1 files changed, 17 insertions, 0 deletions
diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 9d92fbc6a9..98f79b3f76 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -1491,6 +1491,11 @@ class TestM17N < Test::Unit::TestCase
   end
 
   def test_scrub
+    str = "\u3042\u3044"
+    assert_not_same(str, str.scrub)
+    str.force_encoding(Encoding::ISO_2022_JP) # dummy encoding
+    assert_not_same(str, str.scrub)
+
     assert_equal("\uFFFD\uFFFD\uFFFD", u("\x80\x80\x80").scrub)
     assert_equal("\uFFFDA", u("\xF4\x80\x80A").scrub)
 
@@ -1529,4 +1534,16 @@ class TestM17N < Test::Unit::TestCase
                  "\xff".force_encoding(Encoding::UTF_32LE).
                  scrub)
   end
+
+  def test_scrub_bang
+    str = "\u3042\u3044"
+    assert_same(str, str.scrub!)
+    str.force_encoding(Encoding::ISO_2022_JP) # dummy encoding
+    assert_same(str, str.scrub!)
+
+    str = u("\x80\x80\x80")
+    str.scrub!
+    assert_same(str, str.scrub!)
+    assert_equal("\uFFFD\uFFFD\uFFFD", str)
+  end
 end