rbinstall.rb: gem subdirectories

* tool/rbinstall.rb (gem): Gem.ensure_gem_subdirectories makes
  subdirectories group-writable, so make them with $dir_mode.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38870 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Fri Jan 18 12:54:21 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* tool/rbinstall.rb (gem): Gem.ensure_gem_subdirectories makes
+	  subdirectories group-writable, so make them with $dir_mode.
+
 Fri Jan 18 11:24:33 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/win32ole/win32ole.c (ole_initialize): uninitialize OLE at thread

tool/rbinstall.rb

@@ -688,7 +688,9 @@ install?(:ext, :comm, :gem) do
   $:.unshift(File.join(srcdir, "lib"))
   require("rubygems.rb")
   gem_dir = Gem.default_dir
-  directories = Gem.ensure_gem_subdirectories(gem_dir)
+  # Gem.ensure_gem_subdirectories makes subdirectories group-writable.
+  directories = Gem::REPOSITORY_SUBDIRECTORIES
+  makedirs([gem_dir, *directories.map {|name| File.join(gem_dir, name)}])
   prepare "default gems", gem_dir, directories
 
   spec_dir = File.join(gem_dir, directories.grep(/^spec/)[0])