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_4@58631 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 20 insertions, 1 deletions

diff --git a/lib/fileutils.rb b/lib/fileutils.rb
index 6662b90932..94934233df 100644
--- a/lib/fileutils.rb
+++ b/lib/fileutils.rb
@@ -202,6 +202,7 @@ 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, mode
diff --git a/test/fileutils/test_fileutils.rb b/test/fileutils/test_fileutils.rb
index 4d790a74bc..0534b1b08e 100644
--- a/test/fileutils/test_fileutils.rb
+++ b/test/fileutils/test_fileutils.rb
@@ -905,6 +905,24 @@ 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'
diff --git a/version.h b/version.h
index 11a6cb9b01..145e1302db 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.2"
 #define RUBY_RELEASE_DATE "2017-05-09"
-#define RUBY_PATCHLEVEL 125
+#define RUBY_PATCHLEVEL 126
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 5