* lib/rubygems: Update to RubyGems 2.4.1 master(713ab65)

Complete history at:
  https://github.com/rubygems/rubygems/blob/master/History.txt#L3-L216
* test/rubygems:  ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47582 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/rubygems/commands/contents_command.rb

@@ -8,7 +8,8 @@ class Gem::Commands::ContentsCommand < Gem::Command
 
   def initialize
     super 'contents', 'Display the contents of the installed gems',
-          :specdirs => [], :lib_only => false, :prefix => true
+          :specdirs => [], :lib_only => false, :prefix => true,
+          :show_install_dir => false
 
     add_version_option
 
@@ -32,6 +33,11 @@ class Gem::Commands::ContentsCommand < Gem::Command
       options[:prefix] = prefix
     end
 
+    add_option(      '--[no-]show-install-dir',
+               'Show only the gem install dir') do |show, options|
+      options[:show_install_dir] = show
+    end
+
     @path_kind = nil
     @spec_dirs = nil
     @version   = nil
@@ -65,7 +71,12 @@ prefix or only the files that are requireable.
     names = gem_names
 
     names.each do |name|
-      found = gem_contents name
+      found =
+        if options[:show_install_dir] then
+          gem_install_dir name
+        else
+          gem_contents name
+        end
 
       terminate_interaction 1 unless found or names.length > 1
     end
@@ -115,6 +126,16 @@ prefix or only the files that are requireable.
     true
   end
 
+  def gem_install_dir name
+    spec = spec_for name
+
+    return false unless spec
+
+    say spec.gem_dir
+
+    true
+  end
+
   def gem_names # :nodoc:
     if options[:all] then
       Gem::Specification.map(&:name)