Suppress warning

Author: drbrain

test/test_rdoc_options.rb

@@ -20,6 +20,8 @@ def test_check_files
     out, err = capture_io do
       Dir.mktmpdir do |dir|
         begin
+          unreadable = nil # variable for windows
+
           Dir.chdir dir do
             if RUBY_PLATFORM =~ /mswin|mingw/ then
               unreadable = open 'unreadable'
@@ -34,7 +36,7 @@ def test_check_files
             @options.check_files
           end
         ensure
-          unreadable.close if defined?(unreadable)
+          unreadable.close if unreadable
         end
       end
     end