlib/rubygems/commands/sources_command.rb b/lib/ruby/stdlib/rubygems/commands/sources_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/remote_fetcher'
 require 'rubygems/spec_fetcher'

diff --git a/lib/ruby/stdlib/rubygems/commands/specification_command.rb b/lib/ruby/stdlib/rubygems/commands/specification_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/version_option'

diff --git a/lib/ruby/stdlib/rubygems/commands/stale_command.rb b/lib/ruby/stdlib/rubygems/commands/stale_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Commands::StaleCommand < Gem::Command

diff --git a/lib/ruby/stdlib/rubygems/commands/uninstall_command.rb b/lib/ruby/stdlib/rubygems/commands/uninstall_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/version_option'
 require 'rubygems/uninstaller'

diff --git a/lib/ruby/stdlib/rubygems/commands/unpack_command.rb b/lib/ruby/stdlib/rubygems/commands/unpack_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/installer'
 require 'rubygems/version_option'

diff --git a/lib/ruby/stdlib/rubygems/commands/update_command.rb b/lib/ruby/stdlib/rubygems/commands/update_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/command_manager'
 require 'rubygems/dependency_installer'
@@ -84,6 +85,7 @@ def check_update_arguments # :nodoc:
   end
 
   def execute
+
     if options[:system] then
       update_rubygems
       return

diff --git a/lib/ruby/stdlib/rubygems/commands/which_command.rb b/lib/ruby/stdlib/rubygems/commands/which_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Commands::WhichCommand < Gem::Command

diff --git a/lib/ruby/stdlib/rubygems/commands/yank_command.rb b/lib/ruby/stdlib/rubygems/commands/yank_command.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 require 'rubygems/local_remote_options'
 require 'rubygems/version_option'
@@ -31,7 +32,7 @@ def arguments # :nodoc:
   end
 
   def usage # :nodoc:
-    "#{program_name} GEM -v VERSION [-p PLATFORM] [--undo] [--key KEY_NAME]"
+    "#{program_name} GEM -v VERSION [-p PLATFORM] [--key KEY_NAME] [--host HOST]"
   end
 
   def initialize
@@ -40,25 +41,25 @@ def initialize
     add_version_option("remove")
     add_platform_option("remove")
 
-    add_option('--undo') do |value, options|
-      options[:undo] = true
+    add_option('--host HOST',
+               'Yank from another gemcutter-compatible host') do |value, options|
+      options[:host] = value
     end
 
     add_key_option
+    @host = nil
   end
 
   def execute
-    sign_in
+    @host = options[:host]
+
+    sign_in @host
 
     version   = get_version_from_requirements(options[:version])
     platform  = get_platform_from_requirements(options)
 
     if version then
-      if options[:undo] then
-        unyank_gem(version, platform)
-      else
-        yank_gem(version, platform)
-      end
+      yank_gem(version, platform)
     else
       say "A version argument is required: #{usage}"
       terminate_interaction
@@ -70,16 +71,11 @@ def yank_gem(version, platform)
     yank_api_request(:delete, version, platform, "api/v1/gems/yank")
   end
 
-  def unyank_gem(version, platform)
-    say "Unyanking gem from #{host}..."
-    yank_api_request(:put, version, platform, "api/v1/gems/unyank")
-  end
-
   private
 
   def yank_api_request(method, version, platform, api)
     name = get_one_gem_name
-    response = rubygems_api_request(method, api) do |request|
+    response = rubygems_api_request(method, api, host) do |request|
       request.add_field("Authorization", api_key)
 
       data = {

diff --git a/lib/ruby/stdlib/rubygems/compatibility.rb b/lib/ruby/stdlib/rubygems/compatibility.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # :stopdoc:
 
 #--

diff --git a/lib/ruby/stdlib/rubygems/config_file.rb b/lib/ruby/stdlib/rubygems/config_file.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -200,11 +201,12 @@ def initialize(args)
       result.merge load_file file
     end
 
-
     @hash = operating_system_config.merge platform_config
-    @hash = @hash.merge system_config
-    @hash = @hash.merge user_config
-    @hash = @hash.merge environment_config
+    unless arg_list.index '--norc'
+      @hash = @hash.merge system_config
+      @hash = @hash.merge user_config
+      @hash = @hash.merge environment_config
+    end
 
     # HACK these override command-line args, which is bad
     @backtrace                  = @hash[:backtrace]                  if @hash.key? :backtrace
@@ -304,9 +306,18 @@ def rubygems_api_key
   # Sets the RubyGems.org API key to +api_key+
 
   def rubygems_api_key= api_key
+    set_api_key :rubygems_api_key, api_key
+
+    @rubygems_api_key = api_key
+  end
+
+  ##
+  # Set a specific host's API key to +api_key+
+
+  def set_api_key host, api_key
     check_credentials_permissions
 
-    config = load_file(credentials_path).merge(:rubygems_api_key => api_key)
+    config = load_file(credentials_path).merge(host => api_key)
 
     dirname = File.dirname credentials_path
     Dir.mkdir(dirname) unless File.exist? dirname
@@ -318,7 +329,7 @@ def rubygems_api_key= api_key
       f.write config.to_yaml
     end
 
-    @rubygems_api_key = api_key
+    load_api_keys # reload
   end
 
   def load_file(filename)

diff --git a/lib/ruby/stdlib/rubygems/core_ext/kernel_gem.rb b/lib/ruby/stdlib/rubygems/core_ext/kernel_gem.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # RubyGems adds the #gem method to allow activation of specific gem versions
 # and overrides the #require method on Kernel to make gems appear as if they

diff --git a/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb b/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/defaults.rb b/lib/ruby/stdlib/rubygems/defaults.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem
   DEFAULT_HOST = "https://rubygems.org"
 

diff --git a/lib/ruby/stdlib/rubygems/dependency.rb b/lib/ruby/stdlib/rubygems/dependency.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The Dependency class holds a Gem name and a Gem::Requirement.
 
@@ -274,8 +275,9 @@ def merge other
   end
 
   def matching_specs platform_only = false
+    env_req = Gem.env_requirement(name)
     matches = Gem::Specification.stubs_for(name).find_all { |spec|
-      requirement.satisfied_by? spec.version
+      requirement.satisfied_by?(spec.version) && env_req.satisfied_by?(spec.version)
     }.map(&:to_spec)
 
     if platform_only
@@ -306,9 +308,9 @@ def to_specs
 
       if specs.empty?
         total = Gem::Specification.to_a.size
-        msg   = "Could not find '#{name}' (#{requirement}) among #{total} total gem(s)\n"
+        msg   = "Could not find '#{name}' (#{requirement}) among #{total} total gem(s)\n".dup
       else
-        msg   = "Could not find '#{name}' (#{requirement}) - did find: [#{specs.join ','}]\n"
+        msg   = "Could not find '#{name}' (#{requirement}) - did find: [#{specs.join ','}]\n".dup
       end
       msg << "Checked in 'GEM_PATH=#{Gem.path.join(File::PATH_SEPARATOR)}', execute `gem env` for more information"
 

diff --git a/lib/ruby/stdlib/rubygems/dependency_installer.rb b/lib/ruby/stdlib/rubygems/dependency_installer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/dependency_list'
 require 'rubygems/package'

diff --git a/lib/ruby/stdlib/rubygems/dependency_list.rb b/lib/ruby/stdlib/rubygems/dependency_list.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/deprecate.rb b/lib/ruby/stdlib/rubygems/deprecate.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Provides a single method +deprecate+ to be used to declare when
 # something is going away.

diff --git a/lib/ruby/stdlib/rubygems/doctor.rb b/lib/ruby/stdlib/rubygems/doctor.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/user_interaction'
 

diff --git a/lib/ruby/stdlib/rubygems/errors.rb b/lib/ruby/stdlib/rubygems/errors.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # This file contains all the various exceptions and other errors that are used
 # inside of RubyGems.

diff --git a/lib/ruby/stdlib/rubygems/exceptions.rb b/lib/ruby/stdlib/rubygems/exceptions.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # TODO: the documentation in here is terrible.
 #
 # Each exception needs a brief description and the scenarios where it is
@@ -137,7 +138,7 @@ def build_message # :nodoc:
     requester  = requester ? requester.spec.full_name : 'The user'
     dependency = @request.dependency
 
-    message = "#{requester} requires #{dependency} but it conflicted:\n"
+    message = "#{requester} requires #{dependency} but it conflicted:\n".dup
 
     @conflicts.each do |_, conflict|
       message << conflict.explanation
@@ -267,4 +268,3 @@ def version
 # Backwards compatible typo'd exception class for early RubyGems 2.0.x
 
 Gem::UnsatisfiableDepedencyError = Gem::UnsatisfiableDependencyError # :nodoc:
-
diff --git a/lib/ruby/stdlib/rubygems/ext.rb b/lib/ruby/stdlib/rubygems/ext.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/ext/build_error.rb b/lib/ruby/stdlib/rubygems/ext/build_error.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Raised when there is an error while building extensions.
 

diff --git a/lib/ruby/stdlib/rubygems/ext/builder.rb b/lib/ruby/stdlib/rubygems/ext/builder.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/ext/cmake_builder.rb b/lib/ruby/stdlib/rubygems/ext/cmake_builder.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/command'
 
 class Gem::Ext::CmakeBuilder < Gem::Ext::Builder

diff --git a/lib/ruby/stdlib/rubygems/ext/configure_builder.rb b/lib/ruby/stdlib/rubygems/ext/configure_builder.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/ext/ext_conf_builder.rb b/lib/ruby/stdlib/rubygems/ext/ext_conf_builder.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -11,9 +12,20 @@ class Gem::Ext::ExtConfBuilder < Gem::Ext::Builder
   FileEntry = FileUtils::Entry_ # :nodoc:
 
   def self.build(extension, directory, dest_path, results, args=[], lib_dir=nil)
-    # relative path required as some versions of mktmpdir return an absolute
-    # path which breaks make if it includes a space in the name
-    tmp_dest = get_relative_path(Dir.mktmpdir(".gem.", "."))
+    tmp_dest = Dir.mktmpdir(".gem.", ".")
+
+    # Some versions of `mktmpdir` return absolute paths, which will break make
+    # if the paths contain spaces. However, on Ruby 1.9.x on Windows, relative
+    # paths cause all C extension builds to fail.
+    #
+    # As such, we convert to a relative path unless we are using Ruby 1.9.x on
+    # Windows. This means that when using Ruby 1.9.x on Windows, paths with
+    # spaces do not work.
+    #
+    # Details: https://github.com/rubygems/rubygems/issues/977#issuecomment-171544940
+    #
+    # TODO: Make this unconditional when rubygems no longer supports Ruby 1.9.x.
+    tmp_dest = get_relative_path(tmp_dest) unless Gem.win_platform? && RUBY_VERSION <= '2.0'
 
     t = nil
     Tempfile.open %w"siteconf .rb", "." do |siteconf|
@@ -80,4 +92,3 @@ def self.get_relative_path(path)
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/ext/rake_builder.rb b/lib/ruby/stdlib/rubygems/ext/rake_builder.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/gem_runner.rb b/lib/ruby/stdlib/rubygems/gem_runner.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/gemcutter_utilities.rb b/lib/ruby/stdlib/rubygems/gemcutter_utilities.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/remote_fetcher'
 
 ##
@@ -68,9 +69,14 @@ def rubygems_api_request(method, path, host = nil, allowed_push_host = nil, &blo
       terminate_interaction 1 # TODO: question this
     end
 
-    if allowed_push_host and self.host != allowed_push_host
-      alert_error "#{self.host.inspect} is not allowed by the gemspec, which only allows #{allowed_push_host.inspect}"
-      terminate_interaction 1
+    if allowed_push_host
+      allowed_host_uri = URI.parse(allowed_push_host)
+      host_uri         = URI.parse(self.host)
+
+      unless (host_uri.scheme == allowed_host_uri.scheme) && (host_uri.host == allowed_host_uri.host)
+        alert_error "#{self.host.inspect} is not allowed by the gemspec, which only allows #{allowed_push_host.inspect}"
+        terminate_interaction 1
+      end
     end
 
     uri = URI.parse "#{self.host}/#{path}"
@@ -109,7 +115,7 @@ def sign_in sign_in_host = nil
 
     with_response response do |resp|
       say "Signed in."
-      Gem.configuration.rubygems_api_key = resp.body
+      set_api_key host, resp.body
     end
   end
 
@@ -150,5 +156,13 @@ def with_response response, error_prefix = nil
     end
   end
 
+  def set_api_key host, key
+    if host == Gem::DEFAULT_HOST
+      Gem.configuration.rubygems_api_key = key
+    else
+      Gem.configuration.set_api_key host, key
+    end
+  end
+
 end
 
diff --git a/lib/ruby/stdlib/rubygems/indexer.rb b/lib/ruby/stdlib/rubygems/indexer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/package'
 require 'time'

diff --git a/lib/ruby/stdlib/rubygems/install_default_message.rb b/lib/ruby/stdlib/rubygems/install_default_message.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/user_interaction'
 

diff --git a/lib/ruby/stdlib/rubygems/install_message.rb b/lib/ruby/stdlib/rubygems/install_message.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/user_interaction'
 

diff --git a/lib/ruby/stdlib/rubygems/install_update_options.rb b/lib/ruby/stdlib/rubygems/install_update_options.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -173,6 +174,12 @@ def add_install_update_options
                 "meet version requirements") do |value, options|
       options[:minimal_deps] = true
     end
+
+    add_option(:"Install/Update", "--[no-]post-install-message",
+                "Print post install message") do |value, options|
+      options[:post_install_message] = value
+    end
+
   end
 
   ##

diff --git a/lib/ruby/stdlib/rubygems/installer.rb b/lib/ruby/stdlib/rubygems/installer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -212,15 +213,21 @@ def check_executable_overwrite filename # :nodoc:
       next unless io.gets =~ /This file was generated by RubyGems/
 
       ruby_executable = true
-      existing = io.read.slice(/^gem (['"])(.*?)(\1),/, 2)
+      existing = io.read.slice(%r{
+          ^(
+            gem \s |
+            load \s Gem\.bin_path\(
+          )
+          (['"])(.*?)(\2),
+        }x, 3)
     end
 
     return if spec.name == existing
 
     # somebody has written to RubyGems' directory, overwrite, too bad
     return if Gem.default_bindir != @bin_dir and not ruby_executable
 
-    question = "#{spec.name}'s executable \"#{filename}\" conflicts with "
+    question = "#{spec.name}'s executable \"#{filename}\" conflicts with ".dup
 
     if ruby_executable then
       question << existing
@@ -296,7 +303,7 @@ def install
       write_cache_file
     end
 
-    say spec.post_install_message unless spec.post_install_message.nil?
+    say spec.post_install_message if options[:post_install_message] && !spec.post_install_message.nil?
 
     Gem::Installer.install_lock.synchronize { Gem::Specification.reset }
 
@@ -626,7 +633,8 @@ def process_options # :nodoc:
       :bin_dir      => nil,
       :env_shebang  => false,
       :force        => false,
-      :only_install_dir => false
+      :only_install_dir => false,
+      :post_install_message => true
     }.merge options
 
     @env_shebang         = options[:env_shebang]
@@ -711,7 +719,6 @@ def app_script_text(bin_file_name)
   end
 end
 
-gem '#{spec.name}', version
 load Gem.bin_path('#{spec.name}', '#{bin_file_name}', version)
 TEXT
   end

diff --git a/lib/ruby/stdlib/rubygems/installer_test_case.rb b/lib/ruby/stdlib/rubygems/installer_test_case.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/test_case'
 require 'rubygems/installer'
 

diff --git a/lib/ruby/stdlib/rubygems/local_remote_options.rb b/lib/ruby/stdlib/rubygems/local_remote_options.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -23,7 +24,7 @@ def accept_uri_http
         raise OptionParser::InvalidArgument, value
       end
 
-      unless ['http', 'https', 'file'].include?(uri.scheme)
+      unless ['http', 'https', 'file', 's3'].include?(uri.scheme)
          raise OptionParser::InvalidArgument, value
       end
 

diff --git a/lib/ruby/stdlib/rubygems/mock_gem_ui.rb b/lib/ruby/stdlib/rubygems/mock_gem_ui.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'stringio'
 require 'rubygems/user_interaction'
 

diff --git a/lib/ruby/stdlib/rubygems/name_tuple.rb b/lib/ruby/stdlib/rubygems/name_tuple.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 #
 # Represents a gem of name +name+ at +version+ of +platform+. These
@@ -53,7 +54,7 @@ def full_name
       "#{@name}-#{@version}"
     else
       "#{@name}-#{@version}-#{@platform}"
-    end.untaint
+    end.dup.untaint
   end
 
   ##

diff --git a/lib/ruby/stdlib/rubygems/package.rb b/lib/ruby/stdlib/rubygems/package.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #--
 # Copyright (C) 2004 Mauricio Julio Fernández Pradier
 # See LICENSE.txt for additional licensing information.
@@ -58,7 +59,7 @@ def initialize message, source = nil
       if source
         @path = source.path
 
-        message << " in #{path}" if path
+        message = message + " in #{path}" if path
       end
 
       super message
@@ -382,7 +383,7 @@ def extract_tar_gz io, destination_dir, pattern = "*" # :nodoc:
           FileUtils.chmod entry.header.mode, destination
         end if entry.file?
 
-        File.symlink(install_location(entry.header.linkname, destination_dir), destination) if entry.symlink?
+        File.symlink(entry.header.linkname, destination) if entry.symlink?
 
         verbose destination
       end

diff --git a/lib/ruby/stdlib/rubygems/package/digest_io.rb b/lib/ruby/stdlib/rubygems/package/digest_io.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # IO wrapper that creates digests of contents written to the IO it wraps.
 

diff --git a/lib/ruby/stdlib/rubygems/package/file_source.rb b/lib/ruby/stdlib/rubygems/package/file_source.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The primary source of gems is a file on disk, including all usages
 # internal to rubygems.

diff --git a/lib/ruby/stdlib/rubygems/package/io_source.rb b/lib/ruby/stdlib/rubygems/package/io_source.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Supports reading and writing gems from/to a generic IO object.  This is
 # useful for other applications built on top of rubygems, such as

diff --git a/lib/ruby/stdlib/rubygems/package/old.rb b/lib/ruby/stdlib/rubygems/package/old.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -63,7 +64,7 @@ def extract_files destination_dir
 
         destination = install_location full_name, destination_dir
 
-        file_data = ''
+        file_data = String.new
 
         read_until_dashes io do |line|
           file_data << line
@@ -94,7 +95,7 @@ def extract_files destination_dir
   # Reads the file list section from the old-format gem +io+
 
   def file_list io # :nodoc:
-    header = ''
+    header = String.new
 
     read_until_dashes io do |line|
       header << line
@@ -134,7 +135,7 @@ def spec
 
     return @spec if @spec
 
-    yaml = ''
+    yaml = String.new
 
     @gem.with_read_io do |io|
       skip_ruby io
@@ -175,4 +176,3 @@ def verify
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/package/source.rb b/lib/ruby/stdlib/rubygems/package/source.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class Gem::Package::Source # :nodoc:
 end
 
diff --git a/lib/ruby/stdlib/rubygems/package/tar_header.rb b/lib/ruby/stdlib/rubygems/package/tar_header.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #--
 # Copyright (C) 2004 Mauricio Julio Fernández Pradier
 # See LICENSE.txt for additional licensing information.
@@ -226,4 +227,3 @@ def oct(num, len)
   end
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/package/tar_reader.rb b/lib/ruby/stdlib/rubygems/package/tar_reader.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #--
 # Copyright (C) 2004 Mauricio Julio Fernández Pradier
 # See LICENSE.txt for additional licensing information.
@@ -120,4 +121,3 @@ def seek name # :yields: entry
 end
 
 require 'rubygems/package/tar_reader/entry'
-
diff --git a/lib/ruby/stdlib/rubygems/package/tar_reader/entry.rb b/lib/ruby/stdlib/rubygems/package/tar_reader/entry.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #++
 # Copyright (C) 2004 Mauricio Julio Fernández Pradier
 # See LICENSE.txt for additional licensing information.

diff --git a/lib/ruby/stdlib/rubygems/package/tar_test_case.rb b/lib/ruby/stdlib/rubygems/package/tar_test_case.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/test_case'
 require 'rubygems/package'
 

diff --git a/lib/ruby/stdlib/rubygems/package/tar_writer.rb b/lib/ruby/stdlib/rubygems/package/tar_writer.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #--
 # Copyright (C) 2004 Mauricio Julio Fernández Pradier
 # See LICENSE.txt for additional licensing information.

diff --git a/lib/ruby/stdlib/rubygems/package_task.rb b/lib/ruby/stdlib/rubygems/package_task.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # Copyright (c) 2003, 2004 Jim Weirich, 2009 Eric Hodel
 #
 # Permission is hereby granted, free of charge, to any person obtaining

diff --git a/lib/ruby/stdlib/rubygems/path_support.rb b/lib/ruby/stdlib/rubygems/path_support.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 #
 # Gem::PathSupport facilitates the GEM_HOME and GEM_PATH environment settings
@@ -21,43 +22,36 @@ class Gem::PathSupport
   # Constructor. Takes a single argument which is to be treated like a
   # hashtable, or defaults to ENV, the system environment.
   #
-  def initialize(env=ENV)
-    @env = env
-
-    # note 'env' vs 'ENV'...
-    @home     = env["GEM_HOME"] || ENV["GEM_HOME"] || Gem.default_dir
+  def initialize(env)
+    @home     = env["GEM_HOME"] || Gem.default_dir
 
     if File::ALT_SEPARATOR then
       @home   = @home.gsub(File::ALT_SEPARATOR, File::SEPARATOR)
     end
 
-    self.path = env["GEM_PATH"] || ENV["GEM_PATH"]
+    @path = split_gem_path env["GEM_PATH"], @home
 
-    @spec_cache_dir =
-      env["GEM_SPEC_CACHE"] || ENV["GEM_SPEC_CACHE"] ||
-        Gem.default_spec_cache_dir
+    @spec_cache_dir = env["GEM_SPEC_CACHE"] || Gem.default_spec_cache_dir
 
     @spec_cache_dir = @spec_cache_dir.dup.untaint
   end
 
   private
 
   ##
-  # Set the Gem search path (as reported by Gem.path).
+  # Split the Gem search path (as reported by Gem.path).
 
-  def path=(gpaths)
+  def split_gem_path gpaths, home
     # FIX: it should be [home, *path], not [*path, home]
 
     gem_path = []
 
-    # FIX: I can't tell wtf this is doing.
-    gpaths ||= (ENV['GEM_PATH'] || "").empty? ? nil : ENV["GEM_PATH"]
-
     if gpaths
-      if gpaths.kind_of?(Array)
-        gem_path = gpaths.dup
-      else
-        gem_path = gpaths.split(Gem.path_separator)
+      gem_path = gpaths.split(Gem.path_separator)
+      # Handle the path_separator being set to a regexp, which will cause
+      # end_with? to error
+      if gpaths =~ /#{Gem.path_separator}\z/
+        gem_path += default_path
       end
 
       if File::ALT_SEPARATOR then
@@ -66,15 +60,21 @@ def path=(gpaths)
         end
       end
 
-      gem_path << @home
+      gem_path << home
     else
-      gem_path = Gem.default_path + [@home]
-
-      if defined?(APPLE_GEM_HOME)
-        gem_path << APPLE_GEM_HOME
-      end
+      gem_path = default_path
     end
 
-    @path = gem_path.uniq
+    gem_path.uniq
+  end
+
+  # Return the default Gem path
+  def default_path
+    gem_path = Gem.default_path + [@home]
+
+    if defined?(APPLE_GEM_HOME)
+      gem_path << APPLE_GEM_HOME
+    end
+    gem_path
   end
 end
diff --git a/lib/ruby/stdlib/rubygems/platform.rb b/lib/ruby/stdlib/rubygems/platform.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require "rubygems/deprecate"
 
 ##

diff --git a/lib/ruby/stdlib/rubygems/psych_additions.rb b/lib/ruby/stdlib/rubygems/psych_additions.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # This exists just to satisfy bugs in marshal'd gemspecs that
 # contain a reference to YAML::PrivateType. We prune these out
 # in Specification._load, but if we don't have the constant, Marshal

diff --git a/lib/ruby/stdlib/rubygems/psych_tree.rb b/lib/ruby/stdlib/rubygems/psych_tree.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem
   if defined? ::Psych::Visitors
     class NoAliasYAMLTree < Psych::Visitors::YAMLTree

diff --git a/lib/ruby/stdlib/rubygems/rdoc.rb b/lib/ruby/stdlib/rubygems/rdoc.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/user_interaction'
 require 'fileutils'

diff --git a/lib/ruby/stdlib/rubygems/remote_fetcher.rb b/lib/ruby/stdlib/rubygems/remote_fetcher.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 require 'rubygems/request'
 require 'rubygems/uri_formatter'

diff --git a/lib/ruby/stdlib/rubygems/request.rb b/lib/ruby/stdlib/rubygems/request.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'net/http'
 require 'thread'
 require 'time'
@@ -155,7 +156,7 @@ def perform_request request # :nodoc:
           if Net::HTTPOK === incomplete_response
             reporter.fetch(file_name, incomplete_response.content_length)
             downloaded = 0
-            data = ''
+            data = String.new
 
             incomplete_response.read_body do |segment|
               data << segment
@@ -222,7 +223,7 @@ def reset(connection)
   end
 
   def user_agent
-    ua = "RubyGems/#{Gem::VERSION} #{Gem::Platform.local}"
+    ua = "RubyGems/#{Gem::VERSION} #{Gem::Platform.local}".dup
 
     ruby_version = RUBY_VERSION
     ruby_version += 'dev' if RUBY_PATCHLEVEL == -1

diff --git a/lib/ruby/stdlib/rubygems/request/connection_pools.rb b/lib/ruby/stdlib/rubygems/request/connection_pools.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'thread'
 
 class Gem::Request::ConnectionPools # :nodoc:

diff --git a/lib/ruby/stdlib/rubygems/request/http_pool.rb b/lib/ruby/stdlib/rubygems/request/http_pool.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A connection "pool" that only manages one connection for now.  Provides
 # thread safe `checkout` and `checkin` methods.  The pool consists of one

diff --git a/lib/ruby/stdlib/rubygems/request/https_pool.rb b/lib/ruby/stdlib/rubygems/request/https_pool.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class Gem::Request::HTTPSPool < Gem::Request::HTTPPool # :nodoc:
   private
 

diff --git a/lib/ruby/stdlib/rubygems/request_set.rb b/lib/ruby/stdlib/rubygems/request_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'tsort'
 
 ##
@@ -76,6 +77,11 @@ class Gem::RequestSet
 
   attr_reader :vendor_set # :nodoc:
 
+  ##
+  # The set of source gems imported via load_gemdeps.
+
+  attr_reader :source_set
+
   ##
   # Creates a RequestSet for a list of Gem::Dependency objects, +deps+.  You
   # can then #resolve and #install the resolved list of dependencies.
@@ -105,6 +111,7 @@ def initialize *deps
     @sorted              = nil
     @specs               = nil
     @vendor_set          = nil
+    @source_set          = nil
 
     yield self if block_given?
   end
@@ -142,7 +149,6 @@ def install options, &block # :yields: request, installer
       return requests
     end
 
-    cache_dir = options[:cache_dir] || Gem.dir
     @prerelease = options[:prerelease]
 
     requests = []
@@ -157,13 +163,11 @@ def install options, &block # :yields: request, installer
         end
       end
 
-      path = req.download cache_dir
-
-      inst = Gem::Installer.at path, options
-
-      yield req, inst if block_given?
+      spec = req.spec.install options do |installer|
+        yield req, installer if block_given?
+      end
 
-      requests << inst.install
+      requests << spec
     end
 
     return requests if options[:gemdeps]
@@ -271,10 +275,11 @@ def install_into dir, force = true, options = {}
   def load_gemdeps path, without_groups = [], installing = false
     @git_set    = Gem::Resolver::GitSet.new
     @vendor_set = Gem::Resolver::VendorSet.new
+    @source_set = Gem::Resolver::SourceSet.new
 
     @git_set.root_dir = @install_dir
 
-    lock_file = "#{File.expand_path(path)}.lock".untaint
+    lock_file = "#{File.expand_path(path)}.lock".dup.untaint
     begin
       tokenizer = Gem::RequestSet::Lockfile::Tokenizer.from_file lock_file
       parser = tokenizer.make_parser self, []
@@ -338,6 +343,7 @@ def resolve set = Gem::Resolver::BestSet.new
     @sets << set
     @sets << @git_set
     @sets << @vendor_set
+    @sets << @source_set
 
     set = Gem::Resolver.compose_sets(*@sets)
     set.remote = @remote

diff --git a/lib/ruby/stdlib/rubygems/request_set/gem_dependency_api.rb b/lib/ruby/stdlib/rubygems/request_set/gem_dependency_api.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A semi-compatible DSL for the Bundler Gemfile and Isolate gem dependencies
 # files.
@@ -204,6 +205,7 @@ def initialize set, path
     @installing         = false
     @requires           = Hash.new { |h, name| h[name] = [] }
     @vendor_set         = @set.vendor_set
+    @source_set         = @set.source_set
     @gem_sources        = {}
     @without_groups     = []
 
@@ -362,6 +364,7 @@ def gem name, *requirements
     source_set ||= gem_path       name, options
     source_set ||= gem_git        name, options
     source_set ||= gem_git_source name, options
+    source_set ||= gem_source     name, options
 
     duplicate = @dependencies.include? name
 
@@ -407,11 +410,7 @@ def gem_git name, options # :nodoc:
 
     pin_gem_source name, :git, repository
 
-    reference = nil
-    reference ||= options.delete :ref
-    reference ||= options.delete :branch
-    reference ||= options.delete :tag
-    reference ||= 'master'
+    reference = gem_git_reference options
 
     submodules = options.delete :submodules
 
@@ -420,6 +419,36 @@ def gem_git name, options # :nodoc:
     true
   end
 
+  ##
+  # Handles the git options from +options+ for git gem.
+  #
+  # Returns reference for the git gem.
+
+  def gem_git_reference options # :nodoc:
+    ref    = options.delete :ref
+    branch = options.delete :branch
+    tag    = options.delete :tag
+
+    reference = nil
+    reference ||= ref
+    reference ||= branch
+    reference ||= tag
+    reference ||= 'master'
+
+    if ref && branch
+      warn <<-WARNING
+Gem dependencies file #{@path} includes git reference for both ref and branch but only ref is used.
+      WARNING
+    end
+    if (ref||branch) && tag
+      warn <<-WARNING
+Gem dependencies file #{@path} includes git reference for both ref/branch and tag but only ref/branch is used.
+      WARNING
+    end
+
+    reference
+  end
+
   private :gem_git
 
   ##
@@ -480,6 +509,23 @@ def gem_path name, options # :nodoc:
 
   private :gem_path
 
+  ##
+  # Handles the source: option from +options+ for gem +name+.
+  #
+  # Returns +true+ if the source option was handled.
+
+  def gem_source name, options # :nodoc:
+    return unless source = options.delete(:source)
+
+    pin_gem_source name, :source, source
+
+    @source_set.add_source_gem name, source
+
+    true
+  end
+
+  private :gem_source
+
   ##
   # Handles the platforms: option from +options+.  Returns true if the
   # platform matches the current platform.
@@ -526,6 +572,7 @@ def gem_requires name, options # :nodoc:
     else
       @requires[name] << name
     end
+    raise ArgumentError, "Unhandled gem options #{options.inspect}" unless options.empty?
   end
 
   private :gem_requires
@@ -611,6 +658,7 @@ def gemspec options = {}
 
     add_dependencies groups, spec.development_dependencies
 
+    @vendor_set.add_vendor_gem spec.name, path
     gem_requires spec.name, options
   end
 
@@ -650,6 +698,7 @@ def pin_gem_source name, type = :default, source = nil
       when :default then '(default)'
       when :path    then "path: #{source}"
       when :git     then "git: #{source}"
+      when :source  then "source: #{source}"
       else               '(unknown)'
       end
 
@@ -798,4 +847,3 @@ def source url
   Gem::RequestSet::GemDepedencyAPI = self # :nodoc:
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/request_set/lockfile.rb b/lib/ruby/stdlib/rubygems/request_set/lockfile.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Parses a gem.deps.rb.lock file and constructs a LockSet containing the
 # dependencies found inside.  If the lock file is missing no LockSet is
@@ -129,8 +130,8 @@ def add_GIT out, git_requests
       [source.repository, source.rev_parse]
     end
 
-    out << "GIT"
     by_repository_revision.each do |(repository, revision), requests|
+      out << "GIT"
       out << "  remote: #{repository}"
       out << "  revision: #{revision}"
       out << "  specs:"
@@ -143,9 +144,8 @@ def add_GIT out, git_requests
           out << "      #{dep.name}#{dep.requirement.for_lockfile}"
         end
       end
+      out << nil
     end
-
-    out << nil
   end
 
   def relative_path_from dest, base # :nodoc:

diff --git a/lib/ruby/stdlib/rubygems/request_set/lockfile/parser.rb b/lib/ruby/stdlib/rubygems/request_set/lockfile/parser.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class Gem::RequestSet::Lockfile::Parser
   ###
   # Parses lockfiles
@@ -324,15 +325,24 @@ def peek # :nodoc:
     @tokens.peek
   end
 
-  def pinned_requirement name # :nodoc:
-    spec = @set.sets.select { |set|
-      Gem::Resolver::GitSet    === set or
-        Gem::Resolver::VendorSet === set
-    }.map { |set|
-      set.specs[name]
-    }.compact.first
+  if [].respond_to? :flat_map
+    def pinned_requirement name # :nodoc:
+      requirement = Gem::Dependency.new name
+      specification = @set.sets.flat_map { |set|
+        set.find_all(requirement)
+      }.compact.first
 
-    spec.version
+      specification && specification.version
+    end
+  else # FIXME: remove when 1.8 is dropped
+    def pinned_requirement name # :nodoc:
+      requirement = Gem::Dependency.new name
+      specification = @set.sets.map { |set|
+        set.find_all(requirement)
+      }.flatten(1).compact.first
+
+      specification && specification.version
+    end
   end
 
   ##
@@ -342,4 +352,3 @@ def unget token # :nodoc:
     @tokens.unshift token
   end
 end
-
diff --git a/lib/ruby/stdlib/rubygems/request_set/lockfile/tokenizer.rb b/lib/ruby/stdlib/rubygems/request_set/lockfile/tokenizer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'strscan'
 require 'rubygems/request_set/lockfile/parser'
 

diff --git a/lib/ruby/stdlib/rubygems/requirement.rb b/lib/ruby/stdlib/rubygems/requirement.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require "rubygems/version"
 require "rubygems/deprecate"
 

diff --git a/lib/ruby/stdlib/rubygems/resolver.rb b/lib/ruby/stdlib/rubygems/resolver.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/dependency'
 require 'rubygems/exceptions'
 require 'rubygems/util'
@@ -278,6 +279,7 @@ def allow_missing?(dependency)
 require 'rubygems/resolver/installer_set'
 require 'rubygems/resolver/lock_set'
 require 'rubygems/resolver/vendor_set'
+require 'rubygems/resolver/source_set'
 
 require 'rubygems/resolver/specification'
 require 'rubygems/resolver/spec_specification'

diff --git a/lib/ruby/stdlib/rubygems/resolver/activation_request.rb b/lib/ruby/stdlib/rubygems/resolver/activation_request.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Specifies a Specification object that should be activated.  Also contains a
 # dependency that was used to introduce this activation.
@@ -49,15 +50,27 @@ def development?
   # Downloads a gem at +path+ and returns the file path.
 
   def download path
-    if @spec.respond_to? :source
+    Gem.ensure_gem_subdirectories path
+
+    if @spec.respond_to? :sources
+      exception = nil
+      path = @spec.sources.find{ |source|
+        begin
+          source.download full_spec, path
+        rescue exception
+        end
+      }
+      return path      if path
+      raise  exception if exception
+
+    elsif @spec.respond_to? :source
       source = @spec.source
+      source.download full_spec, path
+
     else
       source = Gem.sources.first
+      source.download full_spec, path
     end
-
-    Gem.ensure_gem_subdirectories path
-
-    source.download full_spec, path
   end
 
   ##

diff --git a/lib/ruby/stdlib/rubygems/resolver/api_set.rb b/lib/ruby/stdlib/rubygems/resolver/api_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The global rubygems pool, available via the rubygems.org API.
 # Returns instances of APISpecification.

diff --git a/lib/ruby/stdlib/rubygems/resolver/api_specification.rb b/lib/ruby/stdlib/rubygems/resolver/api_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Represents a specification retrieved via the rubygems.org API.
 #

diff --git a/lib/ruby/stdlib/rubygems/resolver/best_set.rb b/lib/ruby/stdlib/rubygems/resolver/best_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The BestSet chooses the best available method to query a remote index.
 #

diff --git a/lib/ruby/stdlib/rubygems/resolver/composed_set.rb b/lib/ruby/stdlib/rubygems/resolver/composed_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A ComposedSet allows multiple sets to be queried like a single set.
 #

diff --git a/lib/ruby/stdlib/rubygems/resolver/conflict.rb b/lib/ruby/stdlib/rubygems/resolver/conflict.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Used internally to indicate that a dependency conflicted
 # with a spec that would be activated.

diff --git a/lib/ruby/stdlib/rubygems/resolver/current_set.rb b/lib/ruby/stdlib/rubygems/resolver/current_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A set which represents the installed gems. Respects
 # all the normal settings that control where to look

diff --git a/lib/ruby/stdlib/rubygems/resolver/dependency_request.rb b/lib/ruby/stdlib/rubygems/resolver/dependency_request.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Used Internally. Wraps a Dependency object to also track which spec
 # contained the Dependency.

diff --git a/lib/ruby/stdlib/rubygems/resolver/git_set.rb b/lib/ruby/stdlib/rubygems/resolver/git_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A GitSet represents gems that are sourced from git repositories.
 #

diff --git a/lib/ruby/stdlib/rubygems/resolver/git_specification.rb b/lib/ruby/stdlib/rubygems/resolver/git_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A GitSpecification represents a gem that is sourced from a git repository
 # and is being loaded through a gem dependencies file through the +git:+

diff --git a/lib/ruby/stdlib/rubygems/resolver/index_set.rb b/lib/ruby/stdlib/rubygems/resolver/index_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The global rubygems pool represented via the traditional
 # source index.

diff --git a/lib/ruby/stdlib/rubygems/resolver/index_specification.rb b/lib/ruby/stdlib/rubygems/resolver/index_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Represents a possible Specification object returned from IndexSet.  Used to
 # delay needed to download full Specification objects when only the +name+

diff --git a/lib/ruby/stdlib/rubygems/resolver/installed_specification.rb b/lib/ruby/stdlib/rubygems/resolver/installed_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # An InstalledSpecification represents a gem that is already installed
 # locally.

diff --git a/lib/ruby/stdlib/rubygems/resolver/installer_set.rb b/lib/ruby/stdlib/rubygems/resolver/installer_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A set of gems for installation sourced from remote sources and local .gem
 # files
@@ -137,10 +138,14 @@ def find_all req
 
       local_source = Gem::Source::Local.new
 
-      if local_spec = local_source.find_gem(name, dep.requirement) then
-        res << Gem::Resolver::IndexSpecification.new(
-          self, local_spec.name, local_spec.version,
-          local_source, local_spec.platform)
+      begin
+        if local_spec = local_source.find_gem(name, dep.requirement) then
+          res << Gem::Resolver::IndexSpecification.new(
+            self, local_spec.name, local_spec.version,
+            local_source, local_spec.platform)
+        end
+      rescue Gem::Package::FormatError
+        # ignore
       end
     end
 

diff --git a/lib/ruby/stdlib/rubygems/resolver/local_specification.rb b/lib/ruby/stdlib/rubygems/resolver/local_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A LocalSpecification comes from a .gem file on the local filesystem.
 

diff --git a/lib/ruby/stdlib/rubygems/resolver/lock_set.rb b/lib/ruby/stdlib/rubygems/resolver/lock_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A set of gems from a gem dependencies lockfile.
 
@@ -27,11 +28,9 @@ def initialize sources
 
   def add name, version, platform # :nodoc:
     version = Gem::Version.new version
-
-    specs = @sources.map do |source|
-      Gem::Resolver::LockSpecification.new self, name, version, source,
-                                           platform
-    end
+    specs = [
+      Gem::Resolver::LockSpecification.new(self, name, version, @sources, platform)
+    ]
 
     @specs.concat specs
 

diff --git a/lib/ruby/stdlib/rubygems/resolver/lock_specification.rb b/lib/ruby/stdlib/rubygems/resolver/lock_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The LockSpecification comes from a lockfile (Gem::RequestSet::Lockfile).
 #
@@ -6,13 +7,16 @@
 
 class Gem::Resolver::LockSpecification < Gem::Resolver::Specification
 
-  def initialize set, name, version, source, platform
+  attr_reader :sources
+
+  def initialize set, name, version, sources, platform
     super()
 
     @name     = name
     @platform = platform
     @set      = set
-    @source   = source
+    @source   = sources.first
+    @sources  = sources
     @version  = version
 
     @dependencies = []

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo.rb
@@ -1 +1,2 @@
+# frozen_string_literal: true
 require 'rubygems/resolver/molinillo/lib/molinillo'
diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo.rb
@@ -1,5 +1,10 @@
+# frozen_string_literal: true
 require 'rubygems/resolver/molinillo/lib/molinillo/gem_metadata'
 require 'rubygems/resolver/molinillo/lib/molinillo/errors'
 require 'rubygems/resolver/molinillo/lib/molinillo/resolver'
 require 'rubygems/resolver/molinillo/lib/molinillo/modules/ui'
 require 'rubygems/resolver/molinillo/lib/molinillo/modules/specification_provider'
+
+# Gem::Resolver::Molinillo is a generic dependency resolution algorithm.
+module Gem::Resolver::Molinillo
+end
diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'set'
 require 'tsort'
 
@@ -14,8 +15,10 @@ def each
 
     include TSort
 
+    # @visibility private
     alias_method :tsort_each_node, :each
 
+    # @visibility private
     def tsort_each_child(vertex, &block)
       vertex.successors.each(&block)
     end
@@ -41,12 +44,14 @@ def self.tsort(vertices)
     #   by {Vertex#name}
     attr_reader :vertices
 
+    # Initializes an empty dependency graph
     def initialize
       @vertices = {}
     end
 
     # Initializes a copy of a {DependencyGraph}, ensuring that all {#vertices}
     # are properly copied.
+    # @param [DependencyGraph] other the graph to copy.
     def initialize_copy(other)
       super
       @vertices = {}
@@ -100,6 +105,7 @@ def add_child_vertex(name, payload, parent_names, requirement)
       vertex
     end
 
+    # Adds a vertex with the given name, or updates the existing one.
     # @param [String] name
     # @param [Object] payload
     # @return [Vertex] the vertex that was added to `self`
@@ -121,6 +127,10 @@ def detach_vertex_named(name)
         v.incoming_edges.delete(e)
         detach_vertex_named(v.name) unless v.root? || v.predecessors.any?
       end
+      vertex.incoming_edges.each do |e|
+        v = e.origin
+        v.outgoing_edges.delete(e)
+      end
     end
 
     # @param [String] name
@@ -150,6 +160,8 @@ def add_edge(origin, destination, requirement)
 
     private
 
+    # Adds a new {Edge} to the dependency graph without checking for
+    # circularity.
     def add_edge_no_circular(origin, destination, requirement)
       edge = Edge.new(origin, destination, requirement)
       origin.outgoing_edges << edge
@@ -174,6 +186,7 @@ class Vertex
       attr_accessor :root
       alias_method :root?, :root
 
+      # Initializes a vertex with the given name and payload.
       # @param [String] name see {#name}
       # @param [Object] payload see {#payload}
       def initialize(name, payload)
@@ -240,6 +253,7 @@ def ==(other)
           successors.to_set == other.successors.to_set
       end
 
+      # @param  [Vertex] other the other vertex to compare to
       # @return [Boolean] whether the two vertices are equal, determined
       #   solely by {#name} and {#payload} equality
       def shallow_eql?(other)

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/errors.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/errors.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
   # An error that occurred during the resolution process
   class ResolverError < StandardError; end
@@ -11,6 +12,7 @@ class NoSuchDependencyError < ResolverError
     # @return [Array<Object>] the specifications that depended upon {#dependency}
     attr_accessor :required_by
 
+    # Initializes a new error with the given missing dependency.
     # @param [Object] dependency @see {#dependency}
     # @param [Array<Object>] required_by @see {#required_by}
     def initialize(dependency, required_by = [])
@@ -19,6 +21,8 @@ def initialize(dependency, required_by = [])
       super()
     end
 
+    # The error message for the missing dependency, including the specifications
+    # that had this dependency.
     def message
       sources = required_by.map { |r| "`#{r}`" }.join(' and ')
       message = "Unable to find a specification for `#{dependency}`"
@@ -36,6 +40,7 @@ class CircularDependencyError < ResolverError
     # [Set<Object>] the dependencies responsible for causing the error
     attr_reader :dependencies
 
+    # Initializes a new error with the given circular vertices.
     # @param [Array<DependencyGraph::Vertex>] nodes the nodes in the dependency
     #   that caused the error
     def initialize(nodes)
@@ -50,6 +55,7 @@ class VersionConflict < ResolverError
     #   resolution to fail
     attr_reader :conflicts
 
+    # Initializes a new error with the given version conflicts.
     # @param [{String => Resolution::Conflict}] conflicts see {#conflicts}
     def initialize(conflicts)
       pairs = []

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/gem_metadata.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/gem_metadata.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
-  VERSION = '0.4.0'
+  # The version of Gem::Resolver::Molinillo.
+  VERSION = '0.4.3'.freeze
 end
diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/modules/specification_provider.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/modules/specification_provider.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
   # Provides information about specifcations and dependencies to the resolver,
   # allowing the {Resolver} class to remain generic while still providing power

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/modules/ui.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/modules/ui.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
   # Conveys information about the resolution process to a user.
   module UI
@@ -57,7 +58,8 @@ def debug(depth = 0)
     #
     # @return [Boolean]
     def debug?
-      @debug_mode ||= ENV['MOLINILLO_DEBUG']
+      return @debug_mode if defined?(@debug_mode)
+      @debug_mode = ENV['MOLINILLO_DEBUG']
     end
   end
 end
diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/resolution.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/resolution.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
   class Resolver
     # A specific resolution from a given {Resolver}
@@ -38,6 +39,7 @@ class Resolution
       # @return [Array] the dependencies that were explicitly required
       attr_reader :original_requested
 
+      # Initializes a new resolution.
       # @param [SpecificationProvider] specification_provider
       #   see {#specification_provider}
       # @param [UI] resolver_ui see {#resolver_ui}
@@ -340,33 +342,56 @@ def attempt_to_activate_existing_spec(existing_node)
       # @return [Boolean] Whether the possibility was swapped into {#activated}
       def attempt_to_swap_possibility
         swapped = activated.dup
-        swapped.vertex_named(name).payload = possibility
-        return unless swapped.vertex_named(name).requirements.
+        vertex = swapped.vertex_named(name)
+        vertex.payload = possibility
+        return unless vertex.requirements.
             all? { |r| requirement_satisfied_by?(r, swapped, possibility) }
-        attempt_to_activate_new_spec
+        return unless new_spec_satisfied?
+        actual_vertex = activated.vertex_named(name)
+        actual_vertex.payload = possibility
+        fixup_swapped_children(actual_vertex)
+        activate_spec
+      end
+
+      # Ensures there are no orphaned successors to the given {vertex}.
+      # @param [DependencyGraph::Vertex] vertex the vertex to fix up.
+      # @return [void]
+      def fixup_swapped_children(vertex)
+        payload = vertex.payload
+        dep_names = dependencies_for(payload).map(&method(:name_for))
+        vertex.successors.each do |succ|
+          if !dep_names.include?(succ.name) && !succ.root? && succ.predecessors.to_a == [vertex]
+            debug(depth) { "Removing orphaned spec #{succ.name} after swapping #{name}" }
+            activated.detach_vertex_named(succ.name)
+            requirements.delete_if { |r| name_for(r) == succ.name }
+          end
+        end
       end
 
       # Attempts to activate the current {#possibility} (given that it hasn't
       # already been activated)
       # @return [void]
       def attempt_to_activate_new_spec
-        satisfied = begin
-          locked_requirement = locked_requirement_named(name)
-          requested_spec_satisfied = requirement_satisfied_by?(requirement, activated, possibility)
-          locked_spec_satisfied = !locked_requirement ||
-            requirement_satisfied_by?(locked_requirement, activated, possibility)
-          debug(depth) { 'Unsatisfied by requested spec' } unless requested_spec_satisfied
-          debug(depth) { 'Unsatisfied by locked spec' } unless locked_spec_satisfied
-          requested_spec_satisfied && locked_spec_satisfied
-        end
-        if satisfied
+        if new_spec_satisfied?
           activate_spec
         else
           create_conflict
           unwind_for_conflict
         end
       end
 
+      # @return [Boolean] whether the current spec is satisfied as a new
+      # possibility.
+      def new_spec_satisfied?
+        locked_requirement = locked_requirement_named(name)
+        requested_spec_satisfied = requirement_satisfied_by?(requirement, activated, possibility)
+        locked_spec_satisfied = !locked_requirement ||
+          requirement_satisfied_by?(locked_requirement, activated, possibility)
+        debug(depth) { 'Unsatisfied by requested spec' } unless requested_spec_satisfied
+        debug(depth) { 'Unsatisfied by locked spec' } unless locked_spec_satisfied
+        requested_spec_satisfied && locked_spec_satisfied
+      end
+
       # @param [String] requirement_name the spec name to search for
       # @return [Object] the locked spec named `requirement_name`, if one
       #   is found on {#base}
@@ -392,7 +417,7 @@ def activate_spec
       # @return [void]
       def require_nested_dependencies_for(activated_spec)
         nested_dependencies = dependencies_for(activated_spec)
-        debug(depth) { "Requiring nested dependencies (#{nested_dependencies.map(&:to_s).join(', ')})" }
+        debug(depth) { "Requiring nested dependencies (#{nested_dependencies.join(', ')})" }
         nested_dependencies.each { |d| activated.add_child_vertex(name_for(d), nil, [name_for(activated_spec)], d) }
 
         push_state_for_requirements(requirements + nested_dependencies, nested_dependencies.size > 0)

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb
@@ -1,9 +1,10 @@
+# frozen_string_literal: true
 require 'rubygems/resolver/molinillo/lib/molinillo/dependency_graph'
 
 module Gem::Resolver::Molinillo
   # This class encapsulates a dependency resolver.
   # The resolver is responsible for determining which set of dependencies to
-  # activate, with feedback from the the {#specification_provider}
+  # activate, with feedback from the {#specification_provider}
   #
   #
   class Resolver
@@ -17,6 +18,7 @@ class Resolver
     #   during the resolution process
     attr_reader :resolver_ui
 
+    # Initializes a new resolver.
     # @param  [SpecificationProvider] specification_provider
     #   see {#specification_provider}
     # @param  [UI] resolver_ui

diff --git a/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/state.rb b/lib/ruby/stdlib/rubygems/resolver/molinillo/lib/molinillo/state.rb
@@ -1,12 +1,13 @@
+# frozen_string_literal: true
 module Gem::Resolver::Molinillo
   # A state that a {Resolution} can be in
-  # @attr [String] name
-  # @attr [Array<Object>] requirements
-  # @attr [DependencyGraph] activated
-  # @attr [Object] requirement
-  # @attr [Object] possibility
-  # @attr [Integer] depth
-  # @attr [Set<Object>] conflicts
+  # @attr [String] name the name of the current requirement
+  # @attr [Array<Object>] requirements currently unsatisfied requirements
+  # @attr [DependencyGraph] activated the graph of activated dependencies
+  # @attr [Object] requirement the current requirement
+  # @attr [Object] possibilities the possibilities to satisfy the current requirement
+  # @attr [Integer] depth the depth of the resolution
+  # @attr [Set<Object>] conflicts unresolved conflicts
   ResolutionState = Struct.new(
     :name,
     :requirements,

diff --git a/lib/ruby/stdlib/rubygems/resolver/requirement_list.rb b/lib/ruby/stdlib/rubygems/resolver/requirement_list.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The RequirementList is used to hold the requirements being considered
 # while resolving a set of gems.

diff --git a/lib/ruby/stdlib/rubygems/resolver/set.rb b/lib/ruby/stdlib/rubygems/resolver/set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Resolver sets are used to look up specifications (and their
 # dependencies) used in resolution.  This set is abstract.

diff --git a/lib/ruby/stdlib/rubygems/resolver/source_set.rb b/lib/ruby/stdlib/rubygems/resolver/source_set.rb
@@ -0,0 +1,48 @@
+##
+# The SourceSet chooses the best available method to query a remote index.
+#
+# Kind off like BestSet but filters the sources for gems
+
+class Gem::Resolver::SourceSet < Gem::Resolver::Set
+
+  ##
+  # Creates a SourceSet for the given +sources+ or Gem::sources if none are
+  # specified.  +sources+ must be a Gem::SourceList.
+
+  def initialize
+    super()
+
+    @links = {}
+    @sets  = {}
+  end
+
+  def find_all req # :nodoc:
+    if set = get_set(req.dependency.name)
+      set.find_all req
+    else
+      []
+    end
+  end
+
+  # potentially no-op
+  def prefetch reqs # :nodoc:
+    reqs.each do |req|
+      if set = get_set(req.dependency.name)
+        set.prefetch reqs
+      end
+    end
+  end
+
+  def add_source_gem name, source
+    @links[name] = source
+  end
+
+private
+
+  def get_set(name)
+    link = @links[name]
+    @sets[link] ||= Gem::Source.new(link).dependency_resolver_set if link
+  end
+
+end
+
diff --git a/lib/ruby/stdlib/rubygems/resolver/spec_specification.rb b/lib/ruby/stdlib/rubygems/resolver/spec_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The Resolver::SpecSpecification contains common functionality for
 # Resolver specifications that are backed by a Gem::Specification.

diff --git a/lib/ruby/stdlib/rubygems/resolver/specification.rb b/lib/ruby/stdlib/rubygems/resolver/specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A Resolver::Specification contains a subset of the information
 # contained in a Gem::Specification.  Only the information necessary for

diff --git a/lib/ruby/stdlib/rubygems/resolver/stats.rb b/lib/ruby/stdlib/rubygems/resolver/stats.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class Gem::Resolver::Stats
   def initialize
     @max_depth = 0

diff --git a/lib/ruby/stdlib/rubygems/resolver/vendor_set.rb b/lib/ruby/stdlib/rubygems/resolver/vendor_set.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A VendorSet represents gems that have been unpacked into a specific
 # directory that contains a gemspec.

diff --git a/lib/ruby/stdlib/rubygems/resolver/vendor_specification.rb b/lib/ruby/stdlib/rubygems/resolver/vendor_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A VendorSpecification represents a gem that has been unpacked into a project
 # and is being loaded through a gem dependencies file through the +path:+

diff --git a/lib/ruby/stdlib/rubygems/security.rb b/lib/ruby/stdlib/rubygems/security.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -339,7 +340,7 @@ class Exception < Gem::Exception; end
   # Digest algorithm used to sign gems
 
   DIGEST_ALGORITHM =
-    if defined?(OpenSSL::Digest) then
+    if defined?(OpenSSL::Digest::SHA1) then
       OpenSSL::Digest::SHA1
     end
 
@@ -355,7 +356,7 @@ class Exception < Gem::Exception; end
   # Algorithm for creating the key pair used to sign gems
 
   KEY_ALGORITHM =
-    if defined?(OpenSSL::PKey) then
+    if defined?(OpenSSL::PKey::RSA) then
       OpenSSL::PKey::RSA
     end
 

diff --git a/lib/ruby/stdlib/rubygems/security/policies.rb b/lib/ruby/stdlib/rubygems/security/policies.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem::Security
 
   ##

diff --git a/lib/ruby/stdlib/rubygems/security/policy.rb b/lib/ruby/stdlib/rubygems/security/policy.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/user_interaction'
 
 ##
@@ -157,7 +158,7 @@ def check_trust chain, digester, trust_dir
     path = Gem::Security.trust_dir.cert_path root
 
     unless File.exist? path then
-      message = "root cert #{root.subject} is not trusted"
+      message = "root cert #{root.subject} is not trusted".dup
 
       message << " (root of signing cert #{chain.last.subject})" if
         chain.length > 1
@@ -292,4 +293,3 @@ def verify_signatures spec, digests, signatures
   alias to_s name # :nodoc:
 
 end
-
diff --git a/lib/ruby/stdlib/rubygems/security/signer.rb b/lib/ruby/stdlib/rubygems/security/signer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Basic OpenSSL-based package signing class.
 

diff --git a/lib/ruby/stdlib/rubygems/security/trust_dir.rb b/lib/ruby/stdlib/rubygems/security/trust_dir.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The TrustDir manages the trusted certificates for gem signature
 # verification.

diff --git a/lib/ruby/stdlib/rubygems/server.rb b/lib/ruby/stdlib/rubygems/server.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'webrick'
 require 'zlib'
 require 'erb'

diff --git a/lib/ruby/stdlib/rubygems/source.rb b/lib/ruby/stdlib/rubygems/source.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'uri'
 require 'fileutils'
 

diff --git a/lib/ruby/stdlib/rubygems/source/git.rb b/lib/ruby/stdlib/rubygems/source/git.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'digest'
 require 'rubygems/util'
 

diff --git a/lib/ruby/stdlib/rubygems/source/installed.rb b/lib/ruby/stdlib/rubygems/source/installed.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Represents an installed gem.  This is used for dependency resolution.
 

diff --git a/lib/ruby/stdlib/rubygems/source/local.rb b/lib/ruby/stdlib/rubygems/source/local.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The local source finds gems in the current directory for fulfilling
 # dependencies.

diff --git a/lib/ruby/stdlib/rubygems/source/lock.rb b/lib/ruby/stdlib/rubygems/source/lock.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A Lock source wraps an installed gem's source and sorts before other sources
 # during dependency resolution.  This allows RubyGems to prefer gems from

diff --git a/lib/ruby/stdlib/rubygems/source/specific_file.rb b/lib/ruby/stdlib/rubygems/source/specific_file.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # A source representing a single .gem file.  This is used for installation of
 # local gems.

diff --git a/lib/ruby/stdlib/rubygems/source/vendor.rb b/lib/ruby/stdlib/rubygems/source/vendor.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # This represents a vendored source that is similar to an installed gem.
 

diff --git a/lib/ruby/stdlib/rubygems/source_list.rb b/lib/ruby/stdlib/rubygems/source_list.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/source'
 
 ##
@@ -9,7 +10,7 @@
 # Or by adding them:
 #
 #   sources = Gem::SourceList.new
-#   sources.add 'https://rubygems.example'
+#   sources << 'https://rubygems.example'
 #
 # The most common way to get a SourceList is Gem.sources.
 
@@ -58,7 +59,7 @@ def <<(obj)
             Gem::Source.new(URI.parse(obj))
           end
 
-    @sources << src
+    @sources << src unless @sources.include?(src)
     src
   end
 

diff --git a/lib/ruby/stdlib/rubygems/source_local.rb b/lib/ruby/stdlib/rubygems/source_local.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/source'
 require 'rubygems/source_local'
 

diff --git a/lib/ruby/stdlib/rubygems/source_specific_file.rb b/lib/ruby/stdlib/rubygems/source_specific_file.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/source/specific_file'
 
 # TODO warn upon require, this file is deprecated.

diff --git a/lib/ruby/stdlib/rubygems/spec_fetcher.rb b/lib/ruby/stdlib/rubygems/spec_fetcher.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems/remote_fetcher'
 require 'rubygems/user_interaction'
 require 'rubygems/errors'

diff --git a/lib/ruby/stdlib/rubygems/specification.rb b/lib/ruby/stdlib/rubygems/specification.rb
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.
@@ -1191,6 +1192,7 @@ def self.non_nil_attributes
   def self.normalize_yaml_input(input)
     result = input.respond_to?(:read) ? input.read : input
     result = "--- " + result unless result =~ /\A--- /
+    result = result.dup
     result.gsub!(/ !!null \n/, " \n")
     # date: 2011-04-26 00:00:00.000000000Z
     # date: 2011-04-26 00:00:00.000000000 Z
@@ -1682,6 +1684,8 @@ def conflicts
         (conflicts[spec] ||= []) << dep
       end
     }
+    env_req = Gem.env_requirement(name)
+    (conflicts[self] ||= []) << env_req unless env_req.satisfied_by? version
     conflicts
   end
 
@@ -1699,6 +1703,7 @@ def conficts_when_loaded_with?(list_of_specs) # :nodoc:
   # Return true if there are possible conflicts against the currently loaded specs.
 
   def has_conflicts?
+    return true unless Gem.env_requirement(name).satisfied_by?(version)
     self.dependencies.any? { |dep|
       if dep.runtime? then
         spec = Gem.loaded_specs[dep.name]
@@ -2333,7 +2338,7 @@ def ri_dir
 
   def ruby_code(obj)
     case obj
-    when String            then obj.dump
+    when String            then obj.dump + ".freeze"
     when Array             then '[' + obj.map { |x| ruby_code x }.join(", ") + ']'
     when Hash              then
       seg = obj.keys.sort.map { |k| "#{k.to_s.dump} => #{obj[k].to_s.dump}" }
@@ -2523,22 +2528,22 @@ def to_ruby
       dependencies.each do |dep|
         req = dep.requirements_list.inspect
         dep.instance_variable_set :@type, :runtime if dep.type.nil? # HACK
-        result << "      s.add_#{dep.type}_dependency(%q<#{dep.name}>, #{req})"
+        result << "      s.add_#{dep.type}_dependency(%q<#{dep.name}>.freeze, #{req})"
       end
 
       result << "    else"
 
       dependencies.each do |dep|
         version_reqs_param = dep.requirements_list.inspect
-        result << "      s.add_dependency(%q<#{dep.name}>, #{version_reqs_param})"
+        result << "      s.add_dependency(%q<#{dep.name}>.freeze, #{version_reqs_param})"
       end
 
       result << '    end'
 
       result << "  else"
       dependencies.each do |dep|
         version_reqs_param = dep.requirements_list.inspect
-        result << "    s.add_dependency(%q<#{dep.name}>, #{version_reqs_param})"
+        result << "    s.add_dependency(%q<#{dep.name}>.freeze, #{version_reqs_param})"
       end
       result << "  end"
     end
@@ -2760,10 +2765,13 @@ def validate packaging = true
       end
 
       if !Gem::Licenses.match?(license)
-        warning <<-warning
-WARNING: license value '#{license}' is invalid.  Use a license identifier from
+        suggestions = Gem::Licenses.suggestions(license)
+        message = <<-warning
+license value '#{license}' is invalid.  Use a license identifier from
 http://spdx.org/licenses or '#{Gem::Licenses::NONSTANDARD}' for a nonstandard license.
         warning
+        message += "Did you mean #{suggestions.map { |s| "'#{s}'"}.join(', ')}?\n" unless suggestions.nil?
+        warning(message)
       end
     }
 

diff --git a/lib/ruby/stdlib/rubygems/stub_specification.rb b/lib/ruby/stdlib/rubygems/stub_specification.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # Gem::StubSpecification reads the stub: line from the gemspec.  This prevents
 # us having to eval the entire gemspec in order to find out certain

diff --git a/lib/ruby/stdlib/rubygems/syck_hack.rb b/lib/ruby/stdlib/rubygems/syck_hack.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # :stopdoc:
 
 # Hack to handle syck's DefaultKey bug

diff --git a/lib/ruby/stdlib/rubygems/test_case.rb b/lib/ruby/stdlib/rubygems/test_case.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # TODO: $SAFE = 1
 
 begin
@@ -541,7 +542,7 @@ def create_tmpdir
   # Enables pretty-print for all tests
 
   def mu_pp(obj)
-    s = ''
+    s = String.new
     s = PP.pp obj, s
     s = s.force_encoding(Encoding.default_external) if defined? Encoding
     s.chomp
@@ -569,7 +570,7 @@ def read_binary(path)
   def write_file(path)
     path = File.join @gemhome, path unless Pathname.new(path).absolute?
     dir = File.dirname path
-    FileUtils.mkdir_p dir
+    FileUtils.mkdir_p dir unless File.directory? dir
 
     open path, 'wb' do |io|
       yield io if block_given?
@@ -1306,12 +1307,22 @@ def v string
   def vendor_gem name = 'a', version = 1
     directory = File.join 'vendor', name
 
+    FileUtils.mkdir_p directory
+
+    save_gemspec name, version, directory
+  end
+
+  ##
+  # create_gemspec creates gem specification in given +direcotry+ or '.'
+  # for the given +name+ and +version+.
+  #
+  # Yields the +specification+ to the block, if given
+
+  def save_gemspec name = 'a', version = 1, directory = '.'
     vendor_spec = Gem::Specification.new name, version do |specification|
       yield specification if block_given?
     end
 
-    FileUtils.mkdir_p directory
-
     open File.join(directory, "#{name}.gemspec"), 'w' do |io|
       io.write vendor_spec.to_ruby
     end
@@ -1482,3 +1493,4 @@ def self.key_path key_name
 pid = $$
 END {tmpdirs.each {|dir| Dir.rmdir(dir)} if $$ == pid}
 Gem.clear_paths
+
diff --git a/lib/ruby/stdlib/rubygems/test_utilities.rb b/lib/ruby/stdlib/rubygems/test_utilities.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'tempfile'
 require 'rubygems'
 require 'rubygems/remote_fetcher'

diff --git a/lib/ruby/stdlib/rubygems/text.rb b/lib/ruby/stdlib/rubygems/text.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rubygems'
 
 ##
@@ -70,4 +71,3 @@ def levenshtein_distance str1, str2
     return x
   end
 end
-
diff --git a/lib/ruby/stdlib/rubygems/uninstaller.rb b/lib/ruby/stdlib/rubygems/uninstaller.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/uri_formatter.rb b/lib/ruby/stdlib/rubygems/uri_formatter.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'cgi'
 require 'uri'
 

diff --git a/lib/ruby/stdlib/rubygems/user_interaction.rb b/lib/ruby/stdlib/rubygems/user_interaction.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/util.rb b/lib/ruby/stdlib/rubygems/util.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # This module contains various utility methods as module methods.
 
@@ -24,7 +25,7 @@ def self.gunzip(data)
   def self.gzip(data)
     require 'zlib'
     require 'stringio'
-    zipped = StringIO.new('','w')
+    zipped = StringIO.new(String.new, 'w')
     zipped.set_encoding Encoding::BINARY if Object.const_defined? :Encoding
 
     Zlib::GzipWriter.wrap zipped do |io| io.write data end

diff --git a/lib/ruby/stdlib/rubygems/util/licenses.rb b/lib/ruby/stdlib/rubygems/util/licenses.rb
@@ -1,4 +1,9 @@
+# frozen_string_literal: true
+require 'rubygems/text'
+
 class Gem::Licenses
+  extend Gem::Text
+
   NONSTANDARD = 'Nonstandard'.freeze
 
   # Software Package Data Exchange (SPDX) standard open-source software
@@ -326,4 +331,13 @@ class Gem::Licenses
   def self.match?(license)
     !REGEXP.match(license).nil?
   end
+
+  def self.suggestions(license)
+    by_distance = IDENTIFIERS.group_by do |identifier|
+      levenshtein_distance(identifier, license)
+    end
+    lowest = by_distance.keys.min
+    return unless lowest < license.size
+    by_distance[lowest]
+  end
 end
diff --git a/lib/ruby/stdlib/rubygems/util/list.rb b/lib/ruby/stdlib/rubygems/util/list.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module Gem
   class List
     include Enumerable

diff --git a/lib/ruby/stdlib/rubygems/validator.rb b/lib/ruby/stdlib/rubygems/validator.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/rubygems/version.rb b/lib/ruby/stdlib/rubygems/version.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ##
 # The Version class processes string versions into comparable
 # values. A version string should normally be a series of numbers
@@ -218,7 +219,7 @@ def initialize version
 
   def bump
     @bump ||= begin
-                segments = self.segments.dup
+                segments = self.segments
                 segments.pop while segments.any? { |s| String === s }
                 segments.pop if segments.size > 1
 
@@ -281,7 +282,10 @@ def encode_with coder # :nodoc:
   # A version is considered a prerelease if it contains a letter.
 
   def prerelease?
-    @prerelease ||= !!(@version =~ /[a-zA-Z]/)
+    unless instance_variable_defined? :@prerelease
+      @prerelease = !!(@version =~ /[a-zA-Z]/)
+    end
+    @prerelease
   end
 
   def pretty_print q # :nodoc:
@@ -294,7 +298,7 @@ def pretty_print q # :nodoc:
 
   def release
     @release ||= if prerelease?
-                   segments = self.segments.dup
+                   segments = self.segments
                    segments.pop while segments.any? { |s| String === s }
                    self.class.new segments.join('.')
                  else
@@ -303,20 +307,14 @@ def release
   end
 
   def segments # :nodoc:
-
-    # segments is lazy so it can pick up version values that come from
-    # old marshaled versions, which don't go through marshal_load.
-
-    @segments ||= @version.scan(/[0-9]+|[a-z]+/i).map do |s|
-      /^\d+$/ =~ s ? s.to_i : s
-    end
+    _segments.dup
   end
 
   ##
   # A recommended version for use with a ~> Requirement.
 
   def approximate_recommendation
-    segments = self.segments.dup
+    segments = self.segments
 
     segments.pop    while segments.any? { |s| String === s }
     segments.pop    while segments.size > 2
@@ -335,8 +333,8 @@ def <=> other
     return unless Gem::Version === other
     return 0 if @version == other._version
 
-    lhsegments = segments
-    rhsegments = other.segments
+    lhsegments = _segments
+    rhsegments = other._segments
 
     lhsize = lhsegments.size
     rhsize = rhsegments.size
@@ -363,4 +361,14 @@ def <=> other
   def _version
     @version
   end
+
+  def _segments
+    # segments is lazy so it can pick up version values that come from
+    # old marshaled versions, which don't go through marshal_load.
+    # since this version object is cached in @@all, its @segments should be frozen
+
+    @segments ||= @version.scan(/[0-9]+|[a-z]+/i).map do |s|
+      /^\d+$/ =~ s ? s.to_i : s
+    end.freeze
+  end
 end
diff --git a/lib/ruby/stdlib/rubygems/version_option.rb b/lib/ruby/stdlib/rubygems/version_option.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #--
 # Copyright 2006 by Chad Fowler, Rich Kilmer, Jim Weirich and others.
 # All rights reserved.

diff --git a/lib/ruby/stdlib/ubygems.rb b/lib/ruby/stdlib/ubygems.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # This file allows for the running of rubygems with a nice
 # command line look-and-feel: ruby -rubygems foo.rb
 #--

diff --git a/spec/compiler/general_spec.rb b/spec/compiler/general_spec.rb
@@ -1068,5 +1068,21 @@ def a; __callee__; end
         expect(y).to eq(1)
       end
     end
+
+    it "handles circular optional argument assignment" do
+      begin
+        verbose = $VERBOSE
+        $VERBOSE = nil
+
+        run('def foo(a = a, b = b, c = c); [a.inspect, b.inspect, c.inspect]; end; foo') do |x|
+          expect(x).to eq(["nil", "nil", "nil"])
+        end
+        run('def foo; yield; end; foo {|a = a, b = b, c = c|; [a.inspect, b.inspect, c.inspect]}') do |x|
+          expect(x).to eq(["nil", "nil", "nil"])
+        end
+      ensure
+        $VERBOSE = verbose
+      end
+    end
   end
 end
diff --git a/test/jruby/test_nkf.rb b/test/jruby/test_nkf.rb
diff --git a/test/mri/excludes/TestKconv.rb b/test/mri/excludes/TestKconv.rb
diff --git a/test/truffle/integration/rails.sh → test/truffle/integration/rails.sh_excluded b/test/truffle/integration/rails.sh → test/truffle/integration/rails.sh_excluded
Original file line number	Diff line number	Diff line change
		@@ -1 +1,2 @@
		# frozen_string_literal: true
		require 'rubygems/resolver/molinillo/lib/molinillo'