move the test for [ruby-core:14288].

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14525 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

bootstraptest/test_knownbug.rb

@@ -3,14 +3,6 @@
 # So all tests will cause failure.
 #
 
-assert_equal 'ok', %q{
-  open("tmp", "w") {|f| f.write "a\u00FFb" }
-  s = open("tmp", "r:iso-8859-1:utf-8") {|f|
-    f.gets("\xFF".force_encoding("iso-8859-1"))
-  }
-  s == "a\xFF" ? :ok : :ng
-}, '[ruby-core:14288]'
-
 assert_equal 'ok', %q{
   open("require-lock-test.rb", "w") {|f|
     f.puts "sleep 0.1"

test/ruby/test_io_m17n.rb

@@ -0,0 +1,22 @@
+require 'test/unit'
+require 'tmpdir'
+
+class TestIOM17N < Test::Unit::TestCase
+  def with_tmpdir
+    Dir.mktmpdir {|dir|
+      Dir.chdir dir
+      yield dir
+    }
+  end
+
+  def test_conversion
+    with_tmpdir {
+      open("tmp", "w") {|f| f.write "before \u00FF after" }
+      s = open("tmp", "r:iso-8859-1:utf-8") {|f|
+        f.gets("\xFF".force_encoding("iso-8859-1"))
+      }
+      assert_equal("before \xFF".force_encoding("iso-8859-1"), s, '[ruby-core:14288]')
+    }
+  end
+end
+