[ruby/rdoc] HOME is preserved by RDoc::TestCase

https://github.com/ruby/rdoc/commit/6c4801d1f6

test/rdoc/test_rdoc_markdown.rb

@@ -8,6 +8,8 @@ require 'rdoc/markdown'
 class TestRDocMarkdown < RDoc::TestCase
 
   def setup
+    super
+
     @RM = RDoc::Markup
 
     @parser = RDoc::Markdown.new

test/rdoc/test_rdoc_ri_driver.rb

@@ -13,7 +13,6 @@ class TestRDocRIDriver < RDoc::TestCase
     FileUtils.mkdir_p @home_ri
 
     @orig_ri = ENV['RI']
-    @orig_home = ENV['HOME']
     ENV['HOME'] = @tmpdir
     @rdoc_home = File.join ENV["HOME"], ".rdoc"
     FileUtils.mkdir_p @rdoc_home
@@ -33,7 +32,6 @@ class TestRDocRIDriver < RDoc::TestCase
   end
 
   def teardown
-    ENV['HOME'] = @orig_home
     ENV['RI'] = @orig_ri
     FileUtils.rm_rf @tmpdir