merge revision(s) 57640: [Backport #13214]

fileutils.rb: do not make root

	* lib/fileutils.rb (FileUtils#mkdir_p): no need to make root
	  directory which should be exist and cannot be made with mkdir
	  recent Cygwin can make a directory contains a colon.
	  [Bug #13214]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@58120 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/fileutils.rb

@@ -221,6 +221,7 @@ module FileUtils
         stack.push path
         path = File.dirname(path)
       end
+      stack.pop                 # root directory should exist
       stack.reverse_each do |dir|
         begin
           fu_mkdir dir, options[:mode]

test/fileutils/test_fileutils.rb

@@ -895,6 +895,24 @@ class TestFileUtils < Test::Unit::TestCase
     mkdir_p '/'
   end
 
+  if /mswin|mingw|cygwin/ =~ RUBY_PLATFORM
+    def test_mkdir_p_root
+      if /cygwin/ =~ RUBY_PLATFORM
+        tmpdir = `cygpath -ma .`.chomp
+      else
+        tmpdir = Dir.pwd
+      end
+      skip "No drive letter" unless /\A[a-z]:/i =~ tmpdir
+      drive = "./#{$&}"
+      assert_file_not_exist drive
+      mkdir_p "#{tmpdir}/none/dir"
+      assert_directory "none/dir"
+      assert_file_not_exist drive
+    ensure
+      Dir.rmdir(drive) if drive and File.directory?(drive)
+    end
+  end
+
   def test_mkdir_p_file_perm
     mkdir_p 'tmp/tmp/tmp', :mode => 07777
     assert_directory 'tmp/tmp/tmp'

version.h

@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.2.7"
 #define RUBY_RELEASE_DATE "2017-03-26"
-#define RUBY_PATCHLEVEL 452
+#define RUBY_PATCHLEVEL 453
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3