* transcode.c (str_encode): returns duplicated string if nothing

  changed.  [ruby-core:18578]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19349 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 6 insertions, 0 deletions

diff --git a/test/ruby/test_transcode.rb b/test/ruby/test_transcode.rb
index 5abeed88ee..8770328bc1 100644
--- a/test/ruby/test_transcode.rb
+++ b/test/ruby/test_transcode.rb
@@ -582,4 +582,10 @@ class TestTranscode < Test::Unit::TestCase
     assert_raise(Encoding::ConversionUndefined) { "\u203E".encode("CP51932") }
   end
 
+  def test_nothing_changed
+    a = "James".force_encoding("US-ASCII")
+    b = a.encode("Shift_JIS")
+    assert_equal(Encoding::US_ASCII, a.encoding)
+    assert_equal(Encoding::Shift_JIS, b.encoding)
+  end
 end