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

Merge RubyGems-2.7.5 from upstream.

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

	test_gem_util.rb: fix broken test

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

	test_gem_commands_setup_command.rb: BUNDLER_VERS

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

	no need to set bundled bundler unless Gem::USE_BUNDLER_FOR_GEMDEPS


	revert r62302 and force to define the version constant


	Merge RubyGems 2.7.6 from upstream.

	  It fixed some security vulnerabilities.

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

	fix regexp literal warning.

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

	Remove unnecessary `[]`s

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

test/rubygems/test_gem_commands_owner_command.rb

@@ -43,6 +43,31 @@ EOF
     assert_match %r{- 4}, @ui.output
   end
 
+  def test_show_owners_dont_load_objects
+    skip "testing a psych-only API" unless defined?(::Psych::DisallowedClass)
+
+    response = <<EOF
+---
+- email: !ruby/object:Object {}
+  id: 1
+  handle: user1
+- email: user2@example.com
+- id: 3
+  handle: user3
+- id: 4
+EOF
+
+    @fetcher.data["#{Gem.host}/api/v1/gems/freewill/owners.yaml"] = [response, 200, 'OK']
+
+    assert_raises Psych::DisallowedClass do
+      use_ui @ui do
+        @cmd.show_owners("freewill")
+      end
+    end
+
+  end
+
+
   def test_show_owners_setting_up_host_through_env_var
     response = "- email: user1@example.com\n"
     host = "http://rubygems.example"