* bootstraptest/test_io.rb: test for [ruby-dev:38131].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@23288 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

bootstraptest/test_io.rb

@@ -92,3 +92,9 @@ assert_normal_exit %q{
     r1.close; w1.close
   }, '', ["INT"] or break
 end
+
+assert_normal_exit %q{
+  r, w = IO.pipe
+  STDOUT.reopen(w)
+  STDOUT.reopen(__FILE__, "r")
+}, '[ruby-dev:38131]'