* test/rake/test_task_arguments.rb: makes ENV empty during tests

because ENV may change the behavior of Rake::TaskArguments.
  [ruby-core:29984]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27737 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Tue May 11 21:53:18 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* test/rake/test_task_arguments.rb: makes ENV empty during tests
+	  because ENV may change the behavior of Rake::TaskArguments.
+	  [ruby-core:29984]
+
 Tue May 11 15:14:30 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* enc/utf_8.c: Add new alias UTF-8-HFS for UTF8-MAC.

test/rake/test_task_arguments.rb

@@ -3,9 +3,14 @@ require 'rake'
 
 ######################################################################
 class Rake::TestTaskArguments < Test::Unit::TestCase
+  def setup
+    @backup = ENV.to_hash
+    ENV.clear
+  end
+
   def teardown
-    ENV.delete('rev')
-    ENV.delete('VER')
+    ENV.clear
+    @backup.each {|k, v| ENV[k] = v }
   end
 
   def test_empty_arg_list_is_empty